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Sample records for involved field radiotherapy

  1. Involved-field radiotherapy for esophageal squamous cell carcinoma: theory and practice.

    PubMed

    Li, Minghuan; Zhang, Xiaoli; Zhao, Fen; Luo, Yijun; Kong, Li; Yu, Jinming

    2016-01-01

    Esophageal carcinoma (EC) is characterized by a high rate of lymph node metastasis and its spread pattern is not always predictable. Chemoradiotherapy has an important role in the treatment of EC in both the inoperable and the pre-operative settings. However, regarding the target volume for radiation, different clinical practices exist. Theoretically, in addition to the clinical target volume administered to the gross lesion, it might seem logical to deliver a certain dose to the uninvolved regional lymph node area at risk for microscopic disease. However, in practice, it is difficult because of the intolerance of normal tissue to radiotherapy (RT), particularly if all regions containing the cervical, mediastinal, and upper abdominal nodes are covered. To date, the use of elective nodal irradiation (ENI) is still controversial in the field of radiotherapy. Some investigators use involved-field radiotherapy (IFRT) in order to reduce treatment-related toxicities. It is thought that micrometastases can be controlled, to some extent, by chemotherapy and the abscopal effects of radiation. It is the presence of overtly involved lymph nodes rather than the micrometastatic nodes negatively affects survival in patients with EC. In another hand, lymph nodes stationed near primary tumors also receive considerable incidental irradiation doses that may contribute to the elimination of subclinical lesions. These data indicate that an irradiation volume covering only the gross tumor is appropriate. When using ENI or IFRT, very few patients experience solitary regional node failure and out-of-field lymph node failure is not common. Primary tumor recurrence and distant metastases, rather than regional lymph node failure, affect the overall survival in patients with EC. The available evidence indicates that the use of ENI seems to prevent or delay regional nodal relapse rather than improve survival. In a word, these data suggest that IFRT is feasible in EC patients. PMID:26846932

  2. Risk of Developing Cardiovascular Disease After Involved Node Radiotherapy Versus Mantle Field for Hodgkin Lymphoma

    SciTech Connect

    Maraldo, Maja V.; Brodin, Nils Patrik; Vogelius, Ivan R.; Aznar, Marianne C.; Munck af Rosenschoeld, Per; Petersen, Peter M.; Specht, Lena

    2012-07-15

    Purpose: Hodgkin lymphoma (HL) survivors are known to have increased cardiac mortality and morbidity. The risk of developing cardiovascular disease after involved node radiotherapy (INRT) is currently unresolved, inasmuch as present clinical data are derived from patients treated with the outdated mantle field (MF) technique. Methods and Materials: We included all adolescents and young adults with supradiaphragmatic, clinical Stage I-II HL treated at our institution from 2006 to 2010 (29 patients). All patients were treated with chemotherapy and INRT to 30 to 36 Gy. We then simulated a MF plan for each patient with a prescribed dose of 36 Gy. A logistic dose-response curve for the 25-year absolute excess risk of cardiovascular disease was derived and applied to each patient using the individual dose-volume histograms. Results: The mean doses to the heart, four heart valves, and coronary arteries were significantly lower for INRT than for MF treatment. However, the range in doses with INRT treatment was substantial, and for a subgroup of patients, with lymphoma below the fourth thoracic vertebrae, we estimated a 25-year absolute excess risk of any cardiac event of as much as 5.1%. Conclusions: Our study demonstrates a potential for individualizing treatment by selecting the patients for whom INRT provides sufficient cardiac protection for current technology; and a subgroup of patients, who still receive high cardiac doses, who would benefit from more advanced radiation technique.

  3. Impact of involved field radiotherapy in partial response after doxorubicin-based chemotherapy for advanced aggressive non-Hodgkin's lymphoma

    SciTech Connect

    Moser, Elizabeth C. . E-mail: e.c.moser@lumc.nl; Kluin-Nelemans, Hanneke C.; Carde, Patrice; Meerwaldt, Jacobus H.; Tirelli, Umberto; Aleman, Berthe M.P.; Baars, Joke; Thomas, Jose; Glabbeke, Martine van; Noordijk, Evert M.

    2006-11-15

    Purpose: Whether salvage therapy in patients with advanced aggressive non-Hodgkin's lymphoma (NHL) in partial remission (PR) should consist of radiotherapy or autologous stem-cell transplantation (ASCT) is debatable. We evaluated the impact of radiotherapy on outcome in PR patients treated in four successive European Organization for Research and Treatment of Cancer trials for aggressive NHL. Patients and Methods: Records of 974 patients (1980-1999) were reviewed regarding initial response, final outcome, and type and timing of salvage treatment. After 8 cycles of doxorubicin-based chemotherapy, 227 NHL patients were in PR and treated: 114 received involved field radiotherapy, 16 ASCT, 93 second-line chemotherapy, and 4 were operated. Overall survival (OS) and progression-free survival (PFS) after radiotherapy were estimated (Kaplan-Meier method) and compared with other treatments (log-rank). Impact on survival was evaluated by multivariate analysis (Cox proportional hazards model). Results: The median PFS in PR patients was 4.2 years and 48% remained progression-free at 5 years. Half of the PR patients converted to a complete remission. After conversion, survival was comparable to patients directly in complete remission. Radiotherapy resulted in better OS and PFS compared with other treatments, especially in patients with low to intermediate International Prognostic Index score, bulky disease, or nodal disease only. Correction by multivariate analysis for prognostic factors such as stage, bulky disease, and number of extranodal locations showed that radiotherapy was clearly the most significant factor affecting both OS and PFS. Conclusion: This retrospective analysis demonstrates that radiotherapy can be effective for patients in PR after fully dosed chemotherapy; assessment in a randomized trial (radiotherapy vs. ASCT) is justified.

  4. Dosimetric and Clinical Outcomes of Involved-Field Intensity-Modulated Radiotherapy After Chemotherapy for Early-Stage Hodgkin's Lymphoma With Mediastinal Involvement

    SciTech Connect

    Lu Ningning; Li Yexiong; Wu Runye; Zhang Ximei; Wang Weihu; Jin Jing; Song Yongwen; Fang Hui; Ren Hua; Wang Shulian; Liu Yueping; Liu Xinfan; Chen Bo; Dai Jianrong; Yu Zihao

    2012-09-01

    Purpose: To evaluate the dosimetric and clinical outcomes of involved-field intensity-modulated radiotherapy (IF-IMRT) for patients with early-stage Hodgkin's lymphoma (HL) with mediastinal involvement. Methods and Materials: Fifty-two patients with early-stage HL that involved the mediastinum were reviewed. Eight patients had Stage I disease, and 44 patients had Stage II disease. Twenty-three patients (44%) presented with a bulky mediastinum, whereas 42 patients (81%) had involvement of both the mediastinum and either cervical or axillary nodes. All patients received combination chemotherapy followed by IF-IMRT. The prescribed radiation dose was 30-40 Gy. The dose-volume histograms of the target volume and critical normal structures were evaluated. Results: The median mean dose to the primary involved regions (planning target volume, PTV1) and boost area (PTV2) was 37.5 Gy and 42.1 Gy, respectively. Only 0.4% and 1.3% of the PTV1 and 0.1% and 0.5% of the PTV2 received less than 90% and 95% of the prescribed dose, indicating excellent PTV coverage. The median mean lung dose and V20 to the lungs were 13.8 Gy and 25.9%, respectively. The 3-year overall survival, local control, and progression-free survival rates were 100%, 97.9%, and 96%, respectively. No Grade 4 or 5 acute or late toxicities were reported. Conclusions: Despite the large target volume, IF-IMRT gave excellent dose coverage and a favorable prognosis, with mild toxicity in patients with early-stage mediastinal HL.

  5. Use of CD-ROM-based tool for analyzing contouring variations in involved-field radiotherapy for Stage III NSCLC

    SciTech Connect

    Soernsen De Koste, John R. van . E-mail: j.vansornsendekoste@vumc.nl; Senan, Suresh; Underberg, Rene W.M.; Oei, Swie Swat; Elshove, Dionne; Slotman, Ben J.; Lagerwaard, Frank J.

    2005-10-01

    Background: Interclinician variability in defining target volumes is a problem in conformal radiotherapy. A CD-ROM-based contouring tool was used to conduct a dummy run in an international trial of involved-field chemoradiotherapy for Stage III non-small-cell lung cancer. Methods and Materials: The CT scan of an eligible patient was installed on an 'auto-run' CD-ROM incorporating a contouring program based on ImageJ for Windows, which runs on any personal computer equipped with a CD-ROM drive. This tool was initially piloted at four academic centers and was subsequently mailed, together with all relevant clinical, radiologic, and positron emission tomography findings, to all participating centers in the international trial. Clinicians were instructed to contour separate gross tumor volumes (GTVs) for the tumor and two enlarged nodes and a clinical target volume for the hilus. A reference 'consensus' target volume for each target was jointly generated by three other clinicians. Results: The data received from the four academic centers and 16 study participants were suitable for analysis. Data from one center was unsuitable for detailed analysis because the target volumes were contoured at 1.2-cm intervals. GTVs were available for a total of 21 tumors and 19 nodes, and 15 hilar clinical target volumes were available. The mean GTV of the primary tumor was 13.6 cm{sup 3} (SD, 5.2; median, 12.3; range, 8.3-26.9). The variation in the center of the mass relative to the mean center of the mass in the left-right, ventrodorsal, and craniocaudal axes was 1.5, 0.4, and 1.0 mm, respectively. The largest volume variation was observed for the right hilar clinical target volume (mean, 33.7 cm{sup 3}; SD, 31.2; median, 20.3; range, 4.8-109.9). Smaller variations were observed for the subcarinal node (mean, GTV, 1.9 cm{sup 3}; SD, 1.2; median, 1.7; range, 0.5-5.3), except caudally where the node was difficult to distinguish from the pericardium. The 'consensus' volumes for all

  6. Optimal scheduling to reduce morbidity of involved field radiotherapy with transplantation for lymphomas: a prospective Australasian Leukaemia and Lymphoma Group Study.

    PubMed

    Wirth, A; Prince, H M; Wolf, M; Stone, J M; Matthews, J; Gibson, J; Macleod, C; Szer, J; Grigg, A; To, B; Roos, D; Schwarer, A P; Davis, S

    2005-02-01

    This study evaluated delivery of involved field radiotherapy (IFRT) with transplantation for lymphomas timed to minimise toxicity. Patients transplanted for lymphoma had infradiaphragmatic disease irradiated pre-transplant and supradiaphragmatic disease post transplant. A total of 31 patients were studied, with a median follow-up duration of 4 years. Transplant conditioning was according to clinician preference. In all, 14 patients had pre-transplant abdominopelvic IFRT and 19 had post transplant IFRT (including three who had pre-transplant IFRT). Grade III-IV haematological toxicity from pre-transplant IFRT occurred in three patients and from post transplant IFRT in 10 patients. Pre-transplant IFRT had no effect on haematological recovery post transplant, but was associated with a trend towards increased gastrointestinal toxicity (P = 0.094). Pneumonitis due to post transplant thoracic IFRT occurred in one patient. Two patients failed in involved sites after completion of protocol radiotherapy. One case of myelodysplasia has been reported. As sequenced in this study, IFRT was feasible and produced a low incidence of severe pulmonary and haematological toxicities. Patient selection, field size and radiotherapy dose warrant further study.

  7. Complete response of myeloid sarcoma with cardiac involvement to radiotherapy.

    PubMed

    Yang, Wen-Chi; Yao, Ming; Chen, Yu-Hsuan; Kuo, Sung-Hsin

    2016-06-01

    We present a rare case of intracardiac myeloid sarcoma (MS) of acute myeloid leukemia (AML) and who responds completely well to low-dose radiotherapy. This 19-year-old young man initially presented with AML and received standard chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, he developed intracardiac isolated MS relapse with the presentation of exertional dyspnea and superior vena cava (SVC) syndrome 3 years later. He then received radiotherapy with 24 Gy at a 12 daily fractions using forward "field in field" intensity modulated radiotherapy technique. He dramatically had improved clinical symptoms, and complete remission was achieved one month after completing radiotherapy. Our result is in line with anecdotal case reports showed that radiotherapy with 15 Gy in 10 fractions or with 24 Gy in 12 fractions resulted in good response and less toxicity of 2 cases of MS with cardiac involvement. These results indicate that a modest radiotherapy dose, 24 Gy, achieves good local control of MS with cardiac involvement. PMID:27293853

  8. Complete response of myeloid sarcoma with cardiac involvement to radiotherapy

    PubMed Central

    Yang, Wen-Chi; Yao, Ming; Chen, Yu-Hsuan

    2016-01-01

    We present a rare case of intracardiac myeloid sarcoma (MS) of acute myeloid leukemia (AML) and who responds completely well to low-dose radiotherapy. This 19-year-old young man initially presented with AML and received standard chemotherapy followed by allogeneic hematopoietic stem cell transplantation (HSCT). However, he developed intracardiac isolated MS relapse with the presentation of exertional dyspnea and superior vena cava (SVC) syndrome 3 years later. He then received radiotherapy with 24 Gy at a 12 daily fractions using forward “field in field” intensity modulated radiotherapy technique. He dramatically had improved clinical symptoms, and complete remission was achieved one month after completing radiotherapy. Our result is in line with anecdotal case reports showed that radiotherapy with 15 Gy in 10 fractions or with 24 Gy in 12 fractions resulted in good response and less toxicity of 2 cases of MS with cardiac involvement. These results indicate that a modest radiotherapy dose, 24 Gy, achieves good local control of MS with cardiac involvement. PMID:27293853

  9. Dosimetric Comparison of Involved-Field Three-Dimensional Conformal Photon Radiotherapy and Breast-Sparing Proton Therapy for the Treatment of Hodgkin's Lymphoma in Female Pediatric Patients

    SciTech Connect

    Andolino, David L.; Hoene, Ted; Xiao, Lu; Buchsbaum, Jeffrey; Chang, Andrew L.

    2011-11-15

    Purpose: To assess the potential reduction in breast dose for young girls with Hodgkin's lymphoma (HL) treated with breast-sparing proton therapy (BS-PT) as compared with three-dimensional conformal involved-field photon radiotherapy (3D-CRT). Methods and Materials: The Clarian Health Cancer Registry was queried for female pediatric patients with the diagnosis of HL who received radiotherapy at the Indiana University Simon Cancer Center during 2006-2009. The original CT simulation images were obtained, and 3D-CRT and BS-PT plans delivering 21 Gy or cobalt gray equivalent (CGE) in 14 fractions were created for each patient. Dose-volume histogram data were collected for both 3D-CRT and BS-PT plans and compared by paired t test for correlated samples. Results: The cancer registry provided 10 female patients with Ann Arbor Stage II HL, aged 10-18 years at the time of treatment. Both mean and maximum breast dose were significantly less with BS-PT compared with 3D-CRT: 0.95 CGE vs. 4.70 Gy (p < 0.001) and 21.07 CGE vs. 23.11 Gy (p < 0.001), respectively. The volume of breast receiving 1.0 Gy/CGE and 5.0 Gy/CGE was also significantly less with BS-PT, 194 cm{sup 3} and 93 cm{sup 3}, respectively, compared with 790 cm{sup 3} and 360 cm{sup 3} with 3D-CRT (p = 0.009, 0.013). Conclusion: Breast-sparing proton therapy has the potential to reduce unnecessary breast dose in young girls with HL by as much as 80% relative to involved-field 3D-CRT.

  10. Predicted Risk of Radiation-Induced Cancers After Involved Field and Involved Node Radiotherapy With or Without Intensity Modulation for Early-Stage Hodgkin Lymphoma in Female Patients

    SciTech Connect

    Weber, Damien C.; Johanson, Safora; Peguret, Nicolas; Cozzi, Luca; Olsen, Dag R.

    2011-10-01

    Purpose: To assess the excess relative risk (ERR) of radiation-induced cancers (RIC) in female patients with Hodgkin lymphoma (HL) female patients treated with conformal (3DCRT), intensity modulated (IMRT), or volumetric modulated arc (RA) radiation therapy. Methods and Materials: Plans for 10 early-stage HL female patients were computed for 3DCRT, IMRT, and RA with involved field RT (IFRT) and involvednode RT (INRT) radiation fields. Organs at risk dose--volume histograms were computed and inter-compared for IFRT vs. INRT and 3DCRT vs. IMRT/RA, respectively. The ERR for cancer induction in breasts, lungs, and thyroid was estimated using both linear and nonlinear models. Results: The mean estimated ERR for breast, lung, and thyroid were significantly lower (p < 0.01) with INRT than with IFRT planning, regardless of the radiation delivery technique used, assuming a linear dose-risk relationship. We found that using the nonlinear model, the mean ERR values were significantly (p < 0.01) increased with IMRT or RA compared to those with 3DCRT planning for the breast, lung, and thyroid, using an IFRT paradigm. After INRT planning, IMRT or RA increased the risk of RIC for lung and thyroid only. Conclusions: In this comparative planning study, using a nonlinear dose--risk model, IMRT or RA increased the estimated risk of RIC for breast, lung, and thyroid for HL female patients. This study also suggests that INRT planning, compared to IFRT planning, may reduce the ERR of RIC when risk is predicted using a linear model. Observing the opposite effect, with a nonlinear model, however, questions the validity of these biologically parameterized models.

  11. Does the Addition of Involved Field Radiotherapy to High-Dose Chemotherapy and Stem Cell Transplantation Improve Outcomes for Patients With Relapsed/Refractory Hodgkin Lymphoma?

    SciTech Connect

    Kahn, Shannon; Flowers, Christopher; Xu Zhiheng; Esiashvili, Natia

    2011-09-01

    Purpose: To evaluate the value of adding involved field radiotherapy (IFRT) to patients with relapsed/refractory Hodgkin lymphoma (HL) undergoing high-dose chemotherapy (HDCT) and stem cell transplantation (SCT). Methods and Materials: Ninety-two patients with relapsed/refractory HL undergoing HDCT and SCT from 1995 to 2008 were analyzed in a case-control design. Forty-six HL patients treated with IFRT within 2 months of SCT were matched to 46 HL patients who did not receive IFRT based on age, stage at relapse, timing of relapse, histology, and year of SCT. All were evaluated for response, survival, and toxicity with a median followup of 63.5 months. Results: There was a trend for better disease control in patients receiving IFRT. Specifically, 10/46 IFRT patients (22%) relapsed/progressed after SCT compared with 17/46 control patients (37%). Of the failures after IFRT, 70% were inside the radiation field, all in sites of bulky disease. In patients with nonbulky disease, IFRT also resulted in significantly improved outcomes (failure rate 6% vs. 33%, respectively). When stratified by disease bulk, the use of IFRT was found to significantly improve DFS (p = 0.032), but did not affect OS. In addition, IFRT and nonbulky disease were found to be positive prognostic indicators for DFS with hazard ratios of 0.357 (p = 0.032) and 0.383 (p = 0.034), respectively. Grade IV/V toxicities were significantly higher in the IFRT vs. non-IFRT group (28% vs. 2%; p < 0.001), observed only in patients receiving a busulfan-based conditioning regimen. Conclusion: Patients with refractory or relapsed HL undergoing HDCT and SCT have a high risk of relapse in sites of prior disease involvement, especially in sites of bulky disease. The use of IFRT is associated with a lower risk of disease progression in these sites; however bulky disease sites are still difficult to control. Toxicity risk is significant, particularly when busulfan-based conditioning is combined with IFRT, and alternative

  12. A prospective study of reduced-dose three-course CHOP followed by involved-field radiotherapy for patients 70 years old or more with localized aggressive non-Hodgkin's lymphoma

    SciTech Connect

    Shikama, Naoto . E-mail: shikama@hsp.md.shinshu-u.ac.jp; Oguchi, Masahiko; Isobe, Koichi; Nakamura, Katsumasa; Tamaki, Yoshio; Hasegawa, Masatoshi; Kodaira, Takeshi; Sasaki, Shigeru; Kagami, Yoshikazu

    2006-09-01

    Purpose: We conducted a multicenter prospective study to evaluate the efficacy and safety of reduced-dose three-course CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) followed by involved-field radiotherapy for elderly patients with localized aggressive non-Hodgkin's lymphoma. The primary endpoint was compliance with the combined modality. Methods and Materials: This study included untreated patients, {>=}70 years old, with diffuse aggressive lymphoma, Stage IA or contiguous nonbulky Stage IIA. 80%-CHOP (cyclophosphamide 600 mg/m{sup 2}, doxorubicin 40 mg/m{sup 2}, vincristine 1.1 mg/m{sup 2}, and prednisolone at 80 mg/day for 5 days) was repeated every 3 weeks. After three cycles of chemotherapy, involved-field radiotherapy was performed with a radiation dose of 30-50 Gy in 15-28 fractions. Results: Twenty-four patients with a median age of 75 years (range, 70-84 years) were enrolled. The compliance rate of the protocol study was 87.5% (95% confidence interval [CI], 67.6-97.3). Three patients received only two cycles of chemotherapy because of toxicity or second neoplasm. There were no deaths caused by severe toxicity. The 3-year progression-free and overall survival rates were 83.1% (95% CI, 75.4-90.8) and 82.9% (95% CI, 75.1-90.6), respectively. Conclusion: Three-course 80%-CHOP followed by involved-field radiotherapy may be safe for administration to elderly patients over 70 years old. The next step is to evaluate three-course 80%-CHOP and rituximab followed by radiotherapy in elderly patients with localized disease.

  13. Involved-Node and Involved-Field Volumetric Modulated Arc vs. Fixed Beam Intensity-Modulated Radiotherapy for Female Patients With Early-Stage Supra-Diaphragmatic Hodgkin Lymphoma: A Comparative Planning Study

    SciTech Connect

    Weber, Damien C.; Peguret, Nicolas; Dipasquale, Giovanna; Cozzi, Luca

    2009-12-01

    Purpose: A comparative treatment planning study was performed to compare volumetric-modulated arc (RA) to conventional intensity modulated (IMRT) for involved-field (IFRT) and involved-node (INRT) radiotherapy for Hodgkin lymphoma (HL). Methods and Materials: Plans for 10 early-stage HL female patients were computed for RA and IMRT. First, the planning target volume (PTV) coverage and organs at risk (OAR) dose deposition was assessed between the two modalities. Second, the OAR (lung, breast, heart, thyroid, and submandibular gland) dose-volume histograms were computed and compared for IFRT and INRT, respectively. Results: For IFRT and INRT, PTV coverage was equally homogeneous with both RA and IMRT. By and large, the OAR irradiation with IFRT planning was not significantly different between RA and IMRT. For INRT, doses computed for RA were, however, usually lower than those with IMRT, particularly so for the lung, breast, and thyroid. Regardless of RA and IMRT modalities, a significant 20-50% decrease of the OAR computed mean doses was observed with INRT when compared with IFRT (Breast D{sub Mean} 1.5 +- 1.1 vs. 2.6 +- 1.7 Gy, p < 0.01 and 1.6 +- 1.1 vs. 2.9 +- 1.9 Gy, p < 0.01 for RA and IMRT, respectively). Conclusions: RA and IMRT results in similar level of dose homogeneity. With INRT but not IFRT planning, the computed doses to the PTV and OAR were usually higher and lower with RA when compared to IMRT. Regardless of the treatment modality, INRT when compared with IFRT planning led to a significant decrease in OAR doses, particularly so for the breast and heart.

  14. Quality Control of Involved Field Radiotherapy in Patients With Early-Favorable (HD10) and Early-Unfavorable (HD11) Hodgkin's Lymphoma: An Analysis of the German Hodgkin Study Group

    SciTech Connect

    Eich, Hans Theodor Engenhart-Cabillic, Rita; Hansemann, Katja; Lukas, Peter; Schneeweiss, Angelika; Seegenschmiedt, Heinrich; Skripnitchenko, Roman; Staar, Susanne; Willich, Normann; Mueller, Rolf-Peter

    2008-08-01

    Purpose: The German Hodgkin Study Group (GHSG) set up a radiotherapy (RT) reference center within the Department of Radiation Oncology at University of Cologne to undertake quality assurance of the group's clinical studies. In the HD10 trial (early-favorable stages) and HD11 trial (early-unfavorable stages) all patients received involved field (IF)-RT (30 Gy vs. 20 Gy) within a combined-modality approach. For these patients a central prospective review of all diagnostic imaging was performed by expert radiation oncologists to control disease extension and to define IF treatment volume. Methods and Materials: On the basis of simulation films, verification films, and radiotherapy case report form (CRF) an expert panel evaluated retrospectively the adequacy of irradiated IF treatment portals according to the RT prescription, applied radiation doses, treatment time, and technical parameters. Results: Between 1999 and 2006 a total of 825 of 1370 randomized patients of the HD10 trial (60%) and 954 of 1422 patients of the HD11 trial (67%) were evaluated by the panel. Radiotherapy was rated as suboptimal in 47% of all reviewed cases. Although the participating RT centers received a precise RT prescription, most difficulties occurred in the adequate coverage of the IF (40%), followed by technical faults (12%). Deviations from the prescribed single daily dose (1.8-2 Gy), weekly dose, and total reference dose were rare (1%). Conclusions: As a consequence of these findings, radiation oncologists were trained on the definition of IF-RT at GHSG meetings and at the annual meetings of the German Society for Therapeutic Radiation Oncology. Possible correlations between RT quality and relapse rate will be investigated.

  15. Mild Toxicity and Favorable Prognosis of High-Dose and Extended Involved-Field Intensity-Modulated Radiotherapy for Patients With Early-Stage Nasal NK/T-Cell Lymphoma

    SciTech Connect

    Wang Hua; Li Yexiong; Wang Weihu; Jin Jing; Dai Jianrong; Wang Shulian; Liu Yueping; Song Yongwen; Wang Zhaoyang; Liu Qingfeng; Fang Hui; Qi Shunan; Liu Xinfan; Yu Zihao

    2012-03-01

    Purpose: The value of intensity-modulated radiotherapy (IMRT) for early-stage nasal NK/T-cell lymphoma has not been previously reported. The aim of the present study was to assess the dosimetric parameters, toxicity, and treatment outcomes of patients with nasal NK/T-cell lymphoma. Methods and Materials: Between 2003 and 2008, 42 patients with early-stage nasal NK/T-cell lymphoma underwent definitive high-dose and extended involved-field IMRT with or without combination chemotherapy. The median radiation dose to the primary tumor was 50 Gy. The dose-volume histograms of the target volume and critical normal structures were evaluated in all patients. The locoregional control, overall survival, and progression-free survival were calculated using the Kaplan-Meier method. Results: The average mean dose delivered to the planning target volume was 55.5 Gy. Only 1.3% and 2.5% of the planning target volume received <90% and 95% of the prescribed dose, respectively, indicating excellent planning target volume coverage. The mean dose and average dose to the parotid glands was 15 Gy and 14 Gy, respectively. With a median follow-up time of 27 months, the 2-year locoregional control, overall survival, and progression-free survivalrate was 93%, 78%, and 74%, respectively. No Grade 4 or 5 acute or late toxicity was reported. Conclusions: High-dose and extended involved-field IMRT for patients with early-stage nasal NK/T-cell lymphoma showed favorable locoregional control, overall survival, and progression-free survival, with mild toxicity. The dose constraints of IMRT for the parotid glands can be limited to <20 Gy in these patients.

  16. Treatment of stage i and ii mediastinal Hodgkin disease: a comparison of involved fields, extended fields, and involved fields followed by MOPP in patients stage by laparotomy

    SciTech Connect

    Hagemeister, F.B.; Fuller, L.M.; Sullivan, J.A.; North, L.; Velasquez, W.; Conrad, F.G.; McLaughlin, P.; Butter, J.J.; Shullenberger, C.C.

    1981-12-01

    Three treatment programs for Stage I and II mediastinal Hodgkin disease (established by laparotomy) were compared. Involved-field radiotherapy + MOPP gave a disease-free survival rate of 97%, significantly different from 62% and 55% for involved and extended fields, respectively. Corresponding survival figures of 97%, 88%, and 84% were not signiticantly different statistically due to salvage with radiotherapy and/or chemotherapy. Among patients given radiotherapy alone, the survival figure of 94% for limited mediastinal disease was significantly better than 63% for extensive mediastinal and hilar disease; corresponding disease-free figures of 72% and 35% were also significantly different. Constitutional symptoms were an important prognostic factor in disease-free survival following the use of involved fields; hilar disease was important only with large mediastinal masses. Most relapses were intrathoracic; MOPP alone salvaged only 47%. Treatment of State I and II Hodgkin disease should be based on symptoms, extent of mediastinal disease, and hilar involvement.

  17. Stereotactic radiotherapy for malignancies involving the trigeminal and facial nerves.

    PubMed

    Cuneo, K C; Zagar, T M; Brizel, D M; Yoo, D S; Hoang, J K; Chang, Z; Wang, Z; Yin, F F; Das, S K; Green, S; Ready, N; Bhatti, M T; Kaylie, D M; Becker, A; Sampson, J H; Kirkpatrick, J P

    2012-06-01

    Involvement of a cranial nerve caries a poor prognosis for many malignancies. Recurrent or residual disease in the trigeminal or facial nerve after primary therapy poses a challenge due to the location of the nerve in the skull base, the proximity to the brain, brainstem, cavernous sinus, and optic apparatus and the resulting complex geometry. Surgical resection caries a high risk of morbidity and is often not an option for these patients. Stereotactic radiosurgery and radiotherapy are potential treatment options for patients with cancer involving the trigeminal or facial nerve. These techniques can deliver high doses of radiation to complex volumes while sparing adjacent critical structures. In the current study, seven cases of cancer involving the trigeminal or facial nerve are presented. These patients had unresectable recurrent or residual disease after definitive local therapy. Each patient was treated with stereotactic radiation therapy using a linear accelerator based system. A multidisciplinary approach including neuroradiology and surgical oncology was used to delineate target volumes. Treatment was well tolerated with no acute grade 3 or higher toxicity. One patient who was reirradiated experienced cerebral radionecrosis with mild symptoms. Four of the seven patients treated had no evidence of disease after a median follow up of 12 months (range 2-24 months). A dosimetric analysis was performed to compare intensity modulated fractionated stereotactic radiation therapy (IM-FSRT) to a 3D conformal technique. The dose to 90% (D90) of the brainstem was lower with the IM-FSRT plan by a mean of 13.5 Gy. The D95 to the ipsilateral optic nerve was also reduced with IM-FSRT by 12.2 Gy and the D95 for the optic chiasm was lower with FSRT by 16.3 Gy. Treatment of malignancies involving a cranial nerve requires a multidisciplinary approach. Use of an IM-FSRT technique with a micro-multileaf collimator resulted in a lower dose to the brainstem, optic nerves and chiasm

  18. Involved-Node Radiotherapy and Modern Radiation Treatment Techniques in Patients With Hodgkin Lymphoma

    SciTech Connect

    Paumier, Amaury; Ghalibafian, Mithra; Beaudre, Anne; Ferreira, Ivaldo; Pichenot, Charlotte; Messai, Taha; Lessard, Nathalie Athalie; Lefkopoulos, Dimitri; Girinsky, Theodore

    2011-05-01

    Purpose: To assess the clinical outcome of the involved-node radiotherapy (INRT) concept using modern radiation treatments (intensity-modulated radiotherapy [IMRT]or deep-inspiration breath-hold radiotherapy [DIBH) in patients with localized supradiaphragmatic Hodgkin lymphoma. Methods and Materials: All but 2 patients had early-stage Hodgkin lymphoma, and they were treated with chemotherapy prior to irradiation. Radiation treatments were delivered using the INRT concept according to European Organization for Research and Treatment of Cancer guidelines. IMRT was performed with the patient free-breathing. For the adapted breath-hold technique, a spirometer dedicated to DIBH radiotherapy was used. Three-dimensional conformal radiotherapy was performed with those patients. Results: Fifty patients with Hodgkin lymphoma (48 patients with primary Hodgkin lymphoma, 1 patient with recurrent disease, and 1 patient with refractory disease) entered the study from January 2003 to August 2008. Thirty-two patients were treated with IMRT, and 18 patients were treated with the DIBH technique. The median age was 28 years (range, 17-62 years). Thirty-four (68%) patients had stage I - (I-IIA) IIA disease, and 16 (32%) patients had stage I - (I-IIB) IIB disease. All but 3 patients received three to six cycles of adriamycin, bleomycin, vinblastine, and dacarbazine (ABVD). The median radiation doses to patients treated with IMRT and DIBH were, respectively, 40 Gy (range, 21.6-40 Gy) and 30.6 Gy (range, 19.8-40 Gy). Protection of various organs at risk was satisfactory. Median follow-up was 53.4 months (range, 19.1-93 months). The 5-year progression-free and overall survival rates for the whole population were 92% (95% confidence interval [CI], 80%-97%) and 94% (95% CI, 75%-98%), respectively. Recurrences occurred in 4 patients: 2 patients had in-field relapses, and 2 patients had visceral recurrences. Grade 3 acute lung toxicity (transient pneumonitis) occurred in 1 case. Conclusions

  19. Could Radiotherapy Effectiveness Be Enhanced by Electromagnetic Field Treatment?

    PubMed Central

    Francisco, Artacho-Cordón; del Mar, Salinas-Asensio María; Irene, Calvente; Sandra, Ríos-Arrabal; Josefa, León; Elisa, Román-Marinetto; Nicolás, Olea; Isabel, Núñez María

    2013-01-01

    One of the main goals in radiobiology research is to enhance radiotherapy effectiveness without provoking any increase in toxicity. In this context, it has been proposed that electromagnetic fields (EMFs), known to be modulators of proliferation rate, enhancers of apoptosis and inductors of genotoxicity, might control tumor recruitment and, thus, provide therapeutic benefits. Scientific evidence shows that the effects of ionizing radiation on cellular compartments and functions are strengthened by EMF. Although little is known about the potential role of EMFs in radiotherapy (RT), the radiosensitizing effect of EMFs described in the literature could support their use to improve radiation effectiveness. Thus, we hypothesized that EMF exposure might enhance the ionizing radiation effect on tumor cells, improving the effects of RT. The aim of this paper is to review reports of the effects of EMFs in biological systems and their potential therapeutic benefits in radiotherapy. PMID:23867611

  20. Radiotherapy for Early Mediastinal Hodgkin Lymphoma According to the German Hodgkin Study Group (GHSG): The Roles of Intensity-Modulated Radiotherapy and Involved-Node Radiotherapy

    SciTech Connect

    Koeck, Julia; Abo-Madyan, Yasser; Lohr, Frank; Stieler, Florian; Kriz, Jan; Mueller, Rolf-Peter; Wenz, Frederik; Eich, Hans Theodor

    2012-05-01

    Purpose: Cure rates of early Hodgkin lymphoma (HL) are high, and avoidance of late complications and second malignancies have become increasingly important. This comparative treatment planning study analyzes to what extent target volume reduction to involved-node (IN) and intensity-modulated (IM) radiotherapy (RT), compared with involved-field (IF) and three-dimensional (3D) RT, can reduce doses to organs at risk (OAR). Methods and Materials: Based on 20 computed tomography (CT) datasets of patients with early unfavorable mediastinal HL, we created treatment plans for 3D-RT and IMRT for both the IF and IN according to the guidelines of the German Hodgkin Study Group (GHSG). As OAR, we defined heart, lung, breasts, and spinal cord. Dose-volume histograms (DVHs) were evaluated for planning target volumes (PTVs) and OAR. Results: Average IF-PTV and IN-PTV were 1705 cm{sup 3} and 1015 cm{sup 3}, respectively. Mean doses to the PTVs were almost identical for all plans. For IF-PTV/IN-PTV, conformity was better with IMRT and homogeneity was better with 3D-RT. Mean doses to the heart (17.94/9.19 Gy for 3D-RT and 13.76/7.42 Gy for IMRT) and spinal cord (23.93/13.78 Gy for 3D-RT and 19.16/11.55 Gy for IMRT) were reduced by IMRT, whereas mean doses to lung (10.62/8.57 Gy for 3D-RT and 12.77/9.64 Gy for IMRT) and breasts (left 4.37/3.42 Gy for 3D-RT and 6.04/4.59 Gy for IMRT, and right 2.30/1.63 Gy for 3D-RT and 5.37/3.53 Gy for IMRT) were increased. Volume exposed to high doses was smaller for IMRT, whereas volume exposed to low doses was smaller for 3D-RT. Pronounced benefits of IMRT were observed for patients with lymph nodes anterior to the heart. IN-RT achieved substantially better values than IF-RT for almost all OAR parameters, i.e., dose reduction of 20% to 50%, regardless of radiation technique. Conclusions: Reduction of target volume to IN most effectively improves OAR sparing, but is still considered investigational. For the time being, IMRT should be considered for

  1. Left-sided breast cancer irradiation using rotational and fixed-field radiotherapy

    SciTech Connect

    Qi, X. Sharon; Liu, Tian X.; Liu, Arthur K.; Newman, Francis; Rabinovitch, Rachel; Kavanagh, Brian; Hu, Y. Angie

    2014-10-01

    The 3-dimensional conformal radiotherapy (3DCRT) technique is the standard for breast cancer radiotherapy. During treatment planning, not only the coverage of the planning target volume (PTV) but also the minimization of the dose to critical structures, such as the lung, heart, and contralateral breast tissue, need to be considered. Because of the complexity and variations of patient anatomy, more advanced radiotherapy techniques are sometimes desired to better meet the planning goals. In this study, we evaluated external-beam radiation treatment techniques for left breast cancer using various delivery platforms: fixed-field including TomoDirect (TD), static intensity-modulated radiotherapy (sIMRT), and rotational radiotherapy including Elekta volumetric-modulated arc therapy (VMAT) and tomotherapy helical (TH). A total of 10 patients with left-sided breast cancer who did or did not have positive lymph nodes and were previously treated with 3DCRT/sIMRT to the entire breast were selected, their treatment was planned with Monaco VMAT, TD, and TH. Dosimetric parameters including PTV coverage, organ-at-risk (OAR) sparing, dose-volume histograms, and target minimum/maximum/mean doses were evaluated. It is found that for plans providing comparable PTV coverage, the Elekta VMAT plans were generally more inhomogeneous than the TH and TD plans. For the cases with regional node involvement, the average mean doses administered to the heart were 9.2 (± 5.2) and 8.8 (± 3.0) Gy in the VMAT and TH plans compared with 11.9 (± 6.4) and 11.8 (± 9.2) Gy for the 3DCRT and TD plans, respectively, with slightly higher doses given to the contralateral lung or breast or both. On average, the total monitor units for VMAT plans are 11.6% of those TH plans. Our studies have shown that VMAT and TH plans offer certain dosimetric advantages over fixed-field IMRT plans for advanced breast cancer requiring regional nodal treatment. However, for early-stage breast cancer fixed-field

  2. How to identify rectal sub-regions likely involved in rectal bleeding in prostate cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Dréan, G.; Acosta, O.; Ospina, J. D.; Voisin, C.; Rigaud, B.; Simon, A.; Haigron, P.; de Crevoisier, R.

    2013-11-01

    Nowadays, the de nition of patient-speci c constraints in prostate cancer radiotherapy planning are solely based on dose-volume histogram (DVH) parameters. Nevertheless those DVH models lack of spatial accuracy since they do not use the complete 3D information of the dose distribution. The goal of the study was to propose an automatic work ow to de ne patient-speci c rectal sub-regions (RSR) involved in rectal bleeding (RB) in case of prostate cancer radiotherapy. A multi-atlas database spanning the large rectal shape variability was built from a population of 116 individuals. Non-rigid registration followed by voxel-wise statistical analysis on those templates allowed nding RSR likely correlated with RB (from a learning cohort of 63 patients). To de ne patient-speci c RSR, weighted atlas-based segmentation with a vote was then applied to 30 test patients. Results show the potentiality of the method to be used for patient-speci c planning of intensity modulated radiotherapy (IMRT).

  3. Methodology for determining doses to in-field, out-of-field and partially in-field organs for late effects studies in photon radiotherapy

    NASA Astrophysics Data System (ADS)

    Howell, Rebecca M.; Scarboro, Sarah B.; Taddei, Phillip J.; Krishnan, Sunil; Kry, Stephen F.; Newhauser, Wayne D.

    2010-12-01

    An important but little examined aspect of radiation dosimetry studies involving organs outside the treatment field is how to assess dose to organs that are partially within a treatment field; this question is particularly important for studies intended to measure total absorbed dose in order to predict the risk of radiogenic late effects, such as second cancers. The purpose of this investigation was therefore to establish a method to categorize organs as in-field, out-of-field or partially in-field that would be applicable to both conventional and modern radiotherapy techniques. In this study, we defined guidelines to categorize the organs based on isodose inclusion criteria, developed methods to assess doses to partially in-field organs, and then tested the methods by applying them to a case of intensity-modulated radiotherapy for hepatocellular carcinoma based on actual patient data. For partially in-field organs, we recommend performing a sensitivity test to determine whether potential inaccuracies in low-dose regions of the DVH (from the treatment planning system) have a substantial effect on the mean organ dose, i.e. >5%. In such cases, we suggest supplementing calculated DVH data with measured dosimetric data using a volume-weighting technique to determine the mean dose.

  4. Methodology for determining doses to in-field, out-of-field and partially in-field organs for late effects studies in photon radiotherapy.

    PubMed

    Howell, Rebecca M; Scarboro, Sarah B; Taddei, Phillip J; Krishnan, Sunil; Kry, Stephen F; Newhauser, Wayne D

    2010-12-01

    An important but little examined aspect of radiation dosimetry studies involving organs outside the treatment field is how to assess dose to organs that are partially within a treatment field; this question is particularly important for studies intended to measure total absorbed dose in order to predict the risk of radiogenic late effects, such as second cancers. The purpose of this investigation was therefore to establish a method to categorize organs as in-field, out-of-field or partially in-field that would be applicable to both conventional and modern radiotherapy techniques. In this study, we defined guidelines to categorize the organs based on isodose inclusion criteria, developed methods to assess doses to partially in-field organs, and then tested the methods by applying them to a case of intensity-modulated radiotherapy for hepatocellular carcinoma based on actual patient data. For partially in-field organs, we recommend performing a sensitivity test to determine whether potential inaccuracies in low-dose regions of the DVH (from the treatment planning system) have a substantial effect on the mean organ dose, i.e. >5%. In such cases, we suggest supplementing calculated DVH data with measured dosimetric data using a volume-weighting technique to determine the mean dose.

  5. Evaluation of the field-in-field technique with lung blocks for breast tangential radiotherapy.

    PubMed

    Tanaka, Hidekazu; Hayashi, Shinya; Kajiura, Yuichi; Kitahara, Masashi; Matsuyama, Katsuya; Kanematsu, Masayuki; Hoshi, Hiroaki

    2015-08-01

    Several studies have reported the advantages of the field-in-field (FIF) technique in breast radiotherapy, including dose reduction in the lungs by using lung field blocks. We evaluated the FIF technique with lung blocks for breast tangential radiotherapy. Sixteen patients underwent free breathing (FB) computed tomography (CT), followed by two CT procedures performed during breath hold after light inhalation (IN) and light exhalation (EX). Three radiotherapy plans were created using the FIF technique based on the FB-CT images: one without lung blocks (LB0) and two with lung blocks whose monitor units (MUs) were 5 (LB5) and 10 (LB10), respectively. These plans were copied to the IN-CT and EX-CT images. V20Gy, V30Gy, and V40Gy of the ipsilateral lung and V100%, V95%, and the mean dose (Dmean) to the planning target volume (PTV) were analyzed. The extent of changes in these parameters on the IN-plan and EX-plan compared with the FB-plan was evaluated. V20Gy, V30Gy, and V40Gy were significantly smaller for FB-LB5 and FB-LB10 than for FB-LB0; similar results were obtained for the IN-plan and EX-plan. V100%, V95%, and Dmean were also significant smaller for FB-LB5 and FB-LB10 than for FB-LB0. The extent of changes in V20Gy, V30Gy, and V40Gy on the IN-plan and EX-plan compared with the FB-plan was not statistically significant. Lung blocks were useful for dose reduction in the lung and a simultaneous PTV decrease. This technique should not be applied in the general population.

  6. Jaw position uncertainty and adjacent fields in breast cancer radiotherapy.

    PubMed

    Hedin, Emma; Bäck, Anna; Chakarova, Roumiana

    2015-11-08

    Locoregional treatment of breast cancer involves adjacent, half blocked fields matched at isocenter. The objective of this work is to study the dosimetric effects of the uncertainties in jaw positioning for such a case, and how a treatment planning protocol including adjacent field overlap of 1 mm affects the dose distribution. A representative treatment plan, involving 6 and 15 photon beams, for a patient treated at our hospital is chosen. Monte Carlo method (EGSnrc/BEAMnrc) is used to simulate the treatment. Uncertainties in jaw positioning of ± 1 mm are addressed, which implies extremes in reality of 2 mm field gap/overlap when planning adjacent fields without overlap and 1 mm gap or 3 mm overlap for a planning protocol with 1 mm overlap. Dosimetric parameters for PTV, lung and body are analyzed. Treatment planning protocol with 1 mm overlap of the adjacent fields does not considerably counteract possible underdosage of the target in the case studied. PTV-V95% is for example reduced from 95% for perfectly aligned fields to 90% and 91% for 2 mm and 1 mm gap, respectively. However, the risk of overdosage in PTV and in healthy soft tissue is increased when following the protocol with 1 mm overlap. A 3 mm overlap compared to 2 mm overlap results in an increase in maximum dose to PTV, PTV-D2%, from 113% to 121%. V120% for 'Body-PTV' is also increased from 5 cm(3) to 14 cm(3). A treatment planning protocol with 1 mm overlap does not considerably improve the coverage of PTV in the case of erroneous jaw positions causing gap between fields, but increases the overdosage in PTV and doses to healthy tissue, in the case of overlapping fields, for the case investigated.

  7. A Dosimetric Evaluation of Conventional Helmet Field Irradiation Versus Two-Field Intensity-Modulated Radiotherapy Technique

    SciTech Connect

    Yu, James B.; Shiao, Stephen L.; Knisely, Jonathan . E-mail: jonathan.knisely@yale.edu

    2007-06-01

    Purpose: To compare dosimetric differences between conventional two-beam helmet field irradiation (external beam radiotherapy, EBRT) of the brain and a two-field intensity-modulated radiotherapy (IMRT) technique. Methods and Materials: Ten patients who received helmet field irradiation at our institution were selected for study. External beam radiotherapy portals were planned per usual practice. Intensity-modulated radiotherapy fields were created using the identical field angles as the EBRT portals. Each brain was fully contoured along with the spinal cord to the bottom of the C2 vertebral body. This volume was then expanded symmetrically by 0.5 cm to construct the planning target volume. An IMRT plan was constructed using uniform optimization constraints. For both techniques, the nominal prescribed dose was 3,000 cGy in 10 fractions of 300 cGy using 6-MV photons. Comparative dose-volume histograms were generated for each patient and analyzed. Results: Intensity-modulated radiotherapy improved dose uniformity over EBRT for whole brain radiotherapy. The mean percentage of brain receiving >105% of dose was reduced from 29.3% with EBRT to 0.03% with IMRT. The mean maximum dose was reduced from 3,378 cGy (113%) for EBRT to 3,162 cGy (105%) with IMRT. The mean percent volume receiving at least 98% of the prescribed dose was 99.5% for the conventional technique and 100% for IMRT. Conclusions: Intensity-modulated radiotherapy reduces dose inhomogeneity, particularly for the midline frontal lobe structures where hot spots occur with conventional two-field EBRT. More study needs to be done addressing the clinical implications of optimizing dose uniformity and its effect on long-term cognitive function in selected long-lived patients.

  8. [Radiotherapy of skin cancers].

    PubMed

    Hennequin, C; Rio, E; Mahé, M-A

    2016-09-01

    The indications of radiotherapy for skin cancers are not clearly defined because of the lack of randomised trials or prospective studies. For basal cell carcinomas, radiotherapy frequently offers a good local control, but a randomized trial showed that surgery is more efficient and less toxic. Indications of radiotherapy are contra-indications of surgery for patients older than 60, non-sclerodermiform histology and occurring in non-sensitive areas. Adjuvant radiotherapy could be proposed to squamous cell carcinomas, in case of poor prognostic factors. Dose of 60 to 70Gy are usually required, and must be modulated to the size of the lesions. Adjuvant radiotherapy seems beneficial for desmoplastic melanomas but not for the other histological types. Prophylactic nodal irradiation (45 to 50Gy), for locally advanced tumours (massive nodal involvement), decreases the locoregional failure rate but do not increase survival. Adjuvant radiotherapy (50 to 56Gy) for Merckel cell carcinomas increases also the local control rate, as demonstrated by meta-analysis and a large epidemiological study. Nodal areas must be included, if there is no surgical exploration (sentinel lymph node dissection). Kaposi sarcomas are radiosensitive and could be treated with relatively low doses (24 to 30Gy). Also, cutaneous lymphomas are good indications for radiotherapy: B lymphomas are electively treated with limited fields. The role of total skin electron therapy for T-lymphomas is still discussed; but palliative radiotherapy is very efficient in case of cutaneous nodules. PMID:27522189

  9. MR-guided breast radiotherapy: feasibility and magnetic-field impact on skin dose

    NASA Astrophysics Data System (ADS)

    van Heijst, Tristan C. F.; den Hartogh, Mariska D.; Lagendijk, Jan J. W.; Desirée van den Bongard, H. J. G.; van Asselen, Bram

    2013-09-01

    The UMC Utrecht MRI/linac (MRL) design provides image guidance with high soft-tissue contrast, directly during radiotherapy (RT). Breast cancer patients are a potential group to benefit from better guidance in the MRL. However, due to the electron return effect, the skin dose can be increased in presence of a magnetic field. Since large skin areas are generally involved in breast RT, the purpose of this study is to investigate the effects on the skin dose, for whole-breast irradiation (WBI) and accelerated partial-breast irradiation (APBI). In ten patients with early-stage breast cancer, targets and organs at risk (OARs) were delineated on postoperative CT scans co-registered with MRI. The OARs included the skin, comprising the first 5 mm of ipsilateral-breast tissue, plus extensions. Three intensity-modulated RT techniques were considered (2× WBI, 1× APBI). Individual beam geometries were used for all patients. Specially developed MRL treatment-planning software was used. Acceptable plans were generated for 0 T, 0.35 T and 1.5 T, using a class solution. The skin dose was augmented in WBI in the presence of a magnetic field, which is a potential drawback, whereas in APBI the induced effects were negligible. This opens possibilities for developing MR-guided partial-breast treatments in the MRL.

  10. Radiotherapy of early glottic cancer.

    PubMed

    Harwood, A R; Hawkins, N V; Keane, T; Cummings, B; Beale, F A; Rider, W D; Bryce, D P

    1980-03-01

    Patients (383) with stage Tis, Tla and Tlb NoMo glottic cancer are reviewed. Radiotherapy cured 93% of Tis patients and 86% of Tla and Tlb cases. Of all recurrences, 63% were cured. No patient with stage Tis died as a result of tumor and only 5% of stage Tla and Tlb died from tumor. Involvement of the anterior commissure or both vocal cords did not influence control rates by radiotherapy. Mobility of the vocal cord and size of radiotherapy field were significant factors influencing control by radiotherapy. Late recurrences and/or second primaries in the larynx following radiotherapy are rare. Second primaries in the respiratory tract (especially lung) are common and are as important a cause of death as laryngeal cancer in T1 cases. It is concluded that moderate dose radiotherapy with surgery for salvage is a highly effective method of management for early glottic cancer. PMID:7359967

  11. Prognostic Value of Prevertebral Space Involvement in Nasopharyngeal Carcinoma Based on Intensity-Modulated Radiotherapy

    SciTech Connect

    Zhou Guanqun; Mao YanPing; Chen Lei; Li Wenfei; Liu Lizhi; Sun Ying; Chen Yong; Tian Li; Lin Aihua; Li Li; and others

    2012-03-01

    Purpose: To investigate the prognostic significance of prevertebral space involvement (PSI) in patients with nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: A retrospective review of data from 506 biopsy-proven, nonmetastatic NPCs was performed. Patients underwent magnetic resonance imaging examinations and received IMRT as their primary treatment. Results: In this series, 161 NPC patients (31.8%) had PSI. Parapharyngeal space (p < 0.001), skull base (p < 0.001), and paranasal sinuses (p = 0.009) were associated with PSI after multivariate analysis. The 4-year overall survival (OS), local relapse-free survival (LRFS), distant metastasis-free survival (DMFS) for NPC patients with and without PSI was 69.1% and 89.2% (p < 0.0001), 83.9% and 96.4% (p < 0.0001), and 71.6% and 89.6% (p < 0.0001), respectively. Multivariate analysis identified PSI as an independent negative prognostic factor for both OS (HR = 1.478-4.380; p = 0.001) and DMFS (HR = 1.389-4.174; p = 0.002). Patients with PSI had similar survival rates in OS and DMFS (p = 0.241 and p = 0.493, respectively) to that of T4 disease, while the differences between PSI and T3 disease in both OS and DMFS were distinctly significant (p = 0.029 and p = 0.029, respectively). Conclusions: For NPC patients treated with IMRT, PSI was found to be an independent prognostic factor for both OS and DMFS. It seems reasonable that PSI should be classified as a T4 disease on the basis of the current American Joint Committee on Cancer staging classification criteria.

  12. Progressive Muscle Atrophy and Weakness After Treatment by Mantle Field Radiotherapy in Hodgkin Lymphoma Survivors

    SciTech Connect

    Leeuwen-Segarceanu, Elena M. van; Dorresteijn, Lucille D.A.; Pillen, Sigrid; Biesma, Douwe H.; Vogels, Oscar J.M.; Alfen, Nens van

    2012-02-01

    Purpose: To describe the damage to the muscles and propose a pathophysiologic mechanism for muscle atrophy and weakness after mantle field radiotherapy in Hodgkin lymphoma (HL) survivors. Methods and Materials: We examined 12 patients treated by mantle field radiotherapy between 1969 and 1998. Besides evaluation of their symptoms, the following tests were performed: dynamometry; ultrasound of the sternocleidomastoid, biceps, and antebrachial flexor muscles; and needle electromyography of the neck, deltoid, and ultrasonographically affected arm muscles. Results: Ten patients (83%) experienced neck complaints, mostly pain and muscle weakness. On clinical examination, neck flexors were more often affected than neck extensors. On ultrasound, the sternocleidomastoid was severely atrophic in 8 patients, but abnormal echo intensity was seen in only 3 patients. Electromyography of the neck muscles showed mostly myogenic changes, whereas the deltoid, biceps, and antebrachial flexor muscles seemed to have mostly neurogenic damage. Conclusions: Many patients previously treated by mantle field radiotherapy develop severe atrophy and weakness of the neck muscles. Neck muscles within the radiation field show mostly myogenic damage, and muscles outside the mantle field show mostly neurogenic damage. The discrepancy between echo intensity and atrophy suggests that muscle damage is most likely caused by an extrinsic factor such as progressive microvascular fibrosis. This is also presumed to cause damage to nerves within the radiated field, resulting in neurogenic damage of the deltoid and arm muscles.

  13. A Dosimetric Analysis of IMRT and Multistatic Fields Techniques for Left Breast Radiotherapy

    SciTech Connect

    Moon, Seong Kwon; Kim, Yeon Sil; Kim, Soo Young; Lee, Mi Jo; Keum, Hyun Sup; Kim, Seung Jin; Youn, Seon Min

    2011-10-01

    The purpose of this study was to analyze the dosimetric difference between intensity-modulated radiation therapy (IMRT) using 3 or 5 beams and multistatic field technique (MSF) in radiotherapy of the left breast. We made comparative analysis of two kinds of radiotherapy that can achieve improved dose homogeneity. First is a MSF that uses both major and small irradiation fields at the same time. The other is IMRT using 3 or 5 beams with an inverse planning system using multiple static multileaf collimators. We made treatment plans for 16 early left breast cancer patients who were randomly selected and had undergone breast conserving surgery and radiotherapy, and analyzed them in the dosimetric aspect. For the mean values of V{sub 95} and dose homogeneity index, no statistically significant difference was observed among the three therapies. Extreme hot spots receiving >110% of prescribed dose were not found in any of the three methods. Using Tukey's test, IMRT showed a significantly larger increase in exposure dose to the ipsilateral lung and the heart than MSF in the low-dose area, but in the high-dose area, MSF showed a slight increase. To improve dose homogeneity, the application of MSF, which can be easily planned and applied more widely, is considered optimal as an alternative to IMRT for radiotherapy of early left breast cancer.

  14. Assessment of Extended-Field Radiotherapy for Stage IIIC Endometrial Cancer Using Three-Dimensional Conformal Radiotherapy, Intensity-Modulated Radiotherapy, and Helical Tomotherapy

    SciTech Connect

    Lian Jidong Mackenzie, Marc; Joseph, Kurian; Pervez, Nadeem; Dundas, George; Urtasun, Raul; Pearcey, Robert

    2008-03-01

    Purpose: To perform a dosimetric comparison of three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and helical tomotherapy (HT) plans for pelvic and para-aortic RT in postoperative endometrial cancer patients; and to evaluate the integral dose (ID) received by critical structures within the radiation fields. Methods and Materials: We selected 10 patients with Stage IIIC endometrial cancer. For each patient, three plans were created with 3D-CRT, IMRT, and HT. The IMRT and HT plans were both optimized to keep the mean dose to the planning target volume (PTV) the same as that with 3D-CRT. The dosimetry and ID for the critical structures were compared. A paired two-tailed Student t test was used for data analysis. Results: Compared with the 3D-CRT plans, the IMRT plans resulted in lower IDs in the organs at risk (OARs), ranging from -3.49% to -17.59%. The HT plans showed a similar result except that the ID for the bowel increased 0.27%. The IMRT and HT plans both increased the IDs to normal tissue (see and text for definition), pelvic bone, and spine (range, 3.31-19.7%). The IMRT and HT dosimetry showed superior PTV coverage and better OAR sparing than the 3D-CRT dosimetry. Compared directly with IMRT, HT showed similar PTV coverage, lower Ids, and a decreased dose to most OARs. Conclusion: Intensity-modulated RT and HT appear to achieve excellent PTV coverage and better sparing of OARs, but at the expense of increased IDs to normal tissue and skeleton. HT allows for additional improvement in dosimetry and sparing of most OARs.

  15. Water-equivalent dosimeter array for small-field external beam radiotherapy

    SciTech Connect

    Archambault, Louis; Beddar, A. Sam; Gingras, Luc; Lacroix, Frederic; Roy, Rene; Beaulieu, Luc

    2007-05-15

    With the increasing complexity of dose patterns external beam radiotherapy, there is a great need for new types of dosimeters. We studied the first prototype of a new dosimeter array consisting of water-equivalent plastic scintillating fibers for dose measurement in external beam radiotherapy. We found that this array allows precise, rapid dose evaluation of small photon fields. Starting with a dosimeter system constructed with a single scintillating fiber coupled to a clear optical fiber and read using a charge coupled device camera, we looked at the dosimeter's spatial resolution under small radiation fields and angular dependence. Afterward, we analyzed the camera's light collection to determine the maximum array size that could be built. Finally, we developed a prototype made of ten scintillating fiber detectors to study the behavior and precision of this system in simple dosimetric situations. The scintillation detector showed no measurable angular dependence. Comparison of the scintillation detector and a small-volume ion chamber showed agreement except for 1x1 and 0.5x5.0 cm{sup 2} fields where the output factor measured by the scintillator was higher. The actual field of view of the camera could accept more than 4000 scintillating fiber detectors simultaneously. Evaluation of the dose profile and depth dose curve using a prototype with ten scintillating fiber detectors showed precise, rapid dose evaluation even with placement of more than 75 optical fibers in the field to simulate what would happen in a larger array. We concluded that this scintillating fiber dosimeter array is a valuable tool for dose measurement in external beam radiotherapy. It possesses the qualities necessary to evaluate small and irregular fields with various incident angles such as those encountered in intensity-modulated radiotherapy, radiosurgery, and tomotherapy.

  16. Commissioning a Miniature Multileaf Collimator for Small Field Radiotherapy

    SciTech Connect

    Eaton, David Twyman, Nicola; Thomas, Simon

    2010-04-01

    The aim of this study was to determine dosimetric data for the Siemens ModuLeaf miniature multileaf collimator. Acquiring accurate data for small fields requires careful evaluation of different measurement techniques and dosimeters. Output factors were measured using several different detectors. Comparing these results demonstrated the relative under-response of the devices as the field size approaches the active area of the detector. Measurements obtained with a diamond detector, radiographic film, 0.125 cm{sup 3} cylindrical and advanced Markus ionization chambers agreed (within 0.7%) down to a field size of 2 x 2 cm. For smaller field sizes, only the diamond detector and the film agreed within their relative uncertainties. Head scatter factors were measured in brass and Perspex miniphantoms using the cylindrical chamber positioned at the isocenter, and in the Perspex miniphantom at extended distances. For field sizes of less than 3 x 3 cm, only the measurements with the brass miniphantom at the isocenter and the Perspex miniphantom at extended distances agreed (within 0.8%). The effect on the miniphantom measurements of using a low scatter support stand was also quantified. Beam profiles were measured using radiographic film. An unexpected artifact was found in these images because of increased backscatter from white lines inscribed and painted on the phantom. Percentage depth doses (PDDs) measured with and without the ModuLeaf attached agreed for all field sizes down to 3 x 3 cm. Below this field size, tissue maximum ratios (TMRs) were measured using an advanced Markus chamber. The 3 x 3 cm ModuLeaf TMR data agreed with the non-ModuLeaf PDD data within their relative uncertainties. This study investigated the use of several different measurement methods from which accurate dosimetric parameters can be obtained without the need to acquire specialist detectors.

  17. Adjuvant paclitaxel and carboplatin chemotherapy with involved field radiation in advanced endometrial cancer: A sequential approach

    SciTech Connect

    Lupe, Krystine; Kwon, Janice . E-mail: Janice.kwon@lhsc.on.ca; D'Souza, David; Gawlik, Christine; Stitt, Larry; Whiston, Frances; Nascu, Patricia; Wong, Eugene; Carey, Mark S.

    2007-01-01

    Purpose: To determine the feasibility of adjuvant paclitaxel and carboplatin chemotherapy interposed with involved field radiotherapy for women with advanced endometrial cancer. Methods and Materials: This was a prospective cohort study of women with Stage III and IV endometrial cancer. Adjuvant therapy consisted of 4 cycles of paclitaxel (175 mg/m{sup 2}) and carboplatin (350 mg/m{sup 2}) every 3 weeks, followed sequentially by external beam radiotherapy (RT) to the pelvis (45 Gy), followed by an additional two cycles of chemotherapy. Para-aortic RT and/or HDR vault brachytherapy (BT) were added at the discretion of the treating physician. Results: Thirty-three patients (median age, 63 years) received treatment between April 2002 and June 2005. Median follow-up was 21 months. Stage distribution was as follows: IIIA (21%), IIIC (70%), IVB (9%). Combination chemotherapy was successfully administered to 30 patients (91%) and 25 patients (76%), before and after RT respectively. Nine patients (27%) experienced acute Grade 3 or 4 chemotherapy toxicities. All patients completed pelvic RT; 19 (58%) received standard 4-field RT and 14 (42%) received intensity-modulated radiotherapy. Ten (30%) received extended field radiation. Four patients (12%) experienced acute Grade 3 or 4 RT toxicities. Six (18%) patients developed chronic RT toxicity. There were no treatment-related deaths. Two-year disease-free and overall survival rates were both 55%. There was only one pelvic relapse (3%). Conclusions: Adjuvant treatment with combination chemotherapy interposed with involved field radiation in advanced endometrial cancer was well tolerated. This protocol may be suitable for further evaluation in a clinical trial.

  18. Radiotherapy Treatment Plans With RapidArc for Prostate Cancer Involving Seminal Vesicles and Lymph Nodes

    SciTech Connect

    Yoo, Sua; Wu, Q. Jackie; Lee, W. Robert; Yin Fangfang

    2010-03-01

    Purpose: Dosimetric results and treatment delivery efficiency of RapidArc plans to those of conventional intensity-modulated radiotherapy (IMRT) plans were compared using the Eclipse treatment planning system for high-risk prostate cancer. Materials and Methods: This study included 10 patients. The primary planning target volume (PTV{sub P}) contained prostate, seminal vesicles, and pelvic lymph nodes with a margin. The boost PTV (PTV{sub B}) contained prostate and seminal vesicles with a margin. The total prescription dose was 75.6 Gy (46.8 Gy to PTV{sub P} and an additional 28.8 Gy to PTV{sub B}; 1.8 Gy/fraction). Three plans were generated for each PTV: Multiple-field IMRT, one-arc RapidArc (1ARC), and two-arc RapidArc (2ARC). Results: In the primary IMRT with PTV{sub P}, average mean doses to bladder, rectum and small bowel were lower by 5.9%, 7.7% and 4.3%, respectively, than in the primary 1ARC and by 3.6%, 4.8% and 3.1%, respectively, than in the primary 2ARC. In the boost IMRT with PTV{sub B}, average mean doses to bladder and rectum were lower by 2.6% and 4.8% than with the boost 1ARC and were higher by 0.6% and 0.2% than with the boost 2ARC. Integral doses were 7% to 9% higher with RapidArc than with IMRT for both primary and boost plans. Treatment delivery time was reduced by 2-7 minutes using RapidArc. Conclusion: For PTVs including prostate, seminal vesicles, and lymph nodes, IMRT performed better in dose sparing for bladder, rectum, and small bowel than did RapidArc. For PTVs including prostate and seminal vesicles, RapidArc with two arcs provided plans comparable to those for IMRT. The treatment delivery is more efficient with RapidArc.

  19. A Gravitational Experiment Involving Inhomogeneous Electric Fields

    SciTech Connect

    Datta, T.; Yin Ming; Vargas, Jose

    2004-02-04

    Unification of gravitation with other forms of interactions, particularly with electromagnetism, will have tremendous impacts on technology and our understanding of nature. The economic impact of such an achievement will also be unprecedented and far more extensive than the impact experienced in the past century due to the unification of electricity with magnetism and optics. Theoretical unification of gravitation with electromagnetism using classical differential geometry has been pursued since the late nineteen twenties, when Einstein and Cartan used teleparallelism for the task. Recently, Vargas and Torr have followed the same line of research with more powerful mathematics in a more general geometric framework, which allows for the presence of other interactions. Their approach also uses Kaehler generalization of Cartan's exterior calculus, which constitutes a language appropriate for both classical and quantum physics. Given the compelling nature of teleparallelism (path-independent equality of vectors at a distance) and the problems still existing with energy-momentum in general relativity, it is important to seek experimental evidence for such expectations. Such experimental programs are likely to provide quantitative guidance to the further development of current and future theories. We too, have undertaken an experimental search for potential electrically induced gravitational (EIG) effects. This presentation describes some of the practical concerns that relates to our investigation of electrical influences on laboratory size test masses. Preliminary results, appear to indicate a correlation between the application of a spatially inhomogeneous electric field and the appearance of an additional force on the test mass. If confirmed, the presence of such a force will be consistent with the predictions of Vargas-Torr. More importantly, proven results will shed new light and clearer understanding of the interactions between gravitational and electromagnetic

  20. A Gravitational Experiment Involving Inhomogeneous Electric Fields

    NASA Astrophysics Data System (ADS)

    Datta, T.; Yin, Ming; Vargas, Jose

    2004-02-01

    Unification of gravitation with other forms of interactions, particularly with electromagnetism, will have tremendous impacts on technology and our understanding of nature. The economic impact of such an achievement will also be unprecedented and far more extensive than the impact experienced in the past century due to the unification of electricity with magnetism and optics. Theoretical unification of gravitation with electromagnetism using classical differential geometry has been pursued since the late nineteen twenties, when Einstein and Cartan used teleparallelism for the task. Recently, Vargas and Torr have followed the same line of research with more powerful mathematics in a more general geometric framework, which allows for the presence of other interactions. Their approach also uses Kähler generalization of Cartan's exterior calculus, which constitutes a language appropriate for both classical and quantum physics. Given the compelling nature of teleparallelism (path-independent equality of vectors at a distance) and the problems still existing with energy-momentum in general relativity, it is important to seek experimental evidence for such expectations. Such experimental programs are likely to provide quantitative guidance to the further development of current and future theories. We too, have undertaken an experimental search for potential electrically induced gravitational (EIG) effects. This presentation describes some of the practical concerns that relates to our investigation of electrical influences on laboratory size test masses. Preliminary results, appear to indicate a correlation between the application of a spatially inhomogeneous electric field and the appearance of an additional force on the test mass. If confirmed, the presence of such a force will be consistent with the predictions of Vargas-Torr. More importantly, proven results will shed new light and clearer understanding of the interactions between gravitational and electromagnetic

  1. [Exclusive radiotherapy for a facial basal cell carcinoma with trigeminal ganglion involvement].

    PubMed

    Longeac, M; Lapeyre, M; Delbet Dupas, C; Barthélémy, I; Pham Dang, N

    2016-06-01

    Basal cell carcinomas with symptomatic perineural invasion are rare entities. We report the case of a 60year-old man (with a grafted kidney), surgically treated in 2007 for a sclerodermiform basal cell carcinoma infiltrating the left nostril. Five years later, a painful left hemifacial hypoesthesia associated with an ulcus rodens of the nasolabial fold appeared. A biopsy confirmed a recurrence. MRI showed an enhancement of the trigeminal ganglion. The patient had a trigeminal perineural invasion secondary to a cutaneous basal cell carcinoma. He received a local intensity-modulated radiotherapy alone (70Gy in 33 sessions), administered from the skin tumour to the skull base. Three years after the end of treatment, the patient is in radiological and clinical remission, with partial recovery of the hypoesthesia. Evolution was marked by iterative corneal ulcers and decreased visual acuity. Modalities of treatment by surgery and/or radiation therapy and complications are poorly described in the literature. PMID:27105681

  2. Three-dimensional customized bolus for intensity-modulated radiotherapy in a patient with Kimura's disease involving the auricle.

    PubMed

    Park, J W; Yea, J W

    2016-05-01

    In radiotherapy, a commercial bolus often does not provide a suitable fit over irregular surfaces. To address this issue, we fabricated a customized bolus using 3D printing technology. The aim of our study was to evaluate the application of this 3D-printed bolus in a clinical setting. The patient was a 45-year-old man with recurrent Kimura's disease involving the auricle, receiving radiotherapy in our oncology department. A customized bolus, 5mm in thickness, was fabricated based on reconstruction of computed tomography (CT) images. The bolus was printed on a Dimension 1200 series SST 3D printer. Repeat CT-based simulation indicated an acceptable fit of the 3D-printed bolus to the target region, with a maximum air gap of less than 5mm at the tragus. Most of the surface area of the target region was covered by the 95% isodose line. The plan with the 3D-printed bolus improved target coverage compared to that without a bolus. And the plan with the 3D-printed bolus yielded comparable results to those with the paraffin wax bolus. In conclusion, a customized bolus using a 3D printer was successfully applied to an irregular surface. PMID:27020714

  3. Feasibility of normal tissue dose reduction in radiotherapy using low strength magnetic field

    PubMed Central

    Shin, Youngseob; Jung, In-Hye; Kwak, Jungwon

    2015-01-01

    Purpose Toxicity of mucosa is one of the major concerns of radiotherapy (RT), when a target tumor is located near a mucosal lined organ. Energy of photon RT is transferred primarily by secondary electrons. If these secondary electrons could be removed in an internal cavity of mucosal lined organ, the mucosa will be spared without compromising the target tumor dose. The purpose of this study was to present a RT dose reduction in near target inner-surface (NTIS) of internal cavity, using Lorentz force of magnetic field. Materials and Methods Tissue equivalent phantoms, composed with a cylinder shaped internal cavity, and adjacent a target tumor part, were developed. The phantoms were irradiated using 6 MV photon beam, with or without 0.3 T of perpendicular magnetic field. Two experimental models were developed: single beam model (SBM) to analyze central axis dose distributions and multiple beam model (MBM) to simulate a clinical case of prostate cancer with rectum. RT dose of NTIS of internal cavity and target tumor area (TTA) were measured. Results With magnetic field applied, bending effect of dose distribution was visualized. The depth dose distribution of SBM showed 28.1% dose reduction of NTIS and little difference in dose of TTA with magnetic field. In MBM, cross-sectional dose of NTIS was reduced by 33.1% with magnetic field, while TTA dose were the same, irrespective of magnetic field. Conclusion RT dose of mucosal lined organ, located near treatment target, could be modulated by perpendicular magnetic field. PMID:26484306

  4. Magnetic-field-induced dose effects in MR-guided radiotherapy systems: dependence on the magnetic field strength.

    PubMed

    Raaijmakers, A J E; Raaymakers, B W; Lagendijk, J J W

    2008-02-21

    Several institutes are currently working on the development of a radiotherapy treatment system with online MR imaging (MRI) modality. The main difference between their designs is the magnetic field strength of the MRI system. While we have chosen a 1.5 Tesla (T) magnetic field strength, the Cross Cancer Institute in Edmonton will be using a 0.2 T MRI scanner and the company Viewray aims to use 0.3 T. The magnetic field strength will affect the severity of magnetic field dose effects, such as the electron return effect (ERE): considerable dose increase at tissue air boundaries due to returning electrons. This paper has investigated how the ERE dose increase depends on the magnetic field strength. Therefore, four situations where the ERE occurs have been simulated: ERE at the distal side of the beam, the lateral ERE, ERE in cylindrical air cavities and ERE in the lungs. The magnetic field comparison values were 0.2, 0.75, 1.5 and 3 T. Results show that, in general, magnetic field dose effects are reduced at lower magnetic field strengths. At the distal side, the ERE dose increase is largest for B = 0.75 T and depends on the irradiation field size for B = 0.2 T. The lateral ERE is strongest for B = 3 T but shows no effect for B = 0.2 T. Around cylindrical air cavities, dose inhomogeneities disappear if the radius of the cavity becomes small relative to the in-air radius of the secondary electron trajectories. At larger cavities (r > 1 cm), dose inhomogeneities exist for all magnetic field strengths. In water-lung-water phantoms, the ERE dose increase takes place at the water-lung transition and the dose decreases at the lung-water transition, but these effects are minimal for B = 0.2 T. These results will contribute to evaluating the trade-off between magnetic field dose effects and image quality of MR-guided radiotherapy systems.

  5. Radiation Field Design and Patterns of Locoregional Recurrence Following Definitive Radiotherapy for Breast Cancer

    SciTech Connect

    Chen, Susie A.; Schuster, David M.; Mister, Donna; Liu Tian; Godette, Karen; Torres, Mylin A.

    2013-02-01

    Purpose: Locoregional control is associated with breast cancer-specific and overall survival in select women with breast cancer. Although several patient, tumor, and treatment characteristics have been shown to contribute to locoregional recurrence (LRR), studies evaluating factors related to radiotherapy (XRT) technique have been limited. We investigated the relationship between LRR location and XRT fields and dose delivered to the primary breast cancer in women experiencing subsequent locoregional relapse. Methods and Materials: We identified 21 women who were previously treated definitively with surgery and XRT for breast cancer. All patients developed biopsy-result proven LRR and presented to Emory University Hospital between 2004 and 2010 for treatment. Computed tomography (CT) simulation scans with XRT dose files for the initial breast cancer were fused with {sup 18}F-labeled fluorodeoxyglucose positron emission tomography (FDG PET)/CT images in DICOM (Digital Imaging and Communications in Medicine) format identifying the LRR. Each LRR was categorized as in-field, defined as {>=}95% of the LRR volume receiving {>=}95% of the prescribed whole-breast dose; marginal, defined as LRR at the field edge and/or not receiving {>=}95% of the prescribed dose to {>=}95% of the volume; or out-of-field, that is, LRR intentionally not treated with the original XRT plan. Results: Of the 24 identified LRRs (3 patients experienced two LRRs), 3 were in-field, 9 were marginal, and 12 were out-of-field. Two of the 3 in-field LRRs were marginal misses of the additional boost XRT dose. Out-of-field LRRs consisted of six supraclavicular and six internal mammary nodal recurrences. Conclusions: Most LRRs in our study occurred in areas not fully covered by the prescribed XRT dose or were purposely excluded from the original XRT fields. Our data suggest that XRT technique, field design, and dose play a critical role in preventing LRR in women with breast cancer.

  6. Indolent non-Hodgkin lymphoma primarily involving the hard palate: outcome following radiotherapy.

    PubMed

    Milgrom, Sarah A; Yahalom, Joachim

    2013-06-01

    The aim of this study was to report the clinical and pathological characteristics, treatment strategies and outcome in patients with indolent non-Hodgkin lymphoma (NHL) primarily involving the hard palate. Nine consecutive patients with indolent NHL of the hard palate were identified. The palate was a site of initial disease for six patients (four stage IAE and two stage IIIAE) and of relapse for three. There were four cases of grade 1-2 follicular lymphoma (FL), two of mantle cell lymphoma (MCL) and three of marginal zone lymphoma (MZL). All nine patients received involved site radiation therapy (RT) alone. There was no grade ≥ 3 toxicity. At a median follow-up of 55 months, 5-year freedom from local progression was 100%, disease-free survival was 38% and overall survival was 80%. In conclusion, involved site RT is well tolerated and provides excellent local control in the management of indolent lymphoma of the hard palate. PMID:23083063

  7. Assessment of Out-of-Field Doses in Radiotherapy of Brain Lesions in Children

    SciTech Connect

    Taylor, Michael L.; Kron, Tomas; Franich, Rick D.

    2011-03-01

    Purpose: To characterize the out-of-field doses in pediatric radiotherapy and to identify simple methods by which out-of-field dose might be minimized, with a view to reducing the risk of secondary cancers. Methods and Materials: With the aim of characterizing the peripheral doses under different treatment conditions, the dose measurements in an anthropomorphic child phantom were taken in various organs and critical structures outside the primary field using thermoluminescent dosimetry. The doses from a Varian 600C and Varian Trilogy linear accelerator, both at 6 MV, were investigated. Results: Larger field sizes have been shown to result in greater peripheral doses close to the primary beam, with the difference becoming less significant at large distances, indicating that most of out-of-field doses result from head leakage and collimator scatter >40 cm from the primary field. The use of lead shields has been shown to reduce the absorbed dose resulting from leakage. Aligning the craniocaudal axis of the patient with the x-plane of the collimator resulted in a dose reduction of 40%, for both machines. Out-of-field doses from the Varian Trilogy were shown to be approximately 40% greater than those from the 600C linear accelerator, despite being operated at the same energy. Conclusion: Out-of-field doses to pediatric patients can be minimized by using simple treatment options, such as using the single-energy mode linear accelerator rather than the multimode, orienting the couch and collimator such that the patient lies along the x-plane and avoiding fields directed along the trunk of the body.

  8. Proton Radiotherapy: The Biological Effect of Treating Alternating Subsets of Fields for Different Treatment Fractions

    SciTech Connect

    Engelsman, Martijn; DeLaney, Thomas F.; Hong, Theodore S.

