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Sample records for accelerated radiotherapy carbogen

  1. ACUTE TOXICITY PROFILE AND COMPLIANCE TO ACCELERATED RADIOTHERAPY PLUS CARBOGEN AND NICOTINAMIDE FOR CLINICAL STAGE T2-4 LARYNGEAL CANCER : RESULTS OF A PHASE III RANDOMIZED TRIAL

    Janssens, Geert O.; Terhaard, Chris H.; Doornaert, Patricia A.; Bijl, Hendrik P.; van den Ende, Piet; Chin, Alim; Pop, Lucas A.; Kaanders, Johannes H.

    2012-01-01

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with

  2. Acute toxicity profile and compliance to accelerated radiotherapy plus carbogen and nicotinamide for clinical stage T2-4 laryngeal cancer: results of a phase III randomized trial.

    Janssens, G.O.R.J.; Terhaard, C.H.J.; Doornaert, P.A.; Bijl, H.P.; Ende, P. van den; Chin, A.; Pop, L.A.M.; Kaanders, J.H.A.M.

    2012-01-01

    PURPOSE: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. METHODS AND MATERIALS: From April 2001 to February 2008, 345 patients with

  3. Acute Toxicity Profile and Compliance to Accelerated Radiotherapy Plus Carbogen and Nicotinamide for Clinical Stage T2–4 Laryngeal Cancer: Results of a Phase III Randomized Trial

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with cT2–4 squamous cell laryngeal cancer were randomized to AR (n = 174) and ARCON (n = 171). Acute toxicity was scored weekly until Week 8 and every 2–4 weeks thereafter. Compliance to carbogen and nicotinamide was reported. Results: Between both treatment arms (AR vs. ARCON) no statistically significant difference was observed for incidence of acute skin reactions (moist desquamation: 56% vs. 58%, p = 0.80), acute mucosal reactions (confluent mucositis: 79% vs. 85%, p = 0.14), and symptoms related to acute mucositis (severe pain on swallowing: 53% vs. 58%, p = 0.37; nasogastric tube feeding: 28% vs. 28%, p = 0.98; narcotic medicines required: 58% vs. 58%, p = 0.97). There was a statistically significant difference in median duration of confluent mucositis in favor of AR (2.0 vs 3.0 weeks, p = 0.01). There was full compliance with carbogen breathing and nicotinamide in 86% and 80% of the patients, with discontinuation in 6% and 12%, respectively. Adjustment of antiemesis prophylaxis was needed in 42% of patients. Conclusion: With the exception of a slight increase in median duration of acute confluent mucositis, the present data reveal a similar acute toxicity profile between both regimens and a good compliance with ARCON for clinical stage T2–4 laryngeal cancers. Treatment outcome and late morbidity will determine the real therapeutic benefit.

  4. Acute Toxicity Profile and Compliance to Accelerated Radiotherapy Plus Carbogen and Nicotinamide for Clinical Stage T2-4 Laryngeal Cancer: Results of a Phase III Randomized Trial

    Janssens, Geert O., E-mail: g.janssens@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Terhaard, Chris H. [Department of Radiation Oncology, University Medical Center Utrecht, Utrecht (Netherlands); Doornaert, Patricia A. [Department of Radiation Oncology, VU University Medical Center, Amsterdam (Netherlands); Bijl, Hendrik P. [Department of Radiation Oncology, University Medical Center Groningen, Groningen (Netherlands); Ende, Piet van den [Department of Radiation Oncology, Maastricht University Medical Centre, Maastricht (Netherlands); Chin, Alim [Department of Clinical Oncology, Leiden University Medical Centre, Leiden (Netherlands); Pop, Lucas A.; Kaanders, Johannes H. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

    2012-02-01

    Purpose: To report the acute toxicity profile and compliance from a randomized Phase III trial comparing accelerated radiotherapy (AR) with accelerated radiotherapy plus carbogen and nicotinamide (ARCON) in laryngeal cancer. Methods and Materials: From April 2001 to February 2008, 345 patients with cT2-4 squamous cell laryngeal cancer were randomized to AR (n = 174) and ARCON (n = 171). Acute toxicity was scored weekly until Week 8 and every 2-4 weeks thereafter. Compliance to carbogen and nicotinamide was reported. Results: Between both treatment arms (AR vs. ARCON) no statistically significant difference was observed for incidence of acute skin reactions (moist desquamation: 56% vs. 58%, p = 0.80), acute mucosal reactions (confluent mucositis: 79% vs. 85%, p = 0.14), and symptoms related to acute mucositis (severe pain on swallowing: 53% vs. 58%, p = 0.37; nasogastric tube feeding: 28% vs. 28%, p = 0.98; narcotic medicines required: 58% vs. 58%, p = 0.97). There was a statistically significant difference in median duration of confluent mucositis in favor of AR (2.0 vs 3.0 weeks, p = 0.01). There was full compliance with carbogen breathing and nicotinamide in 86% and 80% of the patients, with discontinuation in 6% and 12%, respectively. Adjustment of antiemesis prophylaxis was needed in 42% of patients. Conclusion: With the exception of a slight increase in median duration of acute confluent mucositis, the present data reveal a similar acute toxicity profile between both regimens and a good compliance with ARCON for clinical stage T2-4 laryngeal cancers. Treatment outcome and late morbidity will determine the real therapeutic benefit.

  5. Radiotherapy with carbogen breathing and nicotinamide in head and neck cancer: feasibility and toxicity

    The feasibility and early toxicity of radiotherapy with carbogen breathing and nicotinamide was tested in 74 head and neck cancer patients. Forty patients with laryngeal and hypopharyngeal tumors were treated with an accelerated schedule combined with carbogen alone (16) or with carbogen and nicotinamide (24). Thirty-four patients with far advanced unresectable tumors of the oral cavity and oropharynx received conventional radiotherapy with carbogen [16] or with carbogen and nicotinamide (18). Some enhancement of skin reaction was observed with nicotinamide but this remained well within limits of tolerance. With the accelerated regimen there was increased severity of mucosal damage expressed as confluent mucositis in 95% of patients which required healing times of 3-4 months in four patients. Eventually restoration of the mucosal lining was complete in all cases. Nausea and vomiting are the most frequent side effects of nicotinamide and were reported by 60% and 36% of the subjects, respectively. In 26% this was reason to discontinue drug intake. Severe renal dysfunction was associated with nicotinamide intake in two patients of this study and in one other patient who presented later. It is our conclusion that radiotherapy combined with carbogen and nicotinamide is a safe treatment with manageable side effects. We recommend not to give nicotinamide concomitantly with nephrotoxic medication or to patients who have impaired renal function. Preliminary tumor control rates are encouraging and clinical testing will be continued

  6. Radiosensitisation in normal tissues with oxygen, carbogen or nicotinamide: therapeutic gain comparisons for fractionated x-ray schedules

    Methods: Radiosensitisation with oxygen, carbogen or nicotinamide alone and oxygen or carbogen combined with nicotinamide was compared in early and late responding normal tissues in rodents. X-ray treatments were delivered as single doses or fractionated schedules of 2 fractions in 1 day, 2, 12 and 36 fractions in an overall time of 12 days and 10 fractions in 5 or 12 days. Acute skin reactions, survival of intestinal crypts, breathing rate, reduction in the packed red-cell volume and clearance of 51Cr-EDTA were used as assays of epidermal, gut, lung and renal damage. Results: Relative to air-breathing mice, carbogen or oxygen produced a small, and not always significant, increase in sensitivity (enhancement ratios ≤ 1.15) in gut, lung and kidneys; however, in skin a dose enhancement of 1.2-1.3 was observed. The effect of nicotinamide in air, carbogen or oxygen was studied only in lung and gut. The drug produced variable but generally significant increases in radiosensitisation (≤ 1.26) in all three gases. Relative to treatments in air, enhancement ratios for nicotinamide alone were usually slightly higher than those observed when either carbogen or oxygen were administered without the drug. With all three modifiers (i.e. oxygen, carbogen, nicotinamide alone or for the drug-gas combinations) there was no significant change in the enhancement ratios observed as the number of radiation dose fractions was varied. Conclusions: Comparisons with fractionated X-ray studies done previously in rodent tumours indicate that a therapeutic benefit, relative to lung, gut and renal damage, would be observed with oxygen or carbogen alone but not with nicotinamide alone. The greatest gain would be achieved with the combination of carbogen and nicotinamide, with which a benefit was observed even relative to epidermal damage. These results indicate that some decrease in normal tissue tolerance could be observed when using these modifiers in clinical radiotherapy and, although

  7. ARCON in experimental and clinical radiotherapy

    Rojas Callejas, Ana Maria

    2004-01-01

    xHypoxia and repopulation of tumour clonogens are two important determinants of treatment outcome in radiotherapy. In general clinical evidence indicates that loco-regional control may be reduced with long overall treatment times and for tumours with low pre-treatment levels of oxygen. Experimental studies with normobaric carbogen and oxygen showed a two-fold enhancement of the efficacy of radiation in a mouse tumour model when combining oxygen with treatment acceleration. It was then demonst...

  8. Accelerated radiotherapy for advanced laryngeal cancer

    The purpose of this study was to evaluate a single institution's outcome for patients with advanced laryngeal cancer treated with accelerated radiotherapy (RT). Fifty-eight patients with advanced laryngeal cancer were treated with curative intent with accelerated RT during the period 1990-1998. Patients received radiotherapy alone or with induction chemotherapy. The 5-year local control (LC) and loco-regional control (LRC) probabilities were both 49% for T3 and 75% for T4 tumors. The 5-year disease-free survival probability was 46% and 68% and overall survival probability was 30% and 39% for T3 and T4 tumors respectively. No significant statistical difference in outcome was found, either between T3 and T4 tumors, or between patients who received induction chemotherapy and those who did not. The treatment results for advanced laryngeal cancer at this institution were comparable to those reported in the literature. The results for T3 and T4 were similar. T4 classification alone should not be an exclusion criterion for larynx preservation. Overall survival was poor, partly because of a high incidence of deaths from intercurrent diseases

  9. Accelerated radiotherapy for advanced laryngeal cancer

    Haugen, Hedda; Mercke, Claes [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Oncology; Johansson, Karl-Axel [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Radiophysics; Ejnell, Hasse; Edstroem, Staffan [Sahlgrenska Univ. Hospital, Goeteborg (Sweden). Dept. of Oto-Rhino-Laryngology

    2005-07-01

    The purpose of this study was to evaluate a single institution's outcome for patients with advanced laryngeal cancer treated with accelerated radiotherapy (RT). Fifty-eight patients with advanced laryngeal cancer were treated with curative intent with accelerated RT during the period 1990-1998. Patients received radiotherapy alone or with induction chemotherapy. The 5-year local control (LC) and loco-regional control (LRC) probabilities were both 49% for T3 and 75% for T4 tumors. The 5-year disease-free survival probability was 46% and 68% and overall survival probability was 30% and 39% for T3 and T4 tumors respectively. No significant statistical difference in outcome was found, either between T3 and T4 tumors, or between patients who received induction chemotherapy and those who did not. The treatment results for advanced laryngeal cancer at this institution were comparable to those reported in the literature. The results for T3 and T4 were similar. T4 classification alone should not be an exclusion criterion for larynx preservation. Overall survival was poor, partly because of a high incidence of deaths from intercurrent diseases.

  10. Improvement of Brain Tissue Oxygenation by Inhalation of Carbogen

    Ashkanian, M.; Borghammer, P.; Gjedde, A.; Ostergaard, L.; Vafaee, M.

    2008-01-01

    confirmed by statistical cluster analysis. Oxygen and carbogen were equally potent in increasing oxygen saturation of arterial blood (Sa(O2)). The present data demonstrate that inhalation of carbogen increases both CBF and Sa(O2) in healthy adults. In conclusion we speculate that carbogen inhalation is...... sufficient for optimal oxygenation of healthy brain tissue, whereas carbogen induces concomitant increases of CBF and Sa(O2).......Hyperoxic therapy for cerebral ischemia is suspected to reduce cerebral blood flow (CBF), due to the vasoconstrictive effect of oxygen on cerebral arterioles. We hypothesized that vasodilation predominates when 5% CO(2) is added to the inhaled oxygen (carbogen). Therefore, we used positron emission...

  11. A therapeutic benefit from combining normobaric carbogen or oxygen with nicotinamide in fractionated X-ray treatments

    The ability of normobaric oxygen and carbogen (95 percent O2 + 5 percent CO2) combined with nicotinamide to enhance the radiosensitivity of two rodent adenocarcinomas and of mouse skin and kidneys was compared with the effects of radiation in air and without the drug. A comparison of the results in tumors and normal tissues showed that significant therapeutic benefit was obtained with normobaric oxygen and carbogen combined with nicotinamide. Toxic side effects of the treatment are unlikely, as prolonged administration of nicotinamide is well tolerated in man. The combination of normobaric carbogen with nicotinamide could be an effective method of enhancing tumor radiosensitivity in clinical radiotherapy where hypoxia limits the outcome of treatment. (author). 45 refs.; 4 fig.; 4 tabs

  12. Potential role of hypoxia imaging using 18F-FAZA PET to guide hypoxia-driven interventions (carbogen breathing or dose escalation) in radiation therapy

    Background and purpose: Hypoxia-driven intervention (oxygen manipulation or dose escalation) could overcome radiation resistance linked to tumor hypoxia. Here, we evaluated the value of hypoxia imaging using 18F-FAZA PET to predict the outcome and guide hypoxia-driven interventions. Material and methods: Two hypoxic rat tumor models were used: rhabdomyosarcoma and 9L-glioma. For the irradiated groups, the animals were divided into two subgroups: breathing either room air or carbogen. 18F-FAZA PET images were obtained just before the irradiation to monitor the hypoxic level of each tumor. Absolute pO2 were also measured using EPR oximetry. Dose escalation was used in Rhabdomyosarcomas. Results: For 9L-gliomas, a significant correlation between 18F-FAZA T/B ratio and tumor growth delay was found; additionally, carbogen breathing dramatically improved the tumor response to irradiation. On the contrary, Rhabdomyosarcomas were less responsive to hyperoxic challenge. For that model, an increase in growth delay was observed using dose escalation, but not when combining irradiation with carbogen. Conclusions: 18F-FAZA uptake may be prognostic of outcome following radiotherapy and could assess the response of tumor to carbogen breathing. 18F-FAZA PET may help to guide the hypoxia-driven intervention with irradiation: carbogen breathing in responsive tumors or dose escalation in tumors non-responsive to carbogen

  13. Quality assurance protocol for linear accelerators used in radiotherapy

    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)

  14. Radiotherapy using a laser proton accelerator

    Murakami, Masao; Miyajima, Satoshi; Okazaki, Yoshiko; Sutherland, Kenneth L; Abe, Mitsuyuki; Bulanov, Sergei V; Daido, Hiroyuki; Esirkepov, Timur Zh; Koga, James; Yamagiwa, Mitsuru; Tajima, Toshiki

    2008-01-01

    Laser acceleration promises innovation in particle beam therapy of cancer where an ultra-compact accelerator system for cancer beam therapy can become affordable to a broad range of patients. This is not feasible without the introduction of a technology that is radically different from the conventional accelerator-based approach. The laser acceleration method provides many enhanced capabilities for the radiation oncologist. It reduces the overall system size and weight by more than one order of magnitude. The characteristics of the particle beams (protons) make them suitable for a class of therapy that might not be possible with the conventional accelerator, such as the ease for changing pulse intensity, the focus spread, the pinpointedness, and the dose delivery in general. A compact, uncluttered system allows a PET device to be located in the vicinity of the patient in concert with the compact gantry. The radiation oncologist may be able to irradiate a localized tumor by scanning with a pencil-like particle...

  15. Neutronic fields produced by a lineal accelerator for radiotherapy

    Measurements and Monte Carlo calculations has been utilized to determine the dosimetric features as well as the neutron spectra of photoneutrons produced around an 18 MV linear accelerator for radiotherapy. Measurements were carried out with bare and Cd covered thermoluminescent dosimeters, TLD600 and TLD700, as well as inside a paraffine moderator. TLD pairs were also utilized as thermal neutrons inside a Bonner sphere spectrometer (au)

  16. Formation Mechanism of Carbogenic Nanoparticles with Dual Photoluminescence Emission

    Krysmann, Marta J.

    2012-01-18

    We present a systematic investigation of the formation mechanism of carbogenic nanoparticles (CNPs), otherwise referred to as C-dots, by following the pyrolysis of citric acid (CA)-ethanolamine (EA) precursor at different temperatures. Pyrolysis at 180 °C leads to a CNP molecular precursor with a strongly intense photoluminescence (PL) spectrum and high quantum yield formed by dehydration of CA-EA. At higher temperatures (230 °C) a carbogenic core starts forming and the PL is due to the presence of both molecular fluorophores and the carbogenic core. CNPs that exhibit mostly or exclusively PL arising from carbogenic cores are obtained at even higher temperatures (300 and 400 °C, respectively). Since the molecular fluorophores predominate at low pyrolysis temperatures while the carbogenic core starts forming at higher temperatures, the PL behavior of CNPs strongly depends on the conditions used for their synthesis. © 2011 American Chemical Society.

  17. Accelerated radiotherapy in advanced head and neck cancer

    The purpose of the study is to present the reasons for introducing concomitant boost accelerated radiotherapy (CBAR) and its practical aspects at advanced head and neck carcinomas (HNC). Accelerated clonogenic repopulation of the tumor during radiotherapy necessitates its termination within the shortest possible term. The differentiated effect of the fractionated dose on both early and late response of tissues requires the use of several smaller daily fractions with an interval between exceeding six hours during all the time of radiotherapy or a part of it. If there is no data about earlier kinetics of the tumor cells, schemes with total dose 69-72 Gy are given preference. The practical aspects of CBAR also are presented: 1. specificity of the clinical target volume (ICRU 50) considering the requirements for beam and fields; 2. irradiation techniques most frequently used and 3. the method of patient immobilization. The characteristic features of CBAR are also discussed: 1. The primary tumor and its subclinical diffusion are irradiated in standard fields or in such with exclusion of the spinal cord at dose up to 54 in 30 fractions for 5.5 weeks. During the first two days, two daily fractions at six-hours interval are delivered with partial exclusion of the spinal cord. The primary tumor is given during the last 2.5 weeks up to total dose 69-72 Gy with a second daily fraction of 1.5 Gy six hours after the first one; 2. The current concepts for spinal cord radiation tolerance and very high risk of transverse myelitis in some accelerated radiotherapeutical schemes are also discussed. The therapeutic approach described is based on the experience got from the conventional fractionation; 3. Without neglecting enhanced acute toxicity CBAR is recommended as a well tolerated radiotherapeutical method

  18. Photoluminescent carbogenic nanoparticles directly derived from crude biomass

    Krysmann, Marta J.

    2012-01-01

    We present an environmentally benign, energy efficient and readily scalable approach to synthesize photoluminescent carbogenic nanoparticles directly from soft tissue biomass. Our approach relies on the pyrolytic decomposition of grass that gives rise to the formation of well-defined nanoparticles. The carbogenic nanoparticles can be readily surface modified, generating a series of highly selective photoluminescent materials that exhibit remarkable stability upon prolonged exposure to aggressive, high-temperature, high-salinity environment. © 2012 The Royal Society of Chemistry.

  19. Effects of carbogen plus fractionated irradiation on KHT tumor oxygenation

    Background and purpose: Numerous studies have demonstrated improvements in the oxygenation of tumor cells following both irradiation and carbogen breathing. The current studies were initiated to measure the combined effects of carbogen inhalation plus single and multi-dose irradiation on tumor oxygen availability, to better define the underlying physiological relationships. Materials and methods: Using KHT murine sarcomas, radiation was delivered to the tumor-bearing legs of non-anesthetized mice. Tumors were quick-frozen prior to or following single or multifraction irradiation and carbogen breathing, and intravascular HbO2 saturation profiles were determined cryospectrophotometrically. Results: HbO2 levels for blood vessels located near the tumor surface initially decreased following 10 Gy irradiation, then increased and remained elevated. Interior HbO2 levels remained unchanged. Following 2.5 Gy, HbO2 changes were minimal. At 24 h following 10 Gy, HbO2 levels were significantly increased compared to non-irradiated controls, and carbogen breathing produced no additional benefit. At 24 h following five fractions of 2 Gy, HbO2 levels throughout the tumor volume were significantly higher in carbogen breathing animals than in air breathing controls. Conclusions: Although peripheral blood vessels demonstrated substantial improvements in oxygenation following irradiation, oxygen availability nearer the tumor center remained at very low levels. The utility of carbogen in enhancing tumor oxygen availability was maintained following five clinically relevant fractions. At higher doses, radiation-induced enhancements in HbO2 levels overshadowed the carbogen effect. For either air or carbogen breathing, a decrease in the percentage of vessels with very low oxygen content did not appear to be a major factor in the reoxygenation of the KHT tumor

  20. Accelerated Deformable Registration of Repetitive MRI during Radiotherapy in Cervical Cancer

    Noe, Karsten Østergaard; Tanderup, Kari; Kiritsis, Christian; Dimopoulos, Johannes; Sørensen, Thomas Sangild; Lindegaard, Jacob; Grau, Cai

    Tumour regression and organ deformations during radiotherapy (RT) of cervical cancer represent major challenges regarding accurate conformation and calculation of dose when using image-guided adaptive radiotherapy. Deformable registration algorithms are able to handle organ deformations, which can...... be useful with advanced tools such as auto segmentation of organs and dynamic adaptation of radiotherapy. The aim of this study was to accelerate and validate deformable registration in MRI-based image-guided radiotherapy of cervical cancer.    ...

