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

International Nuclear Information System (INIS)

Yu, James B.; Shiao, Stephen L.; Knisely, Jonathan

2007-01-01

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

Dosimetric comparison of field in field intensity-modulated radiotherapy technique with conformal radiotherapy techniques in breast cancer

International Nuclear Information System (INIS)

Ercan, T.; Alco, G.; Zengin, F.; Atilla, S.; Dincer, M.; Igdem, S.; Okkan, S.

2010-01-01

The aim of this study was to be able to implement the field-in-field intensity-modulated radiotherapy (FiF) technique in our daily practice for breast radiotherapy. To do this, we performed a dosimetric comparison. Treatment plans were produced for 20 consecutive patients. FiF plans and conformal radiotherapy (CRT) plans were compared for doses in the planning target volume (PTV), the dose homogeneity index (DHI), doses in irradiated soft tissue outside the target volume (SST), ipsilateral lung and heart doses for left breast irradiation, and the monitor unit counts (MU) required for treatment. Averaged values were compared using Student's t-test. With FiF, the DHI is improved 7.0% and 5.7%, respectively (P<0.0001) over the bilateral and lateral wedge CRT techniques. When the targeted volumes received 105% and 110% of the prescribed dose in the PTV were compared, significant decreases are found with the FiF technique. With the 105% dose, the SST, heart, and ipsilateral lung doses and the MU counts were also significantly lower with the FiF technique. The FiF technique, compared to CRT, for breast radiotherapy enables significantly better dose distribution in the PTV. Significant differences are also found for soft tissue volume, the ipsilateral lung dose, and the heart dose. Considering the decreased MUs needed for treatment, the FiF technique is preferred over tangential CRT. (author)

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

International Nuclear Information System (INIS)

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

2007-01-01

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. 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. 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. 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

Randomized clinical trial of post-operative radiotherapy versus concomitant carboplatin and radiotherapy for head and neck cancers with lymph node involvement

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Racadot, Severine; Mercier, Mariette; Dussart, Sophie; Dessard-Diana, Bernadette; Bensadoun, Rene-Jean; Martin, Michel; Malaurie, Emmanuelle; Favrel, Veronique; Housset, Martin; Durdux, Catherine; Journel, Catherine; Calais, Gilles; Huet, Jocelyne; Pillet, Gerard; Hennequin, Christophe; Haddad, Elias; Diana, Christian; Blaska-Jaulerry, Brigitte; Henry-Amar, Michel; Gehanno, Pierre

2008-01-01

Background and purpose: Post-operative radiotherapy is indicated for the treatment of head and neck cancers. In vitro, chemotherapy potentiates the cytotoxic effects of radiation. We report the results of a randomized trial testing post-operative radiotherapy alone versus concomitant carboplatin and radiotherapy for head and neck cancers with lymph node involvement. Materials and methods: The study involved patients undergoing curative-intent surgery for head and neck cancers with histological evidence of lymph node involvement. Patients were randomly assigned to receive radiotherapy alone (54-72 Gy, 30-40 fractions, 6-8 weeks) or identical treatment plus concomitant Carboplatin (50 mg/m 2 administered by IV infusion twice weekly). Results: Between February 1994 and June 2002, 144 patients were included. With a median follow-up of 106 months (95% confidence interval (CI) [92-119]), the 2-year rate of loco-regional control was 73% (95% CI: 0.61-0.84) in the combined treatment group and 68% (95% CI: 0.57-0.80) in the radiotherapy group (p = 0.26). Overall survival did not differ significantly between groups (hazard ratio for death, 1.05; 95% CI: 0.69-1.60; p = 0.81). Conclusions: Twice-weekly administration of carboplatin concomitant to post-operative radiotherapy did not improve local control or overall survival rates in this population of patients with node-positive head and neck cancers

Involved-Field Radiotherapy versus Elective Nodal Irradiation in Combination with Concurrent Chemotherapy for Locally Advanced Non-Small Cell Lung Cancer: A Prospective Randomized Study

Science.gov (United States)

Chen, Ming; Bao, Yong; Ma, Hong-Lian; Wang, Jin; Wang, Yan; Peng, Fang; Zhou, Qi-Chao; Xie, Cong-Hua

2013-01-01

This prospective randomized study is to evaluate the locoregional failure and its impact on survival by comparing involved field radiotherapy (IFRT) with elective nodal irradiation (ENI) in combination with concurrent chemotherapy for locally advanced non-small cell lung cancer. It appears that higher dose could be delivered in IFRT arm than that in ENI arm, and IFRT did not increase the risk of initially uninvolved or isolated nodal failures. Both a tendency of improved locoregional progression-free survival and a significant increased overall survival rate are in favor of IFRT arm in this study. PMID:23762840

Quality control of involved field radiotherapy in the HD 13 and HD 14 trials. Report of the radiotherapy panel of the German Hodgkin Study Group (GHSG)

International Nuclear Information System (INIS)

Kriz, J.; Haverkamp, U.; Eich, H.T.; Baues, C.; Engenhart-Cabillic, R.; Herfarth, K.; Lukas, P.; Pluetschow, A.; Fuchs, M.; Engert, A.; Schmidberger, H.; Staar, S.

2017-01-01

As part of the foundation of the German Hodgkin Study Group (GHSG) in 1978, a central radiotherapy (RT) reference centre was established to evaluate and to improve the quality of treatment. During the study generations, the quality assurance programs (QAP) were continued and adapted to the demands of each study. The purpose of this article is to demonstrate the results of the fifth study generation and to compare them to the previous findings. With the start of the fourth GHSG study generation (HD10-12), a central prospective review of all diagnostic images was established to create an individual treatment plan for each early stage study patient. The quality of involved field RT was retrospectively evaluated by an expert panel of radiation oncologists. In the fifth study generation (HD13-15), the retrospective review of radiotherapy performed was refined and the results were compared with the findings of the fourth generation. The expert panel analyzed the RT planning and application of 1037 (28 %) patients (HD13 n = 465, HD14 n = 572). Simulation films were available in 85 % of cases and verification films in 87 %. RT was assessed as major violation in 46 % (HD13 = 38 %, HD14 = 52 %), minor violation in 9 % (HD13 = 9 %, HD14 = 9 %) and according to the protocol in 45 % (HD13 = 52 %, HD14 = 38 %). The value for QAP of RT within the GHSG trials is well known. Still there were several protocol violations. In the future, the QAP program has to be adapted to the requirements of ''modern RT'' in malignant lymphoma. (orig.) [de

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

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Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A. [University Hospital of Goettingen, Department of Radiotherapy and Radiation Oncology, Goettingen (Germany); Canis, M. [University of Goettingen, Department of Otorhinolaryngology, Head and Neck Surgery, Goettingen (Germany); Alt-Epping, B. [University of Goettingen, Department of Palliative Medicine, Goettingen (Germany)

2014-02-15

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement

International Nuclear Information System (INIS)

Droege, L.H.; Hinsche, T.; Hess, C.F.; Wolff, H.A.; Canis, M.; Alt-Epping, B.

2014-01-01

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting. (orig.)

Fractionated external beam radiotherapy of skull base metastases with cranial nerve involvement.

Science.gov (United States)

Dröge, L H; Hinsche, T; Canis, M; Alt-Epping, B; Hess, C F; Wolff, H A

2014-02-01

Skull base metastases frequently appear in a late stage of various tumor entities and cause pain and neurological disorders which strongly impair patient quality of life. This study retrospectively analyzed fractionated external beam radiotherapy (EBRT) as a palliative treatment approach with special respect to neurological outcome, feasibility and acute toxicity. A total of 30 patients with skull base metastases and cranial nerve disorders underwent EBRT with a mean total dose of 31.6 Gy. Neurological status was assessed before radiotherapy, during radiotherapy and 2 weeks afterwards categorizing orbital, parasellar, middle fossa, jugular foramen and occipital condyle involvement and associated clinical syndromes. Neurological outcome was scored as persistence of symptoms, partial response, good response and complete remission. Treatment-related toxicity and overall survival were assessed. Before EBRT 37 skull base involvement syndromes were determined with 4 patients showing more than 1 syndrome. Of the patients 81.1 % responded to radiotherapy with 10.8 % in complete remission, 48.6 % with good response and 21.6 % with partial response. Grade 1 toxicity of the skin occurred in two patients and grade 1 hematological toxicity in 1 patient under concurrent chemoradiotherapy. Median overall survival was 3.9 months with a median follow-up of 45 months. The use of EBRT for skull base metastases with symptomatic involvement of cranial nerves is marked by good therapeutic success in terms of neurological outcome, high feasibility and low toxicity rates. These findings underline EBRT as the standard therapeutic approach in the palliative setting.

Development of dose audits for complex treatment techniques in radiotherapy

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Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M., E-mail: stefanic@cae.cnea.gov.ar [Centro Regional de Referencia con Patrones Secundarios para Dosimetria - CNEA, Presbitero Juan Gonzalez y Aragon 15, B1802AYA Ezeiza (Argentina)

2014-08-15

This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

Development of dose audits for complex treatment techniques in radiotherapy

International Nuclear Information System (INIS)

Stefanic, A. M.; Molina, L.; Vallejos, M.; Montano, G.; Zaretzky, A.; Saravi, M.

2014-08-01

This work was performed in the frame of a Coordinated Research Project (CRP) with IAEA whose objective was to extend the scope of activities carried out by national TLD-based networks from dosimetry audit for rectangular radiation fields to irregular and small fields relevant to modern radiotherapy. External audit is a crucial element in QA programmes for clinical dosimetry in radiotherapy, therefore a methodology and procedures were developed and were made available for dose measurement of complex radiotherapy parameters used for cancer treatment. There were three audit steps involved in this CRP: TLD based dosimetry for irregular MLC fields for conformal radiotherapy, dosimetry in the presence of heterogeneities and 2D MLC shaped fields relevant to stereotactic radiotherapy and applicable to dosimetry for IMRT. In addition, a new development of film-based 2D dosimetry for testing dose distributions in small field geometry was included. The plan for each audit step involved a pilot study and a trial audit run with a few local hospitals. The pilot study focused on conducting and evaluation of the audit procedures with all participants. The trial audit run was the running of the audit procedures by the participants to test them with a few local radiotherapy hospitals. This work intends to provide audits which are much nearer clinical practice than previous audits as they involve significant testing of Tps methods, as well as verifications to determinate whether hospitals can correctly calculate dose delivery in radiation treatments. (author)

Microdosimetric characterisation of radiation fields for modelling tissue response in radiotherapy

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He Wang

2014-02-01

Full Text Available Purpose: Our overall goal is the development of an approach to model tissue response to radiotherapy in which a tissue is viewed as a statistical ensemble of interacting cells. This involves characterisation of radiation fields on the spatial scale of subcellular structures. On this scale, the spatial distribution of radiation energy imparted to tissue is highly non-uniform and should be characterised in statistical terms. Microdosimetry provides a formalism developed for that purpose. This study addresses limitations of the standard microdosimetric approach to modelling tissue response by introducing two new characteristics that include additional information in a form convenient for this application.Methods: The standard microdosimetric approach is based on the concept of a sensitive volume (SV representing a target volume in the cell. It is considered in isolation from other SVs, implying that energy depositions in different SVs are statistically independent and that individual cells respond to radiation independent of each other. In this study, we examined the latter approximation through analysis of correlation functions. All calculations were performed with Geant4-DNA Monte Carlo code. Results: We found that for some realistic scenarios, spatial correlations of deposited energy can be significant. Two new characteristics of radiation fields are proposed. The first is the specific energy-volume histogram (zVH, which is a microscopic analogue of the dose-volume histogram. The second describes the probability distribution of deposited energies in two SVs without assuming statistical independence between the SVs. Numerical examples for protons and carbon ions of therapeutic energies are presented and discussed.Conclusion: We extended the microdosimetric approach to modelling tissue response by including additional important characteristics and presented them in a more conventional radiotherapy format

Involved-nodal radiation therapy leads to lower doses to critical organs-at-risk compared to involved-field radiation therapy

International Nuclear Information System (INIS)

Mulvihill, David J.; McMichael, Kevin; Goyal, Sharad; Drachtman, Richard; Weiss, Aaron; Khan, Atif J.

2014-01-01

Background: Involved field radiotherapy (IFRT) after cytotoxic chemotherapy has become the standard of care in treating pediatric patients with Hodgkin lymphoma. However, recent interest in shrinking the treatment volume to involved node radiotherapy (INRT) may allow lower doses to critical organ structures. We dosimetrically compared IFRT and INRT treatment approaches. Methods: INRT treatment plans were retrospectively constructed from 17 consecutively treated pediatric patients identified with Hodgkin lymphoma who had been previously treated with conventional IFRT. The radiation doses delivered to organs-at-risk (OARs) with virtual INRT treatment plans based on INRT field design were then compared to the original IFRT treatment plans. Metrics for comparison included mean doses to organs and volumes of organ receiving at least 50% of the original prescription dose (V50%). A one-tailed, paired t-test was then performed to verify statistical significance at an alpha level of 0.05. Results: All organs at risk compared in this investigation (kidneys, heart, thyroid, parotids, and lungs) had significantly lower doses of radiation with INRT when compared to IFRT (p < 0.05). Furthermore, the volume of the breast receiving at least 50% of the initial prescription dose was statistically lower in the INRT plans. Conclusions: Utilizing the concept of INRT results in a reduction of radiation dose to critical organ structures in pediatric patients with Hodgkin lymphoma when compared to the more traditional method of IFRT

Cardiac Side-effects From Breast Cancer Radiotherapy.

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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. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Quality audit for dose determination in the field of radiotherapy using TLD

International Nuclear Information System (INIS)

Kharita, M. H.; Anjak, O.

2010-08-01

Quality audit is one of the important procedures in radiotherapy centers in order to verify the accuracy of the delivered radiation doses. The aim of this work is to establish a procedure for dose audit using TL dosimeters and to apply this procedure in radiotherapy centers. TL Dosimeters were distributed to several radiotherapy centers in Syria and Lebanon (4 with Co-60 and 14 with high energy photon beam radiotherapy units). They were exposed to 2 Gy in order to make an intercomparison study of the absorbed dose in water determined under reference conditions. The results show that only two beams were outside the accepted range, which is ±3.5%. and the were within the accepted range. External Quality audit is one of the important procedures in field of radiotherapy dosimeter in order to verify the accuracy of the radiation doses delivered to patients. (Author)

Analysis of the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy

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Song-Lin Wang

2017-04-01

Full Text Available Objective: To explore the efficacy and safety of conventional radiotherapy of chest wall and clavicular field and three-dimensional conformal radiotherapy in patients after modified radical mastectomy. Methods: A total of 84 patients who were admitted in our hospital after modified radical mastectomy were included in the study and divided into the conventional radiotherapy group (n=42 and the three-dimensional conformal radiotherapy group (n=42 according to different radiotherapy methods. The patients in the conventional radiotherapy group were given conventional radiotherapy of chest wall and clavicular field, while the patients in the three-dimensional conformal radiotherapy group were given three-dimensional conformal radiotherapy. The serum tumor markers and peripheral blood T lymphocyte subsets 6-8 weeks after treatment in the two groups were detected. The clinical efficacy, and toxic and side effects in the two groups were evaluated. Results: The serum CA15-3, CA125, CEA, and CK19 levels after treatment in the two groups were significantly reduced when compared with before treatment, CD3 +,CD4 +, and CD4 +/CD8 + were significantly elevated, while CD8 + was significantly reduced when compared with before treatment, but the comparison of the above indicators between the two groups was not statistically significant. The occurrence rate of radioactive skin damage and pneumonia after treatment in the conventional radiotherapy group was significantly higher than that in the three-dimensional conformal radiotherapy group. Conclusions: The two kinds of radiotherapy schemes have an equal efficacy, but the toxic and side effects of three-dimensional conformal radiotherapy are significantly lower than those by the conventional radiotherapy, with a certain advantage.

Radiotherapy of adult nodal non Hodgkin's lymphoma

International Nuclear Information System (INIS)

Gamen, G.; Thirion, P.

1999-01-01

The role of radiotherapy in the treatment of nodal non-Hodgkin's lymphoma has been modified by the introduction of efficient chemotherapy and the development of different pathological classifications. The recommended treatment of early-stage aggressive lymphomas is primarily a combination chemotherapy. The interest of adjuvant radiotherapy remains unclear and has to be established through large prospective trials. If radiation therapy has to be delivered, the historical results of exclusive radiation therapy showed that involved-fields and a dose of 35-40 Gy (daily fraction of 1.8 Gy, 5 days a week) are the optimal schedule. The interest of radiotherapy in the treatment of advanced-stage aggressive lymphoma is yet to be proven. Further studies had to stratify localized stages according to the factors of the International Prognostic Index. For easy-stage low-grade lymphoma, radiotherapy remains the standard treatment. However, the appropriate technique to use is controversial. Involved-field irradiation at a dose of 35 Gy seems to be the optimal schedule, providing a 10 year disease-free survival rate of 50 % and no major toxicity. There is no standard indication of radiotherapy in the treatment advanced-stage low-grade lymphoma. For 'new' nodal lymphoma's types, the indication of radiotherapy cannot be established (mantle-zone lymphoma, marginal zone B-cell lymphoma) or must take into account the natural history (Burkitt's lymphoma, peripheral T-cell lymphoma) and the sensibility to others therapeutic methods. (authors)

Patients with hip prosthesis: radiotherapy treatment planning considerations

International Nuclear Information System (INIS)

Ganesh, K.M.; Supe, Sanjay S.

2000-01-01

The number of patients with hip prosthesis undergoing radiotherapy for pelvic cancer worldwide is increasing. This might be of importance depending on the materials in the prosthesis and whether any of the treatment fields are involved in the prosthesis. Radiotherapy planning involving the pelvic region of patients having total hip prosthesis has been found to be difficult due to the effect of the prosthesis on the dose distribution. This review is intended to project dosimetric considerations and possible solutions to this uncommon problem

Treating all fields in every radiotherapy session? - Questioning the old dogma (or, pelvis radiotherapy: speculations on fractioning)

International Nuclear Information System (INIS)

Faria, S.L.; Ferrigno, R.; Osti, N.

1995-01-01

Twenty years ago Wilson and Hall published paper on the advisability of treating all fields at each radiotherapy session. That was based on the widely accepted method for calculating the biological effect of fractionated treatment in terms of a single quantity: the concept of a nominal standard dose (NSD). It was the beginning of an old dogma in radiation oncology: treating all fields every day. The basis megavoltage units of treatment in Brazil are cobalt and low energy linacs. The country is poor and it is not rare to have patients waiting lines. Due to that situation since five years ago we have been treating pelvic tumors with four fields (box technique) but irradiating only two fields per day. After treating hundreds of patients this way we have found no increased late complications, particularly subcutaneous tissue fibrosis. Previous data showed that TDE factors equal or lower than 90 were not related to any kind of fibrosis. treating pelvic tumors with the box technique but irradiating only two fields per day gives TDF values little greater than doing all four fields per day, but still lower than 90. That may explain why we have found no fibrosis. The impression is that not to treat all fields at each radiotherapy session may be possible with no increased rate of late complications. (author). 10 refs, 3 tabs, 2 figs

Dosimetric Evaluation of Intensity Modulated Radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate Cancer Treatment

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Bora Uysal

2013-03-01

Full Text Available Objective: The purpose of this dosimetric study is the targeted dose homogeneity and critical organ dose comparison of 7-field Intensity Modulated Radiotherapy (IMRT and 3-D 4-field conformal radiotherapy. Study Design: Cross sectional study. Material and Methods: Twenty patients with low and moderate risk prostate cancer treated at Gülhane Military Medical School Radiation Oncology Department between January 2009 and December 2009 are included in this study. Two seperate dosimetric plans both for 7-field IMRT and 3D-CRT have been generated for each patient to comparatively evaluate the dosimetric status of both techniques and all the patients received 7-field IMRT. Results: Dose-comparative evaluation of two techniques revealed the superiority of IMRT technique with statistically significantly lower femoral head doses along with reduced critical organ dose-volume parameters of bladder V60 (the volume receiving 60 Gy and rectal V40 (the volume receiving 40 Gy and V60. Conclusion: It can be concluded that IMRT is an effective definitive management tool for prostate cancer with improved critical organ sparing and excellent dose homogenization in target organs of prostate and seminal vesicles.

Quality control of involved field radiotherapy in the HD 13 and HD 14 trials. Report of the radiotherapy panel of the German Hodgkin Study Group (GHSG)

Energy Technology Data Exchange (ETDEWEB)

Kriz, J.; Haverkamp, U.; Eich, H.T. [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Baues, C. [University of Cologne, Department of Radiation Oncology, Cologne (Germany); Engenhart-Cabillic, R. [University of Marburg, Department of Radiation Oncology, Marburg (Germany); Herfarth, K. [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Lukas, P. [University of Innsbruck, Department of Radiation Oncology, Innsbruck (Austria); Pluetschow, A.; Fuchs, M.; Engert, A. [University of Cologne, Department of Internal Medicine, Cologne (Germany); Schmidberger, H. [University of Mainz, Department of Radiation Oncology, Mainz (Germany); Staar, S. [Bremen Mitte, Department of Radiation Oncology, Bremen (Germany)

2017-02-15

As part of the foundation of the German Hodgkin Study Group (GHSG) in 1978, a central radiotherapy (RT) reference centre was established to evaluate and to improve the quality of treatment. During the study generations, the quality assurance programs (QAP) were continued and adapted to the demands of each study. The purpose of this article is to demonstrate the results of the fifth study generation and to compare them to the previous findings. With the start of the fourth GHSG study generation (HD10-12), a central prospective review of all diagnostic images was established to create an individual treatment plan for each early stage study patient. The quality of involved field RT was retrospectively evaluated by an expert panel of radiation oncologists. In the fifth study generation (HD13-15), the retrospective review of radiotherapy performed was refined and the results were compared with the findings of the fourth generation. The expert panel analyzed the RT planning and application of 1037 (28 %) patients (HD13 n = 465, HD14 n = 572). Simulation films were available in 85 % of cases and verification films in 87 %. RT was assessed as major violation in 46 % (HD13 = 38 %, HD14 = 52 %), minor violation in 9 % (HD13 = 9 %, HD14 = 9 %) and according to the protocol in 45 % (HD13 = 52 %, HD14 = 38 %). The value for QAP of RT within the GHSG trials is well known. Still there were several protocol violations. In the future, the QAP program has to be adapted to the requirements of ''modern RT'' in malignant lymphoma. (orig.) [German] Seit Gruendung der German Hodgkin Study Group (GHSG) im Jahr 1978 wurde ein zentrales Qualitaetssicherungsprogramm (QAP) der Radiotherapie (RT) etabliert, um die Qualitaet der RT sicherzustellen. Waehrend der fortlaufenden Studiengenerationen wurde dieses QAP kontinuierlich weiterentwickelt. In dieser Auswertung werden die Ergebnisse der fuenften Studiengeneration (HD13-15) praesentiert und mit frueheren Ergebnissen

Small-field fractionated radiotherapy with or without stereotactic boost for vestibular schwannoma

International Nuclear Information System (INIS)

Kagei, K.; Shirato, H.; Suzuki, K.; Isu, T.; Sawamura, Y.; Sakamoto, T.; Fukuda, S.; Nishioka, T.; Hashimoto, S.; Miyasaka, K.

1999-01-01

Purpose: To assess the efficacy and toxicity of small-field fractionated radiotherapy with or without stereotactic boost (SB) for vestibular schwannomas.Methods and materials: Thirty-nine patients with vestibular schwannoma were treated with irradiation between March 1991 and February 1996. Extra-meatal tumor diameters were under 30 mm. Thirty-three patients received small-field fractionated radiotherapy followed by SB. Basic dose schedule was 44 Gy in 22 fractions over 5 1/2 weeks plus 4 Gy in one session. Six patients received small-field fractionated radiotherapy only (40-44 Gy in 20-22 fractions over 5-5 1/2 weeks or 36 Gy in 20 fractions over 5 weeks).< Results: Follow-up ranged from 6 to 69 months (median, 24 months). Tumors decreased in size in 13 cases (33%), were unchanged in 25 (64%), and increased in one (3%). The actuarial 2-year tumor control rate was 97%. Fifteen patients had useful hearing (Gardner-Robertson class 1-2) and 25 patients had testable hearing (class 1-4) before irradiation. The 2-year actuarial rates of useful hearing preservation (free of deterioration from class 1-2 to class 3-5) were 78%. The 2-year actuarial rates of any testable hearing preservation (free of deterioration from class 1-4 to class 5) were 96%. No permanent facial and trigeminal neuropathy developed after irradiation. The 2-year actuarial incidences of facial and trigeminal neuropathies were 8% and 16%, respectively.Conclusions: Small-field fractionated radiotherapy with or without SB provides excellent short-term local control and a relatively low incidence of complications for vestibular schwannoma, although further follow-up is necessary to evaluate the long-term results. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Doses to head and neck normal tissues for early stage Hodgkin lymphoma after involved node radiotherapy

International Nuclear Information System (INIS)

Maraldo, M.V.; Brodin, N.P.; Aznar, M.C.; Vogelius, I.R.; Munck af Rosenschöld, P.; Petersen, P.M.; Specht, L.

2014-01-01

Purpose: To evaluate dose plans for head and neck organs at risk (OARs) for classical Hodgkin lymphoma (HL) patients using involved node radiotherapy (INRT) delivered as 3D conformal radiotherapy (3DCRT), volumetric modulated arc therapy (VMAT), and intensity modulated proton therapy (PT), in comparison to the past mantle field (MF). Materials and methods: Data from 37 patients with cervical lymph node involvement were used. All patients originally received chemotherapy followed by 3DCRT–INRT (30.6 Gy). A VMAT–INRT, PT–INRT (both 30.6 Gy), and a MF plan (36 Gy) were simulated. Doses to head and neck OARs were compared with cumulative DVHs and repeated measures ANOVA. Results: The estimated median mean doses were 15.3, 19.3, 15.4, and 37.3 Gy (thyroid), 10.9, 12.0, 7.9, and 34.5 Gy (neck muscles), 2.3, 11.1, 1.8, and 37.1 Gy (larynx), 1.7, 5.1, 1.3, and 23.8 Gy (pharynx), 0.5, 0.8, 0.01, and 32.3 Gy (ipsilateral parotid), and 2.4, 3.8, 0.7, and 34.7 Gy (ipsilateral submandibular) with 3DCRT, VMAT, PT, and MF (all p < 0.0001), respectively. Conclusion: The use of INRT significantly lowered the estimated radiation dose to the head and neck OARs. VMAT appeared suboptimal compared to 3DCRT and PT, and for some patients, PT offered an additional gain

Historical review of radiotherapy

International Nuclear Information System (INIS)

Onai, Yoshio

1993-01-01

The techniques of radiotherapy have been improved by development of particle accelerators, radionuclides and computers. This paper presents a historical review of the physical and technical aspects of radiotherapy in Japan. Changes in the kinds of radiation, such as X-rays, gamma rays, electrons, neutrons and protons used for external radiotherapy, and the equipment involved are described chronologically, and historical changes in the quality of radiotherapy apparatus are outlined. Patient data acquisition equipment, such as X-ray simulator and X-ray CT, beam modifying devices, patient setup devices, and devices to verify treatment fields and patient doses are reviewed historically. Radiation sources for brachytherapy and internal radiotherapy, and remotely controlled afterloading systems are reviewed chronologically. Historical changes in methods to evaluate absorbed doses, dose monitor systems and beam data acquisition systems are outlined. Changes in methods of calculating dose distributions for external X-ray and electron therapy, brachytherapy and internal radiotherapy by unsealded radionuclides are described and calculation techniques for treatment planning system are reviewed. Annual figures in the numbers of radiotherapy equipment, such as telecobalt and telecesium units, linear accelerators, betatrons, microtrons, stereotactic gamma units, conformation radiotherapy units, remotely controlled afterloading systems, and associated equipment such as X-ray simulators and treatment planning systems are provided, as are changes in the number of accelerators by maximum X-ray energy and maximum electron energy, and in the number of licensed hospitals and clinics using small sealed sources. Changes in techniques of external radiotherapy and brachytherapy are described briefly from the point of view of dose distributions. (author)

Local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer.

Science.gov (United States)

Kimoto, Takuya; Yamazaki, Hideya; Suzuki, Gen; Aibe, Norihiro; Masui, Koji; Tatekawa, Kotoha; Sasaki, Naomi; Fujiwara, Hitoshi; Shiozaki, Atsushi; Konishi, Hirotaka; Nakamura, Satoaki; Yamada, Kei

2017-09-01

Radiotherapy is an effective treatment for the postoperative loco-regional recurrence of esophageal cancer; however, the optimal treatment field remains controversial. This study aims to evaluate the outcome of local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer. We retrospectively investigated 35 patients treated for a postoperative loco-regional recurrence of esophageal cancer with local field radiotherapy between December 2008 and March 2016. The median irradiation dose was 60 Gy (range: 50-67.5 Gy). Thirty-one (88.6%) patients received concurrent chemotherapy. The median follow-up period was 18 months (range: 5-94 months). The 2-year overall survival was 55.7%, with a median survival time of 29.9 months. In the univariate analysis, the maximal diameter ≤20 mm (P = 0.0383), solitary lesion (P = 0.0352), and the complete remission after treatment (P = 0.00411) had a significantly better prognosis. A total of 27 of 35 patients (77.1%) had progressive disease (loco-regional failure [n = 9], distant metastasis [n = 7], and both loco-regional failure and distant metastasis [n = 11]). No patients had Grade 3 or greater mucositis. Local field radiotherapy is a considerable treatment option for postoperative loco-regional recurrence of esophageal cancer. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

The result of radiotherapy for pituitary adenoma

International Nuclear Information System (INIS)

Lee, H. J.; Yang, K. M.; Suh, S. H.

1997-01-01

To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. The study involved a retrospective review of outcome in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median: 97 months). Seventeen were men and 10 were women. The numbers of functioning and non-functioning pituitary adenoma were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy(median: 5040cGy) were delivered over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. For radiation therapy alone, the 5 YSR was 100% and progression free survival rate was 85.8%. The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy , the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose, radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statistically significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluable patients with hyperprolactinoma achieved normalization in 4 and decrement in 5 patients. Only 2 patients developed mild degree of panhypopituitarism. The radiotherapy appears to be effective in controlling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherapy was comparable. There was a trend toward high recurrence rate in patients with nonfunctioning or prolactin secreting tumor and larger radiation field sizes. (author)

The result of radiotherapy for pituitary adenoma

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Lee, H. J.; Yang, K. M.; Suh, S. H. [Inje Univ., Seoul (Korea, Republic of). Coll. of Medicine; Cho, H. L.; Shon, S. C. [Pusan Paik Hospital, Pusan (Korea, Republic of)

1997-12-01

To evaluate the prognostic factors for disease-free survival and long-term results of radiotherapy for pituitary adenoma. The study involved a retrospective review of outcome in a series of 27 patients with pituitary adenoma, between 1984 and 1995 at Paik hospital. The study included 20 patients treated with surgery and postoperative radiotherapy and 7 with radiotherapy alone. The patients were followed for 12-146 months (median: 97 months). Seventeen were men and 10 were women. The numbers of functioning and non-functioning pituitary adenoma were 22 and 5 respectively and those of microadenoma and macroadenoma were 4 and 23 respectively. The radiation doses of 5040-5580cGy(median: 5040cGy) were delivered over 5-7 weeks, using 4MV LINAC. The prognostic factors were analyzed by log-rank test. For radiation therapy alone, the 5 YSR was 100% and progression free survival rate was 85.8%. The tumor was controlled in 6/7 (85.8%). For surgery and postoperative radiotherapy , the 5YSR, progression free survival rate and local control rate were 95%, 84.8%, and 89.5% respectively. The parameters of tumor size, hormone secretion, radiation dose, radiotherapy field size were evaluated in a uni- and multivariate analysis and all the factors were not statistically significant (P>0.05). Eleven of 12 (92%) with visual field defect experienced normalization or improvement, and 5 for 7 evaluable patients with hyperprolactinoma achieved normalization in 4 and decrement in 5 patients. Only 2 patients developed mild degree of panhypopituitarism. The radiotherapy appears to be effective in controlling clinical symptoms and signs resulting from pituitary adenoma. Local control rate with radiotherapy alone or with surgery and postoperative radiotherapy was comparable. There was a trend toward high recurrence rate in patients with nonfunctioning or prolactin secreting tumor and larger radiation field sizes. (author).

Characterisation of neutron fields around high-energy x-ray radiotherapy machines

Czech Academy of Sciences Publication Activity Database

Králík, M.; Turek, Karel

2004-01-01

Roč. 110, 1-4 (2004), s. 503-507 ISSN 0144-8420 Institutional research plan: CEZ:AV0Z1048901 Keywords : radiotherapy machines * neutron fields * high-energy Subject RIV: DN - Health Impact of the Environment Quality Impact factor: 0.617, year: 2003

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

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Farhood B.

2016-06-01

Full Text Available 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.

Second neoplasms following radiotherapy or chemotherapy for cancer

International Nuclear Information System (INIS)

Penn, I.

1982-01-01

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

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

External beam radiotherapy of localized prostatic adenocarcinoma. Evaluation of conformal therapy, field number and target margins

International Nuclear Information System (INIS)

Lennernaes, B.; Rikner, G.; Letocha, H.; Nilsson, S.

1995-01-01

The purpose of the present study was to identify factors of importance in the planning of external beam radiotherapy of prostatic adenocarcinoma. Seven patients with urogenital cancers were planned for external radiotherapy of the prostate. Four different techniques were used, viz. a 4-field box technique and four-, five- or six-field conformal therapy set-ups combined with three different margins (1-3 cm). The evaluations were based on the doses delivered to the rectum and the urinary bladder. A normal tissue complication probability (NTCP) was calculated for each plan using Lyman's dose volume reduction method. The most important factors that resulted in a decrease of the dose delivered to the rectum and the bladder were the use of conformal therapy and smaller margins. Conformal therapy seemed more important for the dose distribution in the urinary bladder. Five- and six-field set-ups were not significantly better than those with four fields. NTCP calculations were in accordance with the evaluation of the dose volume histograms. To conclude, four-field conformal therapy utilizing reduced margins improves the dose distribution to the rectum and the urinary bladder in the radiotherapy of prostatic adenocarcinoma. (orig.)

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

Science.gov (United States)

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).

Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

International Nuclear Information System (INIS)

Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M.

1997-01-01

Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a '3-field' arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors)

Dose profile analysis of small fields in intensity modulated radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Medel B, E. [IMSS, Centro Medico Nacional Manuel Avila Camacho, Calle 2 Nte. 2004, Barrio de San Francisco, 72090 Puebla, Pue. (Mexico); Tejeda M, G.; Romero S, K., E-mail: romsakaren@gmail.com [Benemerita Universidad Autonoma de Puebla, Facultad de Ciencias Fisico Matematicas, Av. San Claudio y 18 Sur, Ciudad Universitaria, 72570 Puebla, Pue.(Mexico)

2015-10-15

Full text: Small field dosimetry is getting a very important worldwide task nowadays. The use of fields of few centimeters is more common with the introduction of sophisticated techniques of radiation therapy, as Intensity Modulated Radiotherapy (IMRT). In our country the implementation of such techniques is just getting started and whit it the need of baseline data acquisition. The dosimetry under small field conditions represents a challenge for the physicists community. In this work, a dose profile analysis was done, using various types of dosimeters for further comparisons. This analysis includes the study of quality parameters as flatness, symmetry, penumbra, and other in-axis measurements. (Author)

Involved-field radiotherapy (IFRT) versus elective nodal irradiation (ENI) in combination with concurrent chemotherapy for 239 esophageal cancers: a single institutional retrospective study

International Nuclear Information System (INIS)

Yamashita, Hideomi; Takenaka, Ryousuke; Omori, Mami; Imae, Toshikazu; Okuma, Kae; Ohtomo, Kuni; Nakagawa, Keiichi

2015-01-01

This retrospective study on early and locally advanced esophageal cancer was conducted to evaluate locoregional failure and its impact on survival by comparing involved field radiotherapy (IFRT) with elective nodal irradiation (ENI) in combination with concurrent chemotherapy. We assessed all patients with esophageal cancer of stages I-IV treated with definitive radiotherapy from June 2000 to March 2014. Between 2000 and 2011, ENI was used for all cases excluding high age cases. After Feb 2011, a prospective study about IFRT was started, and therefore IFRT was used since then for all cases. Concurrent chemotherapy regimen was nedaplatin (80 mg/m 2 at D1 and D29) and 5-fluorouracil (800 mg/m 2 at D1-4 and D29-32). Of the 239 consecutive patients assessed (120 ENI vs. 119 IFRT), 59 patients (24.7 %) had stage IV disease and all patients received at least one cycle of chemotherapy. The median follow-up time for survivors was 34.0 months. There were differences in 3-year local control (44.8 % vs. 55.5 %, p = 0.039), distant control (53.8 % vs. 69.9 %, p = 0.021) and overall survival (34.8 % vs. 51.6 %, p = 0.087) rates between ENI vs. IFRT, respectively. Patients treated with IFRT (8 %) demonstrated a significantly lower risk (p = 0.047) of high grade late toxicities than with ENI (16 %). IFRT did not increase the risk of initially uninvolved or isolated nodal failures (27.5 % in ENI and 13.4 % in IFRT). Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients. Both tendencies of improved loco-regional progression-free survival and a significant increased overall survival rate favored the IFRT arm over the ENI arm in this study

Involved-field radiotherapy (IFRT) versus elective nodal irradiation (ENI) in combination with concurrent chemotherapy for 239 esophageal cancers: a single institutional retrospective study.

Science.gov (United States)

Yamashita, Hideomi; Takenaka, Ryousuke; Omori, Mami; Imae, Toshikazu; Okuma, Kae; Ohtomo, Kuni; Nakagawa, Keiichi

2015-08-14

This retrospective study on early and locally advanced esophageal cancer was conducted to evaluate locoregional failure and its impact on survival by comparing involved field radiotherapy (IFRT) with elective nodal irradiation (ENI) in combination with concurrent chemotherapy. We assessed all patients with esophageal cancer of stages I-IV treated with definitive radiotherapy from June 2000 to March 2014. Between 2000 and 2011, ENI was used for all cases excluding high age cases. After Feb 2011, a prospective study about IFRT was started, and therefore IFRT was used since then for all cases. Concurrent chemotherapy regimen was nedaplatin (80 mg/m(2) at D1 and D29) and 5-fluorouracil (800 mg/m(2) at D1-4 and D29-32). Of the 239 consecutive patients assessed (120 ENI vs. 119 IFRT), 59 patients (24.7%) had stage IV disease and all patients received at least one cycle of chemotherapy. The median follow-up time for survivors was 34.0 months. There were differences in 3-year local control (44.8% vs. 55.5%, p = 0.039), distant control (53.8% vs. 69.9%, p = 0.021) and overall survival (34.8% vs. 51.6%, p = 0.087) rates between ENI vs. IFRT, respectively. Patients treated with IFRT (8 %) demonstrated a significantly lower risk (p = 0.047) of high grade late toxicities than with ENI (16%). IFRT did not increase the risk of initially uninvolved or isolated nodal failures (27.5% in ENI and 13.4% in IFRT). Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients. Both tendencies of improved loco-regional progression-free survival and a significant increased overall survival rate favored the IFRT arm over the ENI arm in this study.

Elective nodal irradiation (ENI) vs. involved field radiotherapy (IFRT) for locally advanced non-small cell lung cancer (NSCLC): A comparative analysis of toxicities and clinical outcomes

International Nuclear Information System (INIS)

Fernandes, Annemarie T.; Shen, Jason; Finlay, Jarod; Mitra, Nandita; Evans, Tracey; Stevenson, James; Langer, Corey; Lin, Lilie; Hahn, Stephen; Glatstein, Eli; Rengan, Ramesh

2010-01-01

Background: Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with locally advanced non-small cell lung cancer (NSCLC). ENI delivers prophylactic radiation to clinically uninvolved lymph nodes, while IFRT only targets identifiable gross nodal disease. Because clinically uninvolved nodal stations may harbor microscopic disease, IFRT raises concerns for increased nodal failures. This retrospective cohort analysis evaluates failure rates and treatment-related toxicities in patients treated at a single institution with ENI and IFRT. Methods: We assessed all patients with stage III locally advanced or stage IV oligometastatic NSCLC treated with definitive radiotherapy from 2003 to 2008. Each physician consistently treated with either ENI or IFRT, based on their treatment philosophy. Results: Of the 108 consecutive patients assessed (60 ENI vs. 48 IFRT), 10 patients had stage IV disease and 95 patients received chemotherapy. The median follow-up time for survivors was 18.9 months. On multivariable logistic regression analysis, patients treated with IFRT demonstrated a significantly lower risk of high grade esophagitis (Odds ratio: 0.31, p = 0.036). The differences in 2-year local control (39.2% vs. 59.6%), elective nodal control (84.3% vs. 84.3%), distant control (47.7% vs. 52.7%) and overall survival (40.1% vs. 43.7%) rates were not statistically significant between ENI vs. IFRT. Conclusions: Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients.

Elective nodal irradiation (ENI) vs. involved field radiotherapy (IFRT) for locally advanced non-small cell lung cancer (NSCLC): A comparative analysis of toxicities and clinical outcomes.

Science.gov (United States)

Fernandes, Annemarie T; Shen, Jason; Finlay, Jarod; Mitra, Nandita; Evans, Tracey; Stevenson, James; Langer, Corey; Lin, Lilie; Hahn, Stephen; Glatstein, Eli; Rengan, Ramesh

2010-05-01

Elective nodal irradiation (ENI) and involved field radiotherapy (IFRT) are definitive radiotherapeutic approaches used to treat patients with locally advanced non-small cell lung cancer (NSCLC). ENI delivers prophylactic radiation to clinically uninvolved lymph nodes, while IFRT only targets identifiable gross nodal disease. Because clinically uninvolved nodal stations may harbor microscopic disease, IFRT raises concerns for increased nodal failures. This retrospective cohort analysis evaluates failure rates and treatment-related toxicities in patients treated at a single institution with ENI and IFRT. We assessed all patients with stage III locally advanced or stage IV oligometastatic NSCLC treated with definitive radiotherapy from 2003 to 2008. Each physician consistently treated with either ENI or IFRT, based on their treatment philosophy. Of the 108 consecutive patients assessed (60 ENI vs. 48 IFRT), 10 patients had stage IV disease and 95 patients received chemotherapy. The median follow-up time for survivors was 18.9 months. On multivariable logistic regression analysis, patients treated with IFRT demonstrated a significantly lower risk of high grade esophagitis (Odds ratio: 0.31, p = 0.036). The differences in 2-year local control (39.2% vs. 59.6%), elective nodal control (84.3% vs. 84.3%), distant control (47.7% vs. 52.7%) and overall survival (40.1% vs. 43.7%) rates were not statistically significant between ENI vs. IFRT. Nodal failure rates in clinically uninvolved nodal stations were not increased with IFRT when compared to ENI. IFRT also resulted in significantly decreased esophageal toxicity, suggesting that IFRT may allow for integration of concurrent systemic chemotherapy in a greater proportion of patients. Copyright 2010 Elsevier Ireland Ltd. All rights reserved.

Current role and future developments of radiotherapy in early-stage favourable Hodgkin's lymphoma

International Nuclear Information System (INIS)

Eich, H.T.; Mueller, R.P.

2007-01-01

The radiosensibility of Hodgkin's lymphoma (HL) is well established since 1902, when Pusey was one of the first to publish about radiotherapeutical treatment of a HL. In the early years, radiotherapy was the only curative treatment for this systemic disease, but the reports of Kaplan and Rosenberg and Peters in the fifties and seventies showed that irradiation of involved lymph node regions only resulted in high local and distant recurrences. The introduction of linear accelerator based high dose extended field (EF)-radiotherapy by Kaplan in Stanford was a milestone in the evolution of definitive curative radiotherapy strategies. The application of the mantle field for supradiaphragmatic and the inverted Y (with or without including the spleen or splenic pedicle) for infradiaphragmatic disease resulted in a dramatic improvement of survival rates in the early stages I and II (Ann Arbor) from 25-30% in the sixties to 65-80% in the eighties. Kaplan reported about a close relationship between radiation dose and cure rates in the case of definitive radiotherapy. A dose of at least 40 Gy resulted in local recurrences below 5% and is today the standard dose for radiotherapy only outside protocols. Despite complete remission rates after radiotherapy of 90-100%, the overall recurrence rate (including in-field, marginal and distant relapses) was between 20 and 30%. Analysis of the relapses revealed some stage migrating risk factors: large mediastinal mass, extra nodal involvement, number of involved lymph node areas (≥ 3) and high ESR. The possibility of more accurate staging by using new imaging techniques like ultrasonography, CT and MRI as well as PET in the recent years resulted e.g. in the definition of early-favourable, early-unfavourable (intermediate) and high risk stages and more specific, risk adapted treatment strategies. The objective of this article is to show recent achievements and developments in the management of early-stage favourable HL exemplified by

Difference in temporal lobe dose between two radiotherapy techniques in the treatment of NPC with anterior nasal involvement

Energy Technology Data Exchange (ETDEWEB)

Wu, V.W.C.; Luk, J.H.Y.; Wong, S.F.T.; Lam, E.C.H.; Fung, M.C.Y.; Tong, S.M.; Ku, I.K.M. [Hong Kong Polytechnic University, Hong Kong, (Hong Kong). Department of Radiography and Optometry

1997-04-01

Nasopharyngeal carcinoma with anterior extension are treated with special radiotherapy techniques. The purpose of this study is to investigate the difference of temporal lobe dose between two radiotherapy techniques (A and B) which are commonly used in the treatment of such condition in Hong Kong. The study is carried out by performing radiation treatments to a humanoid phantom under simulated conditions of the two techniques. The dose measurement is done by thermoluminescent dosimeters (TLD) which are placed inside the phantom. Both techniques employ a `3-field` arrangement: a heavy-weighted anterior facial fields with two lateral opposing facial fields. The main difference lies in the anterior facial field in which technique A uses electron beam throughout while technique B uses a mixture of photon and electron beams. The results demonstrates that technique A delivers higher dose to temporal lobe than technique B. In a course of radical external beam radiotherapy (66 Gy), the mean dose to inferior temporal lobe are 59.29 Gy in technique A and 34.06 Gy in technique B respectively (p < 0.0001). Furthermore, it is found that the temporal lobe dose difference between the two techniques is mainly due to their phase I treatment. (p < 0.0001 for phase I and p = 0.078 for phase II). (authors). 14 refs., 3 tabs., 6 figs.

Isocentric integration of intensity-modulated radiotherapy with electron fields improves field junction dose uniformity in postmastectomy radiotherapy.

Science.gov (United States)

Wright, Pauliina; Suilamo, Sami; Lindholm, Paula; Kulmala, Jarmo

2014-08-01

In postmastectomy radiotherapy (PMRT), the dose coverage of the planning target volume (PTV) with additional margins, including the chest wall, supraclavicular, interpectoral, internal mammary and axillar level I-III lymph nodes, is often compromised. Electron fields may improve the medial dose coverage while maintaining organ at risk (OAR) doses at an acceptable level, but at the cost of hot and cold spots at the electron and photon field junction. To improve PMRT dose coverage and uniformity, an isocentric technique combining tangential intensity-modulated (IM)RT fields with one medial electron field was implemented. For 10 postmastectomy patients isocentric IMRT with electron plans were created and compared with a standard electron/photon mix and a standard tangent technique. PTV dose uniformity was evaluated based on the tolerance range (TR), i.e. the ratio of the standard deviation to the mean dose, a dice similarity coefficient (DSC) and the 90% isodose coverage and the hot spot volumes. OAR and contralateral breast doses were also recorded. IMRT with electrons significantly improved the PTV dose homogeneity and conformity based on the TR and DSC values when compared with the standard electron/photon and tangent technique (p < 0.02). The 90% isodose coverage improved to 86% compared with 82% and 80% for the standard techniques (p < 0.02). Compared with the standard electron/photon mix, IMRT smoothed the dose gradient in the electron and photon field junction and the volumes receiving a dose of 110% or more were reduced by a third. For all three strategies, the OAR and contralateral breast doses were within clinically tolerable limits. Based on these results two-field IMRT combined with an electron field is a suitable strategy for PMRT.

Conformity Index and Homogeneity Index of the Postoperative Whole Breast Radiotherapy.

Science.gov (United States)

Petrova, Deva; Smickovska, Snezana; Lazarevska, Emilija

2017-10-15

The treatment of breast cancer involves a multidisciplinary approach in which radiotherapy plays a key role. The conformity index and the homogeneity index are two analysis tools of a treatment plan using conformal radiotherapy. The purpose of this article is an analysis of these two parameters in the assessment of the treatment plans in 58 patients undergoing postoperative radiotherapy of the whole breast. All 58 patients participating in the study had a conservatively treated early-stage breast cancer. The treatment was performed using a standard regimen of fractionation in 25 fractions up to a total dose of 50 Gy. Dose-volume histograms were generated for both plans with and without segmental fields. Pair samples t-test was used. The technique with segmental fields allowed us more homogeneity distribution when compared to standard two tangential field techniques. The HI values were 1.08 ± 0.01 and 1.09 ± 0.01 for segment and technique with two tangential fields (p conformity and the homogeneity index are important tools in the analysis of the treatment plans during radiation therapy in patients with early-stage breast cancer. Adding segment fields in the administration of radiotherapy in patients with conservatively treated breast cancer can lead to improved dosage homogeneity and conformity.

Large field radiotherapy

International Nuclear Information System (INIS)

Vanasek, J.; Chvojka, Z.; Zouhar, M.

1984-01-01

Calculations may prove that irradiation procedures, commonly used in radiotherapy and represented by large-capacity irradiation techniques, do not exceed certain limits of integral doses with favourable radiobiological action on the organism. On the other hand integral doses in supralethal whole-body irradiation, used in the therapy of acute leukemia, represent radiobiological values which without extreme and exceptional further interventions and teamwork are not compatible with life, and the radiotherapeutist cannot use such high doses without the backing of a large team. (author)

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

Science.gov (United States)

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

2008-02-21

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

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Pulse-resolved radiotherapy dosimetry using fiber-coupled organic scintillators

Energy Technology Data Exchange (ETDEWEB)

Ravnsborg Beierholm, A.

2011-05-15

This PhD project pertains to the development and adaptation of a dosimetry system that can be used to verify the delivery of radiation in modern radiotherapy modalities involving small radiation fields and dynamic radiation delivery. The dosimetry system is based on fibre-coupled organic scintillators and can be perceived as a well characterized, independent alternative to the methods that are in clinical use today. The dosimeter itself does not require a voltage supply, and is composed of water equivalent materials. The dosimeter can be fabricated with a sensitive volume smaller than a cubic millimeter, which is small enough to resolve the small radiation fields encountered in modern radiotherapy. The fast readout of the dosimeter enables measurements on the same time scale as the pulsed radiation delivery from the medical linear accelerators used for treatment. The dosimetry system, comprising fiber-coupled organic scintillators and data acquisition hardware, was developed at the Radiation Research Division at Risoe DTU and tested using clinical x-ray beams at hospitals in Denmark and abroad. Measurements of output factors and percentage depth dose were performed and compared with reference values and Monte Carlo simulations for static square radiation fields for standard (4 cm x 4 cm to 20 cm x 20 cm) and small (down to 0.6 cm x 0.6 cm) field sizes. The accuracy of most of the obtained measurements was good, agreeing with reference and simulated dose values to within 2 % standard deviation for both standard and small fields. This thesis concludes that the new pulse-resolved dosimetry system holds great potential for modern radiotherapy applications, such as stereotactic radiotherapy and intensity-modulated radiotherapy. (Author)

Pulse-resolved radiotherapy dosimetry using fiber-coupled organic scintillators

International Nuclear Information System (INIS)

Ravnsborg Beierholm, A.

2011-05-01

This PhD project pertains to the development and adaptation of a dosimetry system that can be used to verify the delivery of radiation in modern radiotherapy modalities involving small radiation fields and dynamic radiation delivery. The dosimetry system is based on fibre-coupled organic scintillators and can be perceived as a well characterized, independent alternative to the methods that are in clinical use today. The dosimeter itself does not require a voltage supply, and is composed of water equivalent materials. The dosimeter can be fabricated with a sensitive volume smaller than a cubic millimeter, which is small enough to resolve the small radiation fields encountered in modern radiotherapy. The fast readout of the dosimeter enables measurements on the same time scale as the pulsed radiation delivery from the medical linear accelerators used for treatment. The dosimetry system, comprising fiber-coupled organic scintillators and data acquisition hardware, was developed at the Radiation Research Division at Risoe DTU and tested using clinical x-ray beams at hospitals in Denmark and abroad. Measurements of output factors and percentage depth dose were performed and compared with reference values and Monte Carlo simulations for static square radiation fields for standard (4 cm x 4 cm to 20 cm x 20 cm) and small (down to 0.6 cm x 0.6 cm) field sizes. The accuracy of most of the obtained measurements was good, agreeing with reference and simulated dose values to within 2 % standard deviation for both standard and small fields. This thesis concludes that the new pulse-resolved dosimetry system holds great potential for modern radiotherapy applications, such as stereotactic radiotherapy and intensity-modulated radiotherapy. (Author)

Less gastrointestinal toxicity after adjuvant radiotherapy on a small pelvic field compared to a standard pelvic field in patients with endometrial carcinoma

NARCIS (Netherlands)

de Jong, Renske A.; Pras, Elisabeth; Boezen, H. Marike; van der Zee, Ate G. J.; Mourits, Marian J. E.; Arts, Henriette J. G.; Aalders, Jan G.; Slot, Annerie; Timmer, Paul R.; Hollema, Harry; Nijman, Hans W.

Objective: Radiotherapy is associated with short-term and long-term morbidity. This study compared toxicity rates among patients with endometrial carcinoma (EC) treated with adjuvant external beam radiation therapy (EBRT) on a small pelvic field (SmPF) in comparison with a standard pelvic field

Determination of the optimal method for the field-in-field technique in breast tangential radiotherapy

International Nuclear Information System (INIS)

Tanaka, Hidekazu; Hayashi, Shinya; Hoshi, Hiroaki

2014-01-01

Several studies have reported the usefulness of the field-in-field (FIF) technique in breast radiotherapy. However, the methods for the FIF technique used in these studies vary. These methods were classified into three categories. We simulated a radiotherapy plan with each method and analyzed the outcomes. In the first method, a pair of subfields was added to each main field: the single pair of subfields method (SSM). In the second method, three pairs of subfields were added to each main field: the multiple pairs of subfields method (MSM). In the third method, subfields were alternately added: the alternate subfields method (ASM). A total of 51 patients were enrolled in this study. The maximum dose to the planning target volume (PTV) (Dmax) and the volumes of the PTV receiving 100% of the prescription dose (V100%) were calculated. The thickness of the breast between the chest wall and skin surface was measured, and patients were divided into two groups according to the median. In the overall series, the average V100% with ASM (60.3%) was significantly higher than with SSM (52.6%) and MSM (48.7%). In the thin breast group as well, the average V100% with ASM (57.3%) and SSM (54.2%) was significantly higher than that with MSM (43.3%). In the thick breast group, the average V100% with ASM (63.4%) was significantly higher than that with SSM (51.0%) and MSM (54.4%). ASM resulted in better dose distribution, regardless of the breast size. Moreover, planning for ASM required a relatively short time. ASM was considered the most preferred method. (author)

Report on a radiotherapy underdose accident

Energy Technology Data Exchange (ETDEWEB)

Christodoulides, G; Christofides, S [Medical Physics Department, Nicosia General Hospital, 1450 Nicosia (Cyprus)

1999-12-31

Reporting information on accidents and incidents involving radiation sources provides a body of knowledge which can help to prevent accidents of a similar nature. Accident information has to be made available to users, manufacturers and regulators; An international effort to pool and analyse incident and accident information will provide more complete and reliable indicators of root causes and trends and recommendations for future accident avoidance. An accident due to human error involving a superficial x-ray therapy machine and patients treated for postoperative breast cancer is reported here. 43 women receiving radiotherapy treatment have received significantly less radiation dose than the prescribed dose. The worst dose percentage within the radiation field was 20% of the prescribed dose. The worst dose percentage on the operation scar of the breast was 52% of the prescribed radiation dose. The response to accidents/incidents in radiotherapy is discussed. (authors) 4 refs., 5 figs., 1 tabs.

