Science.gov

Sample records for involved field radiotherapy

  1. 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.

  2. Upfront Chemotherapy and Involved-Field Radiotherapy Results in More Relapses Than Extended Radiotherapy for Intracranial Germinomas: Modification in Radiotherapy Volume Might Be Needed

    SciTech Connect

    Eom, Keun-Yong; Kim, Il Han Park, Charn Il; Kim, Hak Jae; Kim, Jin Ho.; Kim, Kyubo; Kim, Seung Ki; Wang, Kyu-Chang; Cho, Byung-Gyu; Jung, Hee-Won; Heo, Dae Seog; Kang, Hyoung Jin; Shin, Hee Young; Ahn, Hyo Seop

    2008-07-01

    Purpose: To retrospectively compare the outcome of upfront chemotherapy plus radiotherapy (CRT) and the outcome of the use of extended radiotherapy (RT) only for intracranial germinoma. Methods and Materials: Of 81 patients with tissue-confirmed intracranial germinoma, 42 underwent CRT and 39 underwent RT only. For CRT, one to five cycles of upfront chemotherapy was followed by involved-field or extended-field RT, for which the dose was dependent on the M stage. For RT only, all 39 patients underwent craniospinal RT alone. The median follow-up was 68 months. Results: The 5- and 10-year overall survival rate was 100% and 92.5% for RT alone and 92.9% and 92.9% for CRT, respectively. The 5-year recurrence-free survival rate was 100.0% for RT and 88.1% for CRT (p = 0.0279). No recurrences developed in patients given RT, but four relapses developed in patients who had received CRT-three in the brain and one in the spine. Only one patient achieved complete remission from salvage treatment. The proportion of patients requiring hormonal replacement was greater for patients who received RT than for those who had received CRT (p = 0.0106). Conclusions: The results of our study have shown that the better quality of life provided by CRT was compensated for by the greater rate of relapse. The possible benefit of including the ventricles in involved-field RT after upfront chemotherapy, specifically for patients with initial negative seeding, should be addressed in a prospective study.

  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. Involved field radiotherapy for limited stage Hodgkin lymphoma: balancing treatment efficacy against long-term toxicities.

    PubMed

    Goda, Jayant S; Tsang, Richard W

    2009-09-01

    Limited stage Hodgkin lymphoma (HL) refers to patients with stage IA or IIA disease in the absence of any bulky mass or unfavourable prognostic factors. In this group, the long-term disease control with treatment can be expected in more than 90%, and management has now been directed to make strategies to reduce late morbidities related to therapy. With the advent of very effective chemotherapy, the role of radiation therapy has evolved from a first line single modality treatment, to an adjuvant therapy following brief cycles of chemotherapy. Optimal radiation volume and dose parameters have been refined in the combined modality setting. Furthermore, with the progress in diagnostic functional imaging and advances in radiotherapy, it is possible to accurately deliver low to moderate doses of radiation to defined regions resulting in durable control of disease. This review will evaluate the literature that shapes the current standard of care in limited stage Hodgkin lymphoma with special emphasis on the use of limited field radiotherapy.

  7. 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.

  8. Treatment of limited stage follicular lymphoma with Rituximab immunotherapy and involved field radiotherapy in a prospective multicenter Phase II trial-MIR trial

    PubMed Central

    2011-01-01

    Background The optimal treatment of early stage follicular Lymphoma is a matter of debate. Radiation therapy has frequently been applied with a curative approach beside watchful waiting. Involved field, extended field and total nodal radiation techniques are used in various protocols, but the optimal radiation field still has to be defined. Follicular lymphoma is characterized by stable expression of the CD20 antigen on the tumour cells surface. The anti CD20 antibody Rituximab (Mabthera®) has shown to be effective in systemic therapy of FL in primary treatment, relapse and maintenance therapy. Methods/design The MIR (Mabthera® and Involved field Radiation) study is a prospective multicenter trial combining systemic treatment with the anti CD20 antibody Rituximab (Mabthera®) in combination with involved field radiotherapy (30 - 40 Gy). This trial aims at testing the combination's efficacy and safety with an accrual of 85 patients. Primary endpoint of the study is progression free survival. Secondary endpoints are response rate to Rituximab, complete remission rate at week 18, relapse rate, relapse pattern, relapse free survival, overall survival, toxicity and quality of life. Discussion The trial evaluates the efficacy of Rituximab to prevent out-filed recurrences in early stage nodal follicular lymphoma and the safety of the combination of Rituximab and involved field radiotherapy. It also might show additional risk factors for a later recurrence (e.g. remission state after Rituximab only). Trial Registration ClinicalTrials (NCT): NCT00509184 PMID:21352561

  9. 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

  10. A comparison of mantle versus involved-field radiotherapy for Hodgkin's lymphoma: reduction in normal tissue dose and second cancer risk

    PubMed Central

    Koh, Eng-Siew; Tran, Tu Huan; Heydarian, Mostafa; Sachs, Rainer K; Tsang, Richard W; Brenner, David J; Pintilie, Melania; Xu, Tony; Chung, June; Paul, Narinder; Hodgson, David C

    2007-01-01

    Background Hodgkin's lymphoma (HL) survivors who undergo radiotherapy experience increased risks of second cancers (SC) and cardiac sequelae. To reduce such risks, extended-field radiotherapy (RT) for HL has largely been replaced by involved field radiotherapy (IFRT). While it has generally been assumed that IFRT will reduce SC risks, there are few data that quantify the reduction in dose to normal tissues associated with modern RT practice for patients with mediastinal HL, and no estimates of the expected reduction in SC risk. Methods Organ-specific dose-volume histograms (DVH) were generated for 41 patients receiving 35 Gy mantle RT, 35 Gy IFRT, or 20 Gy IFRT, and integrated organ mean doses were compared for the three protocols. Organ-specific SC risk estimates were estimated using a dosimetric risk-modeling approach, analyzing DVH data with quantitative, mechanistic models of radiation-induced cancer. Results Dose reductions resulted in corresponding reductions in predicted excess relative risks (ERR) for SC induction. Moving from 35 Gy mantle RT to 35 Gy IFRT reduces predicted ERR for female breast and lung cancer by approximately 65%, and for male lung cancer by approximately 35%; moving from 35 Gy IFRT to 20 Gy IFRT reduces predicted ERRs approximately 40% more. The median reduction in integral dose to the whole heart with the transition to 35 Gy IFRT was 35%, with a smaller (2%) reduction in dose to proximal coronary arteries. There was no significant reduction in thyroid dose. Conclusion The significant decreases estimated for radiation-induced SC risks associated with modern IFRT provide strong support for the use of IFRT to reduce the late effects of treatment. The approach employed here can provide new insight into the risks associated with contemporary IFRT for HL, and may facilitate the counseling of patients regarding the risks associated with this treatment. PMID:17362522

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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.

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

    SciTech Connect

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

    2008-08-01

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

  20. 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.

  1. Treatment planning and delivery of involved field radiotherapy in advanced Hodgkin's disease: results from a questionnaire-based audit for the UK Stanford V regimen vs ABVD clinical trial quality assurance programme (ISRCTN 64141244).

    PubMed

    Diez, P; Hoskin, P J; Aird, E G A

    2007-10-01

    This questionnaire forms the basis of the quality assurance (QA) programme for the UK randomized Phase III study of the Stanford V regimen versus ABVD for treatment of advanced Hodgkin's disease to assess differences between participating centres in treatment planning and delivery of involved-field radiotherapy for Hodgkin's lymphoma The questionnaire, which was circulated amongst 42 participating centres, consisted of seven sections: target volume definition and dose prescription; critical structures; patient positioning and irradiation techniques; planning; dose calculation; verification; and future developments The results are based on 25 responses. One-third plan using CT alone, one-third use solely the simulator and the rest individualize, depending on disease site. Eleven centres determine a dose distribution for each patient. Technique depends on disease site and whether CT or simulator planning is employed. Most departments apply isocentric techniques and use immobilization and customized shielding. In vivo dosimetry is performed in 7 centres and treatment verification occurs in 24 hospitals. In conclusion, the planning and delivery of treatment for lymphoma patients varies across the country. Conventional planning is still widespread but most centres are moving to CT-based planning and virtual simulation with extended use of immobilization, customized shielding and compensation.

  2. 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.

  3. Feasibility of Elective Nodal Irradiation (ENI) and Involved Field Irradiation (IFI) in Radiotherapy for the Elderly Patients (Aged ≥ 70 Years) with Esophageal Squamous Cell Cancer: A Retrospective Analysis from a Single Institute

    PubMed Central

    Guo, Hongbo; Zhang, Yan; Shi, Fang; Han, Anqin; Li, Minghuan; Kong, Li; Yu, Jinming

    2015-01-01

    Purpose We conducted a retrospective analysis to assess the feasibility of involved field irradiation (IFI) in elderly patients with esophageal squamous cell cancer (ESCC). Materials and Methods We performed a retrospective review of the records of elderly patients (≥ 70 years) with unresectable ESCC and no distant metastases who received treatment with radiotherapy between January 2009 and March 2013. According to the irradiation volume, patients were allocated into either the elective nodal irradiation (ENI) group or the IFI group. Overall survival (OS), progression-free survival (PFS) and treatment-related toxicities were compared between the two groups. Results A total of 137 patients were enrolled. Fifty-four patients (39.4%) were allocated to the ENI group and 83 patients (60.6%) to the IFI group, the median doses in the two groups were 60 Gy and 59.4 Gy, respectively. For the entire group, the median survival time (MST) and PFS were 16 months and 12 months, respectively. The median PFS and 3-year PFS rate in the ENI group were 13 months and 20.6%, compared to 11 months and 21.0% in the IFI groups (p = 0.61). The MST and 3-year OS rate in the ENI and IFI groups were 17 months and 26.4% and 15.5 months and 21.7%, respectively (p = 0.25). The rate of grade ≥ 3 acute irradiation esophagitis in the ENI group was significantly higher than that in the IFI group (18.5% vs. 6.0%; p = 0.027). Other grade ≥ 3 treatment-related toxicities did not significantly differ between the two groups. Conclusions IFI resulted in decreased irradiation toxicities without sacrificing OS in elderly patients with ESCC. PMID:26636574

  4. 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

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

    SciTech Connect

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

    1981-12-01

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

  6. 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

  7. 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

  8. 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.

  9. 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

  10. 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

  11. Dosimetric Comparison of Three Different Involved Nodal Irradiation Techniques for Stage II Hodgkin's Lymphoma Patients: Conventional Radiotherapy, Intensity-Modulated Radiotherapy, and Three-Dimensional Proton Radiotherapy

    SciTech Connect

    Chera, Bhishamjit S.; Rodriguez, Christina; Morris, Christopher G.; Louis, Debbie; Yeung, Daniel; Li Zuofeng; Mendenhall, Nancy P.

    2009-11-15

    Purpose: To compare the dose distribution to targeted and nontargeted tissues in Hodgkin's lymphoma patients using conventional radiotherapy (CRT), intensity-modulated RT (IMRT), and three-dimensional proton RT (3D-PRT). Methods and Materials: CRT, IMRT, and 3D-PRT treatment plans delivering 30 cobalt Gray equivalent (CGE)/Gy to an involved nodal field were created for 9 Stage II Hodgkin's lymphoma patients (n = 27 plans). The dosimetric endpoints were compared. Results: The planning target volume was adequately treated using all three techniques. The IMRT plan produced the most conformal high-dose distribution; however, the 3D-PRT plan delivered the lowest mean dose to nontarget tissues, including the breast, lung, and total body. The relative reduction in the absolute lung volume receiving doses of 4-16 CGE/Gy for 3D-PRT compared with CRT ranged from 26% to 37% (p < .05), and the relative reduction in the absolute lung volume receiving doses of 4-10 CGE/Gy for 3D-PRT compared with IMRT was 48-65% (p < .05). The relative reduction in absolute total body volume receiving 4-30 CGE/Gy for 3D-PRT compared with CRT was 47% (p < .05). The relative reduction in absolute total body volume receiving a dose of 4 CGE/Gy for 3D-PRT compared with IMRT was 63% (p = .03). The mean dose to the breast was significantly less for 3D-PRT than for either IMRT or CRT (p = .03) The mean dose and absolute volume receiving 4-30 CGE/Gy for the heart, thyroid, and salivary glands were similar for the three modalities. Conclusion: In this favorable subset of Hodgkin's lymphoma patients without disease in or below the hila, 3D-PRT significantly reduced the dose to the breast, lung, and total body. These observed dosimetric advantages might improve the clinical outcomes of Hodgkin's lymphoma patients by reducing the risk of late radiation effects related to low-to-moderate doses in nontargeted tissues.

  12. Field measurements involve various techniques

    SciTech Connect

    Moore, D.P.; Byars, H.G. )

    1990-07-30

    A number of field techniques are available to determine the extent of corrosion on production equipment. This article on oil field corrosion explains the use of corrosion coupons, several types of probes, and various inspection techniques, and shows how to monitor iron content in water.

  13. Quantification of static magnetic field effects on radiotherapy ionization chambers

    NASA Astrophysics Data System (ADS)

    Agnew, J.; O’Grady, F.; Young, R.; Duane, S.; Budgell, G. J.

    2017-03-01

    Integrated magnetic resonance (MR) imaging and radiotherapy (RT) delivery machines are currently being developed, with some already in clinical use. It is anticipated that the strong magnetic field used in some MR-RT designs will have a significant impact on routine measurements of dose in the MR-linac performed using ionization chambers, which provide traceability back to a primary standard definition of dose. In particular, the presence of small air gaps around ionization chambers may introduce unacceptably high uncertainty into these measurements. In this study, we investigate and quantify the variation attributable to air gaps for several routinely-used cylindrical ionization chambers in a magnetic field, as well as the effect of the magnetic field alone on the response of the chambers. The measurements were performed in a Co-60 beam, while the ionization chambers were positioned in custom-made Perspex phantoms between the poles of an electromagnet, which was capable of generating magnetic fields of up to 2 T field strength, although measurements were focused around 1.5 T. When an asymmetric air gap was rotated at cardinal angles around the ionization chambers investigated here, variation of up to 8.5  ±  0.2 percentage points (PTW 31006 chamber) was observed in an applied magnetic field of 1.5 T. The minimum peak-to-peak variation was 1.1  ±  0.1% (Exradin A1SL). When the same experiment was performed with a well-defined air gap of known position using the PTW 30013 chamber, a variation of 3.8  ±  0.2% was observed. When water was added to the phantom cavity to eliminate all air gaps, the variation for the PTW 30013 was reduced to 0.2  ±  0.01%.

  14. Quantification of static magnetic field effects on radiotherapy ionization chambers.

    PubMed

    Agnew, J; O'Grady, F; Young, R; Duane, S; Budgell, G J

    2017-03-07

    Integrated magnetic resonance (MR) imaging and radiotherapy (RT) delivery machines are currently being developed, with some already in clinical use. It is anticipated that the strong magnetic field used in some MR-RT designs will have a significant impact on routine measurements of dose in the MR-linac performed using ionization chambers, which provide traceability back to a primary standard definition of dose. In particular, the presence of small air gaps around ionization chambers may introduce unacceptably high uncertainty into these measurements. In this study, we investigate and quantify the variation attributable to air gaps for several routinely-used cylindrical ionization chambers in a magnetic field, as well as the effect of the magnetic field alone on the response of the chambers. The measurements were performed in a Co-60 beam, while the ionization chambers were positioned in custom-made Perspex phantoms between the poles of an electromagnet, which was capable of generating magnetic fields of up to 2 T field strength, although measurements were focused around 1.5 T. When an asymmetric air gap was rotated at cardinal angles around the ionization chambers investigated here, variation of up to 8.5  ±  0.2 percentage points (PTW 31006 chamber) was observed in an applied magnetic field of 1.5 T. The minimum peak-to-peak variation was 1.1  ±  0.1% (Exradin A1SL). When the same experiment was performed with a well-defined air gap of known position using the PTW 30013 chamber, a variation of 3.8  ±  0.2% was observed. When water was added to the phantom cavity to eliminate all air gaps, the variation for the PTW 30013 was reduced to 0.2  ±  0.01%.

  15. 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).

  16. Measurement of Thyroid Dose by TLD arising from Radiotherapy of Breast Cancer Patients from Supraclavicular Field

    PubMed Central

    Farhood, B.; Bahreyni Toossi, M.T.; Vosoughi, H.; Khademi, S.; Knaup, C.

    2016-01-01

    Background: Breast cancer is the most frequently diagnosed cancer and the leading global cause of cancer death among women worldwide. Radiotherapy plays a significant role in treatment of breast cancer and reduces locoregional recurrence and eventually improves survival. The treatment fields applied for breast cancer treatment include: tangential, axillary, supraclavicular and internal mammary fields. Objective: In the present study, due to the presence of sensitive organ such as thyroid inside the supraclavicular field, thyroid dose and its effective factors were investigated. Materials and Methods: Thyroid dose of 31 female patients of breast cancer with involved supraclavicular lymph nodes which had undergone radiotherapy were measured. For each patient, three TLD-100 chips were placed on their thyroid gland surface, and thyroid doses of patients were measured. The variables of the study include shield shape, the time of patient’s setup, the technologists’ experience and qualification. Finally, the results were analyzed by ANOVA test using SPSS 11.5 software. Results: The average age of the patients was 46±10 years. The average of thyroid dose of the patients was 140±45 mGy (ranged 288.2 and 80.8) in single fraction. There was a significant relationship between the thyroid dose and shield shape. There was also a significant relationship between the thyroid dose and the patient’s setup time. Conclusion: Beside organ at risk such as thyroid which is in the supraclavicular field, thyroid dose possibility should be reduced. For solving this problem, an appropriate shield shape, the appropriate time of the patient’s setup, etc. could be considered. PMID:27853722

  17. 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.

  18. Out-of-field doses in radiotherapy: Input to epidemiological studies and dose-risk models.

    PubMed

    Harrison, Roger

    2017-04-06

    Out-of-field doses in radiotherapy have been increasingly studied in recent years because of the generally improved survival of patients who have received radiotherapy as part of their treatment for cancer and their subsequent risk of a second malignancy. This short article attempts to identify some current problems, challenges and opportunities for dosimetry developments in this field. Out-of-field doses and derived risk estimates contribute to general knowledge about radiation effects on humans as well as contributing to risk-benefit considerations for the individual patient. It is suggested that for input into epidemiological studies, the complete dose description (i.e. the synthesis of therapy and imaging doses from all the treatment and imaging modalities) is ideally required, although there is currently no common dosimetry framework which easily covers all modalities. A general strategy for out-of-field dose estimation requires development and improvement in several areas including (i) dosimetry in regions of steep dose gradient close to the field edge (ii) experimentally verified analytical and Monte Carlo models for out-of-field doses (iii) the validity of treatment planning system algorithms outside the field edge (iv) dosimetry of critical sub-structures in organs at risk (v) mixed field (including neutron) dosimetry in proton and ion radiotherapy and photoneutron production in high energy photon beams (vi) the most appropriate quantities to use in neutron dosimetry in a radiotherapy context and (vii) simplification of measurement methods in regions distant from the target volume.

  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.

  20. 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.

  1. Precision radiotherapy for brain tumors

    PubMed Central

    Yan, Ying; Guo, Zhanwen; Zhang, Haibo; Wang, Ning; Xu, Ying

    2012-01-01

    OBJECTIVE: Precision radiotherapy plays an important role in the management of brain tumors. This study aimed to identify global research trends in precision radiotherapy for brain tumors using a bibliometric analysis of the Web of Science. DATA RETRIEVAL: We performed a bibliometric analysis of data retrievals for precision radiotherapy for brain tumors containing the key words cerebral tumor, brain tumor, intensity-modulated radiotherapy, stereotactic body radiation therapy, stereotactic ablative radiotherapy, imaging-guided radiotherapy, dose-guided radiotherapy, stereotactic brachytherapy, and stereotactic radiotherapy using the Web of Science. SELECTION CRITERIA: Inclusion criteria: (a) peer-reviewed articles on precision radiotherapy for brain tumors which were published and indexed in the Web of Science; (b) type of articles: original research articles and reviews; (c) year of publication: 2002-2011. Exclusion criteria: (a) articles that required manual searching or telephone access; (b) Corrected papers or book chapters. MAIN OUTCOME MEASURES: (1) Annual publication output; (2) distribution according to country; (3) distribution according to institution; (4) top cited publications; (5) distribution according to journals; and (6) comparison of study results on precision radiotherapy for brain tumors. RESULTS: The stereotactic radiotherapy, intensity-modulated radiotherapy, and imaging-guided radiotherapy are three major methods of precision radiotherapy for brain tumors. There were 260 research articles addressing precision radiotherapy for brain tumors found within the Web of Science. The USA published the most papers on precision radiotherapy for brain tumors, followed by Germany and France. European Synchrotron Radiation Facility, German Cancer Research Center and Heidelberg University were the most prolific research institutes for publications on precision radiotherapy for brain tumors. Among the top 13 research institutes publishing in this field, seven

  2. Clinical tolerance in large field radiotherapy--the knowledge gained over the last ten years.

    PubMed

    Gocheva, Lilia B

    2010-01-01

    Malignant disorders are still far from being successfully managed in spite of the apparent progress achieved by surgical treatment, high energy radiotherapy (RT) and chemotherapy (CHT). They keep being the second most frequent cause of lethal outcomes both in Bulgaria and in most countries of the world. One of the promising approaches to increasing the efficaciousness of treatment is development and use of methods that are in full accord with the modern requirements of a complex therapy. Over the last fifty years, large field radiation techniques, applied as systemic therapy in oncology, have been investigated and established. These techniques show the transition in oncology to using actively various variants of large field radiotherapy (LFR), the "heavy artillery" of oncoradiologic practice, as an alternative or adjunct therapy to chemotherapy (CHT). In the present paper we review the current knowledge in the field and present the clinical experience accumulated over the last ten years with respect to clinical tolerance in the major large-field radiotherapy techniques--total body irradiation, half body irradiation, whole abdominal irradiation, total and partial lymphoid irradiation. Described in detail are the contemporary knowledge about clinical and hematologic tolerance in total body irradiation as part of the myelo- and nonmyeloablative conditioning regimens as well as in half body irradiation as a systemic therapy in oncology. We also present the amassed experience in clinical tolerance in partial body irradiation in the form of whole abdominal and total or partial lymphoid irradiation. Another point worth noting based again on the experience gained over the last ten years is that for LFR we need to develop a radiotherapy technique that is designed carefully to achieve an optimal therapeutic effect that should include the disease control, good clinical tolerance and reduction of post-radiotherapy sequelae.

  3. 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.

  4. 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.

  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. 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.

  7. 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

  8. [Dropped Head Syndrome after whiplash injury in a patient treated for a Hodgkin's lymphoma by mantle field radiotherapy].

    PubMed

    Schlienger, M; Ferroir, J-P; Huguet, F; Deluen, F; Pène, F; Marseguerra, R; Touboul, E

    2013-02-01

    The authors report a case of Dropped Head Syndrome with an unusually rapid onset after an accident in a patient with a history of Hodgkin's lymphoma cured by chemotherapy and mantle field radiotherapy and compare this case to the rare published cases of chronic Dropped Head Syndrome occurring after this type of treatment. A 56-year-old man was treated at the age 36 years for supra-diaphragmatic Hodgkin's lymphoma by chemotherapy and mantle field radiotherapy according to a standard technique and standard doses (40Gy, 20 fractions, 27 days). Seventeen years after the end of treatment, he experienced a violent whiplash injury, rapidly followed by a Dropped Head Syndrome, similar to the cases of chronic Dropped Head Syndrome already described in the context of Hodgkin's lymphoma (permanent flexion of the head, only reduced in the supine position). Physical and neurophysiological examination, electromyogram, and magnetic resonance imaging confirmed the diagnosis of Dropped Head Syndrome. Very few treatment options are available for the major disability related to Dropped Head Syndrome. This type of subacute onset of Dropped Head Syndrome has not been previously described. The good results of radiation therapy after chemotherapy allow a dose reduction to 30Gy in the involved regions. This, together with recent progress in treatment planning, should allow eradication of these complications.

  9. 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.

  10. 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

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

    PubMed

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

    2016-06-01

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

  12. 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.

  13. 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.

  14. SU-E-T-17: A Comparison of Forward and Field in Field Intensity Modulation Radiotherapy Planning for Breast Cancer

    SciTech Connect

    Liu, T; Sun, T; Chen, J; Zhang, G

    2015-06-15

    Purpose: To compare the dosimetric difference in forward intensity modulation radiotherapy(fIMRT) and field in field IMRT (FIF IMRT)planning for breast cancer. Methods: Ten patients received radiotherapy are selected.For each patient,two treatment plans(fIMRT and FIF IMRT) were designed with Varian Eclipse ver11.0 treatment planning system.Evaluate the dose parameters of targets, organs at risk (OAR), monitor units and treatment time, using dose-volume histogram (DVH). Results: There were no significant difference were found in conformal index (CI), homogeneity index (HI) of PTV,V5,V10,V20,V30,V40,V50 of heart, lung and monitor unit(MU)(P>0.05).The differences were significant in the treatment time(fIMRT=8.3min,FIF IMRT=2.5,p<0.05). Conclusion: FIF IMRT is equal to fIMRT in dosimetril evaluation. Due to much less delivery time,FIF IMRT is an efficient technique in treating patients by reduceing the uncomfortable influnce which could effect the treatment.

  15. 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

  16. 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

  17. 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.

  18. A Gravitational Experiment Involving Inhomogeneous Electric Fields

    NASA Astrophysics Data System (ADS)

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

    2004-02-01

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

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

    SciTech Connect

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

    2011-03-01

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

  20. 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.

  1. 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.

  2. Nonlinear scalar field equations involving the fractional Laplacian

    NASA Astrophysics Data System (ADS)

    Byeon, Jaeyoung; Kwon, Ohsang; Seok, Jinmyoung

    2017-04-01

    In this paper we study the existence, regularity, radial symmetry and decay property of a mountain pass solution for nonlinear scalar field equations involving the fractional Laplacian under an almost optimal class of continuous nonlinearities.

  3. 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.

  4. 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.

  5. 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

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

    PubMed

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

    2016-08-01

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

  7. Electron Conformal Radiotherapy for Post-Mastectomy Irradiation: A Bolus-Free, Multi-Energy, Multi-Segmented Field Algorithm

    DTIC Science & Technology

    2005-08-01

    that compared to customized electron bolu s radiotherapy for post-mastectomy irradiation, ECT with multi-energy, multi-segmente d treatment fields has...PTV dos e homogeneity was quite good . Use of the treatment plan modification techniques improved dose sparin g for the non-target portion of the...phantom . For the patient treatment plans, the algorithm provided acceptable results for PTV conformality and dose homogeneity, in comparison to the bolus

  8. 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.

  9. Who and What Does Involvement Involve? A Multi-Sited Field Study of Involvement of Relatives in Danish Psychiatry.

    PubMed

    Oute, Jeppe; Petersen, Anders; Huniche, Lotte

    2015-01-01

    This article gives an account of aspects of a multi-sited field study of involvement of relatives in Danish psychiatry. By following metaphors of involvement across three sites of the psychiatric system-a family site, a clinical site and a policy site-the first author (J.O.) investigated how, and on what grounds, involvement of relatives is perceived in Danish psychiatry. Paradoxically, the current understanding of involvement of relatives fails to take into consideration the perspectives of the relatives per se and families that were being studied. By analyzing involvement from a discourse theoretical perspective laid out by Ernesto Laclau and Chantal Mouffe, the aim of this study is to show how the dominant discourse about involvement at the political and clinical sites is constituted by understandings of mentally ill individuals and by political objectives of involvement. The analysis elucidates how a psycho-ideological discourse positions the mentally ill person as weak, incapable, and ineffective. By contrast, the supporting relative is positioned as a strong, capable, and effective co-therapist. Furthermore, the analysis considers how this dominant discourse of involvement is constituted by a broader discourse of neoliberalism and market orientation, which justifies involvement as a subtle institutionalization of social control. The article highlights that the role of the relative as a co-therapist may be contested by the families' discourse, which emphasizes issues concerning the responsibility toward the mental health of the ill individual as well as toward the psychological milieu of the family.

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

    SciTech Connect

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

    2010-10-01

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

  11. Dose enhancement in radiotherapy of small lung tumors using inline magnetic fields: A Monte Carlo based planning study

    SciTech Connect

    Oborn, B. M.; Ge, Y.; Hardcastle, N.; Metcalfe, P. E.; Keall, P. J.

    2016-01-15

    Purpose: To report on significant dose enhancement effects caused by magnetic fields aligned parallel to 6 MV photon beam radiotherapy of small lung tumors. Findings are applicable to future inline MRI-guided radiotherapy systems. Methods: A total of eight clinical lung tumor cases were recalculated using Monte Carlo methods, and external magnetic fields of 0.5, 1.0, and 3 T were included to observe the impact on dose to the planning target volume (PTV) and gross tumor volume (GTV). Three plans were 6 MV 3D-CRT plans while 6 were 6 MV IMRT. The GTV’s ranged from 0.8 to 16 cm{sup 3}, while the PTV’s ranged from 1 to 59 cm{sup 3}. In addition, the dose changes in a 30 cm diameter cylindrical water phantom were investigated for small beams. The central 20 cm of this phantom contained either water or lung density insert. Results: For single beams, an inline magnetic field of 1 T has a small impact in lung dose distributions by reducing the lateral scatter of secondary electrons, resulting in a small dose increase along the beam. Superposition of multiple small beams leads to significant dose enhancements. Clinically, this process occurs in the lung tissue typically surrounding the GTV, resulting in increases to the D{sub 98%} (PTV). Two isolated tumors with very small PTVs (3 and 6 cm{sup 3}) showed increases in D{sub 98%} of 23% and 22%. Larger PTVs of 13, 26, and 59 cm{sup 3} had increases of 9%, 6%, and 4%, describing a natural fall-off in enhancement with increasing PTV size. However, three PTVs bounded to the lung wall showed no significant increase, due to lack of dose enhancement in the denser PTV volume. In general, at 0.5 T, the GTV mean dose enhancement is around 60% lower than that at 1 T, while at 3 T, it is 5%–60% higher than 1 T. Conclusions: Monte Carlo methods have described significant and predictable dose enhancement effects in small lung tumor plans for 6 MV radiotherapy when an external inline magnetic field is included. Results of this study

  12. Monte Carlo modeling of converging small-field contrast-enhanced radiotherapy of prostate.

    PubMed

    Garnica-Garza, H M

    2013-09-01

    Radiation therapy using a kilovoltage X-ray source to irradiate a target previously loaded with a radiological contrast agent, contrast-enhanced radiotherapy (CERT), has been shown both theoretically and in a preliminary experimental study to represent a potential alternative to high-energy treatments. It has also been shown, however, to produce an integral dose that can be up to twice that resulting from a conventional megavoltage treatment. In this work, using a realistic patient model and Monte Carlo simulation, a CERT prostate treatment plan is designed that makes use of a plurality of small circular beams aimed at the target in such a way as to minimize the radiological trajectory to the target volume. Gold nanoparticles are assumed to be the contrast agent. Two cases are examined, one with a concentration level in the target of 10 mg-Au per gram of tissue and the second with a concentration of 3 mg-Au per gram of tissue in the target. A background concentration of 1 mg of contrast agent per gram of tissue was assumed everywhere else in both cases. The Cimmino feasibility algorithm was then used to find each beam weight in order to obtain the prescribed target dose, set at 72 Gy to 100% of the tumor volume. It is shown that the approach using the small circular fields, a radiosurgery treatment, produces treatment plans with excellent absorbed dose distributions while at the same time it reduces by up to 60% the non-tumor integral dose imparted to the irradiated subject. A brief discussion on the technology necessary to clinically implement this treatment modality is also presented.

  13. Methods for improving limited field-of-view radiotherapy reconstructions using imperfect a priori images.

    PubMed

    Ruchala, Kenneth J; Olivera, Gustavo H; Kapatoes, Jeffrey M; Reckwerdt, Paul J; Mackie, Thomas R

    2002-11-01

    There are many benefits to having an online CT imaging system for radiotherapy, as it helps identify changes in the patient's position and anatomy between the time of planning and treatment. However, many current online CT systems suffer from a limited field-of-view (LFOV) in that collected data do not encompass the patient's complete cross section. Reconstruction of these data sets can quantitatively distort the image values and introduce artifacts. This work explores the use of planning CT data as a priori information for improving these reconstructions. Methods are presented to incorporate this data by aligning the LFOV with the planning images and then merging the data sets in sinogram space. One alignment option is explicit fusion, producing fusion-aligned reprojection (FAR) images. For cases where explicit fusion is not viable, FAR can be implemented using the implicit fusion of normal setup error, referred to as normal-error-aligned reprojection (NEAR). These methods are evaluated for multiday patient images showing both internal and skin-surface anatomical variation. The iterative use of NEAR and FAR is also investigated, as are applications of NEAR and FAR to dose calculations and the compensation of LFOV online MVCT images with kVCT planning images. Results indicate that NEAR and FAR can utilize planning CT data as imperfect a priori information to reduce artifacts and quantitatively improve images. These benefits can also increase the accuracy of dose calculations and be used for augmenting CT images (e.g., MVCT) acquired at different energies than the planning CT.

  14. 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

  15. 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.

  16. Dosimetric comparison of intensity modulated radiotherapy isocentric field plans and field in field (FIF) forward plans in the treatment of breast cancer.

    PubMed

    Al-Rahbi, Zakiya Salem; Al Mandhari, Zahid; Ravichandran, Ramamoorthy; Al-Kindi, Fatma; Davis, Cheriyathmanjiyil Anthony; Bhasi, Saju; Satyapal, Namrata; Rajan, Balakrishnan

    2013-01-01

    The present study is aimed at comparing the planning and delivery efficiency between three-dimensional conformal radiotherapy (3D-CRT), field-in-field, forward planned, intensity modulated radiotherapy (FIF-FP-IMRT), and inverse planned intensity modulated radiotherapy (IP-IMRT). Treatment plans of 20 patients with left-sided breast cancer, 10 post-mastectomy treated to a prescribed dose of 45 Gy to the chest wall in 20 fractions, and 10 post-breast-conserving surgery to a prescribed dose of 50 Gy to the whole breast in 25 fractions, with 3D-CRT were selected. The FiF-FP-IMRT plans were created by combining two open fields with three to four segments in two tangential beam directions. Eight different beam directions were chosen to create IP-IMRT plans and were inversely optimized. The homogeneity of dose to planning target volume (PTV) and the dose delivered to heart and contralateral breast were compared among the techniques in all the 20 patients. All the three radiotherapy techniques achieved comparable radiation dose delivery to PTV-95% of the prescribed dose covering > 95% of the breast PTV. The mean volume of PTV receiving 105% (V105) of the prescribed dose was 1.7% (range 0-6.8%) for IP-IMRT, 1.9% for FP-IMRT, and 3.7% for 3D-CRT. The homogeneity and conformity indices (HI and CI) were similar for 3D-CRT and FP-IMRT, whereas the IP-IMRT plans had better conformity index at the cost of less homogeneity. The 3D-CRT and FiF-FP-IMRT plans achieved similar sparing of critical organs. The low-dose volumes (V5Gy) in the heart and lungs were larger in IP-IMRT than in the other techniques. The value of the mean dose to the ipsilateral lung was higher for IP-IMRT than the values for with FiF-FP-IMRT and 3D-CRT. In the current study, the relative volume of contralateral breast receiving low doses (0.01, 0.6, 1, and 2Gy) was significantly lower for the FiF-FP-IMRT and 3D-CRT plans than for the IP-IMRT plan. Compared with 3D-CRT and IP-IMRT, FiF-FP-IMRT proved to be a

  17. Dosimetric comparison of intensity modulated radiotherapy isocentric field plans and field in field (FIF) forward plans in the treatment of breast cancer

    PubMed Central

    Al-Rahbi, Zakiya Salem; Al Mandhari, Zahid; Ravichandran, Ramamoorthy; Al-Kindi, Fatma; Davis, Cheriyathmanjiyil Anthony; Bhasi, Saju; Satyapal, Namrata; Rajan, Balakrishnan

    2013-01-01

    The present study is aimed at comparing the planning and delivery efficiency between three-dimensional conformal radiotherapy (3D-CRT), field-in-field, forward planned, intensity modulated radiotherapy (FIF-FP-IMRT), and inverse planned intensity modulated radiotherapy (IP-IMRT). Treatment plans of 20 patients with left-sided breast cancer, 10 post-mastectomy treated to a prescribed dose of 45 Gy to the chest wall in 20 fractions, and 10 post-breast-conserving surgery to a prescribed dose of 50 Gy to the whole breast in 25 fractions, with 3D-CRT were selected. The FiF-FP-IMRT plans were created by combining two open fields with three to four segments in two tangential beam directions. Eight different beam directions were chosen to create IP-IMRT plans and were inversely optimized. The homogeneity of dose to planning target volume (PTV) and the dose delivered to heart and contralateral breast were compared among the techniques in all the 20 patients. All the three radiotherapy techniques achieved comparable radiation dose delivery to PTV-95% of the prescribed dose covering > 95% of the breast PTV. The mean volume of PTV receiving 105% (V105) of the prescribed dose was 1.7% (range 0-6.8%) for IP-IMRT, 1.9% for FP-IMRT, and 3.7% for 3D-CRT. The homogeneity and conformity indices (HI and CI) were similar for 3D-CRT and FP-IMRT, whereas the IP-IMRT plans had better conformity index at the cost of less homogeneity. The 3D-CRT and FiF-FP-IMRT plans achieved similar sparing of critical organs. The low-dose volumes (V5Gy) in the heart and lungs were larger in IP-IMRT than in the other techniques. The value of the mean dose to the ipsilateral lung was higher for IP-IMRT than the values for with FiF-FP-IMRT and 3D-CRT. In the current study, the relative volume of contralateral breast receiving low doses (0.01, 0.6, 1, and 2Gy) was significantly lower for the FiF-FP-IMRT and 3D-CRT plans than for the IP-IMRT plan. Compared with 3D-CRT and IP-IMRT, FiF-FP-IMRT proved to be a

  18. 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.