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

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

  2. Mild hyperthermia alone or in combination with carbogen is effective in increasing tumor pO2

    Purpose/Objective: We have studied the effect of mild temperature hyperthermia (MTH) on pO2 with or without carbogen breathing and the radio response in three different rodent tumors. Materials and Methods: SCK mammary carcinoma of A/J mice, FSall fibrosarcoma of C3H mice, and R3230 AC mammary carcinoma of Fischer rats were used. The changes in pO2 in these tumors by MTH alone or in combination with carbogen (95% O2 + 5% CO2) breathing were studied. The MTH was done by immersing the legs bearing s.c. tumors into a water bath and the pO2 was measured using an Eppendorf pO2 Histograph machine. The influence of MTH on the effect of X-irradiation (250 kVp) on tumors was investigated with tumor growth delay and the in vivo-in vitro excision assay for hypoxic cell fraction. Results: The pO2 in all three tumor types was increased significantly by MTH. The most effective heating conditions were 60 min at 41.5 deg. C for SCK and FSall, and 30 min at 42.5 deg. C for R3230 AC. Carbogen breathing alone increased the pO2, but the effect of carbogen was dramatically enhanced when combined with heating. FSall tumors heated at 41.5 deg. C for 60 min before receiving a dose of 20 Gy took an average of 3 days longer than tumors receiving heat after irradiation to grow to four times their original volume. The identical conditions in SCK tumors heated before irradiation caused a 5 day growth delay. Effect of heating before or after irradiation on cell survival in tumor was determined using in vivo-in vitro excision assay method. Heating FSall tumors before irradiation for 30 min at 41.5 deg. C caused marked reduction in the hypoxic cell fraction. Cell survival studies in the SCK and R3230 AC tumors are currently being studied as well as the radiation response of all three tumors after heating combined with carbogen breathing. Conclusion: These results indicate that MTH is very effective in increasing the tumor oxygenation and the response of human tumors to radiotherapy. The

  3. Accelerated partial breast irradiation using robotic radiotherapy: a dosimetric comparison with tomotherapy and three-dimensional conformal radiotherapy

    Rault, Erwann; Lacornerie, Thomas; Dang, Hong-Phuong; Crop, Frederik; Lartigau, Eric; Reynaert, Nick; Pasquier, David

    2016-01-01

    Background Accelerated partial breast irradiation (APBI) is a new breast treatment modality aiming to reduce treatment time using hypo fractionation. Compared to conventional whole breast irradiation that takes 5 to 6 weeks, APBI is reported to induce worse cosmetic outcomes both when using three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT). These late normal tissue effects may be attributed to the dose volume effect because a large portion of the no...

  4. Prospective Trial of Accelerated Partial Breast Intensity-Modulated Radiotherapy

    Purpose: To examine the feasibility and acute toxicities of an accelerated, partial breast, intensity-modulated radiotherapy (IMRT) protocol. Methods and Materials: Between February 2004 and August 2005, 55 patients with Stage I breast cancer and initial follow-up were enrolled at four facilities on a HealthONE and Western institutional review board-approved accelerated partial breast IMRT protocol. All patients were treated in 10 equal fractions delivered twice daily within 5 consecutive days. The first 7 patients were treated to 34 Gy, and the remaining 48 patients were treated to 38.5 Gy. Results: The median follow-up after IMRT was 10 months (range, <1-19) and after diagnosis was 11.5 months (range, 2-21). No local or distant recurrences developed. The T stage distribution was as follows: T1a in 11 patients, T1b in 24, and T1c in 20. The median tumor size was 9 mm (range, 1-20 mm). Breast cosmesis was judged by the patient as poor by 2, good by 12, and excellent by 40 (1 patient was legally blind) and by the physician as poor for 1, good for 10, and excellent for 44 patients. Breast pain, as judged by patient, was none in 34, mild in 19, moderate in 2, and severe in 0 patients. There was a single report of telangiectasia but no incidents of significant edema. Compared with historic controls for whom three-dimensional treatment planning techniques were used, IMRT provided similar dose delivery to the target while reducing the volume of normal breast included in the 100%, 75%, and 50% isodose lines. Conclusion: This initial report prospectively explored the feasibility of accelerated partial breast IMRT. After short-term follow-up, the dose delivery and clinical outcomes were very acceptable. We believe this regimen deserves additional investigation under institutional review board guidance

  5. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Rasmussen, Rune, E-mail: rune333@gmail.com [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Claesson, Magnus [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark); Stangerup, Sven-Eric [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Roed, Henrik [Department of Radiation Oncology, Rigshospitalet, Copenhagen (Denmark); Christensen, Ib Jarle [Finsen Laboratory, Rigshospitalet, Copenhagen (Denmark); Caye-Thomasen, Per [Ear, Nose, and Throat Department, Rigshospitalet, Copenhagen (Denmark); Juhler, Marianne [Department of Neurosurgery, Rigshospitalet, Copenhagen (Denmark)

    2012-08-01

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a 'wait-and-scan' group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  6. Fractionated Stereotactic Radiotherapy of Vestibular Schwannomas Accelerates Hearing Loss

    Objective: To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hearing preservation was also investigated. Methods and Materials: Forty-two patients receiving FSRT between 1997 and 2008 with a minimum follow-up of 2 years were included. All patients received 54 Gy in 27-30 fractions during 5.5-6.0 weeks. Clinical and audiometry data were collected prospectively. From a “wait-and-scan” group, 409 patients were selected as control subjects, matched by initial audiometric parameters. Radiation dose to the cochlea was measured using the original treatment plan and then related to changes in acoustic parameters. Results: Actuarial 2-, 4-, and 10-year tumor control rates were 100%, 91.5%, and 85.0%, respectively. Twenty-one patients had serviceable hearing before FSRT, 8 of whom (38%) retained serviceable hearing at 2 years after FSRT. No patients retained serviceable hearing after 10 years. At 2 years, hearing preservation rates in the control group were 1.8 times higher compared with the group receiving FSRT (P=.007). Radiation dose to the cochlea was significantly correlated to deterioration of the speech reception threshold (P=.03) but not to discrimination loss. Conclusion: FSRT accelerates the naturally occurring hearing loss in patients with vestibular schwannoma. Our findings, using fractionation of radiotherapy, parallel results using single-dose radiation. The radiation dose to the cochlea is correlated to hearing loss measured as the speech reception threshold.

  7. Avoidance of treatment interruption: an unrecognized benefit of accelerated radiotherapy in oropharyngeal carcinomas?

    Allal, Abdelkarim Said; De Pree, Christian; Dulguerov, Pavel; Bieri, Sabine; Maire, Daphne Isabel; Kurtz, John

    1999-01-01

    To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas.

  8. Salvage surgery after radical accelerated radiotherapy with concomitant boost technique for head and neck carcinomas

    Taussky, Daniel; Dulguerov, Pavel; Allal, Abdelkarim Said

    2005-01-01

    Definitive radiotherapy (RT) for head and neck cancer is increasingly used to preserve organ function, whereas surgery is reserved for treatment failure. However, data are sparse regarding the feasibility of salvage surgery, particularly for unselected patients after accelerated RT.

  9. Late course accelerated hyperfractionation radiotherapy for nasopharyngeal carcinoma

    Objective: To study the efficacy of late course accelerated fractionation (LCAF) radio- therapy in the treatment of nasopharyngeal carcinoma(NPC). The end-po s were local control, radiation-induced complications, factors influencing survival. Methods: From December 1995 to April 1998, 178 NPC patients were admitted for radiation treatment. The radiation beam used was 60Co γ or 6 MV X-ray. For the first two-thirds of the treatment, two daily fractions of 1.2 Gy were given to the primary lesion , with an interval of ≥6 hours, 5 days per week to a total dose of 48 Gy/40 fractions, over a period of 4 weeks. For the last one third of the treatment, i. e. beginning from the 5th week, an accelerated hyperfractionation schedule was carried out. The dose per fraction was increased to 1.5 Gy, 2 fractions per day with an interval of ≥6 hours, the total dose for this part of the protocol was 30 Gy/20 fractions over 2 weeks. Thus the total dose was 78 Gy in 60 fractions in 6 weeks. Results: All patients completed the treatment. Acute mucositis: none in 2 patients, Grade 1 in 43 , Grade 2 in 78, Grade 3 in 52, and Grade 4 in 3 patients. Local control rate: the 5 -year nasopharyngeal local control rate was 87.7%, and the cervical lymph node local control rate was 85.7%. The 5-year distant metastasis rate was 26.1%, and 5-year survivals was 67.9%. Sixteen patients had radiation-induced cranial nerve palsy. Conclusions: With this treatment schedule, patient's tolerance is good, local control and 5 year survivals are better than control groups of conventional fractionation and hyperfractionation radiotherapy. Radiation-related late complication does not increase. Randomized clinical trials are being carried out to further confirm the efficacy of LCAF for nasopharyngeal carcinoma. (authors)

  10. Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis

    Bourhis, J.; Overgaard, Jens; Audry, H.;

    2006-01-01

    BACKGROUND: Several trials have studied the role of unconventional fractionated radiotherapy in head and neck squamous cell carcinoma, but the effect of such treatment on survival is not clear. The aim of this meta-analysis was to assess whether this type of radiotherapy could improve survival......-specified categories: hyperfractionated, accelerated, and accelerated with total dose reduction. FINDINGS: 15 trials with 6515 patients were included. The median follow-up was 6 years. Tumours sites were mostly oropharynx and larynx; 5221 (74%) patients had stage III-IV disease (International Union Against Cancer...... radiotherapy (2% with accelerated fractionation without total dose reduction and 1.7% with total dose reduction at 5 years, p=0.02). There was a benefit on locoregional control in favour of altered fractionation versus conventional radiotherapy (6.4% at 5 years; p<0.0001), which was particularly efficient in...

  11. Accelerated hyperfractionated radiotherapy for locally advanced cervix cancer

    Purpose: A phase II trial was designed to evaluate the toxicity and outcome of patients with locally advanced cervix cancer treated with accelerated hyperfractionated radiotherapy (AHFX). Methods and Materials: In this prospective trial, AHFX doses of 1.25 Gy were administered twice daily at least 6 hours apart to a total pelvic dose of 57.5 Gy. A booster dose was then administered via either low-dose rate brachytherapy or external beam therapy to a smaller volume. All patients were accrued and treated at Peter MacCallum Cancer Institute (PMCI) between 1986 until April 1991. Results: Sixty-one eligible patients were enrolled in this protocol; 2 (3.2%) had Stage IIB; 42 (68.9%) had Stage III; 8 (13.1%) had Stage IV and 9 (14.8%) had recurrent cervical cancer. Fifty-two patients (85%) completed the planned external beam without a treatment break. Thirty patients had acute toxicity that required regular medication. One patient died of acute treatment related toxicity. Fifty-five patients received booster therapy: 45 with intrauterine brachytherapy, 6 with interstitial brachytherapy, and 4 with external beam. The median follow-up of surviving patients was 6 years. Overall 5-year survival is 27% and 5-year relapse free survival is 36%. Nineteen patients died with pelvic disease and the actuarial local control rate was 66%. There were 8 severe late complications observed in 7 patients. Seven required surgical intervention (an actuarial rate of 27%). Five patients also required total hip replacement. Conclusions: The local control rate was favorable compared with other series that have used standard fractionation, although overall survival remained similar. The severe late complication rate was high for this protocol and higher than similar protocols reported in the literature

  12. Clinical Experience With Image-Guided Radiotherapy in an Accelerated Partial Breast Intensity-Modulated Radiotherapy Protocol

    Purpose: To explore the feasibility of fiducial markers for the use of image-guided radiotherapy (IGRT) in an accelerated partial breast intensity modulated radiotherapy protocol. Methods and Materials: Nineteen patients consented to an institutional review board approved protocol of accelerated partial breast intensity-modulated radiotherapy with fiducial marker placement and treatment with IGRT. Patients (1 patient with bilateral breast cancer; 20 total breasts) underwent ultrasound guided implantation of three 1.2- x 3-mm gold markers placed around the surgical cavity. For each patient, table shifts (inferior/superior, right/left lateral, and anterior/posterior) and minimum, maximum, mean error with standard deviation were recorded for each of the 10 BID treatments. The dose contribution of daily orthogonal films was also examined. Results: All IGRT patients underwent successful marker placement. In all, 200 IGRT treatment sessions were performed. The average vector displacement was 4 mm (range, 2-7 mm). The average superior/inferior shift was 2 mm (range, 0-5 mm), the average lateral shift was 2 mm (range, 1-4 mm), and the average anterior/posterior shift was 3 mm (range, 1 5 mm). Conclusions: This study shows that the use of IGRT can be successfully used in an accelerated partial breast intensity-modulated radiotherapy protocol. The authors believe that this technique has increased daily treatment accuracy and permitted reduction in the margin added to the clinical target volume to form the planning target volume.

  13. Feasibility and early results of accelerated radiotherapy for head and neck carcinoma in the elderly

    Allal, Abdelkarim Said; Maire, Daphne Isabel; Becker, Minerva; Dulguerov, Pavel

    2000-01-01

    Accelerated radiotherapy (RT) represents a promising method with which to improve the treatment outcome in patients with head and neck carcinoma. However, its applicability to elderly patients has not been well established. This study assessed treatment toxicities, patient compliance, and oncologic results in patients age >/= 70 years who were treated with an accelerated concomitant boost RT schedule.

  14. Fractionated stereotactic radiotherapy of vestibular schwannomas accelerates hearing loss

    Rasmussen, Rune; Claesson, Magnus; Stangerup, Sven-Eric;

    2012-01-01

    To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea and hear......To evaluate long-term tumor control and hearing preservation rates in patients with vestibular schwannoma treated with fractionated stereotactic radiotherapy (FSRT), comparing hearing preservation rates to an untreated control group. The relationship between radiation dose to the cochlea...

  15. Accelerated Partial Breast Irradiation with Intensity-Modulated Radiotherapy Is Feasible for Chinese Breast Cancer Patients

    He, Zhenyu; Wu, Sangang; Zhou, Juan; Li, Fengyan; Sun, Jiayan; Lin, Qin; Lin, Huanxin; Guan, Xunxing

    2014-01-01

    Purpose Several accelerated partial breast irradiation (APBI) techniques are being investigated in patients with early-stage breast cancer. The present study evaluated the feasibility, early toxicity, initial efficacy, and cosmetic outcomes of accelerated partial breast intensity-modulated radiotherapy (IMRT) for Chinese female patients with early-stage breast cancer after breast-conserving surgery. Methods A total of 38 patients met the inclusion criteria and an accelerated partial breast in...

  16. Fractionated irradiation combined with carbogen breathing and nicotinamide of two human glioblastomas grafted in nude mice

    SUN, Lin-Quan; Buchegger, Franz; COUCKE, Philippe; MIRIMANOFF

    2001-01-01

    This study addressed the potential radiosensitizing effect of nicotinamide and/or carbogen on human glioblastoma xenografts in nude mice. U-87MG and LN-Z308 tumors were irradiated with either 20 fractions over 12 days or 5 fractions over 5 days in air-breathing mice, mice injected with nicotinamide, mice breathing carbogen, or mice receiving nicotinamide plus carbogen. The responses to treatment were assessed using local control and moist desquamation. In U-87MG tumors, the enhancement ratios...

  17. Comparison of remote results of conventional fractionation radiotherapy and late course accelerated hyperfractionation radiotherapy for nasopharyngeal carcinoma

    Objective: To compare the long-term effects of conventional fractionation (CF) radio-therapy and late course accelerated hyperfractionation (LCAHF) radiotherapy of nasopharyngeal carcinoma (NPC), and to arrive at a appropriate NPC radiotherapy protocol. Methods: According to the criteria, 496 patients with NPC were allotted to our retrospective analysis, including 269 in the CF group and 227 in the LCAHF group. Two large lateral opposing fields were first used to treat the nasopharynx and the upper neck at a fraction of 2 Gy daily, 5 days per week. After 36-40 Gy, two small lateral opposing fields were used to boost the primary tumor while the spinal cord shielded. In the CF group, the accumulated total dose of naso-pharynx was 68-76 Gy at 2 Gy daily. In the LCAHF group, the radiation fraction of primary tumor was 1.5 Gy twice daily, with a minimum of six-hour interval in the late course. The accumulated total dose was 69-72 Gy. Survival was assessed by Kaplan-Meier method and Logrank analysis. Results: The 5-year primary site control, tumor-free survival and overall survival rates was 65.4% ,61.5% and 68.1% in the LCAHF group and 52.8%, 49.4% and 57.5% in the CF group. The difference between the two groups were significant (P=0.006, 0.006 and 0.031). Further analysis showed that LCAHF improved the primary site control, tumor-free survival and overall survival rates of T2-T3 NPC (P0.05). Conclusions: When compared with conventional fractionation radiotherapy, late course accelerated hyperfractionation radiotherapy, being tolerable, definitely can improve the local control, tumor-free survival and overall survival in patients with nasopharyngeal carcinoma. But the recurrence rates of cervical lymph nodes and distant metastasis were similar in between these two groups. (authors)

  18. Prolonged survival when temozolomide is added to accelerated radiotherapy for glioblastoma multiforme

    The goal of this study was to evaluate accelerated radiotherapy with and without temozolomide (TMZ) for glioblastoma multiforme (GBM). This retrospective analysis evaluated 86 patients with histologically proven GBM who were treated with accelerated radiotherapy of 1.8 Gy twice daily to a total dose of 54 Gy within 3 weeks. Median age was 62 years and median Karnofsky index was 90. A total of 41 patients received radiotherapy only from 2002-2005 and 45 patients were treated with TMZ concomitantly and after radiotherapy from 2005-2007. Median overall survival (OS) was 12.5 months and 2-year OS was 15.4%. Patient characteristics were well balanced between the two groups except for better performance status (p = 0.05) and higher frequency of retreatment for the first recurrence (p = 0.02) in the TMZ group. Age at diagnosis (HR 2.83) and treatment with TMZ (HR 0.60) were correlated with OS in the multivariate analysis: treatment with and without TMZ resulted in median OS of 16 months and 11.3 months, respectively. Hematological toxicity grade > II was observed in 2/45 patients and 5/37 patients during simultaneous radiochemotherapy and adjuvant TMZ. TMZ added to accelerated radiotherapy for GBM resulted in prolonged overall survival with low rates of severe hematological toxicity. (orig.)

  19. PhoNeS: A novel approach to BNCT with conventional radiotherapy accelerators

    PhoNeS (Photo Neutron Source) is an INFN project devoted to the optimization of the neutron production and moderation in radiotherapy linear accelerators. LinAcs producing high energy (15-25MeV) photon beams are becoming widespread. At this energy neutron photo-production is unavoidable and the neutron dose must be controlled and reduced during normal radiotherapy. A technique known as BNCT (Boron Neutron Capture Therapy) uses neutrons for radiotherapic treatments: the cells are given a drug containing B10 which undergoes fission after neutron capture, inducing heavy damages to the DNA of the cell itself. This paper will describe the moderator developed by PhoNeS and the results in terms of neutron flux and spectrum and photon contamination of the measurements performed on several radiotherapy accelerators

  20. Particle-beam accelerators for radiotherapy and radioisotopes

    The philosophy used in developing the new PIGMI technology was that the parameters chosen for physics research machines are not necessarily the right ones for a dedicated therapy or radioisotope machine. In particular, the beam current and energy can be optimized, and the design should emphasize minimum size, simplicity and reliability of operation, and economy in capital and operating costs. A major part of achieving these goals lay in raising the operating frequency and voltage gradient of the accelerator, which shrinks the diameter and length of the components. Several other technical innovations resulted in major system improvements. One of these is a radically new type of accelerator structure named the radio-frequency quadrupole (RFQ) accelerator. This allowed us to eliminate the large, complicated ion source used in previous ion accelerators, and to achieve a very high quality accelerated beam. Also, by using advanced permanent magnet materials to make the focusing elements, the system becomes much simpler. Other improvements have been made in all of the accelerator components and in the methods for operating them. These will be described, and design and costing information examples given for several possible therapy and radioisotope production machines

  1. Quality Assesment Of Photon And Electron Beams From Siemens PRIMUS Radiotherapy Accelerator

    There are two types of radiation from SIEMENS Primus Radiotherapy Accelerator at the National Cancer Hospital (K Hospital): electron and photon beams. Electron beams with four different energies of 6; 9; 12 and 15 MeV. Photon beams with two different energies: 6 MV and 15 MV. The symmetry as well as flatness of profiles created by all these beams are very important factors using in clinical practice. This report presents the method using water phantom to define absorbed dose distribution in medium of all beams. This is an effective and accurate method to define quality of radiation beams with different field sizes using in radiotherapy. (author)

  2. Comparison between continuous accelerated hyperfractionated and late-course accelerated hyperfractionated radiotherapy for esophageal carcinoma

    Purpose: To compare the treatment results and toxicity of continuous accelerated hyperfractionated (CAHF) and late-course accelerated hyperfractionated (LCAF) radiotherapy (RT) for esophageal carcinoma. Methods and Materials: Between August 1996 and March 1999, 101 patients with squamous cell carcinoma of the esophagus were randomized into two groups: 49 to the CAHF group and 52 to the LCAF group. Patients in the CAHF group received RT at 1.5 Gy/fraction b.i.d. (6-h interval), 5 d/wk, to a total dose 66 Gy in 44 fractions during 4.4 weeks. The patients in the LCAF group received conventional fractionation RT, 1.8 Gy/fraction, to a dose of 41.4 Gy in 23 fractions during 4.6 weeks, followed by accelerated fractionation RT using reduced fields, b.i.d., at 1.5 Gy/fraction, with a minimal interval of 6 h between fractions. The total dose was 68.4 Gy in 41 fraction during 6.4 weeks. Patient age, gender, performance score, diet, lesion location, lesion length, stage, and fractionation (CAHF or LCAF) were entered into the univariate and multivariate analyses. Results: All patients finished the treatment course, except for 1 patient in the CAHF group because of severe acute esophagitis. The rate of Grade I, II, and III acute bronchitis was 18.4% (9 of 49), 30.6% (15 of 49), and 8.2% (4 of 49) in the CAHF group and 13.5% (7 of 52), 21.2% (11 of 52), and 3.8% (2 of 52) in the LCAF group, respectively. However, the difference between the two groups was not statistically significant (p=0.084). The rate of Grade I, II, III, and IV acute esophagitis was 6.1% (3 of 49), 32.7% (16 of 49), 46.9% (23 of 49), and 14.3% (7 of 49) in the CAHF group and 26.9% (14 of 52), 32.7% (17 of 52), 7.7% (4 of 52), and 1.9% (1 of 52) in the LCAF group, respectively. The difference was statistically significant (p<0.001). The local control rate at 1, 2, and 3 years was 88.7%, 83.9%, and 55.9% in the CAHF group and 80.7%, 71.4%, and 57.1% in the LCAF group, respectively (p=0.1251). The 1-, 2-, and 3

  3. Accelerated ray tracing for radiotherapy dose calculations on a GPU

    M. de Greef; J. Crezee; J.C. van Eijk; R. Pool; A. Bel

    2009-01-01

    PURPOSE: The graphical processing unit (GPU) on modern graphics cards offers the possibility of accelerating arithmetically intensive tasks. By splitting the work into a large number of independent jobs, order-of-magnitude speedups are reported. In this article, the possible speedup of PLATO's ray t

  4. Study of the Accelerator Technology Development for Cancer Radiotherapy

    The hadronic particle beams including both protons, neutrons and charged particles have been studied for cancer therapy by a number of research centers in several countries during the past two decades. In this paper is briefly discussed concerning the accelerator type and its applications. The future trends are seen in the new technological developments like the use of proton gantries, beam scanning techniques, improved patient handling system and in the increasing precision of treatment. (author)

  5. The results of accelerated radiotherapy and concomitant cisplatin administration in advanced oropharyngeal cancer

    The accelerated radiotherapy and concomitant infusion of cisplatin in low doses was evaluated in 15 patients with advanced squamous cell carcinoma of the oral cavity and oral part of pharynx. Clinical complete response was seen in 6 of 15 patients (40%) and 4 patients (26.6%) were alive 12 months with no evidence of disease, of all group of 15 patients 9 (60%) were alive 12 months after treatment. (author)

  6. Acceleration of pubertal development following pituitary radiotherapy for Cushing's disease

    Nicholl, R.M.; Kirk, J.M.W.; Grossman, A.B.; Plowman, P.N.; Besser, G.M.; Savage, M.O. (Saint Bartholomew' s Hospital, London (United Kingdom))

    1993-01-01

    A 7-year-old boy with pituitary dependent Cushing's disease was treated with pituitary irradiation following unsuccessful microadenomectomy. This led to normalization of the hypercortisolaemia, but was followed by GH deficiency. Two years after radiotherapy he had the onset of pubertal development with testicular enlargement to 8 ml bilaterally. Pubertal regression was induced using the long-acting GnRH analogue goserelin. Acceleration of skeletal maturation was also arrested, resulting in improvement of final height prediction. Irradiation directly to the hypothalamo-pituitary region, as well as whole brain irradiation, may thus be associated with accelerated pubertal development. (author).