Transition from 2-D radiotherapy to 3-D conformal and intensity modulated radiotherapy

International Nuclear Information System (INIS)

2008-05-01

in number in the near future. Since these treatment techniques are perceived as the cutting-edge of development in the field, there is a concern that centres and countries need orientation as to the preparatory conditions and resources involved. In addition the current status of the evidence supporting the use of IMRT in terms of patient outcomes has to be kept in mind when planning to invest in these technologies. To respond to the needs of Member States to establish the guidelines for the transition from 2-D radiotherapy through 3-D CRT to IMRT several consultants and advisory group meetings were convened to discuss the necessary steps and the milestones for the transfer from 2-D to 3-D conformal radiotherapy and to IMRT. As a result, the present report serves as complementary recommendations to an IAEA recent publication on setting-up a basic radiotherapy programme. Both reports provide a comprehensive overview of the required radiotherapy infrastructure and processes for a broad spectrum of radiotherapy services. The current publication is addressed to those professionals and administrators involved in the development, implementation and management of radiation oncology programmes who seek to improve the conventional approach with the aim of achieving higher precision by transition from simpler radiation treatment approaches to advanced radiotherapy. This report provides the guidelines and highlights the milestones to be achieved by radiotherapy centres in the transition from 2-D to 3-D treatment planning and delivery and further, in transitioning to IMRT. These guidelines and milestones facilitate the process and represent continuation of the work at the IAEA for providing access to safer and better quality treatment for the steadily increasing number of cancer patients in Member States

Supplemental computational phantoms to estimate out-of-field absorbed dose in photon radiotherapy

Science.gov (United States)

Gallagher, Kyle J.; Tannous, Jaad; Nabha, Racile; Feghali, Joelle Ann; Ayoub, Zeina; Jalbout, Wassim; Youssef, Bassem; Taddei, Phillip J.

2018-01-01

The purpose of this study was to develop a straightforward method of supplementing patient anatomy and estimating out-of-field absorbed dose for a cohort of pediatric radiotherapy patients with limited recorded anatomy. A cohort of nine children, aged 2-14 years, who received 3D conformal radiotherapy for low-grade localized brain tumors (LBTs), were randomly selected for this study. The extent of these patients’ computed tomography simulation image sets were cranial only. To approximate their missing anatomy, we supplemented the LBT patients’ image sets with computed tomography images of patients in a previous study with larger extents of matched sex, height, and mass and for whom contours of organs at risk for radiogenic cancer had already been delineated. Rigid fusion was performed between the LBT patients’ data and that of the supplemental computational phantoms using commercial software and in-house codes. In-field dose was calculated with a clinically commissioned treatment planning system, and out-of-field dose was estimated with a previously developed analytical model that was re-fit with parameters based on new measurements for intracranial radiotherapy. Mean doses greater than 1 Gy were found in the red bone marrow, remainder, thyroid, and skin of the patients in this study. Mean organ doses between 150 mGy and 1 Gy were observed in the breast tissue of the girls and lungs of all patients. Distant organs, i.e. prostate, bladder, uterus, and colon, received mean organ doses less than 150 mGy. The mean organ doses of the younger, smaller LBT patients (0-4 years old) were a factor of 2.4 greater than those of the older, larger patients (8-12 years old). Our findings demonstrated the feasibility of a straightforward method of applying supplemental computational phantoms and dose-calculation models to estimate absorbed dose for a set of children of various ages who received radiotherapy and for whom anatomies were largely missing in their original

External beam abdominal radiotherapy in patients with seminoma stage I: field type, testicular dose, and spermatogenesis

International Nuclear Information System (INIS)

Jacobsen, Kari Dolven; Olsen, Dag Rune; Fossaa, Kristian; Fossaa, Sophie Dorothea

1997-01-01

Purpose: To establish a predictive model for the estimation of the gonadal dose during adjuvant para-aortic (PA) or dog leg (DL: PA plus ipsilateral iliac) field radiotherapy in patients with testicular seminoma. Methods and Materials: The surface gonadal dose was measured in patients with seminoma Stage I receiving PA or DL radiotherapy. Sperm cell analysis was performed before and 1 year after irradiation. PA and DL radiotherapy were simulated in the Alderson phantom while we measured the dose to the surface and middle of an artificial testicle, varying its position within realistic anatomical constraints. The symphysis-to-testicle distance (STD), field length, and thickness of the patient were experimental variables. The developed mathematical model was validated in subsequent patients. Results: The mean gonadal dose in patients was 0.09 and 0.32 Gy after PA and DL irradiation, respectively (p < 0.001). DL radiotherapy, but not PA irradiation led to significant reduction of the sperm count 1 year after irradiation. The gonadal dose-reducing effect of PA irradiation was confirmed in the Alderson phantom. A significant correlation was found between the STD and the gonadal dose during DL irradiation. A mathematical model was established for calculation of the gonadal dose and confirmed by measurements in patients. Conclusions: During radiotherapy of seminoma, the gonadal dose decreases with increasing STD. It is possible to predict the individual gonadal dose based on delivered midplane dose and STD

Efficacy of neoadjuvant chemotherapy and radiotherapy for the histology-confirmed intracranial germinoma-preliminary report

Energy Technology Data Exchange (ETDEWEB)

Noh, Young Ju; Kim, Hak Jae; Heo, Dae Seog; Shin, Hee Yung; Kim, Il Han [Seoul National University College of Medicine, Seoul (Korea, Republic of)

2002-06-15

We intended to decrease late CNS reaction after radical radiotherapy for an intracranial germinoma by using combined neoadjuvant chemotherapy and involved-field radiotherapy. The efficacy in terms of its acute toxicity and short-term relapse patterns was analyzed. Eighteen patients were treated with combined neoadjuvant chemotherapy and radiotherapy between 1995 and 2001. The chemotherapy regimen used was the Children's Cancer Group (CCG) 9921A (cisplatin, cyclophosphamide, VP-16, vincristine) for 5 patients younger than 16 years, BEP(bleomycin, VP-16, cisplatin) for 12 patients, and EP (VP-16, cisplatin) for 1 patient. The radiotherapy covered the whole craniospinal axis for 5 patients, the whole brain for 1, and the partial brain (involved field) for 12. the primary lesion received tumour doses between 3,960 and 5,400 cGy. The male to female ratio was 16:2 and the median age was 16 years old. The tumors were located in the pineal gland in 12 patients, in the suprasellar region in 1, in the basal ganglia in 1, in the thalamus in 1. Three patients had multiple lesions and ventricular seedings were shown at MRI. In 3 patients, tumor cells were detected in the cerebrospinal fluid and MRI detected a spinal seeding in 2 patients. The response to neoadjuvant chemotherapy was complete remission in 5 patients, partial remission in 12, and no response in 1. However, after radiotherapy, all except 1 patient experienced complete remission. The toxicity during or after chemotherapy greater than or equal to grade III was remarkable; hematologic toxicity was observed in 11 patients, liver toxicity in none, kidney toxicity in none, and gastrointestinal toxicity in one. One patient suffered from bleomycin-induced pneumonitis. Radiotherapy was therefore stopped and the patient eventually died of respiratory failure. The other 17 are alive without any evidence of disease or relapse during an average of 20 months follow-up. A high response rate and disease control was

Efficacy of neoadjuvant chemotherapy and radiotherapy for the histology-confirmed intracranial germinoma-preliminary report

International Nuclear Information System (INIS)

Noh, Young Ju; Kim, Hak Jae; Heo, Dae Seog; Shin, Hee Yung; Kim, Il Han

2002-01-01

We intended to decrease late CNS reaction after radical radiotherapy for an intracranial germinoma by using combined neoadjuvant chemotherapy and involved-field radiotherapy. The efficacy in terms of its acute toxicity and short-term relapse patterns was analyzed. Eighteen patients were treated with combined neoadjuvant chemotherapy and radiotherapy between 1995 and 2001. The chemotherapy regimen used was the Children's Cancer Group (CCG) 9921A (cisplatin, cyclophosphamide, VP-16, vincristine) for 5 patients younger than 16 years, BEP(bleomycin, VP-16, cisplatin) for 12 patients, and EP (VP-16, cisplatin) for 1 patient. The radiotherapy covered the whole craniospinal axis for 5 patients, the whole brain for 1, and the partial brain (involved field) for 12. the primary lesion received tumour doses between 3,960 and 5,400 cGy. The male to female ratio was 16:2 and the median age was 16 years old. The tumors were located in the pineal gland in 12 patients, in the suprasellar region in 1, in the basal ganglia in 1, in the thalamus in 1. Three patients had multiple lesions and ventricular seedings were shown at MRI. In 3 patients, tumor cells were detected in the cerebrospinal fluid and MRI detected a spinal seeding in 2 patients. The response to neoadjuvant chemotherapy was complete remission in 5 patients, partial remission in 12, and no response in 1. However, after radiotherapy, all except 1 patient experienced complete remission. The toxicity during or after chemotherapy greater than or equal to grade III was remarkable; hematologic toxicity was observed in 11 patients, liver toxicity in none, kidney toxicity in none, and gastrointestinal toxicity in one. One patient suffered from bleomycin-induced pneumonitis. Radiotherapy was therefore stopped and the patient eventually died of respiratory failure. The other 17 are alive without any evidence of disease or relapse during an average of 20 months follow-up. A high response rate and disease control was experienced

Gene therapy and radiotherapy in malignant tumor

International Nuclear Information System (INIS)

Zhang Yaowen; Cao Yongzhen; Li Jin; Wang Qin

2008-01-01

Tumor treatment is one of the most important fields in medical research. Nowadays, a novel method which is combined gene therapy with radiotherapy plays an important role in the field of cancer research, and mainly includes immune gene therapy combined with radiotherapy, suicide gene therapy or tumor suppressor gene therapy combined with radiotherapy, antiangiogenesis gene therapy combined with radiotherapy and protective gene therapy combined with radiotherapy based on the technical features. This review summarized the current status of combined therapies of gene therapy and radiotherapy and possible mechanism. (authors)

Patterns of failure of diffuse large B-cell lymphoma patients after involved-site radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Holzhaeuser, Eva; Berlin, Maximilian; Bezold, Thomas; Mayer, Arnulf; Schmidberger, Heinz [University Medical Center Mainz, Department of Radiation Oncology and Radiotherapy, Mainz (Germany); Wollschlaeger, Daniel [University Medical Center Mainz, Institute for Medical Biostatistics, Epidemiology and Informatics, Mainz (Germany); Hess, Georg [University Medical Center Mainz, Department of Internal Medicine, Mainz (Germany)

2017-12-15

Radiotherapy (RT) in combination with chemoimmunotherapy is highly efficient in the treatment of diffuse large B-cell lymphoma (DLBCL). This retrospective analysis evaluated the efficacy of the treatment volume and the dose concept of involved-site RT (ISRT). We identified 60 histologically confirmed stage I-IV DLBCL patients treated with multimodal cytotoxic chemoimmunotherapy and followed by consolidative ISRT from 2005-2015. Progression-free survival (PFS) and overall survival (OS) were estimated by Kaplan-Meier method. Univariate analyses were performed by log-rank test and Mann-Whitney U-test. After initial chemoimmunotherapy (mostly R-CHOP; rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone), 19 (36%) patients achieved complete response (CR), 34 (64%) partial response (PR) or less. Excluded were 7 (12%) patients with progressive disease after chemoimmunotherapy. All patients underwent ISRT with a dose of 40 Gy. After a median follow-up of 44 months, 79% of the patients remained disease free, while 21% presented with failure, progressive systemic disease, or death. All patients who achieved CR after chemoimmunotherapy remained in CR. Of the patients achieving PR after chemotherapy only 2 failed at the initial site within the ISRT volume. No marginal relapse was observed. Ann Arbor clinical stage I/II showed significantly improved PFS compared to stage III/IV (93% vs 65%; p ≤ 0.021). International Prognostic Index (IPI) score of 0 or 1 compared to 2-5 has been associated with significantly increased PFS (100% vs 70%; p ≤ 0.031). Postchemoimmunotherapy status of CR compared to PR was associated with significantly increased PFS (100% vs 68%; p ≤ 0.004) and OS (100% vs 82%; p ≤ 0.026). Only 3 of 53 patients developed grade II late side effects, whereas grade III or IV side effects have not been observed. These data suggest that a reduction of the RT treatment volume from involved-field (IF) to involved-site (IS) is sufficient because

Ptanning radiotherapy of brain neoplasms

International Nuclear Information System (INIS)

Smirnov, R.V.

1982-01-01

It is emphasized that radiotherapy planing of neuro-oncologicai patients secures maximum optimization of radiation treatment. The planning involves preparation of anatomical profile diagrams of patient's head with plotted focal contrours; choise of ionizinq radiation type, directions of the working beam and dimensions and number of irradiation fields; choise of single dose vaiues and detemination of optimat distribution of integarl does in time; determination of focal projection on head surface of patients

Can field-in-field technique replace wedge filter in radiotherapy treatment planning: a comparative analysis in various treatment sites

International Nuclear Information System (INIS)

Prabhakar, R.; Julka, P.K.; Rath, G.K.

2008-01-01

The aim of the study was to show whether field-in-field (FIF) technique can be used to replace wedge filter in radiation treatment planning. The study was performed in cases where wedges are commonly used in radiotherapy treatment planning. Thirty patients with different malignancies who received radiotherapy were studied. This includes patients with malignancies of brain, head and neck, breast, upper and lower abdomen. All the patients underwent computed tomography scanning and the datasets were transferred to the treatment planning system. Initially, wedge based planning was performed to achieve the best possible dose distribution inside the target volume with multileaf collimators (Plan1). Wedges were removed from a copy of the same plan and FIF plan was generated (Plan2). The two plans were then evaluated and compared for mean dose, maximum dose, median dose, doses to 2% (D 2 ) and 98% (D 9 8) of the target volume, volume receiving greater than 107% of the prescribed dose (V>107%), volume receiving less than 95% of the prescribed dose (V 2 , V>107% and CI for more of the sites with statistically significant reduction in monitor units. FIF results in better dose distribution in terms of homogeneity in most of the sites. It is feasible to replace wedge filter with FIF in radiotherapy treatment planning.

To understand radiotherapy

International Nuclear Information System (INIS)

2009-01-01

Dealing with the use of radiotherapy for adults, this guide indicates when a radiotherapy is suggested, how it acts, how the treatment is chosen, which are the professionals involved. It describes how an external radiotherapy takes place and its various techniques, the different types of side effects (general, specific to the treated zone, late effects). It indicates which organs can be treated by curie-therapy, the different curie-therapy treatment modalities, how a curie-therapy takes place and which are its side effects. It outlines how to better cope with radiotherapy (how to be supported, the important role of relatives, everyday life questions, rights). It indicates and comments the different measures adopted for the safety and quality of radiotherapy

Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

International Nuclear Information System (INIS)

Cho, Oyeon; Chun, Mi Son; Oh, Young Taek; Kim, Mi Hwa; Park, Hae Jin; Nam, Sang Soo; Heo, Jae Sung; Noh, O Kyu; Park, Sung Ho

2013-01-01

Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p 98% of prescribed dose were 99.7% for CF and 99.5% for MF. Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

A multileaf collimator field prescription preparation system for conventional radiotherapy

International Nuclear Information System (INIS)

Du, M.N.; Yu, C. X.; Symons, M.; Yan, D.; Taylor, R.; Matter, R.C.; Gustafson, G.; Martinez, A.; Wong, J.W.

1995-01-01

Purpose: The purpose of this work is to develop a prescription preparation system for efficient field shaping using a multileaf collimator that can be used in community settings as well as research institutions. The efficiency advantage of the computer-controlled multileaf collimator, over cerrobend blocks, to shape radiation fields has been shown in conformal treatments, which typically require complete volumetric computerized tomographic data for three-dimensional radiation treatment planning--a utility not readily available to the general community. As a result, most patients today are treated with conventional radiation therapy. Therefore, we believe that it is very important to fully use the same efficiency advantage of multileaf collimator as a block replacement in conventional practice. Methods and Material: The multileaf collimator prescription preparation system developed by us acquires prescription images from different sources, including film scanner and radiation treatment planning systems. The multileaf collimator angle and leaf positions are set from the desired field contour defined on the prescription image, by minimizing the area discrepancies. Interactive graphical tools include manual adjustment of collimator angle and leaf positions, and definition of portions of the field edges that require maximal conformation. Data files of the final leaf positions are transferred to the multileaf collimator controller via a dedicated communication link. Results: We have implemented the field prescription preparation system and a network model for integrating the multileaf collimator and other radiotherapy modalities for routine treatments. For routine plan evaluation, isodose contours measured with film in solid water phantom at prescription depth are overlaid on the prescription image. Preliminary study indicates that the efficiency advantage of the MLC over cerrobend blocks in conformal therapy also holds true for conventional treatments. Conclusion: Our

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

International Nuclear Information System (INIS)

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

2010-01-01

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 -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.

Adjuvant and Definitive Radiotherapy for Adrenocortical Carcinoma

International Nuclear Information System (INIS)

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

2011-01-01

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.

Toxicities and effects of involved-field irradiation with concurrent cisplatin for unresectable carcinoma of the pancreas

International Nuclear Information System (INIS)

Kawakami, Hiroyuki; Uno, Takashi; Isobe, Kouichi; Ueno, Naoyuki; Aruga, Takashi; Sudo, Kentaro; Yamaguchi, Taketo; Saisho, Hiromitsu; Kawata, Tetsuya; Ito, Hisao

2005-01-01

Purpose: To evaluate local effects and acute toxicities of involved field irradiation with concurrent cisplatin (CDDP) for unresectable pancreatic carcinoma. Materials and Methods: Thirty-three patients with unresectable pancreatic carcinoma were treated with chemoradiotherapy. Sixteen were Stage IVA; 17 were Stage IVB. The total prescribed dose of radiotherapy was 50 Gy/25 fractions or 50.4 Gy/28 fractions, using a three-dimensionally determined involved-field that included only the primary tumor and clinically enlarged lymph nodes. Twelve patients received a daily i.v. infusion of CDDP; 21 patients received a combination of CDDP and 5-fluorouracil either i.v. or through the proper hepatic artery. Results: Twenty-seven (82%) patients completed planned chemoradiotherapy. Nausea was the most frequent complaint. No patient experienced Grade 4 toxicities. More than half achieved pain relief. As for the primary site, only 4 patients (12%) achieved a partial response at 4 weeks; however, 3 additional patients attained >50% tumor reduction thereafter. The most frequent site of disease progression was the liver, and only 3 patients developed local progression alone. No regional lymph nodal progression outside the treatment field was seen. Median survival time and survival at 1 year were 7.1 months and 27%, respectively, for the entire group. Difference in overall survival between patients with and without distant metastases was significant (p = 0.01). Conclusions: Involved-field irradiation with concurrent daily CDDP was well tolerated without compromising locoregional effects

Magnetic resonance imaging in the evaluation of standard radiotherapy field borders in patients with uterine cervix cancer

International Nuclear Information System (INIS)

Freire, Geison Moreira; Dias, Rodrigo Souza; Giordani, Adelmo Jose; Segreto, Helena Regina Comodo; Segreto, Roberto Araujo; Ribalta, Julisa Chamorro Lascasas

2010-01-01

Objective: to evaluate, by means of magnetic resonance imaging, the standardized field borders in radiotherapy for malignant neoplasm of uterine cervix, and to determine the role of this method in the reduction of possible planning errors related to the conventional technique. Materials and methods: magnetic resonance imaging studies for planning of treatment of 51 patients with uterine cervix cancer were retrospectively analyzed. The parameters assessed were the anterior and posterior field borders on sagittal section. Results: The anterior field border was inappropriate in 20 (39.2%) patients and geographic miss was observed in 37.3% of cases in the posterior border. The inappropriateness of both field borders did not correlate with clinical parameters such as patients' age, tumor staging, histological type and degree. Conclusion: the evaluation of standardized field borders with the use of magnetic resonance imaging has demonstrated high indices of inappropriateness of the lateral field borders, as well as the relevant role of magnetic resonance imaging in the radiotherapy planning for patients with uterine cervix cancer with a view to reduce the occurrence of geographic miss of the target volume. (author)

Respiratory gating and multi field technique radiotherapy for esophageal cancer

International Nuclear Information System (INIS)

Ohta, Atsushi; Kaidu, Motoki; Tanabe, Satoshi

2017-01-01

To investigate the effects of a respiratory gating and multi field technique on the dose-volume histogram (DVH) in radiotherapy for esophageal cancer. Twenty patients who underwent four-dimensional computed tomography for esophageal cancer were included. We retrospectively created the four treatment plans for each patient, with or without the respiratory gating and multi field technique: No gating-2-field, No gating-4-field, Gating-2-field, and Gating-4-field plans. We compared the DVH parameters of the lung and heart in the No gating-2-field plan with the other three plans.Result In the comparison of the parameters in the No gating-2-field plan, there are significant differences in the Lung V 5Gy , V 20Gy , mean dose with all three plans and the Heart V 25Gy -V 40Gy with Gating-2-field plan, V 35Gy , V 40Gy , mean dose with No Gating-4-field plan and V 30Gy -V 40Gy , and mean dose with Gating-4-field plan. The lung parameters were smaller in the Gating-2-field plan and larger in the No gating-4-field and Gating-4-field plans. The heart parameters were all larger in the No gating-2-field plan. The lung parameters were reduced by the respiratory gating technique and increased by the multi field technique. The heart parameters were reduced by both techniques. It is important to select the optimal technique according to the risk of complications. (author)

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

International Nuclear Information System (INIS)

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.

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Implementation of small field radiotherapy dosimetry for spinal metastase case

Science.gov (United States)

Rofikoh, Wibowo, W. E.; Pawiro, S. A.

2017-07-01

The main objective of this study was to know dose profile of small field radiotherapy in the spinal metastase case with source axis distance (SAD) techniques. In addition, we evaluated and compared the dose planning of stereotactic body radiation therapy (SBRT) and conventional techniques to measurements with Exradin A16 and Gafchromic EBT3 film dosimeters. The results showed that film EBT3 had a highest precision and accuracy with the average of the standard deviation of ±1.7 and maximum discrepancy of 2.6 %. In addition, the average value of Full Wave Half Maximum (FWHM) and its largest deviation in small field size of 0.8 x 0.8 cm2 are 0.82 cm and 16.3 % respectively, while it was found around 2.36 cm and 3 % for the field size of 2.4 x 2.4 cm2. The comparison between penumbra width and the collimation was around of 37.1 % for the field size of 0.8 x 0.8 cm2, while it was found of 12.4 % for the field size of 2.4 x 2.4 cm2.

Dosimetric evaluation of tomography and four-box field conformal radiotherapy in locally advanced rectal cancer

International Nuclear Information System (INIS)

Yu, Mina; Lee, Hyo Chun; Chung, Mi Joo; Kim, Sung Hwan; Lee, Jong Hoon; Jang, Hong Seok; Jeon, Dong Min; Cheon, Geum Seong

2013-01-01

To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, Vn Gy, Dmin, Dmax, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p 0.001). But, V26.25 Gy and V27.5 Gywere not significantly different between the two modalities. Tomotherapy showed higher Dmax and lower Dmin. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

Dosimetric evaluation of tomography and four-box field conformal radiotherapy in locally advanced rectal cancer

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Yu, Mina; Lee, Hyo Chun; Chung, Mi Joo; Kim, Sung Hwan; Lee, Jong Hoon [Dept. of Radiation Oncology, St. Vincent' s Hospital, The Catholic University of Korea College of Medicine, Suwon (Korea, Republic of); Jang, Hong Seok; Jeon, Dong Min; Cheon, Geum Seong [Dept. of Radiation Oncology, Seoul St. Mary' s Hospital, The Catholic University of Korea College of Medicine, Seoul (Korea, Republic of)

2013-12-15

To report the results of dosimetric comparison between intensity-modulated radiotherapy (IMRT) using Tomotherapy and four-box field conformal radiotherapy (CRT) for pelvic irradiation of locally advanced rectal cancer. Twelve patients with locally advanced rectal cancer who received a short course preoperative chemoradiotherapy (25 Gy in 5 fractions) on the pelvis using Tomotherapy, between July 2010 and December 2010, were selected. Using their simulation computed tomography scans, Tomotherapy and four-box field CRT plans with the same dose schedule were evaluated, and dosimetric parameters of the two plans were compared. For the comparison of target coverage, we analyzed the mean dose, Vn Gy, Dmin, Dmax, radical dose homogeneity index (rDHI), and radiation conformity index (RCI). For the comparison of organs at risk (OAR), we analyzed the mean dose. Tomotherapy showed a significantly higher mean target dose than four-box field CRT (p 0.001). But, V26.25 Gy and V27.5 Gywere not significantly different between the two modalities. Tomotherapy showed higher Dmax and lower Dmin. The Tomotherapy plan had a lower rDHI than four-box field CRT (p = 0.000). Tomotherapy showed better RCI than four-box field CRT (p = 0.007). For OAR, the mean irradiated dose was significantly lower in Tomotherapy than four-box field CRT. In locally advanced rectal cancer, Tomotherapy delivers a higher conformal radiation dose to the target and reduces the irradiated dose to OAR than four-box field CRT.

Measurement and modeling of out-of-field doses from various advanced post-mastectomy radiotherapy techniques

Science.gov (United States)

Yoon, Jihyung; Heins, David; Zhao, Xiaodong; Sanders, Mary; Zhang, Rui

2017-12-01

More and more advanced radiotherapy techniques have been adopted for post-mastectomy radiotherapies (PMRT). Patient dose reconstruction is challenging for these advanced techniques because they increase the low out-of-field dose area while the accuracy of out-of-field dose calculations by current commercial treatment planning systems (TPSs) is poor. We aim to measure and model the out-of-field radiation doses from various advanced PMRT techniques. PMRT treatment plans for an anthropomorphic phantom were generated, including volumetric modulated arc therapy with standard and flattening-filter-free photon beams, mixed beam therapy, 4-field intensity modulated radiation therapy (IMRT), and tomotherapy. We measured doses in the phantom where the TPS calculated doses were lower than 5% of the prescription dose using thermoluminescent dosimeters (TLD). The TLD measurements were corrected by two additional energy correction factors, namely out-of-beam out-of-field (OBOF) correction factor K OBOF and in-beam out-of-field (IBOF) correction factor K IBOF, which were determined by separate measurements using an ion chamber and TLD. A simple analytical model was developed to predict out-of-field dose as a function of distance from the field edge for each PMRT technique. The root mean square discrepancies between measured and calculated out-of-field doses were within 0.66 cGy Gy-1 for all techniques. The IBOF doses were highly scattered and should be evaluated case by case. One can easily combine the measured out-of-field dose here with the in-field dose calculated by the local TPS to reconstruct organ doses for a specific PMRT patient if the same treatment apparatus and technique were used.

Comparison of treatment outcomes between involved-field and elective nodal irradiation in limited-stage small cell lung cancer

International Nuclear Information System (INIS)

Han, Tae-Jin; Kim, Hak-Jae; Wu, Hong-Gyun; Heo, Dae-Seog; Kim, Young-Whan; Lee, Se-Hoon

2012-01-01

The present study was performed to assess the usefulness of involved-field irradiation and the impact of 18 F-fluorodeoxyglucose-positron emission tomography-based staging on treatment outcomes in limited-stage small cell lung cancer. Eighty patients who received definitive chemoradiotherapy for limited-stage small cell lung cancer were retrospectively analyzed. Fifty patients were treated with involved-field irradiation, which means that the radiotherapy portal includes only clinically identifiable tumors. The other 30 patients were irradiated with a comprehensive portal, including uninvolved mediastinal and/or supraclavicular lymph nodes, so-called elective nodal irradiation. No significant difference was seen in clinical factors between the two groups. At a median follow-up of 27 months (range, 5-75 months), no significant differences were observed in 3 year overall survival (44.6 vs. 54.1%, P=0.220) and 3 year progression-free survival (24.4 vs. 42.8%, P=0.133) between the involved-field irradiation group and the elective nodal irradiation group, respectively. For patients who did not undergo positron emission tomography scans, 3 year overall survival (29.3 vs. 56.3%, P=0.022) and 3 year progression-free survival (11.0 vs. 50.0%, P=0.040) were significantly longer in the elective nodal irradiation group. Crude incidences of isolated nodal failure were 6.0% in the involved-field irradiation group and 0% in the elective nodal irradiation group, respectively. All isolated nodal failures were developed in patients who had not undergone positron emission tomography scans in their initial work-ups. If patients did not undergo positron emission tomography-based staging, the omission of elective nodal irradiation resulted in impaired survival outcomes and raised the risk of isolated nodal failure. Therefore, involved-field irradiation for limited-stage small cell lung cancer might be reasonable only with positron emission tomography scan implementation. (author)

Adjuvant radiotherapy versus observation alone for patients at risk of lymph-node field relapse after therapeutic lymphadenectomy for melanoma : a randomised trial

NARCIS (Netherlands)

Burmeister, Bryan H.; Henderson, Michael A.; Ainslie, Jill; Fisher, Richard; Di Iulio, Juliana; Smithers, B. Mark; Hong, Angela; Shannon, Kerwin; Scolyer, Richard A.; Carruthers, Scott; Coventry, Brendon J.; Babington, Scott; Duprat, Joao; Hoekstra, Harald J.; Thompson, John F.

Background The use of radiotherapy after therapeutic lymphadenectomy for patients with melanoma at high risk of further lymph-node field and distant recurrence is controversial. Decisions for radiotherapy in this setting are made on the basis of retrospective, non-randomised studies. We did this

Two Metachronous Neoplasms in the Radiotherapy Fields of a Young Man With Familial Adenomatous Polyposis

Directory of Open Access Journals (Sweden)

Patrick A. Williams BS

2013-04-01

Full Text Available Background: It is recognized that various radiation-induced malignancies often follow childhood radiotherapy. Radiation-induced neoplasms have been shown to occur with increased frequency in syndromes due to mutated tumor suppressor genes. There exist no recommendations for the management of cancer patients with germline APC gene mutations. Preclinical data suggest that APC gene mutations cause enhanced radiosensitivity, but no clinical observations exist that show that patients with this mutation are at higher risk for radiation-induced malignancies. Results: We report the case of a 32-year-old man with a genetic diagnosis of familial adenomatous polyposis (FAP who initially presented at age 10 with a medulloblastoma treated with radiotherapy and surgery. Radiation-induced papillary thyroid carcinoma followed 13 years later. Finally, radiation-induced soft tissue osteosarcoma occurred with widespread metastasis 20 years thereafter. Conclusions: This is the first report of 2 malignancies in the prior radiotherapy fields of a patient with a genetic diagnosis of FAP. More important, this suggests that APC-defective cells are at an enhanced sensitivity to the carcinogenic effects of radiotherapy compared with APC-proficient cells. This could argue for genetic screening in affected members of these families and for creation of treatment recommendations to more seriously consider the risks of radiation therapy.

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

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Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Berris, Theocharis; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P. O. Box 2208, 71003 Iraklion, Crete (Greece); Varveris, Charalambos; Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

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

Determination of Absorbed Dose in Large 60-Co Fields Radiotherapy

International Nuclear Information System (INIS)

Hrsak, H.

2003-01-01

Radiation in radiotherapy has selective impact on ill and healthy tissue. During the therapy the healthy tissue receives certain amount of dose. Therefore dose calculations in outer radiotherapy must be accurate because too high doses produce damage in healthy tissue and too low doses cannot ensure efficient treatment of cancer cells. A requirement on accuracy in the dose calculations has lead to improvement of detectors, and development of absolute and relative dosimetry. Determination of the dose distribution with use of computer is based on data provided by the relative dosimetry. This paper compares the percentage depth doses in cubic water phantoms of various dimensions with percentage depth doses calculated with use of Mayneord factor from the experimental depth doses measured in water phantom of large dimension. Depth doses in water phantoms were calculated by the model of empirical dosimetrical functions. The calculations were based on the assumption that large 6 0C o photon field exceeds the phantom's limits. The experimental basis for dose calculations by the model of empirical dosimetrical functions were exposure doses measured in air and dose reduction factors because of finite phantom dimensions. Calculations were performed by fortran 90 software. It was found that the deviation of dosimetric model was small in comparison to the experimental data. (author)

Concurrent chemoradiotherapy for advanced pancreatic cancer. 1,000 mg/m{sup 2} gemcitabine can be administered using limited-field radiotherapy

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Yamazaki, Hideya [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; National Hospital Organization, Osaka National Hospital, Osaka (Japan). Dept. of Radiology; Nishiyama, Kinji; Koizumi, Masahiko; Tanaka, Eiichi [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Radiation Oncology; Ioka, Tatsuya; Uehara, Hiroyuki; Iishi, Hiroyasu; Nakaizumi, Akihiko [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Internal Medicine; Ohigashi, Hiroaki; Ishikawa, Osamu [Osaka Medical Center for Cancer and Cardiovascular Disease, Osaka (Japan). Dept. of Surgery

2007-06-15

Purpose: To examine the feasibility of concurrent use of full-dose gemcitabine (GEM) and radiotherapy for advanced pancreatic cancer. Patient and Methods: 22 patients with advanced pancreatic cancer were subjected to concurrent chemoradiotherapy (GEM 1,000 mg/m2 weekly, three times during 4 weeks). They received limited-field irradiation by three-dimensional radiotherapy planning. Results: Of the 22 patients, 16 (72%) completed the treatment (50 Gy irradiation and at least three times concurrent administration of 1 g/m{sup 2} GEM). One patient with unresectable tail cancer showed peritonitis carcinomatosa and both chemotherapy and radiotherapy had to be stopped. Dose reduction or omission of GEM was necessary in another four patients. In addition, radiotherapy was discontinued in one patient for fatigue. Grade 3 hematologic toxicity was detected in eight patients (36%), and grade 3 nonhematologic toxicity (anorexia) in one patient (5%). In total, the response rate amounted to 32% (seven partial responses), and the median survival time (MST) was 16 months. Among the twelve patients who received preoperative chemoradiotherapy, nine underwent surgery and showed a survival rate of 78% at 1 year. Another 13 patients without surgery showed 14 months of MST. No regional lymph node failure has appeared so far. Conclusion: Limited-field radiotherapy enables the safe concurrent administration of 1,000 mg/m{sup 2} GEM.

Efficient CT simulation of the four-field technique for conformal radiotherapy of prostate carcinoma

International Nuclear Information System (INIS)

Valicenti, Richard K.; Waterman, Frank M.; Croce, Raymond J.; Corn, Benjamin; Suntharalingam, Nagalingam; Curran, Walter J.

1997-01-01

Purpose: Conformal radiotherapy of prostate carcinoma relies on contouring of individual CT slices for target and normal tissue localization. This process can be very time consuming. In the present report, we describe a method to more efficiently localize pelvic anatomy directly from digital reconstructed radiographs (DRRs). Materials and Methods: Ten patients with prostate carcinoma underwent CT simulation (the spiral mode at 3 mm separation) for conformal four-field 'box' radiotherapy. The bulbous urethra and bladder were opacified with iodinated contrast media. On lateral and anteroposterior DRRs, the volume of interest (VOI) was restricted to 1.0-1.5 cm tissue thickness to optimize digital radiograph reconstruction of the prostate and seminal vesicles. By removing unessential voxel elements, this method provided direct visualization of those structures. For comparison, the targets of each patient were also obtained by contouring CT axial slices. Results: The method was successfully performed if the target structures were readily visualized and geometrically corresponded to those generated by contouring axial images. The targets in 9 of 10 patients were reliable representations of the CT-contoured volumes. One patient had 18 mm variation due to the lack of bladder opacification. Using VOIs to generate thin tissue DRRs, the time required for target and normal tissue localization was on the average less than 5 min. Conclusion: In CT simulation of the four-field irradiation technique for prostate carcinoma, thin-tissue DRRs allowed for efficient and accurate target localization without requiring individual axial image contouring. This method may facilitate positioning of the beam isocenter and provide reliable conformal radiotherapy

Conventional radiotherapy of localized right side breast cancer after radical mastectomy: development of innovative “field in field” technique

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Goran Marošević

2011-12-01

Full Text Available Introduction: The aim of this paper is to study the distribution of the therapy dosage applied by a modified conventional “field in field” technique and compare it to the distribution of the dosage applied by the standard conventional technique.Methods: The study included ten patients with right side breast cancer, after they were exposed to radical mastectomy and chemotherapy. Radiotherapy dosage of TD 50 Gy in 25 fractions was applied to the anterolateral side of the right thoracic wall, with two opposite conventional tangential fields by the linear accelerator Elekta Synergy and the energy of 6 megavolts (MV. A delineation of the target volume (CTV – Clinical Target Volume was done within conventional fields. At the XiO system for planning we included additional fields within the existing conventional fields, which was the so called “field in field” technique. On the basis of CTV the Dose Volume  Histogram (DVH was calculated for conventional and “field in field” plans. VD90%, VD95%, VD107%, VD115%, CI and HI were calculated for both techniques. Means were pared with the paired Student's t-test. The results were considered significantly different if p<0.05.Results: VD90% and VD 95% were significantly higher for the “field in field” technique. Therefore, CI also favored the “field in field” technique (p=0.02. There was no difference in VD107% and VD115% between the compared groups. Consequently, there was no statistically significant difference in HI (1.13±0.03 vs.1.13±0.03, p=0.06.Conclusion: Conventional postoperative radiotherapy of localized right side breast cancer by “field in field” technique provides excellent coverage of the target volume by radiotherapy isodose.

Carbon-ion radiotherapy for marginal lymph node recurrences of cervical cancer after definitive radiotherapy: a case report

International Nuclear Information System (INIS)

Tamaki, Tomoaki; Nakano, Takashi; Ohno, Tatsuya; Kiyohara, Hiroki; Noda, Shin-ei; Ohkubo, Yu; Ando, Ken; Wakatsuki, Masaru; Kato, Shingo; Kamada, Tadashi

2013-01-01

Recurrences of cervical cancer after definitive radiotherapy often occur at common iliac or para-aortic lymph nodes as marginal lymph node recurrences. Patients with these recurrences have a chance of long-term survival by optimal re-treatment with radiotherapy. However, the re-irradiation often overlaps the initial and the secondary radiotherapy fields and can result in increased normal tissue toxicities in the bowels or the stomach. Carbon-ion radiotherapy, a form of particle beam radiotherapy using accelerated carbon ions, offers more conformal and sharp dose distribution than X-ray radiotherapy. Therefore, this approach enables the delivery of high radiation doses to the target while sparing its surrounding normal tissues. Marginal lymph node recurrences in common iliac lymph nodes after radiotherapy were treated successfully by carbon-ion radiotherapy in two patients. These two patients were initially treated with a combination of external beam radiotherapy and intracavitary and interstitial brachytherapy. However, the diseases recurred in the lymph nodes near the border of the initial radiotherapy fields after 22 months and 23 months. Because re-irradiation with X-ray radiotherapy may deliver high doses to a section of the bowels, carbon-ion radiotherapy was selected to treat the lymph node recurrences. A total dose of 48 Gy (RBE) in 12 fractions over 3 weeks was given to the lymph node recurrences, and the tumors disappeared completely with no severe acute toxicities. The two patients showed no evidence of disease for 75 months and 63 months after the initial radiotherapy and for 50 months and 37 months after the carbon-ion radiotherapy, respectively. No severe late adverse effects are observed in these patients. The two presented cases suggest that the highly conformal dose distribution of carbon-ion radiotherapy may be beneficial in the treatment of marginal lymph node recurrences after radiotherapy. In addition, the higher biological effect of carbon

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

International Nuclear Information System (INIS)

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

2011-01-01

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.

Geometric accuracy of field alignment in fractionated stereotactic conformal radiotherapy of brain tumors

International Nuclear Information System (INIS)

Kortmann, Rolf D.; Becker, Gerd; Perelmouter, Jury; Buchgeister, Markus; Meisner, Christoph; Bamberg, Michael

1999-01-01

Purpose: To assess the accuracy of field alignment in patients undergoing three-dimensional (3D) conformal radiotherapy of brain tumors, and to evaluate the impact on the definition of planning target volume and control procedures. Methods and Materials: Geometric accuracy was analyzed in 20 patients undergoing fractionated stereotactic conformal radiotherapy for brain tumors. Rigid head fixation was achieved by using cast material. Transfer of stereotactic coordinates was performed by an external positioning device. The accuracy during treatment planning was quantitatively assessed by using repeated computed tomography (CT) examinations in treatment position (reproducibility of isocenter). Linear discrepancies were measured between treatment plan and CT examination. In addition, for each patient, a series of 20 verifications were taken in orthogonal projections. Linear discrepancies were measured between first and all subsequent verifications (accuracy during treatment delivery). Results: For the total group of patients, the distribution of deviations during treatment setup showed mean values between -0.3-1.2 mm, with standard deviations (SD) of 1.3-2.0 mm. During treatment delivery, the distribution of deviations revealed mean values between 0.7-0.8 mm, with SDs of 0.5-0.6 mm, respectively. For all patients, deviations for the transition to the treatment machine were similar to deviations during subsequent treatment delivery, with 95% of all absolute deviations between less than 2.8 and 4.6 mm. Conclusion: Random fluctuations of field displacements during treatment planning and delivery prevail. Therefore, our quantitative data should be considered when prescribing the safety margins of the planning target volume. Repeated CT examination are useful to detect operator errors and large random or systematic deviations before start of treatment. Control procedures during treatment delivery appear to be of limited importance. In addition, our findings should help to

Impact of field number and beam angle on functional image-guided lung cancer radiotherapy planning

Science.gov (United States)

Tahir, Bilal A.; Bragg, Chris M.; Wild, Jim M.; Swinscoe, James A.; Lawless, Sarah E.; Hart, Kerry A.; Hatton, Matthew Q.; Ireland, Rob H.

2017-09-01

To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 magnetic resonance imaging (3He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment 3He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving  ⩾20 Gy (V20) were compared with plans that minimised 3He MRI defined functional lung receiving  ⩾20 Gy (fV20). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV20 and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV90). Incorporation of 3He MRI led to median reductions in fV20 of 1.3% (range: 0.2-9.3% p  =  0.04) and 0.2% (range: 0 to 4.1%; p  =  0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised 3He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.

Determination of two- and three-dimensional radiation fields for neutron radiotherapy planning

International Nuclear Information System (INIS)

Boehm, J.K.

1986-01-01

The thesis deals with the computerized investigations for fast neutron radiotherapy planning, explaining the calculation and modelling of local dose distributions in patients as a result of mixed neutron and gamma radiation fields. For a computed irradiation program (elaborated for instance by the COMRAD program system), dose distribution functions are required for the simulation of multi-field or moving beam irradiations, the functions being derived semi-empirically by non-linear regression. The necessary data on stationary field doses are derived by measurements or by computed simulation with specific transport programs from the nuclear engineering sector. Transport calculations show the effects of inhomogeneities in the patient's body on the dose distribution. The determined, strong inhomogneity effects (lungs, head) have to be taken into account as precisely as possible in order to achieve optimum irradiation planning. (orig./HP) [de

A longitudinal evaluation of early anatomical changes of parotid gland in intensity modulated radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space involvement.

Science.gov (United States)

Zhang, Yingting; Lin, Chengguang; Wu, Jianhua; Jiang, Xiaobo; Lee, Shara W Y; Tam, Shing-Yau; Wu, Vincent W C

2017-09-01

Radiotherapy of nasopharyngeal carcinoma patients with parapharyngeal space (PPS) involvement may deliver high dose to the parotid gland. This study evaluated parotid gland changes during and up to 3 months after radiotherapy. Kilovoltage computed tomography (CT) scans of head and neck region of 39 nasopharyngeal carcinoma patients with PPS involvement were performed at pre-radiotherapy, 10th, 20th and 30th fractions and 3 months after treatment. The parotid glands were contoured in pre-radiotherapy planning CT scan and in subsequent scans. Dice similarity coefficient (DSC), percentage volume change and centroid movement between the planning CT and the subsequent CTs were obtained from the contouring software. In addition, the distance between medial and lateral borders of parotid glands from the mid-line at various time intervals were also measured. The ipsilateral parotid gland received a mean dose of about 5 Gy higher than the contralateral side. The mean DSC and parotid volume decreased by more than 30% at 20th fraction and reached the minimum at 30th fraction. Partial recovery was observed at 3 months after treatment. The centroid displacement followed a similar pattern, which moved medially and superiorly by an average of 0.30 cm and 0.18 cm, respectively, at 30th fraction. The changes in ipsilateral gland were slightly greater than the contralateral side. Substantial volume change and medial movement of parotid gland were observed with slightly greater magnitude in the ipsilateral side. Adaptive radiotherapy was suggested at around 15th to 20th fraction so as to optimise the original dose distribution of the plan. © 2017 The Authors. Journal of Medical Radiation Sciences published by John Wiley & Sons Australia, Ltd on behalf of Australian Society of Medical Imaging and Radiation Therapy and New Zealand Institute of Medical Radiation Technology.

Involved field radiotherapy (IFRT) versus elective nodal irradiation (ENI) for locally advanced non-small cell lung cancer: a meta-analysis of incidence of elective nodal failure (ENF).

Science.gov (United States)

Li, Ruijian; Yu, Liang; Lin, Sixiang; Wang, Lina; Dong, Xin; Yu, Lingxia; Li, Weiyi; Li, Baosheng

2016-09-21

The use of involved field radiotherapy (IFRT) has generated concern about the increasing incidence of elective nodal failure (ENF) in contrast to elective nodal irradiation (ENI). This meta-analysis aimed to provide more reliable and up-to-date evidence on the incidence of ENF between IFRT and ENI. We searched three databases for eligible studies where locally advanced non-small cell lung cancer (NSCLC) patients received IFRT or ENI. Outcome of interest was the incidence of ENF. The fixed-effects model was used to pool outcomes across the studies. There were 3 RCTs and 3 cohort studies included with low risk of bias. There was no significant difference in incidence of ENF between IFRT and ENI either among RCTs (RR = 1.38, 95 % CI: 0.59-3.25, p = 0.46) or among cohort studies (RR = 0.99, 95 % CI: 0.46-2.10, p = 0.97). There was also no significant difference in incidence of ENF between IFRT and ENI when RCTs and cohort studies were combined (RR = 1.15, 95 % CI: 0.65-2.01, p = 0.64). I 2 of test for heterogeneity was 0 %. This meta-analysis provides more reliable and stable evidence that there is no significant difference in incidence of ENF between IFRT and ENI.

Long-term results of radiotherapy for 104 patients with Graves' orbitopathy

International Nuclear Information System (INIS)

Qu Baolin; Yang Dong; Feng Linchun; Luo Zhiyuan

2008-01-01

Objective: To evaluate the long-term outcome and the sequelae of Graves' orbitopathy treated with radiotherapy, and to specify the prognostic factors. Methods: From 1979 to 1999, 104 patients with progressive Graves' orbitopathy were treated with conventional orbital radiotherapy. Post globe and pituitary irradiation of 25-35 Gy was given to 56 patients, which was followed by a boost of 15-20 Gy to the pituitary. Follow-up time was 7.5 - 25.0 years. The result of radiotherapy was analyzed. Results: Overall response rate was 71.1%. The response rate of patients with soft-tissue infiltration, corneal involvement, proptosis, sight loss and extraocular muscle dysfunction was 88.4%, 75.1%, 55.6%, 68.8% and 64.4%, respectively. Twelve patients (11.5%) developed cataracts 2.5-18.3 years (median 11.2 years) after irradiation. One patient developed left-eye retinopathy 3.2 years after irradiation. No patient developed secondary tumor within the irradiation field. Conclusions: Orbital radiotherapy for progressive Graves' orbitopathy, being effective and safe, can control the disease progression and improve the symptoms. The side effect of radiotherapy is fewer than other treatment modalities. (authors)

Radiotherapy in differentiated thyroid cancer: Optimal dose distribution using a wax bolus

International Nuclear Information System (INIS)

Mayer, R.; Stucklschweiger, G.; Oechs, A.; Pakish, B.; Hackl, A.; Preidler, K.; Szola, D.

1994-01-01

The study includes 53 patients with differentiated thyroid cancer, who underwent surgical and radioiodine therapy as well as hormone therapy. Postoperative radiotherapy was performed in all patients in 'mini-mantle-technique' with parallel opposed fields, followed by an anterior boost-field with electrons up to 60-64 Gy, using a wax bolus for optimal dose distribution in the target volume sparing out the spinal cord as much as possible. The dose to the spinal cord did not exceed 44 Gy in any case. The study shows that radiotherapy with doses up to 60-64 Gy plays an important role in postsurgical therapeutic management. Therefore nonradical surgery is a less important prognostic factor for survival and local recurrence in patients with differentiated thyroid cancer than histological diagnosis in combination with age and lymph node involvement

Extracranial stereotactic radiotherapy: preliminary results with the CyberKnife.

Science.gov (United States)

Lartigau, Eric; Mirabel, Xavier; Prevost, Bernard; Lacornerie, Thomas; Dubus, Francois; Sarrazin, Thierry

2009-04-01

In the field of radiation oncology, equipment for fractionated radiotherapy and single-dose radiosurgery has become increasingly accurate, together with the introduction of robotized treatments. A robot is a device that can be programmed to carry out accurate, repeated and adjusted tasks in a given environment. Treatment of extracranial lesions involves taking into account organ mobility (tumor and healthy tissue) whilst retaining the ability to stereotactically locate the target. New imaging techniques (single-photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), positron emission tomography (PET)) provide further relevant information to slice images (computed tomography (CT) scans, MRI) for target definition. Hypo-fractionated treatments can only be used for curative treatment if the target is accurately defined and tracked during treatment. The CyberKnife is a non-invasive system of radiosurgery and fractionated stereotactic radiotherapy. For intracranial lesions treated by single-dose radiosurgery, it has been used to treat meningioma, acoustic neuromas, pituitary adenoma, metastases, arteriovenous malformations and refractory pain (trigeminal neuralgia). More than 10,000 patients have been treated worldwide. Currently, the most significant developments are in the field of extracranial stereotactic radiotherapy (lung, liver, reirradiation, prostate, etc.). Clinical results obtained in the CyberKnife Nord-Ouest program after 1 year of experience are presented. Copyright 2009 S. Karger AG, Basel.

Clinical outcome of extended-field irradiation vs. pelvic irradiation using intensity-modulated radiotherapy for cervical cancer.

Science.gov (United States)

Ouyang, Yi; Wang, Yanhong; Chen, Kai; Cao, Xinping; Zeng, Yiming

2017-12-01

The aim of the present study was to evaluate the distinctions in survival and toxicity between patients with cervical cancer with common iliac node or para-aortic node involvement, who were treated with extended-field intensity-modulated radiotherapy (EF-IMRT) and patients with or without lower involved pelvic nodes, who were treated with pelvic IMRT. A total of 55 patients treated with EF-IMRT and 52 patients treated with pelvic IMRT at the Sun Yat-Sen University Cancer Center (Guangzhou, China) were retrospectively analyzed. Patients treated with EF-IMRT had the highest level of lymph node involvement to the para-aortic or common iliac nodes, while patients treated with pelvic IMRT had no para-aortic or common iliac nodes involved (Pirradiation was a protective prognostic factor for OS and DFS. A total of 16 patients in the EF-IMRT group and 13 patients in the pelvic IMRT group experienced treatment failure (P=0.67), with the patterns of failure being the same for the two groups (P=0.88). The cumulative incidence of grade 3 and 4 acute toxicities in the EF-IMRT group was 34.5%, in comparison with 19.2% in the pelvic group (P=0.048). The results of the present study suggest that patients with cervical cancer with grossly involved common iliac or para-aortic nodes should be electively subjected to EF irradiation to improve the survival and alter patterns of recurrence. Notably, EF irradiation delivered via IMRT exhibits an increased toxicity incidence, however, this remains within an acceptable range.

The history and evolution of radiotherapy and radiation oncology in Austria

International Nuclear Information System (INIS)

Kogelnik, H. Dieter

1996-01-01

Austria has a longstanding and eventful history in the field of radiotherapy and radiation oncology. The founder of radiotherapy, Leopold Freund, began his well-documented first therapeutic irradiation on November 24, 1896, in Vienna. He also wrote the first textbook of radiotherapy in 1903. Further outstanding Viennese pioneers in the fields of radiotherapy, radiobiology, radiation physics, and diagnostic radiology include Gottwald Schwarz, Robert Kienboeck, and Guido Holzknecht. Because many of the leading Austrian radiologists had to emigrate in 1938, irreparable damage occurred at that time for the medical speciality of radiology. After World War II, the recovery in the field of radiotherapy and radiation oncology started in Austria in the early sixties. Eleven radiotherapy centers have been established since that time, and an independent society for radio-oncology, radiobiology, and medical radiophysics was founded in 1984. Finally, in March 1994, radiotherapy-radio-oncology became a separate clinical speciality

Radiotherapeutic aspects of the treatment of adult patients with supradiaphragmatic Hodgkin's disease CS I/II. Pt. 1; Regarding the indications of primary and adjuvant radiotherapy. Fragen und Aspekte zur Radiotherapie bei erwachsenen Patienten mit lokalisierten supradiaphragmalen Stadien (CS I/II) eines Morbus Hodgkin. T. 1; Fragen und Aspekte zu den Indikationen einer primaeren und einer adjuvanten Radiotherapie

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Glanzmann, C. (Universitaetsspital, Klinik fuer Radio-Onkologie, Zurich (Switzerland)); Luetolf, U.M. (Universitaetsspital, Klinik fuer Radio-Onkologie, Zurich (Switzerland))

1993-08-01

Randomized studies of chemo- vs radiotherapy in patients with PS I/II A and some PS III A have shown conflicting results. Patients with supra-diaphragmatic Hodkin's disease and CS I/II can be subdivided according to radiotherapy as: 1. Patients with a very low or a low recurrence risk of approximately 10 to 20%: Patients less than 40 years old and CS I/II A NS/LP with less than three involved regions and no bulky mediastinal mass and an ESR below 30 mm. In the other patients, primary irradiation of an extended mantle field without a staging laparotomy is an acceptable primary treatment, achieving a recurrence-free survival rate of approximately 80%. Another option is a staging laparotomy with splenectomy and a mantle radiotherapy for PS I/II. Few groups prefer primary chemotherapy alone or some type of a reduced chemotherapy with lesser toxicity combined with localized radiotherapy and long-term observations of a larger group of patients after the last type of treatment have to confirm the excellent early results. 2. Patients with an intermediate recurrence risk of approximately 20 to 40%: Patients, who do not belong to group one or group 3. Patients less than 50 years old with CS I/II and an ESR less than 50 mm and without bulky mediastinal involvement and with one of the following signs: Three involved regions or MC or one B symptom. A patient with more than one of these signs or with two or three B symptoms should be classified in group 3. For these patients, we recommend staging laparotomy and radiotherapy if PS I/II or primary chemotherapy with or without radiotherapy of the involved regions. 3. Patients with a high recurrence risk (40% or higher): (Abstract Truncated)

Conformal fields in prostate radiotherapy: A comparison between measurement, calculation and simulation

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Seied R Mahdavi

2012-01-01

Full Text Available Aims: The objective of this study is to evaluate the accuracy of a treatment planning system (TPS for calculating the dose distribution parameters in conformal fields (CF. Dosimetric parameters of CF′s were compared between measurement, Monte Carlo simulation (MCNP4C and TPS calculation. Materials and Methods: Field analyzer water phantom was used for obtaining percentage depth dose (PDD curves and beam profiles (BP of different conformal fields. MCNP4C was used to model conformal fields dose specification factors and head of linear accelerator varian model 2100C/D. Results: Results showed that the distance to agreement (DTA and dose difference (DD of our findings were well within the acceptance criteria of 3 mm and 3%, respectively. Conclusions: According to this study it can be revealed that TPS using equivalent tissue air ratio calculation method is still convenient for dose prediction in non small conformal fields normally used in prostate radiotherapy. It was also showed that, since there is a close correlation with Monte Carlo simulation, measurements and TPS, Monte Carlo can be further confirmed for implementation and calculation dose distribution in non standard and complex conformal irradiation field for treatment planning systems.

Testicular function after radiotherapy to inverted 'Y' field for malignant lymphoma

International Nuclear Information System (INIS)

Asbjoernsen, G.; Molne, K.; Klepp, O.; Aakvaag, A.

1976-01-01

Testicular function was estimated by sperm counts, hormone assays and recording of reported conceptions in 9 patients irradiated for malignant lymphoma. The treatment had been an inverted 'Y' field including the inguinal regions with, in addition, a mantle field in 8 patients. Azoospermia or severe oligozoospermia was found in all but 1 patient, and the FSH levels were uniformly elevated. Testosterone and LH were within normal limits except in 2 patients with slightly subnormal testosterone levels. 7 of the patients were married to women of fertile age, and in 3 cases the wife became pregnant and gave birth to a healthy child. The time lapses from irradiation to conception were 18, 40 and 57 months. 2 of these patients had severe oligozoospermia on examination 2 and 4 months respectively from conception. Thus fertility may possibly be underestimated by sperm counting and hormone assays after this type of radiotherapy. (author)

Testicular function after radiotherapy to inverted 'Y' field for malignant lymphoma

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Asbjoernsen, G; Molne, K; Klepp, O; Aakvaag, A [Norske Radiumhospital, Oslo; Rikshospitalet, Oslo (Norway))

1976-01-01

Testicular function was estimated by sperm counts, hormone assays and recording of reported conceptions in 9 patients irradiated for malignant lymphoma. The treatment had been an inverted 'Y' field including the inguinal regions with, in addition, a mantle field in 8 patients. Azoospermia or severe oligozoospermia was found in all but 1 patient, and the FSH levels were uniformly elevated. Testosterone and LH were within normal limits except in 2 patients with slightly subnormal testosterone levels. 7 of the patients were married to women of fertile age, and in 3 cases the wife became pregnant and gave birth to a healthy child. The time lapses from irradiation to conception were 18, 40 and 57 months. 2 of these patients had severe oligozoospermia on examination 2 and 4 months respectively from conception. Thus fertility may possibly be underestimated by sperm counting and hormone assays after this type of radiotherapy.