  19. 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

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

    PubMed

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

    2004-02-21

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

  1. Involvement of adrenal medulla grafts in the open field behavior.

    PubMed

    Jousselin-Hosaja, M; Venault, P; Tobin, C; Joubert, C; Delacour, J; Chapouthier, G

    2001-06-01

    Immunohistochemical and behavioral techniques were used to study the effects of adrenal medulla grafts, implanted in striatum after bilateral kainic acid (KA) lesions of this structure, on the open field behavior of mice. KA-induced behavioral changes in leaning, grooming and locomotor activity of the open field test were significantly improved after grafting of the adrenal medulla, and in some respects, fully restored. Immunohistochemical identification showed that grafts contained neuron-like cells with a tyrosine hydroxylase (TH), phenylethanolamine N-methyltransferase, gamma-aminobutyric acid (GABA), choline acetyltransferase (ChAT), and enkephalin-like immunostainings. A likely interpretation of this complex pattern of results is that adrenal medullary grafts may restore the deficits of GABAergic neurons which in turn reverse the abnormalities in emotionality and locomotion. Neurobiologically, these behavioral improvements probably involve GABAergic and catecholaminergic factors of adrenal medulla grafts, although other neuroactive substances, such as acetylcholine and enkephalins, cannot be excluded.

  2. 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.

  3. Measurement of magnetic fields produced by a "magnetic deflector" for the removal of electron contamination in radiotherapy.

    PubMed

    Damrongkijudom, N; Oborn, B; Butson, M; Rosenfeld, A

    2006-12-01

    Electron contamination generated from interactions of x-rays with components in a medical linear accelerator's head can increase damage to skin and subcutaneous tissue during radiotherapy through increased dose deposition. Skin and subcutaneous dose from high energy x-rays can be reduced using magnetic fields to sweep the electron contamination away from the radiation treatment field. This work is aimed at investigating the magnetic fields generated by an improved magnetic deflector which utilizes Nd2Fe14B magnets. Magnetic field strengths generated by the deflector have been simulated using Vizimag 3.0 magnetic modelling software. The improved deflector has a more uniform magnetic field strength than its predecessor and is optimised to easily fit on a clinical linear accelerator. Experimental measurements of the magnetic field strengths produced have also been performed for comparison. Results show a relatively good match to Vizimag modelling in the central regions of the deflector. Reductions of skin and subcutaneous dose up to 34% of original values were seen for a 20 x 20 cm2 field at 6MV x-ray energy.

  4. 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

  5. Low-Dose-Area-Constrained Helical TomoTherapy-Based Whole Breast Radiotherapy and Dosimetric Comparison with Tangential Field-in-Field IMRT

    PubMed Central

    Qiu, Jie; Yang, Bo; Hou, Xiaorong; Zhang, Fuquan

    2013-01-01

    Background and Purpose. To present a novel helical TomoTherapy-based method for whole breast radiotherapy that has better dosimetry and also has acceptable low-dose regions for lungs, heart, and contralateral breast compared with tangential field-in-field IMRT (FIF-IMRT). Material and Methods. Ten patients with left-side breast cancer were planned with low-dose-area-constrained helical TomoTherapy (LDC-HT) and FIF-IMRT. Dosimetry was compared for all techniques. Results. Coverage of the whole breast was adequate with both techniques. Homogeneity index (HI) and conformity index (CI) were better with LDC-HT. LDC-HT showed dosimetry advantages over FIF-IMRT for ipsilateral lung and heart in not only high-dose levels but also in low-dose levels such as V10 Gy and V5 Gy. For contralateral lung, both techniques can provide good protection, although the mean dose of LDC-HT is higher than that of FIF-IMRT. Conclusions. With LDC-HT, we obtained adequate target coverage, better HI and CI of target volume, better sparing of organs at risk, and acceptably low-dose areas compared with FIF-IMRT. LDC-HT could be a feasible method in whole breast radiotherapy. Clinical benefits of LDC-HT need further investigation. PMID:24024197

  6. Stereotactic radiotherapy for spinal intradural metastases developing within or adjacent to the previous irradiation field--report of three cases.

    PubMed

    Mori, Yoshimasa; Hashizume, Chisa; Shibamoto, Yuta; Kobayashi, Tatsuya; Nakazawa, Hisato; Hagiwara, Masahiro; Tsugawa, Takahiko

    2013-08-01

    Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT. Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients' death from the primary cancer (10, 22, and 5 months). Neurological symptoms were stable or improved in all 3 patients. Palliative SRT using Novalis is expected to be safe and effective even if the patient develops spinal intradural metastases within or adjacent to the previous irradiation field.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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

    2015-11-08

    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.

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

    PubMed Central

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

    2013-01-01

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

  14. 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

  15. Discontinuous finite element space-angle treatment of the first order linear Boltzmann transport equation with magnetic fields: Application to MRI-guided radiotherapy

    SciTech Connect

    St Aubin, J.; Keyvanloo, A.; Fallone, B. G.

    2016-01-15

    Purpose: The advent of magnetic resonance imaging (MRI) guided radiotherapy systems demands the incorporation of the magnetic field into dose calculation algorithms of treatment planning systems. This is due to the fact that the Lorentz force of the magnetic field perturbs the path of the relativistic electrons, hence altering the dose deposited by them. Building on the previous work, the authors have developed a discontinuous finite element space-angle treatment of the linear Boltzmann transport equation to accurately account for the effects of magnetic fields on radiotherapy doses. Methods: The authors present a detailed description of their new formalism and compare its accuracy to GEANT4 Monte Carlo calculations for magnetic fields parallel and perpendicular to the radiation beam at field strengths of 0.5 and 3 T for an inhomogeneous 3D slab geometry phantom comprising water, bone, and air or lung. The accuracy of the authors’ new formalism was determined using a gamma analysis with a 2%/2 mm criterion. Results: Greater than 98.9% of all points analyzed passed the 2%/2 mm gamma criterion for the field strengths and orientations tested. The authors have benchmarked their new formalism against Monte Carlo in a challenging radiation transport problem with a high density material (bone) directly adjacent to a very low density material (dry air at STP) where the effects of the magnetic field dominate collisions. Conclusions: A discontinuous finite element space-angle approach has been proven to be an accurate method for solving the linear Boltzmann transport equation with magnetic fields for cases relevant to MRI guided radiotherapy. The authors have validated the accuracy of this novel technique against GEANT4, even in cases of strong magnetic field strengths and low density air.

  16. In vivo surface dose measurement using GafChromic film dosimetry in breast cancer radiotherapy: comparison of 7-field IMRT, tangential IMRT and tangential 3D-CRT

    PubMed Central

    2014-01-01

    Purpose The purpose of this study was to compare the surface dose of 7-field IMRT (7 F-IMRT), tangential beam IMRT (TB-IMRT), and tangential beam 3D-CRT (3D-CRT) of breast cancer patients receiving adjuvant radiotherapy by means of in vivo GafChromic film dosimetry. Material and methods Breast cancer patients receiving adjuvant radiotherapy of the whole breast or the chest wall were eligible for the study. Study patients were treated with a treatment plan using two different radiotherapy techniques (first patient series, 3D-CRT followed by TB-IMRT; second patient series, TB-IMRT followed by 7 F-IMRT). The surface dose was evaluated on three consecutive treatment fractions per radiotherapy technique using in vivo GafChromic film dosimetry. The paired t-test was used to assess the difference of in vivo GafChromic film readings or calculated plan parameters of the compared pairs of radiation techniques for statistical significance. Results Forty-five unselected breast cancer patients were analysed in this study. 7 F-IMRT significantly reduced the surface dose compared to TB-IMRT. Differences were greatest in the central and lateral breast or chest wall region and amounted to a dose reduction of -11.8% to -18.8%. No significant difference of the surface dose was observed between TB-IMRT and 3D-CRT. A corresponding observation was obtained for the calculated skin dose derived from dose-volume histograms. Conclusions In adjuvant breast cancer radiotherapy, 7 F-IMRT offers a significantly reduced surface dose compared to TB-IMRT or 3D-CRT. PMID:25022449

  17. The practical application of scintillation dosimetry in small-field photon-beam radiotherapy.

    PubMed

    Burke, Elisa; Poppinga, Daniela; Schönfeld, Andreas A; Harder, Dietrich; Poppe, Björn; Looe, Hui Khee

    2017-03-22

    Plastic scintillation detectors are a new instrument of stereotactic photon-beam dosimetry. The clinical application of the plastic scintillation detector Exradin W1 at the Siemens Artiste and Elekta Synergy accelerators is a matter of current interest. In order to reduce the measurement uncertainty, precautions have to be taken with regard to the geometrical arrangement of the scintillator, the light-guide fiber and the photodiode in the radiation field. To determine the "Cerenkov light ratio" CLR with a type A uncertainty below 1%, the Cerenkov calibration procedure for small-field measurements based on the two-channel spectral method was used. Output factors were correctly measured with the W1 for field sizes down to 0.5×0.5cm(2) with a type A uncertainty of 1.8%. Measurements of small field dose profiles and percentage depth dose curves were carried out with the W1 using automated water phantom profile scans, and a type A uncertainty for dose maxima of 1.4% was achieved. The agreement with a synthetic diamond detector (microDiamond, PTW Freiburg) and a plane parallel ionization chamber (Roos chamber, PTW Freiburg) in relative dose measurements was excellent. In oversight of all results, the suitability of the plastic scintillation detector Exradin W1 for clinical dosimetry under stereotactic conditions, in particular the tried and tested procedures for CLR determination, output factor measurement and automated dose profile scans in water phantoms, have been confirmed.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Does MRI-detected cranial nerve involvement affect the prognosis of locally advanced nasopharyngeal carcinoma treated with intensity modulated radiotherapy?

    PubMed

    Zong, Jingfeng; Lin, Shaojun; Chen, Yunbin; Wang, Bingyi; Xiao, Youping; Lin, Jin; Li, Rui; Pan, Jianji

    2014-01-01

    Nasopharyngeal carcinoma (NPC) is one of the common cancers in South China. It can easily invade into cranial nerves, especially in patients with local advanced disease. Despite the fact that the magnetic resonance imaging (MRI) findings are not always consistent with the symptoms of CN palsy, MRI is recommended for the detection of CN involvement (CNI). However, the prognostic impact of MRI-detected CNI in NPC patients is still controversial. To investigate the prognostic value of MRI detected CNI, we performed a retrospective analysis on the clinical data of 375 patients with NPC who were initially diagnosed by MRI. All patients had T3-4 disease and received radical intensity modulated radiation therapy (IMRT) as their primary treatment. The incidence of MRI-detected CNI was 60.8%. A higher incidence of MRI-detected CNI was observed in T4 disease compared with T3 disease (96.8% vs. 42.8%, P<0.001), and a higher incidence was also found in patients with Stage IV disease compared with those with Stage III disease (91.5% vs. 42.3%; P<0.001). The local relapse-free survival (LRFS), distant metastasis-free survival (DMFS), and overall survival (OS) of patients with T3 disease, with or without MRI-detected CNI, was superior to that of patients with T4 disease (P<0.05). No significant differences in LRFS, DMFS or OS were observed between T3 patients with or without MRI-detected CNI. The survival of Stage III patients with or without MRI-detected CNI was significantly superior to that of Stage IV patients (P<0.01), but there was no significant difference between Stage III patients with or without MRI-detected CNI for all endpoints. Therefore, when treated with IMRT, MRI-detected CNI in patients with NPC does not appear to affect the prognosis. In patients with clinical T3 disease, the presence of MRI-detected CNI is not sufficient evidence for defining T4 disease.

  3. 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.

  4. 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.

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

    PubMed Central

    2014-01-01

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

  6. 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.

  7. 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

  8. 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.

  9. SU-E-T-206: Comparison of EBT and EBT3 RadioChromic Films in Radiation Field of Parotid Cancer Radiotherapy

    SciTech Connect

    Toosi, T Bahreyni; Mianaei, F Khorshidi; Ghorbani, M; Khabbaz Kazemi, N Mohammadian; Mohammadi, M; Meigooni, A Soleimani

    2015-06-15

    Purpose: The aim of the current study is to compare EBT and EBT3 RadioChromic films in dosimetry of radiotherapy fields for treatment of parotid cancer. Methods: The calibrations of EBT and EBT3 films were performed with the same setups for doses ranging from 0.2 Gy to 5 Gy using 6 MV photon beam of a Siemens Primus linac. These films were scanned in color mode (RGB) by a Microtek (1000XL) scanner and the red color channel data was extracted. Treatment planning for parotid cancer radiation therapy was performed on a RANDO phantom. Skin dose was measured at different points in the right anterior oblique (RAO) and right posterior oblique (RPO) fields by EBT and EBT3 films. Results: Dosimetry was performed with the same conditions for the two film types for calibration and in-phantom in parotid cancer radiotherapy. The measured net optical density (NOD) in EBT film was in some extent higher than that from EBT3 film. The minimum difference between these two films under calibration conditions was about 2.9% (for 0.2 Gy). However, the maximum difference was 35.5% (for 0.5 Gy). In the therapeutic fields of parotid cancer radiotherapy at different points, the measured dose from EBT film was higher than the EBT3 film. In these fields the minimum and maximum measured dose differences were 16.0% and 25.5%, respectively. Conclusion: With the same irradiation and reading conditions, EBT film demonstrates higher NOD than the EBT3 film. This effect may be related to the higher sensitivity of EBT film over EBT3 film. However, the obtained dose differences between these two films in low dose range can be due to the differences in fitting functions applied following the calibration process.

  10. 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

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

    PubMed

    Yuan, Jun; Lei, Mingjun; Yang, Zhen; Fu, Jun; Huo, Lei; Hong, Jidong

    2016-07-01

    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.

  12. 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.

  13. 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.

  14. 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.

  15. [Radiotherapy of breast cancer].

    PubMed

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

    2016-09-01

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

  16. 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

  17. Combination chemotherapy and radiotherapy in non-Hodgkin's lymphomata.

    PubMed Central

    Bonadonna, G.; De Lena, M.; Lattuada, A.; Milani, F.; Monfardini, S.; Beretta, G.

    1975-01-01

    The results obtained with intensive chemotherapy and intensive chemotherapy plus radiotherapy in non-Hodgkin's lymphomata are reported. A quintuple drug regimen (mechloretamine, adriamycin, bleomycin, vincristine and prednisone) in histiocytic lymphomata (Stage III and IV) yielded complete remissions in 53% and complete plus partial remissions in 77%. These figures were 44% and 64% respectively in lymphocytic lymphoma. In Stage III complete responders after combination chemotherapy were subsequently irradiated (involved field irradiation). The median duration of complete remission after completion of radiotherapy was 9-5 months in histiocytic and 12-0 months in lymphocytic lymphomata. At 2 years actuarial survival in Stage III and IV was better in patients with the lymphocytic type and with nodular pattern than with histiocytic and diffuse patterns. A more recent trial compares, in Stage IV patients, cyclophosphamide, vincristine and prednisone (CVP) versus adriamycin, bleomycin and prednisone (ABP). Although the number of evaluable patients is still limited, there appears to be no difference in the response rate between CVP and ABP. In Stages I and II, 6 cycles of CVP were given as adjuvant treatment after radiotherapy. At the present moment, there is no statistical difference in the relapse rate between the group of patients treated with radiotherapy alone and that with radiotherapy plus CVP. PMID:52367

  18. 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.

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

    DOEpatents

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

    2015-05-19

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

  20. 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.

  1. RapidArc radiotherapy for whole pelvic lymph node in cervical cancer with 6 and 15 MV: a treatment planning comparison with fixed field IMRT

    PubMed Central

    Zhai, De-Yin; Yin, Yong; Gong, Guan-Zhong; Liu, Tong-Hai; Chen, Jin-Hu; Ma, Chang-Sheng; Lu, Jie

    2013-01-01

    Dosimetric differences were investigated among single and dual arc RapidArc and fixed-field intensity-modulated radiotherapy (f-IMRT) treatment plans for whole pelvic irradiation of lymph nodes. A total of 12 patients who had undergone radical surgery for cervical cancer and who had demonstrated multiple pelvic lymph node metastases were treated with radiotherapy. For all 12 cases, 7-field IMRT, single-arc RapidArc and dual-arc RapidArc were applied with 6 MV and 15 MV X-ray energies. The radiation dosimetric parameters for the different plans were compared with one another. All the plans met the clinical requirements. The homogeneity, conformity and external volume indices of f-IMRT and dual-arc RapidArc were better than for single-arc RapidArc (P < 0.05), while the differences between f-IMRT and dual-arc RapidArc were not significant. There were no significant differences in the radiation dose to organs at risk, except for the small bowel receiving >40 Gy (f-IMRT and dual-arc < single-arc, P < 0.05). The differences in dose distributions between the two applied X-ray energies for each of the modality plans were not significant. RapidArc plans resulted in fewer monitor units than the corresponding f-IMRT plans. Also, there were no differences between the two photon energies, except for a reduction in the number of MUs for 15 MV (P > 0.05). Compared to f-IMRT, no significant dosimetric benefits were found using RapidArc for whole pelvic lymph node irradiation. However, RapidArc has been associated with shorter treatment time and fewer monitor units, supporting the case for its safety and efficacy for pelvic irradiation. PMID:23283869

  2. Radiotherapy for bone pain.

    PubMed Central

    Needham, P R; Mithal, N P; Hoskin, P J

    1994-01-01

    Painful bone metastases are a common problem for cancer patients. Although current evidence supports the use of a single fraction of radiotherapy as the treatment of choice, many radiotherapists, for a variety of reasons, continue to use fractionated regimens. Over one six month period 105 patients received external beam irradiation for painful bone metastases at the Royal London Hospital (RLH). Thirty-one per cent of the patients were aged 70 or over. The treatment of 97 of these patients was assessed. They had a total of 280 sites treated over the course of their disease. Fifty-nine per cent of sites treated received a fractionated course of radiotherapy. Site significantly influenced fractionation. Overall response rates of 82% were achieved. Fractionation did not appear to influence this. Ten patients received large field irradiation. Fifteen patients had five or more sites irradiated, of whom only one received hemibody irradiation. PMID:7523672

  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. Bone Health and Pelvic Radiotherapy.

    PubMed

    Higham, C E; Faithfull, S

    2015-11-01

    Survivors who have received pelvic radiotherapy make up many of the long-term cancer population, with therapies for gynaecological, bowel, bladder and prostate malignancies. Individuals who receive radiotherapy to the pelvis as part of their cancer treatment are at risk of insufficiency fractures. Symptoms of insufficiency fractures include pelvic and back pain and immobility, which can affect substantially quality of life. This constellation of symptoms can occur within 2 months of radiotherapy up to 63 months post-treatment, with a median incidence of 6-20 months. As a condition it is under reported and evidence is poor as to the contributing risk factors, causation and best management to improve the patient's bone health and mobility. As radiotherapy advances, chronic symptoms, such as insufficiency fractures, as a consequence of treatment need to be better understood and reviewed. This overview explores the current evidence for the effect of radiotherapy on bone health and insufficiency fractures and identifies what we know and where gaps in our knowledge lie. The overview concludes with the need to take seriously complaints of pelvic pain from patients after pelvic radiotherapy and to investigate and manage these symptoms more effectively. There is a clear need for definitive research in this field to provide the evidence-based guidance much needed in practice.

  5. Optimization of the interface between radiology, surgery, radiotherapy, and pathology in head and neck tumor surgery: a navigation-assisted multidisciplinary network.

    PubMed

    Guijarro-Martínez, R; Gellrich, N-C; Witte, J; Tapioles, D; von Briel, C; Kolotas, C; Achinger, J; Hailemariam, S; Schulte, H; Rohner, D; Hammer, B

    2014-02-01

    A navigation-assisted multidisciplinary network to improve the interface between radiology, surgery, radiotherapy, and pathology in the field of head and neck cancer is described. All implicated fields are integrated by a common server platform and have remote data access in a ready-to-use format. The margins of resection and exact locations of biopsies are mapped intraoperatively. The pathologist uses the numerical coordinates of these samples to precisely trace each specimen in the anatomical field. Subsequently, map-guided radiotherapy is planned. In addition to the benefits of image-guided resection, this model enables radiotherapy planning according to the specific coordinates of the resection defect plus any residually affected sites identified by the pathologist. Irradiation of adjacent healthy structures is thereby minimized. In summary, the navigation-assisted network described grants timely multidisciplinary feedback between all fields involved, attains meticulous pathological definition, and permits optimized coordinate-directed radiotherapy.

  6. 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

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

    PubMed Central

    1994-01-01

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

  8. 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.

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

    SciTech Connect

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

    2012-01-01

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

  10. Gibberellins are involved in effect of near-null magnetic field on Arabidopsis flowering.

    PubMed

    Xu, Chunxiao; Yu, Yang; Zhang, Yuxia; Li, Yue; Wei, Shufeng

    2017-01-01

    We previously found that flowering of Arabidopsis was suppressed by near-null magnetic field, which was related to the modification of cryptochrome. To disclose the physiological mechanism of this effect, we detected gibberellin (GA) levels and expressions of GA biosynthetic and signaling genes in wild type Arabidopsis plants and cryptochrome double mutant, cry1/cry2, grown in near-null magnetic field. We found that levels of GA4 , GA9 , GA34 , and GA51 in wild type plants in near-null magnetic field were significantly decreased compared with local geomagnetic field controls. However, GA levels in cry1/cry2 mutants in near-null magnetic field were similar to controls. Expressions of three GA20-oxidase (GA20ox) genes (GA20ox1, GA20ox2, and GA20ox3) and four GA3-oxidase (GA3ox) genes (GA3ox1, GA3ox2, GA3ox3, and GA3ox4) in wild type plants in near-null magnetic field were significantly reduced compared with controls, while expressions of GA20ox4, GA20ox5, GA2-oxidase (GA2ox) genes, and GA signaling-related genes in wild type plants in near-null magnetic field were not significantly different from controls. In contrast, expressions of all the detected GA biosynthetic and signaling genes in cry1/cry2 mutants were not affected by near-null magnetic field. Moreover, transcriptions of flowering-related genes, LFY and SOC1, in wild type plants were downregulated by near-null magnetic field, while they were not affected by near-null magnetic field in cry1/cry2 mutants. Our results suggest that the effect of near-null magnetic field on Arabidopsis flowering is GA-related, which is caused by cryptochrome-involved suppression of GA biosynthesis. Bioelectromagnetics. 38:1-10, 2017. © 2016 Wiley Periodicals, Inc.

  11. A Conformal Mapping Suitable for Problems Involving Interaction Between Given Geometries and Known Far Fields.

    DTIC Science & Technology

    1984-09-01

    A conformal transformation formula using Riemann-Stieltjes integrals is derived for use with problems involving the interaction between a given finite-sized geometry and a known far field. The derivative of this transformation is non-singular in the domain considered and tends to one at infinity. A formula is derived for transformation from the unit circle to the exterior of an arbitrarily given continuous curve with bounded variation . A special case of the transformation is very similar

  12. 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.

  13. 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.

  14. Bystander effects and radiotherapy.

    PubMed

    Marín, Alicia; Martín, Margarita; Liñán, Olga; Alvarenga, Felipe; López, Mario; Fernández, Laura; Büchser, David; Cerezo, Laura

    2015-01-01

    Radiation-induced bystander effects are defined as biological effects expressed after irradiation by cells whose nuclei have not been directly irradiated. These effects include DNA damage, chromosomal instability, mutation, and apoptosis. There is considerable evidence that ionizing radiation affects cells located near the site of irradiation, which respond individually and collectively as part of a large interconnected web. These bystander signals can alter the dynamic equilibrium between proliferation, apoptosis, quiescence or differentiation. The aim of this review is to examine the most important biological effects of this phenomenon with regard to areas of major interest in radiotherapy. Such aspects include radiation-induced bystander effects during the cell cycle under hypoxic conditions when administering fractionated modalities or combined radio-chemotherapy. Other relevant aspects include individual variation and genetics in toxicity of bystander factors and normal tissue collateral damage. In advanced radiotherapy techniques, such as intensity-modulated radiation therapy (IMRT), the high degree of dose conformity to the target volume reduces the dose and, therefore, the risk of complications, to normal tissues. However, significant doses can accumulate out-of-field due to photon scattering and this may impact cellular response in these regions. Protons may offer a solution to reduce out-of-field doses. The bystander effect has numerous associated phenomena, including adaptive response, genomic instability, and abscopal effects. Also, the bystander effect can influence radiation protection and oxidative stress. It is essential that we understand the mechanisms underlying the bystander effect in order to more accurately assess radiation risk and to evaluate protocols for cancer radiotherapy.

  15. [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.

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

    PubMed

    Lárraga-Gutiérrez, José Manuel

    2015-08-07

    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.

  17. 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.

  18. 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

  19. [Radiotherapy of bone metastases].

    PubMed

    Thureau, S; Vieillard, M-H; Supiot, S; Lagrange, J-L

    2016-09-01

    Radiotherapy plays a major role in palliative treatment of bone metastases. Recent developments of stereotactic radiotherapy and intensity modulated radiation therapy give the possibility to treat oligometastatic diseases. The objective of this paper is to report indications and treatment modalities of radiotherapy in these situations.

  20. 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

  1. 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.

  2. The Driving Visual Field and a History of Motor Vehicle Collision Involvement in Older Drivers: A Population-Based Examination

    PubMed Central

    Huisingh, Carrie; McGwin, Gerald; Wood, Joanne; Owsley, Cynthia

    2015-01-01

    Purpose. We designed a visual field test focused on the field utilized while driving to examine associations between field impairment and motor vehicle collision involvement in 2000 drivers aged 70 years or older. Methods. The “driving visual field test” involved measuring light sensitivity for 20 targets in each eye, extending 15° superiorly, 30° inferiorly, 60° temporally, and 30° nasally. The target locations were selected on the basis that they fell within the field region utilized when viewing through the windshield of a vehicle or viewing the dashboard while driving. Monocular fields were combined into a binocular field based on the more sensitive point from each eye. Severe impairment in the overall field or a region was defined as average sensitivity in the lowest quartile of sensitivity. At-fault collision involvement for 5 years prior to enrollment was obtained from state records. Poisson regression was used to calculate crude and adjusted rate ratios (RRs) examining the association between field impairment and at-fault collision involvement. Results. Drivers with severe binocular field impairment in the overall driving visual field had a 40% increased rate of at-fault collision involvement (RR, 1.40; 95% confidence interval [CI]: 1.07–1.83). Impairment in the lower and left fields was associated with elevated collision rates (RR, 1.40; 95% CI: 1.07–1.82 and RR, 1.49; 95% CI: 1.15–1.92, respectively), whereas impairment in the upper and right field regions was not. Conclusions. Results suggest that older drivers with severe impairment in the lower or left region of the driving visual field are more likely to have a history of at-fault collision involvement. PMID:25395488

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

    SciTech Connect

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

    2009-01-01

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

  4. Radiotherapy on hidradenocarcinoma

    PubMed Central

    Lalya, Issam; Hadadi, Khalid; Tazi, El Mehdi; Lalya, Ilham; Bazine, Amine; Andaloussy, Khalid; Elmarjany, Mohamed; Sifat, Hassan; Hassouni, Khalid; Kebdani, Tayeb; Mansouri, Hamid; Benjaafar, Noureddine; Elgueddari, Brahim Khalil

    2011-01-01

    Context: Clear cell Hidradenocarcinoma is a rare carcinoma arising from sweat glands. It is an aggressive tumor that most metastasizes to regional lymph nodes and distant viscera; surgery with safe margins is the mainstay of treatment. Case Report: We report a case of 68-year-old woman who presented with an invasive clear cell hidradenocarcinoma situated in the left parotid area which recurred 5 months after surgery, this recurrence was managed successfully by high-dose irradiation of the tumor bed (66 Gy) and regional lymphatic chains (50 Gy), after a follow-up of more than 15 months, the patient is in good local control without significant toxicity. Conclusion: Post operative radiotherapy allows better local control and should be mandatory when histological features predictive of recurrence are present: positive margins, histology poorly differentiated, perineural invasion, vascular and lymphatic invasion, lymph node involvement, and extracapsular spread. PMID:22540063

  5. The involvement of Ca2+ and integrins in directional responses of zebrafish keratocytes to electric fields.

    PubMed

    Huang, Ling; Cormie, Peter; Messerli, Mark A; Robinson, Kenneth R

    2009-04-01

    Many cells respond directionally to small DC electrical fields (EFs) by an unknown mechanism, but changes in intracellular Ca(2+) are widely assumed to be involved. We have used zebrafish (Danio rerio) keratocytes in an effort to understand the nature of the EF-cell interaction. We find that the adult zebrafish integument drives substantial currents outward through wounds produced by scale removal, establishing that keratocytes near the wound will experience endogenous EFs. Isolated keratocytes in culture turn toward the cathode in fields as small as 7 mV mm(-1), and the response is independent of cell size. Epidermal sheets are similarly sensitive. The frequency of intracellular Ca(2+) spikes and basal Ca(2+) levels were increased by EFs, but the spikes were not a necessary aspect of migration or EF response. Two-photon imaging failed to detect a pattern of gradients of Ca(2+) across the lamellipodia during normal or EF-induced turning but did detect a sharp, stable Ca(2+) gradient at the junction of the lamellipodium and the cell body. We conclude that gradients of Ca(2+) within the lamellipodium are not required for the EF response. Immunostaining revealed an anode to cathode gradient of integrin beta1 during EF-induced turning, and interference with integrin function attenuated the EF response. Neither electrophoretic redistribution of membrane proteins nor asymmetric perturbations of the membrane potential appear to be involved in the EF response, and we propose a new model in which hydrodynamic forces generated by electro-osmotic water flow mediate EF-cell interactions via effects on focal adhesions.

  6. Efficacy and complications of radiotherapy of anterior visual pathway tumors

    SciTech Connect

    Capo, H.; Kupersmith, M.J. )

    1991-02-01

    A progressive disturbance in visual acuity or visual field, along with an unexplained optic nerve atrophy, suggests the possibility of a tumor. Tumors that frequently affect the anterior visual pathway include primary optic nerve sheath meningiomas, intracranial meningiomas, optic gliomas, pituitary tumors, and craniopharyngiomas. The location of these tumors sometimes prohibits a complete surgical excision that might jeopardize the visual system. Radiation therapy, however, can be beneficial in these cases. This article reviews the indications for radiotherapy of tumors that involve the anterior visual pathway, along with the possible complications. Cases that present the effect of radiation therapy and radiation damage are presented.131 references.

  7. 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

  8. [Radiotherapy of hypopharynx cancers].

    PubMed

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

    2016-09-01

    The intensity-modulated radiotherapy is the gold standard in the treatment of hypopharynx cancers. Early T1 and T2 tumours could be treated by exclusive radiotherapy or surgery. For tumours requiring total pharyngolaryngectomy (T2 or T3), induction chemotherapy followed by exclusive radiotherapy or concurrent chemoradiotherapy are possible. For T4 tumours, 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, curative dose is 70Gy and 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 for locally advanced cancers with dose levels based on pathologic criteria (66Gy for R1 resection, 50 to 54Gy for complete resection). Volume delineation is based on guidelines.

  9. Heavy-ion radiotherapy

    NASA Astrophysics Data System (ADS)

    Kanai, Tatsuaki

    2000-11-01

    Heavy-ion radiotherapy using high-energy carbon beams has been performed at the National Institute of Radiological Sciences, Japan. The physical frame works for heavy-ion radiotherapy are established using physical understandings of radiation physics. In order to increase the accuracy of heavy-ion radiotherapy, many physical problems should be solved. Unsolved problems, such as the depth dose distributions, range of heavy-ion in patients and heavy-ion dosimetry in the radiation therapy, are discussed. .

  10. [Radiotherapy of oropharynx carcinoma].

    PubMed

    Servagi Vernat, S; Tochet, F; Vieillevigne, L; Pointreau, Y; Maingon, P; Giraud, P

    2016-09-01

    Indication, doses, technique of radiotherapy and concomitant chemotherapy for oropharynx carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed.

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

    SciTech Connect

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

    2013-07-01

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

  12. 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

  13. Frontal eye field involvement in sustaining visual attention: evidence from transcranial magnetic stimulation.

    PubMed

    Esterman, Michael; Liu, Guanyu; Okabe, Hidefusa; Reagan, Andrew; Thai, Michelle; DeGutis, Joe

    2015-05-01

    The frontal eye field (FEF), particularly the right FEF, is broadly implicated in top-down control of transient acts of attention, but less is known about its involvement in sustained attention. Although neuroimaging studies of sustained attention tasks commonly find FEF activation, it is unclear how this region contributes to moment-to-moment fluctuations in sustained performance. We sought to determine if the FEF plays a critical role in sustained attention, and if that role differs between periods of worse performance (out-of-the-zone) and periods of better performance (in-the-zone). We used offline 1 Hz repetitive transcranial magnetic stimulation (TMS) to temporarily attenuate either right or left FEF excitability while participants performed a go/no-go sustained attention task (the gradual onset continuous performance task). The results demonstrate that following TMS to the right FEF, sustained attention during in-the-zone periods significantly worsened both in terms of lower accuracy and increased reaction time variability. In contrast, applying TMS to the left FEF did not significantly affect accuracy or variability. These results demonstrate that the right FEF plays a crucial role in supporting optimal sustained attention.

  14. 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.

  15. 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).

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

    PubMed

    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.

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

    PubMed Central

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

    1995-01-01

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

  18. [Prostate cancer external beam radiotherapy].

    PubMed

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

    2016-09-01

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

  19. Radiotherapy of stage IEA primary breast lymphoma: case report.

    PubMed

    Juretić, Antonio; Zivković, Mirko; Samija, Mirko; Bagović, Davorin; Purisić, Anka; Viculin, Tomislav; Bistrović, Matija; Stanec, Mladen; Juzbasić, Stjepan; Lesar, Miro; Tomek, Rudolf

    2002-10-01

    A 47-year-old woman was referred for the treatment to our Hospital because of a palpable nodule in the upper medial quadrant of her right breast. After tumor excision, pathohistological examination showed a follicular center cell lymphoma grade 2, B-cell type (CD20+, bc16+, CD10+, bcl2+). The final diagnosis was stage IEA primary extranodal non-Hodgkin s breast lymphoma. The involved breast was irradiated isocentrically with two opposite 6-megavolt (MeV) photon beams delivered from the linear accelerator (tangential fields) using asymmetric collimator opening. Radiation volume, inclinations of the medial and lateral field, and the part of the underlying chest wall and lung parenchyma were determined during the radiotherapy simulation process. The total irradiation dose was 44 Gy delivered in single daily doses of 2 Grays (Gy). After breast photon irradiation, a boost to the tumor bed was performed by a direct 12 MeV electron beam, with a total dose of 6 Gy delivered over three days. Since primary non-Hodgkin lymphoma of the breast is rather rare, there has been no uniform approach to its treatment. The advantage of applying the asymmetric collimator jaw opening in breast radiotherapy is the instant reduction of the dose at margin fields, resulting in both the protection of neighboring lung parenchyma and the good coverage of planned target volume.

  20. 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)

  1. 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.

  2. Radiotherapy-induced hypopituitarism: a review.

    PubMed

    Sathyapalan, Thozhukat; Dixit, Sanjay

    2012-05-01

    Hypopituitarism is a disorder caused by impaired hormonal secretions from the hypothalamic-pituitary axis. Radiotherapy is the most common cause of iatrogenic hypopituitarism. The hypothalamic-pituitary axis inadvertently gets irradiated in patients receiving prophylactic cranial radiotherapy for leukemia, total body irradiation and radiotherapy for intracranial, base skull, sinonasal and nasopharyngeal tumors. Radiation-induced hypopituitarism (RIH) is insidious, progressive and largely nonreversible. Mostly, RIH involves one hypothalamic-pituitary axis; however, multiple hormonal axes deficiency starts developing at higher doses. Although the clinical effects of the hypopituitarism are more profound in children and young adults, its implications in older adults are being increasingly recognized. The risk continues to persist or increase up to 10 years following radiation exposure. The clinical management of hypopituitarism is challenging both for the patients and healthcare providers. Here we have reviewed the scale of the problem, the risk factors and the management of RIH.

  3. 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.

  4. 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.

  5. Involvement of eddy currents in the mutagenicity of ELF magnetic fields.

    PubMed

    Koana, T; Okada, M O; Takashima, Y; Ikehata, M; Miyakoshi, J

    2001-05-09

    Possible carcinogenic and/or mutagenic activity of extremely low frequency magnetic fields was examined using somatic mutation and recombination test system of Drosophila melanogaster. An X-linked semi-dominant DNA repair defective mutation mei-41(D5) was introduced into the conventional mwh/flr test system to enhance mutant spot frequency. Virgin females of w mei-41(D5)/FM6; flr/TM6 were crossed with w mei-41(D5)/Y; mwh jv; spa(pol) males. The F(1) third instar larvae were exposed to a 50Hz, 20mT sinusoidal AC magnetic field for 24h. After moulting from pupal cases, their wings were examined under a bright field microscope to detect hair spots with mwh or flr mutant morphology. The exposure caused a statistically significant enhancement in somatic recombination spot frequency. Mutant spots arising due to chromosomal non-disjunction or terminal deletion also increased but the frequency of spots resulting from point mutation was not altered. The enhancement in the recombination spot frequency was suppressed to the control level when a culture medium without electrolytes was used during exposure. When larvae were exposed to a magnetic field in an annular dish, flies from the outer ring showed more mutant spots compared to those from the inner ring. These results suggest that the detected mutagenic activity was that of the induced eddy current, rather than that of the magnetic field itself.

