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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. Involved-field radiotherapy for patients in partial remission after chemotherapy for advanced Hodgkin's lymphoma

    SciTech Connect

    Aleman, Berthe M.P. . E-mail: b.aleman@nki.nl; Raemaekers, John M.M.; Tomisic, Radka; Baaijens, Margreet H.A.; Bortolus, Roberto; Lybeert, Marnix L.M.; Maazen, Richard W.M. van der; Girinsky, Theodore; Demeestere, Geertrui; Lugtenburg, Pieternella; Lievens, Yolande; Jong, Daphne de; Pinna, Antonella; Henry-Amar, Michel

    2007-01-01

    Purpose: The use of radiotherapy in patients with advanced Hodgkin's lymphoma (HL) is controversial. The purpose of this study was to describe the role of radiotherapy in patients with advanced HL who were in partial remission (PR) after chemotherapy. Methods: In a prospective randomized trial, patients <70 years old with previously untreated Stage III-IV HL were treated with six to eight cycles of mechlorethamine, vincristine, procarbazine, prednisone/doxorubicin, bleomycine, vinblastine hybrid chemotherapy. Patients in complete remission (CR) after chemotherapy were randomized between no further treatment and involved-field radiotherapy (IF-RT). Those in PR after six cycles received IF-RT (30 Gy to originally involved nodal areas and 18-24 Gy to extranodal sites with or without a boost). Results: Of 739 enrolled patients, 57% were in CR and 33% in PR after chemotherapy. The median follow-up was 7.8 years. Patients in PR had bulky mediastinal involvement significantly more often than did those in CR after chemotherapy. The 8-year event-free survival and overall survival rate for the 227 patients in PR who received IF-RT was 76% and 84%, respectively. These rates were not significantly different from those for CR patients who received IF-RT (73% and 78%) or for those in CR who did not receive IF-RT (77% and 85%). The incidence of second malignancies in patients in PR who were treated with IF-RT was similar to that in nonirradiated patients. Conclusion: Patients in PR after six cycles of mechlorethamine, vincristine, procarbazine, prednisone/doxorubicine, bleomycine, vinblastine treated with IF-RT had 8-year event-free survival and overall survival rates similar to those of patients in CR, suggesting a definite role for RT in these patients.

  3. 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.

  4. 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.

  5. Low-Dose Involved-Field Radiotherapy as Alternative Treatment of Nodular Lymphocyte Predominance Hodgkin's Lymphoma

    SciTech Connect

    Haas, Rick L.M. Girinsky, Theo; Aleman, Berthe; Henry-Amar, Michel; Boer, Jan-Paul de; Jong, Daphne de

    2009-07-15

    Purpose: Nodular lymphocyte predominance Hodgkin's lymphoma is a very rare disease, characterized by an indolent clinical course, with sometimes very late relapses occurring in a minority of all patients. Considerable discussion is ongoing on the treatment of primary and relapsed disease. Patients and Methods: A group of 9 patients were irradiated to a dose of 4 Gy on involved areas only. Results: After a median follow-up of 37 months (range, 6-66), the overall response rate was 89%. Six patients had complete remission (67%), two had partial remission (22%), and one had stable disease (11%). Of 8 patients, 5 developed local relapse 9-57 months after radiotherapy. No toxicity was noted. Conclusion: In nodular lymphocyte predominance Hodgkin's lymphoma, low-dose radiotherapy provided excellent response rates and lasting remissions without significant toxicity.

  6. 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.

  7. 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

  8. 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

  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. 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

  11. 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.

  12. Primary Mediastinal Large B-Cell Lymphoma: Results of Intensive Chemotherapy Regimens (MACOP-B/VACOP-B) Plus Involved Field Radiotherapy on 53 Patients. A Single Institution Experience

    SciTech Connect

    Mazzarotto, Renzo . E-mail: renzo.mazzarotto@unipd.it; Boso, Caterina; Vianello, Federica; Aversa, Maria Savina; Chiarion-Sileni, Vanna; Trentin, Livio; Zambello, Renato; Muzzio, Pier Carlo; Fiore, Davide; Sotti, Guido

    2007-07-01

    Purpose: The optimal therapy for primary mediastinal large B-cell lymphoma (PMLBCL) remains undefined. The superiority of intensive chemotherapy regimens (Methotrexate, Doxorubicin, Cyclophosphamide, Vincristine, Prednisone, Bleomycin [MACOP-B]/Etoposide, Doxorubicin, Cyclophosphamide, Vincristine, Prednisone, Bleomycin [VACOP-B]) over Cyclophosphamide, Doxorubicin, Vincristine, Prednisone (CHOP)-like chemotherapy is upheld by some authors. The role of radiotherapy is still debated. In the absence of randomized trials, we report clinical findings and treatment response in 53 consecutive patients treated with intensive chemotherapy and mediastinal involved-field radiation therapy (IFRT). Methods and Material: Fifty-three consecutive patients with PMLBCL were retrospectively analyzed. Planned treatment consisted of induction chemotherapy (I-CT; Prednisone, Methotrexate, Doxorubicin, Cyclophosphamide, Etoposide-Mechloroethamine, Vincristine, Procarbazine, Prednisone [ProMACE-MOPP] in the first 2 patients, MACOP-B in the next 11, and VACOP-B in the last 40) followed by IFRT. Planned treatment was concluded in 43 of 53 patients; in 10 patients, I-CT was not immediately followed by IFRT. Among these 10 patients, 6 received high-dose chemotherapy (HD-CT) followed by IFRT, 2 received HD-CT, and 2 received no further treatment. Results: After a median follow-up of 93.9 months (range, 6-195 months), 45 of 53 patients (84.9%) were alive without disease. Eight patients died: 7 of PMLBCL and 1 of toxicity during HD-CT. The 5-year disease-free survival (DFS) and overall survival rates were 93.42% and 86.6%, respectively. The response rates after I-CT were complete response (CR) in 20 (37.73%) and partial response (PR) in 30 (56.60%); 3 patients (5.66%) were considered nonresponders. Among patients in PR after chemotherapy, 92% obtained a CR after IFRT. Conclusions: Our report confirms the efficacy of intensive chemotherapy plus mediastinal IFRT. IFRT plays a pivotal role in

  13. 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

  14. MACOP-B and Involved-Field Radiotherapy Is an Effective and Safe Therapy for Primary Mediastinal Large B Cell Lymphoma

    SciTech Connect

    De Sanctis, Vitaliana; Finolezzi, Erica; Osti, Mattia Falchetto; Grapulin, Lavinia; Alfo, Marco; Pescarmona, Edoardo; Berardi, Francesca; Natalino, Fiammetta; Moleti, Maria Luisa; Di Rocco, Alice; Enrici, Riccardo Maurizi; Foa, Robin; Martelli, Maurizio

    2008-11-15

    Purpose: To report the clinical findings and long-term results of front-line, third-generation MACOP-B (methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin) chemotherapy and mediastinal involved-field radiotherapy (IFRT) in 85 consecutive, previously untreated patients with primary mediastinal large B cell lymphoma (PMLBCL) diagnosed and managed at a single institution. Methods and Materials: Between 1991 and April 2004, 92 consecutive, untreated patients with PMLBCL were treated at our institution. The median age was 33 years (range, 15-61 years), 46 patients (50%) showed a mediastinal syndrome at onset; 52 patients (57%) showed a low/low-intermediate (0 to 1) and 40 patients (43%) an intermediate-high/high (2 to 3) International Prognostic Index (IPI) score. Eighty-five patients were treated with standard chemotherapy (MACOP-B), and 80 underwent mediastinal IFRT at a dose of 30-36 Gy. Results: After a MACOP-B regimen, the overall response rate was 87% and the partial response rate 9%. After chemotherapy, {sup 67}Ga scintigraphy/positron emission tomography results were positive in 43 of 52 patients (83%), whereas after IFRT 11 of 52 patients (21%) remained positive (p < 0.0001). After a median follow-up of 81 months (range, 2-196 months), progression or relapse was observed in 15 of 84 patients (18%). The projected 5-year overall survival and progression-free survival rates were 87% and 81%, respectively. The 5-year overall survival and progression-free survival rates were better for patients with an IPI of 0 to 1 than for those with an IPI of 2 to 3 (96% vs. 73% [p = 0.002] and 90% vs. 67% [p = 0.007], respectively). Conclusions: Combined-modality treatment with intensive chemotherapy plus mediastinal IFRT induces high response and lymphoma-free survival rates. Involved-field RT plays an important role in inducing negative results on {sup 67}Ga scintigraphy/positron emission tomography in patients responsive to chemotherapy.

  15. 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.

  16. 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.

  17. Stage I/II follicular lymphoma: spread of bcl-2/IgH+ cells in blood and bone marrow from primary site of disease and possibility of clearance after involved field radiotherapy.

    PubMed

    Pulsoni, Alessandro; Starza, Irene Della; Frattarelli, Natalia; Ghia, Emanuela; Carlotti, Emanuela; Cavalieri, Elena; Matturro, Angela; Tempera, Settimio; Rambaldi, Alessandro; Foà, Robin

    2007-05-01

    Stage I/IIA follicular lymphoma (FL) is considered a localised disease that can be adequately treated with radiotherapy alone. Bone marrow (BM) and peripheral blood (PB) involvement in FL was investigated by polymerase chain reaction (PCR) in a series of 24 consecutive patients with histologically revised diagnosis and treated with involved field radiotherapy. Despite the limited stage, Bcl-2/IgH+ cells were found at diagnosis in PB and/or BM of 16 patients (66.6%). After treatment, in 9/15 Bcl-2/IgH positive evaluable patients, a disappearance of Bcl-2/IgH+ cells was observed, which persisted after a median follow-up of 43.5 months (range 11-70) in all but one patient. Quantitative PCR demonstrated the feasibility of clearing PB and BM Bcl-2+ cells after local irradiation of the primary site of the disease only when the basal number of lymphoma cells was <1:100 000. Patients with Bcl-2/IgH+ cells at diagnosis or after treatment had a higher likelihood of relapse. Thus, despite a negative BM biopsy, the majority of localised FL Bcl-2/IgH+ cells were found in the PB and BM. Lymphoma cells can reversibly spread from the affected lymph node to PB and BM and, in a proportion of cases, durably disappear after irradiation. The possibility of a persistent lymphoma cell clearance is proportional to the amount of cells detected at presentation by quantitative PCR. PMID:17408460

  18. Efficacy of abbreviated Stanford V chemotherapy and involved-field radiotherapy in early-stage Hodgkin lymphoma: mature results of the G4 trial†

    PubMed Central

    Advani, R. H.; Hoppe, R. T.; Baer, D.; Mason, J.; Warnke, R.; Allen, J.; Daadi, S.; Rosenberg, S. A.; Horning, S. J.

    2013-01-01

    Introduction To assess the efficacy of an abbreviated Stanford V regimen in patients with early-stage Hodgkin lymphoma (HL). Patients and methods Patients with untreated nonbulky stage I–IIA supradiaphragmatic HL were eligible for the G4 study. Stanford V chemotherapy was administered for 8 weeks followed by radiation therapy (RT) 30 Gy to involved fields (IF). Freedom from progression (FFP), disease-specific survival (DSS) and overall survival (OS) were estimated. Results All 87 enrolled patients completed the abbreviated regimen. At a median follow-up of 10 years, FFP, DSS and OS are 94%, 99% and 94%, respectively. Therapy was well tolerated with no treatment-related deaths. Conclusions Mature results of the abbreviated Stanford V regimen in nonbulky early-stage HL are excellent and comparable to the results from other contemporary therapies. PMID:23136225

  19. A Phase I Study of Chemoradiotherapy With Use of Involved-Field Conformal Radiotherapy and Accelerated Hyperfractionation for Stage III Non-Small Cell Lung Cancer: WJTOG 3305

    SciTech Connect

    Tada, Takuhito; Chiba, Yasutaka; Tsujino, Kayoko; Fukuda, Haruyuki; Nishimura, Yasumasa; Kokubo, Masaki; Negoro, Shunichi; Kudoh, Shinzoh; Fukuoka, Masahiro; Nakagawa, Kazuhiko; Nakanishi, Yoichi

    2012-05-01

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non-small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non-small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m{sup 2}) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m{sup 2}). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade {>=}4 esophagitis and neutropenic fever and Grade {>=}3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  20. 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.

  1. Intensity-modulated radiotherapy for lymphoma involving the mediastinum

    SciTech Connect

    Goodman, Karyn A.; Toner, Sean; Hunt, Margie; Wu, Elisa J.; Yahalom, Joachim . E-mail: yahalomj@mskcc.org

    2005-05-01

    Purpose: To determine the feasibility, potential advantage, and indications for intensity-modulated radiotherapy (IMRT) in the treatment of Hodgkin's lymphoma or non-Hodgkin's lymphoma involving excessively large mediastinal disease volumes or requiring repeat RT. Methods and materials: Sixteen patients with Hodgkin's lymphoma (n = 11) or non-Hodgkin's lymphoma (n = 5) undergoing primary radiotherapy or repeat RT delivered via an IMRT plan were studied. The indications for using an IMRT plan were previous mediastinal RT (n = 5) or extremely large mediastinal treatment volumes (n 11). For each patient, IMRT, conventional parallel-opposed (AP-PA), and three-dimensional conformal (3D-CRT) plans were designed using 6-MV X-rays to deliver doses ranging from 18 to 45 Gy (median, 36 Gy). The plans were compared with regard to dose-volume parameters. The IMRT/AP-PA and IMRT/3D-CRT ratios were calculated for each parameter. Results: For all patients, the mean lung dose was reduced using IMRT, on average, by 12% compared with AP-PA and 14% compared with 3D-CRT. The planning target volume coverage was also improved using IMRT compared with AP-PA but was not different from the planning target volume coverage obtained with 3D-CRT. Conclusion: In selected patients with Hodgkin's lymphoma and non-Hodgkin's lymphoma involving the mediastinum, IMRT provides improved planning target volume coverage and reduces pulmonary toxicity parameters. It is feasible for RT of large treatment volumes and allows repeat RT of relapsed disease without exceeding cord tolerance. Additional follow-up is necessary to determine whether improvements in dose delivery affect long-term morbidity and disease control.

  2. 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

  3. 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

  4. Long term outcome of localized aggressive non-Hodgkin lymphoma treated with a short weekly chemotherapy regimen (doxorubicin, cyclophosphamide, bleomycin, vincristine, and prednisone) and involved field radiotherapy: result of a Gruppo Italiano Multiregionale per lo Studio dei Linfomi e Leucenie (GIMURELL) study.

    PubMed

    Cabras, Maria Giuseppina; Mamusa, Angela Maria; Vitolo, Umberto; Freilone R, Roberto; Dessalvi, Paolo; Orsucci, Lorella; Tonso, Anna; Levis, Alessandro; Liberati, Marina; Lay, Giancarlo; Angelucci, Emanuele

    2009-09-01

    Recently, management of limited stage diffuse large cell lymphoma (DLCL) is trending toward a low intensity chemotherapy approach. Since 1993 we have used a brief weekly (6 weeks) chemotherapy scheme (Doxorubicin, Cyclophosphamide, Bleomycin, Vincristine, and Prednisone = ACOP-B) followed by involved field radiotherapy in 207 consecutive patients with well defined localized DLCL without age limit (median 57 years, range 18-85). Treatment was completed as designed in 183 of 207 patients (88%). One hundred and ninety-nine patients (96%) achieved complete remission. At a median follow-up of 66 months 170 patients are alive (82%), 168 of them free of disease. Twenty-nine patients experienced relapse after achieving a complete remission. Kaplan-Meier, risk of relapse was 24% after 13 years. Thirty (14.5%) patients have died, 14 (6.8%) due to lymphoma progression, one due to regimen toxicity and 15 (7.2%) from other causes while remaining in complete remission. The probability of overall survival and event free survival at 13 years was 78% (95% CI 70-87%) and 63% (95% CI 50-75), respectively. Crude rate of secondary malignancy was 5.26 /1000 person-years. The ACOP-B regimen plus involved field radiotherapy is well tolerated both short and long term and is an effective chemotherapy scheme for very well defined limited stage aggressive non-Hodgkin lymphomas in all age categories. PMID:19579074

  5. 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

  6. Radiotherapy-induced gut toxicity: Involvement of matrix metalloproteinases and the intestinal microvasculature.

    PubMed

    Stansborough, Romany L; Al-Dasooqi, Noor; Bateman, Emma H; Keefe, Dorothy M K; Gibson, Rachel J

    2016-05-01

    Purpose To review the literature surrounding the involvement of the endothelium and matrix metalloproteinases (MMP) in radiotherapy-induced gut toxicity (RIGT) and further elucidate its complex pathobiology. Results RIGT involves damage to the gastrointestinal mucosa and is associated with diarrhoea, pain, and rectal bleeding depending on the area of exposure. The mechanisms underpinning RIGT are complex and have not yet been elucidated. Members of the MMP family, particularly MMP-2 and -9, have recently been identified as being key markers in RIGT and chemotherapy-induced gut toxicity (CIGT). Furthermore, the microvasculature has long been implicated in the development of toxicities following both chemotherapy and radiotherapy, however, the mechanisms behind this are yet to be explored. Conclusions It is proposed that matrix metalloproteinases are key regulators of endothelial mediators, and may play a key role in inducing damage to intestinal microvasculature following radiotherapy. PMID:26917115

  7. 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

  8. 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

  9. Bone involvement in young patients with non-Hodgkin's lymphoma: efficacy of chemotherapy without local radiotherapy.

    PubMed

    Haddy, T B; Keenan, A M; Jaffe, E S; Magrath, I T

    1988-10-01

    Of 95 young non-Hodgkin's lymphoma patients entered consecutively on the National Cancer Institute (NCI) Protocol 7704, 26 (27.4%) had involvement of one or more bones. The mean age of these 26 patients was 16.6 years, and the male to female ratio was 3.3:1. Tumor histology included undifferentiated Burkitt's lymphoma in 12, undifferentiated non-Burkitt's lymphoma in two, undifferentiated, unspecified lymphoma in one, diffuse large cell lymphoma in three, and lymphoblastic lymphoma in eight patients. Most had extensive disease; two patients had isolated bone lesions, one had lesions of two bones without involvement of other tissues, and 23 had either multiple bone lesions or single bone lesions with involvement of other tissues. Eight of the 26 patients had bone marrow involvement. Of a subgroup of 12 patients with jaw disease, 11 had undifferentiated lymphoma and one had diffuse large cell lymphoma. Only one had primary a jaw tumor, with two quadrants of the jaw involved. All 26 patients were treated with chemotherapy; only two received radiotherapy initially for bone lesions. Predicted survival of the 26 patients at 5 years is 53.2%. The 12 patients who remain disease free have a mean survival of 62.1 months (range, 22 to 100 months). Our results call into question the role of radiotherapy in the treatment of bone lesions in non-Hodgkin's lymphoma. PMID:3167201

  10. 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).