  7. Physical-dosimetric enabling a dual linear accelerator 3D planning systems for radiotherapy

    The process of commissioning clinical linear accelerator requires a dual comprehensive study of the therapeutic beam parameters, both photons Electron. All information gained by measuring physical and dosimetric these beams must be analyzed, processed and refined for further modeling in computer-based treatment planning (RTPS). Of professionalism of this process will depend on the accuracy and precision of the calculations the prescribed doses. This paper aims to demonstrate availability clinical linear accelerator system-RTPS with late radiotherapy treatments shaped beam of photons and electrons. (author)

  8. Radiotherapy

    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

  9. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  10. Response of Hepatoma 9618a and Normal Liver to Host Carbogen and Carbon Monoxide Breathing

    Robinson, Simon P.; Loreta M. Rodrigues; Griffiths, John R.; Marion Stubbs

    1999-01-01

    The effects of hyperoxia (induced by host carbogen 95% oxygen/5% carbon dioxide breathing. and hypoxia (induced by host carbon monoxide CO at 660 ppm. breathing) were compared by using noninvasive magnetic resonance (MR) methods to gain simultaneous information on blood flow/oxygenation and the bioenergetic status of rat Morris H9618a hepatomas. Both carbogen and CO breathing induced a 1.5- to 2-fold increase in signal intensity in blood oxygenation level dependent (BOLD) MR images. This was ...

  11. Predictors for Clinical Outcomes After Accelerated Partial Breast Intensity-Modulated Radiotherapy

    Purpose: To correlate the treatment planning parameters with the clinical outcomes in patients treated with accelerated partial breast intensity-modulated radiotherapy. Methods and Materials: A total of 105 patients with Stage I breast cancer were treated between February 2004 and March 2007 in a Phase II prospective trial and had detailed information available on the planning target volume (PTV), ipsilateral breast volume (IBV), PTV/IBV ratio, lung volume, chest wall volume, surgery to radiotherapy interval, follow-up interval, breast pain, and cosmesis. The first 7 of these patients were treated to 34 Gy, and the remaining 98 were treated to 38.5 Gy. All patients were treated twice daily for 5 consecutive days. Univariate and multivariate analyses were performed. Results: The median follow-up was 13 months. No recurrences or deaths were observed. Of the 105 patients, 30 reported mild or moderate breast pain in their most recently recorded follow-up visit. The irradiated lung volume (p 35 Gy (p 35 Gy) and to lung correlated with reports of mild pain after accelerated partial breast intensity-modulated radiotherapy. Also, the PTV, but not the PTV/IBV ratio, was predictive of post-treatment reports of pain.

  12. Study on fluorescence properties of carbogenic nanoparticles and their application for the determination of ferrous succinate

    Sun Wen [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China); Du Yingxiang, E-mail: du_yingxiang@126.co [Department of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China) and Key Laboratory of Modern Chinese Medicines, Ministry of Education, China Pharmaceutical University, Nanjing 210009 (China); Wang Yunqing [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China)

    2010-08-15

    A new type of fluorescent nanomaterial named carbogenic nanoparticles (NPs) has drawn considerable attention recently. In this study, we adopted a direct and simple synthetic method to produce the carbogenic NPs and investigated the fluorescence properties of the as-prepared carbogenic NPs in detail. It was found that the fluorescence of carbogenic NPs was stable with the variance of environmental conditions such as pH, temperature and UV irradiation. More interestingly, we found carbogenic NPs exhibited high selectivity and sensitivity towards ferric ions. Under optimum conditions, a good linear relationship could be obtained between the fluorescence intensity and concentration of ferric ions in the range of 5.0x10{sup -5}-5.0x10{sup -4} mol L{sup -1}, and the limit of detection is 11.2 {mu}mol L{sup -1}. Based on the fluorescence quenching of carbogenic NPs, a rapid and specific quantitative method was proposed for the determination of ferrous succinate. The content of ferrous succinate in commercial tablets determined by the present method was agreed with the spectrophotometric method results and the reproducibility and the recovery of the proposed method were satisfactory.

  13. Study on fluorescence properties of carbogenic nanoparticles and their application for the determination of ferrous succinate

    A new type of fluorescent nanomaterial named carbogenic nanoparticles (NPs) has drawn considerable attention recently. In this study, we adopted a direct and simple synthetic method to produce the carbogenic NPs and investigated the fluorescence properties of the as-prepared carbogenic NPs in detail. It was found that the fluorescence of carbogenic NPs was stable with the variance of environmental conditions such as pH, temperature and UV irradiation. More interestingly, we found carbogenic NPs exhibited high selectivity and sensitivity towards ferric ions. Under optimum conditions, a good linear relationship could be obtained between the fluorescence intensity and concentration of ferric ions in the range of 5.0x10-5-5.0x10-4 mol L-1, and the limit of detection is 11.2 μmol L-1. Based on the fluorescence quenching of carbogenic NPs, a rapid and specific quantitative method was proposed for the determination of ferrous succinate. The content of ferrous succinate in commercial tablets determined by the present method was agreed with the spectrophotometric method results and the reproducibility and the recovery of the proposed method were satisfactory.

  14. Response of Hepatoma 9618a and Normal Liver to Host Carbogen and Carbon Monoxide Breathing

    Simon P. Robinson

    1999-12-01

    Full Text Available The effects of hyperoxia (induced by host carbogen 95% oxygen/5% carbon dioxide breathing. and hypoxia (induced by host carbon monoxide CO at 660 ppm. breathing were compared by using noninvasive magnetic resonance (MR methods to gain simultaneous information on blood flow/oxygenation and the bioenergetic status of rat Morris H9618a hepatomas. Both carbogen and CO breathing induced a 1.5- to 2-fold increase in signal intensity in blood oxygenation level dependent (BOLD MR images. This was due to a decrease in deoxyhemoglobin (deoxyHb, which acts as an endogenous contrast agent, caused either by formation of oxyhemoglobin in the case of carbogen breathing, or carboxyhemoglobin with CO breathing. The results were confirmed by observation of similar changes in deoxyHb in arterial blood samples examined ex vivo after carbogen or CO breathing. There was no change in nucleoside triphosphates (NTP/PI in either tumor or liver after CO breathing, whereas NTP/Pl increased twofold in the hepatoma (but not in the liver after carbogen breathing. No changes in tumor intracellular pH were seen after either treatment, whereas extracellular pH became more alkaline after CO breathing and more acid after carbogen breathing, respectively. This tumor type and the liver are unaffected by CO breathing at 660 ppm, which implies an adequate oxygen supply.

  15. Late course accelerated hyperfractionated radiotherapy for clinical T1-2 esophageal carcinoma

    Kuai-Le Zhao; Yang Wang; Xue-Hui Shi

    2003-01-01

    AIM: This retrospective study was designed to analyze the results and the failure patterns of late course accelerated hyperfractionated radiotherapy for clinical T1-2NoMo esophageal carcinoma. METHODS: From Aug. 1994 to Feb. 2001, 56 patients with clinical T1-2 esophageal carcinoma received late course accelerated hyperfractionated radiotherapy in Cancer Hospital,Fudan University. All patients had been histologically proven to have squamous cell carcinoma (SCC) and were diagnosed to be T1-2NoMo by CT scan. All patients were treated with conventional fractionation (CF) irradiation during the first twothirds course of the treatment to a dose of about 41.4Gy/23fx/4 to 5 weeks, Which was then followed by accelerated hyperfractionation irradiation using reduced fields, twice daily at 1.SGy per fraction, to a dose about 27Gy/18 fx. Thus the total dose was 67-70Gy/40-43fx/40-49 d. RESULTS: The 1-, 3- and 5-year overall survival was 90.9 %,54.6 %, 47.8 % respectively. The 1-, 3- and 5-year local control rate was 90.9 %, 84.5 % and 84.5 %, respectively.Twenty-five percent (14/56) patients had distant metastasis and/or lymph nodes metastasis alone. Eight point nine percent (5/56) patients had local disease alone. Another 3.6 % (2/56) patients had regional relapse and distant metastasis. CONCLUSION: Late course accelerated hyperfractionated radiotherapy is effective on clinical T1-2 esophageal carcinoma.The main failure pattern is distant metastasis.

  16. Randomized study on late course accelerated hyperfractionation radiotherapy plus cisplatin in the treatment of esophageal carcinomas

    Objective: To investigate the therapeutic results of late course accelerated hyperfractionation (LCAH) radiotherapy plus cisplatin as a radiosensitizer in the treatment of esophageal carcinoma. Methods: One hundred and four patients with squamou s cell carcinoma of the esophagus were randomized into two groups: LCAH alone group (53 patients) and LCAH + cisplatin group (51 patients). The same irradiation technique was given for both groups with conventional fractionation (2 Gy daily, 5 times a week) in the first 3 weeks and late course accelerated hyperfractionation (1.5 Cry twice daily, a minimum interfraction interval of 6 hours, 5 days per week) in the last 2 weeks. The total dose was 60 Gy/5 wks. In LCAH + cisplatin group, cisplatin was given simultaneous with 20 mg once daily for 5 days in the 1st and 5th weeks. The acute and late side effects were evaluated during :and after the treatment. Results: The median survival time was 12.2 months and 17.0 months in the LCAH alone group and LCAH + cisplatin group. The 1- and 3-year survival rates in LCAH group were 52.8 % and 20.8%; while those of LCAH + cisplatin group were 58.0 % and 24.0% (P>0.05). The acute gastrointestinal toxicities and hematological toxicities were obvious in LCAH + cisplatin group, but no increased acute esophagitis or late complications was observed. Conclusions: Late course accelerated hyperfractionation radio-therapy used simultaneously with cisplatin tends to increase the overall survival rate compared with the late course accelerated hyperfractionation radiotherapy alone in the treatment of esophageal carcinoma. (authors)

  17. Toshiba's accelerator technology and approach toward higher performance and downsizing for heavy-ion radiotherapy

    Toshiba has developed various systems and components for particle beam accelerators, and delivered a number of accelerator systems including for SPring-8, which is the world's largest-class synchrotron radiation facility, as well as for the Central Japan Synchrotron Radiation Facility (provisional name). Combining our proprietary technologies cultivated through our experience in the development of particle beam accelerators, we are promoting the development of an accelerator for heavy-ion radiotherapy. Toward the higher performance and downsizing of its accelerator, we are also focusing on the research and development of both an ion source applying laser beam technologies, and a superconducting deflecting magnet for accelerators. (author)

  18. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  19. Visual Outcome in Meningiomas Around Anterior Visual Pathways Treated With Linear Accelerator Fractionated Stereotactic Radiotherapy

    Stiebel-Kalish, Hadas, E-mail: kalishhadas@gmail.com [Neuro-Ophthalmology Unit, Rabin Medical Center, Petah Tikva (Israel); Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Reich, Ehud [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Department of Ophthalmology, Rabin Medical Center, Petah Tikva (Israel); Gal, Lior [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Rappaport, Zvi Harry [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Department of Neurosurgery, Rabin Medical Center, Petah Tikva (Israel); Nissim, Ouzi [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Department of Neurosurgery, Sheba Medical Center, Ramat Gan (Israel); Pfeffer, Raphael [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Spiegelmann, Roberto [Sackler School of Medicine, Tel Aviv University, Tel Aviv (Israel); Stereotactic Radiosurgery Unit, Sheba Medical Center, Ramat Gan (Israel); Department of Neurosurgery, Sheba Medical Center, Ramat Gan (Israel)

    2012-02-01

    Purpose: Meningiomas threatening the anterior visual pathways (AVPs) and not amenable for surgery are currently treated with multisession stereotactic radiotherapy. Stereotactic radiotherapy is available with a number of devices. The most ubiquitous include the gamma knife, CyberKnife, tomotherapy, and isocentric linear accelerator systems. The purpose of our study was to describe a case series of AVP meningiomas treated with linear accelerator fractionated stereotactic radiotherapy (FSRT) using the multiple, noncoplanar, dynamic conformal rotation paradigm and to compare the success and complication rates with those reported for other techniques. Patients and Methods: We included all patients with AVP meningiomas followed up at our neuro-ophthalmology unit for a minimum of 12 months after FSRT. We compared the details of the neuro-ophthalmologic examinations and tumor size before and after FSRT and at the end of follow-up. Results: Of 87 patients with AVP meningiomas, 17 had been referred for FSRT. Of the 17 patients, 16 completed >12 months of follow-up (mean 39). Of the 16 patients, 11 had undergone surgery before FSRT and 5 had undergone FSRT as first-line management. Tumor control was achieved in 14 of the 16 patients, with three meningiomas shrinking in size after RT. Two meningiomas progressed, one in an area that was outside the radiation field. The visual function had improved in 6 or stabilized in 8 of the 16 patients (88%) and worsened in 2 (12%). Conclusions: Linear accelerator fractionated RT using the multiple noncoplanar dynamic rotation conformal paradigm can be offered to patients with meningiomas that threaten the anterior visual pathways as an adjunct to surgery or as first-line treatment, with results comparable to those reported for other stereotactic RT techniques.

  20. A real time scintillating fiber dosimeter for gamma and neutron monitoring on radiotherapy accelerators

    Bartesaghi, G. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy)]. E-mail: giacomobartesaghi@libero.it; Conti, V. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy); Prest, M. [INFN Sez. di Milano and Universita dell' Insubria, Como (Italy); Mascagna, V. [Universita dell' Insubria, Como (Italy); Scazzi, S. [Universita dell' Insubria, Como (Italy); Cappelletti, P. [Ospedale Sant' Anna, Como (Italy); Frigerio, M. [Ospedale Sant' Anna, Como (Italy); Gelosa, S. [Ospedale Sant' Anna, Como (Italy); Monti, A. [Ospedale Sant' Anna, Como (Italy); Ostinelli, A. [Ospedale Sant' Anna, Como (Italy); Mozzanica, A. [INFN Sez. di Pavia and Universita di Brescia (Italy); Bevilacqua, R. [Universita di Trieste and INFN sez. di Trieste (Italy); Giannini, G. [Universita di Trieste and INFN sez. di Trieste (Italy); Totaro, P. [Universita di Trieste and INFN sez. di Trieste (Italy); Vallazza, E. [INFN Sez. di Trieste (Italy)

    2007-03-01

    The quality of the radiotherapic treatment depends strongly on the capability to measure the dose released in the treated volume and the one absorbed by the surrounding volumes, which is mainly due to the scattered radiation produced by the primary beam interaction with the accelerator collimating system. Radiotherapy linear accelerators produce electron (6-20MeV) and photon (6, 18MV) irradiating fields up to 40x40cm{sup 2}. Photons with energies greater than 8MeV generate neutrons via photoproduction which are being studied for possible BNCT applications. We have developed a prototype of a real time dosimeter with 1mm diameter scintillating and clear fibers readout by multianode photomultipliers. For neutron applications, the fibers have been coupled with boron loaded scintillator. We will describe the dosimeter and the results of the tests comparing them to the ones obtained with the standard dosimeters.

  1. Hyperfractionated-accelerated radiotherapy followed by radical surgery in locally advanced tumors of the oral cavity

    Hoeller, U. [Dept. of Radiotherapy, Radiooncology and Nuclear Medicine, Vivantes Klinikum Neukoelln, Berlin (Germany); Biertz, I.; Tribius, S.; Alberti, W. [Dept. of Radiotherapy and Radiooncology, Univ. Hospital Hamburg-Eppendorf (Germany); Flinzberg, S.; Schmelzle, R. [Dept. of Dental, Oral and Maxillofacial Surgery, Univ. Hospital Hamburg-Eppendorf (Germany)

    2006-03-15

    Purpose: to evaluate the outcome of hyperfractionated-accelerated radiotherapy and subsequent planned primary tumor resection and radical neck dissection in locally advanced tumors of the oral cavity. Patients and Methods: this retrospective analysis evaluates 126 subsequent patients who were treated between 1988 and 1997 for locally advanced tumors of the oral cavity (with extension into the oropharynx in 17 patients), 34 (27%) AJCC stage III and 92 (73%) stage IV. Primary tumor and nodal metastases were irradiated with 1.4 Gy bid to a median total dose of 72.8 Gy (range 58.8-75.6 Gy). Then, planned radical surgery of the primary site according to the initial tumor extent and cervical nodes was performed. Median follow-up of living patients was 6 years (range 1-11 years). Results: 4 weeks after radiotherapy, 14 patients (11%) had complete tumor remission, 92 (73%) partial remission, 15 (12%) no change, and five (4%) progressive disease. Complete resection was achieved in 117 (93%) patients (nine incomplete resections). 5-year locoregional control rate was 62 {+-} 9%, overall survival 36 {+-} 9%. Surgery-related morbidity occurred in 42 patients (33%; mainly delayed wound healing and fistulae), overall severe treatment-related morbidity in 46 patients (36%). 24/84 relapse-free patients (29%) required a percutaneous gastrostomy or nasal tube {>=} 1 year after therapy. Conclusion: in this study, the outcome of combined curative radiotherapy and planned surgery of the primary tumor and neck nodes was comparable to reported results of hyperfractionated radiotherapy with or without salvage surgery of the neck nodes with respect to locoregional control and overall survival. Planned surgery carries a substantial risk of morbidity and seems to offer no benefit in comparison to salvage surgery of the neck nodes only. Therefore, salvage surgery is preferred. (orig.)

  2. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  3. Vertical mammaplasty associated with accelerated partial breast radiotherapy: how oncoplastic surgery techniques associated with modern techniques of radiotherapy can improve the aesthetic outcome in selected patients

    Couto, Henrique Lima, E-mail: enriquecouto@hotmail.com [Santa Fe Women' s and Maternity Hospital, Belo Horizonte, MG (Brazil); Amorim, Washington Cancado; Guimaraes, Rodrigo [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Hospital Geral; Ramires, Leandro Cruz; Castilho, Marcus Simoes [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Fac. de Medicina; Dominguez, Lorena Lima Coto [Universidade Estacio de Sa (UNESA), Rio de Janeiro, EJ (Brazil)

    2014-07-15

    Breast cancer is the second most common type of cancer in the world, being the most common among women, responsible for 22% of new cases each year. It's surgical and radiation treatment evolved from radical procedures (Halsted radical mastectomy and total external breast radiotherapy) to less radical and more conservative procedures. With the use of modern oncoplastic surgery techniques and accelerated partial breast radiotherapy, selected patients can benefit with better aesthetic results, fewer side effects, and more comfortable and brief treatments. (author)

  4. Carbogen inhalation increases oxygen transport to hypoperfused brain tissue in patients with occlusive carotid artery disease: increased oxygen transport to hypoperfused brain

    Ashkanian, Mahmoud; Gjedde, Albert; Mouridsen, Kim;

    2009-01-01

    Sa(O2) are readily obtained with carbogen, while oxygen increases only Sa(O2). Thus, carbogen improves oxygen transport to brain tissue more efficiently than oxygen alone. Further studies with more subjects are, however, needed to investigate the applicability of carbogen for long-term inhalation and...