    2011-02-01

    Purpose: Common practice in proton radiotherapy is to deliver a subset of all fields in the treatment plan on any given treatment day. We investigate using biological modeling if the resulting variation in daily dose to normal tissues has a relevant detrimental biological effect. Methods and Materials: For four patient groups, the cumulative normalized total dose (NTD) was determined for normal tissues (OARs) of each patient using the clinically delivered fractionation schedule (FS{sub clin}), and for hypothetical fractionation schedules delivering all fields every day (FS{sub all}) or only a single field each day (FS{sub single}). Cumulative three-dimensional NTD distributions were summarized using the generalized equivalent uniform dose (gEUD) model. Results: For the skull base/cervical spine chordoma group, the largest effect is a 4-Gy increase in gEUD of the chiasm when treating only a subset of fields on any day. For lung cancer and pancreatic cancer patients, the variation in the gEUD of normal tissues is <0.2 Gy. For the prostate group, FS{sub clin} increases the gEUD of the femoral heads by 9 Gy compared with FS{sub all}. Use of FS{sub single} resulted in the highest NTD to normal tissues for any patient. FS{sub all} resulted in an integral NTD to the patient that is on average 5% lower than FS{sub clin} and 10% lower than FS{sub single}. Conclusion: The effects of field set of the day treatment delivery depend on the tumor site and number of fields treated each day. Modeling these effects may be important for accurate risk assessment.

  9. The Impact of Radiotherapy Fields in the Treatment of Patients With Choroid Plexus Carcinoma

    SciTech Connect

    Mazloom, Ali; Wolff, Johannes E.; Paulino, Arnold C.

    2010-09-01

    Purpose: To perform a comprehensive literature review and analysis of cases dealing with choroid plexus carcinoma (CPC) to determine the optimal radiotherapy (RT) treatment field. Methods and Materials: A PubMed search of English language articles from 1979 to 2008 was performed, yielding 33 articles with 56 patients who had available data regarding RT treatment field. The median age at diagnosis was 2.7 years (range, 1 month-53 years). Of 54 patients with data regarding type of surgery, 21 (38.9%) had complete resection. Chemotherapy was delivered to 27 (48%) as part of initial therapy. The RT treatment volume was the craniospinal axis in 38 (68%), whole brain in 9 (16%), and tumor/tumor bed in 9 (16%). Median follow-up for surviving patients was 40 months. Results: The 5-year overall survival and progression-free survival (PFS) rates were 59.5% and 37.2%, respectively. Complete resection (p = 0.035) and use of craniospinal irradiation (CSI; p = 0.025) were found to positively affect PFS. The 5-year PFS for patients who had CSI vs. whole brain and tumor/tumor bed RT were 44.2% and 15.3%. For the 19 patients who relapsed, 9 (47%) had a recurrence in the RT field, 6 (32%) had a recurrence outside the RT field, and 4 (21%) had a recurrence inside and outside the irradiated field. Conclusion: Patients with CPC who received CSI had better PFS compared with those receiving less than CSI. This study supports the use of CSI in the multimodality management of patients with CPC.

  10. Dosimetric comparison between coplanar and non coplanar field radiotherapy for ethmoid sinus cancer

    PubMed Central

    Serre, Antoine; Idri, Katia; Fenoglietto, Pascal; Ailleres, Norbert; Santoro, Lore; Lemanski, Claire; Garrel, Renaud; Makeieff, Marc; Allaw, Ali; Dubois, Jean-Bernard; Azria, David

    2007-01-01

    Background To compare non coplanar field (NCF) with coplanar field (CF) -intensity-modulated radiotherapy (IMRT) planning for ethmoid cancer. Methods Seven patients treated with NCF IMRT for ethmoid cancer were studied. A CF IMRT optimization was prepared with the same constraints as for the NCF treatment. The maximum point doses (D max) obtained for the different optic pathway structures (OPS) should differ no more than 3% from those achieved with the NCF IMRT plan. The distribution of the dose in the target volume and in the critical structures was compared between the two techniques, as well as the Conformity (CI) and the Homogeneity Indexes (HI) in the target volume. Results We noted no difference between the two techniques in the OPS for the D1, D2, and D5%, in the inner ear and controlateral lens for the average Dmax, in the temporo-mandibular joints for the average mean dose, in the cord and brainstem for the average D1%. The dose-volume histograms were slightly better with the NCF treatment plan for the planning target volume (PTV) with a marginally better HI but no impact on CI. We found a great improvement in the PTV coverage with the CF treatment plan for two patients with T4 tumors. Conclusion IMRT is one of the treatment options for ethmoid cancer. The PTV coverage is optimal without compromising the protection of the OPS. The impact of non coplanar versus coplanar set up is very slight. PMID:17877793

  11. Early Clinical Outcome With Concurrent Chemotherapy and Extended-Field, Intensity-Modulated Radiotherapy for Cervical Cancer

    SciTech Connect

    Beriwal, Sushil . E-mail: beriwals@upmc.edu; Gan, Gregory N.; Heron, Dwight E.; Selvaraj, Raj N.; Kim, Hayeon; Lalonde, Ron; Kelley, Joseph L.; Edwards, Robert P.

    2007-05-01

    Purpose: To assess the early clinical outcomes with concurrent cisplatin and extended-field intensity-modulated radiotherapy (EF-IMRT) for carcinoma of the cervix. Methods and Materials: Thirty-six patients with Stage IB2-IVA cervical cancer treated with EF-IMRT were evaluated. The pelvic lymph nodes were involved in 19 patients, and of these 19 patients, 10 also had para-aortic nodal disease. The treatment volume included the cervix, uterus, parametria, presacral space, upper vagina, and pelvic, common iliac, and para-aortic nodes to the superior border of L1. Patients were assessed for acute toxicities according to the National Cancer Institute Common Toxicity Criteria for Adverse Events, version 3.0. All late toxicities were scored with the Radiation Therapy Oncology Group late toxicity score. Results: All patients completed the prescribed course of EF-IMRT. All but 2 patients received brachytherapy. Median length of treatment was 53 days. The median follow-up was 18 months. Acute Grade {>=}3 gastrointestinal, genitourinary, and myelotoxicity were seen in 1, 1, and 10 patients, respectively. Thirty-four patients had complete response to treatment. Of these 34 patients, 11 developed recurrences. The first site of recurrence was in-field in 2 patients (pelvis in 1, pelvis and para-aortic in 1) and distant in 9 patients. The 2-year actuarial locoregional control, disease-free survival, overall survival, and Grade {>=}3 toxicity rates for the entire cohort were 80%, 51%, 65%, and 10%, respectively. Conclusion: Extended-field IMRT with concurrent chemotherapy was tolerated well, with acceptable acute and early late toxicities. The locoregional control rate was good, with distant metastases being the predominant mode of failure. We are continuing to accrue a larger number of patients and longer follow-up data to further extend our initial observations with this approach.

  12. Whole-Field Simultaneous Integrated-Boost Intensity-Modulated Radiotherapy for Patients With Nasopharyngeal Carcinoma

    SciTech Connect

    Wong, Frank C.S.; Ng, Alice W.Y.; Lee, Victor H.F.; Lui, Collin M.M.; Yuen, K.-K.; Sze, W.-K.; Leung, T.-W.; Tung, Stewart Y.

    2010-01-15

    Purpose: To retrospectively review the outcomes of our patients with newly diagnosed nondisseminated nasopharyngeal carcinoma treated with intensity-modulated radiotherapy using a whole-field simultaneous integrated-boost technique. Methods and Materials: A total of 175 patients treated with WF-SIB between mid-2004 and 2005 were eligible for study inclusion. The distribution of disease by stage was Stage IA in 10.9%, Stage IIA in 2.3%, Stage IIB in 21.7%, Stage III in 41.1%, Stage IVA in 14.9%, and Stage IVB in 9.1%. Of the 175 patients, 2 (1.2%), 10 (5.7%), and 163 (93.1%) had World Health Organization type I, II, and III histologic features, respectively. We prescribed 70 Gy, 60 Gy, and 54 Gy delivered in 33 fractions within 6.5 weeks at the periphery of three planning target volumes (PTV; PTV70, PTV60, and PTV54, respectively). Of the 175 patients, 46 with early T-stage disease received a brachytherapy boost, and 127 with advanced local or regional disease received chemotherapy. Results: The median follow-up period was 34 months. The overall 3-year local failure-free survival, regional failure-free survival, distant failure-free survival, and overall survival rate was 93.6%, 93.3%, 86.6%, and 87.2%, respectively. Cox regression analysis showed Stage N2-N3 disease (p = .029) and PTV (p = .024) to be independent factors predicting a greater risk of distant failure and poor overall survival, respectively. Grade 3 acute mucositis/pharyngitis occurred in 23.4% of patients, and Stage T4 disease was the only significant predictor of mucositis/pharyngitis (p = .021). Conclusion: Whole-field simultaneous integrated-boost intensity-modulated radiotherapy with a dose >70 Gy achieved excellent locoregional control, without an excess incidence of severe, acute mucositis/pharyngitis, in the present study. Strategies for using such highly conformal treatment for patients with a large tumor and late N-stage disease are potential areas of investigation for future studies.

  13. Breast dosimetry in transverse and longitudinal field MRI-Linac radiotherapy systems

    SciTech Connect

    Mahdavi, S. R.; Esmaeeli, A. D.; Pouladian, M.; Sardari, D.; Bagheri, S.; Monfared, A. S.

    2015-02-15

    Purpose: In the framework of developing the integration of a MRI-Linac system, configurations of MRI-Linac units were simulated in order to improve the dose distribution in tangential breast radiotherapy using transverse and longitudinal magnetic field geometries of Lorentz force for both medial and lateral tangential fields. Methods: In this work, the GEANT4 Monte Carlo (MC) code was utilized to compare dose distributions in breast radiotherapy for Linac-MR systems in the transverse and longitudinal geometries within humanoid phantoms across a range of magnetic field strengths of 0.5 and 1.5 T. The dose increment due to scattering from the coils was investigated for both geometries as well. Computed tomography images of two patients were used for MC simulations. One patient had intact breast while the other was mastectomized. In the simulations, planning and methods of chest wall irradiation were similar to the actual clinical planning. Results: In a longitudinal geometry, the magnetic field is shown to restrict the lateral spread of secondary electrons to the lung, heart, and contralateral organs, which reduced the mean dose of the ipsilateral lung and heart by means of 17.2% and 6% at 1.5 T, respectively. The transverse configuration exhibits a significant increase in tissue interface effects, which increased dose buildup in the entrance regions of the lateral and medial tangent beams to the planning target volume (PTV) and improved dose homogeneity within the PTV. The improved relative average homogeneity index for two patients to the PTV at magnetic field strength of 1.5 T with respect to no magnetic field case evaluated was 11.79% and 34.45% in the LRBP and TRBP geometries, respectively. In both geometries, the simulations show significant mean dose reductions in the contralateral breast and chest wall skin, respectively, by a mean of 16.6% and 24.9% at 0.5 T and 17.2% and 28.1% at 1.5 T in the transverse geometry, and 10.56% and 14.6% at 0.5 T and 11.3% and

  14. The field size matters: low dose external beam radiotherapy for thumb carpometacarpal osteoarthritis : Importance of field size.

    PubMed

    Kaltenborn, Alexander; Bulling, Elke; Nitsche, Mirko; Carl, Ulrich Martin; Hermann, Robert Michael

    2016-08-01

    The purpose of this work was to evaluate the efficacy of low-dose radiotherapy (RT) for thumb carpometacarpal osteoarthritis (rhizarthrosis). The responses of 84 patients (n = 101 joints) were analyzed 3 months after therapy (n = 65) and at 12 months (n = 27). Patients were treated with 6 fractions of 1 Gy, two times a week, with a linear accelerator. At the end of therapy, about 70 % of patients reported a response (partial remission or complete remission), 3 months later about 60 %, and 1 year after treatment 70 %. In univariate regression analysis, higher patient age and field size greater than 6 × 4 cm were associated with response to treatment, while initial increase of pain under treatment was predictive for treatment failure. Duration of RT series (more than 18 days), gender, time of symptoms before RT, stress pain or rest pain, or prior ortheses use, injections, or surgery of the joint were not associated with treatment efficacy. In multivariate regression analysis, only field size and initial pain increase were highly correlated with treatment outcome. In conclusion, RT represents a useful treatment option for patients suffering from carpometacarpal osteoarthritis. In contrast to other benign indications, a larger field size (>6 × 4 cm) seems to be more effective than smaller fields and should be evaluated in further prospective studies. PMID:27300369

  15. SU-E-T-98: Dependence of Radiotherapy Couch Transmission Factors On Field Size and Couch-Isocenter Distance

    SciTech Connect

    Benhabib, S; Duan, J; Wu, X; Cardan, R; Shen, S; Huang, M; Popple, R; Brezovich, I

    2014-06-01

    Purpose: The dosimetric effect of the treatment couch is non-negligible in today's radiotherapy treatment. To accurately include couch in dose calculation, we investigated the dependence of couch transmission factors on field size and couch-isocenter distance. Methods: Couch transmission factors for Varian Exact Couch were determined by taking the ratios of ionization of a posterior-anterior beam with and without the couch in the beam path. Measurements were performed at the isocenter using a PTW cylindrical ionization chamber (Model 31030) with an Aluminum buildup cap of 1.1 cm thick for the 6 MV photon beam. Ionization readings for beam sizes ranging from 2 × 2 cm2 to 40 × 40 cm2 were taken. Transmission factors for couch-isocenter distances ranging from 3 cm to 20 cm were also investigated. Results: The couch transmission factors increased with the field size approximately in an exponential manner. For the field sizes that we tested, the transmission factor ranged from 0.976 to 0.992 for couch-isocenter distance of 3 cm. The transmission factor was also monotonically dependent on couch-isocenter separation distance, but in a lighter magnitude. For the tested couch heights, the transmission factor ranged from 0.974 – 0.972 for 2 × 2 cm2 field size and 0.992 – 0.986 for 40 × 40 cm2 field size. The dependence on couch-isocenter distance is stronger for larger field size. Conclusions: The transmission factor of a radiotherapy treatment couch increases with field size of the radiation beam and its distance from the isocenter. Such characterization of the couch transmission factor helps improve the accuracy of couch modeling for radiotherapy treatment planning.

  16. Whole brain radiotherapy plus simultaneous in-field boost with image guided intensity-modulated radiotherapy for brain metastases of non-small cell lung cancer

    PubMed Central

    2014-01-01

    Background Whole brain radiotherapy (WBRT) plus sequential focal radiation boost is a commonly used therapeutic strategy for patients with brain metastases. However, recent reports on WBRT plus simultaneous in-field boost (SIB) also showed promising outcomes. The objective of present study is to retrospectively evaluate the efficacy and toxicities of WBRT plus SIB with image guided intensity-modulated radiotherapy (IG-IMRT) for inoperable brain metastases of NSCLC. Methods Twenty-nine NSCLC patients with 87 inoperable brain metastases were included in this retrospective study. All patients received WBRT at a dose of 40 Gy/20 f, and SIB boost with IG-IMRT at a dose of 20 Gy/5 f concurrent with WBRT in the fourth week. Prior to each fraction of IG-IMRT boost, on-line positioning verification and correction were used to ensure that the set-up errors were within 2 mm by cone beam computed tomography in all patients. Results The one-year intracranial control rate, local brain failure rate, and distant brain failure rate were 62.9%, 13.8%, and 19.2%, respectively. The two-year intracranial control rate, local brain failure rate, and distant brain failure rate were 42.5%, 30.9%, and 36.4%, respectively. Both median intracranial progression-free survival and median survival were 10 months. Six-month, one-year, and two-year survival rates were 65.5%, 41.4%, and 13.8%, corresponding to 62.1%, 41.4%, and 10.3% of intracranial progression-free survival rates. Patients with Score Index for Radiosurgery in Brain Metastases (SIR) >5, number of intracranial lesions <3, and history of EGFR-TKI treatment had better survival. Three lesions (3.45%) demonstrated radiation necrosis after radiotherapy. Grades 2 and 3 cognitive impairment with grade 2 radiation leukoencephalopathy were observed in 4 (13.8%) and 4 (13.8%) patients. No dosimetric parameters were found to be associated with these late toxicities. Patients received EGFR-TKI treatment had higher incidence of grades 2–3

  17. Coplanar intensity-modulated radiotherapy class solution for patients with prostate cancer with bilateral hip prostheses with and without nodal involvement

    SciTech Connect

    Lee, Young K.; McVey, Gerard P.; South, Chris P.; Dearnaley, David P.

    2013-07-01

    Dose distributions for prostate radiotherapy are difficult to predict in patients with bilateral hip prostheses in situ, due to image distortions and difficulty in dose calculation. The feasibility of delivering curative doses to prostate using intensity-modulated radiotherapy (IMRT) in patients with bilateral hip prostheses was evaluated. Planning target volumes for prostate only (PTV1) and pelvic nodes (PTV2) were generated from data on 5 patients. PTV1 and PTV2 dose prescriptions were 70 Gy and 60 Gy, respectively, in 35 fractions, and an additional nodal boost of 65 Gy was added for 1 plan. Rectum, bladder, and bowel were also delineated. Beam angles and segments were chosen to best avoid entering through the prostheses. Dose-volume data were assessed with respect to clinical objectives. The plans achieved the required prescription doses to the PTVs. Five-field IMRT plans were adequate for patients with relatively small prostheses (head volumes<60 cm{sup 3}) but 7-field plans were required for patients with larger prostheses. Bowel and bladder doses were clinically acceptable for all patients. Rectal doses were deemed clinically acceptable, although the V{sub 50} {sub Gy} objective was not met for 4/5 patients. We describe an IMRT solution for patients with bilateral hip prostheses of varying size and shape, requiring either localized or whole pelvic radiotherapy for prostate cancer.

  18. Decreasing Temporal Lobe Dose With Five-Field Intensity-Modulated Radiotherapy for Treatment of Pituitary Macroadenomas

    SciTech Connect

    Parhar, Preeti K.; Duckworth, Tamara; Shah, Parinda; DeWyngaert, J. Keith; Narayana, Ashwatha; Formenti, Silvia C.; Shah, Jinesh N.

    2010-10-01

    Purpose: To compare temporal lobe dose delivered by three pituitary macroadenoma irradiation techniques: three-field three-dimensional conformal radiotherapy (3D-CRT), three-field intensity-modulated radiotherapy (3F IMRT), and a proposed novel alternative of five-field IMRT (5F IMRT). Methods and Materials: Computed tomography-based external beam radiotherapy planning was performed for 15 pituitary macroadenoma patients treated at New York University between 2002 and 2007 using: 3D-CRT (two lateral, one midline superior anterior oblique [SAO] beams), 3F IMRT (same beam angles), and 5F IMRT (same beam angles with additional right SAO and left SAO beams). Prescription dose was 45 Gy. Target volumes were: gross tumor volume (GTV) = macroadenoma, clinical target volume (CTV) = GTV, and planning target volume = CTV + 0.5 cm. Structure contouring was performed by two radiation oncologists guided by an expert neuroradiologist. Results: Five-field IMRT yielded significantly decreased temporal lobe dose delivery compared with 3D-CRT and 3F IMRT. Temporal lobe sparing with 5F IMRT was most pronounced at intermediate doses: mean V25Gy (% of total temporal lobe volume receiving {>=}25 Gy) of 13% vs. 28% vs. 29% for right temporal lobe and 14% vs. 29% vs. 30% for left temporal lobe for 5F IMRT, 3D-CRT, and 3F IMRT, respectively (p < 10{sup -7} for 5F IMRT vs. 3D-CRT and 5F IMRT vs. 3F IMRT). Five-field IMRT plans did not compromise target coverage, exceed normal tissue dose constraints, or increase estimated brain integral dose. Conclusions: Five-field IMRT irradiation technique results in a statistically significant decrease in the dose to the temporal lobes and may thus help prevent neurocognitive sequelae in irradiated pituitary macroadenoma patients.

  19. Regional lymph node radiotherapy in breast cancer: single anterior supraclavicular field vs. two anterior and posterior opposed supraclavicular fields

    PubMed Central

    Houshyari, Mohammad; Kashi, Amir Shahram Yousefi; Varaki, Sakineh Soleimani; Rakhsha, Afshin; Blookat, Eftekhar Rajab

    2015-01-01

    Background: The treatment of lymph nodes engaged in breast cancer with radiotherapy leads to improved locoregional control and enhanced survival rates in patients after surgery. The aim of this study was to compare two treatment techniques, namely single anterior posterior (AP) supraclavicular field with plan depth and two anterior and posterior opposed (AP/PA) supraclavicular fields. In the study, we also examined the relationships between the depth of supraclavicular lymph nodes (SCLNs) and the diameter of the wall of the chest and body mass index (BMI). Methods: Forty patients with breast cancer were analyzed using computed tomography (CT) scans. In planning target volume (PTV), the SCLNs and axillary lymph nodes (AXLNs) were contoured, and, with the attention to PTV, supraclavicular (SC) depth was measured. The dosage that reached the aforementioned lymph nodes and the level of hot spots were investigated using two treatment methods, i.e., 1) AP/PA and 2) AP with three-dimensional (3D) planning. Each of these methods was analyzed using the program Isogray for the 6 MV compact accelerator, and the diameter of the wall of the chest was measured using the CT scan at the center of the SC field. Results: Placing the plan such that 95% of the target volume with 95% or greater of the prescribed dose of 50 Gy (V95) had ≥95% concordance in both treatment techniques. According to the PTV, the depth of SCLNs and the diameter of the wall of the chest were 3–7 and 12–21cm, respectively. Regression analysis showed that the mean SC depth (the mean Plan depth) and the mean diameter of the wall of the chest were related directly to BMI (p<0.0001, adjusted R2=0.67) and (p<0.0001, adjusted R2=0.71), respectively. Conclusion: The AP/PA treatment technique was a more suitable choice of treatment than the AP field, especially for overweight and obese breast cancer patients. However, in the AP/PA technique, the use of a single-photon, low energy (6 MV) caused more hot spots

  20. Patterns of Failure and Treatment-Related Toxicity in Advanced Cervical Cancer Patients Treated Using Extended Field Radiotherapy With Curative Intent

    SciTech Connect

    Rajasooriyar, Chrishanthi; Van Dyk, Sylvia; Bernshaw, David; Kondalsamy-Chennakesavan, Srinivas; Barkati, Maroie; Narayan, Kailash

    2011-06-01

    Purpose: The purpose of this study was to evaluate the patterns of failure and overall survival (OS) and disease-free survival (DFS) rates in cervical cancer patients who had metastatic disease in common iliac or para-aortic lymph nodes and were treated with curative intent, using extended field radiotherapy (EFRT). Methods and Materials: This was a retrospective study involving 39 patients treated from January 1996 to June 2007, using EFRT with concurrent chemotherapy and intracavitary brachytherapy. EFRT consisted of 45 Gy in 1.8-Gy fractions. Radiation to involved nodes was boosted to a total dose of 50.4 to 54 Gy. Primary tumor radiation was boosted to a dose of 80 Gy using brachytherapy. Results: Overall, 30 patients (77%) have relapsed. The 5-year OS rate was 26% (95% confidence interval [CI], 11-44). The 5-year DFS rate was 19.4% (95% CI, 8-35). Only 3 patients (7.5%) experienced treatment failure exclusively within the treatment field, and 2 patients underwent salvage treatment. Grade 3 to 4 acute bone marrow and gastrointestinal toxicities were observed in 10 (26%) and 7 (18%) patients, respectively. Conclusions: Concurrent chemotherapy and EFRT treatment was well tolerated. Most patients showed failure at multiple sites and outside the treatment field. Only 3/39 patients had failures exclusively within the treatment field, and 2 underwent salvage treatment.

  1. The Impact of Extent and Location of Mediastinal Lymph Node Involvement on Survival in Stage III Non-Small Cell Lung Cancer Patients Treated With Definitive Radiotherapy

    SciTech Connect

    Fernandes, Annemarie T.; Mitra, Nandita; Xanthopoulos, Eric; Evans, Tracey; Stevenson, James; Langer, Corey; Kucharczuk, John C.; Lin, Lilie; Rengan, Ramesh

    2012-05-01

    Purpose: Several surgical series have identified subcarinal, contralateral, and multilevel nodal involvement as predictors of poor overall survival in patients with Stage III non-small-cell lung cancer (NSCLC) treated with definitive resection. This retrospective study evaluates the impact of extent and location of mediastinal lymph node (LN) involvement on survival in patients with Stage III NSCLC treated with definitive radiotherapy. Methods and Materials: We analyzed 106 consecutive patients with T1-4 N2-3 Stage III NSCLC treated with definitive radiotherapy at University of Pennsylvania between January 2003 and February 2009. For this analysis, mediastinal LN stations were divided into four mutually exclusive groups: supraclavicular, ipsilateral mediastinum, contralateral mediastinum, and subcarinal. Patients' conditions were then analyzed according to the extent of involvement and location of mediastinal LN stations. Results: The majority (88%) of patients received sequential or concurrent chemotherapy. The median follow-up time for survivors was 32.6 months. By multivariable Cox modeling, chemotherapy use (hazard ratio [HR]: 0.21 [95% confidence interval (CI): 0.07-0.63]) was associated with improved overall survival. Increasing primary tumor [18F]-fluoro-2-deoxy-glucose avidity (HR: 1.11 [CI: 1.06-1.19]), and subcarinal involvement (HR: 2.29 [CI: 1.11-4.73]) were significant negative predictors of overall survival. On univariate analysis, contralateral nodal involvement (HR: 0.70 [CI: 0.33-1.47]), supraclavicular nodal involvement (HR: 0.78 [CI: 0.38-1.67]), multilevel nodal involvement (HR: 0.97 [CI: 0.58-1.61]), and tumor size (HR: 1.04 [CI: 0.94-1.14]) did not predict for overall survival. Patients with subcarinal involvement also had lower rates of 2-year nodal control (51.2% vs. 74.9%, p = 0.047) and 2-year distant control (28.4% vs. 61.2%, p = 0.043). Conclusions: These data suggest that the factors that determine oncologic outcome in Stage III NSCLC

  2. Field classes: key to involve and attract students to soils

    NASA Astrophysics Data System (ADS)

    Muggler, Cristine Carole; Cardoso, Irene Maria; da Silva Lopes, Angelica

    2015-04-01

    Soil genesis is a subject taught to students of Agrarian Sciences and Geography at the Federal University of Viçosa in Minas Gerais, Brazil. Each semester 200 to 250 students inscribe for it. It is organized as the first 60 hours course on soils for 1st and 2nd year's students. The course has a distinct pedagogical approach, which is based on Paulo Freire's education principles, known as socio constructivism. In such approach, learning environments and materials are prepared to stimulate dialogues and exchange of knowledge between students themselves, strengthening that their role is crucial to their own learning. During the course, students have different types of practical classes: indoors, in a class room or at the Earth Sciences museum and outdoors, in the field. In the class room they have the opportunity to handle materials -minerals, rocks, soils and maps-, follow demonstrations and perform small experiments. The classes given in the museum intend a broadening of the subjects approached in theoretical and practical classes. In the field classes the students are organized in small groups with the task to investigate soil formation by observation and description of geology, landscape, land use, soil expositions and some of the soil properties. Attracting students to soils involves looking at meanings and perceptions related to soils they bring with themselves and follow this up to sensitize and create awareness about their importance. With this aim, it is also included, as part of the evaluation, a final voluntary presentation that many of the students do. The presentation can be a song, a poem, a sketch or whatever they propose and create. Many of the presentations bring topics related to the new perception about soils they get during the semester and to ideas or questions raised in the field classes. A survey with the students showed that field classes are by far the preferred classes and they are considered more dynamic. Since students have less and less

  3. Extended field intensity-modulated radiotherapy plus concurrent nedaplatin treatment in cervical cancer

    PubMed Central

    LIU, YUNQIN; YU, JINMING; QIAN, LITING; ZHANG, HONGYAN; MA, JUN

    2016-01-01

    The present study assessed the efficacy and toxicity of definitive extended-field intensity-modulated radiotherapy (EF-IMRT) plus concurrent chemotherapy in cervical cancer. A total of 48 patients with cervical cancer received the planning target volume between 39.6 and 50.4 Gy in 1.8–2.0 Gy daily fractions, while the enlarged pelvic and/or para-aortic nodes were treated with a total dose of 55–60 Gy in 2.0–2.4 Gy daily fractions using simultaneous integrated boost-IMRT. All patients underwent high dose-rate brachytherapy. Concurrent to EF-IMRT, nedaplatin was administered weekly at a median dose of 30 mg/m2 (range, 25–40 mg/m2) for 5 weeks with a total of 150 mg/m2. Of the 48 patients, 46 patients exhibited initial complete responses and 2 patients had partial responses, with a response rate of 100%. After 4–24 months of treatment, 12 patients (27.08%) had local and/or distant failure and 39 patients (81.25%) were alive at the last follow-up. The 12-month overall survival (OS) and disease-free survival (DFS) were 87.5 and 75.8%, respectively, while the 24-month OS and DFS were 69.7 and 49.7%, respectively. Grade ≥3 acute neutropenia and thrombcytopenia occurred in 20 (41.7%) and 4 (8.3%) patients, respectively, while 2 patients (4.2%) developed grade ≥3 diarrhea and 2 (4.2%) had grade ≥3 late toxicities. However, no patients exhibited grade ≥3 vomiting. Thus, concurrent nedaplatin chemotherapy with definitive EF-IMRT was effective and relatively safe for treating patients with cervical cancer. Furthermore, EF-IMRT was able to deliver ≤60 Gy to enlarged para-aortic and/or pelvic nodes using simultaneous integrated boost without increased acute and late gastrointestinal toxicity. PMID:27123128

  4. Out-of-field organ doses and associated radiogenic risks from para-aortic radiotherapy for testicular seminoma

    SciTech Connect

    Mazonakis, Michalis Berris, Theocharis; Damilakis, John; Varveris, Charalambos; Lyraraki, Efrossyni

    2014-05-15

    Purpose: The aims of this study were to (a) calculate the radiation dose to out-of-field organs from radiotherapy for stage I testicular seminoma and (b) estimate the associated radiogenic risks. Methods: Monte Carlo methodology was employed to model radiation therapy with typical anteroposterior and posteroanterior para-aortic fields on an anthropomorphic phantom simulating an average adult. The radiation dose received by all main and remaining organs that defined by the ICRP publication 103 and excluded from the treatment volume was calculated. The effect of field dimensions on each organ dose was determined. Additional therapy simulations were generated by introducing shielding blocks to protect the kidneys from primary radiation. The gonadal dose was employed to assess the risk of heritable effects for irradiated male patients of reproductive potential. The lifetime attributable risks (LAR) of radiotherapy-induced cancer were estimated using gender- and organ-specific risk coefficients for patient ages of 20, 30, 40, and 50 years old. The risk values were compared with the respective nominal risks. Results: Para-aortic irradiation to 20 Gy resulted in out-of-field organ doses of 5.0–538.6 mGy. Blocked field treatment led to a dose change up to 28%. The mean organ dose variation by increasing or decreasing the applied field dimensions was 18.7% ± 3.9% and 20.8% ± 4.5%, respectively. The out-of-field photon doses increased the lifetime intrinsic risk of developing thyroid, lung, bladder, prostate, and esophageal cancer by (0.1–1.4)%, (0.4–1.1)%, (2.5–5.4)%, (0.2–0.4)%, and (6.4–9.2)%, respectively, depending upon the patient age at exposure and the field size employed. A low risk for heritable effects of less than 0.029% was found compared with the natural incidence of these defects. Conclusions: Testicular cancer survivors are subjected to an increased risk for the induction of bladder and esophageal cancer following para-aortic radiotherapy. The

  5. Improvement of dose distribution in breast radiotherapy using a reversible transverse magnetic field Linac-MR unit

    SciTech Connect

    Esmaeeli, A. D.; Mahdavi, S. R.; Pouladian, M.; Bagheri, S.; Monfared, A. S.

    2014-01-15

    Purpose: To investigate the improvement in dose distribution in tangential breast radiotherapy using a reversible transverse magnetic field that maintains the same direction of Lorentz force between two fields. The investigation has a potential application in future Linac-MR units. Methods: Computed tomography images of four patients and magnetic fields of 0.25–1.5 Tesla (T) were used for Monte Carlo simulation. Two patients had intact breast while the other two had mastectomy. Simulations of planning and chest wall irradiation were similar to the actual clinical process. The direction of superior-inferior magnetic field for the medial treatment beam was reversed for the lateral beam. Results: For the ipsilateral lung and heart mean doses were reduced by a mean (range) of 45.8% (27.6%–58.6%) and 26.0% (20.2%–38.9%), respectively, depending on various treatment plan setups. The mean V{sub 20} for ipsilateral lung was reduced by 55.0% (43.6%–77.3%). In addition acceptable results were shown after simulation of 0.25 T magnetic field demonstrated in dose-volume reductions of the heart, ipsilateral lung, and noninvolved skin. Conclusions: Applying a reversible magnetic field during breast radiotherapy, not only reduces the dose to the lung and heart but also produces a sharp drop dose volume histogram for planning target volume, because of bending of the path of secondary charged particles toward the chest wall by the Lorentz force. The simulations have shown that use of the magnetic field at 1.5 T is not feasible for clinical applications due to the increase of ipsilateral chest wall skin dose in comparison to the conventional planning while 0.25 T is suitable for all patients due to dose reduction to the chest wall skin.

  6. Monte Carlo simulation of the photoneutron field in linac radiotherapy treatments with different collimation systems

    NASA Astrophysics Data System (ADS)

    Zanini, A.; Durisi, E.; Fasolo, F.; Ongaro, C.; Visca, L.; Nastasi, U.; Burn, K. W.; Scielzo, G.; Adler, J. O.; Annand, J. R. M.; Rosner, G.

    2004-02-01

    Bremsstrahlung photon beams produced by linac accelerators are currently the most commonly used method of radiotherapy for tumour treatments. When the photon energy exceeds 10 MeV the patient receives an undesired dose due to photoneutron production in the accelerator head. In the last few decades, new sophisticated techniques such as multileaf collimators have been used for a better definition of the target volume. In this case it is crucial to evaluate the photoneutron dose produced after giant dipole resonance (GDR) excitation of the high Z materials (mainly tungsten and lead) constituting the collimator leaves in view of the optimization of the radiotherapy treatment. A Monte Carlo approach has been used to calculate the photoneutron dose arising from the GDR reaction during radiotherapy with energetic photon beams. The simulation has been performed using the code MCNP4B-GN which is based on MCNP4B, but includes a new routine GAMMAN to model photoneutron production. Results for the facility at IRCC (Istituto per la Ricerca e la Cura del Cancro) Candiolo (Turin), which is based on 18 MV x-rays from a Varian Clinac 2300 C/D, are presented for a variety of different collimator configurations.

  7. Parent and Community Involvement. Field Review Edition. Teacher's Manual.

    ERIC Educational Resources Information Center

    Decker, Larry E.; And Others

    The role of the classroom teacher in the success of parent and community involvement efforts in American public schools is this document's focus. Because schools need to discover new ways to foster parental and community involvement in education, this document outlines a new perspective concerning parental and community involvement that…

  8. A prospective comparison of acute intestinal toxicity following whole pelvic versus small field intensity-modulated radiotherapy for prostate cancer

    PubMed Central

    Kim, Yeon Joo; Park, Jin-hong; Yun, In-Ha; Kim, Young Seok

    2016-01-01

    Purpose To compare the acute intestinal toxicity of whole pelvic (WP) and small field (SF) intensity-modulated radiotherapy (IMRT) for prostate cancer using dosimetric and metabolic parameters as well as clinical findings. Methods Patients who received IMRT in either a definitive or postoperative setting were prospectively enrolled. Target volume and organs at risk including intestinal cavity (IC) were delineated in every patient by a single physician. The IC volume that received a 10–50 Gy dose at 5-Gy intervals (V10–V50) and the percentage of irradiated volume as a fraction of total IC volume were calculated. Plasma citrulline levels, as an objective biological marker, were checked at three time points: baseline and after exposure to 30 Gy and 60 Gy. Results Of the 41 patients, only six experienced grade 1 acute intestinal toxicity. Although all dose–volume parameters were significantly worse following WP than SF IMRT, there was no statistically significant relationship between these dosimetric parameters and clinical symptoms. Plasma citrulline levels did not show a serial decrease by radiotherapy volume difference (WP versus SF) and were not relevant to the irradiated doses. Conclusion Given that WP had comparable acute intestinal toxicities to those associated with SF, WP IMRT appears to be a feasible approach for the treatment of prostate cancer despite dosimetric disadvantages. PMID:27022287

  9. Complete response after chemotherapy and radiotherapy of a tonsillar histiocytic sarcoma with regional lymph node involvement: a case report and review of the literature.

    PubMed

    Chen, Xingxing; Zhang, Li; Wang, Jian; Gu, Yajia; Tuan, Jeffrey; Ma, Xuejun; Hong, Xiaonan; Yu, Xiaoli; Guo, Xiaomao

    2015-01-01

    We describe a case of tonsillar histiocytic sarcoma (HS) with regional lymph node involvement and complete response after multi-disciplinary therapy. Immunohistochemistry showed strong positive tumor staining for CD 68, and negative staining for CD20, CD45R0 and CD30 and non-cohesive proliferation of neoplastic histiocytes. Systemic chemotherapy with cyclophosphamide, doxorubicin, vincristine, prednisone, and etoposide (CHOP-E) chemotherapy followed by radiotherapy was delivered to the patient. No evidence of recurrent disease existed on regular follow up three years later. The diagnostic methods and the practical treatment solutions are discussed here. We believe that although HS has been regarded as a potentially fatal disease entity, there remain some cases that do not pursue such an aggressive clinical course. PMID:26629225

  10. SU-E-T-596: Axillary Nodes Radiotherapy Boost Field Dosimetric Impact Study: Oblique Field and Field Optimization in 3D Conventional Breast Cancer Radiation Treatment

    SciTech Connect

    Su, M; Sura, S

    2014-06-01

    Purpose: To evaluate dosimetric impact of two axillary nodes (AX) boost techniques: (1) posterior-oblique optimized field boost (POB), (2) traditional posterior-anterior boost (PAB) with field optimization (O-PAB), for a postmastectomy breast patient with positive axillary lymph nodes. Methods: Five patients, 3 left and 2 right chest walls, were included in this study. All patients were simulated in 5mm CT slice thickness. Supraclavicular (SC) and level I/II/III AX were contoured based on the RTOG atlas guideline. Five treatment plans, (1) tangential chest wall, (2) oblique SC including AX, (3) PAB, O-PAB and POB, were created for each patient. Three plan sums (PS) were generated by sum one of (3) plan with plan (1) and (2). The field optimization was done through PS dose distribution, which included a field adjustment, a fractional dose, a calculation location and a gantry angle selection for POB. A dosimetric impact was evaluated by comparing a SC and AX coverage, a PS maximum dose, an irradiated area percentage volume received dose over 105% prescription dose (V105), an ipsi-laterial mean lung dose (MLD), an ipsi-laterial mean humeral head dose (MHHD), a mean heart dose (MHD) (for left case only) and their DVH amount these three technique. Results: O-PAB, POB and PAB dosimetric results showed that there was no significant different on SC and AX coverage (p>0.43) and MHD (p>0.16). The benefit of sparing lung irradiation from PAB to O-PAB to POB was significant (p<0.004). PAB showed a highest PS maximum dose (p<0.005), V105 (p<0.023) and MLD (compared with OPAB, p=0.055). MHHD showed very sensitive to the patient arm positioning and anatomy. O-PAB convinced a lower MHHD than PAB (p=0.03). Conclusion: 3D CT contouring plays main role in accuracy radiotherapy. Dosimetric advantage of POB and O-PAB was observed for a better normal tissue irradiation sparing.

  11. Number and Location of Positive Nodes, Postoperative Radiotherapy, and Survival After Esophagectomy With Three-Field Lymph Node Dissection for Thoracic Esophageal Squamous Cell Carcinoma

    SciTech Connect

    Chen Junqiang; Pan Jianji; Zheng Xiongwei; Zhu Kunshou; Li Jiancheng; Chen Mingqiang; Wang Jiezhong; Liao Zhongxing

    2012-01-01

    Purpose: To analyze influences of the number and location of positive lymph nodes and postoperative radiotherapy on survival for patients with thoracic esophageal squamous cell carcinoma (TE-SCC) treated with radical esophagectomy with three-field lymphadenectomy. Methods and Materials: A total of 945 patients underwent radical esophagectomy plus three-field lymph node dissection for node-positive TE-SCC at Fujian Provincial Tumor Hospital between January 1993 and March 2007. Five hundred ninety patients received surgery only (S group), and 355 patients received surgery, followed 3 to 4 weeks later by postoperative radiotherapy (S+R group) to a median total dose of 50 Gy in 25 fractions. We assessed potential associations among patient-, tumor-, and treatment-related factors and overall survival. Results: Five-year overall survival rates were 32.8% for the entire group, 29.6% for the S group, and 38.0% for the S+R group (p = 0.001 for S vs. S+R). Treatment with postoperative radiotherapy was particularly beneficial for patients with {>=}3 positive nodes and for those with metastasis in the upper (supraclavicular and upper mediastinal) region or both the upper and lower (mediastinal and abdominal) regions (p < 0.05). Postoperative radiotherapy was also associated with lower recurrence rates in the supraclavicular and upper and middle mediastinal regions (p < 0.05). Sex, primary tumor length, number of positive nodes, pathological T category, and postoperative radiotherapy were all independent predictors of survival. Conclusions: Postoperative radiotherapy was associated with better survival for patients with node-positive TE-SCC, particularly those with three or more positive nodes and positive nodes in the supraclavicular and superior mediastinal regions.

  12. Ductal Carcinoma In Situ of the Breast With Close or Focally Involved Margins Following Breast-Conserving Surgery: Treatment With Reexcision or Radiotherapy With Increased Dosage

    SciTech Connect

    Monteau, Amelie; Sigal-Zafrani, Brigitte; Kirova, Youlia M.; Fourchotte, Virginie; Bollet, Marc A.; Vincent-Salomon, Anne; Asselain, Bernard; Salmon, Remy J. M.D.; Fourquet, Alain

    2009-11-15

    Purpose: Following breast-conserving surgery for DCIS, reexcision before radiotherapy is recommended when margins are close or involved. We investigated whether an additional radiation dose could replace reexcision. Methods: We selected 208 women with DCIS of the breast treated with breast-conserving surgery between 1992 and 2002 who had either close margins (< 2 mm) (89 pts) or focally (< 1 mm) or minimally (1-15 mm) involved margins (119 pts). Sixty-one patients (29%) underwent reexcision before irradiation and 147 patients (71%) received breast irradiation with boost, without reexcision. Results: Median follow-up was 89 months. Median age was 53 years with 7 patients less than 41. Involved margins were less frequent in the non reexcision group than in the reexcised group (50% vs. 74%, p = 0.0019). All other clinical and histological features were comparable. Median whole-breast radiation dose was 50 Gy. Median total doses to the tumour bed were 67 Gy (range, 45-77) and 60 Gy (range, 46-74), respectively (p < 0.0001). Of the 61 reexcised patients, 56% had residual DCIS and 6% had invasive cancer. Six underwent a mastectomy for persistent margin involvement. Seven-year locoregional failure rates were 9.3% without, and 9.6% with reexcision (ns). No differences were observed when adjusting for margin status. Conclusion: In carefully selected patients with close (< 2 mm) or focally/minimally involved margins, reexcision may be avoided and satisfactory local control achieved by increasing the radiation dose to the tumour bed to at least 66 Gy. These results only apply to patients older than 40 and would need confirmation in independent series.

  13. Probability of mediastinal involvement in non-small-cell lung cancer: a statistical definition of the clinical target volume for 3-dimensional conformal radiotherapy?

    SciTech Connect

    Giraud, Philippe . E-mail: philippe.giraud@curie.net; De Rycke, Yann; Lavole, Armelle; Milleron, Bernard; Cosset, Jean-Marc; Rosenzweig, Kenneth E.

    2006-01-01

    : To more accurately define the CTVn in NSCLC three-dimensional conformal radiotherapy, we propose a software that evaluates the risk of mediastinal lymph node involvement from easily accessible individual pretreatment parameters.

  14. A practical and theoretical definition of very small field size for radiotherapy output factor measurements

    SciTech Connect

    Charles, P. H. Crowe, S. B.; Langton, C. M.; Trapp, J. V.; Cranmer-Sargison, G.; Thwaites, D. I.; Kairn, T.; Knight, R. T.; Kenny, J.

    2014-04-15

    Purpose: This work introduces the concept of very small field size. Output factor (OPF) measurements at these field sizes require extremely careful experimental methodology including the measurement of dosimetric field size at the same time as each OPF measurement. Two quantifiable scientific definitions of the threshold of very small field size are presented. Methods: A practical definition was established by quantifying the effect that a 1 mm error in field size or detector position had on OPFs and setting acceptable uncertainties on OPF at 1%. Alternatively, for a theoretical definition of very small field size, the OPFs were separated into additional factors to investigate the specific effects of lateral electronic disequilibrium, photon scatter in the phantom, and source occlusion. The dominant effect was established and formed the basis of a theoretical definition of very small fields. Each factor was obtained using Monte Carlo simulations of a Varian iX linear accelerator for various square field sizes of side length from 4 to 100 mm, using a nominal photon energy of 6 MV. Results: According to the practical definition established in this project, field sizes ≤15 mm were considered to be very small for 6 MV beams for maximal field size uncertainties of 1 mm. If the acceptable uncertainty in the OPF was increased from 1.0% to 2.0%, or field size uncertainties are 0.5 mm, field sizes ≤12 mm were considered to be very small. Lateral electronic disequilibrium in the phantom was the dominant cause of change in OPF at very small field sizes. Thus the theoretical definition of very small field size coincided to the field size at which lateral electronic disequilibrium clearly caused a greater change in OPF than any other effects. This was found to occur at field sizes ≤12 mm. Source occlusion also caused a large change in OPF for field sizes ≤8 mm. Based on the results of this study, field sizes ≤12 mm were considered to be theoretically very small for 6

  15. Quality assurance for radiotherapy in prostate cancer: Point dose measurements in intensity modulated fields with large dose gradients

    SciTech Connect

    Escude, Lluis . E-mail: lluis.escude@gmx.net; Linero, Dolors; Molla, Meritxell; Miralbell, Raymond

    2006-11-15

    Purpose: We aimed to evaluate an optimization algorithm designed to find the most favorable points to position an ionization chamber (IC) for quality assurance dose measurements of patients treated for prostate cancer with intensity-modulated radiotherapy (IMRT) and fields up to 10 cm x 10 cm. Methods and Materials: Three cylindrical ICs (PTW, Freiburg, Germany) were used with volumes of 0.6 cc, 0.125 cc, and 0.015 cc. Dose measurements were made in a plastic phantom (PMMA) at 287 optimized points. An algorithm was designed to search for points with the lowest dose gradient. Measurements were made also at 39 nonoptimized points. Results were normalized to a reference homogeneous field introducing a dose ratio factor, which allowed us to compare measured vs. calculated values as percentile dose ratio factor deviations {delta}F (%). A tolerance range of {delta}F (%) of {+-}3% was considered. Results: Half of the {delta}F (%) values obtained at nonoptimized points were outside the acceptable range. Values at optimized points were widely spread for the largest IC (i.e., 60% of the results outside the tolerance range), whereas for the two small-volume ICs, only 14.6% of the results were outside the tolerance interval. No differences were observed when comparing the two small ICs. Conclusions: The presented optimization algorithm is a useful tool to determine the best IC in-field position for optimal dose measurement conditions. A good agreement between calculated and measured doses can be obtained by positioning small volume chambers at carefully selected points in the field. Large chambers may be unreliable even in optimized points for IMRT fields {<=}10 cm x 10 cm.

  16. Comparison of IGRT Registration Strategies for Optimal Coverage of Primary Lung Tumors and Involved Nodes Based on Multiple Four-Dimensional CT Scans Obtained Throughout the Radiotherapy Course

    SciTech Connect

    Mohammed, Nasiruddin; Kestin, Larry; Grills, Inga; Shah, Chirag; Glide-Hurst, Carri; Yan, Di; Ionascu, Dan

    2012-03-15

    Purpose: To investigate the impact of primary tumor and involved lymph node (LN) geometry (centroid, shape, volume) on internal target volume (ITV) throughout treatment for locally advanced non-small cell lung cancer using weekly four-dimensional computed tomography (4DCT). Methods and Materials: Eleven patients with advanced non-small cell lung cancer were treated using image-guided radiotherapy with acquisition of weekly 10-Phase 4DCTs (n = 51). Initial ITV was based on planning 4DCT. Master-ITV incorporated target geometry across the entire treatment (all 4DCTs). Geographic miss was defined as the % Master-ITV positioned outside of the initial planning ITV after registration is complete. Registration strategies considered were bony (B), primary tumor soft tissue alone (T), and registration based on primary tumor and involved LNs (T{sub L}N). Results: The % geographic miss for the primary tumor, mediastinal, and hilar lymph nodes based on each registration strategy were (1) B: 30%, 30%, 30%; (2) T: 21%, 40%, 36%; and (3) T{sub L}N: 26%, 26%, 27%. Mean geographic expansions to encompass 100% of the primary tumor and involved LNs were 1.2 {+-} 0.7 cm and 0.8 {+-} 0.3 cm, respectively, for B and T{sub L}N. Primary and involved LN expansions were 0.7 {+-} 0.5 cm and 1.1 {+-} 0.5 cm for T. Conclusion: T is best for solitary targets. When treatments include primary tumor and LNs, B and T{sub L}N provide more comprehensive geographic coverage. We have identified high % geographic miss when considering multiple registration strategies. The dosimetric implications are the subject of future study.

  17. Dose Distribution Analysis of Axillary Lymph Nodes for Three-Dimensional Conformal Radiotherapy With a Field-in-Field Technique for Breast Cancer

    SciTech Connect

    Ohashi, Toshio Takeda, Atsuya; Shigematsu, Naoyuki; Fukada, Junichi; Sanuki, Naoko; Amemiya, Atsushi; Kubo, Atsushi

    2009-01-01

    Purpose: We previously reported that most of axillary regions could be irradiated by the modified tangential irradiation technique (MTIT). The purpose of this study was to determine whether the three-dimensional conformal radiotherapy (3D-CRT) with a field-in-field technique improves dosimetry for the breast and axillary nodes. Methods and Materials: Fifty patients with left-sided breast cancer were enrolled. With MTIT, we planned the radiation field to be wider in the cranial direction than the standard tangential fields to include the axillary regions. With 3D-CRT, a field-in-field technique was used to spare the heart and contralateral breast to the extent possible by applying the multileaf collimator manually. Dose-volume histograms were compared for the breast, axillary region, heart, lung, and other normal tissues. Results: There were no significant differences in the percent volume of the breast receiving >90% of the prescribed dose (V90) between MTIT and 3D-CRT. The mean V90 of the level I to III axillary regions were increased from 93.7%, 48.2%, and 41.3% with MTIT to 97.6%, 85.8%, and 82.8% with 3D-CRT. 3D-CRT significantly reduced the volume of the heart receiving >30 Gy (mean, 7.6 vs. 15.9 mL), the percent volume of the bilateral lung receiving >20 Gy (7.4% vs. 8.9%), and the volume of other normal tissues receiving >107% of the prescribed dose (0.1 vs. 2.9 mL). Conclusion: The use of 3D-CRT with a field-in-field technique improves axillary node coverage, while decreasing doses to the heart, lungs, and the other normal tissues, compared with MTIT.

  18. Ototoxicity evaluation in medulloblastoma patients treated with involved field boost using intensity-modulated radiation therapy (IMRT): a retrospective review

    PubMed Central

    2014-01-01

    Background Ototoxicity is a known side effect of combined radiation therapy and cisplatin chemotherapy for the treatment of medulloblastoma. The delivery of an involved field boost by intensity modulated radiation therapy (IMRT) may reduce the dose to the inner ear when compared with conventional radiotherapy. The dose of cisplatin may also affect the risk of ototoxicity. A retrospective study was performed to evaluate the impact of involved field boost using IMRT and cisplatin dose on the rate of ototoxicity. Methods Data from 41 medulloblastoma patients treated with IMRT were collected. Overall and disease-free survival rates were calculated by Kaplan-Meier method Hearing function was graded according to toxicity criteria of Pediatric Oncology Group (POG). Doses to inner ear and total cisplatin dose were correlated with hearing function by univariate and multivariate data analysis. Results After a mean follow-up of 44 months (range: 14 to 72 months), 37 patients remained alive, with two recurrences, both in spine with CSF involvement, resulting in a disease free-survival and overall survival of 85.2% and 90.2%, respectively. Seven patients (17%) experienced POG Grade 3 or 4 toxicity. Cisplatin dose was a significant factor for hearing loss in univariate analysis (p < 0.03). In multivariate analysis, median dose to inner ear was significantly associated with hearing loss (p < 0.01). POG grade 3 and 4 toxicity were uncommon with median doses to the inner ear bellow 42 Gy (p < 0.05) and total cisplatin dose of less than 375 mg/m2 (p < 0.01). Conclusions IMRT leads to a low rate of severe ototoxicity. Median radiation dose to auditory apparatus should be kept below 42 Gy. Cisplatin doses should not exceed 375 mg/m2. PMID:25041714

  19. Monte Carlo simulations of patient dose perturbations in rotational-type radiotherapy due to a transverse magnetic field: A tomotherapy investigation

    SciTech Connect

    Yang, Y. M.; Geurts, M.; Smilowitz, J. B.; Bednarz, B. P.; Sterpin, E.

    2015-02-15

    Purpose: Several groups are exploring the integration of magnetic resonance (MR) image guidance with radiotherapy to reduce tumor position uncertainty during photon radiotherapy. The therapeutic gain from reducing tumor position uncertainty using intrafraction MR imaging during radiotherapy could be partially offset if the negative effects of magnetic field-induced dose perturbations are not appreciated or accounted for. The authors hypothesize that a more rotationally symmetric modality such as helical tomotherapy will permit a systematic mediation of these dose perturbations. This investigation offers a unique look at the dose perturbations due to homogeneous transverse magnetic field during the delivery of Tomotherapy{sup ®} Treatment System plans under varying degrees of rotational beamlet symmetry. Methods: The authors accurately reproduced treatment plan beamlet and patient configurations using the Monte Carlo code GEANT4. This code has a thoroughly benchmarked electromagnetic particle transport physics package well-suited for the radiotherapy energy regime. The three approved clinical treatment plans for this study were for a prostate, head and neck, and lung treatment. The dose heterogeneity index metric was used to quantify the effect of the dose perturbations to the target volumes. Results: The authors demonstrate the ability to reproduce the clinical dose–volume histograms (DVH) to within 4% dose agreement at each DVH point for the target volumes and most planning structures, and therefore, are able to confidently examine the effects of transverse magnetic fields on the plans. The authors investigated field strengths of 0.35, 0.7, 1, 1.5, and 3 T. Changes to the dose heterogeneity index of 0.1% were seen in the prostate and head and neck case, reflecting negligible dose perturbations to the target volumes, a change from 5.5% to 20.1% was observed with the lung case. Conclusions: This study demonstrated that the effect of external magnetic fields can

  20. Interfraction Displacement of Primary Tumor and Involved Lymph Nodes Relative to Anatomical Landmarks in Image–guided Radiotherapy of Locally Advanced Lung Cancer

    PubMed Central

    Jan, Nuzhat; Balik, Salim; Hugo, Geoffrey D.; Mukhopadhyay, Nitai; Weiss, Elisabeth

    2014-01-01

    Purpose Image-guided radiotherapy for patients with locally advanced lung cancer relies on bony landmarks and carina or - if visible - the primary tumor (PT) for daily patient alignment, neglecting potential variations in the relative position of PT and involved lymph nodes (LN). This study analyzes PT and LN position changes relative to each other and relative to anatomical landmarks during conventionally fractionated radiotherapy. Methods and Materials In 12 patients with locally advanced non-small cell lung cancer PT, LN, carina and one thoracic vertebra were manually contoured on weekly 4D fan beam CTs. Systematic and random interfraction displacements of all contoured structures were identified in the three cardinal directions, resulting setup margins were calculated. Time trends and the effect of volume changes on displacements were analyzed. Results Three-dimensional displacement vectors and systematic/random interfraction displacements were smaller for carina than vertebra both for PT and LN. For PT, mean 3D displacement vectors with carina-based alignment were 7 mm/SD 4 mm versus 9 mm/SD 5 mm with bony anatomy (p<0.0001). For LN, smaller displacements were found with carina- (5 mm/SD 3 mm, p<0.0001) and vertebra-based (6 mm/SD 3 mm, p=0.002) alignment compared to using PT for setup (8 mm/SD 5 mm). Primary tumor and LN displacements relative to bone and carina were independent (p>0.05). Displacements between PT and bone (p=0.04), and between PT and LN (p=0.01) were significantly correlated with PT volume regression. Displacements between LN and carina were correlated with LN volume change (p=0.03). Conclusions Carina-based setup results in a more reproducible PT and LN alignment than bony anatomy setup. Considering the independence of PT and LN displacement and the impact of volume regression on displacements over time, repeated CT imaging even with primary tumorbased alignment is recommended in locally advanced disease. PMID:24239387

  1. Neutron spectral measurements in an intense photon field associated with a high-energy x-ray radiotherapy machine.

    PubMed

    Holeman, G R; Price, K W; Friedman, L F; Nath, R

    1977-01-01

    High-energy x-ray radiotherapy machines in the supermegavoltage region generate complex neutron energy spectra which make an exact evaluation of neutron shielding difficult. Fast neutrons resulting from photonuclear reactions in the x-ray target and collimators undergo successive collisions in the surrounding materials and are moderated by varying amounts. In order to examine the neutron radiation exposures quantitatively, the neutron energy spectra have been measured inside and outside the treatment room of a Sagittaire medical linear accelerator (25-MV x rays) located at Yale-New Haven Hospital. The measurements were made using a Bonner spectrometer consisting of 2-, 3-, 5-, 8-, 10- and 12-in.-diameter polyethylene spheres with 6Li and 7Li thermoluminescent dosimeter (TLD) chips at the centers, in addition to bare and cadmium-covered chips. The individual TLD chips were calibrated for neutron and photon response. The spectrometer was calibrated using a known PuBe spectrum Spectrometer measurements were made at Yale Electron Accelerator Laboratory and results compared with a neutron time-of-flight spectrometer and an activation technique. The agreement between the results from these independent methods is found to be good, except for the measurements in the direct photon beam. Quality factors have been inferred for the neutron fields inside and outside the treatment room. Values of the inferred quality factors fall primarily between 4 and 8, depending on location.

  2. Effect of Adjuvant Magnetic Fields in Radiotherapy on Non-Small-Cell Lung Cancer Cells In Vitro

    PubMed Central

    Feng, Jianguo; Sheng, Huaying; Zhu, Chihong; Jiang, Hao; Ma, Shenglin

    2013-01-01

    Objectives. To explore sensitization and possible mechanisms of adjuvant magnetic fields (MFs) in radiotherapy (RT) of non-small-cell lung cancer. Methods. Human A549 lung adenocarcinoma cells were treated with MF, RT, and combined MF-RT. Colony-forming efficiency was calculated, cell cycle and apoptosis were measured, and changes in cell cycle- and apoptosis-related gene expression were measured by microarray. Results. A 0.5 T, 8 Hz stationary MF showed a duration-dependent inhibitory effect lasting for 1–4 hours. The MF-treated groups had significantly greater cell inhibition than did controls (P < 0.05). Surviving fractions and growth curves derived from colony-forming assay showed that the MF-only, RT-only, and MF-RT groups had inhibited cell growth; the MF-RT group showed a synergetic effect. Microarray of A549 cells exposed for 1 hour to MF showed that 19 cell cycle- and apoptosis-related genes had 2-fold upregulation and 40 genes had 2-fold downregulation. MF significantly arrested cells in G2 and M phases, apparently sensitizing the cells to RT. Conclusions. MF may inhibit A549 cells and can increase their sensitivity to RT, possibly by affecting cell cycle- and apoptosis-related signaling pathways. PMID:24224175

  3. Teachers as Secondary Players: Involvement in Field Trips to Natural Environments

    NASA Astrophysics Data System (ADS)

    Alon, Nirit Lavie; Tal, Tali

    2016-07-01

    This study focused on field trips to natural environments where the teacher plays a secondary role alongside a professional guide. We investigated teachers' and field trip guides' views of the teacher's role, the teacher's actual function on the field trip, and the relationship between them. We observed field trips, interviewed teachers and guides, and administered questionnaires. We found different levels of teacher involvement, ranging from mainly supervising and giving technical help, to high involvement especially in the cognitive domain and sometimes in the social domain. Analysis of students' self-reported outcomes showed that the more students believe their teachers are involved, the higher the self-reported learning outcomes.

  4. A 1.5 T transverse magnetic field in radiotherapy of rectal cancer: Impact on the dose distribution

    SciTech Connect

    Uilkema, Sander Heide, Uulke van der; Sonke, Jan-Jakob; Triest, Baukelien van; Nijkamp, Jasper; Moreau, Michel

    2015-12-15

    Purpose: MRI guidance during radiotherapy has the potential to enable more accurate dose delivery, optimizing the balance between local control and treatment related toxicity. However, the presence of a permanent magnetic field influences the dose delivery, especially around air cavities. Here, electrons are able to return to the surface through which they entered the air cavity (electron return effect, ERE) locally resulting in dose hot- and cold-spots. Where RT of rectal cancer patients might benefit from MRI guidance for margin reduction, air cavities in and around the target volume are frequently present. The purpose of this research is to evaluate the impact of the presence of a 1.5 T transverse magnetic field on dose delivery in patients with rectal cancer. Methods: Ten patients treated with 5 × 5 Gy RT having large changes in pelvic air content were selected out of a cohort of 33 patients. On the planning CT, a 1.5 T, 6 MV, 7-field intensity modulated radiotherapy (IMRT) plan was created. This plan was subsequently recalculated on daily CT scans. For each daily CT, the CTV V{sub 95%} and V{sub 107%} and bowel area V{sub 5Gy}, V{sub 10Gy}, V{sub 15Gy}, V{sub 20Gy}, and V{sub 25Gy} were calculated to evaluate the changes in dose distribution from fraction to fraction. For comparison, the authors repeated this procedure for the 0 T situation. To study the effect of changing air cavities separate from other anatomical changes, the authors also generated artificial air cavities in the CTV of one patient (2 and 5 cm diameter), in the high dose gradient region (2 cm), and in the low dose area (2 cm). Treatment plans were optimized without and with each simulated air cavity. For appearing and disappearing air cavities, the CTV V{sub 95%} and V{sub 107%} were evaluated. The authors also evaluated the ERE separate from attenuation changes locally around appearing gas pockets. Results: For the ten patients, at 1.5 T, the V{sub 95%} was influenced by both appearing and

  5. Brentuximab vedotin and AVD followed by involved-site radiotherapy in early stage, unfavorable risk Hodgkin lymphoma.

    PubMed

    Kumar, Anita; Casulo, Carla; Yahalom, Joachim; Schöder, Heiko; Barr, Paul M; Caron, Philip; Chiu, April; Constine, Louis S; Drullinsky, Pamela; Friedberg, Jonathan W; Gerecitano, John F; Hamilton, Audrey; Hamlin, Paul A; Horwitz, Steven M; Jacob, Alexandra G; Matasar, Matthew J; McArthur, Gianna N; McCall, Susan J; Moskowitz, Alison J; Noy, Ariela; Palomba, Maria L; Portlock, Carol S; Straus, David J; VanderEls, Nicholas; Verwys, Stephanie L; Yang, Joanna; Younes, Anas; Zelenetz, Andrew D; Zhang, Zhigang; Moskowitz, Craig H

    2016-09-15

    This multicenter pilot study assessed the safety and efficacy of brentuximab vedotin (BV) and AVD (adriamycin, vinblastine, and dacarbazine) followed by 30 Gy involved site radiation therapy (ISRT). Patients with newly diagnosed, early stage classical Hodgkin lymphoma (HL) with unfavorable-risk features were treated with 4 cycles of BV and AVD. Patients who achieved a negative positron emission tomography (PET) scan (Deauville score of 1-3) received 30 Gy ISRT. Thirty patients received treatment and were assessable for toxicity. Twenty-nine patients completed 4 cycles of BV + AVD, and 25 patients BV + AVD + 30 Gy ISRT. No clinically significant noninfectious pneumonitis was observed. Serious adverse events (≥grade 3) were reported in 4 patients, including febrile neutropenia, peripheral neuropathy, and hypertension. After 2 and 4 cycles of BV + AVD, 90% (26 of 29) and 93% (27 or 29) of patients achieved a negative PET scan, respectively. Two patients with biopsy-proven primary refractory HL were treated off-study. All 25 patients who completed BV + AVD + ISRT achieved a complete response. With a median follow-up of 18.8 months, by intent to treat, the 1-year progression-free survival is 93.3% (95% confidence interval, 84-102). Overall, the treatment was well-tolerated with no evidence of significant pulmonary toxicity. The majority of patients (≥90%) achieved negative interim PET scans after 2 and 4 cycles of BV + AVD. Excluding the 2 primary refractory patients, all patients are disease free, suggesting that this is a highly active treatment program even in patients with substantial disease bulk. This trial was registered at www.clinicaltrials.gov as #NCT01868451.

  6. Dosimetric Comparison Between Intensity-Modulated with Coplanar Field and 3D Conformal Radiotherapy with Noncoplanar Field for Postocular Invasion Tumor

    SciTech Connect

    Tu Wenyong; Liu Lu Zeng Jun; Yin Weidong; Li Yun

    2010-07-01

    This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 deg., 30-45 deg., 240-270 deg., and 310-335 deg. degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D{sub max} and D{sub min} dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p < 0.001). Physical endpoints for target showed the mean target dose to be low in the CF IMRT plan, caused by a large target dose in homogeneity (p < 0.001). The impact of NCF 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed.

  7. Thermal and epithermal neutron fluence rate gradient measurements by PADC detectors in LINAC radiotherapy treatments-field

    SciTech Connect

    Barrera, M. T. Barros, H.; Pino, F.; Sajo-Bohus, L.; Dávila, J.

    2015-07-23

    LINAC VARIAN 2100 is where energetic electrons produce Bremsstrahlung radiation, with energies above the nucleon binding energy (E≈5.5MeV). This radiation induce (γ,n) and (e,e’n) reactions mainly in the natural tungsten target material (its total photoneutron cross section is about 4000 mb in a energy range from 9-17 MeV). These reactions may occur also in other components of the system (e.g. multi leaf collimator). During radiation treatment the human body may receive an additional dose inside and outside the treated volume produced by the mentioned nuclear reactions. We measured the neutron density at the treatment table using nuclear track detectors (PADC-NTD). These covered by a boron-converter are employed, including a cadmium filter, to determine the ratio between two groups of neutron energy, i.e. thermal and epithermal. The PADC-NTD detectors were exposed to the radiation field at the iso-center during regular operation of the accelerator. Neutron are determined indirectly by the converting reaction {sup 10}B(n,α){sup 7}Li the emerging charged particle leave their kinetic energy in the PADC forming a latent nuclear track, enlarged by chemical etching (6N, NaOH, 70°C). Track density provides information on the neutron density through calibration coefficient (∼1.6 10{sup 4} neutrons /track) obtained by a californium source. We report the estimation of the thermal and epithermal neutron field and its gradient for photoneutrons produced in radiotherapy treatments with 18 MV linear accelerators. It was obsered that photoneutron production have higher rate at the iso-center.

  8. Thermal and epithermal neutron fluence rate gradient measurements by PADC detectors in LINAC radiotherapy treatments-field

    NASA Astrophysics Data System (ADS)

    Barrera, M. T.; Barros, H.; Pino, F.; Dávila, J.; Sajo-Bohus, L.

    2015-07-01

    LINAC VARIAN 2100 is where energetic electrons produce Bremsstrahlung radiation, with energies above the nucleon binding energy (E≈5.5MeV). This radiation induce (γ,n) and (e,e'n) reactions mainly in the natural tungsten target material (its total photoneutron cross section is about 4000 mb in a energy range from 9-17 MeV). These reactions may occur also in other components of the system (e.g. multi leaf collimator). During radiation treatment the human body may receive an additional dose inside and outside the treated volume produced by the mentioned nuclear reactions. We measured the neutron density at the treatment table using nuclear track detectors (PADC-NTD). These covered by a boron-converter are employed, including a cadmium filter, to determine the ratio between two groups of neutron energy, i.e. thermal and epithermal. The PADC-NTD detectors were exposed to the radiation field at the iso-center during regular operation of the accelerator. Neutron are determined indirectly by the converting reaction 10B(n,α)7Li the emerging charged particle leave their kinetic energy in the PADC forming a latent nuclear track, enlarged by chemical etching (6N, NaOH, 70°C). Track density provides information on the neutron density through calibration coefficient (˜1.6 104 neutrons /track) obtained by a californium source. We report the estimation of the thermal and epithermal neutron field and its gradient for photoneutrons produced in radiotherapy treatments with 18 MV linear accelerators. It was obsered that photoneutron production have higher rate at the iso-center.

  9. Low-Dose Radiotherapy in Indolent Lymphoma

    SciTech Connect

    Rossier, Christine; Schick, Ulrike; Miralbell, Raymond; Mirimanoff, Rene O.; Weber, Damien C.; Ozsahin, Mahmut

    2011-11-01

    Purpose: To assess the response rate, duration of response, and overall survival after low-dose involved-field radiotherapy in patients with recurrent low-grade lymphoma or chronic lymphocytic leukemia (CLL). Methods and Materials: Forty-three (24 women, 19 men) consecutive patients with indolent lymphoma or CLL were treated with a total dose of 4 Gy (2 x 2 Gy) using 6- 18-MV photons. The median age was 73 years (range, 39-88). Radiotherapy was given either after (n = 32; 75%) or before (n = 11; 25%) chemotherapy. The median time from diagnosis was 48 months (range, 1-249). The median follow-up period was 20 months (range, 1-56). Results: The overall response rate was 90%. Twelve patients (28%) had a complete response, 15 (35%) had a partial response, 11 (26%) had stable disease, and 5 (11%) had progressive disease. The median overall survival for patients with a positive response (complete response/partial response/stable disease) was 41 months; for patients with progressive disease it was 6 months (p = 0.001). The median time to in-field progression was 21 months (range, 0-24), and the median time to out-field progression was 8 months (range, 0-40). The 3-year in-field control was 92% in patients with complete response (median was not reached). The median time to in-field progression was 9 months (range, 0.5-24) in patients with partial response and 6 months (range, 0.6-6) in those with stable disease (p < 0.05). Younger age, positive response to radiotherapy, and no previous chemotherapy were the best factors influencing the outcome. Conclusions: Low-dose involved-field radiotherapy is an effective treatment in the management of patients with recurrent low-grade lymphoma or CLL.

  10. SU-E-J-198: Out-Of-Field Dose and Surface Dose Measurements of MRI-Guided Cobalt-60 Radiotherapy

    SciTech Connect

    Lamb, J; Agazaryan, N; Cao, M; Low, D; Thomas, D; Yang, Y

    2015-06-15

    Purpose: To measure quantities of dosimetric interest in an MRI-guided cobalt radiotherapy machine that was recently introduced to clinical use. Methods: Out-of-field dose due to photon scatter and leakage was measured using an ion chamber and solid water slabs mimicking a human body. Surface dose was measured by irradiating stacks of radiochromic film and extrapolating to zero thickness. Electron out-of-field dose was characterized using solid water slabs and radiochromic film. Results: For some phantom geometries, up to 50% of Dmax was observed up to 10 cm laterally from the edge of the beam. The maximum penetration was between 1 and 2 mm in solid water, indicating an electron energy not greater than approximately 0.4 MeV. Out-of-field dose from photon scatter measured at 1 cm depth in solid water was found to fall to less than 10% of Dmax at a distance of 1.2 cm from the edge of a 10.5 × 10.5 cm field, and less that 1% of Dmax at a distance of 10 cm from field edge. Surface dose was measured to be 8% of Dmax. Conclusion: Surface dose and out-of-field dose from the MRIguided cobalt radiotherapy machine was measured and found to be within acceptable limits. Electron out-of-field dose, an effect unique to MRI-guided radiotherapy and presumed to arise from low-energy electrons trapped by the Lorentz force, was quantified. Dr. Low is a member of the scientific advisory board of ViewRay, Inc.

  11. Long-Term Follow-Up of Dose-Adapted and Reduced-Field Radiotherapy With or Without Chemotherapy for Central Nervous System Germinoma

    SciTech Connect

    Jensen, Ashley W.; Issa Laack, Nadia N.; Buckner, Jan C.; Schomberg, Paula J.; Wetmore, Cynthia J.; Brown, Paul D.

    2010-08-01

    Purpose: To update our institutional experience with neoadjuvant chemotherapy and minimized radiotherapy vs. radiation monotherapy for intracranial germinoma. Methods and Materials: We retrospectively reviewed records of 59 patients with diagnosis of primary intracranial germinoma between 1977 and 2007. Treatment was irradiation alone or neoadjuvant platinum-based chemotherapy and local irradiation (initial tumor plus margin) for patients with localized complete response and reduced-dose craniospinal irradiation for others. Results: For the chemoradiotherapy group (n = 28), median follow-up was 7 years. No patient died. The freedom from progression (FFP) rate was 88% at 5 years and 80% at 10 years. In 4 patients, disease recurred 1.1 to 6.8 years after diagnosis. All were young male patients who received 30.6 Gy to local fields after complete response to chemotherapy. The FFP rate was 88% for local irradiation vs. 100% for more extensive fields (p = .06). For the radiotherapy-alone group (n = 31), median follow-up was 15 years. Overall and disease-free survival rates were 93% and 93% at 5 years and 90% and 87% at 15 years. In 5 patients, disease recurred 1.1 to 4.9 years after diagnosis. Most patients in this group were young men 18 to 23 years of age with suprasellar primary disease treated with about 50 Gy to local fields. The FFP rate was 44% for local irradiation vs. 100% for more extensive fields (p < .01). Conclusions: The addition of neoadjuvant chemotherapy to local-field radiotherapy reduced central nervous system cancer recurrence when high-risk patients were excluded by thorough pretreatment staging. There was trend toward improved central nervous system tumor control when larger fields (whole brain, whole ventricle, or craniospinal axis) were used.

  12. Field-in-field plan does not improve the dosimetric outcome compared with the wedged beams plan for breast cancer radiotherapy

    SciTech Connect

    Sun, Li-Min; Meng, Fan-Yun; Yang, Tsung-Han; Tsao, Min-Jen

    2014-04-01

    To evaluate and compare the dosimetry of field-in-field (FIF) and wedged beams (WB) techniques for patients with breast cancer receiving adjuvant radiotherapy after conservative surgery. A total of 89 patients with breast cancer participated in this study. Each patient received a computed tomography–based treatment plan with opposed tangential fields. Two planning techniques (FIF and WB) were generated for each patient by using the Pinnacle treatment-planning system. Three indices, the homogeneity index (HI), conformity index (CI), and uniformity index (UI), as well as maximum dose (D{sub max}), median dose (D{sub 50}), number of portals, monitor unit (MU), and lung volume at 20 Gy (lung{sub 20}) were used for comparison. The mean values tested using a t-test indicated that the WB technique had a significantly lower HI (p < 0.0001), a significantly higher CI (p < 0.0001), and a significantly higher D{sub 50} (p = 0.0002) than did the FIF technique. The FIF technique had a significantly higher D{sub max} compared with the WB technique, but lung{sub 20} did not exhibit a significant difference. By contrast, the FIF technique had a significantly higher UI and a significantly lower MU compared with the WB technique, but a significantly higher number of portals were found in the FIF technique. The FIF technique did not demonstrate superior dosimetric results. The WB technique had a significantly lower HI, higher CI, lower D{sub max}, and lower number of portals; but the FIF technique had a significantly higher UI and lower MU.

  13. Dosimetric comparison between intensity-modulated radiotherapy and RapidArc with single arc and dual arc for malignant glioma involving the parietal lobe

    PubMed Central

    YUAN, JUN; LEI, MINGJUN; YANG, ZHEN; FU, JUN; HUO, LEI; HONG, JIDONG

    2016-01-01

    The aim of the present study was to evaluate the difference in treatment plan quality, monitor units (MUs) per fraction and dosimetric parameters between IMRT (intensity-modulated radiotherapy) and RapidArc with single arc (RA1) and dual arc (RA2) for malignant glioma involving the parietal lobe. Treatment plans for IMRT and RA1 and RA2 were prepared for 10 patients with malignant gliomas involving the parietal lobe. The Wilcoxon matched-pair signed-rank test was used to compare the plan quality, monitor units and dosimetric parameters between IMRT and RA1 and RA2 through dose-volume histograms. Dnear-max (D2%) to the left lens, right lens and left optical nerve in RA1 were less compared with those in IMRT; D2% to the right lens and right optic nerve in RA2 were less compared with those in IMRT. D2% to the optic chiasma in RA2 was small compared with that in RA1. The median dose (D50%) to the right lens and right optic nerve in RA1 and RA2 was less compared with the identical parameters in IMRT, and D50% to the brain stem in RA2 was less compared with that in RA1. The volume receiving at least 45 Gy (V45) or V50 in normal brain tissue (whole brain minus the planning target volume 2; B-P) in RA1 was less compared with that in IMRT. V30, V35, V40, V45, or V50 in B-P in RA2 was less compared with that in IMRT. The MUs per fraction in RA1 and RA2 were significantly less compared with those in IMRT. All differences with a P-value<0.05 were considered to be significantly different. In conclusion, RA1 and RA2 markedly reduced the MUs per fraction, and spared partial organs at risk and B-P compared with IMRT. PMID:27330795

  14. Electric-field enhanced performance in catalysis and solid-state devices involving gases

    DOEpatents

    Blackburn, Bryan M.; Wachsman, Eric D.; Van Assche, IV, Frederick Martin

    2015-05-19

    Electrode configurations for electric-field enhanced performance in catalysis and solid-state devices involving gases are provided. According to an embodiment, electric-field electrodes can be incorporated in devices such as gas sensors and fuel cells to shape an electric field provided with respect to sensing electrodes for the gas sensors and surfaces of the fuel cells. The shaped electric fields can alter surface dynamics, system thermodynamics, reaction kinetics, and adsorption/desorption processes. In one embodiment, ring-shaped electric-field electrodes can be provided around sensing electrodes of a planar gas sensor.

  15. Intraoperative radiotherapy: the Japanese experience. [Betatron

    SciTech Connect

    Abe, M.; Takahashi, M.

    1981-07-01

    Clinical results of intraoperative radiotherapy (IOR) which have been obtained since 1964 in Japan were reviewed. In this radiotherapy a cancerocidal dose can be delivered safely to the lesions, since critical organs are shifted from the field so that the lesions may be exposed directly to radiation. Intraoperative radiotherapy has spread in Japan and the number of institutions in which this radiotherapy is performed has continued to increase to a total of 26 in 1979. The total number of patients treated was 717. It has been demonstrated that intraoperative radiotherapy has definite effects on locally advanced abdominal neoplasms and unresectable radioresistant tumors.

  16. Analysis of a teleportation scheme involving cavity field states in a linear superposition of Fock states

    NASA Astrophysics Data System (ADS)

    Carvalho, C. R.; Guerra, E. S.; Jalbert, Ginette

    2008-04-01

    We analyse a teleportation scheme of cavity field states. The experimental sketch discussed makes use of cavity quantum electrodynamics involving the interaction of Rydberg atoms with superconducting (micromaser) cavities as well as with classical microwave (Ramsey) cavities. In our scheme the Ramsey cavities and the atoms play the role of auxiliary systems used to teleport a field state, which is formed by a linear superposition of vacuum |∅> and the one-photon state |1>, from a micromaser cavity to another.