  6. 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

  7. Effect of topical vasoconstrictor exposure upon tumoricidal radiotherapy.

    PubMed

    Fahl, William E

    2014-08-15

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

  8. 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…

  9. [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.

  10. [Radiotherapy for retroperitoneal sarcomas].

    PubMed

    Sargos, P; Stoeckle, E; Henriques de Figueiredo, B; Antoine, M; Delannes, M; Mervoyer, A; Kantor, G

    2016-10-01

    The management of retroperitoneal sarcoma can be very challenging, and the quality of initial treatment strategy appears to be a crucial prognostic factor. En bloc surgery is currently the standard of care for these rare tumours and perioperative treatments such as chemotherapy or radiotherapy have not been validated yet. However, local-regional relapse constitutes the most common disease course. While adjuvant radiotherapy is less and less common due to gastrointestinal toxicities, preoperative radiation therapy offers numerous advantages and is being evaluated as part of a national multicentre phase II study (TOMOREP trial) and is the subject of a European randomized phase III study (STRASS trial). The objective of this article is to present data on preoperative irradiation in terms of dose, volumes and optimal radiotherapy techniques for the treatment of this rare disease.

  11. 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

  12. 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

  13. Results of patient specific quality assurance for patients undergoing stereotactic ablative radiotherapy for lung lesions.

    PubMed

    Hardcastle, Nicholas; Clements, Natalie; Chesson, Brent; Aarons, Yolanda; Cramb, Jim; Siva, Shankar; Wanigaratne, Derrick M; Ball, David; Kron, Tomas

    2014-03-01

    Hypofractionated image guided radiotherapy of extracranial targets has become increasingly popular as a treatment modality for inoperable patients with one or more small lesions, often referred to as stereotactic ablative body radiotherapy (SABR). This report details the results of the physical quality assurance (QA) program used for the first 33 lung cancer SABR radiotherapy 3D conformal treatment plans in our centre. SABR involves one or few fractions of high radiation dose delivered in many small fields or arcs with tight margins to mobile targets often delivered through heterogeneous media with non-coplanar beams. We have conducted patient-specific QA similar to the more common intensity modulated radiotherapy QA with particular reference to motion management. Individual patient QA was performed in a Perspex phantom using point dose verification with an ionisation chamber and radiochromic film for verification of the dose distribution both with static and moving detectors to verify motion management strategies. While individual beams could vary by up to 7%, the total dose in the target was found to be within ±2% of the prescribed dose for all 33 plans. Film measurements showed qualitative and quantitative agreement between planned and measured isodose line shapes and dimensions. The QA process highlighted the need to account for couch transmission and demonstrated that the ITV construction was appropriate for the treatment technique used. QA is essential for complex radiotherapy deliveries such as SABR. We found individual patient QA helpful in setting up the technique and understanding potential weaknesses in SABR workflow, thus providing confidence in SABR delivery.

  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. 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

  16. 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

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

    PubMed

    Vaughan, Timothy E; Weaver, James C

    2005-05-01

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

  18. Brain necrosis after radiotherapy for primary intracerebral tumor.

    PubMed

    Hohwieler, M L; Lo, T C; Silverman, M L; Freidberg, S R

    1986-01-01

    Radiotherapy is a standard postoperative treatment for cerebral glioma. We have observed the onset of symptoms related to brain necrosis, as opposed to recurrent tumor, in surviving patients. This has been manifest as dementia with a computed tomographic pattern of low density in the frontal lobe uninvolved with tumor, but within the field of radiotherapy. Two patients presented with mass lesions also unrelated to recurrent tumor. We question the necessity of full brain irradiation and suggest that radiotherapy techniques be altered to target the tumor and not encompass the entire brain.

  19. 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.

  20. SU-E-T-340: Dosimetry of a Small Field Electron Beam for Innovative Radiotherapy of Small Surface Or Internal Tumors

    SciTech Connect

    Reft, C; Lu, Z; Noonan, J

    2015-06-15

    Purpose: An innovative small high intensity electron beams with energies from 6 to 12 MeV is being developed at Argonne National Laboratory to deliver an absorbed dose via a catheter to small malignant and nonmalignant lesions. This study reports on the initial dosimetric characteristics of this electron beam. These include output calibration, percent depth dose, beam profiles and leakage through the catheter. Methods: To simulate the narrow electron beam, the Argonne Wakefield Accelerator is used to produce high energy electron beams. The electron beam from the accelerator is monitored by measuring the current through a transmission coil while the beam shape is observed with a fluorescent screen. The dosimetry properties of the electron beam transmitting through bone and tissue-like materials are measured with nanodot optically stimulated luminescent dosimeters and EDR radiographic film. The 6 MV photon beam from a Varian True beam linac is used to calibrate both the OSLDs and the film. Results: The beam characteristics of the 12 MeV beam were measured. The properties of the small diameter, 5 mm, beam differs from that of broad clinical electron beams from radiotherapy linacs. Due to the lack of scatter from the narrow beam, the maximum dose is at the surface and the depth of the 50% depth dose is 35 mm compared to 51 mm for a clinical 12 MeV. The widths of the 90% isodose measured at the surface and depths of 2, 6, 12, and 16 mm varied from 6.6 to 8.8 mm while the widths of the FWHM isodose varied from 7.8 to 25.5 mm. Conclusion: Initial beam measurements show favorable dosimetric properties for its use in treating either small surface or internal lesions, particularly to deliver radiation at the time of surgery to maximize the dose to the lesion and spare normal tissue.

  1. 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.

  2. 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.

  3. 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.

  4. [Radiotherapy for Graves' ophthalmopathy].

    PubMed

    Kuhnt, T; Müller, A C; Janich, M; Gerlach, R; Hädecke, J; Duncker, G I W; Dunst, J

    2004-11-01

    Graves' ophthalmopathy (GO) is the most frequent extrathyroidal manifestation of Graves' disease, an autoimmune disorder of the thyroid, whereas the precise pathogenesis still remains unclear. In Hashimoto's thyroiditis the occurrence of proptosis is an extremely rare event. The therapy for middle and severe courses of GO shows in partly disappointing results, although several therapy modalities are possible (glucocorticoid therapy, radiotherapy, antithyroid drug treatment, surgery). All these therapies lead in only 40 - 70 % to an improvement of the pathogenic symptoms. An intensive interdisciplinary cooperation is necessary to satisfy the requirements for the treatment of Graves' ophthalmopathy. As a consequence of the very different results of the few of clinical studies that were accomplished with reference to this topic, treatment by radiotherapy in the management of the disease is presently controversially discussed. In the German-speaking countries the radiotherapy is, however, firmly established as a therapy option in the treatment of the moderate disease classes (class 2-5 according to NO SPECS), especially if diplopia is present. This article describes the sequences, dosages and fractionation schemes as well as the risks and side effects of the radiotherapy. Altogether, radiotherapy is assessed as an effective and sure method. The administration of glucocorticoids can take place before the beginning of or during the radiotherapy. For the success of treatment the correct selection of patients who may possibly profit from a radiotherapy is absolutely essential. By realising that GO proceeds normally over a period of 2-5 years, which is followed by a period of fibrotic alteration, the application of the radiotherapy in the early, active phase is indispensable. A precise explanation for the effects of radiotherapy in treatment of the GO does not exist at present. The determination of the most effective irradiation doses was made from retrospectively evaluated

  5. 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

  6. 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

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

    PubMed

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

    2012-08-01

    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.

  8. Melanoma: Last call for radiotherapy.

    PubMed

    Espenel, Sophie; Vallard, Alexis; Rancoule, Chloé; Garcia, Max-Adrien; Guy, Jean-Baptiste; Chargari, Cyrus; Deutsch, Eric; Magné, Nicolas

    2017-02-01

    Melanoma is traditionally considered to be a radioresistant tumor. However, radiotherapy and immunotherapy latest developments might upset this radiobiological dogma. Stereotactic radiotherapy allows high dose per fraction delivery, with high dose rate. More DNA lethal damages, less sublethal damages reparation, endothelial cell apoptosis, and finally clonogenic cell dysfunction are produced, resulting in improved local control. Radiotherapy can also enhance immune responses, inducing neoantigens formation, tumor antigen presentation, and cytokines release. A synergic effect of radiotherapy with immunotherapy is expected, and might lead to abscopal effects. If hadrontherapy biological properties seem able to suppress hypoxia-induced radioresistance and increase biological efficacy, ballistic advantages over photon radiations might also improve radiotherapy outcomes on usually poor prognosis locations. The present review addresses biological and clinical effects of high fraction dose, bystander effect, abscopal effect, and hadrontherapy features in melanoma. Clinical trials results are warranted to establish indications of innovative radiotherapy in melanoma.

  9. Accident prevention in radiotherapy

    PubMed Central

    Holmberg, O

    2007-01-01

    In order to prevent accidents in radiotherapy, it is important to learn from accidents that have occurred previously. Lessons learned from a number of accidents are summarised and underlying patterns are looked for in this paper. Accidents can be prevented by applying several safety layers of preventive actions. Categories of these preventive actions are discussed together with specific actions belonging to each category of safety layer. PMID:21614274

  10. [Radiotherapy of bladder cancer].

    PubMed

    Riou, O; Chauvet, B; Lagrange, J-L; Martin, P; Llacer Moscardo, C; Charissoux, M; Lauche, O; Aillères, N; Fenoglietto, P; Azria, D

    2016-09-01

    Surgery (radical cystectomy) is the standard treatment of muscle-invasive bladder cancer. Radiochemotherapy has risen as an alternative treatment option to surgery as part as organ-sparing combined modality treatment or for patients unfit for surgery. Radiochemotherapy achieves 5-year bladder intact survival of 40 to 65% and 5-year overall survival of 40 to 50% with excellent quality of life. This article introduces the French recommendations for radiotherapy of bladder cancer: indications, exams, technique, dosimetry, delivery and image guidance.

  11. Radiotherapy DICOM packet sniffing.

    PubMed

    Ackerly, T; Gesoand, M; Smith, R

    2008-09-01

    The Digital Imaging and Communications in Medicine (DICOM) standard is meant to allow communication of medical images between equipment provided by different vendors, but when two applications do not interact correctly in a multi-vendor environment it is often first necessary to demonstrate non-compliance of either the sender or the receiver before a resolution to the problem can be progressed. Sometimes the only way to do this is to monitor the network communication between the two applications to find out which one is not complying with the DICOM standard. Packet sniffing is a technique of network traffic analysis by passive observation of all information transiting a point on the network, regardless of the specified sender or receiver. DICOM packet sniffing traps and interprets the network communication between two DICOM applications to determine which is non compliant. This is illustrated with reference to three examples, a radiotherapy planning system unable to receive CT data from a particular CT scanner, a radiotherapy simulator unable to print correctly on a DICOM printer, and a PACS unable to respond when queried about what images it has in its archive by a radiotherapy treatment planning system. Additionally in this work it has been proven that it is feasible to extract DICOM images from the intercepted network data. This process can be applied to determine the cause of a DICOM image being rendered differently by the sender and the receiver.

  12. Imaging in radiotherapy.

    PubMed

    Van den Berge, D L; De Ridder, M; Storme, G A

    2000-10-01

    Radiotherapy, more then any other treatment modality, relies heavily and often exclusively on medical imaging to determine the extent of disease and the spatial relation between target region and neighbouring healthy tissues. Radically new approaches to radiation delivery are inspired on CT scanning and treat patients in a slice-by-slice fashion using intensity modulated megavoltage fan beams. For quality assurance of complex 3-D dose distributions, MR based 3-D verificative dosimetry on irradiated phantoms has been described. As treatment delivery becomes increasingly refined, the need for accurate target definition increases as well and sophisticated imaging tools like image fusion and 3-D reconstruction are routinely used for treatment planning. While in the past patients were positioned on the treatment machines based exclusively on surface topography and the well-known skin marks, such approach is no longer sufficient for high-accuracy radiotherapy and special imaging tools like on-line portal imaging are used to verify and correct target positioning. Much of these applications rely on digital image processing, transmission and storage, and the development of standards, like DICOM and PACS have greatly contributed to these applications. Digital imaging plays an increasing role in many areas in radiotherapy and has been fundamental in new developments that have demonstrated impact on patient care.

  13. [Radiotherapy for primary lung carcinoma].

    PubMed

    Giraud, P; Lacornerie, T; Mornex, F

    2016-09-01

    Indication, doses, technique of radiotherapy and concomitant chemotherapy, for primary lung carcinoma are presented. The recommendations for delineation of the target volumes and organs at risk are detailed.

  14. Open field exposure facilitates recovery from an aversive emotional event: Involvement of adrenergic and cholinergic transmitter systems.

    PubMed

    Psyrdellis, Mariana; Pautassi, Ricardo Marcos; Justel, Nadia

    2016-10-28

    Successive negative contrast (SNC) is an incentive relativity procedure that has been widely used to model emotional reactivity in rodents. The reward downshift experienced during SNC is thought to result in frustration. The exploration of a novel open field (OF), a complex situation involving stress induction and novelty detection, can enhance or block the acquisition of associative and non-associative memories. Previous experiments found a modulatory effect of OF, applied before downshift trials, on SNC. This schedule, however, can affect retention performance by influencing attentional, motivational, motor or sensory-perceptual mechanisms at training or retention testing. The use of post-training OF exposure avoids these confounds. This work assessed the effect of OF exposure after the acquisition of the downshifted memory, with the goal of targeting the consolidation of this mnemonic trace. We also investigated the involvement of the cholinergic and adrenergic systems in this phenomenon. The results indicated that OF facilitates recovery from reward loss and that both transmitter systems, cholinergic and adrenergic, play a role in this effect of OF.

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

    PubMed Central

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

    2016-01-01

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

  16. 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.

  17. Non-reference condition correction factor kNR of typical radiation detectors applied for the dosimetry of high-energy photon fields in radiotherapy.

    PubMed

    Chofor, Ndimofor; Harder, Dietrich; Poppe, Björn

    2012-09-01

    According to accepted dosimetry protocols, the "radiation quality correction factor"k(Q) accounts for the energy-dependent changes of detector responses under the conditions of clinical dosimetry for high-energy photon radiations. More precisely, a factor k(QR) is valid under reference conditions, i.e. at a point on the beam axis at depth 10 cm in a large water phantom, for 10×10 cm(2) field size, SSD 100 cm and the given radiation quality with quality index Q. Therefore, a further correction factor k(NR) has been introduced to correct for the influences of spectral quality changes when detectors are used under non-reference conditions such as other depths, field sizes and off-axis distances, while under reference conditions k(NR) is normalized to unity. In this paper, values of k(NR) are calculated for 6 and 15 MV photon beams, using published data of the energy-dependent responses of various radiation detectors to monoenergetic photon radiations, and weighting these responses with validated photon spectra of clinical high-energy photon beams from own Monte-Carlo-calculations for a wide variation of the non-reference conditions within a large water phantom. Our results confirm the observation by Scarboro et al. [26] that k(NR) can be represented by a unique function of the mean energy Em, weighted by the spectral photon fluence. Accordingly, the numerical variations of Em with depth, field size and off-axis distance have been provided. Throughout all considered conditions, the deviations of the k(NR) values from unity are at most 2% for a Farmer type ion chamber, and they remain below 15% for the thermoluminescent detectors LiF:Mg,Ti and LiF:Mg,Cu,P. For the shielded diode EDP-10, k(NR) varies from unity up to 20%, while the unshielded diode EDD-5 shows deviations up to 60% in the peripheral region. Thereby, the restricted application field of unshielded diodes has been clarified. For small field dosimetry purposes k(NR) can be converted into k(NCSF), the non

  18. 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.

  19. Radiotherapy in Glioblastoma: the Past, the Present and the Future.

    PubMed

    Gzell, C; Back, M; Wheeler, H; Bailey, D; Foote, M

    2017-01-01

    The aim of this review is to explore the changing utility of radiotherapy in the treatment of patients with glioblastoma over the past 60 years. Together with surgery, radiotherapy has always been the cornerstone of treatment of glioblastoma, but techniques have significantly advanced over this time. The exploration of early two-dimensional techniques, investigation of dose escalation, concomitant chemotherapy and modern techniques, including intensity-modulated radiotherapy, image-guided radiotherapy, and volumetric-modulated arc therapy will be covered. In addition, current controversies including decreasing margin size, re-irradiation, treatment of elderly patients, and novel imaging tracers will be discussed. Future directions including immunotherapy and tumour treating fields are examined. Radiotherapy-based treatments cannot rely solely on advances in chemotherapy or immunotherapy to improve the overall survival of patients with glioblastoma. Radiation oncology needs to continue to develop and improve the delivery, target definition, and dose of radiotherapy to these patients to improve their survival and the toxicity associated with treatment.

  20. Results of radiotherapy in non round cell spinal metastasis.

    PubMed

    Kraiwattanapong, Chaiwat; Buranapanitkit, Boonsin; Kiriratnikom, Theerasan

    2004-03-01

    Spinal metastases are commonly encountered by physicians in a variety of clinical fields. There are some controversies in choice of treatment between surgery and radiotherapy. This report is a study of the outcomes of radiotherapy for metastatic nonround cell tumors of the spine. Medical records and films of 31 patients who were treated with radiotherapy at Songklanakarind Hospital were retrospectively reviewed. The most common primary tumors were prostate and breast. One patient had spinal metastases from malignant serous cystadenoma of the fallopian tube of which no previous report has been published. This patient had excellent results after radiotherapy. Back and neck pain were the primary symptoms of the patients, while motor or sensory deficits (or both) were found in 58 per cent of the cases. Seven patients had neurological recovery and 18 patients had pain relief after radiotherapy. Cause of compression is the only factor effecting the result from univariate and multivariate analysis. Spinal cord compressed by a tumor had a better recovery than those which were compressed by a bony fragment or intervertebral disc. The authors concluded that radiotherapy remains a good treatment for patient with non round cell spinal metastasis. Cause of spinal cord compression is the only factor predicting the result of treatment.

  1. Particle radiotherapy for prostate cancer.

    PubMed

    Shioyama, Yoshiyuki; Tsuji, Hiroshi; Suefuji, Hiroaki; Sinoto, Makoto; Matsunobu, Akira; Toyama, Shingo; Nakamura, Katsumasa; Kudo, Sho

    2015-01-01

    Recent advances in external beam radiotherapy have allowed us to deliver higher doses to the tumors while decreasing doses to the surrounding tissues. Dose escalation using high-precision radiotherapy has improved the treatment outcomes of prostate cancer. Intensity-modulated radiation therapy has been widely used throughout the world as the most advanced form of photon radiotherapy. In contrast, particle radiotherapy has also been under development, and has been used as an effective and non-invasive radiation modality for prostate and other cancers. Among the particles used in such treatments, protons and carbon ions have the physical advantage that the dose can be focused on the tumor with only minimal exposure of the surrounding normal tissues. Furthermore, carbon ions also have radiobiological advantages that include higher killing effects on intrinsic radio-resistant tumors, hypoxic tumor cells and tumor cells in the G0 or S phase. However, the degree of clinical benefit derived from these theoretical advantages in the treatment of prostate cancer has not been adequately determined. The present article reviews the available literature on the use of particle radiotherapy for prostate cancer as well as the literature on the physical and radiobiological properties of this treatment, and discusses the role and the relative merits of particle radiotherapy compared with current photon-based radiotherapy, with a focus on proton beam therapy and carbon ion radiotherapy.

  2. Characteristics of in vivo radiotherapy dosimetry.

    PubMed

    Edwards, C R; Mountford, P J

    2009-11-01

    The recent discussion and debate about the use of in vivo dosimetry as a routine component of the radiotherapy treatment process has not included the limitations introduced by the physical characteristics of the detectors. Although a robust calibration procedure will ensure acceptable uncertainties in the measurements of tumour dose, further work is required to confirm the accuracy of critical organ measurements with a diode or a thermoluminescent dosemeter outside the main field owing to limitations caused by a non-uniform X-ray energy response of the detector, differences between the X-ray energy spectrum inside and outside the main field, and contaminating electrons.

  3. 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

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

    PubMed

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

    1984-01-01

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

  5. Radiotherapy in the UK

    SciTech Connect

    Ramsay, S.

    1993-10-09

    What is wrong with radiation treatment in the UK Is it bad practice or merely bad publicity Between 1982 and 1991, 1,000 patients receiving isocentric radiation therapy at the North Staffordshire Royal Infirmary received a substantial underdose of radiation; the clinical report on this incident was published last week. The operator had been using a correction factor for tumor-to-skin distance, unaware that this factor had already been applied by the computer system. Although the report pointed out that it is not surprising that the clinicians were not alerted to the undertreatment, is also noted that there were no resources at the hospital to audit the outcome of radiotherapy.

  6. [Radiotherapy during pregnancy].

    PubMed

    Mazeron, R; Barillot, I; Mornex, F; Giraud, P

    2016-09-01

    The diagnostic of cancer during pregnancy is a rare and delicate situation. As the developments of the embryo and the human fetus are extremely sensitive to ionizing radiations, the treatment of these tumors should be discussed. The studies - preclinical and clinical - based mostly on exposure accidents show that subdiaphragmatic treatments are possible during pregnancy. When radiotherapy is used, phantom estimations of the dose to the fetus, confirmed by in vivo measurements are required. Irradiation and imaging techniques should be arranged to decrease as much as possible the dose delivered to the fetus and hold below the threshold of 0.1Gy.

  7. SU-E-T-399: Evaluation of Selection Criteria for Computational Human Phantoms for Use in Out-Of-Field Organ Dosimetry for Radiotherapy Patients

    SciTech Connect

    Pelletier, C; Jung, J; Lee, C; Pyakuryal, A; Lee, C; Kim, J

    2015-06-15

    Purpose: To quantify the dosimetric uncertainty due to organ position errors when using height and weight as phantom selection criteria in the UF/NCI Hybrid Phantom Library for the purpose of out-of-field organ dose reconstruction. Methods: Four diagnostic patient CT images were used to create 7-field IMRT plans. For each patient, dose to the liver, right lung, and left lung were calculated using the XVMC Monte Carlo code. These doses were taken to be the ground truth. For each patient, the phantom with the most closely matching height and weight was selected from the body size dependent phantom library. The patient plans were then transferred to the computational phantoms and organ doses were recalculated. Each plan was also run on 4 additional phantoms with reference heights and or weights. Maximum and mean doses for the three organs were computed, and the DVHs were extracted and compared. One sample t-tests were performed to compare the accuracy of the height and weight matched phantoms against the additional phantoms in regards to both maximum and mean dose. Results: For one of the patients, the height and weight matched phantom yielded the most accurate results across all three organs for both maximum and mean doses. For two additional patients, the matched phantom yielded the best match for one organ only. In 13 of the 24 cases, the matched phantom yielded better results than the average of the other four phantoms, though the results were only statistically significant at the .05 level for three cases. Conclusion: Using height and weight matched phantoms does yield better results in regards to out-of-field dosimetry than using average phantoms. Height and weight appear to be moderately good selection criteria, though this selection criteria failed to yield any better results for one patient.

  8. 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.

  9. Fertility impairment in radiotherapy

    PubMed Central

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

    2016-01-01

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

  10. [Hodgkin's lymphoma and radiotherapy].

    PubMed

    Datsenko, P V; Panshin, G A

    2015-01-01

    After a median observation time of 4,5 years, 440 patients with Hodgkin's lymphoma stage I-IV to the Ann Arbor classification were treated with radiotherapy (2200 lymph areas) and ABVD (n=204) or BEACOPP (n=117) or CEA/ABVD (lomustine, etoposide, adriamycine, bleomycine, vinblastine and dacarbacine; n=119) regimens in 1995-2012. Correct allocation of groups with "CR or PR ≥80%" and "PR: 0-79%", after first-line chemotherapy, is extremely important for following RT planning. Adaptation of patients with Hodgkin's lymphoma can take place only after successful treatment, the probability of relapse and fear of repeated courses strongly interfere with this process, especially in the first years after its closure. Duration of remission period, especially in young people, is no less important than the criteria for overall survival. It is impossible to build recommendations for treatment for Hodgkin's lymphoma, based only on long-term survival rates. Importance of radiotherapy in reducing the number of relapses is undeniable, so the idea that the development of the role of chemotherapy in the treatment of the ray method Hodgkin's lymphoma gradually becomes secondary is in serious doubt. Our findings suggest the importance of both maintaining a high disease-free survival and reducing long-term complications in designing treatments of Hodgkin's lymphoma.

  11. [Stereotactic radiosurgery and radiotherapy for brain metastases].

    PubMed

    Tanguy, Ronan; Métellus, Philippe; Mornex, Françoise; Mazeron, Jean-Jacques

    2013-01-01

    Brain metastases management is still controversial even though many trials are trying to define the respective roles of neurosurgery, whole-brain radiotherapy, single-dose stereotactic radiotherapy and fractionated stereotactic radiotherapy. In this article, we review data from trials that examine the role of radiosurgery and fractionated stereotactic radiotherapy in the management of brain metastases.

  12. Effects of 2.45 GHz microwave fields on liposomes entrapping glycoenzyme ascorbate oxidase: evidence for oligosaccharide side chain involvement.

    PubMed

    Ramundo-Orlando, Alfonsina; Liberti, Micaela; Mossa, Giuseppe; D'Inzeo, Guglielmo

    2004-07-01

    Previous observations reported by our group indicate that 2.45 GHz microwave fields at specific absorption rate (SAR) of 5.6 W/kg reduce the enzyme activity rate of ascorbate oxidase (AO) trapped in liposomes. In this study, we report dose-response studies on these AO containing liposomes irradiated at different SAR values (1.4, 2.8, 4.2, and 5.6 W/kg). No response was observed for SAR below 5.6 W/kg. Liposomes entrapping functional AO in its deglycated form (AO-D) were also used. In this case, no MW related enzyme activity changes were observed, demonstrating a direct involvement of oligosaccharide chains of AO. Furthermore, the catalytic properties of both AO and AO-D were not impaired by MW irradiation, neither in homogeneous solution nor loaded in liposomes, excluding possible changes in the conformation of enzyme as a mechanism. Our results suggest that the oligosaccharide chains of AO are critical to elicit the microwave observed effects on lipid membrane.

  13. Identification and expression analysis of the genes involved in serotonin biosynthesis and transduction in the field cricket Gryllus bimaculatus.

    PubMed

    Watanabe, T; Sadamoto, Hitoshi; Aonuma, H

    2011-10-01

    Serotonin (5-HT) modulates various aspects of behaviours such as aggressive behaviour and circadian behaviour in the cricket. To elucidate the molecular basis of the cricket 5-HT system, we identified 5-HT-related genes in the field cricket Gryllus bimaculatus DeGeer. Complementary DNA of tryptophan hydroxylase and phenylalanine-tryptophan hydroxylase, which convert tryptophan into 5-hydroxy-L-tryptophan (5-HTP), and that of aromatic L-amino acid decarboxylase, which converts 5-HTP into 5-HT, were isolated from a cricket brain cDNA library. In addition, four 5-HT receptor genes (5-HT(1A) , 5-HT(1B) , 5-HT(2α) , and 5-HT(7) ) were identified. Expression analysis of the tryptophan hydroxylase gene TRH and phenylalanine-tryptophan hydroxylase gene TPH, which are selectively involved in neuronal and peripheral 5-HT synthesis in Drosophila, suggested that two 5-HT synthesis pathways co-exist in the cricket neuronal tissues. The four 5-HT receptor genes were expressed in various tissues at differential expression levels, suggesting that the 5-HT system is widely distributed in the cricket.

  14. 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.

  15. 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.

  16. Radiotherapy in Phyllodes Tumour

    PubMed Central

    Sasidharan, Balukrishna; Manipadam, Marie Therese; Paul, M J; Backianathan, Selvamani

    2017-01-01

    Introduction Phyllodes Tumour (PT) of the breast is a relatively rare breast neoplasm (<1%) with diverse range of pathology and biological behaviour. Aim To describe the clinical course of PT and to define the role of Radiotherapy (RT) in PT of the breast. Materials and Methods Retrospective analysis of hospital data of patients with PT presented from 2005 to 2014 was done. Descriptive statistics was used to analyze the results. Simple description of data was done in this study. Age and duration of symptoms were expressed in median and range. Percentages, tables and general discussions were used to understand the meaning of the data analyzed. Results Out of the 98 patients, 92 were eligible for analysis. The median age of presentation was 43 years. A total of 64/92 patients were premenopausal. There was no side predilection for this tumour but 57/92 patients presented as an upper outer quadrant lump. Fifty percent of the patients presented as giant (10 cm) PT. The median duration of symptoms was 12 months (range: 1-168 months). A 60% of patients had Benign (B), 23% had Borderline (BL) and 17% had malignant (M) tumours. The surgical treatment for benign histology included Lumpectomy (L) for 15%, Wide Local Excision (WLE) for 48%, and Simple Mastectomy (SM) for 37%. All BL and M tumours were treated with WLE or SM. There was no recurrence in B and BL group when the margin was ≥1 cm. All non-metastatic M tumours received adjuvant RT irrespective of their margin status. Total 3/16 patients with M developed local recurrence. Total 6/16 M patients had distant metastases (lung or bone). Our median duration of follow up was 20 months (range: 1-120 months). Conclusion Surgical resection with adequate margins (>1 cm) gave excellent local control in B and BL tumours. For patients with BL PT, local radiotherapy is useful, if margins are close or positive even after the best surgical resection. There is a trend towards improved local control with adjuvant radiotherapy for

  17. 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

  18. [Respiratory synchronization and breast radiotherapy].

    PubMed

    Mège, A; Ziouèche-Mottet, A; Bodez, V; Garcia, R; Arnaud, A; de Rauglaudre, G; Pourel, N; Chauvet, B

    2016-10-01

    Adjuvant radiation therapy following breast cancer surgery continues to improve locoregional control and overall survival. But the success of highly targeted-conformal radiotherapy such as intensity-modulated techniques, can be compromised by respiratory motion. The intrafraction motion can potentially result in significant under- or overdose, and also expose organs at risk. This article summarizes the respiratory motion and its effects on imaging, dose calculation and dose delivery by radiotherapy for breast cancer. We will review the methods of respiratory synchronization available for breast radiotherapy to minimize the respiratory impact and to spare organs such as heart and lung.

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

    PubMed

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

    2013-10-01

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

  20. State of the art of radiotherapy.

    PubMed

    Garrido, Pilar; Olmedo, Eugenia

    2013-06-01

    Locally advanced or stage III disease accounts for ~30% of patients with non-small-cell lung cancer (NSCLC), which means only in the United States, more than 50,000 new patients each year. Stage III is a very heterogeneous disease, the management of patients is complex and several conditions (performance status, weight loss, comorbidities, characteristics of nodal involvement or resectability) must be considered before selecting the best treatment, which in most cases is chemotherapy (CT) and radiotherapy (RT). In this article, we will review key changes in the management of unresectable stage III during the last decades. Also we will highlight some challenges and areas of active research.

  1. Unilateral Radiotherapy for the Treatment of Tonsil Cancer

    SciTech Connect

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

    2012-05-01

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

  2. 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.

  3. 50-Hz extremely low frequency electromagnetic fields enhance cell proliferation and DNA damage: possible involvement of a redox mechanism.

    PubMed

    Wolf, Federica I; Torsello, Angela; Tedesco, Beatrice; Fasanella, Silvia; Boninsegna, Alma; D'Ascenzo, Marcello; Grassi, Claudio; Azzena, Gian Battista; Cittadini, Achille

    2005-03-22

    HL-60 leukemia cells, Rat-1 fibroblasts and WI-38 diploid fibroblasts were exposed for 24-72 h to 0.5-1.0-mT 50-Hz extremely low frequency electromagnetic field (ELF-EMF). This treatment induced a dose-dependent increase in the proliferation rate of all cell types, namely about 30% increase of cell proliferation after 72-h exposure to 1.0 mT. This was accompanied by increased percentage of cells in the S-phase after 12- and 48-h exposure. The ability of ELF-EMF to induce DNA damage was also investigated by measuring DNA strand breaks. A dose-dependent increase in DNA damage was observed in all cell lines, with two peaks occurring at 24 and 72 h. A similar pattern of DNA damage was observed by measuring formation of 8-OHdG adducts. The effects of ELF-EMF on cell proliferation and DNA damage were prevented by pretreatment of cells with an antioxidant like alpha-tocopherol, suggesting that redox reactions were involved. Accordingly, Rat-1 fibroblasts that had been exposed to ELF-EMF for 3 or 24 h exhibited a significant increase in dichlorofluorescein-detectable reactive oxygen species, which was blunted by alpha-tocopherol pretreatment. Cells exposed to ELF-EMF and examined as early as 6 h after treatment initiation also exhibited modifications of NF kappa B-related proteins (p65-p50 and I kappa B alpha), which were suggestive of increased formation of p65-p50 or p65-p65 active forms, a process usually attributed to redox reactions. These results suggest that ELF-EMF influence proliferation and DNA damage in both normal and tumor cells through the action of free radical species. This information may be of value for appraising the pathophysiologic consequences of an exposure to ELF-EMF.

  4. 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.

  5. Radiotherapy Planning using MRI

    PubMed Central

    Schmidt, Maria A; Payne, Geoffrey S

    2016-01-01

    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 minimised, 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. PMID:26509844

  6. [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.

  7. [Radiotherapy for nasopharyngeal carcinoma].

    PubMed

    Maingon, P; Blanchard, P; Bidault, F; Calmels, L

    2016-09-01

    Nasapharyngeal carcinoma is a rare disease. Oftenly, the diagnostic is made for advanced disease. Localized tumors, T1 or T2 NO observed a good prognosis and are locally controlled in more than 90 % of the cases by radiotherapy alone. The standard treatment of locally advanced disease is combined chemoradiation. A special vigilance of fast decrease of the volume of the pathological lymph nodes, sometimes associated to loss of weight might indicate an adaptive dosimetric revision. The treatment of recurrent disease is of great importance. Surgical indications are limited but should be discussed in multidisciplinary tumor board when possible. Surgical nodal sampling has to be proposed for nodal recurrence as well as reirradiation, which could be indicated according to the technical issues.

  8. Pion radiotherapy at LAMPF

    SciTech Connect

    Bush, S.E.; Smith, A.R.; Zink, S.

    1982-12-01

    Clinical investigations of pi meson radiotherapy were conducted by the Cancer Research and Treatment Center of the University of New Mexico and the Los Alamos National Laboratory from 1974 until 1982. Two hundred and thirty patients have been treated for a variety of locally advanced primary and metastatic neoplasms. One hundred and ninety-six patients have been followed for a minimum of 18 months. Crude survival data range from 11% for unresectable pancreatic carcinoma to 82% for Stages C and D1 adenocarcinoma of the prostate. Acute tolerance of normal tissues is approximately 4500 pion rad in 36 fractions over 7 weeks. Severe chronic reactions have appeared with increasing frequency after doses in excess of 4000 pion rad.

  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. Adapting radiotherapy to hypoxic tumours

    NASA Astrophysics Data System (ADS)

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

    2006-10-01

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

  11. 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.

  12. 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

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

    PubMed

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

    1992-09-01

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

  14. Radiotherapy for extramammary Paget disease of the anogenital region.

    PubMed

    Dilmé-Carreras, Elisabet; Iglesias-Sancho, Maribel; Márquez-Balbás, Gemma; Sola-Ortigosa, Joaquín; Umbert-Millet, Pablo

    2011-07-01

    Extramammary Paget disease is a rare condition that most commonly affects the anogenital region in the elderly. The treatment of choice has been surgical excision of the affected area with adequate depth and lateral margins, criteria that cannot always be fulfilled, especially when the vulva, anal canal, or penis are involved. More recently radiotherapy has been suggested as a suitable treatment when surgical excision or other modalities are not appropriate. We report a case of anogenital extramammary Paget disease and the clinical response to treatment with radiotherapy. The aim of this article is to review relevant aspects of radiotherapy as a first-choice curative treatment in specific situations of anogenital extramammary Paget disease in situ.

  15. Status of carbon-ion radiotherapy facilities in Japan

    NASA Astrophysics Data System (ADS)

    Kitagawa, Atsushi

    2013-05-01

    Carbon-ion radiotherapy has large physical and biological advantages, and clinical results performed by HIMAC at NIRS awaken a deep interest. Several hospital-specified facilities are recently under commissioning or construction in Japan. Carbon-ion radiotherapy is based on the advanced technology in wide various fields. In order to promote this treatment method to the daily treatment, constant cooperative efforts by public and private organizations are necessary, i.e. providing of abundant clinical data, technology transfer, personnel training, organizing of the specialists' network, and so on. The present status and future prospects in Japan are reported.

  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. Calcium signaling in lymphocytes and ELF fields. Evidence for an electric field metric and a site of interaction involving the calcium ion channel.

    PubMed

    Liburdy, R P

    1992-04-13

    Calcium influx increased during mitogen-activated signal transduction in thymic lymphocytes exposed to a 22 mT, 60 Hz magnetic field (E induced = 1.7 mV/cm, 37 degrees C, 60 min). To distinguish between an electric or a magnetic field dependence a special multi-ring annular cell culture plate based on Faraday's Law of Induction was employed. Studies show a dependence on the strength of the induced electric field at constant magnetic flux density. Moreover, exposure to a pure 60 Hz electric field or to a magnetically-induced electric field of identical strength resulted in similar changes in calcium transport. The first real-time monitoring of [Ca2+]i during application of a 60 Hz electric field revealed an increase in [Ca2+]i observed 100 s after mitogen stimulation; this suggests that the plateau phase rather than the early phase of calcium signaling was influenced. The hypothesis was tested by separating, in time, the early release of calcium from intracellular stores from the influx of extracellular calcium. In calcium-free buffer, 60 Hz field exerted little influence on the early release of calcium from intracellular stores. In contrast, addition of extracellular calcium during exposure enhanced calcium influx through the plasma membrane. Alteration of the plateau phase of calcium signaling implicates the calcium channel as a site of field interaction. In addition, an electric field exposure metric is mechanistically consistent with a cell-surface interaction site.