  11. Radiotherapy.

    PubMed

    Adamietz, Irenaus A

    2010-01-01

    The intrathoracic growth of the tumor causes several severe symptoms as cough, dyspnea, chest pain, hemoptysis, hoarseness, anorexia/nausea, and dysphagia. In patients with manifest or threatening symptoms radiotherapy (RT) as an effective measure should be implemented into the management concept. Palliative RT radiotherapy prefers short hypofractionated schemas (e.g. 10 x 3 Gy, 4 x 5 Gy, 2 x 8 Gy, 1 x 10 Gy). Careful radiation planning supports the precision of palliative RT and reduces significantly the complication rate. A good response and prolonged palliation effects (6-12 months) can be achieved in many cases. However, the minimum biologically equivalent dose should not be less than 35 Gy. RT produces a good outcome in all types of metastases of lung carcinoma. In emergencies like VCSS or spinal cord compression RT should be initiated immediately. The selection of the optimal therapy for locally advanced lung carcinoma with malignant airway obstruction is difficult. Both brachytherapy and percutaneous irradiation are effective, however published results including local a sum of response, functionality and life quality demonstrates more benefit by percutaneous RT. Due to different physical properties of these two methods the combination of brachytherapy and external beam irradiation may be advantageous. PMID:19955803

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

    PubMed Central

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

    2015-01-01

    ABSTRACT 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. PMID:26412879

  13. 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. PMID:26412879

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Pancreatic Neuroendocrine Tumors With Involved Surgical Margins: Prognostic Factors and the Role of Adjuvant Radiotherapy

    SciTech Connect

    Arvold, Nils D.; Willett, Christopher G.; Fernandez-del Castillo, Carlos; Ryan, David P.; Ferrone, Cristina R.; Clark, Jeffrey W.; Blaszkowsky, Lawrence S.; Deshpande, Vikram; Niemierko, Andrzej; Allen, Jill N.; Kwak, Eunice L.; Wadlow, Raymond C.; Zhu, Andrew X.; Warshaw, Andrew L.; Hong, Theodore S.

    2012-07-01

    Purpose: Pancreatic neuroendocrine tumors (pNET) are rare neoplasms associated with poor outcomes without resection, and involved surgical margins are associated with a worse prognosis. The role of adjuvant radiotherapy (RT) in these patients has not been characterized. Methods and Materials: We retrospectively evaluated 46 consecutive patients with positive or close (<1 mm) margins after pNET resection, treated from 1983 to 2010, 16 of whom received adjuvant RT. Median RT dose was 50.4 Gy in 1.8-Gy fractions; half the patients received concurrent chemotherapy with 5-fluorouracil or capecitabine. No patients received adjuvant chemotherapy. Cox multivariate analysis (MVA) was used to analyze factors associated with overall survival (OS). Results: Median age at diagnosis was 56 years, and 52% of patients were female. Median tumor size was 38 mm, 57% of patients were node-positive, and 11% had a resected solitary liver metastasis. Patients who received RT were more likely to have larger tumors (median, 54 mm vs. 30 mm, respectively, p = 0.002) and node positivity (81% vs. 33%, respectively, p = 0.002) than those not receiving RT. Median follow-up was 39 months. Actuarial 5-year OS was 62% (95% confidence interval [CI], 41%-77%). In the group that did not receive RT, 3 patients (10%) experienced local recurrence (LR) and 5 patients (18%) developed new distant metastases, while in the RT group, 1 patient (6%) experienced LR and 5 patients (38%) developed distant metastases. Of all recurrences, 29% were LR. On MVA, male gender (adjusted hazard ratio [AHR] = 3.81; 95% CI, 1.21-11.92; p = 0.02) and increasing tumor size (AHR = 1.02; 95% CI, 1.01-1.04; p = 0.007) were associated with decreased OS. Conclusions: Long-term survival is common among patients with involved-margin pNET. Despite significantly worse pathologic features among patients receiving adjuvant RT, rates of LR between groups were similar, suggesting that RT might aid local control, and merits further

  19. [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

  20. 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

  1. Involved-Field, Low-Dose Chemoradiotherapy for Early-Stage Anal Carcinoma

    SciTech Connect

    Hatfield, Paul; Cooper, Rachel; Sebag-Montefiore, David

    2008-02-01

    Purpose: To report the results of patients with early-stage anal cancer treated using a low-dose, reduced-volume, involved-field chemoradiotherapy protocol. Methods and Materials: Between June 2000 and June 2006, 21 patients were treated with external beam radiotherapy (30 Gy in 15 fractions within 3 weeks) and concurrent chemotherapy (bolus mitomycin-C 12 mg/m{sup 2} on Day 1 to a maximum of 20 mg followed by infusion 5-fluorouracil 1,000 mg/m{sup 2}/24 h on Days 1-4). Of the 21 patients, 18 underwent small-volume, involved-field radiotherapy and 3 were treated with anteroposterior-posteroanterior parallel-opposed pelvic fields. Of the 21 patients, 17 had had lesions that were excised with close (<1 mm) or involved margins, 1 had had microinvasive disease on biopsy, and 3 had had macroscopic tumor <2 cm in diameter (T1). All were considered to have Stage N0 disease radiologically. Results: After a median follow-up of 42 months, only 1 patient (4.7%) had experienced local recurrence and has remained disease free after local excision. No distant recurrences or deaths occurred. Only 1 patient could not complete treatment (because of Grade 3 gastrointestinal toxicity). Grade 3-4 hematologic toxicity occurred in only 2 patients (9.5%). No significant late toxicity was identified. Conclusion: The results of our study have shown that for patients with anal carcinoma who have residual microscopic or very-small-volume disease, a policy of low-dose, reduced-volume, involved-field chemoradiotherapy produces excellent local control and disease-free survival, with low rates of acute and late toxicity.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Clinical Applications of Geometrical Field Matching in Radiotherapy Based on a New Analytical Solution

    SciTech Connect

    Hernandez, Victor; Arenas, Meritxell; Pons, Ferran; Sempau, Josep

    2011-07-01

    A new analytical formalism has been published recently that provides all the parameters necessary for geometrical field matching in radiotherapy. The present work applies the general expressions for craniospinal irradiation, breast irradiation with a supraclavicular half-field, and breast irradiation with a supraclavicular full-field. We also explore the formalism as a tool to analyze and compare different techniques. Field matching is achieved by imposing both parallelism and coincidence between the side planes of adjacent fields. The rotation angles and either the field aperture for a certain isocenter position or the isocenter coordinates for a given field aperture are supplied. All of the already known exact solutions are reproduced. New expressions for the field aperture and for the isocenter coordinates, which were not previously available, are also computed. If tangential fields at a fixed source-to-skin distance are used together with a supraclavicular full-field, different apertures for each tangential field are required to achieve a correct match. If an isocentric technique for the tangential fields or a supraclavicular half-field is used, this complication is avoided. The breast technique with the supraclavicular half-field is recommended, because it presents several advantages with respect to the supraclavicular full-field. This formalism provides a useful tool in cases where matching of adjacent fields is necessary.

  8. Consideration of the radiation dose delivered away from the treatment field to patients in radiotherapy

    PubMed Central

    Taylor, Michael L.; Kron, Tomas

    2011-01-01

    Radiation delivery to cancer patients for radiotherapy is invariably accompanied by unwanted radiation to other parts of the patient’s body. Traditionally, considerable effort has been made to calculate and measure the radiation dose to the target as well as to nearby critical structures. Only recently has attention been focused also on the relatively low doses that exist far from the primary radiation beams. In several clinical scenarios, such doses have been associated with cardiac toxicity as well as an increased risk of secondary cancer induction. Out-of-field dose is a result of leakage and scatter and generally difficult to predict accurately. The present review aims to present existing data, from measurements and calculations, and discuss its implications for radiotherapy. PMID:21731221

  9. [The control of radiation protection in the field of radiotherapy by the French Nuclear Safety Authority (ASN)].

    PubMed

    Godet, J-L

    2007-11-01

    During the last months, several incidents at radiotherapy services occurred in France; one of these accidents led to the death of several patients or required further heavy surgical acts. In this context, ASN (Autorité de sûreté nucléaire) issued an experimental guide for the notification of radiation protection events and achieved, in dialogue with professional organisations, a new scale intended to facilitate public information on radiotherapy incidents. ASN is also fully involved in the preparation of the action plan managed by the Health ministry in order to improve the safety of treatment in radiotherapy. PMID:17962062

  10. 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

  11. Inquiry-Based Field Studies Involving Teacher-Scientist Collaboration.

    ERIC Educational Resources Information Center

    Odom, Arthur Louis

    2001-01-01

    Describes a collaborative professional development program, Inquiry-Based Field Studies Involving Teacher-Scientist Collaboration, that uses scientist-teacher teams to improve teachers' understanding of scientific inquiry. Reports that the project allowed teachers to develop a deeper understanding on the nature of science. (Author/YDS)

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

    NASA Astrophysics Data System (ADS)

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

    2008-02-01

    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.

  13. 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

  14. Follow-up Thallium-201 scintigraphy after mantle field radiotherapy for Hodgkin's disease

    SciTech Connect

    Pierga, J.Y.; Girinski, T.; Henry-Amar, M. ); Maunoury, C.; Valette, H.; Tchernia, G.; Desgrez, A. ); Socie, G. Hopital St Louis, Paris ); Cosset, J.M. Institut Curie, Paris )

    1993-04-02

    Assessment of the long-term cardiac effects of mediastinal radiotherapy for Hodgkin's disease, by Thallium scintigraphy. 32 patients (14 males and 18 females) who underwent mantle field radiotherapy for Hodgkin's disease were included in this study. Twenty patients received 4 fractions of 2.5 Gy per week and 12, five fraction of 2 Gy per week, delivered on alternate days. All the patients, except three, performed exercise testing electrocardiogram and Thallium-201 tomoscintigraphy. The average time interval from completion of treatment to the study was 7 years (range 3--13 years). No patients had clinical symptoms of cardiac disease. Mean age at the time of the study was 35 years (range 23--48 years). Two electrocardiograms revealed left bundle branch block and the patients were excluded from the study. Only one out of 27 exercise electrocardiograms was abnormal in a patient with mitral valve prolapse, who was also excluded from the study. Twenty-six scintigraphies were evaluable. Twenty-two (85%) were clearly abnormal with partial or complete redistribution on delayed images. The anterior region was affected in 19 of these cases (86%). Four explorations were undoubtedly normal. Coronary angiography was not performed for ethical reasons in these asymptomatic patients. Despite possible false positive tests, the high rate of abnormality (85%) in this small series is striking. These preliminary data justify larger studies and a close long-term follow-up of these patients. 24 refs., 1 fig., 2 tabs.

  15. Dosimetry and field matching for radiotherapy to the breast and superclavicular fossa

    NASA Astrophysics Data System (ADS)

    Winfield, Elizabeth

    Radiotherapy for early breast cancer aims to achieve local disease control and decrease loco-regional recurrence rates. Treatment may be directed to breast or chest wall alone or, include regional lymph nodes. When using tangential fields to treat the breast a separate anterior field directed to the axilla and supraclavicular fossa (SCF) is needed to treat nodal areas. The complex geometry of this region necessitates matching of adjacent radiation fields in three dimensions. The potential exists for zones of overdosage or underdosage along the match line. Cosmetic results may be compromised if treatment fields are not accurately aligned. Techniques for field matching vary between centres in the UK. A study of dosimetry across the match line region using different techniques, as reported in the multi-centre START Trial Quality Assurance (QA) programme, was undertaken. A custom-made anthropomorphic phantom was designed to assess dose distribution in three dimensions using film dosimetry. Methods with varying degrees of complexity were employed to match tangential and SCF beams. Various techniques combined half beam blocking and machine rotations to achieve geometric alignment. Matching of asymmetric beams allowed a single isocentre technique to be used. Where field matching was not undertaken a gap between tangential and SCF fields was employed. Results demonstrated differences between techniques in addition to variations within the same technique between different centres. Geometric alignment techniques produced more homogenous dose distributions in the match region than gap techniques or those techniques not correcting for field divergence. For this multi-centre assessment of match plane techniques film dosimetry used in conjunction with a breast shaped phantom provided relative dose information. This study has highlighted the difficulties of matching treatment fields to achieve homogenous dose distribution through the region of the match plane and the degree of

  16. 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.

  17. 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.

  18. 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.

  19. Sparkling Geomagnetic Field: Involving Schools in Geomagnetic Research

    NASA Astrophysics Data System (ADS)

    Bailey, Rachel; Leonhardt, Roman; Leichter, Barbara

    2014-05-01

    Solar activity will be reaching a maximum in 2013/2014 as the sun reaches the end of its cycle, bringing with it an opportunity to study in greater detail the effect of solar wind or "space weather" on our planet's magnetic field. Heightened solar activity leads to a larger amount of clouds of energetic particles bombarding the Earth. Although the Earth's magnetic field shields us from most of these particles, the field becomes distorted and compacted by the solar wind, which leads to magnetic storms that we detect from the surface. These storms cause aurorae at higher latitudes and can lead to widespread disruption of communication and navigation equipment all over the Earth when sufficiently strong. This project, "Sparkling Geomagnetic Field," is a part of Austria's Sparkling Science programme, which aims to involve schools in active scientific research to encourage interest in science from a young age. Researchers from the Central Institute for Meteorology and Geodynamics (ZAMG) in Vienna have worked hand-in-hand with three schools across Austria to set up regional geomagnetic stations consisting of state-of-the-art scalar and vector magnetometers to monitor the effects of the solar wind on the geomagnetic field. The students have been an active part of the research team from the beginning, first searching for a suitable location to set up the stations as well as later overseeing the continued running of the equipment and analysing the data output. Through this project the students will gain experience in contemporary scientific methods: data processing and analysis, field work, as well as equipment setup and upkeep. A total of three stations have been established with schools in Innsbruck, Tamsweg and Graz at roughly equal distances across Austria to run alongside the already active station in the Conrad Observatory near Vienna. Data acquisition runs through a data logger and software developed to deliver data in near realtime. This network allows for

  20. 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.

  1. 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

  2. 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.

  3. 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

  4. Involved-Field Radiation Therapy for Locoregionally Recurrent Ovarian Cancer

    PubMed Central

    Brown, Aaron P.; Jhingran, Anuja; Klopp, Ann H.; Schmeler, Kathleen M.; Ramirez, Pedro T.; Eifel, Patricia J.

    2015-01-01

    Objective To evaluate the effectiveness of definitive involved-field radiation therapy (IFRT) for selected patients with locoregionally-recurrent ovarian cancer. Methods We retrospectively reviewed records of 102 epithelial ovarian cancer patients treated with definitive IFRT (≥45 Gy). IFRT was directed to localized nodal (49%) and extranodal (51%) recurrences. Results The median time from diagnosis to IFRT was 36 months (range, 1–311), and the median follow-up after IFRT was 37 months (range, 1–123). Patients received a median of three chemotherapy courses before IFRT (range, 0–9). Five-year overall (OS) and progression-free survival (PFS) rates after IFRT were 40% and 24% respectively; the 5-year in-field disease control rate was 71%. Thirty-five patients (35%) had no evidence of disease at a median of 38 months after IFRT (range, 7–122), including 25 continuously without disease for a median of 61 months (range, 17–122) and 10 with salvage treatment following disease recurrence, disease-free for a median of 39 months after salvage treatment (range, 7–92). Eight clear cell carcinoma patients had higher 5-year OS (88% versus 37%; p=0.05) and PFS (75% versus 20%; p=0.01) rates than other patients. Patients sensitive to initial platinum chemotherapy had a higher 5-year OS rate than platinum-resistant patients (43% versus 27%, p=0.03). Patients who required chemotherapy for recurrence after IFRT often benefitted from longer chemotherapy-free intervals after than before IFRT. Conclusions Definitive IFRT can yield excellent local control, protracted disease-free intervals, and even cures in carefully selected patients. RT should be considered a tool in the curative management of locoregionally-recurrent ovarian cancer. PMID:23648467

  5. 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.

  6. 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…

  7. 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.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology

    PubMed Central

    Schreiber, Eric C.; Chang, Sha X.