  17. Electric field-directed fibroblast locomotion involves cell surface molecular reorganization and is calcium independent

    PubMed Central

    1994-01-01

    Directional cellular locomotion is thought to involve localized intracellular calcium changes and the lateral transport of cell surface molecules. We have examined the roles of both calcium and cell surface glycoprotein redistribution in the directional migration of two murine fibroblastic cell lines, NIH 3T3 and SV101. These cell types exhibit persistent, cathode directed motility when exposed to direct current electric fields. Using time lapse phase contrast microscopy and image analysis, we have determined that electric field-directed locomotion in each cell type is a calcium independent process. Both exhibit cathode directed motility in the absence of extracellular calcium, and electric fields cause no detectable elevations or gradients of cytosolic free calcium. We find evidence suggesting that galvanotaxis in these cells involves the lateral redistribution of plasma membrane glycoproteins. Electric fields cause the lateral migration of plasma membrane concanavalin A receptors toward the cathode in both NIH 3T3 and SV101 fibroblasts. Exposure of directionally migrating cells to Con A inhibits the normal change of cell direction following a reversal of electric field polarity. Additionally, when cells are plated on Con A- coated substrata so that Con A receptors mediate cell-substratum adhesion, cathode-directed locomotion and a cathodal accumulation of Con A receptors are observed. Immunofluorescent labeling of the fibronectin receptor in NIH 3T3 fibroblasts suggests the recruitment of integrins from large clusters to form a more diffuse distribution toward the cathode in field-treated cells. Our results indicate that the mechanism of electric field directed locomotion in NIH 3T3 and SV101 fibroblasts involves the lateral redistribution of plasma membrane glycoproteins involved in cell-substratum adhesion. PMID:7929557

  18. CT Simulation to Evaluate of Pelvic Lymph Node Coverage in Conventional Radiotherapy Fields Based on Bone and Vessels Landmarks in Prostate Cancer Patients

    PubMed Central

    Yousefi Kashi, Amir Shahram; Khaledi, Samira; Houshyari, Mohammad

    2016-01-01

    Background Radiotherapy is the gold standard for treatment of prostrate cancer as it can cover an adequate area of tissues at risk for metastasis. Objectives We evaluated the Pelvic lymph node coverage of conventional radiotherapy fields based on bone and vessels landmarks using computed tomography (CT) simulation in patients with prostate cancer referred to Shohada-e-Tajrish hospital. Patients and Methods In this cross sectional study, 40 patients with prostate cancer at the Stage T1c to T3b were studied. Pelvic lymph nodes were contoured by using pelvic vessels as surrogate markers. The distances were measured at different points of anterior-posterior (AP) and lateral fields and distances > 5 mm or more between the contoured nodes and the field borders. Results Mean and standard deviation of the aortic bifurcation from the superior border was 4.73 ± 1.16 cm, the distance of common iliac bifurcation from the superior border was 1.11 ± 1.25 cm, the mean (SD) distance of right external iliac from the lateral border of AP field was 2.06 ± 0.48 cm and for left external iliac artery was 1.90 ± 0.56 cm. The distance of the external iliac artery from the anterior border of the lateral field was 2.30 ± 0.74 cm. The distance of the external iliac artery from pelvic rim was 0.59 ± 0.59 cm, distance of bifurcation of iliac from sacroiliac joint was 0.82 ± 1.01 cm, the size of the pelvic rim was 12.30 ± 0.64 cm, sacral width was 8.29 ± 1.01 cm, anterior promontory symphysis distance was 12.02 ± 0.92 cm and posterior promontory symphysis distance was 10.98 ± 0.73 cm. Conclusions We observed that conventional radiotherapy using CT simulation based on bone and vessels landmarks provided adequate coverage of pelvic lymph nodes in our patients with prostate cancer.

  19. SU-E-T-272: Radiation Damage Comparison Between Intensity Modulated Radiotherapy and Field-In-Field Technique in Breast Cancer Treatments

    SciTech Connect

    Ai, H; Zhang, H

    2014-06-01

    Purpose: To compare normal tissue complications between IMRT and FIF treatment in breast cancer. Methods: 16 patients treated with IMRT plan and 20 patients treated with FIF plan were evaluated in this study. Both kinds of plans were generated using Eclipse treatment planning system by dosimetrist following clinical radiotherapy treatment guidelines. The plans were reviewed and approved by radiation oncologist. The average survival fraction (SF) for three different normal tissue cells of each concerned structure can be calculated from differential dose volume histogram (DVH) using linear quadratic model. The three types of normal tissues include radiosensitive, moderately radiosensitive and radio-resistant that represents 70%, 50% and 30% survival fractions, respectively, for a 2-Gy open field. Equivalent uniform doses (EUD) for corresponding normal tissues of each structure were calculated. Results: The EUDs of the lungs, heart, healthy breast and spinal cord with both IMRT and FIF treatments were calculated. Considering the average value of all IMRT plans, the lung of treated side absorbed 16.0% of dosage prescribed to the tumor if the radiosensitivity of the lung is similar to the radiosensitive cell line. For moderately radiosensitive and radio-resistant lung tissue, the average EUDs can be 18.9% and 22.4% of prescription. In contrast, patients treated with FIF plans were delivered 6.0%, 7.5% and 10.3% of prescribed dose for radiosensitive, moderately radiosensitive and radio-resistant lung tissue, respectively. Comparing heart EUDs between IMRT and FIF plans, average absorbed doses in IMRT treatment were 7.7%, 8.7% and 9.7% of prescription for three types of heart normal tissue cell lines while FIF treatments delivered only 1.3%, 1.5% and 1.6% of prescription dose. For the other organs, the results were similar. Conclusion: The results indicated that breast cancer treatment using IMRT technique had more normal tissue damage than FIF treatment. FIF demonstrated

  20. Radiotherapy Accidents

    NASA Astrophysics Data System (ADS)

    Mckenzie, Alan

    A major benefit of a Quality Assurance system in a radiotherapy centre is that it reduces the likelihood of an accident. For over 20 years I have been the interface in the UK between the Institute of Physics and Engineering in Medicine and the media — newspapers, radio and TV — and so I have learned about radiotherapy accidents from personal experience. In some cases, these accidents did not become public and so the hospital cannot be identified. Nevertheless, lessons are still being learned.

  1. Involved field radiation for Hodgkin's lymphoma: The actual dose to breasts in close proximity

    SciTech Connect

    Dabaja, Bouthaina; Wang Zhonglo; Stovall, Marilyn; Baker, Jamie S.; Smith, Susan A.; Khan, Meena; Ballas, Leslie; Salehpour, Mohammad R.

    2012-01-01

    To decrease the risk of late toxicities in Hodgkin's lymphoma (HL) patients treated with radiation therapy (RT) (HL), involved field radiation therapy (IFRT) has largely replaced the extended fields. To determine the out-of-field dose delivered from a typical IFRT to surrounding critical structures, we measured the dose at various points in an anthropomorphic phantom. The phantom is divided into 1-inch-thick slices with the ability to insert TLDs at 3-cm intervals grid spacing. Two treatment fields were designed, and a total of 45 TLDs were placed (equally spaced) at the margin of the each of the 2 radiation fields. After performing a computed tomography simulation, 2 treatment plans targeting the mediastinum, a typical treatment field in patients with early stage HL, were generated. A total dose of 3060 cGy was delivered to the gross tumor volume for each field consecutively. The highest measured dose detected at 1 cm from the field edge in the planning target volume was 496 cGy, equivalent to 16% of the isocentric dose. The dose dropped significantly with increasing distance from the field edge. It ranged from 1.1-3.9% of the isocentric dose at a distance of 3.2-4 cm to <1.6% at a distance of >6 cm. Although the computer treatment planning system (CTPS) frequently underestimated the dose delivered, the difference in dose between measured and generated by CTPS was <2.5% in 90 positions measured. The collateral dose of radiation to breasts from IFRT is minimal. The out-of-field dose, although mildly underestimated by CTPS, becomes insignificant at >3 cm from the field edge of the radiation field.

  2. [Radiotherapy of breast cancer].

    PubMed

    Hennequin, C; Barillot, I; Azria, D; Belkacémi, Y; Bollet, M; Chauvet, B; Cowen, D; Cutuli, B; Fourquet, A; Hannoun-Lévi, J M; Leblanc, M; Mahé, M A

    2016-09-01

    In breast cancer, radiotherapy is an essential component of the treatment. After conservative surgery for an infiltrating carcinoma, radiotherapy must be systematically performed, regardless of the characteristics of the disease, because it decreases the rate of local recurrence and by this way, specific mortality. Partial breast irradiation could not be proposed routinely but only in very selected and informed patients. For ductal carcinoma in situ, adjuvant radiotherapy must be also systematically performed after lumpectomy. After mastectomy, chest wall irradiation is required for pT3-T4 tumours and if there is an axillary nodal involvement, whatever the number of involved lymph nodes. After neo-adjuvant chemotherapy and mastectomy, in case of pN0 disease, chest wall irradiation is recommended if there is a clinically or radiologically T3-T4 or node positive disease before chemotherapy. Axillary irradiation is recommended only if there is no axillary surgical dissection and a positive sentinel lymph node. Supra and infra-clavicular irradiation is advised in case of positive axillary nodes. Internal mammary irradiation must be discussed case by case, according to the benefit/risk ratio (cardiac toxicity). Dose to the chest wall or the breast must be between 45-50Gy with a conventional fractionation. A boost dose over the tumour bed is required if the patient is younger than 60 years old. Hypofractionation (42.5 Gy in 16 fractions, or 41.6 Gy en 13 or 40 Gy en 15) is possible after tumorectomy and if a nodal irradiation is not mandatory. Delineation of the breast, the chest wall and the nodal areas are based on clinical and radiological evaluations. 3D-conformal irradiation is the recommended technique, intensity-modulated radiotherapy must be proposed only in case of specific clinical situations. Respiratory gating could be useful to decrease the cardiac dose. Concomitant administration of chemotherapy in unadvised, but hormonal treatment could be start with

  3. [Radiotherapy of cerebral metastases].

    PubMed

    Soffietti, R

    1984-05-31

    Radiotherapy of brain metastases is almost always palliative, as histologically documented cures are exceptional. Radiotherapy alone improves neurological symptoms in two-thirds of cases, but median survivals do not generally exceed 6 months. Whole brain radiation is mandatory as the lesions are often multiple, even when they escape clinical demonstration. There is no definite difference in prognosis after conventional rather than concentrated treatments. The role of steroids in the prevention and/or control of the acute effects of radiotherapy is controversial. Favorable prognostic factors are a good neurological and performance status, a solitary brain metastasis of a primary tumor under control, some histological types (i.e.: metastases from "oat" cell carcinomas, breast carcinomas, non-Hodgkin lymphomas are more responsive). Surgical excision before radiotherapy improves survival (6-12 months), especially in solitary metastases from melanomas, colon and renal tumors. Reirradiation can be useful, but the risk of delayed damage to the normal tissue in patients with longer survival (solitary operated and irradiated metastases) must be considered. The search for new radiotherapeutic modalities must be based on a deeper understanding of the biological factors involved in the response to radiation through controlled anatomo-clinical studies and biological research on experimental models.

  4. Second neoplasms following radiotherapy or chemotherapy for cancer

    SciTech Connect

    Penn, I.

    1982-02-01

    While radiotherapy and antineoplastic chemotherapy often control malignancies they may, paradoxically, cause new cancers to develop as long-term complications. Although almost any type of neoplasm can occur, radiation-induced malignancies are most likely to affect the myelopoietic tissues and the thyroid gland. The former tissues are also most frequently involved by chemotherapy. The combination of intensive radiotherapy and intensive chemotherapy is particularly leukemogenic. Acute myeloid leukemia has occurred with increased frequency following treatment of Hodgkin's disease, non-Hodgkin's lymphoma, multiple myeloma, ovarian cancer, polycythemia vera, carcinoma of the thyroid gland, and carcinoma of the breast. Radiation-induced malignancies usually occur in the field of irradiation. Tumors developing in an irradiated field include a substantial number of soft tissue sarcomas or osteosarcomas. There is a 20-fold increase of second cancers following treatment of childhood malignancies, mostly sarcomas of bone and soft tissues, but including leukemia, and carcinomas of the thyroid gland, skin, and breast. The latent period between radiotherapy and the appearance of a second cancer ranges from 2 years to several decades, often being 10-15 years. With chemotherapy the mean latent period is shorter, approximately 4 years. The mechanism of oncogenesis by radiotherapy or chemotherapy is poorly understood and probably involves a complex interplay of somatic mutation, co-oncogenic effects, depression of host immunity, stimulation of cellular proliferation, and genetic susceptibility.

  5. Involved site radiation therapy for the treatment of early-stage Hodgkin lymphoma in adolescents and young adults

    PubMed Central

    Portlock, Carol S

    2016-01-01

    Radiation therapy technology has permitted the development of new treatment planning techniques. Involved field, involved node, and involved site radiotherapy fields are discussed and compared. Indications for and implications of combined modality therapy are examined, particularly as pertinent to the adolescent and young adult population. PMID:26767184

  6. [External radiotherapy for hepatocellular carcinoma].

    PubMed

    Girard, N; Mornex, F

    2011-02-01

    For a long time radiotherapy has been excluded from the therapeutic strategy for hepatocellular carcinoma, given its significant toxicity on the non-tumoral liver parenchyma. Conformal radiation is a recent advance in the field of radiotherapy, allowing dose escalation and combination with other therapeutic options for hepatocellular carcinoma, including trans-arterial chemo-embolization. Conformal radiotherapy is associated with interesting features, especially in cirrhotic patients: wide availability, non-invasiveness, possibility to target multiple localizations anywhere within the liver parenchyma, and favorable tolerance profile even in patients with cirrhosis and/or in a poor medical condition. Recently, radiation delivery has been optimized through several technical developments: respiratory gating and intensity-modulated radiotherapy, which allow a better focalization of the ballistics, stereotactic techniques and proton-beam radiotherapy, whose availability is currently limited in Europe. Given the high response rates of hepatocellular carcinoma to radiation, conformal radiotherapy may be regarded as a curative-intent treatment for hepatocellular carcinoma, similar to surgery and per-cutaneous techniques. Yet the impact of radiotherapy has to be evaluated in randomized trials to better integrate in the complex therapeutic algorithm of hepatocellular carcinoma.

  7. Regional Nodal Involvement and Patterns of Spread Along In-Transit Pathways in Children With Rhabdomyosarcoma of the Extremity: A Report From the Children's Oncology Group;Rhabdomyosarcoma; Regional failure; In-transit nodes; Radiotherapy; Extremity

    SciTech Connect

    La, Trang H.; Wolden, Suzanne L.; Rodeberg, David A.; Hawkins, Douglas S.; Anderson, James R.; Donaldson, Sarah S.

    2011-07-15

    Purpose: To evaluate the incidence and prognostic factors for regional failure, with attention to the in-transit pathways of spread, in children with nonmetastatic rhabdomyosarcoma of the extremity. Methods and Materials: The Intergroup rhabdomyosarcoma studies III, IV-Pilot, and IV enrolled 226 children with rhabdomyosarcoma of the extremity. Failure at the in-transit (epitrochlear/brachial and popliteal) and proximal (axillary/infraclavicular and inguinal/femoral) lymph nodes was evaluated. The median follow-up for the surviving patients was 10.4 years. Results: Of the 226 children, 55 (24%) had clinical or pathologic evidence of either in-transit and/or proximal lymph node involvement at diagnosis. The actuarial 5-year risk of regional failure was 12%. The prognostic factors for poor regional control were female gender and lymph node involvement at diagnosis. In the 116 patients with a distal extremity primary tumor, 5% had in-transit lymph node involvement at diagnosis. The estimated 5-year incidences of in-transit and proximal nodal failure was 12% and 8%, respectively. The in-transit failure rate was 0% for patients who underwent radiotherapy and/or underwent lymph node sampling of the in-transit nodal site but was 15% for those who did not (p = .07). However, the 5-year event-free survival rate did not differ between these two groups (64% vs. 55%, respectively, p = .47). Conclusion: The high incidence of regional involvement necessitates aggressive identification and treatment of regional lymph nodes in patients with rhabdomyosarcoma of the extremity. In patients with distal extremity tumors, in-transit failures were as common as failures in more proximal regional sites. Patients who underwent complete lymph node staging with appropriate radiotherapy to the in-transit nodal site, if indicated, were at a slightly lower risk of in-transit failure.

  8. Adjuvant and Definitive Radiotherapy for Adrenocortical Carcinoma

    SciTech Connect

    Sabolch, Aaron; Feng, Mary; Griffith, Kent; Hammer, Gary; Doherty, Gerard; Ben-Josef, Edgar

    2011-08-01

    Purpose: To evaluate the impact of both adjuvant and definitive radiotherapy on local control of adrenocortical carcinoma. Methods and Materials: Outcomes were analyzed from 58 patients with 64 instances of treatment for adrenocortical carcinoma at the University of Michigan's Multidisciplinary Adrenal Cancer Clinic. Thirty-seven of these instances were for primary disease, whereas the remaining 27 were for recurrent disease. Thirty-eight of the treatment regimens involved surgery alone, 10 surgery plus adjuvant radiotherapy, and 16 definitive radiotherapy for unresectable disease. The effects of patient, tumor, and treatment factors were modeled simultaneously using multiple variable Cox proportional hazards regression for associations with local recurrence, distant recurrence, and overall survival. Results: Local failure occurred in 16 of the 38 instances that involved surgery alone, in 2 of the 10 that consisted of surgery plus adjuvant radiotherapy, and in 1 instance of definitive radiotherapy. Lack of radiotherapy use was associated with 4.7 times the risk of local failure compared with treatment regimens that involved radiotherapy (95% confidence interval, 1.2-19.0; p = 0.030). Conclusions: Radiotherapy seems to significantly lower the risk of local recurrence/progression in patients with adrenocortical carcinoma. Adjuvant radiotherapy should be strongly considered after surgical resection.

  9. Exposures involving perturbations of the EM field have non-linear effects on radiation response and can alter the expression of radiation induced bystander effects

    NASA Astrophysics Data System (ADS)

    Mothersill, Carmel; Seymour, Colin

    2012-07-01

    Our recent data suggest there is a physical component to the bystander signal induced by radiation exposure and that alternative medicine techniques such as Reiki and acupuncture or exposures to weak EM fields alter the response of cells to direct irradiation and either altered bystander signal production or altered the response of cells receiving bystander signals. Our proposed mechanism to explain these findings is that perturbation of electromagnetic (EM) fields is central to the induction of low radiation dose responses especially non-targeted bystander effects. In this presentation we review the alternative medicine data and other data sets from our laboratory which test our hypothesis that perturbation of bio-fields will modulate radiation response in the low dose region. The other data sets include exposure to MRI, shielding using lead and or Faraday cages, the use of physical barriers to bystander signal transmission and the use of membrane channel blockers. The data taken together strongly suggest that EM field perturbation can modulate low dose response and that in fact the EM field rather than the targeted deposition of ionizing energy in the DNA may be the key determinant of dose response in a cell or organism The results also lead us to suspect that at least when chemical transmission is blocked, bystander signals can be transmitted by other means. Our recent experiments suggest light signals and volatiles are not likely. We conclude that alternative medicine and other techniques involving electromagnetic perturbations can modify the response of cells to low doses of ionizing radiation and can induce bystander effects similar to those seen in medium transfer experiments. In addition to the obvious implications for mechanistic studies of low dose effects, this could perhaps provide a novel target to exploit in space radiation protection and in optimizing therapeutic gain during radiotherapy.

  10. Evaluation of sound fields in a concert hall involving scattered reflections applying the subjective preference theory

    NASA Astrophysics Data System (ADS)

    Suzumura, Yukio

    2003-08-01

    Convex tilted rear walls in a stage enclosure, an array of circular columns installed in front of walls, and triangular reflectors above the stage were newly adopted as scattering obstacles in an acoustic design of Tsuyama Music Cultural Hall, called ``Bell Fole‸t Tsuyama.'' The fundamental shape of the hall was designed using the theory of subjective preference. To calculate the effects of scattered reflections on a sound field in a real concert hall is extremely laborious. For this reason, the evaluation of effects of scattered reflections on the sound field in the hall was made experimentally by use of a 110 acoustical scale. After construction of the hall, therefore, sound fields of the hall, which involves scattered reflections caused by the tilted convex rear, by the array of circular columns, and by the triangular reflectors, were measured using four orthogonal physical factors (LL, Δt1, Tsub, IACC) described in the theory and the acoustical character of these scattering obstacles was clarified. Results clearly showed that these new attempts on scattered reflections substantially improved the quality of the sound field in the hall. Thesis advisor: Yoichi Ando Copies of this thesis written in English can be obtained from Yukio Suzumura. E-mail address: ysuzu11@lapis.plala.or.jp

  11. Frontal eye fields involved in shifting frame of reference within working memory for scenes.

    PubMed

    Wallentin, Mikkel; Roepstorff, Andreas; Burgess, Neil

    2008-01-31

    Working memory (WM) evoked by linguistic cues for allocentric spatial and egocentric spatial aspects of a visual scene was investigated by correlating fMRI BOLD signal (or "activation") with performance on a spatial-relations task. Subjects indicated the relative positions of a person or object (referenced by the personal pronouns "he/she/it") in a previously shown image relative to either themselves (egocentric reference frame) or shifted to a reference frame anchored in another person or object in the image (allocentric reference frame), e.g. "Was he in front of you/her?" Good performers had both shorter response time and more correct responses than poor performers in both tasks. These behavioural variables were entered into a principal component analysis. The first component reflected generalised performance level. We found that the frontal eye fields (FEF), bilaterally, had a higher BOLD response during recall involving allocentric compared to egocentric spatial reference frames, and that this difference was larger in good performers than in poor performers as measured by the first behavioural principal component. The frontal eye fields may be used when subjects move their internal gaze during shifting reference frames in representational space. Analysis of actual eye movements in three subjects revealed no difference between egocentric and allocentric recall tasks where visual stimuli were also absent. Thus, the FEF machinery for directing eye movements may also be involved in changing reference frames within WM. PMID:17915262

  12. Clinical, dosimetric, and radiographic correlation of radiation injury involving the brainstem and the medial temporal lobes following stereotactic radiotherapy for neoplasms of central skull base.

    PubMed

    Schipani, Stefano; Jain, Rajan; Shah, Keyur; Rock, Jack P; Movsas, Benjamin; Rosenblum, Mark; Ryu, Samuel

    2010-06-01

    Stereotactic Radiotherapy (SRT) is more commonly used for skull base tumors in conjunction with the technical development of radiation intensity modulation. Purpose of this study is to correlate clinical and radiographic characteristics of delayed radiation injury (RI) occurring around central skull base following SRT with SRT dosimetric data. Total of six patients were identified to have developed RI in the vicinity of SRT target volume out of 141 patients who received SRT in he center or near-center of the skull base. The images and medical records were retrospectively reviewed. The analysis was performed for RI location, time of development, imaging and clinical characteristics and evolution of RI and correlated with SRT dosimetric analysis using image fusion with follow-up MRI scans. Mean follow-up time was 24 +/- 9 months. During the follow-up period, twelve sites of RI were found in 6 patients. They were clinically symptomatic in 4/6 patients (66.6%) at median 12.5 months after SRT. Mean time interval between SRT and detection of RI was 9 +/- 3, 18.5 +/- 5, and 13.5 months for brainstem, temporal lobe, and cerebellum/labyrinth lesions, respectively. All RI lesions were included in the region of high SRT doses. After steroid and symptomatic treatment, 50% of RI lesions showed complete response, and 40% showed partial response. RI can occur around the skull base because of irregular shape of target tumor, its close proximity to normal brain parenchyma, and inhomogeneity of dose distribution. Brainstem lesions occurred earlier than temporal lobe RI. The majority of the RI lesions, not mixed with the tumor in this study, showed radiographic and clinical improvement with steroid and symptomatic treatments. PMID:20376551

  13. Involvement of Difference in Decrease of Hemoglobin Level in Poor Prognosis of Stage I and II Nasopharyngeal Carcinoma: Implication in Outcome of Radiotherapy

    SciTech Connect

    Gao Jin; Tao Yalan; Li Guo; Yi Wei; Xia Yunfei

    2012-03-15

    Purpose: To investigate the effect of hemoglobin (Hb) concentration and the difference in its decrease during treatment on outcome of radiotherapy (RT) alone for patients with Stage I and II nasopharyngeal carcinoma. Methods and Materials: A total of 572 patients with Stage I-II nasopharyngeal carcinoma with RT alone between January 2001 and December 2004 were retrospectively analyzed. Patient characteristics, tumor variables, and Hb level, including pre-RT Hb, mid-RT Hb, and dynamic change of Hb between pre- and post- RT and its difference in decrease ( White-Up-Pointing-Small-Triangle Hb) were subjected to univariate and multivariable analysis to identify factors that predict disease-specific survival (DSS), local regional recurrence-free survival (LRFS), and metastases-free survival (MFS). Results: The 5-year DSS was poorer in the Hb continuous decrease group than in the Hb noncontinuous decrease group (84% vs. 89%; p = 0.008). There was poorer 5-year DSS in patients with White-Up-Pointing-Small-Triangle Hb of >11.5 g/L than in those with White-Up-Pointing-Small-Triangle Hb of {<=}11.5 g/L (82% vs. 89%; p = 0.001), and poorer LRFS (79% vs. 83%; p = 0.035). Univariate and multivariate analysis showed that Hb decrease difference with greater than 11.5 g/L was an independent prognostic factor for DSS and LRFS. Conclusions: The difference in decrease of Hb level during the course of radiation treatment appeared as a poor prognostic factor in Stage I and II nasopharyngeal carcinoma patients.

  14. Chemotherapy combined with high-dose extended-field radiotherapy for stage I extranodal nasal-type natural killer/T-cell lymphoma

    PubMed Central

    Luo, Jialin; Cao, Caineng; Zhu, Yuan; Liu, Peng; Liu, Luying; Lu, Ke; Zhang, Na; Zhou, Ning

    2016-01-01

    Background and objective The objective of the study was to evaluate the efficiency of chemotherapy (CT) combined with high-dose extended-field radiotherapy (RT) in stage I extranodal nasal-type natural killer/T-cell lymphoma (NKTCL). Patients and methods Between January 2001 and November 2010, 103 stage I extranodal nasal-type NKTCL patients were retrospectively analyzed. Of these patients, 75 patients were treated by RT plus CT and 28 patients were treated by RT alone. CT included cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or CHOP-like regimen. Results The median follow-up time was 42.6 months (range, 7.4–126.7 months). For patients in the RT alone group, the 5-year estimated progression-free survival (PFS) and overall survival (OS) rates were 67.0% and 71.4%, respectively. For patients in the RT + CT group, the 5-year estimated PFS and OS rates were 69.0% and 63.7%, respectively. In multivariate analysis, CT was an independent factor for PFS. Conclusion The doxorubicin-based CT combined with high-dose extended-field RT yielded promising outcomes for stage I extranodal nasal-type NKTCL, and CT was an independent factor for PFS. PMID:27785062

  15. 'Nurturing the brain' as an emerging research field involving child neurology.

    PubMed

    Ito, Masao

    2004-10-01

    'Nurturing the brain' is an emerging research field integrating brain science, child care and education, which also involves child neurology. It has emerged from the recent remarkable progress in brain science and strong social demands for improvements in child care and education. This article reviews the current status of three major research themes in this field. First, developmental disorders represented by attention deficit/hyperactivity disorder, autism and Asperger syndrome often introduce difficulties in child care and education, which are to be addressed by appropriate assessment and treatment of affected children based on new knowledge of the pathogenesis of these disorders. Second, recent progress in research on the critical/sensitive periods of development of brain structures and functions promises useful advice for teachers and parents regarding optimal timing and ways of teaching various subjects. Third, the development of the brain throughout infancy, childhood and adolescence is paralleled by the growth and maturation of the mind. Neuronal mechanisms underlying the theory of mind, mirror neurons, internal model, cognitive control, and cognitive emotion regulation are important themes that bridge our understandings of the brain and the mind. PMID:15351077

  16. Experimental determination of field factors ([Formula: see text]) for small radiotherapy beams using the daisy chain correction method.

    PubMed

    Lárraga-Gutiérrez, José Manuel

    2015-08-01

    Recently, Alfonso et al proposed a new formalism for the dosimetry of small and non-standard fields. The proposed new formalism is strongly based on the calculation of detector-specific beam correction factors by Monte Carlo simulation methods, which accounts for the difference in the response of the detector between the small and the machine specific reference field. The correct calculation of the detector-specific beam correction factors demands an accurate knowledge of the linear accelerator, detector geometry and composition materials. The present work shows that the field factors in water may be determined experimentally using the daisy chain correction method down to a field size of 1 cm × 1 cm for a specific set of detectors. The detectors studied were: three mini-ionization chambers (PTW-31014, PTW-31006, IBA-CC01), three silicon-based diodes (PTW-60018, IBA-SFD and IBA-PFD) and one synthetic diamond detector (PTW-60019). Monte Carlo simulations and experimental measurements were performed for a 6 MV photon beam at 10 cm depth in water with a source-to-axis distance of 100 cm. The results show that the differences between the experimental and Monte Carlo calculated field factors are less than 0.5%-with the exception of the IBA-PFD-for field sizes between 1.5 cm × 1.5 cm and 5 cm × 5 cm. For the 1 cm × 1 cm field size, the differences are within 2%. By using the daisy chain correction method, it is possible to determine measured field factors in water. The results suggest that the daisy chain correction method is not suitable for measurements performed with the IBA-PFD detector. The latter is due to the presence of tungsten powder in the detector encapsulation material. The use of Monte Carlo calculated [Formula: see text] is encouraged for field sizes less than or equal to 1 cm × 1 cm for the dosimeters used in this work. PMID:26161448

  17. Management of radiotherapy-induced skin reactions.

    PubMed

    Trueman, Ellen

    2015-04-01

    Radiotherapy is a highly effective cancer treatment that not only offers cure but also excellent palliation of disease related symptoms and complications. Although radiotherapy is primarily an outpatient treatment, delivered within specialist centres, a diverse range of health professionals may be involved in the treatment pathway before, during and after treatment. Radiotherapy can, and does, make a significant contribution to improving a patient's wellbeing through effective symptom management. However, treatment-related side-effects do occur, with an acute skin reaction being one of the most common. It is imperative that radiotherapy-induced skin reactions are correctly assessed and appropriately managed in promoting patient comfort, treatment compliance and enhanced quality of life. This article describes how the use of a recognised assessment tool and evidence-based guidelines can facilitate consistent, high-quality care in the management of radiotherapy-induced skin reactions.

  18. Final results from a multicenter prospective study ( JROSG 05–5) on postoperative radiotherapy for patients with ductal carcinoma in situ with an involved surgical margin or close margin widths of 1 mm or less

    PubMed Central

    Shikama, Naoto; Sekiguchi, Kenji; Nakamura, Naoki; Sekine, Hiroshi; Nakayama, Yuko; Imanaka, Kazufumi; Akiba, Takeshi; Aoki, Masahiko; Hatayama, Yoshiomi; Ogo, Etsuyo; Kagami, Yoshikazu; Kawashima, Miho; Karasawa, Kumiko

    2015-01-01

    This multicenter prospective study ( Japanese Radiation Oncology Study Group: JROSG 05-5) aimed to evaluate the effectiveness of postoperative radiotherapy (PORT) in patients with ductal carcinoma in situ (DCIS) with an involved surgical margin or close margin widths of ≤1 mm or less. PORT consisted of whole-breast irradiation (50 Gy in 25 fractions) followed by boost irradiation (10 Gy in 5 fractions). Eligibility criteria were as follows: (i) DCIS without an invasive carcinoma component, (ii) age between 20 and 80 years old, (iii) involved margin or close margin widths of ≤1 mm, (iv) refusal of re-resection, (v) performance status of 0–2, and (vi) written informed consent. The primary endpoint was ipsilateral breast tumor recurrence (IBTR), and secondary endpoints were overall survival (OS), relapse-free survival (RFS), recurrence patterns, and adverse events. A total of 37 patients from 12 institutions were enrolled from January 2007 to May 2009. The median follow-up time was 62 months (range, 28–85 months). The median pathological tumor size was 2.5 cm (range, 0.3–8.5 cm). Of the 37 patients, 21 had involved margins, and 16 had close margins. The 5-year IBTR, OS and RFS rates were 6% (95% confidence interval [CI]: 2–21), 97% (95% CI: 83–99) and 91% (95% CI: 77–97), respectively. Two patients developed local recurrence at the original site after 39 and 58 months. No severe adverse events were found. Our study suggests that this PORT regimen could be a treatment option for patients with DCIS with involved margin or close margin who don't desire re-resection. PMID:26093369

  19. High-Dose Conformal Radiotherapy for Patients With Stage III Non-Small-Cell Lung Carcinoma

    SciTech Connect

    Nakayama, Hidetsugu; Satoh, Hiroaki; Kurishima, Koichi; Ishikawa, Hiroichi; Tokuuye, Koichi

    2010-11-01

    Purpose: To determine the effectiveness of high-dose conformal radiotherapy to the involved field for patients with Stage III non-small-cell lung cancer (NSCLC). Methods and Materials: Between May 1999 and April 2006, a total of 100 consecutive patients with inoperable Stage IIIA or IIIB NSCLC with a performance score of 0 to 2 and treatment by radical radiotherapy combined with chemotherapy were included. Up to August 2002, 33 patients underwent conventional radiotherapy of 56 Gy to 66 Gy using anteroposterior opposite ports to the primary tumor and elective lymph nodes (conventional group). After September 2002, the remaining 67 patients underwent high-dose radiotherapy of 66 Gy to 84 Gy to the involved volume with three-dimensional (3-D) conformal radiotherapy (conformal group). Results: The median survival was 13.2 months (95% confidence interval [CI], 7.5-18.5 months) in the conventional group and 17.3 months (95% CI, 10.7- 24.0 months) in the conformal group. The overall survival at 3 years were 9.1% (95% CI, -0.7-18.9%) in the conventional group and 31.0% (95% CI, 18.9-43.1%) in the conformal group; the conformal group had a significantly better overall survival (p < 0.05). The radiotherapy method (hazard ratio = 0.55, p < 0.05) and performance status (hazard ratio = 1.48, p < 0.05) were shown to be statistically significant independent prognostic factors. Conclusions: Based on the practical experience reported here, 3-D conformal radiotherapy allowed dose escalation without excessive toxicity, and may improve overall survival rates for patients with Stage III NSCLC.

  20. Kidney-Sparing Methods for Extended-Field Intensity-Modulated Radiotherapy (EF-IMRT) in Cervical Carcinoma Treatment.

    PubMed

    Kunogi, Hiroaki; Yamaguchi, Nanae; Terao, Yasuhisa; Sasai, Keisuke

    2016-01-01

    Coplanar extended-field intensity-modulated radiation therapy (EF-IMRT) targeting the whole-pelvic and para-aortic lymph nodes in patients with advanced cervical cancer results in impaired creatinine clearance. An improvement in renal function cannot be expected unless low-dose (approximately 10 Gy) kidney exposure is reduced. The dosimetric method should be considered during EF-IMRT planning to further reduce low-dose exposure to the kidneys. To assess the usefulness of non-coplanar EF-IMRT with kidney-avoiding beams to spare the kidneys during cervical carcinoma treatment in dosimetric analysis between non-coplanar and coplanar EF-IMRT, we compared the doses of the target organ and organs at risk, including the kidney, in 10 consecutive patients. To estimate the influence of EFRT on renal dysfunction, creatinine clearance values after treatment were also examined in 18 consecutive patients. Of these 18 patients, 10 patients who were included in the dosimetric analysis underwent extended field radiation therapy (EFRT) with concurrent chemotherapy, and eight patients underwent whole-pelvis radiation therapy with concurrent chemotherapy to treat cervical carcinoma between April 2012 and March 2015 at our institution. In the dosimetric analysis, non-coplanar EF-IMRT was effective at reducing low-dose (approximately 10 Gy) exposure to the kidneys, thus maintaining target coverage and sparing other organs at risk, such as the small bowel, rectum, and bladder, compared with coplanar EF-IMRT. Renal function in all 10 patients who underwent EFRT, including coplanar EF-IMRT (with kidney irradiation), was low after treatment, and differed significantly from that of the eight patients who underwent WPRT (no kidney irradiation) 6 months after the first day of treatment (P = 0.005). In conclusion, non-coplanar EF-IMRT should be considered in patients with advanced cervical cancer, particularly in patients with a long life expectancy or with pre-existing renal dysfunction. PMID

  1. Clinical quality standards for radiotherapy

    PubMed Central

    2012-01-01

    Aim of the study The technological progress that is currently being witnessed in the areas of diagnostic imaging, treatment planning systems and therapeutic equipment has caused radiotherapy to become a high-tech and interdisciplinary domain involving staff of various backgrounds. This allows steady improvement in therapy results, but at the same time makes the diagnostic, imaging and therapeutic processes more complex and complicated, requiring every stage of those processes to be planned, organized, controlled and improved so as to assure high quality of services provided. The aim of this paper is to present clinical quality standards for radiotherapy as developed by the author. Material and methods In order to develop the quality standards, a comparative analysis was performed between European and Polish legal acts adopted in the period of 1980-2006 and the universal industrial ISO 9001:2008 standard, defining requirements for quality management systems, and relevant articles published in 1984-2009 were reviewed, including applicable guidelines and recommendations of American, international, European and Polish bodies, such as the American Association of Physicists in Medicine (AAPM), the European Society for Radiotherapy & Oncology (ESTRO), the International Atomic Energy Agency (IAEA), and the Organisation of European Cancer Institutes (OECI) on quality assurance and management in radiotherapy. Results As a result, 352 quality standards for radiotherapy were developed and categorized into the following three groups: 1 – organizational standards; 2 – physico-technical standards and 3 – clinical standards. Conclusion Proposed clinical quality standards for radiotherapy can be used by any institution using ionizing radiation for medical purposes. However, standards are of value only if they are implemented, reviewed, audited and improved, and if there is a clear mechanism in place to monitor and address failure to meet agreed standards. PMID:23788854

  2. Factors involved in the relaxation of female pig urethra evoked by electrical field stimulation.

    PubMed Central

    Werkström, V.; Persson, K.; Ny, L.; Bridgewater, M.; Brading, A. F.; Andersson, K. E.

    1995-01-01

    1. Non-adrenergic, non-cholinergic (NANC) relaxations induced by electrical field stimulation (EFS) were studied in pig isolated urethra. The mechanism for relaxation was characterized by measurement of cyclic nucleotides and by study of involvement of different subsets of voltage-operated calcium channels (VOCCs). 2. EFS evoked frequency-dependent and tetrodotoxin-sensitive relaxations in the presence of propranolol (1 microM), phentolamine (1 microM) and scopolamine (1 microM). At low frequencies (< 12 Hz), relaxations were rapid, whereas at high (> 12 Hz) frequencies distinct biphasic relaxations were evoked. The latter consisted of a rapidly developing first phase followed by a more long-lasting second phase. 3. Treatment with the NO-synthesis inhibitor NG-nitro-L-arginine (L-NOARG; 0.3 mM) inhibited relaxations at low frequencies of stimulation. At high frequencies (> 12 Hz) only the first relaxation phase was affected. 4. Measurement of cyclic nucleotides in preparations subjected to continuous nerve-stimulation, revealed an increase in guanosine 3':5'-cyclic monophosphate (cyclic GMP) levels from 1.3 +/- 0.3 to 3.0 +/- 0.4 pmol mg-1 protein (P < 0.01). In the presence of L-NOARG, there was a significant decrease in cyclic GMP content to control. However, there was no increase in cyclic GMP content in response to EFS. Levels of cyclic AMP remained unchanged following EFS. 5. Treatment with the N-type VOCC-inhibitor, omega-conotoxin GVIA (0.1 microM) reduced NO-dependent relaxations, the effect being most pronounced at low frequencies (1-4 Hz) of stimulation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8564225

  3. Consolidation Radiotherapy in Primary Central Nervous System Lymphomas: Impact on Outcome of Different Fields and Doses in Patients in Complete Remission After Upfront Chemotherapy

    SciTech Connect

    Ferreri, Andres Jose Maria; Verona, Chiara; Politi, Letterio Salvatore; Chiara, Anna; Perna, Lucia; Villa, Eugenio; Reni, Michele

    2011-05-01

    Purpose: Avoidance radiotherapy or reduction of irradiation doses in patients with primary central nervous system lymphoma (PCNSL) in complete remission (CR) after high-dose methotrexate (HD-MTX)-based chemotherapy has been proposed to minimize the neurotoxicity risk. Nevertheless, no study has focused on the survival impact of radiation parameters, as far as we know, and the optimal radiation schedule remains to be defined. Methods and Materials: The impact on outcome and neurologic performance of different radiation fields and doses was assessed in 33 patients with PCNSL who achieved CR after MTX-containing chemotherapy and were referred to consolidation whole-brain irradiation (WBRT). Patterns of relapse were analyzed on computed tomography-guided treatment planning, and neurologic impairment was assessed by the Mini Mental Status Examination. Results: At a median follow-up of 50 months, 21 patients are relapse-free (5-year failure-free survival [FFS], 51%). WBRT doses {>=}40 Gy were not associated with improved disease control in comparison with a WBRT dose of 30 to 36 Gy (relapse rate, 46% vs. 30%; 5-year FFS, 51% vs. 50%; p = 0.26). Disease control was not significantly different between patients irradiated to the tumor bed with 45 to 54 Gy or with 36 to 44 Gy, with a 5-year FFS of 35% and 44% (p = 0.43), respectively. Twenty patients are alive (5-year overall survival, 54%); WB and tumor bed doses did not have an impact on survival. Impairment as assessed by the Mini Mental Status Examination was significantly more common in patients treated with a WBRT dose {>=}40 Gy. Conclusion: Consolidation with WBRT 36 Gy is advisable in patients with PCNSL in CR after HD-MTX-based chemotherapy. Higher doses do not change the outcome and could increase the risk of neurotoxicity.

  4. Prospective Study of Alternating Chemoradiotherapy Consisting of Extended-Field Dynamic Conformational Radiotherapy and Systemic Chemotherapy Using 5-FU and Nedaplatin for Patients in High-Risk Group With Cervical Carcinoma

    SciTech Connect

    Kodaira, Takeshi Fuwa, Nobukazu; Nakanishi, Toru; Tachibana, Hiroyuki; Nakamura, Tatsuya; Tomita, Natsuo; Nakahara, Rie; Inokuchi, Haruo

    2009-01-01

    Purpose: To assess the efficacy of alternating chemoradiotherapy combined with extended-field conformal radiotherapy for patients with high-risk cervical cancer. Methods and Materials: Patients with previously untreated cervical cancer, with Stage III/IVA disease, or Stage IB/II with high-risk factor (primary tumor diameter {>=}50 mm or positive lymph node) were entered into this study. Three cycles of chemotherapy with 3,500 mg/m{sup 2} of 5-fluorouracil (5-FU) and nedaplatin (NDP) were accompanied with pelvic irradiation of 45.6-51.3 Gy in 24-27 fractions over 6 weeks. Prophylactic (36 Gy/20 fractions) or definitive (45-56 Gy) irradiation for para-aortic region was followed by pelvic irradiation. Results: Between 1998 and 2004, 40 patients were recruited for this protocol study. Eighteen patients from Phase I setting were registered. Twenty-two patients were treated with NDP of 140 mg/m{sup 2} (the recommended dose) in the Phase II segment. Twenty-five patients had T3 disease, and 25 patients had nodal disease including para-aortic involvement (n = 5). Overall/progression-free survival rates at 5 years were 78.8 and 66.5%, respectively. The median follow-up time was 61.8 months (25.5-106.7). Hematologic and gastrointestinal Grade 3 or more toxicities were relatively high rate (27.5-45%); however, they were well manageable. Two for bladder toxicity of Grade 3 were noted. Comparing the data from historical control group evaluated by magnetic resonance imaging, alternating chemoradiotherapy revealed a significant favorable factor for survival and disease recurrence in multivariate analysis (p < 0.05). Conclusion: Acquired results from our unique protocol for cervical cancer with high-risk factor were thought to be promising, considering that the majority of our cohort consisted of high-risk population.

  5. [Epoetin alfa in radiotherapy].

    PubMed

    Trodella, L; Balducci, M; Gambacorta, M A; Mantini, G

    1998-01-01

    Sixty per cent of oncologic patients need radiation therapy for cure or palliation. In fact, in most neoplastic diseases, a better local control positively impacts on disease-free survival and overall survival. The efficacy of radiotherapy depends on several factors: while some are tumor-related, others are host-related. Radiobiological phenomena are also important: ionizing radiation is responsible for cell damage (double rupture of DNA chains), mostly an indirect mechanism with the formation of free radicals. Their toxic action is enhanced by the oxygen partial pressure at the cellular level. A number of studies have confirmed that good tissue oxygenation is a function of a high hemoglobin level in the peripheral blood (Hb > or = 13 g/dL). Unfortunately, these values are rarely present in oncologic patients due to the disease-related toxicosis as well as to the therapy induced hematologic toxicity. The treatment of anemia is free of risk for the recent developments in technology which with gene cloning and the technique of recombinant DNA has allowed the production of human recombinant erythropoietin. Erythropoietin is produced by the interstitial cells of renal tubules in response to hypoxia. It prevents apoptosis and promotes erythroid proliferation and differentiation with consequent reticulocyte release and hemoglobin synthesis. It is not completely understood whether the efficacy of radiotherapy depends on hemoglobin values present at the start of irradiation (often less than 12-13 g/dL) or on the higher ones observed during and at the end of radiotherapy. Therefore, preventive systemic erythropoietin therapy in non anemic patients in terms of costs/benefits is at present non sustainable. To the contrary, in patients undergoing radiotherapy to extended fields or aggressive multimodal treatments, for the higher risk of anemia, the early use of this treatment can be hypothesized in case of initial anemia to improve therapy compliance and prevent negative

  6. SU-E-T-592: Relationship Between Dose of Distribution and Area of Segment Fields Among Different Intensity-Modulated Radiotherapy Planning in Cervix Cancer

    SciTech Connect

    Qiu, R; Wang, Y; Cao, Y; Zhang, R; Shang, K; Chi, Z

    2014-06-01

    Purpose: In premise of uninfluenced to dose distribution of tumor target and organ at risk(OAR) in cervical cancer,area of segment fields was changed to increase efficacy and optimize treatment method by designing different plan of intensity modulated radiotherapy(IMRT). Methods: 12 cases of cervical cancer were confirmed in pathology and treated with step and shoot IMRT. Dose of PTV was 50Gy/25fractions. Every patient was designed 9 treatment plans of IMRT by Pinnacle 8.0m planning system,each plan was used with 9 beams of uniform distribution and fixing incidence direction(200°,240°,280°,320°,0°,40°,80°,120°and 160°respectively),and designed for delivery on Elekta Synergy linear accelerator. All plans were optimized with the direct machine parameter optimization(DMPO) algorithm using the same set of optimization objectives. Number of maximum segment field was defined at 80 and minimum MU in each segment was 5MU,and minimal segment area was 2*1cm{sup 2},2*2cm{sup 2},3*3cm{sup 2},4*4cm{sup 2},5*5cm{sup 2},6*6cm{sup 2},7*7cm{sup 2},8*8cm{sup 2}and 9*9cm{sup 2},respectively.Coverage,homogeneity and conformity of PTV,sparing of OAR, MU and number of segment were compared. Results: In this group, mean volume of PTV was 916.8±228.7 cm{sup 3}. Compared with the area of minimal segment field increased from 2*1cm{sup 2} to 9*9 cm{sup 2},the number of mean MU was decreased from 1405±170 to 490±47 and the number of segment field was reduced from 76±4 to 39±7 respectively(p<0.05). When the limit of minimal segment area was increased from 2*1cm{sup 2} to 7*7 cm{sup 2},dose distribution of PTV,OAR,CI,HI and V{sub 2} {sub 3} were not different (p>0.05),but when the minimal segment area was 8*8 cm{sup 2} and 9*9 cm{sup 2},they were changed compared with 7*7 cm{sup 2} and below(p<0.05). Conclusion: The minimal segment field of IMRT plan designed by Pinnacle 8.0m planning system in cervical carcinoma should be enlarge reasonably and minimal segment area of 7*7 cm

  7. [Conformal radiotherapy: principles and classification].

    PubMed

    Rosenwald, J C; Gaboriaud, G; Pontvert, D

    1999-01-01

    'Conformal radiotherapy' is the name fixed by usage and given to a new form of radiotherapy resulting from the technological improvements observed during, the last ten years. While this terminology is now widely used, no precise definition can be found in the literature. Conformal radiotherapy refers to an approach in which the dose distribution is more closely 'conformed' or adapted to the actual shape of the target volume. However, the achievement of a consensus on a more specific definition is hampered by various difficulties, namely in characterizing the degree of 'conformality'. We have therefore suggested a classification scheme be established on the basis of the tools and the procedures actually used for all steps of the process, i.e., from prescription to treatment completion. Our classification consists of four levels: schematically, at level 0, there is no conformation (rectangular fields); at level 1, a simple conformation takes place, on the basis of conventional 2D imaging; at level 2, a 3D reconstruction of the structures is used for a more accurate conformation; and level 3 includes research and advanced dynamic techniques. We have used our personal experience, contacts with colleagues and data from the literature to analyze all the steps of the planning process, and to define the tools and procedures relevant to a given level. The corresponding tables have been discussed and approved at the European level within the Dynarad concerted action. It is proposed that the term 'conformal radiotherapy' be restricted to procedures where all steps are at least at level 2.

  8. Consumer Involvement in Evaluation and Quality Assurance Efforts: Review of Current Efforts in the Field of Developmental Disabilities.

    ERIC Educational Resources Information Center

    Ashline, Melissa

    This review of the professional and programmatic literature in the field of developmental disabilities focuses on ways in which individuals with developmental disabilities and their families are becoming increasingly involved in program evaluation and quality assurance efforts. Three major movements are having an impact on this activity: state and…

  9. Force field analysis: a model for promoting adolescents' involvement in their own health care.

    PubMed

    MacDuffie, Heather; DePoy, Elizabeth

    2004-07-01

    This article advances a three-step model for engaging adolescents in shaping their own health care supports and services through systems and social change that rely on principles of force field analysis. Consistent with health promotion values and trends for evidence-based practice, force field analysis provides a systematic and multilevel approach to problem assessment, resolution, and social change that is particularly appropriate for adolescents. The article reviews relevant literature, proposes the model, and concludes with a comparative illustration and critical analysis of the use of force field analysis to promote adolescent health. PMID:15228786

  10. Medical Applications: Proton Radiotherapy

    NASA Astrophysics Data System (ADS)

    Keppel, Cynthia

    2009-05-01

    Proton therapy is a highly advanced and precise form of radiation treatment for cancer. Due to the characteristic Bragg peak associated with ion energy deposition, proton therapy provides the radiation oncologist with an improved method of treatment localization within a patient, as compared with conventional radiation therapy using X-rays or electrons. Controlling disease and minimizing side effects are the twin aims of radiation treatment. Proton beams enhance the opportunity for both by facilitating maximal dose to tumor and minimal dose to surrounding tissue. In the United States, five proton radiotherapy centers currently treat cancer patients, with more in the construction phase. New facilities and enabling technologies abound. An overview of the treatment modality generally, as well as of the capabilities and research planned for the field and for the Hampton University Proton Therapy Institute in particular, will be presented.

  11. Volumetric-modulated arc therapy vs conventional fixed-field intensity-modulated radiotherapy in a whole-ventricular irradiation: A planning comparison study

    SciTech Connect

    Sakanaka, Katsuyuki; Mizowaki, Takashi; Sato, Sayaka; Ogura, Kengo; Hiraoka, Masahiro

    2013-07-01

    This study evaluated the dosimetric difference between volumetric-modulated arc therapy (VMAT) and conventional fixed-field intensity-modulated radiotherapy (cIMRT) in whole-ventricular irradiation. Computed tomography simulation data for 13 patients were acquired to create plans for VMAT and cIMRT. In both plans, the same median dose (100% = 24 Gy) was prescribed to the planning target volume (PTV), which comprised a tumor bed and whole ventricles. During optimization, doses to the normal brain and body were reduced, provided that the dose constraints of the target coverage were satisfied. The dose-volume indices of the PTV, normal brain, and body as well as monitor units were compared between the 2 techniques by using paired t-tests. The results showed no significant difference in the homogeneity index (0.064 vs 0.065; p = 0.824) of the PTV and conformation number (0.78 vs 0.77; p = 0.065) between the 2 techniques. In the normal brain and body, the dose-volume indices showed no significant difference between the 2 techniques, except for an increase in the volume receiving a low dose in VMAT; the absolute volume of the normal brain and body receiving 1 Gy of radiation significantly increased in VMAT by 1.6% and 8.3%, respectively, compared with that in cIMRT (1044 vs 1028 mL for the normal brain and 3079.2 vs 2823.3 mL for the body; p<0.001). The number of monitor units to deliver a 2.0-Gy fraction was significantly reduced in VMAT compared with that in cIMRT (354 vs 873, respectively; p<0.001). In conclusion, VMAT delivers IMRT to complex target volumes such as whole ventricles with fewer monitor units, while maintaining target coverage and conformal isodose distribution comparable to cIMRT; however, in addition to those characteristics, the fact that the volume of the normal brain and body receiving a low dose would increase in VMAT should be considered.

  12. Observation of near-field dipolar interactions involved in a metal nanoparticle chain waveguide.

    PubMed

    Apuzzo, A; Février, M; Salas-Montiel, R; Bruyant, A; Chelnokov, A; Lérondel, G; Dagens, B; Blaize, S

    2013-03-13

    We present near-field measurements of transverse plasmonic wave propagation in a chain of gold elliptical nanocylinders fed by a silicon refractive waveguide at optical telecommunication wavelengths. Eigenmode amplitude and phase imaging by apertureless scanning near-field optical microscopy allows us to measure the local out-of-plane electric field components and to reveal the exact nature of the excited localized surface plasmon resonances. Furthermore, the coupling mechanism between subsequent metal nanoparticles along the chain is experimentally analyzed by spatial Fourier transformation on the complex near-field cartography, giving a direct experimental proof of plasmonic Bloch mode propagation along array of localized surface plasmons. Our work demonstrates the possibility to characterize multielement plasmonic nanostructures coupled to a photonic waveguide with a spatial resolution of less than 30 nm. This experimental work constitutes a prerequisite for the development of integrated nanophotonic devices.

  13. Neural field simulator: two-dimensional spatio-temporal dynamics involving finite transmission speed

    PubMed Central

    Nichols, Eric J.; Hutt, Axel

    2015-01-01

    Neural Field models (NFM) play an important role in the understanding of neural population dynamics on a mesoscopic spatial and temporal scale. Their numerical simulation is an essential element in the analysis of their spatio-temporal dynamics. The simulation tool described in this work considers scalar spatially homogeneous neural fields taking into account a finite axonal transmission speed and synaptic temporal derivatives of first and second order. A text-based interface offers complete control of field parameters and several approaches are used to accelerate simulations. A graphical output utilizes video hardware acceleration to display running output with reduced computational hindrance compared to simulators that are exclusively software-based. Diverse applications of the tool demonstrate breather oscillations, static and dynamic Turing patterns and activity spreading with finite propagation speed. The simulator is open source to allow tailoring of code and this is presented with an extension use case. PMID:26539105

  14. [Radiotherapy for Thyroid Cancer].

    PubMed

    Jingu, Keiichi; Maruoka, Shin; Umezawa, Rei; Takahashi, Noriyoshi

    2015-06-01

    Radioactive 131I therapy for differentiated thyroid cancer has been used since the 1940s and is an established and effective treatment. In contrast, external beam radiotherapy (EBRT) was considered to be effective for achieving local control but not for prolonging survival. Although clinicians were hesitant to administer EBRT owing to the potential radiation-induced adverse effects of 2 dimensional (2D)-radiotherapy until 2000, it is expected that adverse effects will be reduced and treatment efficacy improved through the introduction of more advanced techniques for delivering radiation (eg, 3D-radiotherapy and intensity modulated radiotherapy [IMRT]). The prognosis of undifferentiated thyroid cancer is known to be extremely bad, although in very rare cases, multimodality therapy (total or subtotal resection, chemotherapy, and radiotherapy) has allowed long-term survival. Here, we report the preliminary results of using hypofractionated radiotherapy for undifferentiated thyroid cancer in our institution. PMID:26199238

  15. The Impact of Field Trips and Family Involvement on Mental Models of the Desert Environment

    ERIC Educational Resources Information Center

    Judson, Eugene

    2011-01-01

    This study examined the mental models of the desert environment held by fourth- and seventh-grade students in the USA and whether those mental models could be affected by: (1) classroom field trips to a desert riparian preserve, and (2) interaction with family members at the same preserve. Results generally indicated that students in this study…

  16. Radiotherapy of Cervical Cancer.

    PubMed

    Vordermark, Dirk

    2016-01-01

    Curative-intent radical radiotherapy of cervical cancer consists of external-beam radiotherapy, brachytherapy, and concomitant chemotherapy with cisplatin. For each element, new developments aim to improve tumor control rates or treatment tolerance. Intensity-modulated radiotherapy (IMRT) has been shown to reduce gastrointestinal toxicity and can be used to selectively increase the radiotherapy dose. Individualized, image-guided brachytherapy enables better adaptation of high-dose volumes to the tumor extension. Intensification of concomitant or sequential systemic therapy is under evaluation. PMID:27614991

  17. Technical advances in external radiotherapy for hepatocellular carcinoma

    PubMed Central

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-01-01

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy. PMID:27621577

  18. Technical advances in external radiotherapy for hepatocellular carcinoma

    PubMed Central

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-01-01

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy.

  19. Technical advances in external radiotherapy for hepatocellular carcinoma.

    PubMed

    Park, Shin-Hyung; Kim, Jae-Chul; Kang, Min Kyu

    2016-08-28

    Radiotherapy techniques have substantially improved in the last two decades. After the introduction of 3-dimensional conformal radiotherapy, radiotherapy has been increasingly used for the treatment of hepatocellular carcinoma (HCC). Currently, more advanced techniques, including intensity-modulated radiotherapy (IMRT), stereotactic ablative body radiotherapy (SABR), and charged particle therapy, are used for the treatment of HCC. IMRT can escalate the tumor dose while sparing the normal tissue even though the tumor is large or located near critical organs. SABR can deliver a very high radiation dose to small HCCs in a few fractions, leading to high local control rates of 84%-100%. Various advanced imaging modalities are used for radiotherapy planning and delivery to improve the precision of radiotherapy. These advanced techniques enable the delivery of high dose radiotherapy for early to advanced HCCs without increasing the radiation-induced toxicities. However, as there have been no effective tools for the prediction of the response to radiotherapy or recurrences within or outside the radiation field, future studies should focus on selecting the patients who will benefit from radiotherapy. PMID:27621577

  20. Radiotherapy Treatment Planning for Testicular Seminoma

    SciTech Connect

    Wilder, Richard B.; Buyyounouski, Mark K.; Efstathiou, Jason A.; Beard, Clair J.

    2012-07-15

    Virtually all patients with Stage I testicular seminoma are cured regardless of postorchiectomy management. For patients treated with adjuvant radiotherapy, late toxicity is a major concern. However, toxicity may be limited by radiotherapy techniques that minimize radiation exposure of healthy normal tissues. This article is an evidence-based review that provides radiotherapy treatment planning recommendations for testicular seminoma. The minority of Stage I patients who choose adjuvant treatment over surveillance may be considered for (1) para-aortic irradiation to 20 Gy in 10 fractions, or (2) carboplatin chemotherapy consisting of area under the curve, AUC = 7 Multiplication-Sign 1-2 cycles. Two-dimensional radiotherapy based on bony anatomy is a simple and effective treatment for Stage IIA or IIB testicular seminoma. Centers with expertise in vascular and nodal anatomy may consider use of anteroposterior-posteroanterior fields based on three-dimensional conformal radiotherapy instead. For modified dog-leg fields delivering 20 Gy in 10 fractions, clinical studies support placement of the inferior border at the top of the acetabulum. Clinical and nodal mapping studies support placement of the superior border of all radiotherapy fields at the top of the T12 vertebral body. For Stage IIA and IIB patients, an anteroposterior-posteroanterior boost is then delivered to the adenopathy with a 2-cm margin to the block edge. The boost dose consists of 10 Gy in 5 fractions for Stage IIA and 16 Gy in 8 fractions for Stage IIB. Alternatively, bleomycin, etoposide, and cisplatin chemotherapy for 3 cycles or etoposide and cisplatin chemotherapy for 4 cycles may be delivered to Stage IIA or IIB patients (e.g., if they have a horseshoe kidney, inflammatory bowel disease, or a history of radiotherapy).

  1. Planning National Radiotherapy Services

    PubMed Central

    Rosenblatt, Eduardo

    2014-01-01

    Countries, states, and island nations often need forward planning of their radiotherapy services driven by different motives. Countries without radiotherapy services sponsor patients to receive radiotherapy abroad. They often engage professionals for a feasibility study in order to establish whether it would be more cost-beneficial to establish a radiotherapy facility. Countries where radiotherapy services have developed without any central planning, find themselves in situations where many of the available centers are private and thus inaccessible for a majority of patients with limited resources. Government may decide to plan ahead when a significant exodus of cancer patients travel to another country for treatment, thus exposing the failure of the country to provide this medical service for its citizens. In developed countries, the trigger has been the existence of highly visible waiting lists for radiotherapy revealing a shortage of radiotherapy equipment. This paper suggests that there should be a systematic and comprehensive process of long-term planning of radiotherapy services at the national level, taking into account the regulatory infrastructure for radiation protection, planning of centers, equipment, staff, education programs, quality assurance, and sustainability aspects. Realistic budgetary and cost considerations must also be part of the project proposal or business plan. PMID:25505730

  2. Field detection capability of immunochemical assays during criminal investigations involving the use of TNT.

    PubMed

    Romolo, Francesco Saverio; Ferri, Elida; Mirasoli, Mara; D'Elia, Marcello; Ripani, Luigi; Peluso, Giuseppe; Risoluti, Roberta; Maiolini, Elisabetta; Girotti, Stefano

    2015-01-01

    The capability to collect timely information about the substances employed on-site at a crime scene is of fundamental importance during scientific investigations in crimes involving the use of explosives. TNT (2,4,6-trinitrotoluene) is one of the most employed explosives in the 20th century. Despite the growing use of improvised explosives, criminal use and access to TNT is not expected to decrease. Immunoassays are simple and selective analytical tests able to detect molecules and their immunoreactions can occur in portable formats for use on-site. This work demonstrates the application of three immunochemical assays capable of detecting TNT to typical forensic samples from experimental tests: an indirect competitive ELISA with chemiluminescent detection (CL-ELISA), a colorimetric lateral flow immunoassay (LFIA) based on colloidal gold nanoparticles label, and a chemiluminescent-LFIA (CL-LFIA). Under optimised working conditions, the LOD of the colorimetric LFIA and CL-LFIA were 1 μg mL(-1) and 0.05 μg mL(-1), respectively. The total analysis time for LFIAs was 15 min. ELISA proved to be a very effective laboratory approach, showing very good sensitivity (LOD of 0.4 ng mL(-1)) and good reproducibility (CV value about 7%). Samples tested included various materials involved in controlled explosions of improvised explosive devices (IEDs), as well as hand swabs collected after TNT handling tests. In the first group of tests, targets covered with six different materials (metal, plastic, cardboard, carpet fabric, wood and adhesive tape) were fixed on top of wooden poles (180 cm high). Samples of soil from the explosion area and different materials covering the targets were collected after each explosion and analysed. In the second group of tests, hand swabs were collected with and without hand washing after volunteers simulated the manipulation of small charges of TNT. The small amount of solution required for each assay allows for several analyses. Results of

  3. Molecular change signal-to-noise criteria for interpreting experiments involving exposure of biological systems to weakly interacting electromagnetic fields.

    PubMed

    Vaughan, Timothy E; Weaver, James C

    2005-05-01

    We describe an approach to aiding the design and interpretation of experiments involving biological effects of weakly interacting electromagnetic fields that range from steady (dc) to microwave frequencies. We propose that if known biophysical mechanisms cannot account for an inferred, underlying molecular change signal-to-noise ratio, (S/N)gen, of a observed result, then there are two interpretation choices: (1) there is an unknown biophysical mechanism with stronger coupling between the field exposure and the ongoing biochemical process, or (2) the experiment is responding to something other than the field exposure. Our approach is based on classical detection theory, the recognition that weakly interacting fields cannot break chemical bonds, and the consequence that such fields can only alter rates of ongoing, metabolically driven biochemical reactions, and transport processes. The approach includes both fundamental chemical noise (molecular shot noise) and other sources of competing chemical change, to be compared quantitatively to the field induced change for the basic case that the field alters a single step in a biochemical network. Consistent with pharmacology and toxicology, we estimate the molecular dose (mass associated with field induced molecular change per mass tissue) resulting from illustrative low frequency field exposures for the biophysical mechanism of voltage gated channels. For perspective, we then consider electric field-mediated delivery of small molecules across human skin and into individual cells. Specifically, we consider the examples of iontophoretic and electroporative delivery of fentanyl through skin and electroporative delivery of bleomycin into individual cells. The total delivered amount corresponds to a molecular change signal and the delivery variability corresponds to generalized chemical noise. Viewed broadly, biological effects due to nonionizing fields may include animal navigation, medical applications, and environmental

  4. Role of FDG-PET in the Definition of Involved-Field Radiation Therapy and Management for Pediatric Hodgkin's Lymphoma

    SciTech Connect

    Lang Robertson, Virginia; Anderson, Cynthia S.; Keller, Frank G.; Halkar, Raghuveer; Goodman, Michael; Marcus, Robert B.; Esiashvili, Natia

    2011-06-01

    Purpose: To evaluate positron emission tomography-computed tomography (PET-CT) influences in involved-field radiation therapy (IFRT) field design in pediatric Hodgkin's lymphoma (HL). Materials and Methods: From June 2003 to February 2008, 30 pediatric HL patients were treated at Children's Healthcare of Atlanta (CHOA) and Emory University Department of Radiation Oncology with both chemotherapy and IFRT. Diagnostic contrast-enhanced CT and PET-CT were coregistered using image fusion software. Both were reviewed for all potential sites of involvement and correlated to determine concordance and discordance. They were used in IFRT planning to determine the influence of PET-CT on target volumes and field design. Results: There were 546 regions analyzed by both PET and CT modalities. Image sets were concordant in 468 regions and discordant in 78, yielding 86% concordance overall. Analysis by weighted {kappa} statistic showed 'intermediate to good' fit overall and for nodal sites, but 'poor' agreement for extranodal sites. If discordant, a site was most likely PET+/CT-. Integration of PET information caused a change in staging in 15 (50%) patients, 7 upstaged and 8 downstaged. The IFRT volumes were adjusted on the basis of initial PET-CT finding in 21 (70%) patients, with 32 sites added and 15 excluded. There were four relapses, only one outside IFRT fields, but all were successfully salvaged. Conclusion: PET-CT represents an important tool in the management of pediatric patients with HL and has a substantial influence on both initial staging and radiation treatment target definition and field design.

  5. Identification of gonadal soma-derived factor involvement in Monopterus albus (protogynous rice field eel) sex change.

    PubMed

    Zhu, Yefei; Wang, Chunlei; Chen, Xiaowu; Guan, Guijun

    2016-07-01

    We studied molecular events and potential mechanisms underlying the process of female-to-male sex transformation in the rice field eel (Monopterus albus), a protogynous hermaphrodite fish in which the gonad is initially a female ovary and transforms into male testes. We cloned and identified a novel gonadal soma derived factor (GSDF), which encodes a member of the transforming growth factor-beta superfamily. gsdf expression was measured in gonads of female, intersex and male with reverse transcription-PCR and gsdf's role in sex transformation was studied with qPCR, histological analysis and dual-color in situ hybridization assays and compared to other sex-related genes. gsdf was correlated to Sertoli cell differentiation, indicating involvement in testicular differentiation and sex transformation from female to male in this species. A unique expression pattern reveals a potential role of gsdf essential for the sex transformation of rice field eels. PMID:27230579

  6. [Elective radiotherapy of the regional lymph node areas in breast cancer].

    PubMed

    Poortmans, P-M-P

    2006-11-01

    In breast cancer patients, the incidence of involvement of the regional lymph nodes and the risk for developing a locoregional recurrence are highly influenced by several prognostic factors. A meta-analysis of the EBCTCG showed a reduction of about 70% of the locoregional recurrence rate with radiotherapy for all patients, independent of age, characteristics of the tumour or the administration of systemic treatment. At the same time, this meta-analysis confirmed that radiotherapy can lead to an increased risk for developing contralateral breast cancer and to an increase in the risk of non-breast cancer related mortality, mainly due to cardiac and pulmonary toxicity. Because of this, the net effect of regional radiotherapy will be strongly influenced by the individual risk factors of the patients and by the quality of the technical aspects of the radiotherapy. The thin line between the benefits of elective regional lymph node irradiation and the possible late toxicity for patients with early stage breast cancer is currently the subject of several prospective randomised trials, the results of which will only become available in several years. Moreover, recent developments in the field of novel prognostic factors will open completely new ways to be explored, which might give us new tools for estimating the individual benefit/risk ratio for every single patient. PMID:16962355

  7. Complications from radiotherapy.

    PubMed

    Dhermain, Frédéric; Barani, Igor J

    2016-01-01

    Radiotherapy (RT) of the brain is associated with significant stigma in the neuro-oncology community. This is primarily because of the potentially severe complications with which it may be associated. These complications, especially in subacute and latent settings, are often unpredictable, potentially progressive, and irreversible. The onset of complications may start from the first fraction of 2 Gy, continuing over several months after end of RT with persistent drowsiness and apathy. It may also extend over many years with progressive onset of neurocognitive impairments such as memory decline, and diminished focus/attention. For long-term survivors, such as young patients irradiated for a favorable low-grade glioma, quality of life can be seriously impacted by RT. It is essential, as in the pediatric field, to propose patient-specific regimens from the very outset of therapy. The use of molecular biomarkers to better predict survival, control of comorbidities along with judicious use of medications such as steroids and antiepileptics, improved targeting with the help of modern imaging and RT techniques, modulation of the dose, and fractionation aimed at limiting integral dose to the healthy brain all have the potential to minimize treatment-related complications while maintaining the therapeutic efficacy for which RT is known. Sparing "radiosensitive" areas such as hippocampi could have a modest but measurable impact with regard to cognitive preservation, an effect that can possibly be enhanced when used in conjunction with memantine and/or donepezil. PMID:26948357

  8. Recruitment in Radiotherapy

    ERIC Educational Resources Information Center

    Deeley, T. J.; And Others

    1976-01-01

    The Faculty Board of Radiotherapy and Oncology of the Royal College of Radiobiologists surveyed the factors thought to influence recruitment into the specialty. Possible factors listed in replies of 36 questionnaires are offered. (LBH)

  9. Molecular Imaging and Radiotherapy: Theranostics for Personalized Patient Management

    PubMed Central

    Velikyan, Irina

    2012-01-01

    This theme issue presents current achievements in the development of radioactive agents, pre-clinical and clinical molecular imaging, and radiotherapy in the context of theranostics in the field of oncology. PMID:22768022

  10. [Identification of predictive biomarkers to radiotherapy outcome through proteomics approaches].

    PubMed

    Lacombe, J; Mange, A; Azria, D; Solassol, J

    2013-02-01

    The success of radiotherapy mainly depends on the total administered dose. This dose must be homogenously delivered onto the tumor and must preserve the surrounding healthy tissue. However, several patients are hypersensitive to ionizing radiations and may develop important radiation-induced early and late side effects. The prediction of these side effects remains currently impossible, involving to limit the given dose with the risk to decrease the therapeutic benefit for patients. Therefore, one of the major challenges in radiobiology is to accurately predict tumour radioresistance and to determine normal tissue radiosensitivity to tailor treatment. Several studies have been carried out and different predictive assays have been described in this field. However, none of them showed significant results for clinical use. For several years, many technological advances in proteomic fields have been performed in order to identify new biomarkers. After a brief description of the main characteristics of tumor radioresistance and normal tissue radiosensitivity, we will develop in this review the different approaches proposed so far to identify predictive tools of radiotherapy outcome. We will then analyze in detail how proteomic studies can improve the understanding of mechanisms associated with radiosensitivity of healthy tissue and radioresistance of tumor cells and how they could highlight new predictive biomarkers in radiobiology.

  11. Effect of topical vasoconstrictor exposure upon tumoricidal radiotherapy.

    PubMed

    Fahl, William E

    2014-08-15

    Topical application of the alpha adrenergic vasoconstrictors norepinephrine, phenylephrine or epinephrine to skin or mucosa in alcohol:water-based delivery vehicles minutes before irradiation has recently been shown to protect skin and mucosa cells against radiotherapy-induced toxicities in both preclinical and clinical studies. The protective mechanism is thought to involve transient skin or mucosal vasoconstriction with secondary, transient hypoxia and associated radioprotection. Regarding possible protection of tumor cell nests within the radiotherapy field, the endothelial cell-abnormal stroma constructed blood vessels generally found in human tumors commonly lack adrenergic receptor-containing smooth muscle cells that are required to achieve vasoconstriction. Consistent with this, we show here that topical application of norepinephrine or phenylephrine to broken or intact skin over human Cal-27 or A-431 xeonograft, or mouse solid L1210 allograft tumors growing subcutaneously in nude mice, showed no effect upon radiation-induced tumor growth inhibition. Although vasoconstrictor-induced nude mouse skin blanch was seen minutes after topical application of 600 mM norepinephrine, no blanching was seen within the A-431 xenograft tumors. Radiation dermatitis was severe 11 days post-irradiation (2 × 13.8 Gy) in the irradiated field containing xenograft tumors in mice that received topical delivery vehicle, but was absent in mice that received topical norepinephrine. Topical vasoconstrictor-conferred prevention of radiation dermatitis without discernible radioprotection of three histologically diverse xenograft or allograft tumors supports further development of the topical vasoconstrictor therapeutic strategy in humans.

  12. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2014-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  13. A systematic review of antiproton radiotherapy

    NASA Astrophysics Data System (ADS)

    Bittner, Martin-Immanuel; Grosu, Anca-Ligia; Wiedenmann, Nicole; Wilkens, Jan

    2013-01-01

    Antiprotons have been proposed as possible particles for radiotherapy; over the past years, the renewed interest in the potential biomedical relevance led to an increased research activity. It is the aim of this review to deliver a comprehensive overview regarding the evidence accumulated so far, analysing the background and depicting the current status of antiprotons in radiotherapy. A literature search has been conducted, including major scientific and commercial databases. All articles and a number of relevant conference abstracts published in the respective field have been included in this systematic review. The physical basis of antiproton radiotherapy is complex; however, the characterisation of the energy deposition profile supports its potential use in radiotherapy. Also the dosimetry improved considerably over the past few years. Regarding the biological properties, data on the effects on cells are presented; however, definite conclusions regarding the relative biological effectiveness cannot be made at the moment and radiobiological evidence of enhanced effectiveness remains scarce. In addition, there is new evidence supporting the potential imaging properties, for example for online dose verification. Clinical settings which might profit from the use of antiprotons have been further tracked. Judging from the evidence available so far, clinical constellations requiring optimal sparing in the entrance region of the beam and re-irradiations might profit most from antiproton radiotherapy. While several open questions remain to be answered, first steps towards a thorough characterisation of this interesting modality have been made.

  14. Rapid field identification of subjects involved in firearm-related crimes based on electroanalysis coupled with advanced chemometric data treatment.

    PubMed

    Cetó, Xavier; O'Mahony, Aoife M; Samek, Izabela A; Windmiller, Joshua R; del Valle, Manel; Wang, Joseph

    2012-12-01

    We demonstrate a novel system for the detection and discrimination of varying levels of exposure to gunshot residue from subjects in various control scenarios. Our aim is to address the key challenge of minimizing the false positive identification of individuals suspected of discharging a firearm. The chemometric treatment of voltammetric data from different controls using Canonical Variate Analysis (CVA) provides several distinct clusters for each scenario examined. Multiple samples were taken from subjects in controlled tests such as secondary contact with gunshot residue (GSR), loading a firearm, and postdischarge of a firearm. These controls were examined at both bare carbon and gold-modified screen-printed electrodes using different sampling methods: the 'swipe' method with integrated sampling and electroanalysis and a more traditional acid-assisted q-tip swabbing method. The electroanalytical fingerprint of each sample was examined using square-wave voltammetry; the resulting data were preprocessed with Fast Fourier Transform (FFT), followed by CVA treatment. High levels of discrimination were thus achieved in each case over 3 classes of samples (reflecting different levels of involvement), achieving maximum accuracy, sensitivity, and specificity values of 100% employing the leave-one-out validation method. Further validation with the 'jack-knife' technique was performed, and the resulting values were in good agreement with the former method. Additionally, samples from subjects in daily contact with relevant metallic constituents were analyzed to assess possible false positives. This system may serve as a potential method for a portable, field-deployable system aimed at rapidly identifying a subject who has loaded or discharged a firearm to verify involvement in a crime, hence providing law enforcement personnel with an invaluable forensic tool in the field.

  15. Radiotherapy for stage I seminoma of the testis: Organ equivalent dose to partially in-field structures and second cancer risk estimates on the basis of a mechanistic, bell-shaped, and plateau model

    SciTech Connect

    Mazonakis, Michalis Damilakis, John; Varveris, Charalambos; Lyraraki, Efrossyni

    2015-11-15

    Purpose: The aim of the current study was to (a) calculate the organ equivalent dose (OED) and (b) estimate the associated second cancer risk to partially in-field critical structures from adjuvant radiotherapy for stage I seminoma of the testis on the basis of three different nonlinear risk models. Methods: Three-dimensional plans were created for twelve patients who underwent a treatment planning computed tomography of the abdomen. The plans for irradiation of seminoma consisted of para-aortic anteroposterior and posteroanterior fields giving 20 Gy to the target site with 6 MV photons. The OED of stomach, colon, liver, pancreas, and kidneys, that were partially included in the treatment volume, was calculated using differential dose–volume histograms. The mechanistic, bell-shaped, and plateau models were employed for these calculations provided that organ-specific parameters were available for the subsequent assessment of the excess absolute risk (EAR) for second cancer development. The estimated organ-specific lifetime risks were compared with the respective nominal intrinsic probabilities for cancer induction. Results: The mean OED, which was calculated from the patients’ treatment plans, varied from 0.54 to 6.61 Gy by the partially in-field organ of interest and the model used for dosimetric calculations. The difference between the OED of liver derived from the mechanistic model with those from the bell-shaped and plateau models was less than 1.8%. An even smaller deviation of 1.0% was observed for colon. For the rest organs of interest, the differences between the OED values obtained by the examined models varied from 8.6% to 50.0%. The EAR for stomach, colon, liver, pancreas, and kidney cancer induction at an age of 70 yr because of treatment of a typical 39-yr-old individual was up to 4.24, 11.39, 0.91, 3.04, and 0.14 per 10 000 persons-yr, respectively. Patient’s irradiation was found to elevate the lifetime intrinsic risks by 8.3%–63.0% depending

  16. [Radiotherapy of larynx cancers].