  18. Clinical exuberance of classic Kaposi's sarcoma and response to radiotherapy.

    PubMed

    Trujillo, Jeniffer Muñoz; Alves, Natália Ribeiro de Magalhães; Medeiros, Paula Mota; Azulay-Abulafia, Luna; Alves, Maria de Fátima Guimarães Scotelaro; Gripp, Alexandre Carlos

    2015-01-01

    Kaposi's sarcoma (KS) is a multicentric vascular neoplasm, with cutaneous and extracutaneous involvement. Different clinical and epidemiological variants have been identified. The classic form is manifested mainly in elderly men with indolent and long-term evolution, with lesions localized primarily in the lower extremities. We present two cases of classic Kaposi's sarcoma (CKS) in two female patients with extensive, exuberant skin involvement and rapid evolution, with good response to radiotherapy.

  19. Modeling the Risk of Secondary Malignancies after Radiotherapy

    PubMed Central

    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

  20. Understanding Entry-Level Student Affairs Practitioners' Perceptions of and Involvement in Professional Development in the Student Affairs Field

    ERIC Educational Resources Information Center

    Stafford, John D.

    2012-01-01

    The purpose of this study was to investigate entry-level student affairs practitioners' perceptions of professional development and their involvement in individualized professional development opportunities within the student affairs field. The literature review explored the founding of student affairs, a historical review of student affairs,…

  1. Effect of radiotherapy on the natural killer (NK)-cell activity of cancer patients

    SciTech Connect

    McGinnes, K.; Florence, J.; Penny, R.

    1987-05-01

    The aim of this study was to determine the effect of radiotherapy on peripheral blood natural killer (NK)-cell number and activity in 15 patients with cancer, prior to the commencement and at the completion of radiotherapy. The following observations were made. Prior to radiotherapy NK activity could not be correlated with the stage of malignancy. In all patients with advanced disease and with subnormal baseline NK activity, the outcome of radiotherapy was unfavorable. Following radiotherapy to sites including the mediastinum, patients had decreased NK activity compared with those receiving treatment to other sites. This decrease was not related to the dose of radiotherapy or stage of malignancy. The tumor response was favorable in most patients whose NK activity decreased as a result of radiotherapy. The decrease in NK activity may be associated with a decrease in the percentage of NK (N901) cells in the peripheral blood. The reduction in NK activity in those patients receiving mediastinal irradiation may be due to the large volume of blood which transits the field, so that the NK cells, or their more radiosensitive precursors, may be damaged and/or differentiation inhibited. Thus, these new observations show that radiotherapy does indeed affect the NK activity in cancer patients predominantly when the irradiation site includes the mediastinum.

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

    PubMed

    Maingon, P

    2016-10-01

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

  3. [Postoperative radiotherapy of prostate cancer].

    PubMed

    Guérif, S; Latorzeff, I; Lagrange, J-L; Hennequin, C; Supiot, S; Garcia, A; François, P; Soulié, M; Richaud, P; Salomon, L

    2014-10-01

    Between 10 and 40% of patients who have undergone a radical prostatectomy may have a biologic recurrence. Local or distant failure represents the possible patterns of relapse. Patients at high-risk for local relapse have extraprostatic disease, positive surgical margins or seminal vesicles infiltration or high Gleason score at pathology. Three phase-III randomized clinical trials have shown that, for these patients, adjuvant irradiation reduces the risk of tumoral progression without higher toxicity. Salvage radiotherapy for late relapse allows a disease control in 60-70% of the cases. Several research in order to improve the therapeutic ratio of the radiotherapy after prostatectomy are evaluate in the French Groupe d'Étude des Tumeurs Urogénitales (Gétug) and of the French association of urology (Afu). The Gétug-Afu 17 trial will provide answers to the question of the optimal moment for postoperative radiotherapy for pT3-4 R1 pN0 Nx patients, with the objective of comparing an immediate treatment to a differed early treatment initiated at biological recurrence. The Gétug-Afu 22 questions the place of a short hormonetherapy combined with image-guided, intensity-modulated radiotherapy (IMRT) in adjuvant situation for a detectable prostate specific antigen (PSA). The implementation of a multicenter quality control within the Gétug-Afu in order to harmonize a modern postoperative radiotherapy will allow the development of a dose escalation IMRT after surgery.

  4. Our intraoperative boost radiotherapy experience and applications

    PubMed Central

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

    2016-01-01

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

  5. Expanding global access to radiotherapy.

    PubMed

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

    2015-09-01

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

  6. [Head and neck adaptive radiotherapy].

    PubMed

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

    2013-10-01

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

  7. Inflammatory Skin Conditions Associated With Radiotherapy.

    PubMed

    Hernández Aragüés, I; Pulido Pérez, A; Suárez Fernández, R

    2017-04-01

    Radiotherapy for cancer is used increasingly. Because skin cells undergo rapid turnover, the ionizing radiation of radiotherapy has collateral effects that are often expressed in inflammatory reactions. Some of these reactions-radiodermatitis and recall phenomenon, for example-are very familiar to dermatologists. Other, less common radiotherapy-associated skin conditions are often underdiagnosed but must also be recognized.

  8. Radiotherapy supports protective tumor-specific immunity

    PubMed Central

    Gupta, Anurag; Sharma, Anu; von Boehmer, Lotta; Surace, Laura; Knuth, Alexander; van den Broek, Maries

    2012-01-01

    Radiotherapy is an important therapeutic option for the treatment of cancer. Growing evidence indicates that, besides inducing an irreversible DNA damage, radiotherapy promotes tumor-specific immune response, which significantly contribute to therapeutic efficacy. We postulate that radiotherapy activates tumor-associated dendritic cells, thus changing the tolerogenic tumor environment into an immunogenic one. PMID:23264910

  9. Second Malignant Neoplasms Following Radiotherapy

    PubMed Central

    Kumar, Sanath

    2012-01-01

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

  10. Liver-Directed Radiotherapy for Hepatocellular Carcinoma

    PubMed Central

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

    2016-01-01

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

  11. 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.

  12. Arterial stiffness is increased in Hodgkin lymphoma survivors treated with radiotherapy.

    PubMed

    van Leeuwen-Segarceanu, Elena M; Dorresteijn, Lucille D A; Vogels, Oscar J M; Biesma, Douwe H; Bos, Willem-Jan W

    2013-08-01

    Radiotherapy has been associated with an increased risk for cardiovascular disease (CVD) in Hodgkin lymphoma survivors (HLS). Identifying subjects most likely to develop these complications is challenging. Arterial stiffness has been frequently used as an early marker of CVD, but has never previously been investigated in patients treated with radiotherapy. The carotid-femoral pulse wave velocity (PWV) and the distensibility coefficient (DC) of the common carotid artery were used as markers of arterial stiffness. Eighty-two HLS and 40 age- and gender-matched control subjects were studied. The aorta and the carotid arteries were situated within the radiation field in 50 and 39 patients. Mean PWV was not significantly different in HLS treated with radiotherapy on the mediastinum when compared to HLS treated without mediastinal radiotherapy and to controls. If HLS were 40 years or older at radiotherapy their PWV was significantly higher (8.54 m/s) than patients irradiated at a younger age (7.14 m/s, p = 0.004) and controls (6.91 m/s, p < 0.001), after adjusting for current age and other CVD risk factors. Mean DC was lower, indicative of stiffer arteries, in HLS treated with radiotherapy on the common carotid artery (2.79) than in HLS without radiotherapy (3.35, p = 0.029) and versus controls (3.60, p = 0.001). DC was lowest in HLS treated at 35 years of age or later (2.05), compared to HLS irradiated at a younger age (2.98, p = 0.046). In HLS, radiotherapy is associated with increased arterial stiffness. The effect of radiotherapy seems most evident when radiotherapy is administered at ages above 35-40 years.

  13. Radiotherapy dosimetry using a commercial OSL system

    SciTech Connect

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

    2008-04-15

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

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

    PubMed

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

    2015-10-01

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

  15. Light effects on the multicellular magnetotactic prokaryote 'Candidatus Magnetoglobus multicellularis' are cancelled by radiofrequency fields: the involvement of radical pair mechanisms.

    PubMed

    de Melo, Roger Duarte; Acosta-Avalos, Daniel

    2017-02-01

    'Candidatus Magnetoglobus multicellularis' is the most studied multicellular magnetotactic prokaryote. It presents a light-dependent photokinesis: green light decreases the translation velocity whereas red light increases it, in comparison to blue and white light. The present article shows that radio-frequency electromagnetic fields cancel the light effect on photokinesis. The frequency to cancel the light effect corresponds to the Zeeman resonance frequency (DC magnetic field of 4 Oe and radio-frequency of 11.5 MHz), indicating the involvement of a radical pair mechanism. An analysis of the orientation angle relative to the magnetic field direction shows that radio-frequency electromagnetic fields disturb the swimming orientation when the microorganisms are illuminated with red light. The analysis also shows that at low magnetic fields (1.6 Oe) the swimming orientation angles are well scattered around the magnetic field direction, showing that magnetotaxis is not efficiently in the swimming orientation to the geomagnetic field. The results do not support cryptochrome as being the responsible chromophore for the radical pair mechanism and perhaps two different chromophores are necessary to explain the radio-frequency effects.

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

    SciTech Connect

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

    1991-01-01

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

  17. Two cytochrome P450 genes are involved in imidacloprid resistance in field populations of the whitefly, Bemisia tabaci, in China.

    PubMed

    Yang, Xin; Xie, Wen; Wang, Shao-li; Wu, Qing-jun; Pan, Hui-peng; Li, Ru-mei; Yang, Ni-na; Liu, Bai-ming; Xu, Bao-yun; Zhou, Xiaomao; Zhang, You-jun

    2013-11-01

    The sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae), is an invasive and damaging pest of field crops worldwide. The neonicotinoid insecticide imidacloprid has been widely used to control this pest. We assessed the species composition (B vs. Q), imidacloprid resistance, and association between imidacloprid resistance and the expression of five P450 genes for 14-17 B. tabaci populations in 12 provinces in China. Fifteen of 17 populations contained only B. tabaci Q, and two populations contained both B and Q. Seven of 17 populations exhibited moderate to high resistance to imidacloprid, and eight populations exhibited low resistance to imidacloprid, compared with the most susceptible field WHHB population. In a study of 14 of the populations, resistance level was correlated with the expression of the P450 genes CYP6CM1 and CYP4C64 but not with the expression of CYP6CX1, CYP6CX4, or CYP6DZ7. This study indicates that B. tabaci Q has a wider distribution in China than previously reported. Resistance to imidacloprid in field populations of B. tabaci is associated with the increased expression of two cytochrome P450 genes (CYP6CM1 and CYP4C64).

  18. 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

  19. 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.

  20. Radiotherapy T1 glottic carcinoma

    SciTech Connect

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

    1989-11-01

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

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

    PubMed

    Castellanos, María Esperanza

    2006-01-01

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

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

    SciTech Connect

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

    2005-11-01

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

  3. Radiotherapy-induced right ventricular remodelling: The missing piece of the puzzle.

    PubMed

    Tadic, Marijana; Cuspidi, Cesare; Hering, Dagmara; Venneri, Lucia; Grozdic-Milojevic, Isidora

    2017-02-01

    The number of studies demonstrating that right ventricular structure, function and mechanics are valuable predictors of cardiovascular and total morbidity and mortality in patients with a wide range of cardiovascular conditions is constantly increasing. Most studies that evaluated the influence of radiotherapy on the heart focused on left ventricular remodelling, which is why current guidelines only recommend detailed assessment of the left ventricle. Data regarding right ventricular changes in cancer patients treated with radiotherapy are scarce. Given that radiotherapy more often induces late cardiac impairment - unlike chemotherapy-induced cardiotoxicity, which is usually acute - it is quite reasonable to follow these patients echocardiographically for a long time (even for 20years after initiation of radiotherapy). Investigations that have followed cancer survivors for at least 10years after radiotherapy agree that right ventricular structure, systolic/diastolic function and mechanics are significantly impaired. The mechanisms of radiation-induced right ventricular remodelling are still unclear, but it is thought that fibrosis is the dominant factor in myocardial remodelling and vascular changes. Many factors may contribute to right ventricular impairment during and after radiotherapy: cumulative radiation dose; dose per treatment; delivery technique; radiation target (chest and mediastinum); and co-morbidities. In this review, we aim to provide a comprehensive overview of the potential mechanisms of radiation-induced right ventricular remodelling, and to summarize clinical studies involving radiotherapy-treated cancer patients.

  4. Enhancing radiotherapy for lung cancer using immunoadjuvants delivered in situ from new design radiotherapy biomaterials: a preclinical study

    NASA Astrophysics Data System (ADS)

    Hao, Yao; Yasmin-Karim, Sayeda; Moreau, Michele; Sinha, Neeharika; Sajo, Erno; Ngwa, Wilfred

    2016-12-01

    Studies show that radiotherapy of a primary tumor in combination with immunoadjuvants (IA) can result in increased survival or immune-mediated regression of metastasis outside the radiation field, a phenomenon known as abscopal effect. However, toxicities due to repeated systematic administration of IA have been shown to be a major obstacle in clinical trials. To minimize the toxicities and prime a more potent immune response, Ngwa et al have proposed that inert radiotherapy biomaterials such as fiducials could be upgraded to multifunctional ones loaded with IA for in situ delivery directly into the tumor sub-volume at no additional inconvenience to patients. In this preliminary study, the potential of such an approach is investigated for lung cancer using anti-CD40 antibody. First the benefit of using the anti-CD40 delivered in situ to enhance radiotherapy was tested in mice with subcutaneous tumors generated with the Lewis Lung cancer cell line LL/2 (LLC-1). The tumors were implanted on both flanks of the mice to simulate metastasis. Tumors on one flank were treated with and without anti-CD40 and the survival benefits compared. An experimentally determined in vivo diffusion coefficient for nanoparticles was then employed to estimate the time for achieving intratumoral distribution of the needed minimal concentrations of anti-CD40 nanoparticles if released from a multifuntional radiotherapy biomaterials. The studies show that the use of anti-CD40 significantly enhanced radiotherapy effect, slowing the growth of the treated and untreated tumors, and increasing survival. Meanwhile our calculations indicate that for a 2-4 cm tumor and 7 mg g-1 IA concentrations, it would take 4.4-17.4 d, respectively, following burst release, for the required concentration of IA nanoparticles to accumulate throughout the tumor during image-guided radiotherapy. The distribution of IA could be customized as a function of loading concentrations or nanoparticle size to fit current

  5. 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

  6. Monte Carlo dose calculations in advanced radiotherapy

    NASA Astrophysics Data System (ADS)

    Bush, Karl Kenneth

    The remarkable accuracy of Monte Carlo (MC) dose calculation algorithms has led to the widely accepted view that these methods should and will play a central role in the radiotherapy treatment verification and planning of the future. The advantages of using MC clinically are particularly evident for radiation fields passing through inhomogeneities, such as lung and air cavities, and for small fields, including those used in today's advanced intensity modulated radiotherapy techniques. Many investigators have reported significant dosimetric differences between MC and conventional dose calculations in such complex situations, and have demonstrated experimentally the unmatched ability of MC calculations in modeling charged particle disequilibrium. The advantages of using MC dose calculations do come at a cost. The nature of MC dose calculations require a highly detailed, in-depth representation of the physical system (accelerator head geometry/composition, anatomical patient geometry/composition and particle interaction physics) to allow accurate modeling of external beam radiation therapy treatments. To perform such simulations is computationally demanding and has only recently become feasible within mainstream radiotherapy practices. In addition, the output of the accelerator head simulation can be highly sensitive to inaccuracies within a model that may not be known with sufficient detail. The goal of this dissertation is to both improve and advance the implementation of MC dose calculations in modern external beam radiotherapy. To begin, a novel method is proposed to fine-tune the output of an accelerator model to better represent the measured output. In this method an intensity distribution of the electron beam incident on the model is inferred by employing a simulated annealing algorithm. The method allows an investigation of arbitrary electron beam intensity distributions and is not restricted to the commonly assumed Gaussian intensity. In a second component of

  7. 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.

  8. 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.

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

    PubMed

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

    2016-01-01

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

  10. Electronic compensation using multileaf collimation for involved field radiation to the neck and mediastinum in non-Hodgkin's lymphoma and Hodgkin's lymphoma

    SciTech Connect

    MacDonald, Shelly; Bernard, Shelley; Balogh, Alex; Spencer, David; Sawchuk, Stephen . E-mail: stephen.sawchuk@swedish.org

    2005-06-30

    An efficient procedure is required for the preparation, planning, and delivery of radiation therapy for involved field radiation to the neck and mediastinum. This technique must reduce tissue complications while maintaining dose uniformity. An elegant intensity-modulated radiation therapy (IMRT) treatment that is forward planned has been developed. Both static fields and static subfields shaped by multileaf collimators (MLCs) and asymmetric jaws are used. Patients receiving involved field radiation to the neck and mediastinum are planned in 3 dimensions (3D), where 3D dose compensation is provided using subfields consisting of MLC or asymmetric jaws instead of physical compensators or wedges. Forward planning is performed, usually generating 2 pairs of parallel-opposed fields, with at least 1 of them consisting of subfields to eliminate elevated dose regions. Efficiency in the preparation, planning, and delivery of treatment has been achieved for more than 10 patients. Verification of treatment setup, target anatomy, and MLC configuration is quick when using an electronic portal imaging device. Thermoluminescent dosimeters (TLDs) have verified point-dose uniformity noticeably to {+-} 5%. An efficient technique using forward planning for simple IMRT consisting of static MLC and asymmetric jaws has been developed.

  11. Xeroderma pigmentosum and medulloblastoma: chromosomal damage to lymphocytes during radiotherapy

    SciTech Connect

    Gianneli, F.; Avery, J.; Polani, P.E.; Terrell, C.; Giammusso, V.

    1981-10-01

    The effects of radiotherapy on a patient with xeroderma pigmentosum (XP) of complementation group C and medulloblastoma are reported. His lymphocytes showed no x-ray-induced chromatid damage, but unstable chromosomal aberrations increased throughout the course of radiotherapy as observed also in two other children (patients 2 and 3) with a similar tumor. Such damage was more dependent on spinal than cranial irradiation, lowest in the XP patient and highest in patient 3. Interindividual differences seemed largely due to the relative volume of body irradiated, but the damage in patient 3 remained relatively high even after accounting for such a factor. A maximum of 36, 68, and 77% of lymphocytes had aberrations in the XP and patients 2 and 3, respectively, but chromosomal damage did not show a Poisson distribution and indicated admixture of irradiated and nonirradiated cells. The relative frequency of the irradiated cells was estimated and seemed proportional to the ratios of the average irradiated field to the total body area. The XP patient showed no preferential loss of highly damaged cells and seemed not to suffer excessive chromosomal damage; he had a normal clinical response to and a favorable outcome of radiotherapy. These findings reduce anxiety on the use of radiotherapy in XP patients or at least in those of group C.

  12. Contrast enhancement of high-energy radiotherapy films.

    PubMed

    Reinstein, L E; Orton, C G

    1979-11-01

    An order-of-magnitude improvment in the contrast of high-energy localization and verification films has been achieved through the application of a simple, inexpensive, contrast enhancement technique. The method involves making reversal contact "prints" of the original film onto ordinary X-ray fi-m with equipment commonly available in any radiotherapy department. This results in "gamma multiplication". The theory as well as several applications of this effect are presented.

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

    SciTech Connect

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

    2011-08-01

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

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

    PubMed

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

    2015-01-01

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

  15. Radiotherapy and chemoradiation after surgery for early cervical cancer

    PubMed Central

    Rogers, Linda; Siu, Shing Shun N; Luesley, David; Bryant, Andrew; Dickinson, Heather O

    2014-01-01

    Background This is an updated version of the original Cochrane review first published in Issue 4, 2009. There is an ongoing debate about the indications for, and value of, adjuvant pelvic radiotherapy after radical surgery in women with early cervical cancer. Certain combinations of pathological risk factors are thought to represent sufficient risk for recurrence, that they justify the use of postoperative pelvic radiotherapy, though this has never been shown to improve overall survival, and use of more than one type of treatment (surgery and radiotherapy) increases the risks of side effects and complications. Objectives To evaluate the effectiveness and safety of adjuvant therapies (radiotherapy, chemotherapy followed by radiotherapy, chemoradiation) after radical hysterectomy for early-stage cervical cancer (FIGO stages IB1, IB2 or IIA). Search methods For the original review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), Issue 4, 2008. The Cochrane Gynaecological Cancer Group Trials Register, MEDLINE (January 1950 to November 2008), EMBASE (1950 to November 2008). We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field. For this update, we extended the database searches to September 2011 and searched the MetaRegister for ongoing trials. Selection criteria Randomised controlled trials (RCTs) that compared adjuvant therapies (radiotherapy, chemotherapy followed by radiotherapy, or chemoradiation) with no radiotherapy or chemoradiation, in women with a confirmed histological diagnosis of early cervical cancer who had undergone radical hysterectomy and dissection of the pelvic lymph nodes. Data collection and analysis Two review authors independently abstracted data and assessed risk of bias. Information on grade 3 and 4 adverse events was collected from the trials. Results were pooled using random-effects meta-analyses. Main results Two RCTs

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

    PubMed

    Roma, E; Bond, T; Jeffrey, P

    2014-09-01

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

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

    PubMed

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

    2011-12-15

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

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

    PubMed

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

    2016-04-01

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

  19. A review of uncertainties in radiotherapy dose reconstruction and their impacts on dose-response relationships.

    PubMed

    Vũ Bezin, Jérémi; Allodji, Rodrigue S; Mège, Jean-Pierre; Beldjoudi, Guillaume; Saunier, Fleur; Chavaudra, Jean; Deutsch, Eric; de Vathaire, Florent; Bernier, Valérie; Carrie, Christian; Lefkopoulos, Dimitri; Diallo, Ibrahima

    2017-03-20

    Proper understanding of the risk of radiation-induced late effects for patients receiving external photon beam radiotherapy requires the determination of reliable dose-response relationships. Although significant efforts have been devoted to improving dose estimates for the study of late effects, the most often questioned explanatory variable is still the dose. In this work, based on a literature review, we provide an in-depth description of the radiotherapy dose reconstruction process for the study of late effects. In particular, we focus on the identification of the main sources of dose uncertainty involved in this process and summarise their impacts on the dose-response relationship for radiotherapy late effects. We provide a number of recommendations for making progress in estimating the uncertainties in current studies of radiotherapy late effects and reducing these uncertainties in future studies.

  20. Long-Term Outcomes of Radiotherapy for Pituitary Adenomas

    SciTech Connect

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

    2008-07-15

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

  1. Apoptosis in cervical squamous carcinoma: predictive value for survival following radiotherapy

    PubMed Central

    Paxton, J; Bolger, B; Armour, A; Symonds, R; Mao, J; Burnett, R

    2000-01-01

    Background—Apoptosis, or programmed cell death, can be induced by radiotherapy. The extent of apoptosis in a tumour before treatment may have important implications for response to radiotherapy and long term survival. Aim—To examine the extent of apoptosis in tumour tissue from patients with squamous carcinoma of the cervix before radiotherapy, and to correlate this with response to treatment and prognosis. Methods—The percentage of apoptotic cells was assessed in 146 carcinomas of the cervix from patients scheduled to receive radiotherapy. The CAS 200 static image analysis system was used to count the number of tumour nuclei per high power field, while the numbers of apoptotic cells in the same field were visualised simultaneously on the image analyser and recorded manually. Results—The median apoptotic level was 0.73%. Patients were divided into two groups around the median. There was no statistically significant difference in outcome between the two groups as determined by long term survival following radiotherapy. Conclusions—The CAS 200 static image analyser system can be used to assist in the rapid semiautomated assessment of apoptosis in conventionally prepared tissue. The results suggest that the apoptotic state of a tumour before treatment is of no value in predicting response to radiotherapy and subsequent prognosis. Tumour stage, size, and BrdU labelling index, as a measure of proliferation rate, remain the most important prognostic factors in terms of predicting local tumour control. Key Words: apoptosis • uterine cervix • squamous cell carcinoma PMID:10823138

  2. [Stereotactic radiotherapy for pelvic tumors].

    PubMed

    Mazeron, R; Fumagalli, I

    2014-01-01

    Extracranial stereotactic radiotherapy is booming. The development and spread of dedicated accelerators coupled with efficient methods of repositioning can now allow treatments of mobile lesions with moderate size, with high doses per fraction. Intuitively, except for the prostate, pelvic tumours, often requiring irradiation of regional lymph node drainage, lend little to this type of treatment. However, in some difficult circumstances, such as boost or re-radiation, stereotactic irradiation condition is promising and clinical experiences have already been reported.

  3. Intraoperative radiotherapy for breast cancer

    PubMed Central

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

    2014-01-01

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

  4. 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.

  5. TOPICAL REVIEW: Anatomical imaging for radiotherapy

    NASA Astrophysics Data System (ADS)

    Evans, Philip M.

    2008-06-01

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

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

    SciTech Connect

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

    2007-02-01

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

  7. Toxic Epidermal Necrolysis in Polymedicated Patient Treated With Radiotherapy

    PubMed Central

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

    2015-01-01

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

  8. Development of an integral system test for image-guided radiotherapy

    SciTech Connect

    Rowbottom, Carl G.; Jaffray, David A.

    2004-12-01

    An integral system test was developed to determine the precision and accuracy of an image-guided radiotherapy system involving an x-ray volumetric imaging device mounted onto the gantry of a medical linear accelerator. The test was designed to interrogate the system components as a whole without deconstructing the individual sources of error. The integral system test was based on the imaging of an unambiguous stationary object in the treatment position and so took no account of patient related errors. An array of micromosfets interspersed within slices of a tissue equivalent phantom was developed as an imaging test object. It has previously been demonstrated that micromosfets have a very small active volume, are clearly visible on CT images, and produce no significant artifacts. In addition, the active volume of the micromosfets can be accurately inferred radiographically via the use of x-ray volumetric imaging. X-ray volumetric imaging was performed with the object in the treatment position, then reconstructed and transferred to a treatment planning system. With the phantom remaining undisturbed in the treatment position a series of treatment fields were designed to produce a series of fields with the leaf edge sweeping across active volume of the micromosfets. The fields were delivered with a micro-MLC to dosimetrically verify the position of the mosfets and compare with dose values produced by the treatment planning system. It was demonstrated that the systematic gantry flex could be accounted for by the imaging and delivery systems. For the delivery system small changes in leaf positions of the micro-MLC were required to account for gantry flex. The position of the micromosfets determined by the 50% dose position was on average (0.15{+-}0.13) mm away from the position determined radiographically for the x and y axes, and (1.0{+-}0.14) mm for the z axis. This implies that a margin of approximately 0.2 mm in the axial plane and 1.0 mm in the superior

  9. Prospective multicenter study of combined treatment with chemotherapy and radiotherapy in breast cancer women with the rare clinical scenario of ipsilateral supraclavicular node recurrence without distant metastases

    SciTech Connect

    Pergolizzi, Stefano . E-mail: Stefano.Pergolizzi@unime.it; Adamo, Vincenzo; Russi, Elvio; Santacaterina, Anna; Maisano, Roberto; Numico, Gianmauro; Palazzolo, Carmela; Ferrau, Francesco; Settineri, Nicola; Altavilla, Giuseppe; Girlando, Andrea; Spadaro, Pietro; Cascinu, Stefano

    2006-05-01

    Purpose: To evaluate the role of chemotherapy combined with curative radiotherapy in breast cancer patients who presented with recurrent ipsilateral supraclavicular lymph node metastases (ISLM) without 'nonregional disease,' we designed an observational study performed prospectively. Patients and Methods: Forty-four consecutive patients with ISLM from breast cancer as part of recurrent regional disease without distant metastases were included in this study. All patients received chemotherapy with doxorubicin-based schema or paclitaxel for six courses and curative radiotherapy (60 Gy/30 fractions of 2 Gy/5 days a week). An 'involved field' radiation was delivered during the interval between the third and fourth chemotherapy course; hormonal therapy was given based on receptor status. Results: The rate of overall clinical response after chemotherapy and radiotherapy was 94.9%. Median time to progression and overall survival were 28 and 40 months, respectively; the 5-year actuarial overall survival and disease-free survival rates were 35% (95% confidence interval, 19-51) and 20% (95% confidence interval, 6-34), respectively. Conclusion: A curative course of intravenous chemotherapy and radical irradiation is feasible in patients with ISLM. All patients presenting recurrence in supraclavicular nodes should be treated with definitive locoregional treatments and systemic therapy because the outcomes are better than might be historically assumed.

  10. Postoperative radiotherapy for residual tumor of primary mediastinal carcinoid teratoma

    PubMed Central

    Tu, Lingli; Sun, Lan; Zhou, Yu; Gong, Youling; Xue, Jianxin; Gao, Jun; Lu, You

    2013-01-01

    A 36-year-old woman had presented with dry cough for 2 months. Thoracic computed tomography (CT) scan showed a 12 cm × 8 cm ×5 cm mass in the anterior mediastinum. Due to intimately involving the aortic arch, tumor was removed incompletely. Residual tumor remained approximate 2 cm × 3 cm × 4 cm. Histologic diagnosis was a mature cystic teratoma containing a carcinoid. Subsequently, radiotherapy (RT) was administrated on residual tumor for a total dose of 50 Gy at 2 Gy/d fraction in 25 fractions. At 2-year follow-up, the patient had stable disease. In conclusion, adjuvant radiotherapy with 50 Gy is an effective approach for residual tumor of mediastinal carcinoid teratoma. PMID:23585961

  11. Stereotactic body radiotherapy: current strategies and future development

    PubMed Central

    2016-01-01

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

  12. Hypofractionated adjuvant whole breast radiotherapy: progress and prospects.

    PubMed

    Yarnold, John; Haviland, Joanne

    2010-11-01

    Published results of randomised trials involving >7000 women confirm the safety and efficacy of hypofractionated schedules of adjuvant radiotherapy for women with early breast cancer using fraction sizes between 2 and 3 Gy assuming appropriate downward adjustments to total dose. Unnecessary concerns relating to heart tolerance, suboptimal dose distribution and duration of follow up need not discourage the routine adoption of 15- or 16-fraction schedules in women treated by breast conservation surgery for early breast cancer. Regardless of fractionation regimen, dose escalation to the index quadrant in high risk subgroups will result in a greater relative increase in late adverse effects than tumour control, a therapeutic disadvantage that can only be overcome by exploiting a marked dose-volume effect. A 15-fraction schedule of whole breast radiotherapy is unlikely to represent the lower limits of hypofractionation, and the preliminary results of a 5-fraction regimen are encouraging.

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

    SciTech Connect

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

    2012-03-01

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

  14. Adjuvant Radiotherapy for Gastric Cancer: A Dosimetric Comparison of 3-Dimensional Conformal Radiotherapy, Tomotherapy (registered) and Conventional Intensity Modulated Radiotherapy Treatment Plans

    SciTech Connect

    Dahele, Max; Skinner, Matthew; Schultz, Brenda; Cardoso, Marlene; Bell, Chris; Ung, Yee C.

    2010-07-01

    Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  16. Intensity-Modulated Radiotherapy Might Increase Pneumonitis Risk Relative to Three-Dimensional Conformal Radiotherapy in Patients Receiving Combined Chemotherapy and Radiotherapy: A Modeling Study of Dose Dumping

    SciTech Connect

    Vogelius, Ivan S.; Westerly, David C.; Cannon, George M.; Mackie, Thomas R.; Mehta, Minesh P.; Sugie, Chikao; Bentzen, Soren M.

    2011-07-01

    Purpose: To model the possible interaction between cytotoxic chemotherapy and the radiation dose distribution with respect to the risk of radiation pneumonitis. Methods and Materials: A total of 18 non-small-cell lung cancer patients previously treated with helical tomotherapy at the University of Wisconsin were selected for the present modeling study. Three treatment plans were considered: the delivered tomotherapy plans; a three-dimensional conformal radiotherapy (3D-CRT) plan; and a fixed-field intensity-modulated radiotherapy (IMRT) plan. The IMRT and 3D-CRT plans were generated specifically for the present study. The plans were optimized without adjusting for the chemotherapy effect. The effect of chemotherapy was modeled as an independent cell killing process by considering a uniform chemotherapy equivalent radiation dose added to all voxels of the organ at risk. The risk of radiation pneumonitis was estimated for all plans using the Lyman and the critical volume models. Results: For radiotherapy alone, the critical volume model predicts that the two IMRT plans are associated with a lower risk of radiation pneumonitis than the 3D-CRT plan. However, when the chemotherapy equivalent radiation dose exceeds a certain threshold, the radiation pneumonitis risk after IMRT is greater than after 3D-CRT. This threshold dose is in the range estimated from clinical chemoradiotherapy data sets. Conclusions: Cytotoxic chemotherapy might affect the relative merit of competing radiotherapy plans. More work is needed to improve our understanding of the interaction between chemotherapy and the radiation dose distribution in clinical settings.

  17. Stereotactic fractionated radiotherapy for the treatment of benign meningiomas

    SciTech Connect

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

    2006-11-15

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

  18. An assessment of radiotherapy dosimeters based on CVD grown diamond

    NASA Astrophysics Data System (ADS)

    Ramkumar, S.; Buttar, C. M.; Conway, J.; Whitehead, A. J.; Sussman, R. S.; Hill, G.; Walker, S.

    2001-03-01

    Diamond is potentially a very suitable material for use as a dosimeter for radiotherapy. Its radiation hardness, the near tissue equivalence and chemical inertness are some of the characteristics of diamond, which make it well suited for its application as a dosimeter. Recent advances in the synthesis of diamond by chemical vapour deposition (CVD) technology have resulted in the improvement in the quality of material and increased its suitability for radiotherapy applications. We report in this paper, the response of prototype dosimeters based on two different types (CVD1 and CVD2) of CVD diamond to X-rays. The diamond devices were assessed for sensitivity, dependence of response on dose and dose rate, and compared with a Scanditronix silicon photon diode and a PTW natural diamond dosimeter. The diamond devices of CVD1 type showed an initial increase in response with dose, which saturates after ≈6 Gy. The diamond devices of CVD2 type had a response at low fields (<1162.8 V/cm) that was linear with dose and dose rate. At high fields (>1162.8 V/cm), the CVD2-type devices showed polarisation and dose-rate dependence. The sensitivity of the CVD diamond devices varied between 82 and 1300 nC/Gy depending upon the sample type and the applied voltage. The sensitivity of CVD diamond devices was significantly higher than that of natural diamond and silicon dosimeters. The results suggest that CVD diamond devices can be fabricated for successful use in radiotherapy applications.

  19. New developments in intracranial stereotactic radiotherapy for metastases.

    PubMed

    Pinkham, M B; Whitfield, G A; Brada, M

    2015-05-01

    Brain metastases are common and the prognosis for patients with multiple brain metastases treated with whole brain radiotherapy is limited. As systemic disease control continues to improve, the expectations of radiotherapy for brain metastases are growing. Stereotactic radiosurgery (SRS) as a high precision localised irradiation given in a single fraction prolongs survival in patients with a single brain metastasis and functional independence in those with up to three brain metastases. SRS technology has become commonplace and is available in many radiation oncology and neurosurgery departments. With increasing use there is a need for appropriate patient selection, refinement of dose-fractionation and safe integration of SRS with other treatment modalities. We review the evidence for current practice and new developments in the field, with a specific focus on patient-relevant outcomes.

  20. Particle Accelerators for Radiotherapy:. Present Status and Future

    NASA Astrophysics Data System (ADS)

    Maciszewski, Wieslaw; Scharf, Waldemar

    2004-07-01

    The paper describes the development of the application of particle accelerators in the treatment of cancer diseases over the past fifty years. Special emphasis is put on the routine application of conventional electron accelerators delivering electron and photon beams. This is the largest group of devices for radiotherapy (over 7500 machines operating worldwide). The number of patients reaches 5 million per year. The medical electron linacs have recently undergone considerable modifications of construction, in particular the systems of radiation field shaping. Contemporary accelerators for radiotherapy are equipped with multi-leaf collimators (MLC) which, in conjunction with IMRT (Intensity Modulation Radiation Therapy) technique and special system of therapy planning, assure considerably higher precision, effectiveness and quality of treatment.

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

    SciTech Connect

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

    2005-12-01

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

  2. Identification of predominant genes involved in regulation and execution of senescence-associated nitrogen remobilization in flag leaves of field grown barley.

    PubMed

    Hollmann, Julien; Gregersen, Per L; Krupinska, Karin

    2014-07-01

    The transcriptomes of senescing flag leaves collected from barley field plots with standard or high nitrogen supply were compared to identify genes specifically associated with nitrogen remobilization during leaf senescence under agronomically relevant conditions. In flag leaves collected in field plots with high nitrogen supply, the decline in chlorophyll content was delayed. By comparing changes in gene expression for the two nitrogen levels, it was possible to discriminate genes related to nitrogen remobilization during senescence and genes involved in other processes associated with the late development of leaves under field conditions. Predominant genes that were more strongly upregulated during senescence of flag leaves from plants with standard nitrogen supply included genes encoding the transcription factor HvNAC026, serine type protease SCPL51, and the autophagy factors APG7 and ATG18F. Elevated expression of these genes in senescing leaves from plants with standard nitrogen supply indicates important roles of the corresponding proteins in nitrogen remobilization. In comparison, the genes upregulated in both flag leaf samples might have roles in general senescence processes associated with late leaf development. Among these genes were the transcription factor genes HvNAC001, HvNAC005, HvNAC013, HvWRKY12 and MYB, genes encoding the papain-like cysteine peptidases HvPAP14 and HvPAP20, as well as a subtilase gene.