    2012-01-01

    Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Methods: Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Results: Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. Conclusions: Monte Carlo simulations demonstrate

  13. Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology

    SciTech Connect

    Schreiber, Eric C.; Chang, Sha X.

    2012-08-15

    Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Methods: Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 {mu}m at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Results: Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy/min/A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 {mu}m. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 {mu}m. Conclusions: Monte Carlo simulations

  14. 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

  15. 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

  16. 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.

  17. A dosimetric analysis of volumetric-modulated arc radiotherapy with jaw width restriction vs 7 field intensity-modulated radiotherapy for definitive treatment of cervical cancer

    PubMed Central

    Huang, B; Fang, Z; Huang, Y; Lin, P

    2014-01-01

    Objective: Radiation therapy treatment planning was performed to compare the dosimetric difference between volumetric-modulated arc radiotherapy (RapidArc™ v. 10; Varian® Medical Systems, Palo Alto, CA) and 7-field intensity-modulated radiotherapy (7f-IMRT) in the definitive treatment of cervical cancer. Methods: 13 patients with cervical cancer were enrolled in this study. Planning target volume (PTV) 50 and PTV60 were prescribed at a dose of 50 and 60 Gy in 28 fractions, respectively. The dose to the PTV60 was delivered as a simultaneous integrated boost to the pelvic lymph nodes. Owing to the mechanical limitation of the multileaf collimator in which the maximum displacement was limited to 15 cm, two types of RapidArc with different jaw width restrictions (15 and 20–23 cm) were investigated to evaluate their dosimetric differences. The RapidArc plan type with dosimetric superiority was then compared against the 7f-IMRT on the target coverage, sparing of the organs at risk (OARs), monitor units, treatment time and delivery accuracy to determine whether RapidArc is beneficial for the treatment of cervical cancer. Results: The 15-cm jaw width restriction had better performance compared with the restrictions that were longer than 15 cm in the sparing of the OARs. The 15-cm RapidArc spared the OARs, that is, the bladder, rectum, small intestine, femoral heads and bones, and improved treatment efficiency compared with 7f-IMRT. Both techniques delivered a high quality-assurance passing rate (>90%) according to the Γ3mm,3% criterion. Conclusion: RapidArc with a 15-cm jaw width restriction spares the OARs and improves treatment efficiency in cervical cancer compared with 7f-IMRT. Advances in knowledge: This study describes the dosimetric superiority of RapidArc with a 15-cm jaw width restriction and explores the feasibility of using RapidArc for the definitive treatment of cervical cancer. PMID:24834477

  18. Successful Salvage Radiotherapy for a Chemo-refractory, Non-resectable, Undifferentiated Pleomorphic Sarcoma Lung Metastasis with Pericardial Involvement: A Case Report.

    PubMed

    Al-Hajri, Thuraya; Chan, Jessica; Caudrelier, Jean-Michel

    2016-01-01

    We report a case of an undifferentiated pleomorphic sarcoma in a 73-year-old female, with a solitary lung metastasis involving the pericardium that progressed on first-line chemotherapy. Partial removal of the lesion was achieved after lingular segmentectomy, which required en-bloc pericardial resection due to deep pericardial invasion. However, the residual disease significantly grew despite second-line chemotherapy, and the tumor became unresectable due to near encasement of the left anterior descending coronary artery. Therefore, we opted for a salvage radical dose of intensity-modulated radiotherapy (60Gy in 25 fractions) to the pericardial lesion. No acute side effects were observed, and after three years of follow-up, good local control has been achieved with no significant late effects observed. This case suggests that radical radiotherapy using IMRT could be considered to treat sarcomatous pericardial lesions in patients who do not respond to chemotherapy and who are inoperable or non-resectable. PMID:26918213

  19. Quality Assurance in Radiotherapy

    NASA Astrophysics Data System (ADS)

    Mckenzie, Alan

    A common feature of the Radiotherapy Centres where there have been major accidents involving incorrect radiotherapy treatment is that they did not operate good Quality Assurance systems. A Quality Assurance system is sometimes called a Quality Management system, and it is designed to give assurance that quality standards are being met. One of the "spin offs" from operating a Quality Management system is that it reduces the likelihood of a radiotherapy accident. A detailed account of how to set up a quality system in radiotherapy has been given in an ESTRO booklet.2

  20. Development of Automated Image Analysis Tools for Verification of Radiotherapy Field Accuracy with AN Electronic Portal Imaging Device.

    NASA Astrophysics Data System (ADS)

    Dong, Lei

    1995-01-01

    The successful management of cancer with radiation relies on the accurate deposition of a prescribed dose to a prescribed anatomical volume within the patient. Treatment set-up errors are inevitable because the alignment of field shaping devices with the patient must be repeated daily up to eighty times during the course of a fractionated radiotherapy treatment. With the invention of electronic portal imaging devices (EPIDs), patient's portal images can be visualized daily in real-time after only a small fraction of the radiation dose has been delivered to each treatment field. However, the accuracy of human visual evaluation of low-contrast portal images has been found to be inadequate. The goal of this research is to develop automated image analysis tools to detect both treatment field shape errors and patient anatomy placement errors with an EPID. A moments method has been developed to align treatment field images to compensate for lack of repositioning precision of the image detector. A figure of merit has also been established to verify the shape and rotation of the treatment fields. Following proper alignment of treatment field boundaries, a cross-correlation method has been developed to detect shifts of the patient's anatomy relative to the treatment field boundary. Phantom studies showed that the moments method aligned the radiation fields to within 0.5mm of translation and 0.5^ circ of rotation and that the cross-correlation method aligned anatomical structures inside the radiation field to within 1 mm of translation and 1^ circ of rotation. A new procedure of generating and using digitally reconstructed radiographs (DRRs) at megavoltage energies as reference images was also investigated. The procedure allowed a direct comparison between a designed treatment portal and the actual patient setup positions detected by an EPID. Phantom studies confirmed the feasibility of the methodology. Both the moments method and the cross -correlation technique were

  1. Highly effective local control and palliation of mantle cell lymphoma with involved-field radiation therapy (IFRT)

    SciTech Connect

    Rosenbluth, Benjamin D. . E-mail: rosenblb@mskcc.org; Yahalom, Joachim

    2006-07-15

    Purpose: Although radiosensitivity of mantle cell lymphoma (MCL) has been demonstrated in vitro, radiotherapy is rarely employed in treatment of MCL. We studied clinical responses of MCL patients treated with involved-field radiation therapy (IFRT) predominantly for local control and/or palliation. Methods and Materials: A total of 21 consecutive patients (38 sites) treated with IFRT for MCL were retrospectively analyzed. Median age was 68. Seventeen patients had Stage IV/relapsed disease, 1 had Stage II, and 3 had Stage I disease. Most patients received prior chemotherapy, with an average of two combinations per patient. Mean number of sites treated per patient was two. Mean total dose was 30 Gy. Results: Mean follow-up was 13 months. Overall local response rate was 100%. Complete response was obtained in 64% of the sites and partial response in 36%. Average time to response was 20 days. Twenty-eight sites had a response before radiation therapy was complete. Of 16 sites associated with pre-IFRT pain or discomfort, 15 exhibited post-IFRT relief. Thirteen sites (34%) exhibited local progression, with a median time to progression of 10 months, and an average response duration of 9 months. Five patients experienced Grade II radiation-related toxicity. No Grade III toxicity was reported. Twelve-month overall survival for patients receiving IFRT was 55%. Conclusions: Radiotherapy provided effective and lasting local responses in MCL patients and was associated with minimal toxicity. Radiation doses required for most lesions were relatively low and responses were noticed early in the course of treatment. Radiation therapy should be considered early in the course of relapsing, refractory, or localized MCL.

  2. 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

  3. 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.

  4. Cardiac Side-effects From Breast Cancer Radiotherapy.

    PubMed

    Taylor, C W; Kirby, A M

    2015-11-01

    Breast cancer radiotherapy reduces the risk of cancer recurrence and death. However, it usually involves some radiation exposure of the heart and analyses of randomised trials have shown that it can increase the risk of heart disease. Estimates of the absolute risks of radiation-related heart disease are needed to help oncologists plan each individual woman's treatment. The risk for an individual woman varies according to her estimated cardiac radiation dose and her background risk of ischaemic heart disease in the absence of radiotherapy. When it is known, this risk can then be compared with the absolute benefit of the radiotherapy. At present, many UK cancer centres are already giving radiotherapy with mean heart doses of less than 3 Gy and for most women the benefits of the radiotherapy will probably far outweigh the risks. Technical approaches to minimising heart dose in breast cancer radiotherapy include optimisation of beam angles, use of multileaf collimator shielding, intensity-modulated radiotherapy, treatment in a prone position, treatment in deep inspiration (including the use of breath-hold and gating techniques), proton therapy and partial breast irradiation. The multileaf collimator is suitable for many women with upper pole left breast cancers, but for women with central or lower pole cancers, breath-holding techniques are now recommended in national UK guidelines. Ongoing work aims to identify ways of irradiating pan-regional lymph nodes that are effective, involve minimal exposure of organs at risk and are feasible to plan, deliver and verify. These will probably include wide tangent-based field-in-field intensity-modulated radiotherapy or arc radiotherapy techniques in combination with deep inspiratory breath-hold, and proton beam irradiation for women who have a high predicted heart dose from intensity-modulated radiotherapy. PMID:26133462

  5. 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.

  6. Magnetic confinement of electron and photon radiotherapy dose: A Monte Carlo simulation with a nonuniform longitudinal magnetic field

    SciTech Connect

    Chen Yu; Bielajew, Alex F.; Litzenberg, Dale W.; Moran, Jean M.; Becchetti, Frederick D.

    2005-12-15

    It recently has been shown experimentally that the focusing provided by a longitudinal nonuniform high magnetic field can significantly improve electron beam dose profiles. This could permit precise targeting of tumors near critical areas and minimize the radiation dose to surrounding healthy tissue. The experimental results together with Monte Carlo simulations suggest that the magnetic confinement of electron radiotherapy beams may provide an alternative to proton or heavy ion radiation therapy in some cases. In the present work, the external magnetic field capability of the Monte Carlo code PENELOPE was utilized by providing a subroutine that modeled the actual field produced by the solenoid magnet used in the experimental studies. The magnetic field in our simulation covered the region from the vacuum exit window to the phantom including surrounding air. In a longitudinal nonuniform magnetic field, it is observed that the electron dose can be focused in both the transverse and longitudinal directions. The measured dose profiles of the electron beam are generally reproduced in the Monte Carlo simulations to within a few percent in the region of interest provided that the geometry and the energy of the incident electron beam are accurately known. Comparisons for the photon beam dose profiles with and without the magnetic field are also made. The experimental results are qualitatively reproduced in the simulation. Our simulation shows that the excessive dose at the beam entrance is due to the magnetic field trapping and focusing scattered secondary electrons that were produced in the air by the incident photon beam. The simulations also show that the electron dose profile can be manipulated by the appropriate control of the beam energy together with the strength and displacement of the longitudinal magnetic field.

  7. 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.

  8. 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.

  9. Toward automatic field selection and planning using Monte Carlo-based direct aperture optimization in modulated electron radiotherapy

    NASA Astrophysics Data System (ADS)

    Alexander, Andrew; DeBlois, François; Seuntjens, Jan

    2010-08-01

    Modulated electron radiotherapy (MERT) has been proven to produce optimal plans for shallow tumors. This study investigates automated approaches to the field determination process in generating optimal MERT plans for few-leaf electron collimator (FLEC)-based MERT, by generating a large database of pre-calculated beamlets stored as phase-space files. Beamlets can be used in an overlapping feathered pattern to reduce the effect of abutting fields, which can contribute to dose inhomogeneities within the target. Beamlet dose calculation was performed by Monte Carlo (MC) simulations prior to direct aperture optimization (DAO). The second part of the study examines a preliminary clinical comparison between FLEC-based MERT and helical TomoTherapy. A MERT plan for spinal irradiation was not able to conform to the PTV dose constraints as closely as the TomoTherapy plan, although the TomoTherapy plan was taken as is, i.e. not Monte Carlo re-calculated. Despite the remaining gradients in the PTV, the MERT plan was superior in reducing the low-dose bath typical of TomoTherapy plans. In conclusion, the FLEC-based MERT planning techniques developed within the study produced promising MERT plans with minimal user input. The phase-space database reduces the MC calculation time and the feathered field pattern improves target homogeneity. With further investigations, FLEC-based MERT will find an important niche in clinical radiation therapy.

  10. Definitive extended field intensity-modulated radiotherapy and concurrent cisplatin chemosensitization in the treatment of IB2-IIIB cervical cancer

    PubMed Central

    Zhang, Guangyu; He, Fangfang; Fu, Chunli; Zhang, Youzhong; Yang, Qiuan; Wang, Jianbo

    2014-01-01

    Objective To assess the toxicity of delivering extended field intensity-modulated radiotherapy (EF-IMRT) and concurrent cisplatin chemotherapy for locally advanced cervical carcinoma. Methods Forty-five patients who underwent EF-IMRT and concurrent cisplatin chemotherapy for the treatment of stage IB2 to IIIB cervical cancer were retrospectively reviewed. The clinical target volume included all areas of gross and potentially microscopic disease and regional lymph node regions. All patients underwent high-dose-rate brachytherapy. The acute and late toxicity were scored using the Common Terminology Criteria for Adverse Events and the Radiation Therapy Oncology Group late radiation morbidity scoring criteria, respectively. Results The median follow-up was 28 months (range, 5 to 62 months). Forty-two patients had a complete response, and three had a persistent disease. Of those 42 patients, 15 patients (35.7%) had recurrence. The regions of recurrence were in-field in 2 patients and out-field in 13 patients. Acute grade ≥3 gastrointestinal, genitourinary and hematologic toxicity occurred in 3, 1, and 9 patients, respectively. Three patients (6.7%) suffered from late grade 3 toxicities. Seven patients experienced ovarian transposition, 5 of those patients (71%) maintained ovarian function. Thirty-eight patients (84.4%) were alive at the last follow-up. Conclusion Concurrent cisplatin chemotherapy with EF-IMRT was safe. The acute and late toxicities are acceptable. EF-IMRT provides an opportunity to preserve endocrine function for patients with ovarian transposition. PMID:24459576

  11. 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

  12. A general analytical solution to the geometrical problem of field matching in radiotherapy

    SciTech Connect

    Hernandez, V.; Arenas, M.; Pons, F.; Sempau, J.

    2009-09-15

    Purpose: Several authors studied the problem of geometrical matching of fields produced by medical linear accelerators. However, a general solution has yet to be published. Currently available solutions are based on parallelism arguments. This study provides a general solution, considering not only parallelism but also field sizes. Methods: A fixed field with arbitrary field size, gantry, collimator, and couch angle is considered, and another field with a fixed gantry angle is matched to it. A single reference system attached to the treatment couch is used, and two approaches are followed. In the first approach, fixed field sizes are assumed and parallelism of the adjacent field-side planes is imposed. In the second approach, fixed isocenter positions are considered and both parallelism and coincidence between field-side planes are required. Results: When fixed field sizes are assumed, rotation angles are obtained; however, the isocenters may need to be shifted to make side planes coincident and therefore achieve a proper match. When fixed isocenter positions are considered, solutions for all parameters, including the field size, are obtained and an exact geometrical match is achieved. Conclusions: General expressions to the field-matching problem are found for the two approaches followed, fixed field sizes, and fixed isocenter positions. These results can be applied to any treatment technique and can easily be implemented in modern treatment planning systems.

  13. 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.

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

    SciTech Connect

    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. Treatment of early clinically staged Hodgkin's disease with a combination of ABVD chemotherapy plus limited field radiotherapy.

    PubMed

    Karmiris, T D; Grigoriou, E; Tsantekidou, M; Spanou, E; Mihalakeas, H; Baltadakis, J; Apostolidis, J; Pagoni, M; Karakasis, D; Bakiri, M; Mitsouli, C; Harhalakis, N; Nikiforakis, E

    2003-09-01

    The current management of early stage Hodgkin's disease (HD) is usually based on clinical staging, combined modality therapy and the use of less toxic chemotherapy regimens. This approach entails high cure rates, while ensures less long term toxicity with avoidance of laparotomy. The aim of this study was to assess the efficacy of a brief course of Adriamycin, Bleomycin, Vinblastine, Dacarbazine (ABVD) chemotherapy followed by limited field radiotherapy (RT) in favorable clinical stage (CS) I and IIA HD. Forty patients, aged 17-68 (median 34) years, with favorable CS I and IIA HD, without bulky mediastinal disease, have been treated with 4-6 (median 4) cycles of ABVD plus limited field RT. Twenty seven (67%) patients received 4 cycles of chemotherapy, while 13 received 5-6 cycles. Thirty five (87%) patients received limited field RT with dose 24-36 Gy and five (13%) received extended field with 36-46 Gy. All patients responded completely to chemotherapy. One patient experienced a relapse two months after the end of therapy. All patients are alive; 39 in continuous complete remission. With a median follow-up period of 44 months (range 18-101) the actuarial overall and progress free survival was 100 and 97% at 5 years. We did not observe any case of secondary leukemia or solid tumor. Pulmonary toxicity was mild in cases of mediastinal irradiation. Considering the short follow-up time and the small number of patients, the combination of a brief course of ABVD plus regional RT is a very efficacious treatment of favorable CS I and IIA HD with mild toxicity. However, long term survival data are needed, which could give confident answers regarding the risk of late therapy related complications, particularly second malignancies. PMID:14565654

  16. 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

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

    PubMed Central

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

    2015-01-01

    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® 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 be

  18. Experimental assessment of out-of-field dose components in high energy electron beams used in external beam radiotherapy.