    PubMed

    Pointreau, Y; Lafond, C; Legouté, F; Trémolières, P; Servagi-Vernat, S; Giraud, P; Maingon, P; Calais, G; Lapeyre, M

    2016-09-01

    Intensity-modulated radiotherapy is the gold standard in the treatment of larynx cancers (except T1 glottic tumour). Early T1 and T2 tumours may be treated by exclusive radiation or surgery. For tumours requiring total laryngectomy (T2 or T3), induction chemotherapy followed by exclusive radiotherapy or concurrent chemoradiotherapy is possible. For T4 tumour, surgery must be proposed. The treatment of lymph nodes is based on the initial treatment of the primary tumour. In non-surgical procedure, in case of sequential radiotherapy, the curative dose is 70Gy and the prophylactic dose is 50Gy. An integrated simultaneous boost radiotherapy is allowed (70Gy in 2Gy per fraction and 56Gy in 1.8Gy per fraction or 70Gy in 2.12Gy per fraction). Postoperatively, radiotherapy is used in locally advanced cancer with dose levels based on pathologic criteria (66Gy for R1 resection, 50 to 54Gy for complete resection). Volume delineation was based on guidelines. PMID:27521037

  17. Reconstruction of organ dose for external radiotherapy patients in retrospective epidemiologic studies

    NASA Astrophysics Data System (ADS)

    Lee, Choonik; Jung, Jae Won; Pelletier, Christopher; Pyakuryal, Anil; Lamart, Stephanie; Kim, Jong Oh; Lee, Choonsik

    2015-03-01

    Organ dose estimation for retrospective epidemiological studies of late effects in radiotherapy patients involves two challenges: radiological images to represent patient anatomy are not usually available for patient cohorts who were treated years ago, and efficient dose reconstruction methods for large-scale patient cohorts are not well established. In the current study, we developed methods to reconstruct organ doses for radiotherapy patients by using a series of computational human phantoms coupled with a commercial treatment planning system (TPS) and a radiotherapy-dedicated Monte Carlo transport code, and performed illustrative dose calculations. First, we developed methods to convert the anatomy and organ contours of the pediatric and adult hybrid computational phantom series to Digital Imaging and Communications in Medicine (DICOM)-image and DICOM-structure files, respectively. The resulting DICOM files were imported to a commercial TPS for simulating radiotherapy and dose calculation for in-field organs. The conversion process was validated by comparing electron densities relative to water and organ volumes between the hybrid phantoms and the DICOM files imported in TPS, which showed agreements within 0.1 and 2%, respectively. Second, we developed a procedure to transfer DICOM-RT files generated from the TPS directly to a Monte Carlo transport code, x-ray Voxel Monte Carlo (XVMC) for more accurate dose calculations. Third, to illustrate the performance of the established methods, we simulated a whole brain treatment for the 10 year-old male phantom and a prostate treatment for the adult male phantom. Radiation doses to selected organs were calculated using the TPS and XVMC, and compared to each other. Organ average doses from the two methods matched within 7%, whereas maximum and minimum point doses differed up to 45%. The dosimetry methods and procedures established in this study will be useful for the reconstruction of organ dose to support

  18. [Prostate cancer external beam radiotherapy].

    PubMed

    de Crevoisier, R; Pommier, P; Latorzeff, I; Chapet, O; Chauvet, B; Hennequin, C

    2016-09-01

    The prostate external beam radiotherapy techniques are described, when irradiating the prostate or after prostatectomy, with and without pelvic lymph nodes. The following parts are presented: indications of radiotherapy, total dose and fractionation, planning CT image acquisition, volume of interest delineation (target volumes and organs at risk) and margins, Intensity modulated radiotherapy planning and corresponding dose-volume constraints, and finally Image guided radiotherapy. PMID:27516051

  19. Radiotherapy of inoperable lung cancer

    SciTech Connect

    Namer, M.; Lalanne, C.M.; Boublil, J.L.; Hery, M.; Chauvel, P.; Verschoore, J.; Aubanel, J.M.; Bruneton, J.N.

    1980-08-01

    Evaluation of loco-regional results obtained by radiotherapy for 31 patients with inoperable epidermoid lung cancer revealed objective remission (over 50%) in only 25% of patients. These results emphasize the limited effectiveness of radiotherapy in such cases and point out the need for increased research in radiotherapy techniques if survival rates are to be improved.

  20. [Radiotherapy for brain metastases].

    PubMed

    Latorzeff, I; Antoni, D; Gaudaire-Josset, S; Feuvret, L; Tallet-Richard, A; Truc, G; Noël, G

    2016-09-01

    Radiotherapy for brain metastases has become more multifaceted. Indeed, with the improvement of the patient's life expectancy, side effects must be undeniably avoided and the retreatments or multiple treatments are common. The cognitive side effects should be warned and the most modern techniques of radiation therapy are used regularly to reach this goal. The new classifications of patients with brain metastases help guiding treatment more appropriately. Stereotactic radiotherapy has supplanted whole brain radiation therapy both for patients with metastases in place and for those who underwent surgery. Hippocampus protection is possible with intensity-modulated radiotherapy. Its relevance in terms of cognitive functioning should be more clearly demonstrated but the requirement, for using it, is increasingly strong. While addressing patients in palliative phase, the treatment of brain metastases is one of the localisations where technical thinking is the most challenging. PMID:27523410

  1. [Radiotherapy in Europe].

    PubMed

    Verheij, M; Slotman, B J

    2016-01-01

    Radiotherapy plays an important part in the curing of cancer patients and is an effective treatment for tumour-related symptoms. However, in many countries the level of access to this treatment modality is unacceptably low due to shortage of infrastructure, modern apparatus and trained staff. In Europe it is mainly the Eastern European countries that are behind in the provision of and accessibility to radiotherapy. Worldwide investment to narrow the gap would put an end to these undesirable differences. In addition, these investments would deliver economic benefits, especially in low-to-middle income countries. In this article, on the basis of a number of recently published reports, we discuss the differences that exist in the geographical spread of radiotherapy departments and the availability of apparatus within Europe. In conclusion we also take a short look at the Dutch situation. PMID:27334085

  2. Use of a Conventional Low Neck Field (LNF) and Intensity-Modulated Radiotherapy (IMRT): No Clinical Detriment of IMRT to an Anterior LNF During the Treatment of Head-and Neck-Cancer

    SciTech Connect

    Turaka, Aruna; Li Tianyu; Nicolaou, Nicos; Lango, Miriam N.; Burtness, Barbara; Horwitz, Eric M.; Ridge, John A.; Feigenberg, Steven J.

    2011-01-01

    Purpose: To determine differences in clinical outcomes using intensity-modulated radiotherapy (IMRT) or a standard low neck field (LNF) to treat low neck. Methods and Materials: This is a retrospective, single-institution study. Ninety-one patients with squamous cell carcinoma of the head and neck were treated with curative intent. According to physician preference, some patients were treated with LNF (Planning Target Volume 3) field using a single anterior photon field matched to the IMRT field. Field junctions were not feathered. The endpoints were time to failure and use of a percutaneous endoscopic gastrostomy (PEG) tube (as a surrogate of laryngeal edema causing aspiration), and analysis was done with {chi}{sup 2} and log-rank tests. Results: Median follow-up was 21 months (range, 2-89 months). Median age was 60 years. Thirty-seven patients (41%) were treated with LNF, 84% were Stage III or IV. A PEG tube was required in 30%, as opposed to 33% without the use of LNF. Node 2 or 3 neck disease was treated more commonly without LNF (38% vs. 24%, p = 0.009). Failures occurred in 12 patients (13%). Only 1 patient treated with LNF failed regionally, 4.5 cm above the match line. The 3-year disease-free survival rate was 87% and 79% with LNF and without LNF, respectively (p = 0.2), and the 3-year LR failure rate was 4% and 21%, respectively (p = 0.04). Conclusions: Using LNF to treat the low neck did not increase the risk of regional failure 'in early T and early N diseases' or decrease PEG tube requirements.

  3. Radiotherapy induced hip joint avascular necrosis—Two cases report

    PubMed Central

    Michalecki, Łukasz; Gabryś, Dorota; Kulik, Roland; Wydmański, Jerzy; Trela, Krystyna

    2011-01-01

    Background Avascular necrosis (AVN) refers to the death of osteocytes and osteoblasts. Sites such as the femoral head, the head of the humerus and the mandibula with restricted access to local blood supply are particularly vulnerable to osteonecrosis. A combination of several factors is responsible for ischaemia and is associated with AVN: corticosteroids, alcohol abuse, Cushing's syndrome, SLE, systemic vasculitis, RA, scleroderma, haemoglobinopathies, radiotherapy. Management is based on proper diagnosis and treatment – conservative, pharmacological or surgical. Radiotherapy has become an integral part of the therapeutic programme of cancer patients. However, early and late after-effects of irradiation still constitute a significant issue in clinical practice. Aim The aim of this report is to present two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic irradiation and draw physicians’ attention to that clinical problem which continues to be underestimated. Materials and methods This report documents two cases of acetabular protrusion and femoral head deformities after a therapeutic pelvic radiation. Results Avascular necrosis (AVN) constitutes a severe and challenging long-term complication in radiation oncology. Conclusion It is necessary to take into account bone structures among organ at risk (OAR) involved in irradiation fields. The detailed analysis of the dose distribution and the use of collimators allow to decrease the total dose to OAR. An adequate management, early diagnosis and prompt, proper treatment may protect patients from long-term morbidities. PMID:24376980

  4. HDAC up-regulation in early colon field carcinogenesis is involved in cell tumorigenicity through regulation of chromatin structure.

    PubMed

    Stypula-Cyrus, Yolanda; Damania, Dhwanil; Kunte, Dhananjay P; Cruz, Mart Dela; Subramanian, Hariharan; Roy, Hemant K; Backman, Vadim

    2013-01-01

    Normal cell function is dependent on the proper maintenance of chromatin structure. Regulation of chromatin structure is controlled by histone modifications that directly influence chromatin architecture and genome function. Specifically, the histone deacetylase (HDAC) family of proteins modulate chromatin compaction and are commonly dysregulated in many tumors, including colorectal cancer (CRC). However, the role of HDAC proteins in early colorectal carcinogenesis has not been previously reported. We found HDAC1, HDAC2, HDAC3, HDAC5, and HDAC7 all to be up-regulated in the field of human CRC. Furthermore, we observed that HDAC2 up-regulation is one of the earliest events in CRC carcinogenesis and observed this in human field carcinogenesis, the azoxymethane-treated rat model, and in more aggressive colon cancer cell lines. The universality of HDAC2 up-regulation suggests that HDAC2 up-regulation is a novel and important early event in CRC, which may serve as a biomarker. HDAC inhibitors (HDACIs) interfere with tumorigenic HDAC activity; however, the precise mechanisms involved in this process remain to be elucidated. We confirmed that HDAC inhibition by valproic acid (VPA) targeted the more aggressive cell line. Using nuclease digestion assays and transmission electron microscopy imaging, we observed that VPA treatment induced greater changes in chromatin structure in the more aggressive cell line. Furthermore, we used the novel imaging technique partial wave spectroscopy (PWS) to quantify nanoscale alterations in chromatin. We noted that the PWS results are consistent with the biological assays, indicating a greater effect of VPA treatment in the more aggressive cell type. Together, these results demonstrate the importance of HDAC activity in early carcinogenic events and the unique role of higher-order chromatin structure in determining cell tumorigenicity.

  5. Prostate cancer radiotherapy 2002: the way forward.

    PubMed

    Lukka, Himu; Pickles, Tom; Morton, Gerard; Catton, Charles; Souhami, Luis; Warde, Padraig

    2005-02-01

    In November 2000, the GU Radiation Oncologists of Canada had their first meeting, "Controversies in prostate cancer radiotherapy: consensus development". The success of this meeting prompted a second meeting, held in December 2002 to discuss "The Way Forward" in prostate radiotherapy. Radiation oncologists from across Canada were brought together and integrated with key opinion leaders in prostate cancer treatment from throughout North America. The group debated current controversies including: intensity modulated radiotherapy (IMRT), external beam hypofractionation, high dose-rate brachytherapy, and hormone therapy in the management of prostate cancer. The meeting also sought to identify and prioritize clinical trial opportunities and to highlight steps required to achieve these research goals. In summary, advances involving IMRT have enabled the use of higher radiation doses without increasing morbidity. With renewed interest in hypofractionated radiation schedules, the value of hypofractionation using IMRT was discussed and initial results from ongoing clinical trials were presented. The emerging role for high dose-rate brachytherapy in higher risk patients was also discussed. Based on existing preliminary evidence the group expressed enthusiasm for further investigation of the role for brachytherapy in intermediate to high-risk patients. Despite significant advances in radiotherapy, hormone therapy continues to play an important role in prostate cancer treatment for patients with intermediate and high-risk disease. Although evidence supports the effectiveness of hormone therapy, the optimal timing, and duration of hormonal treatment are unclear. Results from ongoing clinical trials will provide insight into these questions and will assist in the design of future clinical trials.

  6. Radiotherapy for craniopharyngioma.

    PubMed

    Aggarwal, Ajay; Fersht, Naomi; Brada, Michael

    2013-03-01

    Radiotherapy remains the mainstay of multidisciplinary management of patients with incompletely resected and recurrent craniopharyngioma. Advances in imaging and radiotherapy technology offer new alternatives with the principal aim of improving the accuracy of treatment and reducing the volume of normal brain receiving significant radiation doses. We review the available technologies, their technical advantages and disadvantages and the published clinical results. Fractionated high precision conformal radiotherapy with image guidance remains the gold standard; the results of single fraction treatment are disappointing and hypofractionation should be used with caution as long term results are not available. There is insufficient data on the use of protons to assess the comparative efficacy and toxicity. The precision of treatment delivery needs to be coupled with experienced infrastructure and more intensive quality assurance to ensure best treatment outcome and this should be carried out within multidisciplinary teams experienced in the management of craniopharyngioma. The advantages of the combined skills and expertise of the team members may outweigh the largely undefined clinical gain from novel radiotherapy technologies.

  7. [Radiotherapy of lymphomas].

    PubMed

    Barillot, I; Mahé, M A; Antoni, D; Hennequin, C

    2016-09-01

    Radiotherapy for Hodgkin's lymphoma has evolved over time but retains a dominant position in the treatment of early stage tumours. Its indications are more limited for non-Hodgkin's lymphomas, but the techniques follow the same principles whatever the histological type. This review presents the French recommendations in terms of preparation and choice of irradiation techniques. PMID:27521031

  8. Errors in Radiotherapy: Motivation for Development of New Radiotherapy Quality Assurance Paradigms

    SciTech Connect

    Fraass, Benedick A.

    2008-05-01

    Modern radiotherapy practice has rapidly evolved during the past decade, making use of many highly complex and/or automated processes for planning and delivery, including new techniques, like intensity-modulated radiotherapy driven by inverse planning optimization methods, or near real-time image-guided adaptive therapy based on fluoroscopic or tomographic imaging on the treatment machine. In spite of the modern technology, or potentially because of it in some instances, errors and other problems continue to have a significant impact on the field. This report reviews example errors and problems, discusses some of the quality assurance issues that these types of problems raise, and motivates the development of more modern and sophisticated approaches to assure quality for our clinical radiotherapy treatment methods.

  9. ASSOCIATION BETWEEN RADIOTHERAPY VS NO RADIOTHERAPY BASED ON EARLY RESPONSE TO VAMP CHEMOTHERAPY AND SURVIVAL AMONG CHILDREN WITH FAVORABLE RISK HODGKIN LYMPHOMA

    PubMed Central

    Metzger, Monika L.; Weinstein, Howard J.; Hudson, Melissa M.; Billett, Amy L.; Larsen, Eric C.; Friedmann, Alison; Howard, Scott C.; Donaldson, Sarah S.; Krasin, Matthew J.; Kun, Larry E.; Marcus, Karen J.; Yock, Torunn I.; Tarbell, Nancy; Billups, Catherine A.; Wu, Jianrong; Link, Michael P.

    2012-01-01

    Context Maintaining excellent cure rates in pediatric Hodgkin lymphoma while minimizing toxicity. Objective To evaluate the efficacy of 4 cycles of vinblastine, Adriamycin, methotrexate, and prednisone (VAMP) in patients with favorable risk Hodgkin lymphoma who achieve a complete response after 2 cycles and do not receive radiotherapy. Design, Setting, and Patients Multi-institutional, unblinded, non-randomized single group phase II clinical trial to assess the need for radiotherapy based on early response to chemotherapy. Eighty-eight eligible patients with Hodgkin lymphoma stage I and II (< 3 nodal sites, no B symptoms, mediastinal bulk, or extranodal extension) enrolled between March 3, 2000 through December 9, 2008. Data frozen March 12, 2012. Interventions Patients who achieved a complete response (n=47) after 2 cycles received no radiotherapy, and those with less than complete response (n=41) were given 25.5 Gy involved field radiotherapy. Main Outcome Measures 2-year event-free survival was the primary outcome measure. A 2-year event-free survival of greater than 90% was desired, and 80% was considered to be unacceptably low. Results Two-year event-free survival was 90.8% (95% CI, 84.7% – 96.9%); for patients who did not require radiotherapy it was 89.4% (95% CI, 80.8% – 98%), compared with 92.5% (95% CI, 84.5% – 100%) for those who did (P=0.61). Most common acute side effects were neuropathic pain (2% of patients), nausea/vomiting (3% of patients), neutropenia (32% of cycles), and febrile neutropenia (2% of patients). Nine patients (10%) were hospitalized 11 times (3% of cycles) for febrile neutropenia or non-neutropenic infection. Long term side effects after radiotherapy were asymptomatic compensated hypothyroidism in 9 patients (10%), osteonecrosis and moderate osteopenia in 2 patients each, subclinical pulmonary dysfunction in 12 patients (26%) and asymptomatic left ventricular dysfunction in 4 patients (5%). No second malignant neoplasms were

  10. ANDRILL: INVOLVING TEACHERS IN FIELD RESEARCH ENHANCES THE TRANSFER OF SCIENTIFIC KNOWLEDGE TO CLASSROOMS AND TO OTHER EDUCATORS

    NASA Astrophysics Data System (ADS)

    Cattadori, M.; Huffman, L. T.; Trummel, B.

    2009-12-01

    For most educators, the end of a field research experience is truly the beginning. From the knowledge gained and the excitement of living and working in a harsh environment like Antarctica, ARISE (ANDRILL Research Immersion for Science Educators) participants create enhanced learning experiences and resources for their students and for the professional development of other teachers. ANDRILL (Antarctic geological DRILLing) is an multi-national and interdisciplinary research project involving Italy, Germany , New Zealand, and USA. The core concept of its Education and Public Outreach Program is to embed educators as integral members on the science research teams, allowing them to participate in every phase of the mission. Their primary goal is to develop effective and innovative educational approaches for the communication of the scientific and technical aspects of the drilling program. ANDRILL has developed an exemplary teacher research experience model that differs from most by supporting a collaborative team of international educators rather than just one teacher. During the first two years of drilling projects, 2006 and 2007, ANDRILL took 16 educators from 4 countries to Antarctica. From those experiences, a growing collaborative network of polar science educators is nurtured, many valuable resources and examples of professional development have been created, and lessons have been learned and evaluated for future teacher research immersion experiences. An Italian ARISE participant and ANDRILL’s Education and Outreach Coordinator will present how ARISE has been at the core of developing transformational programs and resources in both countries including: [1] Flexhibit, a digital series of climate change materials designed for informal and formal learning environments that have been translated into Italian, German, French, Arabic, Spanish, and New Zealand English, (2) C2S2: Climate Change Student Summits, which provide professional development and resources for

  11. Proton beam radiotherapy of iris melanoma

    SciTech Connect

    Damato, Bertil . E-mail: Bertil@damato.co.uk; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

    2005-09-01

    Purpose: To report on outcomes after proton beam radiotherapy of iris melanoma. Methods and Materials: Between 1993 and 2004, 88 patients with iris melanoma received proton beam radiotherapy, with 53.1 Gy in 4 fractions. Results: The patients had a mean age of 52 years and a median follow-up of 2.7 years. The tumors had a median diameter of 4.3 mm, involving more than 2 clock hours of iris in 32% of patients and more than 2 hours of angle in 27%. The ciliary body was involved in 20%. Cataract was present in 13 patients before treatment and subsequently developed in another 18. Cataract had a 4-year rate of 63% and by Cox analysis was related to age (p = 0.05), initial visual loss (p < 0.0001), iris involvement (p < 0.0001), and tumor thickness (p < 0.0001). Glaucoma was present before treatment in 13 patients and developed after treatment in another 3. Three eyes were enucleated, all because of recurrence, which had an actuarial 4-year rate of 3.3% (95% CI 0-8.0%). Conclusions: Proton beam radiotherapy of iris melanoma is well tolerated, the main problems being radiation-cataract, which was treatable, and preexisting glaucoma, which in several patients was difficult to control.

  12. Inorganic chemistry in nuclear imaging and radiotherapy: current and future directions

    PubMed Central

    Carroll, Valerie; Demoin, Dustin W.; Hoffman, Timothy J; Jurisson, Silvia S

    2013-01-01

    Summary Radiometals play an important role in diagnostic and therapeutic radiopharmaceuticals. This field of radiochemistry is multidisciplinary, involving radiometal production, separation of the radiometal from its target, chelate design for complexing the radiometal in a biologically stable environment, specific targeting of the radiometal to its in vivo site, and nuclear imaging and/or radiotherapy applications of the resultant radiopharmaceutical. The critical importance of inorganic chemistry in the design and application of radiometal-containing imaging and therapy agents is described from a historical perspective to future directions. PMID:25382874

  13. Self-incompatibility-induced programmed cell death in field poppy pollen involves dramatic acidification of the incompatible pollen tube cytosol.

    PubMed

    Wilkins, Katie A; Bosch, Maurice; Haque, Tamanna; Teng, Nianjun; Poulter, Natalie S; Franklin-Tong, Vernonica E

    2015-03-01

    Self-incompatibility (SI) is an important genetically controlled mechanism to prevent inbreeding in higher plants. SI involves highly specific interactions during pollination, resulting in the rejection of incompatible (self) pollen. Programmed cell death (PCD) is an important mechanism for destroying cells in a precisely regulated manner. SI in field poppy (Papaver rhoeas) triggers PCD in incompatible pollen. During SI-induced PCD, we previously observed a major acidification of the pollen cytosol. Here, we present measurements of temporal alterations in cytosolic pH ([pH]cyt); they were surprisingly rapid, reaching pH 6.4 within 10 min of SI induction and stabilizing by 60 min at pH 5.5. By manipulating the [pH]cyt of the pollen tubes in vivo, we show that [pH]cyt acidification is an integral and essential event for SI-induced PCD. Here, we provide evidence showing the physiological relevance of the cytosolic acidification and identify key targets of this major physiological alteration. A small drop in [pH]cyt inhibits the activity of a soluble inorganic pyrophosphatase required for pollen tube growth. We also show that [pH]cyt acidification is necessary and sufficient for triggering several key hallmark features of the SI PCD signaling pathway, notably activation of a DEVDase/caspase-3-like activity and formation of SI-induced punctate actin foci. Importantly, the actin binding proteins Cyclase-Associated Protein and Actin-Depolymerizing Factor are identified as key downstream targets. Thus, we have shown the biological relevance of an extreme but physiologically relevant alteration in [pH]cyt and its effect on several components in the context of SI-induced events and PCD.

  14. Radiotherapy of primary cutaneous follicle center lymphoma: case report and review of literature

    PubMed Central

    2013-01-01

    Primary cutaneous follicle center lymphoma is an indolent primary cutaneous B-cell lymphoma originating from the follicle center cells, composed of a combination of centrocytes (small and large cleaved cells) and centroblasts (large noncleaved cells) with a follicular, follicular/diffuse, or diffuse growth pattern. Lesions are mostly located on the head, neck and trunk. A case is presented of a 56-year-old male patient with primary cutaneous follicle center lymphoma, with lesions involving the skin of the back, shoulders, presternal area and right forearm. As the patient presented a disseminated cutaneous form of the disease that involved several anatomical regions, complete work-up was followed by superficial fractionated radiotherapy of eight fields in VI expositions, with total irradiation dose of 1400 cGy upon the following fields: right and left pectoral region, left and right shoulders, right suprascapular region, and proximal third of the right forearm. Total irradiation dose applied upon each field for the lesions located on the left and right side of the back was 1500 cGy. This therapy resulted in significant reduction of visible tumor. The patient was regularly followed up on outpatient basis for 12 months of radiotherapy, being free from local recurrence and systemic spread of the disease. PMID:23786884

  15. Whole-pelvic radiotherapy with spot-scanning proton beams for uterine cervical cancer: a planning study

    PubMed Central

    Hashimoto, Shingo; Shibamoto, Yuta; Iwata, Hiromitsu; Ogino, Hiroyuki; Shibata, Hiroki; Toshito, Toshiyuki; Sugie, Chikao; Mizoe, Jun-etsu

    2016-01-01

    The aim of this study was to compare the dosimetric parameters of whole-pelvic radiotherapy (WPRT) for cervical cancer among plans involving 3D conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), or spot-scanning proton therapy (SSPT). The dose distributions of 3D-CRT-, IMRT-, and SSPT-based WPRT plans were compared in 10 patients with cervical cancer. All of the patients were treated with a prescribed dose of 50.4 Gy in 1.8-Gy daily fractions, and all of the plans involved the same planning target volume (PTV) constrictions. A 3D-CRT plan involving a four-field box, an IMRT plan involving seven coplanar fields, and an SSPT plan involving four fields were created. The median PTV D95% did not differ between the 3D-CRT, IMRT and SSPT plans. The median conformity index 95% and homogeneity index of the IMRT and SSPT were better than those of the 3D-CRT. The homogeneity index of the SSPT was better than that of the IMRT. SSPT resulted in lower median V20 values for the bladder wall, small intestine, colon, bilateral femoral heads, skin, and pelvic bone than IMRT. Comparing the Dmean values, SSPT spared the small intestine, colon, bilateral femoral heads, skin and pelvic bone to a greater extent than the other modalities. SSPT can reduce the irradiated volume of the organs at risk compared with 3D-CRT and IMRT, while maintaining excellent PTV coverage. Further investigations of SSPT are warranted to assess its role in the treatment of cervical cancer. PMID:27380800

  16. Involved Field Radiation After Autologous Stem Cell Transplant for Diffuse Large B-Cell Lymphoma in the Rituximab Era

    SciTech Connect

    Biswas, Tithi; Dhakal, Sughosh; Chen Rui; Hyrien, Ollivier; Bernstein, Steven; Friedberg, Jonathan W.; Fisher, Richard I.; Liesveld, Jane; Phillips, Gordon; Constine, Louis S.

    2010-05-01

    Purpose: For patients with recurrent or refractory large B-cell non-Hodgkin's lymphoma, high-dose chemotherapy and autologous stem cell transplant (ASCT) is the treatment of choice. We evaluated the role of involved field radiation therapy (IFRT) post-ASCT for patients initially induced with cyclophosphamide, adriamycin, vincristine, and prednisone (CHOP) or, more recently, rituximab-CHOP (R-CHOP). Materials and Methods: Between May 1992 and April 2005, 176 patients underwent ASCT for recurrent or refractory large B-cell non-Hodgkin's lymphoma; 164 patients were evaluable for endpoint analysis. Fifty percent of the CHOP group (n = 131), and 39% of the R-CHOP group (n = 33), received IFRT. Follow-up from the time of transplant was a median/mean of 1.7/3 years (range, 0.03-13 years). Results: The 5-year overall survival (OS) and disease-specific survival (DSS) improved with IFRT in both the R-CHOP (p = 0.006 and 0.02, respectively) and CHOP (p = 0.02 and p = 0.04, respectively) groups. IFRT was associated with a 10% (p = 0.17) reduction in local failure, alone or with a distant site. On univariate analysis, IFRT was associated with superior OS (hazard ratio [HR] = 0.50 [95% CI 0.32, 0.78]; p = 0.002) and DSS (HR = 0.53 [95% CI 0.33, 0.86]; p = 0.009). Presence of B symptoms was adverse (p = 0.03). On multivariate analysis, only IFRT was associated with significant improvement in OS (HR = 0.35 [0.18, 0.68]; p = 0.002) and DSS (HR = 0.39 [95% CI 0.18, 0.84]; p = 0.01). Conclusions: Recognizing that positive and negative patient selection bias exists for the use of IFRT post-ASCT, patients initially treated with CHOP or R-CHOP and who undergo ASCT for recurrent or refractory disease may benefit from subsequent IFRT presumably due to enhanced local control that can translate into a survival advantage.

  17. [How to maximize skin care during radiotherapy?].

    PubMed

    Fromantin, I; Lesport, G; Le Mée, M

    2015-10-01

    No consensual guidelines exist regarding the management of early effects of radiotherapy. But preventive and curative care strategies could be adapted in the aim to delay erythema, limit complications and improve patients' comfort. Prevention involves encouraging patients to take care of their skin, avoid moisture, frictions, sun exposition and dry soap. When these rules seem insufficient, products (dressings, solution, or cream) could be prescribed, according to the individual risk of each patient. Preventive measures are accentuated when radiodermatitis appears and/or topics indicated for wound healing could be applied. Care (education, dressing, observation) needs a multidisciplinary approach. Improvements of radiotherapy treatments (methods, techniques) have been the most effective evolution on radiodermatitis. PMID:26344433

  18. Radiotherapy equipment--purchase or lease?

    PubMed

    Nisbet, A; Ward, A

    2001-08-01

    Against a background of increasing demand for radiotherapy equipment, this study was undertaken to investigate options for equipment procurement, in particular to compare purchase with lease. The perceived advantages of lease are that equipment can be acquired within budget and cashflow constraints, with relatively low amounts of cash leaving the NHS in the first year, avoiding the necessity of capitalizing the equipment and providing protection against the risk of obsolescence associated with high technology equipment. The perceived disadvantages of leasing are that the Trust does not own the equipment, leasing can be more expensive in revenue terms, the tender process is extended and there may be lease conditions to be met, which may be costly and/or restrictive. There are also a number of technical considerations involved in the leasing of radiotherapy equipment that influence the financial analysis and practical operation of the radiotherapy service. The technical considerations include servicing and planned preventative maintenance, upgrades, spare parts, subsequent purchase of "add ons", modification of equipment, research and development work, commencement of the lease period, return of equipment at the end of the lease period and negotiations at the end of the lease period. A study from Raigmore Hospital, Inverness is described, which involves the procurement of new, state-of-the-art radiotherapy equipment. This provides an overview of the procurement process, including a summary of the advantages and disadvantages of leasing, with the figures from the financial analysis presented and explained. In addition, a detailed description is given of the technical considerations to be taken into account in the financial analysis and negotiation of any lease contract.

  19. Radiotherapy equipment--purchase or lease?

    PubMed

    Nisbet, A; Ward, A

    2001-08-01

    Against a background of increasing demand for radiotherapy equipment, this study was undertaken to investigate options for equipment procurement, in particular to compare purchase with lease. The perceived advantages of lease are that equipment can be acquired within budget and cashflow constraints, with relatively low amounts of cash leaving the NHS in the first year, avoiding the necessity of capitalizing the equipment and providing protection against the risk of obsolescence associated with high technology equipment. The perceived disadvantages of leasing are that the Trust does not own the equipment, leasing can be more expensive in revenue terms, the tender process is extended and there may be lease conditions to be met, which may be costly and/or restrictive. There are also a number of technical considerations involved in the leasing of radiotherapy equipment that influence the financial analysis and practical operation of the radiotherapy service. The technical considerations include servicing and planned preventative maintenance, upgrades, spare parts, subsequent purchase of "add ons", modification of equipment, research and development work, commencement of the lease period, return of equipment at the end of the lease period and negotiations at the end of the lease period. A study from Raigmore Hospital, Inverness is described, which involves the procurement of new, state-of-the-art radiotherapy equipment. This provides an overview of the procurement process, including a summary of the advantages and disadvantages of leasing, with the figures from the financial analysis presented and explained. In addition, a detailed description is given of the technical considerations to be taken into account in the financial analysis and negotiation of any lease contract. PMID:11511499

  20. Risk-adaptive radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Yusung

    Currently, there is great interest in integrating biological information into intensity-modulated radiotherapy (IMRT) treatment planning with the aim of boosting high-risk tumor subvolumes. Selective boosting of tumor subvolumes can be accomplished without violating normal tissue complication constraints using information from functional imaging. In this work we have developed a risk-adaptive optimization-framework that utilizes a nonlinear biological objective function. Employing risk-adaptive radiotherapy for prostate cancer, it is possible to increase the equivalent uniform dose (EUD) by up to 35.4 Gy in tumor subvolumes having the highest risk classification without increasing normal tissue complications. Subsequently, we have studied the impact of functional imaging accuracy, and found on the one hand that loss in sensitivity had a large impact on expected local tumor control, which was maximal when a low-risk classification for the remaining low risk PTV was chosen. While on the other hand loss in specificity appeared to have a minimal impact on normal tissue sparing. Therefore, it appears that in order to improve the therapeutic ratio a functional imaging technique with a high sensitivity, rather than specificity, is needed. Last but not least a comparison study between selective boosting IMRT strategies and uniform-boosting IMRT strategies yielding the same EUD to the overall PTV was carried out, and found that selective boosting IMRT considerably improves expected TCP compared to uniform-boosting IMRT, especially when lack of control of the high-risk tumor subvolumes is the cause of expected therapy failure. Furthermore, while selective boosting IMRT, using physical dose-volume objectives, did yield similar rectal and bladder sparing when compared its equivalent uniform-boosting IMRT plan, risk-adaptive radiotherapy, utilizing biological objective functions, did yield a 5.3% reduction in NTCP for the rectum. Hence, in risk-adaptive radiotherapy the

  1. Developments in radiotherapy.

    PubMed

    Svensson, Hans; Möller, Torgil R

    2003-01-01

    A systematic assessment of radiotherapy for cancer was conducted by The Swedish Council on Technology Assessment in Health Care (SBU) in 2001. The assessment included a review of future developments in radiotherapy and an estimate of the potential benefits of improved radiotherapy in Sweden. The conclusions reached from this review can be summarized as: Successively better knowledge is available on dose-response relationships for tumours and normal tissues at different fractionation schedules and treated volumes. Optimization of dose levels and fractionation schedules should improve the treatment outcome. Improved treatment results may be expected with even more optimized fractionation schedules. The radiosensitivity of the tumour is dependent on the availability of free oxygen in the cells. The oxygen effect has been studied for a long time and new knowledge has emerged, but there is still no consensus on the best way to minimize its negative effect in the treatment of hypoxic tumours. Development in imaging techniques is rapid, improving accuracy in outlining targets and organs at risk. This is a prerequisite for advanced treatment planning. More accurate treatment can be obtained using all the computer techniques that are successively made available for calculating dose distributions, controlling the accelerator and multileaf collimator (MLC) and checking patient set-up. Optimized treatment plans can be achieved using inverse dose planning and intensity modulation radiation therapy (IMRT). Optimization algorithms based on biological data from clinical trials could be a part of future dose planning. New genetic markers might be developed that give a measure of the radiation responsiveness of tumours and normal tissue. This could lead to more individualized treatments. New types of radiation sources may be expected: protons, light ions, and improved beams (and compounds) for boron neutron capture therapy (BNCT). Proton accelerators with scanned-beam systems and

  2. Neck muscle atrophy and soft-tissue fibrosis after neck dissection and postoperative radiotherapy for oral cancer

    PubMed Central

    Kim, Jinu; Shin, Eun Seow; Kim, Jeong Eon; Yoon, Sang Pil

    2015-01-01

    Late complications of head and neck cancer survivors include neck muscle atrophy and soft-tissue fibrosis. We present an autopsy case of neck muscle atrophy and soft-tissue fibrosis (sternocleidomastoid, omohyoid, digastric, sternohyoid, sternothyroid, and platysma muscles) within the radiation field after modified radical neck dissection type I and postoperative radiotherapy for floor of mouth cancer. A 70-year-old man underwent primary tumor resection of the left floor of mouth, left marginal mandibulectomy, left modified radical neck dissection type I, and reconstruction with a radial forearm free flap. The patient received adjuvant radiotherapy. The dose to the primary tumor bed and involved neck nodes was 63 Gy in 35 fractions over 7 weeks. Areas of subclinical disease (left lower neck) received 50 Gy in 25 fractions over 5 weeks. Adjuvant chemotherapy was not administered. PMID:26756035

  3. [Exchange of medical imaging and data information in radiotherapy: needs, methods and current limits].

    PubMed

    Manens, J P

    1997-01-01

    Extension of the image network within radiotherapy departments provides the technical infrastructure which is made necessary by the rapid evolution of techniques in the field of diagnosis and treatment in radiotherapy. The system is aimed at managing the whole set of data (textual data and images) that are needed for planning and control of treatments. The radiotherapy network addresses two objectives: managing both the information necessary for treatment planning (target volumes definition, planning dosimetry) and the control of all parameters involved during the patient's treatment under the treatment unit. The major challenge is to improve the quality of treatment. Multimodal imaging is a major advance as it allows the use of new dosimetry and simulation techniques. The need for standards to exchange medical imaging information is now recognized by all the institutions and a majority of users and manufacturers. It is widely accepted that the lack of standard has been one of the fundamental obstacles in the deployment of operational "Picture Archiving Communication Systems". The International Standard Organisation Open System Interconnection model is the standard reference mode used to describe network protocols. The network is based on the Ethernet and TCP/IP protocol that provides the means to interconnect imaging devices and workstations dedicated to specific image processing or machines used in radiotherapy. The network uses Ethernet cabled on twisted-pair (10 BaseT) or optical fibres in a star-shaped physical layout. Dicom V3.0 supports fundamental network interactions: transfer of images (computerized tomography magnetic resonance imaging query and retrieve of images), printing on network attached cameras, support of HIS/RIS related interfacing and image management. The supplement to the Dicom standard, Dicom RT, specifies five data objects known in Dicom as Information Object Definition for relevant radiotherapy. Dicom RT objects can provide a mean for

  4. [Exchange of medical imaging and data information in radiotherapy: needs, methods and current limits].

    PubMed

    Manens, J P

    1997-01-01

    Extension of the image network within radiotherapy departments provides the technical infrastructure which is made necessary by the rapid evolution of techniques in the field of diagnosis and treatment in radiotherapy. The system is aimed at managing the whole set of data (textual data and images) that are needed for planning and control of treatments. The radiotherapy network addresses two objectives: managing both the information necessary for treatment planning (target volumes definition, planning dosimetry) and the control of all parameters involved during the patient's treatment under the treatment unit. The major challenge is to improve the quality of treatment. Multimodal imaging is a major advance as it allows the use of new dosimetry and simulation techniques. The need for standards to exchange medical imaging information is now recognized by all the institutions and a majority of users and manufacturers. It is widely accepted that the lack of standard has been one of the fundamental obstacles in the deployment of operational "Picture Archiving Communication Systems". The International Standard Organisation Open System Interconnection model is the standard reference mode used to describe network protocols. The network is based on the Ethernet and TCP/IP protocol that provides the means to interconnect imaging devices and workstations dedicated to specific image processing or machines used in radiotherapy. The network uses Ethernet cabled on twisted-pair (10 BaseT) or optical fibres in a star-shaped physical layout. Dicom V3.0 supports fundamental network interactions: transfer of images (computerized tomography magnetic resonance imaging query and retrieve of images), printing on network attached cameras, support of HIS/RIS related interfacing and image management. The supplement to the Dicom standard, Dicom RT, specifies five data objects known in Dicom as Information Object Definition for relevant radiotherapy. Dicom RT objects can provide a mean for

  5. Effects of Setup Errors and Shape Changes on Breast Radiotherapy

    SciTech Connect

    Mourik, Anke van; Kranen, Simon van; Hollander, Suzanne den; Sonke, Jan-Jakob; Herk, Marcel van; Vliet-Vroegindeweij, Corine van

    2011-04-01

    Purpose: The purpose of the present study was to quantify the robustness of the dose distributions from three whole-breast radiotherapy (RT) techniques involving different levels of intensity modulation against whole patient setup inaccuracies and breast shape changes. Methods and Materials: For 19 patients (one computed tomography scan and five cone beam computed tomography scans each), three treatment plans were made (wedge, simple intensity-modulated RT [IMRT], and full IMRT). For each treatment plan, four dose distributions were calculated. The first dose distribution was the original plan. The other three included the effects of patient setup errors (rigid displacement of the bony anatomy) or breast errors (e.g., rotations and shape changes of the breast with respect to the bony anatomy), or both, and were obtained through deformable image registration and dose accumulation. Subsequently, the effects of the plan type and error sources on target volume coverage, mean lung dose, and excess dose were determined. Results: Systematic errors of 1-2 mm and random errors of 2-3 mm (standard deviation) were observed for both patient- and breast-related errors. Planning techniques involving glancing fields (wedge and simple IMRT) were primarily affected by patient errors ({approx}6% loss of coverage near the dorsal field edge and {approx}2% near the skin). In contrast, plan deterioration due to breast errors was primarily observed in planning techniques without glancing fields (full IMRT, {approx}2% loss of coverage near the dorsal field edge and {approx}4% near the skin). Conclusion: The influences of patient and breast errors on the dose distributions are comparable in magnitude for whole breast RT plans, including glancing open fields, rendering simple IMRT the preferred technique. Dose distributions from planning techniques without glancing open fields were more seriously affected by shape changes of the breast, demanding specific attention in partial breast

  6. Second cancers following radiotherapy for cancer

    SciTech Connect

    Curtis, R.E.

    1997-03-01

    The study of second cancer risk after radiotherapy provides a unique opportunity to study carcinogenesis since large groups of humans are deliberately exposed to substantial doses of radiation in order to cure disease. Detailed radiotherapy records for cancer patients allow precise quantification of organ dose, and population-based cancer registries are frequently available to provide access to large groups of patients who are closely followed for long periods. Moreover, cancer patients treated with surgery alone (no radiation) are frequently available to serve as a non-irradiated comparison group. New information can be provided on relatively insensitive organs, and low dose exposures in the range of scientific interest are received by organs outside the radiation treatment fields. This paper will review several recently completed studies that characterize the risk of radiation-induced second cancers. Emphasis will be given to studies providing new information on the dose-response relationship of radiation-induced leukemia, breast cancer and lung cancer.

  7. [Effectiveness of radiotherapy in patients with lymphogranulomatosis depending on the stage of the disease].

    PubMed

    Mendeleev, I M; Miasnikov, A A; Oleĭnik, V A

    1984-01-01

    The authors review variants of radiotherapy of patients with lymphogranulomatosis. Regard the method of irradiation with broad fields of complicated configuration as preferable. Point to the advisability of using one or another method depending on the disease stage. Describe the conditions necessary, in their opinion, for successful radiotherapy of lymphogranulomatosis patients.

  8. Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

    SciTech Connect

    Eldebawy, Eman; Parker, William; Abdel Rahman, Wamied; Freeman, Carolyn R.

    2012-03-01

    Purpose: To determine the best treatment technique for patients with retinoblastoma requiring radiotherapy to the whole eye. Methods and Materials: Treatment plans for 3 patients with retinoblastoma were developed using 10 radiotherapy techniques including electron beams, photon beam wedge pair (WP), photon beam three-dimensional conformal radiotherapy (3D-CRT), fixed gantry intensity-modulated radiotherapy (IMRT), photon volumetric arc therapy (VMAT), fractionated stereotactic radiotherapy, and helical tomotherapy (HT). Dose-volume analyses were carried out for each technique. Results: All techniques provided similar target coverage; conformity was highest for VMAT, nine-field (9F) IMRT, and HT (conformity index [CI] = 1.3) and lowest for the WP and two electron techniques (CI = 1.8). The electron techniques had the highest planning target volume dose gradient (131% of maximum dose received [D{sub max}]), and the CRT techniques had the lowest (103% D{sub max}) gradient. The volume receiving at least 20 Gy (V{sub 20Gy}) for the ipsilateral bony orbit was lowest for the VMAT and HT techniques (56%) and highest for the CRT techniques (90%). Generally, the electron beam techniques were superior in terms of brain sparing and delivered approximately one-third of the integral dose of the photon techniques. Conclusions: Inverse planned image-guided radiotherapy delivered using HT or VMAT gives better conformity index, improved orbital bone and brain sparing, and a lower integral dose than other techniques.

  9. A comparative dosimetric study of volumetric-modulated arc therapy vs. fixed field intensity-modulated radiotherapy in postoperative irradiation of stage IB-IIA high-risk cervical cancer

    PubMed Central

    QIAO, LILI; CHENG, JIAN; LIANG, NING; XIE, JIAN; LUO, HUI; ZHANG, JIANDONG

    2016-01-01

    The aim of the present study was to compare the dosimetry features of volumetric-modulated arc therapy (VMAT) and fixed field intensity-modulated radiotherapy (f-IMRT) in postoperative irradiation of stage IB-IIA high-risk cervical cancer. Fifteen patients exhibiting stage IB-IIA high-risk cervical cancer, who had been treated with postoperative adjuvant concurrent radiochemotherapy, were selected. The clinical target volume (CTV) and organs at risk (OARs) were delineated according to contrast computed tomography images. The planning target volume (PTV) was subsequently produced by using 1 cm uniform expansion of the CTV. The treatment plans were intended to deliver 50 Gy in 25 fractions. The OARs that were contoured included the bladder, rectum, small bowel and femoral heads. Dose volume histograms were used to evaluate the dose distribution in the PTV and OARs. VMAT and f-IMRT treatment plans resulted in similar dose coverage of the PTV. VMAT was superior to f-IMRT in conformity (P<0.05), and resulted in a reduction of OARs irradiated at high dose levels (V40 and V50) compared with f-IMRT (P<0.05), particularly for the bladder. However, the doses of low levels (V10 and V20) delivered to OARs with f-IMRT were slightly reduced compared with VMAT (P<0.05). For ambilateral femoral heads, VMAT demonstrated improved sparing compared with f-IMRT, with regard to D5 (P<0.05). Furthermore, VMAT treatment plans revealed a significant reduction in monitor units (MU) and treatment time. VMAT techniques exhibited similar PTV coverage compared with f-IMRT. At doses of high levels delivered to OARs, VMAT demonstrated improved sparing compared with f-IMRT, particularly for the bladder, while significantly reducing treatment time and MU number. PMID:26893675

  10. [Juvenile angiofibroma. Results of radiotherapy].

    PubMed

    Rosset, A; Korzeniowski, S

    1990-01-01

    8 patients with the nasofibromata were treated by radiotherapy in Oncologic Center in Kraków. In most part of these patients tumors exceeded the nasopharynx or gave the massive postoperational recurrencies. Complete regression was obtained in 6 out of 8 cases. The radiation changes are described. The radiotherapy is effective in more advanced and recurrent stages of the juvenile nasofibroma.

  11. Role of Radiotherapy and Newer Techniques in the Treatment of GI Cancers.

    PubMed

    Hajj, Carla; Goodman, Karyn A

    2015-06-01

    The role of radiotherapy in multidisciplinary treatment of GI malignancies is well established. Recent advances in imaging as well as radiotherapy planning and delivery techniques have made it possible to target tumors more accurately while sparing normal tissues. Intensity-modulated radiotherapy is an advanced method of delivering radiation using cutting-edge technology to manipulate beams of radiation. The role of intensity-modulated radiotherapy is growing for many GI malignancies, such as cancers of the stomach, pancreas, esophagus, liver, and anus. Stereotactic body radiotherapy is an emerging treatment option for some GI tumors such as locally advanced pancreatic cancer and primary or metastatic tumors of the liver. Stereotactic body radiotherapy requires a high degree of confidence in tumor location and subcentimeter accuracy of the delivered dose. New image-guided techniques have been developed to overcome setup uncertainties at the time of treatment, including real-time imaging on the linear accelerator. Modern imaging techniques have also allowed for more accurate pretreatment staging and delineation of the primary tumor and involved sites. In particular, magnetic resonance imaging and positron emission tomography scans can be particularly useful in radiotherapy planning and assessing treatment response. Molecular biomarkers are being investigated as predictors of response to radiotherapy with the intent of ultimately moving toward using genomic and proteomic determinants of therapeutic strategies. The role of all of these new approaches in the radiotherapeutic management of GI cancers and the evolving role of radiotherapy in these tumor sites will be highlighted in this review. PMID:25918298

  12. Surgery Followed by Radiotherapy Versus Radiotherapy Alone for Metastatic Spinal Cord Compression From Unfavorable Tumors

    SciTech Connect

    Rades, Dirk; Huttenlocher, Stefan; Bajrovic, Amira; Karstens, Johann H.; Adamietz, Irenaeus A.; Kazic, Nadja; Rudat, Volker; Schild, Steven E.

    2011-12-01

    Purpose: Despite a previously published randomized trial, controversy exists regarding the benefit of adding surgery to radiotherapy for metastatic spinal cord compression (MSCC). It is thought that patients with MSCC from relatively radioresistant tumors or tumors associated with poor functional outcome after radiotherapy alone may benefit from surgery. This study focuses on these tumors. Methods and Materials: Data from 67 patients receiving surgery plus radiotherapy (S+RT) were matched to 134 patients (1:2) receiving radiotherapy alone (RT). Groups were matched for 10 factors and compared for motor function, ambulatory status, local control, and survival. Additional separate matched-pair analyses were performed for patients receiving direct decompressive surgery plus stabilization of involved vertebrae (DDSS) and patients receiving laminectomy (LE). Results: Improvement of motor function occurred in 22% of patients after S+RT and 16% after RT (p = 0.25). Posttreatment ambulatory rates were 67% and 61%, respectively (p = 0.68). Of nonambulatory patients, 29% and 19% (p = 0.53) regained ambulatory status. One-year local control rates were 85% and 89% (p = 0.87). One-year survival rates were 38% and 24% (p = 0.20). The matched-pair analysis of patients receiving LE showed no significant differences between both therapies. In the matched-pair analysis of patients receiving DDSS, improvement of motor function occurred more often after DDSS+RT than RT (28% vs. 19%, p = 0.024). Posttreatment ambulatory rates were 86% and 67% (p = 0.30); 45% and 18% of patients regained ambulatory status (p = 0.29). Conclusions: Patients with MSCC from an unfavorable primary tumor appeared to benefit from DDSS but not LE when added to radiotherapy in terms of improved functional outcome.

  13. Cellular signalling effects in high precision radiotherapy

    NASA Astrophysics Data System (ADS)

    McMahon, Stephen J.; McGarry, Conor K.; Butterworth, Karl T.; Jain, Suneil; O'Sullivan, Joe M.; Hounsell, Alan R.; Prise, Kevin M.

    2015-06-01

    Radiotherapy is commonly planned on the basis of physical dose received by the tumour and surrounding normal tissue, with margins added to address the possibility of geometric miss. However, recent experimental evidence suggests that intercellular signalling results in a given cell’s survival also depending on the dose received by neighbouring cells. A model of radiation-induced cell killing and signalling was used to analyse how this effect depends on dose and margin choices. Effective Uniform Doses were calculated for model tumours in both idealised cases with no delivery uncertainty and more realistic cases incorporating geometric uncertainty. In highly conformal irradiation, a lack of signalling from outside the target leads to reduced target cell killing, equivalent to under-dosing by up to 10% compared to large uniform fields. This effect is significantly reduced when higher doses per fraction are considered, both increasing the level of cell killing and reducing margin sensitivity. These effects may limit the achievable biological precision of techniques such as stereotactic radiotherapy even in the absence of geometric uncertainties, although it is predicted that larger fraction sizes reduce the relative contribution of cell signalling driven effects. These observations may contribute to understanding the efficacy of hypo-fractionated radiotherapy.

  14. Multimedia educational services in stereotactic radiotherapy.

    PubMed

    Bazioglou, M; Theodorou, K; Kappas, C

    1999-01-01

    The computer-based learning methods in medicine have been well established as stand-alone learning systems. Recently, these systems were enriched with the use of telematics technology to provide distance learning capabilities. Stereotactic radiotherapy is one of the most representative advanced radiotherapy techniques. Due to the multidisciplinary character of the technique and the rapid evolution of technology implemented, the demands in training have increased. The potential of interactive multimedia and Internet technologies for the achievement of distance learning capabilities in this domain are investigated. The realization of a computer-based educational program in stereotactic radiotherapy in a multimedia format is a new application in the computer-aided distance learning field. The system is built according to a client and server architecture, based on the Internet infrastructure, and composed of server nodes. The impact of the system may be described in terms of: time and transportation costs saving, flexibility in training (scheduling, rate and subject selection), online communication and interaction with experts, cost effective access to material (delivery or access by a large number of users and revision of the material by avoiding high costs of computer-based training systems and database development). PMID:10394345

  15. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  16. Imaging in radiotherapy

    NASA Astrophysics Data System (ADS)

    Calandrino, R.; Del Maschio, A.; Cattaneo, G. M.; Castiglioni, I.

    2009-09-01

    The diagnostic methodologies used for the radiotherapy planning have undergone great developments in the last 30 years. Since the 1980s, after the introduction of the CT scanner, the modality for the planning moved beyond the planar 2D assessment to approach a real and more realistic volumetric 3D definition. Consequently the dose distribution, previously obtained by means of an overly simple approximation, became increasingly complex, better tailoring the true shape of the tumour. The final therapeutic improvement has been obtained by a parallel increase in the complexity of the irradiating units: the Linacs for therapy have, in fact, been equipped with a full accessory set capable to modulate the fluence (IMRT) and to check the correct target position continuously during the therapy session (IMRT-IGRT). The multimodal diagnostic approach, which integrates diagnostic information, from images of the patient taken with CT, NMR, PET and US, further improves the data for a biological and topological optimization of the radiotherapy plan and consequently of the dose distribution in the Planning Target Volume. Proteomic and genomic analysis will be the next step in tumour diagnosis. These methods will provide the planners with further information, for a true personalization of the treatment regimen and the assessment of the predictive essays for each tumour and each patient.

  17. Fertility impairment in radiotherapy

    PubMed Central

    Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning.

  18. Fertility impairment in radiotherapy.

    PubMed

    Biedka, Marta; Kuźba-Kryszak, Tamara; Nowikiewicz, Tomasz; Żyromska, Agnieszka

    2016-01-01

    Infertility as a result of antineoplastic therapy is becoming a very important issue due to the growing incidence of neoplastic diseases. Routinely applied antineoplastic treatments and the illness itself lead to fertility disorders. Therapeutic methods used in antineoplastic treatment may cause fertility impairment or sterilization due to permanent damage to reproductive cells. The risk of sterilization depends on the patient's sex, age during therapy, type of neoplasm, radiation dose and treatment area. It is known that chemotherapy and radiotherapy can lead to fertility impairment and the combination of these two gives an additive effect. The aim of this article is to raise the issue of infertility in these patients. It is of growing importance due to the increase in the number of children and young adults who underwent radiotherapy in the past. The progress in antineoplastic therapy improves treatment results, but at the same time requires a deeper look at existential needs of the patient. Reproductive function is an integral element of self-esteem and should be taken into account during therapy planning. PMID:27647982

  19. Adjuvant radiotherapy for cutaneous melanoma: Comparing hypofractionation to conventional fractionation

    SciTech Connect

    Chang, Daniel T.; Amdur, Robert J.; Morris, Christopher G. M.S.; Mendenhall, William M. . E-mail: mendewil@shands.ufl.edu

    2006-11-15

    Purpose: To examine locoregional control after adjuvant radiotherapy (RT) for cutaneous melanoma and compare outcomes between conventional fractionation and hypofractionation. Methods and Materials: Between January 1980 and June 2004, 56 patients with high-risk disease were treated with adjuvant RT. Indications for RT included: recurrent disease, cervical lymph node involvement, lymph nodes >3 cm, more than three lymph nodes involved, extracapsular extension, gross residual disease, close or positive margins, or satellitosis. Hypofractionation was used in 41 patients (73%) and conventional fractionation was used in 15 patients (27%). Results: The median age was 61 years (21->90). The median follow-up among living patients was 4.4 years (range, 0.6-14.4 years). The primary site was located in the head and neck in 49 patients (87%) and below the clavicles in 7 patients (13%). There were 7 in-field locoregional failures (12%), 3 out-of-field regional failures (5%), and 24 (43%) distant failures. The 5-year in-field locoregional control (ifLRC) and freedom from distant metastases (FFDM) rates were 87% and 43%, respectively. The 5-year cause-specific (CSS) and overall survival (OS) was 57% and 46%, respectively. The only factor associated with ifLRC was satellitosis (p = 0.0002). Nodal involvement was the only factor associated with FFDM (p = 0.0007), CSS (p = 0.0065), and OS (p = 0.016). Two patients (4%) who experienced severe late complications, osteoradionecrosis of the temporal bone and radiation plexopathy, and both received hypofractionation (5%). Conclusions: Although surgery and adjuvant RT provides excellent locoregional control, distant metastases remain the major cause of mortality. Hypofractionation and conventional fractionation are equally efficacious.

  20. Response of lymphangiectasis to radiotherapy. [X-ray

    SciTech Connect

    Kurczynski, E.; Horwitz, S.J.

    1981-07-15

    A 14-year-old girl with lymphangiectasis of the skull causing rapid extensive destruction of the left orbit, zygoma, mandible, sphenoid, and occiput underwent radiotherapy with 2000 rad to the entire skull, mandible, and upper cervical vertebrae. Three years later, progression of the disease has ceased, and the involved bone is slowly remineralizing.

  1. Unilateral Radiotherapy for the Treatment of Tonsil Cancer

    SciTech Connect

    Chronowski, Gregory M.; Garden, Adam S.; Morrison, William H.; Frank, Steven J.; Schwartz, David L.; Shah, Shalin J.; Beadle, Beth M.; Gunn, G. Brandon; Kupferman, Michael E.; Ang, Kian K.; Rosenthal, David I.

    2012-05-01

    Purpose: To assess, through a retrospective review, clinical outcomes of patients with squamous cell carcinoma of the tonsil treated at the M. D. Anderson Cancer Center with unilateral radiotherapy techniques that irradiate the involved tonsil region and ipsilateral neck only. Methods and Materials: Of 901 patients with newly diagnosed squamous cell carcinoma of the tonsil treated with radiotherapy at our institution, we identified 102 that were treated using unilateral radiotherapy techniques. All patients had their primary site of disease restricted to the tonsillar fossa or anterior pillar, with <1 cm involvement of the soft palate. Patients had TX (n = 17 patients), T1 (n = 52), or T2 (n = 33) disease, with Nx (n = 3), N0 (n = 33), N1 (n = 23), N2a (n = 21), or N2b (n = 22) neck disease. Results: Sixty-one patients (60%) underwent diagnostic tonsillectomy before radiotherapy. Twenty-seven patients (26%) underwent excision of a cervical lymph node or neck dissection before radiotherapy. Median follow-up for surviving patients was 38 months. Locoregional control at the primary site and ipsilateral neck was 100%. Two patients experienced contralateral nodal recurrence (2%). The 5-year overall survival and disease-free survival rates were 95% and 96%, respectively. The 5-year freedom from contralateral nodal recurrence rate was 96%. Nine patients required feeding tubes during therapy. Of the 2 patients with contralateral recurrence, 1 experienced an isolated neck recurrence and was salvaged with contralateral neck dissection only and remains alive and free of disease. The other patient presented with a contralateral base of tongue tumor and involved cervical lymph node, which may have represented a second primary tumor, and died of disease. Conclusions: Unilateral radiotherapy for patients with TX-T2, N0-N2b primary tonsil carcinoma results in high rates of disease control, with low rates of contralateral nodal failure and a low incidence of acute toxicity

  2. Using sediment transport and river restoration to link research and education, and promote K-12 female involvement in STEM fields

    NASA Astrophysics Data System (ADS)

    Yager, E. M.; Bradley-Eitel, K.

    2011-12-01

    The focus of this CAREER award is to better understand and predict the mechanics of sediment transport, to link research and education through courses and shared field sites, and to increase female interest in STEM fields. To accomplish the education component of this proposal we have focused on the following three activities: 1) a Keystone course on the scientific method, 2) a Women Outside with Science (WOWS) camp and 3) a permanent field site for research and education on river processes. In the Keystone Course, students investigated the impact of roughness addition, in sediment-starved river reaches (e.g. downstream of dams), on the retention of gravel used for spawning. They developed research questions and hypotheses, designed and conducted a set of scaled laboratory flume experiments, analyzed their data and wrote a draft manuscript of their results. Student feedback was overwhelmingly positive on the merits of this course, which included hands-on learning of the following: basic sediment transport and fluvial geomorphology, applied statistics, laboratory methods, and scientific writing skills. Students sometimes struggled when flume experiments did not progress as planned, and in the analysis and interpretation of complex data. Some of the students in the course have reanalyzed data, conducted additional experiments and are currently rewriting the manuscript for submission to a peer-reviewed journal. Such a course fundamentally links research and teaching, and provides an introduction to research for advanced undergraduates or beginning graduate students. We have also run one summer WOWS camp, which was a ten day camping and inquiry based research experience for 20 female junior-high and high-school students. The girls studied climate change and water related issues, worked on a restoration project on the Little Salmon River, met with a fish biologist and did fish habitat surveys and studied water quality along the North Fork of the Payette River while on a

  3. Biological optimization of heterogeneous dose distributions in systemic radiotherapy

    SciTech Connect

    Strigari, Lidia; D'Andrea, Marco; Maini, Carlo Ludovico; Sciuto, Rosa; Benassi, Marcello

    2006-06-15

    The standard computational method developed for internal radiation dosimetry is the MIRD (medical internal radiation dose) formalism, based on the assumption that tumor control is given by uniform dose and activity distributions. In modern systemic radiotherapy, however, the need for full 3D dose calculations that take into account the heterogeneous distribution of activity in the patient is now understood. When information on nonuniform distribution of activity becomes available from functional imaging, a more patient specific 3D dosimetry can be performed. Application of radiobiological models can be useful to correlate the calculated heterogeneous dose distributions to the current knowledge on tumor control probability of a homogeneous dose distribution. Our contribution to this field is the introduction of a parameter, the F factor, already used by our group in studying external beam radiotherapy treatments. This parameter allows one to write a simplified expression for tumor control probability (TCP) based on the standard linear quadratic (LQ) model and Poisson statistics. The LQ model was extended to include different treatment regimes involving source decay, incorporating the repair '{mu}' of sublethal radiation damage, the relative biological effectiveness and the effective 'waste' of dose delivered when repopulation occurs. The sensitivity of the F factor against radiobiological parameters ({alpha},{beta},{mu}) and the influence of the dose volume distribution was evaluated. Some test examples for {sup 131}I and {sup 90}Y labeled pharmaceuticals are described to further explain the properties of the F factor and its potential applications. To demonstrate dosimetric feasibility and advantages of the proposed F factor formalism in systemic radiotherapy, we have performed a retrospective planning study on selected patient case. F factor formalism helps to assess the total activity to be administered to the patient taking into account the heterogeneity in

  4. Development of targeted radiotherapy systems

    NASA Astrophysics Data System (ADS)

    Ferro, Guillermina; Murphy, Consuelo A.; Villarreal, José E.; Pedraza, Martha; García, Laura; Tendilla, José I.; Paredes, Lydia

    2001-10-01

    Conventional or external beam radiotherapy, has been a viable alternative for cancer treatment. Although this technique is effective, its use is limited if the patient has multiple malignant lesions (metastases). An alternative approach is based on the design of radiopharmaceuticals that, to be administered in the patient, are directed specifically toward the target cell producing a selective radiation delivery. This treatment is known as targeted radiotherapy. We have summarized and discussed some results related to our investigations on the development of targeted radiotherapy systems, including aspects of internal dosimetry.

  5. Kinetic magnetic-field effect involving the small biologically relevant inorganic radicals NO and O2(·-).

    PubMed

    Karogodina, Tatiana Y; Dranov, Igor G; Sergeeva, Svetlana V; Stass, Dmitry V; Steiner, Ulrich E

    2011-06-20

    Oxidation of dihydrorhodamine 123 (DHR) to rhodamine 123 (RH) by oxoperoxonitrite (ONOO(-)), formed through recombination of NO and O(2)(·-) radicals resulting from thermal decomposition of 3-morpholinosydnonimine (SIN-1) in buffered aerated aqueous solution at pH 7.6, represents a kinetic model system of the reactivity of NO and O(2)(·-) in biochemical systems. A magnetic-field effect (MFE) on the yield of RH detected in this system is explored in the full range of fields between 0 and 18 T. It is found to increase in a nearly linear fashion up to a value of 5.5±1.6 % at 18 T and 23 °C (3.1±0.7 % at 40 °C). A theoretical framework to analyze the MFE in terms of the magnetic-field-enhanced recombination rate constant k(rec) of NO and O(2)(·-) due to magnetic mixing of T(0) and S spin states of the radical pair by the Δg mechanism is developed, including estimation of magnetic properties (g tensor and spin relaxation times) of NO and O(2)(·-) in aqueous solution, and calculation of the MFE on k(rec) using the theoretical formalism of Gorelik at al. The factor with which the MFE on k(rec) is translated to the MFE on the yield of ONOO(-) and RH is derived for various kinetic scenarios representing possible sink channels for NO and O(2)(·-). With reasonable assumptions for the values of some unknown kinetic parameters, the theoretical predictions account well for the observed MFE.

  6. Graduate student involvement with designing inquiry-based Earth science field projects for the secondary-level classroom

    NASA Astrophysics Data System (ADS)

    McDermott, J. M.; Scherf, L.; Ward, S.; Cady, P.; Bromley, J.; Varner, R. K.; Froburg, E.

    2008-12-01

    In a secondary-level Earth System Science (ESS) curriculum, the most authentic learning is achieved through the inquiry-based application of real-world research methods in the context of modern understanding of the interconnected components of the Earth System (e.g. lithosphere, hydrosphere, atmosphere, and biosphere). Following the intensive ESST-1 summer institute at UNH, during which teachers enhance their ESS content knowledge via interactions with UNH faculty, staff, and graduate students, each participating teacher is paired with one graduate student fellow for the duration of the school year. This graduate fellow provides a continuing link between the secondary-level school teaching environment and university resources, facilitating the implementation of new content knowledge and current scientific research methodology into the classroom setting. According to the National Science Education Standards (1), scientific inquiry is the central strategy for teaching science. "In successful science classrooms, teachers and students collaborate in the pursuit of ideas... Students formulate questions and devise ways to answer them, they collect data and decide how to represent it, they organize data to generate knowledge, and they test the reliability of the knowledge they have generated. As they proceed, students explain and justify their work to themselves and to one another, learn to cope with problems such as the limitations of equipment, and react to challenges posed by the teacher and by classmates." To speak to these goals, an ongoing local wetland field study has been conceptualized and implemented in three example classrooms (seventh grade general science, ninth grade physical science and tenth grade biology) in two school systems (Oyster River Middle School in Durham, NH and Berlin High School in Berlin, NH). These field studies were conducted using authentic scientific equipment to collect data, including a Li-Cor 840 infrared CO2 analyzer and handmade

  7. [Task sharing with radiotherapy technicians in image-guided radiotherapy].

    PubMed

    Diaz, O; Lorchel, F; Revault, C; Mornex, F

    2013-10-01

    The development of accelerators with on-board imaging systems now allows better target volumes reset at the time of irradiation (image-guided radiotherapy [IGRT]). However, these technological advances in the control of repositioning led to a multiplication of tasks for each actor in radiotherapy and increase the time available for the treatment, whether for radiotherapy technicians or radiation oncologists. As there is currently no explicit regulatory framework governing the use of IGRT, some institutional experiments show that a transfer is possible between radiation oncologists and radiotherapy technicians for on-line verification of image positioning. Initial training for every technical and drafting procedures within institutions will improve audit quality by reducing interindividual variability. PMID:24007955

  8. [Hepatic tumors and radiotherapy].

    PubMed

    Rio, E; Mornex, F; Peiffert, D; Huertas, A

    2016-09-01

    Recent technological developments led to develop the concept of focused liver radiation therapy. We must distinguish primary and secondary tumors as the indications are restricted and must be discussed as an alternative to surgical or medical treatments. For hepatocellular carcinoma 5 to 10cm (or more), a conformational radiation with or without intensity modulation is performed. Stereotactic body radiotherapy (SBRT) is being evaluated and is increasingly proposed as an alternative to radiofrequency ablative treatment for primary or secondary tumors (typically less than 5cm). Tumor (and liver) movements induced by respiratory motions must be taken into account. Strict dosimetric criteria must be met with particular attention to the dose-volume histograms to liver and the hollow organs, including cases of SBRT. PMID:27521035

  9. Adapting radiotherapy to hypoxic tumours

    NASA Astrophysics Data System (ADS)

    Malinen, Eirik; Søvik, Åste; Hristov, Dimitre; Bruland, Øyvind S.; Rune Olsen, Dag

    2006-10-01

    In the current work, the concepts of biologically adapted radiotherapy of hypoxic tumours in a framework encompassing functional tumour imaging, tumour control predictions, inverse treatment planning and intensity modulated radiotherapy (IMRT) were presented. Dynamic contrast enhanced magnetic resonance imaging (DCEMRI) of a spontaneous sarcoma in the nasal region of a dog was employed. The tracer concentration in the tumour was assumed related to the oxygen tension and compared to Eppendorf histograph measurements. Based on the pO2-related images derived from the MR analysis, the tumour was divided into four compartments by a segmentation procedure. DICOM structure sets for IMRT planning could be derived thereof. In order to display the possible advantages of non-uniform tumour doses, dose redistribution among the four tumour compartments was introduced. The dose redistribution was constrained by keeping the average dose to the tumour equal to a conventional target dose. The compartmental doses yielding optimum tumour control probability (TCP) were used as input in an inverse planning system, where the planning basis was the pO2-related tumour images from the MR analysis. Uniform (conventional) and non-uniform IMRT plans were scored both physically and biologically. The consequences of random and systematic errors in the compartmental images were evaluated. The normalized frequency distributions of the tracer concentration and the pO2 Eppendorf measurements were not significantly different. 28% of the tumour had, according to the MR analysis, pO2 values of less than 5 mm Hg. The optimum TCP following a non-uniform dose prescription was about four times higher than that following a uniform dose prescription. The non-uniform IMRT dose distribution resulting from the inverse planning gave a three times higher TCP than that of the uniform distribution. The TCP and the dose-based plan quality depended on IMRT parameters defined in the inverse planning procedure (fields

  10. Ichthyosiform scaling secondary to megavoltage radiotherapy

    SciTech Connect

    Ross, E.V. )

    1991-07-01

    Acquired ichthyosis is a rare dermatosis associated with a number of malignancies. Side effects seen on the skin secondary to megavoltage radiotherapy are uncommon but may include fine dry desquamation and tanning. The authors present a case of ichthyosiform scaling limited to the radiation fields in a patient treated for brain metastases of a primary small cell lung carcinoma. The reader is reminded that side effects of megavoltage treatment do occur on the skin. A brief review of these effects is included. 5 references.

  11. Radiotherapy for intraarticular venous malformations of the knee.

    PubMed

    Fujita, Takeshi; Okimoto, Tomoaki; Ito, Katsuyoshi; Tanabe, Masahiro; Matsunaga, Naofumi

    2014-11-01

    Intraarticular venous malformation (IAVM) of the knee is a rare vascular disease that manifests with pain, swelling, and hemarthrosis. A young man with left knee pain and swelling was admitted to our institution for the treatment of the IAVM of the left knee which was diagnosed by a local orthopedic doctor via arthroscopy. A total dose of 40 Gy of radiotherapy was delivered with a daily dose of 2.0 Gy using 6 MV X-ray beams and a linear accelerator through anteroposterior portals. Fifteen months after radiotherapy, follow-up examination using radiologic imaging showed distinct shrinkage of the venous malformations. Swelling and pain of the left knee had decreased, and range of motion of the left knee was maintained. This report describes a case involving a 38-year-old man with IAVM of the left knee in whom favorable outcomes were obtained in response to radiotherapy. PMID:25017778

  12. Role of additional radiotherapy in advanced stages of Hodgkin's disease.

    PubMed

    Meerwaldt, J H; Coleman, C N; Fischer, R I; Lister, T A; Diehl, V

    1992-09-01

    Although radiotherapy is widely used as additional treatment following chemotherapy, its precise role has never been clearly proven. Relapses tend to occur in previously involved bulky sites. Non-randomized studies may suggest a positive effect of the addition of radiotherapy. This effect however, might also be caused by selection. Randomized studies have not resulted in a survival advantage for the patients treated with additional radiotherapy compared to no further treatment or additional chemotherapy. The SWOG study 7808 suggest a 20% benefit in remission duration for the nodular sclerosis histology subgroup. Definitive conclusions have to wait for more mature results of randomized studies including the ongoing EORTC study and the possibility to perform an overview of all studies. PMID:1280464

  13. Role of additional radiotherapy in advanced stages of Hodgkin's disease.

    PubMed

    Meerwaldt, J H; Coleman, C N; Fischer, R I; Lister, T A; Diehl, V

    1992-09-01

    Although radiotherapy is widely used as additional treatment following chemotherapy, its precise role has never been clearly proven. Relapses tend to occur in previously involved bulky sites. Non-randomized studies may suggest a positive effect of the addition of radiotherapy. This effect however, might also be caused by selection. Randomized studies have not resulted in a survival advantage for the patients treated with additional radiotherapy compared to no further treatment or additional chemotherapy. The SWOG study 7808 suggest a 20% benefit in remission duration for the nodular sclerosis histology subgroup. Definitive conclusions have to wait for more mature results of randomized studies including the ongoing EORTC study and the possibility to perform an overview of all studies.

  14. Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy.

    PubMed

    Hidaka, Takako; Chuman, Hideki; Nao-I, Nobuhisa

    2016-01-01

    Herein, we report a case of nontraumatic bilateral rhegmatogenous retinal detachment (RRD) during external beam radiotherapy for nonocular tumor, presented as an observational case study in conjunction with a review of the relevant literature. A 65-year-old male was referred to our hospital due to bilateral RRD. He underwent a biopsy for a tumor of the left frontal lobe 4 months prior to presentation, and the tumor had been diagnosed as primary central nerve system B-cell type lymphoma. He received chemotherapy and external beam radiotherapy for 1 month. There were no traumatic episodes. Bilateral retinal detachment occurred during a series of radiotherapies. Simultaneous nontraumatic bilateral retinal detachment is rare. The effects of radiotherapy on ocular functionality, particularly in cases involving retinal adhesion and vitreous contraction, may include RRD. Thus, it is necessary to closely monitor the eyes of patients undergoing radiotherapy, particularly those undergoing surgery for retinal detachment and those with a history of photocoagulation for retinal tears, a relevant family history, or risk factors known to be associated with RRD. PMID:27462261

  15. Factors involved in sustained use of point-of-use water disinfection methods: a field study from Flores Island, Indonesia.

    PubMed

    Roma, E; Bond, T; Jeffrey, P

    2014-09-01

    Many scientific studies have suggested that point-of-use water treatment can improve water quality and reduce the risk of infectious diseases. Despite the ease of use and relatively low cost of such methods, experience shows the potential benefits derived from provision of such systems depend on recipients' acceptance of the technology and its sustained use. To date, few contributions have addressed the problem of user experience in the post-implementation phase. This can diagnose challenges, which undermine system longevity and its sustained use. A qualitative evaluation of two household water treatment systems, solar disinfection (SODIS) and chlorine tablets (Aquatabs), in three villages was conducted by using a diagnostic tool focusing on technology performance and experience. Cross-sectional surveys and in-depth interviews were used to investigate perceptions of involved stakeholders (users, implementers and local government). Results prove that economic and functional factors were significant in using SODIS, whilst perceptions of economic, taste and odour components were important in Aquatabs use. Conclusions relate to closing the gap between factors that technology implementers and users perceive as key to the sustained deployment of point-of-use disinfection technologies.

  16. Factors involved in sustained use of point-of-use water disinfection methods: a field study from Flores Island, Indonesia.

    PubMed

    Roma, E; Bond, T; Jeffrey, P

    2014-09-01

    Many scientific studies have suggested that point-of-use water treatment can improve water quality and reduce the risk of infectious diseases. Despite the ease of use and relatively low cost of such methods, experience shows the potential benefits derived from provision of such systems depend on recipients' acceptance of the technology and its sustained use. To date, few contributions have addressed the problem of user experience in the post-implementation phase. This can diagnose challenges, which undermine system longevity and its sustained use. A qualitative evaluation of two household water treatment systems, solar disinfection (SODIS) and chlorine tablets (Aquatabs), in three villages was conducted by using a diagnostic tool focusing on technology performance and experience. Cross-sectional surveys and in-depth interviews were used to investigate perceptions of involved stakeholders (users, implementers and local government). Results prove that economic and functional factors were significant in using SODIS, whilst perceptions of economic, taste and odour components were important in Aquatabs use. Conclusions relate to closing the gap between factors that technology implementers and users perceive as key to the sustained deployment of point-of-use disinfection technologies. PMID:25252361

  17. Modification of hydrological properties in a fine textured soil following field application of pelletized biochar: investigation of the mechanism involved.

    NASA Astrophysics Data System (ADS)

    Costanza Andrenelli, Maria; Mocali, Stefano; Pellegrini, Sergio; Vignozzi, Nadia

    2016-04-01

    The application of pelletized biochar is seldom employed in field, and its effect on soil hydrological behaviour scarcely investigated. Biochar is usually added in powdered or granular form to improve the homogeneity of distribution, meanwhile favouring its interaction with soil matrix. In this study we evaluated the possibility of applying pelletized biochar as soil conditioner to enhance, during a single cropping season, the hydrological behaviour of a silty clay loam soil prone to structure degradation. For that purpose, the water retention curves (WRCs) were determined on undisturbed soil samples (0-15 cm) three months after the addition, at the rate of 14 Mg ha-1, of two differently pyrolyzed biochars (B1 and B2). Starting from the WRCs the pore size distribution was determined. The gravimetric water content at both field capacity (-10 kPa) and wilting point (-1,500 kPa) was also measured on biochar samples to assess their available water capacity (AWC). In both the treatments, soil bulk density (BD) was significantly lower compared to control, apparently as direct consequence of the addition of low density pellets. Actually, excluding the intrinsic biochar porosity from soil bulk density calculation, BD values of the treated soils remain lower of around 10% over control. Such findings suggest that a modification of soil structural characteristics might have been induced by pellet addition. Data of the WRCs indicate a significant increase of transmission (500-50 micron), storage (50-0.5 micron) and AWC pores (30-0.2 micron) in the amended soils. The two biochars affected the AWC by direct pore contribution, but the extent of such effect was related to the biochar type: the tested pelletized biomass seems to have positive effects provided that the pyrolysis temperature does not exceed 800°C, as in the case of B1. The overall hydrological improvement might be correlated to both the inherent biochar retention capacity and a merely mechanical process of

  18. Modification of hydrological properties in a fine textured soil following field application of pelletized biochar: investigation of the mechanism involved.