  3. Development of online quality assurance automation tool "SmartQC" for radiotherapy clinics

    NASA Astrophysics Data System (ADS)

    Zaks, Daniel

    Radiotherapy has existed as a clinical medical procedure since as early as 1900, and has become an essential component of modern hospitals. It is predicted that, sometime between the years 2010 and 2020, the number of patients receiving radiation therapy during their initial treatment is expected to rise by 22% from 470,000 per year to 575,000 per year Due to the potential for harm in radiotherapy, quality assurance is an essential element at every stage of modern clinical workflow. The quality and use of time in QA procedures and checks is an important issue that has significant impact on both practice and research in the field of radiotherapy. This thesis documents the results of development and results of tools addressing that question. While the motivation for radiotherapy QA is principally about improving quality of patient care, and developing radiotherapy research tools, we also discuss the relevance of QA to radiotherapy malpractice lawsuits and related financial costs. We show that in the treatment plan check performed by the medical physicist---also known as the second check or physics check---a substantial fraction (~33%) of the average time is spent on non-physics related analysis. We also demonstrate the development and implementation of a web-based system, referred to as PlanTracker within this thesis, to track the status of the plan. This thesis concludes with further developments being considered as an outgrowth of this system.

  4. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James R.

    2002-04-30

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

  5. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    SciTech Connect

    Venhuizen, James Robert

    2002-04-01

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

  6. SU-E-T-91: Accuracy of Dose Calculation Algorithms for Patients Undergoing Stereotactic Ablative Radiotherapy

    SciTech Connect

    Tajaldeen, A; Ramachandran, P; Geso, M

    2015-06-15

    algorithms in lung cancer radiotherapy involving small fields. However, further investigation by Monte Carlo simulation is required to confirm our results.

  7. Radiotherapy in patients with connective tissue diseases.

    PubMed

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

    2016-03-01

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

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

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

  10. A systematic evaluation of abscopal responses following radiotherapy in patients with metastatic melanoma treated with ipilimumab

    PubMed Central

    Chandra, Ravi A; Wilhite, Tyler J; Balboni, Tracy A; Alexander, Brian M; Spektor, Alexander; Ott, Patrick A; Ng, Andrea K; Hodi, F Stephen; Schoenfeld, Jonathan D

    2015-01-01

    Case reports and preclinical data suggest radiotherapy and immunotherapy may synergize to generate “abscopal” responses outside the radiation field. This phenomenon remains relatively unexplored, prompting our systematic evaluation of metastatic melanoma patients treated with the CTLA-4 inhibitor ipilimumab and palliative radiation therapy. We evaluated 47 consecutive metastatic melanoma patients treated with ipilimumab and 65 courses of radiation. Responses of index lesions outside the radiation field were compared before and after radiotherapy, and parameters associated with favorable response were assessed. Median survival was 28 months, with an estimated 20% 5-y survival. Index lesions shrank in 7 instances prior to radiation therapy (11%), compared with 16 instances (25%) after radiation therapy; in 11 of the latter instances (69%), the index lesion had been increasing in size prior to radiotherapy (P = 0.03). In 68% of cases, radiotherapy was associated with an improved rate of index lesion response (P = 0.006). Radiation fraction size ≤ 3 Gy was the only parameter identified associated with favorable index lesion response (P = 0.014). Our systematic review of melanoma patients treated with radiotherapy and ipilimumab suggests that a subset of patients may have more favorable out-of-field responses following treatment with radiation. Interestingly, we found that multiple fraction radiation regimens were associated with a more favorable response. These results are encouraging regarding potential synergies between radiation and immunotherapy, but suggest that attention and even prospective testing of radiation parameters critical to producing abscopal effects in human patients would be of value. PMID:26451318

  11. Prognostic factors in the radiotherapy of Graves' ophthalmopathy

    SciTech Connect

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

    1990-08-01

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

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

    PubMed Central

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

    2016-01-01

    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

  13. 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.

  14. Some factors influencing salivary function when treating with radiotherapy

    SciTech Connect

    Mira, J.G.; Wescott, W.B.; Starcke, E.N.; Shannon, I.L.

    1981-04-01

    Salivary flow rate was studied in 29 patients treated with external irradiation to head and neck areas. Resting saliva samples were collected before, during the radiotherapy course and follow-up. Several parameters were investigated: field arrangement, amount of salivary glands irradiated, dose to these glands, initial FR, its recovery during and after irradiation, and influence of therapy interruption in FR. It was found that the level of the upper border of the field is a critical factor when using parallel-opposed lateral fields to the upper neck area and lateral face. More than 50% of the parotids have to be outside the fields to prevent severe dryness. Neck fields which do not encompass salivary glands do not decrease salivary secretion. There is some relation between the initial FR and the dose necessary to produce dryness: patients with high initial salivary FR require higher doses. FR recovery occurs during weekend interruptions before xerostomia develops. Interruptions of therapy for more than two weeks during the radiotherapy course prior to development of dryness might decrease late xerostomia, at least in patients with high initial FR. Objective recovery of the FR has not been observed after treatment in spite of the subjective improvement in the sensation of dryness of some patients.

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  16. Ion-induced nuclear radiotherapy

    DOEpatents

    Horn, Kevin M.; Doyle, Barney L.

    1996-01-01

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

  17. Ion-induced nuclear radiotherapy

    DOEpatents

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

    1996-08-20

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

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

    PubMed

    Clark, Catharine H; Aird, Edwin G A; Bolton, Steve; Miles, Elizabeth A; Nisbet, Andrew; Snaith, Julia A D; Thomas, Russell A S; Venables, Karen; Thwaites, David I

    2015-01-01

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

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

    PubMed Central

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

    2015-01-01

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

  20. Studies of the cranial base in 23 patients with cri-du-chat syndrome suggest a cranial developmental field involved in the condition.

    PubMed

    Kjaer, I; Niebuhr, E

    1999-01-01

    The purpose of the present study was to investigate the cranial base on profile radiographs of patients with cri-du-chat syndrome and to relate the findings to current knowledge of brain malformation in an attempt to localize the developmental field affected in cri-du-chat syndrome. The material of profile radiographs of 23 patients was collected in Denmark in the 1970s. Twenty-two patients had terminal deletions of chromosome 5 (5p13.3, 5p14.1, 5p14.2, and 5p14.3), and one patient had an interstitial deletion. The cranial base angle (n-s-ba) was in most cases reduced and in no cases increased compared to age-related standards for normal individuals. Malformations in the bony contours of the sella turcica and the clivus occurred in cri-du-chat patients with terminal deletions. This specific cranial base region develops around the notochord at the location from where the rhombencephalic-derived brainstem, pons, and cerebellum have developed dorsally, and from where the neurons to the larynx have migrated ventrally. As the cranial base, the cerebellum and the larynx are involved in cri-du-chat syndrome, and attention is drawn to a new developmental field which comprises the dorsum sellae, clivus, cerebellum, and larynx. This field seemingly originates from the same notochordal location. The study has demonstrated a cranial base malformation in cri-du-chat patients, which ought to be elucidated in future research and combined with neurological and chromosomal investigations.

  1. Selecting radiotherapy dose distributions by means of constrained optimization problems.

    PubMed

    Alfonso, J C L; Buttazzo, G; García-Archilla, B; Herrero, M A; Núñez, L

    2014-05-01

    The main steps in planning radiotherapy consist in selecting for any patient diagnosed with a solid tumor (i) a prescribed radiation dose on the tumor, (ii) bounds on the radiation side effects on nearby organs at risk and (iii) a fractionation scheme specifying the number and frequency of therapeutic sessions during treatment. The goal of any radiotherapy treatment is to deliver on the tumor a radiation dose as close as possible to that selected in (i), while at the same time conforming to the constraints prescribed in (ii). To this day, considerable uncertainties remain concerning the best manner in which such issues should be addressed. In particular, the choice of a prescription radiation dose is mostly based on clinical experience accumulated on the particular type of tumor considered, without any direct reference to quantitative radiobiological assessment. Interestingly, mathematical models for the effect of radiation on biological matter have existed for quite some time, and are widely acknowledged by clinicians. However, the difficulty to obtain accurate in vivo measurements of the radiobiological parameters involved has severely restricted their direct application in current clinical practice.In this work, we first propose a mathematical model to select radiation dose distributions as solutions (minimizers) of suitable variational problems, under the assumption that key radiobiological parameters for tumors and organs at risk involved are known. Second, by analyzing the dependence of such solutions on the parameters involved, we then discuss the manner in which the use of those minimizers can improve current decision-making processes to select clinical dosimetries when (as is generally the case) only partial information on model radiosensitivity parameters is available. A comparison of the proposed radiation dose distributions with those actually delivered in a number of clinical cases strongly suggests that solutions of our mathematical model can be

  2. Early versus delayed postoperative radiotherapy for treatment of low-grade gliomas

    PubMed Central

    Sarmiento, J Manuel; Venteicher, Andrew S; Patil, Chirag G

    2015-01-01

    Background In most people with low-grade gliomas (LGG), the primary treatment regimen remains a combination of surgery followed by postoperative radiotherapy. However, the optimal timing of radiotherapy is controversial. It is unclear whether to use radiotherapy in the early postoperative period, or whether radiotherapy should be delayed until tumour progression occurs. Objectives To assess the effects of early postoperative radiotherapy versus radiotherapy delayed until tumour progression for low-grade intracranial gliomas in people who had initial biopsy or surgical resection. Search methods We searched up to September 2014 the following electronic databases: the Cochrane Register of Controlled Trials (CENTRAL, Issue 8, 2014), MEDLINE (1948 to Aug week 3, 2014), and EMBASE (1980 to Aug week 3, 2014) to identify trials for inclusion in this Cochrane review. Selection criteria We included randomised controlled trials (RCTs) that compared early versus delayed radiotherapy following biopsy or surgical resection for the treatment of people with newly diagnosed intracranial LGG (astrocytoma, oligodendroglioma, mixed oligoastrocytoma, astroblastoma, xanthoastrocytoma, or ganglioglioma). Radiotherapy may include conformal external beam radiotherapy (EBRT) with linear accelerator or cobalt-60 sources, intensity-modulated radiotherapy (IMRT), or stereotactic radiosurgery (SRS). Data collection and analysis Three review authors independently assessed the trials for inclusion and risk of bias, and extracted study data. We resolved any differences between review authors by discussion. Adverse effects were also extracted from the study report. We performed meta-analyses using a random-effects model with inverse variance weighting. Main results We included one large, multi-institutional, prospective RCT, involving 311 participants; the risk of bias in this study was unclear. This study found that early postoperative radiotherapy is associated with an increase in time to

  3. Characterizing geometric accuracy and precision in image guided gated radiotherapy

    NASA Astrophysics Data System (ADS)

    Tenn, Stephen Edward

    Gated radiotherapy combined with intensity modulated or three-dimensional conformal radiotherapy for tumors in the thorax and abdomen can deliver dose distributions which conform closely to tumor shapes allowing increased tumor dose while sparing healthy tissues. These conformal fields require more accurate and precise placement than traditional fields or tumors may receive suboptimal dose thereby reducing tumor control probability. Image guidance based on four-dimensional computed tomography (4DCT) provides a means to improve accuracy and precision in radiotherapy. The ability of 4DCT to accurately reproduce patient geometry and the ability of image guided gating equipment to position tumors and place fields around them must be characterized in order to determine treatment parameters such as tumor margins. Fiducial based methods of characterizing accuracy and precision of equipment for 4DCT planning and image guided gated radiotherapy (IGGRT) are presented with results for specific equipment. Fiducial markers of known geometric orientation are used to characterize 4DCT image reconstruction accuracy. Accuracy is determined under different acquisition protocols, reconstruction phases, and phantom trajectories. Targeting accuracy of fiducial based image guided gating is assessed by measuring in-phantom field positions for different motions, gating levels and target rotations. Synchronization parameters for gating equipment are also determined. Finally, end-to-end testing is performed to assess overall accuracy and precision of the equipment under controlled conditions. 4DCT limits fiducial geometric distance errors to 2 mm for repeatable target trajectories and to 5 mm for a pseudo-random trajectory. Largest offsets were in the longitudinal direction. If correctly calibrated and synchronized, the IGGRT system tested here can target reproducibly moving tumors with accuracy better than 1.2 mm. Gating level can affect accuracy if target motion is asymmetric about the

  4. Data required for testicular dose calculation during radiotherapy of seminoma

    SciTech Connect

    Mazonakis, Michalis; Kokona, Georgiana; Varveris, Haralambos; Damilakis, John; Gourtsoyiannis, Nicholas

    2006-07-15

    The purpose of this study was to provide the required data for the direct calculation of testicular dose resulting from radiotherapy in patients with seminoma. Paraortic (PA) treatment fields and dog-leg (DL) portals including paraortic and ipsilateral pelvic nodes were simulated on a male anthropomorphic phantom equipped with an artificial testicle. Anterior and posterior irradiations were performed for five different PA and DL field dimensions. Dose measurements were carried out using a calibrated ionization chamber. The dependence of testicular dose upon the distance separating the testicle from the treatment volume and upon the tissue thickness at the entrance point of the beam was investigated. A clamshell lead shield was used to reduce testicular dose. The scattered dose to testicle was measured in nine patients using thermoluminescent dosimeters. Phantom and patient exposures were generated with a 6 MV x-ray beam. Linear and nonlinear regression analysis was employed to obtain formulas describing the relation between the radiation dose to an unshielded and/or shielded testicle with the field size and the distance from the inferior field edge. Correction factors showing the variation of testicular dose with the patient thickness along beam axis were found. Bland-Altman statistical analysis showed that testicular dose obtained by the proposed calculation method may differ from the measured dose value by less than 25%. The current study presents a method providing reasonable estimations of testicular dose for individual patients undergoing PA or DL radiotherapy.

  5. Stereotactic Body Radiotherapy for Oligometastatic Lung Tumors

    SciTech Connect

    Norihisa, Yoshiki; Nagata, Yasushi Takayama, Kenji; Matsuo, Yukinori; Sakamoto, Takashi; Sakamoto, Masato; Mizowaki, Takashi; Yano, Shinsuke; Hiraoka, Masahiro

    2008-10-01

    Purpose: Since 1998, we have treated primary and oligometastatic lung tumors with stereotactic body radiotherapy (SBRT). The term 'oligometastasis' is used to indicate a small number of metastases limited to an organ. We evaluated our clinical experience of SBRT for oligometastatic lung tumors. Methods and Materials: A total of 34 patients with oligometastatic lung tumors were included in this study. The primary involved organs were the lung (n = 15), colorectum (n = 9), head and neck (n = 5), kidney (n = 3), breast (n = 1), and bone (n = 1). Five to seven, noncoplanar, static 6-MV photon beams were used to deliver 48 Gy (n = 18) or 60 Gy (n = 16) at the isocenter, with 12 Gy/fraction within 4-18 days (median, 12 days). Results: The overall survival rate, local relapse-free rate, and progression-free rate at 2 years was 84.3%, 90.0%, and 34.8%, respectively. No local progression was observed in tumors irradiated with 60 Gy. SBRT-related pulmonary toxicities were observed in 4 (12%) Grade 2 cases and 1 (3%) Grade 3 case. Patients with a longer disease-free interval had a greater overall survival rate. Conclusion: The clinical result of SBRT for oligometastatic lung tumors in our institute was comparable to that after surgical metastasectomy; thus, SBRT could be an effective treatment of pulmonary oligometastases.

  6. Radiotherapy for extreme hypertrophic pulmonary osteoarthropathy associated with malignancy.

    PubMed

    Yeo, W; Leung, S F; Chan, A T; Chiu, K W

    1996-01-01

    A patient with florid hypertrophic pulmonary osteoarthropathy (HPOA) associated with metastatic nasopharyngeal carcinoma is presented. Despite the presence of metastatic disease in the thorax and in bone, the patient's main symptom was severe pain from the HPOA, which was temporarily relieved by chemotherapy. Her disease subsequently progressed during chemotherapy and the pain became resistant to conventional treatment, including high dose morphine, non-steriodal anti-inflammatory agents and steriods. It was only with local radiation to the involved joints that the pain could be controlled. Our patient demonstrates that local radiotherapy is an option for the palliation of extreme HPOA.

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

    SciTech Connect

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

    2008-06-01

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

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

    SciTech Connect

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

    2012-07-15

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

  9. [Radiotherapy of benign intracranial tumors].

    PubMed

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

    2016-09-01

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

  10. 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.

  11. Radiotherapy for Pancreatic Neuroendocrine Tumors

    SciTech Connect

    Contessa, Joseph N.; Griffith, Kent A.; Wolff, Elizabeth; Ensminger, William; Zalupski, Mark; Ben-Josef, Edgar

    2009-11-15

    Purpose: Pancreatic neuroendocrine tumors (PNTs) are rare malignant neoplasms considered to be resistant to radiotherapy (RT), although data on efficacy are scarce. We reviewed our institutional experience to further delineate the role of RT for patients with PNTs. Methods and Materials: Between 1986 and 2006, 36 patients with PNTs were treated with RT to 49 sites. Of these 36 patients, 23 had radiographic follow-up data, which were used to determine the tumor response rate and freedom from local progression. Long-term toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events. Results: The overall response rate to RT was 39% (13% complete response, 26% partial response, 56% stable disease, and 4% progressive disease). A significant difference in the freedom from local progression between the groups receiving either greater than or less than the median 2 Gy/fraction biologically equivalent dose of 49.6 Gy was found, with all radiographic progression occurring in patients who had received <=32 Gy. The actuarial 3-year local freedom from progression rate was 49%. Palliation was achieved in 90% of patients, with either improvement or resolution of symptoms after RT. Of 35 patients, 33 had metastatic disease at their referral for RT, and the median overall survival for this patient population was 2 years. Three long-term Grade 3 or greater toxicities were recorded. Conclusion: RT is an effective modality for achieving local control in patients with PNTs. RT produces high rates of symptomatic palliation and freedom from local progression. Prospective trials of radiotherapy for PNTs are warranted.

  12. Present Status of Radiotherapy in Clinical Practice

    NASA Astrophysics Data System (ADS)

    Duehmke, Eckhart

    Aims of radiation oncology are cure from malignant diseases and - at the same time preservation of anatomy (e.g. female breast, uterus, prostate) and organ functions (e.g. brain, eye, voice, sphincter ani). At present, methods and results of clinical radiotherapy (RT) are based on experiences with natural history and radiobiology of malignant tumors in properly defined situations as well as on technical developments since World War II in geometrical and biological treatment planning in teletherapy and brachytherapy. Radiobiological research revealed tolerance limits of healthy tissues to be respected, effective total treatment doses of high cure probability depending on histology and tumor volume, and - more recently - altered fractionation schemes to be adapted to specific growth fractions and intrinsic radiosensitivities of clonogenic tumor cells. In addition, Biological Response Modifiers (BRM), such as cis-platinum, oxygen and hyperthermia may steepen cell survival curves of hypoxic tumor cells, others - such as tetrachiordekaoxid (TCDO) - may enhance repair of normal tissues. Computer assisted techniques in geometrical RT-planning based on individual healthy and pathologic anatomy (CT, MRT) provide high precision RT for well defined brain lesions by using dedicated linear accelerators (Stereotaxy). CT-based individual tissue compensators help with homogenization of distorted dose distributions in magna field irradiation for malignant lymphomas and with total body irradiation (TBI) before allogeneic bone marrow transplantation, e.g. for leukemia. RT with fast neutrons, Boron Neutron Capture Therapy (BNCT), RT with protons and heavy ions need to be tested in randomized trials before implementation into clinical routine.

  13. Second cancers following radiotherapy for cervical cancer

    SciTech Connect

    Kleinerman, R.A.; Curtis, R.E.; Boice, J.D. Jr.; Flannery, J.T.; Fraumeni, J.F. Jr.

    1982-11-01

    Incidence of second primary cancers was evaluated in 7,127 women with invasive cancer of the cervix uteri, diagnosed between 1935 and 1978, and followed up to 38 years (average, 8.9 yr) in Connecticut. Among 5,997 women treated with radiation, 449 developed second primary cancers compared with 313 expected (relative risk . 1.4) on the basis of rates from the Connecticut Tumor Registry. Excess incidence was noticeable 15 years or more after radiotherapy and attributed mostly to cancers of sites in or near the radiation field, especially the bladder, kidneys, rectum, corpus uteri, and ovaries. No excess was found for these sites among the 1,130 nonirradiated women. The ratio of observed to expected cancers for these sites did not vary appreciably by age at irradiation. The data suggested that high-dose pelvic irradiation was associated with increase in cancers of the bladder, kidneys, rectum, ovaries, corpus uteri, and non-Hodgkin's lymphoma but, apparently, not leukemia, Hodgkin's disease, breast cancer, or colon cancer.

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

    SciTech Connect

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

    2014-10-01

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

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

    SciTech Connect

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

    2005-12-01

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

  16. Intraoperative Radiotherapy in Childhood Malignant Astrocytoma

    PubMed Central

    Rana, Sohail R.; Haddy, Theresa B.; Ashayeri, Ebrahim; Goldson, Alfred L.

    1984-01-01

    A 12-year-old black male patient with glioblastoma multiforme was treated with intraoperative radiotherapy followed by conventional external beam radiation and chemotherapy. The authors' clinical experience with these therapeutic measures is discussed. PMID:6330375

  17. Historical aspects of heavy ion radiotherapy

    SciTech Connect

    Raju, M.R.

    1995-03-01

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

  18. Imaging Instrumentation and Techniques for Precision Radiotherapy

    NASA Astrophysics Data System (ADS)

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

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

  19. [Conformal radiotherapy for vertebral bone metastasis].

    PubMed

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

    2016-10-01

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

  20. [Hopes of high dose-rate radiotherapy].

    PubMed

    Fouillade, Charles; Favaudon, Vincent; Vozenin, Marie-Catherine; Romeo, Paul-Henri; Bourhis, Jean; Verrelle, Pierre; Devauchelle, Patrick; Patriarca, Annalisa; Heinrich, Sophie; Mazal, Alejandro; Dutreix, Marie

    2017-03-07

    In this review, we present the synthesis of the newly acquired knowledge concerning high dose-rate irradiations and the hopes that these new radiotherapy modalities give rise to. The results were presented at a recent symposium on the subject.

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

    PubMed

    Servagi-Vernat, S; Tochet, F

    2016-09-01

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

  2. Heavy particle radiotherapy: prospects and pitfalls

    SciTech Connect

    Faju, M.R.

    1980-01-01

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

  3. Intracranial aneurysm formation after radiotherapy for medulloblastoma

    PubMed Central

    Kamide, Tomoya; Mohri, Masanao; Misaki, Kouichi; Uchiyama, Naoyuki; Nakada, Mitsutoshi

    2016-01-01

    Background: The development of an intracranial aneurysm after radiotherapy is rare but secondary effect of cranial irradiation in a primary disease treatment. Case Description: The patient was a 17-year-old male adolescent who was diagnosed as having a posterior fossa medulloblastoma when he was 8 years old. He had undergone tumor resection with radiotherapy and chemotherapy. A distal posterior inferior cerebellar artery aneurysm was identified by magnetic resonance imaging 8 years after radiotherapy and grew rapidly throughout the next 1 year. The patient underwent microsurgical clipping and was discharged without deficit. Conclusion: This experience demonstrates that physicians caring for patients who have undergone intracranial radiotherapy should carefully consider the possibility of an aneurysmal formation when conducting follow-up imaging. PMID:27999713

  4. Colonic explosion during treatment of radiotherapy complications in prostatic cancer

    PubMed Central

    TRASTULLI, STEFANO; BARILLARO, IVAN; DESIDERIO, JACOPO; DI ROCCO, GIORGIO; COCHETTI, GIOVANNI; MECARELLI, VALERIO; CIROCCHI, ROBERTO; SANTORO, ALBERTO; BOSELLI, CARLO; REDLER, ADRIANO; AVENIA, NICOLA; NOYA, GIUSEPPE

    2012-01-01

    The use of lasers has been of great importance in the field of endoscopy and surgery for their applications in coagulation and the ability to vaporize tissue. In the 1990s, new machines were introduced based on a different technology, the argon-plasma-coagulation (APC) system. This technology causes different biological effects without direct contact. An example is the hemostasis of bleeding. In the literature, several cases of complications have been reported during endoscopic treatment with APC. In this study, we report our experience of a case with colon explosion during an APC procedure for bleeding due to radiotherapy and also review the literature on the complications of APC treatment. PMID:23162622

  5. Radiotherapy applications of patients with malignant mesothelioma: A single center experience

    PubMed Central

    Akmansu, Muge; Erpolat, Ozge Petek; Goksel, Fatih; Tunc, Evrim; Ozturk, Can

    2012-01-01

    Background In the management of malignant pleural mesothelioma, radiotherapy has been used for the purpose of prophylaxis to reduce the incidence of recurrence at surgical insertion sites or palliate the symptoms. Aim The purpose of the study was to evaluate the techniques and effectiveness of radiotherapy in malignant pleural mesothelioma. Materials and methods Forty-four (18 female, 26 male) patients diagnosed with malignant pleural mesothelioma were retrospectively evaluated. All patients had surgery or thoracoscopic biopsy for diagnosis, staging or treatment and all received palliative or prophylactic radiotherapy. Fifty-seven percent of the patients received chemotherapy. Results Prophylactic radiation was applied to 27 patients with 4–15 MeV electron energies. The median radiotherapy dose was 30 Gy with 3 Gy daily fraction dose. During treatment, 12 patients had grade 1 erythema according to the RTOG scale. In 3 (12%) patients, a local failure at treatment field was observed. Palliative radiotherapy was applied to 17 patients for pain palliation. The median radiation dose was 40 Gy with 2 Gy daily fraction dose by using 6–18 MV photon and/or 4–12 MeV electron energies. Two patients had grade 1 erythema and one patient had grade 2 odynophagy according to the RTOG scale. For 10 (59%) patients, palliation of chest pain was delivered. No late toxicity was observed for all cases. Conclusion Our experience showed that prophylactic and palliative radiotherapy are effective and safe therapy modalities in malignant pleural mesothelioma in preventing seeding metastasis at intervention sites or relieving pain. Prospective randomized studies are still needed to determine the benefits of radiotherapy application and to indicate optimum dose schemes. PMID:24416534

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

    SciTech Connect

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

    2008-03-01

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

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

    SciTech Connect

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

    2010-08-01

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

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

    SciTech Connect

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

    2012-07-01

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

  9. [Radiotherapy for small cell lung carcinoma].

    PubMed

    Pourel, N

    2016-10-01

    Radiotherapy for small cell lung carcinoma has known significant improvements over the past 10 years especially through routine use of PET-CT in the initial work-up and contouring before treatment. Prophylactic cranial irradiation remains a standard of care for locally advanced disease and is a subject of controversy for metastatic disease. A new indication for thoracic radiotherapy may soon arise for metastatic disease, still confirmation studies are ongoing.

  10. Blisters - an unusual effect during radiotherapy.

    PubMed

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

    2013-11-01

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

  11. Radiotherapy in the treatment of vertebral hemangiomas

    SciTech Connect

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

    1985-02-01

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

  12. 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.

  13. A comparative study on the risk of second primary cancers in out-of-field organs associated with radiotherapy of localized prostate carcinoma using Monte Carlo-based accelerator and patient models

    PubMed Central

    Bednarz, Bryan; Athar, Basit; Xu, X. George

    2010-01-01

    Purpose: A physician’s decision regarding an ideal treatment approach (i.e., radiation, surgery, and∕or hormonal) for prostate carcinoma is traditionally based on a variety of metrics. One of these metrics is the risk of radiation-induced second primary cancer following radiation treatments. The aim of this study was to investigate the significance of second cancer risks in out-of-field organs from 3D-CRT and IMRT treatments of prostate carcinoma compared to baseline cancer risks in these organs. Methods: Monte Carlo simulations were performed using a detailed medical linear accelerator model and an anatomically realistic adult male whole-body phantom. A four-field box treatment, a four-field box treatment plus a six-field boost, and a seven-field IMRT treatment were simulated. Using BEIR VII risk models, the age-dependent lifetime attributable risks to various organs outside the primary beam with a known predilection for cancer were calculated using organ-averaged equivalent doses. Results: The four-field box treatment had the lowest treatment-related second primary cancer risks to organs outside the primary beam ranging from 7.3×10−9 to 2.54×10−5%∕MU depending on the patients age at exposure and second primary cancer site. The risks to organs outside the primary beam from the four-field box and six-field boost and the seven-field IMRT were nearly equivalent. The risks from the four-field box and six-field boost ranged from 1.39×10−8 to 1.80×10−5%∕MU, and from the seven-field IMRT ranged from 1.60×10−9 to 1.35×10−5%∕MU. The second cancer risks in all organs considered from each plan were below the baseline risks. Conclusions: The treatment-related second cancer risks in organs outside the primary beam due to 3D-CRT and IMRT is small. New risk assessment techniques need to be investigated to address the concern of radiation-induced second cancers from prostate treatments, particularly focusing on risks to organs inside the primary beam

  14. Radiotherapy treatment of keloid scars with a kilovoltage X-ray parallel pair.

    PubMed

    Eaton, David J; Barber, Elizabeth; Ferguson, Leila; Mark Simpson, G; Collis, Christopher H

    2012-03-01

    An established treatment for keloids is surgery and radiotherapy, using a single applied field. However, earlobe keloids lend themselves to a parallel opposed pair approach. Delivery with a superficial X-ray unit is practicable and improves homogeneity within the treatment volume. It has been implemented in this centre since 2007.

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

    SciTech Connect

    Koukourakis, Michael I.

    2015-05-29

    Introduction: Radiotherapy is an equivalent alternative or complement to radical prostatectomy, with high therapeutic efficacy. High risk patients, however, experience high relapse rates, so that research on radio-sensitization is the most evident route to improve curability of this common disease. Materials and methods: In the current study we investigated the autophagic activity in a series of patients with localized prostate tumors treated with radical radiotherapy, using the LC3A and the LAMP2a proteins as markers of autophagosome and lysosome cellular content, respectively. The role of autophagy on prostate cancer cell line resistance to radiation was also examined. Results: Using confocal microscopy on tissue biopsies, we showed that prostate cancer cells have, overall, high levels of LC3A and low levels of LAMP2a compared to normal prostate glands. Tumors with a ‘highLC3A/lowLAMP2a’ phenotype, suggestive of intensified lysosomal consumption, had a significantly poorer biochemical relapse free survival. The PC3 radioresistant cell line sustained remarkably its autophagic flux ability after radiation, while the DU145 radiosensitive one experiences a prolonged blockage of the autophagic process. This was assessed with aggresome accumulation detection and LC3A/LAMP2a double immunofluorescence, as well as with sequestrosome/p62 protein detection. By silencing the LC3A or LAMP2a expression, both cell lines became more sensitive to escalated doses of radiation. Conclusions: High base line autophagy activity and cell ability to sustain functional autophagy define resistance of prostate cancer cells to radiotherapy. This can be reversed by blocking up-regulated components of the autophagy pathway, which may prove of importance in the field of clinical radiotherapy. - Highlights: • High LC3A and low LAMP2a levels is a frequent expression pattern of prostate carcinoma. • This pattern of intensified autophagic flux relates with high relapse rates after

  16. Radiotherapy for Vestibular Schwannomas: A Critical Review

    SciTech Connect

    Murphy, Erin S.; Suh, John H.

    2011-03-15

    Vestibular schwannomas are slow-growing tumors of the myelin-forming cells that cover cranial nerve VIII. The treatment options for patients with vestibular schwannoma include active observation, surgical management, and radiotherapy. However, the optimal treatment choice remains controversial. We have reviewed the available data and summarized the radiotherapeutic options, including single-session stereotactic radiosurgery, fractionated conventional radiotherapy, fractionated stereotactic radiotherapy, and proton beam therapy. The comparisons of the various radiotherapy modalities have been based on single-institution experiences, which have shown excellent tumor control rates of 91-100%. Both stereotactic radiosurgery and fractionated stereotactic radiotherapy have successfully improved cranial nerve V and VII preservation to >95%. The mixed data regarding the ideal hearing preservation therapy, inherent biases in patient selection, and differences in outcome analysis have made the comparison across radiotherapeutic modalities difficult. Early experience using proton therapy for vestibular schwannoma treatment demonstrated local control rates of 84-100% but disappointing hearing preservation rates of 33-42%. Efforts to improve radiotherapy delivery will focus on refined dosimetry with the goal of reducing the dose to the critical structures. As future randomized trials are unlikely, we suggest regimented pre- and post-treatment assessments, including validated evaluations of cranial nerves V, VII, and VIII, and quality of life assessments with long-term prospective follow-up. The results from such trials will enhance the understanding of therapy outcomes and improve our ability to inform patients.

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

    SciTech Connect

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

    2009-08-01

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

  18. Technical Note: DIRART- A software suite for deformable image registration and adaptive radiotherapy research

    SciTech Connect

    Yang Deshan; Brame, Scott; El Naqa, Issam; Aditya, Apte; Wu Yu; Murty Goddu, S.; Mutic, Sasa; Deasy, Joseph O.; Low, Daniel A.

    2011-01-15

    Purpose: Recent years have witnessed tremendous progress in image guide radiotherapy technology and a growing interest in the possibilities for adapting treatment planning and delivery over the course of treatment. One obstacle faced by the research community has been the lack of a comprehensive open-source software toolkit dedicated for adaptive radiotherapy (ART). To address this need, the authors have developed a software suite called the Deformable Image Registration and Adaptive Radiotherapy Toolkit (DIRART). Methods: DIRART is an open-source toolkit developed in MATLAB. It is designed in an object-oriented style with focus on user-friendliness, features, and flexibility. It contains four classes of DIR algorithms, including the newer inverse consistency algorithms to provide consistent displacement vector field in both directions. It also contains common ART functions, an integrated graphical user interface, a variety of visualization and image-processing features, dose metric analysis functions, and interface routines. These interface routines make DIRART a powerful complement to the Computational Environment for Radiotherapy Research (CERR) and popular image-processing toolkits such as ITK. Results: DIRART provides a set of image processing/registration algorithms and postprocessing functions to facilitate the development and testing of DIR algorithms. It also offers a good amount of options for DIR results visualization, evaluation, and validation. Conclusions: By exchanging data with treatment planning systems via DICOM-RT files and CERR, and by bringing image registration algorithms closer to radiotherapy applications, DIRART is potentially a convenient and flexible platform that may facilitate ART and DIR research.

  19. Current role of modern radiotherapy techniques in the management of breast cancer

    PubMed Central

    Ozyigit, Gokhan; Gultekin, Melis

    2014-01-01

    Breast cancer is the most common type of malignancy in females. Advances in systemic therapies and radiotherapy (RT) provided long survival rates in breast cancer patients. RT has a major role in the management of breast cancer. During the past 15 years several developments took place in the field of imaging and irradiation techniques, intensity modulated RT, hypofractionation and partial-breast irradiation. Currently, improvements in the RT technology allow us a subsequent decrease in the treatment-related complications such as fibrosis and long-term cardiac toxicity while improving the loco-regional control rates and cosmetic results. Thus, it is crucial that modern radiotherapy techniques should be carried out with maximum care and efficiency. Several randomized trials provided evidence for the feasibility of modern radiotherapy techniques in the management of breast cancer. However, the role of modern radiotherapy techniques in the management of breast cancer will continue to be defined by the mature results of randomized trials. Current review will provide an up-to-date evidence based data on the role of modern radiotherapy techniques in the management of breast cancer. PMID:25114857

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

    NASA Astrophysics Data System (ADS)

    Lárraga-Gutiérrez, José Manuel

    2015-08-01

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

  1. Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector

    NASA Astrophysics Data System (ADS)

    Sánchez-Doblado, F.; Domingo, C.; Gómez, F.; Sánchez-Nieto, B.; Muñiz, J. L.; García-Fusté, M. J.; Expósito, M. R.; Barquero, R.; Hartmann, G.; Terrón, J. A.; Pena, J.; Méndez, R.; Gutiérrez, F.; Guerre, F. X.; Roselló, J.; Núñez, L.; Brualla-González, L.; Manchado, F.; Lorente, A.; Gallego, E.; Capote, R.; Planes, D.; Lagares, J. I.; González-Soto, X.; Sansaloni, F.; Colmenares, R.; Amgarou, K.; Morales, E.; Bedogni, R.; Cano, J. P.; Fernández, F.

    2012-10-01

    Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation is therefore essential for a reasonable assessment of these associated risks. This work aimed to develop a method to estimate neutron-equivalent doses in multiple organs of radiotherapy patients. The method involved the convolution, at 16 reference points in an anthropomorphic phantom, of the normalized Monte Carlo neutron fluence energy spectra with the kerma and energy-dependent radiation weighting factor. This was then scaled with the total neutron fluence measured with passive detectors, at the same reference points, in order to obtain the equivalent doses in organs. The latter were correlated with the readings of a neutron digital detector located inside the treatment room during phantom irradiation. This digital detector, designed and developed by our group, integrates the thermal neutron fluence. The correlation model, applied to the digital detector readings during patient irradiation, enables the online estimation of neutron-equivalent doses in organs. The model takes into account the specific irradiation site, the field parameters (energy, field size, angle incidence, etc) and the installation (linac and bunker geometry). This method, which is suitable for routine clinical use, will help to systematically generate the dosimetric data essential for the improvement of current risk-estimation models.

  2. Estimation of neutron-equivalent dose in organs of patients undergoing radiotherapy by the use of a novel online digital detector.