  5. Prostate stereotactic ablative body radiotherapy using a standard linear accelerator: Toxicity, biochemical, and pathological outcomes

    Background and purpose: Biological dose escalation through stereotactic ablative radiotherapy (SABR) holds promise of improved patient convenience, system capacity and tumor control with decreased cost and side effects. The objectives are to report the toxicities, biochemical and pathologic outcomes of this prospective study. Materials and methods: A phase I/II study was performed where low risk localized prostate cancer received SABR 35 Gy in 5 fractions, once weekly on standard linear accelerators. Common Terminology Criteria for Adverse Events v3.0 and Radiation Therapy Oncology Group late morbidity scores were used to assess acute and late toxicities, respectively. Biochemical control (BC) was defined by the Phoenix definition. Results: As of May 2012, 84 patients have completed treatment with a median follow-up of 55 months (range 13–68 months). Median age was 67 years and median PSA was 5.3 ng/ml. The following toxicities were observed: acute grade 3+: 0% gastrointestinal (GI), 1% genitourinary (GU), 0% fatigue; late grade 3+: 1% GI, 1% GU. Ninety-six percent were biopsy negative post-treatment. The 5-year BC was 98%. Conclusions: This novel technique employing standard linear accelerators to deliver an extreme hypofractionated schedule of radiotherapy is feasible, well tolerated and shows excellent pathologic and biochemical control

  6. Transient perfusion and radiosensitizing effect after nicotinamide, carbogen, and perflubron emulsion administration

    In order to improve the effect of radiation on tumour response, nicotinamide, perflubron emulsion and carbogen were administered which act on both diffusion limited hypoxia and intermittent perfusion limited hypoxia. These treatments were used in different combinations. The maximal radiosensitizing effect was found with the combination of the three treatments. The aim of this study was to use a double staining method (Hoechst 33342 and DiOC7(3)) to evaluate the influence of nicotinamide, perflubron emulsion and carbogen on transient perfusion in three tumour cell lines transplanted onto nude mice: one rodent (EMT6), two human (HRT18, a rectal adenocarcinoma; and Na11+, a melanoma). For untreated groups, the percentage of closed and mismatched vessels depended on the tumour cell line. Carbogen alone or carbogen plus perflubron emulsion decreased the number of mismatched and closed vessels only for the two human cell lines. Nicotinamide was effective in decreasing the percentage of mismatched and closed vessels only for the melanoma cell line. The combination of nicotinamide, carbogen and perflubron emulsion was the most effective at decreasing both percentage of mismatched and closed vessels in all three tumours studies. This combination was also the most effective at enhancing the radiation response in all three tumours

  7. Effects of hyperbaric oxygen and normobaric carbogen on the radiation response of the rat rhabdomyosarcoma R1H

    Purpose: Hypoxic tumor cells are an important factor of radioresistance. Hyperbaric oxygen (HBO) and normobaric carbogen (95% oxygen, 5% carbon dioxide) increase the oxygen delivery to tumors. This study was performed to explore changes of tumor oxygenation during a course of fractionated irradiation and to determine the effectiveness of normobaric carbogen and HBO during the final phase of the radiation treatment. Methods and Materials: Experiments were performed on the rhabdomyosarcoma R1H growing on WAG/Rij rats. After 20 X-ray fractions of 2 Gy within 4 weeks, oxygen partial pressure (pO2) was measured using the Eppendorf oxygen electrode under ambient conditions, with normobaric carbogen or HBO at a pressure of 240 kPa. Following the 4-week radiation course, a top-up dose of 10-50 Gy was applied in 2-10 fractions of 5 Gy with or without hyperoxygenation. Results: HBO but not carbogen significantly increased the median pO2 in irradiated tumors. The radiation doses to control 50% of tumors were 38.0 Gy, 29.5 Gy, and 25.0 Gy for air, carbogen, and HBO, respectively. Both high oxygen content gas inspirations led to significantly improved tumor responses with oxygen enhancement ratios (OERs) of 1.3 for normobaric carbogen and 1.5 for HBO (air vs. carbogen: p=0.044; air vs. HBO: p=0.02; carbogen vs. HBO: p=0.048). Conclusion: Both normobaric carbogen and HBO significantly improved the radiation response of R1H tumors. HBO appeared to be more effective than normobaric carbogen, both with regard to tumor oxygenation and response to irradiation

  8. Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

    Gatti, M.; Bresciani, S.; Ponzone, R.; Panaia, R.; Salatino, A.; Stasi, M.; Gabriele, P. [IRCC, Candiolo (Italy)

    2011-10-15

    Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was < 10 mm in 33 patients (53%) and > 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long

  9. Accelerated superfractionated radiotherapy for inflammatory breast carcinoma: complete response predicts outcome and allows for breast conservation

    Purpose: Chemotherapy and accelerated superfractionated radiotherapy were prospectively applied for inflammatory breast carcinoma with the intent of breast conservation. The efficacy, failure patterns, and patient tolerance utilizing this approach were analyzed. Methods and Materials: Between 1983 and 1996, 52 patients with inflammatory breast carcinoma presented to the Medical College of Virginia Hospitals of VCU and the New England Medical Center. Thirty-eight of these patients were jointly evaluated in multidisciplinary breast clinics and managed according to a defined prospectively applied treatment policy. Patients received induction chemotherapy, accelerated superfractionated radiotherapy, selected use of mastectomy, and concluded with additional chemotherapy. The majority were treated with 1.5 Gy twice daily to field arrangements covering the entire breast and regional lymphatics. An additional 18-21 Gy was then delivered to the breast and clinically involved nodal regions. Total dose to clinically involved areas was 63-66 Gy. Following chemoradiotherapy, patients were evaluated with physical examination, mammogram, and fine needle aspiration x 3. Mastectomy was reserved for those patients with evidence of persistent or progressive disease in the involved breast. All patients received additional chemotherapy. Results: Median age was 51 years. Median follow-up was 23.9 months (6-86) months. The breast preservation rate at the time of last follow-up was 74%. The treated breast or chest wall as the first site of failure occurred in only 13%, and the ultimate local control rate with the selected use of mastectomy was 74%. Ten patients underwent mastectomy, 2 of which had pathologically negative specimens despite a clinically palpable residual mass. Response to chemotherapy was predictive of treatment outcome. Of the 15 patients achieving a complete response, 87% remain locoregionally controlled without the use of mastectomy. Five-year overall survival for

  10. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    Pedicini Piernicola

    2012-08-01

    Full Text Available Abstract Purpose To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr and the reduction of the effective doubling time (TD during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC. Methods A survey of the published papers comparing 3-years of local regional control rate (LCR for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr, respectively. By obtaining the TD from the above analysis and the sub-sites’ potential doubling time (Tpot from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif, was estimated. Results The averages of TD were 77 (27-9095% days in LEGFr and 8.8 (7.3-11.095% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites’ TD were 5.9 (6.6, 5.9 (6.6, 4.6 (6.1, 14.3 (12.9 days, with respect to literature immunohistochemical (flow cytometry data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29, 0.33 (0.29, 0.42 (0.31, 0.14 (0.15 Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. Conclusions A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck

  11. Correlation between egfr expression and accelerated proliferation during radiotherapy of head and neck squamous cell carcinoma

    To investigate the correlation between the expression of Epidermal Growth Factor receptor (EGFr) and the reduction of the effective doubling time (TD) during radiotherapy treatment and also to determine the dose per fraction to be taken into account when the overall treatment time (OTT) is reduced in accelerated radiotherapy of head and neck squamous cell carcinoma (HNSCC). A survey of the published papers comparing 3-years of local regional control rate (LCR) for a total of 2162 patients treated with conventional and accelerated radiotherapy and with a pretreatment assessment of EGFr expression, was made. Different values of TD were obtained by a model incorporating the overall time corrected biologically effective dose (BED) and a 3-year clinical LCR for high and low EGFr groups of patients (HEGFr and LEGFr), respectively. By obtaining the TD from the above analysis and the sub-sites’ potential doubling time (Tpot) from flow cytometry and immunohistochemical methods, we were able to estimate the average TD for each sub-site included in the analysis. Moreover, the dose that would be required to offset the modified proliferation occurring in one day (Dprolif), was estimated. The averages of TD were 77 (27-90)95% days in LEGFr and 8.8 (7.3-11.0)95% days in HEGFr, if an onset of accelerated proliferation TK at day 21 was assumed. The correspondent HEGFr sub-sites’ TD were 5.9 (6.6), 5.9 (6.6), 4.6 (6.1), 14.3 (12.9) days, with respect to literature immunohistochemical (flow cytometry) data of Tpot for Oral-Cavity, Oro-pharynx, Hypo-pharynx, and Larynx respectively. The Dprolif for the HEGFr groups were 0.33 (0.29), 0.33 (0.29), 0.42 (0.31), 0.14 (0.15) Gy/day if α = 0.3 Gy-1 and α/β = 10 Gy were assumed. A higher expression of the EGFr leads to enhanced proliferation. This study allowed to quantify the extent of the effect which EGFr expression has in terms of reduced TD and Dprolif for each head and neck sub-site

  12. Toxicity and cosmetic outcome of three-dimensional conformal radiotherapy for accelerated partial breast irradiation

    Full text of publication follows: Purpose.- To analyse the incidence and severity of acute and late normal tissue toxicity and cosmetic outcome using three - dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. Patients and Methods.- 70 patients with stage I disease were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation, in an approved protocol. The prescribed dose was 34 Gy in all patients delivered in 10 fractions over 5 consecutive days. On all CT scans gross tumor volume (GTV ) was defined around surgical clips. A 1.5 cm margin was added in order to account for clinical target volume (CTV) . A margin of 1 cm was added to CTI to define the planning target volume (PTV). The dose-volume constraints were followed in accordance with the specifications as dictated in the NSABP/RTOG protocol. After treatment, patients underwent a clinical and cosmetic evaluation every 3 months. Late toxicity was evaluated according to the RTOG grading schema. The cosmetic assessment was performed by the physicians using the controlateral untreated breast as the reference (Harvard scale). Results.- Median patient age was 66 years (range 51-80). Median follow-up was 15 months (range 6-46). Tumor size was 2 cm in 4(6%). The mean value of the ratio between the PTV and the whole ipsilateral breast volume was 38 % and the median percentage whole breast volume that received 95 % of prescribed dose was 34% (range 16%-55%). The rate of G1 and G2 acute skin toxicity was 28% and 2% respectively and the late toxicity was 17% (G1). G2 or greater toxicities were not observed. The most pronounced G1 late toxicity was subcutaneous fibrosis, developed in 3 patients. The cosmetic outcome was excellent in 83% and good in 17%. Conclusion.- Accelerated partial breast irradiation using three-dimensional conformal radiotherapy is technically feasible with very low acute and late toxicity. Long-term results are needed to assess

  13. Quality of life in patients with oropharynx carcinomas: assessment after accelerated radiotherapy with or without chemotherapy versus radical surgery and postoperative radiotherapy

    Allal, Abdelkarim Said; Nicoucar, Kevin; Mach, Nicolas; Dulguerov, Pavel

    2003-01-01

    In oropharyngeal carcinomas, it is assumed that the effectiveness of the different treatment approaches is roughly equivalent, whereas the functional outcome after radical radiotherapy (RT) is superior to that associated with primary surgery. The aim of this study is to assess quality of life (QoL) outcomes of patients after two treatment strategies: radical surgery with postoperative RT and accelerated concomitant boost RT with or without chemotherapy.

  14. Radiotherapy

    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

  15. Preoperative concurrent CBDCA chemotherapy and accelerated hyperfractionated radiotherapy for squamous cell carcinoma of the maxillary region

    Between 1994 and 2000, 28 patients with T3/T4 squamus cell carcinoma of the maxillary region (maxillary sinus, 22; maxillary gingiva, 4; maxillary bone, 1; buccal mucosa, 1) had accelerated hyperfractionated radiotherapy combined with simultaneous CBDCA chemotherapy preoperatively, at Chiba Cancer Center Hospital. The protocol consisted of combined therapy with accelerated hyperfractionated irradiation of 1.6 Gy, twice a day, to a total dose of 32.0-51.2 Gy and concurrent intra-arterial or intravenous infusion of CBDCA 20-30 mg/body/day for a cumulative total dose of 270-480 mg. After completion of the preoperative combined therapy, the clinical CR rate was 17.9%, and the good PR·CR rate was 32.1%. According to the initial findings and response to the combined therapy, all patients had maxillectomy (subtotal, 3; total, 16; extended, 9) 4 weeks after completion of the preoperative combined therapy. Postoperatively, the complete pathologic response (Ohboshi and Shimozato's classification, grade III and IV) rate was 28.6%. And the actuarial local control rate was 85.7%, with a mean follow-up of 46.2 months. Based on these results, we believe this preoperative therapy with CBDCA chemotherapy and accelerated hyperfractionated radiation is a significant choice as treatment for squamous cell cancer of the maxillary region. (author)

  16. Effectiveness of custom neutron shielding in the maze of radiotherapy accelerators

    An investigation was performed to examine the neutron dose equivalent in a radiotherapy maze lined with a customised neutron shielding material. The accelerator investigated was a Varian Clinac 2100C/D using 18 MV photons, and the neutron shielding utilised at this centre was PremadexTM commercially available neutron shielding. Based on Monte Carlo simulations, properly installed customised neutron shielding may reduce the neutron dose equivalent by up to a factor of 8 outside the maze, depending upon the installation. In addition, it was determined that the neutron dose near the entrance to the maze may be reduced by approximately 40% by using customised neutron shielding in the maze, as compared with a facility not using this shielding. This would have a positive dose-saving effect in doorless maze designs. (author)

  17. Challenges in Linear Accelerator Radiotherapy for Chordomas and Chondrosarcomas of the Skull Base: Focus on Complications

    Hauptman, Jason S., E-mail: jhauptman@mednet.ucla.edu [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Barkhoudarian, Garni; Safaee, Michael; Gorgulho, Alessandra [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Tenn, Steven; Agazaryan, Nzhde; Selch, Michael [Department of Radiation Oncology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); De Salles, Antonio A.F. [Division of Stereotactic and Functional Neurosurgery, Department of Neurosurgery, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States); Department of Radiation Oncology, University of California, Los Angeles, David Geffen School of Medicine, Los Angeles, CA (United States)

    2012-06-01

    Purpose: Intracranial chordomas and chondrosarcomas are histologically low-grade, locally invasive tumors that infiltrate the skull base. Currently, consensus therapy includes surgical resection and adjuvant radiotherapy. Radiation delivery is typically limited by the proximity of these tumors to critical skull base structures. Methods: This is a retrospective review of 13 cases of chordomas and 2 cases of chondroid chondrosarcomas of the skull based treated with linear accelerator stereotactic radiotherapy (SRT, n = 10) or stereotactic radiosurgery (SRS, n = 5). The average time to the most recent follow-up visit was 4.5 years. The tumor characteristics, treatment details, and outcomes were recorded. Each radiation plan was reviewed, and the dosage received by the brainstem, optic apparatus, and pituitary was calculated. Results: Of the 10 patients treated with SRT, 6 were found to have unchanged or decreased tumor size as determined from radiographic follow-up. Of the 5 patients treated with SRS, 3 were found to have stable or unchanged tumors at follow-up. The complications included 1 SRT patient who developed endocrinopathy, 2 patients (1 treated with SRS and the other with SRT), who developed cranial neuropathy, and 1 SRS patient who developed visual deficits. Additionally, 1 patient who received both SRS and SRT within 2 years for recurrence experienced transient medial temporal lobe radiation changes that resolved. Conclusions: Where proton beam therapy is unavailable, linear accelerator-based SRT or radiosurgery remains a safe option for adjuvant therapy of chordomas and chondrosarcomas of the skull base. The exposure of the optic apparatus, pituitary stalk, and brainstem must be considered during planning to minimize complications. If the optic apparatus is included in the 80% isodose line, it might be best to fractionate therapy. Exposure of the pituitary stalk should be kept to <30 Gy to minimize endocrine dysfunction. Brainstem exposure should be

  18. Accelerated radiotherapy for T1, 2 glottic carcinoma: analysis of results with KI-67 index

    Purpose: Hyperfractionated and accelerated radiotherapy without a split was performed to improve the local control probability of early glottic carcinomas. We analyzed the results of this regimen by using the Ki-67 index. Methods and Materials: Over a 12-year period, 85 T1N0M0 glottic cancers and 50 T2N0M0 glottic cancers were treated with conventional fractionation (CF) from 1984 to 1989 and with accelerated fractionation (AF) since 1990. The CF program consisted of five daily fractions of 2 Gy per week, for a total of 64 Gy. The AF program consisted of 1.72 Gy per fraction, two fractions per day, 5 days a week, for a total of 55 or 58 Gy. The specimens, taken before radiotherapy, were immunohistochemically stained with anti-Ki-67 antibody. Results: The 5-year local control probability for T1 tumors was 79.6 ± 6.9% with CF treatment, whereas with AF it was 86.9 ± 5.6%. For T2 tumors it was 62.7 ± 12.2% with CF, whereas it was 74.7 ± 7.8% with AF. The difference between CF and AF did not reach the point of statistical significance. However, when T1 tumors had a Ki-67 index lower than 50%, the local control rate achieved with AF was significantly better than that with CF (p = 0.018). When the tumors had a Ki-67 index that was 50% or more, there was no difference in the local control rate between CF and AF, whether they were T1 or T2. The peak mucosal reactions at the larynx and/or hypopharynx were much more severe and appeared at smaller doses and earlier in AF than in CF. The patients with AF showed no severe late complications. Conclusions: AF could not obtain statistically significant improvement in local control probability of T1 or T2 glottic carcinomas

  19. Challenges in Linear Accelerator Radiotherapy for Chordomas and Chondrosarcomas of the Skull Base: Focus on Complications

    Purpose: Intracranial chordomas and chondrosarcomas are histologically low-grade, locally invasive tumors that infiltrate the skull base. Currently, consensus therapy includes surgical resection and adjuvant radiotherapy. Radiation delivery is typically limited by the proximity of these tumors to critical skull base structures. Methods: This is a retrospective review of 13 cases of chordomas and 2 cases of chondroid chondrosarcomas of the skull based treated with linear accelerator stereotactic radiotherapy (SRT, n = 10) or stereotactic radiosurgery (SRS, n = 5). The average time to the most recent follow-up visit was 4.5 years. The tumor characteristics, treatment details, and outcomes were recorded. Each radiation plan was reviewed, and the dosage received by the brainstem, optic apparatus, and pituitary was calculated. Results: Of the 10 patients treated with SRT, 6 were found to have unchanged or decreased tumor size as determined from radiographic follow-up. Of the 5 patients treated with SRS, 3 were found to have stable or unchanged tumors at follow-up. The complications included 1 SRT patient who developed endocrinopathy, 2 patients (1 treated with SRS and the other with SRT), who developed cranial neuropathy, and 1 SRS patient who developed visual deficits. Additionally, 1 patient who received both SRS and SRT within 2 years for recurrence experienced transient medial temporal lobe radiation changes that resolved. Conclusions: Where proton beam therapy is unavailable, linear accelerator-based SRT or radiosurgery remains a safe option for adjuvant therapy of chordomas and chondrosarcomas of the skull base. The exposure of the optic apparatus, pituitary stalk, and brainstem must be considered during planning to minimize complications. If the optic apparatus is included in the 80% isodose line, it might be best to fractionate therapy. Exposure of the pituitary stalk should be kept to <30 Gy to minimize endocrine dysfunction. Brainstem exposure should be

  20. Five Year Outcome of 145 Patients With Ductal Carcinoma In Situ (DCIS) After Accelerated Breast Radiotherapy

    Background: Accelerated whole-breast radiotherapy (RT) with tumor bed boost in the treatment of early invasive breast cancer has demonstrated equivalent local control and cosmesis when compared with standard RT. Its efficacy in the treatment of ductal carcinoma in situ (DCIS) remains unknown. Methods and Materials: Patients treated for DCIS with lumpectomy and negative margins were eligible for 2 consecutive hypofractionated whole-breast RT clinical trials. The first trial (New York University [NYU] 01-51) prescribed to the whole breast 42 Gy (2.8 Gy in 15 fractions) and the second trial (NYU 05-181) 40.5 Gy (2.7 Gy in 15 fractions) with an additional daily boost of 0.5 Gy to the surgical cavity. Results: Between 2002 and 2009, 145 DCIS patients accrued, 59 to the first protocol and 86 to the second trial. Median age was 56 years and 65% were postmenopausal at the time of treatment. Based on optimal sparing of normal tissue, 79% of the patients were planned and treated prone and 21% supine. At 5 years' median follow-up (60 months; range 2.6-105.5 months), 6 patients (4.1%) experienced an ipsilateral breast recurrence in all cases of DCIS histology. In 3/6 patients, recurrence occurred at the original site of DCIS and in the remaining 3 cases outside the original tumor bed. New contralateral breast cancers arose in 3 cases (1 DCIS and 2 invasive carcinomas). Cosmetic self-assessment at least 2 years after treatment is available in 125 patients: 91% reported good-to-excellent and 9% reported fair-to-poor outcomes. Conclusions: With a median follow-up of 5 years, the ipsilateral local recurrence rate is 4.1%, comparable to that reported from the NSABP (National Surgical Adjuvant Breast and Bowel Project) trials that employed 50 Gy in 25 fractions of radiotherapy for DCIS. There were no invasive recurrences. These results provide preliminary evidence that accelerated hypofractionated external beam radiotherapy is a viable option for DCIS.

  1. Five Year Outcome of 145 Patients With Ductal Carcinoma In Situ (DCIS) After Accelerated Breast Radiotherapy

    Ciervide, Raquel [Department of Radiation Oncology, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States); Dhage, Shubhada; Guth, Amber; Shapiro, Richard L.; Axelrod, Deborah M.; Roses, Daniel F. [Department of Surgery, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States); Formenti, Silvia C., E-mail: silvia.formenti@nyumc.org [Department of Radiation Oncology, New York University School of Medicine, NYU Langone Medical Center, New York, New York (United States)

    2012-06-01

    Background: Accelerated whole-breast radiotherapy (RT) with tumor bed boost in the treatment of early invasive breast cancer has demonstrated equivalent local control and cosmesis when compared with standard RT. Its efficacy in the treatment of ductal carcinoma in situ (DCIS) remains unknown. Methods and Materials: Patients treated for DCIS with lumpectomy and negative margins were eligible for 2 consecutive hypofractionated whole-breast RT clinical trials. The first trial (New York University [NYU] 01-51) prescribed to the whole breast 42 Gy (2.8 Gy in 15 fractions) and the second trial (NYU 05-181) 40.5 Gy (2.7 Gy in 15 fractions) with an additional daily boost of 0.5 Gy to the surgical cavity. Results: Between 2002 and 2009, 145 DCIS patients accrued, 59 to the first protocol and 86 to the second trial. Median age was 56 years and 65% were postmenopausal at the time of treatment. Based on optimal sparing of normal tissue, 79% of the patients were planned and treated prone and 21% supine. At 5 years' median follow-up (60 months; range 2.6-105.5 months), 6 patients (4.1%) experienced an ipsilateral breast recurrence in all cases of DCIS histology. In 3/6 patients, recurrence occurred at the original site of DCIS and in the remaining 3 cases outside the original tumor bed. New contralateral breast cancers arose in 3 cases (1 DCIS and 2 invasive carcinomas). Cosmetic self-assessment at least 2 years after treatment is available in 125 patients: 91% reported good-to-excellent and 9% reported fair-to-poor outcomes. Conclusions: With a median follow-up of 5 years, the ipsilateral local recurrence rate is 4.1%, comparable to that reported from the NSABP (National Surgical Adjuvant Breast and Bowel Project) trials that employed 50 Gy in 25 fractions of radiotherapy for DCIS. There were no invasive recurrences. These results provide preliminary evidence that accelerated hypofractionated external beam radiotherapy is a viable option for DCIS.