    NASA Astrophysics Data System (ADS)

    Costanza Andrenelli, Maria; Mocali, Stefano; Pellegrini, Sergio; Vignozzi, Nadia

    2016-04-01

    The application of pelletized biochar is seldom employed in field, and its effect on soil hydrological behaviour scarcely investigated. Biochar is usually added in powdered or granular form to improve the homogeneity of distribution, meanwhile favouring its interaction with soil matrix. In this study we evaluated the possibility of applying pelletized biochar as soil conditioner to enhance, during a single cropping season, the hydrological behaviour of a silty clay loam soil prone to structure degradation. For that purpose, the water retention curves (WRCs) were determined on undisturbed soil samples (0-15 cm) three months after the addition, at the rate of 14 Mg ha‑1, of two differently pyrolyzed biochars (B1 and B2). Starting from the WRCs the pore size distribution was determined. The gravimetric water content at both field capacity (-10 kPa) and wilting point (-1,500 kPa) was also measured on biochar samples to assess their available water capacity (AWC). In both the treatments, soil bulk density (BD) was significantly lower compared to control, apparently as direct consequence of the addition of low density pellets. Actually, excluding the intrinsic biochar porosity from soil bulk density calculation, BD values of the treated soils remain lower of around 10% over control. Such findings suggest that a modification of soil structural characteristics might have been induced by pellet addition. Data of the WRCs indicate a significant increase of transmission (500-50 micron), storage (50-0.5 micron) and AWC pores (30-0.2 micron) in the amended soils. The two biochars affected the AWC by direct pore contribution, but the extent of such effect was related to the biochar type: the tested pelletized biomass seems to have positive effects provided that the pyrolysis temperature does not exceed 800°C, as in the case of B1. The overall hydrological improvement might be correlated to both the inherent biochar retention capacity and a merely mechanical process of

  19. Enhanced Glutamatergic Synaptic Plasticity in the Hippocampal CA1 Field of Food-Restricted Rats: Involvement of CB1 Receptors.

    PubMed

    Talani, Giuseppe; Licheri, Valentina; Biggio, Francesca; Locci, Valentina; Mostallino, Maria Cristina; Secci, Pietro Paolo; Melis, Valentina; Dazzi, Laura; Carta, Gianfranca; Banni, Sebastiano; Biggio, Giovanni; Sanna, Enrico

    2016-04-01

    The endogenous endocannabinoid system has a crucial role in regulating appetite and feeding behavior in mammals, as well as working memory and reward mechanisms. In order to elucidate the possible role of cannabinoid type-1 receptors (CB1Rs) in the regulation of hippocampal plasticity in animals exposed to food restriction (FR), we limited the availability of food to a 2-h daily period for 3 weeks in Sprague-Dawley rats. FR rats showed a higher long-term potentiation at hippocampal CA1 excitatory synapses with a parallel increase in glutamate release when compared with animals fed ad libitum. FR rats showed a significant increase in the long-term spatial memory determined by Barnes maze. FR was also associated with a decreased inhibitory effect of the CB1R agonist win55,212-2 on glutamatergic field excitatory postsynaptic potentials, together with a decrease in hippocampal CB1R protein expression. In addition, hippocampal brain-derived neurotrophic factor protein levels and mushroom dendritic spine density were significantly enhanced in FR rats. Altogether, our data suggest that alterations of hippocampal CB1R expression and function in FR rats are associated with dendritic spine remodeling and functional potentiation of CA1 excitatory synapses, and these findings are consistent with increasing evidence supporting the idea that FR may improve cognitive functions.

  20. Leukemia Cutis of the Face, Scalp, and Neck Treated with Non-coplanar Split Field Volumetric Modulated Arc Therapy: A Case Report

    PubMed Central

    Alite, Fiori; Steber, Jennifer; Emami, Bahman; Surucu, Murat

    2015-01-01

    Malignancies with a superficial involvement of the scalp present a unique technical challenge for radiation treatment planning. As an example of this, leukemic infiltration of the superficial skin as the only presentation of the disease is a rare entity. For such cases, radiation oncologists have typically treated with 3D conformal radiotherapy with matched electron fields, a technique that can lead to significant dose inhomogeneity. In this report, we describe the case of a patient with leukemia cutis with a superficial involvement of the scalp, face, and shoulders that was treated with volumetric modulated arc radiotherapy, with an impressive clinical response.  PMID:26848419

  1. Sensory mechanisms involved in the induction of pseudopregnancy by progesterone: increased sensitivity to stimulation of the pudendal sensory field.

    PubMed

    Luque, E H; Castro-Vazquez, A

    1983-07-01

    The sensory mechanisms that participate in the induction of pseudopregnancy after a single injection of progesterone were investigated. Unless otherwise indicated, rats were kept in group cages and vaginal smears were taken daily. Progesterone evoked pseudopregnancy in a dose-dependent manner when administered to proestrous or estrous rats that received no cervicovaginal stimulation. The probability of pseudopregnancy after progesterone was higher on estrus. Cervicovaginal stimulation of proestrous rats that received 5 mg progesterone 10 h before was performed with a rod with a sliding stop attached to regulate its intravaginal penetration. Progesterone facilitated responsiveness to this stimulus, although the amount injected was not significantly effective in increasing the incidence of pseudopregnancy in nonstimulated rats. However, the mere application of the stop of the stimulator on the perineal skin was followed by a significantly higher incidence of pseudopregnancy in progesterone-injected rats than in their vehicle-injected controls, which suggested an action of the steroid on perineal sensitivity. Accordingly, the pseudopregnancy-evoking effect of progesterone was clearly inhibited by refraining from taking vaginal smears for 5 days after steroid injection on estrus. No further inhibition was observed after isolating the animals in single rat cages. However, daily finger stimulation of the perineal skin of nonsmeared rats restored to a normal level response to progesterone. Furthermore, this response was severely impaired by transecting the pudendal nerves before the injection. It is concluded that pseudopregnancy is induced in progesterone-treated rats through sensory stimulation of the pudendal receptive field and it is suggested that the pudendal nerve may subserve as a secondary afferent system to elicit the pseudopregnancy response. The possibility progesterone also acts on other afferent systems including the main afferent system constituted by the

  2. Combination Short-Course Preoperative Irradiation, Surgical Resection, and Reduced-Field High-Dose Postoperative Irradiation in the Treatment of Tumors Involving the Bone

    SciTech Connect

    Wagner, Timothy D. Kobayashi, Wendy; Dean, Susan; Goldberg, Saveli I.; Kirsch, David G.; Suit, Herman D.; Hornicek, Francis J.; Pedlow, Francis X.; Raskin, Kevin A.; Springfield, Dempsey S.; Yoon, Sam S.; Gebhardt, Marc C.; Mankin, Henry J.; DeLaney, Thomas F.

    2009-01-01

    Purpose: To assess the feasibility and outcomes of combination short-course preoperative radiation, resection, and reduced-field (tumor bed without operative field coverage) high-dose postoperative radiation for patients with solid tumors mainly involving the spine and pelvis. Methods and Materials: Between 1982 and 2006, a total of 48 patients were treated using this treatment strategy for solid tumors involving bone. Radiation treatments used both photons and protons. Results: Of those treated, 52% had chordoma, 31% had chondrosarcoma, 8% had osteosarcoma, and 4% had Ewing's sarcoma, with 71% involving the pelvis/sacrum and 21% elsewhere in the spine. Median preoperative dose was 20 Gy, with a median of 50.4 Gy postoperatively. With 31.8-month median follow-up, the 5-year overall survival (OS) rate is 65%; 5-year disease-free survival (DFS) rate, 53.8%; and 5-year local control (LC) rate, 72%. There were no significant differences in OS, DFS, and LC according to histologic characteristics. Between primary and recurrent disease, there was no significant difference in OS rates (74.4% vs. 51.4%, respectively; p = 0.128), in contrast to DFS (71.5% vs. 18.3%; p = 0.0014) and LC rates (88.9% vs. 30.9%; p = 0.0011) favoring primary disease. After resection, 10 patients experienced delayed wound healing that did not significantly impact on OS, DFS, or LC. Conclusion: This approach is promising for patients with bone sarcomas in which resection will likely yield close/positive margins. It appears to inhibit tumor seeding with an acceptable rate of wound-healing complications. Dose escalation is accomplished without high-dose preoperative radiation (likely associated with higher rates of acute wound healing delays) or large-field postoperative radiation only (likely associated with late normal tissue toxicity). The LC and DFS rates are substantially better for patients with primary than recurrent sarcomas.

  3. Integrating Geriatric Assessment into Decision-Making after Prostatectomy: Adjuvant Radiotherapy, Salvage Radiotherapy, or None?

    PubMed Central

    Goineau, Aurore; d’Aillières, Bénédicte; de Decker, Laure; Supiot, Stéphane

    2015-01-01

    Despite current advancements in the field, management of older prostate cancer patients still remains a big challenge for Geriatric Oncology. The International Society of Geriatric Oncology (ISGO) has recently updated its recommendations in this area, and these have been widely adopted, notably by the European Association of Urology. This article outlines the principles that should be observed in the management of elderly patients who have recently undergone prostatectomy for malignancy or with a biochemical relapse following prostatectomy. Further therapeutic intervention should not be considered in those patients who are classified as frail in the geriatric assessment. In patients presenting better health conditions, salvage radiotherapy is to be preferred to adjuvant radiotherapy, which is only indicated in certain exceptional cases. Radiotherapy of the operative bed presents a higher risk to the elderly. Additionally, hormone therapy clearly shows higher side effects in older patients and therefore it should not be administered to asymptomatic patients. We propose a decision tree based on the ISGO recommendations, with specific modifications for patients in biochemical relapse. PMID:26528437

  4. [Adaptative radiotherapy: The case for MRI-guided radiotherapy].

    PubMed

    Maingon, P

    2016-10-01

    The concept of image-guided radiotherapy benefits from the development of magnetic resonance imaging (MRI) associated with different capacities of tissue analyses such as spectroscopy or diffusion analysis. The production of devices allowing the repositioning of patients through MRI represents a strong added value without delivering any additional dose to the patient while the optimization of the adaptative strategies are facilitated by a better contrast of the soft tissues compared to the scanner. The advantages of MRI are well demonstrated for brain tumours, head and neck carcinomas, pelvic tumors, mediastinal malignancies, gastrointestinal tract diseases. Adaptative radiotherapy inaugurates a new area of radiotherapy with different modalities. Several technological solutions are provided or discussed allowing the patients to benefit from thses new technologies as soon as possible.

  5. [Adaptative radiotherapy: The case for MRI-guided radiotherapy].

    PubMed

    Maingon, P

    2016-10-01

    The concept of image-guided radiotherapy benefits from the development of magnetic resonance imaging (MRI) associated with different capacities of tissue analyses such as spectroscopy or diffusion analysis. The production of devices allowing the repositioning of patients through MRI represents a strong added value without delivering any additional dose to the patient while the optimization of the adaptative strategies are facilitated by a better contrast of the soft tissues compared to the scanner. The advantages of MRI are well demonstrated for brain tumours, head and neck carcinomas, pelvic tumors, mediastinal malignancies, gastrointestinal tract diseases. Adaptative radiotherapy inaugurates a new area of radiotherapy with different modalities. Several technological solutions are provided or discussed allowing the patients to benefit from thses new technologies as soon as possible. PMID:27599686

  6. Our intraoperative boost radiotherapy experience and applications

    PubMed Central

    Günay, Semra; Alan, Ömür; Yalçın, Orhan; Türkmen, Aygen; Dizdar, Nihal

    2016-01-01

    Objective: To present our experience since November 2013, and case selection criteria for intraoperative boost radiotherapy (IObRT) that significantly reduces the local recurrence rate after breast conserving surgery in patients with breast cancer. Material and Methods: Patients who were suitable for IObRT were identified within the group of patients who were selected for breast conserving surgery at our breast council. A MOBETRON (mobile linear accelerator for IObRT) was used for IObRt during surgery. Results: Patients younger than 60 years old with <3 cm invasive ductal cancer in one focus (or two foci within 2 cm), with a histologic grade of 2–3, and a high possibility of local recurrence were admitted for IObRT application. Informed consent was obtained from all participants. Lumpectomy and sentinel lymph node biopsy was performed and advancement flaps were prepared according to the size and inclination of the conus following evaluation of tumor size and surgical margins by pathology. Distance to the thoracic wall was measured, and a radiation oncologist and radiation physicist calculated the required dose. Anesthesia was regulated with slower ventilation frequency, without causing hypoxia. The skin and incision edges were protected, the field was radiated (with 6 MeV electron beam of 10 Gy) and the incision was closed. In our cases, there were no major postoperative surgical or early radiotherapy related complications. Conclusion: The completion of another stage of local therapy with IObRT during surgery positively effects sequencing of other treatments like chemotherapy, hormonotherapy and radiotherapy, if required. IObRT increases disease free and overall survival, as well as quality of life in breast cancer patients. PMID:26985156

  7. Dosimetry in steep dose-rate gradient radiation fields: A challenge in clinical applications

    SciTech Connect

    Massillon-JL, G.

    2010-12-07

    The fundamental goal of radiotherapy is to reduce the damage to normal tissue and optimize the dose to the tumor with an associated high probability of cure. Because of this, an accurate and precise knowledge of the radiation dose distribution delivered around the tumor volume during radiotherapy treatments such as stereotactic radiosurgery, intensity modulated radiotherapy or brachytherapy with low-energy X-ray and beta particle sources is of great importance. However, in each of these radiation fields, there exists a steep dose-rate gradient which makes it very difficult to perform accurate dose measurements. In this work, the physics phenomena involved in the energy absorption for each of these situations are discussed, and a brief revision of what the Medical Physics community is doing is presented.

  8. Dosimetry in steep dose-rate gradient radiation fields: A challenge in clinical applications

    NASA Astrophysics Data System (ADS)

    Massillon-JL, G.

    2010-12-01

    The fundamental goal of radiotherapy is to reduce the damage to normal tissue and optimize the dose to the tumor with an associated high probability of cure. Because of this, an accurate and precise knowledge of the radiation dose distribution delivered around the tumor volume during radiotherapy treatments such as stereotactic radiosurgery, intensity modulated radiotherapy or brachytherapy with low-energy X-ray and beta particle sources is of great importance. However, in each of these radiation fields, there exists a steep dose-rate gradient which makes it very difficult to perform accurate dose measurements. In this work, the physics phenomena involved in the energy absorption for each of these situations are discussed, and a brief revision of what the Medical Physics community is doing is presented.

  9. Temporal Change in Brain Natriuretic Peptide After Radiotherapy for Thoracic Esophageal Cancer

    SciTech Connect

    Jingu, Keiichi Nemoto, Kenji; Kaneta, Tomohiro; Oikawa, Minako; Ogawa, Yoshihiro; Ariga, Hisanori; Takeda, Ken; Sakayauchi, Toru; Fujimoto, Keisuke; Narazaki, Kakutaro; Takai, Yoshihiro; Nakata, Eiko; Fukuda, Hiroshi; Takahashi, Shoki; Yamada, Shogo

    2007-12-01

    Purpose: To investigate the relationships of plasma levels of brain natriuretic peptide (BNP) with abnormal {sup 18}F-fluorodeoxyglucose (FDG) accumulation in the myocardium corresponding to irradiated fields and temporal changes in BNP, which is used as an index of heart remodeling, after radiotherapy for the mediastinum. Materials and Methods: Brain natriuretic peptide concentrations were measured before and after radiotherapy for thoracic esophageal cancer, and the change in BNP concentration after radiotherapy was investigated. Moreover, FDG accumulation in the myocardium was investigated in patients who had undergone FDG positron emission tomography less than 14 days before or after measurement of BNP concentration, and the Mann-Whitney U test was used to detect significant difference between BNP concentrations in patients with and without abnormal FDG accumulation corresponding to the irradiated field. Results: There was significant difference between the levels of BNP in patients without abnormal FDG accumulation in the irradiated myocardium and in patients with abnormal FDG accumulation (p < 0.001). The levels of BNP in the 9-24 months after radiotherapy group and in the >24 months after radiotherapy group were significantly higher than the levels in the before radiotherapy group, immediately after radiotherapy group, 1-2 months after radiotherapy group, and control group. Conclusions: The level of BNP was significantly increased more than 9 months after the start of radiotherapy and was significantly higher in patients who had high FDG accumulation corresponding to the irradiated field. The results of this study indicate that BNP concentration might be an early indicator of radiation-induced myocardial damage.

  10. Stereotactic Body Radiotherapy for Lesions of the Spine and Paraspinal Regions

    SciTech Connect

    Nelson, John W.; Yoo, David S.; Sampson, John H.; Isaacs, Robert E.; Larrier, Nicole A.; Marks, Lawrence B.; Yin Fangfang; Wu, Q. Jackie; Wang Zhiheng; Kirkpatrick, John P.

    2009-04-01

    Purpose: To describe our experience and clinical strategy for stereotactic body radiotherapy (SBRT) of spinal lesions. Methods and Materials: Thirty-two patients with 33 spinal lesions underwent computed tomography-based simulation while free breathing. Gross/clinical target volumes included involved portions of the vertebral body and paravertebral/epidural tumor. Planning target volume (PTV) expansion was 6 mm axially and 3 mm radially; the cord was excluded from the PTV. Biologic equivalent dose was calculated using the linear quadratic model with {alpha}/{beta} = 3 Gy. Treatment was linear accelerator based with on-board imaging; dose was adjusted to maintain cord dose within tolerance. Survival, local control, pain, and neurologic status were monitored. Results: Twenty-one patients are alive at 1 year (median survival, 14 months). Median follow-up is 6 months for all patients (7 months for survivors). Mean previous radiotherapy dose to 22 patients was 35 Gy, and median interval was 17 months. Renal (31%), breast, and lung (19% each) were the most common histologic sites. Three SBRT fractions (range, one to four fractions) of 7 Gy (range, 5-16 Gy) were delivered. Median cord and target biologic equivalent doses were 70 Gy{sub 3} and 34.3 Gy{sub 10}, respectively. Thirteen patients reported complete and 17 patients reported partial pain relief at 1 month. There were four failures (mean, 5.8 months) with magnetic resonance imaging evidence of in-field progression. No dosimetric parameters predictive of failure were identified. No treatment-related toxicity was seen. Conclusions: Spinal SBRT is effective in the palliative/re-treatment setting. Volume expansion must ensure optimal PTV coverage while avoiding spinal cord toxicity. The long-term safety of spinal SBRT and the applicability of the linear-quadratic model in this setting remain to be determined, particularly the time-adjusted impact of prior radiotherapy.

  11. Systematic Endobronchial Ultrasound-guided Mediastinal Staging Versus Positron Emission Tomography for Comprehensive Mediastinal Staging in NSCLC Before Radical Radiotherapy of Non-small Cell Lung Cancer: A Pilot Study.

    PubMed

    Steinfort, Daniel P; Siva, Shankar; Leong, Tracy L; Rose, Morgan; Herath, Dishan; Antippa, Phillip; Ball, David L; Irving, Louis B

    2016-02-01

    Despite known limitations of positron emission tomography (PET) for mediastinal staging of non-small cell lung cancer (NSCLC), radiation treatment fields are generally based on PET-identified disease extent. However, no studies have examined the accuracy of FDG-PET/CT on a per-node basis in patients being considered for curative-intent radiotherapy in NSCLC.In a prospective trial, patients with NSCLC being considered for definitive thoracic radiotherapy (± systemic chemotherapy) underwent minimally invasive systematic mediastinal evaluation with endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) following noninvasive staging with integrated PET-CT.Thirty patients underwent EBUS-TBNA, with TBNA performed from a mean 2.5 lymph node (LN) stations per patient (median 3, range 1-5). Discordant findings between PET-CT and EBUS-TBNA were observed in 10 patients (33%, 95% CI 19%-51%). PET-occult LN metastases were demonstrated by EBUS in 4 patients, whereas a lesser extent of mediastinal involvement, compared with FDG-PET, was demonstrated by EBUS in 6 patients, including 2 patients downstaged from cN3 to pN2. LNs upstaged by EBUS were significantly smaller than nodes downstaged by EBUS, 7.5 mm (range 7-9) versus 12 mm (range 6-21), P = 0.005.A significant proportion of patients considered for definitive radiotherapy (+/-chemotherapy) undergoing systematic mediastinal evaluation with EBUS-TBNA in this study have an extent of mediastinal NSCLC involvement discordant with that indicated by PET-CT. Systematic EBUS-TBNA may aid in defining the extent of mediastinal involvement in NSCLC patients undergoing radiotherapy. Systematic EBUS-TBNA has the potential to contribute significantly to radiotherapy planning and delivery, by either identifying occult nodal metastases, or demonstrating FDG-avid LNs to be disease-free. PMID:26937894

  12. Voice following radiotherapy.

    PubMed

    Stoicheff, M L

    1975-04-01

    This study was undertaken to provide information on the voice of patients following radiotherapy for glottic cancer. Part I presents findings from questionnaires returned by 227 of 235 patients successfully irradiated for glottic cancer from 1960 through 1971. Part II presents preliminary findings on the speaking fundamental frequencies of 22 irradiated patients. Normal to near-normal voice was reported by 83 percent of the 227 patients; however, 80 percent did indicate persisting vocal difficulties such as fatiguing of voice with much usage, inability to sing, reduced loudness, hoarse voice quality and inability to shout. Amount of talking during treatments appeared to affect length of time for voice to recover following treatments in those cases where it took from nine to 26 weeks; also, with increasing years since treatment, patients rated their voices more favorably. Smoking habits following treatments improved significantly with only 27 percent smoking heavily as compared with 65 percent prior to radiation therapy. No correlation was found between smoking (during or after treatments) and vocal ratings or between smoking and length of time for voice to recover. There was no relationship found between reported vocal ratings and stage of the disease. Data on mean speaking fundamental frequency seem to indicate a trend toward lower frequencies in irradiated patients as compared with normals. A trend was also noted in both irradidated and control groups for lower speaking fundamental frequencies in heavy smokers compared with non-smokers or previous smokers. These trends would indicate some vocal cord thickening or edema in irradiated patients and in heavy smokers. It is suggested that the study of irradiated patients' voices before, during and following treatments by means of audio, aerodynamic and acoustic instrumentation would yield additional information of diagnostic value on recovery of laryngeal function. It is also suggested that the voice pathologist could

  13. Introduction to suspension levels: radiotherapy.

    PubMed

    Horton, P; Lillicrap, S; Lamm, I-L; Lehmann, W

    2013-02-01

    In 2007, the European Commission (EC) commissioned a group of experts to undertake the revision of Report Radiation Protection (RP 91) 'Criteria for acceptability of radiological (including radiotherapy) and nuclear medicine installations' written in 1997. The revised draft report was submitted to the EC in 2010, who issued it for public consultation. The EC has commissioned the same group of experts to consider the comments of the public consultation for further improvement of the revised report. The EC intends to publish the final report under its Radiation Report Series as RP 162. This paper describes the background to the selection of the key performance parameters for radiotherapy equipment and sets out the sources of their criteria of acceptability including suspension levels for a wide range of radiotherapy equipment.

  14. Expanding global access to radiotherapy.

    PubMed

    Atun, Rifat; Jaffray, David A; Barton, Michael B; Bray, Freddie; Baumann, Michael; Vikram, Bhadrasain; Hanna, Timothy P; Knaul, Felicia M; Lievens, Yolande; Lui, Tracey Y M; Milosevic, Michael; O'Sullivan, Brian; Rodin, Danielle L; Rosenblatt, Eduardo; Van Dyk, Jacob; Yap, Mei Ling; Zubizarreta, Eduardo; Gospodarowicz, Mary

    2015-09-01

    Radiotherapy is a critical and inseparable component of comprehensive cancer treatment and care. For many of the most common cancers in low-income and middle-income countries, radiotherapy is essential for effective treatment. In high-income countries, radiotherapy is used in more than half of all cases of cancer to cure localised disease, palliate symptoms, and control disease in incurable cancers. Yet, in planning and building treatment capacity for cancer, radiotherapy is frequently the last resource to be considered. Consequently, worldwide access to radiotherapy is unacceptably low. We present a new body of evidence that quantifies the worldwide coverage of radiotherapy services by country. We show the shortfall in access to radiotherapy by country and globally for 2015-35 based on current and projected need, and show substantial health and economic benefits to investing in radiotherapy. The cost of scaling up radiotherapy in the nominal model in 2015-35 is US$26·6 billion in low-income countries, $62·6 billion in lower-middle-income countries, and $94·8 billion in upper-middle-income countries, which amounts to $184·0 billion across all low-income and middle-income countries. In the efficiency model the costs were lower: $14·1 billion in low-income, $33·3 billion in lower-middle-income, and $49·4 billion in upper-middle-income countries-a total of $96·8 billion. Scale-up of radiotherapy capacity in 2015-35 from current levels could lead to saving of 26·9 million life-years in low-income and middle-income countries over the lifetime of the patients who received treatment. The economic benefits of investment in radiotherapy are very substantial. Using the nominal cost model could produce a net benefit of $278·1 billion in 2015-35 ($265·2 million in low-income countries, $38·5 billion in lower-middle-income countries, and $239·3 billion in upper-middle-income countries). Investment in the efficiency model would produce in the same period an even

  15. Expanding global access to radiotherapy.

    PubMed

    Atun, Rifat; Jaffray, David A; Barton, Michael B; Bray, Freddie; Baumann, Michael; Vikram, Bhadrasain; Hanna, Timothy P; Knaul, Felicia M; Lievens, Yolande; Lui, Tracey Y M; Milosevic, Michael; O'Sullivan, Brian; Rodin, Danielle L; Rosenblatt, Eduardo; Van Dyk, Jacob; Yap, Mei Ling; Zubizarreta, Eduardo; Gospodarowicz, Mary

    2015-09-01

    Radiotherapy is a critical and inseparable component of comprehensive cancer treatment and care. For many of the most common cancers in low-income and middle-income countries, radiotherapy is essential for effective treatment. In high-income countries, radiotherapy is used in more than half of all cases of cancer to cure localised disease, palliate symptoms, and control disease in incurable cancers. Yet, in planning and building treatment capacity for cancer, radiotherapy is frequently the last resource to be considered. Consequently, worldwide access to radiotherapy is unacceptably low. We present a new body of evidence that quantifies the worldwide coverage of radiotherapy services by country. We show the shortfall in access to radiotherapy by country and globally for 2015-35 based on current and projected need, and show substantial health and economic benefits to investing in radiotherapy. The cost of scaling up radiotherapy in the nominal model in 2015-35 is US$26·6 billion in low-income countries, $62·6 billion in lower-middle-income countries, and $94·8 billion in upper-middle-income countries, which amounts to $184·0 billion across all low-income and middle-income countries. In the efficiency model the costs were lower: $14·1 billion in low-income, $33·3 billion in lower-middle-income, and $49·4 billion in upper-middle-income countries-a total of $96·8 billion. Scale-up of radiotherapy capacity in 2015-35 from current levels could lead to saving of 26·9 million life-years in low-income and middle-income countries over the lifetime of the patients who received treatment. The economic benefits of investment in radiotherapy are very substantial. Using the nominal cost model could produce a net benefit of $278·1 billion in 2015-35 ($265·2 million in low-income countries, $38·5 billion in lower-middle-income countries, and $239·3 billion in upper-middle-income countries). Investment in the efficiency model would produce in the same period an even

  16. [Head and neck adaptive radiotherapy].

    PubMed

    Graff, P; Huger, S; Kirby, N; Pouliot, J

    2013-10-01

    Onboard volumetric imaging systems can provide accurate data of the patient's anatomy during a course of head and neck radiotherapy making it possible to assess the actual delivered dose and to evaluate the dosimetric impact of complex daily positioning variations and gradual anatomic changes such as geometric variations of tumors and normal tissues or shrinkage of external contours. Adaptive radiotherapy is defined as the correction of a patient's treatment planning to adapt for individual variations observed during treatment. Strategies are developed to selectively identify patients that require replanning because of an intolerable dosimetric drift. Automated tools are designed to limit time consumption. Deformable image registration algorithms are the cornerstones of these strategies, but a better understanding of their limits of validity is required before adaptive radiotherapy can be safely introduced to daily practice. Moreover, strict evaluation of the clinical benefits is yet to be proven.

  17. [Adaptive radiotherapy in routine: The radiation oncologist's point of view].

    PubMed

    Henriques de Figueiredo, B; Petit, A; Sargos, P; Kantor, G; Pouypoudat, C; Saut, O; Zacharatou, C; Antoine, M

    2015-10-01

    Adaptive radiotherapy is defined as all processes leading to the modification of a treatment plan on the basis of patient-specific variations observed during the course of a treatment. This concept is currently of particular relevance due to the development of onboard volumetric imaging systems, which allow for daily viewing of variations in both tumour and organs at risk in terms of position, shape or volume. However, its application in routine clinical practice is limited due to the demanding nature of the processes involved (re-delineation and replanning) and increased dependence on available human resources. Even if "online" strategies, based on deformable image registration (DIR) algorithms, could lead to a reduction in both work and calculation time, for the moment their use is limited to the research field due to uncertainties surrounding the validity of results gathered. Other strategies without DIR can be used as "offline" or "hybrid offline-online" strategies that seem to offer a compromise between time consumption and therapeutic gain for the patient. PMID:26337475

  18. [Adaptive radiotherapy in routine: The radiation oncologist's point of view].

    PubMed

    Henriques de Figueiredo, B; Petit, A; Sargos, P; Kantor, G; Pouypoudat, C; Saut, O; Zacharatou, C; Antoine, M

    2015-10-01

    Adaptive radiotherapy is defined as all processes leading to the modification of a treatment plan on the basis of patient-specific variations observed during the course of a treatment. This concept is currently of particular relevance due to the development of onboard volumetric imaging systems, which allow for daily viewing of variations in both tumour and organs at risk in terms of position, shape or volume. However, its application in routine clinical practice is limited due to the demanding nature of the processes involved (re-delineation and replanning) and increased dependence on available human resources. Even if "online" strategies, based on deformable image registration (DIR) algorithms, could lead to a reduction in both work and calculation time, for the moment their use is limited to the research field due to uncertainties surrounding the validity of results gathered. Other strategies without DIR can be used as "offline" or "hybrid offline-online" strategies that seem to offer a compromise between time consumption and therapeutic gain for the patient.

  19. Liver-Directed Radiotherapy for Hepatocellular Carcinoma

    PubMed Central

    Keane, Florence K.; Wo, Jennifer Y.; Zhu, Andrew X.; Hong, Theodore S.

    2016-01-01

    Background The incidence of hepatocellular carcinoma (HCC) continues to increase world-wide. Many patients present with advanced disease with extensive local tumor or vascular invasion and are not candidates for traditionally curative therapies such as orthotopic liver transplantation (OLT) or resection. Radiotherapy (RT) was historically limited by its inability to deliver a tumoricidal dose; however, modern RT techniques have prompted renewed interest in the use of liver-directed RT to treat patients with primary hepatic malignancies. Summary The aim of this review was to discuss the use of external beam RT in the treatment of HCC, with particular focus on the use of stereotactic body radiotherapy (SBRT). We review the intricacies of SBRT treatment planning and delivery. Liver-directed RT involves accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. We also summarize the published data on liver-directed RT, and demonstrate that it is associated with excellent local control and survival rates, particularly in patients who are not candidates for OLT or resection. Key Messages Modern liver-directed RT is safe and effective for the treatment of HCC, particularly in patients who are not candidates for OLT or resection. Liver-directed RT, including SBRT, depends on accurate target identification, precise and reproducible patient immobilization, and assessment of target and organ motion. Further prospective studies are needed to fully delineate the role of liver-directed RT in the treatment of HCC. PMID:27493895

  20. Predicting toxicity in radiotherapy for prostate cancer.

    PubMed

    Landoni, Valeria; Fiorino, Claudio; Cozzarini, Cesare; Sanguineti, Giuseppe; Valdagni, Riccardo; Rancati, Tiziana

    2016-03-01

    This comprehensive review addresses most organs at risk involved in planning optimization for prostate cancer. It can be considered an update of a previous educational review that was published in 2009 (Fiorino et al., 2009). The literature was reviewed based on PubMed and MEDLINE database searches (from January 2009 up to September 2015), including papers in press; for each section/subsection, key title words were used and possibly combined with other more general key-words (such as radiotherapy, dose-volume effects, NTCP, DVH, and predictive model). Publications generally dealing with toxicity without any association with dose-volume effects or correlations with clinical risk factors were disregarded, being outside the aim of the review. A focus was on external beam radiotherapy, including post-prostatectomy, with conventional fractionation or moderate hypofractionation (<4Gy/fraction); extreme hypofractionation is the topic of another paper in this special issue. Gastrointestinal and urinary toxicity are the most investigated endpoints, with quantitative data published in the last 5years suggesting both a dose-response relationship and the existence of a number of clinical/patient related risk factors acting as dose-response modifiers. Some results on erectile dysfunction, bowel toxicity and hematological toxicity are also presented. PMID:27068274

  1. Quality of Radiotherapy Reporting in Randomized Controlled Trials of Hodgkin's Lymphoma and Non-Hodgkin's Lymphoma: A Systematic Review

    SciTech Connect

    Bekelman, Justin E. Yahalom, Joachim

    2009-02-01

    Purpose: Standards for the reporting of radiotherapy details in randomized controlled trials (RCTs) are lacking. Although radiotherapy (RT) is an important component of curative therapy for Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL), we postulated that RT reporting may be inadequate in Phase III HL and NHL trials. Methods and Materials: We searched PubMed and the Cochrane registry for reports of RCTs involving RT and either HL or NHL published between 1998 and 2007. We screened 133 titles and abstracts to identify relevant studies. We included a total of 61 reports. We assessed these reports for the presence of six quality measures: target volume, radiation dose, fractionation, radiation prescription, quality assurance (QA) process use, and adherence to QA (i.e., reporting of major or minor deviations). Results: Of 61 reports, 23 (38%) described the target volume. Of the 42 reports involving involved-field RT alone, only 8 (19%) adequately described the target volume. The radiation dose and fractionation was described in most reports (54 reports [89%] and 39 reports [64%], respectively). Thirteen reports specified the RT prescription point (21%). Only 12 reports (20%) described using a RT QA process, and 7 reports (11%) described adherence to the QA process. Conclusion: Reporting of RT in HL and NHL RCTs is deficient. Because the interpretation, replication, and application of RCT results depend on adequate description and QA of therapeutic interventions, consensus standards for RT reporting should be developed and integrated into the peer-review process.

  2. Synchronous bilateral squamous cell carcinoma of the lung successfully treated using intensity-modulated radiotherapy

    PubMed Central

    Loo, S W; Smith, S; Promnitz, D A; Van Tornout, F

    2012-01-01

    We present a case of synchronous bilateral inoperable lung cancer which required treatment with external beam radiotherapy to a radical dose. Intensity-modulated radiotherapy (IMRT) was used. More conformal dose distribution within the planning target volume was obtained using IMRT than the conventional technique. Dose–volume constraints defined for the lungs were met. Treatment was subsequently delivered using a seven-field IMRT plan. The patient remains alive and disease-free 48 months after the completion of radiotherapy. IMRT can be considered an effective treatment for synchronous bilateral lung cancer. PMID:21937610

  3. Second Malignant Neoplasms Following Radiotherapy

    PubMed Central

    Kumar, Sanath

    2012-01-01

    More than half of all cancer patients receive radiotherapy as a part of their treatment. With the increasing number of long-term cancer survivors, there is a growing concern about the risk of radiation induced second malignant neoplasm [SMN]. This risk appears to be highest for survivors of childhood cancers. The exact mechanism and dose-response relationship for radiation induced malignancy is not well understood, however, there have been growing efforts to develop strategies for the prevention and mitigation of radiation induced cancers. This review article focuses on the incidence, etiology, and risk factors for SMN in various organs after radiotherapy. PMID:23249860

  4. Evaluation of different in vitro assays of inherent sensitivity as predictors of radiotherapy response

    SciTech Connect

    Schwartz, J.L. Chicago Univ., IL . Medical Center); Beckett, M.A.; Mustafi, R.; Weichselbaum, R.R. . Medical Center); Vaughan, A.T.M. . Stritch School of Medicine)

    1991-01-01

    The inherent sensitivity of cells within a tumor plays an important role in the response of the tumor to radiotherapy. Clonogenic assays show that cells established from in-field radiotherapy failures are significantly more resistant to radiation than cell lines established from pre-treatment samples. Clonogenic assays fail to predict tumor response to radiotherapy, however. The failure might be due to the small sample size in this study, or the complicating factors of staging, surgery, and chemotherapy, and/or in vivo selection by radiotherapy for resistant tumor cells. In vitro selection for resistant cell lines does not appear to be a complicating factor. Nonclonogenic assays such as those that measure DNA strand break rejoining rates (filter elution, pulse-field gel electrophoresis) or chromosome structure (flow cytometric analysis) show promise as alternative rapid assays of radiation sensitivity and possibly tumor response. 16 refs., 2 figs.

  5. Radiotherapy dosimetry using a commercial OSL system

    SciTech Connect

    Viamonte, A.; Rosa, L. A. R. da; Buckley, L. A.; Cherpak, A.; Cygler, J. E.

    2008-04-15

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al{sub 2}O{sub 3}:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for {sup 60}Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al{sub 2}O{sub 3}:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures.

  6. Radiotherapy dosimetry using a commercial OSL system.

    PubMed

    Viamonte, A; da Rosa, L A R; Buckley, L A; Cherpak, A; Cygler, J E

    2008-04-01

    A commercial optically stimulated luminescence (OSL) system developed for radiation protection dosimetry by Landauer, Inc., the InLight microStar reader, was tested for dosimetry procedures in radiotherapy. The system uses carbon-doped aluminum oxide, Al2O3:C, as a radiation detector material. Using this OSL system, a percent depth dose curve for 60Co gamma radiation was measured in solid water. Field size and SSD dependences of the detector response were also evaluated. The dose response relationship was investigated between 25 and 400 cGy. The decay of the response with time following irradiation and the energy dependence of the Al2O3:C OSL detectors were also measured. The results obtained using OSL dosimeters show good agreement with ionization chamber and diode measurements carried out under the same conditions. Reproducibility studies show that the response of the OSL system to repeated exposures is 2.5% (1sd), indicating a real possibility of applying the Landauer OSL commercial system for radiotherapy dosimetric procedures. PMID:18491518

  7. The interrelationship of research in the laboratory and the field to assess hydration status and determine mechanisms involved in water regulation during physical activity.

    PubMed

    Stachenfeld, Nina S

    2014-05-01

    Changes in skin blood and sweating are the primary mechanisms for heat loss in humans. A hot, humid environment concomitant with dehydration limits the ability to increase skin blood flow for the purpose of transferring heat from the body core to skin surface and evaporate sweat to maintain core temperature within safe limits during exercise. Adequate hydration improves thermoregulation by maintaining blood volume to support skin blood flow and sweating. Humans rely on fluid intake to maintain total body water and blood volume, and have developed complex mechanisms to sense changes in the amount and composition of fluid in the body. This paper addresses the interrelationship of research in the laboratory and the field to assess hydration status involved in body water and temperature regulation during exercise. In the controlled setting of a research laboratory, investigators are able to investigate the contributions of volume and tonicity of fluid in the plasma to body water and temperature regulation during exercise and recovery. For example, laboratory studies have shown that tonicity in a rehydration beverage maintains the thirst mechanism (and stimulates drinking), and contributes to the ongoing stimulation of renal fluid retention hormones, ultimately leading to a more complete rehydration. Research in the field cannot control the environment precisely, but these studies provide a natural, 'real-life' setting to study fluid and temperature regulation during exercise. The conditions encountered in the field are closest to the environment during competition, and data collected in the field can have an immediate impact on performance and safety during exercise. There is an important synergy between these two methods of collecting data that support performance and protect athletes from harm during training and improve performance during competition. PMID:24791921

  8. [Which rules apply to hypofractionated radiotherapy?].

    PubMed

    Supiot, S; Clément-Colmou, K; Paris, F; Corre, I; Chiavassa, S; Delpon, G

    2015-10-01

    Hypofractionated radiotherapy is now more widely prescribed due to improved targeting techniques (intensity modulated radiotherapy, image-guided radiotherapy and stereotactic radiotherapy). Low dose hypofractionated radiotherapy is routinely administered mostly for palliative purposes. High or very high dose hypofractionated irradiation must be delivered according to very strict procedures since every minor deviation can lead to major changes in dose delivery to the tumor volume and organs at risk. Thus, each stage of the processing must be carefully monitored starting from the limitations and the choice of the hypofractionation technique, tumour contouring and dose constraints prescription, planning and finally dose calculation and patient positioning verification.

  9. Unilateral Cervical Polyneuropathies following Concurrent Bortezomib, Cetuximab, and Radiotherapy for Head and Neck Cancer.

    PubMed

    Elghouche, Alhasan; Shokri, Tom; Qin, Yewen; Wargo, Susannah; Citrin, Deborah; Van Waes, Carter

    2016-01-01

    We report a constellation of cervical polyneuropathies in a patient treated with concurrent bortezomib, cetuximab, and cisplatin alongside intensity modulated radiotherapy for carcinoma of the tonsil with neck metastasis. The described deficits include brachial plexopathy, cervical sensory neuropathy, and oculosympathetic, recurrent laryngeal, and phrenic nerve palsies within the ipsilateral radiation field. Radiation neuropathy involving the brachial plexus is typically associated with treatment of breast or lung cancer; however, increased awareness of this entity in the context of investigational agents with potential neuropathic effects in head and neck cancer has recently emerged. With this report, we highlight radiation neuropathy in the setting of investigational therapy for head and neck cancer, particularly since these sequelae may present years after therapy and entail significant and often irreversible morbidity.

  10. Significance of Cox-2 expression in rectal cancers with or without preoperative radiotherapy

    SciTech Connect

    Pachkoria, Ketevan; Zhang Hong; Adell, Gunnar; Jarlsfelt, Ingvar; Sun Xiaofeng . E-mail: xiao-feng.sun@ibk.liu.se

    2005-11-01

    Purpose: Radiotherapy has reduced local recurrence of rectal cancers, but the result is not satisfactory. Further biologic factors are needed to identify patients for more effective radiotherapy. Our aims were to investigate the relationship of cyclooxygenase-2 (Cox-2) expression to radiotherapy, and clinicopathologic/biologic variables in rectal cancers with or without radiotherapy. Methods and Materials: Cox-2 expression was immunohistochemically examined in distal normal mucosa (n = 28), in adjacent normal mucosa (n = 107), in primary cancer (n = 138), lymph node metastasis (n = 30), and biopsy (n = 85). The patients participated in a rectal cancer trial of preoperative radiotherapy. Results: Cox-2 expression was increased in primary tumor compared with normal mucosa (p < 0.0001), but there was no significant change between primary tumor and metastasis. Cox-2 positivity was or tended to be related to more p53 and Ki-67 expression, and less apoptosis (p {<=} 0.05). In Cox-2-negative cases of either biopsy (p = 0.01) or surgical samples (p = 0.02), radiotherapy was related to less frequency of local recurrence, but this was not the case in Cox-2-positive cases. Conclusion: Cox-2 expression seemed to be an early event involved in rectal cancer development. Radiotherapy might reduce a rate of local recurrence in the patients with Cox-2 weakly stained tumors, but not in those with Cox-2 strongly stained tumors.

  11. Second primary tumors following radiotherapy for childhood cancer

    SciTech Connect

    Hawkins, M.M. )

    1990-11-01

    Among a cohort of 9,279 survivors of childhood neoplasms other than retinoblastoma treated in Britain before 1980, the cumulative risk of a second primary tumor (SPT) by 25 years from 3-year survival was 3.7%. This corresponds to about five times the number expected from rates of cancer occurring in the general population. In the absence of both radiotherapy and chemotherapy, there was four times the expected number of subsequent cancers. The risk of an SPT associated with radiotherapy but not chemotherapy and both radiotherapy and chemotherapy were 6 and 9 times that expected, respectively. There is evidence that radiotherapy was involved in the development of many of the SPT's observed. However, case-control investigations are required to examine the relationship between relative risk of an SPT and therapy in detail. Secondary leukemia appears to occur more frequently among more recently diagnosed children with cancer. It is important to continue to monitor the occurrence of SPT's with a view to identifying the least carcinogenic therapies that are consistent with not compromising survival prospects.

  12. [New technologies: needs and challenges in radiotherapy in Latin America].

    PubMed

    Castellanos, María Esperanza

    2006-01-01

    The cumulative experience gathered over more than a century of practice of radiotherapy has demonstrated the latter's importance not only for the palliative treatment of a fraction of cancer cases, but mainly for the curative treatment of an even greater proportion of such cases. In light of the changes in technology, the ever-increasing access developing countries to such technology, and its current coverage in Latin America, any efforts in this area should be aimed at improving the quality of the radiotherapy services and centers that are already in place. This involves developing their technological assets to the fullest, expanding their services, and complying with the minimum quality requirements established for second-level facilities. Each center should be equipped to carry out all stages of the radiotherapy process, from simulation through treatment verification and patient follow-up, with a high level of quality (level 2). To achieve this, it should possess the necessary technology and properly-trained staff that are required for the purpose. Collaborative efforts in the Region should also prioritize helping countries implement national treatment standards for all stages of the radiotherapy process and promoting the implementation of validated quality assurance programs.

  13. Technical Advances and Pitfalls in Head and Neck Radiotherapy

    PubMed Central

    Parvathaneni, Upendra; Laramore, George E.; Liao, Jay J.

    2012-01-01

    Intensity Modulated Radiotherapy (IMRT) is the standard of care in the treatment of head and neck squamous cell carcinomas (HNSCC) based on level 1 evidence. Technical advances in radiotherapy have revolutionized the treatment of HNSCC, with the most tangible gain being a reduction in long term morbidity. However, these benefits come with a serious and sobering price. Today, there is a greater chance of missing the target/tumor due to uncertainties in target volume definition by the clinician that is demanded by the highly conformal planning process involved with IMRT. Unless this is urgently addressed, our patients would be better served with the historically practiced non conformal radiotherapy, than IMRT which promises lesser morbidity. Image guided radiotherapy (IGRT) ensures the level of set up accuracy warranted to deliver a highly conformal treatment plan and should be utilized with IMRT, where feasible. Proton therapy has a theoretical physical advantage over photon therapy due to a lack of “exit dose”. However, clinical data supporting the routine use of this technology for HNSCC are currently sparse. The purpose of this article is to review the literature, discuss the salient issues and make recommendations that address the gaps in knowledge. PMID:22701482

  14. Radiotherapy of chondrosarcoma of bone

    SciTech Connect

    Harwood, A.R.; Krajbich, J.I.; Fornasier, V.L.

    1980-06-01

    A retrospective analysis of 31 cases of chondrosarcoma of bone treated by radiotherapy is presented. In comparison with other large series, our group of patients were found to have been unfavourably selected with respect to the known prognostic factors: histology site, adequacy of operative treatment, and presenting symptoms. Twelve patients with primary chondrosarcoma were radically irradiated; 6 of these 12 have been alive and well without tumor for periods ranging from three and a half to 16 years and 3 of these are alive and well for 15 years or more following radiotherapy. The other 6 patients responded or desease stabilized following radiotherapy for periods ranging from 16 months to eight years. One poorly differentiated tumor was radically irradiated and did not respond. Eleven patients were irradiated palliatively, generally with low doses of irradiation, and only 4 responded transiently for periods ranging from three to 12 months. Seven patients with mesenchymal and dedifferentiated tumors were radically irradiated. Four responded or disease stabilized, and 1 of these patients was alive and well at 3 years; 3 did not respond. Six died with distant metastasis. It is concluded that chondrosarcoma of bone is a radioresponsive tumor and the place of radiotherapy in the treatment of this disease and the reason for its being labelled a radioresistant tumor are discussed. The problems of assessing response of chondrosarcoma to therapy are also discussed. It is suggested that chemotherapy may have a role in the management of mesenchymal and dedifferentiated chondrosarcoma.

  15. Pancreatic cancer: chemotherapy and radiotherapy

    PubMed Central

    Andrén-Sandberg, Åke

    2011-01-01

    Pancreatic cancer in many cases appears in a non-curatively resectable stage when the diagnosis is made. Palliative treatment become an option in the patients with advanced stage. The present article reviewed chemotherapy and radiotherapy in various advanced stage of pancreatic cancer. PMID:22540056

  16. Radiotherapy T1 glottic carcinoma

    SciTech Connect

    Zablow, A.I.; Erba, P.S.; Sanfillippo, L.J.

    1989-11-01

    From 1970 to 1985, curative radiotherapy was administered to 63 patients with stage I carcinoma of the true vocal cords. Precision radiotherapeutic technique yields cure rates comparable to surgical results. Good voice quality was preserved in a high percentage of patients.

  17. Conformal Radiotherapy in the Treatment of Advanced Juvenile Nasopharyngeal Angiofibroma With Intracranial Extension: An Institutional Experience

    SciTech Connect

    Chakraborty, Santam; Ghoshal, Sushmita; Patil, Vijay Maruti; Oinam, Arun Singh; Sharma, Suresh C.

    2011-08-01

    Purpose: To describe the results of conformal radiotherapy in advanced juvenile nasopharyngeal angiofibroma in a tertiary care institution. Methods and Materials: Retrospective chart review was conducted for 8 patients treated with conformal radiotherapy between 2006 and 2009. The median follow-up was 17 months. All patients had Stage IIIB disease with intracranial extension. Radiotherapy was considered as treatment because patients were deemed inoperable owing to extensive intracranial/intraorbital extension or proximity to optic nerve. All but 1 patient were treated with intensity-modulated radiotherapy using seven coplanar fields. Median (range) dose prescribed was 39.6 (30-46) Gy. Actuarial analysis of local control and descriptive analysis of toxicity profile was conducted. Results: Despite the large and complex target volume (median planning target volume, 292 cm{sup 3}), intensity-modulated radiotherapy achieved conformal dose distributions (median van't Reit index, 0.66). Significant sparing of the surrounding organs at risk was obtained. No significant Grade 3/4 toxicities were experienced during or after treatment. Actual local control at 2 years was 87.5%. One patient died 1 month after radiotherapy secondary to massive epistaxis. The remaining 7 patients had progressive resolution of disease and were symptom-free at last follow-up. Persistent rhinitis was the only significant toxicity, seen in 1 patient. Conclusions: Conformal radiotherapy results in good local control with minimal acute and late side effects in juvenile nasopharyngeal angiofibromas, even in the presence of advanced disease.

  18. Cost calculation: a necessary step towards widespread adoption of advanced radiotherapy technology.

    PubMed

    Lievens, Yolande; Borras, Jose Maria; Grau, Cai

    2015-01-01

    Radiotherapy costs are an often underestimated component of the economic assessment of new radiotherapy treatments and technologies. That the radiotherapy budget only consumes a finite part of the total cancer and healthcare budget does not relieve us from our responsibility to balance the extra costs to the additional benefits of new, more advanced, but typically also more expensive treatments we want to deliver. Yet, in contrast to what is the case for oncology drugs, literature evidence remains limited, as well for economic evaluations comparing new radiotherapy interventions as for cost calculation studies. Even more cumbersome, the available costing studies in the field of radiotherapy fail to accurately capture the real costs of our treatments due to the large variation in cost inputs, in scope of the analysis, in costing methodology. And this is not trivial. Accurate resource cost accounting lays the basis for the further steps in health technology assessment leading to radiotherapy investments and reimbursement, at the local, the national and the worldwide level. In the current paper we review some evidence from the existing costing literature and discuss how such data can be used to support reimbursement setting and investment cases for new radiotherapy equipment and infrastructure.

  19. The cancer burden in the United Kingdom in 2007 due to radiotherapy.

    PubMed

    Maddams, Jacob; Parkin, D Maxwell; Darby, Sarah C

    2011-12-15

    The number of long-term cancer survivors in the general population of the UK is substantial and increasing rapidly. Many cancer survivors have been treated with radiotherapy but the likely number of radiotherapy-related second cancers has not previously been estimated. We used estimates of the numbers of cancer survivors in the UK at the beginning of 2007, in conjunction with estimates of the relative risk of a second primary cancer associated with previous radiotherapy from the United States Surveillance Epidemiology and End Results (SEER) programme, to estimate the numbers of incident cancers in the UK in 2007 that were associated with radiotherapy for a previous cancer and that may have been caused by it. We estimated that 1,346 cases of cancer, or about 0.45% of the 298,000 new cancers registered in the UK in 2007, were associated with radiotherapy for a previous cancer. The largest numbers of radiotherapy-related second cancers were lung cancer (23.7% of the total), oesophageal cancer (13.3%), and female breast cancer (10.6%); 54% of radiotherapy-related second cancers were in individuals aged 75 or over. The highest percentages of second cancers related to radiotherapy were among survivors of Hodgkin's disease and cancers of the oral cavity and pharynx and cervix uteri; over 15% of second cancers among these survivors were associated with radiotherapy for the first cancer. These calculations, which involve a number of assumptions and approximations, provide a reasonable, if conservative, estimate of the fraction of incident cancers in the UK that are attributable to past radiation therapy.

  20. Monte Carlo verification of gel dosimetry measurements for stereotactic radiotherapy

    NASA Astrophysics Data System (ADS)

    Kairn, T.; Taylor, M. L.; Crowe, S. B.; Dunn, L.; Franich, R. D.; Kenny, J.; Knight, R. T.; Trapp, J. V.

    2012-06-01

    The quality assurance of stereotactic radiotherapy and radiosurgery treatments requires the use of small-field dose measurements that can be experimentally challenging. This study used Monte Carlo simulations to establish that PAGAT dosimetry gel can be used to provide accurate, high-resolution, three-dimensional dose measurements of stereotactic radiotherapy fields. A small cylindrical container (4 cm height, 4.2 cm diameter) was filled with PAGAT gel, placed in the parietal region inside a CIRS head phantom and irradiated with a 12-field stereotactic radiotherapy plan. The resulting three-dimensional dose measurement was read out using an optical CT scanner and compared with the treatment planning prediction of the dose delivered to the gel during the treatment. A BEAMnrc/DOSXYZnrc simulation of this treatment was completed, to provide a standard against which the accuracy of the gel measurement could be gauged. The three-dimensional dose distributions obtained from Monte Carlo and from the gel measurement were found to be in better agreement with each other than with the dose distribution provided by the treatment planning system's pencil beam calculation. Both sets of data showed close agreement with the treatment planning system's dose distribution through the centre of the irradiated volume and substantial disagreement with the treatment planning system at the penumbrae. The Monte Carlo calculations and gel measurements both indicated that the treated volume was up to 3 mm narrower, with steeper penumbrae and more variable out-of-field dose, than predicted by the treatment planning system. The Monte Carlo simulations allowed the accuracy of the PAGAT gel dosimeter to be verified in this case, allowing PAGAT gel to be utilized in the measurement of dose from stereotactic and other radiotherapy treatments, with greater confidence in the future. Experimental aspects of this work were originally presented at the Engineering and Physical Sciences in Medicine

  1. Endorectal MRI assessment of local relapse after surgery for prostate cancer: A model to define treatment field guidelines for adjuvant radiotherapy in patients at high risk for local failure

    SciTech Connect

    Miralbell, Raymond . E-mail: Raymond.Miralbell@hcuge.ch; Vees, Hansjoerg; Lozano, Joan; Khan, Haleem; Molla, Meritxell; Hidalgo, Alberto; Linero, Dolors; Rouzaud, Michel

    2007-02-01

    Purpose: To assess the role of endorectal magnetic resonance imaging (MRI) in defining local relapse after radical prostatectomy for prostate cancer to help to reassess the clinical target volume (CTV) for adjuvant postprostatectomy radiotherapy. Methods and Materials: Sixty patients undergoing an endorectal MRI before salvage radiotherapy were selected. Spatial coordinates of the relapses were assessed using two reference points: the inferior border of the pubic symphysis (point 1) and the urethro-vesical anastomosis (point 2). Every lesion on MRI was delineated on the planning computed tomography and center of mass coordinates were plotted in two separate diagrams (along the x, y, and z axes) with the urethro-vesical anastomosis as the coordinate origin. An 'ideal' CTV was constructed, centered at a point defined by the mathematical means of each of the three coordinates with dimensions defined as twice 2 standard deviations in each of the three axes. The dosimetric impact of the new CTV definition was evaluated in six adjuvantly treated patients. Results: The ideal CTV center of mass was located at coordinates 0 (x), -5 (y), and -3 (z) mm with SDs of 6 (x), 6 (y), and 9 (z) mm, respectively. The CTV size was 24 (x) x 24 (y) x 36 (z) mm. Significant rectal sparing was observed with the new CTV. Conclusions: A CTV with an approximately cylindrical shape ({approx}4 x 3 cm) centered 5 mm posterior and 3 mm inferior to the urethro-vesical anastomosis was defined. Such CTV may reduce the irradiation of normal nontarget tissue in the pelvis potentially improving treatment tolerance.

  2. Assessment of function and quality of life in a phase II multi-institutional clinical trial of fractionated simultaneous in-field boost radiotherapy for patients with 1-3 metastases.

    PubMed

    Bauman, Glenn; Yartsev, Slav; Roberge, David; MacRae, Robert; Roa, Wilson; Panet-Raymond, Valerie; Masucci, Laura; Yaremko, Brian; D'Souza, David; Palma, David; Sexton, Tracy; Yu, Edward; Pantarotto, Jason R; Ahmad, Belal; Fisher, Barbara; Dar, A Rashid; Lambert, Carole; Pond, Gregory; Stitt, Larry; Tay, Keng Yeow; Rodrigues, George

    2016-07-01

    We examined functional outcomes and quality of life of whole brain radiotherapy (WBRT) with integrated fractionated stereotactic radiotherapy boost (FSRT) for brain metastases treatment. Eighty seven people with 1-3 brain metastases (54/87 lung primary, 42/87 single brain metastases) were enrolled on this Phase II trial of WBRT (30 Gy/10) + simultaneous FSRT, (60 Gy/10). Median overall follow-up and survival was 5.4 months, 6 month actuarial intra-lesional control was 78 %; only 1 patient exhibited grade 4 toxicity (worsened seizures); most treatment related toxicity was grade 1 or 2; 2/87 patients demonstrated asymptomatic radiation necrosis on follow-up imaging. Mean (Min-Max) baseline KPS, Mini Mental Status Exam (MMSE) and FACT-BR quality of life were 83 (70-100), 28 (21-30) and 143 (98-153). Lower baseline MMSE (but not KPS or FACT-Br) was associated with worse survival after adjusting for age, number of metastases, primary and extra-cranial disease status. Crude rates of deterioration (>10 points decrease from baseline for KPS and FACT-Br, MMSE fall to <27) ranged from 26 to 38 % for KPS, 32-59 % for FACT-Br and 0-16 % for MMSE depending on the time-point assessed with higher rates generally noted at earlier time points (≤6 months post-treatment). Using a linear mixed models analysis, significant declines from baseline were noted for KPS and FACT-Br (largest effects at 6 weeks to 3 months) with no significant change in MMSE. The effects on function and quality of life of this integrated treatment of WBRT + simultaneous FSRT were similar to other published series combining WBRT + radiosurgery.

  3. Long-Term Outcomes of Radiotherapy for Pituitary Adenomas

    SciTech Connect

    Snead, Felicia E. Amdur, Robert J. M.D.; Morris, Christopher G. M.S.; Mendenhall, William M.

    2008-07-15

    Purpose: To evaluate long-term local control and toxicity for pituitary adenomas treated with fractionated radiotherapy (RT). Methods and Materials: The records of 100 patients with pituitary adenomas treated between 1983 and 2003 were retrospectively reviewed. Thirty-one patients had hormone-secreting tumors; 69 patients were treated with surgery and postoperative RT. Median follow-up was 6.7 years (range, 0.6-20.2 years) for all patients and 6.2 years (range, 2-20.2 years) for living patients. The mean dose delivered was 45 Gy (range, 43-50.4 Gy). Results: The 10-year actuarial local control rates for nonsecreting and secreting adenomas were 98% and 73%, respectively (p 0.0015). Actuarial 10-year cause-specific survival (CSS) rates were 95% and 88%, and overall survival rates were 66% and 79% for nonsecreting and secreting adenomas, respectively. Involvement of the sphenoid sinus was found to be significantly associated with decreased 10-year CSS (p = 0.0453). When compared with the two- or three-field techniques, stereotactic RT was associated with improved CSS (p = 0.0775). CSS was not significantly associated with hormone excretion, extent of surgery, or whether RT was administrated postoperatively or for salvage after a postsurgical recurrence. New cases of hypopituitarism occurred in 35 patients. One patient experienced vision loss, and one patient developed a post-treatment glioma. Conclusions: This is one of the most mature series in the literature that documents excellent results with fractionated RT for pituitary adenoma. We recommend 45 Gy at 1.8 Gy per fraction using stereotactic noncoplanar fields.

  4. Dosimetric comparison of intensity modulated radiotherapy techniques and standard wedged tangents for whole breast radiotherapy.

    PubMed

    Fong, Andrew; Bromley, Regina; Beat, Mardi; Vien, Din; Dineley, Jude; Morgan, Graeme

    2009-02-01

    Prior to introducing intensity modulated radiotherapy (IMRT) for whole breast radiotherapy (WBRT) into our department we undertook a comparison of the dose parameters of several IMRT techniques and standard wedged tangents (SWT). Our aim was to improve the dose distribution to the breast and to decrease the dose to organs at risk (OAR): heart, lung and contralateral breast (Contra Br). Treatment plans for 20 women (10 right-sided and 10 left-sided) previously treated with SWT for WBRT were used to compare (a) SWT; (b) electronic compensators IMRT (E-IMRT); (c) tangential beam IMRT (T-IMRT); (d) coplanar multi-field IMRT (CP-IMRT); and (e) non-coplanar multi-field IMRT (NCP-IMRT). Plans for the breast were compared for (i) dose homogeneity (DH); (ii) conformity index (CI); (iii) mean dose; (iv) maximum dose; (v) minimum dose; and dose to OAR were calculated (vi) heart; (vii) lung and (viii) Contra Br. Compared with SWT, all plans except CP-IMRT gave improvement in at least two of the seven parameters evaluated. T-IMRT and NCP-IMRT resulted in significant improvement in all parameters except DH and both gave significant reduction in doses to OAR. As on initial evaluation NCP-IMRT is likely to be too time consuming to introduce on a large scale, T-IMRT is the preferred technique for WBRT for use in our department. PMID:19453534

  5. Low-Dose Involved-Field Radiation in the Treatment of Non-Hodgkin Lymphoma: Predictors of Response and Treatment Failure

    SciTech Connect

    Russo, Andrea L.; Chen, Yu-Hui; Martin, Neil E.; Vinjamoori, Anant; Luthy, Sarah K.; Freedman, Arnold; Michaelson, Evan M.; Silver, Barbara; Mauch, Peter M.; Ng, Andrea K.

    2013-05-01

    Purpose: To investigate clinical and pathologic factors significant in predicting local response and time to further treatment after low-dose involved-field radiation therapy (LD-IFRT) for non-Hodgkin lymphoma (NHL). Methods and Materials: Records of NHL patients treated at a single institution between April 2004 and September 2011 were retrospectively reviewed. Low-dose involved-field radiation therapy was given as 4 Gy in 2 fractions over 2 consecutive days. Treatment response and disease control were determined by radiographic studies and/or physical examination. A generalized estimating equation model was used to assess the effect of tumor and patient characteristics on disease response. A Cox proportional hazards regression model was used to assess time to further treatment. Results: We treated a total of 187 sites in 127 patients with LD-IFRT. Histologies included 66% follicular, 9% chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma, 10% marginal zone, 6% mantle cell lymphoma (MCL), and 8% other. Median follow-up time was 23.4 months (range, 0.03-92.2 months). The complete response, partial response, and overall response rates were 57%, 25%, and 82%, respectively. A CLL histology was associated with a lower response rate (odds ratio 0.2, 95% confidence interval 0.1-0.5, P=.02). Tumor size, site, age at diagnosis, and prior systemic therapy were not associated with response. The median time to first recurrence was 13.6 months. Those with CLL and age ≤50 years at diagnosis had a shorter time to further treatment for local failures (hazard ratio [HR] 3.63, P=.01 and HR 5.50, P=.02, respectively). Those with CLL and MCL had a shorter time to further treatment for distant failures (HR 11.1 and 16.3, respectively, P<.0001). Conclusions: High local response rates were achieved with LD-IFRT across most histologies. Chronic lymphocytic leukemia and MCL histologies and age ≤50 years at diagnosis had a shorter time to further treatment after LD-IFRT.

  6. Frontal eye field, where art thou? Anatomy, function, and non-invasive manipulation of frontal regions involved in eye movements and associated cognitive operations

    PubMed Central

    Vernet, Marine; Quentin, Romain; Chanes, Lorena; Mitsumasu, Andres; Valero-Cabré, Antoni

    2014-01-01

    The planning, control and execution of eye movements in 3D space relies on a distributed system of cortical and subcortical brain regions. Within this network, the Eye Fields have been described in animals as cortical regions in which electrical stimulation is able to trigger eye movements and influence their latency or accuracy. This review focuses on the Frontal Eye Field (FEF) a “hub” region located in Humans in the vicinity of the pre-central sulcus and the dorsal-most portion of the superior frontal sulcus. The straightforward localization of the FEF through electrical stimulation in animals is difficult to translate to the healthy human brain, particularly with non-invasive neuroimaging techniques. Hence, in the first part of this review, we describe attempts made to characterize the anatomical localization of this area in the human brain. The outcome of functional Magnetic Resonance Imaging (fMRI), Magneto-encephalography (MEG) and particularly, non-invasive mapping methods such a Transcranial Magnetic Stimulation (TMS) are described and the variability of FEF localization across individuals and mapping techniques are discussed. In the second part of this review, we will address the role of the FEF. We explore its involvement both in the physiology of fixation, saccade, pursuit, and vergence movements and in associated cognitive processes such as attentional orienting, visual awareness and perceptual modulation. Finally in the third part, we review recent evidence suggesting the high level of malleability and plasticity of these regions and associated networks to non-invasive stimulation. The exploratory, diagnostic, and therapeutic interest of such interventions for the modulation and improvement of perception in 3D space are discussed. PMID:25202241

  7. Patterns of Failure and Local Control After Intraoperative Electron Boost Radiotherapy to the Presacral Space in Combination with Total Mesorectal Excision in Patients with Locally Advanced Rectal Cancer

    SciTech Connect

    Roeder, Falk; Treiber, Martina; Oertel, Susanne; Dinkel, Julien; Timke, Carmen; Funk, Angela; Garcia-Huttenlocher, Helena; Bischof, Marc; Weitz, Juergen; Harms, Wolfgang; Hensley, Frank W.; Buchler, Markus W.; Debus, Juergen; Krempien, Robert . E-mail: robert_krempien@med.uni-heidelberg.de

    2007-04-01

    Purpose: To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition. Methods and Materials: We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.4 Gy), and in 88% simultaneous chemotherapy was applied. Median follow-up was 59 months. Results: Local failure was observed in 17 patients (7%), resulting in a 5-year local control rate of 92%. Only complete resection and absence of nodal involvement correlated positively with local control. Considering IOERT fields, seven infield recurrences were seen in the presacral space, resulting in a 5-year local control rate of 97%. The remaining local relapses were located as follows: retrovesical/retroprostatic (5), anastomotic site (2), promontorium (1), ileocecal (1), and perineal (1). Conclusion: Intraoperative electron beam radiotherapy as part of a multimodal treatment approach including TME is a highly effective regimen to prevent local failure. The presacral space remains the site of highest risk for local failure, but IOERT can decrease the percentage of relapses in this area.

  8. Patterns of Locoregional Recurrence After Surgery and Radiotherapy or Chemoradiation for Rectal Cancer

    SciTech Connect

    Yu, T.-K.; Bhosale, Priya R.; Crane, Christopher H.; Iyer, Revathy B.; Skibber, John M. M.D.; Rodriguez-Bigas, Miguel A.; Feig, Barry W.; Chang, George J.; Eng, Cathy; Wolff, Robert A.; Janjan, Nora A.; Delclos, Marc E.; Krishnan, Sunil; Das, Prajnan

    2008-07-15

    Purpose: To identify patterns of locoregional recurrence in patients treated with surgery and preoperative or postoperative radiotherapy or chemoradiation for rectal cancer. Methods and Materials: Between November 1989 and October 2001, 554 patients with rectal cancer were treated with surgery and preoperative (85%) or postoperative (15%) radiotherapy, with 95% receiving concurrent chemotherapy. Among these patients, 46 had locoregional recurrence as the first site of failure. Computed tomography images showing the site of recurrence and radiotherapy simulation films were available for 36 of the 46 patients. Computed tomography images were used to identify the sites of recurrence and correlate the sites to radiotherapy fields in these 36 patients. Results: The estimated 5-year locoregional control rate was 91%. The 36 patients in the study had locoregional recurrences at 43 sites. There were 28 (65%) in-field, 7 (16%) marginal, and 8 (19%) out-of-field recurrences. Among the in-field recurrences, 15 (56%) occurred in the low pelvis, 6 (22%) in the presacral region, 4 (15%) in the mid-pelvis, and 2 (7%) in the high pelvis. Clinical T stage, pathologic T stage, and pathologic N stage were significantly associated with the risk of in-field locoregional recurrence. The median survival after locoregional recurrence was 24.6 months. Conclusions: Patients treated with surgery and radiotherapy or chemoradiation for rectal cancer had a low risk of locoregional recurrence, with the majority of recurrences occurring within the radiation field. Because 78% of in-field recurrences occur in the low pelvic and presacral regions, consideration should be given to including the low pelvic and presacral regions in the radiotherapy boost field, especially in patients at high risk of recurrence.

  9. Toxic Epidermal Necrolysis in Polymedicated Patient Treated With Radiotherapy

    PubMed Central

    Pérez-Calderón, Remedios; Corrales-Vargas, Silvia; Jiménez-Ferrera, Gloria; Rodríguez-Nevado, Isabel; Díaz-Delgado, Mario

    2015-01-01

    Temozolomide is an oral alkylating agent indicated for the treatment of patients with glioblastoma multiforme concomitantly with radiotherapy and subsequently as monotherapy treatment. We report the case of a patient who developed toxic epidermal necrolysis (TEN) while she was being treated with chemoradiotherapy and several drugs. Cutaneous tests were performed with the drugs involved with negative result. Although the occurrence of TEN contraindicates suspected drug readministration, we based the decision to perform the controlled administration of temozolomide on the following reasons: (1) the poor prognosis of the underlying disease, (2) the lack of therapeutic alternatives, (3) the suspicion that other drugs taken by the patient simultaneously may be responsible (as anticonvulsants and trimethoprim sulfamethoxazole [TMP-SMX]), and (4) temozolomide was the first choice for treating the patient's disease. The administration of a cumulative dose of 60 mg of temozolomide caused a slight skin reaction. Given this result, we conducted controlled administration of other drugs involved. Dexamethasone, codeine, omeprazole and levetiracetam were well tolerated. However, TMP-SMX produced a similar reaction to that caused by temozolomide. In conclusion, we present the first case of TEN induced by temozolomide and TMP-SMX associated with cranial radiotherapy confirmed by controlled administration. Radiotherapy in combination with these drugs could have favored TEN, as some authors have postulated, but we cannot prove this. PMID:25729629

  10. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    NASA Astrophysics Data System (ADS)

    Evans, Philip M.

    2008-06-01

    scans is taken on different days. Both allow planning to account for variability intrinsic to the patient. Treatment verification has been carried out using a variety of technologies including: MV portal imaging, kV portal/fluoroscopy, MVCT, conebeam kVCT, ultrasound and optical surface imaging. The various methods have their pros and cons. The four x-ray methods involve an extra radiation dose to normal tissue. The portal methods may not generally be used to visualize soft tissue, consequently they are often used in conjunction with implanted fiducial markers. The two CT-based methods allow measurement of inter-fraction variation only. Ultrasound allows soft-tissue measurement with zero dose but requires skilled interpretation, and there is evidence of systematic differences between ultrasound and other data sources, perhaps due to the effects of the probe pressure. Optical imaging also involves zero dose but requires good correlation between the target and the external measurement and thus is often used in conjunction with an x-ray method. The use of anatomical imaging in radiotherapy allows treatment uncertainties to be determined. These include errors between the mean position at treatment and that at planning (the systematic error) and the day-to-day variation in treatment set-up (the random error). Positional variations may also be categorized in terms of inter- and intra-fraction errors. Various empirical treatment margin formulae and intervention approaches exist to determine the optimum strategies for treatment in the presence of these known errors. Other methods exist to try to minimize error margins drastically including the currently available breath-hold techniques and the tracking methods which are largely in development. This paper will review anatomical imaging techniques in radiotherapy and how they are used to boost the therapeutic benefit of the treatment.

  11. Intraoperative radiotherapy for breast cancer

    PubMed Central

    Williams, Norman R.; Pigott, Katharine H.; Brew-Graves, Chris

    2014-01-01

    Intra-operative radiotherapy (IORT) as a treatment for breast cancer is a relatively new technique that is designed to be a replacement for whole breast external beam radiotherapy (EBRT) in selected women suitable for breast-conserving therapy. This article reviews twelve reasons for the use of the technique, with a particular emphasis on targeted intra-operative radiotherapy (TARGIT) which uses X-rays generated from a portable device within the operating theatre immediately after the breast tumour (and surrounding margin of healthy tissue) has been removed. The delivery of a single fraction of radiotherapy directly to the tumour bed at the time of surgery, with the capability of adding EBRT at a later date if required (risk-adaptive technique) is discussed in light of recent results from a large multinational randomised controlled trial comparing TARGIT with EBRT. The technique avoids irradiation of normal tissues such as skin, heart, lungs, ribs and spine, and has been shown to improve cosmetic outcome when compared with EBRT. Beneficial aspects to both institutional and societal economics are discussed, together with evidence demonstrating excellent patient satisfaction and quality of life. There is a discussion of the published evidence regarding the use of IORT twice in the same breast (for new primary cancers) and in patients who would never be considered for EBRT because of their special circumstances (such as the frail, the elderly, or those with collagen vascular disease). Finally, there is a discussion of the role of the TARGIT Academy in developing and sustaining high standards in the use of the technique. PMID:25083504

  12. Organ-specific radiation-induced cancer risk estimates due to radiotherapy for benign pigmented villonodular synovitis

    NASA Astrophysics Data System (ADS)

    Mazonakis, Michalis; Tzedakis, Antonis; Lyraraki, Efrossyni; Damilakis, John

    2016-09-01

    Pigmented villonodular synovitis (PVNS) is a benign disease affecting synovial membranes of young and middle-aged adults. The aggressive treatment of this disorder often involves external-beam irradiation. This study was motivated by the lack of data relating to the radiation exposure of healthy tissues and radiotherapy-induced cancer risk. Monte Carlo methodology was employed to simulate a patient’s irradiation for PVNS in the knee and hip joints with a 6 MV photon beam. The average radiation dose received by twenty-two out-of-field critical organs of the human body was calculated. These calculations were combined with the appropriate organ-, age- and gender-specific risk coefficients of the BEIR-VII model to estimate the lifetime probability of cancer development. The risk for carcinogenesis to colon, which was partly included in the treatment fields used for hip irradiation, was determined with a non-linear mechanistic model and differential dose-volume histograms obtained by CT-based 3D radiotherapy planning. Risk assessments were compared with the nominal lifetime intrinsic risk (LIR) values. Knee irradiation to 36 Gy resulted in out-of-field organ doses of 0.2–24.6 mGy. The corresponding range from hip radiotherapy was 1.2–455.1 mGy whereas the organ equivalent dose for the colon was up to 654.9 mGy. The organ-specific cancer risks from knee irradiation for PVNS were found to be inconsequential since they were at least 161.5 times lower than the LIRs irrespective of the patient’s age and gender. The bladder and colon cancer risk from radiotherapy in the hip joint was up to 3.2 and 6.6 times smaller than the LIR, respectively. These cancer risks may slightly elevate the nominal incidence rates and they should not be ignored during the patient’s treatment planning and follow-up. The probabilities for developing any other solid tumor were more than 20 times lower than the LIRs and, therefore, they may be considered as small.

  13. Organ-specific radiation-induced cancer risk estimates due to radiotherapy for benign pigmented villonodular synovitis.

    PubMed

    Mazonakis, Michalis; Tzedakis, Antonis; Lyraraki, Efrossyni; Damilakis, John

    2016-09-01

    Pigmented villonodular synovitis (PVNS) is a benign disease affecting synovial membranes of young and middle-aged adults. The aggressive treatment of this disorder often involves external-beam irradiation. This study was motivated by the lack of data relating to the radiation exposure of healthy tissues and radiotherapy-induced cancer risk. Monte Carlo methodology was employed to simulate a patient's irradiation for PVNS in the knee and hip joints with a 6 MV photon beam. The average radiation dose received by twenty-two out-of-field critical organs of the human body was calculated. These calculations were combined with the appropriate organ-, age- and gender-specific risk coefficients of the BEIR-VII model to estimate the lifetime probability of cancer development. The risk for carcinogenesis to colon, which was partly included in the treatment fields used for hip irradiation, was determined with a non-linear mechanistic model and differential dose-volume histograms obtained by CT-based 3D radiotherapy planning. Risk assessments were compared with the nominal lifetime intrinsic risk (LIR) values. Knee irradiation to 36 Gy resulted in out-of-field organ doses of 0.2-24.6 mGy. The corresponding range from hip radiotherapy was 1.2-455.1 mGy whereas the organ equivalent dose for the colon was up to 654.9 mGy. The organ-specific cancer risks from knee irradiation for PVNS were found to be inconsequential since they were at least 161.5 times lower than the LIRs irrespective of the patient's age and gender. The bladder and colon cancer risk from radiotherapy in the hip joint was up to 3.2 and 6.6 times smaller than the LIR, respectively. These cancer risks may slightly elevate the nominal incidence rates and they should not be ignored during the patient's treatment planning and follow-up. The probabilities for developing any other solid tumor were more than 20 times lower than the LIRs and, therefore, they may be considered as small. PMID:27499236

  14. Organ-specific radiation-induced cancer risk estimates due to radiotherapy for benign pigmented villonodular synovitis

    NASA Astrophysics Data System (ADS)

    Mazonakis, Michalis; Tzedakis, Antonis; Lyraraki, Efrossyni; Damilakis, John

    2016-09-01

    Pigmented villonodular synovitis (PVNS) is a benign disease affecting synovial membranes of young and middle-aged adults. The aggressive treatment of this disorder often involves external-beam irradiation. This study was motivated by the lack of data relating to the radiation exposure of healthy tissues and radiotherapy-induced cancer risk. Monte Carlo methodology was employed to simulate a patient’s irradiation for PVNS in the knee and hip joints with a 6 MV photon beam. The average radiation dose received by twenty-two out-of-field critical organs of the human body was calculated. These calculations were combined with the appropriate organ-, age- and gender-specific risk coefficients of the BEIR-VII model to estimate the lifetime probability of cancer development. The risk for carcinogenesis to colon, which was partly included in the treatment fields used for hip irradiation, was determined with a non-linear mechanistic model and differential dose-volume histograms obtained by CT-based 3D radiotherapy planning. Risk assessments were compared with the nominal lifetime intrinsic risk (LIR) values. Knee irradiation to 36 Gy resulted in out-of-field organ doses of 0.2-24.6 mGy. The corresponding range from hip radiotherapy was 1.2-455.1 mGy whereas the organ equivalent dose for the colon was up to 654.9 mGy. The organ-specific cancer risks from knee irradiation for PVNS were found to be inconsequential since they were at least 161.5 times lower than the LIRs irrespective of the patient’s age and gender. The bladder and colon cancer risk from radiotherapy in the hip joint was up to 3.2 and 6.6 times smaller than the LIR, respectively. These cancer risks may slightly elevate the nominal incidence rates and they should not be ignored during the patient’s treatment planning and follow-up. The probabilities for developing any other solid tumor were more than 20 times lower than the LIRs and, therefore, they may be considered as small.