Study and establishment of a computer program for radiotherapy treatment planning development

International Nuclear Information System (INIS)

Djennaoui, N.

1987-02-01

The modern radiotherapy requires the use of computers. In addition to their accuracy, computers involve an appreciable saving of time in the calculation of isodoses, permitting us to change several times a technique in order to choose the best dose distribution for each case of tumor. The aim of this work was to set a computer program calculating a suitable dose distribution for a given treatment. The algorithm of calculation of the depth dose used in our program permits us to calculate the dose distribution for all photon energies used in radiotherapy, whatever are the energy and modification of the field by the use of wedge filters or bolus [fr

Pattern of failures in gastric cancer patients with lymph node involvement treated by surgery, intraoperative and external beam radiotherapy

International Nuclear Information System (INIS)

Glehen, O.; Peyrat, P.; Beaujard, A.C.; Chapet, O.; Romestaing, P.; Sentenac, I.; Francois, Y.; Vignal, J.; Gerard, J.P.; Gilly, F.N.

2003-01-01

Aims: High local failure rates in gastric cancer have been reported, up to 67%. To achieve a better local control, we evaluated intraoperative radiotherapy (IORT) and external beam radiotherapy (EBRT) in association with surgery for gastric cancer patients with lymph node involvement. We report here the analysis of the patterns of failure for patients involved in this IORT protocol. Material and methods: Forty-two positive lymph node (N+) gastric cancer patients were operated on (31 total, three subtotal and eight extended gastrectomies) with IORT procedure between 1985 and 1997 (33 males, nine females, mean age 61.3 years). IORT was focused on coeliac area (mean dose 15 Gy), followed by EBRT (46 Gy) in 36 patients. Ten patients were pN1 and 32 were pN2. A concurrent systemic chemotherapy (five Fluoro-Uracil and Cisplatinum) was performed in 14 patients. Results: One patient died postoperatively. Actuarial pN+ 10 year survival rate was 44.8%. The 5 year actuarial local control and disease-free survival rates were 78.8 and 47.5%, respectively. As far as patterns of failure were explored, 5 patients have a local coeliac recurrence (12%) and 12 have distant metastases with no evidence of coeliac recurrence. Conclusion: This retrospective analysis suggests a potential effect of IORT and/or EBRT in promoting local control and long-term survival in gastric cancer patients with lymph node involvement

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

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Yang, Y. M.; Geurts, M.; Smilowitz, J. B.; Bednarz, B. P., E-mail: bbednarz2@wisc.edu [Department of Medical Physics, Wisconsin Institutes for Medical Research, University of Wisconsin, Madison, Wisconsin 53703 (United States); Sterpin, E. [Molecular Imaging, Radiotherapy and Oncology, Université catholique de Louvain, Brussels, Belgium 1348 (Belgium)

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

Radiotherapy Treatment Planning for Testicular Seminoma

International Nuclear Information System (INIS)

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

2012-01-01

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 × 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).

Radiotherapy Treatment Planning for Testicular Seminoma

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Wilder, Richard B., E-mail: richardbwilder@yahoo.com [Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL (United States); Buyyounouski, Mark K. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, PA (United States); Efstathiou, Jason A. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA (United States); Beard, Clair J. [Department of Radiation Oncology, Dana-Farber/Brigham and Women' s Cancer Center, Boston, MA (United States)

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).

Indications for quality assurance in conformal radiotherapy in Italy

International Nuclear Information System (INIS)

Banci Buonamici, F.; DE Angelis, C.; Rosi, A.; Tabocchini, M.A.; Iotti, C.; Olmi, P.

2008-01-01

Intensity-Modulated Radiation Therapy (IMRT) is an advanced and promising technique of external beam irradiation. IMRT is able to conform the dose distribution to the 3D tumour shape also for complex geometries, preserving surrounding normal tissues and reducing the probability of side effects. IMRT is a time consuming and complex technique and its use demands high level quality assurance. It is, therefore, very important to define conditions for its utilization. Professionals of Radiotherapy Centres, with experience in the IMRT use, have constituted a multidisciplinary working group with the aim of developing indications in this field. Purpose of the present document is to highlight relevant aspects of the technique, but also to underline the high complexity of the technique, whose implementation requires extreme attention of the staff of Radiotherapy Centres involved [it

Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

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Mazonakis, Michalis, E-mail: mazonak@med.uoc.gr; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, Iraklion, Crete 71003 (Greece); Tzedakis, Antonis [Department of Medical Physics, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, Iraklion, Crete 71110 (Greece)

2016-04-15

Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D{sub av}) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D{sub av} and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D{sub av} range for the out-of-field organs was 4.9 × 10{sup −4} to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated

Radiation dose and cancer risk to out-of-field and partially in-field organs from radiotherapy for symptomatic vertebral hemangiomas

International Nuclear Information System (INIS)

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

2016-01-01

Purpose: Vertebral hemangiomas (VHs) are the most common benign tumors of the spine that may cause bone resorption. Megavoltage irradiation is usually the treatment of choice for the management of symptomatic VHs. The current study was conducted to estimate the risk for carcinogenesis from radiotherapy of this benign disease on the basis of the calculated radiation doses to healthy organs. Methods: The Monte Carlo N-particle transport code was employed to simulate the irradiation with 6 MV x-rays of a VH presented in the cervical, upper thoracic, lower thoracic, and lumbar spine. The average radiation dose (D_a_v) received by each critical organ located outside the primarily irradiated area was calculated. Three-dimensional treatment plans were also generated for the VHs occurring at the four different sites of the spinal cord based on patients’ computed tomography data. The organ equivalent dose (OED) to each radiosensitive structure, which was partly encompassed by the applied treatment fields, was calculated with the aid of differential dose–volume histograms. The D_a_v and the OED values were combined with a linear-no-threshold model and a nonlinear mechanistic model, respectively, to estimate the organ-, age-, and gender-specific lifetime attributable risks (LARs) for cancer development. The estimated risks were compared with the respective nominal lifetime intrinsic risks (LIRs) for the unexposed population. Results: For a standard target dose of 34 Gy, the OED varied from 0.39–5.15 Gy by the organ of interest and the irradiation site. The D_a_v range for the out-of-field organs was 4.9 × 10"−"4 to 0.56 Gy. The LAR for the appearance of malignancies in the partially in-field organs after radiotherapy of male and female patients was (0.08%–1.8%) and (0.09%–1.9%), respectively. These risk values were 1.5–15.5 times lower when compared to the respective LIRs. The lifetime probability for out-of-field cancer induction in irradiated males and

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

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Oborn, B. M., E-mail: brad.oborn@gmail.com [Illawarra Cancer Care Centre (ICCC), Wollongong, NSW 2500, Australia and Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong, NSW 2500 (Australia); Ge, Y. [Sydney Medical School, University of Sydney, NSW 2006 (Australia); Hardcastle, N. [Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, NSW 2065 (Australia); Metcalfe, P. E. [Centre for Medical Radiation Physics (CMRP), University of Wollongong, Wollongong NSW 2500, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia); Keall, P. J. [Sydney Medical School, University of Sydney, NSW 2006, Australia and Ingham Institute for Applied Medical Research, Liverpool, NSW 2170 (Australia)

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

Surface dose measurements in and out of field. Implications for breast radiotherapy with megavoltage photon beams

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Lonski, Peta; Kron, Tomas [Peter MacCallum Cancer Centre, Melbourne (Australia); RMIT Univ., Melbourne (Australia); Ramachandran, Prabhakar; Franich, Rick [Peter MacCallum Cancer Centre, Melbourne (Australia)

2017-07-01

This study examines the difference in surface dose between flat and flattening filter free (FFF) photon beams in the context of breast radiotherapy. The surface dose was measured for 6 MV, 6 MV FFF, 10 MV, 10 MV FFF and 18 MV photon beams using a thin window ionisation chamber for various field sizes. Profiles were acquired to ascertain the change in surface dose off-axis. Out-of-field measurements were included in a clinically representative half beam block tangential breast field. In the field centres of FFF beams the surface dose was found to be increased for small fields and decreased for large fields compared to flat beams. For FFF beams, surface dose was found to decrease off-axis and resulted in lower surface dose out-of-field compared to flat beams.

Status of Radiotherapy around the World: Radiotherapy in China. Chapter 25.6

International Nuclear Information System (INIS)

Zhu, Ci; Yin, Wei Bo; Chen, Bo; Zhang, Chun Li; Zhang, Hong Zhi; Li, Ye Xiong

2017-01-01

China’s experience of using radiotherapy to treat cancer began with the installation of the first superficial X ray machine at Peking Union Medical College Hospital in early 1920, followed by the first 200 kV deep X ray machine installed at the French Hospital in Shanghai in 1923, and the first Chinese radiotherapy department established at the Affiliated Hospital of Peking University in 1932. However, the field of radiotherapy in China was still in its infancy between the 1930s and 1960s, as all operating machines were imported from foreign countries, making radiotherapy very difficult to access for cancer patients. Progress was slow until the mid-1970s, when the first batch of megavoltage machines (cobalt-60 machines and linacs) was produced by Chinese manufacturers. Owing to the efforts of radiotherapy pioneers such as Wu Huanxing, Gu Xianzhi, Liu Taifu, and Yin Weibo, who brought radiotherapy to China and shaped how Chinese patients would be treated today, radiotherapy was installed as one of the mainstream modalities of cancer treatment. In 1986, the China Society for Radiation Oncology (CSTRO) was founded, indicating that a network advancing radiation oncology practice in China was taking shape. One year later, the first issue of the Chinese Journal of Radiation Oncology was published, offering a platform for the timely exchange and sharing of laboratory and clinical research outcomes among radiation oncology professions across the country. During the past two decades, with the introduction of the gamma knife and stereotactic radiotherapy, 3-D conformal radiotherapy, IMRT, IGRT and other advanced techniques, China experienced not only a big jump in its radiotherapy equipment and facilities, but also a dramatic growth in the excellence of radiation oncology specialist staff nationwide

An adaptive radiotherapy planning strategy for bladder cancer using deformation vector fields

International Nuclear Information System (INIS)

Vestergaard, Anne; Kallehauge, Jesper Folsted; Petersen, Jørgen Breede Baltzer; Høyer, Morten; Søndergaard, Jimmi; Muren, Ludvig Paul

2014-01-01

Purpose: Adaptive radiotherapy (ART) has considerable potential in treatment of bladder cancer due to large inter-fractional changes in shape and size of the target. The aim of this study was to compare our clinically applied method for plan library creation that involves manual bladder delineations (Clin-ART) with a method using the deformation vector fields (DVFs) resulting from intensity-based deformable image registrations (DVF-based ART). Materials and methods: The study included thirteen patients with urinary bladder cancer who had daily cone beam CTs (CBCTs) acquired for set-up. In both ART strategies investigated, three plan selection volumes were generated using the CBCTs from the first four fractions; in Clin-ART boolean combinations of delineated bladders were used, while the DVF-based strategy applied combinations of the mean and standard deviation of patient-specific DVFs. The volume ratios (VRs) of the course-averaged PTV for the two ART strategies relative the non-adaptive PTV were calculated. Results: Both Clin-ART and DVF-based ART considerably reduced the course-averaged PTV, compared to non-adaptive RT. The VR for DVF-based ART was lower than for Clin-ART (0.65 vs. 0.73; p < 0.01). Conclusions: DVF-based ART for bladder irradiation has a considerable normal tissue sparing potential surpassing our already highly conformal clinically applied ART strategy

An adaptive radiotherapy planning strategy for bladder cancer using deformation vector fields.

Science.gov (United States)

Vestergaard, Anne; Kallehauge, Jesper Folsted; Petersen, Jørgen Breede Baltzer; Høyer, Morten; Søndergaard, Jimmi; Muren, Ludvig Paul

2014-09-01

Adaptive radiotherapy (ART) has considerable potential in treatment of bladder cancer due to large inter-fractional changes in shape and size of the target. The aim of this study was to compare our clinically applied method for plan library creation that involves manual bladder delineations (Clin-ART) with a method using the deformation vector fields (DVFs) resulting from intensity-based deformable image registrations (DVF-based ART). The study included thirteen patients with urinary bladder cancer who had daily cone beam CTs (CBCTs) acquired for set-up. In both ART strategies investigated, three plan selection volumes were generated using the CBCTs from the first four fractions; in Clin-ART boolean combinations of delineated bladders were used, while the DVF-based strategy applied combinations of the mean and standard deviation of patient-specific DVFs. The volume ratios (VRs) of the course-averaged PTV for the two ART strategies relative the non-adaptive PTV were calculated. Both Clin-ART and DVF-based ART considerably reduced the course-averaged PTV, compared to non-adaptive RT. The VR for DVF-based ART was lower than for Clin-ART (0.65 vs. 0.73; p<0.01). DVF-based ART for bladder irradiation has a considerable normal tissue sparing potential surpassing our already highly conformal clinically applied ART strategy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

New quality assurance program integrating ''modern radiotherapy'' within the German Hodgkin Study Group

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Kriz, J.; Haverkamp, U.; Eich, H.T. [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Baues, C.; Marnitz-Schulze, S. [University of Cologne, Department of Radiation Oncology, Koeln (Germany); Engenhart-Cabillic, R. [University of Marburg, Department of Radiation Oncology, Marburg (Germany); Herfarth, K. [University of Heidelberg, Department of Radiation Oncology, Heidelberg (Germany); Lukas, P. [University of Innsbruck, Department of Radiation Oncology, Innsbruck (Austria); Schmidberger, H. [University of Mainz, Department of Radiation Oncology, Mainz (Germany); Fuchs, M.; Engert, A. [University of Cologne, Department of Internal Medicine, Koeln (Germany)

2017-02-15

Field design changed substantially from extended-field RT (EF-RT) to involved-field RT (IF-RT) and now to involved-node RT (IN-RT) and involved-site RT (IS-RT) as well as treatment techniques in radiotherapy (RT) of Hodgkin's lymphoma (HL). The purpose of this article is to demonstrate the establishment of a quality assurance program (QAP) including modern RT techniques and field designs within the German Hodgkin Study Group (GHSG). In the era of modern conformal RT, this QAP had to be fundamentally adapted and a new evaluation process has been intensively discussed by the radiotherapeutic expert panel of the GHSG. The expert panel developed guidelines and criteria to analyse ''modern'' field designs and treatment techniques. This work is based on a dataset of 11 patients treated within the sixth study generation (HD16-17). To develop a QAP of ''modern RT'', the expert panel defined criteria for analysing current RT procedures. The consensus of a modified QAP in ongoing and future trials is presented. With this schedule, the QAP of the GHSG could serve as a model for other study groups. (orig.) [German] Nicht nur die Zielvolumendefinitionen haben sich von der Extended-Field- (EF-RT) ueber die Involved-Field- (IF-RT) bis zur Involved-Node- (IN-RT) und Involved-Site-Radiotherapie (IS-RT) weiterentwickelt. Auch die Radiotherapie(RT)-Techniken in der Behandlung von Patienten mit Hodgkin-Lymphom haben Aenderungen erfahren. Wir moechten aufzeigen, wie die Arbeit des Qualitaetssicherungsprogramms (QAP) innerhalb der Deutschen Hodgkin Studiengruppe (German Hodgkin Study Group [GHSG]) in der Aera der ''modernen RT'' hinsichtlich intensitaetsmodulierter RT (IMRT) und bildgefuehrter RT (IGRT), aber auch hinsichtlich moderner Felddefinitionen wie bei der IN-RT angepasst wurde. In der Aera der ''modernen RT'' wurde das QAP vom radiotherapeutischen Expertenpanel der GHSG im Rahmen einiger

Radiotherapy in the management of orbital lymphoma

International Nuclear Information System (INIS)

Bolek, Timothy W.; Moyses, H. Michael; Marcus, Robert B.; Gorden, Lemuel; Maiese, Russell L.; Almasri, Nidal M.; Mendenhall, Nancy Price

1999-01-01

Purpose: This retrospective study reviews the treatment technique, disease outcome, and complications of radiotherapy used in the management of lymphoma involving the orbits. Patients and Methods: Thirty-eight patients were treated between May 1969 and January 1995, with a median follow-up of 8.3 years. All patients had biopsy-proven orbital lymphoma. Twenty patients who had limited disease were treated with curative intent, and 18 patients who had known systemic disease were treated with palliative intent. Of the 20 patients treated with curative intent, 14 had low-grade and 6 had intermediate- or high-grade disease. None received chemotherapy. Most patients received treatment with 250 kVP or 60 Co radiation, using either an en face anterior field or wedged anterior and lateral fields. Median treatment dose was 25 Gy. Lens shielding was performed if possible. For patients treated for cure, cause-specific survival and freedom from distant relapse were calculated using the Kaplan-Meier method. Results: Control of disease in the orbit was achieved in all but 1 patient, who developed an out-of-field recurrence after irradiation of a lacrimal tumor and was salvaged with further radiotherapy. In the patients treated curatively, the 5-year rate of actuarial freedom from distant relapse was 61% for those with low-grade and 33% for those with intermediate/high-grade disease (p = 0.08). Cause-specific survival at 5 years was 89% for patients with low-grade and 33% for those with intermediate/high-grade disease (p = 0.005). Two patients with low-grade disease had contralateral orbital failures; both were salvaged with further irradiation. Acute toxicity was minimal. Cataracts developed in 7 of 21 patients treated without lens shielding and 0 of 17 patients treated with lens shielding. No patient developed significant late lacrimal toxicity. Conclusion: Radiotherapy is a safe and effective local treatment in the management of orbital lymphoma

Designing the safety of healthcare. Participation of ergonomics to the design of cooperative systems in radiotherapy.

Science.gov (United States)

Munoz, Maria Isabel; Bouldi, Nadia; Barcellini, Flore; Nascimento, Adelaide

2012-01-01

This communication deals with the involvement of ergonomists in a research-action design process of a software platform in radiotherapy. The goal of the design project is to enhance patient safety by designing a workflow software that supports cooperation between professionals producing treatment in radiotherapy. The general framework of our approach is the ergonomics management of a design process, which is based in activity analysis and grounded in participatory design. Two fields are concerned by the present action: a design environment which is a participatory design process that involves software designers, caregivers as future users and ergonomists; and a reference real work setting in radiotherapy. Observations, semi-structured interviews and participatory workshops allow the characterization of activity in radiotherapy dealing with uses of cooperative tools, sources of variability and non-ruled strategies to manage the variability of the situations. This production of knowledge about work searches to enhance the articulation between technocentric and anthropocentric approaches, and helps in clarifying design requirements. An issue of this research-action is to develop a framework to define the parameters of the workflow tool, and the conditions of its deployment.

Cancer occurring after radiotherapy and chemotherapy

International Nuclear Information System (INIS)

Holm, L.E.

1990-01-01

Radiotherapy and chemotherapy can effectively control cancer but can also cause new cancers to develop as long-term complications. Almost all types of cancer have been associated with radiotherapy. The breast, thyroid, and bone marrow are the organs most susceptible to radiation carcinogenesis. The bone marrow is also most frequently involved by chemotherapy and the leukemia risk is much higher than after radiotherapy. The combination of intensive radiotherapy and chemotherapy is particularly leukemogenic. The latent period between radiotherapy/chemotherapy and the appearance of a second primary cancer ranges from a few years to several decades. The risk for a second primary cancer following radiotherapy or chemotherapy emphasizes the need for life long follow-up of patients receiving such treatments. This is particularly the case in individuals with long life expectancy, for example, patients treated for childhood neoplasms. The benefits of radiotherapy and chemotherapy in oncology exceed the risks for second primary cancers. Efforts should be directed towards identifying those patients who will benefit from the treatments so that only they are exposed to the risk. 33 references

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

International Nuclear Information System (INIS)

Ceovic, Romana; Jovanovic, Ivana; Kostovic, Kresimir; Rados, Jaka; Dotlic, Snjezana; Radman, Ivo; Kulisic, Sandra Marinovic; Loncaric, Davorin

2013-01-01

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

Improving bladder cancer treatment with radiotherapy using separate intensity modulated radiotherapy plans for boost and elective fields

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Van Rooijen, D.; Van de Kamer, J.; Hulshof, M.; Koning, C.; Bel, A. [Department of Radiation Oncology, Academic Medical Center, Amsterdam (Netherlands)

2010-06-01

The aim of this study is to investigate to what extent IMRT can decrease the dose to the organs at risk in bladder cancer treatment compared with conformal treatment while making separate treatment plans for the elective field and the boost. Special attention is paid to sparing small intestines. Twenty patients who were treated with the field-in-field technique (FiF) were re-planned with intensity modulated radiotherapy (IMRT) using five and seven beams, respectively. Separate treatment plans were made for the elective field (including the pelvic lymph nodes) and the boost, which enables position correction for bone and tumour separately. The prescribed dose was 40 Gy to the elective field and 55 or 60 Gy to the planning target volume (PTV). For bladder and rectum, V{sub 45}Gy and V{sub 55}Gy were compared, and for small intestines, V{sub 25}Gy and V{sub 40}Gy. The dose distribution with IMRT conformed better to the shape of the target. There was no significant difference between the techniques in dose to the healthy bladder. The median V{sub 40}Gy of the small intestines decreased from 114 to 66 cc (P = 0.001) with five beam IMRT, and to 55 cc (P = 0.001) with seven beam IMRT compared with FiF. V{sub 45}Gy for rectum decreased from 34.2% to 17.5% (P = 0.004) for both five and seven beam plans, while V{sub 55}Gy for rectum remained the same. With IMRT, a statistically significant dose decrease to the small intestines can be achieved while covering both tumour and elective PTV adequately.

Improving bladder cancer treatment with radiotherapy using separate intensity modulated radiotherapy plans for boost and elective fields

International Nuclear Information System (INIS)

Van Rooijen, D.; Van de Kamer, J.; Hulshof, M.; Koning, C.; Bel, A.

2010-01-01

The aim of this study is to investigate to what extent IMRT can decrease the dose to the organs at risk in bladder cancer treatment compared with conformal treatment while making separate treatment plans for the elective field and the boost. Special attention is paid to sparing small intestines. Twenty patients who were treated with the field-in-field technique (FiF) were re-planned with intensity modulated radiotherapy (IMRT) using five and seven beams, respectively. Separate treatment plans were made for the elective field (including the pelvic lymph nodes) and the boost, which enables position correction for bone and tumour separately. The prescribed dose was 40 Gy to the elective field and 55 or 60 Gy to the planning target volume (PTV). For bladder and rectum, V 45 Gy and V 55 Gy were compared, and for small intestines, V 25 Gy and V 40 Gy. The dose distribution with IMRT conformed better to the shape of the target. There was no significant difference between the techniques in dose to the healthy bladder. The median V 40 Gy of the small intestines decreased from 114 to 66 cc (P = 0.001) with five beam IMRT, and to 55 cc (P = 0.001) with seven beam IMRT compared with FiF. V 45 Gy for rectum decreased from 34.2% to 17.5% (P = 0.004) for both five and seven beam plans, while V 55 Gy for rectum remained the same. With IMRT, a statistically significant dose decrease to the small intestines can be achieved while covering both tumour and elective PTV adequately.

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).

Science.gov (United States)

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.

Multileaf collimator in radiotherapy

International Nuclear Information System (INIS)

Jeraj, M.; Robar, V.

2004-01-01

Background. Basic goal of radiotherapy treatment is the irradiation of a target volume while minimizing the amount of radiation absorbed in healthy tissue. Shaping the beam is an important way of minimizing the absorbed dose in healthy tissue and critical structures. Conventional collimator jaws are used for shaping a rectangular treatment field; but, as usually treatment volume is not rectangular, additional shaping is required. On a linear accelerator, lead blocks or individually made Cerroben TM blocks are attached onto the treatment head under standard collimating system. Another option is the use of multileaf collimator (MLC). Conclusions. Multileaf collimator is becoming the main tool for beam shaping on the linear accelerator. It is a simple and useful system in the preparation and performance of radiotherapy treatment. Multileaf collimators are reliable, as their manufacturers developed various mechanisms for their precision, control and reliability, together with reduction of leakage and transmission of radiation between and through the leaves. Multileaf collimator is known today as a very useful clinical system for simple field shaping, but its use is getting even more important in dynamic radiotherapy, with the leaves moving during irradiation. This enables a precise dose delivery on any part of a treated volume. Intensity modulated radiotherapy (IMRT), the therapy of the future, is based on the dynamic use of MLC. (author)

International Organizations Involved in Cancer Radiotherapy. Chapter 27

International Nuclear Information System (INIS)

Zietman, A.; Valentini, V.; Jimenez, P.; Luciani, S.; Gospodarowicz, M.

2017-01-01

American Society for Radiation Oncology (ASTRO): The American Society for Radiation Oncology (ASTRO) was founded in 1958 with the goal of providing a unified voice for the emerging discipline of radiation oncology. Until the 1990s, its focus was primarily academic, organizing an annual scientific and educational meeting and providing research awards and recognition. In the 1990s, however, the important role of advocacy on behalf of the specialty in Washington, DC, became increasingly clear. As in the case of most other major specialty societies in the United States of America, this is now a major thrust of ASTRO’s activities, focusing on such issues as regulation, reimbursement and safety. Along with this, the educational and research components have continued to expand. The research mission has been strengthened by the formation of the Radiation Oncology Institute, which is funded by members and vendors and which finances studies of critical importance to the specialty. The annual meeting is now a major international event and has become the biggest radiation oncology meeting in the world, with over 12 000 attendees and 2000 presentations. Fifty per cent of the presentations now come from countries outside the USA. In addition, ASTRO leads or cosponsors nine other, smaller annual or biennial meetings, with the number of attendees ranging from 300 to 2000. These include: the multidisciplinary symposia on genitourinary, gastrointestinal and breast cancers sponsored by the American Society of Clinical Oncology; a cancer imaging meeting with the Radiological Society of North America; head and neck and thoracic meetings; and intensity modulated radiation therapy and stereotactic body radiotherapy practicals with the American Association of Physicists in Medicine. European Society for Radiotherapy and Oncology (ESTRO): ESTRO has recently articulated a primary vision that will shape and influence the direction of the society’s activities in the coming years. Thus

Intraoperative radiotherapy for cancer of the pancreas

International Nuclear Information System (INIS)

Manabe, Tadao; Nagai, Toshihiro; Tobe, Takayoshi; Shibamoto, Yuta; Takahashi, Masaharu; Abe, Mitsuyuki

1985-01-01

Seven patients treated by intraoperative radiotherapy for cancer of the pancreas were evaluated. Three patients undergoing pancreaticoduodenectomy for cancer of the head of the pancreas received a dose of 2,500--3,000 rad (6--10 MeV Betatron) intraoperatively with or without external beam irradiation at a dose of 2,520 rad (10 MeV lineac X-ray). One patient developed radiation pancreatitis and died 0.8 month after surgery. Autopsy revealed the degeneration of cancer cells in the involved superior mesenteric artery. One died of hepatic metastasis 8.5 months after surgery, however, recurrence was not found in the irradiation field. The other patient who had external beam irradiation combined with intraoperative radiotherapy is alive 7.5 months after surgery. Four patients with unresectable cancer of the body of the pancreas received a dose of 2,500--3,000 rad (13--18 MeV Betatron) intraoperatively with or without external beam irradiation at a dose of 1,500--5,520 rad (10 MeV lineac X-ray). One patient died of peritonitis carcinomatosa 3.0 months after surgery. One patient died of DIC 0.6 month after surgery. Two patients are alive 1.0 and 6.5 months after surgery. In these patients with intraoperative radiotherapy for unresectable cancer of the pancreas, remarkable effects on relief of pain and shrinkage of tumor were obtained. Further pursuit of intraoperative and external beam radiotherapies in combination with pancreatectomy should be indicated in an attempt to prolong survival of patient with cancer of the pancreas. (author)

A Comparative Dosimetric Study of Adjuvant 3D Conformal Radiotherapy for Operable Stomach Cancer Versus AP-PA Conventional Radiotherapy in NCI-Cairo

International Nuclear Information System (INIS)

El-Hossiny, H.A.; Diab, N.A.; El-Taher, M.M.

2009-01-01

This study was to compare this multiple field conformal technique to the AP-PA technique with respect to target volume coverage and dose to normal tissues. Materials and Methods: Seventeen patients with stages II-III denocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy presented to radiotherapy department in National Cancer Institute, Cairo in period between February 2009 to March 2010 using 3D conformal radiotherapy technique that consisted of a mono isocentric arrangement employing 4-6 radiation fields. For each patient, a second radiotherapy treatment plan was done using an antroposterior (AP-PA) fields, the two techniques were then compared using dose volume histogram (DVH) analysis. Results: Comparing different DVHs, it was found that the planning target volume (PTV) was adequately covered in both (3D and 2D) plans while the left kidney and spinal cord demonstrate lower radiation doses on using the conformal technique. The liver doses is higher in the 3D tecq, but still well below liver tolerance. Conclusions: Both 3D conformal radiotherapy and AP-PA conventional techniques doses are within range of normal tissues tolerance. Regarding the left kidney and spinal cord the 3D conformal radiotherapy is superior than the AP-PA conventional techniques but with higher doses to the liver in the 3D conformal radiotherapy compared to the AP-PA conventional techniques

[Optimization of radiotherapy planning for non-small cell lung cancer (NSCLC) using 18FDG-PET].

Science.gov (United States)

Schmidt, S; Nestle, U; Walter, K; Licht, N; Ukena, D; Schnabel, K; Kirsch, C M

2002-10-01

In recent years, FDG-PET examinations have become more important for problems in oncology, especially in staging of bronchogenic carcinoma. In the retrospective study presented here, the influence of PET on the planning of radiotherapy for patients with non-small-cell lung cancer (NSCLC) was investigated. The study involved 39 patients with NSCLC who had been examined by PET for staging. They received radiotherapy on the basis of the anterior/posterior portals including the primary tumour and the mediastinum planned according to CT- and bronchoscopic findings. The results of the PET examination were not considered in initial radiotherapy planning. The portals were retrospectively redefined on the basis of FDG uptake considering the size and localization of the primary tumour; and FDG activities outside the mediastinal part of the portals. In 15 out of 39 patients, the CT/PET-planned portals differed from the CT-planned ones. In most causes (n = 12) the CT/PET field was smaller than the CT field. The median geometric field size of the portals was 179 cm2, after redefinition using PET 166 cm2. In 20 patients with disturbed ventilation caused by the tumour (atelectasis, dystelectosis), a correction of the portal was suggested significantly more frequently than in the other patients (p = 0.03). Our results demonstrate the synergism of topographical (CT) and metabolic (FDG-PET) information, which could be helpful in planning radiotherapy of bronchial carcinoma, especially for patients with disturbed ventilation.

Pulse-resolved radiotherapy dosimetry using fiber-coupled organic scintillators

DEFF Research Database (Denmark)

Beierholm, Anders Ravnsborg

scintillators and can be perceived as a well characterized, independent alternative to the methods that are in clinical use today. The dosimeter itself does not require a voltage supply, and is composed of water equivalent materials. The dosimeter can be fabricated with a sensitive volume smaller than a cubic...... millimeter, which is small enough to resolve the small radiation fields encountered in modern radiotherapy. The fast readout of the dosimeter enables measurements on the same time scale as the pulsed radiation delivery from the medical linear accelerators used for treatment. The dosimetry system, comprising...... for both standard and small fields. This thesis concludes that the new pulse-resolved dosimetry system holds great potential for modern radiotherapy applications, such as stereotactic radiotherapy and intensity-modulated radiotherapy....

Telemedicine in radiotherapy treatment planning: requirements and applications

International Nuclear Information System (INIS)

Olsen, D.R.; Bruland, O.S.; Davis, B.J.

2000-01-01

Telemedicine facilitates decentralized radiotherapy services by allowing remote treatment planning and quality assurance of treatment delivery. A prerequisite is digital storage of relevant data and an efficient and reliable telecommunication system between satellite units and the main radiotherapy clinic. The requirements of a telemedicine system in radiotherapy is influenced by the level of support needed. In this paper we differentiate between three categories of telemedicine support in radiotherapy. Level 1 features video conferencing and display of radiotherapy images and dose plans. Level 2 involves replication of selected data from the radiotherapy database - facilitating remote treatment planning and evaluation. Level 3 includes real-time, remote operations, e.g. target volume delineation and treatment planning performed by the team at the satellite unit under supervision and guidance from more experienced colleagues at the main clinic. (author)

Costing in Radiotherapy. Chapter 18

International Nuclear Information System (INIS)

Zubizarreta, E.; Lievens, Y.; Levin, V.C.; Van Der Merwe, D.

2017-01-01

The available literature on the cost of radiotherapy yields a large variation in data related to the specifics of the methodology used (the viewpoint of the analysis, time frame, health care system, etc.) and to the cost components and radiotherapy activities included. To overcome this difficulty, the reimbursement paid by medical insurance is commonly used as a proxy for the actual radiotherapy costs. Costs, however, generally bear little or no resemblance to charges, as the latter also include allowances for non-capacity use and profit margins. Accurate resource cost data are therefore more valid and should ideally be used in the context of economic evaluations and public health provisions. In addition to the theoretical problems related to obtaining accurate costs, it is difficult to interpret cost data across country borders because of differences in economics. If this is already the case for high income countries, using these cost data for low and middle income countries (LMICs) is even more problematic. Thus, there clearly is a need for calculations performed from the viewpoint of LMICs to prevent misapprehensions based on conclusions derived from data from their high income counterparts. The IAEA endeavours to assist Member States in accumulating appropriate and sufficient cost data for the initiation or expansion of radiation oncology services. Although relatively simple and easy to understand, the IAEA has found that in many countries where it has been involved in the establishment of new radiotherapy departments, the basic principles of cost calculation for radiotherapy facilities were not followed by the local planners. Radiotherapy needs careful planning, organization and a strong quality assurance (QA) programme in order to deliver safe treatments, due to the complexity of the planning and treatment process and the possibility of systematic errors. Administrators should be aware that the cost of building a radiotherapy facility and buying machines

Capillary haemangioma involving the middle and external ear: radiotherapy as a treatment method

International Nuclear Information System (INIS)

Pavamani, S.P.; Ram, T.S.; Viswanathan, P.N.; Viswanathan, F.R.; Surendrababu, N.R.S.; Thomas, M.

2007-01-01

Capillary haemangiomas rarely occur in the auditory canal and have mainly been managed with surgical excision or kept on close follow up for development of symptoms. Radiotherapy, as a treatment method, has not been reported previously in the published work. We describe a study of a capillary haemangioma in the auditory canal of a 26-year-old woman who presented with bleeding. She was treated with radiotherapy, after the lesion was found to be unsuitable for surgery and embolization. The patient remains well 5 years after completion of treatment

Comparison of metastatic disease after local tumour treatment with radiotherapy or surgery in various tumour models

International Nuclear Information System (INIS)

Ruiter, J. de; Cramer, S.J.; Lelieveld, P.; Putten, L.M. van

1982-01-01

Spontaneous metastases in lymph nodes and/or the lung were obtained after tumour cell inoculation of four mouse tumours and one rat tumour into the foot-pads of syngeneic animals or their F 1 hybrids. Following local radiotherapy with doses of 45-80 Gy, significantly more mice died with metastases than following local amputation of the tumour-bearing foot when the 2661 carcinoma was involved. No significant difference was observed after these treatments for the other tumours. The enhancement of metastatic growth after local radiotherapy in the 2661 carcinoma seems not to be due to incomplete killing of tumour cells in the foot. The presence of irradiated normal structures and tumour tissue after radiotherapy promoted the outgrowth of 2661 carcinoma cells which were outside the radiation field at the time of treatment. Evidently, even under similar experimental conditions, radiotherapy may enhance the growth of metastases from some tumours and not from others. (author)

Prospective randomized trail on chrono-chemotherapy + late course three dimensional conformal radio-therapy and conventional chemotherapy plus radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Jin Feng; Ouyang Jinling; Dong Hongmin; Wu Weili; Chen Haixia; He Zhihui

2005-01-01

Objective: To compare the therapeutic effects, toxic side effects of late-course three dimensional conformal radiotherapy plus chrono-chemotherapy (DDP + 5-FU/CF) and conventional radiotherapy plus chemotherapy for nasopharyngeal carcinoma (NPC). Methods: Eighty -six NPC patients admitted from Feb. 2001 to Jan. 2002 were divided randomly into two groups: 1. Chrono-chemotherapy + late course three dimensional conformal radiotherapy(CCR) group-44 patients were treated by late course three dimensional conformal radio-therapy plus chrono-chemotherapy, and 2. Routine-chemotherapy-radiotherapy (RCR) group-42 patients were treated by routine chemotherapy plus radiotherapy. The patients in CCR and RCR group were comparable in age, KPS, stage and pathology. All patients were treated by combined chemotherapy and radiotherapy, with chemotherapy stared 2 weeks ahead of radiotherapy. Chemotherapy: Braun pump was used in all drug infusions; 1. CCR group-DDP 80 mg/ m 2 starting from 10:00 until 22:00, 5-Fu 750 mg/d/m 2 starting from 22:00 until 10:00 next day, CF 200 mg/d/m 2 starting from 10:00 every day, infused at normal speed. These drugs were given for 3 days, 14 days as one cycle, totally 2 cycle, and 2. RCR group-with the same drugs at the same total dose, only with the difference being DDP and CF given QD, starting from 10:00 but at the normal speed. 5-Fu was given through-out the day and continuously for 3 days, totally for 2 cycles. Radiotherapy: linear accelerator irradiation was given to either group. Composite facio-cervical field + anterior cervical tangential field to D T 40 Gy/4w, followed by the coned down per-auricular field plus anterior tangential field or β beam irradiation. In CCR group, after D T 40gy/4w, late course 3-dimensional conformal radiotherapy (3DCRT) was used to add D T 30Gy/3w. In RCR group, routine radiotherapy of 40 Gy/w was supplemented with 30 Gy/3w. The total dose in either group was 70 Gy/7w at the nasopharynx, D T 60-70 Gy/6-7w at the

Quality assurance procedure for assessing mechanical accuracy of a radiation field center in stereotactic radiotherapy

International Nuclear Information System (INIS)

Tatsumi, Daisaku; Ienaga, Akinori; Nakada, Ryosei; Yomoda, Akane; Inoue, Makoto; Ichida, Takao; Hosono, Masako

2012-01-01

Stereotactic radiotherapy requires a quality assurance (QA) program that ensures the mechanical accuracy of a radiation field center. We have proposed a QA method for achieving the above requirement by conducting the Winston Lutz test using an electronic portal image device (EPID). An action limit was defined as three times the standard deviation. Then, the action limits for mean deviations of the radiation field center during collimator rotation, gantry rotation, and couch rotation in clockwise and counterclockwise resulted in 0.11 mm, 0.52 mm, 0.37 mm, and 0.41 mm respectively. Two years after the QA program was launched, the mean deviation of the radiation field center during gantry rotation exceeded the above action limit. Consequently, a mechanical adjustment for the gantry was performed, thereby restoring the accuracy of the radiation field center. A field center shift of 0.5 mm was also observed after a micro multi-leaf collimator was unmounted. (author)

Dosimetric and geometric evaluation of an open low-field magnetic resonance simulator for radiotherapy treatment planning of brain tumours

DEFF Research Database (Denmark)

Kristensen, B.H.; Laursen, F.J.; Logager, V.

2008-01-01

Background and purpose: Magnetic resonance (MR) imaging is superior to computed tomography (CT) in radiotherapy of brain tumours. In this study an open low-field MR-simulator is evaluated in order to eliminate the cost of and time spent on additional CT scanning. Materials and methods: Eleven...

Two cases with giant lung abscess originating in the irradiated lung field following the concurrent chemo-radiotherapy of lung cancer

Energy Technology Data Exchange (ETDEWEB)

Ikeda, Takeshi; Inui, Hiroyuki; Yukawa, Susumu; Nomoto, Hiroshi (Wakayama Medical Coll. (Japan)); Minakata, Yoshiaki; Yamagata, Toshiyuki

1992-05-01

Two patients with giant lung abscess originating in the irradiated lung field are reported. Lung abscesses occurred during the term of leukopenia following the concurrent chemo-radiotherapy of lung cancer. Both patients were diagnosed as small cell lung cancer, and were treated concurrently with chemotherapy (Cisplatin + Etoposide) and radiotherapy (total 40-50 Gy). Case 1 was a 59 years old male. Seven weeks after the first irradiation, a giant lung abscess was caused by methicillin resistant staphylococcus aureus (MRSA) originated in the lung field with radiation pneumonitis, and giant bronchial fistula was formed, that showed the specific bronchofiberscopic findings. Case 2 was a 67 years old male. Twelve weeks after the first irradiation, a giant lung abscess was caused by pseudomonas aeruginosa originated in the irradiated lung field following the formation of a pneumatocele. MRSA and pseudomonas aeruginosa are important as cause of hospital infection, and both can cause lung abscess. However, in our cases, lung abscess were formed just in the irradiated lung field and rapidly enlarged. These clinical findings suggested that myelosuppression and radiation injury of lung tissue might cause such giant lung abscess. (author).

Two cases with giant lung abscess originating in the irradiated lung field following the concurrent chemo-radiotherapy of lung cancer

International Nuclear Information System (INIS)

Ikeda, Takeshi; Inui, Hiroyuki; Yukawa, Susumu; Nomoto, Hiroshi; Minakata, Yoshiaki; Yamagata, Toshiyuki.

1992-01-01

Two patients with giant lung abscess originating in the irradiated lung field are reported. Lung abscesses occurred during the term of leukopenia following the concurrent chemo-radiotherapy of lung cancer. Both patients were diagnosed as small cell lung cancer, and were treated concurrently with chemotherapy (Cisplatin + Etoposide) and radiotherapy (total 40-50 Gy). Case 1 was a 59 years old male. Seven weeks after the first irradiation, a giant lung abscess was caused by methicillin resistant staphylococcus aureus (MRSA) originated in the lung field with radiation pneumonitis, and giant bronchial fistula was formed, that showed the specific bronchofiberscopic findings. Case 2 was a 67 years old male. Twelve weeks after the first irradiation, a giant lung abscess was caused by pseudomonas aeruginosa originated in the irradiated lung field following the formation of a pneumatocele. MRSA and pseudomonas aeruginosa are important as cause of hospital infection, and both can cause lung abscess. However, in our cases, lung abscess were formed just in the irradiated lung field and rapidly enlarged. These clinical findings suggested that myelosuppression and radiation injury of lung tissue might cause such giant lung abscess. (author)

Implementation of a security system in the radiotherapy process

International Nuclear Information System (INIS)

Orellana Salas, A.; Melgar Perez, J.; Arrocha Aceveda, J. F.

2011-01-01

Systems of work within the field of health are complex. Even the most routine activities involving chain and coordinate a number of actions to be developed by different professionals of different specialties. These systems often fail due to a combination of small errors along the process, each insufficient to cause an accident. We must ensure safe systems of work for each process we are involved, so it is essential to implement security systems to evaluate and find the vulnerabilities in all phases of the process. In the Service of Radio Physics and Radiation Protection of Punta de Europa Hospital has implemented a security system for radiotherapy process after the analysis and evaluation of the safety culture of the Service.

Lumboaortic radiotherapy in patients with cervical cancer. Experience of the National Cancer Institute

International Nuclear Information System (INIS)

Santini B, Alejandro; Becerra S, Sergio; Gayan G, Patricio; Carcamo I, Marcela; Bianchi G, Benjamin

2010-01-01

Background: Uterine cancer is still a prevalent disease in Chile. Is common to treat patients with tumors in stages IIB and IIIB where the risk of pelvic and paraortic limph node involvement is very high. Its treatment is radio-chemotherapy. Objective: To present a retrospective analysis of patients that suffered cervix-uterine cancer who were treated with radiotherapy including the aortic-lumbar area. Methods: From the revision of patients who were treated of cervix-uterine cancer between the years 1995 and 2007, 39 were treated including aortic-lumbar chains. Evolution and toxicity were analyzed. Two radiotherapy techniques were used. The first one, during the nineties, included two parallel previous and later and opposed fields, and a second technique, currently used, where pelvis and paraortic are radiated at the same time through four lateral (AP-PA) fields. Results: The dosimeter analysis of both techniques shows that there is a higher volume of radiated normal tissue with the two fields techniques, mainly in the small bowel. On the other hand, the toxicity was significantly different being today's technique less toxic and showing low gastrointestinal

Cranial radiotherapy guided by computed tomography with or without fields conformation in pediatric

International Nuclear Information System (INIS)

Fernandez, Diego; Caussa, Lucas; Murina, Patricia; Zunino, Silvia

2007-01-01

Many malignancies in children can be cured by radiotherapy, acute toxicity and the significant effect of delayed treatment are worrying for the patient, family and society. Therefore, the end of the pediatric radiotherapy is to maintain or improve the cure rate of cancer, diminishing the aftermath of treatment. The goal of this study is to measure differences in doses to the healthy tissue of the central nervous system with two radiotherapy techniques, both guided by computed tomography [es

Radiotherapy in supratentorial gliomas. A study of 821 cases

International Nuclear Information System (INIS)

Heesters, M.; Molenaar, W.; Go, G.K.

2003-01-01

Purpose: Analysis of the results of radiotherapy in a large group of cerebral gliomas with identification of prognostic factors and the outcome with respect to different decades of treatment. Patients and Methods: Two decades (1979-1999) of radiotherapy in supratentorial astrocytic and oligodendroglial tumors (n = 821) at the University Hospital Groningen were retrospectively evaluated. Prognostic factors for survival were analyzed. Two decades of radiotherapy treatment were compared with respect to radiotherapy dose and treatment-field design. Results: Glioblastoma multiforme, including gliosarcoma, was the most frequent supratentorial glioma (n = 442) with a poor survival, i.e., median survival time (MST) 7 months, especially in patients > 50 years of age and with poor performance. Patients with good performance were selected for radiotherapy with an optimum dose of 60 Gy local-field irradiation. However, in patients with poor prognosis, no radiotherapy was applied or a shorter treatment scheme was given. Anaplastic astrocytomas (n = 131) were treated in the same way as glioblastoma multiforme. Over time, a decrease in radiation dose (from 60 to 45 Gy) and from whole brain irradiation to local-field treatment was observed, following the literature. In low-grade gliomas, prognostic factors for survival were age, performance, and extent of resection. Gemistocytic astrocytoma (n = 15) had an inferior survival compared to astrocytoma (MST 46 vs. 54 months), but a superior survival compared to anaplastic astrocytoma (MST 10 months). The presence of an oligodendroglial component in a glioma implied a superior survival compared to the astrocytic gliomas. The inherent biology of the glioma is reflected by the study of recurrent tumors with progression to higher grades of malignancy in 32-40% and by the histology of recurrent oligodendroglial tumors. In comparing two decades of radiotherapy in gliomas, no differences in survival were observed despite the technological

Radiotherapy in supratentorial gliomas. A study of 821 cases

Energy Technology Data Exchange (ETDEWEB)

Heesters, M. [Dept. of Radiotherapy, Groningen Univ. Hospital (Netherlands); Molenaar, W. [Dept. of Pathology, Groningen Univ. Hospital (Netherlands); Go, G.K. [Dept. of Neurosurgery, Groningen Univ. Hospital (Netherlands)

2003-09-01

Purpose: Analysis of the results of radiotherapy in a large group of cerebral gliomas with identification of prognostic factors and the outcome with respect to different decades of treatment. Patients and Methods: Two decades (1979-1999) of radiotherapy in supratentorial astrocytic and oligodendroglial tumors (n = 821) at the University Hospital Groningen were retrospectively evaluated. Prognostic factors for survival were analyzed. Two decades of radiotherapy treatment were compared with respect to radiotherapy dose and treatment-field design. Results: Glioblastoma multiforme, including gliosarcoma, was the most frequent supratentorial glioma (n = 442) with a poor survival, i.e., median survival time (MST) 7 months, especially in patients > 50 years of age and with poor performance. Patients with good performance were selected for radiotherapy with an optimum dose of 60 Gy local-field irradiation. However, in patients with poor prognosis, no radiotherapy was applied or a shorter treatment scheme was given. Anaplastic astrocytomas (n = 131) were treated in the same way as glioblastoma multiforme. Over time, a decrease in radiation dose (from 60 to 45 Gy) and from whole brain irradiation to local-field treatment was observed, following the literature. In low-grade gliomas, prognostic factors for survival were age, performance, and extent of resection. Gemistocytic astrocytoma (n = 15) had an inferior survival compared to astrocytoma (MST 46 vs. 54 months), but a superior survival compared to anaplastic astrocytoma (MST 10 months). The presence of an oligodendroglial component in a glioma implied a superior survival compared to the astrocytic gliomas. The inherent biology of the glioma is reflected by the study of recurrent tumors with progression to higher grades of malignancy in 32-40% and by the histology of recurrent oligodendroglial tumors. In comparing two decades of radiotherapy in gliomas, no differences in survival were observed despite the technological

Poster - 21: Verification of Monitor Unit Calculations for Breast Field-In-Field Three-Dimensional Conformal Radiotherapy Plans

International Nuclear Information System (INIS)

Kosztyla, Robert; Pierce, Greg; Ploquin, Nicolas; Roumeliotis, Michael; Schinkel, Colleen

2016-01-01

Purpose: To determine the source of systematic monitor unit (MU) calculation discrepancies between RadCalc and Eclipse treatment planning software for three-dimensional conformal radiotherapy field-in-field breast treatments. Methods: Data were reviewed for 28 patients treated with a field-in-field breast technique with MU calculations from RadCalc that were larger than MU calculations from Eclipse for at least one field. The distance of the calculation point from the jaws was measured in each field’s beam’s-eye-view and compared with the percentage difference in MU (%ΔMU) between RadCalc and Eclipse. 10×10, 17×13 and 20×20 cm 2 beam profiles were measured using the Profiler 2 diode array for 6-MV photon beams and compared with profiles calculated with Eclipse and RadCalc using a gamma analysis (3%, 3 mm). Results: The mean %ΔMU was 1.3%±0.3%. There was a statistically-significant correlation between %ΔMU and the distance of the calculation point from the Y jaw (r=−0.43, p<0.001). RadCalc profiles differed from measured profiles, especially near the jaws. The gamma pass rate for 6-MV fields of 17×13 cm 2 field size was 95%±1% for Eclipse-generated profiles and 53%±20% for RadCalc-generated profiles (p=0.01). Conclusions: Calculations using RadCalc for field-in-field breast plans resulted in MUs that were larger than expected from previous clinical experience with wedged plans with calculation points far from the jaws due to the position of the calculation point near the jaws in the beam’s-eye-view of each field.

Poster - 21: Verification of Monitor Unit Calculations for Breast Field-In-Field Three-Dimensional Conformal Radiotherapy Plans

Energy Technology Data Exchange (ETDEWEB)

Kosztyla, Robert; Pierce, Greg; Ploquin, Nicolas; Roumeliotis, Michael; Schinkel, Colleen [Tom Baker Cancer Centre, Calgary, AB, Tom Baker Cancer Centre, Tom Baker Cancer Centre, Tom Baker Cancer Centre, Calgary, AB, Tom Baker Cancer Centre, Calgary, AB (Canada)

2016-08-15

Purpose: To determine the source of systematic monitor unit (MU) calculation discrepancies between RadCalc and Eclipse treatment planning software for three-dimensional conformal radiotherapy field-in-field breast treatments. Methods: Data were reviewed for 28 patients treated with a field-in-field breast technique with MU calculations from RadCalc that were larger than MU calculations from Eclipse for at least one field. The distance of the calculation point from the jaws was measured in each field’s beam’s-eye-view and compared with the percentage difference in MU (%ΔMU) between RadCalc and Eclipse. 10×10, 17×13 and 20×20 cm{sup 2} beam profiles were measured using the Profiler 2 diode array for 6-MV photon beams and compared with profiles calculated with Eclipse and RadCalc using a gamma analysis (3%, 3 mm). Results: The mean %ΔMU was 1.3%±0.3%. There was a statistically-significant correlation between %ΔMU and the distance of the calculation point from the Y jaw (r=−0.43, p<0.001). RadCalc profiles differed from measured profiles, especially near the jaws. The gamma pass rate for 6-MV fields of 17×13 cm{sup 2} field size was 95%±1% for Eclipse-generated profiles and 53%±20% for RadCalc-generated profiles (p=0.01). Conclusions: Calculations using RadCalc for field-in-field breast plans resulted in MUs that were larger than expected from previous clinical experience with wedged plans with calculation points far from the jaws due to the position of the calculation point near the jaws in the beam’s-eye-view of each field.

Imaging and concomitant dose in radiotherapy

International Nuclear Information System (INIS)

Negi, P.S.

2008-01-01

Image guidance in radiotherapy now involves multiple imaging procedures for planning, simulation, set-up inter and intrafraction monitoring. Presently ALARA (i.e. as low as reasonable achievable) is the principle of management of dose to radiation workers and patients in any diagnostic imaging procedures including image guided surgery. The situation is different in repeated radiographic/fluoroscopic imaging performed for simulation, dose planning, patient positioning and set-up corrections during preparation/execution of Image guided radiotherapy (IGRT) as well as for Intensity Modulated Radiotherapy (IMRT). Reported imaging and concomitant doses will be highlighted and discussed for the management and optimization of imaging techniques in IMRT and IGRT

Evaluating efficiency of split VMAT plan for prostate cancer radiotherapy involving pelvic lymph nodes

Energy Technology Data Exchange (ETDEWEB)

Mun, Jun Ki; Son, Sang Jun; Kim, Dae Ho; Seo, Seok Jin [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

2015-12-15

The purpose of this study is to evaluate the efficiency of Split VMAT planning(Contouring rectum divided into an upper and a lower for reduce rectum dose) compare to Conventional VMAT planning(Contouring whole rectum) for prostate cancer radiotherapy involving pelvic lymph nodes. A total of 9 cases were enrolled. Each case received radiotherapy with Split VMAT planning to the prostate involving pelvic lymph nodes. Treatment was delivered using TrueBeam STX(Varian Medical Systems, USA) and planned on Eclipse(Ver. 10.0.42, Varian, USA), PRO3(Progressive Resolution Optimizer 10.0.28), AAA(Anisotropic Analytic Algorithm Ver. 10.0.28). Lower rectum contour was defined as starting 1 cm superior and ending 1 cm inferior to the prostate PTV, upper rectum is a part, except lower rectum from the whole rectum. Split VMAT plan parameters consisted of 10 MV coplanar 360° arcs. Each arc had 30° and 30° collimator angle, respectively. An SIB(Simultaneous Integrated Boost) treatment prescription was employed delivering 50.4 Gy to pelvic lymph nodes and 63- 70 Gy to the prostate in 28 fractions. D{sub mean} of whole rectum on Split VMAT plan was applied for DVC(Dose Volume Constraint) of the whole rectum for Conventional VMAT plan. In addition, all parameters were set to be the same of existing treatment plans. To minimize the dose difference that shows up randomly on optimizing, all plans were optimized and calculated twice respectively using a 0.2 cm grid. All plans were normalized to the prostate PTV{sub 100%} = 90% or 95%. A comparison of D{sub mean} of whole rectum, upperr ectum, lower rectum, and bladder, V{sub 50%} of upper rectum, total MU and H.I.(Homogeneity Index) and C.I.(Conformity Index) of the PTV was used for technique evaluation. All Split VMAT plans were verified by gamma test with portal dosimetry using EPID. Using DVH analysis, a difference between the Conventional and the Split VMAT plans was demonstrated. The Split VMAT plan demonstrated better in the D

Postoperative radiotherapy for prostate cancer. Morbidity of local-only or local-plus-pelvic radiotherapy

International Nuclear Information System (INIS)

Waldstein, Cora; Poetter, Richard; Widder, Joachim; Goldner, Gregor; Doerr, Wolfgang

2018-01-01

The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer. Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups. For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5-year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5-year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%. Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4-field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects. (orig.) [de

Evaluation of compensation in breast radiotherapy: a planning study using multiple static fields

International Nuclear Information System (INIS)

Donovan, Ellen M.; Johnson, Ursula; Shentall, Glyn; Evans, Philip M.; Neal, Anthony J.; Yarnold, John R.