    PubMed

    Sánchez-Doblado, F; Domingo, C; Gómez, F; Sánchez-Nieto, B; Muñiz, J L; García-Fusté, M J; Expósito, M R; Barquero, R; Hartmann, G; Terrón, J A; Pena, J; Méndez, R; Gutiérrez, F; Guerre, F X; Roselló, J; Núñez, L; Brualla-González, L; Manchado, F; Lorente, A; Gallego, E; Capote, R; Planes, D; Lagares, J I; González-Soto, X; Sansaloni, F; Colmenares, R; Amgarou, K; Morales, E; Bedogni, R; Cano, J P; Fernández, F

    2012-10-07

    Neutron peripheral contamination in patients undergoing high-energy photon radiotherapy is considered as a risk factor for secondary cancer induction. Organ-specific neutron-equivalent dose estimation is therefore essential for a reasonable assessment of these associated risks. This work aimed to develop a method to estimate neutron-equivalent doses in multiple organs of radiotherapy patients. The method involved the convolution, at 16 reference points in an anthropomorphic phantom, of the normalized Monte Carlo neutron fluence energy spectra with the kerma and energy-dependent radiation weighting factor. This was then scaled with the total neutron fluence measured with passive detectors, at the same reference points, in order to obtain the equivalent doses in organs. The latter were correlated with the readings of a neutron digital detector located inside the treatment room during phantom irradiation. This digital detector, designed and developed by our group, integrates the thermal neutron fluence. The correlation model, applied to the digital detector readings during patient irradiation, enables the online estimation of neutron-equivalent doses in organs. The model takes into account the specific irradiation site, the field parameters (energy, field size, angle incidence, etc) and the installation (linac and bunker geometry). This method, which is suitable for routine clinical use, will help to systematically generate the dosimetric data essential for the improvement of current risk-estimation models.

  3. Radiation Pneumonitis After Conventional Radiotherapy For Breast Cancer: A Prospective Study

    PubMed Central

    Isiah, Rajesh; Subhashini, J; Backianathan, Selvamani; Thangakunam, Balamugesh; Christopher, Devasagayam J

    2015-01-01

    Background Loco-regional radiotherapy is an important treatment modality in breast cancer and radiation pneumonitis (RP) is one of the early toxicities. Aim To study the occurrence, correlation of RP with patient and radiotherapy related factors and the effects on pulmonary function following conventional radiotherapy in breast cancer. Settings and Design Prospective study, from a tertiary hospital in a developing country. Materials and Methods Prospective analysis of clinical symptoms, pulmonary function and radiologic changes was done prior to and 12 weeks after adjuvant radiotherapy (n=46). Statistical analysis was done using SPSS version 10 software. Results Radiological and clinical RP was seen in 45.65% (n=21) and 19.56% (n=9) respectively. RP was significantly higher with age >50 years (OR 4.4), chest wall irradiation with electrons, (electrons 83.3% vs cobalt60 32.4%, p=0.02) and supraclavicular field treatment with 6 MV photons (p= 0.011). There was significant relationship between Inferior Lung Distance (ILD) and RP (p=0.013). The fall in Total Lung Capacity (TLC) was significantly more in those with RP (p=0.02). Conclusion Clinical RP occurs in almost one-fifth of breast cancer patients treated with conventional radiotherapy. Chest wall irradiation with electrons, supraclavicular field irradiation with 6 MV photons, higher ILD and age >50 years was associated with increased RP. The pulmonary function parameter most affected was TLC. The factors associated with increased RP should be considered when adjuvant radiotherapy is planned to minimize its likelihood and intervene appropriately. PMID:26393189

  4. Esophageal Stenosis Associated With Tumor Regression in Radiotherapy for Esophageal Cancer: Frequency and Prediction

    SciTech Connect

    Atsumi, Kazushige; Shioyama, Yoshiyuki; Arimura, Hidetaka; Terashima, Kotaro; Matsuki, Takaomi; Ohga, Saiji; Yoshitake, Tadamasa; Nonoshita, Takeshi; Tsurumaru, Daisuke; Ohnishi, Kayoko; Asai, Kaori; Matsumoto, Keiji; Nakamura, Katsumasa; Honda, Hiroshi

    2012-04-01

    Purpose: To determine clinical factors for predicting the frequency and severity of esophageal stenosis associated with tumor regression in radiotherapy for esophageal cancer. Methods and Materials: The study group consisted of 109 patients with esophageal cancer of T1-4 and Stage I-III who were treated with definitive radiotherapy and achieved a complete response of their primary lesion at Kyushu University Hospital between January 1998 and December 2007. Esophageal stenosis was evaluated using esophagographic images within 3 months after completion of radiotherapy. We investigated the correlation between esophageal stenosis after radiotherapy and each of the clinical factors with regard to tumors and therapy. For validation of the correlative factors for esophageal stenosis, an artificial neural network was used to predict the esophageal stenotic ratio. Results: Esophageal stenosis tended to be more severe and more frequent in T3-4 cases than in T1-2 cases. Esophageal stenosis in cases with full circumference involvement tended to be more severe and more frequent than that in cases without full circumference involvement. Increases in wall thickness tended to be associated with increases in esophageal stenosis severity and frequency. In the multivariate analysis, T stage, extent of involved circumference, and wall thickness of the tumor region were significantly correlated to esophageal stenosis (p = 0.031, p < 0.0001, and p = 0.0011, respectively). The esophageal stenotic ratio predicted by the artificial neural network, which learned these three factors, was significantly correlated to the actual observed stenotic ratio, with a correlation coefficient of 0.864 (p < 0.001). Conclusion: Our study suggested that T stage, extent of involved circumference, and esophageal wall thickness of the tumor region were useful to predict the frequency and severity of esophageal stenosis associated with tumor regression in radiotherapy for esophageal cancer.

  5. Mechanical and dosimetric quality control for computer controlled radiotherapy treatment equipment.

    PubMed

    Thompson, A V; Lam, K L; Balter, J M; McShan, D L; Martel, M K; Weaver, T A; Fraass, B A; Ten Haken, R K

    1995-05-01

    Modern computer controlled radiotherapy treatment equipment offers the possibility of delivering complex, multiple field treatments with minimal operator intervention, thus making multiple field conformal therapy practical. Conventional quality control programs are inadequate for this new technology, so new quality control procedures are needed. A reasonably fast, sensitive, and complete daily quality control program has been developed in our clinic that includes nearly automated mechanical as well as dosimetric tests. Automated delivery of these quality control fields is performed by the control system of the MM50 racetrack microtron, directed by the CCRS sequence processor [D. L. McShan and B. A. Fraass, Proceedings of the XIth International Conference on the use of computers in Radiation Therapy, 20-24 March 1994, Manchester, U.K. (North Western Medical Physics Department, Manchester, U.K., 1994), pp. 210-211], which controls the treatment process. The mechanical tests involve multiple irradiations of a single film to check the accuracy and reproducibility of the computer controlled setup of gantry and collimator angles, table orientation, collimator jaws, and multileaf collimator shape. The dosimetric tests, which involve multiple irradiations of an array of ionization chambers in a commercial dose detector (Keithly model 90100 Tracker System) rigidly attached to the head of the treatment gantry, check the output and symmetry of the treatment unit as a function of gantry and collimator angle and other parameters. For each of the dosimetric tests, readings from the five ionization chambers are automatically read out, stored, and analyzed by the computer, along with the geometric parameters of the treatment unit for that beam.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. On Involvement.

    ERIC Educational Resources Information Center

    Greene, Michael B.

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

  7. Modality comparison for small animal radiotherapy: A simulation study

    SciTech Connect

    Bazalova, Magdalena Nelson, Geoff; Noll, John M.; Graves, Edward E.

    2014-01-15

    Purpose: Small animal radiation therapy has advanced significantly in recent years. Whereas in the past dose was delivered using a single beam and a lead shield for sparing of healthy tissue, conformal doses can be now delivered using more complex dedicated small animal radiotherapy systems with image guidance. The goal of this paper is to investigate dose distributions for three small animal radiation treatment modalities. Methods: This paper presents a comparison of dose distributions generated by the three approaches—a single-field irradiator with a 200 kV beam and no image guidance, a small animal image-guided conformal system based on a modified microCT scanner with a 120 kV beam developed at Stanford University, and a dedicated conformal system, SARRP, using a 220 kV beam developed at Johns Hopkins University. The authors present a comparison of treatment plans for the three modalities using two cases: a mouse with a subcutaneous tumor and a mouse with a spontaneous lung tumor. A 5 Gy target dose was calculated using the EGSnrc Monte Carlo codes. Results: All treatment modalities generated similar dose distributions for the subcutaneous tumor case, with the highest mean dose to the ipsilateral lung and bones in the single-field plan (0.4 and 0.4 Gy) compared to the microCT (0.1 and 0.2 Gy) and SARRP (0.1 and 0.3 Gy) plans. The lung case demonstrated that due to the nine-beam arrangements in the conformal plans, the mean doses to the ipsilateral lung, spinal cord, and bones were significantly lower in the microCT plan (2.0, 0.4, and 1.9 Gy) and the SARRP plan (1.5, 0.5, and 1.8 Gy) than in single-field irradiator plan (4.5, 3.8, and 3.3 Gy). Similarly, the mean doses to the contralateral lung and the heart were lowest in the microCT plan (1.5 and 2.0 Gy), followed by the SARRP plan (1.7 and 2.2 Gy), and they were highest in the single-field plan (2.5 and 2.4 Gy). For both cases, dose uniformity was greatest in the single-field irradiator plan followed by

  8. Analysis of late toxicity associated with external beam radiation therapy for prostate cancer with uniform setting of classical 4-field 70 Gy in 35 fractions: a survey study by the Osaka Urological Tumor Radiotherapy Study Group

    PubMed Central

    Yoshioka, Yasuo; Suzuki, Osamu; Nishimura, Kazuo; Inoue, Hitoshi; Hara, Tsuneo; Yoshida, Ken; Imai, Atsushi; Tsujimura, Akira; Nonomura, Norio; Ogawa, Kazuhiko

    2013-01-01

    We aimed to analyse late toxicity associated with external beam radiation therapy (EBRT) for prostate cancer using uniform dose-fractionation and beam arrangement, with the focus on the effect of 3D (CT) simulation and portal field size. We collected data concerning patients with localized prostate adenocarcinoma who had been treated with EBRT at five institutions in Osaka, Japan, between 1998 and 2006. All had been treated with 70 Gy in 35 fractions, using the classical 4-field technique with gantry angles of 0°, 90°, 180° and 270°. Late toxicity was evaluated strictly in terms of the Common Terminology Criteria for Adverse Events Version 4.0. In total, 362 patients were analysed, with a median follow-up of 4.5 years (range 1.0–11.6). The 5-year overall and cause-specific survival rates were 93% and 96%, respectively. The mean ± SD portal field size in the right–left, superior–inferior, and anterior–posterior directions was, respectively, 10.8 ± 1.1, 10.2 ± 1.0 and 8.8 ± 0.9 cm for 2D simulation, and 8.4 ± 1.2, 8.2 ± 1.0 and 7.7 ± 1.0 cm for 3D simulation (P < 0.001). No Grade 4 or 5 late toxicity was observed. The actuarial 5-year Grade 2–3 genitourinary and gastrointestinal (GI) late toxicity rates were 6% and 14%, respectively, while the corresponding late rectal bleeding rate was 23% for 2D simulation and 7% for 3D simulation (P < 0.001). With a uniform setting of classical 4-field 70 Gy/35 fractions, the use of CT simulation and the resultant reduction in portal field size were significantly associated with reduced late GI toxicity, especially with less rectal bleeding. PMID:22988284

  9. Radiotherapy issues in elderly breast cancer patients.

    PubMed

    Kunkler, Ian

    2012-12-01

    Breast cancer in the elderly is a rising health care challenge. Under-treatment is common. While the proportion of older patients receiving adjuvant radiotherapy (RT) is rising, the proportion undergoing breast-conserving surgery without irradiation has also risen. The evidence base for loco-regional treatment is limited, reflecting the historical exclusion of older patients from randomised trials. The 2011 Oxford overview shows that the risk of first recurrence is halved in all age groups by adjuvant RT after breast-conserving surgery, although the absolute benefit in older 'low-risk' patients is small. There is level 1 evidence that a breast boost after breast-conserving surgery and whole-breast irradiation reduces local recurrence in older as in younger women, although in the former the absolute reduction is modest. Partial breast irradiation (external beam or intraoperative or postoperative brachytherapy) is potentially an attractive option for older patients, but the evidence base is insufficient to recommend it routinely. Similarly, shortened (hypofractionated) dose fraction schedules may be more convenient for older patients and are supported by level 1 evidence. There remains uncertainty about whether there is a subgroup of older low-risk patients in whom postoperative RT can be omitted after breast-conserving surgery. Biomarkers of 'low risk' are needed to refine the selection of patients for the omission of adjuvant RT. The role of postmastectomy irradiation is well established for 'high-risk' patients but uncertain in the intermediate-risk category of patients with 1-3 involved axillary nodes or node-negative patients with other risk factors where its role is investigational.

  10. Combining radiotherapy and angiogenesis inhibitors: Clinical trial design

    SciTech Connect

    Citrin, Deborah . E-mail: citrind@mail.nih.gov; Menard, Cynthia; Camphausen, Kevin

    2006-01-01

    Radiotherapy (RT) plays a vital role in the multimodality treatment of cancer. Recent advances in RT have primarily involved improvements in dose delivery. Future improvements in tumor control and disease outcomes will likely involve the combination of RT with targeted therapies. Preclinical evaluations of angiogenesis inhibitors in combination with RT have yielded promising results with increased tumor 'cure.' It remains to be seen whether these improvements in tumor control in the laboratory will translate into improved outcomes in the clinic. Multiple differences between these agents and cytotoxic chemotherapy must be taken into account when designing clinical trials evaluating their effectiveness in combination with RT. We discuss important considerations for designing clinical trials of angiogenesis inhibitors with RT.

  11. Fiducial marker guided prostate radiotherapy: a review.

    PubMed

    O'Neill, Angela G M; Jain, Suneil; Hounsell, Alan R; O'Sullivan, Joe M

    2016-12-01

    Image-guided radiotherapy (IGRT) is an essential tool in the accurate delivery of modern radiotherapy techniques. Prostate radiotherapy positioned using skin marks or bony anatomy may be adequate for delivering a relatively homogeneous whole-pelvic radiotherapy dose, but these surrogates are not reliable when using reduced margins, dose escalation or hypofractionated stereotactic radiotherapy. Fiducial markers (FMs) for prostate IGRT have been in use since the 1990s. They require surgical implantation and provide a surrogate for the position of the prostate gland. A variety of FMs are available and they can be used in a number of ways. This review aimed to establish the evidence for using prostate FMs in terms of feasibility, implantation procedures, types of FMs used, FM migration, imaging modalities used and the clinical impact of FMs. A search strategy was defined and a literature search was carried out in Medline. Inclusion and exclusion criteria were applied, which resulted in 50 articles being included in this review. The evidence demonstrates that FMs provide a more accurate surrogate for the position of the prostate than either external skin marks or bony anatomy. A combination of FM alignment and soft-tissue analysis is currently the most effective and widely available approach to ensuring accuracy in prostate IGRT. FM implantation is safe and well tolerated. FM migration is possible but minimal. Standardization of all techniques and procedures in relation to the use of prostate FMs is required. Finally, a clinical trial investigating a non-surgical alternative to prostate FMs is introduced.

  12. Pain and quality of life in patients undergoing radiotherapy for spinal metastatic disease treatment

    PubMed Central

    2013-01-01

    Background Radiotherapy is an important tool in the control of pain in patients with spinal metastatic disease. We aimed to evaluate pain and of quality of life of patients with spinal metastatic disease undergoing radiotherapy with supportive treatment. Methods The study enrolled 30 patients. From January 2008 to January 2010, patients selection included those treated with a 20 Gy tumour dose in five fractions. Patients completed the visual analogue scale for pain assessment and the SF-36 questionnaire for quality of life assessment. Results The most frequent primary sites were breast, multiple myeloma, prostate and lymphoma. It was found that 14 spinal metastatic disease patients (46.66%) had restricted involvement of three or fewer vertebrae, while 16 patients (53.33%) had cases involving more than three vertebrae. The data from the visual analogue scale evaluation of pain showed that the average initial score was 5.7 points, the value 30 days after the end of radiotherapy was 4.60 points and the average value 6 months after treatment was 4.25 points. Notably, this final value was 25.43% lower than the value from the initial analysis. With regard to the quality of life evaluation, only the values for the functional capability and social aspects categories of the questionnaire showed significant improvement. Conclusion Radiotherapy with supportive treatment appears to be an important tool for the treatment of pain in patients with spinal metastatic disease. PMID:23418821

  13. A dose comparison of proton radiotherapy and photon radiotherapy for pediatric brain tumor

    NASA Astrophysics Data System (ADS)

    Kim, S. Y.; Cho, J. H.

    2014-12-01

    The purpose of this study was to investigate the effectiveness of photon radiotherapy and to compare the dose of treatment planning between proton radiotherapy and 3D conformal radiation therapy (3D-CRT) for pediatric brain tumor patients. This study was conducted in five pediatric brain tumor patients who underwent craniospinal irradiation treatment from October 2013 to April 2014 in the hospital. The study compared organs at risk (OARs) by assessing the dose distribution of normal tissue from the proton plan and 3D-CRT. Furthermore, this study assessed the treatment plans by looking at the homogeneity index (HI) and conformity index (CI). As a result, the study revealed OARs due to the small volume proton radiotherapy dose distribution in the normal tissue. Also, by comparing HI and CI between the 3D-CRT and proton radiotherapy plan, the study found that the dose of proton radiotherapy plan was homogenized. When conducting 3D-CRT and proton radiotherapy in a dose-volume histogram comparison, the dose of distribution turned out to be low. Consequently, proton radiotherapy is used for protecting the normal tissue, and is used in tumor tissue as a homogenized dose for effective treatment.

  14. Navigated marker placement for motion compensation in radiotherapy

    NASA Astrophysics Data System (ADS)

    Winterstein, A.; März, K.; Franz, A. M.; Hafezi, M.; Fard, N.; Sterzing, F.; Mehrabi, A.; Maier-Hein, L.

    2015-03-01

    Radiotherapy is frequently used to treat unoperated or partially resected tumors. Tumor movement, e.g. caused by respiration, is a major challenge in this context. Markers can be implanted around the tumor prior to radiation therapy for accurate tracking of tumor movement. However, accurate placement of these markers while keeping a secure margin around the target and while taking into account critical structures is a difficult task. Computer-assisted needle insertion has been an active field of research in the past decades. However, the challenge of navigated marker placement for motion compensated radiotherapy has not yet been addressed. This work presents a system to support marker implantation for radiotherapy under consideration of safety margins and optimal marker configuration. It is designed to allow placement of markers both percutaneously and during an open liver surgery. To this end, we adapted the previously proposed EchoTrack system which integrates ultrasound (US) imaging and electromagnetic (EM) tracking in a single mobile modality. The potential of our new marker insertion concept was evaluated in a phantom study by inserting sets of three markers around dedicated targets (n=22) simultaneously spacing the markers evenly around the target as well as placing the markers in a defined distance to the target. In all cases the markers were successfully placed in a configuration fulfilling the predefined criteria. This includes a minimum distance of 18.9 ± 2.4 mm between marker and tumor as well as a divergence of 2.1 ± 1.5 mm from the planned marker positions. We conclude that our system has high potential to facilitate the placement of markers in suitable configurations for surgeons without extensive experience in needle punctions as high quality configurations were obtained even by medical non-experts.

  15. Patterns of Radiotherapy Practice for Patients With Cervical Cancer (1999-2001): Patterns of Care Study in Japan

    SciTech Connect

    Toita, Takafumi Kodaira, Takeshi; Shinoda, Atsunori; Uno, Takashi; Akino, Yuichi; Mitsumori, Michihide; Teshima, Teruki

    2008-03-01

    Purpose: To describe the patterns of definitive radiotherapy practice for patients with uterine cervical cancer from 1999 to 2001 in Japan. Methods and Materials: The Japanese Patterns of Care Study (JPCS) working group conducted a third extramural audit survey of 68 institutions and collected specific information on 324 cervical cancer patients treated with definitive radiotherapy. Results: Almost all patients (96%) were treated with whole pelvic radiotherapy using opposing anteroposterior fields (87%). A midline block was used in 70% of the patients. Intracavitary brachytherapy (ICBT) was applied in 82% of cases. Most patients (89%) were treated with high-dose rate (HDR) ICBT. Calculation of doses to organs at risk (ICRU 38) was performed for rectum in 25% of cases and for bladder in 18% of cases. Only 3% of patients were given intravenous conscious sedation during ICBT applicator insertions. The median total biologically effective dose at point A (EBRT+ICBT) was 74 Gy{sub 10} in cases treated with HDR-ICBT. There was no significant difference in total biologically effective dose between stages. The median overall treatment time was 47 days. Concurrent chemoradiation was applied in 17% of patients. Conclusions: This study describes the general patterns of radiotherapy practice for uterine cervical cancer in Japan. Although methods of external radiotherapy seemed to be appropriate, there was room for improvement in ICBT practice, such as pretreatment. A substantial difference in total radiotherapy dose between Japan and the United States was observed.

  16. Postoperative Intensity-Modulated Radiotherapy in Low-Risk Endometrial Cancers: Final Results of a Phase I Study

    SciTech Connect

    Macchia, Gabriella; Cilla, Savino M.P.; Ferrandina, Gabriella; Padula, Gilbert D.A.; Deodato, Francesco; Digesu, Cinzia; Caravatta, Luciana; Picardi, Vincenzo; Corrado, Giacomo; Piermattei, Angelo; Valentini, Vincenzo; Cellini, Numa; Scambia, Giovanni; Morganti, Alessio Giuseppe

    2010-04-15

    Purpose: To determine the maximum tolerated dose of short-course radiotherapy (intensity-modulated radiotherapy technique) to the upper two thirds of the vagina in endometrial cancers with low risk of local recurrence. Patients and Methods: A Phase I clinical trial was performed. Eligible patients had low-risk resected primary endometrial adenocarcinomas. Radiotherapy was delivered in 5 fractions over 1 week. The planning target volume was the clinical target volume plus 5 mm. The clinical target volume was defined as the upper two thirds of the vagina as evidenced at CT simulation by a vaginal radio-opaque device. The planning target volume was irradiated by a seven-field intensity-modulated radiotherapy technique, planned by the Plato Sunrise inverse planning system. A first cohort of 6 patients received 25 Gy (5-Gy fractions), and a subsequent cohort received 30 Gy (6-Gy fractions). The Common Toxicity Criteria scale, version 3.0, was used to score toxicity. Results: Twelve patients with endometrial cancer were enrolled. Median age was 58 years (range, 49-74 years). Pathologic stage was IB (83.3%) and IC (16.7%). Median tumor size was 30 mm (range, 15-50 mm). All patients completed the prescribed radiotherapy. No patient experienced a dose-limiting toxicity at the first level, and the radiotherapy dose was escalated from 25 to 30 Gy. No patients at the second dose level experienced dose-limiting toxicity. The most common Grade 2 toxicity was gastrointestinal, which was tolerable and manageable. Conclusions: The maximum tolerated dose of short-course radiotherapy was 30 Gy at 6 Gy per fraction. On the basis of this result, we are conducting a Phase II study with radiotherapy delivered at 30 Gy.

  17. Differences in breast tissue oxygenation following radiotherapy.

    PubMed

    Dornfeld, Ken; Gessert, Charles E; Renier, Colleen M; McNaney, David D; Urias, Rodolfo E; Knowles, Denise M; Beauduy, Jean L; Widell, Sherry L; McDonald, Bonita L

    2011-08-01

    Tissue perfusion and oxygenation changes following radiotherapy may result from and/or contribute to the toxicity of treatment. Breast tissue oxygenation levels were determined in the treated and non-treated breast 1 year after radiotherapy for breast conserving treatment. Transcutaneous oxygenation varied between subjects in both treated and non-treated breast. Subjects without diabetes mellitus (n=16) had an average oxygenation level of 64.8 ± 19.9mmHg in the irradiated breast and an average of 72.3 ± 18.1mmHg (p=0.018) at the corresponding location in the control breast. Patients with diabetes (n=4) showed a different oxygenation pattern, with lower oxygenation levels in control tissue and no decrease in the irradiated breast. This study suggests oxygenation levels in normal tissues vary between patients and may respond differently after radiotherapy.

  18. Oral verrucous carcinoma. Treatment with radiotherapy

    SciTech Connect

    Nair, M.K.; Sankaranarayanan, R.; Padmanabhan, T.K.; Madhu, C.S.

    1988-02-01

    Fifty-two cases of oral verrucous carcinoma treated with radiotherapy at the Regional Cancer Centre, Trivandrum, Kerala, India in 1982 were evaluated to determine the distribution within the oral cavity, clinical extent, and effectiveness of radiotherapy in controlling the disease. The most common site was the buccal mucosa. Fifty percent of the patients had clinically negative regional lymph nodes and 33% were in earlier stages (T1, T2, N0, and M0). The overall 3-year no evidence of disease (NED) survival rate was 44%. The 3-year NED survival rate with radium implant was 86%. We cannot comment on anaplastic transformation after radiotherapy because our treatment failures have not been subjected for biopsy concerning this matter. Because the results are comparable with those of well-differentiated squamous cell carcinoma, we think that the treatment policies advocated for oral squamous cell carcinoma are also applicable to oral verrucous carcinoma.

  19. [Good practice of image-guided radiotherapy].

    PubMed

    de Crevoisier, R; Créhange, G; Castelli, J; Lafond, C; Delpon, G

    2015-10-01

    Image-guided radiotherapy (IGRT) aims to take into account the anatomical variations occurring during the course of radiotherapy, by direct or indirect visualization of the target volume followed by a corrective action. The movements of the target, or at least the set-up errors are corrected by moving the treatment table, corresponding to the simplest and most validated IGRT modality in a standard practice. The deformations of the target volume and organs at risk are however much more common, and unfortunately much more complicated to consider, requiring multiple planning before or during the treatment, corresponding to the adaptive radiotherapy strategies. The planning target volume must be carefully chosen according to these anatomic variations. This article reviews the modalities of IGRT, standard or under evaluation, according to the different tumour sites.

  20. One hundred years of radiotherapy in Turkey.

    PubMed

    Dincer, M; Kuter, S

    2001-10-01

    The study and practice of radiology in Turkey began in 1897, only 2 years after the discovery of X-rays. A simple X-ray machine was constructed in Istanbul, consisting of a Crookes tube, a Ruhmkorff coil, and a home-made battery. This machine was first used on wounded soldiers, for diagnostic purposes. The first report of X-rays being used therapeutically in Turkey was published in a national journal in 1904. By 1933, the most up-to-date radiotherapy equipment of the time had been installed in every major city in the country. Innovative radiotherapy techniques, such as rotational treatment, were also being tried in 1930s. Today, there are 45 radiotherapy centres in Turkey, and 400 radiation oncologists and 80 medical physicists practise there.

  1. Threshold dose for peripheral neuropathy following intraoperative radiotherapy (IORT) in a large animal model

    SciTech Connect

    Kinsella, T.J.; DeLuca, A.M.; Barnes, M.; Anderson, W.; Terrill, R.; Sindelar, W.F. )

    1991-04-01

    Radiation injury to peripheral nerve is a dose-limiting toxicity in the clinical application of intraoperative radiotherapy, particularly for pelvic and retroperitoneal tumors. Intraoperative radiotherapy-related peripheral neuropathy in humans receiving doses of 20-25 Gy is manifested as a mixed motor-sensory deficit beginning 6-9 months following treatment. In a previous experimental study of intraoperative radiotherapy-related neuropathy of the lumbro-sacral plexus, an approximate inverse linear relationship was reported between the intraoperative dose (20-75 Gy range) and the time to onset of hind limb paresis (1-12 mos following intraoperative radiotherapy). The principal histological lesion in irradiated nerve was loss of large nerve fibers and perineural fibrosis without significant vascular injury. Similar histological changes in irradiated nerves were found in humans. To assess peripheral nerve injury to lower doses of intraoperative radiotherapy in this same large animal model, groups of four adult American Foxhounds received doses of 10, 15, or 20 Gy to the right lumbro-sacral plexus and sciatic nerve using 9 MeV electrons. The left lumbro-sacral plexus and sciatic nerve were excluded from the intraoperative field to allow each animal to serve as its own control. Following treatment, a complete neurological exam, electromyogram, and nerve conduction studies were performed monthly for 1 year. Monthly neurological exams were performed in years 2 and 3 whereas electromyogram and nerve conduction studies were performed every 3 months during this follow-up period. With follow-up of greater than or equal to 42 months, no dog receiving 10 or 15 Gy IORT shows any clinical or laboratory evidence of peripheral nerve injury. However, all four dogs receiving 20 Gy developed right hind limb paresis at 8, 9, 9, and 12 mos following intraoperative radiotherapy.

  2. Simple Carotid-Sparing Intensity-Modulated Radiotherapy Technique and Preliminary Experience for T1-2 Glottic Cancer

    SciTech Connect

    Rosenthal, David I.; Fuller, Clifton D.; Barker, Jerry L.; Mason, Bryan M.S.; Garcia, John A. C.; Lewin, Jan S.; Holsinger, F. Christopher; Stasney, C. Richard; Frank, Steven J.; Schwartz, David L.; Morrison, William H.; Garden, Adam S.; Ang, K. Kian

    2010-06-01

    Purpose: To investigate the dosimetry and feasibility of carotid-sparing intensity-modulated radiotherapy (IMRT) for early glottic cancer and to report preliminary clinical experience. Methods and Materials: Digital Imaging and Communications in Medicine radiotherapy (DICOM-RT) datasets from 6 T1-2 conventionally treated glottic cancer patients were used to create both conventional IMRT plans. We developed a simplified IMRT planning algorithm with three fields and limited segments. Conventional and IMRT plans were compared using generalized equivalent uniform dose and dose-volume parameters for in-field carotid arteries, target volumes, and organs at risk. We have treated 11 patients with this simplified IMRT technique. Results: Intensity-modulated radiotherapy consistently reduced radiation dose to the carotid arteries (p < 0.05) while maintaining the clinical target volume coverage. With conventional planning, median carotid V35, V50, and V63 were 100%, 100%, and 69.0%, respectively. With IMRT planning these decreased to 2%, 0%, and 0%, respectively (p < 0.01). Radiation planning and treatment times were similar for conventional radiotherapy and IMRT. Treatment results have been excellent thus far. Conclusions: Intensity-modulated radiotherapy significantly reduced unnecessary radiation dose to the carotid arteries compared with conventional lateral fields while maintaining clinical target volume coverage. Further experience and longer follow-up will be required to demonstrate outcomes for cancer control and carotid artery effects.

  3. Family Involvement.

    ERIC Educational Resources Information Center

    Liontos, Lynn Balster

    1992-01-01

    Family involvement in schools will work only when perceived as an enlarged concept focusing on all children, including those from at-risk families. Each publication reviewed here is specifically concerned with family involvement strategies concerned with all children or targeted at primarily high risk students. Susan McAllister Swap looks at three…

  4. Patterns of Regional Recurrence After Definitive Radiotherapy for Cervical Cancer

    SciTech Connect

    Beadle, Beth M.; Jhingran, Anuja; Yom, Sue S.; Ramirez, Pedro T.; Eifel, Patricia J.

    2010-04-15

    Purpose: To determine the patterns of regional recurrence in patients treated with definitive radiotherapy (RT) for cervical cancer. Methods and Materials: The records of 198 patients treated with definitive RT for cervical cancer between 1980 and 2000 who experienced a regional recurrence without a central or distal vaginal recurrence were reviewed. All patients received a combination of external-beam RT and intracavitary brachytherapy. In the 180 patients with a documented location of regional recurrence, the relationship between the recurrence and the radiation fields was determined. Results: The median time to regional recurrence was 13 months (range, 2-85 months). Of the 180 patients who had an evaluable regional recurrence, 119 (66%) had a component of marginal failure; 71 patients recurred above-the-field, 2 patients occurred in the inguinal nodes, and 2 patients recurred above-the-field and in the inguinal nodes. In addition, 105 patients (58%) had a component of in-field failure; 59 patients recurred in-field only, 39 patients recurred in-field and above-the-field, 2 patients recurred in-field, above-the-field, and in the inguinal nodes, and 5 patients recurred in-field and in the inguinal nodes. The median survival after regional recurrence was 8 months (range, 0-194 months). Conclusions: Most regional recurrences after definitive RT for cervical cancer include a component of marginal failure, usually immediately superior to the radiation field. These recurrences suggest a deficiency in target volume. Recurrences also occur in-field, suggesting a deficiency in dose. Developments in pretreatment staging, field delineation, dose escalation, and posttreatment surveillance may help to improve outcome in these patients.

  5. Pelvic radiotherapy and sexual function in women

    PubMed Central

    Froeding, Ligita Paskeviciute

    2015-01-01

    Background During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors. Methods An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities. Results The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients. Conclusions

  6. Meningioma after radiotherapy for Hodgkin's disease.

    PubMed

    Deutsch, M; Rosenstein, M; Figura, J H

    1999-08-01

    The most common second primary tumors after treatment of childhood Hodgkin's disease are leukemia, lymphoma, breast cancer, soft tissue sarcoma, and thyroid cancer. Although intracranial meningioma has been reported after radiotherapy to the scalp for benign conditions and for intracranial primary brain tumors, this appears to be an extremely rare sequelae of treatment for Hodgkin's disease. The authors describe a 15-year-old boy who underwent radiotherapy for Hodgkin's disease and in whom a meningioma developed in the posterior fossa 27 years later.

  7. Prevention of accidental exposure in radiotherapy: the risk matrix approach.

    PubMed

    Vilaragut, J J; Duménigo, C; Delgado, J M; Morales, J; McDonnell, J D; Ferro, R; Ortiz López, P; Ramírez, M L; Pérez Mulas, A; Papadopulos, S; Gonçalves, M; López Morones, R; Sánchez Cayuela, C; Cascajo Castresana, A; Somoano, F; Álvarez, C; Guillén, A; Rodríguez, M; Pereira, P P; Nader, A

    2013-02-01

    Knowledge and lessons from past accidental exposures in radiotherapy are very helpful in finding safety provisions to prevent recurrence. Disseminating lessons is necessary but not sufficient. There may be additional latent risks for other accidental exposures, which have not been reported or have not occurred, but are possible and may occur in the future if not identified, analyzed, and prevented by safety provisions. Proactive methods are available for anticipating and quantifying risk from potential event sequences. In this work, proactive methods, successfully used in industry, have been adapted and used in radiotherapy. Risk matrix is a tool that can be used in individual hospitals to classify event sequences in levels of risk. As with any anticipative method, the risk matrix involves a systematic search for potential risks; that is, any situation that can cause an accidental exposure. The method contributes new insights: The application of the risk matrix approach has identified that another group of less catastrophic but still severe single-patient events may have a higher probability, resulting in higher risk. The use of the risk matrix approach for safety assessment in individual hospitals would provide an opportunity for self-evaluation and managing the safety measures that are most suitable to the hospital's own conditions.

  8. SU-C-17A-07: The Development of An MR Accelerator-Enabled Planning-To-Delivery Technique for Stereotactic Palliative Radiotherapy Treatment of Spinal Metastases

    SciTech Connect

    Hoogcarspel, S J; Kontaxis, C; Velden, J M van der; Bol, G H; Vulpen, M van; Lagendijk, J J W; Raaymakers, B W

    2014-06-01

    Purpose: To develop an MR accelerator-enabled online planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases. The technical challenges include; automated stereotactic treatment planning, online MR-based dose calculation and MR guidance during treatment. Methods: Using the CT data of 20 patients previously treated at our institution, a class solution for automated treatment planning for spinal bone metastases was created. For accurate dose simulation right before treatment, we fused geometrically correct online MR data with pretreatment CT data of the target volume (TV). For target tracking during treatment, a dynamic T2-weighted TSE MR sequence was developed. An in house developed GPU based IMRT optimization and dose calculation algorithm was used for fast treatment planning and simulation. An automatically generated treatment plan developed with this treatment planning system was irradiated on a clinical 6 MV linear accelerator and evaluated using a Delta4 dosimeter. Results: The automated treatment planning method yielded clinically viable plans for all patients. The MR-CT fusion based dose calculation accuracy was within 2% as compared to calculations performed with original CT data. The dynamic T2-weighted TSE MR Sequence was able to provide an update of the anatomical location of the TV every 10 seconds. Dose calculation and optimization of the automatically generated treatment plans using only one GPU took on average 8 minutes. The Delta4 measurement of the irradiated plan agreed with the dose calculation with a 3%/3mm gamma pass rate of 86.4%. Conclusions: The development of an MR accelerator-enabled planning-todelivery technique for stereotactic palliative radiotherapy treatment of spinal metastases was presented. Future work will involve developing an intrafraction motion adaptation strategy, MR-only dose calculation, radiotherapy quality-assurance in a magnetic field, and streamlining the entire treatment

  9. Measuring neutron spectra in radiotherapy using the nested neutron spectrometer

    SciTech Connect

    Maglieri, Robert Evans, Michael; Seuntjens, Jan; Kildea, John; Licea, Angel

    2015-11-15

    Purpose: Out-of-field neutron doses resulting from photonuclear interactions in the head of a linear accelerator pose an iatrogenic risk to patients and an occupational risk to personnel during radiotherapy. To quantify neutron production, in-room measurements have traditionally been carried out using Bonner sphere systems (BSS) with activation foils and TLDs. In this work, a recently developed active detector, the nested neutron spectrometer (NNS), was tested in radiotherapy bunkers. Methods: The NNS is designed for easy handling and is more practical than the traditional BSS. Operated in current-mode, the problem of pulse pileup due to high dose-rates is overcome by measuring current, similar to an ionization chamber. In a bunker housing a Varian Clinac 21EX, the performance of the NNS was evaluated in terms of reproducibility, linearity, and dose-rate effects. Using a custom maximum-likelihood expectation–maximization algorithm, measured neutron spectra at various locations inside the bunker were then compared to Monte Carlo simulations of an identical setup. In terms of dose, neutron ambient dose equivalents were calculated from the measured spectra and compared to bubble detector neutron dose equivalent measurements. Results: The NNS-measured spectra for neutrons at various locations in a treatment room were found to be consistent with expectations for both relative shape and absolute magnitude. Neutron fluence-rate decreased with distance from the source and the shape of the spectrum changed from a dominant fast neutron peak near the Linac head to a dominant thermal neutron peak in the moderating conditions of the maze. Monte Carlo data and NNS-measured spectra agreed within 30% at all locations except in the maze where the deviation was a maximum of 40%. Neutron ambient dose equivalents calculated from the authors’ measured spectra were consistent (one standard deviation) with bubble detector measurements in the treatment room. Conclusions: The NNS may

  10. Calcium, oxidative stress and connexin channels, a harmonious orchestra directing the response to radiotherapy treatment?