  15. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  16. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon.

  17. Stereotactic body radiotherapy: current strategies and future development.

    PubMed

    Tsang, Maverick W K

    2016-07-01

    Stereotactic body radiotherapy (SBRT) has emerged as the standard treatment for medically inoperable early-staged non-small cell lung cancer (NSCLC). The local control rate after SBRT is over 90%. Some forms of tumour motion management and image-guided radiation delivery techniques are the prerequisites for fulfilment of its goal to deliver a high radiation dose to the tumour target without overdosing surrounding normal tissues. In this review, the current strategies of tumour motion management will be discussed, followed by an overview of various image-guided radiotherapy (RT) systems and devices available for clinical practice. Besides medically inoperable stage I NSCLC, SBRT has also been widely adopted for treatment of oligometastasis involving the lungs. Its possible applications in various other cancer illnesses are under extensive exploration. The progress of SBRT is critically technology-dependent. With advancement of technology, the ideal of personalised, effective and yet safe SBRT is already on the horizon. PMID:27606082

  18. Standard-Fractionated Radiotherapy for Optic Nerve Sheath Meningioma: Visual Outcome Is Predicted by Mean Eye Dose

    SciTech Connect

    Abouaf, Lucie; Girard, Nicolas; Lefort, Thibaud; D'hombres, Anne; Tilikete, Caroline; Vighetto, Alain; Mornex, Francoise

    2012-03-01

    Purpose: Radiotherapy has shown its efficacy in controlling optic nerve sheath meningiomas (ONSM) tumor growth while allowing visual acuity to improve or stabilize. However, radiation-induced toxicity may ultimately jeopardize the functional benefit. The purpose of this study was to identify predictive factors of poor visual outcome in patients receiving radiotherapy for ONSM. Methods and Materials: We conducted an extensive analysis of 10 patients with ONSM with regard to clinical, radiologic, and dosimetric aspects. All patients were treated with conformal radiotherapy and subsequently underwent biannual neuroophthalmologic and imaging assessments. Pretreatment and posttreatment values of visual acuity and visual field were compared with Wilcoxon's signed rank test. Results: Visual acuity values significantly improved after radiotherapy. After a median follow-up time of 51 months, 6 patients had improved visual acuity, 4 patients had improved visual field, 1 patient was in stable condition, and 1 patient had deteriorated visual acuity and visual field. Tumor control rate was 100% at magnetic resonance imaging assessment. Visual acuity deterioration after radiotherapy was related to radiation-induced retinopathy in 2 patients and radiation-induced mature cataract in 1 patient. Study of radiotherapy parameters showed that the mean eye dose was significantly higher in those 3 patients who had deteriorated vision. Conclusions: Our study confirms that radiotherapy is efficient in treating ONSM. Long-term visual outcome may be compromised by radiation-induced side effects. Mean eye dose has to be considered as a limiting constraint in treatment planning.

  19. Long-term follow-up of salvage radiotherapy in Hodgkin's lymphoma after chemotherapy failure

    SciTech Connect

    Campbell, Belinda; Wirth, Andrew . E-mail: andrew.wirth@petermac.org; Milner, Alvin; Di Iulio, Juliana; MacManus, Michael; Ryan, Gail M.

    2005-12-01

    Purpose: To evaluate the long-term results of salvage radiotherapy (SRT) for Hodgkin's lymphoma after chemotherapy failure. Methods and Materials: We reviewed 81 patients undergoing SRT for persistent or recurrent Hodgkin's lymphoma after chemotherapy; 19 also received conventional-dose salvage chemotherapy. Results: At SRT, the median patient age was 31 years. Of the 81 patients, 81% had Stage I-II, 25.9% had B symptoms, 14.8% had bulky disease, and 7.4% had extranodal disease. A less than a complete response (CR) to the last chemotherapy regimen occurred in 47%. SRT was generally limited to one side of the diaphragm, and the median dose was 36 Gy. After SRT, 75% of patients achieved a CR, with 82% retaining durable in-field control. In-field failure was associated with less than a CR to the last chemotherapy regimen (p = 0.0287). Most failures were at distant sites, with 60% in previously involved sites. The 10-year freedom from treatment failure and overall survival rates were 32.8% and 45.7%, respectively. The adverse prognostic factors for freedom from treatment failure were age >50 years (p < 0.001), B symptoms (p < 0.001), extranodal disease (p = 0.012), and less than a CR to the last chemotherapy regimen (p = 0.001). The adverse prognostic factors for overall survival were male gender (p = 0.034), age >50 years (p < 0.001), B symptoms (p = 0.002), and less than a CR to the last chemotherapy regimen (p = 0.002). Favorable cohorts had a 10-year freedom from treatment failure rate of 51% and overall survival rate of 92%. Conclusions: Salvage radiotherapy is effective for selected patients with Hodgkin's lymphoma after chemotherapy failure and should be considered for incorporation into salvage programs.

  20. Stereotactic fractionated radiotherapy for the treatment of benign meningiomas

    SciTech Connect

    Candish, Charles; McKenzie, Michael . E-mail: mmckenzi@bccancer.bc.edu; Clark, Brenda G.; Ma, Roy; Lee, Richard; Vollans, Emily; Robar, James; Gete, Ermias; Martin, Monty

    2006-11-15

    Purpose: To assess the use of stereotactic fractionated radiotherapy (SRT) for the treatment of meningiomas. Methods and Materials: Between April 1999 and October 2004, 38 patients underwent SRT. Of 34 patients (36 tumors) assessed, the median age was 53 years. The indication was primary treatment in 26 cases (no histology) and postoperative in 10 cases. The most common sites were cavernous sinus (17), optic nerve (6), and cerebellopontine angle (5). The median gross target volume and planning target volume were 8.9 cm{sup 3} and 18.9 cm{sup 3}, respectively. Stereotactic treatment was delivered with 6-MV photons with static conformal fields (custom-made blocks, 9 patients, and micromultileaf collimator, 25 patients). Median number of fields was six. The median dose prescribed was 50 Gy (range, 45-50.4 Gy) in 28 fractions. The median homogeneity and conformality indices were 1.1 and 1.79, respectively. Results: Treatment was well tolerated. Median follow-up was 26 months with 100% progression-free survival. One patient developed an area of possible radionecrosis related to previous radiotherapy, and 2 men developed mild hypogonadism necessitating testosterone replacement. The vision of 5 of 6 patients with optic pathway meningiomas improved or remained static. Conclusions: Stereotactic fractionated radiotherapy for the treatment of meningiomas is practical, and with early follow-up, seems to be effective.

  1. On Involvement.

    ERIC Educational Resources Information Center

    Greene, Michael B.

    Involvement Ratings In Settings (IRIS), a multi-dimensional non-verbal scale of involvement adaptable to a time-sampling method of data collection, was constructed with the aid of the videotapes of second-grade Follow Through classrooms made by CCEP. Scales were defined through observations of involved and alienated behavior, and the IRIS was…

  2. A Kindler syndrome-associated squamous cell carcinoma treated with radiotherapy.

    PubMed

    Caldeira, Ademar; Trinca, William Correia; Flores, Thais Pires; Costa, Andrea Barleze; Brito, Claudio de Sá; Weigert, Karen Loureiro; Matos, Maryana Schwartzhaupt; Nicolini, Carmela; Obst, Fernando Mariano

    2016-01-01

    Kindler syndrome1, 2 is a genetic disorder mainly characterized by increased skin fragility and photosensitivity,3, 4 making the use of treatments based on radiation difficult or even prohibited. Thus, cases reporting Kindler syndrome patients treated with radiotherapy are rare. In this study, we report clinical outcomes and care provided for a rare case of a Kindler syndrome patient submitted to radiotherapy. Diagnosed with squamous cell carcinoma involving the buccal mucosa, the patient was exclusively treated with radiotherapy, with 70 Gy delivered on the PTV with the Volumetric Modulated Arc technique. The patient's reaction regarding control of the lesion is relevant compared to patients not affected by the syndrome. We noticed acute reactions of the skin and buccal mucosa after few radiotherapy sessions, followed by a fast reduction in the tumor volume. The efficacy of radiotherapy along with multidisciplinary actions allowed treatment continuity, leading to a complete control of the lesion and life quality improvement and showed that the use of radiotherapy on Kindler syndrome patients is possible. PMID:27660560

  3. A review of recently published radiotherapy treatment guidelines for bone metastases: Contrasts or convergence?

    PubMed Central

    Lutz, Stephen; Chow, Edward

    2012-01-01

    Bone metastases are a common manifestation of malignancy, and external beam radiotherapy (EBRT) effectively and safely palliates the pain caused by this clinical circumstance. The myriad of EBRT dosing schemes and complexities involved with coordinating radiotherapy with other interventions necessitated the need for bone metastases treatment guidelines. Here we compare and contrast the bone metastases radiotherapy treatment guidelines recently published by the American Society for Radiation Oncology (ASTRO) and the American College of Radiology (ACR). These evaluations acknowledge current controversies in treatment approaches, they evaluate the nuances of ASTRO and ACR task force decision-making regarding standard approaches to care, and they project the upcoming research results that may clarify approaches to palliative radiotherapy for bone metastases. The results of these two dedicated radiotherapy guidelines are compared to the brief mentions of radiotherapy for bone metastases in the National Comprehensive Cancer Network (NCCN) guidelines. Finally, the paper describes how treatment guidelines may influence patterns of care and reimbursement by their use as quality measures by groups such as the National Quality Forum (NQF). PMID:26909250

  4. Effect of radiotherapy on brain glucose metabolism in patients operated on for low grade astrocytoma

    PubMed Central

    Bruehlmeier, M; Roelcke, U; Amsler, B; Schubert, K; Hausmann, O; von Ammon, K; Radu, E; Gratzl, O; Landmann, C; Leenders, K

    1999-01-01

    OBJECTIVE—To assess the effect of postoperative radiotherapy on brain glucose metabolism (CMRGlu) of operated patients with low grade astrocytomas.
METHODS—PET and 18F-fluorodeoxyglucose was used to measure absolute CMRGlu in patients with fibrillary astrocytoma (WHO II) of the frontal lobe, who did (n=7) or did not (n=12) receive radiotherapy subsequent to first debulking tumour resection. In addition, statistical parametric mapping (SPM95) was applied to assess the pattern of relative CMRGlu associated with the frontal tumour. Data were compared with 12 healthy controls.
RESULTS—A global reduction of absolute CMRGlu was found when either patients with or without radiotherapy were compared with controls (ROI analysis). Brain areas of relative CMRGlu reduction were found in the brain ipsilateral and contralateral to the tumour, comparing both patient groups with controls by SPM ("tumour diaschisis effect"). Superimposed, absolute CMRGlu in the contralateral frontal, parietal, occipital cortex as well as in the white matter was on average 17% lower in patients receiving radiotherapy than in patients who did not.
CONCLUSIONS—The data discriminate a tumour effect from a radiotherapy effect, and support the view of adverse effects of radiotherapy on brain not directly involved by tumour.

 PMID:10209180

  5. Self-Incompatibility-Induced Programmed Cell Death in Field Poppy Pollen Involves Dramatic Acidification of the Incompatible Pollen Tube Cytosol1[OPEN

    PubMed Central

    Wilkins, Katie A.; Bosch, Maurice; Haque, Tamanna; Teng, Nianjun; Poulter, Natalie S.; Franklin-Tong, Vernonica E.

    2015-01-01

    Self-incompatibility (SI) is an important genetically controlled mechanism to prevent inbreeding in higher plants. SI involves highly specific interactions during pollination, resulting in the rejection of incompatible (self) pollen. Programmed cell death (PCD) is an important mechanism for destroying cells in a precisely regulated manner. SI in field poppy (Papaver rhoeas) triggers PCD in incompatible pollen. During SI-induced PCD, we previously observed a major acidification of the pollen cytosol. Here, we present measurements of temporal alterations in cytosolic pH ([pH]cyt); they were surprisingly rapid, reaching pH 6.4 within 10 min of SI induction and stabilizing by 60 min at pH 5.5. By manipulating the [pH]cyt of the pollen tubes in vivo, we show that [pH]cyt acidification is an integral and essential event for SI-induced PCD. Here, we provide evidence showing the physiological relevance of the cytosolic acidification and identify key targets of this major physiological alteration. A small drop in [pH]cyt inhibits the activity of a soluble inorganic pyrophosphatase required for pollen tube growth. We also show that [pH]cyt acidification is necessary and sufficient for triggering several key hallmark features of the SI PCD signaling pathway, notably activation of a DEVDase/caspase-3-like activity and formation of SI-induced punctate actin foci. Importantly, the actin binding proteins Cyclase-Associated Protein and Actin-Depolymerizing Factor are identified as key downstream targets. Thus, we have shown the biological relevance of an extreme but physiologically relevant alteration in [pH]cyt and its effect on several components in the context of SI-induced events and PCD. PMID:25630437

  6. Dosimetric Evaluation of Different Intensity-Modulated Radiotherapy Techniques for Breast Cancer After Conservative Surgery.

    PubMed

    Zhang, Fuli; Wang, Yadi; Xu, Weidong; Jiang, Huayong; Liu, Qingzhi; Gao, Junmao; Yao, Bo; Hou, Jun; He, Heliang

    2015-10-01

    Intensity-modulated radiotherapy (IMRT) potentially leads to a more favorite dose distribution compared to 3-dimensional or conventional tangential radiotherapy (RT) for breast cancer after conservative surgery or mastectomy. The aim of this study was to compare dosimetric parameters of the planning target volume (PTV) and organs at risk (OARs) among helical tomotherapy (HT), inverse-planned IMRT (IP-IMRT), and forward-planned field in field (FP-FIF) IMRT techniques after breast-conserving surgery. Computed tomography scans from 20 patients (12 left sided and 8 right sided) previously treated with T1N0 carcinoma were selected for this dosimetric planning study. We designed HT, IP-IMRT, and FP-FIF plans for each patient. Plans were compared according to dose-volume histogram analysis in terms of PTV homogeneity and conformity indices (HI and CI) as well as OARs dose and volume parameters. Both HI and CI of the PTV showed statistically significant difference among IP-IMRT, FP-FIF, and HT with those of HT were best (P < .05). Compared to FP-FIF, IP-IMRT showed smaller exposed volumes of ipsilateral lung, heart, contralateral lung, and breast, while HT indicated smaller exposed volumes of ipsilateral lung but larger exposed volumes of contralateral lung and breast as well as heart. In addition, HT demonstrated an increase in exposed volume of ipsilateral lung (except for fraction of lung volume receiving >30 Gy and 20 Gy), heart, contralateral lung, and breast compared with IP-IMRT. For breast cancer radiotherapy (RT) after conservative surgery, HT provides better dose homogeneity and conformity of PTV compared to IP-IMRT and FP-FIF techniques, especially for patients with supraclavicular lymph nodes involved. Meanwhile, HT decreases the OAR volumes receiving higher doses with an increase in the volumes receiving low doses, which is known to lead to an increased rate of radiation-induced secondary malignancies. Hence, composite factors including dosimetric advantage

  7. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James R.

    2002-04-30

    This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

  8. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James Robert

    2002-04-01

    This report summarizes the major activities and accomplishments of the Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Radiotherapy Research Program for calendar year 2001. Applications of supportive research and development, as well as technology deployment in the fields of chemistry, radiation physics and dosimetry, and neutron source design and demonstration are described. Contributions in the fields of physics and biophysics include development of advanced patient treatment planning software, feasibility studies of accelerator neutron source technology for Neutron Capture Therapy (NCT), and completion of major modifications to the research reactor at Washington State University to produce an epithermal-neutron beam for NCT research applications.

  9. Role of radiotherapy in the management of hepatocellular carcinoma: A systematic review

    PubMed Central

    Kalogeridi, Maria-Aggeliki; Zygogianni, Anna; Kyrgias, George; Kouvaris, John; Chatziioannou, Sofia; Kelekis, Nikolaos; Kouloulias, Vassilis

    2015-01-01

    Many patients with hepatocellular carcinoma (HCC) present with advanced disease, not amenable to curative therapies such as surgery, transplantation or radiofrequency ablation. Treatment options for this group of patients include transarterial chemoembolization (TACE) and radiation therapy. Especially TACE, delivering a highly concentrated dose of chemotherapy to tumor cells while minimizing systemic toxicity of chemotherapy, has given favorable results on local control and survival. Radiotherapy, as a therapeutic modality of internal radiation therapy with radioisotopes, has also achieved efficacious tumor control in advanced disease. On the contrary, the role of external beam radiotherapy for HCC has been limited in the past, due to the low tolerance of surrounding normal liver parenchyma. However, technological innovations in the field of radiotherapy treatment planning and delivery, have provided the means of delivering radical doses to the tumor, while sparing normal tissues. Advanced and highly conformal radiotherapy approaches such as stereotactic body radiotherapy and proton therapy, evaluated for efficacy and safety for HCC, report encouraging results. In this review, we present the role of radiotherapy in hepatocellular carcinoma patients not suitable for radical treatment. PMID:25625001

  10. Investigating the influence of respiratory motion on the radiation induced bystander effect in modulated radiotherapy

    NASA Astrophysics Data System (ADS)

    Cole, Aidan J.; McGarry, Conor K.; Butterworth, Karl T.; McMahon, Stephen J.; Hounsell, Alan R.; Prise, Kevin M.; O'Sullivan, Joe M.

    2013-12-01

    Respiratory motion introduces complex spatio-temporal variations in the dosimetry of radiotherapy and may contribute towards uncertainties in radiotherapy planning. This study investigates the potential radiobiological implications occurring due to tumour motion in areas of geometric miss in lung cancer radiotherapy. A bespoke phantom and motor-driven platform to replicate respiratory motion and study the consequences on tumour cell survival in vitro was constructed. Human non-small-cell lung cancer cell lines H460 and H1299 were irradiated in modulated radiotherapy configurations in the presence and absence of respiratory motion. Clonogenic survival was calculated for irradiated and shielded regions. Direction of motion, replication of dosimetry by multi-leaf collimator (MLC) manipulation and oscillating lead shielding were investigated to confirm differences in cell survival. Respiratory motion was shown to significantly increase survival for out-of-field regions for H460/H1299 cell lines when compared with static irradiation (p < 0.001). Significantly higher survival was found in the in-field region for the H460 cell line (p < 0.030). Oscillating lead shielding also produced these significant differences. Respiratory motion and oscillatory delivery of radiation dose to human tumour cells has a significant impact on in- and out-of-field survival in the presence of non-uniform irradiation in this in vitro set-up. This may have important radiobiological consequences for modulated radiotherapy in lung cancer.

  11. Prognostic factors in the radiotherapy of Graves' ophthalmopathy

    SciTech Connect

    Petersen, I.A.; Kriss, J.P.; McDougall, I.R.; Donaldson, S.S. )

    1990-08-01

    Between April 1968 and February 1988, 311 patients with symptomatic and progressive Graves' ophthalmopathy were treated with megavoltage orbital radiotherapy. The patients were divided into three groups: I treated with 20 Gy/2 weeks; II treated with 30 Gy/3 weeks, and III received 20 Gy/2 weeks. The degree of eye involvement was evaluated numerically before and after therapy for each of five parameters: soft tissue signs, proptosis, eye muscle impairment, corneal involvement, and sight loss. Pre-treatment and current thyroid diagnosis and status were also noted. To evaluate the effects of radiotherapy alone, follow-up was terminated at the time any eye surgery was done; for those not treated surgically the minimum follow-up was 12 months. Because there were significant demographic differences between the patient groups, the results of each group were analyzed separately. A stepwise linear regression analysis was performed to determine if there were any significant variables affecting outcome. Based on these data formulae were derived which enable outcome to be predicted in any patient. Before therapy more than 90% of patients in all groups had soft tissue and eye muscle involvement, whereas 65-75% had proptosis and about half 50% had some degree of sight loss. Radiotherapy arrested progression of ophthalmic parameters in all but 1-6% of the patients. Objective and symptomatic improvement was noted for all parameters assessed, but there was marked individual variability. The best responses were noted for soft tissue, corneal involvement, and sight loss; however over half the patients had some improvement in eye muscle function and proptosis. Factors which resulted in less favorable outcome included male gender, advanced age, need for concurrent therapy for hyperthyroidism, and no history of hyperthyroidism. No complications have been observed.

  12. Radiotherapy in patients with connective tissue diseases.

    PubMed

    Giaj-Levra, Niccolò; Sciascia, Savino; Fiorentino, Alba; Fersino, Sergio; Mazzola, Rosario; Ricchetti, Francesco; Roccatello, Dario; Alongi, Filippo

    2016-03-01

    The decision to offer radiotherapy in patients with connective tissue diseases continues to be challenging. Radiotherapy might trigger the onset of connective tissue diseases by increasing the expression of self-antigens, diminishing regulatory T-cell activity, and activating effectors of innate immunity (dendritic cells) through Toll-like receptor-dependent mechanisms, all of which could potentially lead to breaks of immune tolerance. This potential risk has raised some debate among radiation oncologists about whether patients with connective tissue diseases can tolerate radiation as well as people without connective tissue diseases. Because the number of patients with cancer and connective tissue diseases needing radiotherapy will probably increase due to improvements in medical treatment and longer life expectancy, the issue of interactions between radiotherapy and connective tissue diseases needs to be clearer. In this Review, we discuss available data and evidence for patients with connective tissue diseases treated with radiotherapy.

  13. Patient setup for PET/CT acquisition in radiotherapy planning.

    PubMed

    Coffey, Mary; Vaandering, Aude

    2010-09-01

    PET/CT imaging modalities have been shown to be useful in the diagnosis, staging, and monitoring of malignant diseases. Its inclusion into the treatment planning process is now central to modern radiotherapy practice. However, it is essential to be cognisant of the factors that are necessary in order to ensure that the acquired images are consistent with the requirements for both treatment planning and treatment delivery. Essential parameters required in image acquisition for radiotherapy planning and treatment include consistencies of table tops and the use of laser light for patient set-up. But they also include the accurate definition of the patient's initial positioning and the use of proper immobilization devices in the radiotherapy department. While determining this optimum set-up, patient psychological factors and limitations that may be due to the subsequent use of PET/CT for planning purposes need to be taken into account. Furthermore, patient set-up data need to be properly recorded and transmitted to the imaging departments. To ensure the consistency of patient set-up, the radiation therapist should ideally be directly involved in informing and positioning the patient on the PET/CT. However, a proper exchange of patient-related information can also be achieved by a close liaison between the two departments and by the use of clear detailed protocols per type of patient set-up and/or per localization of tumour site. PMID:20727605

  14. Radiotherapy dosimetry audit: three decades of improving standards and accuracy in UK clinical practice and trials

    PubMed Central

    Aird, Edwin GA; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia AD; Thomas, Russell AS; Venables, Karen; Thwaites, David I

    2015-01-01

    Dosimetry audit plays an important role in the development and safety of radiotherapy. National and large scale audits are able to set, maintain and improve standards, as well as having the potential to identify issues which may cause harm to patients. They can support implementation of complex techniques and can facilitate awareness and understanding of any issues which may exist by benchmarking centres with similar equipment. This review examines the development of dosimetry audit in the UK over the past 30 years, including the involvement of the UK in international audits. A summary of audit results is given, with an overview of methodologies employed and lessons learnt. Recent and forthcoming more complex audits are considered, with a focus on future needs including the arrival of proton therapy in the UK and other advanced techniques such as four-dimensional radiotherapy delivery and verification, stereotactic radiotherapy and MR linear accelerators. The work of the main quality assurance and auditing bodies is discussed, including how they are working together to streamline audit and to ensure that all radiotherapy centres are involved. Undertaking regular external audit motivates centres to modernize and develop techniques and provides assurance, not only that radiotherapy is planned and delivered accurately but also that the patient dose delivered is as prescribed. PMID:26329469

  15. Temporal compartmental dosing effects for robotic prostate stereotactic body radiotherapy

    NASA Astrophysics Data System (ADS)

    Shiao, Stephen L.; Sahgal, Arjun; Hu, Weigang; Jabbari, Siavash; Chuang, Cynthia; Descovich, Martina; Hsu, I.-Chow; Gottschalk, Alexander R.; Roach, Mack, III; Ma, Lijun

    2011-12-01

    The rate of dose accumulation within a given area of a target volume tends to vary significantly for non-isocentric delivery systems such as Cyberknife stereotactic body radiotherapy. In this study, we investigated whether intra-target temporal dose distributions produce significant variations in the biological equivalent dose. For the study, time courses of ten patients were reconstructed and calculation of a biologically equivalent uniform dose (EUD) was performed using a formula derived from the linear quadratic model (α/β = 3 for prostate cancer cells). The calculated EUD values obtained for the actual patient treatments were then compared with theoretical EUD values for delivering the same physical dose distribution except that the whole target being irradiated continuously (e.g. large-field ‘dose-bathing’ type of delivery). For all the case, the EUDs for the actual treatment delivery were found to correlate strongly with the EUDs for the large-field delivery: a linear correlation coefficient of R2 = 0.98 was obtained and the average EUD for the actual Cyberknife delivery was somewhat higher (5.0 ± 4.7%) than that for the large-field delivery. However, no statistical significance was detected between the two types of delivery (p = 0.21). We concluded that non-isocentric small-field Cyberknife delivery produced consistent biological dosing that tracked well with the constant-dose-rate, large-field-type delivery for prostate stereotactic body radiotherapy.

  16. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue.

  17. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, K.M.; Doyle, B.L.

    1996-08-20

    Ion-induced Nuclear Radiotherapy (INRT) is a technique for conducting radiosurgery and radiotherapy with a very high degree of control over the spatial extent of the irradiated volume and the delivered dose. Based upon the concept that low energy, ion induced atomic and nuclear reactions can be used to produce highly energetic reaction products at the site of a tumor, the INRT technique is implemented through the use of a conduit-needle or tube which conducts a low energy ion beam to a position above or within the intended treatment area. At the end of the conduit-needle or tube is a specially fabricated target which, only when struck by the ion beam, acts as a source of energetic radiation products. The inherent limitations in the energy, and therefore range, of the resulting reaction products limits the spatial extent of irradiation to a pre-defined volume about the point of reaction. Furthermore, since no damage is done to tissue outside this irradiated volume, the delivered dose may be made arbitrarily large. INRT may be used both as a point-source of radiation at the site of a small tumor, or as a topical bath of radiation to broad areas of diseased tissue. 25 figs.

  18. Metastasis-Induced Acute Pancreatitis Successfully Treated with Chemotherapy and Radiotherapy in a Patient with Small Cell Lung Cancer

    PubMed Central

    Okutur, Kerem; Bozkurt, Mustafa; Korkmaz, Taner; Karaaslan, Ercan; Guner, Levent; Goksel, Suha; Demir, Gokhan

    2015-01-01

    Although involvement of pancreas is a common finding in small cell lung cancer (SCLC), metastasis-induced acute pancreatitis (MIAP) is very rare. A 50-year-old female with SCLC who had limited disease and achieved full response after treatment presented with acute pancreatitis during her follow-up. The radiologic studies revealed a small area causing obliteration of the pancreatic duct without mass in the pancreatic neck, and endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) confirmed the metastasis of SCLC. The patient was treated successfully with systemic chemotherapy and radiotherapy delivered to pancreatic field. In SCLC, cases of MIAP can be encountered with conventional computed tomography with no mass image, and positron emission tomography and EUS-FNA can be useful for diagnosis of such cases. Aggressive systemic and local treatment can prolong survival, especially in patients with good performance status. PMID:26075124

  19. Predicting radiotherapy-induced cardiac perfusion defects

    SciTech Connect

    Das, Shiva K.; Baydush, Alan H.; Zhou Sumin; Miften, Moyed; Yu Xiaoli; Craciunescu, Oana; Oldham, Mark; Light, Kim; Wong, Terence; Blazing, Michael; Borges-Neto, Salvador; Dewhirst, Mark W.; Marks, Lawrence B.

    2005-01-01

    The purpose of this work is to compare the efficacy of mathematical models in predicting the occurrence of radiotherapy-induced left ventricular perfusion defects assessed using single-photon emission computed tomography (SPECT). The basis of this study is data from 73 left-sided breast/chestwall patients treated with tangential photon fields. The mathematical models compared were three commonly used parametric models [Lyman normal tissue complication probability (LNTCP), relative serialty (RS), generalized equivalent uniform dose (gEUD)] and a nonparametric model (Linear discriminant analysis--LDA). Data used by the models were the left ventricular dose--volume histograms, or SPECT-based dose-function histograms, and the presence/absence of SPECT perfusion defects 6 months postradiation therapy (21 patients developed defects). For the parametric models, maximum likelihood estimation and F-tests were used to fit the model parameters. The nonparametric LDA model step-wise selected features (volumes/function above dose levels) using a method based on receiver operating characteristics (ROC) analysis to best separate the groups with and without defects. Optimistic (upper bound) and pessimistic (lower bound) estimates of each model's predictive capability were generated using ROC curves. A higher area under the ROC curve indicates a more accurate model (a model that is always accurate has area=1). The areas under these curves for different models were used to statistically test for differences between them. Pessimistic estimates of areas under the ROC curve using dose-volume histogram/dose-function histogram inputs, in order of increasing prediction accuracy, were LNTCP (0.79/0.75), RS (0.80/0.77), gEUD (0.81/0.78), and LDA (0.84/0.86). Only the LDA model benefited from SPECT-based regional functional information. In general, the LDA model was statistically superior to the parametric models. The LDA model selected as features the left ventricular volumes above

  20. Randomized Clinical Trial to Assess the Efficacy of Radiotherapy in Primary Mediastinal Large B-Lymphoma

    SciTech Connect

    Aviles, Agustin; Neri, Natividad; Fernandez, Raul; Huerta-Guzman, Judith; Nambo, Maria J.

    2012-07-15

    Purpose: We developed a controlled clinical trial to assess the efficacy and toxicity of adjuvant-involved field radiotherapy (IFRT) in patients with primary mediastinal B-cell lymphoma that achieved complete response after the patients were treated with cyclophosphamide, doxorubicin, vincristine, prednisone, and rituximab (R-CHOP-14). Methods and Materials: Between January 2001 and June 2004, 124 consecutive patients who were in complete remission after dose dense chemotherapy and rituximab administration (R-CHOP14) were randomly assigned to received IFRT (30 Gy). Sixty-three patients received IFR, and 61 patients did not (control group). Results: The study aimed to include 182 patients in each arm but was closed prematurely because in a security analysis (June 2004), progression and early relapse were more frequent in patients that did not received IFRT. Patients were followed until March 2009, at which point actuarial curves at 10 years showed that progression free-survival was 72% in patients who received IFR and 20% in the control group (p < 0.001), overall survival was 72% and 31%, respectively (p < 0.001). Acute toxicity was mild and well tolerated. Discussion: Adjuvant radiotherapy to sites of bulky disease was the only difference to have an improvement in outcome in our patients; the use of rituximab during induction did not improve complete response rates and did affect overall survival; patients who received rituximab but not IFRT had a worse prognosis. Conclusions: The use of IFRT in patients with primary mediastinal B-cell lymphoma who achieved complete response remain as the best treatment available, even in patients that received rituximab during induction.

  1. Patterns of Failure and Toxicity after Intensity-Modulated Radiotherapy for Head and Neck Cancer

    SciTech Connect

    Schoenfeld, Gordon O.; Amdur, Robert J.; Morris, Christopher G.; Li, Jonathan G.; Hinerman, Russell W.; Mendenhall, William M.

    2008-06-01

    Purpose: To determine the outcome of patients treated with intensity-modulated radiotherapy (IMRT) for head and neck cancer. Methods and Materials: We reviewed the charts of 100 consecutive patients treated with IMRT for squamous cell carcinoma of the oropharynx (64%), nasopharynx (16%), hypopharynx (14%), and larynx (6%). Most patients were treated with a concomitant boost schedule to 72 Gy. Of the 100 patients, 54 (54%) received adjuvant chemotherapy, mostly concurrent cisplatin. The dosimetry plans for patients with either locoregional failure or Grade 4-5 complications were reviewed and fused over the computed tomography images corresponding with the location of the event. Marginal failures were defined as those that occurred at a region of high-dose falloff, where conventional fields would have provided better coverage. Results: The median follow-up of living patients was 3.1 years (range, 1-5.2 years). The 3-year rate of local control, locoregional control, freedom from relapse, cause-specific survival, and overall survival for all patients was 89%, 87%, 72%, 78%, and 71%, respectively. The 3-year rate of freedom from relapse, cause-specific survival, and overall survival for the 64 oropharynx patients was 86%, 92%, and 84%, respectively. Of the 10 local failures, 2 occurred at the margin of the high-dose planning target volume. Both regional failures occurred within the planning target volume. No locoregional failures occurred outside the planning target volume. Of the 100 patients, 8 and 5 had Grade 4 and 5 complications from treatment, respectively. All patients with Grade 5 complications had received adjuvant chemotherapy. No attempt was made to discriminate between the complications from IMRT and other aspects of the patients' treatment. Conclusion: Intensity-modulated radiotherapy did not compromise the outcome compared with what we have achieved with conventional techniques. The 2 cases of recurrence in the high-dose gradient region highlight the

  2. [Current status and perspectives of radiotherapy for esophageal cancer].

    PubMed

    Wu, S X; Wang, L H

    2016-09-23

    Esophageal cancer is one of the most common cancers in China. More than 80% of esophageal cancer patients are diagnosed at a late stage and are not eligible for surgery. Radiotherapy is one of the most important modalities in esophageal cancer treatment. Here we reviewed the advances in esophageal cancer radiotherapy and radiotherapy-based combined-modality therapy, such as optimization of radiation dose and target volume, application of precise radiotherapy technique and the integration of radiotherapy with chemotherapy and targeted therapy.

  3. Automated radiotherapy treatment plan integrity verification

    SciTech Connect

    Yang Deshan; Moore, Kevin L.

    2012-03-15

    Purpose: In our clinic, physicists spend from 15 to 60 min to verify the physical and dosimetric integrity of radiotherapy plans before presentation to radiation oncology physicians for approval. The purpose of this study was to design and implement a framework to automate as many elements of this quality control (QC) step as possible. Methods: A comprehensive computer application was developed to carry out a majority of these verification tasks in the Philips PINNACLE treatment planning system (TPS). This QC tool functions based on both PINNACLE scripting elements and PERL sub-routines. The core of this technique is the method of dynamic scripting, which involves a PERL programming module that is flexible and powerful for treatment plan data handling. Run-time plan data are collected, saved into temporary files, and analyzed against standard values and predefined logical rules. The results were summarized in a hypertext markup language (HTML) report that is displayed to the user. Results: This tool has been in clinical use for over a year. The occurrence frequency of technical problems, which would cause delays and suboptimal plans, has been reduced since clinical implementation. Conclusions: In addition to drastically reducing the set of human-driven logical comparisons, this QC tool also accomplished some tasks that are otherwise either quite laborious or impractical for humans to verify, e.g., identifying conflicts amongst IMRT optimization objectives.

  4. The predicted relative risk of premature ovarian failure for three radiotherapy modalities in a girl receiving craniospinal irradiation

    NASA Astrophysics Data System (ADS)

    Pérez-Andújar, A.; Newhauser, W. D.; Taddei, P. J.; Mahajan, A.; Howell, R. M.

    2013-05-01

    In girls and young women, irradiation of the ovaries can reduce the number of viable ovarian primordial follicles, which may lead to premature ovarian failure (POF) and subsequently to sterility. One strategy to minimize this late effect is to reduce the radiation dose to the ovaries. A primary means of reducing dose is to choose a radiotherapy technique that avoids irradiating nearby normal tissue; however, the relative risk of POF (RRPOF) due to the various therapeutic options has not been assessed. This study compared the predicted RRPOF after craniospinal proton radiotherapy, conventional photon radiotherapy (CRT) and intensity-modulated photon radiotherapy (IMRT). We calculated the equivalent dose delivered to the ovaries of an 11-year-old girl from therapeutic and stray radiation. We then predicted the percentage of ovarian primordial follicles killed by radiation and used this as a measure of the RRPOF; we also calculated the ratio of the relative risk of POF (RRRPOF) among the three radiotherapies. Proton radiotherapy had a lower RRPOF than either of the other two types. We also tested the sensitivity of the RRRPOF between photon and proton therapies to the anatomic position of the ovaries, i.e., proximity to the treatment field (2 ≤ RRRPOF ≤ 10). We found that CRT and IMRT have higher risks of POF than passive-scattering proton radiotherapy (PRT) does, regardless of uncertainties in the ovarian location. Overall, PRT represents a lower RRPOF over the two other modalities.

  5. [Network meta-analysis on selecting Chinese medical injections in radiotherapy for esophageal cancer].

    PubMed

    Ge, Long; Mao, Lei; Tian, Jin-hui; Shi, Fang-yu; Lou Li-li; Qiu, Xia; Li, Jin-long; Yang, Ke-hu

    2015-09-01

    To assess the clinical effect and safety of Chinese traditional medicine injection combined with radiotherapy for esophageal cancer. The relative randomized controlled trials (RCTs) of Chinese medical injections (CMI) combined with radiotherapy as well as simple radiotherapy for esophageal cancer were searched from PubMed, Cochrane Library, EMBASE, Chinese Biomedical Literature Database(CBM), China National Knowledge Infrastructure (CNKI), Wanfang Database and VIP Database as at September 2014. Two researchers completed the data extraction and quality evaluation independently. The data were analyzed by GeMTC 0.14.3 and Stata 12. 0 software. Finally, 43 RCTs involving 3 289 patients were finally included. The star network was constructed by different comparison groups. The results of network meta-analysis showed that the seven CMIs combined with radiotherapy was superior to simple radiotherapy in the treatment of esophageal cancer in efficacy, quality of life, and reduction in the incidence of nausea and leucopenia, but with no significant difference among the seven CMIs. Probability ranking result showed a great possibility for Shenqi Fuzheng and astragalus polysaccharide injections in improving the overall response rate and quality of life, which were followed by cinobufagin and kangai injections. However, only one study was included for Shenqi Fuzheng and astragalus polysaccharide injections. Therefore, cinobufagin or kangai injections were preferred in improving the overall response rate and quality of life. Aidi or compound sophora injections were better than other CMIs in reducing? the incidences of nausea (III-IV) and leukopenia. More RCTs of Shenqi Fuzheng and astragalus polysaccharide injections combined with radiotherapy for patients with esophageal cancer were expected in the future to confirm our results. Moreover, study findings will be reported, particularly for the adverse events in radiotherapy for esophageal cancer.

  6. Experience of radioactive needle implants in the Institute of Radiotherapy Hospital Kuala Lumpur.

    PubMed

    Lim, G C; Azhar, M T

    1997-03-01

    This retrospective study of radioactive needle implants at the Institute of Radiotherapy and Oncology, Kuala Lumpur Hospital serves as an audit of our practice as well as a demonstration of the usefulness of this technique of brachytherapy. A variety of tumour sites were implanted, of which over two-thirds involved the tongue and buccal mucosa. Although most of the implants were carried out with radical intent, one-tenth of these implants were performed for palliation. Radiotherapy techniques employed are described. The crude survival ranged from 1 month to 109 months while the disease free interval ranged from 0 months to 102 months.

  7. Volumetric-modulated arc radiotherapy for pancreatic malignancies: Dosimetric comparison with sliding-window intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy

    SciTech Connect

    Nabavizadeh, Nima Simeonova, Anna O.; Waller, Joseph G.; Romer, Jeanna L.; Monaco, Debra L.; Elliott, David A.; Tanyi, James A.; Fuss, Martin; Thomas, Charles R.; Holland, John M.

    2014-10-01

    Volumetric-modulated arc radiotherapy (VMAT) is an iteration of intensity-modulated radiotherapy (IMRT), both of which deliver highly conformal dose distributions. Studies have shown the superiority of VMAT and IMRT in comparison with 3-dimensional conformal radiotherapy (3D-CRT) in planning target volume (PTV) coverage and organs-at-risk (OARs) sparing. This is the first study examining the benefits of VMAT in pancreatic cancer for doses more than 55.8 Gy. A planning study comparing 3D-CRT, IMRT, and VMAT was performed in 20 patients with pancreatic cancer. Treatments were planned for a 25-fraction delivery of 45 Gy to a large field followed by a reduced-volume 8-fraction external beam boost to 59.4 Gy in total. OARs and PTV doses, conformality index (CI) deviations from 1.0, monitor units (MUs) delivered, and isodose volumes were compared. IMRT and VMAT CI deviations from 1.0 for the large-field and the boost plans were equivalent (large field: 0.032 and 0.046, respectively; boost: 0.042 and 0.037, respectively; p > 0.05 for all comparisons). Both IMRT and VMAT CI deviations from 1.0 were statistically superior to 3D-CRT (large field: 0.217, boost: 0.177; p < 0.05 for all comparisons). VMAT showed reduction of the mean dose to the boost PTV (VMAT: 61.4 Gy, IMRT: 62.4 Gy, and 3D-CRT: 62.3 Gy; p < 0.05). The mean number of MUs per fraction was significantly lower for VMAT for both the large-field and the boost plans. VMAT delivery time was less than 3 minutes compared with 8 minutes for IMRT. Although no statistically significant dose reduction to the OARs was identified when comparing VMAT with IMRT, VMAT showed a reduction in the volumes of the 100% isodose line for the large-field plans. Dose escalation to 59.4 Gy in pancreatic cancer is dosimetrically feasible with shorter treatment times, fewer MUs delivered, and comparable CIs for VMAT when compared with IMRT.

  8. Radiotherapy in Ewing tumors of the vertebrae: Treatment results and local relapse analysis of the Chess 81/86 and EICESS 92 trials

    SciTech Connect

    Schuck, Andreas . E-mail: schuck@uni-muenster.de; Ahrens, Susanne; Schorlemer, Ines von; Kuhlen, Michaela; Paulussen, Michael; Hunold, Andrea; Gosheger, Georg; Winkelmann, Winfried; Dunst, Juergen; Willich, Normann; Juergens, Heribert

    2005-12-01

    Purpose: Treatment results in patients with Ewing tumors of the vertebrae enrolled in the Cooperative Ewing's Sarcoma Study (CESS) 81, 86, and the European Intergroup Cooperative Ewing's Sarcoma Study (EICESS) 92 trials were analyzed with special emphasis on radiation-associated factors. Patients and Methods: A retrospective analysis was performed on 116 patients with primary tumors of the cervical, thoracic, or lumbar vertebrae treated between 1981 and 1999. Furthermore, a relapse analysis was done on those patients who underwent radiotherapy and subsequently had a local recurrence. Results: A total of 64.6% of the patients received definitive radiotherapy; 27.5% of patients had surgery and radiotherapy. Only 4 patients (3.4%) underwent definitive surgery. Twenty-seven patients presented with metastases at diagnosis. 22.4% of the total group developed a local relapse. Among the subgroup with definitive radiotherapy, local recurrence was seen in 17 of 75 patients (22.6%). Event-free survival and survival at 5 years were 47% and 58%, respectively. Of the 14 evaluable patients with a local relapse after radiotherapy, 13 were in-field. No correlation between radiation dose and local control could be found. Conclusion: Surgery with wide resection margins is rarely possible. The results after definitive radiotherapy in vertebral tumors are comparable to those of other tumor sites when definitive radiotherapy is given. Nearly all local relapses after radiotherapy are in-field.

  9. Personnel radiation dose considerations in the use of an integrated PET-CT scanner for radiotherapy treatment planning.

    PubMed

    Carson, K J; Young, V A L; Cosgrove, V P; Jarritt, P H; Hounsell, A R

    2009-11-01

    The acquisition of radiotherapy planning scans on positron emission tomography (PET)-CT scanners requires the involvement of radiotherapy radiographers. This study assessed the radiation dose received by these radiographers during this process. Radiotherapy planning (18)F-fluorodeoxyglucose ((18)F-FDG) PET-CT scans were acquired for 28 non-small cell lung cancer patients. In order to minimise the radiation dose received, a two-stage process was used in which the most time-consuming part of the set-up was performed before the patient received their (18)F-FDG injection. Throughout this process, the radiographers wore electronic personal dosemeters and recorded the doses received at different stages of the process. The mean total radiation dose received by a radiotherapy radiographer was 5.1+/-2.6 microSv per patient. The use of the two-stage process reduced the time spent in close proximity to the patient by approximately a factor of four. The two-stage process was effective in keeping radiation dose to a minimum. The use of a pre-injection set-up session reduces the radiation dose to the radiotherapy radiographers because of their involvement in PET-CT radiotherapy treatment planning scans by approximately a factor of three. PMID:19332513

  10. [Conformal radiotherapy of brain tumors].

    PubMed

    Haie-Meder, C; Beaudré, A; Breton, C; Biron, B; Cordova, A; Dubray, B; Mazeron, J J

    1999-01-01

    Conformal irradiation of brain tumours is based on the three-dimensional reconstruction of the targeted volumes and at-risk organ images, the three-dimensional calculation of the dose distribution and a treatment device (immobilisation, beam energy, collimation, etc.) adapted to the high precision required by the procedure. Each step requires an appropriate methodology and a quality insurance program. Specific difficulties in brain tumour management are related to GTV and CTV definition depending upon the histological type, the quality of the surgical resection and the medical team. Clinical studies have reported dose escalation trials, mostly in high-grade gliomas and tumours at the base of the skull. Clinical data are now providing a better knowledge of the tolerance of normal tissues. As for small tumours, the implementation of beam intensity modulation is likely to narrow the gap between conformal and stereotaxic radiotherapy. PMID:10572510

  11. [Radiotherapy of benign intracranial tumors].

    PubMed

    Delannes, M; Latorzeff, I; Chand, M E; Huchet, A; Dupin, C; Colin, P

    2016-09-01

    Most of the benign intracranial tumors are meningiomas, vestibular schwannomas, pituitary adenomas, craniopharyngiomas, and glomus tumors. Some of them grow very slowly, and can be observed without specific treatment, especially if they are asymptomatic. Symptomatic or growing tumors are treated by surgery, which is the reference treatment. When surgery is not possible, due to the location of the lesion, or general conditions, radiotherapy can be applied, as it is if there is a postoperative growing residual tumor, or a local relapse. Indications have to be discussed in polydisciplinary meetings, with precise evaluation of the benefit and risks of the treatments. The techniques to be used are the most modern ones, as multimodal imaging and image-guided radiation therapy. Stereotactic treatments, using fractionated or single doses depending on the size or the location of the tumors, are commonly realized, to avoid as much a possible the occurrence of late side effects. PMID:27523417

  12. Experimental determination of field factors (\\Omega _{{{Q}_{\\text{clin}}},{{Q}_{\\text{msr}}}}^{{{f}_{\\text{clin}}},{{f}_{\\text{msr}}}} ) for small radiotherapy beams using the daisy chain correction method

    NASA Astrophysics Data System (ADS)

    Lárraga-Gutiérrez, José Manuel

    2015-08-01

    Recently, Alfonso et al proposed a new formalism for the dosimetry of small and non-standard fields. The proposed new formalism is strongly based on the calculation of detector-specific beam correction factors by Monte Carlo simulation methods, which accounts for the difference in the response of the detector between the small and the machine specific reference field. The correct calculation of the detector-specific beam correction factors demands an accurate knowledge of the linear accelerator, detector geometry and composition materials. The present work shows that the field factors in water may be determined experimentally using the daisy chain correction method down to a field size of 1 cm  ×  1 cm for a specific set of detectors. The detectors studied were: three mini-ionization chambers (PTW-31014, PTW-31006, IBA-CC01), three silicon-based diodes (PTW-60018, IBA-SFD and IBA-PFD) and one synthetic diamond detector (PTW-60019). Monte Carlo simulations and experimental measurements were performed for a 6 MV photon beam at 10 cm depth in water with a source-to-axis distance of 100 cm. The results show that the differences between the experimental and Monte Carlo calculated field factors are less than 0.5%—with the exception of the IBA-PFD—for field sizes between 1.5 cm  ×  1.5 cm and 5 cm  ×  5 cm. For the 1 cm  ×  1 cm field size, the differences are within 2%. By using the daisy chain correction method, it is possible to determine measured field factors in water. The results suggest that the daisy chain correction method is not suitable for measurements performed with the IBA-PFD detector. The latter is due to the presence of tungsten powder in the detector encapsulation material. The use of Monte Carlo calculated k{{Q\\text{clin}},{{Q}\\text{msr}}}{{f\\text{clin}},{{f}\\text{msr}}} is encouraged for field sizes less than or equal to 1 cm  ×  1 cm for the dosimeters used in this work.

  13. Planning tools for modulated electron radiotherapy

    SciTech Connect

    Surucu, Murat; Klein, Eric E.; Mamalui-Hunter, Maria; Mansur, David B.; Low, Daniel A.

    2010-05-15

    Purpose: To develop tools to plan modulated electron radiotherapy (MERT) and to compare the MERT plans to conventional or intensity modulated radiotherapy (IMRT) treatment plans. Methods: Monte Carlo dose calculations of electron fields shaped with the inherent photon multileaf collimators (MLCs) were investigated in this study. Treatment plans for four postmastectomy breast cancer patients were generated using MERT. The distances from the patient skin surfaces to the distal planning target volume surfaces were computed along the beam axis direction to determine the physical depth. Electron beam energies were selected to provide target coverage at these depths and energy bins were generated. A custom built MERT treatment planning graphical user interface (MERTgui) was used to shape the electron bins into deliverable electron segments. Monte Carlo dose distribution simulations were performed using the MLC-defined segments generated from the MERTgui. A custom built superposition gui was used to combine doses for each segment using relative weights and final MERT treatment plans were compared to the conventional or IMRT treatment plans. In addition, a demonstration of combined MERT and IMRT treatment plans was performed. Results: The MERT treatment plans provided acceptable target organ coverage in all cases. Relative to 3D conventional or IMRT treatment plans, the MERT plans predicted lower heart doses in all cases; average of the heart D{sub 20} of all plans was reduced from 14.1 to 3.3 Gy. The contralateral breast and contralateral lung doses decreased substantially with MERT planning compared to IMRT (on average, contralateral breast heart D{sub 20} was reduced from 8.7 to 0.7 Gy and contralateral lung D{sub 20} was reduced from 8.4 to 1.2 Gy with MERT). Ipsilateral lung D{sub 20} was lower with MERT than with the conventional plans (44.6 vs 29.2 Gy with MERT), but greater when compared against IMRT treatment plans (25.4 vs 28.9 Gy with MERT). A MERT and IMRT

  14. Case study thoracic radiotherapy in an elderly patient with pacemaker: The issue of pacing leads

    SciTech Connect

    Kirova, Youlia M.; Menard, Jean; Chargari, Cyrus; Mazal, Alejandro; Kirov, Krassen

    2012-07-01

    To assess clinical outcome of patients with pacemaker treated with thoracic radiation therapy for T8-T9 paravertebral chloroma. A 92-year-old male patient with chloroma presenting as paravertebral painful and compressive (T8-T9) mass was referred for radiotherapy in the Department of Radiation Oncology, Institut Curie. The patient presented with cardiac dysfunction and a permanent pacemaker that had been implanted prior. The decision of Multidisciplinary Meeting was to deliver 30 Gy in 10 fractions for reducing the symptoms and controlling the tumor growth. The patient received a total dose of 30 Gy in 10 fractions using 4-field conformal radiotherapy with 20-MV photons. The dose to pacemaker was 0.1 Gy but a part of the pacing leads was in the irradiation fields. The patient was treated the first time in the presence of his radiation oncologist and an intensive care unit doctor. Moreover, the function of his pacemaker was monitored during the entire radiotherapy course. No change in pacemaker function was observed during any of the radiotherapy fractions. The radiotherapy was very well tolerated without any side effects. The function of the pacemaker was checked before and after the radiotherapy treatment by the cardiologist and no pacemaker dysfunction was observed. Although updated guidelines are needed with acceptable dose criteria for implantable cardiac devices, it is possible to treat patients with these devices and parts encroaching on the radiation field. This case report shows we were able to safely treat our patient through a multidisciplinary approach, monitoring the patient during each step of the treatment.

  15. A set of fortran subroutines for optimizing radiotherapy plans.

    PubMed

    Redpath, A T; Vickery, B L; Wright, D H

    1975-12-01

    Quadratic Programming techniques have been applied to the optimization of radiation field weighting in Radiotherapy planning. Wedge selection has also been included by means of an exhaustive search. The radiation dose at any point in the patient may be constrained to be less than a stated percentage of the tumour dose. The routines have been successfully interfaced into a small computer interactive planning system, but they could represent an even more powerful tool in batch and time sharing systems. Minimum operator intervention is required in their use.

  16. Radiotherapy for Rectal Cancer Is Associated With Reduced Serum Testosterone and Increased FSH and LH

    SciTech Connect

    Bruheim, Kjersti Svartberg, Johan; Carlsen, Erik; Dueland, Svein; Haug, Egil; Skovlund, Eva; Tveit, Kjell Magne; Guren, Marianne G.

    2008-03-01

    Purpose: It is known that scattered radiation to the testes during pelvic radiotherapy can affect fertility, but there is little knowledge on its effects on male sex hormones. The aim of this study was to determine whether radiotherapy for rectal cancer affects testosterone production. Methods and Materials: All male patients who had received adjuvant radiotherapy for rectal cancer from 1993 to 2003 were identified from the Norwegian Rectal Cancer Registry. Patients treated with surgery alone were randomly selected from the same registry as control subjects. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and sex hormone binding globulin (SHBG) were analyzed, and free testosterone was calculated (N = 290). Information about the radiotherapy treatment was collected from the patient hospital charts. Results: Serum FSH was 3 times higher in the radiotherapy group than in the control group (median, 18.8 vs. 6.3 IU/L, p <0.001), and serum LH was 1.7 times higher (median, 7.5 vs. 4.5 IU/l, p <0.001). In the radiotherapy group, 27% of patients had testosterone levels below the reference range (8-35 nmol/L), compared with 10% of the nonirradiated patients (p <0.001). Irradiated patients had lower serum testosterone (mean, 11.1 vs. 13.4 nmol/L, p <0.001) and lower calculated free testosterone (mean, 214 vs. 235 pmol/L, p <0.05) than control subjects. Total testosterone, calculated free testosterone, and gonadotropins were related to the distance from the bony pelvic structures to the caudal field edge. Conclusions: Increased serum levels of gonadotropins and subnormal serum levels of testosterone indicate that curative radiotherapy for rectal cancer can result in permanent testicular dysfunction.

  17. Radiation-Induced Cancers From Modern Radiotherapy Techniques: Intensity-Modulated Radiotherapy Versus Proton Therapy

    SciTech Connect

    Yoon, Myonggeun; Ahn, Sung Hwan; Kim, Jinsung; Shin, Dong Ho; Park, Sung Yong; Lee, Se Byeong; Shin, Kyung Hwan; Cho, Kwan Ho

    2010-08-01

    Purpose: To assess and compare secondary cancer risk resulting from intensity-modulated radiotherapy (IMRT) and proton therapy in patients with prostate and head-and-neck cancer. Methods and Materials: Intensity-modulated radiotherapy and proton therapy in the scattering mode were planned for 5 prostate caner patients and 5 head-and-neck cancer patients. The secondary doses during irradiation were measured using ion chamber and CR-39 detectors for IMRT and proton therapy, respectively. Organ-specific radiation-induced cancer risk was estimated by applying organ equivalent dose to dose distributions. Results: The average secondary doses of proton therapy for prostate cancer patients, measured 20-60cm from the isocenter, ranged from 0.4 mSv/Gy to 0.1 mSv/Gy. The average secondary doses of IMRT for prostate patients, however, ranged between 3 mSv/Gy and 1 mSv/Gy, approximately one order of magnitude higher than for proton therapy. Although the average secondary doses of IMRT were higher than those of proton therapy for head-and-neck cancers, these differences were not significant. Organ equivalent dose calculations showed that, for prostate cancer patients, the risk of secondary cancers in out-of-field organs, such as the stomach, lungs, and thyroid, was at least 5 times higher for IMRT than for proton therapy, whereas the difference was lower for head-and-neck cancer patients. Conclusions: Comparisons of organ-specific organ equivalent dose showed that the estimated secondary cancer risk using scattering mode in proton therapy is either significantly lower than the cases in IMRT treatment or, at least, does not exceed the risk induced by conventional IMRT treatment.

  18. The use of strontium-90 Beta radiotherapy as adjuvant treatment for conjunctival melanoma.

    PubMed

    Cohen, Victoria M L; Papastefanou, Vasilios P; Liu, S; Stoker, Ian; Hungerford, John L

    2013-01-01

    Background/Aims. To report the safety and efficacy of strontium (Sr(90)) beta radiotherapy as adjuvant treatment for conjunctival melanoma. Methods. A retrospective cohort study was undertaken from 1999 to 2007 of all patients who underwent Sr(90) beta radiotherapy for incompletely excised conjunctival melanoma. Failure of treatment was defined as recurrence of a conjunctival melanoma at the same location following beta radiotherapy. Results. Twenty patients underwent Sr(90) beta radiotherapy for incompletely excised conjunctival melanoma. Median follow-up interval was 59 months (8-152). All patients had conjunctival melanoma involving the bulbar conjunctiva. Underlying diagnoses included PAM with atypia in 60% (12 of 20), PAM without atypia in 15% (3 of 20), and de novo conjunctival melanoma in 25% (5 of 20). Following Sr(90) beta radiotherapy, in 90% (18 out of 20) local control was achieved and visual acuity was not affected in any patient. Three patients (15%) had dry eye symptoms, episcleritis, and descemetcoele, respectively. No cataract or secondary glaucoma was reported. Conclusions. Sr(90) treatment is a very effective adjuvant treatment after excisional biopsy and cryotherapy for conjunctival melanoma with a local success rate of 90%. The treatment is not associated with significant side effects and visual acuity is not affected.

  19. Radiotherapy systems using proton and carbon beams.

    PubMed

    Jongen, Y

    2008-01-01

    Radiotherapy using proton beams (proton therapy) is rapidly taking an important role among the techniques used in cancer therapy. At the end of 2007, 65.000 patients had been treated for cancer by proton beams in one of the 34 proton therapy facilities operating in the world. When compared to the now classical IMRT, and for a similar dose to the tumor, proton therapy provides a lower integral dose to the healthy organs surrounding the tumor. It is generally accepted that any reduction of the dose to healthy organs reduces the probability of radiation induced complications and of secondary malignancies. Proton therapy equipment can be obtained today from well established medical equipment companies such as Varian, Hitachi or Mitsubishi. But it is a Belgian company, Ion Beam Applications of Louvain-la-Neuve that is the undisputed leader in this market, with more than 55% of the world installed base. In addition to the now classical proton therapy equipments, using synchrotrons or cyclotrons as accelerators, new solutions have been proposed, claiming to be more compact and less expensive. A small startup company from Boston (Still Rivers) is proposing a very high magnetic field, gantry mounted superconducting synchrocyclotron. The us Company Tomotherapy is working to develop a new accelerator concept invented at Lawrence Livermore National Laboratory: the Dielectric Wall Accelerator. Besides proton beam therapy, which is progressively becoming an accepted part of radiation therapy, interest is growing for another form of radiotherapy using ions heavier than protons. Carbon ions have, even to a higher degree, the ballistic selectivity of protons. In addition, carbon ions stopping in the body exhibit a very high Linear Energy Transfer (LET). From this high LET results a very high Relative Biological Efficiency (RBE). This high RBE allows carbon ions to treat efficiently tumors who are radio-resistant and which are difficult to treat with photons or protons. The largest

  20. [Radiotherapy of carcinoma of the salivary glands].

    PubMed

    Servagi-Vernat, S; Tochet, F

    2016-09-01

    Indication, doses, and technique of radiotherapy for salivary glands carcinoma are presented, and the contribution of neutrons and carbon ions. The recommendations for delineation of the target volumes and organs at risk are detailed. PMID:27521038

  1. Imaging Instrumentation and Techniques for Precision Radiotherapy

    NASA Astrophysics Data System (ADS)

    Parodi, Katia; Parodi, Katia; Thieke, Christian; Thieke, Christian

    Over the last decade, several technological advances have considerably improved the achievable precision of dose delivery in radiation therapy. Clinical exploitation of the superior tumor-dose conformality offered by modern radiotherapy techniques like intensity-modulated radiotherapy and ion beam therapy requires morphological and functional assessment of the tumor during the entire therapy chain from treatment planning to beam application and treatment response evaluation. This chapter will address the main rationale and role of imaging in state-of-the-art external beam radiotherapy. Moreover, it will present the status of novel imaging instrumentation and techniques being nowadays introduced in clinical use or still under development for image guidance and, ultimately, dose guidance of precision radiotherapy.

  2. Historical aspects of heavy ion radiotherapy

    SciTech Connect

    Raju, M.R.

    1995-03-01

    This paper presents historical developments of heavy-ion radiotherapy including discussion of HILAC and HIMAC and discussion of cooperation between Japan and the United States, along with personal reflections.

  3. Heavy particle radiotherapy: prospects and pitfalls

    SciTech Connect

    Faju, M.R.

    1980-01-01

    The use of heavy particles in radiotherapy of tumor volumes is examined. Particles considered are protons, helium ions, heavy ions, negative pions, and fast neutrons. Advantages and disadvantages are discussed. (ACR)

  4. [Conformal radiotherapy for vertebral bone metastasis].

    PubMed

    Faivre, J C; Py, J F; Vogin, G; Martinage, G; Salleron, J; Royer, P; Grandgirard, N; Pasquier, D; Thureau, S

    2016-10-01

    Analgesic external beam radiation therapy is a standard of care for patients with uncomplicated painful bone metastases and/or prevention of bone complications. In case of fracture risk, radiation therapy is performed after surgery in a consolidation of an analgesic purpose and stabilizing osteosynthesis. Radiotherapy is mandatory after vertebroplasty or kyphoplasty. Spinal cord compression - the only emergency in radiation therapy - is indicated postoperatively either exclusively for non surgical indication. Analgesic re-irradiation is possible in the case of insufficient response or recurrent pain after radiotherapy. Metabolic radiation, bisphosphonates or denosumab do not dissuade external radiation therapy for pain relief. Systemic oncological treatments can be suspended with a period of wash out given the risk of radiosensitization or recall phenomenon. Better yet, the intensity modulated radiotherapy and stereotactic radiotherapy can be part of a curative strategy for oligometastatic patients and suggest new treatment prospects. PMID:27614498

  5. Efficacy of radiotherapy in optic gliomas.

    PubMed

    Gould, R J; Hilal, S K; Chutorian, A M

    1987-01-01

    Twenty-five children with optic gliomas were evaluated over a seven year period by sequential computed axial tomography in order to determine the efficacy of radiotherapy as a treatment modality. Indices of tumor progression or regression included both size and contrast enhancement characteristics. Twenty of 25 patients followed during this period received radiotherapy. Of these patients, ten had tumor regression, nine were stable, and one was worse. This result contrasts with five untreated patients, four of whom had tumor progression and one who was stable (x2 = 18.37, p less than .001). One of the children with tumor progression later received radiotherapy and demonstrated marked tumor regression. Of the 18 treated patients who could be tested reliably, visual function and/or regression occurred in seven children. None of the untreated patients improved. There were no definite complications of radiotherapy in this small group.

  6. Freedom From Local and Regional Failure of Contralateral Neck With Ipsilateral Neck Radiotherapy for Node-Positive Tonsil Cancer: Results of a Prospective Management Approach

    SciTech Connect

    Rusthoven, Kyle E. Raben, David; Schneider, Charles; Witt, Robert; Sammons, Sarah; Raben, Adam

    2009-08-01

    Purpose: To review the outcomes of a prospective management approach using ipsilateral neck radiotherapy in the treatment of node-positive squamous cell carcinoma of the tonsil with a well-lateralized primary lesion. Methods and Materials: Between August 2003 and June 2007, 20 patients who presented with squamous cell carcinoma of the tonsil, without involvement of the base of the tongue or midline soft palate, and with Stage N1-N2b disease were prospectively treated with radiotherapy to the primary site and ipsilateral neck. In addition, 18 patients received concurrent chemotherapy. The actuarial freedom from contralateral nodal and in-field progression was determined. Acute and late toxicity were prospectively evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events, version 3, and Radiation Therapy Oncology Group criteria. Results: The nodal disease was Stage N1 in 4 patients, N2a in 3 patients, and N2b in 13 patients. At a median follow-up 19 months (range, 12-40), no in-field or contralateral nodal recurrences had been observed. The 2-year freedom from distant metastasis rate was 87.4%. The actuarial 2-year disease-free and overall survival rates were both 79.5%. Late Radiation Therapy Oncology Group grade 2 xerostomia occurred in 1 patient (5%). No late Grade 3 or greater toxicity was observed. No patient was feeding tube dependent at their last follow-up visit. Conclusion: In carefully selected patients with node-positive, lateralized tonsillar cancer, treatment of the ipsilateral neck and primary site does not appear to increase the risk of contralateral nodal failure and reduces late morbidity compared with historical controls. Although the outcomes with ipsilateral radiotherapy in the present series were promising, these findings require longer follow-up and validation in a larger patient cohort.

  7. Parent Involvement.

    ERIC Educational Resources Information Center

    LaCrosse, Ed

    The paper discusses the rationale and guidelines for parent involvement in HCEEP (Handicapped Children's Early Education Program) projects. Ways of assessing parents' needs are reviewed, as are four types of services to meet the identified needs: parent education, direct participation, parent counseling, and parent provided programs. Materials and…

  8. Concurrent radiotherapy and intrathecal methotrexate for treating leptomeningeal metastasis from solid tumors with adverse prognostic factors: A prospective and single-arm study.

    PubMed

    Pan, Zhenyu; Yang, Guozi; He, Hua; Zhao, Gang; Yuan, Tingting; Li, Yu; Shi, Weiyan; Gao, Pengxiang; Dong, Lihua; Li, Yunqian

    2016-10-15

    The prognosis of leptomeningeal metastasis (LM) from solid tumors is extremely poor, especially for patients with adverse prognostic factors. In this phase II clinical trial, we evaluated the efficacy and safety of intrathecal chemotherapy (IC) combined with concomitant involved-field radiotherapy (IF-RT) for treating LM from solid tumors with adverse prognostic factors. Fifty-nine patients with LM from various solid tumors were enrolled between May 2010 and December 2014. Concurrent therapy consisted of concomitant IC (methotrexate 12.5-15 mg and dexamethasone 5 mg, weekly) and IF-RT (whole brain and/or spinal canal RT, 40 Gy/20f). For patients with low Karnofsky performance status (KPS) score and radiotherapy intolerance, induction IC (1-3 times) was given before concurrent therapy. Thirty-eight patients (64.4%) received subsequent treatments. All patients were followed up at least 6 months after LM diagnosis or until death. Primary endpoint evaluated was clinical response rate. Secondary endpoints were overall survival (OS) and safety. The pathological types included lung cancer (n = 42), breast cancer (n = 11) and others (n = 6). Median KPS score was 40 (range 20-70). Fifty-one patients (86.4%) completed concurrent therapy. The overall response rate was 86.4% (51/59). OS ranged from 0.4 to 36.7 months (median 6.5 months), and 1-year-survival rate was 21.3%. Treatment-related adverse events mainly included acute meningitis, chronic-delayed encephalopathy, radiculitis, myelosuppression and mucositis. Twelve patients (20.3%) had grade III-V toxic reactions. We concluded that IC combined with concomitant IF-RT, with significant efficacy and acceptable toxicity, may be an optimal therapeutic option for treatment of LM from solid tumors with adverse prognostic factors. LM, in which cancer cells spread to membranes enveloping the brain and spinal cord, is a devastating complication of solid cancers. Existing LM therapies center on IC. In this prospective

  9. Radiotherapy in the treatment of vertebral hemangiomas

    SciTech Connect

    Faria, S.L.; Schlupp, W.R.; Chiminazzo, H. Jr.

    1985-02-01

    Symptomatic vertebral hemangiomas are not common. Although radiotherapy has been used as treatment, the data are sparse concerning total dose, fractionation and results. The authors report nine patients with vertebral hemangioma treated with 3000-4000 rad, 200 rad/day, 5 fractions per week, followed from 6 to 62 months. Seventy-seven percent had complete or almost complete disappearance of the symptoms. Radiotherapy schedules are discussed.

  10. Blisters - an unusual effect during radiotherapy.

    PubMed

    Höller, U; Schubert, T; Budach, V; Trefzer, U; Beyer, M

    2013-11-01

    The skin reaction to radiation is regularly monitored in order to detect enhanced radiosensitivity of the patient, unexpected interactions (e.g. with drugs) or any inadvertent overdosage. It is important to distinguish secondary disease from radiation reaction to provide adequate treatment and to avoid unnecessary discontinuation of radiotherapy. A case of bullous eruption or blisters during radiotherapy of the breast is presented. Differential diagnoses bullous pemphigoid, pemphigus vulgaris, and bullous impetigo are discussed and treatment described. PMID:24158604

  11. Intensified autophagy compromises the efficacy of radiotherapy against prostate cancer

    SciTech Connect

    Koukourakis, Michael I.

    2015-05-29

    Introduction: Radiotherapy is an equivalent alternative or complement to radical prostatectomy, with high therapeutic efficacy. High risk patients, however, experience high relapse rates, so that research on radio-sensitization is the most evident route to improve curability of this common disease. Materials and methods: In the current study we investigated the autophagic activity in a series of patients with localized prostate tumors treated with radical radiotherapy, using the LC3A and the LAMP2a proteins as markers of autophagosome and lysosome cellular content, respectively. The role of autophagy on prostate cancer cell line resistance to radiation was also examined. Results: Using confocal microscopy on tissue biopsies, we showed that prostate cancer cells have, overall, high levels of LC3A and low levels of LAMP2a compared to normal prostate glands. Tumors with a ‘highLC3A/lowLAMP2a’ phenotype, suggestive of intensified lysosomal consumption, had a significantly poorer biochemical relapse free survival. The PC3 radioresistant cell line sustained remarkably its autophagic flux ability after radiation, while the DU145 radiosensitive one experiences a prolonged blockage of the autophagic process. This was assessed with aggresome accumulation detection and LC3A/LAMP2a double immunofluorescence, as well as with sequestrosome/p62 protein detection. By silencing the LC3A or LAMP2a expression, both cell lines became more sensitive to escalated doses of radiation. Conclusions: High base line autophagy activity and cell ability to sustain functional autophagy define resistance of prostate cancer cells to radiotherapy. This can be reversed by blocking up-regulated components of the autophagy pathway, which may prove of importance in the field of clinical radiotherapy. - Highlights: • High LC3A and low LAMP2a levels is a frequent expression pattern of prostate carcinoma. • This pattern of intensified autophagic flux relates with high relapse rates after

  12. Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector

    NASA Astrophysics Data System (ADS)

    Sánchez-Doblado, F.; Domingo, C.; Gómez, F.; Sánchez-Nieto, B.; Muñiz, J. L.; García-Fusté, M. J.; Expósito, M. R.; Barquero, R.; Hartmann, G.; Terrón, J. A.; Pena, J.; Méndez, R.; Gutiérrez, F.; Guerre, F. X.; Roselló, J.; Núñez, L.; Brualla-González, L.; Manchado, F.; Lorente, A.; Gallego, E.; Capote, R.; Planes, D.; Lagares, J. I.; González-Soto, X.; Sansaloni, F.; Colmenares, R.; Amgarou, K.; Morales, E.; Bedogni, R.; Cano, J. P.; Fernández, F.

    2012-10-01

    Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation is therefore essential for a reasonable assessment of these associated risks. This work aimed to develop a method to estimate neutron-equivalent doses in multiple organs of radiotherapy patients. The method involved the convolution, at 16 reference points in an anthropomorphic phantom, of the normalized Monte Carlo neutron fluence energy spectra with the kerma and energy-dependent radiation weighting factor. This was then scaled with the total neutron fluence measured with passive detectors, at the same reference points, in order to obtain the equivalent doses in organs. The latter were correlated with the readings of a neutron digital detector located inside the treatment room during phantom irradiation. This digital detector, designed and developed by our group, integrates the thermal neutron fluence. The correlation model, applied to the digital detector readings during patient irradiation, enables the online estimation of neutron-equivalent doses in organs. The model takes into account the specific irradiation site, the field parameters (energy, field size, angle incidence, etc) and the installation (linac and bunker geometry). This method, which is suitable for routine clinical use, will help to systematically generate the dosimetric data essential for the improvement of current risk-estimation models.

  13. Radiotherapy for Vestibular Schwannomas: A Critical Review

    SciTech Connect

    Murphy, Erin S.; Suh, John H.

    2011-03-15

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

  14. Sci—Fri PM: Dosimetry—02: A Nested Neutron Spectrometer to Measure Neutron Spectra in Radiotherapy

    SciTech Connect

    Maglieri, R; Seuntjens, J; Kildea, J; Licea, A

    2014-08-15

    During high-energy radiotherapy treatments, neutrons are produced in the head of the linac through photonuclear interactions. This has been a concern for many years as photoneutrons contribute to the accepted, yet unwanted, out-of-field doses that pose an iatrogenic risk to patients and an occupational risk to personnel. Presently, in-room neutron measurements are difficult and time-consuming and have traditionally been carried out using Bonner spheres with activation foils and TLDs. In this work, a new detector, the Nested Neutron Spectrometer (NNS) is tested for use in radiotherapy bunkers. The NNS is designed for easy handling and is more practical than the traditional Bonner spheres. The NNS, operated in current mode, was used to measure the dose equivalent, average energy and energy spectrum at several positions in a radiotherapy bunker. The average energy and spectra were compared to Monte Carlo simulations while the dose equivalent was compared to bubble detector measurements. The average energies, as measured by the NNS and Monte Carlo simulations, differed by approximately 30% across the bunker. Measurements of the dose equivalent using the NNS and the bubble detectors agreed within 50% in the maze and less than 10% close to the linac head. Apart from some discrepancies at thermal energies, we also found reasonable agreement between NNS-measured and Monte Carlo-simulated spectra at a number of locations within our radiotherapy bunker. Our results demonstrate that the NNS is a suitable detector to be used in high dose-rate radiotherapy environments.

  15. Synergistic anti-tumor effects of zoledronic acid and radiotherapy against metastatic hepatocellular carcinoma.

    PubMed

    Morii, Kazuhiko; Aoyama, Yuhki; Nakamura, Shinichiro; Okushin, Hiroaki

    2015-01-01

    A 72-year-old man with advanced hepatocellular carcinoma and decompensated hepatitis C virus-related cirrhosis suffered from a metastatic femoral fracture. After undergoing radiotherapy, he was only treated with supportive care, except for the administration of zoledronic acid (ZA). Thereafter, the initially elevated serum α-fetoprotein and des-gamma carboxyprothrombin levels declined to within the normal ranges. Hepatic and metastatic adrenal tumors, distant from the radiation field, exhibited a surprising regression. ZA is known to inhibit the activity of osteoclasts, bone-residential macrophages, and has been reported to have a direct anti-tumor effect. ZA may adjust the immunological milieu in tumor microenvironments by inhibiting the tumor-associated macrophages. Because radiotherapy can enhance the presentation of tumor-associated antigens, ZA and radiotherapy may exert synergistic anti-tumor effects. PMID:26466697

  16. Low-cost commercial glass beads as dosimeters in radiotherapy

    NASA Astrophysics Data System (ADS)

    Jafari, S. M.; Bradley, D. A.; Gouldstone, C. A.; Sharpe, P. H. G.; Alalawi, A.; Jordan, T. J.; Clark, C. H.; Nisbet, A.; Spyrou, N. M.

    2014-04-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size (<5 mm), low cost, reusability and inert nature. This study investigated the dosimetric characteristics of glass beads. The beads were irradiated by 6 MV photons using a medical linear-accelerator and 60Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy.

  17. Secondary cancer-incidence risk estimates for external radiotherapy and high-dose-rate brachytherapy in cervical cancer: phantom study.

    PubMed

    Lee, Boram; Ahn, Sung Hwan; Kim, Hyeyoung; Son, Jaeman; Sung, Jiwon; Han, Youngyih; Huh, Seung Jae; Kim, Jin Sung; Kim, Dong Wook; Yoon, Myonggeun

    2016-01-01

    This study was designed to estimate radiation-induced secondary cancer risks from high-dose-rate (HDR) brachytherapy and external radiotherapy for patients with cervical cancer based on measurements of doses absorbed by various organs. Organ doses from HDR brachytherapy and external radiotherapy were measured using glass rod dosimeters. Doses to out-of-field organs were measured at various loca-tions inside an anthropomorphic phantom. Brachytherapy-associated organ doses were measured using a specialized phantom that enabled applicator insertion, with the pelvis portion of the existing anthropomorphic phantom replaced by this new phantom. Measured organ doses were used to calculate secondary cancer risk based on Biological Effects of Ionizing Radiation (BEIR) VII models. In both treatment modalities, organ doses per prescribed dose (PD) mostly depended on the distance between organs. The locations showing the highest and lowest doses were the right kidney (external radiotherapy: 215.2 mGy; brachytherapy: 655.17 mGy) and the brain (external radiotherapy: 15.82 mGy; brachytherapy: 2.49 mGy), respectively. Organ doses to nearby regions were higher for brachytherapy than for external beam therapy, whereas organ doses to distant regions were higher for external beam therapy. Organ doses to distant treatment regions in external radiotherapy were due primarily to out-of-field radiation resulting from scattering and leakage in the gantry head. For brachytherapy, the highest estimated lifetime attributable risk per 100,000 population was to the stomach (88.6), whereas the lowest risks were to the brain (0.4) and eye (0.4); for external radiotherapy, the highest and lowest risks were to the thyroid (305.1) and brain (2.4). These results may help provide a database on the impact of radiotherapy-induced secondary cancer incidence dur-ing cervical cancer treatment, as well as suggest further research on strategies to counteract the risks of radiotherapy-associated secondary

  18. Involvement of the immune response in the cure of metastatic murine CT-26 colon carcinoma by low electric field-enhanced chemotherapy.

    PubMed

    Plotnikov, Alexander; Tichler, Thomas; Korenstein, Rafi; Keisari, Yona

    2005-12-10

    Low electric field cancer treatment-enhanced chemotherapy (LEFCT-EC) is a new treatment modality that combines chemotherapeutic agents and low electric field stimulation. LEFCT-EC was found to destroy malignant mouse tumors and cause massive death of tumor cells. This may enable the immune system cells to efficiently recognize and eliminate tumor cells at the primary tumor site and at metastatic foci. Mice with 15 mm diameter intracutaneous colon carcinomas (CT-26) were injected with BCNU (35 mg/kg), and 2 min later the tumors were exposed to low electric fields (intensity 40 V/cm, pulse duration 180 micros, frequency 500 Hz) for 12 min (LEFCT-EC). We found that treatment with LEFCT-EC achieved complete cure of 93% of the animals. In comparison, electric fields alone (13% cure), chemotherapy alone (0%), surgery (15%) or a combination of surgery and bis-chloroethyl-nitrosurea, carmustine (BCNU; 84%) treatments resulted in lower cure rates. After treatment and cure with LEFCT-EC, 50% of the cured mice developed resistance to a tumor challenge (surgery + BCNU only 15%). Furthermore, splenocytes from cured animals protected naive animals from a tumorigenic dose of tumor cells. Separation of spleen cells into lymphocyte subpopulations indicated a major role for CD4 and CD8 T cells in this protection. FACS analysis revealed restoration of normal splenocyte subpopulation proportions impaired by cytotoxic chemotherapy. Our results suggest that LEFCT-EC can directly destroy primary tumors and facilitate the destruction of metastatic disease by enforcement of antitumor immune responses.