2000-01-01

Purpose: A method that uses electronic portal imaging to design intensity-modulated beams for compensation in breast radiotherapy was implemented using multiple static fields in a planning study. We present the results of the study to verify the algorithm, and to assess improvements to the dosimetry. Methods and Materials: Fourteen patients were imaged with computed tomography (CT) and on a treatment unit using an electronic portal imager. The portal imaging data were used to design intensity-modulated beams to give an ideal dose distribution in the breast. These beams were implemented as multiple static fields added to standard wedged tangential fields. Planning of these treatments was performed on a commercial treatment planning system (Target 2, IGE Medical Systems, Slough, U.K.) using the CT data for each patient. Dose-volume histogram (DVH) analysis of the plans with and without multileaf collimator (MLC) compensation was carried out. This work has been used as the basis for a randomized clinical trial investigating whether improvements in dosimetry are correlated with the reduction of long-term side effects from breast radiotherapy. Results: The planning analysis showed a mean increase in target volume receiving 95-105% of prescribed dose of 7.5% (range -0.8% to 15.9%) when additional MLC compensation was applied. There was no change to the minimum dose for all 14 patient data sets. The change in the volume of breast tissue receiving over 105% of prescribed dose, when applying MLC compensation, was between -1.4% and 11.9%, with positive numbers indicating an improvement. These effects showed a correlation with breast size; the larger the breast the greater the amount of improvement. Conclusions: The method for designing compensation for breast treatments using an electronic portal imager has been verified using planning on CT data for 14 patients. An improvement was seen in planning when applying MLC compensation and this effect was greater the larger the

Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

International Nuclear Information System (INIS)

Hamilton, Russell J.; Kuchnir, Franca T.; Sweeney, Patrick; Rubin, Steven J.; Dujovny, Manuel; Pelizzari, Charles A.; Chen, George T. Y.

1995-01-01

Purpose: Compare the use of static conformal fields with the use of multiple noncoplanar arcs for stereotactic radiosurgery or stereotactic radiotherapy treatment of intracranial lesions. Evaluate the efficacy of these treatment techniques to deliver dose distributions comparable to those considered acceptable in current radiotherapy practice. Methods and Materials: A previously treated radiosurgery case of a patient presenting with an irregularly shaped intracranial lesion was selected. Using a three-dimensional (3D) treatment-planning system, treatment plans using a single isocenter multiple noncoplanar arc technique and multiple noncoplanar conformal static fields were generated. Isodose distributions and dose volume histograms (DVHs) were computed for each treatment plan. We required that the 80% (of maximum dose) isodose surface enclose the target volume for all treatment plans. The prescription isodose was set equal to the minimum target isodose. The DVHs were analyzed to evaluate and compare the different treatment plans. Results: The dose distribution in the target volume becomes more uniform as the number of conformal fields increases. The volume of normal tissue receiving low doses (> 10% of prescription isodose) increases as the number of static fields increases. The single isocenter multiple arc plan treats the greatest volume of normal tissue to low doses, approximately 1.6 times more volume than that treated by four static fields. The volume of normal tissue receiving high (> 90% of prescription isodose) and intermediate (> 50% of prescription isodose) doses decreases by 29 and 22%, respectively, as the number of static fields is increased from four to eight. Increasing the number of static fields to 12 only further reduces the high and intermediate dose volumes by 10 and 6%, respectively. The volume receiving the prescription dose is more than 3.5 times larger than the target volume for all treatment plans. Conclusions: Use of a multiple noncoplanar

MR-only Radiotherapy of prostate cancer

OpenAIRE

Maspero, Matteo

2018-01-01

Radiotherapy is a local approach that involves the use of ionising radiation by exploiting its cell-killing effect to cure cancer. This effect, however, is not specific to damage only cancerous cells and spare healthy cells. Therefore, developments in radiotherapy aimed at reducing treatment uncertainties such that therapeutic radiation dose may be delivered to a malignant tumour while decreasing the dose received by healthy tissues. The recent advances in imaging techniques impacted and radi...

Why Radiotherapy Works. Chapter 6

International Nuclear Information System (INIS)

Tashiro, S.; Nishibuchi, I.; Wondergem, J.

2017-01-01

The history of radiotherapy began in 1895, when Röntgen discovered X rays, and in the following year, radiation was used for medical treatment. In the early days, the development of radiotherapy was based extensively on empiricism. Radiotherapists worked closely with radiation biologists in attempting to describe and understand the phenomena produced by ionizing radiation in the clinic and in biological systems. During the ensuing 120 years, radiotherapy has been improved significantly and, in addition to radiation biology, medical physics has played an important role in the design and development of equipment, quality assurance and dosimetry. Over recent decades, advances have been made in the field of molecular biology. Currently available techniques enable us to elucidate the molecular mechanisms of cellular response to ionizing irradiation, and it is anticipated that the role and contributions of radiation biology in radiotherapy will remain relevant. This chapter describes the clinically important biological points, including knowledge from current molecular biology.

Reproduction of set-up of the fields in x-ray radiotherapy

International Nuclear Information System (INIS)

Izawa, Kazuo; Hata, Kiyoshi; Sasaki, Junichi; Matsugi, Shunpei; Takeshita, Masanori; Okamoto, Hideaki; Nakajima, Tadashi

1985-01-01

We measured the reproducibility of the field in radiotherapy by lineacgram and carried out the measurement of the following sites such as the larynx, pharynx, whole brain and the whole pelvis. The measurement points are 5 in the head and neck, and 7 in pelvis. The data of this study were obtained from 536 film sheets for 62 patients during May 1983 to September 1983 period. We used the XTL-5 localization film and Kyokko GF intensifying screen. The reproducibility error was decided with the use of the average and standard deviations. The following results were obtained: 1) The site that has the minimal error is larynx with 4.8 mm; the maximal error is whole brain with 11.2 mm; and the whole pelvis with 6 mm. 2) The fixing device is always needed at the head and neck site. 3) Using the fixing device, it was comfirmed that the reproducibility error of the field is due to arrangement of place rather than the patients movement during the treatment time. We further aim, to reduce the scattering shown by the standard deviation than the one by the average value. (author)

Radiological diagnostics and radiotherapy in Wilms' tumor

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Kutzner, J

1981-01-01

The possibilities of diagnosing Wilms' tumor correctly have been greatly extended by the introduction of computerised tomography and ultrasonic examination. In view of the fact that Wilms' tumor is subjected to combined treatment involving chemotherapy, surgery and radiotherapy, it appears justified to reduce the dose to 20-30 Gy, depending upon the age of the child and the extension of the tumor. It is believed that preoperative radiotherapy will yield better surgical possibilities in large tumours. Radiotherapy can be omitted in infants in the stages I and II as well as in children in stage I.

CNR considerations for rapid real-time MRI tumor tracking in radiotherapy hybrid devices: Effects of B0 field strength

International Nuclear Information System (INIS)

Wachowicz, K.; De Zanche, N.; Yip, E.; Volotovskyy, V.; Fallone, B. G.

2016-01-01

Purpose: This work examines the subject of contrast-to-noise ratio (CNR), specifically between tumor and tissue background, and its dependence on the MRI field strength, B 0 . This examination is motivated by the recent interest and developments in MRI/radiotherapy hybrids where real-time imaging can be used to guide treatment beams. The ability to distinguish a tumor from background tissue is of primary importance in this field, and this work seeks to elucidate the complex relationship between the CNR and B 0 that is too often assumed to be purely linear. Methods: Experimentally based models of B 0 -dependant relaxation for various tumor and normal tissues from the literature were used in conjunction with signal equations for MR sequences suitable for rapid real-time imaging to develop field-dependent predictions for CNR. These CNR models were developed for liver, lung, breast, glioma, and kidney tumors for spoiled gradient-echo, balanced steady-state free precession (bSSFP), and single-shot half-Fourier fast spin echo sequences. Results: Due to the pattern in which the relaxation properties of tissues are found to vary over B 0 field (specifically the T 1 time), there was always an improved CNR at lower fields compared to linear dependency. Further, in some tumor sites, the CNR at lower fields was found to be comparable to, or sometimes higher than those at higher fields (i.e., bSSFP CNR for glioma, kidney, and liver tumors). Conclusions: In terms of CNR, lower B 0 fields have been shown to perform as well or better than higher fields for some tumor sites due to superior T 1 contrast. In other sites this effect was less pronounced, reversing the CNR advantage. This complex relationship between CNR and B 0 reveals both low and high magnetic fields as viable options for tumor tracking in MRI/radiotherapy hybrids.

Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam

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Al-Ghamdi, H.; Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Maalej, N. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

2008-08-15

In X-ray radiotherapy accelerators, neutrons are produced mainly by ({gamma},n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam and contribute to the patient dose during the treatment of a cancer patient. Knowing the neutron distribution around the radiotherapy accelerator is therefore desired. CR-39 nuclear track detectors (NTDs) were used to study the variation of fast and thermal neutron relative intensities around an 18 MeV linear accelerator X-ray beam with the field sizes of 0, 10x10, 20x20, 30x30 and 40x40cm{sup 2}. For fast neutron detection, bare NTDs were used. For thermal neutron detection, NTDs were covered with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters. The NTDs were placed at different locations in the direction perpendicular to the treatment couch (transversal) and in the direction parallel to the treatment couch (longitudinal) with respect to the isocenter of the accelerator. The fast neutron relative intensity is symmetrical about the beam axis and exhibits an exponential-like drop with distance from the isocenter of the accelerator for all the field sizes. At the primary beam (isocenter), the relative fast neutron intensity is highest for 40x40cm{sup 2} field size and decreases linearly with the decrease in the field size. However, fast neutron intensities do not change significantly with beam size for the measurements outside the primary beam. The fast neutron intensity in the longitudinal direction outside the primary beam decreases linearly with the field size. The thermal neutron intensity, at any location, was found to be almost independent of the field size.

Four R's of radiotherapy

International Nuclear Information System (INIS)

Withers, H.R.

1975-01-01

Radiotherapy given as multiple doses can be effective in sterilizing cancers, but the processes whereby the neoplasm is eradicated and the normal tissues are preserved are not fully understood. The differential between normal tissue and tumor response is enhanced by dose fractionation, single doses resulting in severe normal tissue injury when the dose is sufficient to control a proportion of treated tumors. Data are reviewed from radiobiological studies on laboratory animals and cultured cells that have thrown some light on four of the phenomena that influence the outcome of fractionated-dose radiotherapy, one or more of which may account for the relative sparing of normal tissues. These are repair of sublethal injury in normal and neoplastic cells, reoxygenation of the tumor, redistribution through the division cycle, and regeneration of surviving normal and malignant cells between dose fractions. These have been called the four R's of fractionated radiotherapy. Other factors are involved in the outcome of multifraction radiotherapy, including maintenance of the architectural integrity of the normal tissues, the volume of tissue irradi []ted, the tumor bed, and the immunocompetence of the host. (90 references) (CH)

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

International Nuclear Information System (INIS)

Pierga, J.Y.; Girinski, T.; Henry-Amar, M.; Maunoury, C.; Valette, H.; Tchernia, G.; Desgrez, A.; Socie, G.; Cosset, J.M.

1993-01-01

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

Proton beam radiotherapy of iris melanoma

International Nuclear Information System (INIS)

Damato, Bertil; Kacperek, Andrzej; Chopra, Mona; Sheen, Martin A.; Campbell, Ian R.; Errington, R. Douglas

2005-01-01

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

Testicular dose and hormonal changes after radiotherapy of rectal cancer

International Nuclear Information System (INIS)

Hermann, Robert M.; Henkel, Karsten; Christiansen, Hans; Vorwerk, Hilke; Hille, Andrea; Hess, Clemens F.; Schmidberger, Heinz

2005-01-01

Background and purpose: To measure the dose received by the testicles during radiotherapy for rectal cancer and to determine the contribution of each field of the pelvic box and the relevance for hormonal status. Materials and methods: In 11 patients (mean age 55.2 years) testicular doses were measured with an ionisation chamber between 7 and 10 times during the course of pelvic radiotherapy (50 Gy) for rectal carcinoma. Before and several months after radiotherapy luteinizing hormone, follicle stimulating hormone and total testosterone serum levels were determined. Results: The mean cumulative radiation exposure to the testicles was 3.56 Gy (0.7-8.4 Gy; 7.1% of the prescribed dose). Seventy-three percent received more than 2 Gy to the testicles. Fifty-eight percent of the measured dose was contributed by the p.a. field, 30% by the a.p. field and 12% by the lateral fields. Mean LH and FSH levels were significantly increased after therapy (350%/185% of the pre-treatment values), testosterone levels decreased to 78%. No correlation could be found between changes of hormones and doses to the testis, probably due to the low number of evaluated patients. Conclusions: Radiotherapy of rectal carcinoma causes significant damage to the testis, as shown by increased levels of gonadotropins after radiotherapy. Most of the gonadal dose is delivered by the p.a. field, due to the divergence of the p.a. beam towards the testicles. The reduction in testosterone level may be of clinical concern. Patients who will receive radiotherapy for rectal carcinoma must be instructed about a high risk of permanent infertility, and the risk of endocrine failure (hypogonadism). Larger studies are needed to establish the correlation between testicular radiation dose and hormonal changes in this group of patients

Physics aspects of recent and future concepts in radiotherapy

International Nuclear Information System (INIS)

Georg, D.

2001-01-01

Full text: The development of 3-D conformal radiotherapy (3D-CRT), in which the high dose volume matches as closely as possible the target volume and avoids therefore normal tissue irradiation as far as possible, has been a major theme in radiotherapy for improving the therapeutic window. Conformal radiotherapy is not a new concept but only the technological improvements of the last decade allow its clinical implementation. More recent and advanced forms of 3D-CRT are intensity modulated radiotherapy (IMRT) and stereotactic radiotherapy (SRT). IMRT uses an additional degree of freedom to achieve a new class of conformation: the variation of the primary beam intensity. SRT is based on a three dimensional stereotactic coordinate system which is correlated with the patient and the treatment facility through modern imaging technology. IMRT and SRT are related by common features, e.g. high dose gradients and small fields which require a high geometric precision. A high dosimetric and geometric precision can only be based on a detailed knowledge of the patient specific anatomy. Therefore, IMRT and SRT need to underlie multi-modality imaging studies. Both IMRT and SRT utilize photon beams and multiple field arrangements which increase the volumes of healthy tissue receiving low doses. Photons have a low selectivity along the beam direction implying that the sharp dose gradients are to be compromised. The increased low dose volume as well as the low selectivity of photon beams can be over-come by using proton or ions. Brachytherapy, a form of radiotherapy where encapsuled radioactive sources are placed directly in or in the vicinity of the tumor, is by definition conformal. Endovascular brachytherapy has become a promising new field in radiotherapy for the prevention of (re)stenosis after angioplasty. Although many clinical trials have been performed during the last years specific aspects related to endovascular brachytherapy have not been addressed clearly, such as the

A chronicle of radiotherapy, 1900-1960. Selected chapters of the German literature in the field of radiooncology. Vol. 1

International Nuclear Information System (INIS)

Scherer, E.

1992-01-01

This is the first publication to review the history of development of radiotherapy as a method of treatment, starting with the first publications form the fields of dermatology, gynecology, surgery and internal medicine, showing the whole way up to the emergence of radiooncology as an independent field of work. The most important monographies and many other contributions published in the years from 1912 to 1925 in the journal 'Strahlentherapie und Onkologie' have been compiled in this book to illustrate the various phases of development of techniques and methods as well as of research in the field of physics, or radiobiology. (orig.) [de

Bone Health and Pelvic Radiotherapy.

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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. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

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

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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.

Elective radiotherapy of the regional lymph node areas in breast cancer

International Nuclear Information System (INIS)

Poortmans, P.M.P.

2006-01-01

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

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

International Nuclear Information System (INIS)

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

2007-01-01

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

'Tongue-and-groove' effect in intensity modulated radiotherapy with static multileaf collimator fields

International Nuclear Information System (INIS)

Que, W; Kung, J; Dai, J

2004-01-01

The 'tongue-and-groove problem' in step-and-shoot delivery of intensity modulated radiotherapy is investigated. A 'tongue-and-groove' index (TGI) is introduced to quantify the 'tongue-and-groove' effect in step-and-shoot delivery. Four different types of leaf sequencing methods are compared. The sliding window method and the reducing level method use the same number of field segments to deliver the same intensity map, but the TGI is much less for the reducing level method. The leaf synchronization method of Van Santvoort and Heijmen fails in step-and-shoot delivery, but a new method inspired by the method of Van Santvoort and Heijmen is shown to eliminate 'tongue-and-groove' underdosage completely

Survey on deep learning for radiotherapy.

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Meyer, Philippe; Noblet, Vincent; Mazzara, Christophe; Lallement, Alex

2018-05-17

More than 50% of cancer patients are treated with radiotherapy, either exclusively or in combination with other methods. The planning and delivery of radiotherapy treatment is a complex process, but can now be greatly facilitated by artificial intelligence technology. Deep learning is the fastest-growing field in artificial intelligence and has been successfully used in recent years in many domains, including medicine. In this article, we first explain the concept of deep learning, addressing it in the broader context of machine learning. The most common network architectures are presented, with a more specific focus on convolutional neural networks. We then present a review of the published works on deep learning methods that can be applied to radiotherapy, which are classified into seven categories related to the patient workflow, and can provide some insights of potential future applications. We have attempted to make this paper accessible to both radiotherapy and deep learning communities, and hope that it will inspire new collaborations between these two communities to develop dedicated radiotherapy applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prevention and treatment of radiotherapy-induced oral mucositis: a literature review

International Nuclear Information System (INIS)

Albuquerque, Ieda Lessa de Souza; Camargo, Teresa Caldas

2007-01-01

The prevention and treatment of radiotherapy-induced oral mucositis have still not been fully defined. The current study thus involved a literature search aimed at identifying preventive and therapeutic measures in relation to oral mucositis in patients submitted to radiotherapy, analyzing the level of evidence in the selected studies, identifying which indications for prevention and treatment in the literature pertain to the field of nursing, and critically analyzing the results and their implications for nursing care. This was a systematic literature survey without a meta analysis, consulting the following databases: BIREME, Medline, CancerLit, Scirus, CAPES, Free medical journal, High wire press, SCIELO, and Medscape, from 2000 to 2005. According to observations, nursing care was capable of improving patient's quality of life, promoting education of patients, implementing and supervising oral care programs, and providing guidance on hygiene, prevention, and treatment of oral mucositis, including pain management. However, no Brazilian nursing publications were found on the subject. Research and publications focusing on nursing experience in the prevention and treatment of radiotherapy-related oral mucositis and the implications for patients and nurses are important to provide evidence-based nursing guidelines. (author)

A multi-modality concept for radiotherapy planning with imaging techniques

International Nuclear Information System (INIS)

Schultze, J.

1993-01-01

The reported multi-modality concept of radiotherapy planning in the LAN can be realised in any hospital with standard equipment, although in some cases by way of auxiliary configurations. A software is currently developed as a tool for reducing the entire planning work. The heart of any radiotherapy planning is the therapy simulator, which has to be abreast with the requirements of modern radiotherapy. Integration of tomograpy, digitalisation, and electronic data processing has added important modalities to therapy planning which allow more precise target volume definition, and better biophysical planning. This is what is needed in order to achieve well differentiated radiotherapy for treatment of the manifold tumors, and the quality standards expected by the supervisory quality assurance regime and the population. At present, the CT data still are transferred indirect, on storage media, to the EDP processing system of the radiotherapy planning system. Based on the tomographic slices given by the imaging data, the contours and technical problem solutions are derived automatically, either for multi-field radiotherapy or moving field irradiation, depending on the anatomy or the targets to be protected from ionizing radiation. (orig./VHE) [de

Neutron radiotherapy for adenoid cystic carcinoma of minor salivary glands

International Nuclear Information System (INIS)

Douglas, James G.; Laramore, George E.; Austin-Seymour, Mary; Wui-Jin, Koh; Lindsley, Karen L.; Cho, Paul; Griffin, Thomas W.

1996-01-01

Purpose: To examine the efficacy of fast neutron radiotherapy for the treatment of patients with locally advanced, adenoid cystic carcinoma of minor salivary glands and to identify prognostic variables associated with local control, overall survival, and cause specific survival. Methods and Materials: Eighty-four patients having adenoid cystic carcinoma of minor salivary glands were treated with fast neutron radiotherapy during the years 1985-1994. All patients had either unresectable disease or gross disease remaining after attempted surgical extirpation. Seventeen patients had previously received conventional radiotherapy and their subsequent treatment fields and doses for neutron radiotherapy were modified for critical sites (brainstem, spinal cord, brain). Although the median doses (tumor maximum and tumor minimum) only varied by ≤10%, treatment portals were substantially smaller in these patients because of normal tissue complication considerations. Twelve patients (13%) had distant metastases at the time of treatment and were only treated palliatively with smaller treatment portals and lower median tumor doses (≤80% of the doses delivered to curatively treated patients). Seventy-two patients were treated with curative intent, with nine of these having recurrent tumors after prior full-dose radiotherapy. The median duration of follow-up at the time of analysis was 31.5 months (range 3-115). Sites of disease and number of patients treated per disease site were as follows: paranasal sinus--31; oral cavity--20; oropharynx--12; nasopharynx--11; trachea--6; and other sites in the head and neck--4. Results: The 5-year actuarial local-regional tumor control rate for all patients treated with curative intent was 47%. Patients without involvement of the cavernous sinus, base of skull, or nasopharynx (51 patients) had a 5-year actuarial local-regional control rate of 59%, whereas local-regional control was significantly lower (15%) for patients with tumors involving

Dosimetric comparison between intensity-modulated with coplanar field and 3D conformal radiotherapy with noncoplanar field for postocular invasion tumor.

Science.gov (United States)

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

2010-01-01

This study presents a dosimetric optimization effort aiming to compare noncoplanar field (NCF) on 3 dimensions conformal radiotherapy (3D-CRT) and coplanar field (CF) on intensity-modulated radiotherapy (IMRT) planning for postocular invasion tumor. We performed a planning study on the computed tomography data of 8 consecutive patients with localized postocular invasion tumor. Four fields NCF 3D-CRT in the transverse plane with gantry angles of 0-10 degrees , 30-45 degrees , 240-270 degrees , and 310-335 degrees degrees were isocentered at the center of gravity of the target volume. The geometry of the beams was determined by beam's eye view. The same constraints were prepared with between CF IMRT optimization and NCF 3D-CRT treatment. The maximum point doses (D max) for the different optic pathway structures (OPS) with NCF 3D-CRT treatment should differ in no more than 3% from those with the NCF IMRT plan. Dose-volume histograms (DVHs) were obtained for all targets and organ at risk (OAR) with both treatment techniques. Plans with NCF 3D-CRT and CF IMRT constraints on target dose in homogeneity were computed, as well as the conformity index (CI) and homogeneity index (HI) in the target volume. The PTV coverage was optimal with both NCF 3D-CRT and CF IMRT plans in the 8 tumor sites. No difference was noted between the two techniques for the average D(max) and D(min) dose. NCF 3D-CRT and CF IMRT will yield similar results on CI. However, HI was a significant difference between NCF 3D-CRT and CF IMRT plan (p 3D-CRT versus CF IMRT set-up is very slight. NCF3D-CRT is one of the treatment options for postocular invasion tumor. However, constraints for OARs are needed. 2010 American Association of Medical Dosimetrists. Published by Elsevier Inc. All rights reserved.

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Education for radiological protection in radiotherapy ESTRO recommendations for EU Euratom guidelines

International Nuclear Information System (INIS)

McKenzie, A.; Barrett, A.

2001-01-01

The practice of radiation oncology (radiotherapy) encompasses the clinical care of patients as well as the technical aspects of radiotherapy. Benefits to patients accruing from radiotherapy depend upon the accurate delivery of high doses to the tumour with doses to normal tissues being kept to a minimum. In addition to these patient-centred aspects of radiation protection in radiotherapy, appropriate measures must also be taken to reduce the amount of radiation to staff and the general public to as low a level as is reasonably achievable. In order to achieve these aims, a broad basic training is required in all of the disciplines involved in the delivery of ionising radiation. ESTRO has recommendations for core curricula for the disciplines involved, but this annex lists the elements from these curricula which relate specifically to radiation protection. It is important to reiterate that the extent of training required will depend upon the existing levels of knowledge and training of different groups of professionals in physics, radiobiology etc., and this may vary from state to state specific training objectives for radiation protection in radiotherapy will cover the following subjects: Radiotherapy equipment, safety and accuracy, dosimetric and geometric quantities for accuracy in radiotherapy, radiobiology and radiation risks, radiation treatment planning for optimising delivery of radiation dose, optimal and safe use of radionuclides in radiotherapy, radiation hazards in radiotherapy facilities. (author)

Status and advances of p53-gene therapy and radiotherapy in malignant tumor

International Nuclear Information System (INIS)

Duan Xin; Chinese Academy of Sciences, Beijing; Zhang Hong

2006-01-01

Cancer treatment is one of the most important fields in medical research. All strategies such as radio-therapy, chemotherapy, surgery, and gene-based therapy have their own advantages and disadvantages. Nowadays, a novel method which combined p53-gene therapy with radiotherapy plays an important role in the field of cancer research. This review summarized the current state of combined therapies of p53-gene therapy and radiotherapy, possible mechanism and recent progress. (authors)

Situation of radiotherapy in 2010 - context and methods, data for 2003/2010, synthesis

International Nuclear Information System (INIS)

2011-03-01

Illustrated by data tables and figures, this report first gives an overview of the status and situation of European and French radiotherapy centres, and of care activity authorizations regarding external radiotherapy. It gives an overview of equipment used for treatments and for treatment preparation and delivery, and of the different treatment techniques (three dimensional conformational, intensity-modulated conformational, stereotactic, whole body radiotherapy, proton-therapy). It comments the activity of radiotherapy centres: patients (age, sessions, and treated pathologies), comments data regarding medical and paramedical personnel involved in radiotherapy, and financial data regarding radiotherapy in 2009

Recommendations for the use of PET and PET-CT for radiotherapy planning in research projects.

Science.gov (United States)

Somer, E J; Pike, L C; Marsden, P K

2012-08-01

With the increasing use of positron emission tomography (PET) for disease staging, follow-up and therapy monitoring in a number of oncological indications there is growing interest in the use of PET and PET-CT for radiation treatment planning. In order to create a strong clinical evidence base for this, it is important to ensure that research data are clinically relevant and of a high quality. Therefore the National Cancer Research Institute PET Research Network make these recommendations to assist investigators in the development of radiotherapy clinical trials involving the use of PET and PET-CT. These recommendations provide an overview of the current literature in this rapidly evolving field, including standards for PET in clinical trials, disease staging, volume delineation, intensity modulated radiotherapy and PET-augmented planning techniques, and are targeted at a general audience. We conclude with specific recommendations for the use of PET in radiotherapy planning in research projects.

Radiation myelopathy following transplantation and radiotherapy for non-Hodgkin's lymphoma

International Nuclear Information System (INIS)

Chao, Michael W.T.; Wirth, Andrew; Ryan, Gail; MacManus, Michael; Liew, K.H.

1998-01-01

Background: Combined modality therapy with chemotherapy and radiotherapy has become increasingly popular in the management of solid malignancies. However, unexpected toxicities may arise from their interactions. Methods and Materials: We report the case of a young woman with a large mediastinal non-Hodgkin's lymphoma who underwent high-dose chemotherapy with autologous bone marrow transplantation and involved field radiotherapy, and who developed radiation myelopathy after a latent period of only 3 months. The spinal cord dose did not exceed 40.3 Gy in 22 fractions over 4.5 weeks, which is well within accepted tolerance limits. She had no other identifiable risk factors for radiation myelopathy, suggesting an adverse drug-radiation interaction as the most likely cause of her injury. Results and Conclusions: This represents the first report of radiation myelopathy at accepted safe radiation doses following high-dose chemotherapy with autologous bone marrow transplantation, and we recommend caution in the choice of radiotherapeutic dose in this setting

High-dose rate fractionated interstitial radiotherapy for oropharyngeal carcinoma

Energy Technology Data Exchange (ETDEWEB)

Nose, Takayuki; Inoue, Toshihiko; Inoue, Takehiro; Teshima, Teruki; Murayama, Shigeyuki [Osaka Univ. (Japan). Faculty of Medicine

1995-03-01

The limitations of treating oropharyngeal cancer patients with definitive external radiotherapy are the complications of salivary glands, taste buds, mandible and temporomandibular joints. To avoid these complications we started interstitial radiotherapy as boost after 46 Gy of external radiotherapy. Ten cases (retromolar trigone; 1, soft palate; 1, base of tongue; 3, lateral wall; 5) were treated with this method and seven cases were controlled locally. With short follow-up period, xerostomia and dysgeusia are less than definitive external radiotherapy as clinical impression and no in-field recurrences have been experienced. With markedly increased tumor dose, the local control rate can be improved. This treatment method will be an alternative to definitive external radiotherapy to gain better QOL and higher control rate. (author).

Bowel disease after radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Schofield, P.F.; Holden, D.; Carr, N.D. (Christie Hospital and Holt Radium Inst., Manchester (UK))

1983-06-01

The clinical presentation, operative findings and outcome in 40 patients who required surgery for bowel disease after radiotherapy are presented. The type of presentation varied according to the time after radiotherapy. In the first month, many patients had a proctitis but none required surgery. Five patients were operated on within one month, 2 for radiation-induced acute ileitis and 3 for exacerbations of pre-existing disease (diverticular disease 2, ulcerative colitis 1). The commonest time of presentation was between 3 and 18 months after radiotherapy, when 20 patients needed surgery for bowel disease caused by radiation-induced local ischaemia. Twelve of these patients had chronic perforation, 6 had severe rectal bleeding and 2 had painful anorectal ulceration. Fifteen patients presented between 2 and 24 years after radiotherapy, usually with incomplete intestinal obstruction due to a fibrous stricture, but 2 patients had rectal carcinoma. Wide resection of the involved bowel was the principal method of treatment but any anastomosis was protected by a proximal defunctioning stoma. There was no operative mortality but 10 patients have died subsequently. The danger of dismissing these patients as having incurable malignancy is stressed because, although the condition is infrequent, it is usually amenable to adequate surgery.

Quality Audits In Radiotherapy. Chapter 20

International Nuclear Information System (INIS)

Izewska, J.

2017-01-01

It is widely recognized that quality audits constitute a vital component of quality management in radiotherapy [20.1–20.3]. The main reason why quality audits are considered an important activity is that they help to review the quality of radiotherapy services and improve them. Quality audits check whether radiotherapy practices are adequate, i.e. that what should be done is being done; and in case it is not, audits provide recommendations to encourage improvements to be made. Without some form of auditing, it would be difficult to determine whether radiotherapy services are safe and effective for cancer treatment. In other words, a quality audit in radiotherapy is a method of reviewing whether the quality of activities in a radiotherapy department adheres to the standards of good practices to ensure that the treatment to the cancer patient is optimal. Overall, audits lead to improvements of professional practices and the general quality of services delivered. There are many recommendations regarding quality in radiotherapy practice, both national and international. Practices vary depending on the economic level of States, including specific procedures, equipment and facilities, as well as available resources. Good practices evolve with research developments, including new clinical trial results, progress in evidence based medicine and developments in radiotherapy technology. Quality audits involve the process of fact finding and comparing the findings against criteria for good practices in radiotherapy. Various issues and gaps may be identified by the auditors in the audit process, for example insufficiencies in structure, inadequacies in technology or deviations in procedures. This way the weak points or areas of concern are documented and recommendations for the audited centre are formulated that address these areas with the purpose of improving quality.

Friedrich Dessauer's (1881-1963) contributions to the development of radiotherapy in Turkey

International Nuclear Information System (INIS)

Dinc, Gulten

2007-01-01

Famous physicist Friedrich Dessauer carried out innovative studies in the field of radiotherapy in Turkey where he took refuge escaping from the political situation in Germany before the Second World War. The paper deals with Dessauer's works for the establishment of a radiotherapy institute in Turkey and his contributions to this field

Practical recommendations for breathing-adapted radiotherapy; Bonnes pratiques pour la radiotherapie asservie a la respiration

Energy Technology Data Exchange (ETDEWEB)

Simon, L.; Giraud, P.; Rosenwald, J.C. [Institut Curie, Dept. d' Oncologie-radiotherapie, 75 - Paris (France); Dumas, J.L.; Lorchel, F. [CHU de Besancon, Hopital Jean-Minjoz, Service Radiotherapie, 25 - Besancon (France); Marre, D. [Institut Claudius-Regaud, Dept. des Radiations, 31 - Toulouse (France); Dupont, S. [Hopital Europeen Georges-Pompidou, Service d' Oncoradiotherapie, 75 - Paris (France); Varmenot, N. [Centre Henri-Becquerel, UnitE de Physique Medicale, 76 - Rouen (France); Ginestet, C. [Centre Leon-Berard, Dept. de Radiotherapie, 69 - Lyon (France); Caron, J. [Institut Bergonie, Dept. de Radiotherapie, 33 - Bordeaux (France); Marchesi, V. [Centre Alexis-Vautrin, Dept. de Radiotherapie, 54 - Vandoeuvre-les-Nancy (France); Ferreira, I. [Institut Gustave-Roussy, Dept. d' Oncologie Radiotherapie, 94 - Villejuif (France); Garcia, R. [Institut Sainte-Catherine, Service de Radiotherapie, 84 - Avignon (France)

2007-06-15

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

Risk of ischemic heart disease in women after radiotherapy for breast cancer

DEFF Research Database (Denmark)

Darby, Sarah C.; Ewertz, Marianne; McGale, Paul

2013-01-01

Radiotherapy for breast cancer often involves some incidental exposure of the heart to ionizing radiation. The effect of this exposure on the subsequent risk of ischemic heart disease is uncertain.......Radiotherapy for breast cancer often involves some incidental exposure of the heart to ionizing radiation. The effect of this exposure on the subsequent risk of ischemic heart disease is uncertain....

331 cases of clinically node-negative supraglottic carcinoma of the larynx: a study of a modest size fixed field radiotherapy approach

International Nuclear Information System (INIS)

Sykes, Andrew J.; Slevin, Nicholas J.; Gupta, Nirmal K.; Brewster, Allison E.

2000-01-01

Purpose: For node-negative supraglottic carcinoma of the larynx, radiotherapy with surgery in reserve commonly provides very good results in terms of both local control and survival, while preserving function. However uncertainty exists over the treatment of the node-negative neck. Elective whole neck radiotherapy, while effective, may be associated with significant morbidity. The purpose of this study was to examine our practice of treating a modest size, fixed field to a high biologically effective dose and compare it with the patterns of recurrence from other centers that use different dose/volume approaches. Methods and Materials: Over a 10-year period 331 patients with node-negative supraglottic carcinoma of the larynx were treated with radiotherapy at the Christie Hospital Manchester. Patients were treated with doses of 50-55 Gy in 16 fractions over 3 weeks. Data were collected retrospectively for local and regional control, survival, and morbidity. Results: Overall local control, after surgical salvage in 17 cases, was 79% (T1-92%, T2-81%, T3-67%, T4-73%). Overall regional lymph node control, after surgical salvage in 13 cases, was 84% (T1-91%, T2-88%, T3-81%, T4-72%). Five-year crude survival was 50%, but after correcting for intercurrent deaths was 70% (T1-83%, T2-78%, T3-53%, T4-61%). Serious morbidity requiring surgery was seen in 7 cases (2.1%) and was related to prescribed dose (50 Gy-0%, 52.5 Gy-1.3%, 55 Gy-3.4%). Discussion: Our results confirm that treating a modest size, fixed field to a high biologically effective dose is highly effective. It enables preservation of the larynx in most cases, with acceptable regional control and no loss of survival compared to whole neck radiotherapy regimes

Utility-adjusted analysis of the cost of palliative radiotherapy for bone metastases

International Nuclear Information System (INIS)

Barton, M.B.; Jacob, S.A.

2003-01-01

Palliative radiotherapy is effective in the treatment of bone metastases but is under-utilized, possibly because it is perceived to be expensive. We performed a cost-utility analysis of palliative radiotherapy for bone metastases, evaluating both the actual cost of radiotherapy as well as its impact on quality of life by adjusting for the variation in response to treatment. Hospital records between July 1991 and July 1996 were reviewed to ascertain the number of patients treated with palliative radiotherapy for bone metastases, the average number of fields of radiation delivered to each patient and the average duration of survival. Partial and complete response rates to palliative radiotherapy were obtained from a review of all published randomized controlled trials of radiation treatment of bone metastases. Utility values were assigned to the response rates, and an overall adjusted response rate to radiotherapy was derived. The cost of delivering a field of radiation was calculated. The total cost was divided by the total number of response months to give a utility-adjusted cost per month of palliative radiotherapy. The utility-adjusted cost per month of palliative radiotherapy of bone metastases was found to be AUS$ 100 per month or AUS$ 1200 per utility-adjusted life-year. This study demonstrates that, contrary to popular perception, palliative radiotherapy is a cost-effective treatment modality for bone metastases. Copyright (2003) Blackwell Science Pty Ltd

An analysis of two separate quality audits in UK radiotherapy centres

International Nuclear Information System (INIS)

Aird, E G A

1995-01-01

The CHART quality assurance programme has been used to audit 2 groups of radiotherapy centres for the delivery of radiotherapy: 1. those involved in the CHART Clinical Trial (1991-1995) 2. all London radiotherapy centres (1994-1996) Machinery Tests This paper will seek to illustrate improvements in meeting the criteria set by the QA programme as older linear accelerators are replaced. Phantom Tests The residual errors between measured and calculated doses in anatomical phantoms will be analysed to demonstrate where there are still weaknesses in treatment planning and delivery of radiotherapy

Radiotherapy in Locoregional Recurrent Breast Carcinoma

International Nuclear Information System (INIS)

Ha, Sung Whan; Yang, Mi Gyoung; Chung, Woong Ki; Park, Charn Il; Bang, Yung Jue; Kim, Noe Kyung; Choe, Kuk Jin

1988-01-01

Thirty eight women with recurrent breast carcinoma involving chest wall and/or regional lymph nodes after surgery with or without systemic therapy were treated with radiation between 1979 and 1986. Among them, 5 patients were excluded from analysis because of incomplete treatment. The median follow up of survivors was 30 months (ranged 1-79 months). Fifteen (45%) patients had their disease confined to the chest wall and eighteen patients had lymph node involvement as some of their locoregional recurrent disease. Within 36 months after the initial treatment, 87% of recurrences manifested themselves. All patients had radiotherapy to at least the site of involvement. In 8 patients, recurrent tumors were treated with complete excision followed by radiation. Of the remaining 25 patients, 18(72%) had complete response (CR) following radiotherapy. The actuarial 3-year survival of all patients following locoregional recurrence was 50%. Three year survival was 24% in those 25 patients who had recurrences within 24 months of the initial treatment. For those 8 patients whose recurrences occurred after more than 24 month disease free interval, the 3-year survival was 100%. For those patients with recurrences confined to chest wall alone, 3-year survival was 57%. The patients who had lymph node involvement as part of their locoregional recurrences had a 43% 3-year survival. The majority of them developed distant metastases. Those patients who had a CR showed 63% 3-year survival. On the other hand, 1 year survival was only 33% for those patients who had a less than CR. Three patients developed carcinoma of the contralateral breast following radiotherapy. Three year survival following locoregional recurrence was 40% for patients whose initial treatment for their primary breast carcinoma was surgery and adjuvant systemic therapy. For those patients whose primary breast carcinoma was treated by surgery alone, the 3-year survival following locoregional recurrence was 71%. In

Comparison of curricula in radiation technology in the field of radiotherapy in selected European Union countries

International Nuclear Information System (INIS)

Janaszczyk, A.; Bogusz-Czerniewicz, M.

2011-01-01

Background: Radiation technology is a discipline of medical science which deals with diagnostics, imaging and radiotherapy, that is treatment by ionizing radiation. Aim: To present and compare the existing curricula of radiation technology in selected EU countries. Materials and methods: The research work done for the purpose of the comparative analysis was based on the methods of diagnostic test and document analysis. Results: The comparison of curricula in selected countries, namely Austria, France, the Netherlands and Poland, showed that admission criteria to radiation technology courses are varied and depend on regulations of respective Ministries of Health. The most restrictive conditions, including written tests in biology, chemistry and physics, and psychometric test, are those in France. Contents of basic and specialist subject groups are very similar in all the countries. The difference is in the number of ECT points assigned to particular subjects and the number of course hours offered. The longest practical training is provided in the Netherlands and the shortest one in Poland. The duration of studies in the Netherlands is 4 years, while in Poland it is 3 years. Austria is the only country to offer extra practical training in quality management. Conclusion: Graduates in the compared EU countries have similar level of qualifications in the fields of operation of radiological equipment, radiotherapy, nuclear medicine, foreign language and specialist terminology in the field of medical and physical sciences, general knowledge of medical and physical sciences, and detailed knowledge of radiation technology. (authors)

Radiotherapy-induced hypopituitarism: a review.

Science.gov (United States)

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.

The concept and evolution of involved site radiation therapy for lymphoma

DEFF Research Database (Denmark)

Specht, Lena; Yahalom, Joachim

2015-01-01

We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiation...... therapy is part of the multimodality treatment of lymphoma, and the irradiated tissue volume is much smaller than before, leading to highly significant reductions in the risks of long-term complications....

Quality indicators in radiotherapy

International Nuclear Information System (INIS)

Cionini, Luca; Gardani, Gianstefano; Gabriele, Pietro; Magri, Secondo; Morosini, Pier Luigi; Rosi, Antonella; Viti, Vincenza

2007-01-01

Background and purpose: There is a widespread and increasing tendency to develop hospital performance indicators in the field of accreditation/certification systems and quality benchmarking. A study has been undertaken to develop a set of performance indicators for a typical radiotherapy Centre and to evaluate their ability to provide a continuous quality improvement. Materials and methods: A working group consisting of radiation oncologists, medical physicists and radiation technologists under the coordination of experts in health technology assessment has elaborated a set of general indicators able to monitor performances and the quality level of a typical radiotherapy Centre. The work has been carried out through four steps: a preliminary set of indicators was selected; data on these indicators were collected in a number of Italian radiotherapy Centres and medical physics Services; problems in collection and analysis of data were discussed; a final set of indicators was developed. Results: A final set of 13 indicators is here presented. They concern general structural and/or operational features, health physics activities and accuracy and technical complexity of the treatment. Conclusions: The indicators tested in a few Italian Centres of radiotherapy and medical physics Services are now ready to be utilized by a larger community

CyberKnife robotic stereotactic radiotherapy: technical aspects and medical indications; Radiotherapie stereotaxique robotisee par CyberKnife: aspects techniques et indications

Energy Technology Data Exchange (ETDEWEB)

Bondiau, P.Y.; Benezery, K.; Gerard, J.P.; Herault, J.; Marcie, S.; Angellier, G. [Centre Antoine-Lacassagne, Dept. de Radiotherapie, 06 - Nice (France); Beckendorf, V.; Peiffert, D.; Noel, A. [Centre Alexis-Vautrin, Dept. de Radiotherapie et Curietherapie, 54 - Vandoeuvre-les-Nancy (France); Mirabel, X.; Marchesi, V.; Lacornerie, T.; Dubus, F.; Sarrazin, T.; Lartigau, E. [Centre Oscar-Lambret, Dept. de Radiotherapie, 59 - Lille (France)

2007-11-15

In 2006, 3 sites have been selected by the Institut national of cancer (Lille, Nancy et Nice) to evaluate a radiotherapy robot, the CyberKnife this machine, able to track mobile tumours in real time, gives new possibilities in the field of extra cranial stereotactic radiotherapy. Functionalities and medico economical issues of the machine will be evaluated during 2 years on the 3 sites. (authors)

Esophageal perforation during or after conformal radiotherapy for esophageal carcinoma

International Nuclear Information System (INIS)

Chen Haiyan; Ma Xiumei; Ye Ming; Hou Yanli; Xie Huaying; Bai Yongrui

2014-01-01

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

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

Science.gov (United States)

Alon, Nirit Lavie; Tal, Tali

2017-08-01

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.

Influence of more extensive radiotherapy and adjuvant chemotherapy on long-term outcome of early-stage Hodgkin's disease: a meta-analysis of 23 randomized trials involving 3,888 patients. International Hodgkin's Disease Collaborative Group

DEFF Research Database (Denmark)

Specht, L.; Gray, R.G.; Clarke, M.J.

1998-01-01

PURPOSE: To assess the effect of more extensive radiotherapy and of adjuvant combination chemotherapy on long-term outcome of early-stage Hodgkin's disease. METHODS: In a collaborative worldwide systematic overview, individual patient data were centrally reviewed on 1,974 patients in eight.......7%; P counterbalanced by a nonsignificant excess of deaths from other...... causes (12.4% v 10.0% 10-year risk). CONCLUSION: More extensive radiotherapy fields or the addition of chemotherapy to radiotherapy in the initial treatment of early-stage Hodgkin's disease had a large effect on disease control, but only a small effect on overall survival. Recurrences could be prevented...

Voluntary Breath-hold Technique for Reducing Heart Dose in Left Breast Radiotherapy

Science.gov (United States)

Bartlett, Frederick R.; Colgan, Ruth M.; Donovan, Ellen M.; Carr, Karen; Landeg, Steven; Clements, Nicola; McNair, Helen A.; Locke, Imogen; Evans, Philip M.; Haviland, Joanne S.; Yarnold, John R.; Kirby, Anna M.

2014-01-01

Breath-holding techniques reduce the amount of radiation received by cardiac structures during tangential-field left breast radiotherapy. With these techniques, patients hold their breath while radiotherapy is delivered, pushing the heart down and away from the radiotherapy field. Despite clear dosimetric benefits, these techniques are not yet in widespread use. One reason for this is that commercially available solutions require specialist equipment, necessitating not only significant capital investment, but often also incurring ongoing costs such as a need for daily disposable mouthpieces. The voluntary breath-hold technique described here does not require any additional specialist equipment. All breath-holding techniques require a surrogate to monitor breath-hold consistency and whether breath-hold is maintained. Voluntary breath-hold uses the distance moved by the anterior and lateral reference marks (tattoos) away from the treatment room lasers in breath-hold to monitor consistency at CT-planning and treatment setup. Light fields are then used to monitor breath-hold consistency prior to and during radiotherapy delivery. PMID:25046661

A case of bullous pemphigoid exacerbated by irradiation after breast conservative radiotherapy

International Nuclear Information System (INIS)

Isohashi, Fumiaki; Konishi, Koji; Umegaki, Noriko; Tanei, Tomonori; Koizumi, Masahiko; Yoshioka, Yasuo

2011-01-01

We present a case, considered to be a form of the Koebner phenomenon, of bullous pemphigoid that was exacerbated mainly within the irradiated field after breast conservative radiotherapy. In May 2009, a 60-year-old woman was diagnosed with bullous pemphigoid, which was treated with steroid therapy. The following month, she was diagnosed with breast cancer (invasive ductal carcinoma, pT1cN0M0). After breast conservative surgery in December 2009, conservative radiotherapy to the right breast was performed (50 Gy in 25 fractions). Portal skin showed no serious change (up to grade 1 skin erythema) and no bullous neogenesis during conservative radiotherapy. However, 2 months after conservative radiotherapy, new blisters became exacerbated mainly within the irradiated field but also in the area outside the irradiated field. Increasing the dosage of oral steroid and minocycline resulted in relief of bullous pemphigoid, although patchy skin pigmentation remained especially in the irradiated skin. (author)

The role of primary radiotherapy in acromegaly (abstract)

International Nuclear Information System (INIS)

Ali, M.; Knob, G.

1998-01-01

The aim of the study was to evaluate the role of primary radiotherapy in acromegaly. Fifteen cases were randomly included in this study from 1989 to 1998. The patients were given external radiotherapy using Co/sup 60/ source and 200 cGy/F, 5F/week up to 5000 cGy, Tumor dose (TD). The target volume was irradiated by opposite parallel lateral field. The field size ranged from 4.5 to 6.5 cm. depending upon the tumor size and its extensions. These patients were continuously followed up for variable period depending upon the history of the patient and compliance by serial Growth Hormone (GH) assay and Clinical and Radiological evaluation. Out of these fifteen patients one died of cardiac sequelae. In the remaining treated patients majority has normal or continuously decreasing GH levels. The treatment of Acromegaly includes surgery, radiotherapy, medical treatment or the combination of these with variable success and non is perfect. We used radiotherapy as the primary modality, due to medical contraindication or refusal of patient for surgery and found that this is an effective modality in the treatment of acromegaly even in patients with extra sellar extension of the tumor. (author)

Radiotherapy

International Nuclear Information System (INIS)

Prosnitz, L.R.; Kapp, D.S.; Weissberg, J.B.

1983-01-01

This review highlights developments over the past decade in radiotherapy and attempts to summarize the state of the art in the management of the major diseases in which radiotherapy has a meaningful role. The equipment, radiobiology of radiotherapy and carcinoma of the lung, breast and intestines are highlighted

Effects of radiotherapy on the sense of taste

Energy Technology Data Exchange (ETDEWEB)

Umeyama, Masayoshi; Suzaki, Harumi [Showa Univ., Tokyo (Japan). School of Medicine

2001-07-01

The adverse effects of radiotherapy for cancer in the head and neck region include impairment of the sense of taste and smell and dry mouth. The present study was conducted to examine the effects of such radiotherapy on the sense of taste, in view of its influence on the quality of life of patients with malignant tumors of the head and neck following treatment. In 18 patients with malignant tumors of the head and neck (mean age, 59.9 years) the sense of taste was tested using the filter-paper disc method, serially before and after radiotherapy with {sup 60}Co {gamma} rays, in order to analyze the changes in gustatory threshold after radiotherapy. The patients were also observed for subjective symptoms, including dry mouth and impairment of the sense of taste, and changes in the lingual surface over the course of radiotherapy. No increase in the gustatory threshold or subjective impairment of the sense of taste was noted after radiotherapy when the field of irradiation did not include the tongue (4 cases of laryngeal cancer). When the field of irradiation included a part of the tongue (3 cases of maxillary cancer, 3 cases of hypopharyngeal cancer, 1 case of epipharyngeal cancer) or the entire tongue (2 cases of lingual cancer, 2 cases of cancer of the floor of the mouth, 3 cases of mesopharyngeal cancer), dry mouth was noted after irradiation at 7.2-39.6 Gy, and the gustatory threshold increased after irradiation at 12-40 Gy. Subjective impairment of the sense of taste was also reported after irradiation at 10-25.2 Gy, which was restored to normal within 2-3 months after the end of radiotherapy. In relation to the quality of taste, the gustatory threshold for sweet tastes increased the slowest, and was restored rapidly. In contrast, the gustatory threshold for sour tastes increased most rapidly, and was restored slowly. The relationship between the serum zinc level and the increase in gustatory threshold was unclear. There was a tendency for the lingual surface to

Effects of radiotherapy on the sense of taste

International Nuclear Information System (INIS)

Umeyama, Masayoshi; Suzaki, Harumi

2001-01-01

The adverse effects of radiotherapy for cancer in the head and neck region include impairment of the sense of taste and smell and dry mouth. The present study was conducted to examine the effects of such radiotherapy on the sense of taste, in view of its influence on the quality of life of patients with malignant tumors of the head and neck following treatment. In 18 patients with malignant tumors of the head and neck (mean age, 59.9 years) the sense of taste was tested using the filter-paper disc method, serially before and after radiotherapy with 60 Co γ rays, in order to analyze the changes in gustatory threshold after radiotherapy. The patients were also observed for subjective symptoms, including dry mouth and impairment of the sense of taste, and changes in the lingual surface over the course of radiotherapy. No increase in the gustatory threshold or subjective impairment of the sense of taste was noted after radiotherapy when the field of irradiation did not include the tongue (4 cases of laryngeal cancer). When the field of irradiation included a part of the tongue (3 cases of maxillary cancer, 3 cases of hypopharyngeal cancer, 1 case of epipharyngeal cancer) or the entire tongue (2 cases of lingual cancer, 2 cases of cancer of the floor of the mouth, 3 cases of mesopharyngeal cancer), dry mouth was noted after irradiation at 7.2-39.6 Gy, and the gustatory threshold increased after irradiation at 12-40 Gy. Subjective impairment of the sense of taste was also reported after irradiation at 10-25.2 Gy, which was restored to normal within 2-3 months after the end of radiotherapy. In relation to the quality of taste, the gustatory threshold for sweet tastes increased the slowest, and was restored rapidly. In contrast, the gustatory threshold for sour tastes increased most rapidly, and was restored slowly. The relationship between the serum zinc level and the increase in gustatory threshold was unclear. There was a tendency for the lingual surface to become dry

3D Conformal radiotherapy for gastric cancer-results of a comparative planning study

International Nuclear Information System (INIS)

Leong, Trevor; Willis, David; Joon, Daryl Lim; Condron, Sara; Hui, Andrew; Ngan, Samuel Y.K.

2005-01-01

Background and purpose: Many radiation oncologists are reluctant to use anteroposterior-posteroanterior (AP-PA) field arrangements when treating gastric cancer with adjuvant postoperative radiotherapy due to concerns about normal tissue toxicity, particularly in relation to the kidneys and spinal cord. In this report, we describe a multiple-field conformal radiotherapy technique, and compare this technique to the more commonly used AP-PA technique that was used in the recently reported Intergroup study (INT0116). Materials and methods: Fifteen patients with stages II-IV adenocarcinoma of the stomach were treated with adjuvant postoperative chemoradiotherapy using a standardised 3D conformal radiotherapy technique that consisted of a 'split-field', mono-isocentric arrangement employing 6 radiation fields. For each patient, a second radiotherapy treatment plan was generated utilising AP-PA fields. The two techniques were then compared for target volume coverage and dose to normal tissues using dose volume histogram (DVH) analysis. Results: The conformal technique provides more adequate coverage of the target volume with 99% of the planning target volume (PTV) receiving 95% of the prescribed dose, compared to 93% using AP-PA fields. Comparative DVHs for the right kidney, left kidney and spinal cord demonstrate lower radiation doses using the conformal technique, and although the liver dose is higher, it is still well below liver tolerance. Conclusions: 3D conformal radiotherapy produces superior dose distributions and reduced radiation doses to the kidneys and spinal cord compared to AP-PA techniques, with the potential to reduce treatment toxicity

Stage I/II endometrial carcinomas: preoperative radiotherapy: results

International Nuclear Information System (INIS)

Maingon, P.; Belichard, C.; Horiot, J.C.; Barillot, I.; Fraisse, J.; Collin, F.

1996-01-01

The AIM of this retrospective study is to analyse the indications and the results of treatment of endometrial carcinomas by preoperative radiotherapy. MATERIAL: From 1976 to 1995, 183 patients FIGO stage I or II were treated by preoperative radiotherapy consisting in 95 cases of external radiotherapy (XRT) and brachytherapy (BT) followed by surgery (S) and, in 88 cases of BT alone before surgery, XRT was indicated in cases of grade 2 or 3 and/or cervical involvement. METHODS: XRT was delivered with a 4-fields technique to 40 Gy in 20 fractions with a medial shielding at 30 Gy. BT was done with low dose rate Cs137 and Fletcher-Suit-Delclos applicators with two intra-uterine tubes and vaginal ovoieds. Complications were scored using the French-Italian syllabus. RESULTS: Five-year actuarial survival rates per stage are: Ia=91%, Ib=83%, II=71%, and per grade: G1=80%, G2=79%, G3=90%. Failures were pelvic in 5/183 (2.7%), vaginal in 4 cases (2%) and nodal in 2 cases (1%). Twelve patients developed metastases (6.5%). Complications were analysed during the radiotherapy, after the surgery and with unlimited follow-up. After BT/S, 12 grade 1, 1 grade 2 and 1 grade 3 complications were observed. In the group of patients treated by RT/BT/S, 22 grade 1, 11 grade 2, 4 grade 3 occurred. There is no statistical correlation between complications and parameters of treatment (XRT, hwt, HWT, reference dose to the bladder and rectum, dose rate of brachytherapy). SUMMARY: Preoperative irradiation is an effective and safe treatment of high risk stage I/II endometrial carcinomas. Results seem independent of the pathology grade

Patterns of failure in children with medulloblastoma treated with 3D conformal radiotherapy

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Skowronska-Gardas, Anna; Chojnacka, Marzanna; Morawska-Kaczynska, Marzena; Perek, Danuta; Perek-Polnik, Marta

2007-01-01

Background and purpose: Craniospinal irradiation for medulloblastoma is one of the most complex techniques employed in radiotherapy. Many reports stress the impact of irradiation quality on survival in these patients. Our report presents the outcome and patterns of failure for 95 patients treated with 3D conformal radiotherapy (3D-CRT). Materials and methods: From 1998 to 2003, 95 children with medulloblastoma received 3D conformal radiotherapy. All of them were previously treated with surgery and chemotherapy. The brain and upper spinal cord were treated with two lateral 6 MV photon fields. In four patients, the cribriform plate was irradiated by the additional field. For primary tumour bed we applied two or three photon beams. Spinal cord was irradiated either with 18-20 MeV electron fields or with a mixed beam. Results: With a median follow-up of 48 months, 32/95 patients suffered a multifocal (21) or isolated (11) recurrence. We evaluated every primary site of failure. In all patients, the recurrence appeared within the isodose level of 95-100%. Conclusions: Patterns of failure in medulloblastoma patients treated with 3D conformal radiotherapy indicated that the relapse was mainly associated with poor response to pre-irradiation chemotherapy. We believe that 3D conformal radiotherapy allows avoiding failures, related to radiotherapy uncertainties

Definition of postlumpectomy tumor bed for radiotherapy boost field planning: CT versus surgical clips

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Goldberg, Hadassah; Prosnitz, Robert G.; Olson, John A.; Marks, Lawrence B.