    PubMed

    Decrock, Elke; Hoorelbeke, Delphine; Ramadan, Raghda; Delvaeye, Tinneke; De Bock, Marijke; Wang, Nan; Krysko, Dmitri V; Baatout, Sarah; Bultynck, Geert; Aerts, An; Vinken, Mathieu; Leybaert, Luc

    2017-02-11

    Although radiotherapy is commonly used to treat cancer, its beneficial outcome is frequently hampered by the radiation resistance of tumor cells and adverse reactions in normal tissues. Mechanisms of cell-to-cell communication and how intercellular signals are translated into cellular responses, have become topics of intense investigation, particularly within the field of radiobiology. A substantial amount of evidence is available demonstrating that both gap junctional and paracrine communication pathways can propagate radiation-induced biological effects at the intercellular level, commonly referred to as radiation-induced bystander effects (RIBE). Multiple molecular signaling mechanisms involving oxidative stress, kinases, inflammatory molecules, and Ca(2+) are postulated to contribute to RIBE. Ca(2+) is a highly versatile and ubiquitous second messenger that regulates diverse cellular processes via the interaction with various signaling cascades. It furthermore provides a fast system for the dissemination of information at the intercellular level. Channels formed by transmembrane connexin (Cx) proteins, i.e. hemichannels and gap junction channels, can mediate the cell-to-cell propagation of increases in intracellular Ca(2+) by ministering paracrine and direct cell-cell communication, respectively. We here review current knowledge on radiation-induced signaling mechanisms in irradiated and bystander cells, particularly focusing on the contribution of oxidative stress, Ca(2+) and Cx channels. By illustrating the tight interplay between these different partners, we provide a conceptual framework for intercellular Ca(2+) signaling as a key player in modulating the RIBE and the overall response to radiation.

  11. Identifying radiotherapy target volumes in brain cancer by image analysis.

    PubMed

    Cheng, Kun; Montgomery, Dean; Feng, Yang; Steel, Robin; Liao, Hanqing; McLaren, Duncan B; Erridge, Sara C; McLaughlin, Stephen; Nailon, William H

    2015-10-01

    To establish the optimal radiotherapy fields for treating brain cancer patients, the tumour volume is often outlined on magnetic resonance (MR) images, where the tumour is clearly visible, and mapped onto computerised tomography images used for radiotherapy planning. This process requires considerable clinical experience and is time consuming, which will continue to increase as more complex image sequences are used in this process. Here, the potential of image analysis techniques for automatically identifying the radiation target volume on MR images, and thereby assisting clinicians with this difficult task, was investigated. A gradient-based level set approach was applied on the MR images of five patients with grades II, III and IV malignant cerebral glioma. The relationship between the target volumes produced by image analysis and those produced by a radiation oncologist was also investigated. The contours produced by image analysis were compared with the contours produced by an oncologist and used for treatment. In 93% of cases, the Dice similarity coefficient was found to be between 60 and 80%. This feasibility study demonstrates that image analysis has the potential for automatic outlining in the management of brain cancer patients, however, more testing and validation on a much larger patient cohort is required.

  12. Identifying radiotherapy target volumes in brain cancer by image analysis

    PubMed Central

    Cheng, Kun; Montgomery, Dean; Feng, Yang; Steel, Robin; Liao, Hanqing; McLaren, Duncan B.; Erridge, Sara C.; McLaughlin, Stephen

    2015-01-01

    To establish the optimal radiotherapy fields for treating brain cancer patients, the tumour volume is often outlined on magnetic resonance (MR) images, where the tumour is clearly visible, and mapped onto computerised tomography images used for radiotherapy planning. This process requires considerable clinical experience and is time consuming, which will continue to increase as more complex image sequences are used in this process. Here, the potential of image analysis techniques for automatically identifying the radiation target volume on MR images, and thereby assisting clinicians with this difficult task, was investigated. A gradient-based level set approach was applied on the MR images of five patients with grades II, III and IV malignant cerebral glioma. The relationship between the target volumes produced by image analysis and those produced by a radiation oncologist was also investigated. The contours produced by image analysis were compared with the contours produced by an oncologist and used for treatment. In 93% of cases, the Dice similarity coefficient was found to be between 60 and 80%. This feasibility study demonstrates that image analysis has the potential for automatic outlining in the management of brain cancer patients, however, more testing and validation on a much larger patient cohort is required. PMID:26609418

  13. Extracranial stereotactic radiotherapy: evaluation of PTV coverage and dose conformity.

    PubMed

    Hädinger, Ulrich; Thiele, Wibke; Wulf, Jörn

    2002-01-01

    During the past few years the concept of cranial stereotactic radiotherapy has been successfully extended to extracranial tumoral targets. In our department, hypofractionated treatment of tumours in lung, liver, abdomen, and pelvis is performed in the Stereotactic Body Frame (ELEKTA Instrument AB) since 1997. We present the evaluation of 63 consecutively treated targets (22 lung, 21 liver, 20 abdomen/pelvis) in 58 patients with respect to dose coverage of the planning target volume (PTV) as well as conformity of the dose distribution. The mean PTV coverage was found to be 96.3% +/- 2.3% (lung), 95.0% +/- 4.5% (liver), and 92.1% +/- 5.2% (abdomen/pelvis). For the so-called conformation number we obtained values of 0.73 +/- 0.09 (lung), 0.77 +/- 0.10 (liver), and 0.70 +/- 0.08 (abdomen/pelvis). The results show that highly conformal treatment techniques can be applied also in extracranial stereotactic radiotherapy. This is primarily due to the relatively simple geometrical shape of most of the targets. Especially lung and liver targets turned out to be approximately spherically/cylindrically shaped, so that the dose distribution can be easily tailored by rotational fields.

  14. In vivo skin dose measurement in breast conformal radiotherapy

    PubMed Central

    Soleymanifard, Shokouhozaman; Noghreiyan, Atefeh Vejdani; Ghorbani, Mahdi; Jamali, Farideh; Davenport, David

    2016-01-01

    Aim of the study Accurate skin dose assessment is necessary during breast radiotherapy to assure that the skin dose is below the tolerance level and is sufficient to prevent tumour recurrence. The aim of the current study is to measure the skin dose and to evaluate the geometrical/anatomical parameters that affect it. Material and methods Forty patients were simulated by TIGRT treatment planning system and treated with two tangential fields of 6 MV photon beam. Wedge filters were used to homogenise dose distribution for 11 patients. Skin dose was measured by thermoluminescent dosimeters (TLD-100) and the effects of beam incident angle, thickness of irradiated region, and beam entry separation on the skin dose were analysed. Results Average skin dose in treatment course of 50 Gy to the clinical target volume (CTV) was 36.65 Gy. The corresponding dose values for patients who were treated with and without wedge filter were 35.65 and 37.20 Gy, respectively. It was determined that the beam angle affected the average skin dose while the thickness of the irradiated region and the beam entry separation did not affect dose. Since the skin dose measured in this study was lower than the amount required to prevent tumour recurrence, application of bolus material in part of the treatment course is suggested for post-mastectomy advanced breast radiotherapy. It is more important when wedge filters are applied to homogenize dose distribution. PMID:27358592

  15. Radiotherapy in the management of early breast cancer

    SciTech Connect

    Wang, Wei

    2013-03-15

    Radiotherapy is an indispensible part of the management of all stages of breast cancer. In this article, the common indications for radiotherapy in the management of early breast cancer (stages 0, I, and II) are reviewed, including whole-breast radiotherapy as part of breast-conserving treatment for early invasive breast cancer and pre-invasive disease of ductal carcinoma in situ, post-mastectomy radiotherapy, locoregional radiotherapy, and partial breast irradiation. Key clinical studies that underpin our current practice are discussed briefly.

  16. Radiotherapy for Patients With Metastases to the Spinal Column: A Review of 603 Patients at Shizuoka Cancer Center Hospital

    SciTech Connect

    Mizumoto, Masashi; Harada, Hideyuki; Asakura, Hirofumi; Hashimoto, Takayuki; Furutani, Kazuhisa; Hashii, Haruko; Murata, Hideki; Takagi, Tatsuya; Katagiri, Hirohisa; Takahashi, Mitsuru; Nishimura, Tetsuo

    2011-01-01

    Purpose: Long- and short-course radiotherapy have similar outcomes in the treatment of spinal metastases. Long-course radiotherapy is recommended for patients with good predicted survival to reduce the risk of in-field recurrence, whereas short-course radiotherapy is used for those with poor predicted survival. Therefore, prediction of prognosis and local control is required for selecting the optimal course of radiotherapy. Methods and Materials: The subjects were 603 patients with spinal metastases who received radiotherapy at the Shizuoka Cancer Center Hospital between September 2002 and February 2007. Factors associated with survival and local control were retrospectively investigated by multivariate analyses. Local recurrence was defined as regrowth within the irradiated field or exacerbation of symptoms such as pain and motor deficits. Results: Of the 603 patients, 555 (92%) were followed for 12 months or until death. The survival rates after 6, 12, and 24 months were 50%, 32%, and 19%, respectively, with a median survival of 6.2 months. The median survival periods after long- and short-course radiotherapy were 7.9 and 1.8 months, respectively. In multivariate analysis, primary tumor site, good performance status, absence of previous chemotherapy, absence of visceral metastasis, single bone metastasis, younger age, and nonhypercalcemia were associated with good survival. The local control rates after 6, 12, and 24 months were 91%, 79%, and 69%, respectively, and non-mass-type tumor, breast cancer, and absence of previous chemotherapy were predictors of good local control. Conclusions: Identification of factors associated with good local control and survival may allow selection of an optimal radiotherapy schedule for patients with spinal metastases.

  17. The Leicester radiotherapy bite block: an aid to head and neck radiotherapy.

    PubMed

    Hollows, P; Hayter, J P; Vasanthan, S

    2001-02-01

    We describe the construction of a custom-made bite block to be used during external beam radiotherapy to the oral cavity. The bite block is made with standard maxillofacial prosthetic techniques and materials. The design allows accurate and reproducible positioning of the perioral tissues to aid planning of radiotherapy and treatment. The compressibility of this device improves comfort for the patient, while it is in use.

  18. Post-radiotherapy hypothyroidism in dogs treated for thyroid carcinomas.

    PubMed

    Amores-Fuster, I; Cripps, P; Blackwood, L

    2017-03-01

    Hypothyroidism is a common adverse event after head and neck radiotherapy in human medicine, but uncommonly reported in canine patients. Records of 21 dogs with histologically or cytologically confirmed thyroid carcinoma receiving definitive or hypofractionated radiotherapy were reviewed. Nine cases received 48 Gy in 12 fractions, 10 received 36 Gy in 4 fractions and 2 received 32 Gy in 4 fractions. Seventeen cases had radiotherapy in a post-operative setting. Ten cases developed hypothyroidism (47.6%) after radiotherapy. The development of hypothyroidism was not associated with the radiotherapy protocol used. Median time to diagnosis of hypothyroidism was 6 months (range, 1-13 months). Hypothyroidism is a common side effect following radiotherapy for thyroid carcinomas. Monitoring of thyroid function following radiotherapy is recommended. No specific risk factors have been identified.

  19. Breast Cancer Patients’ Experience of External-Beam Radiotherapy

    PubMed Central

    Schnur, Julie B.; Ouellette, Suzanne C.; Bovbjerg, Dana H.; Montgomery, Guy H.

    2013-01-01

    Radiotherapy is a critical component of treatment for the majority of women with breast cancer, particularly those who receive breast conserving surgery. Although medically beneficial, radiotherapy can take a physical and psychological toll on patients. However, little is known about the specific thoughts and feelings experienced by women undergoing breast cancer radiotherapy. Therefore, the study aim was to use qualitative research methods to develop an understanding of these thoughts and feelings based on 180 diary entries, completed during radiotherapy by 15 women with Stage 0-III breast cancer. Thematic analysis identified four primary participant concerns: (a) a preoccupation with time; (b) fantasies (both optimistic and pessimistic) about life following radiotherapy; (c) the toll their side-effect experience takes on their self-esteem; and (d) feeling mystified by radiotherapy. These themes are consistent with previous literature on illness and identity. These findings have implications for the treatment and care of women undergoing breast cancer radiotherapy. PMID:19380502

  20. Gold Nanoparticle Hyperthermia Reduces Radiotherapy Dose

    PubMed Central

    Lin, Lynn; Slatkin, Daniel N.; Dilmanian, F. Avraham; Vadas, Timothy M.; Smilowitz, Henry M.

    2014-01-01

    Gold nanoparticles can absorb near infrared light, resulting in heating and ablation of tumors. Gold nanoparticles have also been used for enhancing the dose of X-rays in tumors during radiotherapy. The combination of hyperthermia and radiotherapy is synergistic, importantly allowing a reduction in X-ray dose with improved therapeutic results. Here we intratumorally infused small 15 nm gold nanoparticles engineered to be transformed from infrared-transparent to infrared-absorptive by the tumor, which were then heated by infrared followed by X-ray treatment. Synergy was studied using a very radioresistant subcutaneous squamous cell carcinoma (SCCVII) in mice. It was found that the dose required to control 50% of the tumors, normally 55 Gy, could be reduced to <15 Gy (a factor of >3.7). Gold nanoparticles therefore provide a method to combine hyperthermia and radiotherapy to drastically reduce the X-ray radiation needed, thus sparing normal tissue, reducing the side effects, and making radiotherapy more effective. PMID:24990355

  1. Radiotherapy for inverted papilloma: a case report.

    PubMed

    Levendag, P C; Annyas, A A; Escajadillo, J R; Elema, J D

    1984-06-01

    Inverted papilloma is an infrequent tumour of the nasal cavity and paranasal sinuses associated with controversy. The incidence of carcinoma in situ associated with inverted papilloma, has not been very well documented until now. Therefore, we present a case report characterized by an aggressive clinical behaviour, treated by extensive surgery and ultimately controlled by radiotherapy.

  2. Results of radiotherapy for Peyronie's disease

    SciTech Connect

    Niewald, Marcus . E-mail: ramnie@uniklinikum-saarland.de; Wenzlawowicz, Knut v.; Fleckenstein, Jochen; Wisser, Lothar; Derouet, Harry; Ruebe, Christian

    2006-01-01

    Purpose: To retrospectively review the results of radiotherapy for Peyronie's disease. Patients and Methods: In the time interval 1983-2000, 154 patients in our clinic were irradiated for Peyronie's disease. Of those, 101 had at least one complete follow-up data set and are the subject of this study. In the majority of patients, penis deviation was between 30 and 50{sup o}, there were one or two indurated foci with a diameter between 5 and 15 mm. Pain was recorded in 48/92 patients. Seventy-two of the 101 patients received radiotherapy with a total dose of 30 Gy, and 25 received 36 Gy in daily fractions of 2.0 Gy. The remaining patients received the following dosage: 34 Gy (1 patient), 38-40 Gy (3 patients). Mean duration of follow-up was 5 years. Results: The best results ever at any time during follow-up were an improvement of deviation in 47%, reduction of number of foci in 32%, reduction of size of foci in 49%, and less induration in 52%. Approximately 50% reported pain relief after radiotherapy. There were 28 patients with mild acute dermatitis and only 4 patients with mild urethritis. There were no long-term side effects. Conclusion: Our results compare well with those of other studies in the literature. In our patient cohort, radiotherapy was an effective therapy option with only very rare and mild side effects.

  3. Motor function and survival following radiotherapy alone for metastatic epidural spinal cord compression in melanoma patients.

    PubMed

    Huttenlocher, Stefan; Sehmisch, Lena; Rudat, Volker; Rades, Dirk

    2014-12-01

    The major goal of this study was the identification of predictors for motor function and survival after irradiation alone for metastatic epidural spinal cord compression (MESCC) from melanoma. Ten variables (age, gender, performance status, number of involved vertebrae, pre-radiotherapy ambulatory status, further bone metastases, visceral metastases, interval from melanoma diagnosis to MESCC, time developing motor deficits before radiotherapy, fractionation regimen) were investigated for post-radiotherapy motor function, ambulatory status and survival in 27 patients. On multivariate analysis, motor function was significantly associated with time developing motor deficits (P = 0.006). On univariate analysis, post-radiotherapy ambulatory rates were associated with pre-radiotherapy ambulatory status (P < 0.001) and performance status (P = 0.046). Variables having a significant impact on survival in the univariate analysis were performance status (P < 0.001), number of involved vertebrae (P = 0.007), pre-radiotherapy ambulatory status (P = 0.020), further bone metastases (P = 0.023), visceral metastases (P < 0.001), and time developing motor deficits (P = 0.038). On multivariate analysis of survival, the Eastern Cooperative Oncology Group (ECOG) performance status (risk ratio [RR] = 4.35; 95% confidence interval [CI] = 1.04-16.67; P = 0.044) and visceral metastases (RR = 3.70; 95% CI = 1.10-12.50; P = 0.034) remained significant and were included in a survival score. Scoring points were obtained from 6-month survival rates divided by 10. Total scores represented the sum scores of both variables and were 3, 9 or 15 points. Six-month survival rates were 7%, 29% and 100% (P = 0.004). Thus, three predictors for functional outcomes were identified. The newly developed survival score included three prognostic groups. Patients with 3 points may receive 1 × 8 Gy, patients with 9 points 5 × 4 Gy and patients achieving 15 points longer

  4. Radiotherapy Alone With Curative Intent in Patients With Stage I Extranodal Nasal-Type NK/T-Cell Lymphoma

    SciTech Connect

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

    2012-04-01

    Purpose: This study aims to evaluate the outcome and pattern of failure in a large cohort of patients with Stage I NK/T-cell lymphoma of the upper aerodigestive tract treated with radiotherapy alone. Methods and Materials: The pathological diagnosis was confirmed using standard criteria. All patients were treated with high-dose extended-field radiotherapy alone. The median dose was 50 Gy. The primary tumor was located in the nasal cavity (n = 80), Waldeyer ring (n = 5), or oral cavity (n = 2). Results: The overall response to radiotherapy was achieved in 85 of 87 (97.7%) patients, with a complete response rate of 95.4% and a partial response rate of 2.3%. The 5-year overall survival, progression-free survival, and local control rates for all patients were 80%, 69%, and 93%, respectively. Twenty patients (23%) had disease progression or relapse. Of these, 15 patients (17%) developed systemic extranodal disseminations, whereas only 4 (5%) patients had local relapse and 4 (5%) patients had lymph node relapse. Conclusions: Our study suggests that high-dose extended-field radiotherapy alone is a curative therapy and shows favorable clinical outcome in patients with Stage I disease. With the high possibility of local control and primary failure of systemic dissemination, the integration of optimal radiotherapy with more effective systematic therapy is warranted to bring additional improvement to the outcome for these patients.

  5. In vivo dosimetry with diodes in a radiotherapy department in Pakistan.

    PubMed

    Tunio, Mutahir; Rafi, Mansoor; Ali, Shoukat; Ahmed, Zaeem; Zameer, Asad; Hashmi, Altaf; Maqbool, Syed A

    2011-11-01

    The International Commission of Radiological Units (ICRU) sets a tolerance of ±5 % on dose delivery, with more recent data limiting the overall tolerances to ±3 %. One of the best methods for accurate dose delivery and quality check is in vivo dosimetry, while radiotherapy is performed. The present study was carried out to test the applicability of diodes for performing in vivo entrance dose measurements in external photon beam radiotherapy for pelvic tumours and its implementation as quality assurance tool in radiotherapy. During November 2007 to December 2009, in 300 patients who received pelvic radiotherapy on a multileaf-collimator-assisted linear accelerator, the central axis dose was measured by in vivo dosimetry by p-Si diodes. Entrance dose measurements were taken by diodes and were compared with the prescribed dose. Totally 1000 calculations were performed. The mean and standard deviation between measured and prescribed dose was 1.26 ± 2.8 %. In 938 measurements (93.8 %), the deviation was <5 % (1.36 ± 2.9%); in 62 measurements (6.2 %) the mean deviation was >5 % (5.51 ± 2.3 %). Larger variations were seen in lateral and oblique fields more than anteroposterior fields. For larger deviations, patients and diode positional errors were found to be the common factors alone or in combination with other factors. After additional corrections, repeated measurements were achieved within tolerance levels. This study showed that diode-detector-based in vivo dosimetry was simple, cost-effective, provides quick results and can serve as a useful quality assurance tool in radiotherapy. The data acquired in the present study can be used for evaluating output calibration of therapy machine, precision of calculations, effectiveness of treatment plan and patient setup.

  6. Recurrence patterns of locally advanced head and neck squamous cell carcinoma after 3D conformal (chemo)-radiotherapy

    PubMed Central

    2011-01-01

    Background To establish recurrence patterns among locally advanced head and neck non-nasopharyngeal squamous cell carcinoma (HNSCC) patients treated with radical (chemo-) radiotherapy and to correlate the sites of loco-regional recurrence with radiotherapy doses and target volumes Method 151 locally advanced HNSCC patients were treated between 2004-2005 using radical three-dimensional conformal radiotherapy. Patients with prior surgery to the primary tumour site were excluded. The sites of locoregional relapses were correlated with radiotherapy plans by the radiologist and a planning dosimetrist. Results Median age was 59 years (range:34-89). 35 patients had stage III disease, 116 patients had stage IV A/B. 36 patients were treated with radiotherapy alone, 42 with induction chemotherapy, 63 with induction and concomitant chemoradiotherapy and 10 concomitant chemoradiotherapy. Median follow-up was 38 months (range 3-62). 3-year cause specific survival was 66.8%. 125 of 151 (82.8%) achieved a complete response to treatment. Amongst these 125 there were 20 local-regional recurrence, comprising 8 local, 5 regional and 7 simultaneous local and regional; synchronous distant metastases occurred in 7 of the 20. 9 patients developed distant metastases in the absence of locoregional failure. For the 14 local recurrences with planning data available, 12 were in-field, 1 was marginal, and 1 was out-of-field. Of the 11 regional failures with planning data available, 7 were in-field, 1 was marginal and 3 were out-of-field recurrences. Conclusion The majority of failures following non-surgical treatment for locally advanced HNSCC were loco-regional, within the radiotherapy target volume. Improving locoregional control remains a high priority. PMID:21609453

  7. Neo-adjuvant radiotherapy in rectal cancer

    PubMed Central

    Glimelius, Bengt

    2013-01-01

    In rectal cancer treatment, attention has focused on the local primary tumour and the regional tumour cell deposits to diminish the risk of a loco-regional recurrence. Several large randomized trials have also shown that combinations of surgery, radiotherapy and chemotherapy have markedly reduced the risk of a loco-regional recurrence, but this has not yet had any major influence on overall survival. The best results have been achieved when the radiotherapy has been given preoperatively. Preoperative radiotherapy improves loco-regional control even when surgery has been optimized to improve lateral clearance, i.e., when a total mesorectal excision has been performed. The relative reduction is then 50%-70%. The value of radiotherapy has not been tested in combination with more extensive surgery including lateral lymph node clearance, as practised in some Asian countries. Many details about how the radiotherapy is performed are still open for discussion, and practice varies between countries. A highly fractionated radiation schedule (5 Gy × 5), proven efficacious in many trials, has gained much popularity in some countries, whereas a conventionally fractionated regimen (1.8-2.0 Gy × 25-28), often combined with chemotherapy, is used in other countries. The additional therapy adds morbidity to the morbidity that surgery causes, and should therefore be administered only when the risk of loco-regional recurrence is sufficiently high. The best integration of the weakest modality, to date the drugs (conventional cytotoxics and biologicals) is not known. A new generation of trials exploring the best sequence of treatments is required. Furthermore, there is a great need to develop predictors of response, so that treatment can be further individualized and not solely based upon clinical factors and anatomic imaging. PMID:24379566

  8. Phase I/II Clinical Trial of Carbon Ion Radiotherapy for Malignant Gliomas: Combined X-Ray Radiotherapy, Chemotherapy, and Carbon Ion Radiotherapy

    SciTech Connect

    Mizoe, Jun-Etsu Tsujii, Hirohiko; Hasegawa, Azusa D.D.S.; Yanagi, Tsuyoshi; Takagi, Ryo D.D.S.; Kamada, Tadashi; Tsuji, Hiroshi; Takakura, Kintomo

    2007-10-01

    Purpose: To report the results of a Phase I/II clinical trial for patients with malignant gliomas, treated with combined X-ray radiotherapy (XRT), chemotherapy, and carbon ion radiotherapy (CRT). Methods and Materials: Between October 1994 and February 2002, 48 patients with histologically confirmed malignant gliomas (16 anaplastic astrocytoma (AA) and 32 glioblastoma multiforme (GBM) were enrolled in a Phase I/II clinical study. The treatment involved the application of 50 Gy/25 fractions/5 weeks of XRT, followed by CRT at 8 fractions/2 weeks. Nimustine hydrochloride (ACNU) were administered at a dose of 100 mg/m{sup 2} concurrently in weeks 1, 4, or 5 of XRT. The carbon ion dose was increased from 16.8 to 24.8 Gray equivalent (GyE) in 10% incremental steps (16.8, 18.4, 20.0, 22.4, and 24.8 GyE, respectively). Results: There was no Grade 3 or higher acute reaction in the brain. The late reactions included four cases of Grade 2 brain morbidity and four cases of Grade 2 brain reaction among 48 cases. The median survival time (MST) of AA patients was 35 months and that of GBM patients 17 months (p = 0.0035). The median progression-free survival and MST of GBM showed 4 and 7 months for the low-dose group, 7 and 19 months for the middle-dose group, and 14 and 26 months for the high-dose group. Conclusion: The results of combined therapy using XRT, ACNU chemotherapy, and CRT showed the potential efficacy of CRT for malignant gliomas in terms of the improved survival rate in those patients who received higher carbon doses.

  9. Stereotactic body radiotherapy: a critical review for nonradiation oncologists.

    PubMed

    Kirkpatrick, John P; Kelsey, Christopher R; Palta, Manisha; Cabrera, Alvin R; Salama, Joseph K; Patel, Pretesh; Perez, Bradford A; Lee, Jason; Yin, Fang-Fang

    2014-04-01

    Stereotactic body radiotherapy (SBRT) involves the treatment of extracranial primary tumors or metastases with a few, high doses of ionizing radiation. In SBRT, tumor kill is maximized and dose to surrounding tissue is minimized, by precise and accurate delivery of multiple radiation beams to the target. This is particularly challenging, because extracranial lesions often move with respiration and are irregular in shape, requiring careful treatment planning and continual management of this motion and patient position during irradiation. This review presents the rationale, process workflow, and technology for the safe and effective administration of SBRT, as well as the indications, outcome, and limitations for this technique in the treatment of lung cancer, liver cancer, and metastatic disease.

  10. Approximating convex Pareto surfaces in multiobjective radiotherapy planning

    SciTech Connect

    Craft, David L.; Halabi, Tarek F.; Shih, Helen A.; Bortfeld, Thomas R.

    2006-09-15

    Radiotherapy planning involves inherent tradeoffs: the primary mission, to treat the tumor with a high, uniform dose, is in conflict with normal tissue sparing. We seek to understand these tradeoffs on a case-to-case basis, by computing for each patient a database of Pareto optimal plans. A treatment plan is Pareto optimal if there does not exist another plan which is better in every measurable dimension. The set of all such plans is called the Pareto optimal surface. This article presents an algorithm for computing well distributed points on the (convex) Pareto optimal surface of a multiobjective programming problem. The algorithm is applied to intensity-modulated radiation therapy inverse planning problems, and results of a prostate case and a skull base case are presented, in three and four dimensions, investigating tradeoffs between tumor coverage and critical organ sparing.

  11. Esthesioneuroblastoma chemotherapy and radiotherapy for extensive disease: a case report.

    PubMed

    Gupta, Seema; Husain, Nuzhat; Sundar, Sham

    2011-10-05

    Malignant tumors of the nasal cavity are rare. We report the case of a 48 years old man who consulted us with a 2-year history of progressive nasal obstruction, occasional epistaxis, facial pain, and watering of the eyes. A diagnosis of olfactory neuroblastoma was established by histopathology and confirmed by immunohistochemistry. On staging, the mass was classified as a Kadish stage C tumor with extensive involvement of the nasal cavities, nasopharynx, paranasal sinuses and orbit. Endoscopic excision of the mass was done. Traditionally the mainstay of treatment in such locally advanced patients is craniofacial resection followed by adjuvant radiotherapy. Our patient was treated with limited surgery and chemoradiation. Patient is free of recurrence at a follow-up of 5 years. This case report demonstrates the potential efficacy of planned combined modality therapy, including limited surgery and early chemoradiation in the control of locally advanced olfactory neuroblastoma.

  12. Pharyngo-cutaneous fistulae after laryngectomy. Influence of previous radiotherapy and prophylactic metronidazole

    SciTech Connect

    Johansen, L.V.; Overgaard, J.; Elbrond, O.

    1988-02-15

    The development of a pharyngocutaneous fistulae is a major complication after total laryngectomy. In Denmark radiotherapy is the primary treatment for all laryngeal carcinomas. Based on the experience with conventional daily irradiation, a split-course radiation schedule was introduced in 1978. The charts of 106 consecutive patients laryngectomized for recurrence in the years 1975 to 1984 were examined. Thirty-four patients developed a fistula. An evaluation of the different radiotherapy schedules used during this period allowed a dose-response curve to be constructed. It showed a pronounced increase of fistulae with high doses of radiotherapy. Split-course radiotherapy caused a rise in late complications and did not improve tumor control. Large field sizes increased the number of fistulae. High-dose fractions showed a surprisingly high incidence of late complications. Prophylactic metronidazole (introduced in 1980) resulted in a highly significant decrease in the frequency of postoperative fistulae. Patients in whom fistula formed were hospitalized for an average of 54 days, patients without, for 22 days.

  13. Effect of definitive radiotherapy on the long-term outcome in patients with solitary extramedullary plasmacytoma.

    PubMed

    Skóra, Tomasz; Pudełek, Katarzyna; Nowak-Sadzikowska, Jadwiga; Pietrasz, Mariusz; Szyszka-Charewicz, Bogumiła; Jakubowicz, Jerzy

    2015-10-09

    Extramedullary solitary plasmacytoma (EMP) is a rare type of malignancy. This paper presents a retrospective review of the experience with EMP at the Krakow Oncology Center. Records of 17 patients with head and neck EMP, treated with definitive radiotherapy between 1976 and 2009, were analyzed. The total tumour dose ranged from 45 to 70 Gy (median 56 Gy). In four patients with partial response after radiotherapy, adjuvant melphalan-based chemotherapy was applied. The median follow-up period was 8.6 years. The treatment was well tolerated. The estimated 10-year overall survival, disease-free survival, and multiple myeloma-free survival were 68.4%, 49.3%, and 55%, respectively. The 10-year local control rate was 90.9%. No in-field local recurrence was observed. During the follow-up, progression into multiple myeloma was observed in five patients, with a mean time to conversion of 24 months. The only factor adversely affecting overall survival on univariate analysis was the age >56 years, whereas a complete tumour regression after radiotherapy was associated with a significant improvement in both disease-free survival and multiple myeloma-free survival. Despite the high effectiveness of local radiotherapy, there is still a significant treatment failure risk due to the EMP conversion into generalized disease. An attempt to identify prognostic factors may facilitate selection of patients with a high risk of progression to multiple myeloma. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Second Cancers After Fractionated Radiotherapy: Stochastic Population Dynamics Effects

    NASA Technical Reports Server (NTRS)

    Sachs, Rainer K.; Shuryak, Igor; Brenner, David; Fakir, Hatim; Hahnfeldt, Philip

    2007-01-01

    When ionizing radiation is used in cancer therapy it can induce second cancers in nearby organs. Mainly due to longer patient survival times, these second cancers have become of increasing concern. Estimating the risk of solid second cancers involves modeling: because of long latency times, available data is usually for older, obsolescent treatment regimens. Moreover, modeling second cancers gives unique insights into human carcinogenesis, since the therapy involves administering well characterized doses of a well studied carcinogen, followed by long-term monitoring. In addition to putative radiation initiation that produces pre-malignant cells, inactivation (i.e. cell killing), and subsequent cell repopulation by proliferation can be important at the doses relevant to second cancer situations. A recent initiation/inactivation/proliferation (IIP) model characterized quantitatively the observed occurrence of second breast and lung cancers, using a deterministic cell population dynamics approach. To analyze ifradiation-initiated pre-malignant clones become extinct before full repopulation can occur, we here give a stochastic version of this I I model. Combining Monte Carlo simulations with standard solutions for time-inhomogeneous birth-death equations, we show that repeated cycles of inactivation and repopulation, as occur during fractionated radiation therapy, can lead to distributions of pre-malignant cells per patient with variance >> mean, even when pre-malignant clones are Poisson-distributed. Thus fewer patients would be affected, but with a higher probability, than a deterministic model, tracking average pre-malignant cell numbers, would predict. Our results are applied to data on breast cancers after radiotherapy for Hodgkin disease. The stochastic IIP analysis, unlike the deterministic one, indicates: a) initiated, pre-malignant cells can have a growth advantage during repopulation, not just during the longer tumor latency period that follows; b) weekend

  15. Stereotactic radiotherapy of meningiomas compressing optical pathways

    SciTech Connect

    Hamm, Klaus-Detlef . E-mail: khamm@erfurt.helios-kliniken.de; Henzel, Martin; Gross, Markus W.; Surber, Gunnar; Kleinert, Gabriele; Engenhart-Cabillic, Rita

    2006-11-15

    Purpose: Microsurgical resection is usually the treatment of choice for meningiomas, especially for those that compress the optical pathways. However, in many cases of skull-base meningiomas a high risk of neurological deficits and recurrences exist in cases where the complete tumor removal was not possible. In such cases (fractionated) stereotactic radiotherapy (SRT) can offer an alternative treatment option. We evaluated the local control rate, symptomatology, and toxicity. Patients and Methods: Between 1997 and 2003, 183 patients with skull-base meningiomas were treated with SRT, among them were 65 patients with meningiomas that compressed optical pathways (64 benign, 1 atypical). Of these 65 cases, 20 were treated with SRT only, 27 were subtotally resected before SRT, and 18 underwent multiple tumor resections before SRT. We investigated the results until 2005, with a median follow-up of 45 months (range, 22-83 months). The tumor volume (TV = gross tumor volume) ranged from 0.61 to 90.20 cc (mean, 18.9 cc). Because of the risk of new visual disturbances, the dose per fraction was either 2 or 1.8 Gy for all patients, to a total dose of 50 to 60 Gy. Results: The overall survival and the progression-free survival rates for 5 years were assessed to 100% in this patient group. To date, no progression for these meningiomas have been observed. Quantitatively, tumor shrinkage of more than 20%, or more than 2 mm in diameter, was proved in 35 of the 65 cases after SRT. In 29 of the 65 patients, at least 1 of the symptoms improved. On application of the Common Toxicity Criteria (CTC), acute toxicity (Grade 3) was seen in 1 case (worsening of conjunctivitis). Another 2 patients developed late toxicity by LENT-SOMA score, 1 x Grade 1 and 1 x Grade 3 (field of vision loss). Conclusion: As a low-risk and effective treatment option for tumor control, SRT with 1.8 to 2.0 Gy per fraction can also be recommended in case of meningiomas that compress optical pathways. An

  16. Magnetic field effects on the energy deposition spectra of MV photon radiation.

    PubMed

    Kirkby, C; Stanescu, T; Fallone, B G

    2009-01-21

    Several groups worldwide have proposed various concepts for improving megavoltage (MV) radiotherapy that involve irradiating patients in the presence of a magnetic field-either for image guidance in the case of hybrid radiotherapy-MRI machines or for purposes of introducing tighter control over dose distributions. The presence of a magnetic field alters the trajectory of charged particles between interactions with the medium and thus has the potential to alter energy deposition patterns within a sub-cellular target volume. In this work, we use the MC radiation transport code PENELOPE with appropriate algorithms invoked to incorporate magnetic field deflections to investigate electron energy fluence in the presence of a uniform magnetic field and the energy deposition spectra within a 10 microm water sphere as a function of magnetic field strength. The simulations suggest only very minor changes to the electron fluence even for extremely strong magnetic fields. Further, calculations of the dose-averaged lineal energy indicate that a magnetic field strength of at least 70 T is required before beam quality will change by more than 2%.

  17. Resonant X-ray emission spectroscopy reveals d-d ligand-field states involved in the self-assembly of a square-planar platinum complex.

    PubMed

    Garino, Claudio; Gallo, Erik; Smolentsev, Nikolay; Glatzel, Pieter; Gobetto, Roberto; Lamberti, Carlo; Sadler, Peter J; Salassa, Luca

    2012-11-28

    Resonant X-ray Emission Spectroscopy (RXES) is used to characterize the ligand field states of the prototypic self-assembled square-planar complex, [Pt(tpy)Cl]Cl (tpy=2,2':6',2''-terpyridine), and determine the effect of weak metal-metal and π-π interactions on their energy.