  19. Petermann I and II spot size: Accurate semi analytical description involving Nelder-Mead method of nonlinear unconstrained optimization and three parameter fundamental modal field

    NASA Astrophysics Data System (ADS)

    Roy Choudhury, Raja; Roy Choudhury, Arundhati; Kanti Ghose, Mrinal

    2013-01-01

    A semi-analytical model with three optimizing parameters and a novel non-Gaussian function as the fundamental modal field solution has been proposed to arrive at an accurate solution to predict various propagation parameters of graded-index fibers with less computational burden than numerical methods. In our semi analytical formulation the optimization of core parameter U which is usually uncertain, noisy or even discontinuous, is being calculated by Nelder-Mead method of nonlinear unconstrained minimizations as it is an efficient and compact direct search method and does not need any derivative information. Three optimizing parameters are included in the formulation of fundamental modal field of an optical fiber to make it more flexible and accurate than other available approximations. Employing variational technique, Petermann I and II spot sizes have been evaluated for triangular and trapezoidal-index fibers with the proposed fundamental modal field. It has been demonstrated that, the results of the proposed solution identically match with the numerical results over a wide range of normalized frequencies. This approximation can also be used in the study of doped and nonlinear fiber amplifier.

  20. Modality comparison for small animal radiotherapy: A simulation study

    SciTech Connect

    Bazalova, Magdalena Nelson, Geoff; Noll, John M.; Graves, Edward E.

    2014-01-15

    Purpose: Small animal radiation therapy has advanced significantly in recent years. Whereas in the past dose was delivered using a single beam and a lead shield for sparing of healthy tissue, conformal doses can be now delivered using more complex dedicated small animal radiotherapy systems with image guidance. The goal of this paper is to investigate dose distributions for three small animal radiation treatment modalities. Methods: This paper presents a comparison of dose distributions generated by the three approaches—a single-field irradiator with a 200 kV beam and no image guidance, a small animal image-guided conformal system based on a modified microCT scanner with a 120 kV beam developed at Stanford University, and a dedicated conformal system, SARRP, using a 220 kV beam developed at Johns Hopkins University. The authors present a comparison of treatment plans for the three modalities using two cases: a mouse with a subcutaneous tumor and a mouse with a spontaneous lung tumor. A 5 Gy target dose was calculated using the EGSnrc Monte Carlo codes. Results: All treatment modalities generated similar dose distributions for the subcutaneous tumor case, with the highest mean dose to the ipsilateral lung and bones in the single-field plan (0.4 and 0.4 Gy) compared to the microCT (0.1 and 0.2 Gy) and SARRP (0.1 and 0.3 Gy) plans. The lung case demonstrated that due to the nine-beam arrangements in the conformal plans, the mean doses to the ipsilateral lung, spinal cord, and bones were significantly lower in the microCT plan (2.0, 0.4, and 1.9 Gy) and the SARRP plan (1.5, 0.5, and 1.8 Gy) than in single-field irradiator plan (4.5, 3.8, and 3.3 Gy). Similarly, the mean doses to the contralateral lung and the heart were lowest in the microCT plan (1.5 and 2.0 Gy), followed by the SARRP plan (1.7 and 2.2 Gy), and they were highest in the single-field plan (2.5 and 2.4 Gy). For both cases, dose uniformity was greatest in the single-field irradiator plan followed by

  1. Combining radiotherapy and angiogenesis inhibitors: Clinical trial design

    SciTech Connect

    Citrin, Deborah . E-mail: citrind@mail.nih.gov; Menard, Cynthia; Camphausen, Kevin

    2006-01-01

    Radiotherapy (RT) plays a vital role in the multimodality treatment of cancer. Recent advances in RT have primarily involved improvements in dose delivery. Future improvements in tumor control and disease outcomes will likely involve the combination of RT with targeted therapies. Preclinical evaluations of angiogenesis inhibitors in combination with RT have yielded promising results with increased tumor 'cure.' It remains to be seen whether these improvements in tumor control in the laboratory will translate into improved outcomes in the clinic. Multiple differences between these agents and cytotoxic chemotherapy must be taken into account when designing clinical trials evaluating their effectiveness in combination with RT. We discuss important considerations for designing clinical trials of angiogenesis inhibitors with RT.

  2. Fast neutron radiotherapy: For equal or for better

    SciTech Connect

    Broerse, J.J.; Battermann, J.J.

    1981-11-01

    The renewed application of fast neutrons in clinical radiotherapy has been stimulated by fundamental radiobiological findings. The biological effects of high LET radiation, including fast neutrons, are different from those obtained with x rays in at least three respects: the oxygen enhancement ratio, the sensitivity of cells at different phases of the cell cycle, and the contribution of sublethal damage to cell reproductive death. Furthermore, wide variations in relative biological effectiveness (RBE) have been observed for different tumors and normal tissues. Measurements of volume changes in human pulmonary metastases indicate that the RBE for slowly growing tumors which are generally well-differentiated is higher than that for poorly differentiated lesions. Six thousand patients have now been treated with fast neutron beams. The results of the clinical applications vary according to the method of application and to the type of cancer involved: treatment of inoperable malignancies of the salivary gland is very encouraging; the therapeutic gain is rather small for bladder and rectal cancers, soft tissue sarcomas and advanced carcinomas of the cervix; the responses of brain tumors are very disappointing. Most neutron radiotherapy applications have been less than optimal because of inadequate physical and technical conditions. Despite these difficulties, some interesting clinical data have become available. Due to the technical shortcomings, the possible advantages of fast neutrons are probably underestimated for many tumor sites. Well-designed clinical trials, preferably performed with high energy cyclotrons in clinical environments, will provide a decisive answer to the question of the usefulness of the new radiation modality. Key words: fast neutrons, radiotherapy, radiobiology

  3. A Small Physiological Electric Field Mediated Responses of Extravillous Trophoblasts Derived from HTR8/SVneo Cells: Involvement of Activation of Focal Adhesion Kinase Signaling

    PubMed Central

    Zhang, Juan; Ren, Rongmei; Luo, Xuefeng; Fan, Ping; Liu, Xinghui; Liang, Shanshan; Ma, Lei; Yu, Ping; Bai, Huai

    2014-01-01

    Moderate invasion of trophoblast cells into endometrium is essential for the placental development and normal pregnancy. Electric field (EF)-induced effects on cellular behaviors have been observed in many cell types. This study was to investigate the effect of physiological direct current EF (dc EF) on cellular responses such as elongation, orientation and motility of trophoblast cells. Immortalized first trimester extravillous trophoblast cells (HTR-8/SVneo) were exposed to the dc EF at physiological magnitude. Cell images were recorded and analyzed by image analyzer. Cell lysates were used to detect protein expression by Western blot. Cultured in the dc EFs the cells showed elongation, orientation and enhanced migration rate compared with non-EF stimulated cells at field strengths of 100 mV/mm to 200 mV/mm. EF exposure increased focal adhesion kinase (FAK) phosphorylation in a time-dependent manner and increased expression levels of MMP-2. Pharmacological inhibition of FAK impaired the EF-induced responses including motility and abrogated the elevation of MMP-2 expression. However, the expression levels of integrins like integrin α1, α5, αV and β1 were not affected by EF stimulation. Our results demonstrate the importance of FAK activation in migration/motility of trophobalst cells driven by EFs. In addition, it raises the feasibility of using applied EFs to promote placentation through effects on trophoblast cells. PMID:24643246

  4. [Needs and financing of radiotherapy in France and Europe].

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

    Access to high-quality and safe radiotherapy is a prerequisite to assure optimal oncology care in a multidisciplinary environment. In view of supporting long-term radiotherapy planning, actual and predicted radiotherapy needs should be put in context of the nowadays' available resources. The present article reviews the existing data on radiotherapy resources and needs, along with the prevailing reimbursement systems in the different European countries, with a specific emphasis on France. It describes potential incentives of different financing systems on clinical practice and highlights how knowledge of the cost of radiotherapy treatments, by indication and technique, is essential to support correct reimbursement, hence access to radiotherapy. It is expected that such data will help national professional and scientific radiotherapy societies across Europe in their negotiations with policy makers, with the ultimate aim to make radiotherapy accessible to all cancer patients who need it, now and in the decades to come.

  5. [Needs and financing of radiotherapy in France and Europe].

    PubMed

    Defourny, N; Lievens, Y

    2016-10-01

    Access to high-quality and safe radiotherapy is a prerequisite to assure optimal oncology care in a multidisciplinary environment. In view of supporting long-term radiotherapy planning, actual and predicted radiotherapy needs should be put in context of the nowadays' available resources. The present article reviews the existing data on radiotherapy resources and needs, along with the prevailing reimbursement systems in the different European countries, with a specific emphasis on France. It describes potential incentives of different financing systems on clinical practice and highlights how knowledge of the cost of radiotherapy treatments, by indication and technique, is essential to support correct reimbursement, hence access to radiotherapy. It is expected that such data will help national professional and scientific radiotherapy societies across Europe in their negotiations with policy makers, with the ultimate aim to make radiotherapy accessible to all cancer patients who need it, now and in the decades to come. PMID:27599682

  6. Involvement of protein kinase C in the modulation of morphine-induced analgesia and the inhibitory effects of exposure to 60-hz magnetic fields in the land snail, Cepaea nemoralis

    SciTech Connect

    Kavaliers, M.; Ossenkopp, K.P. )

    1990-02-26

    One of the more consistent and dramatic effects of exposure to magnetic fields is the attenuation of morphine-induced analgesia. Results of previous studies have implicated alterations in calcium channel functioning and Ca{sup ++} flux in the mediation of these effects. It is generally accepted that Ca{sup ++}-activated-phospholipid-dependent protein kinase (Protein kinase C; PKC) plays an important role in relaying trans-membrane signaling in diverse Ca{sup ++} dependent cellular processes. In experiment 1 we observed that morphine-induced analgesia in the land snail, Cepaea nemoralis, as measured by the latency of an avoidance behavior to a warmed surface, was reduced by the PKC activator, SC-9, and was enhanced by the PKC inhibitors, H-7 and H-9. In contrast, HA-10004, a potent inhibitor of other protein kinases, but only a very weak inhibitor of PKC, had no effect on morphine-induced analgesia. In experiment 2 exposure of snails for 30 minutes to a 1.0 gauss (rms) 60-Hz magnetic field reduced morphine-induced analgesia. This inhibitory effect of the magnetic field was reduced by the PKC inhibitors, H-7 and H-9, and was augmented by the PKC activator SC-9. These results suggest that: (i) PKC is involved in the modulation of morphine-induced analgesia and, (ii) the inhibitory effects of magnetic fields involve PKC.

  7. Dosimetric Advantage of Intensity-Modulated Radiotherapy for Whole Ventricles in the Treatment of Localized Intracranial Germinoma

    SciTech Connect

    Sakanaka, Katsuyuki; Mizowaki, Takashi; Hiraoka, Masahiro

    2012-02-01

    Purpose: To investigate the dosimetric advantage of intensity-modulated radiotherapy (IMRT) for whole ventricles (WV) in patients with a localized intracranial germinoma receiving induction chemotherapy. Methods and Materials: Data from 12 consecutive patients with localized intracranial germinomas who received induction chemotherapy and radiotherapy were used. Four-field coplanar three-dimensional conformal radiotherapy (3D-CRT) and seven-field coplanar IMRT plans were created. In both plans, 24 Gy was prescribed in 12 fractions for the planning target volume (PTV) involving WV and tumor bed. In IMRT planning, optimization was conducted to reduce the doses to the organs at risk (OARs) as much as possible, keeping the minimum dose equivalent to that of 3D-CRT. The 3D-CRT and IMRT plans were compared in terms of the dose-volume statistics for target coverage and the OARs. Results: IMRT significantly increased the percentage volume of the PTV receiving 24 Gy compared with 3D-CRT (93.5% vs. 84.8%; p = 0.007), while keeping target homogeneity equivalent to 3D-CRT (p = 0.869). The absolute percentage reduction in the irradiated volume of the normal brain receiving 100%, 75%, 50%, and 25% of 24 Gy ranged from 0.7% to 16.0% in IMRT compared with 3D-CRT (p < 0.001). No significant difference was observed in the volume of the normal brain receiving 10% and 5% of 24 Gy between IMRT and 3D-CRT. Conformation number was significantly improved in IMRT (p < 0.001). For other OARs, the mean dose to the cochlea was reduced significantly in IMRT by 22.3% of 24 Gy compared with 3D-CRT (p < 0.001). Conclusions: Compared with 3D-CRT, IMRT for WV improved the target coverage and reduced the irradiated volume of the normal brain in patients with intracranial germinomas receiving induction chemotherapy. IMRT for WV with induction chemotherapy could reduce the late side effects from cranial irradiation without compromising control of the tumor.

  8. Navigated marker placement for motion compensation in radiotherapy

    NASA Astrophysics Data System (ADS)

    Winterstein, A.; März, K.; Franz, A. M.; Hafezi, M.; Fard, N.; Sterzing, F.; Mehrabi, A.; Maier-Hein, L.

    2015-03-01

    Radiotherapy is frequently used to treat unoperated or partially resected tumors. Tumor movement, e.g. caused by respiration, is a major challenge in this context. Markers can be implanted around the tumor prior to radiation therapy for accurate tracking of tumor movement. However, accurate placement of these markers while keeping a secure margin around the target and while taking into account critical structures is a difficult task. Computer-assisted needle insertion has been an active field of research in the past decades. However, the challenge of navigated marker placement for motion compensated radiotherapy has not yet been addressed. This work presents a system to support marker implantation for radiotherapy under consideration of safety margins and optimal marker configuration. It is designed to allow placement of markers both percutaneously and during an open liver surgery. To this end, we adapted the previously proposed EchoTrack system which integrates ultrasound (US) imaging and electromagnetic (EM) tracking in a single mobile modality. The potential of our new marker insertion concept was evaluated in a phantom study by inserting sets of three markers around dedicated targets (n=22) simultaneously spacing the markers evenly around the target as well as placing the markers in a defined distance to the target. In all cases the markers were successfully placed in a configuration fulfilling the predefined criteria. This includes a minimum distance of 18.9 ± 2.4 mm between marker and tumor as well as a divergence of 2.1 ± 1.5 mm from the planned marker positions. We conclude that our system has high potential to facilitate the placement of markers in suitable configurations for surgeons without extensive experience in needle punctions as high quality configurations were obtained even by medical non-experts.

  9. Patterns of Radiotherapy Practice for Patients With Cervical Cancer (1999-2001): Patterns of Care Study in Japan

    SciTech Connect

    Toita, Takafumi Kodaira, Takeshi; Shinoda, Atsunori; Uno, Takashi; Akino, Yuichi; Mitsumori, Michihide; Teshima, Teruki

    2008-03-01

    Purpose: To describe the patterns of definitive radiotherapy practice for patients with uterine cervical cancer from 1999 to 2001 in Japan. Methods and Materials: The Japanese Patterns of Care Study (JPCS) working group conducted a third extramural audit survey of 68 institutions and collected specific information on 324 cervical cancer patients treated with definitive radiotherapy. Results: Almost all patients (96%) were treated with whole pelvic radiotherapy using opposing anteroposterior fields (87%). A midline block was used in 70% of the patients. Intracavitary brachytherapy (ICBT) was applied in 82% of cases. Most patients (89%) were treated with high-dose rate (HDR) ICBT. Calculation of doses to organs at risk (ICRU 38) was performed for rectum in 25% of cases and for bladder in 18% of cases. Only 3% of patients were given intravenous conscious sedation during ICBT applicator insertions. The median total biologically effective dose at point A (EBRT+ICBT) was 74 Gy{sub 10} in cases treated with HDR-ICBT. There was no significant difference in total biologically effective dose between stages. The median overall treatment time was 47 days. Concurrent chemoradiation was applied in 17% of patients. Conclusions: This study describes the general patterns of radiotherapy practice for uterine cervical cancer in Japan. Although methods of external radiotherapy seemed to be appropriate, there was room for improvement in ICBT practice, such as pretreatment. A substantial difference in total radiotherapy dose between Japan and the United States was observed.

  10. [Image-guided radiotherapy and partial delegation to radiotherapy technicians: Clermont-Ferrand experience].

    PubMed

    Loos, G; Moreau, J; Miroir, J; Benhaïm, C; Biau, J; Caillé, C; Bellière, A; Lapeyre, M

    2013-10-01

    The various image-guided radiotherapy techniques raise the question of how to achieve the control of patient positioning before irradiation session and sharing of tasks between radiation oncologists and radiotherapy technicians. We have put in place procedures and operating methods to make a partial delegation of tasks to radiotherapy technicians and secure the process in three situations: control by orthogonal kV imaging (kV-kV) of bony landmarks, control by kV-kV imaging of intraprostatic fiducial goldmarkers and control by cone beam CT (CBCT) imaging for prostate cancer. Significant medical overtime is required to control these three IGRT techniques. Because of their competence in imaging, these daily controls can be delegated to radiotherapy technicians. However, to secure the process, initial training and regular evaluation are essential. The analysis of the comparison of the use of kV/kV on bone structures allowed us to achieve a partial delegation of control to radiotherapy technicians. Controlling the positioning of the prostate through the use and automatic registration of fiducial goldmarkers allows better tracking of the prostate and can be easily delegated to radiotherapy technicians. The analysis of the use of daily cone beam CT for patients treated with intensity modulated irradiation is underway, and a comparison of practices between radiotherapy technicians and radiation oncologists is ongoing to know if a partial delegation of this control is possible. PMID:24011600

  11. A dose comparison of proton radiotherapy and photon radiotherapy for pediatric brain tumor

    NASA Astrophysics Data System (ADS)

    Kim, S. Y.; Cho, J. H.

    2014-12-01

    The purpose of this study was to investigate the effectiveness of photon radiotherapy and to compare the dose of treatment planning between proton radiotherapy and 3D conformal radiation therapy (3D-CRT) for pediatric brain tumor patients. This study was conducted in five pediatric brain tumor patients who underwent craniospinal irradiation treatment from October 2013 to April 2014 in the hospital. The study compared organs at risk (OARs) by assessing the dose distribution of normal tissue from the proton plan and 3D-CRT. Furthermore, this study assessed the treatment plans by looking at the homogeneity index (HI) and conformity index (CI). As a result, the study revealed OARs due to the small volume proton radiotherapy dose distribution in the normal tissue. Also, by comparing HI and CI between the 3D-CRT and proton radiotherapy plan, the study found that the dose of proton radiotherapy plan was homogenized. When conducting 3D-CRT and proton radiotherapy in a dose-volume histogram comparison, the dose of distribution turned out to be low. Consequently, proton radiotherapy is used for protecting the normal tissue, and is used in tumor tissue as a homogenized dose for effective treatment.

  12. SU-C-17A-07: The Development of An MR Accelerator-Enabled Planning-To-Delivery Technique for Stereotactic Palliative Radiotherapy Treatment of Spinal Metastases

    SciTech Connect

    Hoogcarspel, S J; Kontaxis, C; Velden, J M van der; Bol, G H; Vulpen, M van; Lagendijk, J J W; Raaymakers, B W

    2014-06-01

    Purpose: To develop an MR accelerator-enabled online planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases. The technical challenges include; automated stereotactic treatment planning, online MR-based dose calculation and MR guidance during treatment. Methods: Using the CT data of 20 patients previously treated at our institution, a class solution for automated treatment planning for spinal bone metastases was created. For accurate dose simulation right before treatment, we fused geometrically correct online MR data with pretreatment CT data of the target volume (TV). For target tracking during treatment, a dynamic T2-weighted TSE MR sequence was developed. An in house developed GPU based IMRT optimization and dose calculation algorithm was used for fast treatment planning and simulation. An automatically generated treatment plan developed with this treatment planning system was irradiated on a clinical 6 MV linear accelerator and evaluated using a Delta4 dosimeter. Results: The automated treatment planning method yielded clinically viable plans for all patients. The MR-CT fusion based dose calculation accuracy was within 2% as compared to calculations performed with original CT data. The dynamic T2-weighted TSE MR Sequence was able to provide an update of the anatomical location of the TV every 10 seconds. Dose calculation and optimization of the automatically generated treatment plans using only one GPU took on average 8 minutes. The Delta4 measurement of the irradiated plan agreed with the dose calculation with a 3%/3mm gamma pass rate of 86.4%. Conclusions: The development of an MR accelerator-enabled planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases was presented. Future work will involve developing an intrafraction motion adaptation strategy, MR-only dose calculation, radiotherapy quality-assurance in a magnetic field, and streamlining the entire treatment

  13. Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

    SciTech Connect

    Rosenthal, David I.; Fuller, Clifton D.; Barker, Jerry L.; Mason, Bryan M.S.; Garcia, John A. C.; Lewin, Jan S.; Holsinger, F. Christopher; Stasney, C. Richard; Frank, Steven J.; Schwartz, David L.; Morrison, William H.; Garden, Adam S.; Ang, K. Kian

    2010-06-01

    Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

  14. Time delays in gated radiotherapy.

    PubMed

    Smith, Wendy L; Becker, Nathan

    2009-07-28

    In gated radiotherapy, the accuracy of treatment delivery is determined by the accuracy with which both the imaging and treatment beams are gated. If the time delays (the time between the target entering/leaving the gated region and the first/last image acquired or treatment beam on/off) for the imaging and treatment systems are in the opposite directions, they may increase the required internal target volume (ITV) margin, above that indicated by the tolerance for either system measured individually. We measured a gating system's time delay on 3 fluoroscopy systems, and 3 linear accelerator treatment beams, using a motion phantom of known geometry, varying gating type (amplitude vs. phase), beam energy, dose rate, and period. The average beam on imaging time delays were -0.04 +/- 0.05 s (amplitude, 1 SD), -0.11 +/- 0.04 s (phase); while the average beam off imaging time delays were -0.18 +/- 0.08 s (amplitude) and -0.15 +/- 0.04 s (phase). The average beam on treatment time delays were 0.09 +/- 0.02 s (amplitude, 1 SD), 0.10 +/- 0.03 s (phase); while the average beam off time delays for treatment beams were 0.08 +/- 0.02 s (amplitude) and 0.07 +/- 0.02 s (phase). The negative value indicates the images were acquired early, and the positive values show the treatment beam was triggered late. We present a technique for calculating the margin necessary to account for time delays and found that the difference between the imaging and treatment time delays required a significant increase in the ITV margin in the direction of tumor motion at the gated level.

  15. Operations experience at the Bevalac radiotherapy facility

    SciTech Connect

    Alonso, J.R.; Criswell, T.L.; Howard, J.; Chu, W.T.; Singh, R.P.; Geller, D.; Nyman, M.

    1981-03-01

    During the first years of Bevalac operation the biomedical effort concentrated on radiobiology work, laying the foundation for patient radiotherapy. A dedicated radiotherapy area was created in 1978, and in 1979 full-scale patient treatment was begun. As of now over 500 treatments with carbon, neon and argon beams have been delivered to about 50 patients, some as boosts from other modalities and some as complete heavy ion treatments. Up to 12 patients per day have been treated in this facility. Continuing efforts in refining techniques and operating procedures are increasing efficiency and accuracy of treatments, and are contributing to the alleviation of scheduling difficulties caused by the unique requirements of radiotherapy with human patients.

  16. Prevention of accidental exposure in radiotherapy: the risk matrix approach.

    PubMed

    Vilaragut, J J; Duménigo, C; Delgado, J M; Morales, J; McDonnell, J D; Ferro, R; Ortiz López, P; Ramírez, M L; Pérez Mulas, A; Papadopulos, S; Gonçalves, M; López Morones, R; Sánchez Cayuela, C; Cascajo Castresana, A; Somoano, F; Álvarez, C; Guillén, A; Rodríguez, M; Pereira, P P; Nader, A

    2013-02-01

    Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions. PMID:23274816

  17. Magnetic field effects on the energy deposition spectra of MV photon radiation.

    PubMed

    Kirkby, C; Stanescu, T; Fallone, B G

    2009-01-21

    Several groups worldwide have proposed various concepts for improving megavoltage (MV) radiotherapy that involve irradiating patients in the presence of a magnetic field-either for image guidance in the case of hybrid radiotherapy-MRI machines or for purposes of introducing tighter control over dose distributions. The presence of a magnetic field alters the trajectory of charged particles between interactions with the medium and thus has the potential to alter energy deposition patterns within a sub-cellular target volume. In this work, we use the MC radiation transport code PENELOPE with appropriate algorithms invoked to incorporate magnetic field deflections to investigate electron energy fluence in the presence of a uniform magnetic field and the energy deposition spectra within a 10 microm water sphere as a function of magnetic field strength. The simulations suggest only very minor changes to the electron fluence even for extremely strong magnetic fields. Further, calculations of the dose-averaged lineal energy indicate that a magnetic field strength of at least 70 T is required before beam quality will change by more than 2%.

  18. Radiotherapy enhances the toxicity of aminoglutethimide

    SciTech Connect

    Vanek, N.; Hortobagyi, G.N.; Buzdar, A.U. )

    1990-01-01

    We report a case of radiotherapy-enhanced aminoglutethimide skin toxicity in a patient with metastatic breast cancer. This patient was started on aminoglutethimide 6 days prior to radiation therapy, for painful bone metastasis. On day 7 of radiation therapy, she developed an extensive erythematous maculopapular rash over her face, trunk, and extremities. The rash was confluent over the radiation ports, both anteriorly and posteriorly. Aminoglutethimide was discontinued until completion of radiotherapy, and the rash resolved. Concomitant irradiation apparently enhanced the skin toxicity of aminoglutethimide or possibly aminoglutethimide had a radiosensitizing role in this patient.

  19. Pelvic radiotherapy and sexual function in women

    PubMed Central

    Froeding, Ligita Paskeviciute

    2015-01-01

    Background During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors. Methods An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities. Results The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients. Conclusions

  20. Measuring neutron spectra in radiotherapy using the nested neutron spectrometer

    SciTech Connect

    Maglieri, Robert Evans, Michael; Seuntjens, Jan; Kildea, John; Licea, Angel

    2015-11-15

    Purpose: Out-of-field neutron doses resulting from photonuclear interactions in the head of a linear accelerator pose an iatrogenic risk to patients and an occupational risk to personnel during radiotherapy. To quantify neutron production, in-room measurements have traditionally been carried out using Bonner sphere systems (BSS) with activation foils and TLDs. In this work, a recently developed active detector, the nested neutron spectrometer (NNS), was tested in radiotherapy bunkers. Methods: The NNS is designed for easy handling and is more practical than the traditional BSS. Operated in current-mode, the problem of pulse pileup due to high dose-rates is overcome by measuring current, similar to an ionization chamber. In a bunker housing a Varian Clinac 21EX, the performance of the NNS was evaluated in terms of reproducibility, linearity, and dose-rate effects. Using a custom maximum-likelihood expectation–maximization algorithm, measured neutron spectra at various locations inside the bunker were then compared to Monte Carlo simulations of an identical setup. In terms of dose, neutron ambient dose equivalents were calculated from the measured spectra and compared to bubble detector neutron dose equivalent measurements. Results: The NNS-measured spectra for neutrons at various locations in a treatment room were found to be consistent with expectations for both relative shape and absolute magnitude. Neutron fluence-rate decreased with distance from the source and the shape of the spectrum changed from a dominant fast neutron peak near the Linac head to a dominant thermal neutron peak in the moderating conditions of the maze. Monte Carlo data and NNS-measured spectra agreed within 30% at all locations except in the maze where the deviation was a maximum of 40%. Neutron ambient dose equivalents calculated from the authors’ measured spectra were consistent (one standard deviation) with bubble detector measurements in the treatment room. Conclusions: The NNS may

  1. An Unusual Case of Marginal Zone B-Cell Lymphoma Arising in the Breast - Its Diagnosis and the Role of Radiotherapy in its Management.

    PubMed

    Rock, Kathy; Rangaswamy, Guhan; O'Sullivan, Siobhra; Coffey, Jerome

    2011-10-01

    BACKGROUND: Primary lymphoma of the breast accounts for 0.04-0.5% of all breast malignancies and approximately 1% of all extranodal lymphomas. For stage IE node-negative disease, involved field radiotherapy is recommended except for very young women in whom the risk of breast cancer is a concern. The rate of complete response for limited stage extranodal marginal B-cell lymphoma is in excess of 90%. CASE REPORT: We report the case of a 62-year-old lady who presented with a unilateral painless palpable right breast lump. She subsequently underwent a trucut biopsy of the lesion. The histology revealed a low-grade B-cell non-Hodgkin's lymphoma (NHL). Immunohistochemistry showed that more than 95% of the cells were B cells which were CD 20+/CD 45+ and BC L6+. This confirmed the diagnosis of marginal zone lymphoma. Staging work-up was negative for distant metastases. Serum alkaline phosphatase and lactate dehydrogenase were normal. The patient had no 'B' symptoms. Her final diagnosis was clinical stage IAE NHL, and she was referred for curative radiotherapy. CONCLUSION: Radiation treatment is a safe and extremely effective modality of treatment for early stage I marginal zone B-cell lymphomas of the breast.

  2. Inhibition of Cancer Cell Growth by Exposure to a Specific Time-Varying Electromagnetic Field Involves T-Type Calcium Channels

    PubMed Central

    Buckner, Carly A.; Buckner, Alison L.; Koren, Stan A.; Persinger, Michael A.; Lafrenie, Robert M.

    2015-01-01

    Electromagnetic field (EMF) exposures affect many biological systems. The reproducibility of these effects is related to the intensity, duration, frequency, and pattern of the EMF. We have shown that exposure to a specific time-varying EMF can inhibit the growth of malignant cells. Thomas-EMF is a low-intensity, frequency-modulated (25-6 Hz) EMF pattern. Daily, 1 h, exposures to Thomas-EMF inhibited the growth of malignant cell lines including B16-BL6, MDA-MB-231, MCF-7, and HeLa cells but did not affect the growth of non-malignant cells. Thomas-EMF also inhibited B16-BL6 cell proliferation in vivo. B16-BL6 cells implanted in syngeneic C57b mice and exposed daily to Thomas-EMF produced smaller tumours than in sham-treated controls. In vitro studies showed that exposure of malignant cells to Thomas-EMF for > 15 min promoted Ca2+ influx which could be blocked by inhibitors of voltage-gated T-type Ca2+ channels. Blocking Ca2+ uptake also blocked Thomas-EMF-dependent inhibition of cell proliferation. Exposure to Thomas-EMF delayed cell cycle progression and altered cyclin expression consistent with the decrease in cell proliferation. Non-malignant cells did not show any EMF-dependent changes in Ca2+ influx or cell growth. These data confirm that exposure to a specific EMF pattern can affect cellular processes and that exposure to Thomas-EMF may provide a potential anti-cancer therapy. PMID:25875081

  3. In vivo skin dose measurement in breast conformal radiotherapy

    PubMed Central

    Soleymanifard, Shokouhozaman; Noghreiyan, Atefeh Vejdani; Ghorbani, Mahdi; Jamali, Farideh; Davenport, David

    2016-01-01

    Aim of the study Accurate skin dose assessment is necessary during breast radiotherapy to assure that the skin dose is below the tolerance level and is sufficient to prevent tumour recurrence. The aim of the current study is to measure the skin dose and to evaluate the geometrical/anatomical parameters that affect it. Material and methods Forty patients were simulated by TIGRT treatment planning system and treated with two tangential fields of 6 MV photon beam. Wedge filters were used to homogenise dose distribution for 11 patients. Skin dose was measured by thermoluminescent dosimeters (TLD-100) and the effects of beam incident angle, thickness of irradiated region, and beam entry separation on the skin dose were analysed. Results Average skin dose in treatment course of 50 Gy to the clinical target volume (CTV) was 36.65 Gy. The corresponding dose values for patients who were treated with and without wedge filter were 35.65 and 37.20 Gy, respectively. It was determined that the beam angle affected the average skin dose while the thickness of the irradiated region and the beam entry separation did not affect dose. Since the skin dose measured in this study was lower than the amount required to prevent tumour recurrence, application of bolus material in part of the treatment course is suggested for post-mastectomy advanced breast radiotherapy. It is more important when wedge filters are applied to homogenize dose distribution. PMID:27358592

  4. Identifying radiotherapy target volumes in brain cancer by image analysis

    PubMed Central

    Cheng, Kun; Montgomery, Dean; Feng, Yang; Steel, Robin; Liao, Hanqing; McLaren, Duncan B.; Erridge, Sara C.; McLaughlin, Stephen

    2015-01-01

    To establish the optimal radiotherapy fields for treating brain cancer patients, the tumour volume is often outlined on magnetic resonance (MR) images, where the tumour is clearly visible, and mapped onto computerised tomography images used for radiotherapy planning. This process requires considerable clinical experience and is time consuming, which will continue to increase as more complex image sequences are used in this process. Here, the potential of image analysis techniques for automatically identifying the radiation target volume on MR images, and thereby assisting clinicians with this difficult task, was investigated. A gradient-based level set approach was applied on the MR images of five patients with grades II, III and IV malignant cerebral glioma. The relationship between the target volumes produced by image analysis and those produced by a radiation oncologist was also investigated. The contours produced by image analysis were compared with the contours produced by an oncologist and used for treatment. In 93% of cases, the Dice similarity coefficient was found to be between 60 and 80%. This feasibility study demonstrates that image analysis has the potential for automatic outlining in the management of brain cancer patients, however, more testing and validation on a much larger patient cohort is required. PMID:26609418

  5. Radiotherapy for Patients With Metastases to the Spinal Column: A Review of 603 Patients at Shizuoka Cancer Center Hospital

    SciTech Connect

    Mizumoto, Masashi; Harada, Hideyuki; Asakura, Hirofumi; Hashimoto, Takayuki; Furutani, Kazuhisa; Hashii, Haruko; Murata, Hideki; Takagi, Tatsuya; Katagiri, Hirohisa; Takahashi, Mitsuru; Nishimura, Tetsuo

    2011-01-01

    Purpose: Long- and short-course radiotherapy have similar outcomes in the treatment of spinal metastases. Long-course radiotherapy is recommended for patients with good predicted survival to reduce the risk of in-field recurrence, whereas short-course radiotherapy is used for those with poor predicted survival. Therefore, prediction of prognosis and local control is required for selecting the optimal course of radiotherapy. Methods and Materials: The subjects were 603 patients with spinal metastases who received radiotherapy at the Shizuoka Cancer Center Hospital between September 2002 and February 2007. Factors associated with survival and local control were retrospectively investigated by multivariate analyses. Local recurrence was defined as regrowth within the irradiated field or exacerbation of symptoms such as pain and motor deficits. Results: Of the 603 patients, 555 (92%) were followed for 12 months or until death. The survival rates after 6, 12, and 24 months were 50%, 32%, and 19%, respectively, with a median survival of 6.2 months. The median survival periods after long- and short-course radiotherapy were 7.9 and 1.8 months, respectively. In multivariate analysis, primary tumor site, good performance status, absence of previous chemotherapy, absence of visceral metastasis, single bone metastasis, younger age, and nonhypercalcemia were associated with good survival. The local control rates after 6, 12, and 24 months were 91%, 79%, and 69%, respectively, and non-mass-type tumor, breast cancer, and absence of previous chemotherapy were predictors of good local control. Conclusions: Identification of factors associated with good local control and survival may allow selection of an optimal radiotherapy schedule for patients with spinal metastases.

  6. Radiotherapy in the management of early breast cancer

    SciTech Connect

    Wang, Wei

    2013-03-15

    Radiotherapy is an indispensible part of the management of all stages of breast cancer. In this article, the common indications for radiotherapy in the management of early breast cancer (stages 0, I, and II) are reviewed, including whole-breast radiotherapy as part of breast-conserving treatment for early invasive breast cancer and pre-invasive disease of ductal carcinoma in situ, post-mastectomy radiotherapy, locoregional radiotherapy, and partial breast irradiation. Key clinical studies that underpin our current practice are discussed briefly.

  7. [Hypofractionated adjuvant radiotherapy for breast cancer: no signs of increased risk of cardiotoxicity].

    PubMed

    Aleman, Berthe M P; van Leeuwen, Floor E

    2015-01-01

    Adjuvant radiotherapy is frequently used in women with breast cancer to improve both local control of the tumour and overall survival. Hypofractionated regimens are increasingly being used as they involve fewer treatment sessions and, in terms of tumour control, the effects of conventionally fractionated and hypofractionated radiotherapy seem to be comparable. However, there is concern regarding increased cardiotoxicity following hypofractionated radiotherapy treatment to the left side. In order to determine if cardiac mortality increases with hypofractionation relative to conventional fractionation, a Canadian research group performed a retrospective analysis in 5334 women with breast cancer treated between 1990-1998 with postoperative radiotherapy to the breast/chest wall only. At 15-year follow-up the authors concluded that cardiac mortality was not statistically different among patients with left-sided breast cancer whether treated with hypofractionated or conventionally fractionated whole breast/chest wall irradiation. This commentary discusses the data presented in the paper, puts them into perspective and describes the clinical implications.

  8. Postoperative radiotherapy in patients with salivary duct carcinoma: clinical outcomes and prognostic factors

    PubMed Central

    Shinoto, Makoto; Shioyama, Yoshiyuki; Nakamura, Katsumasa; Nakashima, Torahiko; Kunitake, Naonobu; Higaki, Yuichiro; Sasaki, Tomonari; Ohga, Saiji; Yoshitake, Tadamasa; Ohnishi, Kayoko; Asai, Kaori; Hirata, Hideki; Honda, Hiroshi

    2013-01-01

    This study sought to investigate the clinical outcome and the role of postoperative radiotherapy for patients with salivary duct carcinoma (SDC) who had undergone surgery and postoperative radiotherapy. We performed a retrospective analysis of 25 SDC patients treated between 1998 and 2011 with surgery and postoperative radiotherapy. The median prescribed dose was 60 Gy (range, 49.5–61.4 Gy). The clinical target volume (CTV) was defined as the tumor bed in four patients, the tumor bed and ipsilateral neck in 14 patients, and the tumor bed and bilateral neck in six patients. Local control (LC), disease-free survival (DFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and prognostic variables were analyzed with the log-rank test. The 5-year LC, DFS and OS were 67%, 45% and 47%, respectively. Disease recurrence was found in 12 patients: seven as local, four as regional and eight as distant failure. Perineural and lymphovascular invasion was a significant prognostic factor for LC (P = 0.03). Local failure was common, and the presence of local recurrence significantly affected the OS (P < 0.05). We conclude that surgery and postoperative radiotherapy is expected to decrease the risk of local failure and contribute to good prognoses for patients with SDC. It might be advisable to have the CTV include the cranial nerves involved and the corresponding parts of the skull base in cases of pathologically positive perineural invasion. PMID:23559598

  9. Clinical development of new drug-radiotherapy combinations.

    PubMed

    Sharma, Ricky A; Plummer, Ruth; Stock, Julie K; Greenhalgh, Tessa A; Ataman, Ozlem; Kelly, Stephen; Clay, Robert; Adams, Richard A; Baird, Richard D; Billingham, Lucinda; Brown, Sarah R; Buckland, Sean; Bulbeck, Helen; Chalmers, Anthony J; Clack, Glen; Cranston, Aaron N; Damstrup, Lars; Ferraldeschi, Roberta; Forster, Martin D; Golec, Julian; Hagan, Russell M; Hall, Emma; Hanauske, Axel-R; Harrington, Kevin J; Haswell, Tom; Hawkins, Maria A; Illidge, Tim; Jones, Hazel; Kennedy, Andrew S; McDonald, Fiona; Melcher, Thorsten; O'Connor, James P B; Pollard, John R; Saunders, Mark P; Sebag-Montefiore, David; Smitt, Melanie; Staffurth, John; Stratford, Ian J; Wedge, Stephen R

    2016-10-01

    In countries with the best cancer outcomes, approximately 60% of patients receive radiotherapy as part of their treatment, which is one of the most cost-effective cancer treatments. Notably, around 40% of cancer cures include the use of radiotherapy, either as a single modality or combined with other treatments. Radiotherapy can provide enormous benefit to patients with cancer. In the past decade, significant technical advances, such as image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic radiotherapy, and proton therapy enable higher doses of radiotherapy to be delivered to the tumour with significantly lower doses to normal surrounding tissues. However, apart from the combination of traditional cytotoxic chemotherapy with radiotherapy, little progress has been made in identifying and defining optimal targeted therapy and radiotherapy combinations to improve the efficacy of cancer treatment. The National Cancer Research Institute Clinical and Translational Radiotherapy Research Working Group (CTRad) formed a Joint Working Group with representatives from academia, industry, patient groups and regulatory bodies to address this lack of progress and to publish recommendations for future clinical research. Herein, we highlight the Working Group's consensus recommendations to increase the number of novel drugs being successfully registered in combination with radiotherapy to improve clinical outcomes for patients with cancer. PMID:27245279

  10. Breast Cancer Patients’ Experience of External-Beam Radiotherapy

    PubMed Central

    Schnur, Julie B.; Ouellette, Suzanne C.; Bovbjerg, Dana H.; Montgomery, Guy H.

    2013-01-01

    Radiotherapy is a critical component of treatment for the majority of women with breast cancer, particularly those who receive breast conserving surgery. Although medically beneficial, radiotherapy can take a physical and psychological toll on patients. However, little is known about the specific thoughts and feelings experienced by women undergoing breast cancer radiotherapy. Therefore, the study aim was to use qualitative research methods to develop an understanding of these thoughts and feelings based on 180 diary entries, completed during radiotherapy by 15 women with Stage 0-III breast cancer. Thematic analysis identified four primary participant concerns: (a) a preoccupation with time; (b) fantasies (both optimistic and pessimistic) about life following radiotherapy; (c) the toll their side-effect experience takes on their self-esteem; and (d) feeling mystified by radiotherapy. These themes are consistent with previous literature on illness and identity. These findings have implications for the treatment and care of women undergoing breast cancer radiotherapy. PMID:19380502

  11. Radiotherapy Alone With Curative Intent in Patients With Stage I Extranodal Nasal-Type NK/T-Cell Lymphoma

    SciTech Connect

    Li Yexiong; Wang Hua; Jin Jing; Wang Weihu; Liu Qingfeng; Song Yongwen; Wang Zhaoyang; Qi Shunan; Wang Shulian; Liu Yueping; Liu Xinfan; Yu Zihao

    2012-04-01

    Purpose: This study aims to evaluate the outcome and pattern of failure in a large cohort of patients with Stage I NK/T-cell lymphoma of the upper aerodigestive tract treated with radiotherapy alone. Methods and Materials: The pathological diagnosis was confirmed using standard criteria. All patients were treated with high-dose extended-field radiotherapy alone. The median dose was 50 Gy. The primary tumor was located in the nasal cavity (n = 80), Waldeyer ring (n = 5), or oral cavity (n = 2). Results: The overall response to radiotherapy was achieved in 85 of 87 (97.7%) patients, with a complete response rate of 95.4% and a partial response rate of 2.3%. The 5-year overall survival, progression-free survival, and local control rates for all patients were 80%, 69%, and 93%, respectively. Twenty patients (23%) had disease progression or relapse. Of these, 15 patients (17%) developed systemic extranodal disseminations, whereas only 4 (5%) patients had local relapse and 4 (5%) patients had lymph node relapse. Conclusions: Our study suggests that high-dose extended-field radiotherapy alone is a curative therapy and shows favorable clinical outcome in patients with Stage I disease. With the high possibility of local control and primary failure of systemic dissemination, the integration of optimal radiotherapy with more effective systematic therapy is warranted to bring additional improvement to the outcome for these patients.

  12. Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

    SciTech Connect

    Amdur, Robert J. Liu, Chihray; Li, Jonathan; Mendenhall, William; Hinerman, Russell

    2007-10-01

    When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior 'low neck' field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction.

  13. Assessment and Minimization of Contralateral Breast Dose for Conventional and Intensity Modulated Breast Radiotherapy

    SciTech Connect

    Burmeister, Jay Alvarado, Nicole; Way, Sarah; McDermott, Patrick; Bossenberger, Todd; Jaenisch, Harriett; Patel, Rajiv; Washington, Tara

    2008-04-01

    Breast radiotherapy is associated with an increased risk of contralateral breast cancer (CBC) in women under age 45 at the time of treatment. This risk increases with increasing absorbed dose to the contralateral breast. The use of intensity modulated radiotherapy (IMRT) is expected to substantially reduce the dose to the contralateral breast by eliminating scattered radiation from physical beam modifiers. The absorbed dose to the contralateral breast was measured for 5 common radiotherapy techniques, including paired 15 deg. wedges, lateral 30 deg. wedge only, custom-designed physical compensators, aperture based (field-within-field) IMRT with segments chosen by the planner, and inverse planned IMRT with segments chosen by a leaf sequencing algorithm after dose volume histogram (DVH)-based fluence map optimization. Further reduction in contralateral breast dose through the use of lead shielding was also investigated. While shielding was observed to have the most profound impact on surface dose, the radiotherapy technique proved to be most important in determining internal dose. Paired wedges or compensators result in the highest contralateral breast doses (nearly 10% of the prescription dose on the medial surface), while use of IMRT or removal of the medial wedge results in significantly lower doses. Aperture-based IMRT results in the lowest internal doses, primarily due to the decrease in the number of monitor units required and the associated reduction in leakage dose. The use of aperture-based IMRT reduced the average dose to the contralateral breast by greater than 50% in comparison to wedges or compensators. Combined use of IMRT and 1/8-inch-thick lead shielding reduced the dose to the interior and surface of the contralateral breast by roughly 60% and 85%, respectively. This reduction may warrant the use of IMRT for younger patients who have a statistically significant risk of contralateral breast cancer associated with breast radiotherapy.

  14. Results of radiotherapy for Peyronie's disease

    SciTech Connect

    Niewald, Marcus . E-mail: ramnie@uniklinikum-saarland.de; Wenzlawowicz, Knut v.; Fleckenstein, Jochen; Wisser, Lothar; Derouet, Harry; Ruebe, Christian

    2006-01-01

    Purpose: To retrospectively review the results of radiotherapy for Peyronie's disease. Patients and Methods: In the time interval 1983-2000, 154 patients in our clinic were irradiated for Peyronie's disease. Of those, 101 had at least one complete follow-up data set and are the subject of this study. In the majority of patients, penis deviation was between 30 and 50{sup o}, there were one or two indurated foci with a diameter between 5 and 15 mm. Pain was recorded in 48/92 patients. Seventy-two of the 101 patients received radiotherapy with a total dose of 30 Gy, and 25 received 36 Gy in daily fractions of 2.0 Gy. The remaining patients received the following dosage: 34 Gy (1 patient), 38-40 Gy (3 patients). Mean duration of follow-up was 5 years. Results: The best results ever at any time during follow-up were an improvement of deviation in 47%, reduction of number of foci in 32%, reduction of size of foci in 49%, and less induration in 52%. Approximately 50% reported pain relief after radiotherapy. There were 28 patients with mild acute dermatitis and only 4 patients with mild urethritis. There were no long-term side effects. Conclusion: Our results compare well with those of other studies in the literature. In our patient cohort, radiotherapy was an effective therapy option with only very rare and mild side effects.

  15. Radiotherapy reduces sialorrhea in amyotrophic lateral sclerosis.

    PubMed

    Neppelberg, E; Haugen, D F; Thorsen, L; Tysnes, O-B

    2007-12-01

    Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. Sialorrhea is a frequent problem in ALS patients with bulbar symptoms, because of progressive weakness of oral, lingual and pharyngeal muscles. This prospective study aimed to investigate the putative effect of palliative single-dose radiotherapy on problematic sialorrhea in patients with ALS. Twenty patients with ALS and problematic drooling were included; 14 were given radiotherapy with a single fraction of 7.5 Grey (Gy). Five patients were treated with botulinum toxin A (BTX-A) injections (20 U) into the parotid glands; two of these were later given radiotherapy. Symptom assessment, clinical examination and measurements of salivary flow (ml/min) were performed before and after treatment (1-2 weeks, 3 months). Salivary secretion was significantly reduced after radiation treatment, with a mean reduction of 60% (1 week) and 51% (2 weeks). Three months post-treatment, 21% reduction of the salivary secretion was observed compared with salivation before treatment. Mean salivary flow was not reduced after BTX-A treatment in five patients. No serious side-effects were observed with either of the two treatment modalities. Single-dose radiotherapy (7.5 Gy) significantly reduces sialorrhea and is an effective and safe palliative treatment in patients with ALS.

  16. The Role of Radiotherapy in Acromegaly.

    PubMed

    Hannon, Mark J; Barkan, Ariel L; Drake, William M

    2016-01-01

    Radiotherapy has, historically, played a central role in the management of acromegaly, and the last 30 years have seen substantial improvements in the technology used in the delivery of radiation therapy. More recently, the introduction of highly targeted radiotherapy, or 'radiosurgery', has further increased the therapeutic options available in the management of secretory pituitary tumors. Despite these developments, improvements in primary surgical outcomes, an increase in the range and effectiveness of medical therapy options, and long-term safety concerns have combined to dictate that, although still deployed in selected cases, the use of radiotherapy in the management of acromegaly has declined steadily over the past 2 decades. In this article, we review some of the main studies that have documented the efficacy of pituitary radiotherapy on growth hormone hypersecretion and summarize the data around its potential deleterious effects, including hypopituitarism, cranial nerve damage, and the development of radiation-related intracerebral tumors. We also give practical recommendations to guide its future use in patients with acromegaly, generally, as a third-line intervention after neurosurgical intervention in combination with various medical therapy options.

  17. Approximating convex Pareto surfaces in multiobjective radiotherapy planning

    SciTech Connect

    Craft, David L.; Halabi, Tarek F.; Shih, Helen A.; Bortfeld, Thomas R.

    2006-09-15

    Radiotherapy planning involves inherent tradeoffs: the primary mission, to treat the tumor with a high, uniform dose, is in conflict with normal tissue sparing. We seek to understand these tradeoffs on a case-to-case basis, by computing for each patient a database of Pareto optimal plans. A treatment plan is Pareto optimal if there does not exist another plan which is better in every measurable dimension. The set of all such plans is called the Pareto optimal surface. This article presents an algorithm for computing well distributed points on the (convex) Pareto optimal surface of a multiobjective programming problem. The algorithm is applied to intensity-modulated radiation therapy inverse planning problems, and results of a prostate case and a skull base case are presented, in three and four dimensions, investigating tradeoffs between tumor coverage and critical organ sparing.

  18. Hypofractionated radiotherapy for medically inoperable stage I non‐small cell lung cancer

    PubMed Central

    Jiang, Wei; Wang, Jian‐Yang; Wang, Jing‐Bo; Liang, Jun; Hui, Zhou‐Guang; Wang, Xiao‐Zhen; Zhou, Zong‐Mei

    2015-01-01

    Abstract Background To investigate the clinical outcomes and toxicity of hypofractionated radiotherapy for medically inoperable stage I non‐small cell lung cancer (NSCLC). Methods Patients treated with radiotherapy at a dose of 4–6 Gy per fraction using fixed‐field intensity modulated radiotherapy (IMRT) or volumetric‐modulated arc therapy (VMAT) at our hospital from June 2005 to December 2013 were analyzed. The total prescription doses ranged from 50–78 Gy with 4–6 Gy per fraction. The median follow‐up period was 24 months. Results A total of 65 patients with stage I NSCLC were analyzed, including 43 primary NSCLC patients and 22 patients with recurrent or second primary NSCLC. An objective response (complete or partial response) was achieved at six months in 84.6% of patients. The three‐year local control rate was 90.8%. Kaplan–Meier estimates of local failure‐free, progression‐free, overall, and cancer‐specific survival rates at three years were 90.3%, 64.3%, 68.9%, and 88.8%, respectively. The rate of symptomatic radiation pneumonitis was 16.9%, and no grade 4–5 toxicity was observed. Conclusion Favorable local control and outcome was achieved with hypofractionated radiotherapy in patients with inoperable stage I NSCLC with acceptable toxicity. The most common schedule of 6 Gy × 12 fractions may be a promising regimen, and a prospective study is in process. PMID:27148414

  19. Second Cancers After Fractionated Radiotherapy: Stochastic Population Dynamics Effects

    NASA Technical Reports Server (NTRS)

    Sachs, Rainer K.; Shuryak, Igor; Brenner, David; Fakir, Hatim; Hahnfeldt, Philip

    2007-01-01

    When ionizing radiation is used in cancer therapy it can induce second cancers in nearby organs. Mainly due to longer patient survival times, these second cancers have become of increasing concern. Estimating the risk of solid second cancers involves modeling: because of long latency times, available data is usually for older, obsolescent treatment regimens. Moreover, modeling second cancers gives unique insights into human carcinogenesis, since the therapy involves administering well characterized doses of a well studied carcinogen, followed by long-term monitoring. In addition to putative radiation initiation that produces pre-malignant cells, inactivation (i.e. cell killing), and subsequent cell repopulation by proliferation can be important at the doses relevant to second cancer situations. A recent initiation/inactivation/proliferation (IIP) model characterized quantitatively the observed occurrence of second breast and lung cancers, using a deterministic cell population dynamics approach. To analyze ifradiation-initiated pre-malignant clones become extinct before full repopulation can occur, we here give a stochastic version of this I I model. Combining Monte Carlo simulations with standard solutions for time-inhomogeneous birth-death equations, we show that repeated cycles of inactivation and repopulation, as occur during fractionated radiation therapy, can lead to distributions of pre-malignant cells per patient with variance >> mean, even when pre-malignant clones are Poisson-distributed. Thus fewer patients would be affected, but with a higher probability, than a deterministic model, tracking average pre-malignant cell numbers, would predict. Our results are applied to data on breast cancers after radiotherapy for Hodgkin disease. The stochastic IIP analysis, unlike the deterministic one, indicates: a) initiated, pre-malignant cells can have a growth advantage during repopulation, not just during the longer tumor latency period that follows; b) weekend

  20. MO-B-18C-01: Proton Therapy II: Proton Stereotactic Radiotherapy

    SciTech Connect

    Winey, B; Daartz, J

    2014-06-15

    Proton stereotactic radiotherapy shares fundamental principles with general proton therapy physics, specifically range uncertainties and broad beam measurement techniques. Significant differences emerge when treating with smaller field sizes that suffer lateral disequilibrium and when fractions are reduced. This session will explore the history and scope of proton stereotactic radiotherapy in clinical practice. Uncertainties and treatment planning methods specific to stereotactic treatments will be discussed. The session will include an overview of the physical properties of small proton fields and resulting needs for accurate measurements and modeling of dose distributions for radiosurgery treatment planning. Learning Objectives: Understand the clinical rationale for proton radiosurgery. Understand the similarities and differences from general proton therapy. Understand the similarities and differences from photon stereotactic radiosurgery. Understand the basic physics and clinical physics methods for measuring and commissioning a radiosurgery program.

  1. Stereotactic radiotherapy of meningiomas compressing optical pathways

    SciTech Connect

    Hamm, Klaus-Detlef . E-mail: khamm@erfurt.helios-kliniken.de; Henzel, Martin; Gross, Markus W.; Surber, Gunnar; Kleinert, Gabriele; Engenhart-Cabillic, Rita

    2006-11-15

    Purpose: Microsurgical resection is usually the treatment of choice for meningiomas, especially for those that compress the optical pathways. However, in many cases of skull-base meningiomas a high risk of neurological deficits and recurrences exist in cases where the complete tumor removal was not possible. In such cases (fractionated) stereotactic radiotherapy (SRT) can offer an alternative treatment option. We evaluated the local control rate, symptomatology, and toxicity. Patients and Methods: Between 1997 and 2003, 183 patients with skull-base meningiomas were treated with SRT, among them were 65 patients with meningiomas that compressed optical pathways (64 benign, 1 atypical). Of these 65 cases, 20 were treated with SRT only, 27 were subtotally resected before SRT, and 18 underwent multiple tumor resections before SRT. We investigated the results until 2005, with a median follow-up of 45 months (range, 22-83 months). The tumor volume (TV = gross tumor volume) ranged from 0.61 to 90.20 cc (mean, 18.9 cc). Because of the risk of new visual disturbances, the dose per fraction was either 2 or 1.8 Gy for all patients, to a total dose of 50 to 60 Gy. Results: The overall survival and the progression-free survival rates for 5 years were assessed to 100% in this patient group. To date, no progression for these meningiomas have been observed. Quantitatively, tumor shrinkage of more than 20%, or more than 2 mm in diameter, was proved in 35 of the 65 cases after SRT. In 29 of the 65 patients, at least 1 of the symptoms improved. On application of the Common Toxicity Criteria (CTC), acute toxicity (Grade 3) was seen in 1 case (worsening of conjunctivitis). Another 2 patients developed late toxicity by LENT-SOMA score, 1 x Grade 1 and 1 x Grade 3 (field of vision loss). Conclusion: As a low-risk and effective treatment option for tumor control, SRT with 1.8 to 2.0 Gy per fraction can also be recommended in case of meningiomas that compress optical pathways. An

  2. The inaugural Frank Ellis Lecture--latrogenic cancer: the impact of intensity-modulated radiotherapy.

    PubMed

    Hall, E J

    2006-05-01

    It is an honour and personal pleasure to give the inaugural Frank Ellis Lecture to celebrate his 100th birthday, and to acknowledge his enormous contributions to radiation oncology. Intensity-modulated radiotherapy (IMRT) allows dose to be concentrated in the tumour volume while sparing normal tissues. However, the downside to IMRT is the potential to increase the number of radiation-induced second cancers because more fields are used which involves a bigger volume of normal tissue exposed to lower doses. It has been estimated that IMRT may double the incidence of solid cancers in long-term survivors. This may be acceptable in older patients if balanced by an improvement in local tumour control and reduced toxicity. On the other hand, the incidence of second cancers is higher in children, so that doubling it may not be acceptable. IMRT represents a special case for children. First, they are more sensitive to radiation-induced cancer than adults. Second, radiation scattered from the treatment volume is more important in the small body of the child. Third, there is the question of genetic susceptibility, as many childhood cancers involve a germline mutation. The levels of leakage radiation in current Linacs can be reduced, but the cost would be substantial. An alternative strategy is to replace X-rays with protons. This is an advantage only if the proton machine uses a pencil scanning beam, as passive modulation of a scattering foil produces neutrons, which results in an effective dose to the patient higher than that characteristic of IMRT.

  3. Current clinical trials testing the combination of immunotherapy with radiotherapy.

    PubMed

    Kang, Josephine; Demaria, Sandra; Formenti, Silvia

    2016-01-01

    Increasing evidence demonstrates that radiation acts as an immune stimulus, recruiting immune mediators that enable anti-tumor responses within and outside the radiation field. There has been a rapid expansion in the number of clinical trials harnessing radiation to enhance antitumor immunity. If positive, results of these trials will lead to a paradigm shift in the use of radiotherapy. In this review, we discuss the rationale for trials combining radiation with various immunotherapies, provide an update of recent clinical trial results and highlight trials currently in progress. We also address issues pertaining to the optimal incorporation of immunotherapy with radiation, including sequencing of treatment, radiation dosing and evaluation of clinical trial endpoints. PMID:27660705

  4. Correlation Between Acute and Late Toxicity in 973 Prostate Cancer Patients Treated With Three-Dimensional Conformal External Beam Radiotherapy

    SciTech Connect

    Jereczek-Fossa, Barbara A.; Zerini, Dario; Fodor, Cristiana

    2010-09-01

    Purpose: To analyze the correlation between acute and late injury in 973 prostate cancer patients treated with radiotherapy and to evaluate the effect of patient-, tumor-, and treatment-related variables on toxicity. Methods and Materials: Of the 973 patients, 542 and 431 received definitive or postprostatectomy radiotherapy, respectively. Three-dimensional conformal radiotherapy included a six-field technique and two-dynamic arc therapy. Toxicity was classified according to the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. The correlation between acute and late toxicity (incidence and severity) was assessed. Results: Multivariate analysis showed that age {<=}65 years (p = .06) and use of the three-dimensional, six-field technique (p <.0001) correlated significantly with greater acute rectal toxicity. The three-dimensional, six-field technique (p = .0002), dose >70 Gy (p = .014), and radiotherapy duration (p = .05) correlated with greater acute urinary toxicity. Acute rectal toxicity (p <.0001) was the only factor that correlated with late rectal injury on multivariate analysis. Late urinary toxicity correlated with acute urinary events (p <.0001) and was inversely related to the use of salvage radiotherapy (p = .018). A highly significant correlation was found between the incidence of acute and late events for both rectal (p <.001) and urinary (p <.001) reactions. The severity of acute toxicity (Grade 2 or greater) was predictive for the severity of late toxicity for both rectal and urinary events (p <.001). Conclusion: The results of our study have shown that the risk of acute reactions depends on both patient-related (age) and treatment-related (dose, technique) factors. Acute toxicity was an independent significant predictor of late toxicity. These findings might help to predict and prevent late radiotherapy-induced complications.

  5. Pelvic Nodal Radiotherapy in Patients With Unfavorable Intermediate and High-Risk Prostate Cancer: Evidence, Rationale, and Future Directions

    SciTech Connect

    Morikawa, Lisa K.; Roach, Mack

    2011-05-01

    Over the past 15 years, there have been three major advances in the use of external beam radiotherapy in the management of men with clinically localized prostate made. They include: (1) image guided (IG) three-dimensional conformal/intensity modulated radiotherapy; (2) radiation dose escalation; and (3) androgen deprivation therapy. To date only the last of these three advances have been shown to improve overall survival. The presence of occult pelvic nodal involvement could explain the failure of increased conformality and dose escalation to prolong survival, because the men who appear to be at the greatest risk of death from clinically localized prostate cancer are those who are likely to have lymph node metastases. This review discusses the evidence for prophylactic pelvic nodal radiotherapy, including the key trials and controversies surrounding this issue.

  6. Systemic Lupus Erythematosus, Radiotherapy, and the Risk of Acute and Chronic Toxicity: The Mayo Clinic Experience

    SciTech Connect

    Pinn, Melva E.; Gold, Douglas G. M.; Petersen, Ivy A.; Osborn, Thomas G.; Brown, Paul D.; Miller, Robert C.

    2008-06-01

    Purpose: To determine the acute and chronic toxic effects of radiotherapy in patients with systemic lupus erythematosus (SLE). Methods and Materials: Medical records of 21 consecutive patients with SLE, who had received 34 courses of external beam radiotherapy and one low-dose-rate prostate implant, were retrospectively reviewed. Patients with discoid lupus erythematosus were excluded. Results: Median survival was 2.3 years and median follow-up 5.6 years. Eight (42%) of 19 patients evaluable for acute toxicity during radiotherapy experienced acute toxicity of Grade 1 or greater, and 4 (21%) had acute toxicity of Grade 3 or greater. The 5- and 10-year incidence of chronic toxicity of Grade 1 or greater was 45% (95% confidence interval [CI], 22-72%) and 56% (95% CI, 28-81%), respectively. The 5- and 10-year incidence of chronic toxicity of Grade 3 or greater was 28% (95% CI, 18-60%) and 40% (95% CI, 16-72%), respectively. Univariate analysis showed that chronic toxicity of Grade 1 or greater correlated with SLE renal involvement (p < 0.006) and possibly with the presence of five or more American Rheumatism Association criteria (p < 0.053). Chronic toxicity of Grade 3 or greater correlated with an absence of photosensitivity (p < 0.02), absence of arthritis (p < 0.03), and presence of a malar rash (p < 0.04). Conclusions: The risk of acute and chronic toxicity in patients with SLE who received radiotherapy was moderate but was not prohibitive of the use of radiotherapy. Patients with more advanced SLE may be at increased risk for chronic toxicity.

  7. Radiotherapy infrastructure and human resources in Europe - present status and its implications for 2020.

    PubMed

    Datta, Niloy Ranjan; Samiei, Massoud; Bodis, Stephan

    2014-10-01

    Radiotherapy (RT) is required for nearly half of the newly diagnosed cancer patients. To optimise the quality and availability of RT, guidelines have been proposed by European Society for Radiotherapy and Oncology-QUAntification of Radiation Therapy Infrastructure And Staffing Needs (ESTRO-QUARTS) and the International Atomic Energy Agency (IAEA). This study evaluates the present status of RT capacity in Europe and the projected needs by 2020 as per these recommendations. Thirty-nine of the 53 countries, listed in Europe by the UN Statistical Division, whose cancer incidences, teletherapy and human resources were available in the Global Cancer Incidence, Mortality and Prevalence (GLOBOCAN), International Agency for Research on Cancer (IARC) and DIrectory of RAdiotherapy Centres (DIRAC) (IAEA) databases were evaluated. A total of 3550 teletherapy units (TRT), 7017 radiation oncologists (RO), 3685 medical physicists (MP) and 12,788 radiotherapy technologists (RTT) are presently available for the 3.44 million new cancer cases reported annually in these countries. The present infrastructure and human resources in RT are estimated to provide RT access to 74.3% of the patients requiring RT. The current capacity in TRT, RO, MP and RTT when compared with recommended guidelines has a deficit of 25.6%, 18.3%, 22.7% and 10.6%, respectively. Thus, to respond to requirements by 2020, the existing capacity needs to be augmented by an additional 1698 TRTs, 2429 ROs, 1563 MPs and 2956 RTTs. With an imminent rise in cancer incidence, multifaceted strategic planning at national and international levels within a coordinated comprehensive cancer control programme is highly desirable to give adequate access to all patients who require radiotherapy across Europe. Specific steps to address this issue at national and continental levels involving all major stakeholders are proposed.

  8. Evidence-based estimates of the demand for radiotherapy.

    PubMed

    Delaney, G P; Barton, M B

    2015-02-01

    There are different methods that may be used to estimate the future demand for radiotherapy services in a population ranging from expert opinion through to complex modelling techniques. This manuscript describes the use of evidence-based treatment guidelines to determine indications for radiotherapy. It also uses epidemiological data to estimate the proportion of the population who have attributes that suggest a benefit from radiotherapy in order to calculate the overall proportion of a population of new cases of cancer who appropriately could be recommended to undergo radiotherapy. Evidence-based methods are transparent and adaptable to different populations but require extensive information about the indications for radiotherapy and the proportion of cancer cases with those indications in the population. In 2003 this method produced an estimate that 52.4% of patients with a registered cancer-type had an indication for radiotherapy. The model was updated in 2012 because of changes in cancer incidence, stage distributions and indications for radiotherapy. The new estimate of the optimal radiotherapy utilisation rate was 48.3%. The decrease was due to changes in the relative frequency of cancer types and some changes in indications for radiotherapy. Actual rates of radiotherapy utilisation in most populations still fall well below this benchmark. PMID:25455408

  9. Comparison of EBT and EBT3 RadioChromic Film Usage in Parotid Cancer Radiotherapy

    PubMed Central

    Bahreyni Toossi, M.T.; Khorshidi, F.; Ghorbani, M.; Mohamadian, N.; Davenport, D.

    2016-01-01

    Background EBT and EBT3 radioChromic films have been used in radiotherapy dosimetry for years. Objective The aim of the current study is to compare EBT and EBT3 radioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Methods Calibrations of EBT and EBT3 films were performed with identical setups using a 6 MV photon beam of a Siemens Primus linac. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films on a RANDO phantom. Results While dosimetry was performed with the same conditions for the two film types for calibration and in phantom in parotid cancer radiotherapy, the measured net optical density (NOD) in EBT film was found to be higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy) with a maximum difference of 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. Conclusion EBT film demonstrates higher NOD than EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process. PMID:27026949

  10. Radiation transport codes for potential applications related to radiobiology and radiotherapy using protons, neutrons, and negatively charged pions

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.

    1972-01-01

    Several Monte Carlo radiation transport computer codes are used to predict quantities of interest in the fields of radiotherapy and radiobiology. The calculational methods are described and comparisions of calculated and experimental results are presented for dose distributions produced by protons, neutrons, and negatively charged pions. Comparisons of calculated and experimental cell survival probabilities are also presented.

  11. Three-Dimensional Analysis of Recurrence Patterns in Rectal Cancer: The Cranial Border in Hypofractionated Preoperative Radiotherapy Can Be Lowered

    SciTech Connect

    Nijkamp, Jasper; Kusters, Miranda; Beets-Tan, Regina G.H.; Martijn, Hendrik; Beets, Geerard L.; Velde, Cornelis J.H. van de; Marijnen, Corrie A.M.

    2011-05-01

    Purpose: The aim of this study was to determine whether and where the radiotherapy (RT) clinical target volume (CTV) could be reduced in short-course preoperative treatment of rectal cancer patients. Methods and Materials: Patients treated in the Dutch total mesorectal excision trial, with a local recurrence were analyzed. For 94 (25 who underwent radiation therapy 69 who did not) of 114 patients with a local recurrence, the location of the recurrence was placed in a three-dimensionalthree (3D) model. The data in the 3D model were correlated to the clinical trial data to distinguish a group of patients eligible for CTV reduction. Effects of CTV reduction on dose to the small bowel was tested retrospectively in a dataset of 8 patients with three-field conformal plans and intensity-modulated RT (IMRT). Results: The use of preoperative RT mainly reduces anastomotic, lateral, and perineal recurrences. In patients without primary nodal involvement, no recurrences were found cranially of the S2-S3 interspace, irrespective of the delivery of RT. In patients without primary nodal involvement and a negative circumferential resection margin (CRM), only one recurrence was found cranial to the S2-S3 interspace. With a cranially reduced CTV to the S2-S3 interspace, over 60% reduction in absolute small bowel exposure at dose levels from 15 to 35 Gy could be achieved with three-field conventional RT, increasing to 80% when IMRT is also added. Conclusions: The cranial border of the CTV can safely be lowered for patients without expected nodal or CRM involvement, yielding a significant reduction of dose to the small bowel. Therefore, a significant reduction of acute and late toxicity can be expected.

  12. Hypothalamic, pituitary and thyroid dysfunction after radiotherapy to the head and neck

    SciTech Connect

    Samaan, N.A.; Vieto, R.; Schultz, P.N.; Maor, M.; Meoz, R.T.; Sampiere, V.A.; Cangir, A.; Ried, H.L.; Jesse, R.H. Jr.

    1982-11-01

    One hundred-ten patients who had nasopharyngeal cancer and paranasal sinus tumors and were free of the primary disease were studied one to 26 years following radiotherapy. There were 70 males and 40 females ranging in age from 4 to 75 years, with a mean age of 36.5 years. During therapy both the hypothalamus and the anterior pituitary gland were in the field of irradiation. The radiation dose to the hypothalamus and the anterior pituitary gland was estimated to be 400 to 7500 rad with a median dose of 5618 rad to the anterior pituitary gland and a median dose of 5000 rad to the hypothalamus. We found evidence of endocrine deficiencies in 91 of the 110 patients studied. Seventy-six patients showed evidence of one or more hypothalamic lesions and 43 patients showed evidence of primary pituitary deficiency. Forty of the 66 patients who received radiotherapy to the neck for treatment or prevention of lymph node metastasis showed evidence of primary hypothyroidism. The range of the dose to the thyroid area was 3000 to 8800 rad with a median of 5000 rad. One young adult woman who developed galactorrhea and amenorrhea 2 years following radiotherapy showed a high serum prolactin level, but had normal anterior pituitary function and sella turcica. She regained her menses and had a normal pregnancy and delivery following bromocriptine therapy. These results indicate that endocrine deficiencies after radiotherapy for tumors of the head and neck are common and should be detected early and treated. Long-term follow-up of these patients is indicated since complications may appear after the completion of radiotherapy.

  13. Conservative surgery followed by radical radiotherapy in the management of stage I carcinoma of the breast

    SciTech Connect

    Baeza, M.R.; Arraztoa, J.; Sole, J.; Rodriguez, R.

    1982-10-01

    Since October 1976, the treatment policy in our Radiotherapy Center for Stage I carcinoma of the breast has been excision of the tumor mass, when it was cosmetically suitable, followed by irradiation to the breast and peripheral lymphatics. Eighty-three patients were admitted between October 1976 and March 1980. They underwent local excision of the tumor and then received 5000 rad in 5 weeks to the breast, supraclavicular, axillary and internal mammary chain lymph nodes. Each field was treated every day. A boost was then given to the scar, bringing the dose up to 6500 rad, calculated at maximum tumor depth, depending upon the size of the tumor prior to surgery. Cosmetic results were quite good, and the local control rate at 54 months is 98%. The survival with no evidence of disease (NED) at 54 months (acturarial) is 83%. There have been 10 failures: 8 distant, 1 local (in axilla, controlled by surgery, actually NED), and 1 local and distant (scar and brain). Both failures were found with 12 months after treatment, and 8/10 of the failures within 24 months. Twenty-one out of 83 patients have had complications (25.3%); of these, 28.8% were surgical and the remainder resulted from radiotherapy after surgery, either from radiotherapy alone or from combination of treatments. Of the total of 21 complications 18 were mild and 3 were serious. Of those 3 serious complications (3.6%), 2 were a result of radiotherapy, and one because an ill-advised axillary dissection prior to radiotherapy gave a negative axilla and a serious arm edema and painful shoulder. This was the worst complication in the total of 83 patients. These results compare favorably with the results achieved in the same Hospital with radical surgery as far as local tumor control and survival with no evidence of disease (NED) is concerned.

  14. Adjuvant Radiotherapy with Three-Dimensional Conformal Radiotherapy of Lacrimal Gland Adenoid Cystic Carcinoma

    PubMed Central

    Roshan, Vikas; Mallick, Supriya; Chander, Subhash; Sen, Seema; Chawla, Bhavna

    2015-01-01

    Background & Aim Adenoid cystic carcinoma (ACC) of lacrimal gland is a rare tumour with aggressive behaviour. There is sparse data to address optimum therapy for such tumours. So, the present study was aimed at evaluating the role of adjuvant three dimensional conformal radiotherapy (3D-CRT) in cases of incomplete (R1) resection along with review of literature pertaining to management of lacrimal adenoid cystic carcinoma Materials and Methods We retrospectively reviewed the demographic and treatment data of 10 biopsy proven ACC of lacrimal gland patients, treated from December 2006 to June 2013. They were treated with radiotherapy following surgical resection. Eight patients underwent gross total excision of the tumour mass (enbloc excision) followed by conformal radiotherapy to a dose of 60 Gray/30fractions/ 6 weeks. Two patients with advanced disease were treated with palliative radiotherapy after biopsy. Results The median age was 32 years. There were equal numbers of male and female patients. The median duration of symptoms was 7 months. At a median follow up of 21 months, eight patients had no evidence of disease and had complete tumour response, two patients worsened, and one of the two had systemic failure with bone metastasis. Conclusion Despite a small sample size and short follow, enbloc surgical excision with adjuvant radiotherapy is well tolerated and shows good control in ACC of lacrimal gland. PMID:26557600

  15. Radiotherapy for testicular seminoma stage I: treatment results and long-term post-irradiation morbidity in 365 patients

    SciTech Connect

    Fossa, S.D.A.; Aass, N.; Kaalhus, O.

    1989-02-01

    After infradiaphragmatic radiotherapy the cancer-related 10 year survival was 99% in 365 patients with seminoma Stage I referred to the Norwegian Radium Hospital between 1970 and 1982. Thirteen patients relapsed, 11 of them within the first 3 years after treatment. Nine of the recurrent patients were cured by radiotherapy alone (4) or in combination with chemotherapy (5). There is no need to include the inguinal lymph nodes into the irradiation field or to give scrotal irradiation, not even to patients with tumor infiltration beyond the testicular tissue, or to those with prior scrotal or inguinal surgery. At least 1 year after radiotherapy moderate or more severe dyspepsia was observed in 16 patients. Nine patients developed a peptic ulcer. In general, there was no increased risk for development of a second non-germ cell cancer after radiotherapy. However, 4 patients developed a pulmonary cancer indicating a border-line significance of increased risk for this type of malignancy. (p:0.05). In conclusion, infradiaphragmatic radiotherapy remains the optimal routine treatment in seminoma patients with Stage I.

  16. Final Results of a Prospective Study Comparing the Local Control of Short-Course and Long-Course Radiotherapy for Metastatic Spinal Cord Compression

    SciTech Connect

    Rades, Dirk; Lange, Marisa; Veninga, Theo; Stalpers, Lukas J.A.; Bajrovic, Amira; Adamietz, Irenaeus A.; Rudat, Volker; Schild, Steven E.

    2011-02-01

    Purpose: Many patients with metastatic spinal cord compression (MSCC) live long enough to develop a recurrence in the irradiated spinal area. This is the first prospective study that has compared local control of different radiotherapy schedules for MSCC. Methods and Materials: A total of 265 patients treated with radiotherapy alone were included in this prospective nonrandomized study. The primary goal was to compare local control from short-course (1 x 8 Gy/5 x 4 Gy, n = 131) and long-course radiotherapy (10 x 3 Gy/15 x 2.5 Gy/20 x 2 Gy, n = 134). Secondary end points were motor function and survival. The analysis of local control (no MSCC recurrence in the irradiated spinal area) included the 224 patients with improvement or no change of motor deficits during radiotherapy. Eleven additional factors were evaluated for outcomes. Results: One-year local control was 61% after short-course and 81% after long-course radiotherapy (p = 0.005). On multivariate analysis (MVA), improved local control was associated with long-course radiotherapy (p = 0.018). Motor function improved in 37% after short-course and 39% after long-course radiotherapy (p = 0.95). Improved motor function was associated with better performance status (p = 0.015), favorable tumor type (p = 0.034), and slower development of motor deficits (p < 0.001). One-year survival rates were 23% after short-course and 30% after long-course radiotherapy (p = 0.28). On MVA, improved survival was associated with better performance status (p < 0.001), no visceral metastases (p < 0.001), involvement of only one to three vertebrae (p = 0.040), ambulatory status (p = 0.038), and bisphosphonate administration after radiotherapy (p < 0.001). Conclusions: Long-course radiotherapy was associated with better local control, similar functional outcome, and similar survival compared to short-course radiotherapy. Patients with a relatively favorable expected survival should receive long-course radiotherapy.

  17. Parapharyngeal Extension of Nasopharyngeal Carcinoma: Still a Significant Factor in Era of Modern Radiotherapy?

    SciTech Connect

    Ng, Wai T. Chan, Siu H.; Lee, Anne W.M.; Lau, Kam Y.; Yau, Tze K.; Hung, Wai M.; Lee, Michael; Choi, Cheuk W.