2005-01-01

Purpose: To compare the location and extent of the tumor bed as defined by surgical clips and computed tomography (CT) scans, after lumpectomy, for electron boost planning as part of breast radiotherapy. Methods and Materials: Planning CT images of 31 operated breasts in 30 patients who underwent lumpectomy were reviewed. One or more clips were placed in the lumpectomy cavity. Serial CT images were used to measure the depth and transverse and longitudinal dimensions. The area and geometric center of the tumor bed were defined by the clips and CT. Results: The CT and clip measurements were identical for the maximal tumor depth in 27 of 30 patients. The CT bed extended beyond the clips by 0-7 mm medially in the transverse/longitudinal extent (multiclip patients). The median distance between the geometric centers in the coronal plane for the tumor bed center was larger for patients with single clips than for those with multiple clips (p 2 . The CT bed was more readily visible in patients with a shorter interval between surgery and radiotherapy. Conclusion: The maximal depth of the tumor bed was similar using the two methods. The extent and centers of the clip-and CT-determined beds differed significantly. This may indicate an underestimation of the tumor bed as defined by clips only and justifies integration of CT information in boost field planning

Radiotherapy in Cancer Care: Facing the Global Challenge

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Rosenblatt, Eduardo; Zubizarreta, Eduardo

2017-06-01

Cancer treatment is complex and calls for a diverse set of services. Radiotherapy is recognized as an essential tool in the cure and palliation of cancer. Currently, access to radiation treatment is limited in many countries and non-existent in some. This lack of radiotherapy resources exacerbates the burden of disease and underscores the continuing health care disparity among States. Closing this gap represents an essential measure in addressing this global health equity problem. This publication presents a comprehensive overview of the major topics and issues to be taken into consideration when planning a strategy to address this problem, in particular in low and middle income countries. With contributions from leaders in the field, it provides an introduction to the achievements and issues of radiation therapy as a cancer treatment modality around the world. Dedicated chapters focus on proton therapy, carbon ion radiotherapy, intraoperative radiotherapy, radiotherapy for children, HIV/AIDS related malignancies, and costing and quality management issues.

The surgical treatment of failure in cervical lymph nodes after radiotherapy for nasopharyngeal carcinoma: an analysis of 83 patients

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Gu Wendong; Ji Qinghai; Lu Xueguan; Feng Yan

2003-01-01

Objective: To analyze the results of neck dissection in patients who failed in cervical lymph nodes after radiotherapy for nasopharyngeal carcinoma. Methods: Eighty-three patients who received neck dissection due to lymph node persistence or recurrence after definitive radiotherapy were analyzed retrospectively according to the following relevant factors: age, sex, the interval between completion of radiotherapy and surgery, rN stage, postoperative radiotherapy given or not, the adjacent tissues involved or not and the number of positive nodes. Kaplan-Meier method, Log-rank method and Cox method were used in the statistical analysis. Results: The 1-, 3- and 5-year overall survival rates were 80.7%, 47.1% and 34.9%. The interval between completion of radiotherapy and surgery, postoperative radiotherapy given or not, the adjacent tissues involved or not were significantly prognostic factors in statistic analysis. Conclusions: Neck dissection can be applied in the management of cervical lymph node failure in nasopharyngeal carcinoma after radiotherapy. Postoperative radiotherapy should be considered in patients with capsular invasion and/or adjacent tissue involvement

Radiotherapy in primary cerebral lymphoma

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Legros, L.; Benezery, K.; Lagrange, J.L.

1999-01-01

Primary cerebral lymphoma is a rare disease with an unfavorable prognosis. Whole brain radiotherapy has been the standard treatment, but neither the optimal radiation fields nor optimal dose level of the regimen are as yet firmly establisheD. From this review of the literature, it seems that the whole brain must be treated, and a boost to the area of the primary site must be discussed. With regard to dose, the radiation dose-response relationship is not clearly proven. Yet, a minimum dose of 40 Gy is necessary, and the maximum dose is set at 50 Gy because of late neurological sequelae. Because of the poor prognosis of this disease and the risk of late sequelae, other avenues have been explored. Chemotherapy has been studied, seem to have a survival advantage and combinations of radiotherapy and chemotherapy, especially with high-dose methotrexate. Because primary cerebral lymphoma is an uncommon disease, randomized clinical trials that compare radiotherapy alone to chemotherapy plus radiotherapy may not be feasible. Finally, even if chemotherapy seems to have a survival advantage, the regimen of chemotherapy is still a matter of debate. (authors)

A high-precision system for conformal intracranial radiotherapy

International Nuclear Information System (INIS)

Tome, Wolfgang A.; Meeks, Sanford L.; Buatti, John M.; Bova, Francis J.; Friedman, William A.; Li Zuofeng

2000-01-01

Purpose: Currently, optimally precise delivery of intracranial radiotherapy is possible with stereotactic radiosurgery and fractionated stereotactic radiotherapy. We report on an optimally precise optically guided system for three-dimensional (3D) conformal radiotherapy using multiple noncoplanar fixed fields. Methods and Materials: The optically guided system detects infrared light emitting diodes (IRLEDs) attached to a custom bite plate linked to the patient's maxillary dentition. The IRLEDs are monitored by a commercially available stereo camera system, which is interfaced to a personal computer. An IRLED reference is established with the patient at the selected stereotactic isocenter, and the computer reports the patient's current position based on the location of the IRLEDs relative to this reference position. Using this readout from the computer, the patient may be dialed directly to the desired position in stereotactic space. The patient is localized on the first day and a reference file is established for 5 different couch positions. The patient's image data are then imported into a commercial convolution-based 3D radiotherapy planning system. The previously established isocenter and couch positions are then used as a template upon which to design a conformal 3D plan with maximum beam separation. Results: The use of the optically guided system in conjunction with noncoplanar radiotherapy treatment planning using fixed fields allows the generation of highly conformal treatment plans that exhibit a high degree of dose homogeneity and a steep dose gradient. To date, this approach has been used to treat 28 patients. Conclusion: Because IRLED technology improves the accuracy of patient localization relative to the linac isocenter and allows real-time monitoring of patient position, one can choose treatment-field margins that only account for beam penumbra and image resolution without adding margin to account for larger and poorly defined setup uncertainty. This

Dosimetry in radiotherapy. V.1

International Nuclear Information System (INIS)

1988-01-01

A series of symposia on dosimetry in medicine and biology have been held by the IAEA in co-operation with WHO. The present symposium was the first one focusing on ''Dosimetry in Radiotherapy''. The papers presented reflected the different steps in the calibration chain such as the calibration standards established by the National Standards Laboratories and the conversion of the reading of calibrated instruments to the desired quantity, i.e. absorbed dose to water at a reference point in the user's beam at the radiotherapy clinic. The programme further examined the procedures necessary for optimization of the treatment of the patient, such as treatment planning methods, dose distribution studies, new techniques of dose measurement, improvements in the physical dose distributions/conformation therapy and special problems involved in total body treatments. Results of quality assurance in radiotherapy were presented from local hospitals as well as from national and international studies. Refs, figs and tabs

Thalassaemic osteoarthropathy treated with radiotherapy

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Davies, A.N.

1993-01-01

Patients with beta thalassaemia may develop a specific osteoarthropathy involving the feet. A number of different treatments for this condition have been tried, including rest, analgesia and hypertransfusion. We report a case of a patient with thalassaemic osteoarthropathy who responded to radiotherapy after failing conventional treatment. (author)

Spinal Cord Doses in Palliative Lung Radiotherapy Schedules

International Nuclear Information System (INIS)

Ffrrcsi, F.H.; Parton, C.

2006-01-01

Aim: We aim to check the safety of the standard palliative radiotherapy techniques by using the Linear quadratic model for a careful estimation of the doses received by the spinal cord, in all standard palliative lung radiotherapy fields and fractionation. Material and Methods: All patients surveyed at this prospective audit were treated with palliative chest radio-therapy for lung cancer over a period from January to June 2005 by different clinical oncology specialists within the department. Radiotherapy field criteria were recorded and compared with the recommended limits of the MRC trial protocols for the dose and fractionation prescribed. Doses delivered to structures off the field central axis were estimated using a standard CT scan of the chest. Dose estimates were made using an SLPLAN planning system. As unexpected spinal cord toxicity has been reported after hypo fractionated chest radiotherapy, a sagittal view was used to calculate the isodoses along the length of the spinal cord that could lie within the RT field. Equivalent dose estimates are made using the Linear Quadratic Equivalent Dose formula (LQED). The relative radiation sensitivity of spinal cord for myelopathy (the a/b dose) cord has been estimated as a/b = 1 Gy. Results: 17 Gy in 2 fraction and 39 Gy in 13 fraction protocols have spinal cord equivalent doses (using the linear-quadratic model) that lie within the conventional safe limits of 50 Gy in 25 fractions for the 100% isodose. However when the dosimetry is modelled for a 6 MV 100 cm isocentric linac in 3 dimensions, and altered separations and air space inhomogeneity are considered, the D-Max doses consistently fall above this limit on our 3 model patients. Conclusion: The 17 Gy in 2 fraction and 39 Gy in 13 fraction protocol would risk spinal cord damage if the radio therapist was unaware of the potential spinal cord doses. Alterative doses are suggested below 15.5 Gy/ 2 fractions (7 days apart) would be most acceptable

Chest wall desmoid tumours treated with definitive radiotherapy: a plan comparison of 3D conformal radiotherapy, intensity-modulated radiotherapy and volumetric-modulated arc radiotherapy

International Nuclear Information System (INIS)

Liu, Jia; Ng, Diana; Lee, James; Stalley, Paul; Hong, Angela

2016-01-01

Definitive radiotherapy is often used for chest wall desmoid tumours due to size or anatomical location. The delivery of radiotherapy is challenging due to the large size and constraints of normal surrounding structures. We compared the dosimetry of 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc radiotherapy (VMAT) to evaluate the best treatment option. Ten consecutive patients with inoperable chest wall desmoid tumours (PTV range 416–4549 cm 3 ) were selected. For each patient, 3DCRT, IMRT and VMAT plans were generated and the Conformity Index (CI), organ at risk (OAR) doses and monitor unit (MU) were evaluated. The Wilcoxon signed-rank test was used to compare dose delivered to both target and OARs. The mean number of fields for 3DCRT and IMRT were 6.3 ± 2.1, 7.2 ± 1.8. The mean number of arcs for VMAT was 3.7 ± 1.1. The mean conformity index of VMAT (0.98 ± 0.14) was similar to that of IMRT (1.03 ± 0.13), both of which were significantly better than 3DCRT (1.35 ± 0.20; p = 0.005). The mean dose to lung was significantly higher for 3DCRT (11.9Gy ± 7.9) compared to IMRT (9.4Gy ± 5.4, p = 0.014) and VMAT (8.9Gy ± 4.5, p = 0.017). For the 3 females, the low dose regions in the ipsilateral breast for VMAT were generally less with VMAT. IMRT plans required 1427 ± 532 MU per fraction which was almost 4-fold higher than 3DCRT (313 ± 112, P = 0.005). Compared to IMRT, VMAT plans required 60 % less MU (570 ± 285, P = 0.005). For inoperable chest wall desmoid tumours, VMAT delivered equivalent target coverage when compared to IMRT but required 60 % less MU. Both VMAT and IMRT were superior to 3DCRT in terms of better PTV coverage and sparing of lung tissue

Radiotherapy

Directory of Open Access Journals (Sweden)

Rema Jyothirmayi

1999-01-01

Full Text Available Purpose. Conservative treatment in the form of limited surgery and post-operative radiotherapy is controversial in hand and foot sarcomas, both due to poor radiation tolerance of the palm and sole, and due to technical difficulties in achieving adequate margins.This paper describes the local control and survival of 41 patients with soft tissue sarcoma of the hand or foot treated with conservative surgery and radiotherapy. The acute and late toxicity of megavoltage radiotherapy to the hand and foot are described. The technical issues and details of treatment delivery are discussed. The factors influencing local control after radiotherapy are analysed.

Problems of radiotherapy on the brain tumors in children less than two years of age

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Miyagami, Mitsusuke; Tsubokawa, Takashi (Nihon Univ., Tokyo (Japan). School of Medicine); Nishimoto, Hiroshi; Ueno, Yuhichi

1990-06-01

Impaired growth and mental or developmental disturbance due to radiotherapy for 10 cases of brain tumors in the children ages less than 2 years old were evaluated. Six cases of brain tumor which did not involve the hypothalamic-pituitary axis, were followed more than 2 years after cranial or craniospinal irradiation. Four cases irradiated greater than 2900 rad to the whole brain all revealed markedly lower body heights than -2 SD of the medium. Growth impairment was found to be progressive over time, and markedly evident after 2 years following cranial or craniospinal radiotherapy. Somatomedin C in the blood was measured in 8 cases of brain tumors in childhood receiving radiotherapy. The measurement of Somatomedin C showed markedly low values measuring 0.19 to 0.54 U/ml (medium; 0.36 U/ml) in children having lower body height than -2 SD. Mental retardation or developmental disturbances were found in IQ or DQ tests in all of 5 infants or children younger than 2 years with brain tumors who got radiotherapy over 2900 rad to the whole brain. A case of craniopharyngioma, which had 5400 rad for tumor localization at the hypothalamus-pituitary axis and showed markedly low height, was given growth hormone and grew to normal height without distinct side effects. It was suggested that radiotherapy for brain tumors in infants or children should have special care in deciding the dose, field and time of radiation. If low height due to radiotherapy results, growth hormone therapy should be used for its treatment in childhood. (author).

Practical recommendations for breathing-adapted radiotherapy

International Nuclear Information System (INIS)

Simon, L.; Giraud, P.; Rosenwald, J.C.; Dumas, J.L.; Lorchel, F.; Marre, D.; Dupont, S.; Varmenot, N.; Ginestet, C.; Caron, J.; Marchesi, V.; Ferreira, I.; Garcia, R.

2007-01-01

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath-hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active techniques, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily holds his/her breath. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. This work summarizes the different experiences of the centers of the STIC 2003 project. It describes the different techniques, gives an overview of the literature and proposes a practice based on our experience. (authors)

Radiotherapy for cancer patients aged 85 or older

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Kan, Tomoko; Kodani, Kazuhiko; Michimoto, Koichi; Ogawa, Toshihide

2009-01-01

The purpose of this study was to investigate the clinical efficacy and problems of radiotherapy for cancer patients aged 85 or older. Fifty-three patients (26 men, 27 women) who underwent radiotherapy were analyzed retrospectively. Median age was 87 years (range; 85-99). Treatment policy was classified into curative, semi-curative (treatment field or total dose were limited due to performance status) and palliative therapy. Head-and-neck, bladder and skin cancer were the most common primary disease. The treatment was deemed curative in 27%, semi-curative in 13%, and palliative in 49%. Total dose of semi-curative therapy was almost same compared with curative therapy. The rate of treatment completion and effectiveness were not significantly different in curative therapy and semi-curative therapy. We should consider to reduce the field size to gross target volume, but to treat with substantial dose to make radiotherapy safe and effective. We must be aware that elderly patients have basically low tolerability. (author)

Adenocarcinoma of the stomach following radical radiotherapy for testicular cancer

International Nuclear Information System (INIS)

Griffith, C.D.M.; Chadderton, R.; Bourke, J.B.

1990-01-01

Two male patients who underwent curative surgery and adjuvant radiotherapy (with further chemotherapy in one) for testicular cancer developed adenocarcinoma of the stomach 5 and 19 years after treatment. The stomach is included in the field of radiotherapy used to treat the para-aortic lymph nodes and this may lead to dysplastic changes in the stomach mucosa which can lead to frank malignancy. Early endoscopy should be offered to patients with dyspeptic symptoms after adjuvant radiotherapy for testicular cancer. (author)

CNR considerations for rapid real-time MRI tumor tracking in radiotherapy hybrid devices: Effects of B{sub 0} field strength

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Wachowicz, K., E-mail: keith.wachowicz@albertahealthservices.ca; De Zanche, N.; Yip, E. [Division of Medical Physics, Department of Oncology, University of Alberta, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Volotovskyy, V. [Cross Cancer Institute, Alberta Health Services, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada); Fallone, B. G. [Department of Medical Physics, Cross Cancer Institute, 11560 University Avenue, Edmonton, Alberta T6G 1Z2, Canada and Departments of Oncology and Physics, University of Alberta, 11560 University Avenue, Edmonton, Alberta T6G 1Z2 (Canada)

2016-08-15

Purpose: This work examines the subject of contrast-to-noise ratio (CNR), specifically between tumor and tissue background, and its dependence on the MRI field strength, B{sub 0}. This examination is motivated by the recent interest and developments in MRI/radiotherapy hybrids where real-time imaging can be used to guide treatment beams. The ability to distinguish a tumor from background tissue is of primary importance in this field, and this work seeks to elucidate the complex relationship between the CNR and B{sub 0} that is too often assumed to be purely linear. Methods: Experimentally based models of B{sub 0}-dependant relaxation for various tumor and normal tissues from the literature were used in conjunction with signal equations for MR sequences suitable for rapid real-time imaging to develop field-dependent predictions for CNR. These CNR models were developed for liver, lung, breast, glioma, and kidney tumors for spoiled gradient-echo, balanced steady-state free precession (bSSFP), and single-shot half-Fourier fast spin echo sequences. Results: Due to the pattern in which the relaxation properties of tissues are found to vary over B{sub 0} field (specifically the T{sub 1} time), there was always an improved CNR at lower fields compared to linear dependency. Further, in some tumor sites, the CNR at lower fields was found to be comparable to, or sometimes higher than those at higher fields (i.e., bSSFP CNR for glioma, kidney, and liver tumors). Conclusions: In terms of CNR, lower B{sub 0} fields have been shown to perform as well or better than higher fields for some tumor sites due to superior T{sub 1} contrast. In other sites this effect was less pronounced, reversing the CNR advantage. This complex relationship between CNR and B{sub 0} reveals both low and high magnetic fields as viable options for tumor tracking in MRI/radiotherapy hybrids.

Radiotherapy in complex management of Ewing sarcoma

International Nuclear Information System (INIS)

Ruseva, Tz.; Marinova, L.; Hristozova, I.; Sokolov, T.

1996-01-01

Over the period 1981-1995, 32 patients with non-metastatic Ewing sarcoma, aged 2 to 22 years, underwent treatment and follow-up study. A locally advanced tumor is found in 85% of patients. Complex radio- and chemotherapy is carried out in all patients, and additional radical surgery - in eight. 60 Co-radiotherapy with gradual radiation field reduction is applied, applying a local dose of 60 - 64 Gy in the tumor area. Chemotherapy is performed according to the VACA protocol. Local tumor control is achieved in all patients with primary tumor located in long bones, and only in 1 of 5 patients with pelvic localization. The overall survival established is as follows: 1 year survival - 100 %, 2 years - 50 %, 3 years - 40 % and 5 years - 34 %. Local recurrence is recorded in 2 cases (6.2%). The distant metastases observed involve the lungs (13), bones (4), lung and bones (2) and soft tissues (3). The Ewing sarcoma is sensible to chemo- and radiotherapy, but the conventional methods do not improve survival. Based on the analysis of the clinical results, emphasis is laid on the necessity of complex treatment with a special reference to alternative therapeutic approaches. 13 refs., 4 figs., 2 tabs

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

Science.gov (United States)

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

2013-01-01

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

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

International Nuclear Information System (INIS)

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

2013-01-01

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

Bilateral Rhegmatogenous Retinal Detachment during External Beam Radiotherapy

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Takako Hidaka

2016-06-01

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

Biomarkers of Tumour Radiosensitivity and Predicting Benefit from Radiotherapy.

Science.gov (United States)

Forker, L J; Choudhury, A; Kiltie, A E

2015-10-01

Radiotherapy is an essential component of treatment for more than half of newly diagnosed cancer patients. The response to radiotherapy varies widely between individuals and although advances in technology have allowed the adaptation of radiotherapy fields to tumour anatomy, it is still not possible to tailor radiotherapy based on tumour biology. A biomarker of intrinsic radiosensitivity would be extremely valuable for individual dosing, aiding decision making between radical treatment options and avoiding toxicity of neoadjuvant or adjuvant radiotherapy in those unlikely to benefit. This systematic review summarises the current evidence for biomarkers under investigation as predictors of radiotherapy benefit. Only 10 biomarkers were identified as having been evaluated for their radiotherapy-specific predictive value in over 100 patients in a clinical setting, highlighting that despite a rich literature there were few high-quality studies for inclusion. The most extensively studied radiotherapy predictive biomarkers were the radiosensitivity index and MRE11; however, neither has been evaluated in a randomised controlled trial. Although these biomarkers show promise, there is not enough evidence to justify their use in routine practice. Further validation is needed before biomarkers can fulfil their potential and predict treatment outcomes for large numbers of patients. Copyright © 2015 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Low dose preoperative radiotherapy for carcinoma of the oesophagus

International Nuclear Information System (INIS)

Arnott, S.J.; Duncan, W.; Kerr, G.R.; Jack, W.J.L.; Mackillop, W.J.; Walbaum, P.R.; Cameron, E.

1992-01-01

Patients (176) with potentially operable squamous cell carcinoma or adenocarcinoma of middle or lower thirds of oesophagus were randomly assigned to preoperative radiotherapy or surgery alone. Patients assigned to the radiotherapy arm received 20 Gy in 10 treatments over 2 weeks, using parallel opposed 4 MV beams. The preoperative radiotherapy was not associated with any significant acute morbidity or any increase in operative complications. The median survival of the overall group of 176 patients was 8 moths, and the 5-year survival was 13%. There was no significant difference in the survival of the 90 patients who received preoperative radiotherapy and the 86 who were managed by surgery alone. Proportional hazards analysis identified lymph node involvement, high tumor grade and male sex as significant adverse prognostic features, but the treatment option assigned had no prognostic significance. It was concluded that low dose preoperative radiotherapy offered no advantage over surgery alone. (author). 9 refs.; 3 figs.; 6 tabs

Proton minibeam radiotherapy

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Girst, Stefanie

2016-03-08

The risk of developing adverse side effects in the normal tissue after radiotherapy is often limiting for the dose that can be applied to the tumor. Proton minibeam radiotherapy, a spatially fractionated radiotherapy method using sub-millimeter proton beams, similar to grid therapy or microbeam radiation radiotherapy (MRT) using X-rays, has recently been invented at the ion microprobe SNAKE in Munich. The aim of this new concept is to minimize normal tissue injuries in the entrance channel and especially in the skin by irradiating only a small percentage of the cells in the total irradiation field, while maintaining tumor control via a homogeneous dose in the tumor, just like in conventional broad beam radiotherapy. This can be achieved by optimizing minibeam sizes and distances according to the prevailing tumor size and depth such that after widening of the minibeams due to proton interactions in the tissue, the overlapping minibeams produce a homogeneous dose distribution throughout the tumor. The aim of this work was to elucidate the prospects of minibeam radiation therapy compared to conventional homogeneous broad beam radiotherapy in theory and in experimental studies at the ion microprobe SNAKE. Treatment plans for model tumors of different sizes and depths were created using the planning software LAPCERR, to elaborate suitable minibeam sizes and distances for the individual tumors. Radiotherapy-relevant inter-beam distances required to obtain a homogeneous dose in the target volume were found to be in the millimeter range. First experiments using proton minibeams of only 10 μm and 50 μm size (termed microchannels in the corresponding publication Zlobinskaya et al. 2013) and therapy-conform larger dimensions of 100 μm and 180 μm were performed in the artificial human in-vitro skin model EpiDermFT trademark (MatTek). The corresponding inter-beam distances were 500 μm, 1mm and 1.8 mm, respectively, leading to irradiation of only a few percent of the cells

Training in the field of dental CBCT

International Nuclear Information System (INIS)

Cantone, M.C.; Biazzi, L.

2014-01-01

Since some years the Cone Beam CT or CT volumetric Technique 'cone beam' (CBCT examination), developed with clinical applications in fields such as Interventional Radiology, surgery, intraoperative radiotherapy, breast imaging and dental. All the professional figures involved with CBCT must have received adequate training to practice the theoretical radiological application considered and have relevant expertise in the field of radiation protection. This can be especially critical in the area of dental and maxillofacial CBCT, where the dentist has not received adequate training in radiological field. It also required continuous training, in particular when new equipment are adopted and CBCT.

The pioneer of radiotherapy

International Nuclear Information System (INIS)

Camilleri, J.P.; Coursaget, J.

2005-09-01

This work narrates the history of the birth of a new field, the radiology and its application to radiotherapy for these multiform pathologies that are the cancers. Two leading figures will favour this field: Marie Curie, physicist and twice awarded by nobel price, and Claudius Regaud, histologist and become a specialist of the action of ionizing radiations on tissues. They will create the Curie Institute, in relation with the Radium Institute and the support of the Pasteur Institute in 1920. (N.C.)

Optimization of the primary collimator settings for fractionated IMRT stereotactic radiotherapy

International Nuclear Information System (INIS)

Tobler, Matt; Leavitt, Dennis D.; Watson, Gordon

2004-01-01

Advances in field-shaping techniques for stereotactic radiosurgery/radiotherapy have allowed dynamic adjustment of field shape with gantry rotation (dynamic conformal arc) in an effort to minimize dose to critical structures. Recent work evaluated the potential for increased sparing of dose to normal tissues when the primary collimator setting is optimized to only the size necessary to cover the largest shape of the dynamic micro multi leaf field. Intensity-modulated radiotherapy (IMRT) is now a treatment option for patients receiving stereotactic radiotherapy treatments. This multisegmentation of the dose delivered through multiple fixed treatment fields provides for delivery of uniform dose to the tumor volume while allowing sparing of critical structures, particularly for patients whose tumor volumes are less suited for rotational treatment. For these segmented fields, the total number of monitor units (MUs) delivered may be much greater than the number of MUs required if dose delivery occurred through an unmodulated treatment field. As a result, undesired dose delivered, as leakage through the leaves to tissues outside the area of interest, will be proportionally increased. This work will evaluate the role of optimization of the primary collimator setting for these IMRT treatment fields, and compare these results to treatment fields where the primary collimator settings have not been optimized

Radiation caries - an evil eye of radiotherapy

International Nuclear Information System (INIS)

Lakshman, Anusha Rangare

2013-01-01

Although radiotherapy plays an important role in the management of patients with head and neck cancer, it is also associated with several undesired side effects such as radiation caries which is a common, yet serious, complication. The radiotherapy field of exposure frequently includes the salivary glands, oral mucosa, and jaws, thus, leading to various side effects including hyposalivation, mucositis, and taste loss. Irradiated patients are also at increased risk for the development of a rapid, rampant carious process known as radiation caries. Lesions tend to develop four weeks after completion of radiotherapy and affect atypical areas of teeth, such as the lingual surface, incisal edges, and cusp tips. The aim of this paper is to review the clinical features, prevention and management of radiation caries. (author)

Relationship of bone marrow dose to eosinophilia following radiotherapy

International Nuclear Information System (INIS)

Murohashi, Ikuo; Gomi, Hiromichi; Nakano, Takashi; Morita, Shinroku; Arai, Tatsuo; Jinnai, Itsuro; Nara, Nobuo; Bessho, Masami; Hirashima, Kunitake.

1986-01-01

Absolute blood eosinophils were counted prior to and during radiotherapy in a total of 380 patients with carcinoma in the chest, pelvis, or abdomen. The patients were divided into 5 groups by types of cancer, and these groups differed in the irradiation sites or the sizes of radiation field. Accumulated bone marrow dose from the start of radiotherapy to the time when eosinophil count during radiotherapy reached its peak was simultaneously determined. In each group, maximum eosinophil count during radiotherapy was significantly increased compared with the value before radiotherapy. In all groups except one, the increase in eosinophil count following radiotherapy was directly proportional to the bone marrow dose. However, in the most heavily irradiated ovarian cancer group, the increase in eosinophil count was markedly lower. In contrast, neutrophils were reduced in numbers in all groups. These results suggest that bone marrow (red marrow) damage by irradiation results in eosinophilia, and that unimpaired hemopoiesis is also indispensable for such an eosinophil response. Accumulated bone marrow doses of 800 - 900 rad given during 4 weeks fractionated irradiation caused the most prominent eosinophilia. (author)

Tumors in dogs exposed to experimental intraoperative radiotherapy

International Nuclear Information System (INIS)

Johnstone, Peter A.S.; Laskin, William B.; De Luca, Anne Marie; Barnes, Margaret; Kinsella, Timothy J.; Sindelar, William F.

1996-01-01

Purpose: The frequency of radiation-induced neoplasms was determined in dogs enrolled in the National Cancer Institute canine trials of intraoperative radiotherapy (IORT). Methods and Materials: Twelve protocols assessing normal tissue response to IORT involved 238 dogs in a 15-year trial. Eighty-one dogs were followed for > 24 months postoperatively and were assessed for tumor development; 59 of these animals received IORT. Results: Twelve tumors occurred in the 59 dogs receiving IORT. Nine were in the IORT portals and were considered to be radiation induced. No tumors occurred in 13 sham animals or in 9 animals treated with external beam radiotherapy alone. The frequency of radiation-induced malignancies in dogs receiving IORT was 15%, and was 25% in animals receiving ≥ 25 Gy IORT. Frequency of all tumors, including spontaneous lesions, was 20%. Conclusions: Intraoperative radiotherapy contributed to a high frequency of sarcoma induction in these dogs. Unknown to date in humans involved in clinical trials of IORT, this potential complication should be looked for as long-term survivors are followed

Trial study on design of irradiated fields of radiotherapy in cervical and upper thoracic esophageal cancer

International Nuclear Information System (INIS)

Liu Hui; Zeng Zhifan; Cui Nianji; He Zhichun; Huang Shaomin

2006-01-01

Objective: To compare three kinds of irradiation treatment plans for cervical and upper thoracic esophageal cancer, in order to arrived at proper decision for the patient. Methods: From February 2001 to June 2004, 43 such patients were studied with three different simulated treatment plans made including conformal plan, conventional four-field plan and conventional two-field plan for every one. All plans were evaluated with iso- dose curve and dose-volume histogram. Results: GTV on 95% isodose curve was 99.5%, 98.2% and 87.4% in conformal plan, conventional four-field plan and conventional two-field plan, respectively; PTV 1 and PTV 2 on 95% isodose with 97.8%, 97.2%, 94.8% and 95.8%, 86.6%, 73.7%. The volume of > 20 Gy dose of left lung accepted was 18.6%, 17.2% and 32.3%, in conformal plan, conventional four-field plan and conventional two-field plan, respectively; the right lung received 20.5% ,19.9% and 35.5%. Conclusions: Conformal plan is the best in radiotherapy, as it can provide ideal dose distribution of irradiated target with adequate protection of the normal tissues. Conventional four-field plan, being easy to carry, out, can replace the conformal plan in most situations. Conventional two-field has the most uneven dose distribution and largest lung volume irradiated. (authors)

Stereotactic body radiotherapy a practical guide

CERN Document Server

Gaya, Andrew

2015-01-01

Collecting the key information in this burgeoning field into a single volume, this handbook for clinical oncology trainees and consultants covers all of the basic aspects of stereotactic radiotherapy systems and treatment and includes plenty of case studies.

Radiotherapy of uterine body cancer with preliminary cryodestruction of the tumor

International Nuclear Information System (INIS)

Myikhanovs'kij, O.A.

2001-01-01

The study involved 57 patients, of them 28 with cryodestruction of the tumor before radiotherapy and 29 patients with uterine body cancer treated with radiotherapy without cryotherapy (control). In 28 patients of the study group, 3-year survival was 25. In the control unsatisfactory results were observed in 12 of the patients

Clinical quality standards for radiotherapy

Science.gov (United States)

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

Radiotherapy for superficial esophageal cancer of poor risk patients

International Nuclear Information System (INIS)

Kagami, Yoshikazu; Ikeda, Hiroshi; Murayama, Shigeyuki; Yamaguchi, Hajime; Tachimori, Yuji; Kato, Hoichi; Watanabe, Hiroshi; Tokuue, Kouichi; Sumi, Minako; Kawashima, Mitsuhiko; Imai, Atsushi; Nakayama, Shuji

1997-01-01

Purpose/Objective: The reported incidence of superficial esophageal cancer (SEC) has steadily increased in Japan as result of endoscopic examination has been become common. In Japan, treatment of SEC is endoscopical mucosal resection (EMR) for mucosal cancer or esophagectomy with 3 fields lymph nodes resection for submucosal cancer. Radiotherapy is little place for the management of SEC. Because of some reasons, we treated patients with SEC by radiotherapy alternative to surgery. Purpose of this report is to evaluate efficacy of radiotherapy for SEC. Methods and Materials: Between 1989 to 1996, eighteen patients with SEC were treated with radiotherapy at our hospital. Reasons of radiotherapy that was chosen as the primary methods of treatment were refusal of surgery in one patient, poor medical condition in 4 patients and double primary cancer in 13 patients (head and neck: 11, simultaneously: 11). No patients had indication of EMR. Diagnosis was made by endoscopy and radiography. Some patients were examined with endoscopic ultrasound. Two patients (11.1%) had tumor limited to the mucosa and 16 patients (88.9%) had tumor invaded the submucosa. Seven of these tumors (38.9%) were multicentric. All patients had squamous cell carcinoma. There were 17 male patients and one female patient. The age range was 49 years to 87 years with a median of 62 years. Stage of all patients was T1N0M0 according to UICC staging system. Ten patients underwent external radiotherapy (Ex) (50 Gy - 66 Gy) alone and 8 patients did both Ex and intracavitary radiotherapy (IC) (30-60 Gy of Ex with 5-15 Gy of IC). No patients received chemotherapy. Duration of follow-up was 6 months to 96 months with a median of 30 months. Results: The overall survival rate was 55.9% in 3-year and 14% in 5-year, and the cause-specific 5-year survival rate was 100%. Causes of death were malignant tumor other than esophageal cancer in 4 patients, intercurrent disease other than malignant tumor in 3 patients and no

Efficacy and complications of radiotherapy of anterior visual pathway tumors

International Nuclear Information System (INIS)

Capo, H.; Kupersmith, M.J.

1991-01-01

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

Target volume determination in radiotherapy for non-small-cell lung cancer-facts and questions

International Nuclear Information System (INIS)

Kepka, L.; Bujko, K.

2003-01-01

Although the precise target volume definition in conformal radiotherapy is required by ICRU Report 50 and 62, this task in radiotherapy for non-small-cell lung cancer (NSCLC) is often controversial and strict accordance with ICRU requirements is hard to achieve. The Gross Tumour Volume (GTV) definition depends mainly on the imaging method used. We discuss the use of new imaging modalities, like PET, in GTV definition. The Clinical Target Volume (CTV) definition remains a separate, and still unresolved problem, especially in the part concerning the Elective Nodal Irradiation (ENI). Nowadays, there is no unified attitude among radiation oncologists regarding the necessity and extent of ENI. The common use of combined treatment modalities and the tendency to dose escalation, both increasing the potential toxicity, result in the more frequent use of involved-fields techniques. Problems relating to margins during Planning Target Volume (PTV) of lung cancer irradiation are also discussed. Another issue is the Interclinician variability in target volumes definition, especially when there is data indicating that the GTV, as defined by 3 D-treatment planning in NSCLC radiotherapy, may be highly prognostic for survival. We postulate that special attention should be paid to detailed precision of target volume determination in departmental and trial protocols. Careful analysis of patterns of failures from ongoing protocols will enable us to formulate the guidelines for target volume definition in radiotherapy for lung cancer. (author)

Axillary radiotherapy in conservative surgery for early-stage breast cancer (stage I and II).

Science.gov (United States)

García Novoa, Alejandra; Acea Nebril, Benigno; Díaz, Inma; Builes Ramírez, Sergio; Varela, Cristina; Cereijo, Carmen; Mosquera Oses, Joaquín; López Calviño, Beatriz; Seoane Pillado, María Teresa

2016-01-01

Several clinical studies analyze axillary treatment in women with early-stage breast cancer because of changes in the indication for axillary lymph node dissection. The aim of the study is to analyze the impact of axillary radiotherapy in disease-free and overall survival in women with early breast cancer treated with lumpectomy. Retrospective study in women with initial stages of breast carcinoma treated by lumpectomy. A comparative analysis of high-risk women with axillary lymph node involvement who received axillary radiotherapy with the group of women with low risk without radiotherapy was performed. Logistic regression was used to determine factors influencing survival and lymphedema onset. A total of 541 women were included in the study: 384 patients (71%) without axillary lymph node involvement and 157 women (29%) with 1-3 axillary lymph node involvement. Patients with axillary radiotherapy had a higher number of metastatic lymph node compared to non-irradiated (1.6±0.7 vs. 1.4±0.6, P=.02). The group of women with axillary lymph node involvement and radiotherapy showed an overall and disease-free survival at 10 years similar to that obtained in patients without irradiation (89.7% and 77.2%, respectively). 3 lymph nodes involved multiplied by more than 7 times the risk of death (HR=7.20; 95% CI: 1.36 to 38.12). The multivariate analysis showed axillary lymph node dissection as the only variable associated with the development of lymphedema. The incidence of axillary relapse on stage I and II breast cancer is rare. In these patients axillary radiotherapy does not improve overall survival, but contributes to regional control in those patients with risk factors. Copyright © 2016 AEC. Publicado por Elsevier España, S.L.U. All rights reserved.

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

Energy Technology Data Exchange (ETDEWEB)

Kim, Jinu; Shin, Eun Seow; Kim, Jeong Eon; Yoon, Sang Pil [Jeju National University School of Medicine, Jeju (Korea, Republic of); Kim, Young Suk [Dept. of Radiation Oncology, Jeju National University Hospital, Jeju National University School of Medicine, Jeju (Korea, Republic of)

2015-12-15

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

Laparoscopic pelvic sling placement facilitates optimum therapeutic radiotherapy delivery in the management of pelvic malignancy.

LENUS (Irish Health Repository)

Joyce, M

2012-02-01

BACKGROUND: Radiotherapy has a significant role in the management of pelvic malignancies. However, the small intestine represents the main dose limiting organ. Invasive and non-invasive mechanical methods have been described to displace bowel out of the radiation field. We herein report a case series of laparoscopic placement of an absorbable pelvic sling in patients requiring pelvic radiotherapy. METHODS: Six patients were referred to our minimally invasive unit. Four patients required radical radiotherapy for localised prostate cancer, one was scheduled for salvage localised radiotherapy for post-prostatectomy PSA progression and one patient required adjuvant radiotherapy post-cystoprostatectomy for bladder carcinoma. All patients had excessive small intestine within the radiation fields despite the use of non-invasive displacement methods. RESULTS: All patients underwent laparoscopic mesh placement, allowing for an elevation of small bowel from the pelvis. The presence of an ileal conduit or previous surgery did not prevent mesh placement. Post-operative planning radiotherapy CT scans confirmed displacement of the small intestine allowing all patients to receive safely the planned radiotherapy in terms of both volume and radiation schedule. CONCLUSION: Laparoscopic mesh placement represents a safe and efficient procedure in patients requiring high-dose pelvic radiation, presenting with unacceptable small intestine volume in the radiation field. This procedure is also feasible in those that have undergone previous major abdominal surgery.

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

International Nuclear Information System (INIS)

Vieira, Wilson Albieri; Nadalin, Wladimir; Odone Filho, Vicente; Petrilli, Antonio Sergio; Weltman, Eduardo; Chen, Michael Jenwei; Silva, Nasjla Saba da; Cappellano, Andrea Maria; Pereira, Liliane Desgualdo; Gonçalves, Maria Ines Rabelo; Ferrigno, Robson; Hanriot, Rodrigo Morais

2014-01-01

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. 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. 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/m 2 (p < 0.01). 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/m 2

Bystander effects and radiotherapy.

Science.gov (United States)

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.

Effect of radiotherapy on immunity function of cancer patients receiving radiotherapy

International Nuclear Information System (INIS)

Li Xinli; Zhu Shentao; Xu Jiuhong

2003-01-01

Objective: In order to observe the effect of radiotherapy on immunity function of cancer patients receiving radiotherapy. Methods: Cellular immunity is determined by APAAP; Humoral immunity is determined by transmission method. Results: The items of cellular immunity is lower than the control after radiotherapy. These items decrease continually. The difference between before and after radiotherapy has statistic significance. Of all Humoral immunity items, IgA, IgM decreased after radiotherapy and the difference has statistic significance. Conclusions: Radiotherapy can damage patients' immunity function

Intra-operative radiotherapy of malignant tumors: Past, present and perspectives

International Nuclear Information System (INIS)

Mazeron, J.J.; Le Bourgeois, J.P.; Ganem, G.

1986-01-01

Intra-operative radiotherapy consists of electron or photon radiation which is used during the operative procedure. The treatment field is arranged very precisely after critical organs have been previously arranged out of the field. The target volume includes the remaining tumor which could not be removed surgically, and the surrounding tumor bed which is also felt to be high risk for recurrence. It is preferable to have as little tumor remaining as possible before the intra-operative treatment radiation is given. Intra-operative radiotherapy was developed less than a quarter century ago in Japon, and it was later used in U.S.A. The accumulated experience in Japan and U.S.A. is rewieved here. Intra-operative radiotherapy has only recently been introduced to France. The biology, physics and medical and technical problems of intra-operative therapy are discussed [fr

Monte Carlo Treatment Planning for Advanced Radiotherapy

DEFF Research Database (Denmark)

Cronholm, Rickard

This Ph.d. project describes the development of a workflow for Monte Carlo Treatment Planning for clinical radiotherapy plans. The workflow may be utilized to perform an independent dose verification of treatment plans. Modern radiotherapy treatment delivery is often conducted by dynamically...... modulating the intensity of the field during the irradiation. The workflow described has the potential to fully model the dynamic delivery, including gantry rotation during irradiation, of modern radiotherapy. Three corner stones of Monte Carlo Treatment Planning are identified: Building, commissioning...... and validation of a Monte Carlo model of a medical linear accelerator (i), converting a CT scan of a patient to a Monte Carlo compliant phantom (ii) and translating the treatment plan parameters (including beam energy, angles of incidence, collimator settings etc) to a Monte Carlo input file (iii). A protocol...

Radiotherapy in the management of orbital lymphoma

International Nuclear Information System (INIS)

Bolek, Timothy W.; Moyses, H. Michael; Marcus, Robert B.; Mendenhall, Nancy Price

1996-01-01

Purpose/Objective: This retrospective study reviews the treatment technique, disease outcome and complications of radiotherapy used in the management of lymphoma involving the orbits. Materials and Methods: Thirty-eight patients were treated between May 1969 and January 1995 with a median follow-up of 8.3 years. All patients had biopsy-proven orbital lymphoma. Therapy was delivered with curative intent in 20 patients and with palliative intent in 18 patients who had known systemic disease. Of the 20 patients treated with curative intent, 14 had low-grade and 6 had intermediate or high-grade disease. None received chemotherapy. Most patients received treatment with 250 kVP or 60 Co X rays, using either an en face anterior field or wedged anterior and lateral fields. Treatment dose ranged from 5 to 53 Gy with a median of 25 Gy. Lens shielding was performed using either a lead contact lens or a hanging brass shield. For patients treated for cure, cause-specific survival and freedom from distant relapse were calculated using the Kaplan-Meier method. Results: Control of disease in the orbit was achieved in all but 1 patient, who developed an out-of-field recurrence after irradiation of a lacrimal tumor. This patient was salvaged with further radiotherapy. In the patients treated curatively, 5 year actuarial freedom from distant relapse was 61% for those with low-grade and 33% for those with intermediate/high-grade disease (p = 0.08). Cause-specific survival at 5 years was 89% for patients with low-grade and 33% for those with intermediate/high grade disease (p = 0.005). There were 2 contralateral orbital failures, both in patients with low-grade disease, and both patients were salvaged with further irradiation. Treatment failed in nodal sites alone in 4 patients, and none were salvaged. Relapses occurred in both nodal and extra nodal sites in 3 patients, and 2 of them were treated successfully with chemotherapy. Acute toxicity was minimal. Cataracts developed in 7 of 21

Evaluation of lens dose in medulloblastoma radiotherapy

International Nuclear Information System (INIS)

Oliveira, F.L.; Vilela, E.C.; Sousa, S.A; Lima, F.F. de

2007-01-01

The improvement of the applied radiotherapy techniques in the cranial-spinal therapy, which is used in the cases of medulloblastoma, aims the reduction of the risks of future damages in enclosed critical agencies in the irradiation fields. This work aims to evaluate the lens doses due two common techniques used in medulloblastoma radiotherapy. For this, thermoluminescent dosimeters, previously calibrated, were located in an anthropomorphic phantom (ALDERSON - RANDON Laboratory), in the tumor and lens positions. The employed techniques were as following: (1) angled fields technique and (2) half-beam block technique. The phantom was irradiated five times in each technique with two lateral opposed fields in the brain with a total prescribed dose of 1.5 Gy, followed of two posterior spinal fields with the same prescribed dose, using a 6MV accelerator. The results showed that the doses in the first technique were 0.10 +- 0,04 Gy and, in second one, 0.09 +- 0,02 Gy. It was observed that, independent of the employed technique, the lens doses practically are the same. (author)

Radiotherapy of prostate cancer

International Nuclear Information System (INIS)

Krause, S.; Herfarth, K.

2011-01-01

With the development of modern radiation techniques, such as intensity-modulated radiotherapy (IMRT), a dose escalation in the definitive radiotherapy of prostate cancer and a consecutive improvement in biochemical recurrence-free survival (BFS) could be achieved. Among others, investigators at the Memorial Sloan-Kettering Cancer Center (MSKCC) saw 5-year BFS rates of up to 98%. A further gain in effectiveness and safety is expected of hypofractionation schedules, as suggested by data published by Kupelian et al., who saw a low 5-year rate of grade ≥2 rectal side-effects of 4.5%. However, randomized studies are just beginning to mature. Patients with intermediate or high-risk tumors should receive neoadjuvant (NHT) and adjuvant (AHT) androgen deprivation. Bolla et al. could show an increase in 5-year overall survival from 62-78%. The inclusion of the whole pelvis in the treatment field (WPRT) is still controversial. The RTOG 94-13 study showed a significant advantage in disease-free survival after 60 months but long-term data did not yield significant differences between WPRT and irradiation of the prostate alone. The German Society of Urology strongly recommends adjuvant radiotherapy of the prostate bed for pT3 N0 tumors with positive margins. In a pT3 N0 R0 or pT2 N0 R+ situation, adjuvant radiotherapy should at least be considered. So far, no randomized data on NHT and AHT have been published, so androgen deprivation remains an individual decision in the postoperative setting. In a retrospective analysis Spiotto et al. reported a positive effect for adjuvant WPRT and biochemical control. This article summarizes the essential publications on definitive and adjuvant radiotherapy and discusses the additional use of androgen deprivation and WPRT. (orig.) [de

Approaches to radiotherapy in metastatic spinal cord compression.

Science.gov (United States)

Suppl, Morten Hiul

2018-04-01

Metastatic spinal cord compression is caused by the progression of metastatic lesions within the vicinity of the spinal cord. The consequences are very severe with loss of neurological function and severe pain. The standard treatment is surgical intervention followed by radiotherapy or radiotherapy alone. However, the majority of patients are treated with radiotherapy only due to contraindications to surgery and technical inoperability. Stereotactic body radiotherapy is a technology to deliver higher radiation dose to the radiotherapy target with the use of spatial coordinates. This modality has shown positive results in treating lesions in brain and lungs. Hence, it could prove beneficial in metastatic spinal cord compression. We designed and planned a trial to investigate this method in patients with metastatic spinal cord compression. The method was usable but the trial was stopped prematurely due to low accrual that made comparison with surgery impossible. Low accrual is a known problem for trials evaluating new approaches in radiotherapy. Target definition in radiotherapy of metastatic spinal cord compression is defined by patient history, examination and imaging. Functional imaging could provide information to guide target definition with the sparring of normal tissue e.g. spinal cord and hematopoietic tissue of the bone marrow. In future trials this may be used for dose escalation of spinal metastases. The trial showed that PET/MRI was feasible in this group of patients but did not change the radiotherapy target in the included patients. Neurological outcome is similar irrespective of course length and therefore single fraction radiotherapy is recommended for the majority of patients. In-field recurrence is a risk factor of both short and long fractionation schemes and re-irradiation have the potential risk of radiation-induced myelopathy. In a retrospective study of re-irradiation, we investigated the incidence of radiation-induced myelopathy. In our study

Postoperative radiotherapy of uterine sarcoma: A multicentric retrospective study; Radiotherapie postoperatoire dans les sarcomes uterins: etude retrospective multicentrique

Energy Technology Data Exchange (ETDEWEB)

Champetier, C.; Cowen, D. [Service de radiotherapie, hopital de la Timone, 264, rue Saint-Pierre, 13385 Marseille cedex 05 (France); Hannoun-Levi, J.M. [Centre Antoine-Lacassagne, 33, avenue Valombrose, 06100 Nice (France); Resbeut, M. [Centre de radiotherapie Saint-Louis, rue Andre-Blondel, 83100 Toulon (France); Azria, D. [Centre Val-d' Aurelle-Paul-Lamarque, 208, rue des Apothicaires, 34298 Montpellier cedex 5 (France); Salem, N. [Institut Paoli-Calmettes, 232, boulevard Sainte-Marguerite, 13009 Marseille (France); Tessier, E. [Centre azureen de radiotherapie, 1, place du Docteur-Jean-Luc-Broquerie, 06250 Mougins (France); Ellis, S. [Centre catalan de radiotherapie, 80, rue Pascal-Marie-Agasse, 66000 Perpignan (France)

2011-04-15

Purpose. - Surgery is the treatment of choice for localized uterine sarcomas. We conducted a retrospective study to define prognostic factors. Patients and methods. - We studied 111 cases of patients treated by adjuvant radiotherapy for uterine sarcoma in seven French centers. The median decline was 31 months. We conducted a univariate analysis to identify factors correlated with local recurrence. The statistically significant factors were studied in multivariate analysis by Cox model. Results. - The median dose of external beam radiotherapy was 45 Gy. Forty-three percent of patients had vaginal vault brachytherapy and 21 % chemotherapy. Only 6.3 % of patients had complications of acute grade III and 8.1 % of long-term sequelae of radiotherapy. The survival rate at 5 years was 74.6 %. They noted 12.6 % of isolated locoregional recurrences, against 29.7 % for distant recurrences, 80 % were pulmonary. Factors correlated with the risk of locoregional relapse were menopausal status (P = 0.045) and surgical margins suspicious or not healthy (P = 0.0095). The chemotherapy did not improve overall survival or disease free survival but the numbers were low. Conclusion. - The postoperative radiotherapy provides good local control in this disease. Brachytherapy is sometimes done, but it does not improve local control. Chemotherapy is not a standard localized stage but the rate of metastatic recurrence calls for the development of strategies involving systemic treatment with radiotherapy. (authors)

Parotid gland sparing radiotherapy technique using 3-D conformal radiotherapy for nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Lim, Ji Hoon; Kim, Gwi Eon; Keum, Ki Chang; Suh, Chang Ok; Lee, Sang Wook; Park, Hee Chul; Cho, Jae Ho; Chang, Sei Kyung; Loh, Juhn Kyu

2000-01-01

Although using the high energy photon beam with conventional parallel-opposed beams radio-therapy for nasopgaryngeal carcinoma, radiation-induced xerostomia is a troublesome problem for patients. We conducted this study to explore a new parotid gland sparing technique in 3-D conformal radiotherapy (3-DCRT) in an effort to prevent the radiation-induced xerostomia. We performed three different planning for four clinically node-negative nasopharyngeal cancer patients with different location of tumor(intracranial extension, nasal cavity extension, oropharyngeal extension, parapharyngeal extension), and intercompared the plans. Total prescription dose was 70.2 Gy to the isocenter. For plan-A, 2-D parallel opposing fields, a conventional radiotherapy technique, were employed. For plan-B, 2-D parallel opposing fields were used up until 54 Gy and afterwards 3-D non-coplanar beams were used. For plan-C, the new technique, 54Gy was delivered by 3-D conformal 3-port beams (AP and both lateral ports with wedge compensator, shielding both superficial lobes of parotid glands at the AP beam using BEV) from the beginning of the treatment and early spinal cord block (at 36 Gy) was performed. And bilateral posterior necks were treated with electron after 36 Gy. After 54 Gy, non-coplanar beams were used for cone-down plan. We intercompared dose statistics (Dmax, Dmin, Dmean, D95, D05, V95, V05, Volume receiving 46 Gy) and dose volume histograms (DVH) of tumor and normal tissues and NTCP values of parotid glands for the above three plans. For all patients, the new technique (plan-C) was comparable or superior to the other plans in target volume isodose distribution and dose statistics and it has more homogenous target volume coverage. The new technique was most superior to the other plans in parotid glands sparing (volume receiving 46 Gy: 100, 98, 69% for each plan-A, B and C). And it showed the lowest NTCP value of parotid glands in all patients (range of NTCP; 96-100%, 79-99%, 51

A third generation regimen VACOP-B with or without adjuvant radiotherapy for aggressive localized non-Hodgkin's lymphoma: report from the Italian Non-Hodgkin's Lymphoma Co-operative Study Group

Directory of Open Access Journals (Sweden)

G. Santini

2004-05-01

Full Text Available The objective of this multicenter prospective study was to determine the clinical efficacy and toxicity of a polychemotherapeutic third generation regimen, VACOP-B, with or without radiotherapy as front-line therapy in aggressive localized non-Hodgkin's lymphoma. Ninety-three adult patients (47 males and 46 females, median age 45 years with aggressive localized non-Hodgkin's lymphoma, 43 in stage I and 50 in stage II (non-bulky, were included in the study. Stage I patients received VACOP-B for 6 weeks plus involved field radiotherapy and stage II patients received 12 weeks VACOP-B plus involved field radiotherapy on residual masses. Eighty-six (92.5% achieved complete remission and 4 (4.3% partial remission. Three patients (3.2% were primarily resistant. Ten-year probability of survival, progression-free survival and disease-free survival were 87.3, 79.9 and 83.9%, respectively. Eighty-four patients are surviving at a median observation time of 57 months (range: 6-126. Statistical analysis showed no difference between stages I and II in terms of response, ten-year probability of survival, progression-free survival or disease-free survival. Side effects and toxicity were negligible and were similar in the two patient groups. The results of this prospective study suggest that 6 weeks of VACOP-B treatment plus radiotherapy may be the therapy of choice in stage I aggressive non-Hodgkin's lymphoma. Twelve weeks of VACOP-B treatment with or without radiotherapy was shown to be effective and feasible for stage II. These observations need to be confirmed by a phase III study comparing first and third generation protocols in stage I-II aggressive non-Hodgkin's lymphoma.

Moving toward multi-dimensional radiotherapy and the role of radiobiology

International Nuclear Information System (INIS)

Oita, Masataka; Uto, Yoshihiro; Aoyama, Hideki

2014-01-01

Recent radiotherapy for cancer treatment enable the high-precision irradiation to the target under the computed image guidance. Developments of such radiotherapy has played large role in the improved strategy of cancer treatments. In addition, the molecular mechanistic studies related to proliferations of cancer cell contribute the multidisciplinary fields of clinical radiotherapies. Therefore, the combination of the image guidance and molecular targeting of cancer cells make it possible for individualized cancer treatment. Especially, the use of particle beam or boron neutron capture therapy (BNCT) has been spotlighted, and installations of such devices are planned widely. As the progress and collaborations of radiation biology and engineering physics, establishment of a new style of radiotherapy becomes available in post-genome era. In 2010s, the hi-tech machines controlling the spaciotemporal radiotherapy become in practice. Although, there still remains to be improved, e.g., more precise prediction of radiosensitivity or growth of individual tumors, and adverse outcomes after treatments, multi-dimensional optimizations of the individualized irradiations based on the molecular radiation biologies and medical physics are important for further development of radiotherapy. (author)

The United Kingdom's radiotherapy dosimetry audit network

International Nuclear Information System (INIS)

Thwaites, D.I.; Allahverdi, M.; Powley, S.K.; Nisbet, A.