  18. Monetary Incentives in Support of Academic Achievement: Results of a Randomized Field Trial Involving High-Achieving, Low-Resource, Ethnically Diverse Urban Adolescents

    ERIC Educational Resources Information Center

    Spencer, Margaret Beale; Noll, Elizabeth; Cassidy, Elaine

    2005-01-01

    Significant resources have been directed at understanding and alleviating the achievement gap in education. Most programs focused on this aim rely on a top-down approach, including funding for infrastructure improvement, curriculum development, class size, and teacher salaries. This article presents findings from a randomized field trial that…

  19. MO-B-18C-01: Proton Therapy II: Proton Stereotactic Radiotherapy

    SciTech Connect

    Winey, B; Daartz, J

    2014-06-15

    Proton stereotactic radiotherapy shares fundamental principles with general proton therapy physics, specifically range uncertainties and broad beam measurement techniques. Significant differences emerge when treating with smaller field sizes that suffer lateral disequilibrium and when fractions are reduced. This session will explore the history and scope of proton stereotactic radiotherapy in clinical practice. Uncertainties and treatment planning methods specific to stereotactic treatments will be discussed. The session will include an overview of the physical properties of small proton fields and resulting needs for accurate measurements and modeling of dose distributions for radiosurgery treatment planning. Learning Objectives: Understand the clinical rationale for proton radiosurgery. Understand the similarities and differences from general proton therapy. Understand the similarities and differences from photon stereotactic radiosurgery. Understand the basic physics and clinical physics methods for measuring and commissioning a radiosurgery program.

  20. Can immunostimulatory agents enhance the abscopal effect of radiotherapy?

    PubMed

    Levy, Antonin; Chargari, Cyrus; Marabelle, Aurelien; Perfettini, Jean-Luc; Magné, Nicolas; Deutsch, Eric

    2016-07-01

    Ionising radiation (IR) may harm cancer cells through a rare indirect out-of-field phenomenon described as the abscopal effect. Increasing evidence demonstrates that radiotherapy could be capable of generating tumour-specific immune responses. On the other hand, effects of IR also include inhibitory immune signals on the tumour microenvironment. Following these observations, and in the context of newly available immunostimulatory agents in metastatic cancers (anti-cytotoxic T lymphocyte-associated antigen 4 and programmed cell death protein-1 or -ligand 1 [PD1 or PDL-1]), there is a remarkable potential for synergistic combinations of IR with such agents that act through the reactivation of immune surveillance. Here, we present and discuss the pre-clinical and clinical rationale supporting the enhancement of the abscopal effect of IR on the blockade of immune checkpoints and discuss the evolving potential of immunoradiotherapy.

  1. Fractionated but not single dose radiotherapy induces an immune-mediated abscopal effect when combined with anti-CTLA-4 antibody

    PubMed Central

    Dewan, M. Zahidunnabi; Galloway, Ashley E.; Kawashima, Noriko; Dewyngaert, J. Keith; Babb, James S.; Formenti, Silvia C.; Demaria, Sandra

    2009-01-01

    Purpose This study tested the hypothesis that the type of dose-fractionation regimen determines the ability of radiotherapy to synergize with anti-CTLA-4 antibody. Experimental design TSA mouse breast carcinoma cells were injected s.c. into syngeneic mice at two separate sites, defined as a “primary” site that was irradiated, and a “secondary” site outside the radiotherapy field. When both tumors were palpable mice were randomly assigned to 8 groups receiving no radiotherapy or 3 distinct regimens of radiotherapy (20 Gy × 1, 8 Gy × 3 or 6 Gy × 5 fractions in consecutive days) in combination or not with 9H10 mAb against CTLA-4. Mice were followed for tumors growth/regression. Similar experiments were conducted in the MCA38 mouse colon carcinoma model. Results In either of the 2 models tested treatment with 9H10 alone had no detectable effect. Each of the radiotherapy regimens caused comparable growth delay of the primary tumors, but had no effect on the secondary tumors, outside the radiation field. Conversely, the combination of 9H10 and either fractionated radiotherapy regimens achieved enhanced tumor response at the primary site (p<0.0001). Moreover, an abscopal effect, defined as a significant growth inhibition of the tumor outside the field occurred only in mice treated with the combination of 9H10 and fractionated radiotherapy (p<0.01). Frequency of CD8+ T cells showing tumor-specific IFNγ production was proportional to the inhibition of the secondary tumor. Conclusions Fractionated, but not single dose radiotherapy, induces an abscopal effect when in combination with anti-CTLA-4 antibody, in two preclinical carcinoma models. PMID:19706802

  2. Activation of hip prostheses in high energy radiotherapy and resultant dose to nearby tissue.

    PubMed

    Keehan, Stephanie; Smith, Ryan L; Millar, Jeremy; Esser, Max; Taylor, Michael L; Lonski, Peta; Kron, Tomas; Franich, Rick D

    2017-03-01

    High energy radiotherapy can produce contaminant neutrons through the photonuclear effect. Patients receiving external beam radiation therapy to the pelvis may have high-density hip prostheses. Metallic materials such as those in hip prostheses, often have high cross-sections for neutron interaction. In this study, Thackray (UK) prosthetic hips have been irradiated by 18 MV radiotherapy beams to evaluate the additional dose to patients from the activation products. Hips were irradiated in- and out-of field at various distances from the beam isocenter to assess activation caused in-field by photo-activation, and neutron activation which occurs both in and out-of-field. NaI(Tl) scintillator detectors were used to measure the subsequent gamma-ray emissions and their half-lives. High sensitivity Mg, Cu, P doped LiF thermoluminescence dosimeter chips (TLD-100H) were used to measure the subsequent dose at the surface of a prosthesis over the 12 h following an in-field irradiation of 10,000 MU to a hip prosthesis located at the beam isocenter in a water phantom. (53) Fe, (56) Mn, and (52) V were identified within the hip following irradiation by radiotherapy beams. The dose measured at the surface of a prosthesis following irradiation in a water phantom was 0.20 mGy over 12 h. The dose at the surface of prostheses irradiated to 200 MU was below the limit of detection (0.05 mGy) of the TLD100H. Prosthetic hips are activated by incident photons and neutrons in high energy radiotherapy, however, the dose resulting from activation is very small.

  3. Systemic Lupus Erythematosus, Radiotherapy, and the Risk of Acute and Chronic Toxicity: The Mayo Clinic Experience

    SciTech Connect

    Pinn, Melva E.; Gold, Douglas G. M.; Petersen, Ivy A.; Osborn, Thomas G.; Brown, Paul D.; Miller, Robert C.

    2008-06-01

    Purpose: To determine the acute and chronic toxic effects of radiotherapy in patients with systemic lupus erythematosus (SLE). Methods and Materials: Medical records of 21 consecutive patients with SLE, who had received 34 courses of external beam radiotherapy and one low-dose-rate prostate implant, were retrospectively reviewed. Patients with discoid lupus erythematosus were excluded. Results: Median survival was 2.3 years and median follow-up 5.6 years. Eight (42%) of 19 patients evaluable for acute toxicity during radiotherapy experienced acute toxicity of Grade 1 or greater, and 4 (21%) had acute toxicity of Grade 3 or greater. The 5- and 10-year incidence of chronic toxicity of Grade 1 or greater was 45% (95% confidence interval [CI], 22-72%) and 56% (95% CI, 28-81%), respectively. The 5- and 10-year incidence of chronic toxicity of Grade 3 or greater was 28% (95% CI, 18-60%) and 40% (95% CI, 16-72%), respectively. Univariate analysis showed that chronic toxicity of Grade 1 or greater correlated with SLE renal involvement (p < 0.006) and possibly with the presence of five or more American Rheumatism Association criteria (p < 0.053). Chronic toxicity of Grade 3 or greater correlated with an absence of photosensitivity (p < 0.02), absence of arthritis (p < 0.03), and presence of a malar rash (p < 0.04). Conclusions: The risk of acute and chronic toxicity in patients with SLE who received radiotherapy was moderate but was not prohibitive of the use of radiotherapy. Patients with more advanced SLE may be at increased risk for chronic toxicity.

  4. Radiotherapy infrastructure and human resources in Europe - present status and its implications for 2020.

    PubMed

    Datta, Niloy Ranjan; Samiei, Massoud; Bodis, Stephan

    2014-10-01

    Radiotherapy (RT) is required for nearly half of the newly diagnosed cancer patients. To optimise the quality and availability of RT, guidelines have been proposed by European Society for Radiotherapy and Oncology-QUAntification of Radiation Therapy Infrastructure And Staffing Needs (ESTRO-QUARTS) and the International Atomic Energy Agency (IAEA). This study evaluates the present status of RT capacity in Europe and the projected needs by 2020 as per these recommendations. Thirty-nine of the 53 countries, listed in Europe by the UN Statistical Division, whose cancer incidences, teletherapy and human resources were available in the Global Cancer Incidence, Mortality and Prevalence (GLOBOCAN), International Agency for Research on Cancer (IARC) and DIrectory of RAdiotherapy Centres (DIRAC) (IAEA) databases were evaluated. A total of 3550 teletherapy units (TRT), 7017 radiation oncologists (RO), 3685 medical physicists (MP) and 12,788 radiotherapy technologists (RTT) are presently available for the 3.44 million new cancer cases reported annually in these countries. The present infrastructure and human resources in RT are estimated to provide RT access to 74.3% of the patients requiring RT. The current capacity in TRT, RO, MP and RTT when compared with recommended guidelines has a deficit of 25.6%, 18.3%, 22.7% and 10.6%, respectively. Thus, to respond to requirements by 2020, the existing capacity needs to be augmented by an additional 1698 TRTs, 2429 ROs, 1563 MPs and 2956 RTTs. With an imminent rise in cancer incidence, multifaceted strategic planning at national and international levels within a coordinated comprehensive cancer control programme is highly desirable to give adequate access to all patients who require radiotherapy across Europe. Specific steps to address this issue at national and continental levels involving all major stakeholders are proposed.

  5. Radiation transport codes for potential applications related to radiobiology and radiotherapy using protons, neutrons, and negatively charged pions

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.

    1972-01-01

    Several Monte Carlo radiation transport computer codes are used to predict quantities of interest in the fields of radiotherapy and radiobiology. The calculational methods are described and comparisions of calculated and experimental results are presented for dose distributions produced by protons, neutrons, and negatively charged pions. Comparisons of calculated and experimental cell survival probabilities are also presented.

  6. Petermann I and II spot size: Accurate semi analytical description involving Nelder-Mead method of nonlinear unconstrained optimization and three parameter fundamental modal field

    NASA Astrophysics Data System (ADS)

    Roy Choudhury, Raja; Roy Choudhury, Arundhati; Kanti Ghose, Mrinal

    2013-01-01

    A semi-analytical model with three optimizing parameters and a novel non-Gaussian function as the fundamental modal field solution has been proposed to arrive at an accurate solution to predict various propagation parameters of graded-index fibers with less computational burden than numerical methods. In our semi analytical formulation the optimization of core parameter U which is usually uncertain, noisy or even discontinuous, is being calculated by Nelder-Mead method of nonlinear unconstrained minimizations as it is an efficient and compact direct search method and does not need any derivative information. Three optimizing parameters are included in the formulation of fundamental modal field of an optical fiber to make it more flexible and accurate than other available approximations. Employing variational technique, Petermann I and II spot sizes have been evaluated for triangular and trapezoidal-index fibers with the proposed fundamental modal field. It has been demonstrated that, the results of the proposed solution identically match with the numerical results over a wide range of normalized frequencies. This approximation can also be used in the study of doped and nonlinear fiber amplifier.

  7. Intensity-modulated radiotherapy for neoadjuvant treatment of gastric cancer

    SciTech Connect

    Knab, Brian; Rash, Carla; Farrey, Karl; Jani, Ashesh B. . E-mail: jani@rover.uchicago.edu

    2006-01-01

    Radiation therapy plays an integral role in the treatment of gastric cancer in the postsurgery setting, the inoperable/palliative setting, and, as in the case of the current report, in the setting of neoadjuvant therapy prior to surgery. Typically, anterior-posterior/posterior-anterior (AP/PA) or 3-field techniques are used. In this report, we explore the use of intensity-modulated radiotherapy (IMRT) treatment in a patient whose care was transferred to our institution after 3-field radiotherapy (RT) was given to a dose of 30 Gy at an outside institution. If the 3-field plan were continued to 50 Gy, the volume of irradiated liver receiving greater than 30 Gy would have been unacceptably high. To deliver the final 20 Gy, an opposed parallel AP/PA plan and an IMRT plan were compared to the initial 3-field technique for coverage of the target volume as well as dose to the kidneys, liver, small bowel, and spinal cord. Comparison of the 3 treatment techniques to deliver the final 20 Gy revealed reduced median and maximum dose to the whole kidney with the IMRT plan. For this 20-Gy boost, the volume of irradiated liver was lower for both the IMRT plan and the AP/PA plan vs. the 3-field plan. Comparing the IMRT boost plan to the AP/PA boost-dose range (<10 Gy) in comparison to the AP/PA plan; however, the IMRT plan irradiated a smaller liver volume within the higher dose region (>10 Gy) in comparison to the AP/PA plan. The IMRT boost plan also irradiated a smaller volume of the small bowel compared to both the 3-field plan and the AP/PA plan, and also delivered lower dose to the spinal cord in comparison to the AP/PA plan. Comparison of the composite plans revealed reduced dose to the whole kidney using IMRT. The V20 for the whole kidney volume for the composite IMRT plan was 30% compared to approximately 60% for the composite AP/PA plan. Overall, the dose to the liver receiving greater than 30 Gy was lower for the composite IMRT plan and was well below acceptable limits

  8. High dose and compartmental target volume may improve patient outcome after radiotherapy for pelvic bone metastases from hepatocellular carcinoma

    PubMed Central

    Kim, Taehyung; Cha, Hye Jung; Kim, Jun Won; Seong, Jinsil; Lee, Ik Jae

    2016-01-01

    Purpose Pelvic bone metastases are difficult to treat because of complex pelvic bone anatomy and the proximity of normal organs. The adequacy of radiation dose and field coverage was evaluated. Patients and methods We analyzed 146 cases of pelvic bone metastases from HCC treated with radiotherapy (RT). Bone metastases were confirmed using CT/MRI. Subjective pain response was assessed using the visual analogue scale, and treatment-related toxicity with the Common Terminology Criteria for Adverse Events v3.0. Local failure free survival (LFFS) and overall survival were estimated using the Kaplan-Meier method. Results The local control rate was 80.1% and the pain control rate was 68.5%. Compartmental target volume (CTV), encompassing the whole compartment of the involved bone, was found to be a significant factor (1-year LFFS, 78% vs. 50%; p=0.001). Sites of metastasis were categorized as either upper or lower pelvic bone; both categories showed improved local control with CTV. Metastatic lesions that received more than 50 Gy of EQD2 showed more partial response in pain after RT (58% vs. 79%; p=0.007). No patient showed toxicity higher than Grade IV. Conclusion Compartmental RT targeted to the involved bone was associated with improved local control and LFFS. High-dose radiation was associated with an improved treatment response. PMID:27259272

  9. Radiotherapy planning of the pelvis using distortion corrected MR images: the removal of system distortions

    NASA Astrophysics Data System (ADS)

    Tanner, S. F.; Finnigan, D. J.; Khoo, V. S.; Mayles, P.; Dearnaley, D. P.; Leach, M. O.

    2000-08-01

    Image distortion is an important consideration in the use of magnetic resonance (MR) images for radiotherapy planning. The distortion is a consequence of system distortion (arising from main magnetic field inhomogeneity and nonlinearities in the applied magnetic field gradients) and of effects arising from the object/patient being imaged. A two-stage protocol has been developed to correct both system- and object-induced distortion in pelvic images which incorporates measures to maintain the quality, accuracy and consistency of the imaging and correction procedures. The first stage of the correction procedure is described here and involves the removal of system distortion. Object- (patient-) induced effects will be described in a subsequent work. Images are acquired with the patient lying on a flat rigid bed, which reproduces treatment conditions. A frame of marker tubes surrounding the patient and attached to the bed provides quality assurance data in each image. System distortions in the three orthogonal planes are mapped using a separate phantom, which fits closely within the quality control frame. Software has been written which automates the measurement and checking of the many marker positions which the test objects generate and which ensures that patient data are acquired using a consistent imaging protocol. Results are presented which show that the scanner and the phantoms used in measuring distortion give highly reproducible results with mean changes of the order of 0.1 mm between repeated measurements of marker positions in the same imaging session. Effective correction for in-plane components of system distortion is demonstrated.

  10. Hypothalamic, pituitary and thyroid dysfunction after radiotherapy to the head and neck

    SciTech Connect

    Samaan, N.A.; Vieto, R.; Schultz, P.N.; Maor, M.; Meoz, R.T.; Sampiere, V.A.; Cangir, A.; Ried, H.L.; Jesse, R.H. Jr.

    1982-11-01

    One hundred-ten patients who had nasopharyngeal cancer and paranasal sinus tumors and were free of the primary disease were studied one to 26 years following radiotherapy. There were 70 males and 40 females ranging in age from 4 to 75 years, with a mean age of 36.5 years. During therapy both the hypothalamus and the anterior pituitary gland were in the field of irradiation. The radiation dose to the hypothalamus and the anterior pituitary gland was estimated to be 400 to 7500 rad with a median dose of 5618 rad to the anterior pituitary gland and a median dose of 5000 rad to the hypothalamus. We found evidence of endocrine deficiencies in 91 of the 110 patients studied. Seventy-six patients showed evidence of one or more hypothalamic lesions and 43 patients showed evidence of primary pituitary deficiency. Forty of the 66 patients who received radiotherapy to the neck for treatment or prevention of lymph node metastasis showed evidence of primary hypothyroidism. The range of the dose to the thyroid area was 3000 to 8800 rad with a median of 5000 rad. One young adult woman who developed galactorrhea and amenorrhea 2 years following radiotherapy showed a high serum prolactin level, but had normal anterior pituitary function and sella turcica. She regained her menses and had a normal pregnancy and delivery following bromocriptine therapy. These results indicate that endocrine deficiencies after radiotherapy for tumors of the head and neck are common and should be detected early and treated. Long-term follow-up of these patients is indicated since complications may appear after the completion of radiotherapy.

  11. [Radiotherapy as primary treatment for chemodectoma?].

    PubMed

    Verniers, D; Van Limbergen, E; Leysen, J; Ostyn, F; Segers, A

    1990-01-01

    Chemodectomas are slowly growing tumours originating in the chemoreceptor bodies. The diagnosis is based on typical clinical symptoms and radiological investigation. CT scanning with contrast enhancement permits to establish diagnosis in most cases and gives a correct idea of tumour size, tumour extension, displacement of arteries and bone destruction. Small tympanic chemodectomas are successfully managed by surgery, without causing additional cranial nerve palsies. Surgery of larger lesions is frequently followed by a high percentage of local recurrence (greater than 50%) and important morbidity (neurologic sequelae). Our present series confirms that these tumours can successfully be treated by radiotherapy. Persisting local control rates can be obtained in more than 90% of cases with moderate doses (45-50 Gy in 5 weeks) of carefully planned radiotherapy.

  12. [Radiotherapy and targeted therapy/immunotherapy].

    PubMed

    Antoni, D; Bockel, S; Deutsch, E; Mornex, F

    2016-10-01

    Thanks to recent advances achieved in oncologic systemic and local ablative treatment, the treatments become more and more efficient in term of local control and overall survival. Thus, the targeted therapies, immunotherapy or stereotactic radiotherapy have modified the management of patients, especially in case of oligometastatic disease. Many questions are raised by these innovations, particularly the diagnosis and management of new side effects or that of the combination of these different treatments, depending on the type of primary tumor. Fundamental data are available, while clinical data are still limited. Ongoing trials should help to clarify the clinical management protocols. This manuscript is a review of the combination of radiotherapy and targeted therapy/immunotherapy.

  13. Perianal Paget disease treated definitively with radiotherapy.

    PubMed

    Mann, J; Lavaf, A; Tejwani, A; Ross, P; Ashamalla, H

    2012-12-01

    Extramammary Paget disease (empd) is a relatively rare cutaneous disorder described as an apocrine gland tumour occurring in both a benign and a malignant form with metastatic potential. The areas of the body affected are the vulva, perianal region, penis, scrotum, perineum, and axilla, all of which contain apocrine glands. When empd affects the perianal region, it is called perianal Paget disease (ppd). All forms of empd, including ppd, are typically treated by wide surgical excision. Perianal Paget disease usually occurs later in life in patients who are often poor surgical candidates, but the available literature is scarce regarding other treatment modalities, including definitive radiotherapy. We contend that ppd can be safely and effectively treated with radiotherapy, and here, we present the case of a 75-year-old woman with ppd who was successfully so treated. A brief review of the literature concerning the diagnosis, natural history, and treatment of ppd is also included.

  14. Proton Radiotherapy for Solid Tumors of Childhood

    PubMed Central

    Cotter, Shane E.; McBride, Sean M.; Yock, Torunn I.

    2012-01-01

    The increasing efficacy of pediatric cancer therapy over the past four decades has produced many long-term survivors that now struggle with serious treatment related morbidities affecting their quality of life. Radiation therapy is responsible for a significant proportion of these late effects, but a relatively new and emerging modality, proton radiotherapy hold great promise to drastically reduce these treatment related late effects in long term survivors by sparing dose to normal tissues. Dosimetric studies of proton radiotherapy compared with best available photon based treatment show significant dose sparing to developing normal tissues. Furthermore, clinical data are now emerging that begin to quantify the benefit in decreased late treatment effects while maintaining excellent cancer control rates. PMID:22417062

  15. Status of radiotherapy in a multidisciplinary cancer board.

    PubMed

    Ichikawa, Mayumi; Nemoto, Kenji; Miwa, Misako; Ohta, Ibuki; Nomiya, Takuma; Yamakawa, Mayumi; Itho, Yuriko; Fukui, Tadahisa; Yoshioka, Takashi

    2014-03-01

    Multidisciplinary cancer boards (CBs) for making cancer treatment decisions have become popular in many countries; however, the status of radiotherapy in CBs and the influence of CBs on radiotherapy decisions have not been studied. To clarify these issues, we reviewed the minutes of our CBs from February 2010 to March 2012, and we classified planned treatments discussed at the CBs into five categories and analyzed decisions concerning radiotherapy in each category. The fraction of cases for which radiotherapy was recommended was 536/757 (71%). These cases included 478 cases (63%) for which radiation therapy was planned and four cases (0.5%) for which radiation therapy was unexpectedly recommended. On the other hand, radiation therapy was canceled in 21 cases (4%) for which radiation therapy had been planned. This study showed that radiotherapy was discussed in many cases at CBs and that CBs have a great influence on decisions concerning radiotherapy.

  16. Radiotherapy for testicular seminoma stage I: treatment results and long-term post-irradiation morbidity in 365 patients

    SciTech Connect

    Fossa, S.D.A.; Aass, N.; Kaalhus, O.

    1989-02-01

    After infradiaphragmatic radiotherapy the cancer-related 10 year survival was 99% in 365 patients with seminoma Stage I referred to the Norwegian Radium Hospital between 1970 and 1982. Thirteen patients relapsed, 11 of them within the first 3 years after treatment. Nine of the recurrent patients were cured by radiotherapy alone (4) or in combination with chemotherapy (5). There is no need to include the inguinal lymph nodes into the irradiation field or to give scrotal irradiation, not even to patients with tumor infiltration beyond the testicular tissue, or to those with prior scrotal or inguinal surgery. At least 1 year after radiotherapy moderate or more severe dyspepsia was observed in 16 patients. Nine patients developed a peptic ulcer. In general, there was no increased risk for development of a second non-germ cell cancer after radiotherapy. However, 4 patients developed a pulmonary cancer indicating a border-line significance of increased risk for this type of malignancy. (p:0.05). In conclusion, infradiaphragmatic radiotherapy remains the optimal routine treatment in seminoma patients with Stage I.

  17. Postoperative radiotherapy in the management of keloids

    PubMed Central

    Carvajal, Claudia C; Ibarra, Carla M; Arbulo, Douglas L; Russo, Moisés N; Solé, Claudio P

    2016-01-01

    Background The high recurrence rate following keloid resection has generated interest in adjuvant treatments for this disease. Objective This study assesses keloid recurrence when treated with surgery and adjuvant radiotherapy. Methods Retrospective analysis of resected keloids in patients referred to a Chilean radiation oncology centre between 2006 and 2013. Local recurrence was defined as new tissue growth on the surgical scar margin. Results Around103 keloids were analysed in 63 patients treated with 15 Gy in three fraction radiotherapy which was initiated on the same day as the surgery (75% of cases). The median keloid diameter was 6 cm; the most common site was thoracic (22%); the most common cause was prior surgery (35%); 37% caused symptoms, and several (47%) had received prior treatment with corticosteroids (32%), or surgery (30%). The median follow-up was three years, and 94% of recurrences occurred during the first year following treatment. Uni and multivariate analyses showed that an absence of symptoms was a protective factor for recurrence (OR: 0.24), while the time interval from onset to treatment with surgery plus radiotherapy >4.2 years was a risk factor (OR: 2.23). The first year recurrence rate was 32% and stabilised at 32% by the second year with no recurrences after 15 months. Conclusions The combination of surgery and radiotherapy proved to be a good therapeutic alternative in the management of keloids. Our results are similar to those described in the literature for a dose of 15 Gy. Given these results, our centre will implement a new dose escalation protocol to improve future outcomes. PMID:27994646

  18. Radiation transport in a radiotherapy room

    SciTech Connect

    Agosteo, S.; Para, A.F.; Maggioni, B.

    1995-01-01

    The photoneutron dose equivalent in a linac radio-therapy room and its entrance maze was investigated by means of Monte Carlo simulations under different conditions. Particularly, the effect of neutron absorbers and moderator layers placed on the maze walls was considered. The contribution of prompt gamma rays emitted in absorption reactions of thermal neutrons was also taken into account. The simulation results are compared with some experimental measurements in the therapy room and in the maze. 13 refs., 5 figs., 5 tabs.

  19. Partial breast radiotherapy with simple teletherapy techniques.

    PubMed

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  20. Hypothyroidism After Radiotherapy for Nasopharyngeal Cancer Patients

    SciTech Connect

    Wu, Y.-H.; Wang, H-M.; Chen, Hellen Hi-Wen; Lin, C.-Y.; Chen, Eric Yen-Chao; Fan, K.-H.; Huang, S.-F.; Chen, I-How; Liao, C.-T.; Cheng, Ann-Joy; Chang, Joseph Tung-Chieh

    2010-03-15

    Purpose: The aim of this study was to determine the long-term incidence and possible predictive factors for posttreatment hypothyroidism in nasopharyngeal carcinoma (NPC) patients after radiotherapy. Methods and Materials: Four hundred and eight sequential NPC patients who had received regular annual thyroid hormone surveys prospectively after radiotherapy were included in this study. Median patient age was 47.3 years, and 286 patients were male. Thyroid function was prospectively evaluated by measuring thyroid-stimulating hormone (TSH) and serum free thyroxine (FT4) levels. Low FT4 levels indicated clinical hypothyroidism in this study. Results: With a median follow-up of 4.3 years (range, 0.54-19.7 years), the incidence of low FT4 level was 5.3%, 9.0%, and 19.1% at 3, 5, and 10 years after radiotherapy, respectively. Hypothyroidism was more common with early T stage (p = 0.044), female sex (p = 0.037), and three-dimensional conformal therapy with the altered fractionation technique (p = 0.005) after univariate analysis. N stage, chemotherapy, reirradiation, and neck electron boost did not affect the incidence of hypothyroidism. Younger age and conformal therapy were significant factors that determined clinical hypothyroidism after multivariate analysis. Overall, patients presented with a low FT4 level about 1 year after presenting with an elevated TSH level. Conclusion: Among our study group of NPC patients, 19.1% experienced clinical hypothyroidism by 10 years after treatment. Younger age and conformal therapy increased the risk of hypothyroidism. We suggest routine evaluation of thyroid function in NPC patients after radiotherapy. The impact of pituitary injury should be also considered.

  1. Targeting Radiotherapy to Cancer by Gene Transfer

    PubMed Central

    2003-01-01

    Targeted radionuclide therapy is an alternative method of radiation treatment which uses a tumor-seeking agent carrying a radioactive atom to deposits of tumor, wherever in the body they may be located. Recent experimental data signifies promise for the amalgamation of gene transfer with radionuclide targeting. This review encompasses aspects of the integration of gene manipulation and targeted radiotherapy, highlighting the possibilities of gene transfer to assist the targeting of cancer with low molecular weight radiopharmaceuticals. PMID:12721515

  2. Partial breast radiotherapy with simple teletherapy techniques

    SciTech Connect

    Fekete, Gábor; Újhidy, Dóra; Együd, Zsófia; Kiscsatári, Laura; Marosi, Gusztáv; Kahán, Zsuzsanna; Varga, Zoltán

    2015-01-01

    A prospective pilot study of partial breast irradiation (PBI) with conventional vs hypofractionated schedules was set out. The study aimed to determine efficacy, acute and late side effects, and the preference of photon vs electron irradiation based on individual features. Patients were enrolled according to internationally accepted guidelines on PBI. Conformal radiotherapy plans were generated with both photon and electron beams, and the preferred technique based on dose homogeneity and the radiation exposure of healthy tissues was applied. For electron dose verification, a special phantom was constructed. Patients were randomized for fractionation schedules of 25 × 2 vs 13 × 3 Gy. Skin and breast changes were registered at the time of and ≥1 year after the completion of radiotherapy. Dose homogeneity was better with photons. If the tumor bed was located in the inner quadrants, electron beam gave superior results regarding conformity and sparing of organ at risk (OAR). If the tumor was situated in the lateral quadrants, conformity was better with photons. A depth of the tumor bed ≥3.0 cm predicted the superiority of photon irradiation (odds ratio [OR] = 23.6, 95% CI: 5.2 to 107.5, p < 0.001) with >90% sensitivity and specificity. After a median follow-up of 39 months, among 72 irradiated cases, 1 local relapse out of the tumor bed was detected. Acute radiodermatitis of grade I to II, hyperpigmentation, and telangiectasia developed ≥1 year after radiotherapy, exclusively after electron beam radiotherapy. The choice of electrons or photons for PBI should be based on tumor bed location; the used methods are efficient and feasible.

  3. Current concepts on imaging in radiotherapy.

    PubMed

    Lecchi, Michela; Fossati, Piero; Elisei, Federica; Orecchia, Roberto; Lucignani, Giovanni

    2008-04-01

    New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.

  4. The role of radiotherapy in veterinary practice.

    PubMed

    Owen, L N

    1975-11-01

    It is common knowledge today that cancer is by no means an incurable disease and therefore it is no longer necessary to propose euthanasia for all inoperable cases of malignant neoplasia. The veterinary surgeon has a duty to inform his client of current methods of treatment, particularly radiotherapy, which may possibly provide a cure or prolong life without pain for several months. This article outlines the availability and usefulness of this important line of treatment.

  5. Glioblastoma multiforme after radiotherapy for acromegaly

    SciTech Connect

    Piatt, J.H. Jr.; Blue, J.M.; Schold, S.C. Jr.; Burger, P.C.

    1983-07-01

    A case of glioblastoma multiforme that occurred 14 years after radiotherapy for acromegaly is presented. The striking correspondence between the anatomy of the tumor and the geometry of the radiation ports is suggestive of a causal relationship. Previously reported cases of radiation-associated glioma are reviewed, and a brief appraisal of the evidence for induction of these lesions by radiation is presented. The differentiation of radiation-associated neoplasms from radionecrosis is also discussed.

  6. Adaptive Radiotherapy for an Uncommon Chloroma

    PubMed Central

    Majdoul, Soufya; Colson-Durand, Laurianne; To, Nu Hanh; Belkacemi, Yazid

    2016-01-01

    Granulocytic sarcomas, also referred to as chloromas or myeloid sarcomas, are extramedullary neoplasms that are composed of immature myeloid cells. This uncommon disease is known to be radiosensitive. However, the total dose and dose per fraction are not standardized. In addition, during the course of radiation therapy, significant reduction of the tumor is usually obtained. Thus, target volume reduction may require an intermediate radiotherapy plan evaluation for an adaptive treatment. A second plan at mid-dose is highly recommended. PMID:27920690

  7. The effect of hyperbaric oxygen therapy on quality of life in oral and oropharyngeal cancer patients treated with radiotherapy.

    PubMed

    Gerlach, N L; Barkhuysen, R; Kaanders, J H A M; Janssens, G O R J; Sterk, W; Merkx, M A W

    2008-03-01

    Radiotherapy is used in the setting of curative treatment for head and neck cancer. Xerostomia and related problems occur when major salivary glands are included in the irradiation fields. This reduces quality of life (QOL). Hyperbaric oxygen therapy (HBOT) is a well accepted treatment or prevention modality for osteoradionecrosis of the jawbones and soft-tissue necrosis. It is unknown if and to what extent HBOT influences xerostomia and xerostomia-related QOL. To address this, a prospective study was conducted. Twenty-one patients who underwent radiotherapy for an oral or oropharyngeal carcinoma completed a European Organization for Research and Treatment of Cancer QOL questionnaire before HBOT, as part of the treatment/prevention of osteoradionecrosis, and 1 and 2 years after HBOT. Swallowing-related problems significantly decreased in time, and there was a reported subjective increase in saliva quantity and an improvement in sense of taste. The results suggest that HBOT may positively influence these long-term radiotherapy sequelae.

  8. Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

    SciTech Connect

    Amdur, Robert J. Liu, Chihray; Li, Jonathan; Mendenhall, William; Hinerman, Russell

    2007-10-01

    When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior 'low neck' field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction.

  9. Medical treatment for biochemical relapse after radiotherapy.

    PubMed

    Quero, L; Hennequin, C

    2014-10-01

    This article's purpose was to review the medical data justifying the use of a medical treatment for biochemical relapse after external beam radiotherapy. The MEDLINE database was searched to identify relevant information with the following medical subject headings: "prostate cancer", "radiotherapy" and "biochemical relapse". Prognostic factors affecting the overall survival of patients with a biochemical relapse after external beam radiotherapy have been identified: short prostate specific antigen (PSA)-doubling time (< 12 months), high PSA value (> 10 ng/mL) and short interval between treatment and biochemical relapse (< 18 months). If a second local treatment is not feasible, timing to initiate a salvage medical treatment is not defined. Particularly, randomized trials did not demonstrate a significant benefit of an early initiation of androgen deprivation treatment. Some retrospective studies suggest that an early androgen deprivation is justified if poor prognostic factors are found. However, if an androgen deprivation treatment is prescribed, intermittent schedule is non-inferior to a continuous administration and seems to offer a better quality of life. Many non-hormonal treatments have also been evaluated in this setting: only 5-alpha-reductase inhibitors could be proposed in some specific situations. In conclusion, the judicious use of a medical treatment for biochemical relapse is still debated. Given the natural history of this clinical situation, a simple surveillance is justified in many cases.

  10. [Influence of radiotherapy on lymphocyte stimulation].

    PubMed

    Renner, H; Renner, K H; Hassenstein, E

    1976-08-01

    More than 300 lymphocyte cultures of 12 patients with seminomas were examined during the prophylactic radiotherapy and, in several cases, during an extended period until 20.5 months after the end of the treatment. The object of this study was to find out by measuring the capacity of the lymphocytes to be stimulated in vitro wheather they could be damaged by the radiotherapy. Among other reasons, the above mentioned patients were chosen because they had been submitted to irradiations of vast volumes of lymphatic tissues at a uniform focal dose of 4000 rad. The different opinions expressed in the literature (stimulation decreassed resp. increased resp. unchanged) are reflected by our results in such a way that we did not find a qualitative loss of the capacity to be stimulated cultures. The problem of the different opinions about the capacity of lymphocytes to be stimulated after a radiotherapy appears; among other things, to be based on different examination methods. According to these methods- morphological determination of the relative number of lymphoblasts, synthesis of DNA by fluid scintillation counting, or determination of the number of surviving cells in vitro -different results are obtained. It seems not possible to use the lymphocyte stimulation in vitro as a method of testing clinical sideefects occuring during the characteristics of immunity and radiation biology are not differentiated in a more precise manner.

  11. Anal Cancer: An Examination of Radiotherapy Strategies

    SciTech Connect

    Glynne-Jones, Rob; Lim, Faye

    2011-04-01

    The Radiation Therapy Oncology Group 9811, ACCORD-03, and ACT II Phase III trials in anal cancer showed no benefit for cisplatin-based induction and maintenance chemotherapy, or radiation dose-escalation >59 Gy. This review examines the efficacy and toxicity of chemoradiation (CRT) in anal cancer, and discusses potential alternative radiotherapy strategies. The evidence for the review was compiled from randomized and nonrandomized trials of radiation therapy and CRT. A total of 103 retrospective/observational studies, 4 Phase I/II studies, 16 Phase II prospective studies, 2 randomized Phase II studies, and 6 Phase III trials of radiotherapy or chemoradiation were identified. There are no meta-analyses based on individual patient data. A 'one-size-fits-all' approach for all stages of anal cancer is inappropriate. Early T1 tumors are probably currently overtreated, whereas T3/T4 lesions might merit escalation of treatment. Intensity-modulated radiotherapy or the integration of biological therapy may play a role in future.

  12. Personalized radiotherapy: concepts, biomarkers and trial design

    PubMed Central

    Redalen, K R

    2015-01-01

    In the past decade, and pointing onwards to the immediate future, clinical radiotherapy has undergone considerable developments, essentially including technological advances to sculpt radiation delivery, the demonst