    2008-11-15

    Purpose: To retrospectively analyze the prognostic value of parapharyngeal space (PPS) extension after conformal radiotherapy for nasopharyngeal carcinoma. Patients and Methods: Between 1998 and 2005, 700 patients were treated with conformal radiotherapy at 2 Gy/fraction daily to a total of 70 Gy. All patients underwent staging with magnetic resonance imaging. The incidence of PPS was determined, and the extent of involvement was further subclassified regarding the presence or absence of carotid space (CS) involvement. The prognostic parameters, including age, gender, stage, chemotherapy, additional boosting, and extent of PPS involvement, were analyzed by univariate and multivariate analyses. Results: The median duration of follow-up was 51 months, and the 5-year overall survival rate for the whole group was 73%. The overall incidence of PPS extension was high (74%), and 29% had additional extension to the CS. Multivariate analysis showed age, gender, chemotherapy, T stage, and N stage to be significant prognostic factors, but not PPS involvement with or without CS extension. In the subgroup of patients with Stage T2 disease (n = 242), the presence of PPS involvement alone or PPS plus CS extension had no statistically significant effect in terms of local control (p = 0.68), distant metastases (p = 0.34), or overall survival (p = 0.24) compared with those without PPS involvement (Stage T2a). Conclusions: With better tumor delineation by magnetic resonance imaging and improved coverage using modern radiotherapy techniques, PPS extension per se no longer predicts for disease outcome. Hence, subcategorizing Stage T2 disease is no longer important in future International Union Against Cancer/American Joint Committee on Cancer classifications.

  18. [Personalized medicine in radiotherapy: practitioners' perception].

    PubMed

    Britel, Manon; Foray, Nicolas; Préau, Marie

    2015-01-01

    This exploratory study was designed to investigate the representations of radiotherapists in relation to personalized medicine. On the basis of current?>' available radiotherapy predictive tests, we tried to understand how these tests could be used in routine radiotherapy practice and in what way this possible change of practices could affect the role of radiotherapists in treatment protocols. In the absence of any available data allowing the construction of a quantitative tool, qualitative data were recorded by individual interviews with radiotherapists. Based on textual data analysis, a second national quantitative phase was conducted using a self-administered questionnaire. Crossover analysis of the two datasets highlighted the interest of radiotherapists in personalized medicine and the use of predictive tests, while indicating certain limitations and concerns in relation to ethical issues related to personalized medicine in oncology and the physician's position. PMID:26752033

  19. Complications of surgery for radiotherapy skin damage

    SciTech Connect

    Rudolph, R.

    1982-08-01

    Complications of modern surgery for radiotherapy skin damage reviewed in 28 patients who had 42 operations. Thin split-thickness skin grafts for ulcer treatment had a 100 percent complication rate, defined as the need for further surgery. Local flaps, whether delayed or not, also had a high rate of complications. Myocutaneous flaps for ulcers had a 43 percent complication rate, with viable flaps lifting off radiated wound beds. Only myocutaneous flaps for breast reconstruction and omental flaps with skin grafts and Marlex mesh had no complications. The deeper tissue penetration of modern radiotherapy techniques may make skin grafts and flaps less useful. In reconstruction of radiation ulcers, omental flaps and myocutaneous flaps are especially useful, particularly if the radiation damage can be fully excised. The pull of gravity appears detrimental to myocutaneous flap healing and, if possible, should be avoided by flap design.

  20. Radiotherapy of unicentric mediastinal Castleman's disease

    PubMed Central

    Li, Yue-Min; Liu, Peng-Hui; Zhang, Yu-Hai; Xia, Huo-Sheng; Li, Liang-Liang; Qu, Yi-Mei; Wu, Yong; Han, Shou-Yun; Liao, Guo-Qing; Pu, Yong-Dong

    2011-01-01

    Castleman's disease is a slowly progressive and rare lymphoproliferative disorder. Here, we report a 55-year-old woman with superior mediastinal Castleman's disease being misdiagnosed for a long term. We found a 4.3 cm mass localized in the superior mediastinum accompanied with severe clinical symptoms. The patient underwent an exploratory laparotomy, but the mass failed to be totally excised. Pathologic examination revealed a mediastinal mass of Castleman's disease. After radiotherapy of 30 Gy by 15 fractions, the patient no longer presented previous symptoms. At 3 months after radiotherapy of 60 Gy by 30 fractions, Computed tomography of the chest showed significantly smaller mass, indicating partial remission. Upon a 10-month follow-up, the patient was alive and free of symptoms. PMID:21527068

  1. Clinical Applications for Diffusion MRI in Radiotherapy

    PubMed Central

    Tsien, Christina; Cao, Yue; Chenevert, Thomas

    2014-01-01

    In this article, we review the clinical applications of diffusion MR imaging in the radiotherapy treatment of several key clinical sites, including those of the CNS, the head and neck, the prostate and cervix. Diffusion-weighted MRI (DWI) is an imaging technique that is rapidly gaining widespread acceptance due to its ease and wide availability. DWI measures the mobility of water within tissue at the cellular level without the need of any exogenous contrast agent. For radiotherapy treatment planning, DWI improves upon conventional imaging techniques, by better characterization of tumor tissue properties required for tumor grading, diagnosis and target volume delineation. Because diffusion weighted MRI is also a sensitive marker for alterations in tumor cellularity, it has potential clinical applications in the early assessment of treatment response following radiation therapy. PMID:24931097

  2. The efficacy of radiotherapy for vertebral hemangiomas.

    PubMed

    Miszczyk, L; Ficek, K; Trela, K; Spindel, J

    2001-01-01

    Vertebral hemangiomas are benign, slowly growing tumors sometimes causing local pain in the spine and/or neurologic disorders. The present paper includes 14 cases of painful vertebral hemangiomas treated by radiotherapy. All patients were irradiated using standard fractionation scheme with a total dose 20-30 Gy. One month after the treatment complete pain relief was noted in 36% of cases, five months later in 67% of cases, but in the remaining cases partial pain relief was noted. No correlation between treatment outcome and different biological and technical factors was found. No dose-response relationship was noted. The results suggest that anti-inflamatory effect of radiation plays the major role in this kind of treatment and that radiotherapy for vertebral hemangiomas is easy, short and highly effective analgetic treatment modality.

  3. Radiotherapy of nonfunctioning and gonadotroph adenomas.

    PubMed

    Kanner, Andrew A; Corn, Benjamin W; Greenman, Yona

    2009-01-01

    Transsphenoidal surgery is the treatment of choice for NFPA but is seldom curative. The management of patients in whom residual tumor is detected after surgery is not clear-cut. Radiation therapy is effective in controlling tumor mass in the majority of patients, but is associated with long term complications that call for restriction of its use to patients at high risk for tumor growth. New radiation techniques may prove to be safer while retaining the effectiveness of conventional radiotherapy, however longer follow-up is necessary to confirm this assumption. For now, it appears to be safe to withhold radiation and carefully follow patients with small tumor remnants, whereas large remnants from invasive tumors should be considered for radiotherapy. Nevertheless, there are no prospective controlled studies that support this empirical approach. PMID:18286373

  4. Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy

    NASA Astrophysics Data System (ADS)

    Murray, Louise J.; Thompson, Christopher M.; Lilley, John; Cosgrove, Vivian; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M.

    2015-02-01

    Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute

  5. Radiation-induced second primary cancer risks from modern external beam radiotherapy for early prostate cancer: impact of stereotactic ablative radiotherapy (SABR), volumetric modulated arc therapy (VMAT) and flattening filter free (FFF) radiotherapy.

    PubMed

    Murray, Louise J; Thompson, Christopher M; Lilley, John; Cosgrove, Vivian; Franks, Kevin; Sebag-Montefiore, David; Henry, Ann M

    2015-02-01

    Risks of radiation-induced second primary cancer following prostate radiotherapy using 3D-conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), flattening filter free (FFF) and stereotactic ablative radiotherapy (SABR) were evaluated. Prostate plans were created using 10 MV 3D-CRT (78 Gy in 39 fractions) and 6 MV 5-field IMRT (78 Gy in 39 fractions), VMAT (78 Gy in 39 fractions, with standard flattened and energy-matched FFF beams) and SABR (42.7 Gy in 7 fractions with standard flattened and energy-matched FFF beams). Dose-volume histograms from pelvic planning CT scans of three prostate patients, each planned using all 6 techniques, were used to calculate organ equivalent doses (OED) and excess absolute risks (EAR) of second rectal and bladder cancers, and pelvic bone and soft tissue sarcomas, using mechanistic, bell-shaped and plateau models. For organs distant to the treatment field, chamber measurements recorded in an anthropomorphic phantom were used to calculate OEDs and EARs using a linear model. Ratios of OED give relative radiation-induced second cancer risks. SABR resulted in lower second cancer risks at all sites relative to 3D-CRT. FFF resulted in lower second cancer risks in out-of-field tissues relative to equivalent flattened techniques, with increasing impact in organs at greater distances from the field. For example, FFF reduced second cancer risk by up to 20% in the stomach and up to 56% in the brain, relative to the equivalent flattened technique. Relative to 10 MV 3D-CRT, 6 MV IMRT or VMAT with flattening filter increased second cancer risks in several out-of-field organs, by up to 26% and 55%, respectively. For all techniques, EARs were consistently low. The observed large relative differences between techniques, in absolute terms, were very low, highlighting the importance of considering absolute risks alongside the corresponding relative risks, since when absolute

  6. Radiological protection in ion beam radiotherapy: practical guidance for clinical use of new technology.

    PubMed

    Yonekura, Y; Tsujii, H; Hopewell, J W; Ortiz López, P; Cosset, J-M; Paganetti, H; Montelius, A; Schardt, D; Jones, B; Nakamura, T

    2016-06-01

    Recently introduced technologies in radiotherapy have significantly improved the clinical outcome for patients. Ion beam radiotherapy, involving proton and carbon ion beams, provides excellent dose distributions in targeted tumours, with reduced doses to the surrounding normal tissues. However, careful treatment planning is required in order to maximise the treatment efficiency and minimise the dose to normal tissues. Radiation exposure from secondary neutrons and photons, particle fragments, and photons from activated materials should also be considered for radiological protection of the patient and medical staff. Appropriate maintenance is needed for the equipment and air in the treatment room, which may be activated by the particle beam and its secondary radiation. This new treatment requires complex procedures and careful adjustment of parameters for each patient. Therefore, education and training for the personnel involved in the procedure are essential for both effective treatment and patient protection. The International Commission on Radiological Protection (ICRP) has provided recommendations for radiological protection in ion beam radiotherapy in Publication 127 Medical staff should be aware of the possible risks resulting from inappropriate use and control of the equipment. They should also consider the necessary procedures for patient protection when new technologies are introduced into clinical practice.

  7. Radiological protection in ion beam radiotherapy: practical guidance for clinical use of new technology.

    PubMed

    Yonekura, Y; Tsujii, H; Hopewell, J W; Ortiz López, P; Cosset, J-M; Paganetti, H; Montelius, A; Schardt, D; Jones, B; Nakamura, T

    2016-06-01

    Recently introduced technologies in radiotherapy have significantly improved the clinical outcome for patients. Ion beam radiotherapy, involving proton and carbon ion beams, provides excellent dose distributions in targeted tumours, with reduced doses to the surrounding normal tissues. However, careful treatment planning is required in order to maximise the treatment efficiency and minimise the dose to normal tissues. Radiation exposure from secondary neutrons and photons, particle fragments, and photons from activated materials should also be considered for radiological protection of the patient and medical staff. Appropriate maintenance is needed for the equipment and air in the treatment room, which may be activated by the particle beam and its secondary radiation. This new treatment requires complex procedures and careful adjustment of parameters for each patient. Therefore, education and training for the personnel involved in the procedure are essential for both effective treatment and patient protection. The International Commission on Radiological Protection (ICRP) has provided recommendations for radiological protection in ion beam radiotherapy in Publication 127 Medical staff should be aware of the possible risks resulting from inappropriate use and control of the equipment. They should also consider the necessary procedures for patient protection when new technologies are introduced into clinical practice. PMID:26980799

  8. Radiotherapy in the treatment of postoperative chylothorax

    PubMed Central

    2013-01-01

    Background Chylothorax is characterized by the presence of chyle in the pleural cavity. The healing rate of non-operative treatment varies enormously; the maximum success rate in series is 70%. We investigate the efficacy and outcomes of radiotherapy for postoperative chylothorax. Methods Chylothorax was identified based on the quantity and quality of the drainage fluid. Radiation was indicated if the daily chyle flow exceeded 450 ml after complete cessation of oral intake. Radiotherapy consisted of opposed isocentric portals to the mediastinum using 15 MV photon beams from a linear accelerator, a single dose of 1–1.5 Gy, and a maximum of five fractions per week. The radiation target area was the anatomical region between TH3 and TH10 depending on the localization of the resected lobe. The mean doses of the ionizing energy was 8.5 Gy ± 3.5 Gy. Results The median start date of the radiation was the fourth day after chylothorax diagnosis. The patients’ mediastinum was radiated an average of six times. Radiotherapy, in combination with dietary restrictions, was successful in all patients. The median time between the end of the radiation and the removal of the chest tube was one day. One patient underwent wound healing by secondary intention. The median time between the end of radiation and discharge was three days, and the overall hospital stay between the chylothorax diagnosis and discharge was 18 days (range: 11–30 days). After a follow-up of six months, no patient experienced chylothorax recurrence. Conclusions Our results suggest that radiotherapy in combination with dietary restriction in the treatment of postoperative chylothorax is very safe, rapid and successful. This novel interventional procedure can obviate repeat major thoracic surgery and shorten hospital stays and could be the first choice in the treatment of postthoracotomy chylothorax. PMID:23566741

  9. [Impact of radiotherapy on female fertility].

    PubMed

    Mazeron, Renaud; Maroun, Pierre; Cao, Kim; Mbagui, Rodrigue; Slocker-Escarpa, Andrea; Chargari, Cyrus; Haie-Meder, Christine

    2015-05-01

    Radiation therapy may have deleterious effects on female fertility. It can cause ovarian dysfunction, uterine damages or disrupt the hypothalamic-pituitary axis. These effects occur at varying dose levels usually relatively low compared to the prescribed doses. Other co-factors influence the effects of radiation therapy on fertility, such as age or therapy with alkylating agents. This review aims to make an update on the current state of knowledge about the impact of radiotherapy on female fertility.

  10. Hypothyroidism After Radiotherapy for Nasopharyngeal Cancer Patients

    SciTech Connect

    Wu, Y.-H.; Wang, H-M.; Chen, Hellen Hi-Wen; Lin, C.-Y.; Chen, Eric Yen-Chao; Fan, K.-H.; Huang, S.-F.; Chen, I-How; Liao, C.-T.; Cheng, Ann-Joy; Chang, Joseph Tung-Chieh

    2010-03-15

    Purpose: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Methods and Materials: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. Results: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. Conclusion: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered.

  11. Clinical Outcome in Posthysterectomy Cervical Cancer Patients Treated With Concurrent Cisplatin and Intensity-Modulated Pelvic Radiotherapy: Comparison With Conventional Radiotherapy

    SciTech Connect

    Chen, M.-F.; Tseng, C.-J.; Tseng, C.-C.; Kuo, Y.-C.; Yu, C.-Y.; Chen, W.-C. . E-mail: rto_chen@yahoo.com.tw

    2007-04-01

    Purpose: To assess local control and acute and chronic toxicity with intensity-modulated radiation therapy (IMRT) as adjuvant treatment of cervical cancer. Methods and Materials: Between April 2002 and February 2006, 68 patients at high risk of cervical cancer after hysterectomy were treated with adjuvant pelvic radiotherapy and concurrent chemotherapy. Adjuvant chemotherapy consisted of cisplatin (50 mg/m{sup 2}) for six cycles every week. Thirty-three patients received adjuvant radiotherapy by IMRT. Before the IMRT series was initiated, 35 other patients underwent conventional four-field radiotherapy (Box-RT). The two groups did not differ significantly in respect of clinicopathologic and treatment factors. Results: IMRT provided compatible local tumor control compared with Box-RT. The actuarial 1-year locoregional control for patients in the IMRT and Box-RT groups was 93% and 94%, respectively. IMRT was well tolerated, with significant reduction in acute gastrointestinal (GI) and genitourinary (GU) toxicities compared with the Box-RT group (GI 36 vs. 80%, p = 0.00012; GU 30 vs. 60%, p = 0.022). Furthermore, the IMRT group had lower rates of chronic GI and GU toxicities than the Box-RT patients (GI 6 vs. 34%, p = 0.002; GU 9 vs. 23%, p = 0.231). Conclusion: Our results suggest that IMRT significantly improved the tolerance to adjuvant chemoradiotherapy with compatible locoregional control compared with conventional Box-RT. However, longer follow-up and more patients are needed to confirm the benefits of IMRT.

  12. Big Data Analytics for Prostate Radiotherapy.

    PubMed

    Coates, James; Souhami, Luis; El Naqa, Issam

    2016-01-01

    Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose-volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the "RadoncSpace") in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches.

  13. Anal Cancer: An Examination of Radiotherapy Strategies

    SciTech Connect

    Glynne-Jones, Rob; Lim, Faye

    2011-04-01

    The Radiation Therapy Oncology Group 9811, ACCORD-03, and ACT II Phase III trials in anal cancer showed no benefit for cisplatin-based induction and maintenance chemotherapy, or radiation dose-escalation >59 Gy. This review examines the efficacy and toxicity of chemoradiation (CRT) in anal cancer, and discusses potential alternative radiotherapy strategies. The evidence for the review was compiled from randomized and nonrandomized trials of radiation therapy and CRT. A total of 103 retrospective/observational studies, 4 Phase I/II studies, 16 Phase II prospective studies, 2 randomized Phase II studies, and 6 Phase III trials of radiotherapy or chemoradiation were identified. There are no meta-analyses based on individual patient data. A 'one-size-fits-all' approach for all stages of anal cancer is inappropriate. Early T1 tumors are probably currently overtreated, whereas T3/T4 lesions might merit escalation of treatment. Intensity-modulated radiotherapy or the integration of biological therapy may play a role in future.

  14. Personalized radiotherapy: concepts, biomarkers and trial design.

    PubMed

    Ree, A H; Redalen, K R

    2015-07-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points-given the imperative development of open-source data repositories to allow investigators the access to the complex data sets-will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice. PMID:25989697

  15. Accuracy requirements in radiotherapy treatment planning.

    PubMed

    Buzdar, Saeed Ahmad; Afzal, Muhammad; Nazir, Aalia; Gadhi, Muhammad Asghar

    2013-06-01

    Radiation therapy attempts to deliver ionizing radiation to the tumour and can improve the survival chances and/or quality of life of patients. There are chances of errors and uncertainties in the entire process of radiotherapy that may affect the accuracy and precision of treatment management and decrease degree of conformation. All expected inaccuracies, like radiation dose determination, volume calculation, complete evaluation of the full extent of the tumour, biological behaviour of specific tumour types, organ motion during radiotherapy, imaging, biological/molecular uncertainties, sub-clinical diseases, microscopic spread of the disease, uncertainty in normal tissue responses and radiation morbidity need sound appreciation. Conformity can be increased by reduction of such inaccuracies. With the yearly increase in computing speed and advancement in other technologies the future will provide the opportunity to optimize a greater number of variables and reduce the errors in the treatment planning process. In multi-disciplined task of radiotherapy, efforts are needed to overcome the errors and uncertainty, not only by the physicists but also by radiologists, pathologists and oncologists to reduce molecular and biological uncertainties. The radiation therapy physics is advancing towards an optimal goal that is definitely to improve accuracy where necessary and to reduce uncertainty where possible.

  16. Personalized radiotherapy: concepts, biomarkers and trial design

    PubMed Central

    Redalen, K R

    2015-01-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonstration of the benefit of adding concomitant cytotoxic agents to radiotherapy for a range of tumour types and, intriguingly, the increasing integration of targeted therapeutics for biological optimization of radiation effects. Recent molecular and imaging insights into radiobiology will provide a unique opportunity for rational patient treatment, enabling the parallel design of next-generation trials that formally examine the therapeutic outcome of adding targeted drugs to radiation, together with the critically important assessment of radiation volume and dose-limiting treatment toxicities. In considering the use of systemic agents with presumed radiosensitizing activity, this may also include the identification of molecular, metabolic and imaging markers of treatment response and tolerability, and will need particular attention on patient eligibility. In addition to providing an overview of clinical biomarker studies relevant for personalized radiotherapy, this communication will highlight principles in addressing clinical evaluation of combined-modality-targeted therapeutics and radiation. The increasing number of translational studies that bridge large-scale omics sciences with quality-assured phenomics end points—given the imperative development of open-source data repositories to allow investigators the access to the complex data sets—will enable radiation oncology to continue to position itself with the highest level of evidence within existing clinical practice. PMID:25989697

  17. [3D reconstructions in radiotherapy planning].

    PubMed

    Schlegel, W

    1991-10-01

    3D Reconstructions from tomographic images are used in the planning of radiation therapy to study important anatomical structures such as the body surface, target volumes, and organs at risk. The reconstructed anatomical models are used to define the geometry of the radiation beams. In addition, 3D voxel models are used for the calculation of the 3D dose distributions with an accuracy, previously impossible to achieve. Further uses of 3D reconstructions are in the display and evaluation of 3D therapy plans, and in the transfer of treatment planning parameters to the irradiation situation with the help of digitally reconstructed radiographs. 3D tomographic imaging with subsequent 3D reconstruction must be regarded as a completely new basis for the planning of radiation therapy, enabling tumor-tailored radiation therapy of localized target volumes with increased radiation doses and improved sparing of organs at risk. 3D treatment planning is currently being evaluated in clinical trials in connection with the new treatment techniques of conformation radiotherapy. Early experience with 3D treatment planning shows that its clinical importance in radiotherapy is growing, but will only become a standard radiotherapy tool when volumetric CT scanning, reliable and user-friendly treatment planning software, and faster and cheaper PACS-integrated medical work stations are accessible to radiotherapists.

  18. The Prospective Role of Plant Products in Radiotherapy of Cancer: A Current Overview

    PubMed Central

    Hazra, Banasri; Ghosh, Subhalakshmi; Kumar, Amit; Pandey, B. N.

    2012-01-01

    Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Efforts are going on to find chemical compounds which would effectively offer protection to the normal tissues after radiation exposure during radiotherapy of cancer. In this regard, plant-derived compounds might serve as “leads” to design ideal radioprotectors/radiosensitizers. This article reviews some of the recent findings on prospective medicinal plants, phytochemicals, and their analogs, based on both in vitro and in vivo tumor models especially focused with relevance to cancer radiotherapy. Also, pertinent discussion has been presented on the molecular mechanism of apoptotic death in relation to the oxidative stress in cancer cells induced by some of these plant samples and their active constituents. PMID:22291649

  19. Guidelines for delineation of lymphatic clinical target volumes for high conformal radiotherapy: head and neck region

    PubMed Central

    2011-01-01

    The success of radiotherapy depends on the accurate delineation of the clinical target volume. The delineation of the lymph node regions has most impact, especially for tumors in the head and neck region. The purpose of this article was the development an atlas for the delineation of the clinical target volume for patients, who should receive radiotherapy for a tumor of the head and neck region. Literature was reviewed for localisations of the adjacent lymph node regions and their lymph drain in dependence of the tumor entity. On this basis the lymph node regions were contoured on transversal CT slices. The probability for involvement was reviewed and a recommendation for the delineation of the CTV was generated. PMID:21854585

  20. Quantifying Interobserver Variation in Target Definition in Palliative Radiotherapy

    SciTech Connect

    Grabarz, Daniel; Panzarella, Tony; Bezjak, Andrea; Mclean, Michael; Elder, Christine; Wong, Rebecca K.S.

    2011-08-01

    Purpose: To describe the degree of interobserver and intraobserver variability in target and field definition when using three-dimensional (3D) volume- vs. two-dimensional (2D) field-based planning. Methods and Materials: Standardized case scenario and diagnostic imaging for 9 palliative cases (3 bone metastases, 3 palliative lung cancer, and 3 abdominal pelvis soft-tissue disease) were presented to 5 study radiation oncologists. After a decision on what the intended anatomic target should be, observers created two sets of treatment fields, first using a 2D field-based and then a 3D volume-based planning approach. Percent overlap, under-coverage, and over-coverage were used to describe interobserver and intraobserver variations in target definition. Results: The degree of interobserver variation for 2D and 3D planning was similar with a degree of overlap of 76% (range, 56%-85%) and 74% (range, 55%-88%), respectively. When comparing the treatment fields defined by the same observer using the two different planning methods, the mean degree of overlap was 78%; over-coverage, 22%; and under-coverage, 41%. There was statistically significantly more under-coverage when field-based planning was used for bone metastases (33%) vs. other anatomic sites (16%) (p = 0.02). In other words, 2D planning is more likely to result in geographic misses in bone metastases compared with other areas. Conclusions: In palliative radiotherapy clinically significant interobserver and intraobserver variation existed when using both field- and volume-based planning approaches. Strategies that would reduce this variability deserve further investigation.

  1. Monitor Unit Checking in Heterogeneous Stereotactic Body Radiotherapy Treatment Planning

    SciTech Connect

    Higgins, Patrick D.; Adolfson, Troy; Cho, L. Chinsoo; Saxena, Rishik

    2011-10-01

    Treatment of lung cancer using very-high-dose fractionation in small fields requires well-tested dose modeling, a method for density-averaging compound targets constructed from different parts of the breathing cycle, and monitor unit verification of the heterogeneity-corrected treatment plans. The quality and safety of each procedure are dependent on these factors. We have evaluated the dosimetry of our first 26 stereotactic body radiotherapy (SBRT) patients, including 260 treatment fields, planned with the Pinnacle treatment planning system. All targets were combined from full expiration and inspiration computed tomography scans and planned on the normal respiration scan with 6-MV photons. Combined GTVs (cGTVs) have been density-averaged in different ways for comparison of the effect on total monitor units. In addition, we have compared planned monitor units against hand calculations using 2 classic 1D correction methods: (1) effective attenuation and (2) ratio of Tissue-Maximum Ratios (TMRs) to determine the range of efficacy of simple verification methods over difficult-to-perform measurements. Different methods of density averaging for combined targets have been found to have minimal impact on total dose as evidenced by the range of total monitor units generated for each method. Nondensity-corrected treatment plans for the same fields were found to require about 8% more monitor units on average. Hand calculations, using the effective attenuation method were found to agree with Pinnacle calculations for nonproblematic fields to within {+-}10% for >95% of the fields tested. The ratio of TMRs method was found to be unacceptable. Reasonable choices for density-averaging of cGTVs using full inspiration/expiration scans should not strongly affect the planning dose. Verification of planned monitor units, as a check for problematic fields, can be done for 6-MV fields with simple 1D effective attenuation-corrected hand calculations.

  2. Validation of modulated electron radiotherapy delivered with photon multileaf collimation

    NASA Astrophysics Data System (ADS)

    Klein, Eric E.

    There is a challenge in radiotherapy to treat shallow targets due to the inability to provide dose heterogeneity while simultaneously minimizing dose to distal critical organs. There is a niche for Modulated Electron Radiotherapy (MERT) to complement a photon IMRT program. Disease sites such as post-mastectomy chest wall, and subcutaneous lymphoma of the scalp, etc. are better suited for modulated electrons rather than photons, or perhaps a combination. Inherent collimation systems are not conducive for electron beam delivery (in lieu of extended applicators), nor do commercial treatment planning systems model electrons collimated without applicators. The purpose of this study is to evaluate modulation of electrons by inherent photon multileaf collimators, and calculated and optimized by means of Monte Carlo. Modulated electron radiotherapy (MERT) evaluation was conducted with a Trilogy 120 leaf MLC for 6-20 MeV. To provide a sharp penumbra, modulated beams were delivered with short SSDs (70-85cm). Segment widths (SW) ranging from 1 to 10cm were configured for delivery and planning, using BEAMnrc MC code with 109 particles, and DOSXYZnrc calculations. Calculations were set with: voxel size 0.2 x 0.2 x 0.1cm3, and photon/electron transport energy cutoffs of 0.01 MeV/0.521 MeV. Dosimetry was performed with film and micro chambers. Calculated and measured data were analyzed in MatLab. Once validation of static fields was successfully completed, modulated portals (segmented and dynamic) were configured for treatment and calculations. Optimization for target coverage and OAR sparing was achieved by choosing energies according to target depth, and SW according to spatial coverage. Intensity for each segment was optimized by MC methods. Beam sharpness (penumbra) degraded with: decreasing energy and SW, and increasing SSD. PDD decreased significantly with decreasing SW. We have demonstrated excellent calculation/measurement agreement (<3mm). Equal dose profiles were

  3. Dosimetric characteristics of a PIN diode for radiotherapy application.

    PubMed

    Kumar, R; Sharma, S D; Philomina, A; Topkar, A

    2014-08-01

    The PIN diode developed by Bhabha Atomic Research Centre (BARC) was modified for its use as a dosimeter in radiation therapy. For this purpose the diode was mounted on a printed circuit board (PCB) and provided with necessary connections so that its response against irradiation can be recorded by a standard radiotherapy electrometer. The dosimetric characteristics of the diode were studied in Co-60 gamma rays as well as high energy X-rays. The measured sensitivity of this PIN diode is 4 nC/cGy which is about ten times higher than some commercial diode dosimeters. The leakage current from the diode is 0.04 nA. The response of the PIN diode is linear in the range of 20-1000 cGy which covers the full range of radiation dose encountered in radiotherapy treatments. The non-linearity of the diode response is 3.5% at 20 cGy and it is less than 1.5% at higher dose values. Its repeatability is within 0.5%. The angular response variation is about 5.6% within 6608 with respect to normal beam incidence. The response of the PIN diode at 6 and 18 MV X-rays varies within 2% with respect to its response at Co-60 gamma rays. The source to surface distance (SSD) dependence of the PIN diode was studied for Co-60 beam. It was found that the response of the diode decreases almost linearly relative to given dose for beams with constant collimator setting but increasing SSD (decreasing dose-rate). Within this study the diode response varied by about 2.5% between the maximum and minimum SSD. The dose-rate dependence of the PIN diode for 6 and 15 MV-rays was studied. The variation in response of diode for both energies in the studied dose range is less than 1%. The field size dependence of the PIN diode response is within 1% with respect to the response of ionisation chamber. These studies indicate that the characteristics of the PIN diode are suitable for use in radiotherapy dosimetry.

  4. Dosimetric characteristics of a PIN diode for radiotherapy application.

    PubMed

    Kumar, R; Sharma, S D; Philomina, A; Topkar, A

    2014-08-01

    The PIN diode developed by Bhabha Atomic Research Centre (BARC) was modified for its use as a dosimeter in radiation therapy. For this purpose the diode was mounted on a printed circuit board (PCB) and provided with necessary connections so that its response against irradiation can be recorded by a standard radiotherapy electrometer. The dosimetric characteristics of the diode were studied in Co-60 gamma rays as well as high energy X-rays. The measured sensitivity of this PIN diode is 4 nC/cGy which is about ten times higher than some commercial diode dosimeters. The leakage current from the diode is 0.04 nA. The response of the PIN diode is linear in the range of 20-1000 cGy which covers the full range of radiation dose encountered in radiotherapy treatments. The non-linearity of the diode response is 3.5% at 20 cGy and it is less than 1.5% at higher dose values. Its repeatability is within 0.5%. The angular response variation is about 5.6% within 6608 with respect to normal beam incidence. The response of the PIN diode at 6 and 18 MV X-rays varies within 2% with respect to its response at Co-60 gamma rays. The source to surface distance (SSD) dependence of the PIN diode was studied for Co-60 beam. It was found that the response of the diode decreases almost linearly relative to given dose for beams with constant collimator setting but increasing SSD (decreasing dose-rate). Within this study the diode response varied by about 2.5% between the maximum and minimum SSD. The dose-rate dependence of the PIN diode for 6 and 15 MV-rays was studied. The variation in response of diode for both energies in the studied dose range is less than 1%. The field size dependence of the PIN diode response is within 1% with respect to the response of ionisation chamber. These studies indicate that the characteristics of the PIN diode are suitable for use in radiotherapy dosimetry. PMID:24325130

  5. The Influence of Pretreatment Characteristics and Radiotherapy Parameters on Time Interval to Development of Radiation-Associated Meningioma

    SciTech Connect

    Paulino, Arnold C.; Ahmed, Irfan M.; Mai, Wei Y.; Teh, Bin S.

    2009-12-01

    Purpose: To identify pretreatment characteristics and radiotherapy parameters which may influence time interval to development of radiation-associated meningioma (RAM). Methods and Materials: A Medline/PUBMED search of articles dealing with RAM yielded 66 studies between 1981 and 2006. Factors analyzed included patient age and gender, type of initial tumor treated, radiotherapy (RT) dose and volume, and time interval from RT to development of RAM. Results: A total of 143 patients with a median age at RT of 12 years form the basis of this report. The most common initial tumors or conditions treated with RT were medulloblastoma (n = 27), pituitary adenoma (n = 20), acute lymphoblastic leukemia (n = 20), low-grade astrocytoma (n = 19), and tinea capitis (n = 14). In the 116 patients whose RT fields were known, 55 (47.4%) had a portion of the brain treated, whereas 32 (27.6%) and 29 (25.0%) had craniospinal and whole-brain fields. The median time from RT to develop a RAM or latent time (LT) was 19 years (range, 1-63 years). Male gender (p = 0.001), initial diagnosis of leukemia (p = 0.001), and use of whole brain or craniospinal field (p <= 0.0001) were associated with a shorter LT, whereas patients who received lower doses of RT had a longer LT (p < 0.0001). Conclusions: The latent time to develop a RAM was related to gender, initial tumor type, radiotherapy volume, and radiotherapy dose.

  6. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    PubMed

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

  7. Proton Radiotherapy for Liver Tumors: Dosimetric Advantages Over Photon Plans

    SciTech Connect

    Wang Xiaochun Krishnan, Sunil; Zhang Xiaodong; Dong Lei; Briere, Tina; Crane, Christopher H.; Martel, Mary; Gillin, Michael; Mohan, Radhe; Beddar, Sam

    2008-01-01

    The purpose of the study is to dosimetrically investigate the advantages of proton radiotherapy over photon radiotherapy for liver tumors. The proton plan and the photon plan were designed using commercial treatment planning systems. The treatment target dose conformity and heterogeneity and dose-volume analyses of normal structures were compared between proton and photon radiotherapy for 9 patients with liver tumors. Proton radiotherapy delivered a more conformal target dose with slightly less homogeneity when compared with photon radiotherapy. Protons significantly reduced the fractional volume of liver receiving dose greater or equal to 30 Gy (V{sub 30}) and the mean liver dose. The stomach and duodenal V{sub 45} were significantly lower with the use of proton radiotherapy. The V{sub 40} and V{sub 50} of the heart and the maximum spinal cord dose were also significantly lower with the use of proton radiotherapy. Protons were better able to spare one kidney completely and deliver less dose to one (generally the left) kidney than photons. The mean dose to the total body and most critical structures was significantly decreased using protons when compared to corresponding photon plans. In conclusion, our study suggests the dosimetric benefits of proton radiotherapy over photon radiotherapy. These dosimetric advantages of proton plans may permit further dose escalation with lower risk of complications.

  8. Dysphagia after radiotherapy: state of the art and prevention.

    PubMed

    Servagi-Vernat, S; Ali, D; Roubieu, C; Durdux, C; Laccourreye, O; Giraud, P

    2015-02-01

    Adjuvant radiotherapy after surgery or exclusive radiotherapy, with or without concurrent chemotherapy is a valuable treatment option in the great majority of patients with head and neck cancer. Recent technical progress in radiotherapy has resulted in a decreased incidence of xerostomia. Another common toxicity of radiotherapy is dysphagia, which alters the nutritional status and quality of life of patients in remission. The objective of this review is to describe the physiology of swallowing function, the pathophysiology of radiation-induced dysphagia and the various strategies currently available to prevent this complication.

  9. Genome-wide transcription responses to synchrotron microbeam radiotherapy.

    PubMed

    Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

    2012-10-01

    The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam. PMID:22974124

  10. Incidental irradiation of internal mammary lymph nodes in breast cancer: conventional two-dimensional radiotherapy versus conformal three-dimensional radiotherapy*

    PubMed Central

    Leite, Elton Trigo Teixeira; Ugino, Rafael Tsuneki; Santana, Marco Antônio; Ferreira, Denis Vasconcelos; Lopes, Maurício Russo; Pelosi, Edilson Lopes; da Silva, João Luis Fernandes; Carvalho, Heloisa de Andrade

    2016-01-01

    Objective To evaluate incidental irradiation of the internal mammary lymph nodes (IMLNs) through opposed tangential fields with conventional two-dimensional (2D) or three-dimensional (3D) radiotherapy techniques and to compare the results between the two techniques. Materials and Methods This was a retrospective study of 80 breast cancer patients in whom radiotherapy of the IMLNs was not indicated: 40 underwent 2D radiotherapy with computed tomography for dosimetric control, and 40 underwent 3D radiotherapy. The total prescribed dose was 50.0 Gy or 50.4 Gy (2.0 or 1.8 Gy/day, respectively). We reviewed all plans and defined the IMLNs following the Radiation Therapy Oncology Group recommendations. For the IMLNs, we analyzed the proportion of the volume that received 45 Gy, the proportion of the volume that received 25 Gy, the dose to 95% of the volume, the dose to 50% of the volume, the mean dose, the minimum dose (Dmin), and the maximum dose (Dmax). Results Left-sided treatments predominated in the 3D cohort. There were no differences between the 2D and 3D cohorts regarding tumor stage, type of surgery (mastectomy, breast-conserving surgery, or mastectomy with immediate reconstruction), or mean delineated IMLN volume (6.8 vs. 5.9 mL; p = 0.411). Except for the Dmin, all dosimetric parameters presented higher mean values in the 3D cohort (p < 0.05). The median Dmax in the 3D cohort was 50.34 Gy. However, the mean dose to the IMLNs was 7.93 Gy in the 2D cohort, compared with 20.64 Gy in the 3D cohort. Conclusion Neither technique delivered enough doses to the IMLNs to achieve subclinical disease control. However, all of the dosimetric parameters were significantly higher for the 3D technique. PMID:27403017

  11. Variations in Target Volume Definition for Postoperative Radiotherapy in Stage III Non-Small-Cell Lung Cancer: Analysis of an International Contouring Study

    SciTech Connect

    Spoelstra, Femke; Senan, Suresh; Le Pechoux, Cecile; Ishikura, Satoshi; Casas, Francesc; Ball, David; Price, Allan; De Ruysscher, Dirk; Soernsen de Koste, John R. van

    2010-03-15

    Purpose: Postoperative radiotherapy (PORT) in patients with completely resected non-small-cell lung cancer with mediastinal involvement is controversial because of the failure of earlier trials to demonstrate a survival benefit. Improved techniques may reduce toxicity, but the treatment fields used in routine practice have not been well studied. We studied routine target volumes used by international experts and evaluated the impact of a contouring protocol developed for a new prospective study, the Lung Adjuvant Radiotherapy Trial (Lung ART). Methods and Materials: Seventeen thoracic radiation oncologists were invited to contour their routine clinical target volumes (CTV) for 2 representative patients using a validated CD-ROM-based contouring program. Subsequently, the Lung ART study protocol was provided, and both cases were contoured again. Variations in target volumes and their dosimetric impact were analyzed. Results: Routine CTVs were received for each case from 10 clinicians, whereas six provided both routine and protocol CTVs for each case. Routine CTVs varied up to threefold between clinicians, but use of the Lung ART protocol significantly decreased variations. Routine CTVs in a postlobectomy patient resulted in V{sub 20} values ranging from 12.7% to 54.0%, and Lung ART protocol CTVs resulted in values of 20.6% to 29.2%. Similar results were seen for other toxicity parameters and in the postpneumectomy patient. With the exception of upper paratracheal nodes, protocol contouring improved coverage of the required nodal stations. Conclusion: Even among experts, significant interclinician variations are observed in PORT fields. Inasmuch as contouring variations can confound the interpretation of PORT results, mandatory quality assurance procedures have been incorporated into the current Lung ART study.

  12. Hippocampal-sparing whole-brain radiotherapy using Elekta equipment.

    PubMed

    Nevelsky, Alexander; Ieumwananonthachai, Nantakan; Kaidar-Person, Orit; Bar-Deroma, Raquel; Nasrallah, Haitam; Ben-Yosef, Rahamim; Kuten, Abraham

    2013-01-01

    The purpose of this study was to evaluate the feasibility of hippocampal-sparing whole-brain radiotherapy (HS WBRT) using the Elekta Infinity linear accelerator and Monaco treatment planning system (TPS). Ten treatment plans were created for HS-WBRT to a dose of 30 Gy (10 fractions). RTOG 0933 recommendations were applied for treatment planning. Intensity-modulated radiotherapy (IMRT) plans for the Elekta Infinity linear accelerator were created using Monaco 3.1 TPS-based on a nine-field arrangement and step-and-shoot delivery method. Plan evaluation was performed using D2% and D98% for the whole-brain PTV (defined as whole brain excluding hippocampus avoidance region), D100% and maximum dose to the hippocampus, and maximum dose to optic nerves and chiasm. Homogeneity index (HI) defined as (D2%-D98%)/Dmedian was used to quantify dose homogeneity in the PTV. The whole-brain PTV D2% mean value was 37.28 Gy (range 36.95-37.49Gy), and D98% mean value was 25.37 Gy (range 25.40-25.89 Gy). The hippocampus D100% mean value was 8.37 Gy (range 7.48-8.97 Gy) and the hippocampus maximum dose mean value was 14.35 Gy (range 13.48-15.40 Gy). The maximum dose to optic nerves and optic chiasm for all patients did not exceed 37.50 Gy. HI mean value was 0.36 (range 0.34-0.37). Mean number of segments was 105 (range 88-122) and mean number of monitor units was 1724 (range 1622-1914). Gamma evaluation showed that all plans passed 3%, 3 mm criteria with more than 99% of the measured points. These results indicate that Elekta equipment (Elekta Infinity linac and Monaco TPS) can be used for HS WBRT planning according to compliance criteria defined by the RTOG 0933 protocol. PMID:23652251

  13. Integral dose: Comparison between four techniques for prostate radiotherapy

    PubMed Central

    Ślosarek, Krzysztof; Osewski, Wojciech; Grządziel, Aleksandra; Radwan, Michał; Dolla, Łukasz; Szlag, Marta; Stąpór-Fudzińska, Małgorzata

    2014-01-01

    Aim Comparisons of integral dose delivered to the treatment planning volume and to the whole patient body during stereotactic, helical and intensity modulated radiotherapy of prostate. Background Multifield techniques produce large volumes of low dose inside the patient body. Delivered dose could be the result of the cytotoxic injuries of the cells even away from the treatment field. We calculated the total dose absorbed in the patient body for four radiotherapy techniques to investigate whether some methods have a potential to reduce the exposure to the patient. Materials and methods We analyzed CyberKnife plans for 10 patients with localized prostate cancer. Five alternative plans for each patient were calculated with the VMAT, IMRT and TomoTherapy techniques. Alternative dose distributions were calculated to achieve the same coverage for PTV. Integral Dose formula was used to calculate the total dose delivered to the PTV and whole patient body. Results Analysis showed that the same amount of dose was deposited to the treated volume despite different methods of treatment delivery. The mean values of total dose delivered to the whole patient body differed significantly for each treatment technique. The highest integral dose in the patient's body was at the TomoTherapy and CyberKnife treatment session. VMAT was characterized by the lowest integral dose deposited in the patient body. Conclusions The highest total dose absorbed in normal tissue was observed with the use of a robotic radiosurgery system and TomoTherapy. These results demonstrate that the exposure of healthy tissue is a dosimetric factor which differentiates the dose delivery methods. PMID:25859398

  14. Intensity-Modulated Radiotherapy-Based Stereotactic Body Radiotherapy for Medically Inoperable Early-Stage Lung Cancer: Excellent Local Control

    SciTech Connect

    Videtic, Gregory M.M.; Stephans, Kevin; Reddy, Chandana; Gajdos, Stephen; Kolar, Matthew; Clouser, Edward; Djemil, Toufik

    2010-06-01

    Purpose: To validate the use of stereotactic body radiotherapy (SBRT) using intensity-modulated radiotherapy (IMRT) beams for medically inoperable Stage I lung cancer. Methods and Materials: From February 2004 to November 2006, a total of 26 patients with 28 lesions received SBRT using a Novalis/BrainLAB system. Immobilization involved a Bodyfix vacuum cushion. A weighted abdominal belt limited respiratory excursion. Computed tomographic simulation images were acquired at rest, full inhalation, and full exhalation and were merged to generate an internal gross tumor volume (ITV). Dose was prescribed to cover the planning target volume (PTV), defined as PTV = ITV + 3-5 mm set-up margin. Heterogeneity corrections were used. Delivery of 50 Gy in five sequential fractions typically used seven nonopposing, noncoplanar beams. Image-guided target verification was provided by BrainLAB-ExacTrac. Results: Among the 26 patients, the mean age was 74 years (range, 49-88 years). Of the patients, 50% were male and 50% female. The median Karnofsky performance status was 70 (range, 40-100). The median follow-up was 30.9 months (range, 10.4-51.4 months). Tissue diagnosis was contraindicated in seven patients (26.9%). There were 22 T1 (78.6%) and six T2 (21.4%) tumors. The median conformality index was 1.38 (range, 1.12-1.8). The median heterogeneity index was 1.08 (range, 1.04-1.2). One patient (3.6%) developed acute Grade 3 dyspnea and one patient developed late Grade 2 chest wall pain. Actuarial local control and overall survival at 3 years were 94.4% and 52%, respectively. Conclusions: Use of IMRT-based delivery of SBRT using restriction of tumor motion in medically inoperable lung cancer demonstrates excellent local control and favorable survival.

  15. In vivo dosimetry with MOSFETs: Dosimetric characterization and first clinical results in intraoperative radiotherapy

    SciTech Connect

    Consorti, Rita . E-mail: consort@tin.it; Petrucci, Assunta; Fortunato, Falbo; Soriani, Antonella; Marzi, Simona; Iaccarino, Giuseppe; Landoni, Valeria; Benassi, Marcello

    2005-11-01

    Purpose: To investigate the use of metal oxide silicon field effect transistors (MOSFETs) as in vivo dosimetry detectors during electron beams at high dose-per-pulse intraoperative radiotherapy. Methods and Materials: The MOSFET system response in terms of reproducibility, energy, dose rate and temperature dependence, dose-linearity from 1 to 25 Gy, angular response, and dose perturbation was analyzed in the 6-9-MeV electron beam energy range produced by an intraoperative radiotherapy-dedicated mobile accelerator. We compared these with the 6- and 9-MeV electron beams produced by a conventional accelerator. MOSFETs were also used in clinical dosimetry. Results: In experimental conditions, the overall uncertainty of the MOSFET response was within 3.5% ({+-}SD). The investigated electron energies and the dose rate did not significantly influence the MOSFET calibration factors. The dose perturbation was negligible. In vivo dosimetry results were in accordance with the predicted values within {+-}5%. A discordance occurred either for an incorrect position of the dosimeter on the patient or when a great difference existed between the clinical and calibration setup, particularly when performing exit dose measurements. Conclusion: Metal oxide silicon field effect transistors are suitable for in vivo dosimetry during intraoperative radiotherapy because their overall uncertainty is comparable to the accuracy required in target dose delivery.

  16. Immunological interactions in radiotherapy-opening a new window of opportunity.

    PubMed

    Bhattacharyya, Tapesh; Purushothaman, Kiran; Puthiyottil, Sanudev Sadanandan Vadakke; Bhattacharjee, Atanu; Muttah, Geetha

    2016-02-01

    After a span of significant developments & advances we have reached a plateau in all the oncological disciplines in last decade. Escalation of dose of radiotherapy (RT) became possible with emergence of intensity modulated radiotherapy (IMRT) and image guided radiotherapy (IGRT). Different radiosensitizing agents starting from conventional cytotoxic drugs to hypoxic radiosensitizers have been tried to increase the effect of RT. However technological advancement hasn't been translated into significant clinical benefits. Exploiting the immune system to enhance the effect of RT is a relatively new concept and a fast growing area in the field of oncology. RT cannot longer be considered as a localized treatment, but rather as a systemic weapon for solid tumors. The phenomenon of abscopal effect, meaning the action of RT upon distant 'out-of-field' foci of malignancies has been a major focus of recent research, and holds great promise for the future. In this review article we are going to discuss the immunological interactions in RT and its promising clinical implications.

  17. Estimation of effective imaging dose for kilovoltage intratreatment monitoring of the prostate position during cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Ng, J. A.; Booth, J.; Poulsen, P.; Kuncic, Z.; Keall, P. J.

    2013-09-01

    Kilovoltage intratreatment monitoring (KIM) is a novel real-time localization modality where the tumor position is continuously measured during intensity modulated radiation therapy (IMRT) or intensity modulated arc therapy (IMAT) by a kilovoltage (kV) x-ray imager. Adding kV imaging during therapy adds radiation dose. The additional effective dose is quantified for prostate radiotherapy and compared to dose from other localization modalities. The software PCXMC 2.0 was used to calculate the effective dose delivered to a phantom as a function of imager angle and field size for a Varian On-Board Imager. The average angular effective dose was calculated for a field size of 6 cm × 6 cm. The average angular effective dose was used in calculations for different treatment scenarios. Treatment scenarios considered were treatment type and fractionation. For all treatment scenarios, (i.e. conventionally fractionated and stereotactic body radiotherapy (SBRT), IMRT and IMAT), the total KIM dose at 1 Hz ranged from 2-10 mSv. This imaging dose is less than the Navotek radioactive implant dose (64 mSv) and a standard SBRT cone beam computed tomography pretreatment scan dose (22 mSv) over an entire treatment regime. KIM delivers an acceptably low effective dose for daily use as a real-time image-guidance method for prostate radiotherapy.

  18. Volume or Position Changes of Primary Lung Tumor During (Chemo-)Radiotherapy Cannot Be Used as a Surrogate for Mediastinal Lymph Node Changes: The Case for Optimal Mediastinal Lymph Node Imaging During Radiotherapy

    SciTech Connect

    Elmpt, Wouter van; Ollers, Michel; Herwijnen, Henrieke van; Holder, Linda den; Vercoulen, Lindsay; Wouters, Monique; Lambin, Philippe; De Ruysscher, Dirk

    2011-01-01

    Purpose: Primary lung tumors can be visualized mostly with cone beam computed tomography (CT), whereas visualization is much more difficult for mediastinal lymph nodes (LN). If the volumetric and positional changes of the primary tumor could be used as a surrogate for the LN, this would facilitate image-guided radiotherapy. The purpose of this study was to investigate the relationship between the positional and volumetric changes in primary tumors and the involved LN during (chemo)radiotherapy treatment of non-small-cell lung cancer patients. Methods and Materials: [{sup 18}F]fluorodeoxyglucose positron emission tomography/computed tomography imaging was performed before radiotherapy and in the second week of treatment in 35 patients. Gross tumor volumes (GTV) of the primary tumor (GTVprim) and of the involved LN (GTVlymph) were delineated. Changes in position and volume of GTVprim with respect to GTVlymph and the bony anatomy were compared. Results: In individual cases, large displacements up to 1.6 cm and volume changes of 50% of the primary tumor may occur that are not correlated to the changes in involved LN. The volume of GTVprim reduced, on average, by 5.7% {+-} 19.0% and was not correlated with the small increase of 1.4% {+-} 18.2% in involved LN volume. Compared to bony anatomy, displacement of the primary tumor was statistically correlated to the involved LN displacement. Conclusions: Volume and position changes of the primary tumor are not always predictive for LN changes. This suggests that for characterization of involved LN, repeated state-of-the-art mediastinal imaging during radiotherapy may be necessary.

  19. Intensity-Modulated Radiotherapy for Tumors of the Nasal Cavity and Paranasal Sinuses: Clinical Outcomes and Patterns of Failure

    SciTech Connect

    Wiegner, Ellen A.; Daly, Megan E.; Murphy, James D.; Abelson, Jonathan; Chapman, Chris H.; Chung, Melody; Yu, Yao; Colevas, A. Dimitrios; Kaplan, Michael J.; Fischbein, Nancy; Le, Quynh-Thu; Chang, Daniel T.

    2012-05-01

    Purpose: To report outcomes in patients treated with intensity-modulated radiotherapy (IMRT) for tumors of the paranasal sinuses and nasal cavity (PNS/NC). Methods/Materials: Between June 2000 and December 2009, 52 patients with tumors of the PNS/NC underwent postoperative or definitive radiation with IMRT. Twenty-eight (54%) patients had squamous cell carcinoma (SCC). Twenty-nine patients (56%) received chemotherapy. The median follow-up was 26.6 months (range, 2.9-118.4) for all patients and 30.9 months for living patients. Results: Eighteen patients (35%) developed local-regional failure (LRF) at median time of 7.2 months. Thirteen local failures (25%) were observed, 12 in-field and 1 marginal. Six regional failures were observed, two in-field and four out-of-field. No patients treated with elective nodal radiation had nodal regional failure. Two-year local-regional control (LRC), in-field LRC, freedom from distant metastasis (FFDM), and overall survival (OS) were 64%, 74%, 71%, and 66% among all patients, respectively, and 43%, 61%, 61%, and 53% among patients with SCC, respectively. On multivariate analysis, SCC and >1 subsite involved had worse LRC (p = 0.0004 and p = 0.046, respectively) and OS (p = 0.003 and p = 0.046, respectively). Cribriform plate invasion (p = 0.005) and residual disease (p = 0.047) also had worse LRC. Acute toxicities included Grade {>=}3 mucositis in 19 patients (37%), and Grade 3 dermatitis in 8 patients (15%). Six patients had Grade {>=}3 late toxicity including one optic toxicity. Conclusions: IMRT for patients with PNS/NC tumors has good outcomes compared with historical series and is well tolerated. Patients with SCC have worse LRC and OS. LRF is the predominant pattern of failure.

  20. Effectiveness of Radiotherapy for Elderly Patients With Glioblastoma

    SciTech Connect

    Scott, Jacob; Tsai, Ya-Yu; Chinnaiyan, Prakash; Yu, Hsiang-Hsuan Michael

    2011-09-01

    Purpose: Radiotherapy plays a central role in the definitive treatment of glioblastoma. However, the optimal management of elderly patients with glioblastoma remains controversial, as the relative benefit in this patient population is unclear. To better understand the role that radiation plays in the treatment of glioblastoma in the elderly, we analyzed factors influencing patient survival using a large population-based registry. Methods and Materials: A total of 2,836 patients more than 70 years of age diagnosed with glioblastoma between 1993 and 2005 were identified from the Surveillance, Epidemiology, and End Results (SEER) registry. Demographic and clinical variables used in the analysis included gender, ethnicity, tumor size, age at diagnosis, surgery, and radiotherapy. Cancer-specific survival and overall survival were evaluated using the Kaplan-Meier method. Univariate and multivariate analysis were performed using Cox regression. Results: Radiotherapy was administered in 64% of these patients, and surgery was performed in 68%. Among 2,836 patients, 46% received surgery and radiotherapy, 22% underwent surgery only, 18% underwent radiotherapy only, and 14% did not undergo either treatment. The median survival for patients who underwent surgery and radiotherapy was 8 months. The median survival for patients who underwent radiotherapy only was 4 months, and for patients who underwent surgery only was 3 months. Those who received neither surgery nor radiotherapy had a median survival of 2 months (p < 0.001). Multivariate analysis showed that radiotherapy significantly improved cancer-specific survival (hazard ratio [HR], 0.43, 95% confidence interval [CI] 0.38-0.49) after adjusting for surgery, tumor size, gender, ethnicity, and age at diagnosis. Other factors associated with Cancer-specific survival included surgery, tumor size, age at diagnosis, and ethnicity. Analysis using overall survival as the endpoint yielded very similar results. Conclusions: Elderly

  1. Meta-analysis of Genome Wide Association Studies Identifies Genetic Markers of Late Toxicity Following Radiotherapy for Prostate Cancer.

    PubMed

    Kerns, Sarah L; Dorling, Leila; Fachal, Laura; Bentzen, Søren; Pharoah, Paul D P; Barnes, Daniel R; Gómez-Caamaño, Antonio; Carballo, Ana M; Dearnaley, David P; Peleteiro, Paula; Gulliford, Sarah L; Hall, Emma; Michailidou, Kyriaki; Carracedo, Ángel; Sia, Michael; Stock, Richard; Stone, Nelson N; Sydes, Matthew R; Tyrer, Jonathan P; Ahmed, Shahana; Parliament, Matthew; Ostrer, Harry; Rosenstein, Barry S; Vega, Ana; Burnet, Neil G; Dunning, Alison M; Barnett, Gillian C; West, Catharine M L

    2016-08-01

    Nearly 50% of cancer patients undergo radiotherapy. Late radiotherapy toxicity affects quality-of-life in long-term cancer survivors and risk of side-effects in a minority limits doses prescribed to the majority of patients. Development of a test predicting risk of toxicity could benefit many cancer patients. We aimed to meta-analyze individual level data from four genome-wide association studies from prostate cancer radiotherapy cohorts including 1564 men to identify genetic markers of toxicity. Prospectively assessed two-year toxicity endpoints (urinary frequency, decreased urine stream, rectal bleeding, overall toxicity) and single nucleotide polymorphism (SNP) associations were tested using multivariable regression, adjusting for clinical and patient-related risk factors. A fixed-effects meta-analysis identified two SNPs: rs17599026 on 5q31.2 with urinary frequency (odds ratio [OR] 3.12, 95% confidence interval [CI] 2.08-4.69, p-value 4.16×10(-8)) and rs7720298 on 5p15.2 with decreased urine stream (OR 2.71, 95% CI 1.90-3.86, p-value=3.21×10(-8)). These SNPs lie within genes that are expressed in tissues adversely affected by pelvic radiotherapy including bladder, kidney, rectum and small intestine. The results show that heterogeneous radiotherapy cohorts can be combined to identify new moderate-penetrance genetic variants associated with radiotherapy toxicity. The work provides a basis for larger collaborative efforts to identify enough variants for a future test involving polygenic risk profiling. PMID:27515689

  2. ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells.

    PubMed

    Meidanchi, Alireza; Akhavan, Omid; Khoei, Samideh; Shokri, Ali A; Hajikarimi, Zahra; Khansari, Nakisa

    2015-01-01

    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~1 min for 2 mg mL(-1) of the nanoparticles in ethanol) by applying an external magnetic field (~1T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high radioresistant cells) under gamma irradiation of (60)Co source. The nanoparticles exhibited no significant effects on the cancer cells up to the high concentration of 100 μg mL(-1), in the absence of gamma irradiation. The gamma irradiation alone (2Gy dose) also showed no significant effects on the cells. However, gamma irradiation in the presence of 100 μg mL(-1) ZnFe2O4 nanoparticles resulted in ~53% inactivation of the cells (~17 times higher than the inactivation that occurred under gamma irradiation alone) after 24h. The higher cell inactivation was assigned to interaction of gamma radiation with nanoparticles (photoelectric effect), resulting in a high level electron release in the media of the radioresistant cells. Our results indicated that ZnFe2O4 nanoparticles not only can be applied in increasing the efficiency of radiotherapy, but also can be easily separated from the cell environment by using an external magnetic field after the radiotherapy.

  3. Cytogenetic assessment of heterogeneous radiation doses in cancer patients treated with fractionated radiotherapy

    PubMed Central

    Roch-Lefèvre, S; Pouzoulet, F; Giraudet, A L; Voisin, Pa; Vaurijoux, A; Gruel, G; Grégoire, E; Buard, V; Delbos, M; Voisin, Ph; Bourhis, J; Roy, L

    2010-01-01

    The purpose of this study was to evaluate the in vivo dose–response relation of chromosome aberration formation and distribution in a context of localised and fractionated radiotherapy. Cytogenetic analysis was applied to eight patients, all treated for the same tumour localisation; the same localisation was used to prevent the variability usually observed between patients treated with radiotherapy and to allow the corresponding roles of the size of irradiation field and of the dose rate to be studied. The yield of dicentrics, centric rings and fragments was measured in blood samples taken before treatment, during the course of radiotherapy and up to 6 months after. After the first fraction of radiotherapy, we observed that the whole-body dose estimated from the yield of dicentrics and rings was higher (0.35±0.2 Gy) than the calculated equivalent whole-body dose (0.07±0.04 Gy). By contrast, the partial-body dose derived from the Qdr (quotient of dicentrics and rings) model was estimated to be 2.2±0.3 Gy, which agreed quite well with the dose delivered to the tumour (2.1±0.1 Gy). We also found a correlation between the yield of induced chromosome aberrations and the target field size (p = 0.014). U-value analysis showed that the distribution of dicentrics and rings was overdispersed, despite the fractionation of the exposure, and a positive correlation between the U-value and the dose rate was observed (p = 0.017). Overall, these results suggest that the proportion of undamaged lymphocytes could increase with the dose rate. PMID:20739344

  4. ZnFe2O4 nanoparticles as radiosensitizers in radiotherapy of human prostate cancer cells.

    PubMed

    Meidanchi, Alireza; Akhavan, Omid; Khoei, Samideh; Shokri, Ali A; Hajikarimi, Zahra; Khansari, Nakisa

    2015-01-01

    Nanoparticles of high-Z elements exhibit stronger photoelectric effects than soft tissues under gamma irradiation. Hence, they can be used as effective radiosensitizers for increasing the efficiency of current radiotherapy. In this work, superparamagnetic zinc ferrite spinel (ZnFe2O4) nanoparticles were synthesized by a hydrothermal reaction method and used as radiosensitizers in cancer therapy. The magnetic nanoparticles showed fast separation from solutions (e.g., ~1 min for 2 mg mL(-1) of the nanoparticles in ethanol) by applying an external magnetic field (~1T). The ZnFe2O4 nanoparticles were applied in an in vitro radiotherapy of lymph node carcinoma of prostate cells (as high radioresistant cells) under gamma irradiation of (60)Co source. The nanoparticles exhibited no significant effects on the cancer cells up to the high concentration of 100 μg mL(-1), in the absence of gamma irradiation. The gamma irradiation alone (2Gy dose) also showed no significant effects on the cells. However, gamma irradiation in the presence of 100 μg mL(-1) ZnFe2O4 nanoparticles resulted in ~53% inactivation of the cells (~17 times higher than the inactivation that occurred under gamma irradiation alone) after 24h. The higher cell inactivation was assigned to interaction of gamma radiation with nanoparticles (photoelectric effect), resulting in a high level electron release in the media of the radioresistant cells. Our results indicated that ZnFe2O4 nanoparticles not only can be applied in increasing the efficiency of radiotherapy, but also can be easily separated from the cell environment by using an external magnetic field after the radiotherapy. PMID:25492003

  5. Practice Patterns of Radiotherapy in Cervical Cancer Among Member Groups of the Gynecologic Cancer Intergroup (GCIG)

    SciTech Connect

    Gaffney, David K. . E-mail: david.gaffney@hci.utah.edu; Du Bois, Andreas; Narayan, Kailash; Reed, Nick; Toita, Takafumi; Pignata, Sandro; Blake, Peter; Portelance, Lorraine; Sadoyze, Azmat; Poetter, Richard; Colombo, Alessandro; Randall, Marcus; Mirza, Mansoor R.; Trimble, Edward L.

    2007-06-01

    Purpose: The aim of this study was to describe radiotherapeutic practice of the treatment of cervical cancer in member groups of the Gynecologic Cancer Intergroup (GCIG). Methods and Materials: A survey was developed and distributed to the members of the GCIG focusing on details of radiotherapy practice. Different scenarios were queried including advanced cervical cancer, postoperative patients, and para-aortic-positive lymph node cases. Items focused on indications for radiation therapy, radiation fields, dose, use of chemotherapy, brachytherapy and others. The cooperative groups from North America were compared with the other groups to evaluate potential differences in radiotherapy doses. Results: A total of 39 surveys were returned from 13 different cooperative groups. For the treatment of advanced cervical cancer, external beam pelvic doses and total doses to point A were 47 + 3.5 Gy (mean + SD) and 79.1 + 7.9 Gy, respectively. Point A doses were not different between the North American cooperative groups compared with the others (p = 0.103). All groups used concomitant chemotherapy, with 30 of 36 respondents using weekly cisplatin. Of 33 respondents, 31 intervened for a low hemoglobin level. For a para-aortic field, the upper border was most commonly (15 of 24) at the T12-L1 interspace. Maintenance chemotherapy (after radiotherapy) was not performed by 68% of respondents. For vaginal brachytherapy after hysterectomy, 23 groups performed HDR brachytherapy and four groups used LDR brachytherapy. In the use of brachytherapy, there was no uniformity in dose prescription. Conclusions: Radiotherapy practices among member groups of the GCIG are similar in terms of both doses and use of chemotherapy.

  6. The power of integration: radiotherapy and global palliative care.

    PubMed

    Rodin, Danielle; Grover, Surbhi; Elmore, Shekinah N; Knaul, Felicia M; Atun, Rifat; Caulley, Lisa; Herrera, Cristian A; Jones, Joshua A; Price, Aryeh J; Munshi, Anusheel; Gandhi, Ajeet K; Shah, Chiman; Gospodarowicz, Mary

    2016-07-01

    Radiotherapy (RT) is a powerful tool for the palliation of the symptoms of advanced cancer, although access to it is limited or absent in many low- and middle-income countries (LMICs). There are multiple factors contributing to this, including assumptions about the economic feasibility of RT in LMICs, the logical challenges of building capacity to deliver it in those regions, and the lack of political support to drive change of this kind. It is encouraging that the problem of RT access has begun to be included in the global discourse on cancer control and that palliative care and RT have been incorporated into national cancer control plans in some LMICs. Further, RT twinning programs involving high- and low-resource settings have been established to improve knowledge transfer and exchange. However, without large-scale action, the consequences of limited access to RT in LMICs will become dire. The number of new cancer cases around the world is expected to double by 2030, with twice as many deaths occurring in LMICs as in high-income countries (HICs). A sustained and coordinated effort involving research, education, and advocacy is required to engage global institutions, universities, health care providers, policymakers, and private industry in the urgent need to build RT capacity and delivery in LMICs. PMID:27481320

  7. Stereotactic Body Radiotherapy Reirradiation for Recurrent Epidural Spinal Metastases

    SciTech Connect

    Mahadevan, Anand; Floyd, Scott; Wong, Eric; Jeyapalan, Suriya; Groff, Michael; Kasper, Ekkehard

    2011-12-01

    Purpose: When patients show progression after conventional fractionated radiation for spine metastasis, further radiation and surgery may not be options. Stereotactic body radiotherapy (SBRT) has been successfully used in treatment of the spine and may be applicable in these cases. We report the use of SBRT for 60 consecutive patients (81 lesions) who had radiological progressive spine metastasis with epidural involvement after previous radiation for spine metastasis. Methods and Materials: SBRT was used with fiducial and vertebral anatomy-based targeting. The radiation dose was prescribed based on the extent of spinal canal involvement; the dose was 8 Gy Multiplication-Sign 3 = 24 Gy when the tumor did not touch the spinal cord and 5 to 6 Gy x 5 = 25 to 30 Gy when the tumor abutted the cord. The cord surface received up to the prescription dose with no hot spots in the cord. Results: The median overall survival was 11 months, and the median progression-free survival was 9 months. Overall, 93% of patients had stable or improved disease while 7% of patients showed disease progression; 65% of patients had pain relief. There was no significant toxicity other than fatigue. Conclusions: SBRT is feasible and appears to be an effective treatment modality for reirradiation after conventional palliative radiation fails for spine metastasis patients.

  8. Carcinoma of the cervix: surgical staging and radiotherapy with 32 MeV Betatron

    SciTech Connect

    Shah, K.; Olson, M.H.; Dillard, E.A.

    1982-09-01

    Fifty-six patients with squamous cell carcinoma of the cervix were staged by exploratory laparotomy. Twenty-eight of them received radiotherapy with 32 MeV Betatron and intracavitary radium. Twenty-one patients with Stage IB or IIA had a radical hysterectomy, five had post-operative pelvic irradiation, and two had primary exenteration. An overall 23.2% of patients had metastases in the paraaortic fields. Four patients with paraaortic node disease received extended field irradiation: 4500 rad in 5 weeks to paraaortic nodes. Two of them are alive and disease-free at 5.5 to 6.5 years.

  9. Limited-field radiation for bifocal germinoma

    SciTech Connect

    Lafay-Cousin, Lucie . E-mail: lucie.lafay-cousin@sickkids.ca; Millar, Barbara-Ann; Mabbott, Donald; Spiegler, Brenda; Drake, Jim; Bartels, Ute; Huang, Annie; Bouffet, Eric

    2006-06-01

    Purpose: To report the incidence, characteristics, treatment, and outcomes of bifocal germinomas treated with chemotherapy followed by focal radiation. Methods and Materials: This was a retrospective review. Inclusion criteria included radiologic diagnosis of bifocal germinoma involving the pineal and neurohypophyseal region, no evidence of dissemination on spinal MRI, negative results from cerebrospinal fluid cytologic evaluation, and negative tumor markers. Results: Between 1995 and 2004, 6 patients (5 male, 1 female; median age, 12.8 years) fulfilled the inclusion criteria. All had symptoms of diabetes insipidus at presentation. On MRI, 4 patients had a pineal and suprasellar mass, and 2 had a pineal mass associated with abnormal neurohypophyseal enhancement. All patients received chemotherapy followed by limited-field radiation and achieved complete remission after chemotherapy. The radiation field involved the whole ventricular system (range, 2,400-4,000 cGy) with or without a boost to the primary lesions. All patients remain in complete remission at a median follow-up of 48.1 months (range, 9-73.4 months). Conclusions: This experience suggests that bifocal germinoma can be considered a locoregional rather than a metastatic disease. Chemotherapy and focal radiotherapy might be sufficient to provide excellent outcomes. Staging refinement with new diagnostic tools will likely increase the incidence of the entity.

  10. Proton Radiotherapy for Pediatric Central Nervous System Germ Cell Tumors: Early Clinical Outcomes

    SciTech Connect

    MacDonald, Shannon M.; Trofimov, Alexei; Safai, Sairos; Adams, Judith; Fullerton, Barbara; Ebb, David; Tarbell, Nancy J.; Yock, Torunn I.

    2011-01-01

    Purpose: To report early clinical outcomes for children with central nervous system (CNS) germ cell tumors treated with protons; to compare dose distributions for intensity-modulated photon radiotherapy (IMRT), three-dimensional conformal proton radiation (3D-CPT), and intensity-modulated proton therapy with pencil beam scanning (IMPT) for whole-ventricular irradiation with and without an involved-field boost. Methods and Materials: All children with CNS germinoma or nongerminomatous germ cell tumor who received treatment at the Massachusetts General Hospital between 1998 and 2007 were included in this study. The IMRT, 3D-CPT, and IMPT plans were generated and compared for a representative case. Results: Twenty-two patients were treated with 3D-CPT. At a median follow-up of 28 months, there were no CNS recurrences; 1 patient had a recurrence outside the CNS. Local control, progression-free survival, and overall survival rates were 100%, 95%, and 100%, respectively. Comparable tumor volume coverage was achieved with IMRT, 3D-CPT, and IMPT. Substantial normal tissue sparing was seen with any form of proton therapy as compared with IMRT. The use of IMPT may yield additional sparing of the brain and temporal lobes. Conclusions: Preliminary disease control with proton therapy compares favorably to the literature. Dosimetric comparisons demonstrate the advantage of proton radiation over IMRT for whole-ventricle radiation. Superior dose distributions were accomplished with fewer beam angles utilizing 3D-CPT and scanned protons. Intensity-modulated proton therapy with pencil beam scanning may improve dose distribution as compared with 3D-CPT for this treatment.

  11. Nimotuzumab combined with radiotherapy for esophageal cancer: preliminary study of a Phase II clinical trial

    PubMed Central

    Liang, Jun; E, Mingyan; Wu, Gang; Zhao, Lujun; Li, Xia; Xiu, Xia; Li, Ning; Chen, Bo; Hui, Zhouguang; Lv, Jima; Fang, Hui; Tang, Yu; Bi, Nan; Wang, Wenqing; Zhai, Yirui; Li, Tao; Chen, Dongfu; Zou, Shuangmei; Lu, Ning; Perez-Rodríguez, Rolando; Zheng, Junqi; Wang, Luhua

    2013-01-01

    Objective To determine the safety and therapeutic effects of nimotuzumab (h-R3) combined with radiotherapy in esophageal cancer. Methods This Phase II clinical trial involved 42 patients with stage II (inoperable or refused surgery) to stage IV (supraclavicular lymph node metastasis only) esophageal cancers treated between November 2008 and July 2010. All patients had squamous cell carcinomas, and all received three-dimensional conformal radiotherapy and 200 mg nimotuzumab per week during radiotherapy. Results There were 9, 25, and 8 patients with stage II, III and IV disease, respectively. All except two patients received 50–70 Gy radiation; 37 patients (88.1%) received more than five nimotuzumab doses. Grade III toxicities (21.4% of all adverse events) included esophagitis and gastrointestinal, dermatological and hematological toxicities. Complete response, partial response, stable disease, and progressive disease were observed in 0, 22 (52.4%), 17 (40.5%) and 3 (7.1%) patients at 1 month after the treatment. The epidermal growth factor receptor (EGFR) overexpression rate was 95.2%. After a median follow-up of 37 months, the median survival time (MST) was 14 months. The 2 year and 3 year overall survival (OS) rates were 33.3% and 26.2%, respectively. The median progression-free survival (PFS) time was 10 months. The 2 year and 3 year PFS rates were 24.5% and 22.1%, respectively. The MST in the 13 patients with (+++) EGFR expression (group A) and 7 patients with (++) EGFR expression (group B) was 15 and 11 months, respectively. The 2 year and 3 year OS rates were 46.2% and 38.5% in group A and 28.6% and 28.6% in group B, respectively (P = 0.405). Conclusion Although concurrent chemoradiotherapy was the standard care for locally advanced esophageal cancer, radiotherapy was the choice for those who were refused or could not tolerate chemoradiotherapy. Our study shows that nimotuzumab combined with radiotherapy was well tolerated in patients with esophageal cancer

  12. Children Undergoing Radiotherapy: Swedish Parents' Experiences and Suggestions for Improvement.

    PubMed

    Ångström-Brännström, Charlotte; Engvall, Gunn; Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80-90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child's and the parent's view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents' experience when their child undergoes radiotherapy treatment, and to report parents' suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2-16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people's lives upside down, affecting the entire family. Further, the parents experience the child's suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process.

  13. Updates on clinical studies of selenium supplementation in radiotherapy

    PubMed Central

    2014-01-01

    To establish guidelines for the selenium supplementation in radiotherapy we assessed the benefits and risks of selenium supplementation in radiotherapy. Clinical studies on the use of selenium in radiotherapy were searched in the PubMed electronic database in January 2013. Sixteen clinical studies were identified among the 167 articles selected in the initial search. Ten articles were observational studies, and the other 6 articles reported studies on the effects of selenium supplementation in patients with cancer who underwent radiotherapy. The studies were conducted worldwide including European, American and Asian countries between 1987 and 2012. Plasma, serum or whole blood selenium levels were common parameters used to assess the effects of radiotherapy and the selenium supplementation status. Selenium supplementation improved the general conditions of the patients, improved their quality of life and reduced the side effects of radiotherapy. At the dose of selenium used in these studies (200–500 μg/day), selenium supplementation did not reduce the effectiveness of radiotherapy, and no toxicities were reported. Selenium supplementation may offer specific benefits for several types of cancer patients who undergo radiotherapy. Because high-dose selenium and long-term supplementation may be unsafe due to selenium toxicity, more evidence-based information and additional research are needed to ensure the therapeutic benefits of selenium supplementation. PMID:24885670

  14. Optimal radiotherapy utilisation rate in developing countries: An IAEA study.

    PubMed

    Rosenblatt, Eduardo; Barton, Michael; Mackillop, William; Fidarova, Elena; Cordero, Lisbeth; Yarney, Joel; Lim, Gerard; Abad, Anthony; Cernea, Valentin; Stojanovic-Rundic, Suzana; Strojan, Primoz; Kobachi, Lotfi; Quarneti, Aldo

    2015-07-01

    Optimal radiotherapy utilisation rate (RTU) is the proportion of all cancer cases that should receive radiotherapy. Optimal RTU was estimated for 9 Middle Income Countries as part of a larger IAEA project to better understand RTU and stage distribution. PMID:26164776

  15. Children Undergoing Radiotherapy: Swedish Parents’ Experiences and Suggestions for Improvement

    PubMed Central

    Mullaney, Tara; Nilsson, Kristina; Wickart-Johansson, Gun; Svärd, Anna-Maja; Nyholm, Tufve; Lindh, Jack; Lindh, Viveca

    2015-01-01

    Approximately 300 children, from 0 to 18 years old, are diagnosed with cancer in Sweden every year. Of these children, 80–90 of them undergo radiotherapy treatment for their cancer. Although radiotherapy is an encounter with advanced technology, few studies have investigated the child’s and the parent’s view of the procedure. As part of an ongoing multicenter study aimed to improve patient preparation and the care environment in pediatric radiotherapy, this article reports the findings from interviews with parents at baseline. The aim of the present study was twofold: to describe parents’ experience when their child undergoes radiotherapy treatment, and to report parents’ suggestions for improvements during radiotherapy for their children. Sixteen mothers and sixteen fathers of children between 2–16 years old with various cancer diagnoses were interviewed. Data were analyzed using content analysis. The findings showed that cancer and treatment turns people’s lives upside down, affecting the entire family. Further, the parents experience the child’s suffering and must cope with intense feelings. Radiotherapy treatment includes preparation by skilled and empathetic staff. The parents gradually find that they can deal with the process; and lastly, parents have suggestions for improvements during the radiotherapy treatment. An overarching theme emerged: that despair gradually turns to a sense of security, with a sustained focus on and close interaction with the child. In conclusion, an extreme burden was experienced around the start of radiotherapy, though parents gradually coped with the process. PMID:26509449

  16. Toxicity of oral radiotherapy in patients with acquired immunodeficiency syndrome

    SciTech Connect

    Cooper, J.S.; Fried, P.R.

    1987-03-01

    Although radiotherapy is a standard form of management of head and neck tumors, treatment of the oral cavity in patients who have the acquired immunodeficiency syndrome has produced unacceptable toxicity. Five such patients are described as a warning of enhanced toxicity of oral radiotherapy in this patient population.

  17. Randomized, prospective assessment of moisturizer efficacy for the treatment of radiation dermatitis following radiotherapy after breast-conserving surgery

    PubMed Central

    Sekiguchi, Kenji; Ogita, Mami; Akahane, Keiko; Haga, Chiori; Ito, Ryoko; Arai, Satoru; Ishida, Yasushi; Tsukada, Yoichiro; Kawamori, Jiro

    2015-01-01

    Objective The effect of heparinoid moisturizer use after acute skin damage for patients receiving whole-breast radiotherapy after lumpectomy is understudied. Methods A total of 30 patients were randomly assigned to receive heparinoid moisturizer (Group M), and 32 patients comprised the control group (Group C). Patients in Group M were instructed to apply heparinoid moisturizer from 2 weeks following whole-breast radiotherapy, and to continue to use the moisturizer until 3 months after completion of whole-breast radiotherapy. Group C patients were instructed to not apply any topical moisturizer during the study period. The relative ratio of skin water content ratio (RWCR(t) = (It /Nt)/(I0/N0)) between irradiated and non-irradiated field was calculated. Signs and symptoms were also assessed. The primary endpoint was the difference in relative ratio of skin water content ratio between 2 and 4 weeks following whole-breast radiotherapy. Results In Group C, relative ratio of skin water content ratio dropped to 0.80 ± 0.15 at 2 weeks and maintained the low level at 4 weeks following whole-breast radiotherapy. Similarly, in Group M, relative ratio of skin water content ratio dropped to 0.81 ± 0.19 at 2 weeks (prior to application), however, it returned to b