  2. Procedure to measure the neutrons spectrum around a lineal accelerator for radiotherapy

    An experimental procedure was developed, by means of Bonner spheres, to measure the neutrons spectrum around Linacs of medical use that only requires of a single shot of the accelerator; to this procedure we denominate Planetary or Isocentric method. One of the problems associated to the neutrons spectrum measurement in a radiotherapy room with lineal accelerator is because inside the room a mixed, intense and pulsed radiation field takes place affecting the detection systems based on active detector; this situation is solved using a passive detector. In the case of the Bonner spheres spectrometer the active detector has been substituted by activation detectors, trace detectors or thermoluminescent dosimeters. This spectrometer uses several spheres that are situated one at a time in the measurement point, this way to have the complete measurements group the accelerator should be operated, under the same conditions, so many times like spheres have the spectrometer, this activity can consume a long time and in occasions due to the work load of Linac to complicate the measurement process too. The procedure developed in this work consisted on to situate all the spectrometer spheres at the same time and to make the reading by means of a single shot, to be able to apply this procedure, is necessary that before the measurements two characteristics are evaluated: the cross-talking of the spheres and the symmetry conditions of the neutron field. This method has been applied to determine the photo-neutrons spectrum produced by a lineal accelerator of medical use Varian ix of 15 MV to 100 cm of the isocenter located to 5 cm of depth of a solid water mannequin of 30 x 30 x 15 cm. The spectrum was used to determine the total flow and the environmental dose equivalent. (Author)

  3. Radiotherapy

    The need for radiotherapy research is exemplified by the 100,000 cancer patients who will fail treatment locally and/or regionally annually for the next several years but who would benefit from better local treatment modalities. Theoretically, all of the areas of investigation discussed in this projection paper have the potential to significantly improve local-regional treatment of cancer by radiotherapy alone or in combination with other modalities. In many of the areas of investigation discussed in this paper encouraging results have been obtained in cellular and animal tumor studies and in limited studies in humans as well. In the not too distant future the number of patients who would benefit from better local control may increase by tens of thousands if developments in chemotherapy and/or immunotherapy provide a means to eradicate disseminated microscopic foci of cancer. Thus the efforts to improve local-regional control take on even greater significance

  4. Alternating chemotherapy and hyperfractionated accelerated radiotherapy in non-metastatic inflammatory breast cancer; Radiotherapie hyperfractionnee acceleree alternee avec une chimiotherapie dans le cancer du sein inflammatoire non metastatique

    Hasbini, A.; Le Pechoux, C.; Roche, B.; Pignol, J.P.; Abdulkarim, B.; Habrand, J.L. [Institut Gustave Roussy, Dept. de Radiotherapie, 94 - Villejuif (France); Zelek, L.; Spielmann, M. [Institut Gustave Roussy, Dept. d' oncologie Medicale, 94 - Villejuif (France); Arriagada, R. [Instituto de Radiomedicina, IRAM, Santiago, (Chile); Guinebretiere, J.M. [Institut Gustave Roussy, Dept. d' Anatomopothologie, 94 - Villejuif (France); Tardivon, A. [Institut Gustave Roussy, Dept. de Radiodiagnostic, 94 - Villejuif (France)

    2000-08-01

    Based on encouraging results reported in alternating radiotherapy and chemotherapy in inflammatory breast carcinoma, we have tried in this study to optimize locoregional treatment with a hyperfractionated accelerated radiotherapy schedule alternating with chemotherapy. From May 1991 to May 1995, 54 patients, previously untreated, with non-metastatic inflammatory breast cancer were entered in an alternating protocol consisting of eight courses of combined chemotherapy and two series of loco-regional hyperfractionated accelerated radiotherapy with a total dose of 66 Gy. Hyperfractionated accelerated radiotherapy was started after three courses of neo-adjuvant chemotherapy (Adriamycin, Vincristine, Cyclophosphamide, Methotrexate, 5-fluoro-uracil) administered every 21 days {+-}G.CSF. The first series delivered 45 Gy/three weeks to the breast, the axillary, sub-clavicular and internal mammary nodes, with two daily sessions of 1.5 Gy separated by an interval of eight hours, the second series consisted of a boost (21 Gy/14 fractions/10d) alternating with another regimen of anthracycline-based-chemotherapy (a total of five cycles every three weeks). Hormonal treatment was given to all patients. Of the 53 patients evaluated at the end of the treatment, 44(83%) had a complete clinical response, seven (13%) had a partial response (>50%) and two (4%) had tumoral progression. Of the 51 patients who were locally controlled, 18 (35%) presented a locoregional recurrence (LRR); eight(15 %) had to undergo a mastectomy. All the patients but two LRR developed metastases or died of local progressive disease and 26 (50%) developed metastases. With a median follow-up of 39 months (range: 4-74 months), survival rates at three and five years were respectively, 66 and 45% for overall survival and 45 and 36% for disease-free survival. Alternating a combination of chemotherapy and hyperfractionated accelerated radiotherapy is a well-tolerated regimen which provides acceptable local control

  5. Can pure accelerated radiotherapy given as six fractions weekly be an option in locally advanced carcinoma cervix: Results of a prospective randomized phase III trial

    Mukesh Sharma

    2016-01-01

    Conclusions: Accelerated radiotherapy given as six fractions per week is an effective alternative to concomitant chemoradiation in locally advanced carcinoma cervix and has shown lesser toxicities in our study.

  6. Retrospective study on therapy options of brain metastases surgery versus stereotactic radiotherapy with the linear accelerator

    Fortunati, M K S

    2001-01-01

    Background: in the therapy of brain metastases there has been a great progress in the last years. It was shown, that more aggressive therapies can not only extend the survival of the patients, but also improve quality of life. The major question of this study was, whether surgery or stereotactic radiotherapy with the linear accelerator show better results in behalf of the survival. Beside this major question many parameters regarding the patient or his primary cancer were examined. Methods: from the 1st of January 1995 until the 30th of June 2000 233 patients with one or more brain metastases have been treated in the Wagner Jauregg Landesnervenkrankenhaus Oberoesterreich (WJ LNKH OeO). The LINAC has been established on the 1st of July 1997. The patients have been distributed in three groups: 1. LINAC-group: 81 patients have been treated from the 1st of July 1997 until the 30th of June 2000 with the LINAC. 2. Surgery-group: 81 patients have been operated from the 1st of July 1997 until the 30th June 2000. 3 Co...

  7. Late course accelerated hyperfractionation radiotherapy for elderly patients with esophageal carcinoma

    Objective: To study the clinical results and prognostic factors of late course accelerated hyperfractionation radiotherapy (LCAHR) in the treatment of esophageal carcinoma in the elderly. Methods: 105 over 60 year-old patients with esophageal carcinoma who received radical LCAHR, were retrospectively analysed. Radical tumoricidal dose of 67.9-72.0 Gy was delivered in 39-43 fractions over 42-53 days. Results: The 5-year local control rate was 63.7%. The 5-year disease-free survival and overall survival rate were 22.6% and 34.4%. Acute esophagitis and bronchitis were the most common but acceptable radioreactions Grade 1-2. No significant differences were found either in the clinical response or complication, between the 60-69 year and 70-80 year groups. By multivariate analysis, T stage and KPS score were two independent prognostic factors. Of 67 death cases, 31 died of local relapse, 23 of distant metastases, 8 of both and 5 of other causes. Conclusions: LCAHR toxicity, being tolerable for the older esophageal carcinoma patients, may improve their survival and quality of life

  8. Determining optimization of the initial parameters in Monte Carlo simulation for linear accelerator radiotherapy

    Chang, Kwo-Ping; Wang, Zhi-Wei; Shiau, An-Cheng

    2014-02-01

    Monte Carlo (MC) method is a well known calculation algorithm which can accurately assess the dose distribution for radiotherapy. The present study investigated all the possible regions of the depth-dose or lateral profiles which may affect the fitting of the initial parameters (mean energy and the radial intensity (full width at half maximum, FWHM) of the incident electron). EGSnrc-based BEAMnrc codes were used to generate the phase space files (SSD=100 cm, FS=40×40 cm2) for the linac (linear accelerator, Varian 21EX, 6 MV photon mode) and EGSnrc-based DOSXYZnrc code was used to calculate the dose in the region of interest. Interpolation of depth dose curves of pre-set energies was proposed as a preliminary step for optimal energy fit. A good approach for determination of the optimal mean energy is the difference comparison of the PDD curves excluding buildup region, and using D(10) as a normalization method. For FWHM fitting, due to electron disequilibrium and the larger statistical uncertainty, using horn or/and penumbra regions will give inconsistent outcomes at various depths. Difference comparisons should be performed in the flat regions of the off-axis dose profiles at various depths to optimize the FWHM parameter.

  9. Radiobiological characterization of different energy-photon beams used in radiotherapy from linear accelerator

    The main objective of this study was to perform a radiobiological characterization of different energy photon beams (6 MV and 15 MV) from linear accelerator used in radiotherapy, and comparison of different treatment modalities, with special regard to late effects of radiation. Using two end points, cell survival and micronucleus induction, in the biological system (Chines hamster V79 cell line). Chromosomes number was counted and found to be 22 chromosomes per cell. Cells were kept in confluent growth for two days and then exposed to two photon beams and immediately after irradiation were counted and re seeded in different numbered for each dose. For evaluation of surviving fraction samples were incubated at 37oC for 6 days, five samples were counted for each dose. At the same time three samples were seeded for the micronuclei frequency and incubated at 37oC after 24 hours cytochalasin-B was added to block cells in cytokinesis. The survival curve showed similar curves for the two beams and decreased with dose. The micronuclei frequency was positively correlated with dose and the energy of the photon. This indicates the presence of low dose of photoneutrons produced by using high energy photon beams. (Author)

  10. Hypofractionated and Accelerated Radiotherapy With Subcutaneous Amifostine Cytoprotection as Short Adjuvant Regimen After Breast-Conserving Surgery: Interim Report

    Purpose: Short radiotherapy schedules might be more convenient for patients and overloaded radiotherapy departments, provided late toxicity is not increased. We evaluated the efficacy and toxicity of a hypofractionated and highly accelerated radiotherapy regimen supported with cytoprotection provided by amifostine in breast cancer patients treated with breast-conserving surgery. Methods and Materials: A total of 92 patients received 12 consecutive fractions of radiotherapy (3.5 Gy/fraction for 10 fractions) to the breast and/or axillary/supraclavicular area and 4 Gy/fraction for 2 fractions to the tumor bed). Amifostine at a dose of 1,000 mg/d was administered subcutaneously. The follow-up of patients was 30-60 months (median, 39). Results: Using a dose individualization algorithm, 77.1% of patients received 1,000 mg and 16.3% received 750 mg of amifostine daily. Of the 92 patients, 13% interrupted amifostine because of fever/rash symptoms. Acute Grade 2 breast toxicity developed in 6.5% of patients receiving 1,000 mg of amifostine compared with 46.6% of the rest of the patients (p < .0001). The incidence of Grade 2 late sequelae was less frequent in the high amifostine dose group (3.2% vs. 6.6%; p = NS). Grade 1 lung fibrosis was infrequent (3.3%). The in-field relapse rate was 3.3%, and an additional 2.2% of patients developed a relapse in the nonirradiated supraclavicular area. c-erbB-2 overexpression was linked to local control failure (p = .01). Distant metastasis appeared in 13% of patients, and this was marginally related to more advanced T/N stage (p = .06). Conclusion: Within a minimal follow-up of 2.5 years after therapy, hypofractionated and accelerated radiotherapy with subcutaneous amifostine cytoprotection has proved a well-tolerated and effective regimen. Longer follow-up is required to assess the long-term late sequelae.

  11. Avoidance of treatment interruption: an unrecognized benefit of accelerated radiotherapy in oropharyngeal carcinomas?

    Purpose: To assess the impact of treatment interruption on the potential gain in locoregional control obtained with accelerated radiotherapy (RT) compared with conventionally fractionated RT in patients with oropharyngeal carcinomas. Methods and Materials: 152 patients treated with radical RT for oropharyngeal carcinomas between 1979 and 1996 were retrospectively analyzed. According to the American Joint Committee on Cancer (AJCC) staging system, there were 6/30/43/73 stages I/II/III/IV. Sixty-one patients were treated with a conventional RT schedule (median dose 70 Gy in 35 fractions), and 91 patients with either of two 5/5.5-week accelerated RT schedules (median dose 69.6-69.9 Gy in 41 fractions). Discounting weekends, RT was interrupted for 2 consecutive days or more in 53 patients (median duration 11 days, range 2-97), including 67% of the patients in the conventional RT group and 13% in the accelerated RT group. Median follow-up for surviving patients was 55 months (range 23-230). The Cox proportional hazards model was used for the multivariate analysis of factors influencing locoregional control. Results: In univariate analysis, factors associated with a significant decrease in locoregional control included WHO performance status ≥1, advanced AJCC stages (III and IV), conventional RT fractionation, overall treatment time ≥44 days (median), and RT interruption. In the multivariate analysis, when introduced into the model individually, the three significant therapeutic factors remained significant after adjustment for the forced clinical variables. However, when the three therapeutic factors were introduced together into the model, beside the AJCC stage (P = 0.017), only RT interruption remained a significant independent adverse prognostic factor (P = 0.026). Conclusions: This multivariate analysis highlights the potential negative impact of treatment gaps on locoregional control in oropharyngeal carcinomas. This suggests that treatment interruption may be

  12. Short-Course Accelerated Radiotherapy in Palliative Treatment of Advanced Pelvic Malignancies: A Phase I Study

    Caravatta, Luciana [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Padula, Gilbert D.A. [Department of Radiation Oncology, Lacks Cancer Center Saint Mary' s Health Care, Grand Rapids, MI (United States); Macchia, Gabriella, E-mail: gmacchia@rm.unicatt.it [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Ferrandina, Gabriella [Department of Gynecologic Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Bonomo, Pierluigi; Deodato, Francesco; Massaccesi, Mariangela [Department of Radiation Oncology, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Mignogna, Samantha; Tambaro, Rosa [Department of Palliative Therapies, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Rossi, Marco [Department of Anaesthesia, Intensive Care, and Pain Medicine, Fondazione di Ricercae Cura ' Giovanni Paolo II,' Universita Cattolica del S. Cuore, Campobasso (Italy); Flocco, Mariano [' Madre Teresa di Calcutta' Hospice, Larino (Italy); Scapati, Andrea [Department of Radiation Oncology, ' San Francesco' Hospital, Nuoro (Italy); and others

    2012-08-01

    Purpose: To define the maximum tolerated dose of a conformal short-course accelerated radiotherapy in patients with symptomatic advanced pelvic cancer. Methods and Materials: A phase I trial in 3 dose-escalation steps was designed: 14 Gy (3.5-Gy fractions), 16 Gy (4-Gy fractions), and 18 Gy (4.5-Gy fractions). The eligibility criteria included locally advanced and/or metastatic pelvic cancer and Eastern Cooperative Oncology Group performance status of {<=}3. Treatment was delivered in 2 days with twice-daily fractionation and at least an 8-hour interval. Patients were treated in cohorts of 6-12 to define the maximum tolerated dose. The dose-limiting toxicity was defined as any acute toxicity of grade 3 or greater, using the Radiation Therapy Oncology Group scale. Pain was recorded using a visual analog scale. The effect on quality of life was evaluated according to Cancer Linear Analog Scale (CLAS). Results: Of the 27 enrolled patients, 11 were male and 16 were female, with a median age of 72 years (range 47-86). The primary tumor sites were gynecologic (48%), colorectal (33.5%), and genitourinary (18.5%). The most frequent baseline symptoms were bleeding (48%) and pain (33%). Only grade 1-2 acute toxicities were recorded. No patients experienced dose-limiting toxicity. With a median follow-up time of 6 months (range 3-28), no late toxicities were observed. The overall (complete plus partial) symptom remission was 88.9% (95% confidence interval 66.0%-97.8%). Five patients (41.7%) had complete pain relief, and six (50%) showed >30% visual analog scale reduction. The overall response rate for pain was 91.67% (95% confidence interval 52.4%-99.9%). Conclusions: Conformal short course radiotherapy in twice-daily fractions for 2 consecutive days was well tolerated up to a total dose of 18 Gy. A phase II study is ongoing to confirm the efficacy on symptom control and quality of life indexes.

  13. Short-Course Accelerated Radiotherapy in Palliative Treatment of Advanced Pelvic Malignancies: A Phase I Study

    Purpose: To define the maximum tolerated dose of a conformal short-course accelerated radiotherapy in patients with symptomatic advanced pelvic cancer. Methods and Materials: A phase I trial in 3 dose-escalation steps was designed: 14 Gy (3.5-Gy fractions), 16 Gy (4-Gy fractions), and 18 Gy (4.5-Gy fractions). The eligibility criteria included locally advanced and/or metastatic pelvic cancer and Eastern Cooperative Oncology Group performance status of ≤3. Treatment was delivered in 2 days with twice-daily fractionation and at least an 8-hour interval. Patients were treated in cohorts of 6-12 to define the maximum tolerated dose. The dose-limiting toxicity was defined as any acute toxicity of grade 3 or greater, using the Radiation Therapy Oncology Group scale. Pain was recorded using a visual analog scale. The effect on quality of life was evaluated according to Cancer Linear Analog Scale (CLAS). Results: Of the 27 enrolled patients, 11 were male and 16 were female, with a median age of 72 years (range 47-86). The primary tumor sites were gynecologic (48%), colorectal (33.5%), and genitourinary (18.5%). The most frequent baseline symptoms were bleeding (48%) and pain (33%). Only grade 1-2 acute toxicities were recorded. No patients experienced dose-limiting toxicity. With a median follow-up time of 6 months (range 3-28), no late toxicities were observed. The overall (complete plus partial) symptom remission was 88.9% (95% confidence interval 66.0%-97.8%). Five patients (41.7%) had complete pain relief, and six (50%) showed >30% visual analog scale reduction. The overall response rate for pain was 91.67% (95% confidence interval 52.4%-99.9%). Conclusions: Conformal short course radiotherapy in twice-daily fractions for 2 consecutive days was well tolerated up to a total dose of 18 Gy. A phase II study is ongoing to confirm the efficacy on symptom control and quality of life indexes.

  14. Retrospective study on therapy options of brain metastases: surgery versus stereotactic radiotherapy with the linear accelerator

    Background: in the therapy of brain metastases there has been a great progress in the last years. It was shown, that more aggressive therapies can not only extend the survival of the patients, but also improve quality of life. The major question of this study was, whether surgery or stereotactic radiotherapy with the linear accelerator show better results in behalf of the survival. Beside this major question many parameters regarding the patient or his primary cancer were examined. Methods: from the 1st of January 1995 until the 30th of June 2000 233 patients with one or more brain metastases have been treated in the Wagner Jauregg Landesnervenkrankenhaus Oberoesterreich (WJ LNKH OeO). The LINAC has been established on the 1st of July 1997. The patients have been distributed in three groups: 1. LINAC-group: 81 patients have been treated from the 1st of July 1997 until the 30th of June 2000 with the LINAC. 2. Surgery-group: 81 patients have been operated from the 1st of July 1997 until the 30th June 2000. 3 Control-group: 71 patients have been operated from the 1st of January 1995 until the 30th of June 1997, before the LINAC has been established on the 1st of July 1997. Results: There are shown the mean survival times. Therapy options (0,05): LINAC-group: 377 days. Surgery-group: 195 days. Control-group: 285 days. Primary cancer (0,05): unknown primary: 203 days. Cancer of the colon tract: 218 days. Breast cancer: 314 days. Melanoma: 162 days. Kidney: 466 days. Lung 261 days. Others: 439 days. Metastases in one/in both hemispheres (0,05): in one hemisphere 310 days, in both 184 days. All the other parameters (age, sex, Karnofsky-Index, period between diagnose of the primary and the brain metastases, primary cancer therapy, extra cerebral metastases, number of metastases, localization of metastases supra- or infratentoriell, dose/effect relationship in the LINAC-group, whole brain radiotherapy) showed interesting differences, but the results were not statistically

  15. Development and Dosimetric Characterization of a Tissue Substitute (Bolus) For Use in Linear Accelerator Electron Radiotherapy

    We propose the design of a new custom made material, to be used as a tissue substitute in external beam electron radiotherapy, based on cotton fabric and beeswax. Due to its inexpensive, easy preparation, constant thickness, flexibility, uniform density and physical properties similar to those of soft tissue, this bolus will insure personalized optimal dose build up and dose distribution in irregular treatment regions. Materials and Methods: We used commercial Campeche beeswax and 100% cotton fabric to prepare the bolus. Beeswax's physical characteristics were determined by thermal and density analysis. Its chemical properties are to be determined by electronic microscopy. We performed quality control tests and calibration of the Varian 2100C linear accelerator. The tissue equivalence of the material is established for a range of electron energies (6, 9, 12, 16, 20 MeV) using a water equivalent solid phantom (PTW; Freiburg, Germany) and a plane parallel ionization chamber (PTW) associated to a PTW electrometer. Results: Beeswax's absolute density was found to be 0.9181g/ml at 21 deg. C, with a melting point of 45 deg. C. For the bolus elaboration, the cotton fabric was soaked in liquid beeswax and thin sheets of approximately 1 mm were obtained. These presented high flexibility, physical stability (color, texture, thickness) and homogeneity. Determination of this dosimetric characteristics and equivalent thickness are still in process. Discussion and conclusions: Our preliminary results suggest that the tissue substitute is easily made, inexpensive to produce, molds well to the treatment area and its positioning is easy and reproducible over the course of the treatment. So we consider that it's a good alternative to the commercial bolus

  16. Output trends, characteristics, and measurements of three megavoltage radiotherapy linear accelerators.

    Hossain, Murshed

    2014-01-01

    The purpose of this study is to characterize and understand the long-term behavior of the output from megavoltage radiotherapy linear accelerators. Output trends of nine beams from three linear accelerators over a period of more than three years are reported and analyzed. Output, taken during daily warm-up, forms the basis of this study. The output is measured using devices having ion chambers. These are not calibrated by accredited dosimetry laboratory, but are baseline-compared against monthly output which is measured using calibrated ion chambers. We consider the output from the daily check devices as it is, and sometimes normalized it by the actual output measured during the monthly calibration of the linacs. The data show noisy quasi-periodic behavior. The output variation, if normalized by monthly measured "real' output, is bounded between ± 3%. Beams of different energies from the same linac are correlated with a correlation coefficient as high as 0.97, for one particular linac, and as low as 0.44 for another. These maximum and minimum correlations drop to 0.78 and 0.25 when daily output is normalized by the monthly measurements. These results suggest that the origin of these correlations is both the linacs and the daily output check devices. Beams from different linacs, independent of their energies, have lower correlation coefficient, with a maximum of about 0.50 and a minimum of almost zero. The maximum correlation drops to almost zero if the output is normalized by the monthly measured output. Some scatter plots of pairs of beam output from the same linac show band-like structures. These structures are blurred when the output is normalized by the monthly calibrated output. Fourier decomposition of the quasi-periodic output is consistent with a 1/f power law. The output variation appears to come from a distorted normal distribution with a mean of slightly greater than unity. The quasi-periodic behavior is manifested in the seasonally averaged output

  17. Nelson's syndrome: single centre experience using the linear accelerator (LINAC) for stereotactic radiosurgery and fractionated stereotactic radiotherapy.