2003-01-01

The first comprehensive national dosimetry intercomparison in the United Kingdom involving all UK radiotherapy centres was carried out in the late 1980s. Out of this a regular radiotherapy dosimetry audit network evolved in the early 1990s. The network is co-ordinated by the Institute of Physics and Engineering in Medicine and comprises eight co-operative regional groups. Audits are based on site visits using ionization chambers and epoxy resin water substitute phantoms. The basic audit methodology and phantom design follows that of the original national intercomparison exercise. However, most of the groups have evolved more complex methods, to extend the audit scope to include other parameters, other parts of the radiotherapy process and other treatment modalities. A number of the groups have developed phantoms to simulate various clinical treatment situations, enabling the sharing of phantoms and expertise between groups, but retaining a common base. Besides megavoltage external beam photon dosimetry, a number of the groups have also included the audit of kilovoltage X ray beams, electron beams and brachytherapy dosimetry. The National Physical Laboratory is involved in the network and carries out basic beam calibration audits to link the groups. The network is described and the methods and results are illustrated using the Scottish+ group as an example. (author)

An investigation of anxiety about radiotherapy deploying the radiotherapy categorical anxiety scale

International Nuclear Information System (INIS)

Shimotsu, Sakie; Karasawa, Kumiko; Ito, Kana; Saito, Anneyuko I.; Izawa, Hiromi; Kawase, Eri; Horikawa, Naoshi

2010-01-01

Radiotherapy is one of the major methods for treating cancer, but many patients undergoing radiotherapy have deep concerns about receiving radiation treatment. This problem is not generally appreciated and has not been adequately studied. The objective of this investigation was to empirically investigate the anxieties that cancer patients feel towards radiotherapy by using questionnaires to classify and quantitatively measure their concerns. A preliminary interview to develop a questionnaire was carried out with 48 patients receiving radiotherapy to discover their anxieties about on-going treatments. Subsequently, a main study was performed using a questionnaire with 185 patients to classify their types of anxiety and to ascertain the reliability and validity of the responses. Confirmatory factor analysis was then carried out with a 17-item Radiotherapy Categorical Anxiety Scale. Three anxiety factors were abstracted by factor analysis: adverse effects of radiotherapy, environment of radiotherapy, and treatment effects of radiotherapy. Reliability, content validity, and concurrent validity were obtained. The adequacy of the three-factor model of anxiety concerning radiotherapy was confirmed. A 17-item Radiotherapy Categorical Anxiety Scale was formulated to quantitatively measure the specific types of anxiety among cancer patients receiving radiotherapy. (author)

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

Science.gov (United States)

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.

Postmastectomy radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Shikama, Naoto; Koguchi, Masahiko; Sasaki, Shigeru; Kaneko, Tomoki; Shinoda, Atsunori; Nishikawa, Atsushi [Shinshu Univ., Matsumoto, Nagano (Japan). School of Medicine

2000-10-01

Since there have been few reports on postmastectomy radiotherapy having a high evidence level in Japan, the significance of postoperative radiotherapy and the irradiation techniques were reviewed based on reports from Western countries. Authors focused on the indications for postoperative irradiation, irradiation methods (irradiation sites, irradiation techniques; prosthetics, methods of irradiating the chest wall and lymph nodes, timing of irradiation), and complications, and discuss them. The factors thought to be adaptable to postmastectomy radiotherapy have been listed. Axillary lymph node metastasis and the size of the primary focus are thought to be important factors in locoregional recurrence. The chest wall and the supraclavicular lymph nodes are the usual sites of irradiation after mastectomy. The irradiation method consists of tangential irradiation of the chest wall and single-field irradiation of the supraclavicular lymph nodes, with 46-50 Gy in fractional doses of 1.8-2 Gy x 5/w is administered for 4.5-5.5 weeks. The timing of irradiation in the West is generally after chemotherapy. Adverse radiation effects include ischemic heart disease, pneumonitis, arm edema, rib fractures, and brachial plexus paralysis. The frequency of these complications is increased by the combined use of chemotherapy or surgery. The breast cancer cure rate in Japan is generally better than in the West. It remains to be determined whether the clinical data from Europe and America are applicable to the treatment of breast cancer in Japan. To address this issue, a clinical investigation should be performed in Japan with close cooperation between surgeons, physicians, pathologists, and radiotherapists. (K.H.)

Concurrent paclitaxel and radiotherapy. Treatment feasibility studies

International Nuclear Information System (INIS)

Vogt, H.G.; Martin, T.; Kolotas, C.; Hey, S.; Schneider, L.; Templin, T.; Zamboglou, N.; Dornoff, W.; Kettner, H.

1997-01-01

Background: The anti-neoplastic effect of paclitaxel has been demonstrated in various clinical studies in different malignant diseases. Clinical studies have also demonstrated a greater efficacy for simultaneous radio-chemotherapy compared with radiotherapy alone when using radiosensitizing drugs. Based on these clinical and in-vitro data we initiated several pilot studies using paclitaxel as a radiosensitizing agent and we now present our initial experience in its use in a combined modality protocol, radiation and simultaneous chemotherapy with paclitaxel. Methods: I. Concurrent paclitaxel and radiation for locally advanced non-small-cell lung cancer (NSCLC): In a phase-I-study we applicated paclitaxel (45 to 65 mg/m 2 ) as a 3-hour infusion weekly for 3 to 7 weeks simultaneously with primary radiotherapy in shrinking field technique with 5x1.8 Gy/week up to 59.4 Gy. - II. Concurrent paclitaxel and radiation for breast cancer as neoadjuvant or palliative: 50 mg/m 2 paclitaxel as a 3-hour infusion weekly for 6 weeks simultaneous with neoadjuvant or palliative radiotherapy of the breast/chest wall with 5x1.8 Gy/week up to 54.0 Gy. - III./IV. Concurrent paclitaxel/carboplatin and combined radiation (EBRT+brachytherapy) for locally advanced inoperable cancer of the cervix: 50 mg/m 2 paclitaxel as a 3-hour infusion weekly for 5 weeks, 50 mg/m 2 carboplatin at day 1 to 5 in week 1 and 5 simultaneously with external beam radiotherapy of the pelvis with 5x1.8 Gy/week up to 54.0 Gy and endocavitary LDR-brachytherapy (4x5 Gy). - V. Concurrent paclitaxel and radiation for locally advanced inoperable cancer of the bladder: 50 mg/m 2 paclitaxel as a 3-hour infusion weekly for 5 weeks simultaneous with radiotherapy of the pelvis with 5x1.8 Gy/week up to 50.4 Gy. VI. Concurrent paclitaxel and radiation in locally advanced inoperable head and neck cancer: 50 mg/m 2 paclitaxel as a 3-hour infusion weekly for 7 to 8 weeks simultaneous with radiotherapy in shrinking field technique

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

International Nuclear Information System (INIS)

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

2014-01-01

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.

Functional signatures of radio-induction in sarcomas developing in the radiation field after radiotherapy

International Nuclear Information System (INIS)

Hadj-Hamou, N.S.

2010-01-01

Radiotherapy plays an important role in the treatment of cancers. However, exposure to ionizing radiation is a well-known risk factor for secondary cancer development. Currently, rigorous defined scientific criteria are lacking to establish if an individual tumor has a radiation-induced or a sporadic origin. The main aim of my thesis program was to identify a transcriptome signature of the ionizing radiation effects in radiation-induced cancers. The series of cancers used in this study is composed of sarcomas developing in the irradiation field of patients treated by radiotherapy for a primary cancer. Strict selection criteria (histology different from the primary cancer, latency longer than 5 years) were used to establish with a high probability the sarcomas-radiation induced origin. Their transcriptomes were compared with those from patients without irradiation history. A method of classification adapted to small series was used for the study of all the 60 collected sarcomas (34 radiation-induced and 26 sporadic). A learning set composed of 24 sarcomas from known aetiology allowed us to determine a signature of 135 genes discriminating the sarcomas according to their aetiology. The signature classified 86% of the remaining sarcomas as a function of their aetiology with an accuracy of 97%. The analysis of the genes-function shows that the radiation-induced sarcomas suffered the effects of a chronic oxidative stress mainly generated by mitochondrial dysfunctions. This study shows, for the first time, that it is possible to diagnose, at the case by case level, radiation-induced sarcomas on a rigorous scientific basis. (author)

Clinical impact of FDG-PET/CT in the planning of radiotherapy for early-stage Hodgkin lymphoma

DEFF Research Database (Denmark)

Hutchings, Martin; Loft, Annika; Hansen, Mads

2007-01-01

BACKGROUND: Early-stage Hodgkin lymphoma (HL) has excellent survival rates but carries a high risk of late treatment-related adverse effects. Modern, individualised therapeutic strategies require an accurate determination of the extent of the disease. This study investigated the potential impact...... of 2-[18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computerised tomogrpahy (FDG-PET/CT) in the planning of involved field radiotherapy (IFRT). PATIENTS AND METHODS: Thirty patients received staging FDG-PET/CT before therapy, and IFRT after a short course of ABVD (adriamycin, bleomycin......, vinblastine, dacarbazine) chemotherapy. IFRT planning was performed using only the CT data from the FDG-PET/CT scan. Later, the IFRT planning was performed anew using the FDG-PET/CT data as basis for contouring. RESULTS: In 20 out of 30 patients, the radiotherapy (RT) course was unaffected by the addition...

Radiotherapy in the management of primary gliomas involving the intracranial optic nerves and chiasm

International Nuclear Information System (INIS)

Harter, D.J.; Caderao, J.B.; Leavens, M.E.; Young, S.E.

1978-01-01

Surgeons traditionally do not resect optic chiasm gliomas, but megavoltage radiotherapy can be effective treatment. Vision often improves during and after irradiation. Follow-up examination should include an evaluation of endocrine status. In the series reported recurrences became manifest within one year of the treatment

Introduction to dosimetry and risk estimation of second cancer induction following radiotherapy

International Nuclear Information System (INIS)

Harrison, R.M.

2013-01-01

This brief review of dosimetry in second cancer dosimetry introduces work carried out by Working Group 9 (Radiation Protection Dosimetry in Medicine) of the European Radiation Dosimetry Group (EURADOS). The work described in the following papers in this edition was presented at a Workshop on Dosimetry for Second Cancer Risk Estimation given at the EURADOS Annual meeting in Vienna on February 8th 2012. The work concentrates on the measurement of out-of-field doses in water tanks and BOMAB-like phantoms using a variety of dosimeters to measure photon and neutron doses. These include optically stimulated luminescence (OSL), radiophotoluminescence (RPL) and thermoluminescence (TLD) dosimeters for photon dosimetry (together with ion chambers for reference measurements traceable to primary standards) and track etch and bubble detectors for neutron measurements. A discussion of the various phantoms available for these measurements is presented together with a brief introduction to a model for the relationship between organ doses and the risk of induction of second cancers. The estimation of second cancer risks is not trivial and involves processes which are currently incompletely understood. However, progress in this field requires a robust foundation and methodology for the measurement or calculation of organ doses following radiotherapy, so that risks can be placed in perspective, algorithms for out-of-field doses can be compared with measured data, and future epidemiological studies may have a reliable foundation of organ dosimetry for retrospective dosimetry studies. -- Highlights: ► Brief review of second cancer induction following radiotherapy. ► Out-of-field doses for estimating risks to remote organs. ► Introduction to dosimetry techniques and dosimeters used. ► Out-of-field dose measurements in phantoms

Analysis for prognostic factors of radiotherapy for esophageal squamous cell carcinoma

International Nuclear Information System (INIS)

Nakano, Takashi; Ito, Jun; Ito, Ichiro; Yamanaka, Mikio; Suto, Hisao; Mitsuhashi, Norio; Niibe, Hideo

1984-01-01

Two hundred and fifty patients with squamous cell carcinoma of the esophagus were treated at our department from 1969 to 1981 with radiotherapy involving radiation alone and pre-and/or post-operative radiotherapy. For 167 patients receiving radiotherapy alone, 144 were inoperable cases and only 60 patients could be radically treated. The others were palliative treated patients because of the locally advanced state or distant metastases or severe complications. For 83 patients receiving pre-and/or post-operative radiotherapy, 62 were radically treated. Results of radiotherapy were analyzed to elucidate factors responsible for these prognosis. Relative 5 years survival rates for radically treated patients were 26% in radiotherapy alone and 20% in pre-and/or post-operative radiotherapy respectively. In radiotherapy alone, quite a good prognoses could be obtained in the patients with tumors less than 5cm at radiografical finding (42% for 5 yrs), with tumors located in Ei, Ea esophagus (40%), with tumors of serrative and tumorous X-P types (48%, 43%, respectively) and with good radiation response at the end of radiotherapy (54%). From the analysis of 12 patients surviving more than 5 years from onset of treatment, not only tumor size less than 5cm but also radiation response was major factor responsible for the prognosis. It might be important to treat patients precisely according to their own clinical characteristics and considering tumor host relationship. (author)

Challenges in successfully developing three regional radiotherapy centres. The NCCI experience

International Nuclear Information System (INIS)

Greenham, Stuart

2011-01-01

Full text: This presentation will provide an overview of the processes, experience, challenges and success involved in the establishment of the North Coast Cancer Institute (NCCI). The NCCI is a network of three Integrated Oncology centres in Northern New South Wales offering integrated Medical, Radiation and Haematology outpatient services. NCCI was developed as part of the introduction of radiotherapy into a region previously without access to a local radiotherapy service and as a result with poor radiotherapy utilisation and referral rates. NCCI commenced radiotherapy services in Coffs Harbour in May 2007 followed by Port Macquarie in August of the same year and finally in Lismore in May 20 I O. Radiotherapy services commenced with Intensity Modulated Radiotherapy and Image guided radiotherapy as standard of care for some disease sites with remote access to planning systems and electronic workflow process supporting the treatment process. Forming a small team to simultaneously design, build and establish two new treatment centres to take advantage of the most contemporary treatment modalities while also planning for a third centre was a significant challenge. The challenges and successful outcomes will be discussed as part of this presentation.

Radiotherapy of bronchogenic carcinoma

International Nuclear Information System (INIS)

Heilmann, H.P.

1982-01-01

Radiotherapy of branchogenic carcinoma comprises; palliative treatment, postoperative or pre-operative radiotherapy, radiotherapy as part of a combination of chemotherapy and radiotherapy of small cell carcinoma and curative radiotherapy of non-operable non-small cell carcinoma. Atelectasis and obstruction are indications for palliative radiotherapy. Postoperative radiotherapy is given only in cases of incomplete resection or mediastinal metastases. In the treatment of small cell carcinoma by combined irradiation and chemotherapy the mediastinum and primary tumour are irradiated, generally after chemotherapy, and the C.N.S. receives prophylactic radiotherapy. Curative radiotherapy is indicated in cases of non-operable small cell carcinoma. Irradiation with doses of 60-70 Gy produced 5-years-survival rates of 10-14% in cases classified as T 1 -T 2 N 0 M 0 . (orig.) [de

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

International Nuclear Information System (INIS)

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

2013-01-01

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 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.

The role of computed tomography in the radiotherapy of head and neck cancer

International Nuclear Information System (INIS)

Hokama, Yukio; Miura, Kentaro; Katsuyama, Naofumi; Nakano, Masao; Noda, Yutaka; Yamashiro, Masahiro

1983-01-01

The clinical usefullness of computed tomography (CT) was evaluated in 20 patients with carcinoma of the head and neck before, during and after radiotherapy. The role of CT in the radiotherapy of head and neck cancer was studied. In case of carcinoma of nasopharynx and maxillary antrum, bone destruction and tumor configuration in soft tissue were well delineated and usefull for clinical staging and radiotherapy planning. Neck lymph node involvement was also well detected, especially by using contrast enhancement. CT revealed also the structure of metastatic lesion to neck lymph node, for example central necrosis. Many authors have reported the usefullness of CT for radiotherapy planning. But we would emphasize the contribution in the observation of tumor regression by radiotherapy, and follow-up after the therapy. (author)

Radiotherapy physics

International Nuclear Information System (INIS)

Chen, G.T.Y.; Collier, J.M.; Lyman, J.T.; Pitluck, S.

1982-01-01

The Radiotherapy Physics Group works on the physical and biophysical aspects of charged particle radiotherapy. Our activities include the development of isosurvival beams (beams of uniform biological effect), computerized treatment planning development for charged particle radiotherapy, design of compensation to shape dose distributions, and development of dosimetry techniques to verify planned irradiations in both phantoms and patients

Radiotherapy for mucosa-associated lymphoid tissue lymphoma of the ocular adnexa

International Nuclear Information System (INIS)

Monzen, Yoshio; Wadasaki, Koichi; Hasebe, Haruyuki; Nishisaka, Takashi; Fukuhara, Toshiyuki

2011-01-01

We investigated the results of radiotherapy for mucosa-associated lymphoid tissue (MALT) lymphoma of the ocular adnexa. Twenty-one patients with MALT lymphoma of the ocular adnexa were treated with radiotherapy alone at a dose ranging from 30 to 54 Gy. The disease arose from the conjunctiva in 15 patients (9 with bilateral involvement), and from the retrobulbar space in 6 patients (1 with bilateral involvement). All patients with MALT lymphoma achieved a complete response (CR) or unconfirmed CR (CRu). The 5- and 10-year overall survival rates of all patients with MALT lymphoma were 100% and 90%, respectively. The 5- and 10-year cause-specific survival rates were 100% and 100%, respectively. In all patients with delayed toxicity, the radiation dose was more than 40 Gy. Excellent local control and survival can be achieved for patients with MALT lymphoma of the ocular adnexa using radiotherapy alone. (author)

Comprehensive audits of radiotherapy practices: A tool for quality improvement: Quality Assurance Team for Radiation Oncology (QUATRO)

International Nuclear Information System (INIS)

2007-10-01

As part of a comprehensive approach to quality assurance (QA) in the treatment of cancer by radiation, an independent external audit (peer review) is important to ensure adequate quality of practice and delivery of treatment. Quality audits can be of various types and at various levels, either reviewing critical parts of the radiotherapy process (partial audits) or assessing the whole process (comprehensive audits). The IAEA has a long history of providing assistance for dosimetry (partial) audits in radiotherapy to its Member States. Together with the World Health Organization (WHO), it has operated postal audit programmes using thermoluminescence dosimetry (TLD) to verify the calibration of radiotherapy beams since 1969. Furthermore, it has developed a set of procedures for experts undertaking missions to radiotherapy hospitals in Member States for on-site review of dosimetry equipment, data and techniques, measurements and training of local staff. This methodology involves dosimetry and medical radiation physics aspects of the radiotherapy process without entering into clinical areas. The IAEA, through its technical cooperation programme, has received numerous requests from developing countries to perform comprehensive audits of radiotherapy programmes to assess the whole process. including aspects such as organization, infrastructure, and clinical and medical physics components. The objective of a comprehensive clinical audit is to review and evaluate thc quality of all of the components of the practice of radiotherapy at an institution, including its professional competence, with a view to quality improvement. A multidisciplinary team, comprising a radiation oncologist, a medical physicist and a radiotherapy technologist, carries out the audit. The present publication has been field tested by IAEA teams performing audits in radiotherapy programmes in hospitals in Africa, Asia, Europe and Latin America. Their comments, corrections and feedback have been taken

Comprehensive audits of radiotherapy practices: A tool for quality improvement: Quality Assurance Team for Radiation Oncology (QUATRO)

International Nuclear Information System (INIS)

2008-08-01

As part of a comprehensive approach to quality assurance (QA) in the treatment of cancer by radiation, an independent external audit (peer review) is important to ensure adequate quality of practice and delivery of treatment. Quality audits can be of various types and at various levels, either reviewing critical parts of the radiotherapy process (partial audits) or assessing the whole process (comprehensive audits). The IAEA has a long history of providing assistance for dosimetry (partial) audits in radiotherapy to its Member States. Together with the World Health Organization (WHO), it has operated postal audit programmes using thermoluminescence dosimetry (TLD) to verify the calibration of radiotherapy beams since 1969. Furthermore, it has developed a set of procedures for experts undertaking missions to radiotherapy hospitals in Member States for on-site review of dosimetry equipment, data and techniques, measurements and training of local staff. This methodology involves dosimetry and medical radiation physics aspects of the radiotherapy process without entering into clinical areas. The IAEA, through its technical cooperation programme, has received numerous requests from developing countries to perform comprehensive audits of radiotherapy programmes to assess the whole process. including aspects such as organization, infrastructure, and clinical and medical physics components. The objective of a comprehensive clinical audit is to review and evaluate thc quality of all of the components of the practice of radiotherapy at an institution, including its professional competence, with a view to quality improvement. A multidisciplinary team, comprising a radiation oncologist, a medical physicist and a radiotherapy technologist, carries out the audit. The present publication has been field tested by IAEA teams performing audits in radiotherapy programmes in hospitals in Africa, Asia, Europe and Latin America. Their comments, corrections and feedback have been taken

Comparison of RapidArc plans and fixed field intensity modulated radiotherapy planning in cervical cancer radiotherapy

International Nuclear Information System (INIS)

Liu Xiangyu; Liu Xianfeng; He Ya'nan; Yin Wenjuan; Wu Yongzhong

2011-01-01

Objective: To explore the advantages and disadvantages between the RapidArc plans and fixed-field IMRT plan (IMRT). Methods: Ten cases of cervical cancer,aged 55 (36-70), who were to receive post-operative radiotherapy were selected randomly. Single arc (Arc 1), two arcs (Arc 2), and three arc (Arc 3) RapidArc plans and fixed-field IMRT plan were designed respectively in the Eclipse 8.6 planning system. The designing, treatment time, target area, and dose distribution of organs at risk by these 4 planning techniques were compared. Results: The values of average planned treatment time by the Arc 1, Arc 2, and Arc 3 ten cases was 98, 155, 185, and 46 min, respectively. The values of average treatment time in the Varian IX accelerator were 2.15, 3.32, 4.48, and 6.95 min, respectively. The average mean doses were (48.99±1.08),(49.40±0.51), (49.51±0.62), and (48.65±0.92) Gy, respectively. The values of homogeneity index (HI) of target were 1.11±0.07, 1.07±0.02, 1.06±0.02, and 1.12±0.05, respectively. The values of conformal index (CI) of target were 0.73±0.13, 0.87±0.06, 0.87±0.06, and 0.79±0.06, respectively. The doses at rectum, bladder, and small intestine calculated by IMRT plan were the lowest, and the doses at the femoral neck calculated by these 4 plans were similar. Conclusions: The RapidArc plan is superior in dose distribution at target, HI, CI, and treatment time to IMRT, but IMRT plan is superior to RapidArc in planned dose calculation time and protection of organs at risk. However, in general, the RapidArc plan is better in clinical application than IMRT plan. (authors)

Radiotherapy of ovarian epithelial cancer by total orthogonal field irradiation of the abdomen

International Nuclear Information System (INIS)

Delouche, G.; Valinta, D.; Bachelot, F.

1981-01-01

Isotopic intraperitoneal curietherapy by 32 P is the simplest method for irradiating the peritoneum, but it has only limited indications. This irradiation has usually to be given by the percutaneous route, but because of the size of the region to be irradiated it raises delicate problems poorly resolved by the traditional methods applied. For this reason, a particular method is suggested including, among other characteristics: 4 orthogonal fields; 2 sessions daily, irradiating one part of the abdomen in the morning and the other part in the afternoon; spreading of the doses in confirmity with current specifications; and modulation of the total dose as a function of the maximum size of the tumoral remnants. Abdominal radiotherapy is currently the method of choice in cases where lesions are in their early stages, in so far as chemotherapy, much more restrictive for the patient, has not yet demonstrated its long-term efficacy. A controlled clinical study is necessary in order to determine the most effective method [fr

Quality assurance protocol for linear accelerators used in radiotherapy

International Nuclear Information System (INIS)

Petkovska, Sonja

2012-01-01

Radiotherapy is a modality of choice for treatment of malignant diseases. Linear accelerators are the most common devices for implementing external radiation therapy. Taking into account the fact during the treatment, healthy tissue will inevitably be exposed to ionizing radiation, predicted dose in each radiotherapy case should be delivered with the greatest possible accuracy. Medical requirement for quality treatment achieving means as mach as possible dose into volume of interest and the greatest possible healthy tissue protection. From radiation protection point of view, occupational exposure of the staff involved in radiotherapy process should be minimized. To be able to reach it, consistent adherence to the Quality Assurance Programme is necessary. It should be in accordance with higher national and international protocols, because they give guidelines on the necessary standards, procedures, processes, resources and responsibilities that should be defined in structuring the overall radiotherapy quality management. As a part of this Master thesis, quality management as well as Quality Assurance Programme that is necessary to be applied in each radiotherapy center have been prepared. Mandatory dosimetry measurements included in the internal recommendations are also emphasized. Measurement results and external audit by IAEA indicated high accuracy and quality radiotherapy dose delivering in Macedonia. Based on the measurements and analysis, the aim of this Master thesis is offering a Quality Assurance Protocol for external beam radiotherapy that can be used on the national level in Republic of Macedonia. (Author)

Comparison of onboard low-field magnetic resonance imaging versus onboard computed tomography for anatomy visualization in radiotherapy.

Science.gov (United States)

Noel, Camille E; Parikh, Parag J; Spencer, Christopher R; Green, Olga L; Hu, Yanle; Mutic, Sasa; Olsen, Jeffrey R

2015-01-01

Onboard magnetic resonance imaging (OB-MRI) for daily localization and adaptive radiotherapy has been under development by several groups. However, no clinical studies have evaluated whether OB-MRI improves visualization of the target and organs at risk (OARs) compared to standard onboard computed tomography (OB-CT). This study compared visualization of patient anatomy on images acquired on the MRI-(60)Co ViewRay system to those acquired with OB-CT. Fourteen patients enrolled on a protocol approved by the Institutional Review Board (IRB) and undergoing image-guided radiotherapy for cancer in the thorax (n = 2), pelvis (n = 6), abdomen (n = 3) or head and neck (n = 3) were imaged with OB-MRI and OB-CT. For each of the 14 patients, the OB-MRI and OB-CT datasets were displayed side-by-side and independently reviewed by three radiation oncologists. Each physician was asked to evaluate which dataset offered better visualization of the target and OARs. A quantitative contouring study was performed on two abdominal patients to assess if OB-MRI could offer improved inter-observer segmentation agreement for adaptive planning. In total 221 OARs and 10 targets were compared for visualization on OB-MRI and OB-CT by each of the three physicians. The majority of physicians (two or more) evaluated visualization on MRI as better for 71% of structures, worse for 10% of structures, and equivalent for 14% of structures. 5% of structures were not visible on either. Physicians agreed unanimously for 74% and in majority for > 99% of structures. Targets were better visualized on MRI in 4/10 cases, and never on OB-CT. Low-field MR provides better anatomic visualization of many radiotherapy targets and most OARs as compared to OB-CT. Further studies with OB-MRI should be pursued.

Long-term effects of megavoltage radiotherapy in acromegaly

International Nuclear Information System (INIS)

Lam, K.S.L.; Wang, C.; Ma, J.T.C.; Yeung, R.T.T.; Choi, P.

1989-01-01

The progress of 41 Chinese patients with acromegaly treated with megavoltage radiotherapy was reviewed after a mean follow-up of 4.5 (one-ten) years. Nine received prior surgery. Radiotherapy was delivered by a 3-field technique to a total of 4000-5000 cGy in 25 fractions. By life table analysis successful treatment of growth hormone (GH) hypersecretion, as defined by a mean GH concentration of ≤ 10 mu/L, could be expected in 6, 11, 26, 64 and 67% of the patients after one, two, five, eight and ten years respectively. Median intervals before achieving a mean GH level of ≤ 10 Mu/L were 6.6 and 8.6 years following radiotherapy with the higher (4500-5000 cGy) and lower (4000 cGy) doses respectively, suggesting a tendency towards earlier response following radiotherapy with the higher dose. The prevalence of acquired hypopituitarism in patients followed up for over five years was 40% for gonadotrophins, 30% for TSH and 20% for ACTH deficiency respectively. In the majority of patients, acquired hypopituitarism was not apparent within five years after radiotherapy. No mortality or major side effects were noted following radiotherapy. In 34 patients on longterm bromocriptine treatment, mean GH concentrations were normalised in 26.5% of patients. We conclude that with judicious selection of patients and use of adjunctive medical therapy, megavoltage radiotherapy remains a safe and satisfactory form of treatment for acromegaly especially if expert transphenoidal surgery is not readily available. 19 refs., 3 figs., 2 tabs

Stereotactic body radiotherapy for lung cancer: how much does it really cost?

Science.gov (United States)

Lievens, Yolande; Obyn, Caroline; Mertens, Anne-Sophie; Van Halewyck, Dries; Hulstaert, Frank

2015-03-01

Despite the lack of randomized evidence, stereotactic body radiotherapy (SBRT) is being accepted as superior to conventional radiotherapy for patients with T1-2N0 non-small-cell lung cancer in the periphery of the lung and unfit or unwilling to undergo surgery. To introduce SBRT in a system of coverage with evidence development, a correct financing had to be determined. A time-driven activity-based costing model for radiotherapy was developed. Resource cost calculation of all radiotherapy treatments, standard and innovative, was conducted in 10 Belgian radiotherapy centers in the second half of 2012. The average cost of lung SBRT across the 10 centers (6221&OV0556;) is in the range of the average costs of standard fractionated 3D-conformal radiotherapy (5919&OV0556;) and intensity-modulated radiotherapy (7379&OV0556;) for lung cancer. Hypofractionated 3D-conformal radiotherapy and intensity-modulated radiotherapy schemes are less costly (3993&OV0556; respectively 4730&OV0556;). The SBRT cost increases with the number of fractions and is highly dependent of personnel and equipment use. SBRT cost varies more by centre than conventional radiotherapy cost, reflecting different technologies, stages in the learning curve and a lack of clear guidance in this field. Time-driven activity-based costing of radiotherapy is feasible in a multicentre setup, resulting in real-life resource costs that can form the basis for correct reimbursement schemes, supporting an early yet controlled introduction of innovative radiotherapy techniques in clinical practice.

Radiotherapy, the experience of the patients

International Nuclear Information System (INIS)

Verres, R.; Klusmann, D.

1998-01-01

For the patient, a radiotherapy means heavy physical and mental strain. Just like any other medical therapy, radiotherapy demands active cooperation of the patient based on mutual exchange between the patient and the doctor who, in addition to his medical responsibilities, has to develop awareness of the patient's mental condition and the suitable response. This emphatic relationship may in turn and at times mean a heavy burden for the medical staff. The authors have evaluated for this book a great number of records, protocols and questionnaires accumulated in the course of their work with patients of the radiotherapy department. The book is intended as a source of reference and guidance and a help for all persons and staff involved, who have to cope with the situations encountered in daily work in the clinical departments. The book presents experience and information on a wide range of aspects and problems involved, as e.g.: Interpersonal relations, the patient's feeling of being in the hands of technology, the difficulty to keep the delicate balance between confidence and non-confidence, the significance of good relations in the clinic for a successful outcome of the therapy, the ways how mental crises can be handled. The material also includes information on a variety of accompanying therapies, both for the actual treatment periods as well as for post-treatment periods where they may be late effects to be mastered. (orig./CB) [de

Adverse effect after external radiotherapy for brain tumors

International Nuclear Information System (INIS)

Yoshii, Yoshihiko; Takano, Shingo; Yanaka, Kiyoyuki

1989-01-01

This report discusses the effects on normal brain tissue of radiotherapy in relation to age and irradiation dose as determined from whole-brain sections of the autopsied brains with tumors. Twenty four patients (7 glioblastomas, 2 benign gliomas, 12 brain metastases, 2 malignant lymphomas, and 1 pituitary adenoma) older than 65 years (aged), and 17 younger than 65 years (non-aged) were treated by cobalt- or linear accelerator radiotherapy. Nine patients without brain disease (4 aged and 5 non-aged) were used as a control group. The histological findings were evaluated by grading the small and capillary vessels, fibrinoid necrosis, and myelination in the white matter in whole-brain sections. Those findings were compared to the irradiation doses within all radiation fields in whole-brain sections corresponding to CT scans. Hyalinization of the small vessels was observed within the postradiation 12 months in fields exposed to total doses of less than 800 neuret. Hyalinization of the capillary vessels was greater in the irradiated group than in the control group. Demyelination was observed within the postradiation 12 months in fields irradiated by more than 800 neuret in aged patients and in fields irradiated by less than 800 neuret in non-aged patients. Fibrinoid necrosis was observed after the post-radiation 12 months in fields irradiated by less than 800 neuret in aged patients and in fields irradiated by more than 800 neuret in non-aged patients. It is worth noting that in non-aged patients with brain tumors, adverse effects of radiotherapy on vessels and parenchyma were very high even in low-dose radiation areas; and in aged patients fibrinoid necrosis, which indicates irreversible damage of vessels, was observed in low-dose radiation areas. (author)

Whole brain radiotherapy for brain metastases: The technique of irradiation influences the dose to parotid glands

International Nuclear Information System (INIS)

Loos, G.; Paulon, R.; Verrelle, P.; Lapeyre, M.

2012-01-01

In the treatment of brain metastases, whole brain radiotherapy can be carried out according two distinct methods: one using multi-leaf collimator for field shaping and protection of organs at risk, and a second one is to make a rotation of the field to avoid the eyes. The aim of the study was to compare for 10 patients the dose distributions at organs at risk for each method. Patients received 30 Gy in 10 fractions. Except for parotid glands, the dose received by organs at risk and the planning target volume was the same with each method. For whole brain radiotherapy, excluding the cisterna cerebellomedullaris, the mean parotid dose was 9.63 Gy using the multi-leaf collimator versus 12.32 Gy using the field rotation (P = 0.04). For whole brain radiotherapy including the cisterna cerebellomedullaris, the mean parotid dose was 11.12 Gy using the multi-leaf collimator versus 20.06 Gy using field rotation (P < 0.001). Using the multi-leaf collimator seems recommended for whole brain radiotherapy, to reduce the dose to the parotids. (authors)

What information should patients be given before radiotherapy?

International Nuclear Information System (INIS)

Bergerot, Ph.

2009-01-01

Following a number of accidents at radiotherapy units, at Epinal and Toulouse hospitals in particular, and the problems encountered in the summer 2008, mainly caused by a shortage of radiation physicians and probably due to legislation that bears little relation to reality, a national radiotherapy monitoring committee was set up on 15 December 2008 in the presence of Roselyne Bachelot-Narquin, France's Minister for Health and Sport. A first progress report was submitted to the Minister in May 2009. Twelve members sit on this national monitoring committee, including a CISS representative and a person that has received radiotherapy treatment. This demonstrates the seriousness and the commitment required of users on this issue. Radiotherapy, one of the main treatments for cancer, is a loco-regional treatment that uses radiation capable of destroying cancer cells. It can be used on its own, or before, during or after another treatment method (surgery or a medical treatment such as chemotherapy, for example). The decision to treat a patient by means of radiotherapy is based on the opinions of health care professionals discussed at a multidisciplinary team meeting, the minutes of which are sent to the various doctors involved. The radiotherapy treatment prescribed (the technique, total radiation dose, length of the treatment, number of sessions, etc.) is adapted to the individual situation of each patient. It is designed to be as effective as possible in light of the tumour pathology, while protecting neighbouring organs as far as is possible. (author)

Radiotherapy

International Nuclear Information System (INIS)

Zedgenidze, G.A.; Kulikov, V.A.; Mardynskij, Yu.S.

1984-01-01

The technique for roentgenotopometric and medicamentous preparation of patients for radiotherapy has been reported in detail. The features of planning and performing of remote, intracavitary and combined therapy in urinary bladder cancer are considered. The more effective methods of radiotherapy have been proposed taking into account own experience as well as literature data. The comparative evaluation of treatment results and prognosis are given. Radiation pathomorphism of tumors and tissues of urinary bladder is considered in detail. The problems of diagnosis, prophylaxis and treatment of complications following radiodiagnosis and radiotherapy in patients with urinary bladder cancer are illustrated widely

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

Energy Technology Data Exchange (ETDEWEB)

Abouaf, Lucie [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Girard, Nicolas [Radiotherapy-Oncology Department, Lyon Sud Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Lefort, Thibaud [Neuro-Radiology Department, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); D' hombres, Anne [Claude Bernard University, Lyon (France); Tilikete, Caroline; Vighetto, Alain [Neuro-Ophthalmology Unit, Pierre-Wertheimer Hospital, Hospices Civils de Lyon, Lyon (France); Claude Bernard University, Lyon (France); Mornex, Francoise, E-mail: francoise.mornex@chu-lyon.fr [Claude Bernard University, Lyon (France)

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.

Impact of radiotherapy on myasthenia gravis in patients with malignant thymomas

International Nuclear Information System (INIS)

Hou Xiuyu; Xu Yonggang; Gao Hong; Li Ming; Li Gaofeng; Liu Mingyuan

2006-01-01

Objective: To evaluate the change of myasthenia gravis(MG) during radiotherapy for patients with malignant thymomas. Methods: Forty-five with malignant thymomas patients with were analyzed. The median total dose was DT54.2 Gy in 1.8-2.0 Gy/fraction, 5 clays a week. Anti-cholinesterase, such as pyridostigmine was used to control the MG symptoms. Results: Forty-five patients completed radiotherapy on schedule except one from whom the treatment was was with drawn because of respiratory muscle involvement. Among these 44 patients, myasthenic symptom was relieved in 4 to various degrees, 4 progressed, 34 no change and 2 developed cholinergic crisis. Myasthenic symptom was not changed in one patient for whom radiotherapy had been standed before operation nor during the course of postoperative radiotherapy. Conclusions: A course of radiotherapy of DT54.2 Gy, on fractionation of DT1.8-2.0 Gy modal would not aggravate myasthenia. However, proper use of anti-cholinesterase, careful observation and timely drug-adjustment are necessary. (authors)

Cardiac dose sparing and avoidance techniques in breast cancer radiotherapy

International Nuclear Information System (INIS)

Shah, Chirag; Badiyan, Shahed; Berry, Sameer; Khan, Atif J.; Goyal, Sharad; Schulte, Kevin; Nanavati, Anish; Lynch, Melanie; Vicini, Frank A.

2014-01-01

Breast cancer radiotherapy represents an essential component in the overall management of both early stage and locally advanced breast cancer. As the number of breast cancer survivors has increased, chronic sequelae of breast cancer radiotherapy become more important. While recently published data suggest a potential for an increase in cardiac events with radiotherapy, these studies do not consider the impact of newer radiotherapy techniques commonly utilized. Therefore, the purpose of this review is to evaluate cardiac dose sparing techniques in breast cancer radiotherapy. Current options for cardiac protection/avoidance include (1) maneuvers that displace the heart from the field such as coordinating the breathing cycle or through prone patient positioning, (2) technological advances such as intensity modulated radiation therapy (IMRT) or proton beam therapy (PBT), and (3) techniques that treat a smaller volume around the lumpectomy cavity such as accelerated partial breast irradiation (APBI), or intraoperative radiotherapy (IORT). While these techniques have shown promise dosimetrically, limited data on late cardiac events exist due to the difficulties of long-term follow up. Future studies are required to validate the efficacy of cardiac dose sparing techniques and may use surrogates for cardiac events such as biomarkers or perfusion imaging

Comparison of Toxicity Between Intensity-Modulated Radiotherapy and 3-Dimensional Conformal Radiotherapy for Locally Advanced Non-small-cell Lung Cancer.

Science.gov (United States)

Ling, Diane C; Hess, Clayton B; Chen, Allen M; Daly, Megan E

2016-01-01

The role of intensity-modulated radiotherapy (IMRT) in reducing treatment-related toxicity for locally advanced non-small-cell lung cancer (NSCLC) remains incompletely defined. We compared acute toxicity and oncologic outcomes in a large cohort of patients treated with IMRT or 3-dimensional conformal radiotherapy (3-DCRT), with or without elective nodal irradiation (ENI). A single-institution retrospective review was performed evaluating 145 consecutive patients with histologically confirmed stage III NSCLC treated with definitive chemoradiotherapy. Sixty-five (44.8%) were treated with 3-DCRT using ENI, 43 (30.0%) with 3-DCRT using involved-field radiotherapy (IFRT), and 37 (25.5%) with IMRT using IFRT. All patients received concurrent chemotherapy. Comparison of acute toxicities by treatment technique (IMRT vs. 3-DCRT) and extent of nodal irradiation (3-DCRT-IFRT vs. 3-DCRT-ENI) was performed for grade 2 or higher esophagitis or pneumonitis, number of acute hospitalizations, incidence of opioid requirement, percutaneous endoscopic gastrostomy utilization, and percentage weight loss during treatment. Local control and overall survival were analyzed by the Kaplan-Meier method. We identified no significant differences in any measures of acute toxicity by treatment technique or extent of nodal irradiation. There was a trend toward lower rates of grade 2 or higher pneumonitis among IMRT patients compared to 3-DCRT patients (5.4% vs. 23.0%; P = .065). Local control and overall survival were similar between cohorts. Acute and subacute toxicities were similar for patients treated with IMRT and with 3-DCRT with or without ENI, with a nonsignificant trend toward a reduction in pneumonitis with IMRT. Larger studies are needed to better define which patients will benefit from IMRT. Copyright © 2016 Elsevier Inc. All rights reserved.

The implication of hot spots on bone scans within the irradiated field of breast cancer patients treated with mastectomy followed by radiotherapy

International Nuclear Information System (INIS)

Park, Won; Huh, Seung-Jae; Yang, Jung-Hyun

2008-01-01

The objective of this study was to analyze the implication of abnormal hot spots in the irradiated field of patients treated with mastectomy followed by radiotherapy for breast cancer. We reviewed 1842 consecutive bone scans performed on 292 patients treated with a modified radical mastectomy and followed by radiotherapy. If abnormal hot spots at the irradiated sites were detected in the bone scans, we evaluated further studies to determine whether bone metastases were present. Radiation was given using 4 or 6 MV X-rays at a dosage of 50.4 Gy during 5.5 weeks with a dosage per fraction of 1.8 Gy. The follow-up period was 25-136 months (median 57 months). Sixty patients (20.6%) developed bone metastasis. Solitary rib metastases were identified in four patients; all were detected outside of the irradiated field. Of 232 patients who did not develop bone metastases, hot spots in the irradiated field were detected in 30 patients (12.9%). A simple rib facture at the site of a hot spot was demonstrated in four patients. The cumulative incidence of hot spots at 5 years was 12.9%. The cumulative incidence of hot spots was more common in postmenopausal women, patients who were less than 60 kg, patients who received adjuvant hormonal therapy and patients who had radiation that included the supraclavicular area. We confirmed that the hot spots within the irradiated fields might be benign, especially in patients who were postmenopause, had a low body weight, received adjuvant hormonal therapy and who had radiation that included the supraclavicular area. (author)

Evaluation of irradiation position in respiratory-gated radiotherapy using a phantom system simulating patient respiration

International Nuclear Information System (INIS)

Oyama, Masaya; Ueda, Takashi; Kitoh, Satoshi; Tanaka, Takashi; Goka, Tomonori; Ogino, Takashi

2006-01-01

Respiratory-gated (RG) radiotherapy is useful for minimizing the irradiated volume of normal tissues resulting from the shifting of internal structures caused by respiratory movement. The present study was conducted to evaluate the treatment field in RG radiotherapy using a phantom system simulating patient respiration. A phantom system consisting of a 3-cm ball-shaped dummy tumor and film placed in a cork lung phantom was used (THK Co., Ltd.). RG radiotherapy was employed in the expiratory phase. The phantom movement distance was set to 2 cm, and the gating signals from a respiratory-gating system (AZ-733V, Anzai Medical) were varied. The settings used for irradiation were an X-ray energy of 6 MV (PRIMUS, Toshiba Medical Systems), treatment field of 5 cm x 7 cm, and X-ray dose of 100 MU. Images were acquired using an electric portal-imaging device (EPID, OPTIVUE 500), and the X-ray dose distribution was measured by the film method. In images acquired using the EPID, the tumor margins became less clear when the gating signals were increased, and the ITVs were determined to be 3.6 cm, 3.7 cm, 4.2 cm, and 5.1 cm at gating rates of 10%, 25%, 50%, and no gate, respectively. With regard to the X-ray dose distribution measured by the film method, the dose profile in the cephalocaudal direction was shifted toward the expiratory phase, and the degree of shift became greater when the gating signals were increased. In addition, the optimal treatment fields in the cephalocaudal direction were determined to be 5.2 cm, 5.2 cm, 5.6 cm, and 7.0 cm at gating rates of 10%, 25%, 50%, and no gating, respectively. Although RG radiotherapy is useful for improving the accuracy of radiotherapy, the characteristics of the RG radiotherapy technique and the radiotherapy system must be clearly understood when this method is to be employed in clinical practice. Image-guided radiotherapy (IGRT) is now assuming a central role in radiotherapy, and properly identifying internal margins is an

Elevation of PSA after prostate radiotherapy: Rebound or biochemical recurrence?

International Nuclear Information System (INIS)

Toledano, A.; Kanoui, A.; Chiche, R.; Lamallem, H.; Beley, S.; Thibault, F.; Sebe, P.

2008-01-01

The fact that external beam radiotherapy and brachytherapy are now considered to be curative techniques has led to major review of the modalities of follow-up after radiotherapy for prostate cancer. The problem concerns both the diagnosis of recurrence, rapidly announced by elevation of prostatic-specific antigen (PSA), usually at a subclinical stage, and the validity of criteria of biochemical recurrence to allow comparison of various study. Physicians involved in follow-up should be aware of the potential of bounce in PSA follow-up after external beam radiotherapy or brachytherapy. The PSA bounce phenomenon was defined by a rise of PSA values (+ 0.1 -0.8 ng/ml) with a subsequent fall. Biochemical failure after external beam radiotherapy or brachytherapy (with or without hormonotherapy) was defined by Phoenix criteria by a rise of 2 ng/ml above an initial PSA nadir. This definition was more correlated to PSA bounce phenomenon. (authors)

Respiratory gated radiotherapy: current techniques and potential benefits

International Nuclear Information System (INIS)

Giraud, P.; Campana, F.; Rosenwald, J.C.; Cosset, J.M.; Reboul, F.; Garcia, R.; Clippe, S.; Carrie, C.; Dubray, B.

2003-01-01

Respiration-gated radiotherapy offers a significant potential for improvement in the irradiation of tumor sites affected by respiratory motion such as lung, breast and liver tumors. An increased conformality of irradiation fields leading to decreased complications rates of organs at risk (lung, heart...) is expected. Respiratory gating is in line with the need for improved precision required by radiotherapy techniques such as 3D conformal radiotherapy or intensity modulated radiotherapy. Reduction of respiratory motion can be achieved by using either breath hold techniques or respiration synchronized gating techniques. Breath-hold techniques can be achieved with active, in which airflow of the patient is temporarily blocked by a valve, or passive techniques, in which the patient voluntarily breath-hold. Synchronized gating techniques use external devices to predict the phase of the respiration cycle while the patient breaths freely. These techniques presently investigated in several medical centers worldwide. Although promising, the first results obtained in lung and liver cancer patients require confirmation. Physical, technical and physiological questions still remain to be answered. This paper describes the most frequently used gated techniques and the main published clinical reports on the use of respiration-gated radiotherapy in order to evaluate the impact of these techniques. (author)

Gel dosimetry for conformal radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Gambarini, G [Department of Physics of the University and INFN, Milan (Italy)

2005-07-01

With the continuum development of conformal radio therapies, aimed at delivering high dose to tumor tissue and low dose to the healthy tissue around, the necessities has appeared of suitable improvement of dosimetry techniques giving the possibility of obtaining dose images to be compared with diagnostic images. Also if wide software has been developed for calculating dose distributions in the fields of various radiotherapy units, experimental verifications are necessary, in particular in the case of complex geometries in conformal radiotherapy. Gel dosimetry is a promising method for imaging the absorbed dose in tissue-equivalent phantoms, with the possibility of 3D reconstruction of the spatial dose distribution, with milli metric resolution. Optical imaging of gel dosimeters, based on visible light absorbance analysis, has shown to be a reliable technique for achieving dose distributions. (Author)

National arrangements for radiotherapy

International Nuclear Information System (INIS)

2007-01-01

After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the technological and organisational evolution of radiotherapy and presents the distribution of radiotherapy equipment, of radio-therapists and other radiotherapy professionals in France. Within the context of radiotherapy accidents which occurred in 2007, it presents the regulatory arrangements which aimed at improving the safety, short term and middle term arrangements which are needed to support and structure radiotherapy practice quality. It stresses the fact that the system will deeply evolve by implementing a radiotherapy vigilance arrangement and a permanent follow-on and adaptation plan based on surveys and the creation of a national committee

Design and Shielding of Radiotherapy Treatment Facilities; IPEM Report 75, 2nd Edition

Science.gov (United States)

Horton, Patrick; Eaton, David

2017-07-01

Design and Shielding of Radiotherapy Treatment Facilities provides readers with a single point of reference for protection advice to the construction and modification of radiotherapy facilities. The book assembles a faculty of national and international experts on all modalities including megavoltage and kilovoltage photons, brachytherapy and high-energy particles, and on conventional and Monte Carlo shielding calculations. This book is a comprehensive reference for qualified experts and radiation-shielding designers in radiation physics and also useful to anyone involved in the design of radiotherapy facilities.

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

International Nuclear Information System (INIS)

Schwartz, J.L.; Chicago Univ., IL; Beckett, M.A.; Mustafi, R.; Weichselbaum, R.R.; Vaughan, A.T.M.

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

Whither radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Ross, W M

1987-03-01

The 1986 Glyn Evans Memorial Lecture, given at the Joint Provincial Meeting of the Royal College of Radiologists, Sheffield, September 1986, sketches an outline of the history of radiotherapy and discusses the future development of the art. Topics included are siting of centres, training needs, the relationship of radiotherapy to other medical specialities, and the advantages and disadvantages of radiotherapy practitioners forming a separate medical College. (U.K.)

New method in radiotherapy of bronchial carcinoma

International Nuclear Information System (INIS)

Macha, H.N.; Mai, J.; Stadler, M.; Koch, K.; Loddenkemper, R.; Krumhaar, D.; Schumacher, W.; Lungenklinik Heckeshorn, Berlin; Staedtisches Rudolf-Virchow-Krankenhaus, Berlin

1986-01-01

106 patients with inoperable malignant tumours constricting the central bronchial tree underwent endobronchial small-field radiotherapy with iridium-192 at high dose between June 1983 and September 1985. Treatment was performed using the computer-guided after-loading technique and a flexible bronchoscope under local anaesthesia. In complete occlusion of a bronchus by the tumour, a neodymium YAG-laser was applied (57 patients) to allow insertion of the afterloading probe. Endoscopy showed tumour regression in 75% of the patients, accompanied by clinical improvement. Pulmonary function tests, arterial blood gas analyses and pulmonary perfusion scans yielded a highly significant improvement of data after treatment. The procedure also proved effective upon exhaustion of external radiation. Apart from its positive palliation, endobronchial small-field radiotherapy using high doses of iridium-192 also has a curative effect, thus opening up a new approach to the therapy of advanced bronchial carcinoma. (orig.) [de

Radiotherapy in bladder cancer

International Nuclear Information System (INIS)

Rozan, R.

1992-01-01

In 1992, the problem of the vesical radiotherapy is not resolved. The author presents the situation and the different techniques of radiotherapy in bladder cancers: external radiotherapy, only and associated with surgery, interstitial curietherapy and non-classical techniques as per operative radiotherapy, neutron therapy and concurrent radiotherapy with chemotherapy. In order to compare their efficiency, the five-year survival are given in all cases.(10 tabs)

Radiotherapy with concomitant chemotherapy superior to radiotherapy alone in the treatment of locally advanced anal cancer: results of a phase III randomized trial of the EORTC radiotherapy and gastrointestinal tract cooperative groups

International Nuclear Information System (INIS)

Bartelink, H.; Roelofsen, F.; Bosset, J.F.; Eschwege, F.; Rougier, Ph.; Peiffert, D.; Glabbeke, M. van; Pierart, M.

1996-01-01

Purpose: To investigate the potential gain of the concomitant use of radiotherapy and chemotherapy in improving local control and reducing the need for colostomy, a randomized phase-III trial was performed in patients with locally advanced anal cancer. Material and methods: In the period 1987-1994 110 patients were randomized between radiotherapy alone and a combination of radiotherapy and chemotherapy. The patients had tumors larger than 4 cm, or T 3-4 N 0-3 , or T 1-2 N 1-3 anal cancer. Radiotherapy consisted of 45 Gy given in 5 weeks, with a daily dose of 1.8 Gy. After a rest period of 6 weeks a boost of 15 Gy or 20 Gy was given in case of partial or complete response respectively. Chemotherapy was given during radiotherapy, 750 mg/m2 daily as continuous infusion on day 1-5 and 29-33, a single dose of Mitomycin C 15 mg/m 2 was administered on day 1. Results: The addition of chemotherapy to radiotherapy has resulted in an increase in the complete remission rate from 54% to 80%, and from 83% to 94% if results are considered after surgical resections. This has led to a significant improvement in loco-regional control and colostomy free survival (P=0.04, P=0.003 resp.) both in favor of the combined modality treatment. No significant difference was found when severe side effects were considered. The survival rate remained similar in both treatment arms. Skin ulceration, nodal involvement and sex were the most important prognostic factors for both local control and survival. These remained significant after multivariate analysis. The improvement seen in local control by adding chemotherapy to radiotherapy remained also significant after adjusting for prognostic factors in the multivariate analysis. Conclusions: The concomitant use of radiotherapy and chemotherapy resulted in an improved local control rate and a reduction in the need for colostomy in patients with locally advanced anal cancer

Radiotherapy for patients with malignant diseases aged 85 years or older

International Nuclear Information System (INIS)

Asakura, Hirofumi; Mizumoto, Masashi; Zenda, Sadamoto

2007-01-01

The purpose of this study was to assess the efficacy and problems of radiotherapy for patients aged 85 or older. Forty-five patients were assessed (oldest old group): They were 85 years of age or older and had received radiotherapy between September 2002 and September 2005. Sixty-nine patients, 75 years of age at the start of radiotherapy, were also assessed (old group). In the oldest old group, there were 21 men and 24 women, and median age was 87 years (range; 85-99). The sites of disease were: 10 in head and neck, 5 in lung, 5 in malignant lymphoma, 4 in skin, 4 in esophagus, 2 in breast, 2 in uterine cervix, 2 in rectum, 2 in soft tissue, 2 in metastatic bone tumor, 7 in others. The treatment was deemed curative in 49%, palliative in 40%, and others in 11%. Treatment fields were limited due to performance status (PS) or age in 13 patients. The rate of treatment completion was 91% (41/45). Eleven of 26 inpatients were admitted because of difficulty in hospital visit. Seventeen of 19 outpatients needed familial escort. Of patients completed radiotherapy, 47% of the patients achieved complete response (CR), 37% achieved partial response (PR), and 16% achieved no change (NC) in the group of curative radiotherapy, and 88% of the patients achieved effective response, and only 2 cases resulted in ineffective response in the group of palliative radiotherapy. While only one patient received grade 3 dermatitis and mucositis, other patients received grade 2 and below adverse events. Three patients resulted in deterioration of PS, and 2 patients deteriorated dementia. Although higher rates in female patients, worse PS, and limitation of treatment field were seen in the oldest old group, there were no significant difference in terms of the rate of treatment completion, effectiveness, and adverse events between the two groups. Our study showed radiotherapy is effective and well tolerated in patients aged 85 or older. Considering the oldest old requiring radiotherapy

National arrangements for radiotherapy; Mesures nationales pour la radiotherapie. Travail collectif des missions

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

After a presentation of several letters exchanged between the French health ministry and public agencies in charge of public health or nuclear safety after a radiotherapy accident in Epinal, this report comments the evolution of needs in cancerology care and the place given to radiotherapy. It outlines the technological and organisational evolution of radiotherapy and presents the distribution of radiotherapy equipment, of radio-therapists and other radiotherapy professionals in France. Within the context of radiotherapy accidents which occurred in 2007, it presents the regulatory arrangements which aimed at improving the safety, short term and middle term arrangements which are needed to support and structure radiotherapy practice quality. It stresses the fact that the system will deeply evolve by implementing a radiotherapy vigilance arrangement and a permanent follow-on and adaptation plan based on surveys and the creation of a national committee.

The Radiotherapy Dosimetry Audit System In the UK

International Nuclear Information System (INIS)

Thwaites, D.I.

1999-01-01

Two national radiotherapy dosimetry intercomparisons have been earned out in the UK, involving all radiotherapy institutes. The first was concerned with megavoltage photon beams and looked at beam calibration and simple three-field planned distributions in a geometric phantom. The intercomparisons were carried out by an independent intercomparison physicist visiting each department in turn and making measurements with ion chambers, following a fixed protocol. The beam calibration intercomparison was earned out on every 60 C o beam and every MV x-ray beam, whilst the planned comparisons were carried out on one beam only. The plans included effects of wedges, oblique incidence and inhomogeneities. The study was unfunded and took a significant time (1988-1991) to cover the 65 or so centres. It was followed up by a national electron dosimetry intercomparison which was fended (Department of Health) and which ran from 1994-1996. This audited three electron beam energies in each centre (depth dose, beam energy, dose calibration) and also included a follow-up of the original photon beam intercomparison. In general these studies showed good consistency of dosimetry across the UK centres, with mean (measured/locally stated) doses being close to unity and standard deviations of the distributions of values being approx. 1.5 and 1% for photons, 1.8% for electrons for beam calibration and 2.5-3.5% for the planned multi-beam situations. 97-100% of measurements were within the pre-set 3% tolerance for beam calibration and around 90% of the measurements within a pre-set 5% tolerance for planned situations. The studies did highlight some areas where increased on Q A could provide benefits. In particular the photon intercomparison discovered one 60 C o unit mis calibration which led to national recommendations for the implementation of Quality Systems in radiotherapy departments

Adaptive radiotherapy using helical tomotherapy system

International Nuclear Information System (INIS)

Jeswani, Sam; Ruchala, Kenneth; Olivera, Gustavo; Mackie, T.R.