    PubMed

    M Alabdoaburas, Mohamad; Mege, Jean-Pierre; Chavaudra, Jean; Vũ Bezin, Jérémi; Veres, Atilla; De Vathaire, Florent; Lefkopoulos, Dimitri; Diallo, Ibrahima

    2015-01-01

    The purpose of this work was to experimentally investigate the out-of-field dose in a water phantom, with several high energy electron beams used in external beam radiotherapy (RT). The study was carried out for 6, 9, 12, and 18 MeV electron beams, on three different linear accelerators, each equipped with a specific applicator. Measurements were performed in a water phantom, at different depths, for different applicator sizes, and off-axis distances up to 70 cm from beam central axis (CAX). Thermoluminescent powder dosimeters (TLD-700) were used. For given cases, TLD measurements were compared to EBT3 films and parallel-plane ionization chamber measurements. Also, out-of-field doses at 10 cm depth, with and without applicator, were evaluated. With the Siemens applicators, a peak dose appears at about 12-15 cm out of the field edge, at 1 cm depth, for all field sizes and energies. For the Siemens Primus, with a 10 × 10 cm(²) applicator, this peak reaches 2.3%, 1%, 0.9% and 1.3% of the maximum central axis dose (Dmax) for 6, 9, 12 and 18 MeV electron beams, respectively. For the Siemens Oncor, with a 10 × 10 cm(²) applicator, this peak dose reaches 0.8%, 1%, 1.4%, and 1.6% of Dmax for 6, 9, 12, and 14 MeV, respectively, and these values increase with applicator size. For the Varian 2300C/D, the doses at 12.5 cm out of the field edge are 0.3%, 0.6%, 0.5%, and 1.1% of Dmax for 6, 9, 12, and 18 MeV, respectively, and increase with applicator size. No peak dose is evidenced for the Varian applicator for these energies. In summary, the out-of-field dose from electron beams increases with the beam energy and the applicator size, and decreases with the distance from the beam central axis and the depth in water. It also considerably depends on the applicator types. Our results can be of interest for the dose estimations delivered in healthy tissues outside the treatment field for the RT patient, as well as in studies exploring RT long-term effects. PMID:26699572

  19. 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.

  20. 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

  1. Twice-Weekly Hypofractionated Intensity-Modulated Radiotherapy for Localized Prostate Cancer With Low-Risk Nodal Involvement: Toxicity and Outcome From a Dose Escalation Pilot Study

    SciTech Connect

    Zilli, Thomas; Jorcano, Sandra; Rouzaud, Michel; Dipasquale, Giovanna; Nouet, Philippe; Toscas, Jose Ignacio; Casanova, Nathalie; Wang, Hui; Escude, Lluis; Molla, Meritxell; Linero, Dolors; Weber, Damien C.; Miralbell, Raymond

    2011-10-01

    Purpose: To evaluate the toxicity and preliminary outcome of patients with localized prostate cancer treated with twice-weekly hypofractionated intensity-modulated radiotherapy (IMRT). Methods and Materials: Between 2003 and 2006, 82 prostate cancer patients with a nodal involvement risk {<=}20% (Roach index) have been treated to the prostate with or without seminal vesicles with 56 Gy (4 Gy/fraction twice weekly) and an overall treatment time of 6.5 weeks. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicities were scored according to the Radiation Therapy Oncology Group (RTOG) grading system. Median follow-up was 48 months (range, 9-67 months). Results: All patients completed the treatment without interruptions. No patient presented with Grade {>=}3 acute GU or GI toxicity. Of the patients, 4% presented with Grade 2 GU or GI persistent acute toxicity 6 weeks after treatment completion. The estimated 4-year probability of Grade {>=}2 late GU and GI toxicity-free survival were 94.2% {+-} 2.9% and 96.1% {+-} 2.2%, respectively. One patient presented with Grade 3 GI and another patient with Grade 4 GU late toxicity, which were transitory in both cases. The 4-year actuarial biochemical relapse-free survival was 91.3% {+-} 5.9%, 76.4% {+-} 8.8%, and 77.5% {+-} 8.9% for low-, intermediate-, and high-risk groups, respectively. Conclusions: In patients with localized prostate cancer, acute and late toxicity were minimal after dose-escalation administering twice-weekly 4 Gy to a total dose of 56 Gy, with IMRT. Further prospective trials are warranted to further assess the best fractionation schemes for these patients.

  2. Radiation-induced second malignancies after involved-node radiotherapy with deep-inspiration breath-hold technique for early stage Hodgkin Lymphoma: a dosimetric study

    PubMed Central

    2014-01-01

    Background To estimate the risk of radiation induced second cancers after radiotherapy using deep-inspiration breath-hold (DI) technique with three-dimensional conformal (3DCRT) and volumetric arc therapy (VMAT) for patients with Hodgkin’s lymphoma (HL). Methods Early-stage HL with mediastinal and supraclavicular involvement was studied using an Alderson phantom. A whole body CT was performed and all tissues were delineated. The clinical target volumes and planning target volumes (PTV) were determined according to the German Hodgkin study group guidelines. Free-breathing (FB) technique and DI technique were simulated by different safety margins for the PTV definition. In both cases, 30 Gy in 15 fractions was prescribed. Second cancer risk was estimated for various tissues with a second cancer model including fractionation. Results When compared with FB-3DCRT, estimated relative life time attributable risk (LAR) of cancer induction after DI-3DCRT was 0.86, 0.76, 0.94 and 0.92 for breast, lung, esophagus and stomach, respectively. With DI-VMAT, the corresponding values were 2.05, 1.29, 1.01, 0.93, respectively. For breast cancer, the LAR observed with DI-VMAT was not substantially distinguishable from the LAR computed for mantle RT with an administered dose of 40 Gy. Conclusions This study suggests that DI may reduce the LAR of secondary cancers of all OARs and may be a valuable technique when using 3DCRT. Conversely, VMAT may increase substantially the LAR and should be cautiously implemented in clinical practice. PMID:24548307

  3. 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.

  4. 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.

  5. Electron contamination and build-up doses in conformal radiotherapy fields.

    PubMed

    Hounsell, A R; Wilkinson, J M

    1999-01-01

    The dose in the build-up region depends upon the primary photon beam, backscattered radiation from the patient and contamination radiation from outside the patient. In this paper, a model based on measured data is proposed which allows the build-up dose for arbitrarily shaped treatment fields to be determined. The dose in the build-up region is assumed to comprise a primary photon component and a contamination component that is a function of the field size and shape. This contamination component, for modelling purposes, is subdivided into contributions that correspond to elements of 1 cm by 1 cm cross-sectional area at the plane of the isocentre. The magnitude of these components has been obtained by fitting measured data to an exponential function. The exponent was found to vary linearly with depth for energies between 4 MV and 20 MV. The coefficient decreased linearly with depth at 4, 6 and 8 MV, but exhibited a broad build-up region at 20 MV. The primary component, in the build-up region, could be approximated by a 100 - (100 - PSD) e(-mu d) function, where PSD is the primary surface dose. The values obtained during the fitting procedure were used to calculate dose in the build-up region for arbitrarily shaped fields. Good agreement was found in each case. PMID:10071874

  6. 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.

  7. 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.

  8. 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

  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. 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.

  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. Clinical Trial of Prophylactic Extended-Field Carbon-Ion Radiotherapy for Locally Advanced Uterine Cervical Cancer (Protocol 0508)

    PubMed Central

    Wakatsuki, Masaru; Kato, Shingo; Kiyohara, Hiroki; Ohno, Tatsuya; Karasawa, Kumiko; Tamaki, Tomoaki; Ando, Ken; Tsujii, Hirohiko; Nakano, Takashi; Kamada, Tadashi; Shozu, Makio

    2015-01-01

    To evaluate the efficacy and the toxicity of prophylactic extended-field carbon-ion radiotherapy (C-ion RT, Protocol 0508) for locally advanced squamous cell carcinoma of the uterine cervix in phase I / II clinical trial. Between May 2006 and January 2012, 26 patients of Protocol 0508 were treated with C-ion RT. The numbers of patients with stage IIB, IIIB, and IVA disease were 13, 11, and 2, respectively. Twenty patients had pelvic lymph node metastases. Median tumor size was 6.1 cm (range, 4.0–10.0 cm). The treatment consisted of extended-field irradiation of 39.0 gray equivalents (GyE) in 13 fractions, and additional 15.0 GyE in 5 fractions was given to the gross tumor volume (GTV) and surrounding tissues. With regard to local boost, 18.0 GyE in 2 fractions was given to GTV only. Total dose to the cervical tumor was 72.0 GyE over 20 fractions. The median follow-up period was 37 months. Twenty-one patients had grade 1 or 2 acute gastrointestinal toxicity, but all patients completed the treatment on schedule. There were no grade 3 or higher late complications, with 8 patients having grade 1 or 2 toxicities, 1 had grade 2 gastrointestinal toxicity and 2 had grade 2 genitourinary toxicity. Four patients (15.4%) developed local recurrence, and 8 patients (30.8%) had distant metastases. The 2-year local control rate, progression-free survival rate and overall survival rate were 83.6%, 61.5% and 73.1%, respectively. There were no severe acute or late complications in this trial. Prophylactic extended-field C-ion RT for locally advanced squamous cell carcinoma of the uterine cervix was a safe treatment. Although the number of patients in this study was small, the results support further investigations to confirm the therapeutic efficacy and to avoid or reduce toxicity. Trial Registration UMIN-CTR UMIN000016169 PMID:25993047

  13. Limited Chemotherapy and Shrinking Field Radiotherapy for Osteolymphoma (Primary Bone Lymphoma): Results From the Trans-Tasman Radiation Oncology Group 99.04 and Australasian Leukaemia and Lymphoma Group LY02 Prospective Trial;Bone; Lymphoma; Radiotherapy; Chemotherapy; Clinical trial

    SciTech Connect

    Christie, David; Dear, Keith; Le, Thai; Barton, Michael; Wirth, Andrew; Porter, David; Roos, Daniel; Pratt, Gary

    2011-07-15

    Purpose: To establish benchmark outcomes for combined modality treatment to be used in future prospective studies of osteolymphoma (primary bone lymphoma). Methods and Materials: In 1999, the Trans-Tasman Radiation Oncology Group (TROG) invited the Australasian Leukemia and Lymphoma Group (ALLG) to collaborate on a prospective study of limited chemotherapy and radiotherapy for osteolymphoma. The treatment was designed to maintain efficacy but limit the risk of subsequent pathological fractures. Patient assessment included both functional imaging and isotope bone scanning. Treatment included three cycles of CHOP chemotherapy and radiation to a dose of 45 Gy in 25 fractions using a shrinking field technique. Results: The trial closed because of slow accrual after 33 patients had been entered. Accrual was noted to slow down after Rituximab became readily available in Australia. After a median follow-up of 4.3 years, the five-year overall survival and local control rates are estimated at 90% and 72% respectively. Three patients had fractures at presentation that persisted after treatment, one with recurrent lymphoma. Conclusions: Relatively high rates of survival were achieved but the number of local failures suggests that the dose of radiotherapy should remain higher than it is for other types of lymphoma. Disability after treatment due to pathological fracture was not seen.

  14. Estimating the Magnitude and Field-Size Dependence of Radiotherapy-Induced Mortality and Tumor Control After Postoperative Radiotherapy For Non-Small-Cell Lung Cancer: Calculations From Clinical Trials

    SciTech Connect

    Miles, Edward F. . E-mail: edward.miles@duke.edu; Kelsey, Chris R.; Kirkpatrick, John P.; Marks, Lawrence B.

    2007-07-15

    Purpose: To create, on the basis of available data, a mathematical model to describe the tumor stage- and field size-dependent risks/benefits of postoperative radiotherapy (PORT) for non-small-cell lung cancer (NSCLC), and to assess whether this simple model can accurately describe the reported changes in overall survival. Methods and Materials: The increase in overall survival afforded by PORT is assumed equal to the increase in cancer-specific survival minus the rate of RT-induced mortality. The increase in cancer-specific survival is the product of the probabilities of (residual local disease) x (sterilization of residual disease with PORT) x (absence of metastatic disease). Data were extracted from the literature to estimate these probabilities. Different models were considered to relate the RT-induced mortality to field size. Results: The rate of RT-induced mortality seems to be proportional to the cube of the field size. When these mortality rates are included in the model, the predicted changes in overall survival approximate the literature values. Conclusion: Clinical data can be explained by a simple model that suggests that RT-induced mortality is strongly dependent on field size and at least partly offsets the benefit afforded by PORT. Smaller RT fields, tailored to treat the areas most at risk for recurrence, provide the highest therapeutic ratio. The data used do not reflect the impact of chemotherapy, which will reduce the rate of distant metastases and enhance the efficacy of RT.

  15. Out-of-field neutron and leakage photon exposures and the associated risk of second cancers in high-energy photon radiotherapy: current status.

    PubMed

    Takam, R; Bezak, E; Marcu, L G; Yeoh, E

    2011-10-01

    Determination and understanding of out-of-field neutron and photon doses in accelerator-based radiotherapy is an important issue since linear accelerators operating at high energies (>10 MV) produce secondary radiations that irradiate parts of the patient's anatomy distal to the target region, potentially resulting in detrimental health effects. This paper provides a compilation of data (technical and clinical) reported in the literature on the measurement and Monte Carlo simulations of peripheral neutron and photon doses produced from high-energy medical linear accelerators and the reported risk and/or incidence of second primary cancer of tissues distal to the target volume. Information in the tables facilitates easier identification of (1) the various methods and measurement techniques used to determine the out-of-field neutron and photon radiations, (2) reported linac-dependent out-of-field doses, and (3) the risk/incidence of second cancers after radiotherapy due to classic and modern treatment methods. Regardless of the measurement technique and type of accelerator, the neutron dose equivalent per unit photon dose ranges from as low as 0.1 mSv/Gy to as high as 20.4 mSv/Gy. This radiation dose potentially contributes to the induction of second primary cancer in normal tissues outside the treated area. PMID:21756083

  16. 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

  17. Involved-field irradiation in definitive chemoradiotherapy for T4 squamous cell carcinoma of the esophagus

    PubMed Central

    Li, M.; Zhao, F.; Zhang, X.; Shi, F.; Zhu, H.; Han, A.; Zhang, Y.; Kong, L.; Yu, J.

    2016-01-01

    Objectives Definitive concurrent chemoradiotherapy (ccrt) is currently a therapeutic option for locally advanced esophageal cancer. However, clinical practice differs with respect to the target volume for irradiation. The purpose of the present study was to analyze failure patterns and survival, and to determine the feasibility of using involved-field irradiation (ifi) with concurrent chemotherapy for T4 squamous cell carcinoma (scc) of the esophagus. Methods Between January 2003 and January 2013, 56 patients with clinical T4M0 scc of the esophagus received ccrt using ifi. The radiation field included the primary tumour and clinically involved lymph nodes. Target volumes and sites of failure were analyzed, as were treatment-related toxicity and survival time. Results In this 56-patient cohort, 13 patients (23.2%) achieved a complete response, and 21 (37.5%) achieved a partial response, for a total response rate of 60.7%. The major toxicities experienced were leucocytopenia and esophagitis, with 14 patients (25.0%) experiencing grade 3 toxicities. At a median follow-up of 34 months, 48 patients (85.7%) had experienced failure: 39 (69.6%) in-field, 7 (12.5%) elective nodal, and 19 (33.9%) distant. Only 1 patient (1.8%) experienced isolated elective nodal failure. The 1-, 2-, and 3-year survival rates were 39.3%, 21.4%, and 12.5% respectively. Conclusions For patients with T4M0 scc of the esophagus, definitive ccrt using ifi resulted in an acceptable rate of isolated elective nodal failure and an overall survival comparable to that achieved with elective nodal irradiation. A limited radiation therapy target volume, including only clinically involved lesions, would therefore be a feasible choice for this patient subgroup. PMID:27122981

  18. Optimal field-splitting algorithm in intensity-modulated radiotherapy: Evaluations using head-and-neck and female pelvic IMRT cases

    SciTech Connect

    Dou, Xin; Kim, Yusung; Bayouth, John E.; Buatti, John M.; Wu, Xiaodong

    2013-04-01

    To develop an optimal field-splitting algorithm of minimal complexity and verify the algorithm using head-and-neck (H and N) and female pelvic intensity-modulated radiotherapy (IMRT) cases. An optimal field-splitting algorithm was developed in which a large intensity map (IM) was split into multiple sub-IMs (≥2). The algorithm reduced the total complexity by minimizing the monitor units (MU) delivered and segment number of each sub-IM. The algorithm was verified through comparison studies with the algorithm as used in a commercial treatment planning system. Seven IMRT, H and N, and female pelvic cancer cases (54 IMs) were analyzed by MU, segment numbers, and dose distributions. The optimal field-splitting algorithm was found to reduce both total MU and the total number of segments. We found on average a 7.9 ± 11.8% and 9.6 ± 18.2% reduction in MU and segment numbers for H and N IMRT cases with an 11.9 ± 17.4% and 11.1 ± 13.7% reduction for female pelvic cases. The overall percent (absolute) reduction in the numbers of MU and segments were found to be on average −9.7 ± 14.6% (−15 ± 25 MU) and −10.3 ± 16.3% (−3 ± 5), respectively. In addition, all dose distributions from the optimal field-splitting method showed improved dose distributions. The optimal field-splitting algorithm shows considerable improvements in both total MU and total segment number. The algorithm is expected to be beneficial for the radiotherapy treatment of large-field IMRT.