    Wilson, Peter J; Williams, Janet R; Smee, Robert I

    2014-09-01

    Nelson's syndrome is a unique clinical phenomenon of growth of a pituitary adenoma following bilateral adrenalectomies for the control of Cushing's disease. Primary management is surgical, with limited effective medical therapies available. We report our own institution's series of this pathology managed with radiation: prior to 1990, 12 patients were managed with conventional radiotherapy, and between 1990 and 2007, five patients underwent stereotactic radiosurgery (SRS) and two patients fractionated stereotactic radiotherapy (FSRT), both using the linear accelerator (LINAC). Tumour control was equivocal, with two of the five SRS patients having a reduction in tumour volume, one patient remaining unchanged, and two patients having an increase in volume. In the FSRT group, one patient had a decrease in tumour volume whilst the other had an increase in volume. Treatment related morbidity was low. Nelson's syndrome is a challenging clinical scenario, with a highly variable response to radiation in our series. PMID:24825407

  18. Radiosensitivity of mouse lip mucosa: Influence of anesthesia, carbogen, and a new high O2 carrying perfluorochemical emulsion

    The effect of a new perfluorochemical emulsion based on F-66E (54%, w/v) which carries, in combination with carbogen, twice as much oxygen as Fluosol-DA 20% was tested on the radiation response of the lip mucosa of unanesthetized mice. Mice were pretreated with 0.015 ml/g of the F-66E emulsion in the presence of carbogen for 1 h prior to and during irradiation. There was a significant increase in the mortality rate following the highest radiation dose in mice given F-66E emulsion plus carbogen. The reactions of lip mucosa of mice given F-66E emulsion and/or carbogen were not significantly different from that of the control group using three end points (average score, mean peak, incidence of mucosal desquamation), but the peak mucosal reaction was delayed. The radiosensitivity of the mouse lip mucosa to Ethrane, an anesthetic gas inhaled with carbogen, was also tested. The reaction of lip mucosa in the anesthetized mice was significantly greater than that of the control group. There was also a significant increase in the mortality rate following the two highest radiation doses

  19. Prospective, longitudinal electroglottographic study of voice recovery following accelerated hypofractionated radiotherapy for T1/T2 larynx cancer

    Background and purpose: To measure voice outcomes following accelerated hypofractionated radiotherapy for larynx cancer. Materials and methods: Twenty-five patients with T1/T2 glottic cancer underwent serial electroglottographic and acoustic analysis (sustained vowel/i/ and connected speech) before radiotherapy and 1, 6 and 12 months post-treatment. Twenty-five normal subjects served as a reference control population. Results: Pre-treatment measures were significantly worse for larynx cancer patients. Median jitter (0.23% vs 0.97%, p = 0.001) and shimmer (0.62 dB vs 0.98 dB, p = 0.05) and differences in data ranges reflected greater frequency and amplitude perturbation in the larynx cancer patients. Pre-treatment Mean Phonation Time (MPT) was significantly reduced (21 s vs 14.8 s, p = 0.002) in larynx cancer patients. There was a trend towards improvement of jitter, shimmer and normalized noise energy at 12 months post-treatment. MPT improved but remained significantly worse than for normal subjects (21 s vs 16.4 s, p = 0.013). Average fundamental frequency resembled normal subjects, including improvement of the measured range (91.4-244.6 Hz in controls vs 100-201 Hz in post-treatment larynx cancer patients). Conclusions: This non-invasive technique effectively measures post-treatment vocal function in larynx cancer patients. This study demonstrated improvement of many key parameters that influence voice function over 12 months after radiotherapy

  20. Bevacizumab, Capecitabine, Amifostine, and Preoperative Hypofractionated Accelerated Radiotherapy (HypoArc) for Rectal Cancer: A Phase II Study

    Purpose: Bevacizumab has established therapeutic activity in patients with metastatic colorectal cancer, and anti-vascular endothelial growth factor therapy enhances the activity of radiotherapy in experimental models. We assessed the feasibility and efficacy of preoperative radiochemotherapy combined with bevacizumab in patients with rectal cancer. Methods and Materials: Nineteen patients with radiologic T3 and/or N+ rectal carcinoma were treated with preoperative conformal hypofractionated accelerated radiotherapy (3.4 Gy in 10 consecutive fractions) supported with amifostine (500-1,000 mg daily), capecitabine (600 mg/m2 twice daily, 5 days per week), and bevacizumab (5 mg/kg every 2 weeks for 2 cycles). Surgery followed 6 weeks after the end of radiotherapy. A cohort of 14 sequential patients treated with the same regimen without bevacizumab was available for comparison. Results: Grade 2 or 3 diarrhea was noted in 7 of 19 patients (36.8%), which was statistically worse than patients receiving the same regimen without bevacizumab (p = 0.01). A higher incidence of Grade 2 or 3 proctalgia was also noted (21.1%) (p = 0.03). Bladder and skin toxicity was negligible. All toxicities regressed completely within 2 weeks after the end of therapy. Pathologic complete and partial response was noted in 7 of 19 cases (36.8%) and 8 of 19 cases (42.1%). Within a median follow-up of 21 months, none of the patients has had late complications develop and only 1 of 18 evaluable cases (5.5%) has had locoregional relapse. Conclusions: Bevacizumab can be safely combined with hypofractionated radiotherapy and capecitabine as a preoperative radiochemotherapy regimen for patients with rectal cancer. The high pathologic complete response rates urges the testing of bevacizumab in randomized studies.

  1. A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

    Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as

  2. Effect of external shielding for neutrons during radiotherapy for prostate cancer, considering the 2300 CD linear accelerator and voxel phantom

    Thalhofer, J. L.; Roque, H. S.; Rebello, W. F.; Correa, S. A.; Silva, A. X.; Souza, E. M.; Batita, D. V. S.; Sandrini, E. S.

    2014-02-01

    Photoneutron production occurs when high energy photons, greater than 6.7 MeV, interact with linear accelerator head structures. In Brazil, the National Cancer Institute, one of the centers of reference in cancer treatment, uses radiation at 4 angles (0°, 90°, 180° and 270°) as treatment protocol for prostate cancer. With the objective of minimizing the dose deposited in the patient due to photoneutrons, this study simulated radiotherapy treatment using MCNPX, considering the most realistic environment; simulating the radiotherapy room, the Linac 2300 head, the MAX phantom and the treatment protocol with the accelerator operating at 18 MV. In an attempt to reduce the dose deposited by photoneutrons, an external shielding was added to the Linac 2300. Results show that the equivalent dose due to photoneutrons deposited in the patient diminished. The biggest reduction was seen in bone structures, such as the tibia and fibula, and mandible, at approximately 75%. Besides that, organs such as the brain, pancreas, small intestine, lungs and thyroid revealed a reduction of approximately 60%. It can be concluded that the shielding developed by our research group is efficient in neutron shielding, reducing the dose for the patient, and thus, the risk of secondary cancer, and increasing patient survival rates.

  3. Hyperfractionated Accelerated Radiotherapy (HART) with maintenance chemotherapy for metastatic (M1–3) Medulloblastoma – A safety/feasibility study

    Background and purpose: To evaluate feasibility and toxicity of Hyperfractionated Accelerated Radiotherapy (HART) 1.24 Gy b.i.d. followed by chemotherapy for M1–3 Medulloblastoma (MB). The aim of HART was to use hyperfractionation to improve therapeutic ratio combined with acceleration to minimise tumour cell repopulation during radiotherapy (RT). Materials and methods: Between February 2002 and May 2008, 34 eligible patients (22 male, 12 female) aged 3–15 years (median 7) with metastatic MB (M1–9; M2–3, M3–22) received HART with a craniospinal radiotherapy (CSRT) dose of 39.68 Gy followed by 22.32 Gy boost to the whole posterior fossa and 9.92 Gy metastatic boosts. The 8th and subsequent patients received vincristine (VCR) 1.5 mg/m2 weekly × 8 doses over 8 weeks starting during the 1st week of RT. Maintenance chemotherapy comprised 8 six-weekly cycles of VCR 1.5 mg/m2 weekly × 3, CCNU 75 mg/m2 and cisplatin 70 mg/m2. Results: Median duration of HART was 34 days (range 31–38). Grade 3–4 toxicities included mucositis (8), nausea (10), anaemia (5), thrombocytopaenia (2), leucopaenia (24). With 4.5-year median follow-up, 3-year EFS and OS were 59% and 71%, respectively. Of 10 relapses, 1 was outside the central nervous system (CNS), 1 posterior fossa alone and 8 leptomeningeal with 3 also associated with posterior fossa. Conclusion: HART with or without VCR was well tolerated and may have a place in the multi-modality management of high-risk MB

  4. Addition of a hypoxic cell selective cytotoxic agent (mitomycin C or porfiromycin) to Fluosol-DA/carbogen/radiation

    Holden, S.A.; Teicher, B.A. (Dana-Farber Cancer Institute, Boston (USA)); Herman, T.S. (Dana-Farber Cancer Institute, Boston (USA) Joint Center for Radiation Therapy, Boston (USA))

    1990-05-01

    In an effort to develop effictive combination treatments for use with radiation against solid tumors, the cytotoxic effects of the addition of mitomycin C or porfiromycin on treatment with Fluosol-DA/carbogen breathing and radiation in the FSaIIC tumor system were studied. In vitro mitomycin C and porfiromycin were both preferentially cytotoxic toward hypoxic FSaIIC cells. After in vivo exposure, however, the cytotoxicity of mitomycin C toward single cell tumor suspensions obtained from whole tumors was exponential over the dose range studied, but for porfiromycin a plateau in cell killing was observed. With Fluosol-DA/carbogen breathing and single dose radiaiton, addition of either mitomycin C or porfiromycin increased the tumor cell kill achieved at 5 Gy by approximately 1.2 and 1.0 logs, respectively. Less effect was seen with addition of the drugs at the 10 and 15 Gy radiation doses. In tumor growth delay experiments, the addition of either mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation resulted in primarily an additive increase in tumor growth delay. The survival of Hoechst 33342 dye-selected tumor cell subpopulations indicated that Fluosol-DA/carbogen breathing increased the cytotoxicity of radiation (10 Gy) more in the bright cell subpopulation (4-fold) than in the dim cell subpopulation (2-fold) resulting in an overall 4-fold sparing of the dim subpopulation. Mitomycin C and porfiromycin were both more toxic toward the dim cell subpopulations. Addition of mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation (10 Gy) resulted in a primarily additive effect of the drugs and radiation killing in both tumor cell subpopulations. Thus, with mitomycin C/Fluosol-DA/carbogen and radiation there was a 2-fold sparing of dim cells and with profiromycin in the combined treatment a 1.6-fold sparing of the dim cell population. (Abstract Truncated)

  5. Perfusion changes in the RIF-1 tumour and normal tissues after carbogen and nicotinamide, individually and combined.

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

    1995-01-01

    The strategy of combining carbogen breathing and nicotinamide to overcome chronic and acute hypoxia respectively is being evaluated clinically. The effects of both agents individually and in combination on relative perfusion of 400-700 mm3 RIF-1 tumours and normal tissues were measured by 86Rb extraction. Carbogen breathing alone for 6 min increased relative tumour perfusion by 50-70% compared with control at flow rates of 50 to 200 ml min-1, but the effect was lost at 300 ml min-1. All flow ...

  6. Evolution of Hypofractionated Accelerated Radiotherapy for Prostate Cancer – The Sunnybrook Experience

    Hima Bindu Musunuru

    2014-11-01

    Full Text Available Stereotactic Ablative Body Radiotherapy (SABR is a newer method of ultra hypo fractionated radiotherapy that uses combination of image guided radiotherapy (IGRT and intensity modulated radiotherapy(IMRT or volumetric modulated arc therapy(VMAT, to deliver high doses of radiation in a few fractions to a target, at the same time sparing the surrounding organs at risk(OAR.SABR is ideal for treating small volumes of disease and has been introduced in a number of disease sites including brain, lung, liver, spine and prostate. Given the radiobiological advantages of treating prostate cancer with high doses per fraction, SABR is becoming a standard of care for low and intermediate risk prostate cancer patients based upon the results from Sunny Brook and also the US-based prostate SABR consortium. This review examines the development of moderate and ultra hypo fractionation schedules at the Odette Cancer centre, Sunnybrook Health Sciences. Moderate hypo fractionation protocol was first developed in 2001 for intermediate risk prostate cancer and from there on different treatment schedules including SABR evolved for all risk groups.

  7. Prospective randomized trial to compare accelerated (six fractions a week radiotherapy against concurrent chemoradiotherapy (using conventional fractionation in locally advanced head and neck cancers

    Manoj Gupta

    2015-01-01

    Full Text Available Background: Concurrent chemoradiation (CCRT is currently considered to be the standard of care in locally advanced head and neck cancer. The optimum radiotherapy schedule for best local control and acceptable toxicity is not yet clear. We aimed at shortening of treatment time by using accelerated radiation, thereby comparing the disease response, loco-regional tumor control and tolerability of accelerated radiation (six fractions per week against CCRT in locally advanced head and neck cancer. Materials and Methods: We conducted the prospective randomized study for a period of 2 years from June 2011 to May 2013 in 133 untreated patients of histologically confirmed squamous cell carcinoma of head and neck. Study group (66 patients received accelerated radiotherapy with 6 fractions per week (66Gy/33#/5½ weeks. Control group (67 patients received CCRT with 5 fractions per week radiation (66 Gy/33#/6½ weeks along with intravenous cisplatin 30 mg/m 2 weekly. Tumor control, survival, acute and late toxicities were assessed. Results: Median overall treatment time was 38 days and 45 days in the accelerated radiotherapy and concurrent chemoradiation arm, respectively. At a median follow up of 12 months, 41 patients (62.1% in the accelerated radiotherapy arm and 47 patients (70.1% in the CCRT arm were disease free (P = 0.402. Local disease control was comparable in both the arms. Acute toxicities were significantly higher in the CCRT arm as compared with accelerated radiotherapy arm. There was no difference in late toxicities between the two arms. Conclusion: We can achieve, same or near to the same local control, with lower toxicities with accelerated six fractions per week radiation compared with CCRT especially for Indian population.

  8. Effectiveness of surgery and individualized high-dose hyperfractionated accelerated radiotherapy on survival in clinical stage I non-small cell lung cancer. A propensity score matched analysis

    Background and purpose: Surgery is considered the treatment of choice for early-stage non-small cell lung cancer (NSCLC). Patients with poor pulmonary function or other comorbidities are treated with radiotherapy. The objective of this investigation is to compare the 3-year survival of two early-stage NSCLC populations treated in two different hospitals, either by surgical resection (lobectomy) or by individualized high-dose accelerated radiotherapy, after matching patients by propensity scoring analysis. Methods: A retrospective comparative study has been performed on two series of consecutive patients with cytohistological diagnosis of NSCLC, clinically staged IA by means of PET-scan (radiotherapy group) and pathologically staged IA (surgery group). Results: A total of 157 cases were initially selected for the analysis (110 operated and 47 treated by radiotherapy). Patients in the radiotherapy group were older, with higher comorbidity and lower FEV1% with 3-years probability of survival for operated patients higher than that found for patients treated by radiotherapy. After matching by propensity scoring (using age and FEV1%), differences disappear and 3-years probability of survival had no statistical differences. Conclusions: Although this is a non-randomized retrospective analysis, we have not found 3-years survival differences after matching cases between surgery and radiotherapy. Nevertheless, data presented here support the continuous investigation for non-surgical alternatives in this disease.

  9. The Nano-X Linear Accelerator: A Compact and Economical Cancer Radiotherapy System Incorporating Patient Rotation.

    Eslick, Enid M; Keall, Paul J

    2015-10-01

    Rapid technological improvements in radiotherapy delivery results in improved outcomes to patients, yet current commercial systems with these technologies on board are costly. The aim of this study was to develop a state-of-the-art cancer radiotherapy system that is economical and space efficient fitting with current world demands. The Nano-X system is a compact design that is light weight combining a patient rotation system with a vertical 6 MV fixed beam. In this paper, we present the Nano-X system design configuration, an estimate of the system dimensions and its potential impact on shielding cost reductions. We provide an assessment of implementing such a radiotherapy system clinically, its advantages and disadvantages compared to a compact conventional gantry rotating linac. The Nano-X system has several differentiating features from current radiotherapy systems, it is [1] compact and therefore can fit into small vaults, [2] light weight, and [3] engineering efficient, i.e., it rotates a relatively light component and the main treatment delivery components are not under rotation (e.g., DMLCs). All these features can have an impact on reducing the costs of the system. In terms of shielding requirements, leakage radiation was found to be the dominant contributor to the Nano-X vault and as such no primary shielding was necessary. For a low leakage design, the Nano-X vault footprint and concrete volume required is 17 m2 and 35 m3 respectively, compared to 54 m2 and 102 m3 for a conventional compact linac vault, resulting in decreased costs in shielding. Key issues to be investigated in future work are the possible patient comfort concerns associated with the patient rotation system, as well as the magnitude of deformation and subsequent adaptation requirements. PMID:24949649

  10. A randomized study of accelerated fractionation radiotherapy with and without mitomycin C in the treatment of locally advanced head and neck cancer

    Ezzat, M.; Shouman, T.; Zaza, K.;

    2005-01-01

    Objectives: This single-institution study evaluates the feasibility of accelerated fractionation radiotherapy (AF) with and without mitomycin C (MMC) in the treatment of locally advanced head and neck cancer. Patients and Methods: Between May 1998 and October 2001, sixty patients with locally...... advanced stage III and IV of head and neck cancer were randomized into three treatment arms: (1) conventional fractionation radiotherapy (CF) (5 fractions per week); (2) accelerated fractionation radiotherapy (AF) (6 fractions per week); and (3) AF plus Mitomycin C (MMC). Results: The 2-year overall...... survival (OS) of the whole group was 21%. The OS according to treatment arm was 23%, 20%, and 28% in CF, AF, and AF+MMC arms respectively (p<0.19). The 2-year loco-regional control (LC) rate was 22% for the whole group of patients. The LC was 10%, 25%, and 30% for the CF, AF, and AF+MMC respectively (p=0...

  11. Prevalence and peak incidence of acute and late normal tissue morbidity in the DAHANCA 6&7 randomised trial with accelerated radiotherapy for head and neck cancer

    Mortensen, Hanna R.; Overgaard, Jens; Specht, Lena;

    2012-01-01

    BACKGROUND AND PURPOSE: The aim of this report was to describe the incidence and prevalence of acute and late morbidity in the DAHANCA 6&7 multicentre randomised trial with accelerated radiotherapy for squamous cell carcinoma of the head and neck. MATERIALS AND METHODS: The DAHANCA 6&7 study...

  12. Dosimetric comparison of the linear accelerators at the University Clinic of Radiotherapy and Oncology in Skopje, Macedonia

    In radiotherapy practice, for various practical reasons it is important to know whether two or more linear accelerators (linacs) are dosimetric matched and whether the patient’s treatment can be shifted from one linac to another without reducing the treatment quality. This work presents the data from the dosimetric comparison of the two Varian Clinacs 23EX and one Varian Clinac iX at the University Clinic of Radiotherapy and Oncology in Skopje. Both Percentage Depth Dose (PDD) and Beam Profile (BP) curves were compared for the photon energies (6MV, 15MV) in use at the clinic. The comparison was performed using the IBA OmniPro Accept 7.4™ software. The results from the comparison of the PDD curves showed that in the clinically significant region the dose differences were smaller than 1%. The results from the comparison of the in line and cross line BP curves showed that in the flattened area the dose differences were smaller than 2.5%, while in the penumbra region they were usually between 2% and 8%, but sometimes up to 21%. This suggests that for treatments where the influence of the penumbra region is small, the three linacs may be considered to be dosimetric matched. For treatments where the influence of the penumbra region is greater, the patient can be switched to another machine only after recalculation of the treatment plan. (Author)

  13. Application Monte Carlo code calculates dose distribution of the emitted photon beams from linear accelerator in case radiotherapy lung cancer

    The dose distribution calculation is one of major steps in cancer radiotherapy. This paper applies Monte Carlo code, MCNP5, in simulation 15 MV photon beams from linear accelerator of General Hospital of Kien Giang in a case treatment of lung cancer. The settings for beam direction, field size and isocenter position used in MCNP5 must be the same as in treatment plan at hospital to ensure the results from MCNP5 are accurate. We also built a program CODIM by using MATLAB® programming software. This program is used to construct digital voxel phantoms from lung CT images obtained from cancer treatment cases at Kien Giang hospital and then simulate the delivered dose of linac in these phantoms by using MCNP5 simulation code. The results show that there is a difference of 5% in comparison to Prowess Panther program - a semi-empirical simulation program which is being used for treatment planning in Kien Giang hospital. (author)

  14. Supratentorial primitive neuroectodermal tumors (S-PNET) in children: A prospective experience with adjuvant intensive chemotherapy and hyperfractionated accelerated radiotherapy

    Purpose: Supratentorial primitive neuroectodermal tumors (S-PNET) are rare and have a grim prognosis, frequently taking an aggressive course with local relapse and metastatic spread. We report the results of a mono-institutional therapeutic trial. Methods and Materials: We enrolled 15 consecutive patients to preradiation chemotherapy (CT) consisting of high-dose methotrexate, high-dose etoposide, high-dose cyclophosphamide, and high-dose carboplatin, craniospinal irradiation (CSI) with hyperfractionated accelerated radiotherapy (HART) plus focal boost, maintenance with vincristine/lomustine or consolidation with high-dose thiotepa followed by autologous stem-cell rescue. Results: Median age was 9 years; 7 were male, 8 female. Site of disease was pineal in 3, elsewhere in 12. Six patients were had no evidence of disease after surgery (NED). Of those with evidence of disease after surgery (ED), 2 had central nervous system spread. Of the 9 ED patients, 2 had complete response (CR) and 2 partial response (PR) after CT, 4 stable disease, and 1 progressive disease. Of the 7 ED patients before radiotherapy, 1 had CR, 4 PR, and 2 minor response, thus obtaining a 44% CR + PR after CT and 71% after HART. Because of rapid progression in 2 of the first 5 patients, high-dose thiotepa was systematically adopted after HART in the subsequent 10 patients. Six of 15 patients relapsed (4 locally, 1 locally with dissemination, 1 with dissemination) a mean of 6 months after starting CT, 2 developed second tumors; 5 of 6 relapsers died at a median of 13 months. Three-year progression-free survival, event-free survival, and overall survival were 54%, 34%, and 61%, respectively. Conclusion: Hyperfractionated accelerated RT was the main tool in obtaining responses in S-PNET; introducing the myeloablative phase improved the prognosis (3/10 vs. 3/5 relapses), though the outcome remained unsatisfactory despite the adoption of this intensive treatment

  15. Locoregionally advanced carcinoma of the oropharynx: conventional radiotherapy vs. accelerated hyperfractionated radiotherapy vs. concomitant radiotherapy and chemotherapy - a multicenter randomized trial