2008-01-01

As commonly known in the field, adaptive radiation therapy (ART) is the use of feedback to modify a radiotherapy treatment. There are numerous ways in which this feedback can be received and used, and this presentation will discuss some of the implementations of ART being investigated with a helical TomoTherapy system

Parents' Lived Experiences During Their Children's Radiotherapy.

Science.gov (United States)

Gårdling, Jenny; Törnqvist, Erna; Edwinson Månsson, Marie; Hallström, Inger

The aim of radiotherapy is to provide a cure and/or symptomatic relief for children with cancer. Treatment is delivered on a daily basis, 5 days per week, over the course of 5 to 35 days. Many parents find that leaving their children alone during treatment and exposing them to radiation is a challenging experience. To gain an understanding of parents' lived experiences, 10 parents were asked to keep a diary while their children underwent radiotherapy. A descriptive inductive design with a hermeneutic-phenomenological approach was chosen to analyze the diaries. The parents were asked to write down their lived experiences while their children underwent radiotherapy. Daily notes, both short and long, were desirable. The parents described radiotherapy as a balancing act involving a constant attempt to maintain a balance between coercing and protecting their children in order to improve their children's chances of survival. Meanwhile, the parents themselves were struggling with their own despair and feelings of powerlessness. While protecting their children, they experienced a sense of hope and felt that they had gained control. Parents' daily written reflections are important for clinical practice and provide vital knowledge. Parents need support when focusing on coercing and protecting their children and help with information and routines that enable them gain control.

[Porting Radiotherapy Software of Varian to Cloud Platform].

Science.gov (United States)

Zou, Lian; Zhang, Weisha; Liu, Xiangxiang; Xie, Zhao; Xie, Yaoqin

2017-09-30

To develop a low-cost private cloud platform of radiotherapy software. First, a private cloud platform which was based on OpenStack and the virtual GPU hardware was builded. Then on the private cloud platform, all the Varian radiotherapy software modules were installed to the virtual machine, and the corresponding function configuration was completed. Finally the software on the cloud was able to be accessed by virtual desktop client. The function test results of the cloud workstation show that a cloud workstation is equivalent to an isolated physical workstation, and any clients on the LAN can use the cloud workstation smoothly. The cloud platform transplantation in this study is economical and practical. The project not only improves the utilization rates of radiotherapy software, but also makes it possible that the cloud computing technology can expand its applications to the field of radiation oncology.

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.

Science.gov (United States)

Jing, Wang; Zhu, Hui; Guo, Hongbo; Zhang, Yan; Shi, Fang; Han, Anqin; Li, Minghuan; Kong, Li; Yu, Jinming

2015-01-01

We conducted a retrospective analysis to assess the feasibility of involved field irradiation (IFI) in elderly patients with esophageal squamous cell cancer (ESCC). 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. 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. IFI resulted in decreased irradiation toxicities without sacrificing OS in elderly patients with ESCC.

Postoperative radiotherapy for prostate cancer. Morbidity of local-only or local-plus-pelvic radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Waldstein, Cora; Poetter, Richard; Widder, Joachim; Goldner, Gregor [Medical University of Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, General Hospital of Vienna, Vienna (Austria); Doerr, Wolfgang [Medical University of Vienna, Department of Radiation Oncology, Comprehensive Cancer Center, General Hospital of Vienna, Vienna (Austria); Medical University of Vienna, Christian-Doppler Laboratory for Medical Radiation Research for Radiooncology, Vienna (Austria)

2018-01-15

The aim of this work was to characterise actuarial incidence and prevalence of early and late side effects of local versus pelvic three-dimensional conformal postoperative radiotherapy for prostate cancer. Based on a risk-adapted protocol, 575 patients received either local (n = 447) or local-plus-pelvic (n = 128) radiotherapy. Gastrointestinal (GI) and genitourinary (GU) side effects (≥grade 2 RTOG/EORTC criteria) were prospectively assessed. Maximum morbidity, actuarial incidence rate, and prevalence rates were compared between the two groups. For local radiotherapy, median follow-up was 68 months, and the mean dose was 66.7 Gy. In pelvic radiotherapy, the median follow-up was 49 months, and the mean local and pelvic doses were 66.9 and 48.3 Gy respectively. Early GI side effects ≥ G2 were detected in 26% and 42% of patients respectively (p < 0.001). Late GI adverse events were detected in 14% in both groups (p = 0.77). The 5-year actuarial incidence rates were 14% and 14%, while the prevalence rates were 2% and 0% respectively. Early GU ≥ G2 side effects were detected in 15% and 16% (p = 0.96), while late GU morbidity was detected in 18% and 24% (p = 0.001). The 5-year actuarial incidence rates were 16% and 35% (p = 0.001), while the respective prevalence rates were 6% and 8%. Despite the low prevalence of side effects, postoperative pelvic radiotherapy results in significant increases in the actuarial incidence of early GI and late GU morbidity using a conventional 4-field box radiotherapy technique. Advanced treatment techniques like intensity-modulated radiotherapy (IMRT) or volumetric modulated arc radiotherapy (VMAT) should therefore be considered in pelvic radiotherapy to potentially reduce these side effects. (orig.) [German] Ziel der vorgestellten Arbeit ist es, die Haeufigkeit frueher und spaeter Nebenwirkungen nach postoperativer Bestrahlung von Prostatakarzinompatienten zu analysieren. Verglichen wurden dabei die Nebenwirkungen von lokaler

Second Malignanat Solid Neoplasms in Children Treated with Radiotherapy-Report of Two Cases and Review of Literature

International Nuclear Information System (INIS)

Chung, Eun Ji; Suh, Chang Ok; Kim, Gwi Eon; Lyu, Chuhl Joo; Kim, Byung Soo

1995-01-01

Radiotherapy and chemotherapy can effectively control cancer but can also cause new second cancers to develop as long-term complications especially in childhood cancer. We experienced two patients with second malignant solid neoplasm who had been treated with radiation and chemotherapy for childhood cancers. One female patients with rhabdomyosarcoma of the right popliteal fossa was treated with radiotherapy at total dose of 54 Gy. Three years and seven months later, osteosarcoma developed in the field of radiation therapy. The other male patient with non-Hodgkin's lymphoma of the small bowel was treated with radiotherapy and leiomyosarcoma developed in the field of radiotherapy 18 years later. We reviewed the literature of the second malignant neoplasm in children in respect of risk factors. The risk for a second primary cancer following radiotherapy or chemotherapy emphasizes the need for life long follow-up of patients receiving such treatments. Particularly patients treated for childhood cancers

Quality control programme for radiotherapy

International Nuclear Information System (INIS)

Campos de Araujo, A.M.; Viegas, C.C.B.; Viamonte, A.M.

2002-01-01

A 3 years pilot programme started in January 2000 with 33 philanthropic cancer institutions that provides medical services to 60% of the patients from the national social security system. Brazil has today 161 radiotherapy services (144 operating with megavoltage equipment). These 33 institutions are distributed over 19 Brazilian states. The aim of this programme is: To create conditions to allow the participants to apply the radiotherapy with quality and efficacy; To promote up dating courses for the physicians, physicists and technicians of these 33 Institutions. With the following objectives: To recommend dosimetric and radiological protection procedures in order to guarantee the tumor prescribed dose and safe working conditions; To help in establishing and implementing these procedures. The main activities are: local quality control evaluations, postal TLD audits in reference conditions, postal TLD audits in off axis conditions and training. The local quality control program has already evaluated 22 institutions with 43 machines (25 Co-60 and 18 linear accelerators). In these visits we perform dosimetric, electrical, mechanical and safety tests. As foreseen, we found more problems among the old Co-60 machines i.e., field flatness, size, symmetry and relative output factors; lasers positioning system alignment; optical distance indicator; radiation and light field coincidence; optical and mechanical distance indicators agreement, than among the linear accelerators i.e., field flatness and size; lasers positioning system alignment; tray interlocking and wedge filter factors

The comparison of 5-field conformal radiotherapy techniques for the treatment of prostate cancer: The best for femoral head sparing

International Nuclear Information System (INIS)

Zare, Mahkameh; Lashkari, Marzieh; Ghalehtaki, Reza; Ghasemi, Arash; Dehghan Manshadi, Hamidreza; Mir, Ali; Noorollahi, Somayeh; Alamolhoda, Mahboobeh

2016-01-01

External radiotherapy is a standard treatment procedure for localized prostate cancer. Given the relatively high long term survival treatment complications have been brought in center of attention. In this planning study, between 2012 and 2014, CT simulation data of 90 consecutive high-risk prostate cancer patients were collected. In the first phase, all were planned for whole pelvis irradiation up to 46Gy in 23 daily fractions. In the second phase, only the prostate gland was the target of radiation. Next, the subjects were divided randomly into three groups and each received a unique 5field conformal radiation plan including Plan A (Gantry angle: 0, 60, 120, 240, and 300), Plan B (Gantry angles: 0, 90, 120, 240, and 270) and Plan C (Gantry angles: 0, 60, 90, 270, and 300). The total dose was 70Gy. For each patient, the rectum, bladder, and both femoral heads were contoured as the at risk organs (OAR). From dose volume histograms, the proportional dose of PTV V100, the bladder and rectum V80 and V90 and femoral head V50 and V100 were calculated in all subjects and compared across plans. A statistically significant difference in the femoral head V50 and V100 was found between our studied 5field plans so that in Plan A (beam angles: 0, 60, 120, 240 and 300) less dose was received by both heads of femur. This study suggests that 5 field treatment planning including an anterior, two anterior oblique and two posterior oblique portals to be more proper for 3D conformal radiotherapy in order to spare femoral head with acceptable PTV coverage, and bladder and rectal doses.

The future of personalised radiotherapy for head and neck cancer.

Science.gov (United States)

Caudell, Jimmy J; Torres-Roca, Javier F; Gillies, Robert J; Enderling, Heiko; Kim, Sungjune; Rishi, Anupam; Moros, Eduardo G; Harrison, Louis B

2017-05-01

Radiotherapy has long been the mainstay of treatment for patients with head and neck cancer and has traditionally involved a stage-dependent strategy whereby all patients with the same TNM stage receive the same therapy. We believe there is a substantial opportunity to improve radiotherapy delivery beyond just technological and anatomical precision. In this Series paper, we explore several new ideas that could improve understanding of the phenotypic and genotypic differences that exist between patients and their tumours. We discuss how exploiting these differences and taking advantage of precision medicine tools-such as genomics, radiomics, and mathematical modelling-could open new doors to personalised radiotherapy adaptation and treatment. We propose a new treatment shift that moves away from an era of empirical dosing and fractionation to an era focused on the development of evidence to guide personalisation and biological adaptation of radiotherapy. We believe these approaches offer the potential to improve outcomes and reduce toxicity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stereotactic Radiosurgery and Hypofractionated Radiotherapy for Glioblastoma.

Science.gov (United States)

Shah, Jennifer L; Li, Gordon; Shaffer, Jenny L; Azoulay, Melissa I; Gibbs, Iris C; Nagpal, Seema; Soltys, Scott G

2018-01-01

Glioblastoma is the most common primary brain tumor in adults. Standard therapy depends on patient age and performance status but principally involves surgical resection followed by a 6-wk course of radiation therapy given concurrently with temozolomide chemotherapy. Despite such treatment, prognosis remains poor, with a median survival of 16 mo. Challenges in achieving local control, maintaining quality of life, and limiting toxicity plague treatment strategies for this disease. Radiotherapy dose intensification through hypofractionation and stereotactic radiosurgery is a promising strategy that has been explored to meet these challenges. We review the use of hypofractionated radiotherapy and stereotactic radiosurgery for patients with newly diagnosed and recurrent glioblastoma. Copyright © 2017 by the Congress of Neurological Surgeons.

Primary extramammary invasive Paget’s vulvar disease: what is the standard, what are the challenges and what is the future for radiotherapy?

International Nuclear Information System (INIS)

Tolia, Maria; Tsoukalas, Nikolaos; Sofoudis, Chrisostomos; Giaginis, Constantinos; Spyropoulou, Despoina; Kardamakis, Dimitrios; Kouloulias, Vasileios; Kyrgias, George

2016-01-01

Primary invasive Extramammary Paget’s vulvar disease is a rare tumor that is challenging to control. Wide surgical excision represents the standard treatment approach for Primary invasive Extramammary Paget’s vulvar disease. The goal of the current study was to analyze the appropriate indications of radiotherapy in Primary invasive Extramammary Paget's vulvar disease because they are still controversial. We searched the Cochrane Gynecological Cancer Group Trials Register, Cochrane Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE database up to September 2015. Radiotherapy was delivered as a treatment in various settings: i) Radical in 28 cases (range: 60–63 Gy), ii) Adjuvant in 25 cases (range: 39–60 Gy), iii) Salvage in recurrence of 3 patients (63 Gy) and iv) Neoadjuvant in one patient (43.3 Gy). A radiotherapy field that covered the gross tumor site with a 2–5 cm margin for the microscopic disease has been used. Radiotherapy of the inguinal, pelvic or para-aortic lymph node should be considered only for the cases with lymph node metastases within these areas. Radiotherapy alone is an alternative therapeutic approach for patients with extensive inoperable disease or medical contraindications. Definitive radiotherapy can be used in elderly patients and/or with medical contraindications. Adjuvant radiotherapy may be considered in presence of risk factors associated with local recurrence as dermal invasion, lymph node metastasis, close or positive surgical margins, perineal, large tumor diameter, multifocal lesions, extensive disease, coexisting histology of adenocarcinoma or vulvar carcinoma, high Ki-67 expression, adnexal involvement and probably in overexpression of HER-2/neu. Salvage radiotherapy can be given in inoperable loco-regional recurrence and to those who refused additional surgery

Central nervous system involvement by multiple myeloma

DEFF Research Database (Denmark)

Jurczyszyn, Artur; Grzasko, Norbert; Gozzetti, Alessandro

2016-01-01

The multicenter retrospective study conducted in 38 centers from 20 countries including 172 adult patients with CNS MM aimed to describe the clinical and pathological characteristics and outcomes of patients with multiple myeloma (MM) involving the central nervous system (CNS). Univariate......, 97% patients received initial therapy for CNS disease, of which 76% received systemic therapy, 36% radiotherapy and 32% intrathecal therapy. After a median follow-up of 3.5 years, the median overall survival (OS) from the onset of CNS involvement for the entire group was 7 months. Untreated...... untreated patients and patients with favorable cytogenetic profile might be prolonged due to systemic treatment and/or radiotherapy. This article is protected by copyright. All rights reserved....

Estimation of eye absorbed doses in head & neck radiotherapy practices using thermoluminescent detectors

Directory of Open Access Journals (Sweden)

Gh Bagheri

2011-09-01

Full Text Available  Determination of eye absorbed dose during head & neck radiotherapy is essential to estimate the risk of cataract. Dose measurements were made in 20 head & neck cancer patients undergoing 60Co radiotherapy using LiF(MCP thermoluminescent dosimeters. Head & neck cancer radiotherapy was delivered by fields using SAD & SSD techniques. For each patient, 3 TLD chips were placed on each eye. Head & neck dose was about 700-6000 cGy in 8-28 equal fractions. The range of eye dose is estimated to be (3.49-639.1 mGy with a mean of maximum dose (98.114 mGy, which is about 3 % of head & neck dose. Maximum eye dose was observed for distsnces of about 3 cm from edge of the field to eye.

An international review of patient safety measures in radiotherapy practice

International Nuclear Information System (INIS)

Shafiq, Jesmin; Barton, Michael; Noble, Douglas; Lemer, Claire; Donaldson, Liam J.

2009-01-01

Errors from radiotherapy machine or software malfunction usually are well documented as they affect hundreds of patients, whereas random errors affecting individual patients are more difficult to be discovered and prevented. Although major clinical radiotherapy incidents have been reported, many more have remained unrecognised or have not been reported. The literature in this field is limited as it is mostly published as a result of investigation of major errors. We present a review of radiotherapy incidents internationally with the aim of identifying the domains where most errors occur through extensive review and synthesis of published reports, unpublished 'Grey literature' and departmental incident data. Our review of radiotherapy-related events in the last three decades (1976-2007) identified more than seven thousand (N = 7741) incidents and near misses. Three thousand one hundred and twenty-five incidents reported patient harm of variable intensity ranging from underdose increasing the risk of recurrence, to overdose causing toxicity, and even death for 1% (N = 38); 4616 events were near misses with no recognisable patient harm. Based on our review, a radiotherapy risk profile has been published by the WHO World Alliance for Patient Safety that highlights the role of communication, training and strict adherence to guidelines/protocols in improving the safety of radiotherapy process.

Predictive local receptive fields based respiratory motion tracking for motion-adaptive radiotherapy.

Science.gov (United States)

Yubo Wang; Tatinati, Sivanagaraja; Liyu Huang; Kim Jeong Hong; Shafiq, Ghufran; Veluvolu, Kalyana C; Khong, Andy W H

2017-07-01

Extracranial robotic radiotherapy employs external markers and a correlation model to trace the tumor motion caused by the respiration. The real-time tracking of tumor motion however requires a prediction model to compensate the latencies induced by the software (image data acquisition and processing) and hardware (mechanical and kinematic) limitations of the treatment system. A new prediction algorithm based on local receptive fields extreme learning machines (pLRF-ELM) is proposed for respiratory motion prediction. All the existing respiratory motion prediction methods model the non-stationary respiratory motion traces directly to predict the future values. Unlike these existing methods, the pLRF-ELM performs prediction by modeling the higher-level features obtained by mapping the raw respiratory motion into the random feature space of ELM instead of directly modeling the raw respiratory motion. The developed method is evaluated using the dataset acquired from 31 patients for two horizons in-line with the latencies of treatment systems like CyberKnife. Results showed that pLRF-ELM is superior to that of existing prediction methods. Results further highlight that the abstracted higher-level features are suitable to approximate the nonlinear and non-stationary characteristics of respiratory motion for accurate prediction.

Cranial nerve involvement in nasopharyngeal carcinoma: response to radiotherapy and its clinical impact.

Science.gov (United States)

Li, Jian-Cheng; Mayr, Nina A; Yuh, William T C; Wang, Jian Z; Jiang, Guo-Liang

2006-05-01

To evaluate the cranial nerve (CN) palsy associated with nasopharyngeal carcinoma (NPC), we studied factors that influenced the neurologic outcome of radiotherapy (RT), and the patterns and time course of neurologic recovery of CN palsy. Between July 1987 and July 1989, 93 patients who presented with CN palsy at the time of diagnosis of NPC were studied. All patients underwent external-beam RT with either cobalt-60 or 6-MV photon beams to a dose of 69 to 84 Gy at 2 Gy per fraction. The time course and pattern of neurologic recovery (complete, partial, or none) from CN palsy were evaluated. Age, sex, stage, histology, incidence and distribution of types of CNs involved, duration of CN palsy, and time course of tumor response during RT were correlated with the patterns and the time course of neurologic CN recovery by univariate and multivariate analyses. The cases of CN palsy most commonly involved CN V (38%), CN VI (26%), and CN XII (11%), which accounted for the majority of the cases (75%). The time course of CN recovery was variable and protracted. Most patients showed significant improvement upon completion of RT (51%, 19%, and 30% complete, partial, and no recovery, respectively) and further improvement 6 months after RT (58%, 17%, and 25%, respectively). Cranial nerves V, VI, and XII accounted for 75% of cases with no recovery. Recovery was best for CNs II, IX, and XI and the sympathetic nerve (100%, 87%, 100%, and 100%, respectively) and worst for CNs IV, VII, and XII (67%, 60%, and 40%, respectively, with no recovery). Neurologic CN recovery correlated significantly with the pretherapy duration ( or =3 months) of CN palsy (88% versus 62%; p = .002, multivariate analysis), the time course of clinical tumor regression, and neurologic symptom improvement during RT. Age, sex, T stage, N stage, histology, anterior versus posterior CN palsies, and base of skull involvement were not significant. According to our limited data, most patients with CN palsy respond well

Prognostic factors in the radiotherapy of Graves' ophthalmopathy

International Nuclear Information System (INIS)

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

1990-01-01

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

Conformal radiotherapy: principles and classification

International Nuclear Information System (INIS)

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

1999-01-01

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

PLANNING NATIONAL RADIOTHERAPY SERVICES

Directory of Open Access Journals (Sweden)

Eduardo eRosenblatt

2014-11-01

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

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

International Nuclear Information System (INIS)

Miles, Edward F.; Kelsey, Chris R.; Kirkpatrick, John P.; Marks, Lawrence B.

2007-01-01

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

Professional field involvement in ICT curricula at the Dutch UaS

NARCIS (Netherlands)

Frederik, J.A.; Brodnik, A.; Lewin, C.

2015-01-01

This paper analyses Dutch accreditation reports in the field of information and communication technology (ICT) to assess the degree of reported involvement of the professional field in the curricula of universities of applied sciences. Qualitative content analysis of the reports of all the ICT

Magna-field irradiation: physical considerations

Energy Technology Data Exchange (ETDEWEB)

Van Dyk, J.

1983-12-01

Magna-field radiotherapy in the form of total body, half body and total nodal irradiation is becoming increasingly prominent and involves dosimetric problems that are much more pronounced than they are for conventional field sizes. In this review of the physical considerations of magna-field irradiation, a number of possible alternate methods of producing large radiation fields are outlined, the basic beam dosimetry is reviewed and the factors producing dose variation in the patient are considered. Since the lung contains large regions of low density tissues and has a lower tolerance to radiaiton than most other tissues, special consideration is given to methods of dose determination and dose reduction to this organ. The question of accuracy in dose delivery is briefly discussed and the concept of delivering a radiation dose 'as precisely as readily achievable (APARA), technological and biological factors being taken into account' is introduced.

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

International Nuclear Information System (INIS)

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

2012-01-01

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.

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

Energy Technology Data Exchange (ETDEWEB)

Kirova, Youlia M., E-mail: youlia.kirova@curie.net [Department of Radiation Oncology, Institut Curie, Paris (France); Menard, Jean; Chargari, Cyrus; Mazal, Alejandro [Department of Radiation Oncology, Institut Curie, Paris (France); Kirov, Krassen [Department of Anesthesiology and Reanimation, Institut Curie, Paris (France)

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.

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

Science.gov (United States)

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.

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

Energy Technology Data Exchange (ETDEWEB)

Atsumi, Kazushige [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Shioyama, Yoshiyuki, E-mail: shioyama@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Arimura, Hidetaka [Department of Health Sciences, Kyushu University, Fukuoka (Japan); Terashima, Kotaro [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Matsuki, Takaomi [Department of Health Sciences, Kyushu University, Fukuoka (Japan); Ohga, Saiji; Yoshitake, Tadamasa; Nonoshita, Takeshi; Tsurumaru, Daisuke; Ohnishi, Kayoko; Asai, Kaori; Matsumoto, Keiji [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan); Nakamura, Katsumasa [Department of Radiology, Kyushu University Hospital at Beppu, Oita (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka (Japan)

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.

Development of a model for recording and evaluating incidents in radiotherapy

International Nuclear Information System (INIS)

Ribeiro, A.L.C.; Paiva, E. de; Teixeira, F.C.S.

2017-01-01

Radiotherapy has been constantly improving to become increasingly effective, thus contributing to increase the chances of healing patients. In this sense, incident learning gained prominence during successive approaches to patient safety. The objective is to develop a tool for recording and analyzing incidents in radiotherapy and applying it to clinics in Rio de Janeiro in order to implement the policy of quality management and safety culture. Steps were taken that involved the analysis of the process maps for the enrichment of the system (called the Standardized System of Incidents in Radiotherapy - SPIRad) that already has a version in physical form. The proposal is the conversion of this form to a digital tool to be used through the intranet. The next step is to apply it to radiotherapy clinics in Rio de Janeiro and evaluate the results obtained with the objective of possible improvements through feedback from users

Dosimetric comparison of intensity-modulated, conformal, and four-field pelvic radiotherapy boost plans for gynecologic cancer: a retrospective planning study

International Nuclear Information System (INIS)

Chan, Philip; Yeo, Inhwan; Perkins, Gregory; Fyles, Anthony; Milosevic, Michael

2006-01-01

To evaluate intensity-modulated radiation therapy (IMRT) as an alternative to conformal radiotherapy (CRT) or 4-field box boost (4FB) in women with gynecologic malignancies who are unsuitable for brachytherapy for technical or medical reasons. Dosimetric and toxicity information was analyzed for 12 patients with cervical (8), endometrial (2) or vaginal (2) cancer previously treated with external beam pelvic radiotherapy and a CRT boost. Optimized IMRT boost treatment plans were then developed for each of the 12 patients and compared to CRT and 4FB plans. The plans were compared in terms of dose conformality and critical normal tissue avoidance. The median planning target volume (PTV) was 151 cm 3 (range 58–512 cm 3 ). The median overlap of the contoured rectum with the PTV was 15 (1–56) %, and 11 (4–35) % for the bladder. Two of the 12 patients, both with large PTVs and large overlap of the contoured rectum and PTV, developed grade 3 rectal bleeding. The dose conformity was significantly improved with IMRT over CRT and 4FB (p ≤ 0.001 for both). IMRT also yielded an overall improvement in the rectal and bladder dose-volume distributions relative to CRT and 4FB. The volume of rectum that received the highest doses (>66% of the prescription) was reduced by 22% (p < 0.001) with IMRT relative to 4FB, and the bladder volume was reduced by 19% (p < 0.001). This was at the expense of an increase in the volume of these organs receiving doses in the lowest range (<33%). These results indicate that IMRT can improve target coverage and reduce dose to critical structures in gynecologic patients receiving an external beam radiotherapy boost. This dosimetric advantage will be integrated with other patient and treatment-specific factors, particularly internal tumor movement during fractionated radiotherapy, in the context of a future image-guided radiation therapy study

The role of radiotherapy in the management of POEMS syndrome.

Science.gov (United States)

Suh, Yang-Gun; Kim, Young-Suk; Suh, Chang-Ok; Kim, Yu Ri; Cheong, June-Won; Kim, Jin Seok; Cho, Jaeho

2014-11-28

POEMS syndrome is a paraneoplastic syndrome caused by an underlying plasma cell proliferative disease. In this study, we examined the treatment outcomes and role of radiotherapy in the management of POEMS syndrome. In total, 33 patients diagnosed with POEMS syndrome were analyzed. These patients presented with osteosclerotic myeloma (OSM, n = 13), Castleman's disease (CD, n = 4), OSM with CD (n = 10), and vascular endothelial growth factor elevation without gross lesions (VEGFe, n = 6), respectively. The patients were treated by radiotherapy alone (n = 4), chemotherapy alone (n = 16), or a combination thereof (n = 9). The clinical response rates of radiotherapy, chemotherapy, and radiotherapy plus chemotherapy were 75%, 69%, and 89%, respectively. In addition, the hematologic response rates were 50%, 69%, and 71%, respectively. Among the six patients with limited multiple lesions who underwent radiotherapy, the clinical symptoms were improved in five patients after radiotherapy. The median progression-free survival (PFS) was 51 months, and the median overall survival (OS) was 65 months. In univariate analysis, the administration of chemotherapy was significantly associated with better PFS (p = 0.007) and OS (p = 0.020). In contrast, underlying VEGFe was a significant factor worsening PFS (p = 0.035) and OS (p = 0.008). Radiotherapy produces a reliable clinical response and is effective in improving POEMS-associated symptoms that are refractory to chemotherapy in selected patients with clustered or limited multiple lesions that can be covered by single radiation field.

The role of radiotherapy in the management of POEMS syndrome

International Nuclear Information System (INIS)

Suh, Yang-Gun; Kim, Young-Suk; Suh, Chang-Ok; Kim, Yu Ri; Cheong, June-Won; Kim, Jin Seok; Cho, Jaeho

2014-01-01

POEMS syndrome is a paraneoplastic syndrome caused by an underlying plasma cell proliferative disease. In this study, we examined the treatment outcomes and role of radiotherapy in the management of POEMS syndrome. In total, 33 patients diagnosed with POEMS syndrome were analyzed. These patients presented with osteosclerotic myeloma (OSM, n = 13), Castleman’s disease (CD, n = 4), OSM with CD (n = 10), and vascular endothelial growth factor elevation without gross lesions (VEGFe, n = 6), respectively. The patients were treated by radiotherapy alone (n = 4), chemotherapy alone (n = 16), or a combination thereof (n = 9). The clinical response rates of radiotherapy, chemotherapy, and radiotherapy plus chemotherapy were 75%, 69%, and 89%, respectively. In addition, the hematologic response rates were 50%, 69%, and 71%, respectively. Among the six patients with limited multiple lesions who underwent radiotherapy, the clinical symptoms were improved in five patients after radiotherapy. The median progression-free survival (PFS) was 51 months, and the median overall survival (OS) was 65 months. In univariate analysis, the administration of chemotherapy was significantly associated with better PFS (p = 0.007) and OS (p = 0.020). In contrast, underlying VEGFe was a significant factor worsening PFS (p = 0.035) and OS (p = 0.008). Radiotherapy produces a reliable clinical response and is effective in improving POEMS-associated symptoms that are refractory to chemotherapy in selected patients with clustered or limited multiple lesions that can be covered by single radiation field

Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer

DEFF Research Database (Denmark)

Vaidya, Jayant S; Wenz, Frederik; Bulsara, Max

2014-01-01

The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the first analysis of overall survival....

Treatment outcome in patients with vulvar cancer: comparison of concurrent radiotherapy to postoperative radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Lee, Ja Young; Kim, Sung Hwan; Kim, Ki Won; Park, Dong Choon; Yoon, Joo Hee; Yoon, Sei Chul [St. Vincent' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of); Yu, Mina [St. Mary' s Hospital, The Catholic University of Korea School of Medicine, Seoul (Korea, Republic of)

2012-03-15

To evaluate outcome and morbidity in patients with vulvar cancer treated with radiotherapy, concurrent chemoradiotherapy or postoperative radiotherapy. The records of 24 patients treated with radiotherapy for vulvar cancer between July 1993 and September 2009 were retrospectively reviewed. All patients received once daily 1.8-4 Gy fractions external beam radiotherapy to median 51.2 Gy (range, 19.8 to 81.6 Gy) on pelvis and inguinal nodes. Seven patients were treated with primary concurrent chemoradiotherapy, one patient was treated with primary radiotherapy alone, four patients received palliative radiotherapy, and twelve patients were treated with postoperative radiotherapy. Twenty patients were eligible for response evaluation. Response rate was 55% (11/20). The 5-year disease free survival was 42.2% and 5-year overall survival was 46.2%, respectively. Fifty percent (12/24) experienced with acute skin complications of grade III or more during radiotherapy. Late complications were found in 8 patients. 50% (6/12) of patients treated with lymph node dissection experienced severe late complications. One patient died of sepsis from lymphedema. However, only 16.6% (2/12) of patients treated with primary radiotherapy developed late complications. Outcome of patients with vulvar cancer treated with radiotherapy showed relatively good local control and low recurrence. Severe late toxicities remained higher in patients treated with both node dissection and radiotherapy.

Characterizing a pulse-resolved dosimetry system for complex radiotherapy beams using organic scintillators

DEFF Research Database (Denmark)

Beierholm, Anders Ravnsborg; Ottosson, Rickard; Lindvold, Lars René

2011-01-01

A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse w...... and quality assurance of complex radiotherapy treatments.......A fast-readout dosimetry system based on fibre-coupled organic scintillators has been developed for the purpose of conducting point measurements of absorbed dose in radiotherapy beams involving high spatial and temporal dose gradients. The system measures the dose for each linac radiation pulse....... No significant differences between measurements and simulations were observed. The temporal resolution of the system was demonstrated by measuring dose per pulse, beam start-up transients and the quality factor for 6 MV. The precision of dose per pulse measurements was within 2.7% (1 SD) for a 10 cm × 10 cm...

Modality comparison for small animal radiotherapy: A simulation study

Energy Technology Data Exchange (ETDEWEB)

Bazalova, Magdalena, E-mail: bazalova@stanford.edu; Nelson, Geoff; Noll, John M.; Graves, Edward E. [Department of Radiation Oncology, Molecular Imaging Program at Stanford, Stanford University, Stanford, California 94305 (United States)

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

Study of alleviation of peripheral circulation disturbance due to surgery and radiotherapy, 1

International Nuclear Information System (INIS)

Tedo, Tohru; Ohnuma, Isao; Hino, Shigeki; Kanetomo, Takafumi

1979-01-01

133 Xe-clearance in the branium was measured in order to detect circulatory disturbance following surgery and during and after radiotherapy for breast cancer. In 5 of 10 cases (50%) in which surgery and radiotherapy were performed for breast cancer, lowered circulatory function was noted in the affected side. Lowered function was seen in the non-affected side of the 10 cases in 3 (30%), and normal function was observed in 2 (20%). In 4 of 13 cases (75%), including 3 cases in which radiotherapy was performed, many subjective symptoms were noted. Circulatory function was lowered in 3 of the 4 cases. Generally, cases involving many subjective symptoms were of lowered circulatory function. In the cases in which lowered circulatory function was noted in the non-affected side, there were no subjective symptoms. In all the cases in which radiotherapy was continued or in which radiotherapy had almost been completed, a more or less lowered circulatory function was noted. The onset of lowered function and whether surgery or radiotherapy lowered circulation are unknown. (Ueda, J.)

Radiotherapy in small countries.

Science.gov (United States)

Barton, Michael B; Zubizarreta, Eduardo H; Polo Rubio, J Alfredo

2017-10-01

To examine the availability of radiotherapy in small countries. A small country was defined as a country with a population less than one million persons. The economic status of each country was defined using the World Bank Classification. The number of cancers in each country was obtained from GLOBOCAN 2012. The number of cancer cases with an indication or radiotherapy was calculated using the CCORE model. There were 41 countries with a population of under 1 million; 15 were classified as High Income, 15 Upper Middle Income, 10 Lower Middle Income and one Low Income. 28 countries were islands. Populations ranged from 799 (Holy See) to 886450 (Fiji) and the total number of cancer cases occurring in small countries was 21,043 (range by country from 4 to 2476). Overall the total number of radiotherapy cases in small countries was 10982 (range by country from 2 to 1239). Radiotherapy was available in all HIC islands with 80 or more new cases of cancer in 2012 but was not available in any LMIC island. Fiji was the only LMIC island with a large radiotherapy caseload. Similar caseloads in non-island LMIC all had radiotherapy services. Most non-island HIC did not have radiotherapy services presumably because of the easy access to radiotherapy in neighbouring countries. There are no radiotherapy services in any LMIC islands. Copyright © 2017. Published by Elsevier Ltd.

Metastatic cervical lymphadenopathy from uterine leiomyosarcoma with good local response to radiotherapy and chemotherapy

International Nuclear Information System (INIS)

Oh, Yoon Kyeong; Park, Hee Chul; Kee, Keun Hong; Jeon, Ho Jong; Park, You Hwan; Chung, Choon Hai

2000-01-01

The metastasis of uterine leiomyosarcoma to the neck node has not been reported previously and the radiotherapy has been rarely used for the metastatic lesion of the other sites. We report a case of neck metastasis from a uterine leiomyosarcoma, which developed 10 months after surgery and postoperative pelvic radiotherapy. It also involved the parapharyngeal space, adjacent spine, and spinal canal. The metastatic neck mass was inoperable, and was treated by neck radiotherapy (6,000 cGy) and chemotherapy including taxol and carboplatin. The mass has regressed progressively to a nearly impalpable state. She has never developed spinal cord compression syndrome, and has maintained good swallowing for eight months since the neck radiotherapy and chemotherapy. Since the extensive metastatic neck mass showed good local response to high dose radiotherapy and chemotherapy, both treatments may be considered for an unresectable metastatic leiomyosarcoma

The prognostic significance of parapharyngeal tumour involvement in nasopharyngeal carcinoma

International Nuclear Information System (INIS)

Teo, P.Y.; Lee, W.; Yu, P.

1996-01-01

From 1984 to 1989, 903 treatment-naive non-disseminated nasopharyngeal carcinomas (NPCs) were given primary radical radiotherapy. All patients had computed tomographic and endoscopic evaluation of the primary tumour. Potentially significant parameters were analysed by both univariate and multivariate methods for independent significance. In the whole group of patients, the male sex, skull base and cranial nerve(s) involvement, advanced Ho N-level, presence of fixed or partially fixed nodes and nodes contralateral to the side of the bulk of the nasopharyngeal primary, significantly determined survival and distant metastasis rates, whereas skull base and cranial nerve involvement, advanced age and male sex significantly worsened local control. However in the Ho T2No subgroup, parapharyngeal tumour involvement was the most significant prognosticator that determined distant metastasis and survival rates in the absence of the overriding prognosticators of skull base infiltration, cranial nerve(s) palsy, and cervical nodal metastasis. The local tumour control of the Ho T2No was adversely affected by the presence of oropharyngeal tumour extension. The administration of booster radiotherapy (20 Gy) after conventional radiotherapy (60-62.5 Gy) in tumours with parapharyngeal involvement has led to an improvement in local control, short of statistical significance

Results of the national audit in radiotherapy

International Nuclear Information System (INIS)

Alonso Samper, Jose Luis; Dominguez, Lourdes; Alert Silva, Jose; Alfonso Laguardia, Rodolfo; Larrinaga Cortina, Eduardo; Garcia Yip, Fernando; Rodriguez Machado, Jorge; Morales Lopez, Jorge Luis; Silvestre Patallo, Ileana

2009-01-01

The National Audit Programme in Radiotherapy in Cuba working for 8 years regularly visiting each country's radiotherapy service at least once every two years, during the visit involving two medical physicists and radiation oncologist. This paper presents the main features of the program and its main results. Early detection deficiencies in the work of the Radiation Therapy Services that may cause radiological risk situations for both patients and workers and the general public. Help with their comments to the continuous improvement of quality of care. During audit visits is reviewed the whole process of radiotherapy, since the patient comes to the monitoring service. This is done by dividing the audits into three groups or aspects: Clinical Aspects, Aspects of Safety and Quality Control Aspects of the equipment. Methodological guidelines have been established for conducting audits and they serve as standards of quality in radiation therapy, these guidelines also allow the quantification of results. It has identified the main gaps in services that affect the quality of care. After each visit, leave recommendations may be directed to the service itself, to the direction of the provincial hospital or health. Conclusions. We believe that the National Audit Programme in Radiotherapy is an effective tool in controlling the quality of the treatments offered and at the same time with its recommendations helps services to continually improve quality. (Author)

Basic study of cancer immunity and radiotherapy

International Nuclear Information System (INIS)

Shimosato, Yukio; Nagai, Kanji; Ikeuchi, Toshiyuki.

1978-01-01

With respect to anti-tumor effect of radiation, antigenicity and involvement of immunity of an individual with cancer were evaluated under both conditions of natural and insufficient immunity. In animal experiments, it is clear that immunity of the host, especially the function of T-cells, has much to do with the curability of cancer by radiotherapy. In some type of human cancer, not only the histological findings in its healing process following x-ray irradiation but a number of clinical and in vitro experimental results strongly suggest the presence of antigenicity of the T-cells, although it is quite little. The experiments made in a combination of human cancer and nude mice showed a possibility of non-T cells being involved in this mechanism irrespective of whether it is specific, non-specific or not having such an important role as T-cells. There are many problems left unsolved. However, radiotherapy of cancer should be undertaken by maintaining or further improving the immunity of the body in order to obtain good results. (Ueda, J.)

Hyperthermia and radiotherapy

International Nuclear Information System (INIS)

Fitspatrick, C.

1990-01-01

Hyperthermia and radiotherapy have for long been used to assist in the control of tumours, either as separate entities, or, in a combined treatment scheme. This paper outlines why hyperthermia works, thermal dose and the considerations required in the timing when hyperthermia is combined with radiotherapy. Previously reported results for hyperthermia and radiotherapy used together are also presented. 8 refs., 8 tabs

Radiotherapy

International Nuclear Information System (INIS)

Wannenmacher, M.; Debus, J.; Wenz, F.

2006-01-01

The book is focussed on the actual knowledge on the clinical radiotherapy and radio-oncology. Besides fundamental and general contributions specific organ systems are treated in detail. The book contains the following contributions: Basic principles, radiobiological fundamentals, physical background, radiation pathology, basics and technique of brachytherapy, methodology and technique of the stereotactic radiosurgery, whole-body irradiation, operative radiotherapy, hadron therapy, hpyerthermia, combined radio-chemo-therapy, biometric clinical studies, intensity modulated radiotherapy, side effects, oncological diagnostics; central nervous system and sense organs, head-neck carcinomas, breast cancer, thorax organs, esophagus carcinoma, stomach carcinoma, pancreas carcinoma, heptabiliary cancer and liver metastases, rectal carcinomas, kidney and urinary tract, prostate carcinoma, testicular carcinoma, female pelvis, lymphatic system carcinomas, soft tissue carcinoma, skin cancer, bone metastases, pediatric tumors, nonmalignant diseases, emergency in radio-oncology, supporting therapy, palliative therapy

Postoperative radiotherapy in salivary ductal carcinoma: a single institution experience

Energy Technology Data Exchange (ETDEWEB)

Kim, Tae Hyung; Kim, Mi Sun; Choi, Seo Hee; Suh, Yang Gun; Koh, Yoon Woo; Kim, Se Hun; Choi, Eun Chang; Keum, Ki Chang [Yonsei University College of Medicine, Seoul (Korea, Republic of)

2014-09-15

We reviewed treatment outcomes and prognostic factors for patients with salivary ductal carcinoma (SDC) treated with surgery and postoperative radiotherapy from 2005 to 2012. A total of 16 patients were identified and 15 eligible patients were included in analysis. Median age was 61 years (range, 40 to 71 years) and 12 patients (80%) were men. Twelve patients (80%) had a tumor in the parotid gland, 9 (60%) had T3 or T4 disease, and 9 (60%) had positive nodal disease. All patients underwent surgery and postoperative radiotherapy. Postoperative radiotherapy was delivered using 3-dimensional conformal radiotherapy or intensity-modulated radiotherapy. Locoregional failure-free survival (LRFFS), distant failure-free survival (DFFS), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Differences in survival based on risk factors were tested using a log-rank test. Median total radiotherapy dose was 60 Gy (range, 52.5 to 63.6 Gy). Four patients received concurrent weekly chemotherapy with cisplatin. Among 10 patients who underwent surgery with neck dissection, 7 received modified radical neck dissection. With a median follow-up time of 38 months (range, 24 to 105 months), 4-year rates were 86% for LRFFS, 51% for DFFS, 46% for PFS, and 93% for OS. Local failure was observed in 2 patients (13%), and distant failure was observed in 7 (47%). The lung was the most common involved site of distant metastasis. Surgery and postoperative radiotherapy in SDC patients resulted in good local control, but high distant metastasis remained a major challenge.

Multimedia educational services in stereotactic radiotherapy

International Nuclear Information System (INIS)

Bazioglou, M.; Theodorou, K.; Kappas, C.

1999-01-01

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

Postal TLD audits in radiotherapy in the Czech Republic: current status, experience and potential

International Nuclear Information System (INIS)

Ekendahl, Daniela; Kapucianova, Michaela; Dufek, Vladimir

2014-01-01

The paper deals with practice and performance of postal TLD audits in radiotherapy with emphasis on the possibilities of application of the advanced versions that were developed following up technological progress in radiotherapy. The new methodologies of the TLD audit are focused specifically on up-to-date linear accelerators, equipped with multileaf collimators, and modern treatment planning systems. The dose is checked by the TLD not only for reference conditions but also in conditions of radiation fields influenced by presence of inhomogeneities in the irradiated volume. As regards small radiation fields, the check also includes dose profile verification using gafchromic films. The methodologies were tested within pilot studies performed in collaboration with some Czech radiotherapy centers. The results and experience gave evidence of the usefulness and appropriateness of the new TLD audit methodologies. (orig.)

Probabilities of Pulmonary and Cardiac Complications and Radiographic Parameters in Breast Cancer Radiotherapy

Energy Technology Data Exchange (ETDEWEB)

Noh, O Kyu; Paek, Sung Ho; Ahn, Seung Do; Choi, Eun Kyung; Lee, Sang Wook; Song, Si Yeol; Yoon, Sang Min; Kim, Jong Hoon [Dept. of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul (Korea, Republic of)

2010-11-15

To evaluate the relationship between the normal tissue complication probability (NTCP) of 3- dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD (R2=0.808). We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP.

Probabilities of Pulmonary and Cardiac Complications and Radiographic Parameters in Breast Cancer Radiotherapy

International Nuclear Information System (INIS)

Noh, O Kyu; Paek, Sung Ho; Ahn, Seung Do; Choi, Eun Kyung; Lee, Sang Wook; Song, Si Yeol; Yoon, Sang Min; Kim, Jong Hoon

2010-01-01

To evaluate the relationship between the normal tissue complication probability (NTCP) of 3- dimensional (3-D) radiotherapy and the radiographic parameters of 2-dimensional (2-D) radiotherapy such as central lung distance (CLD) and maximal heart distance (MHD). We analyzed 110 patients who were treated with postoperative radiotherapy for breast cancer. A two-field tangential technique, a three-field technique, and the reverse hockey stick method were used. The radiation dose administered to whole breast or the chest wall was 50.4 Gy, whereas a 45 Gy was administered to the supraclavicular field. The NTCPs of the heart and lung were calculated by the modified Lyman model and the relative seriality model. For all patients, the NTCPs of radiation-induced pneumonitis and cardiac mortality were 0.5% and 0.7%, respectively. The NTCP of radiation-induced pneumonitis was higher in patients treated with the reverse hockey stick method than in those treated by other two techniques (0.0%, 0.0%, 3.1%, p<0.001). The NTCP of radiation-induced pneumonitis increased with CLD. The NTCP of cardiac mortality increased with MHD (R2=0.808). We found a close correlation between the NTCP of 3-D radiotherapy and 2-D radiographic parameters. Our results are useful to reanalyze the previous 2-D based clinical reports about breast radiation therapy complications as a viewpoint of NTCP.

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Comparison of Heart and Coronary Artery Doses Associated With Intensity-Modulated Radiotherapy Versus Three-Dimensional Conformal Radiotherapy for Distal Esophageal Cancer

Energy Technology Data Exchange (ETDEWEB)

Kole, Thomas P.; Aghayere, Osarhieme; Kwah, Jason [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yorke, Ellen D. [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Goodman, Karyn A., E-mail: goodmank@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

2012-08-01

Purpose: To compare heart and coronary artery radiation exposure using intensity-modulated radiotherapy (IMRT) vs. four-field three-dimensional conformal radiotherapy (3D-CRT) treatment plans for patients with distal esophageal cancer undergoing chemoradiation. Methods and Materials: Nineteen patients with distal esophageal cancers treated with IMRT from March 2007 to May 2008 were identified. All patients were treated to 50.4 Gy with five-field IMRT plans. Theoretical 3D-CRT plans with four-field beam arrangements were generated. Dose-volume histograms of the planning target volume, heart, right coronary artery, left coronary artery, and other critical normal tissues were compared between the IMRT and 3D-CRT plans, and selected parameters were statistically evaluated using the Wilcoxon rank-sum test. Results: Intensity-modulated radiotherapy treatment planning showed significant reduction (p < 0.05) in heart dose over 3D-CRT as assessed by average mean dose (22.9 vs. 28.2 Gy) and V30 (24.8% vs. 61.0%). There was also significant sparing of the right coronary artery (average mean dose, 23.8 Gy vs. 35.5 Gy), whereas the left coronary artery showed no significant improvement (mean dose, 11.2 Gy vs. 9.2 Gy), p = 0.11. There was no significant difference in percentage of total lung volume receiving at least 10, 15, or 20 Gy or in the mean lung dose between the planning methods. There were also no significant differences observed for the kidneys, liver, stomach, or spinal cord. Intensity-modulated radiotherapy achieved a significant improvement in target conformity as measured by the conformality index (ratio of total volume receiving 95% of prescription dose to planning target volume receiving 95% of prescription dose), with the mean conformality index reduced from 1.56 to 1.30 using IMRT. Conclusions: Treatment of patients with distal esophageal cancer using IMRT significantly decreases the exposure of the heart and right coronary artery when compared with 3D

Radiotherapy gel dosimetry

International Nuclear Information System (INIS)

Baldock, C.

2002-01-01

In radiotherapy, the primary objective is to deliver a prescribed dose of radiation to a tumour or lesion within a patient while minimising the dose delivered to the surrounding healthy tissue. Traditional radiotherapy treatments usually involve simple external or internal irradiations of a tumour. External irradiations are normally achieved in the clinic with photon or electron beams produced by high energy linear accelerators. The photon or electron beams are collimated into regular shapes as they emerge from the treatment head of the unit which is supported by a gantry that can be rotated isocentrically to any position. A discrete number of photon or electron beams with different angles of incidence that intersect at the iso-centre are used to produce a region of high dose around the tumour volume (positioned at the iso-centre). Internal irradiations are normally achieved in the clinic by implanting radioactive sources in and around the tumour or lesion. Such irradiations are characterised by very high doses local to the tumour. Radioactive sources are also used to prevent post-angioplasty restenosis by inserting sources into arteries. Usually when treating a tumour, a compromise is made between tumour control and complications arising from normal tissue damage. One measure of this compromise, the therapeutic ratio, is defined as the radiation dose producing complications in 50% of patients divided by the dose providing tumour control in 50% of the patients. The therapeutic ratio depends on the radiobiological characteristics of the cancerous tissue and surrounding healthy tissues and on the radiation dose distribution achieved by the radiotherapy treatment. It is generally believed that the therapeutic ratio can be minimised by optimising the conformation of the radiation dose distribution to the target volume. This is difficult with traditional radiotherapy techniques since they do not produce dose distributions that adequately cover tumour volumes of complex

Dosimetric Study of Current Treatment Options for Radiotherapy in Retinoblastoma

Energy Technology Data Exchange (ETDEWEB)

Eldebawy, Eman [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada); Department of Radiation Oncology, Children' s Cancer Hospital, Cairo (Egypt); Parker, William, E-mail: william.parker@mcgill.ca [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Abdel Rahman, Wamied [Department of Medical Physics, McGill University Health Centre, Montreal, Quebec (Canada); Freeman, Carolyn R. [Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec (Canada)

2012-03-01

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

Postoperative radiotherapy of uterine sarcoma: A multicentric retrospective study

International Nuclear Information System (INIS)

Champetier, C.; Cowen, D.; Hannoun-Levi, J.M.; Resbeut, M.; Azria, D.; Salem, N.; Tessier, E.; Ellis, S.

2011-01-01

Purpose. - Surgery is the treatment of choice for localized uterine sarcomas. We conducted a retrospective study to define prognostic factors. Patients and methods. - We studied 111 cases of patients treated by adjuvant radiotherapy for uterine sarcoma in seven French centers. The median decline was 31 months. We conducted a univariate analysis to identify factors correlated with local recurrence. The statistically significant factors were studied in multivariate analysis by Cox model. Results. - The median dose of external beam radiotherapy was 45 Gy. Forty-three percent of patients had vaginal vault brachytherapy and 21 % chemotherapy. Only 6.3 % of patients had complications of acute grade III and 8.1 % of long-term sequelae of radiotherapy. The survival rate at 5 years was 74.6 %. They noted 12.6 % of isolated locoregional recurrences, against 29.7 % for distant recurrences, 80 % were pulmonary. Factors correlated with the risk of locoregional relapse were menopausal status (P = 0.045) and surgical margins suspicious or not healthy (P = 0.0095). The chemotherapy did not improve overall survival or disease free survival but the numbers were low. Conclusion. - The postoperative radiotherapy provides good local control in this disease. Brachytherapy is sometimes done, but it does not improve local control. Chemotherapy is not a standard localized stage but the rate of metastatic recurrence calls for the development of strategies involving systemic treatment with radiotherapy. (authors)

Capecitabine and Oxaliplatin Before, During, and After Radiotherapy for High-Risk Rectal Cancer

DEFF Research Database (Denmark)

Larsen, Finn Ole; Markussen, Alice; Jensen, Benny V

2017-01-01

PURPOSE: To evaluate the effect of capecitabine and oxaliplatin before, during, and after radiotherapy for high-risk rectal cancer. PATIENTS AND METHODS: Patients with rectum cancer T4 or T3 involving the mesorectal fascia was included in a prospective phase 2 trial. Liver or lung metastases were...... accepted if the surgeons found them resectable. The patients received 6 weeks of capecitabine and oxaliplatin before chemoradiotherapy (CRT), continued capecitabine and oxaliplatin during radiotherapy, and received 4 weeks of capecitabine and oxaliplatin after CRT. The patients received radiotherapy...... as intensity-modulated radiotherapy. Total mesorectal excision was planned 8 weeks after CRT. The patients were evaluated with magnetic resonance imaging (MRI) before start of treatment, after 6 weeks of chemotherapy, and again just before the operation. The European Organization for Research and Treatment...

New algorithm for risk analysis in radiotherapy

International Nuclear Information System (INIS)

Torres, Antonio; Montes de Oca, Joe

2015-01-01

Risk analyses applied to radiotherapy treatments have become an undeniable necessity, considering the dangers generated by the combination of using powerful radiation fields on patients and the occurrence of human errors and equipment failures during these treatments. The technique par excellence to execute these analyses has been the risk matrix. This paper presents the development of a new algorithm to execute the task with wide graphic and analytic potentialities, thus transforming it into a very useful option for risk monitoring and the optimization of quality assurance. The system SECURE- MR, which is the basic software of this algorithm, has been successfully used in risk analysis regarding different kinds of radiotherapies. Compared to previous methods, It offers new possibilities of analysis considering risk controlling factors as the robustness of reducers of initiators frequency and its consequences. Their analytic capacities and graphs allow novel developments to classify risk contributing factors, to represent information processes as well as accidental sequences. The paper shows the application of the proposed system to a generic process of radiotherapy treatment using a lineal accelerator. (author)

Stereotactic Radiotherapy by 6MV Linear Accelerator

Energy Technology Data Exchange (ETDEWEB)

Oho, Yoon Kyeong; Kim, Mi Hee; Gil, Hak Jun [Catholic University College of Medicine, Seoul (Korea, Republic of)] (and others)

1988-12-15

Eight patients with intracranial tumors or arteriovenous malformation (AVM)s which were less than 3 cm in diameter were treated by a technique of stereotactic radiotherapy during the 4 months period from July 1988 through October 1988 at the Division of Radiation Therapy, Kang-Nam St. Mary's Hospital, Catholic University Medical College. The patients were diagnosed as AVMs in 3 cases, acoustic neurinoma, craniopharyngioma (recurrent), hemangioblastoma, pineocytoma, and pituitary microadenoma in each case. There are several important factors in this procedure, such as localization system, portal, field size, radiation dose, and perioperative supportive care. It is suggested that stereotactic radiotherapy may be performed safely with a radiation dose of 12-30 Gy. So this noninvasive procedure can be used to treat unresectable intracranial tumors or AVMs. Of these, clinical symptoms had been regressed in AVMs in 2 cases at 3 months and 2 months after Stereotactic radiotherapy, one of whom was confirmed slightly regressed on the follow-up angiogram. And also craniopharyngioma and pineocytoma was minimally regressed on 3 month follow-up CT.

Stereotactic Radiotherapy by 6MV Linear Accelerator

International Nuclear Information System (INIS)

Oho, Yoon Kyeong; Kim, Mi Hee; Gil, Hak Jun

1988-01-01

Eight patients with intracranial tumors or arteriovenous malformation (AVM)s which were less than 3 cm in diameter were treated by a technique of stereotactic radiotherapy during the 4 months period from July 1988 through October 1988 at the Division of Radiation Therapy, Kang-Nam St. Mary's Hospital, Catholic University Medical College. The patients were diagnosed as AVMs in 3 cases, acoustic neurinoma, craniopharyngioma (recurrent), hemangioblastoma, pineocytoma, and pituitary microadenoma in each case. There are several important factors in this procedure, such as localization system, portal, field size, radiation dose, and perioperative supportive care. It is suggested that stereotactic radiotherapy may be performed safely with a radiation dose of 12-30 Gy. So this noninvasive procedure can be used to treat unresectable intracranial tumors or AVMs. Of these, clinical symptoms had been regressed in AVMs in 2 cases at 3 months and 2 months after Stereotactic radiotherapy, one of whom was confirmed slightly regressed on the follow-up angiogram. And also craniopharyngioma and pineocytoma was minimally regressed on 3 month follow-up CT

Development of a multichannel dosimeter for radiotherapy

International Nuclear Information System (INIS)

Menezes, Claudio Jose Mesquita

2000-06-01

In radiotherapy, verification of the patient dose is of great important for the success of the treatment. Uncertainties in the evaluation of this dose can produce serious complications such as the loss of the control of the disease and damage to normal tissue. Semiconductor detectors present advantages over other types of radiation detectors such as ionization chambers and thermoluminescent dosimeters including small dimensions, high sensitivity and fast response. In this work, a multichannel dosimetric system is linear with dose, for a 6 MV x-ray beam and also with a beam of cobalt-60 gamma rays. The coefficients of determination of the calibration curves were better then 0,9998 in all cases. The four sensors presented similar response with the dose for different field sizes. The variation of the response was smaller than 1%. In a related study, depth dose was measured, and the results showed a good agreement compared to theoretical values. The angular response of the detectors showed a variation of 7% for angles of 45 deg C. Using the Anderson Random phantom, dose at the isocenter was determined from measurements of the surface dose. From the results obtained it can be concluded that the dosimetric system developed is adequate for the evaluation of many parameters in radiation fields used in radiotherapy. This system can be used to measure the patient entrance dose under treatment conditions, and the equipment can be used in the radiotherapy quality assurance program. (author)

[Development of quality assurance/quality control web system in radiotherapy].