  19. 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.

  20. 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

  1. 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.

  2. TOPICAL REVIEW Dosimetry for ion beam radiotherapy

    NASA Astrophysics Data System (ADS)

    Karger, Christian P.; Jäkel, Oliver; Palmans, Hugo; Kanai, Tatsuaki

    2010-11-01

    Recently, ion beam radiotherapy (including protons as well as heavier ions) gained considerable interest. Although ion beam radiotherapy requires dose prescription in terms of iso-effective dose (referring to an iso-effective photon dose), absorbed dose is still required as an operative quantity to control beam delivery, to characterize the beam dosimetrically and to verify dose delivery. This paper reviews current methods and standards to determine absorbed dose to water in ion beam radiotherapy, including (i) the detectors used to measure absorbed dose, (ii) dosimetry under reference conditions and (iii) dosimetry under non-reference conditions. Due to the LET dependence of the response of films and solid-state detectors, dosimetric measurements are mostly based on ion chambers. While a primary standard for ion beam radiotherapy still remains to be established, ion chamber dosimetry under reference conditions is based on similar protocols as for photons and electrons although the involved uncertainty is larger than for photon beams. For non-reference conditions, dose measurements in tissue-equivalent materials may also be necessary. Regarding the atomic numbers of the composites of tissue-equivalent phantoms, special requirements have to be fulfilled for ion beams. Methods for calibrating the beam monitor depend on whether passive or active beam delivery techniques are used. QA measurements are comparable to conventional radiotherapy; however, dose verification is usually single field rather than treatment plan based. Dose verification for active beam delivery techniques requires the use of multi-channel dosimetry systems to check the compliance of measured and calculated dose for a representative sample of measurement points. Although methods for ion beam dosimetry have been established, there is still room for developments. This includes improvement of the dosimetric accuracy as well as development of more efficient measurement techniques.

  3. 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.

  4. Three-Dimensional Magnetic Field Line Reconnection involving Magnetic Flux Ropes (Invited)

    NASA Astrophysics Data System (ADS)

    Gekelman, W. N.; van Compernolle, B.; Lawrence, E.; Vincena, S. T.

    2010-12-01

    We report on two experiments in which three dimensional magnetic field line reconnection plays a role. Magnetic field line reconnection is a processes in which the magnetic field energy is converted to particle energy and heating accompanied by changes in the magnetic topology. In the first experiment two magnetic flux ropes are generated from initially adjacent pulsed current channels in a background magnetoplasma in the LAPD device at UCLA. The currents exert mutual jXB forces causing them to twist about each other and merge. The currents are not static but move towards or away from each other in time. In addition the currents are observed to filament after merging. Volumetric space-time data show multiple reconnection sites with time-dependent locations. The quasi-separatrix layer (QSL) is a narrow region between the flux ropes. Two field lines on either side of the QSL will have closely spaced foot-points at on end of the flux ropes, but a very different separation at the other end. Outside the QSL, neighboring field lines do not diverge. The QSL has been measured, for the first time in this experiment [1] and its three dimensional development will be shown in movies made from the data. A system involving the reconnection of three flux ropes will also be presented. Three flux ropes are generated by drawing currents through apertures in a carbon shield located in front of a 10 cm diameter cathode immersed in the background magnetoplasma. The currents are observed to twist about themselves, writhe about each other and thrash about due to kink the kink instability. Multiple reconnection regions (which are three dimensional) and a complex QSL are observed. The magnetic helicity is evaluated from volumetric data in both cases and its rate of change is used to estimate the plasma resistivity. These measurements lead one to suspect that magnetic field line reconnection is not an independent topic, which can be studied in isolation, but part of the phenomena associated

  5. Exterior field of slowly and rapidly rotating neutron stars: Rehabilitating spacetime metrics involving hyperextreme objects

    NASA Astrophysics Data System (ADS)

    Manko, V. S.; Ruiz, E.

    2016-05-01

    The 4-parameter exact solution presumably describing the exterior gravitational field of a generic neutron star is presented in a concise explicit form defined by only three potentials. In the equatorial plane, the metric functions of the solution are found to be given by particularly simple expressions that make them very suitable for the use in concrete applications. Following Pappas and Apostolatos, we perform a comparison of the multipole structure of the solution with the multipole moments of the known physically realistic Berti-Stergioulas numerical models of neutron stars to argue that the hyperextreme sectors of the solution are not less (but are possibly even more) important for the correct description of rapidly rotating neutron stars than the subextreme sector involving exclusively the black-hole constituents. We have also worked out in explicit form an exact analog of the well-known Hartle-Thorne approximate metric.

  6. 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.

  7. Cellular processes involved in human epidermal cells exposed to extremely low frequency electric fields.

    PubMed

    Collard, J-F; Hinsenkamp, M

    2015-05-01

    We observed on different tissues and organisms a biological response after exposure to pulsed low frequency and low amplitude electric or electromagnetic fields but the precise mechanism of cell response remains unknown. The aim of this publication is to understand, using bioinformatics, the biological relevance of processes involved in the modification of gene expression. The list of genes analyzed was obtained after microarray protocol realized on cultures of human epidermal explants growing on deepidermized human skin exposed to a pulsed low frequency electric field. The directed acyclic graph on a WebGestalt Gene Ontology module shows six categories under the biological process root: "biological regulation", "cellular process", "cell proliferation", "death", "metabolic process" and "response to stimulus". Enriched derived categories are coherent with the type of in vitro culture, the stimulation protocol or with the previous results showing a decrease of cell proliferation and an increase of differentiation. The Kegg module on WebGestalt has highlighted "cell cycle" and "p53 signaling pathway" as significantly involved. The Kegg website brings out interactions between FoxO, MAPK, JNK, p53, p38, PI3K/Akt, Wnt, mTor or NF-KappaB. Some genes expressed by the stimulation are known to have an exclusive function on these pathways. Analyses performed with Pathway Studio linked cell proliferation, cell differentiation, apoptosis, cell cycle, mitosis, cell death etc. with our microarrays results. Medline citation generated by the software and the fold change variation confirms a diminution of the proliferation, activation of the differentiation and a less well-defined role of apoptosis or wound healing. Wnt and DKK functional classes, DKK1, MACF1, ATF3, MME, TXNRD1, and BMP-2 genes proposed in previous publications after a manual analysis are also highlighted with other genes after Pathway Studio automatic procedure. Finally, an analysis conducted on a list of genes

  8. Radiotherapy for ocular tumours.

    PubMed

    Stannard, C; Sauerwein, W; Maree, G; Lecuona, K

    2013-02-01

    Ocular tumours present a therapeutic challenge because of the sensitive tissues involved and the necessity to destroy the tumour while minimising visual loss. Radiotherapy (RT) is one of several modalites used apart from surgery, laser, cryotherapy, and chemotherapy. Both external beam RT (EBRT) and brachytherapy are used. Tumours of the bulbar conjunctiva, squamous carcinoma and malignant melanoma, can be treated with a radioactive plaque: strontium-90, ruthenium-106 (Ru-106), or iodine-125 (I-125), after excision. If the tumour involves the fornix or tarsal conjunctiva, proton therapy can treat the conjunctiva and spare most of the eye. Alternatively, an I-125 interstitial implant can be used with shielding of the cornea and lens. Conjunctival mucosal-associated lymphoid tissue lymphoma can be treated with an anterior electron field with lens shielding and 25-30 Gray (Gy) in 2 Gy fractions. Discrete retinoblastoma (RB), too large for cryotherapy or thermolaser, or recurrent after these modalities, can be treated with plaque therapy, I-125, or Ru-106. For large RB, multiple tumours, or vitreous seeds the whole eye can be treated with an I-125 applicator, sparing the bony orbit, or with EBRT, under anaesthetic, using X-rays or proton therapy with vacuum contact lenses to fix the eyes in the required position. Post-enucleated orbits at risk for recurrent RB can be treated with an I-125 implant with shielding to reduce the dose to the bony orbit. Uveal malignant melanomas can be treated with plaque or proton therapy with excellent local control. Preservation of vision will depend on the initial size and location of the tumour. PMID:23174750

  9. Radiotherapy for ocular tumours

    PubMed Central

    Stannard, C; Sauerwein, W; Maree, G; Lecuona, K

    2013-01-01

    Ocular tumours present a therapeutic challenge because of the sensitive tissues involved and the necessity to destroy the tumour while minimising visual loss. Radiotherapy (RT) is one of several modalites used apart from surgery, laser, cryotherapy, and chemotherapy. Both external beam RT (EBRT) and brachytherapy are used. Tumours of the bulbar conjunctiva, squamous carcinoma and malignant melanoma, can be treated with a radioactive plaque: strontium-90, ruthenium-106 (Ru-106), or iodine-125 (I-125), after excision. If the tumour involves the fornix or tarsal conjunctiva, proton therapy can treat the conjunctiva and spare most of the eye. Alternatively, an I-125 interstitial implant can be used with shielding of the cornea and lens. Conjunctival mucosal-associated lymphoid tissue lymphoma can be treated with an anterior electron field with lens shielding and 25–30 Gray (Gy) in 2 Gy fractions. Discrete retinoblastoma (RB), too large for cryotherapy or thermolaser, or recurrent after these modalities, can be treated with plaque therapy, I-125, or Ru-106. For large RB, multiple tumours, or vitreous seeds the whole eye can be treated with an I-125 applicator, sparing the bony orbit, or with EBRT, under anaesthetic, using X-rays or proton therapy with vacuum contact lenses to fix the eyes in the required position. Post-enucleated orbits at risk for recurrent RB can be treated with an I-125 implant with shielding to reduce the dose to the bony orbit. Uveal malignant melanomas can be treated with plaque or proton therapy with excellent local control. Preservation of vision will depend on the initial size and location of the tumour. PMID:23174750

  10. 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.

  11. Indications for Salivary Gland Radiotherapy.

    PubMed

    Thomson, David J; Slevin, Nick J; Mendenhall, William M

    2016-01-01

    There is an established role for post-operative radiotherapy in the treatment of benign and malignant salivary gland tumours. For benign disease, the addition of radiotherapy improves local tumour control in cases with incomplete excision, involved surgical margins or multi-focal disease recurrence. After capsule rupture or spillage alone, surveillance should usually be advised. For malignant disease, post-operative radiotherapy is recommended for an advanced tumour stage, high-grade tumour, perineural or lympho-vascular invasion, close or positive resection margins, extra-parotid extension or lymph node involvement. The main benefit is increased loco-regional tumour control, although this may translate into a modest improvement in survival. The possible late side effects of parotid bed irradiation include skin changes, chronic otitis externa, sensorineural hearing loss, osteoradionecrosis and secondary malignancy. Severe complications are rare, but patients should be counselled carefully about the risks. Primary radiotherapy is unlikely to be curative and is reserved to cases in which resection would cause unacceptable functional or cosmetic morbidity or would likely result in subtotal resection (R2) or to patients with distant metastases to gain local tumour control. There are provisional data on the use of charged particle radiotherapy in this setting. Some patients may benefit from synchronous chemotherapy with radiotherapy, but this group is not defined, and data from comparative prospective studies are required before routine clinical use of this treatment. PMID:27093301

  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. Risk of a Second Malignant Neoplasm After Cancer in Childhood Treated With Radiotherapy: Correlation With the Integral Dose Restricted to the Irradiated Fields

    SciTech Connect

    Nguyen, France Rubino, Carole; Guerin, Sylvie; Diallo, Ibrahima; Samand, Akthar; Hawkins, Mike; Oberlin, Odile; Lefkopoulos, Dimitri; De Vathaire, Florent

    2008-03-01

    Purpose: After successful treatment of cancers in childhood, the occurrence of second malignant neoplasm (SMN) came to the fore. Few studies have considered the relationship between the radiation dose received and the risk of developing an SMN. To take into account the heterogeneity of the dose distribution so as to evaluate the overall risk of an SMN after a childhood cancer, we therefore focused on the integral dose restricted to the irradiated fields. Methods and Materials: The study was performed in a cohort of 4,401 patients who were 3-year survivors of all types of childhood cancer treated between 1947 and 1986 in France and Great Britain. For each patient, the integral dose was estimated for the volume inside the beam edges. Results: We found a significant dose-response relationship between the overall risk of an SMN and the estimated integral dose. The excess relative risk for each incremental unit of the integral dose was only 0.008 in a linear model and 0.017 when a negative exponential term was considered, when adjusted for chemotherapy. The risk of SMN occurrence was 2.6 times higher in the case of irradiation. However among patients who had received radiotherapy, only those who had received the highest integral dose actually had a higher risk. Conclusions: The integral dose in our study cannot be considered as a good predictor of later risks. However other studies with the same study design are obviously needed to evaluate the use of the integral dose as a tool for decision making concerning different radiotherapy techniques.

  15. Radiation dose to the lymph drainage area in esophageal cancer with involved-field irradiation

    PubMed Central

    SHEN, WENBIN; GAO, HONGMEI; ZHU, SHUCHAI; LI, YOUMEI; LI, JUAN; LIU, ZHIKUN; SU, JINWEI

    2016-01-01

    The aim of this study was to quantify the radiation dose to the corresponding lymph drainage area in esophageal cancer using three-dimensional conformal radiation therapy (3D-CRT) with involvED-field IRradiation (IFI) and to analyze associated factors. A retrospective analysis oF 81 patients with esophageal cancer was conducted. According to the location of the lesions, the lymph drainage area was delineated and the dosimetric parameters were calculated. The 1-, 3-, 5- and 8-year survival rates of the patients were 67.90, 33.33, 20.99 and 11.11%, respectively. Based on the dose-volume histogram in the treatment plan, we calculated the volume percentage of the planning target volume including clinically positive lymph nodes (PTV-N) receiving radiation doses of 30, 35, 40, 45 and 50 Gy (VPTV-N30-50). The median values of VPTV-N30-50 were 73, 70, 67, 64 and 58%, respectively. The prescribed dose size exhibited no correlation with VPTV-N30-35, but did exhibit a significant correlation with VPTV-N40-50; the radiation field was not correlated with VPTV-N30-45, but exhibited a significant correlation with VPTV-N50; The length of the lesion on esophageal barium meal X-ray and the PTV were significantly correlated with VPTV-N30–50. The analysis of variance revealed that the VPTV-NX value in the upper thoracic segment was higher compared with that in the middle and lower thoracic segments; VPTV-N30-35 values differed significantly according to the different locations of the lesions, whereas VPTV-N40-50 values exhibited no significant differences. The value of VPTV-NX exerted no significant effect on long-term patient survival. Therefore, the corresponding lymph drainage area of esophageal cancer IS subjected to a certain Radiation dose when patients undergo 3D-CRT with IFI, which may play a role in the prevention of regional nodal metastasis. However, this hypothesis requires confirmation by further clinical studies. PMID:26870295

  16. Para-aortic and pelvic extended-field radiotherapy for advanced-stage uterine cancer: dosimetric and toxicity comparison between the four-field box and intensity-modulated techniques

    PubMed Central

    Rabinovich, A.; Bernard, L.; Ramanakumar, A.V.; Stroian, G.; Gotlieb, W.H.; Lau, S.; Bahoric, B.

    2015-01-01

    Background In patients with advanced-stage endometrial carcinoma (eca), extended-field radiotherapy (efrt) is traditionally delivered by the 3-dimensional conformal (3d-crt) 4-field box technique. In recent years, the use of intensity-modulated radiotherapy (imrt) in gynecologic cancers has increased. We compared the delivery of efrt by the 3d-crt and contemporary imrt techniques. Methods After surgical staging and adjuvant chemotherapy in 38 eca patients, efrt was delivered by either imrt or 3d-crt. Doses to the organs at risk, side effects, and outcomes were compared between the techniques. Results Of the 38 eca patients, 33 were stage iiic, and 5 were stage ivb. In the imrt group, maximal doses to rectum, small intestine, and bladder were significantly higher, and mean dose to bladder was lower (p < 0.0001). Most acute gastrointestinal, genitourinary, and hematologic side effects were grade i or ii and were comparable between the groups. In long-term follow-up, only grade 1 cystitis at 3 months was statistically higher in the imrt patients. No grade iii or iv gastrointestinal or genitourinary toxicities were observed. No statistically significant differences in overall and disease-free survival or recurrence rates were observed between the techniques. Conclusions In advanced eca patients, imrt is a safe and effective technique for delivering efrt to the pelvis and para-aortic region, and it is comparable to the 3d-crt 4-field box technique in both side effects and efficacy. For centres in which imrt is not readily available, 3d-crt is a valid alternative. PMID:26715873

  17. 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

  18. 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…

  19. Field deployment of a scope for growth assay involving Gammarus pulex, a freshwater benthic invertebrate

    SciTech Connect

    Maltby, L.; Naylor, C.; Calow, P. )

    1990-06-01

    Scope for growth (SfG) is a measure of the energy balance of an animal (i.e., the difference between energy intake and metabolic output). The SfG of marine invertebrates, particularly the mussel Mytilus edulis, has been successfully used as the basis of a field bioassay to detect a range of stresses both natural (temperature, food, salinity) and anthropogenic (hydrocarbons, sewage sludge). SfG of the freshwater amphipod Gammarus pulex was found to be a sensitive indicator of stress under laboratory conditions and here we describe the field deployment of this technique and present data from three field trials. In every case, SfG was reduced at the downstream polluted site compared with that at an upstream reference site. This reduction in SfG was the result of a decrease in energy intake (absorption) rather than an increase in energy expenditure (respiration).