    Purpose: To compare conventional fractionation radiation therapy (RT), Arm A, vs. split-course accelerated hyperfractionated RT (S-AHF), Arm B, vs. conventional fractionation RT plus concomitant chemotherapy (CT), Arm C, in terms of survival and toxicity for advanced, unresectable epidermoid tumors of oropharynx. Methods and Materials: Between January 1993 and June 1998, 192 previously untreated patients affected with Stage III and IV oropharyngeal carcinoma (excluding T1N1 and T2N1) were accrued in a multicenter, randomized Phase III trial (ORO 93-01). For Arms A and C, 66-70 Gy in 33-35 fractions, 5 days a week, were administered in 6.5-7 weeks to tumor and positive nodes. In Arm B, the dose delivered to tumor and involved nodes was 64-67.2 Gy, giving 2 fractions of 1.6 Gy every day with an interfraction interval of at least 4 h and preferably 6 h, 5 days a week. At 38.4 Gy, a 2-week split was planned; after the split, RT was resumed with the same modality. In Arm C, CT regimen consisted of carboplatin and 5-fluorouracil (CBDCA 75 mg/m2, Days 1-4; 5-FU 1,000 mg/m2 i.v. over 96 h, Days 1-4, recycling every 28 days (at 1st, 5th, and 9th week). Results: No statistically significant difference was detected in overall survival (p=0.129): 40% Arm A vs. 37% Arm B vs. 51% Arm C were alive at 24 months. Similarly, there was no statistically significant difference in terms of event-free survival (p=0.196): 20% for Arm A, 19% for Arm B, and 37% for Arm C were event free at 24 months. On the contrary, the 2-year disease-free survival was significantly different among the three arms (p = 0.022), with a superiority for Arm C. At 24 months, the proportion of patients without relapse was 42% for Arm C vs. 23% for Arm A and 20% for Arm B. Patients in Arm A less frequently developed G3+ acute mucositis than their counterparts in Arm B or C (14.7% vs. 40.3% vs. 44%). Regarding the CT-related acute toxicity, apart from 1 case of fatal nephrotoxicity, only hematologic G3+ (Grade 3 or

  16. Stereotactic radiotherapy of intracranial lesions with micro multi leaf collimator mounted on linear accelerator

    Stereotactic radiotherapy (SRT) is an advancement on three-dimensional conformal radiotherapy (3DCRT) which aims not only to conform the therapeutic dose volume to the shape of the tumor, but also ensures low dose to the other normal tissues. As the therapeutic dose volume tightly covers the tumor, small variation between intended plan and executed plan parameters may lead to significant under-dose of tumor or over-dose of normal tissue, which may result in the failure of the treatment. Therefore, SRT should be carried out through a well-laid out systematic procedure in order to achieve its goal. This paper highlights the systematic procedure and comprehensive quality assurance (QA) involved at various steps of intracranial SRT followed in our hospital and our preliminary experience with brain lab stereotactic system. Of the 18 patients treated so far with SRT, we have analyzed the SRT treatment plans for the first 11 brain tumor patients to highlight the volume of tumor covered by the therapeutic dose and integral dose to other normal tissues. The average gross target volume (GTV) and planning target volume (PTV) treated are 14.07 cc, and 43.72 cc, respectively. Out of the 11 patients treated, 100% volume of PTV is covered by 95% isodose volume in 4 patients, 99% of PTV in another 4 patients and 98% of PTV in the remaining 3 patients. But in all the cases, a minimum volume of 96% of the GTV is adequately covered by 100% dose. The conformity index of PTV varies from 1.27 to 1.56, with a mean value of 1.42. As the target volume decreases from 76 cc to 20 cc, the mean dose within the target volume increases from 1.7 Gy to 1.76 Gy. The average volume of normal brain treated with 80%, 50% and 33% dose are 6.53 cc, 73 cc and 298 cc, respectively. Stereotactic radiotherapy with static beams and micro-multileaf collimator (mMLC) shaped fields gives the flexibility to tailor the irregular shaped target volume, thereby ensuring better dose conformity and homogeneous dose

  17. GPU-accelerated automatic identification of robust beam setups for proton and carbon-ion radiotherapy

    We demonstrate acceleration on graphic processing units (GPU) of automatic identification of robust particle therapy beam setups, minimizing negative dosimetric effects of Bragg peak displacement caused by treatment-time patient positioning errors. Our particle therapy research toolkit, RobuR, was extended with OpenCL support and used to implement calculation on GPU of the Port Homogeneity Index, a metric scoring irradiation port robustness through analysis of tissue density patterns prior to dose optimization and computation. Results were benchmarked against an independent native CPU implementation. Numerical results were in agreement between the GPU implementation and native CPU implementation. For 10 skull base cases, the GPU-accelerated implementation was employed to select beam setups for proton and carbon ion treatment plans, which proved to be dosimetrically robust, when recomputed in presence of various simulated positioning errors. From the point of view of performance, average running time on the GPU decreased by at least one order of magnitude compared to the CPU, rendering the GPU-accelerated analysis a feasible step in a clinical treatment planning interactive session. In conclusion, selection of robust particle therapy beam setups can be effectively accelerated on a GPU and become an unintrusive part of the particle therapy treatment planning workflow. Additionally, the speed gain opens new usage scenarios, like interactive analysis manipulation (e.g. constraining of some setup) and re-execution. Finally, through OpenCL portable parallelism, the new implementation is suitable also for CPU-only use, taking advantage of multiple cores, and can potentially exploit types of accelerators other than GPUs.

  18. Addition of a hypoxic cell selective cytotoxic agent (mitomycin C or porfiromycin) to Fluosol-DA/carbogen/radiation.

    Holden, S A; Herman, T S; Teicher, B A

    1990-05-01

    In an effort to develop effective combination treatments for use with radiation against solid tumors, the cytotoxic effects of the addition of mitomycin C or porfiromycin on treatment with Fluosol-DA/carbogen (95% O2/5% CO2) breathing and radiation in the FSaIIC tumor system were studied. In vitro mitomycin C and porfiromycin were both preferentially cytotoxic toward hypoxic FSaIIC cells. After in vivo exposure, however, the cytotoxicity of mitomycin C toward single cell tumor suspensions obtained from whole tumors was exponential over the dose range studied, but for porfiromycin a plateau in cell killing was observed. With Fluosol-DA/carbogen breathing and single dose radiation, addition of either mitomycin C or porfiromycin increased the tumor cell kill achieved at 5 Gy by approximately 1.2 and 1.0 logs, respectively. Less effect was seen with addition of the drugs at the 10 and 15 Gy radiation doses. In tumor growth delay experiments, the addition of either mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation resulted in primarily an additive increase in tumor growth delay. The survival of Hoechst 33342 dye-selected tumor cell subpopulations indicated that Fluosol-DA/carbogen breathing increased the cytotoxicity of radiation (10 Gy) more in the bright cell subpopulation (4-fold) than in the dim cell subpopulation (2-fold) resulting in an overall 4-fold sparing of the dim subpopulation. Mitomycin C and porfiromycin were both more toxic toward the dim cell subpopulations. Addition of mitomycin C or porfiromycin to Fluosol-DA/carbogen breathing and radiation (10 Gy) resulted in a primarily additive effect of the drugs and radiation killing in both tumor cell subpopulations. Thus, with mitomycin C/Fluosol-DA/carbogen and radiation there was a 2-fold sparing of dim cells and with porfiromycin in the combined treatment a 1.6-fold sparing of the dim cell population. Our results indicate that treatment strategies directed against both oxic and

  19. Determination of radiation levels by neutrons in an accelerator for radiotherapy

    It was determined the radiation levels by neutrons due to photonuclear reactions (γ, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  20. Accelerated partial breast irradiation using 3D conformal radiotherapy: initial clinical experience

    Gatti, M.; Madeddu, A.; Malinverni, G.; Delmastro, E.; Bona, C.; Gabriele, P. [IRCC-Radiotherapy, Candiolo, TO (Italy); Baiotto, B.; Stasi, M. [IRCC-Medical Physics, Candiolo, TO (Italy); Ponzone, R.; Siatis, D. [IRCC-Surgery, Candiolo, TO (Italy)

    2006-11-15

    Accelerated partial breast irradiation using 3D-C.R.T. is technically sophisticate but feasible and acute toxicity to date has been minimal. A C.T.V.-to-P.T.V. margin of 10 mm seems to provide coverage for analyzed patients. However, more patients and additional studies will be needed to validate the accuracy of this margin, and longer follow-up will be needed to assess acute and chronic toxicity, tumor control, and cosmetic results. (author)

  1. Fractionated stereotactic radiotherapy with linear accelerator for uveal melanoma - preliminary Vienna results

    Between June 1997 and February 1998, 21 patients suffering from uveal melanomas have been treated with a sterotactic 6 MeV LINAC (Saturne 43 trademark, General Electric, France) in conjunction with a stereotactic frame system (BrainLAB trademark, Germany). Immobilization of the eye was ensured with an optical fixation system which was proven reliable. During radiotherapy, movements of the irradiated eye were controlled on a monitor and documented by video recording. All patients co-operated very well with the optical fixation system. In 1164 measurements, the median value of horizontal deviation of the diseased eye during treatment was 0.3 mm (range: 0 to 1.3 mm). Median vertical deviation was 0.2 mm (range: 0 to 1.2 mm). For all patients, mean tumor prominence before treatment was 6.0±2.2 mm. In 20 patients, the total dose of 70 Gy (at 80%) was delivered in 5 fractions within 10 days. In one patient with a ciliary body tumor, the total dose of 70 Gy was divided into 7 fractions for better sparing of the anterior eye segment. Results: After a follow-up of at least 6 months, local tumor control was seen in all eyes. Mean tumor thickness reduction after 3, 6 and 9 months was 7%, 13% and 31%, respectively. Up to now, only mild subacute side-effects located in the anterior eye segment have been noticed. (orig.)

  2. Accelerated split-course radiotherapy and concomitant cis-platinum and 5-fluorouracil chemotherapy with folinic acid enhancement in unresectable head and neck cancer

    In patients suffering from locally advanced, unresectable squamous cell carcinoma (SCC) of the base of the tongue, the floor of the mouth, the mobile part of the tongue, the tonsils, the hypopharynx and the larynx radiotherapy yields poor results, due to local failure rather than to distant metastases. Since toxicity of radiotherapy and cytotoxic chemotherapy do not overlap entirely efforts were made to achieve better results combining these two treatment modalities. Clinical trials on simultaneous radiotherapy/chemotherapy focussed on two cytotoxic agents: Cis-dichlorodiammineplatinum(II) (cis-DDP) and 5-flourouracil (5-FU). Another approach to overcome the radioresistance of large SCC adopts accelerated fractionation. The potential tumor doubling time of sqamous cell carcinomas is about four days, and thus repopulation of surviving clonogenic tumor cells during fractionated radiotherapy may be the cause of poor treatment results. In this pilot study a twice daily fractionated split-course radiotherapy is combined with simultaneous administration of cis-DDP and 5-FU with folinic acid (FA) enhancement. (orig.)

  3. Accelerated split-course radiotherapy and concomitant cis-platinum and 5-fluorouracil chemotherapy with folinic acid enhancement in unresectable head and neck cancer

    Wendt, T.G.; Wustrow, T.P.U.; Hartenstein, R.C.; Trott, K.R.

    1988-01-01

    In patients suffering from locally advanced, unresectable squamous cell carcinoma (SCC) of the base of the tongue, the floor of the mouth, the mobile part of the tongue, the tonsils, the hypopharynx and the larynx radiotherapy yields poor results, due to local failure rather than to distant metastases. Since toxicity of radiotherapy and cytotoxic chemotherapy do not overlap entirely efforts were made to achieve better results combining these two treatment modalities. Clinical trials on simultaneous radiotherapy/chemotherapy focussed on two cytotoxic agents: Cis-dichlorodiammineplatinum(II) (cis-DDP) and 5-flourouracil (5-FU). Another approach to overcome the radioresistance of large SCC adopts accelerated fractionation. The potential tumor doubling time of sqamous cell carcinomas is about four days, and thus repopulation of surviving clonogenic tumor cells during fractionated radiotherapy may be the cause of poor treatment results. In this pilot study a twice daily fractionated split-course radiotherapy is combined with simultaneous administration of cis-DDP and 5-FU with folinic acid (FA) enhancement.

  4. Can concomitant-boost accelerated radiotherapy be adopted as routine treatment for head-and-neck cancers? A 10-year single-institution experience

    Allal, Abdelkarim Said; Taussky, Daniel; Mach, Nicolas; Becker, Minerva; Bieri, Sabine; Dulguerov, Pavel

    2004-01-01

    Accelerated schedules are effective in overcoming repopulation during radiotherapy (RT) for head-and-neck cancers, but their feasibility is compromised by increased toxicity. The therapeutic ratio may be particularly favorable for 5-week regimens. This study reports the 10-year experience of a single institution in the routine use of concomitant boost RT as standard radical treatment in all but the most favorable stage patients.

  5. Impact of Schedule Duration on Head and Neck Radiotherapy: Accelerated Tumor Repopulation Versus Compensatory Mucosal Proliferation

    Purpose: To determine how modelled maximum tumor control rates, achievable without exceeding mucositis tolerance (tcpmax-early) vary with schedule duration for head and neck squamous cell carcinoma (HNSCC). Methods and materials: Using maximum-likelihood techniques, we have fitted a range of tcp models to two HNSCC datasets (Withers’ and British Institute of Radiology [BIR]), characterizing the dependence of tcp on duration and equivalent dose in 2 Gy fractions (EQD2). Models likely to best describe future data have been selected using the Akaike information criterion (AIC) and its quasi-AIC extension to overdispersed data. Setting EQD2s in the selected tcp models to levels just tolerable for mucositis, we have plotted tcpmax-early against schedule duration. Results: While BIR dataset tcp fits describe dose levels isoeffective for tumor control as rising significantly with schedule protraction, indicative of accelerated tumor repopulation, repopulation terms in fits to Withers’ dataset do not reach significance after accounting for overdispersion of the data. The tcpmax-early curves calculated from tcp fits to the overall Withers’ and BIR datasets rise by 8% and 0-4%, respectively, between 20 and 50 days duration; likewise, tcpmax-early curves calculated for stage-specific cohorts also generally rise slowly with increasing duration. However none of the increases in tcpmax-early calculated from the overall or stage-specific fits reach significance. Conclusions: Local control rates modeled for treatments which lie just within mucosal tolerance rise slowly but insignificantly with increasing schedule length. This finding suggests that whereas useful gains may be made by accelerating unnecessarily slow schedules until they approach early reaction tolerance, little is achieved by shortening schedules further while reducing doses to remain within mucosal tolerance, an approach that may slightly worsen outcomes.

  6. The role of accelerated hyperfractionated radiotherapy in the treatment of inoperable non-small cell lung cancer: a controlled clinical trial

    Radiotherapy remains the basic form of treatment in cases of non-small cell lung cancer (NSCLC) but there still exist controversies concerning optimal radiotherapy regimen and in particular, the total dose and fractionation schedules. To prove whether the question: if using an unconventional dose fractionation regimen (accelerated hyperfractionation) could improve the results of palliative teleradiotherapy patients with NSCLC. Between 1997 and 2000 in the Cancer Centre in Cracow (COOK) a controlled clinical trial was conducted in a group of 150 patients with locally advanced (III Deg) inoperable and unsuitable for radical radiotherapy NSCLC, with no major symptoms of the disease. In 76 patients conventionally fractionated radiotherapy was performed - 50 Gy in 25 fractions during 5 weeks (CF). 74 patients were irradiated twice a day (AHF); the dose per fraction was 1.25 Gy and the minimum interval between fractions - 6 hours. The total dose was 50 Gy in 40 fractions during 26 days. The probability of 12 months survival was 47.4% in the CF arm and 45.9% in the AHF arm; the probability of 24 months survival was 16.2% and 15.8%, respectively. In all 76 patients in CF arm the treatment was carried out in prescribed time without breaks. Out of 74 patients in the A HF group 8 (10,8%) did not complete the treatment and 2 of then died in 3rd and 4th week of treatment. The use of accelerated hyperfractionation does not improve the results of palliative teleradiotherapy in patients with locally advanced NSCLC without severe symptoms related to intrathoracic tumor. The treatment of choice in this group of patients os conventionally fractionated radiotherapy with a total dose of 50 Gy in 25 fractions in 5 week of treatment. (author)

  7. Accelerated versus conventional fractionated postoperative radiotherapy for advanced head and neck cancer: Results of a multicenter Phase III study

    Purpose: To determine whether, in the postoperative setting, accelerated fractionation (AF) radiotherapy (RT) yields a superior locoregional control rate compared with conventional fractionation (CF) RT in locally advanced squamous cell carcinomas of the oral cavity, oropharynx, larynx, or hypopharynx. Methods and materials: Patients from four institutions with one or more high-risk features (pT4, positive resection margins, pN >1, perineural/lymphovascular invasion, extracapsular extension, subglottic extension) after surgery were randomly assigned to either RT with one daily session of 2 Gy up to 60 Gy in 6 weeks or AF. Accelerated fractionation consisted of a 'biphasic concomitant boost' schedule, with the boost delivered during the first and last weeks of treatment, to deliver 64 Gy in 5 weeks. Informed consent was obtained. The primary endpoint of the study was locoregional control. Analysis was on an intention-to-treat basis. Results: From March 1994 to August 2000, 226 patients were randomized. At a median follow-up of 30.6 months (range, 0-110 months), 2-year locoregional control estimates were 80% ± 4% for CF and 78% ± 5% for AF (p = 0.52), and 2-year overall survival estimates were 67% ± 5% for CF and 64% ± 5% for AF (p = 0.84). The lack of difference in outcome between the two treatment arms was confirmed by multivariate analysis. However, interaction analysis with median values as cut-offs showed a trend for improved locoregional control for those patients who had a delay in starting RT and who were treated with AF compared with those with a similar delay but who were treated with CF (hazard ratio = 0.5, 95% confidence interval 0.2-1.1). Fifty percent of patients treated with AF developed confluent mucositis, compared with only 27% of those treated with CF (p = 0.006). However, mucositis duration was not different between arms. Although preliminary, actuarial Grade 3+ late toxicity estimates at 2 years were 18% ± 4% and 27% ± 6% for CF and AF

  8. Intensity-modulated radiotherapy with simultaneous modulated accelerated boost technique and chemotherapy in patients with nasopharyngeal carcinoma

    To present our experience of intensity-modulated radiotherapy (IMRT) with simultaneous modulated accelerated radiotherapy (SMART) boost technique in patients with nasopharyngeal carcinoma (NPC). Sixty eight patients of NPC were treated between April 2006 and December 2011 including 45 males and 23 females with mean age of 46 (range 15–78). Stage distribution was; stage I 3, stage II 7, stage III 26 and stage IV 32. Among 45 (66.2%) evaluated patients for presence of Epstein-Barr virus (EBV), 40 (88.8%) were positive for EBV. Median radiation doses delivered to gross tumor volume (GTV) and positive neck nodes were 66–70 Gy, 63 Gy to clinical target volume (CTV) and 50.4 Gy to clinically negative neck. In addition 56 (82.4%) patients with bulky tumors (T4/N2+) received neoadjuvant chemotherapy 2–3 cycles (Cisplatin/Docetaxel or Cisplatin/Epirubicin or Cisplatin/5 Flourouracil). Concurrent chemotherapy with radiation was weekly Cisplatin 40 mg/m2 (40 patients) or Cisplatin 100 mg/m2 (28 patients). With a median follow up of 20 months (range 3–43), one patient developed local recurrence, two experienced regional recurrences and distant failure was seen in 3 patients. Estimated 3 year disease free survival (DFS) was 94%. Three year DFS for patients with EBV was 100% as compared to 60% without EBV (p = 0.0009). Three year DFS for patients with undifferentiated histology was 98% as compared to 82% with other histologies (p = 0.02). Acute grade 3 toxicity was seen as 21 (30.9%) having G-III mucositis and 6 (8.8%) with G-III skin reactions. Late toxicity was minimal and loss of taste was seen in 3 patients (7.5%) at time of analysis. IMRT with SMART in combination with chemotherapy is feasible and effective in terms of both the clinical response and safety profile. EBV, histopathology and nodal involvement were found important prognostic factors for locoregional recurrence

  9. Radiobiological Characterization of Two Photon-Beam Energies 6 and 15 MV used in Radiotherapy From Linear Accelerator

    The main objective of this study is to perform radiobiological characterization of two different photon beam energies, 6 MV and 15 MV, from linear accelerator used in radiotherapy, with special regard to late effects of radiation. Two end-points, namely cell survival and micronucleus induction were used for the characterization. Chinese hamster V 79 lung fibroblast cell line to prepare cell culture and to perform the innervate experiments. chromosomes number was counted and found to be 22 chromosomes per cell, this result is in complete agreement with expected 11 pairs of chromosomes representing the genome of this species. Cells were kept in confluent growth for two days and then exposed to two photon beam energies, 6 and 15 MV respectively. Different dose rates were used for the two beam energies, 0.25, 0.5, 1.0, 2.0, 4.0, 7.0 Gy. Cells were counted immediately after irradiation and re seeded, the seeded number of cells was calculated to the dose rate used. Another set of unirradiated cells treated the same as the experimental set was used as a control group. The plating efficiency (PE) was calculated for the control group, then cells were incubated at 37oC for 6 days to construct the survival curve, five samples were counted per dose and the mean was calculated. The two survival curves are similar for photon beam energies (6 and 15 MV) and the surviving fraction was decreased with dose rate. The two curves showed similar values of α and β parameters, this result is expected for the same radiation type (X-ray). For the micronuclei assay three samples for each dose were seeded and incubated at 37oC for 24 hours then Cytochalasin-B was added to block cells in cytokinesis phase of the mitosis. The micronuclei number was counted and plotted with dose. A significant positive correlation was found between dose and micronuclei frequency (P=0.00), moreover, the micronuclei frequency is relatively higher with 15 MV compared with 6 MV energy. This indicates the presence

  10. TLD Intercomparison in accelerators for radiotherapy in three Latin american countries; Intercomparacion TLD en aceleradores para radioterapia en tres paises latinoamericanos

    Gaona, E.; Azorin N, J.; Perez, M.A.; Picon, C.; Castellanos, E.; Plazas, M.C.; Murcia, G.; Archundia, L. [Depto. El Hombre y su Ambiente. Universidad Autonoma Metropolitana, Calz. Del Hueso 1100, 04960 Mexico D.F. (Mexico)

    1998-12-31

    In Radiotherapy one of the objectives is to establish and to give follow up to quality assurance programs which make sure that the doses administered to the patients with cancer are a high probability of a success in external radiation. Likewise, one of the present preoccupations of the United Nations Agencies as well as the International Atomic Energy Agency and the Pan-American Health Organization is the optimal employment of the radiations in the treatment of cancer patients since the administered dose in Radiotherapy suffers considerable variations by the lack of quality assurance programs. The use of Electron linear accelerators requires a program of quality assurance that includes expert personnel, equipment and adequate facilities. The more used methodology for the dosimetry calibration and characterization of X-ray beams and high energy electrons for radiotherapy use is using a ionization chamber dosemeter calibrated in a regional secondary standardization laboratory. However, to establish and give follow up to the quality assurance programs it is necessary the dosimetric intercomparison through TLD. In this study it was designed plastic phantoms with TLD crystals and it was made its characterization to realize an absorbed dose analysis in the crystals exposed at X-ray beams 6 MV and high energy electrons 10 and 12 MeV to standardize the dosimetric procedures and proceeding to realize an International Pilot intercomparison of absorbed doses in TLD crystals in three Latin American countries: Mexico, Peru and Colombia with the participation of accelerators of five different institutions. The found results show that the majority of the measured doses with TLD in the different accelerators were in the 0.95-1.05 range though it had two cases outside of this range. The use of the phantoms with TLD crystals shows that they are of excellent aid to make analysis of the doses administered to the patients and an intercomparison of results to standardize procedures at

  11. Carbogen Breathing Differentially Enhances Blood Plasma Volume and 5-Fluorouracil Uptake in Two Murine Colon Tumor Models with a Distinct Vascular Structure

    Hanneke W.M. van Laarhoven

    2006-06-01

    Full Text Available For the systemic treatment of colorectal cancer, 5-fluorouracil (FU-based chemotherapy is the standard. However, only a subset of patients responds to chemotherapy. Breathing of carbogen (95% O2 and 5% CO2 may increase the uptake of FU through changes in tumor physiology. This study aims to monitor in animal models in vivo the effects of carbogen breathing on tumor blood plasma volume, pH, and energy status, and on FU uptake and metabolism in two colon tumor models C38 and C26a, which differ in their vascular structure and hypoxic status. Phosphorus-31 magnetic resonance spectroscopy (MRS was used to assess tumor pH and energy status, and fluorine-19 MRS was used to follow FU uptake and metabolism. Advanced magnetic resonance imaging methods using ultrasmall particles of iron oxide were performed to assess blood plasma volume. The results showed that carbogen breathing significantly decreased extracellular pH and increased tumor blood plasma volume and FU uptake in tumors. These effects were most significant in the C38 tumor line, which has the largest relative vascular area. In the C26a tumor line, carbogen breathing increased tumor growth delay by FU. In this study, carbogen breathing also enhanced systemic toxicity by FU.