Science.gov (United States)

Okamoto, Hiroyuki; Mochizuki, Toshihiko; Yokoyama, Kazutoshi; Wakita, Akihisa; Nakamura, Satoshi; Ueki, Heihachi; Shiozawa, Keiko; Sasaki, Koji; Fuse, Masashi; Abe, Yoshihisa; Itami, Jun

2013-12-01

Our purpose is to develop a QA/QC (quality assurance/quality control) web system using a server-side script language such as HTML (HyperText Markup Language) and PHP (Hypertext Preprocessor), which can be useful as a tool to share information about QA/QC in radiotherapy. The system proposed in this study can be easily built in one's own institute, because HTML can be easily handled. There are two desired functions in a QA/QC web system: (i) To review the results of QA/QC for a radiotherapy machine, manuals, and reports necessary for routinely performing radiotherapy through this system. By disclosing the results, transparency can be maintained, (ii) To reveal a protocol for QA/QC in one's own institute using pictures and movies relating to QA/QC for simplicity's sake, which can also be used as an educational tool for junior radiation technologists and medical physicists. By using this system, not only administrators, but also all staff involved in radiotherapy, can obtain information about the conditions and accuracy of treatment machines through the QA/QC web system.

Anaplastic astrocytoma 14 years after radiotherapy for pituitary adenoma

Energy Technology Data Exchange (ETDEWEB)

Tamura, Masaru; Misumi, Syuuzou; Kurosaki, Syuuhei; Shibasaki, Takashi; Ohye, Chihiro (Gunma Univ., Maebashi (Japan). School of Medicine)

1992-04-01

A case of anaplastic astrocytoma following radiotherapy for growth hormone secreting pituitary adenoma is presented with a review of the literature. A 43 year old female was admitted with signs of acromegaly and hypertension. An eosinophilic pituitary adenoma was subtotally removed by transsphenoidal approach, followed by 60 Gy irradiation using a 2x2 cm lateral field. Fourteen years later at the age of 57, she suffered from headache, recent-memory disturbance and uncinate fits. CT scan and MRI disclosed ring-like enhanced mass lesion in the left temporal lobe, corresponding to the previous irradiated field. {sup 18}F-FDG PET showed hypermetabolism at the lesion. Left frontotemporal craniotomy was performed, and a reddish gray gelatinous tumor containing necrotic center and cyst was partially removed. Histologically, the tumor consisted of hypercellular astrocytic cells with perivascular pseudorosette. Coagulation necrosis at the center of the tumor, and hyalinosis and fibrosis of the blood vessels in and around the tumor, which might have been caused by the antecedent radiotherapy, were recognized. Postoperative radiotherapy and chemotherapy, were given, however, she expired 13 months after the operation. Seven cases, including ours, of malignant glioma following radiotherapy for pituitary adenoma were reported in the literature. A total dose of irradiation varies from 45 to 95 Gy with a mean of 50 Gy. The period of latency before tumor occurrence ranges from 5 to 22 years with a mean of 10 years. The differentiation of radiation-induced gliomas from radionecrosis of the brain is also discussed. (author).

Anaplastic astrocytoma 14 years after radiotherapy for pituitary adenoma

International Nuclear Information System (INIS)

Tamura, Masaru; Misumi, Syuuzou; Kurosaki, Syuuhei; Shibasaki, Takashi; Ohye, Chihiro

1992-01-01

A case of anaplastic astrocytoma following radiotherapy for growth hormone secreting pituitary adenoma is presented with a review of the literature. A 43 year old female was admitted with signs of acromegaly and hypertension. An eosinophilic pituitary adenoma was subtotally removed by transsphenoidal approach, followed by 60 Gy irradiation using a 2x2 cm lateral field. Fourteen years later at the age of 57, she suffered from headache, recent-memory disturbance and uncinate fits. CT scan and MRI disclosed ring-like enhanced mass lesion in the left temporal lobe, corresponding to the previous irradiated field. 18 F-FDG PET showed hypermetabolism at the lesion. Left frontotemporal craniotomy was performed, and a reddish gray gelatinous tumor containing necrotic center and cyst was partially removed. Histologically, the tumor consisted of hypercellular astrocytic cells with perivascular pseudorosette. Coagulation necrosis at the center of the tumor, and hyalinosis and fibrosis of the blood vessels in and around the tumor, which might have been caused by the antecedent radiotherapy, were recognized. Postoperative radiotherapy and chemotherapy, were given, however, she expired 13 months after the operation. Seven cases, including ours, of malignant glioma following radiotherapy for pituitary adenoma were reported in the literature. A total dose of irradiation varies from 45 to 95 Gy with a mean of 50 Gy. The period of latency before tumor occurrence ranges from 5 to 22 years with a mean of 10 years. The differentiation of radiation-induced gliomas from radionecrosis of the brain is also discussed. (author)

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

International Nuclear Information System (INIS)

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

2010-01-01

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.

Therapeutic Results of Radiotherapy in Rectal Carcinoma -Comparison of Sandwich Technique Radiotherapy with Postoperative Radiotherapy

International Nuclear Information System (INIS)

Huh, Gil Cha; Suh, Hyun Suk; Lee, Hyuk Sang; Kim, Re Hwe; Kim, Chul Soo; Kim, Hong Yong; Kim, Sung Rok

1996-01-01

Purpose : To evaluate the potential advantage for 'sandwich' technique radiotherapy compared to postoperative radiotherapy in respectable rectal cancer. Between January 1989 and May 1994, 60 patients with respectable rectal cancer were treated at Inje University Seoul and Sanggye Paik Hospital.Fifty one patients were available for analysis : 20 patients were treated with sandwich technique radiotherapy and 31 patients were treated with postoperative radiotherapy. In sandwich technique radiotherapy(RT), patients were treated with preoperative RT 1500 cGy/5fx followed by immediate curative resection. Patients staged as Astler-Coller B2, C were considered for postoperative RT with 2500-4500 cGy. In postoperative RT, total radiation dose of 4500-6120 cGy, 180 cGy daily at 4-6 weeks was delivered. Patients were followed for median period of 25 months. Results : The overall 5-year survival rates for sandwich technique RT group and postoperative RT group were 60% and 71%, respectively(p>0.05). The 5-year disease free survival rates for each group were 63%. There was no difference in local failure rate between two groups(11% versus 7%). Incidence of distant metastasis was 11%(2/20) in the sandwich technique RT group and 20%(6/31) in the postoperative RT group(p>0.05). The frequencies of acute and chronic complications were comparable in both groups. Conclusion : The sandwich technique radiotherapy group shows local recurrence and survival similar to those of postoperative RT alone group but reduced distant metastasis compared to postoperative RT group. But long term follow-up and large number of patients is needed to make an any firm conclusion regarding the value of this sandwich technique RT

Reirradiation for recurrent head and neck cancers using charged particle or photon radiotherapy.

Science.gov (United States)

Yamazaki, Hideya; Demizu, Yusuke; Okimoto, Tomoaki; Ogita, Mikio; Himei, Kengo; Nakamura, Satoaki; Suzuki, Gen; Yoshida, Ken; Kotsuma, Tadayuki; Yoshioka, Yasuo; Oh, Ryoongjin

2017-07-01

To examine the outcomes of reirradiation for recurrent head and neck cancers using different modalities. This retrospective study included 26 patients who received charged particle radiotherapy (CP) and 150 who received photon radiotherapy (117 CyberKnife radiotherapy [CK] and 36 intensity-modulated radiotherapy [IMRT]). Inverse probability of treatment weighting (IPTW) involving propensity scores was used to reduce background selection bias. Higher prescribed doses were used in CP than photon radiotherapy. The 1‑year overall survival (OS) rates were 67.9% for CP and 54.1% for photon radiotherapy (p = 0.15; 55% for CK and 51% for IMRT). In multivariate Cox regression, the significant prognostic factors for better survival were nasopharyngeal cancer, higher prescribed dose, and lower tumor volume. IPTW showed a statistically significant difference between CP and photon radiotherapy (p = 0.04). The local control rates for patients treated with CP and photon radiotherapy at 1 year were 66.9% (range 46.3-87.5%) and 67.1% (range 58.3-75.9%), respectively. A total of 48 patients (27%) experienced toxicity grade ≥3 (24% in the photon radiotherapy group and 46% in the CP group), including 17 patients with grade 5 toxicity. Multivariate analysis revealed that younger age and a larger planning target volume (PTV) were significant risk factors for grade 3 or worse toxicity. CP provided superior survival outcome compared to photon radiotherapy. Tumor volume, primary site (nasopharyngeal), and prescribed dose were identified as survival factors. Younger patients with a larger PTV experienced toxicity grade ≥3.

Magnetic Resonance Imaging and conformal radiotherapy: Characterization of MRI alone simulation for conformal radiotherapy. Development and evaluation of an automatic volumes of interest segmentation tool for prostate cancer radiotherapy

International Nuclear Information System (INIS)

Pasquier, David

2006-01-01

Radiotherapy is a curative treatment of malignant tumours. Radiotherapy techniques considerably evolved last years with the increasing integration of medical images in conformal radiotherapy. This technique makes it possible to elaborate a complex ballistics conforming to target volume and sparing healthy tissues. The examination currently used to delineate volumes of interest is Computed Tomography (CT), on account of its geometrical precision and the information that it provides on electronic densities needed to dose calculation. Magnetic Resonance Imaging (MRI) ensures a more precise delineation of target volumes in many locations, such as pelvis and brain. For pelvic tumours, the use of MRI needs image registration, which complicates treatment planning and poses the problem of the lack of in vivo standard method of validation. The obstacles in the use of MRI alone in treatment planning were evaluated. Neither geometrical distortion linked with the system and the patient nor the lack of information on electronic densities represent stumbling obstacles. Distortion remained low even in edge of large field of view on modern machines. The assignment of electronic densities to bone structures and soft tissues in MR images permitted to obtain equivalent dosimetry to that carried out on the original CT, with a good reproducibility and homogeneous distribution within target volume. The assignment of electronic densities could not be carried out using 20 MV photons and suitable ballistics. The development of Image Guided Radiotherapy could facilitate the use of MRI alone in treatment planning. Target volumes and organ at risk delineation is a time consuming task in radiotherapy planning. We took part in the development and evaluated a method of automatic and semi automatic delineation of volumes of interest from MRI images for prostate cancer radiotherapy. For prostate and organ at risk automatic delineation an organ model-based method and a seeded region growing method

Recommendations of the publication ICRP-84: pregnancy and medical irradiation for radiotherapy

International Nuclear Information System (INIS)

Rojkind, Roberto H.

2001-01-01

The malignant diseases in the pregnant women are relatively not much frequent, and some of these cases can be applied radiotherapy for the tumours treatment. The doses involved in the radio therapeutics procedures can produce a significant foetal damage, and the patient or worker has the right to know the magnitude and the potential effects that can be results of the radiotherapy exposure. The publication ICRP-84 of the International Commission of Radiological Protection approaches specific aspect of the individual justification of the medical exposure of the patient pregnant woman, and recommends work procedures for the dose optimization that will receive the fetus. In this communication is commented the content of the radiotherapy section of the mentioned publication

Adjuvant radiotherapy for cutaneous melanoma: Comparing hypofractionation to conventional fractionation

International Nuclear Information System (INIS)

Chang, Daniel T.; Amdur, Robert J.; Morris, Christopher G. M.S.; Mendenhall, William M.

2006-01-01

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

Heart dosimetry in radiotherapy with hybrid computational phantoms

International Nuclear Information System (INIS)

Moignier, Cyril

2014-01-01

segmentation were estimated for a left side breast radiotherapy by simulating different realistic coronary artery topologies in a single representative thorax anatomy and calculating doses due to beam sets, with and without irradiation of the internal mammary chain. The inter-topology variability of the mean dose to the most irradiated coronary artery, the left descending coronary artery, was assessed to 35% and 19% with and without the internal mammary chain irradiation, respectively; and it was of 76% and 49%, respectively, considering the dose to the most irradiated 2% of this coronary artery volume. Finally, an order of magnitude of the differences between measurements by radiochromic films and dose calculations by the ISOgray treatment planning system in the peripheral field area, has been estimated by for both a simple configuration (parallelepiped physical phantom, homogeneous media, open square field) and a complex configuration (anthropomorphic physical phantom, heterogeneous media, rectangular tangential beams with wedge filter). These differences were judged significant essentially around the geometrical border of the irradiation field for both configuration. (author)

Radiotherapy of locally advanced laryngeal cancer: the Gliwice Center of Oncology experience, 1990-1996

International Nuclear Information System (INIS)

Mucha-Malecka, A.; Skladowski, K.; Wygoda, A.; Sasiadek, W.; Tarnawski, R.

2001-01-01

The aim of the study was to assess the efficacy of radiotherapy alone in patients with locally advanced laryngeal cancer T3 - T4, and to establish the prognostic value of the size and the location of the extra laryngeal infiltrations and of emergency tracheostomy. 296 patients with advanced squamous cell cancer of the larynx were radically treated with radiotherapy alone in Center of Oncology in Gliwice between the years 1990 and 1996. There were 221 cases of supraglottic cancer (75%) and 75 of glottic cancer (25%). The stages were as follows: supraglottic cancer: T3 - 113 (51%), T4 - 108 (49%), glottic cancer: T3 - 69 (92%), T4 - 6 (8%). Positive neck nodes were found in 100 patients with supraglottic cancer (45%), and only in 11 patients with glottic cancer (15%). In cases of extra laryngeaI invasion (T4) the pyriform recess was involved in 33%, the base of tongue and valleculae glosso-epiglotticae in 30%, the hypopharyngeal wall in 9% of cases, while a massive involvement of the larynx, the pyriform recess and the base of the tongue was found in 6% of patients. Cartilage involvement was suspected in 22% of patients. Thirty six patients (12%) underwent emergency tracheostomy. Generally, the 3-year local control rate (LC) and disease free survival rate (DSF) were 46% and 41%, respectively. The probability of LC was similar in both supraglottic and glottic cancer: 44% and 47.5% respectively. The presence of involved neck nodes significantly decreased LC and DFS rates in both groups (about 20%). For stage T4 laryngeal cancer the LC rate was correlated with the location of the extra laryngeal infiltrations. Best prognosis was connected with the suspicion of cartilage infiltration - 56% of 3-year LC rate. The worst results were noted in cases of massive infiltrations spreading from larynx through the hypopharynx - 13.5% of 3-year LC rate. Emergency tracheostomy before radiotherapy was very significantly linked to poorer treatment results. The 3-year LC rate in

Study on intraoperative radiotherapy of brain tumors

International Nuclear Information System (INIS)

Uozumi, Akimasa

1990-01-01

Effects of a single large dose radiation on the brain of dogs were investigated for the purpose of determining the optimal dose and radiation field in intraoperative radiotherapy. The right parietal lobe of dogs (three groups, four dogs in each) were radiated at the dose of 30, 40 and 50 Gy respectively at the depth of 1.5 cm by 11 Nev electron beam with field size of 2 cm. CT and histopathological study were performed 2, 6, 12 and 24 months after radiation. L-hemiparesis developed 14 months after radiation in the 30 Gy group and 8 months in the 40 Gy group, 6 months in the 50 Gy group. All animals in the 40 Gy and 50 Gy groups died before 15 months of radiation. CT showed delayed radiation necrosis in all groups. Brain swelling and ventricular displacement in the radiated hemisphere and contralateral ventricular dilatation were depicted on plain CT. Diffuse heterogeneous contrast enhancement (CE) was observed on CE-CT. CT revealed disappearance of radiation necrosis in the 30 Gy group 24 months of radiation, suggesting that radiation necrosis may be dependent on the term after radiation. Histological findings of radiation necrosis were similar in all animals, and the vascular change preceding the parechymal necrosis was not observed. This supports the theory that the vascular alternation dose not play a major role in the production of radiation necrosis. The necrotic area grossly reflected the isodose curve and was observed in the radiation field with 15 to 20 Gy at the depth of 3 to 4.5 cm. Thus, the intraoperative radiotherapy should be planned on the basis of two such factors as electron beam energy and the field size, and the area out of the target should not be radiated at the dose of more than 15 Gy. The author believes that the information would contribute to safer and more effective application of intraoperative radiotherapy on malignant brain tumors. (J.P.N.) 63 refs

Irradiation of the testes in radiotherapy of Hodgkin's disease and testicular tumors

International Nuclear Information System (INIS)

Bakyrdzhiev, S.; Ganchev, M.; Milchev, V.; Naumova, Ts.

1983-01-01

Direct measurements using TLD dosimeters permitted to calculate radiation doses delivered to the testes in radiotherapy for supradiaphragmatic forms of Hodgkin's disease, stages I and II; they were found to constitute from 1 to 2% of focal dose, that is, to amount to 40-80 cGy given in 20 nonuniform fractions. In radiotherapy for subdiaphragmatic forms of the disease, the dose to the testes varied from 360 to 400 cGy. Anthropomorphic, phantom measurements with ionization chambers placed within the phantom testes showed contributions to total testicular dose to vary with individual irradiation fields in these cases. Thus, for instance, 82% of total dose was due to irradiation of both iliac fields; shielding of the testes with lead caps (5mm) reduced this irradiation to one-half. Doses to the testes were relatively large in radiotherapy for testicular tumors (seminomas and teratocarcinomas). By combining radiotherapy with chemotherapy or surgical intervention, permanent cure or long-lasting remissions may be achieved in most cases. In this connection, there arises the question as to the potential risk of patients - mostly young males with maintained reproductive capacity - transmitting radiation - induced genetic damage to their progeny. An attempt was made to appraise such genetic risk from additional above-background exposure. (authors)

An electromechanical, patient positioning system for head and neck radiotherapy

Science.gov (United States)

Ostyn, Mark; Dwyer, Thomas; Miller, Matthew; King, Paden; Sacks, Rachel; Cruikshank, Ross; Rosario, Melvin; Martinez, Daniel; Kim, Siyong; Yeo, Woon-Hong

2017-09-01

In cancer treatment with radiation, accurate patient setup is critical for proper dose delivery. Improper arrangement can lead to disease recurrence, permanent organ damage, or lack of disease control. While current immobilization equipment often helps for patient positioning, manual adjustment is required, involving iterative, time-consuming steps. Here, we present an electromechanical robotic system for improving patient setup in radiotherapy, specifically targeting head and neck cancer. This positioning system offers six degrees of freedom for a variety of applications in radiation oncology. An analytical calculation of inverse kinematics serves as fundamental criteria to design the system. Computational mechanical modeling and experimental study of radiotherapy compatibility and x-ray-based imaging demonstrates the device feasibility and reliability to be used in radiotherapy. An absolute positioning accuracy test in a clinical treatment room supports the clinical feasibility of the system.

Modeling the Risk of Secondary Malignancies after Radiotherapy

Directory of Open Access Journals (Sweden)

Uwe Schneider

2011-11-01

Full Text Available 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

[Principles of radiotherapy of non-small cell lung cancer].

Science.gov (United States)

Esik, Olga; Horváth, Akos; Bajcsay, András; Hideghéty, Katalin; Agócs, László; Pikó, Béla; Lengyel, Zsolt; Petrányi, Agota; Pisch, Julianna

2002-01-01

The long-term survival probability for Hungarian lung cancer patients is 10% worse than the best results published in the most highly developed countries (the mean 5-year survival probability in Hungary is 5%, in contrast with the 15% survival probability in the USA). On the basis of the international recommendations and personal experience, an attempt was made to formulate the guidelines for radiotherapy as one of the fundamental non-small cell lung cancer (NSCLC) treatment modalities for national use. An expert panel was set up comprising physicians from 6 radiotherapeutic centers (the National Institute of Oncology / Semmelweis University, Budapest; the Beth Israel Medical Center, New York; the University of Kaposvár; the University of Essen; the University of Debrecen; and the County Hospital of Gyula). Experts in two important medical fields closely related to radiotherapy (surgery and diagnostic imaging) were also engaged in the elaboration of the manuscript. Discussion of the most important principles of the radiotherapy and an overview of the prognostic factors was followed by a critical analysis of the protocols applied in the radiotherapy of Hungarian NSCLC patients during recent decades. The new guidelines suggested for the radiotherapy of NSCLC are presented separately for the postoperative period, marginally resectable tumors, and the aggressive or non-aggressive radiotherapy of inoperable tumors. Detailed accounts are given of the techniques of external irradiation and brachytherapy, and of the acute and late radiation-induced damage of normal tissues. The authors believe that this document may be instrumental in improving the survival index of Hungarian NSCLC patients in the near future.

A verification methodology for in vivo dosimetry in stereotactic radiotherapy; Uma metodologia para verificacao dosimetrica in vivo em radioterapia estereotaxica

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Amaral, Leonardo L.; Oliveira, Harley F.; Fairbanks, Leandro R., E-mail: leonardo.fis@usp.br [Universidade de Sao Paulo (HCFMRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas; Nicolucci, Patricia; Netto, Thomaz G. [Universidade de Sao Paulo (FFCLRP/USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Departamento de Fisica

2012-12-15

Radiotherapy of brain lesions near critical structures requires a high accuracy in the location and dose. The high precision is achieved by the location of the stereotactic apparatus. The accuracy in dose delivery should be accompanied by an accurate quality control in devices that involve the practice, however, still does not guarantee the dose at the time of therapy. The large number of fields and the small size of these conventional methods difficult dosimetry during treatment. The objective of this work was to develop a verification methodology in vivo dosimetry in stereotactic radiotherapy with the aid of the film radiochromic Linear Accelerator with multi leaf collimators Moduleaf. The technique uses film segments radiochromic Gafchromic EBT2, with dimensions of 1x1 cm{sup 2} in area outside the coupled micro-multileaf Moduleaf Siemens. These films were inserted in the region of the central axis of the beam. The films were irradiated and calibrated to obtain the factors that determine the size dependence of the dosimetric field. With these data, we designed a computer program which calculates the density of a film must acquire when subjected to an exposure in this setting. This study evaluated five non-coplanar plans, the first with 15 fields and the other with 25 fields. Before starting the procedure, the film segment is coupled to the device, and after the treatment, the relative density is evaluated and compared with the calculated. The average value of the verification at the time of radiation dosimetry compared with the calculated by the sheet was 1.5%. The data collected in this study showed a satisfactory agreement between measured and calculated by the program in the densitometer. Thus, a methodology was developed to verify in vivo dosimetry in radiotherapy and stereotactic linear accelerator collimators Moduleaf. (author)

Daily-diary evaluated side-effects of conformal versus conventional prostatic cancer radiotherapy technique

International Nuclear Information System (INIS)

Widmark, A.; Fransson, P.; Franzen, L.; Littbrand, B.; Henriksson, R.

1997-01-01

Conventional 4-field box radiotherapy technique induces high morbidity for patients with localized prostatic cancer. Using a patient daily diary, the present study compared side-effects after conventional radiotherapy with conformal radiotherapy for prostate cancer. Fifty-eight patients treated with the conventional technique (with or without sucralfate) were compared with 72 patients treated with conformal technique. The patient groups were compared with an age-matched control population. Patients treated with conformal technique were also evaluated regarding acute and late urinary problems. Results showed that patients treated with conformal technique reported significantly fewer side-effects as compared with conventional technique. Patients treated with sucralfate also showed slightly decreased intestinal morbidity in comparison to non-sucralfate group. Acute and late morbidity evaluated by the patients was decreased after conformal radiotherapy as compared with the conventional technique. Sucralfate may be of value if conformal radiotherapy is used for dose escalation in prostatic cancer patients. (orig.)

The role of precautionary radiotherapy of the neck in NO laryngeal cancers

International Nuclear Information System (INIS)

Baroncelli, G.; Bonetti, B.; La Face, B.; Moretti, R.

1988-01-01

The role of precautionary radiotherapy of the neck in laryngeal cancers (exept T1-T2 glottic and some T1 supraglottic cancers) NO at the clinical staging was investigated. Two-hundred and fifty-three patients were examined: 143 were irradiated only on T, and 110 also on the neck. Radiotherapy of the neck in the latter group was performed either by means of two large opposed fields of photon beams including T and N, or by means of fields of photon beams on T and electron beams (8x12 cm 2 average) on the neck, to quite exclude any risks for the spinal cord. The dose was 45-50 Gy (2 Gy/fraction/day; 5 fraction/week) in 4-5 weeks. A comparison of the results obtained in the two groups, in terms of survival-rate and relapse-free time, indicates that radiotherapy reduces the change of relapses on N (6.1% vs. 14.62% at 3 years; p=0.04) and improves the patient's survival chances (82.5% vs. 68.4% at 3 years; and 80.8% vs. 63.4% at 5 years). Our data were then compared with literature data on the importance of N field size in radiation treatment. As a rule, some authors enlarge the field to be treated to a total nodal neck irradiation, but their results are not significally different from those we obtained with 8x12 cm 2 field size

Intensity modulation in breast radiotherapy: Development of an innovative field-in-field technique at Institut Gustave-Roussy

International Nuclear Information System (INIS)

Heymann, S.; Bourhis, J.; Bourgier, C.; Verstraet, R.; Pichenot, C.; Vergne, E.; Lefkopoulos, D.; Husson, F.; Kafrouni, H.; Mahe, J.; Kandalaft, B.; Marsiglia, H.

2011-01-01

Purpose. - To assess the potential dosimetric gain of pre-segmentation modulated radiotherapy (OAPS, DosiSoft TM ) of breast, compared to routine 3D conformal radiotherapy. Patients and methods. - Twenty patients treated with conservative surgery for breast cancer (9 right and 11 left sided) with various breast volume (median 537 cm 3 ; range [100-1049 cm 3 ]) have been selected. For each patient, we have delineated a breast volume and a compensation volume (target volumes), as well as organs at risk (lungs and heart). Two treatment plans have been generated: one using the routine 3D conformal technique and the other with the pre-segmentation algorithm of DosiSoft TM (OAPS). The dose distribution were analyzed using the conformity index for target volumes, mean dose and V 30 Gy for the heart, and mean dose, V 20 Gy and V 30 Gy for lungs. Results. - Over the 20 patients, the conformity index increased from 0.897 with routine technique to 0.978 with OAPS (P TM ) is an original method of segmentation of breast. It is automatic, fast and easy, and is able to increase the conformity index, while sparing organ at risk. (authors)

An improved method of radiotherapy for carcinoma of the breast

International Nuclear Information System (INIS)

Kahlhoefer, J.

1991-01-01

This method of radiotherapy of the breast and lymph nodes in cases of breast cancer reduces exposure of the lung and features small gaps and overlaps at the borders of neighbouring fields. The outline of fields, the design of special absorbing blocks and filters, and some notes on treatment planning are given in this paper. (orig.) [de

Contact radiotherapy. Report of technological assessment

International Nuclear Information System (INIS)

Ortholan, Cecile; Melin, Nicole; Lee-Robin, Sun Hae; David, Denis Jean; Pages, Frederique; Devaud, Christine; Noel, Georges; Biga, Julie; Moty-Monnereau, Celine; Canet, Philippe; Lascols, Sylvie; Lamas, Muriel; Ramdine, Jessica; Tuil, Louise

2008-10-01

This report aims at assessing safety, indications, the role in therapeutic strategy, and efficiency of contact radiotherapy. It also aims at answering questions like: is the contact radiotherapy technique validated? What are the indications for contact radiotherapy? What about the efficiency and safety of contact radiotherapy? After a presentation of preliminary notions on radiotherapy (radiation types, dose, and irradiation techniques), the report presents this specific technique of contact radiotherapy: definition, devices, use recommendations, issues of radiation protection, modalities of performance of a contact radiotherapy session, and concerned pathologies. Then, based on a literature survey, this report addresses the various concerned tumours (skin, rectum, brain, breast), indicates some general information about these tumours (epidemiological data, anatomy and classification, therapeutic options, radiotherapy), and proposes an assessment of the efficiency and safety of contact radiotherapy

Clinical treatment planning for stereotactic radiotherapy, evaluation by Monte Carlo simulation

International Nuclear Information System (INIS)

Kairn, T.; Aland, T.; Kenny, J.; Knight, R.T.; Crowe, S.B.; Langton, C.M.; Franich, R.D.; Johnston, P.N.

2010-01-01

Full text: This study uses re-evaluates the doses delivered by a series of clinical stereotactic radiotherapy treatments, to test the accuracy of treatment planning predictions for very small radiation fields. Stereotactic radiotherapy treatment plans for meningiomas near the petrous temporal bone and the foramen magnum (incorp rating fields smaller than I c m2) were examined using Monte Carlo simulations. Important differences between treatment planning predictions and Monte Carlo calculations of doses delivered to stereotactic radiotherapy patients are apparent. For example, in one case the Monte Carlo calculation shows that the delivery a planned meningioma treatment would spare the patient's critical structures (eyes, brainstem) more effectively than the treatment plan predicted, and therefore suggests that this patient could safely receive an increased dose to their tumour. Monte Carlo simulations can be used to test the dose predictions made by a conventional treatment planning system, for dosimetrically challenging small fields, and can thereby suggest valuable modifications to clinical treatment plans. This research was funded by the Wesley Research Institute, Australia. The authors wish to thank Andrew Fielding and David Schlect for valuable discussions of aspects of this work. The authors are also grateful to Muhammad Kakakhel, for assisting with the design and calibration of our linear accelerator model, and to the stereotactic radiation therapy team at Premion, who designed the treatment plans. Computational resources and services used in this work were provided by the HPC and Research Support Unit, QUT, Brisbane, Australia. (author)

Comparative Analysis between preoperative Radiotherapy and postoperative Radiotherapy in Clinical Stage I and II Endometrial Carcinoma

International Nuclear Information System (INIS)

Keum, Ki Chang; Lee, Chang Geol; Chung, Eun Ji; Lee, Sang Wook; Kim, Woo Cheol; Chang, Sei Kyung; Oh, Young Taek; Suh, Chang Ok; Kim, Gwi Eon

1995-01-01

Purpose : To obtain the optical treatment method in patients with endometrial carcinoma(clinical stage FIGO I, II) by comparative analysis between preoperative radiotherapy(pre-op R) and postoperative radiotherapy(post-op RT). Materials and Methods : A retrospective review of 62 endometrial carcinoma patients referred to the Yonsei Cancer Center for radiotherapy between 1985 and 1991 was undertaken. Of 62 patients, 19 patients(Stage I; 12 patients, Stage II; 7 patients) received pre-op RT before TAH(Total Abdominal Hysterectomy) and BSO(Bilateral Salphingoophorectomy) (Group 1) and 43 patients( Stage 1; 32 patients, Stage 2; 11 patients) received post-op RT after TAH and BSO (Group 2). Pre-op irradiation was given 4-6 weeks prior to surgery and post-op RT was administered on 4-5 weeks following surgery. All patients exept 1 patient(Group2; ICR alone) received external irradiation. Seventy percent(13/19) of pre-op RT group and 54 percent(23/42) of post-op RT group received external pelvic irradiation and intracavitary radiation therapy(ICR). External radiation dose was 39.6-55Gy(median 45Gy) in 5-6 week through opposed AP/PA fields or 4-field box technique treating daily, five days per week, 180cGy per fraction. ICR doses were prescribed to point A(20-39.6 Gy, median 39Gy) in Group 1 and 0.5cm depth from vaginal surface (18-30 Gy, median 21Gy) in Group2. Results : The overall 5 year survival rate was 95%. No survival difference between pre-op and post-op RT group.(89.3% vs 97.7%, p>0.1) There was no survival difference by stage, grade and histology between two groups. The survival rate was not affected by presence of residual tumor of surgical specimen after pre-op RT in Group 1(p>0.1), but affected by presence of lymph node metastasis in post-op RT group(p<0.5). The complication rate of pre-op RT group was higher than post-op RT.(16% vs 5%) Conclusion : Post-op radiotherapy offers the advantages of accurate surgical-pathological staging and low complication rate

Radiotherapy for hypersplenism from congestive splenomegaly

International Nuclear Information System (INIS)

Liu, Mu-Tai; Hsieh, Chang-Yo; Chang, Tung-Hao; Lin, Jao-Perng; Huang, Chia-Chun

2004-01-01

We evaluated the effects of splenic irradiation on the common hematological disorders of hypersplenism. From August 2002 to March 2003, five patients with hypersplenism due to congestive splenomegaly underwent splenic irradiation at the Department od Radiation Oncology, Changhua Chirstian Hospital, Taiwan. 3 were males and 2 were females aging from 38 to 66 years. All patients had history of liver cirrhosis. 4 patients underwent thee-dimensional conformal radiotherapy and received conventional radiotherapy with anterior-posterior parallel opposing fields. The followup-period ranged from 1 to 7 months. Thrombocytopenia and splenomegaly were found in all 5 patients by physical examination, hematological test, abdominal sonography and/or abdominal computed tomography. After radiotherapy, thrombocytopenia improved, but leukopenia and anemia did not. No complication due to radiotherapy was found during the follow-up period after splenic irradiation. 2 patients died of hepatocellular carcinoma with active bleeding. One patient died of renal failure due to end-stage renal disease. Based on our results, it seems that splenic irradiation might be effective in treating thrombocytopenia and splenomegaly. Splenic irradiatin seems to be effective for thrombocytopenia, splenomegaly and splenic pain associated with hypersplenism from congenstive splenomegaly. This approach is non-invasive and may be an alternative treatment for splenectomy and splenic embolization for patients with hypersplenism due to congestive splenomegaly. The shortcoming of this study are small sample size, short period of follow-up and lack of randomization. A randomized control trial with more cases and further follow-up of hematological tests and splenic size estimation are warranted to evaluate long term improvement of congestive splenomegaly with thrombocytopeniaafter splenic irradiation

Assessment of leakage dose in vivo in patients undergoing radiotherapy for breast cancer

Directory of Open Access Journals (Sweden)

Peta Lonski

2018-01-01

Full Text Available Background and purpose: Accurate quantification of the relatively small radiation doses delivered to untargeted regions during breast irradiation in patients with breast cancer is of increasing clinical interest for the purpose of estimating long-term radiation-related risks. Out-of-field dose calculations from commercial planning systems however may be inaccurate which can impact estimates for long-term risks associated with treatment. This work compares calculated and measured dose out-of-field and explores the application of a correction for leakage radiation. Materials and methods: Dose calculations of a Boltzmann transport equation solver, pencil beam-type, and superposition-type algorithms from a commercial treatment planning system (TPS were compared with in vivo thermoluminescent dosimetry (TLD measurements conducted out-of-field on the contralateral chest at points corresponding to the thyroid, axilla and contralateral breast of eleven patients undergoing tangential beam radiotherapy for breast cancer. Results: Overall, the TPS was found to under-estimate doses at points distal to the radiation field edge with a modern linear Boltzmann transport equation solver providing the best estimates. Application of an additive correction for leakage (0.04% of central axis dose improved correlation between the measured and calculated doses at points greater than 15 cm from the field edge. Conclusions: Application of a correction for leakage doses within peripheral regions is feasible and could improve accuracy of TPS in estimating out-of-field doses in breast radiotherapy. Keywords: Breast radiotherapy, TLD, Leakage dose, Dose calculation algorithm

Role of radiotherapy in the treatment of meningiomas; Role de la radiotherapie dans le traitement des meningiomes cerebraux

Energy Technology Data Exchange (ETDEWEB)

Noel, G. [Centre de protontherapie, 91 - Orsay (France); Renard, A.; Mazeron, J.J. [Groupe Hospitalier la Pitie-Salpetriere, Service de Radiotherapie, AP-HP, 75 - Paris (France); Valery, C. [Groupe Hospitalier la Pitie-Salpetriere, Service de Neurochirurgie, AP-HP, 75 - Paris (France); Mokhtari, K. [Groupe Hospitalier la Pitie-Salpetriere, Lab. de Neuropathologie Raymond-Escourolle, AP-HP, 75 - Paris (France)

2001-06-01

Role of radiotherapy in the treatment of meningiomas. Cerebral meningiomas account for 15-20% of all cerebral tumours. Although seldom malignant, they frequently recur in spite of complete surgery, which remains the cornerstone of the treatment. In order to decrease the probability of local recurrence, radiotherapy has often been recommended in atypical or malignant meningioma as well as in benign meningioma which was incompletely resected. However, this treatment never was the subject of prospective studies, randomized or not. The purpose of this review of the literature was to give a progress report on the results of different published series in the field of methodology as well as in the techniques of radiotherapy. Proposals for a therapeutic choice are made according to this analysis. For grade I or grade II-III meningiomas, limits of gross tumor volume (GTV) include the tumour in place or the residual tumour after surgery; clinical target volume (CTV) limits include gross tumour volume before surgery with a GTV-CTV distance of 1 and 2 cm respectively. Delivered doses are 55 Gy into CTV and 55-60 Gy and 70 Gy into GTV for grade I and grade II-III meningiomas respectively. (authors)

Improving the accuracy of ionization chamber dosimetry in small megavoltage x-ray fields

Science.gov (United States)

McNiven, Andrea L.

computed tomography dose index (CTDI), a concept normally used in diagnostic radiology. This involved experimental determination of the fan beam thickness using the ion chambers to acquire fan beam profiles and extrapolation to a 'zero-size' detector. In conclusion, improvements have been made in the accuracy of small field dosimetry measurements in stereotactic radiotherapy and helical tomotherapy. This was completed through introduction of an original technique involving micro-CT imaging for sensitive volume determination and potentially ion chamber calibration coefficients, the use of appropriate Monte Carlo derived correction factors for RDF measurement, and the exploitation of the partial volume effect for helical tomotherapy fan beam dosimetry. With improved dosimetry for a wide range of challenging small x-ray field situations, it is expected that the patient's radiation safety will be maintained, and that clinical trials will adopt calibration protocols specialized for modern radiotherapy with small fields or beamlets. Keywords. radiation therapy, ionization chambers, small field dosimetry, stereotactic radiotherapy, helical tomotherapy, micro-CT.

Implementation of a security system in the radiotherapy process; Implantacion de un sistema de seguridad en el proceso radioterapico

Energy Technology Data Exchange (ETDEWEB)

Orellana Salas, A.; Melgar Perez, J.; Arrocha Aceveda, J. F.

2011-07-01

Systems of work within the field of health are complex. Even the most routine activities involving chain and coordinate a number of actions to be developed by different professionals of different specialties. These systems often fail due to a combination of small errors along the process, each insufficient to cause an accident. We must ensure safe systems of work for each process we are involved, so it is essential to implement security systems to evaluate and find the vulnerabilities in all phases of the process. In the Service of Radio Physics and Radiation Protection of Punta de Europa Hospital has implemented a security system for radiotherapy process after the analysis and evaluation of the safety culture of the Service.

Breath-hold technique in conventional APPA or intensity-modulated radiotherapy for Hodgkin's lymphoma. Comparison of ILROG IS-RT and the GHSG IF-RT

Energy Technology Data Exchange (ETDEWEB)

Kriz, Jan; Spickermann, Max; Lehrich, Philipp; Reinartz, Gabriele; Eich, Hans; Haverkamp, Uwe [University of Muenster, Department of Radiation Oncology, Muenster (Germany); Schmidberger, Heinz [University Mainz, Department of Radiation Oncology, Mainz (Germany)

2015-09-15

The present study addresses the role of intensity-modulated radiotherapy (IMRT) in contrast to standard RT (APPA) for patients with Hodgkin's lymphoma (HL) with a focus on deep inspiration breath-hold (DIBH) technique and a comparison between the International Lymphoma Radiation Oncology Group (ILROG) Involved Site Radiotherapy (IS-RT) versus the German Hodgkin Study Group (GHSG) Involved Field Radiotherapy (IF-RT). APPA treatment and 2 IMRT plans were compared for 11 patients with HL. Furthermore, treatment with DIBH versus free breathing (FB) and two different treatment volumes, i.e. IF-RT versus IS-RT, were compared. IMRT was planned as a sliding-window technique with 5 and 7 beam angles. For each patient 12 different treatment plans were calculated (132 plans). Following organs at risk (OAR) were analysed: lung, heart, spinal cord, oesophagus, female breast and skin. Comparisons of the different values with regard to dose-volume histograms (DVH), conformity and homogeneity indices were made. IS-RT reduces treatment volumes. With respect to the planning target volume (PTV), IMRT achieves better conformity but the same homogeneity. Regarding the D{sub mean} for the lung, IMRT shows increased doses, while RT in DIBH reduces doses. The IMRT shows improved values for D{sub max} concerning the spinal cord, whereas the APPA shows an improved D{sub mean} of the lung and the female breast. IS-RT reduces treatment volumes. Intensity-modulated radiotherapy shows advantages in the conformity. Treatment in DIBH also reduces the dose applied to the lungs and the heart. (orig.) [German] Ziel dieser Auswertung ist es, die konventionelle APPA-Feldanordnung mit der Intensitaetsmodulierten Radiotherapie (IMRT) bei Patienten mit Hodgkin-Lymphom (HL) zu vergleichen. Ein besonderer Fokus liegt hierbei auf der Bestrahlung in tiefer Inspiration und Atemanhaltetechnik (DIBH). Des Weiteren wurde die ''Involved-site''-Radiotherapie (IS-RT) der International

Predicted allowable doses to normal organs for biologically targeted radiotherapy

International Nuclear Information System (INIS)

O'Donoghue, J.A.; Wheldon, T.E.; Western Regional Hospital Board, Glasgow

1988-01-01

The authors have used Dale's extension to the ''linear quadratic'' (LQ) model (Dale, 1985) to evaluate ''equivalent doses'' in cases involving exponentially decaying dose rates. This analysis indicates that the dose-rate effect will be a significant determinant of allowable doses to organs such as liver, kidney and lung. These organ tolerance doses constitute independent constraints on the therapeutic intensity of biologically targeted radiotherapy in exactly the same way as for conventional external beam radiotherapy. In the context of marrow rescue they will in all likelihood constitute the dose-limiting side-effects and thus be especially important. (author)

First patients treated with a 1.5 T MRI-Linac: clinical proof of concept of a high-precision, high-field MRI guided radiotherapy treatment

Science.gov (United States)

Raaymakers, B. W.; Jürgenliemk-Schulz, I. M.; Bol, G. H.; Glitzner, M.; Kotte, A. N. T. J.; van Asselen, B.; de Boer, J. C. J.; Bluemink, J. J.; Hackett, S. L.; Moerland, M. A.; Woodings, S. J.; Wolthaus, J. W. H.; van Zijp, H. M.; Philippens, M. E. P.; Tijssen, R.; Kok, J. G. M.; de Groot-van Breugel, E. N.; Kiekebosch, I.; Meijers, L. T. C.; Nomden, C. N.; Sikkes, G. G.; Doornaert, P. A. H.; Eppinga, W. S. C.; Kasperts, N.; Kerkmeijer, L. G. W.; Tersteeg, J. H. A.; Brown, K. J.; Pais, B.; Woodhead, P.; Lagendijk, J. J. W.

2017-12-01

The integration of 1.5 T MRI functionality with a radiotherapy linear accelerator (linac) has been pursued since 1999 by the UMC Utrecht in close collaboration with Elekta and Philips. The idea behind this integrated device is to offer unrivalled, online and real-time, soft-tissue visualization of the tumour and the surroundings for more precise radiation delivery. The proof of concept of this device was given in 2009 by demonstrating simultaneous irradiation and MR imaging on phantoms, since then the device has been further developed and commercialized by Elekta. The aim of this work is to demonstrate the clinical feasibility of online, high-precision, high-field MRI guidance of radiotherapy using the first clinical prototype MRI-Linac. Four patients with lumbar spine bone metastases were treated with a 3 or 5 beam step-and-shoot IMRT plan. The IMRT plan was created while the patient was on the treatment table and based on the online 1.5 T MR images; pre-treatment CT was deformably registered to the online MRI to obtain Hounsfield values. Bone metastases were chosen as the first site as these tumors can be clearly visualized on MRI and the surrounding spine bone can be detected on the integrated portal imager. This way the portal images served as an independent verification of the MRI based guidance to quantify the geometric precision of radiation delivery. Dosimetric accuracy was assessed post-treatment from phantom measurements with an ionization chamber and film. Absolute doses were found to be highly accurate, with deviations ranging from 0.0% to 1.7% in the isocenter. The geometrical, MRI based targeting as confirmed using portal images was better than 0.5 mm, ranging from 0.2 mm to 0.4 mm. In conclusion, high precision, high-field, 1.5 T MRI guided radiotherapy is clinically feasible.

In vivo dosimetry with diodes in a radiotherapy department in Pakistan

International Nuclear Information System (INIS)

Tunio, M.; Rafi, M.; Ali, S.; Ahmed, Z.; Zameer, A.; Hashmi, A.; Maqbool, S. A.

2011-01-01

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 multi-leaf-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 % (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. (authors)

Quality assurance in radiotherapy - a clinical point of view

International Nuclear Information System (INIS)

Merkle, K.; Lessel, A.; Huettner, J.

1990-01-01

Despite the advanced treatment methods now available, the total result in 5-year survival is 40-50% of all patients with malignancies and 20% of these patients will have the chance of a 10-year survival. In the course of their disease a radiotherapy is indicated in about 2/3 of all patients. Thus, radiotherapy makes quite a considerable contribution to the qualitative improvement of the treatment of patients with malignancies. Eradication of the tumor and protection of normal tissue can only be a compromise between tumor control and the production of complications. For the risk assessment of radiotherapy, the steepness of dose-response curves is of paramount importance. That means, small errors in defining and delivering dose can have catastrophic results in terms of failure to control the patient's disease and, on the other side, in terms of complications, that means in quality of life. Although the costs of therapy, in absolute values, vary from one country to the other, it can be stated in rough approximation that a failed radiotherapy will make rise the costs by a factor of 3. According to the fact that in 30-40% of patients, who received radiotherapy, the initial treatment failed to control the primary disease, the enormous additional costs involved become obvious, not to speak of the main argument - the regrowth of the patients's tumor. For the improvement of this situation quality assurance (QA) is an essential prerequisite, which should be guaranteed in all successive steps of radiotherapy. In the paper an analysis is given for all individual steps in the chain of radiotherapeutic measures. (author)

Stereotactic radiotherapy for pediatric intracranial germ cell tumors

International Nuclear Information System (INIS)

Zissiadis, Yvonne; Dutton, Sharon; Kieran, Mark; Goumnerova, Liliana; Scott, R. Michael; Kooy, Hanne M.; Tarbell, Nancy J.

2001-01-01

Purpose: Intracranial germ cell tumors are rare, radiosensitive tumors seen most commonly in the second and third decades of life. Radiotherapy alone has been the primary treatment modality for germinomas, and is used with chemotherapy for nongerminomatous tumors. Stereotactic radiotherapy techniques minimize the volume of surrounding normal tissue irradiated and, hence, the late radiation morbidity. This study reports our experience with stereotactic radiotherapy in this group of tumors. Methods and Materials: Between December 1992 and December 1998, 18 patients with intracranial germ cell tumors were treated with stereotactic radiotherapy. A total of 23 histologically proven tumors were treated. Thirteen patients had a histologic diagnosis of germinoma, and 5 patients had germinoma with nongerminomatous elements. Of those patients with a histologic diagnosis of germinoma, 5 had multiple midline tumors. The median age of the patients was 12.9 years (range, 5.6-17.5 years). Results: A boost using stereotactic radiotherapy was delivered to 19 tumors following whole-brain radiation in 8 cases and craniospinal radiation in 11 cases. Three tumors were treated with stereotactic radiotherapy to the tumor volume alone following chemotherapy, and 1 tumor received a boost using stereotactic radiosurgery following craniospinal radiation. A median dose of 2520 cGy (range, 1500-3600) cGy was given to the whole brain, and a median dose of 2160 (range, 2100-2600) cGy was given to the spinal field. The median boost dose to the tumor was 2600 (range, 2160-3600) cGy, given by stereotactic radiotherapy delivered to the 95% isodose line. At a median follow-up time of 40 (range, 12-73) months, no local or marginal recurrences were reported in patients with germinoma. Two patients with nongerminomatous tumors have relapsed. One had elevation of tumor markers only at 37 months following treatment, and the other had persistent disease following chemotherapy and radiation therapy. Eight

Effects of orbital radiotherapy in 199 cases of Graves' ophthalmopathy

International Nuclear Information System (INIS)

Beckendorf, Veronique; Bey, Pierre; George, Jean Louis; Maalouf, Toufic; Leclere, Jacques; Werhya, Gerard; Luporsi, Elisabeth

1997-01-01

Purpose/Objective: Retrospective study to assess response of Graves' orbitopathy to standardized retrobulbar radiotherapy. Effects on different classes of signs are analysed and prognostic factors are searched. Indications of this treatment can be precise. Materials and methods: One hundred and ninety-nine consecutive patients who had clinically progressive Graves'orbitopathy were treated with radiotherapy between 1977 and 1996. All patients received a 6 MV Xrays orbital irradiation of 20 Gy in 10 fractions and 2 weeks. Signs and symptoms were classified before and after treatment directly or retrospectively according to the 'NO SPECS' recommended classification [J Clin Endocrinol Metab 1977;44:203]. Index of ophthalmopathy and responses were evaluated as described by Donaldson [J Clin Endocrinol Metab 1973;37:276]. Prognostic factors such as age, gender, therapies and response of hyperthyroidism, duration and associated treatment of eye disease are analysed. An investigation through letters sent to the patients and their ophthalmologists documents long term outcome of 128 patients with a mean follow-up of 6 years (2 to 16 years). Results: On 195 evaluable patients, 50 (26%) achieved a good or excellent response -GER-, 98 (50 %) had slight improvement, 37 (19 %) were stable, 10 (5 %) had progression of Grave's ophthalmopathy. By class of signs, GER occurred in 37%, 34%, 38%, 37.5% of cases, respectively for soft tissues involvement, proptosis, extra ocular muscle involvement and optic neuropathy. Corneal involvements yields the best results with 49% GER. Proptosis when moderate form had good results (55% GER), but advanced presentations had poor responses (17% GER). Proptosis decreased of 1 to 3 mm or remained stable. Six patients treated for optic neuropathy experienced aggravation. Same efficacy was observed when radiotherapy was applied as first line therapy or after failure of corticosteroids and when radiotherapy was delayed up to one year after beginning of

A comparison of conformal and intensity-modulated techniques for oesophageal radiotherapy

International Nuclear Information System (INIS)

Nutting, Christopher M.; Bedford, James L.; Cosgrove, Vivian P.; Tait, Diana M.; Dearnaley, David P.; Webb, Steve

2001-01-01

Background and purpose: To investigate the potential of intensity-modulated radiotherapy (IMRT) to reduce lung irradiation in the treatment of oesophageal carcinoma with radical radiotherapy. Materials and methods: A treatment planning study was performed to compare two-phase conformal radiotherapy (CFRT) with IMRT in five patients. The CFRT plans consisted of anterior, posterior and bilateral posterior oblique fields, while the IMRT plans consisted of either nine equispaced fields (9F), or four fields (4F) with orientations equal to the CFRT plans. IMRT plans with seven, five or three equispaced fields were also investigated in one patient. Treatment plans were compared using dose-volume histograms and normal tissue complication probabilities. Results: The 9F IMRT plan was unable to improve on the homogeneity of dose to the planning target volume (PTV), compared with the CFRT plan (dose range, 16.9±4.5 (1 SD) vs. 12.4±3.9%; P=0.06). Similarly, the 9F IMRT plan was unable to reduce the mean lung dose (11.7±3.2 vs. 11.0±2.9 Gy; P=0.2). Similar results were obtained for seven, five and three equispaced fields in the single patient studied. The 4F IMRT plan provided comparable PTV dose homogeneity with the CFRT plan (11.8±3.3 vs. 12.4±3.9%; P=0.6), with reduced mean lung dose (9.5±2.3 vs 11.0±2.9 Gy; P=0.001). Conclusions: IMRT using nine equispaced fields provided no improvement over CFRT. This was because the larger number of fields in the IMRT plan distributed a low dose over the entire lung. In contrast, IMRT using four fields equal to the CFRT fields offered an improvement in lung sparing. Thus, IMRT with a few carefully chosen field directions may lead to a modest reduction in pneumonitis, or allow tumour dose escalation within the currently accepted lung toxicity

2nd Tuebingen radiotherapy symposium: Whole body, large field and whole skin irradiation. Introduction

International Nuclear Information System (INIS)

Huebener, K.H.; Frommhold, W.

1987-01-01

The symposium which took place on the 11th and 12th April 1986 set itself the task of discussing three different groups of radiotherapy topics. The chief issue was whole-body irradiation prior to bone marrow transplants, in which all the therapy centres in West Germany, Austria, East Germany and German-speaking Switzerland made clinical and radiophysical contributions. The second part of the Symposium consisted mainly of talks and discussions on large-field irradiation, more precisely half-body and sequential partial body irradiation. This topic was chosen because this type of therapy is scarcely practised at all, particularly in West Germany, whereas in the United States, East Germany, Switzerland and a number of other countries it has long since become one of the established methods. The last talk at the Symposium explained clinical and radiophysical aspects of whole-skin irradiation. Here too, one was impressed by the wide diversity of the equipment and methods of irradiation used which, nevertheless, all demonstrated satisfactory practical solutions in their common aim of distributing the dose as homogeneously as possible. (orig./MG) [de

Experimental and clinical studies with intraoperative radiotherapy

International Nuclear Information System (INIS)

Sindelar, W.F.; Kinsella, T.; Tepper, J.; Travis, E.L.; Rosenberg, S.A.; Glatstein, E.

1983-01-01

Studies of normal tissue tolerance to intraoperative radiotherapy were done upon 65 dogs subjected to laparotomy and 11 million electron volt electron irradiation in doses ranging from zero to 5,000 rads. Results of studies indicated that intact aorta and vena cava tolerate up to 5,000 rads without loss of structural integrity. Ureteral fibrosis and stenosis develop at doses of 3,000 rads or more. Arterial anastomoses heal after doses of 4,500 rads, but fibrosis can lead to occlusion. Intestinal suture lines heal after doses of 4,500 rads. Bile duct fibrosis and stenosis develop at doses of 2,000 rads or more. Biliary-enteric anastomoses fail to heal at any dose level. A clinical trial of intraoperative radiotherapy combined with radical surgery was performed upon 20 patients with advanced malignant tumors which were considered unlikely to be cured by conventional therapies and which included carcinomas of the stomach, carcinomas of the pancreas, carcinomas involving the hilus of the liver, retroperitoneal sarcomas and osteosarcomas of the pelvis. All patients underwent resection of gross tumor, followed by intraoperative irradiation of the tumor bed and regional nodal basins. Some patients received additional postoperative external beam radiotherapy. Treatment mortality for combined operation and radiotherapy occurred in four of 20 patients. Postoperative complications occurred in four of the 16 surviving patients. Local tumor control was achieved in 11 of the 16 surviving patients, with an over-all median follow-up period of 18 months. The clinical trial suggested that intraoperative radiotherapy is a feasible adjunct to resection in locally advanced tumors, that the resulting mortality and morbidity is similar to that expected from operation alone and that local tumor control may be improved

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

Science.gov (United States)

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.

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

Science.gov (United States)

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

Image-guided radiotherapy for effective radiotherapy delivery

CERN Document Server

Karlsson, Ulf Lennart

2016-01-01

Image-guided radiotherapy (IGRT) is a new radiotherapy technology that combines the rapid dose fall off associated with intensity-modulated radiotherapy (IMRT) and daily tumor imaging allowing for high precision tumor dose delivery and effective sparing of surrounding normal organs. The new radiation technology requires close collaboration between radiologists, nuclear medicine specialists, and radiation oncologists to avoid marginal miss. Modern diagnostic imaging such as positron emission tomography (PET) scans, positron emission tomography with Computed Tomograpgy (PET-CT), and magnetic resonance imaging (MRI) allows the radiation oncologist to target the positive tumor with high accuracy. As the tumor is well visualized during radiation treatment, the margins required to avoid geographic miss can be safely reduced , thus sparing the normal organs from excessive radiation. When the tumor is located close to critical radiosensitive structures such as the spinal cord, IGRT can deliver a high dose of radiatio...