  20. 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

  1. [Antalgic radiotherapy in lumbosacral carcinomatous neuropathies].

    PubMed

    Russi, E G; Gaeta, M; Pergolizzi, S; Settineri, N; Frosina, P; De Renzis, C

    1994-06-01

    Lumbosacral carcinomatous neuropathy (LCN) may be caused by infiltration or compression of the lumbosacral plexi and nerves from intrapelvic or paraaortic neoplasms. The authors submitted 23 patients complaining of LCN with CT documented intrapelvic or paraaortic tumors to palliative radiotherapy. Megavoltage external beam irradiation was administered using a 6-MV linear accelerator. Treatment field sizes ranged from 56 cm2 to 235 cm2 (mean: 150.54 cm2) and encompassed only the site where the disease involved the lumbosacral plexus or its branches. > or = 3 Gy/day fractions were used. Twenty-one of 22 assessable patients (95.4%) obtained LCN pain relief; 19 (86.3%) obtained complete LCN pain relief. The median time to pain progression (TPP) was 150 days (range: 39-510 days). The median survival was 165 days. Seven patients were LCN pain-free at death. Two patients are alive and LCN pain-free. The remaining 12 patients had recurrent LCN pain: four of them were reirradiated at the site of previous neuropathy and only two had partial relief again. The authors conclude that it is advisable to submit to palliative radiotherapy the inoperable disseminated and/or recurrent cancer patients complaining of LCN, to use large fractions not to occupy the extant time of their already short life-expectancy, and to design small fields to avoid acute side-effects. PMID:7518934

  2. 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…

  3. 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.

  4. 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

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

    PubMed Central

    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

  6. Radiotherapy for Head and Neck Cancer

    PubMed Central

    Yeh, Shyh-An

    2010-01-01

    Treatment for patients with head and neck cancer requires a multidisciplinary approach. Radiotherapy is employed as a primary treatment or as an adjuvant to surgery. Each specific subsite dictates the appropriate radiotherapy techniques, fields, dose, and fractionation scheme. Quality of life is also an important issue in the management of head and neck cancer. The radiation-related complications have a tremendous impact on the quality of life. Modern radiotherapy techniques, such as intensity-modulated radiotherapy and image-guided radiotherapy, can offer precise radiation delivery and reduce the dose to the surrounding normal tissues without compromise of target coverage. In the future, efforts should be made in the exploration of novel strategies to improve treatment outcome in patients with head and neck cancer. PMID:22550433

  7. 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.

  8. Details of out-field regional recurrence after involved-field irradiation with concurrent chemotherapy for locally advanced esophageal squamous cell carcinoma

    PubMed Central

    Zhang, Xiaoli; Yu, Jinming; Li, Minghuan; Zhu, Hui

    2016-01-01

    Background The purpose of this study was to describe the patterns of out-field regional recurrence after involved-field irradiation (IFI) in definitive concurrent chemoradiotherapy (CCRT) for locally advanced esophageal squamous cell carcinoma (LA-ESCC) and identify the possible risk factors. Patients and methods Eighty patients with LA-ESCC who received CCRT with IFI between January 2003 and January 2009 at the Shandong Cancer Hospital were recruited and analyzed. Imaging scans demonstrating first sites of failure were compared with original computed tomography-based radiation treatment plans, and failure patterns were defined as in-field, outfield regional (failures in initially uninvolved regional nodes), and distant failures. Results After a median follow-up time of 52.6 months, 24 patients had evidence of out-field regional failure, 43 patients had evidence of in-field failure, and 33 patients had the evidence of distant failure. Multivariate analysis revealed that out-field regional failure was associated with clinical tumor status (T4 vs T1–3, odds ratio [OR] =6.547, P=0.002), tumor length (>8 cm vs ≤8 cm, OR =4.130, P=0.036), response to CCRT (complete response vs no complete response, OR =2.646, P=0.035), and in-field failure (no in-field failure vs in-field failure, OR =1.32, P=0.016). Survival analyses indicated that, compared to in-field failure or distant failure alone group, out-field regional failure alone group tended to have longer overall (P=0.006) and progression-free survival (P=0.164). Conclusion Our data suggested that the predominant failure pattern after IFI was not out-field regional failure, which also did not influence survival significantly, and that out-field regional failure did not shorten the time to disease recurrence, which also did not influence survival significantly. In addition, out-field regional failure was likely to appear later than in-field and distant failures. The relatively advanced local disease followed by poor

  9. 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

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. Differential Pro-Inflammatory Responses of Astrocytes and Microglia Involve STAT3 Activation in Response to 1800 MHz Radiofrequency Fields

    PubMed Central

    Lu, Yonghui; He, Mindi; Zhang, Yang; Xu, Shangcheng; Zhang, Lei; He, Yue; Chen, Chunhai; Liu, Chuan; Pi, Huifeng; Yu, Zhengping; Zhou, Zhou

    2014-01-01

    Microglia and astrocytes play important role in maintaining the homeostasis of central nervous system (CNS). Several CNS impacts have been postulated to be associated with radiofrequency (RF) electromagnetic fields exposure. Given the important role of inflammation in neural physiopathologic processes, we investigated the pro-inflammatory responses of microglia and astrocytes and the involved mechanism in response to RF fields. Microglial N9 and astroglial C8-D1A cells were exposed to 1800 MHz RF for different time with or without pretreatment with STAT3 inhibitor. Microglia and astrocytes were activated by RF exposure indicated by up-regulated CD11b and glial fibrillary acidic protein (GFAP). However, RF exposure induced differential pro-inflammatory responses in astrocytes and microglia, characterized by different expression and release profiles of IL-1β, TNF-α, IL-6, PGE2, nitric oxide (NO), inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2). Moreover, the RF exposure activated STAT3 in microglia but not in astrocytes. Furthermore, the STAT3 inhibitor Stattic ameliorated the RF-induced release of pro-inflammatory cytokines in microglia but not in astrocytes. Our results demonstrated that RF exposure differentially induced pro-inflammatory responses in microglia and astrocytes, which involved differential activation of STAT3 in microglia and astrocytes. Our data provide novel insights into the potential mechanisms of the reported CNS impacts associated with mobile phone use and present STAT3 as a promising target to protect humans against increasing RF exposure. PMID:25275372

  16. Conformal Radiotherapy Facilitates the Delivery of Concurrent Chemotherapy and Radiotherapy: A Case of Primitive Neuroectodermal Tumour of the Chest Wall

    PubMed Central

    Twyman, N.; Earl, H. M.; Burnet, N. G.

    2000-01-01

    We illustrate the principle of conformal radiotherapy by discussing the case of a patient with a primitive neuroectodermal tumour of the chest wall. Recent advances in radiotherapy planning enable precise localization of the planning target volume (PTV) and normal organs at risk of irradiation. Customized blocks are subsequently designed to produce a treatment field that ‘conforms’ to the PTV. The use of conformal radiotherapy (CRT) in this case facilitated the delivery of concurrent chemotherapy and radiotherapy by significantly reducing the volume of red marrow irradiated.The lack of acute and late toxicities was attributed to optimal exclusion of normal tissues from the treatment field, made possible by CRT. PMID:18521292

  17. Morbidity and survival patterns in patients after radical hysterectomy and postoperative adjuvant pelvic radiotherapy

    SciTech Connect

    Fiorica, J.V.; Roberts, W.S.; Greenberg, H.; Hoffman, M.S.; LaPolla, J.P.; Cavanagh, D. )

    1990-03-01

    Morbidity and survival patterns were reviewed in 50 patients who underwent radical hysterectomy, pelvic lymphadenectomy, and adjuvant postoperative pelvic radiotherapy for invasive cervical cancer. Ninety percent of the patients were FIGO stage IB, and 10% were clinical stage IIA or IIB. Indications for adjuvant radiotherapy included pelvic lymph node metastasis, large volume, deep stromal penetration, lower uterine segment involvement, or capillary space involvement. Seventy-two percent of the patients had multiple high-risk factors. An average of 4700 cGy of whole-pelvis radiotherapy was administered. Ten percent of the patients suffered major gastrointestinal complications, 14% minor gastrointestinal morbidity, 12% minor genitourinary complications, one patient a lymphocyst, and one patient lymphedema. Of the five patients with major gastrointestinal morbidity, all occurred within 12 months of treatment. Three patients required intestinal bypass surgery for distal ileal obstructions and all are currently doing well and free of disease. All of the patients who developed recurrent disease had multiple, high-risk factors. The median time of recurrence was 12 months. All patients recurred within the radiated field. Actuarial survival was 90% and disease-free survival 87% at 70 months. It is our opinion that the morbidity of postoperative pelvic radiotherapy is acceptable, and benefit may be gained in such a high-risk patient population.

  18. 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. PMID:23121395

  19. [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

  20. Neutrons and charged particles in radiotherapy. Oncology overview

    SciTech Connect

    Not Available

    1984-10-01

    Oncology Overviews are a service of the International Cancer Research Data Bank (ICRDB) Program of the National Cancer Institute, intended to facilitate and promote the exchange of information between cancer scientists by keeping them aware of literature related to their research being published by other laboratories throughout the world. Each Oncology Overview represents a survey of the literature associated with a selected area of cancer research. It contains abstracts of articles which have been selected and organized by researchers associated with the field. Contents: Neutrons and charged particles in radiotherapy of head and neck cancer; Neutrons and charged particles in radiotherapy of central nervous system cancer; Neutrons and charged particles in radiotherapy of digestive cancer; Neutrons and charged particles in radiotherapy of gynecologic cancer; Neutrons and charged particles in radiotherapy of musculoskeletal cancer; Neutrons and charged particles in radiotherapy of other organ site cancer; Neutrons and charged particles in radiotherapy of multiple site cancer; Neutrons and charged particles in radiotherapy--relative biological effectiveness; Neutrons and charged particles in radiotherapy--instrumentation and technology; Neutrons and charged particles in radiotherapy--reviews.

  1. 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

  2. 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

  3. 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

  4. 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).

  5. 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

  6. 3.4 Radiotherapy

    NASA Astrophysics Data System (ADS)

    Kramer, H.-M.; Selbach, H.-J.; Vatnitsky, S.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Section '3.4 Radiotherapy' of the Chapter '3 Dosimetry in Diagnostic Radiology and Radiotherapy' with the contents:

  7. K-12 educator involvement in the Mars Pathfinder field trips in the Channeled Scabland of Washington and Idaho

    NASA Astrophysics Data System (ADS)

    Edgett, Kenneth S.

    2000-03-01

    In September 1995, thirteen K-12 educators were completely immersed in an activity in which they worked with engineers and scientists as they assessed potential hazards and previewed the possible geology of the site that had been selected for the July 1997 landing of Mars Pathfinder. This site, located in the Ares Vallis outflow channel on Mars, was expected to be quite similar to the terrain of the Channeled Scabland of Washington and Idaho. The 13 educators were tasked with bringing their first-hand experience back to their hometowns and sharing what they had learned with local students, colleagues, and families. In addition, the educators helped conduct public outreach and teacher-training activities in the towns encountered during the field trips. For a wider outreach, the trip activities were also documented for television and print media. For many of the 13 educators, their connection to the Mars mission continued for more than two years, and some remain involved with this type of activity today. For some, these events changed the course and/or outlook of their careers. These activities and events can serve as a model for others considering ways to connect educators, children, and communities to high-visibility geoscience research projects.

  8. 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

  9. Data-driven Markov models and their application in the evaluation of adverse events in radiotherapy.

    PubMed

    Abler, Daniel; Kanellopoulos, Vassiliki; Davies, Jim; Dosanjh, Manjit; Jena, Raj; Kirkby, Norman; Peach, Ken

    2013-07-01

    Decision-making processes in medicine rely increasingly on modelling and simulation techniques; they are especially useful when combining evidence from multiple sources. Markov models are frequently used to synthesize the available evidence for such simulation studies, by describing disease and treatment progress, as well as associated factors such as the treatment's effects on a patient's life and the costs to society. When the same decision problem is investigated by multiple stakeholders, differing modelling assumptions are often applied, making synthesis and interpretation of the results difficult. This paper proposes a standardized approach towards the creation of Markov models. It introduces the notion of 'general Markov models', providing a common definition of the Markov models that underlie many similar decision problems, and develops a language for their specification. We demonstrate the application of this language by developing a general Markov model for adverse event analysis in radiotherapy and argue that the proposed method can automate the creation of Markov models from existing data. The approach has the potential to support the radiotherapy community in conducting systematic analyses involving predictive modelling of existing and upcoming radiotherapy data. We expect it to facilitate the application of modelling techniques in medical decision problems beyond the field of radiotherapy, and to improve the comparability of their results. PMID:23824126

  10. Low-Dose Palliative Radiotherapy for Cutaneous B- and T-Cell Lymphomas

    SciTech Connect

    Neelis, Karen J. Schimmel, Erik C.; Vermeer, Maarten H.; Senff, Nancy J.; Willemze, Rein; Noordijk, Evert M.

    2009-05-01

    Purpose: To determine the efficacy of low-dose palliative radiotherapy for both low-grade malignant cutaneous B-cell lymphomas (CBCLs) and cutaneous T-cell lymphomas (mycosis fungoides). Methods and Materials: A total of 18 patients with low-grade CBCL (10 primary cutaneous marginal zone B-cell and 8 primary cutaneous follicle center lymphomas) with 44 symptomatic plaques and tumors underwent low-dose (4 Gy in two fractions) local radiotherapy. A total of 31 patients with mycosis fungoides were treated at 82 symptomatic sites, initially with 4 Gy and later with 8 Gy in two fractions. Results: The complete response rate for CBCL lesions was 72%. Of the 44 B-cell lymphoma lesions, 13 were re-treated to the same site after a median of 6.3 months because of persistent (n = 8) or recurrent (n = 5) symptomatic disease. Of the mycosis fungoides patients treated with 4 Gy in two fractions (17 lesions), 70% failed to respond. Increasing the dose to 8 Gy in two fractions yielded a complete response rate of 92% (60 of 65 lesions). The patients in whom low-dose radiotherapy failed were retreated with 20 Gy in eight fractions. Conclusion: Our results have demonstrated that low-dose involved-field radiotherapy induces a high response rate in both CBCL and cutaneous T-cell lymphoma lesions without any toxicity. Therefore, this treatment is now our standard palliative treatment. At progression, it is safe and feasible to apply greater radiation doses.

  11. Osteoradionecrosis of the Ribs following Breast Radiotherapy

    PubMed Central

    Nicholls, Luke; Gorayski, Peter; Harvey, Jennifer

    2015-01-01

    Introduction Osteoradionecrosis (ORN) of the chest wall is a rare complication after whole-breast radiotherapy (RT). Herein, we report a case of ORN involving the underlying ribs following adjuvant whole-breast RT using standard fractionation and conduct a review of the literature. Case Report A previously well 43-year-old female with right-sided, early-stage, node-negative breast cancer was treated with breast-conserving surgery. She subsequently underwent adjuvant whole-breast RT receiving 50 Gy in 25 fractions over 5 weeks using standard tangential photon fields with 6 MV photons followed by an electron boost of 10 Gy in 5 fractions according to International Commission on Radiation Units (ICRU) requirements. Eleven months after RT, the patient developed right lateral chest wall pain, with magnetic resonance imaging (MRI) demonstrating two fractures involving the underlying right fifth and sixth ribs associated with fatty marrow changes in the second to sixth ribs, thus raising the possibility of ORN. Treatments including hyperbaric oxygen, pentoxifylline and vitamin E were used with symptomatic improvements. There was demonstrable resolution on follow-up MRI at 2.5 years. Conclusion The incidence of ORN utilising modern RT techniques and standard fractionation is rare. Numerous treatments are available, with variable response rates. Emerging evidence of predictive gene profiling to estimate the risk of radiation sensitivity may assist in individualising preventative strategies to mitigate the risk of ORN. PMID:26351442

  12. 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. PMID:25630437

  13. Towards using a Monolithic Active Pixel Sensor for in vivo beam monitoring of Intensity Modulated Radiotherapy

    NASA Astrophysics Data System (ADS)

    Page, R. F.; Abbott, N. L.; Davies, J.; Dyke, E. L.; Randles, H. J.; Velthuis, J. J.; Fletcher, S.; Gregory, S. D.; Hall, C.; John, A.; Lawrence, H.; Stevens, P. H.; Hugtenburg, R. P.; Tunbridge, V.

    2013-12-01

    The use of Intensity Modulated Radiotherapy (IMRT) for cancer treatments is entering wider use. These treatments involve using a complex configuration of field modifying components, known as Multileaf Collimators (MLC), to dynamically shape the beam. A treatment consists of a sequence of irregular shaped fields, which means real time monitoring and verification is essential. In the current framework the treatment plans are verified before the patient is treated, but not during. The aim of our collaboration is to monitor the treatment being given to the patient. This is achieved by placing a camera system using an ultra-thin Monolithic Active Pixel Sensor (MAPS) upstream of the patient.

  14. 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

  15. 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)

  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. 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.

  18. 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.

  19. 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

  20. 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.

  1. Reconstruction of Organ Dose for External Radiotherapy Patients in Retrospective Epidemiologic Studies

    PubMed Central

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

    2015-01-01

    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 Eclipse system 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 Eclipse 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

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

    PubMed

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

    2015-03-21

    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

  3. 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

  4. Radiotherapy of malignant melanoma

    SciTech Connect

    Cooper, J.S.

    1985-04-01

    The role of radiotherapy in the treatment of malignant melanoma is limited, and surgery generally forms the mainstay of medical practice. However, there are some circumstances in which radiotherapy should be considered the treatment of choice. Symptomatic metastatic lesions in bone or brain can effectively be palliated in a substantial proportion of instances. At the current stage of our knowledge, conventionally fractionated treatment of such lesions forms the standard against which other treatments should be measured. In contrast, metastatic lesions to skin or lymph nodes that do not overlie critical normal structures probably are better treated by high-dose-per-fraction techniques. Radiotherapy may play a definitive role in the treatment of lentigo maligna. The precise optimal energy of the beam to be used remains to be defined. Slightly more penetrating radiation appears to be required for lentigo maligna melanomas. Here, too, the optimal energy remains to be defined. The treatment of nonlentigenous melanomas primarily by radiotherapy is unproved in my opinion. Certainly, the data from the Princess Margaret Hospital is exciting, but I believe it must be corroborated by a well-designed trial before it can be accepted without question. Future directions in treatment of malignant melanoma are likely to include further trials of unconventional fractionation and the use of radiosensitizing agents in conjunction with radiotherapy. The time for dermatologists and radiation therapists to cooperate in such studies is at hand.

  5. [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

  6. Absolute dose calculations for Monte Carlo simulations of radiotherapy beams.

    PubMed

    Popescu, I A; Shaw, C P; Zavgorodni, S F; Beckham, W A

    2005-07-21

    Monte Carlo (MC) simulations have traditionally been used for single field relative comparisons with experimental data or commercial treatment planning systems (TPS). However, clinical treatment plans commonly involve more than one field. Since the contribution of each field must be accurately quantified, multiple field MC simulations are only possible by employing absolute dosimetry. Therefore, we have developed a rigorous calibration method that allows the incorporation of monitor units (MU) in MC simulations. This absolute dosimetry formalism can be easily implemented by any BEAMnrc/DOSXYZnrc user, and applies to any configuration of open and blocked fields, including intensity-modulated radiation therapy (IMRT) plans. Our approach involves the relationship between the dose scored in the monitor ionization chamber of a radiotherapy linear accelerator (linac), the number of initial particles incident on the target, and the field size. We found that for a 10 x 10 cm2 field of a 6 MV photon beam, 1 MU corresponds, in our model, to 8.129 x 10(13) +/- 1.0% electrons incident on the target and a total dose of 20.87 cGy +/- 1.0% in the monitor chambers of the virtual linac. We present an extensive experimental verification of our MC results for open and intensity-modulated fields, including a dynamic 7-field IMRT plan simulated on the CT data sets of a cylindrical phantom and of a Rando anthropomorphic phantom, which were validated by measurements using ionization chambers and thermoluminescent dosimeters (TLD). Our simulation results are in excellent agreement with experiment, with percentage differences of less than 2%, in general, demonstrating the accuracy of our Monte Carlo absolute dose calculations. PMID:16177516

  7. Absolute dose calculations for Monte Carlo simulations of radiotherapy beams

    NASA Astrophysics Data System (ADS)

    Popescu, I. A.; Shaw, C. P.; Zavgorodni, S. F.; Beckham, W. A.

    2005-07-01

    Monte Carlo (MC) simulations have traditionally been used for single field relative comparisons with experimental data or commercial treatment planning systems (TPS). However, clinical treatment plans commonly involve more than one field. Since the contribution of each field must be accurately quantified, multiple field MC simulations are only possible by employing absolute dosimetry. Therefore, we have developed a rigorous calibration method that allows the incorporation of monitor units (MU) in MC simulations. This absolute dosimetry formalism can be easily implemented by any BEAMnrc/DOSXYZnrc user, and applies to any configuration of open and blocked fields, including intensity-modulated radiation therapy (IMRT) plans. Our approach involves the relationship between the dose scored in the monitor ionization chamber of a radiotherapy linear accelerator (linac), the number of initial particles incident on the target, and the field size. We found that for a 10 × 10 cm2 field of a 6 MV photon beam, 1 MU corresponds, in our model, to 8.129 × 1013 ± 1.0% electrons incident on the target and a total dose of 20.87 cGy ± 1.0% in the monitor chambers of the virtual linac. We present an extensive experimental verification of our MC results for open and intensity-modulated fields, including a dynamic 7-field IMRT plan simulated on the CT data sets of a cylindrical phantom and of a Rando anthropomorphic phantom, which were validated by measurements using ionization chambers and thermoluminescent dosimeters (TLD). Our simulation results are in excellent agreement with experiment, with percentage differences of less than 2%, in general, demonstrating the accuracy of our Monte Carlo absolute dose calculations.

  8. Enhancing radiotherapy through a greater understanding of homologous recombination

    PubMed Central

    Barker, Christopher A.; Powell, Simon N.

    2016-01-01

    Radiotherapy for the treatment of cancer can cause a wide range of cellular effects, the most biologically potent of which is the double strand break in DNA. The process of repairing DNA double strand breaks involves one of two major mechanisms: non-homologous end-joining or homologous recombination. In this review, we review the molecular mechanisms of homologous recombination, in particular as it relates to the repair of DNA damage from ionizing radiation. We also present specific situations where homologous recombination may be dysfunctional in human cancers, and how this functional abnormality can be recognized. We also discuss the therapeutic opportunities that can be exploited based on deficiencies in homologous recombination at various steps in the DNA repair pathway. Side-by-side with these potential therapeutic opportunities, we review the contemporary clinical trials in which strategies to exploit these defects in homologous recombination can be enhanced by the use of radiotherapy in conjunction with biologically-targeted agents. We conclude that the field of radiation oncology has only scratched the surface of a potentially highly efficacious therapeutic strategy. PMID:20832019

  9. [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

  10. 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.

  11. [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

  12. [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

  13. 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

  14. Radiotherapy for lung cancer

    SciTech Connect

    Bleehen, N.M.; Cox, J.D.

    1985-05-01

    The role of radiation therapy in the management of lung cancer was reviewed at a workshop held in Cambridge, England, in June 1984. It was concluded that there was a continuing role for radiation therapy in the primary management of small cell lung cancer, including the loco-regional treatment for patients with limited disease. Radical radiotherapy for patients with non-small cell carcinoma could be curative for a proportion of patients with limited disease. Careful planning and quality control was essential. Palliative radiotherapy provided useful treatment for many other patients. Other related aspects of treatment are also presented.

  15. 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

  16. The long term follow-up of early stage follicular lymphoma treated with radiotherapy, chemotherapy or combined modality treatment.

    PubMed

    Sancho, Juan-Manuel; García, Olga; Mercadal, Santiago; Pomares, Helena; Fernández-Alvarez, Rubén; González-Barca, Eva; Tapia, Gustavo; González-García, Esther; Moreno, Miriam; Domingo-Domènech, Eva; Sorigué, Marc; Navarro, José-Tomás; Motlló, Cristina; Fernández-de-Sevilla, Alberto; Feliu, Evarist; Ribera, Josep-Maria

    2015-08-01

    Local (involved-field or recently involved-site) radiotherapy is the standard therapy in limited-stage follicular lymphoma (FL). We retrospectively analyzed the value of chemotherapy in 130 patients with limited-stage FL (46 treated with radiotherapy alone [RT group], 30 with radiotherapy plus chemotherapy [COMBINED group] and 43 with chemotherapy alone [CHEMO group], 11 were managed with observation). Ninety-six percent of patients responded (RT 98%, COMBINED 100%, CHEMO 91%, p=0.179), and 37% (40/107) of patients in complete response relapsed (RT 42%, COMBINED 27%, CHEMO 41%, p=0.371). Progression-free survival (PFS) and overall survival (OS) probabilities at 10 years were similar in RT, COMBINED and CHEMO patients (PFS 41%, 61% and 39% [p=0.167], and OS 77%, 81% and 72% [p=0.821], respectively), while the COMBINED group showed a trend to better time-to-progression (TTP 43%, 72% and 47% [p=0.055]). On multivariate analysis, only a FLIPI score ≥2 showed a trend to influence PFS (HR 2.1 [95% confidence interval 0.9-4.6], p=0.067), and OS (HR 2.4 [0.9-6.5], p=0.084), while patients treated with radiotherapy plus chemotherapy (COMBINED group) showed a significantly better TTP compared with those receiving only RT (HR 0.3 [0.1-0.8], p=0.024). In our study no benefit was observed in survival with the use of systemic therapy compared with local radiotherapy. PMID:26122511

  17. 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

  18. 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.

  19. 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

  20. Biological dose volume histograms during conformal hypofractionated accelerated radiotherapy for prostate cancer

    SciTech Connect

    Koukourakis, Michael I.; Abatzoglou, Ioannis; Touloupidis, Stavros; Manavis, Ioannis

    2007-01-15

    Radiobiological data suggest that prostate cancer has a low {alpha}/{beta} ratio. Large radiotherapy fractions may, therefore, prove more efficacious than standard radiotherapy, while radiotherapy acceleration should further improve control rates. This study describes the radiobiology of a conformal hypofractionated accelerated radiotherapy scheme for the treatment of high risk prostate cancer. Anteroposterior fields to the pelvis deliver a daily dose of 2.7 Gy, while lateral fields confined to the prostate and seminal vesicles deliver an additional daily dose of 0.7 Gy. Radiotherapy is accomplished within 19 days (15 fractions). Dose volume histograms, calculated for tissue specific {alpha}/{beta} ratios and time factors, predict a high biological dose to the prostate and seminal vesicles (77-93 Gy). The biological dose to normal pelvic tissues is maintained at standard levels. Radiobiological dosimetry suggests that, using hypofractionated and accelerated radiotherapy, high biological radiation dose can be given to the prostate without overdosing normal tissues.

  1. 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

  2. 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

  3. Volumetric-modulated arc therapy (RapidArc) vs. conventional fixed-field intensity-modulated radiotherapy for {sup 18}F-FDG-PET-guided dose escalation in oropharyngeal cancer: A planning study

    SciTech Connect

    Teoh, May; Beveridge, Sabeena; Wood, Katie; Whitaker, Stephen; Adams, Elizabeth; Rickard, Donna; Jordan, Tom; Nisbet, Andrew; Clark, Catharine H.

    2013-04-01

    Fluorine-18-fluorodeoxyglucose-positron emission tomography ({sup 18}F-FDG-PET)–guided focal dose escalation in oropharyngeal cancer may potentially improve local control. We evaluated the feasibility of this approach using volumetric-modulated arc therapy (RapidArc) and compared these plans with fixed-field intensity-modulated radiotherapy (IMRT) focal dose escalation plans. Materials and methods: An initial study of 20 patients compared RapidArc with fixed-field IMRT using standard dose prescriptions. From this cohort, 10 were included in a dose escalation planning study. Dose escalation was applied to {sup 18}F-FDG-PET–positive regions in the primary tumor at dose levels of 5% (DL1), 10% (DL2), and 15% (DL3) above standard radical dose (65 Gy in 30 fractions). Fixed-field IMRT and double-arc RapidArc plans were generated for each dataset. Dose-volume histograms were used for plan evaluation and comparison. The Paddick conformity index (CI{sub Paddick}) and monitor units (MU) for each plan were recorded and compared. Both IMRT and RapidArc produced clinically acceptable plans and achieved planning objectives for target volumes. Dose conformity was significantly better in the RapidArc plans, with lower CI{sub Paddick} scores in both primary (PTV1) and elective (PTV2) planning target volumes (largest difference in PTV1 at DL3; 0.81 ± 0.03 [RapidArc] vs. 0.77 ± 0.07 [IMRT], p = 0.04). Maximum dose constraints for spinal cord and brainstem were not exceeded in both RapidArc and IMRT plans, but mean doses were higher with RapidArc (by 2.7 ± 1 Gy for spinal cord and 1.9 ± 1 Gy for brainstem). Contralateral parotid mean dose was lower with RapidArc, which was statistically significant at DL1 (29.0 vs. 29.9 Gy, p = 0.01) and DL2 (29.3 vs. 30.3 Gy, p = 0.03). MU were reduced by 39.8–49.2% with RapidArc (largest difference at DL3, 641 ± 94 vs. 1261 ± 118, p < 0.01). {sup 18}F-FDG-PET–guided focal dose escalation in oropharyngeal cancer is feasible with Rapid

  4. 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

  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. [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

  7. Esophageal perforation during or after conformal radiotherapy for esophageal carcinoma

    PubMed Central

    Chen, Hai-yan; Ma, Xiu-mei; Ye, Ming; Hou, Yan-li; Xie, Hua-Ying; Bai, Yong-rui

    2014-01-01

    The aim of this study was to analyze the risk factors and prognosis for patients with esophageal perforation occurring during or after radiotherapy for esophageal carcinoma. We retrospectively analyzed 322 patients with esophageal carcinoma. These patients received radiotherapy for unresectable esophageal tumors, residual tumors after operation, or local recurrence. Of these, 12 had radiotherapy to the esophagus before being admitted, 68 patients had concurrent chemoradiotherapy (CRT), and 18 patients had esophageal perforation after RT (5.8%). Covered self-expandable metallic stents were placed in 11 patients. Two patients continued RT after stenting and control of infection; one of these suffered a new perforation, and the other had a massive hemorrhage. The median overall survival was 2 months (0–3 months) compared with 17 months in the non-perforation group. In univariate analysis, the Karnofsky performance status (KPS) being ≤70, age younger than 60, T4 stage, a second course of radiotherapy to the esophagus, extracapsular lymph nodes (LN) involving the esophagus, a total dose >100 Gy (biologically effective dose−10), and CRT were risk factors for perforation. In multivariate analysis, age younger than 60, extracapsular LN involving the esophagus, T4 stage, and a second course of radiotherapy to the esophagus were risk factors. In conclusion, patients with T4 stage, extracapsular LN involving the esophagus, and those receiving a second course of RT should be given particular care to avoid perforation. The prognosis after perforation was poor. PMID:24914102

  8. [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

  9. Measurement of neutron ambient dose equivalent in passive carbon-ion and proton radiotherapies

    SciTech Connect

    Yonai, Shunsuke; Matsufuji, Naruhiro; Kanai, Tatsuaki; Matsui, Yuki; Matsushita, Kaoru; Yamashita, Haruo; Numano, Masumi; Sakae, Takeji; Terunuma, Toshiyuki; Nishio, Teiji; Kohno, Ryosuke; Akagi, Takashi

    2008-11-15

    Secondary neutron ambient dose equivalents per the treatment absorbed dose in passive carbon-ion and proton radiotherapies were measured using a rem meter, WENDI-II at two carbon-ion radiotherapy facilities and four proton radiotherapy facilities in Japan. Our measured results showed that (1) neutron ambient dose equivalent in carbon-ion radiotherapy is lower than that in proton radiotherapy, and (2) the difference to the measured neutron ambient dose equivalents among the facilities is within a factor of 3 depending on the operational beam setting used at the facility and the arrangement of the beam line, regardless of the method for making a laterally uniform irradiation field: the double scattering method or the single-ring wobbling method. The reoptimization of the beam line in passive particle radiotherapy is an effective way to reduce the risk of secondary cancer because installing an adjustable precollimator and designing the beam line devices with consideration of their material, thickness and location, etc., can significantly reduce the neutron exposure. It was also found that the neutron ambient dose equivalent in passive particle radiotherapy is equal to or less than that in the photon radiotherapy. This result means that not only scanning particle radiotherapy but also passive particle radiotherapy can provide reduced exposure to normal tissues around the target volume without an accompanied increase in total body dose.

  10. 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

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. [Stereotactic radiotherapy in brain metastases].

    PubMed

    Dhermain, F; Reyns, N; Colin, P; Métellus, P; Mornex, F; Noël, G

    2015-02-01

    Stereotactic radiotherapy of brain metastases is increasingly proposed after polydisciplinary debates among experts. Its definition and modalities of prescription, indications and clinical interest regarding the balance between efficacy versus toxicity need to be discussed. Stereotactic radiotherapy is a 'high precision' irradiation technique (within 1mm), using different machines (with invasive contention or frameless, photons X or gamma) delivering high doses (4 to 25Gy) in a limited number of fractions (usually 1 to 5, ten maximum) with a high dose gradient. Dose prescription will depend on materials, dose constraints to organs at risk varying with fractionation. Stereotactic radiotherapy may be proposed: (1) in combination with whole brain radiotherapy with the goal of increasing (modestly) overall survival of patients with a good performance status, 1 to 3 brain metastases and a controlled extracranial disease; (2) for recurrence of 1-3 brain metastases after whole brain radiotherapy; (3) after complete resection of a large and/or symptomatic brain metastases; (4) after diagnosis of 3-5 asymptomatic new or progressing brain metastases during systemic therapy, with the aim of delaying whole brain radiotherapy (avoiding its potential neurotoxicity) and maintaining a high focal control rate. Only a strict follow-up with clinical and MRI every 3 months will permit to deliver iterative stereotactic radiotherapies without jeopardizing survival. Simultaneous delivering of stereotactic radiotherapy with targeted medicines should be carefully discussed. PMID:25640215

  17. 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

  18. 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.

  19. 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

  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. 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.

  2. Whole body radiotherapy: A TBI-guideline

    PubMed Central

    Quast, Ulrich

    2006-01-01

    Total Body Irradiation (TBI) is one main component in the interdisciplinary treatment of widely disseminated malignancies predominantly of haematopoietic diseases. Combined with intensive chemotherapy, TBI enables myeloablative high dose therapy and immuno-ablative conditioning treatment prior to subsequent transplantation of haematopoietic stem cells: bone marrow stem cells or peripheral blood progenitor stem cells. Jointly prepared by DEGRO and DGMP, the German Society of Radio-Oncology, and the German Association of Medical Physicists, this DEGRO/DGMP-Leitlinie Ganzkoerper-Strahlenbehandlung - DEGRO/DGMP Guideline Whole Body Radiotherapy, summarises the concepts, principles, facts and common methods of Total Body Irradiation and poses a set of recommendations for reliable and successful application of high dose large-field radiotherapy as essential part of this interdisciplinary, multi-modality treatment concept. The guideline is geared towards radio-oncologists, medical physicists, haematooncolo-gists, and all contributing to Whole Body Radiotherapy. To guide centres intending to start or actualise TBI criteria are included. The relevant treatment parameters are defined and a sample of a form is given for reporting TBI to international registries. PMID:21206634

  3. 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

  4. 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

  5. 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

  6. 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.

  7. Gene network and familial analyses uncover a gene network involving Tbx5/Osr1/Pcsk6 interaction in the second heart field for atrial septation.

    PubMed

    Zhang, Ke K; Xiang, Menglan; Zhou, Lun; Liu, Jielin; Curry, Nathan; Heine Suñer, Damian; Garcia-Pavia, Pablo; Zhang, Xiaohua; Wang, Qin; Xie, Linglin

    2016-03-15

    Atrial septal defects (ASDs) are a common human congenital heart disease (CHD) that can be induced by genetic abnormalities. Our previous studies have demonstrated a genetic interaction between Tbx5 and Osr1 in the second heart field (SHF) for atrial septation. We hypothesized that Osr1 and Tbx5 share a common signaling networking and downstream targets for atrial septation. To identify this molecular networks, we acquired the RNA-Seq transcriptome data from the posterior SHF of wild-type, Tbx5(+/) (-), Osr1(+/-), Osr1(-/-) and Tbx5(+/-)/Osr1(+/-) mutant embryos. Gene set analysis was used to identify the Kyoto Encyclopedia of Genes and Genomes pathways that were affected by the doses of Tbx5 and Osr1. A gene network module involving Tbx5 and Osr1 was identified using a non-parametric distance metric, distance correlation. A subset of 10 core genes and gene-gene interactions in the network module were validated by gene expression alterations in posterior second heart field (pSHF) of Tbx5 and Osr1 transgenic mouse embryos, a time-course gene expression change during P19CL6 cell differentiation. Pcsk6 was one of the network module genes that were linked to Tbx5. We validated the direct regulation of Tbx5 on Pcsk6 using immunohistochemical staining of pSHF, ChIP-quantitative polymerase chain reaction and luciferase reporter assay. Importantly, we identified Pcsk6 as a novel gene associated with ASD via a human genotyping study of an ASD family. In summary, our study implicated a gene network involving Tbx5, Osr1 and Pcsk6 interaction in SHF for atrial septation, providing a molecular framework for understanding the role of Tbx5 in CHD ontogeny. PMID:26744331

  8. A binary AxB1-x ionic alkaline pseudocapacitor system involving manganese, iron, cobalt, and nickel: formation of electroactive colloids via in situ electric field assisted coprecipitation

    NASA Astrophysics Data System (ADS)

    Chen, Kunfeng; Yin, Shu; Xue, Dongfeng

    2014-12-01

    A new ``combinatorial transition-metal cation pseudocapacitor'' was demonstrated by designing combinatorial transition-metal cation pseudocapacitors with binary AxB1-x salt electrodes involving manganese, iron, cobalt, and nickel cations in an alkaline aqueous electrolyte. Binary multi-valence cations were crystallized in the colloidal state through an in situ coprecipitation under an electric field. These electroactive colloids absorbed by carbon black and the PVDF matrix are highly redox-reactive with high specific capacitance values, where the specific electrode configuration can create short ion diffusion paths to enable fast and reversible Faradaic reactions. This work shows huge promise for developing high-performance electrical energy storage systems via designing the colloidal state of electroactive cations. Multiple redox cations in the colloidal state can show high redox activities, making them more suitable for potential application in pseudocapacitor systems.A new ``combinatorial transition-metal cation pseudocapacitor'' was demonstrated by designing combinatorial transition-metal cation pseudocapacitors with binary AxB1-x salt electrodes involving manganese, iron, cobalt, and nickel cations in an alkaline aqueous electrolyte. Binary multi-valence cations were crystallized in the colloidal state through an in situ coprecipitation under an electric field. These electroactive colloids absorbed by carbon black and the PVDF matrix are highly redox-reactive with high specific capacitance values, where the specific electrode configuration can create short ion diffusion paths to enable fast and reversible Faradaic reactions. This work shows huge promise for developing high-performance electrical energy storage systems via designing the colloidal state of electroactive cations. Multiple redox cations in the colloidal state can show high redox activities, making them more suitable for potential application in pseudocapacitor systems. Electronic supplementary

  9. Genetics and genomics of radiotherapy toxicity: towards prediction

    PubMed Central

    2011-01-01

    Radiotherapy is involved in many curative treatments of cancer; millions of survivors live with the consequences of treatment, and toxicity in a minority limits the radiation doses that can be safely prescribed to the majority. Radiogenomics is the whole genome application of radiogenetics, which studies the influence of genetic variation on radiation response. Work in the area focuses on uncovering the underlying genetic causes of individual variation in sensitivity to radiation, which is important for effective, safe treatment. In this review, we highlight recent advances in radiotherapy and discuss results from four genome-wide studies of radiotoxicity. PMID:21861849

  10. Evaluation of intra- and inter-fraction motion in breast radiotherapy using electronic portal cine imaging.

    PubMed

    Kron, T; Lee, C; Perera, F; Yu, E

    2004-10-01

    Breast irradiation is one of the most challenging problems in radiotherapy due to the complex shape of the target volume, proximity of radiation sensitive normal structures and breathing motion. It was the aim of the present study to use electronic portal imaging (EPI) during treatment to determine intra- and inter-fraction motion in patients undergoing radiotherapy and to correlate the magnitude of motion with patient specific parameters. EPI cine images were acquired from the medial tangential fields of twenty radiotherapy patients on a minimum of 5 days each over the course of their treatment. The treatments were administered using 10 MV X-rays and dynamic wedges on a Varian Clinac 2100CD linear accelerator. Depending on the incident dose and the angle of the wedge, between 4 and 16 images could be acquired in one session using an EPI device based on liquid ionization chambers (Varian). The border between lung and chest-wall could be easily detected in all images and quantitative measurements were taken for the amount of lung in the field and the distance of the breast tissue from the field edges. Inter-fraction variability was found to be about twice as large as intra-fraction variability. The largest variability was detected in cranio/caudal direction (intra-fraction: 1.3 +/- 0.4 mm; inter-fraction: 2.6 +/- 1.3 mm) while the lung involvement varied by 1.1 +/- 0.2 mm and 1.8 +/- 0.6 mm intra- and inter-fraction, respectively. This indicates that the effect of breathing motion on the amount of radiated lung was not of major concern in the patients studied. Of other patient specific parameters such as body weight, breast separation, field size and location of the target, only increasing age was significantly correlated with larger inter-fraction motion. Acquisition of EPI cine loops proved to be a quick and easy technique to establish the amount of patient movement during breast radiotherapy. The relatively small variability found in the present pilot study

  11. Sequential DICE combined with l-asparaginase chemotherapy followed by involved field radiation in newly diagnosed, stage IE to IIE, nasal and extranodal NK/T-cell lymphoma.

    PubMed

    Dong, Li-Hua; Zhang, Li-Juan; Wang, Wen-Jia; Lei, Wen; Sun, Xing; Du, Jian-Wei; Gao, Xue; Li, Gang-Ping; Li, Yu-Fu

    2016-07-01

    Extranodal natural killer (NK)/T-cell lymphoma is an aggressive lymphoid tumor. Optimal treatment strategies have not yet been fully defined. To explore a more effective treatment, we conducted sequential chemoradiotherapy (SCRT) and evaluated the safety and efficacy. Seventy-eight patients (51 males, 27 females) were analyzed. The complete response (CR) rate was higher for patients in the SCRT group (90.9%) than in the radiotherapy group (77.8%; p = 0.124). The relapse rate (RR) and death rate (DR) were lower in the SCRT group (RR: 6.7% vs 33.3%, p < 0.001; DR: 15.2% vs. 55.6%, p < 0.001). Progression-free survival (PFS) and overall survival (OS) rates of 5 years after diagnosis were significantly higher for patients in the SCRT group (PFS: 89%; OS: 82%) than in the radiotherapy group (PFS: 49%, p < 0.001; OS: 49%, p < 0.001). Treatment-related adverse events were more common in the SCRT group. However, the adverse events were controlled. PMID:26726970

  12. 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.

  13. Dynamic targeting image-guided radiotherapy

    SciTech Connect

    Huntzinger, Calvin; Munro, Peter; Johnson, Scott; Miettinen, Mika; Zankowski, Corey; Ahlstrom, Greg; Glettig, Reto; Filliberti, Reto; Kaissl, Wolfgang; Kamber, Martin; Amstutz, Martin; Bouchet, Lionel; Klebanov, Dan; Mostafavi, Hassan; Stark, Richard

    2006-07-01

    Volumetric imaging and planning for 3-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) have highlighted the need to the oncology community to better understand the geometric uncertainties inherent in the radiotherapy delivery process, including setup error (interfraction) as well as organ motion during treatment (intrafraction). This has ushered in the development of emerging technologies and clinical processes, collectively referred to as image-guided radiotherapy (IGRT). The goal of IGRT is to provide the tools needed to manage both inter- and intrafraction motion to improve the accuracy of treatment delivery. Like IMRT, IGRT is a process involving all steps in the radiotherapy treatment process, including patient immobilization, computed tomogaphy (CT) simulation, treatment planning, plan verification, patient setup verification and correction, delivery, and quality assurance. The technology and capability of the Dynamic Targeting{sup TM} IGRT system developed by Varian Medical Systems is presented. The core of this system is a Clinac (registered) or Trilogy{sup TM} accelerator equipped with a gantry-mounted imaging system known as the On-Board Imager{sup TM} (OBI). This includes a kilovoltage (kV) x-ray source, an amorphous silicon kV digital image detector, and 2 robotic arms that independently position the kV source and imager orthogonal to the treatment beam. A similar robotic arm positions the PortalVision{sup TM} megavoltage (MV) portal digital image detector, allowing both to be used in concert. The system is designed to support a variety of imaging modalities. The following applications and how they fit in the overall clinical process are described: kV and MV planar radiographic imaging for patient repositioning, kV volumetric cone beam CT imaging for patient repositioning, and kV planar fluoroscopic imaging for gating verification. Achieving image-guided motion management throughout the radiation oncology process

  14. Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy

    PubMed Central

    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. 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

  16. Radiotherapy planning using MRI

    NASA Astrophysics Data System (ADS)

    Schmidt, Maria A.; Payne, Geoffrey S.

    2015-11-01

    The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.

  17. [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

  18. Gangliogliomas involving the optic chiasm.

    PubMed

    Liu, G T; Galetta, S L; Rorke, L B; Bilaniuk, L T; Vojta, D D; Molloy, P T; Phillips, P C; Needle, M; Duhaime, A C; Sutton, L N; Volpe, N J

    1996-06-01

    We report three patients with gangliogliomas involving the optic chiasm via distinct mechanisms. The ganglioglioma in one patient likely originated in the temporal lobe and spread medially to involve the chiasm, and diffuse spinal cord dissemination also occurred. Chiasmal involvement in this manner and dissemination at presentation are unusual for gangliogliomas. The tumor in a second patient was intrinsic to the hypothalmus and chiasm, while in the third patient, it involved both optic tracts, and a cyst compressed the chiasm laterally. Two patients developed severe bilateral visual loss, while the other had a stable bitemporal hemianopsia. Two patients received radiotherapy, but one continued to lose vision. Although gangliogliomas rarely involve chiasm, the mechanisms by which they produce chiasmal visual loss may be diverse, and the long-term visual prognosis is variable. PMID:8649567

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. The potential of radiotherapy to enhance the efficacy of renal cell carcinoma therapy

    PubMed Central

    De Wolf, Katrien; Vermaelen, Karim; De Meerleer, Gert; Lambrecht, Bart N; Ost, Piet

    2015-01-01

    Renal cell carcinoma (RCC) is an immunogenic tumor, but uses several immune-suppressive mechanisms to shift the balance from tumor immune response toward tumor growth. Although RCC has traditionally been considered to be radiation resistant, recent evidence suggests that hypofractionated radiotherapy contributes to systemic antitumor immunity. Because the efficacy of antitumor immune responses depends on the complex balance between diverse immune cells and progressing tumor cells, radiotherapy alone is unlikely to induce persistent antitumor immunity. Therefore, the combination of radiotherapy with drugs having synergistic immunomodulatory properties holds great promise with the optimal timing and sequence of modalities depending on the agent used. We highlight the immunomodulatory properties of targeted therapies, such as tyrosine kinase inhibitors, mammalian target of rapamycin (mTOR) inhibitors and vascular endothelial growth factor (VEGF) neutralizing antibodies, and will suggest a combination schedule with radiotherapy based on the available literature. We also address the combination of radiotherapy with innovative treatments in the field of immunotherapy. PMID:26464810

  4. Modeling the risk of secondary malignancies after radiotherapy.

    PubMed

    Schneider, Uwe

    2011-01-01

    In developed countries, more than half of all cancer patients receive radiotherapy at some stage in the management of their disease. However, a radiation-induced secondary malignancy can be the price of success if the primary cancer is cured or at least controlled. Therefore, there is increasing concern regarding radiation-related second cancer risks in long-term radiotherapy survivors and a corresponding need to be able to predict cancer risks at high radiation doses. Of particular interest are second cancer risk estimates for new radiation treatment modalities such as intensity modulated radiotherapy, intensity modulated arc-therapy, proton and heavy ion radiotherapy. The long term risks from such modern radiotherapy treatment techniques have not yet been determined and are unlikely to become apparent for many years, due to the long latency time for solid tumor induction. Most information on the dose-response of radiation-induced cancer is derived from data on the A-bomb survivors who were exposed to γ-rays and neutrons. Since, for radiation protection purposes, the dose span of main interest is between zero and one Gy, the analysis of the A-bomb survivors is usually focused on this range. With increasing cure rates, estimates of cancer risk for doses larger than one Gy are becoming more important for radiotherapy patients. Therefore in this review, emphasis was placed on doses relevant for radiotherapy with respect to radiation induced solid cancer. Simple radiation protection models should be used only with extreme care for risk estimates in radiotherapy, since they are developed exclusively for low dose. When applied to scatter radiation, such models can predict only a fraction of observed second malignancies. Better semi-empirical models include the effect of dose fractionation and represent the dose-response relationships more accurately. The involved uncertainties are still huge for most of the organs and tissues. A major reason for this is that the

  5. CHOP-VP16 chemotherapy and involved field irradiation for high grade non-Hodgkin's lymphomas: a phase II multicentre study.

    PubMed Central

    Köppler, H.; Pflüger, K. H.; Eschenbach, I.; Pfab, R.; Lennert, K.; Wellens, W.; Schmidt, M.; Gassel, W. D.; Kolb, T.; Hässler, R.

    1989-01-01

    Sixty previously untreated patients with high grade non-Hodgkin's lymphomas stages II-IV received cyclophosphamide 750 mg m2 i.v., doxorubicin 50 mg m2 i.v., and vincristine 2 mg i.v. on day 1, prednisolone 100 mg p.o. on days 1-5 and etoposide 100 mg m2 i.v. on days 3-5 (CHOP-VP16). After four courses an involved field irradiation with a total dose of 25 Gy was employed and followed by two additional courses of CHOP-VP16. The overall response rate was 93%, with 49 patients (82%) achieving a complete remission (CR). Seven patients had a partial response and four patients showed no response. During a median follow-up period of 55 months, 22 of the 49 patients with CR relapsed, seven of them achieving a second complete remission with the same drug regimen. A maintained complete remission of up to 68 months was seen in 55% of all patients initially achieving CR. The median survival is 43 months. Mean side-effects of this drug regimen were alopecia (89%), nausea/vomiting (76%) and leukopenia (61%). No therapy-related deaths were seen. The results of this study demonstrate that this combined modality treatment produces high complete remission rates and that more than half of these patients achieve long-term disease-free survival. PMID:2679846

  6. Neurobehavioral and neurometabolic (SPECT) correlates of paranormal information: involvement of the right hemisphere and its sensitivity to weak complex magnetic fields.

    PubMed

    Roll, W G; Persinger, M A; Webster, D L; Tiller, S G; Cook, C M

    2002-02-01

    Experiments were designed to help elucidate the neurophysiological correlates for the experiences reported by Sean Harribance. For most of his life he has routinely experienced "flashes of images" of objects that were hidden and of accurate personal information concerning people with whom he was not familiar. The specificity of details for target pictures of people was correlated positively with the proportion of occipital alpha activity. Results from a complete neuropsychological assessment, Single Photon Emission Computed Tomography (SPECT), and screening electroencephalography suggested that his experiences were associated with increased activity within the parietal lobe and occipital regions of the right hemisphere. Sensed presences (subjectively localized to his left side) were evoked when weak, magnetic fields, whose temporal structure simulated long-term potentiation in the hippocampus, were applied over his right temporoparietal lobes. These results suggest that the phenomena attributed to paranormal or "extrasensory" processes are correlated quantitatively with morphological and functional anomalies involving the right parietotemporal cortices (or its thalamic inputs) and the hippocampal formation. PMID:12325407

  7. 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

  8. 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.

  9. 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

  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.