  12. Impact on cellular immunocompetence by late course accelerated hyperfractionation radiotherapy assisted with cisplatin in the treatment of esophageal carcinoma

    Objective: To investigate the therapeutic results of late course accelerated hyperfractionation radiotherapy (LCAHR) combined with concomitant cisplatin administration as a sensitizer, and to assess the effects on cell-mediated immunocompetence in the treatment of esophageal carcinoma. Methods: From Jan. to Nov. 199, 104 patients with squamous cell carcinoma (SCC) of the esophagus were randomized to receive LCAHR alone (Group A, 53 patients) or LCAHR plus cisplatin (Group B, 51 patients). For both groups, the same radiation technic was given with the conventional fractionation in the first 3 weeks and 1.5 Gy twice daily, a minimum inter fraction interval of 6 hours, 5 days per week in the final 2 weeks. The total dose was 60 Gy/35 fs/5 wk. For the B group patients, cisplatin was given synchronously with 20 mg once daily for 5 days in the 1 st and 5 th weeks. The CD4, CD8 and CD56 expressions in peripheral blood lymphocytes (PBL) were quantitatively assessed with flow cytometry before and during the treatment. Results: The CD4/CD8 ratio of PBL decreased significantly after treatment completion (P < 0.01 in Group A and P < 0.01 in Group B). Whereas the percentage of positive CD56 PBL increased dramatically (P < 0.01 in two groups). There were no evidence that CD expression difference had any statistical or clinical significance. Conclusion: Immunosuppression may be present on cell-mediated immuno-activity (CD4/CD8) and NK cell (CD56)immuno-enhancement may be obtainable on immuno-surveillance, when esophageal carcinoma is being treated by LCAHR with or without cisplatin

  13. Neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer

    The purpose of this study was to examine the safety and feasibility of a novel protocol of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer. A total of 56 patients with lower rectal cancer of cT3N1M0 (Stage III b) was treated with SC-HART followed by radical surgery, and were analyzed in the present study. SC-HART was performed with a dose of 2.5 Gy twice daily, with an interval of at least 6 hours between fractions, up to a total dose of 25 Gy (25 Gy in 10 fractions for 5 days) combined with S-1 for 10 days. Radical surgery was performed within three weeks following the end of the SC-HART. The median age was 64.6 (range, 39-85) years. The median follow-up term was 16.3 (range, 2-53) months. Of the 56 patients, 53 (94.4%) had no apparent adverse events before surgery; 55 (98.2%) completed the full course of neoadjuvant therapy, while one patient stopped chemotherapy because of Grade 3 gastrointestinal toxicity (CTCAE v.3). The sphincter preservation rate was 94.6%. Downstaging was observed in 45 patients (80.4%). Adjuvant chemotherapy was administered to 43 patients (76.8%). The local control rate, disease-free survival rate and disease-specific survival rate were 100%, 91.1% and 100%, respectively. To conclude, SC-HART combined with S-1 for locally advanced rectal cancer was well tolerated and produced good short-term outcomes. SC-HART therefore appeared to have a good feasibility for use in further clinical trials. (author)

  14. Neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer.

    Doi, Hiroshi; Beppu, Naohito; Odawara, Soichi; Tanooka, Masao; Takada, Yasuhiro; Niwa, Yasue; Fujiwara, Masayuki; Kimura, Fumihiko; Yanagi, Hidenori; Yamanaka, Naoki; Kamikonya, Norihiko; Hirota, Shozo

    2013-11-01

    The purpose of this study was to examine the safety and feasibility of a novel protocol of neoadjuvant short-course hyperfractionated accelerated radiotherapy (SC-HART) combined with S-1 for locally advanced rectal cancer. A total of 56 patients with lower rectal cancer of cT3N1M0 (Stage III b) was treated with SC-HART followed by radical surgery, and were analyzed in the present study. SC-HART was performed with a dose of 2.5 Gy twice daily, with an interval of at least 6 hours between fractions, up to a total dose of 25 Gy (25 Gy in 10 fractions for 5 days) combined with S-1 for 10 days. Radical surgery was performed within three weeks following the end of the SC-HART. The median age was 64.6 (range, 39-85) years. The median follow-up term was 16.3 (range, 2-53) months. Of the 56 patients, 53 (94.4%) had no apparent adverse events before surgery; 55 (98.2%) completed the full course of neoadjuvant therapy, while one patient stopped chemotherapy because of Grade 3 gastrointestinal toxicity (CTCAE v.3). The sphincter preservation rate was 94.6%. Downstaging was observed in 45 patients (80.4%). Adjuvant chemotherapy was administered to 43 patients (76.8%). The local control rate, disease-free survival rate and disease-specific survival rate were 100%, 91.1% and 100%, respectively. To conclude, SC-HART combined with S-1 for locally advanced rectal cancer was well tolerated and produced good short-term outcomes. SC-HART therefore appeared to have a good feasibility for use in further clinical trials. PMID:23658415

  15. Whole brain radiotherapy: Prognostic factors and results of a radiation boost delivered through a conventional linear accelerator

    Purpose: Assess prognostic factors for overall survival and the potential benefit of a boost in patients treated with whole brain radiation therapy (WBRT). Methods and materials: From 2002 to 2006, a retrospective analysis was made from 250 unselected consecutive patients with secondary brain metastases from lung cancer, breast cancer and melanoma. Eighteen patients received surgery and were excluded from analysis. Four potential prognostic factors have been studied: primary tumor type, gender, number of metastases and improvement of neurological symptoms after radiation therapy. A subgroup analysis was performed to determine whether an additional boost could potentially improve outcome in patients who presented with less than three metastases, performance status <2, and no surgical resection of their metastasis. Results: Average follow-up was 10.3 months. Median overall survival was 5.6 months and survival rates at 1 and 2 years were 22.7% and 10%, respectively. Age less than 65 (p < 0.01), neurological improvement after WBRT (p < 0.01), and presence of less than three metastases were significant factors for overall survival in multivariate analysis. When focusing on the selected subgroup (120 assessable patients), median overall survival was 4.0 months in patients with no radiation boost, versus 8.9 months in patients with radiation boost (p = 0.0024). Conclusions: Survival and prognostic factors were similar to those found in the literature. Boost delivered after WBRT by a conventional particle accelerator could provide a benefit in selected patients, especially for centers that do not have radiotherapy techniques in stereotactic conditions. This warrants further prospective assessment.

  16. Quality assurance audit in an Australasian phase III trial of accelerated radiotherapy for head and neck cancer (TROG 91.01)

    The Trans-Tasman Radiation Oncology Group (TROG) initiated a randomized trial, testing accelerated (twice daily) radiotherapy against conventional radiotherapy for stage II and stage IV squamous cell carcinoma of the head and neck in 1991. In 1996, the Trial Management Committee arranged for a technical audit of 76 cases from 11 institutions, conducted by investigators from interstate institutions. A 10% unacceptable protocol violation rate was detected, which compares favourably with initial Radiation Therapy Oncology Group (RTOG) experience in the late 1970s. Infrastructural deficits with poor quality of documentation, incomplete retrieval of films and document return have been demonstrated in some cases. The Trans-Tasman Radiation Oncology Group is actively pursuing procedural and resourcing issues in order to redress this and is actively expanding its Quality Assurance (QA) Programme with an intercentre dosimetry study. Ultimately, comprehensive clinical and technical QA site visits are planned. Copyright (1999) Blackwell Science Pty Ltd

  17. Evaluation and Immunohistochemical Qualification of Carbogen-Induced ΔR{sub 2}* as a Noninvasive Imaging Biomarker of Improved Tumor Oxygenation

    Baker, Lauren C.J., E-mail: lauren.baker@icr.ac.uk [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Boult, Jessica K.R.; Jamin, Yann; Gilmour, Lesley D.; Walker-Samuel, Simon; Burrell, Jake S. [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom); Ashcroft, Margaret [Division of Medicine, Centre for Cell Signalling and Molecular Genetics, University College London, London (United Kingdom); Howe, Franklyn A. [St. George' s, University of London, London (United Kingdom); Griffiths, John R. [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Raleigh, James A. [Department of Radiation Oncology, University of North Carolina, Chapel Hill, North Carolina (United States); Kogel, Albert J. van der [University of Nijmegen Medical Centre, Nijmegen (Netherlands); Robinson, Simon P. [Cancer Research UK and EPSRC Cancer Imaging Centre, Division of Radiotherapy and Imaging, The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Surrey (United Kingdom)

    2013-09-01

    Purpose: To evaluate and histologically qualify carbogen-induced ΔR{sub 2}* as a noninvasive magnetic resonance imaging biomarker of improved tumor oxygenation using a double 2-nitroimidazole hypoxia marker approach. Methods and Materials: Multigradient echo images were acquired from mice bearing GH3 prolactinomas, preadministered with the hypoxia marker CCI-103F, to quantify tumor R{sub 2}* during air breathing. With the mouse remaining positioned within the magnet bore, the gas supply was switched to carbogen (95% O{sub 2}, 5% CO{sub 2}), during which a second hypoxia marker, pimonidazole, was administered via an intraperitoneal line, and an additional set of identical multigradient echo images acquired to quantify any changes in tumor R{sub 2}*. Hypoxic fraction was quantified histologically using immunofluorescence detection of CCI-103F and pimonidazole adduct formation from the same whole tumor section. Carbogen-induced changes in tumor pO{sub 2} were further validated using the Oxylite fiberoptic probe. Results: Carbogen challenge significantly reduced mean tumor R{sub 2}* from 116 ± 13 s{sup −1} to 97 ± 9 s{sup −1} (P<.05). This was associated with a significantly lower pimonidazole adduct area (2.3 ± 1%), compared with CCI-103F (6.3 ± 2%) (P<.05). A significant correlation was observed between ΔR{sub 2}* and Δhypoxic fraction (r=0.55, P<.01). Mean tumor pO{sub 2} during carbogen breathing significantly increased from 6.3 ± 2.2 mm Hg to 36.0 ± 7.5 mm Hg (P<.01). Conclusions: The combined use of intrinsic susceptibility magnetic resonance imaging with a double hypoxia marker approach corroborates carbogen-induced ΔR{sub 2}* as a noninvasive imaging biomarker of increased tumor oxygenation.

  18. Preliminary comparison of the therapeutic efficacy of accelerated relative to conventional fractionation radiotherapy by treatment of spontaneous canine malignancies

    Purpose/Objective: This study's ultimate goals involve development of an accelerated fractionation (AF) regimen with an integrated final concomitant boost (CB) and examination of factors prognostic of the CB's therapeutic efficacy which could be measured during the initial AF portion to determine for which patients CB should be used. These endpoints can be accurately determined quickly by evaluating the treatment (tx) of spontaneous canine veterinary patient tumors. Because surviving tumor clonogen growth rate increases after radiotherapy (RT) begins, this accelerated repopulation (AR) should be reduced by AF. Furthermore, CB using a small field encompassing only the tumor bed, given as a second daily tx during the last week of RT, should further reduce AR. The initial portion of this project which is nearing completion was designed to determine if incidentally treated normal tissues could tolerate the AF regimen and project whether addition of the tumor bed CB would also be tolerated. Materials and Methods: Currently 20 canine patients with biopsy proven localized tumors have received canine AF radiotherapy given as 3.2Gy/fraction(fx) administered 5 days a week (Mon-Fri) to a total of 15 fxs (48Gy) within 18 elapsed days. RT is given with a 60Co teletherapy unit. Their tumor response, control, survival, and acute normal tissue responses are being directly compared to results we previously obtained from canines receiving a nearly equivalent dose/fx and total dose conventional fractionation (CF) regimen which was given alone or with adjuvant hyperthermia (HT). In that study the canines were stratified by tumor histology and anatomic site and randomly assigned to receive canine CF (3.5Gy/fx, 3 fxs/week [Mon-Wed-Fri] to 14 fxs (49Gy) in an elapsed time of approx. 30 days) either alone or followed weekly by local HT (44 deg. +/- 2 deg. C) for 30 minutes (5 HT fxs). As is currently done, these CF+/-HT patients were followed up to 3 years to quantitate the magnitudes and

  19. Experimental research of dose distribution and protection for mobile intra-operative radiotherapy accelerator in operating room

    Objective: To study the dose distribution characteristics for mobile intra-operative radiotherapy accelerator (Mobetron) in an operating room, and to provide basic data for developing appropriate radiation protection measures and protection standard. Methods: For most commonly used electron energy 9 MeV, TLD dosimeters were placed at 50, 100, 150 and 200 cm high plane, respectively. For each plane,the measurement points were selected at every 50 cm from the central axis at every 45° at eight different directions. Also different electron energies, such as 4, 6, 9 and 12 MeV, were taken into consideration at the plane at 100 cm height. After 10 Gy with a dose rate of 10 Gy/min were delivered, the TLD dosimeters were used to read out the data. Results: For 9 MeV, at the phantom plane (100 cm high plane), the average doses were 169, 756, 395 and 241 μSv at 50, 100, 150 and 200 cm from the central axis,respectively. The maximum deviation between the doses at 50 cm from the central axis in different angles and their average values were 9.1%. In the identical angle, the average doses of 50, 100, 150 and 200 cm high planes at the distance of 100 cm from central axis were 527, 756, 570 and 141 μSv, respectively. For the energies of 4, 6, 9 and 12 MeV, the average doses were 573, 486, 689 and 781 μSv at 100 cm from the central axis at 90° of 100 cm high plane. Conclusions: For the same energy,the dose values at different directions were decreased by the minus exponential function law with the distance. The doses were uniformly distributed at different directions at the same distance from the central axis. The doses on the plane of 100 cm height were much higher than those at other heights,and the dose values were increased with the election energy. (authors)

  20. Development of an ultrasmall C-band linear accelerator guide for a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head.

    Kamino, Yuichiro; Miura, Sadao; Kokubo, Masaki; Yamashita, Ichiro; Hirai, Etsuro; Hiraoka, Masahiro; Ishikawa, Junzo

    2007-05-01

    We are developing a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1. PMID:17555261

  1. IAEA-HypoX. A randomized multicenter study of the hypoxic radiosensitizer nimorazole concomitant with accelerated radiotherapy in head and neck squamous cell carcinoma

    Metwally, Mohamed Ahmed Hassan; Ali, Rubina; Kuddu, Maire;

    2015-01-01

    multicenter randomized trial in patients with HNSCC. Tumors were treated to a dose of 66-70Gy, 33-35 fractions, 6 fractions per week. NIM was administered in a dose of 1.2gperm(2), 90min before the first daily RT fraction. The primary endpoint was loco-regional failure. The trial was closed prematurely by......PURPOSE: To test the hypothesis that radiotherapy (RT) of head and neck squamous cell carcinoma (HNSCC) can be improved by hypoxic modification using nimorazole (NIM) in association with accelerated fractionation. MATERIALS AND METHODS: The protocol was activated in March 2012 as an international...... HNSCC given the hypoxic modifier NIM in addition to accelerated fractionation RT. However, the trial also revealed that conducting multicenter and multinational study combining drug and RT in developing countries may suffer from uncontrolled and unsolvable problems....

  2. High-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in locally advanced non-small-cell lung cancer: a feasibility study

    Increasing the radiotherapy dose can result in improved local control for non-small-cell lung cancer (NSCLC) and can thereby improve survival. Accelerated hypofractionated radiotherapy can expose tumors to a high dose of radiation in a short period of time, but the optimal treatment regimen remains unclear. The purpose of this study was to evaluate the feasibility of utilizing high-dose accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine (NVB) and carboplatin (CBP) chemotherapy for the treatment of local advanced NSCLC. Untreated patients with unresectable stage IIIA/IIIB NSCLC or patients with a recurrence of NSCLC received accelerated hypofractionated three-dimensional conformal radiotherapy. The total dose was greater than or equal to 60 Gy. The accelerated hypofractionated radiotherapy was conducted once daily at 3 Gy/fraction with 5 fractions per week, and the radiotherapy was completed in 5 weeks. In addition to radiotherapy, the patients also received at least 1 cycle of a concurrent two-drug chemotherapy regimen of NVB and CBP. A total of 26 patients (19 previously untreated cases and 7 cases of recurrent disease) received 60Gy-75Gy radiotherapy with concurrent chemotherapy. All of the patients underwent evaluations for toxicity and preliminary therapeutic efficacy. There were no treatment-related deaths within the entire patient group. The major acute adverse reactions were radiation esophagitis (88.5%) and radiation pneumonitis (42.3%). The percentages of grade III acute radiation esophagitis and grade III radiation pneumonitis were 15.4% and 7.7%, respectively. Hematological toxicities were common and did not significantly affect the implementation of chemoradiotherapy after supportive treatment. Two patients received high dose of 75 Gy had grade III late esophageal toxicity, and none had grade IV and above. Grade III and above late lung toxicity did not occur. High-dose accelerated

  3. Accelerator

    The invention claims equipment for stabilizing the position of the front covers of the accelerator chamber in cyclic accelerators which significantly increases accelerator reliability. For stabilizing, it uses hydraulic cushions placed between the electromagnet pole pieces and the front chamber covers. The top and the bottom cushions are hydraulically connected. The cushions are disconnected and removed from the hydraulic line using valves. (J.P.)

  4. Clinical role of18F-FDG PET/CT-based simultaneous modulated accelerated radiotherapy treatment plan-ning for locally advanced nasopharyngeal carcinoma

    Jianshe Wang; Tianyou Tang Co-first author; Jing Xu; Andrew Z Wang; Liang Li; Junnian Zheng; Longzhen Zhang

    2015-01-01

    Objective The aim of this study was to compare the long-term local control, overal survival, and late toxicities of positron emission tomography/computed tomography (PET/CT)-guided dose escalation radio-therapy versus conventional radiotherapy in the concurrent chemoradiotherapy treatment of local y ad-vanced nasopharyngeal carcinoma (NPC). Methods A total of 48 patients with stage III–IVa NPC were recruited and randomly administered PET/CT-guided dose escalation chemoradiotherapy (group A) or conventional chemoradiotherapy (group B). The dose-escalation radiotherapy was performed using the simultaneous modulated accelerated radiotherapy technique at prescribed doses of 77 gray (Gy) in 32 fractions (f) to the gross target volume (GTV): planning target volume (PTV) 1 received 64 Gy/32 f, while PTV2 received 54.4 Gy/32 f. Patients in group B received uniform-dose intensity-modulated radiotherapy, PTV1 received 70 Gy/35 f and PTV2 received 58 Gy/29 f. Concurrent chemotherapy consisted of cisplatin [20 mg/m2 intravenous (IV) on days 1–4] and docetaxel (75 mg/m2 IV on days 1 and 8) administered during treatment weeks 1 and 4. Al patients received 2–4 cycles of adjuvant chemotherapy of the same dose and drug regimen. Results The use of fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT significantly reduced the treat-ment volume delineation of the GTV in 83.3% (20/24) of patients. The 5-year local recurrence-free survival rates of the two groups were 100% and 79.2%, respectively (P = 0.019). The 5-year disease free survival (DFS) rates were 95.8% and 75.0%, respectively (P = 0.018). The 5-year local progression-free survival and DFS rates were significantly dif erent. The 5-year overal survival (OS) rates were 95.8% and 79.2%, re-spectively. Dif erences in OS improvement were insignificant (P = 0.079). Late toxicities were similar in the two groups. The most common late toxicities of the two arms were grade 1–2 skin dystrophy, xerostomia, subcutaneous fibrosis, and

  5. Hyperfractionated accelerated radiotherapy with concomitant integrated boost of 70-75 Gy in 5 weeks for advanced head and neck cancer. A phase I dose escalation study

    Cvek, J.; Skacelikova, E.; Otahal, B.; Halamka, M.; Feltl, D. [University Hospital Ostrava (Czech Republic). Dept. of Oncology; Kubes, J. [University Hospital Bulovka, Prague (Czech Republic). Dept. of Radiation Oncology; Kominek, P. [University Hospital Ostrava (Czech Republic). Dept. of Otolaryngology

    2012-08-15

    Background and purpose: The present study was performed to evaluate the feasibility of a new, 5-week regimen of 70-75 Gy hyperfractionated accelerated radiotherapy with concomitant integrated boost (HARTCIB) for locally advanced, inoperable head and neck cancer. Methods and materials: A total of 39 patients with very advanced, stage IV nonmetastatic head and neck squamous cell carcinoma (median gross tumor volume 72 ml) were included in this phase I dose escalation study. A total of 50 fractions intensity-modulated radiotherapy (IMRT) were administered twice daily over 5 weeks. Prescribed total dose/dose per fraction for planning target volume (PTV{sub tumor}) were 70 Gy in 1.4 Gy fractions, 72.5 Gy in 1.45 Gy fractions, and 75 Gy in 1.5 Gy fractions for 10, 13, and 16 patients, respectively. Uninvolved lymphatic nodes (PTV{sub uninvolved}) were irradiated with 55 Gy in 1.1 Gy fractions using the concomitant integrated boost. Results: Acute toxicity was evaluated according to the RTOG/EORTC scale; the incidence of grade 3 mucositis was 51% in the oral cavity/pharynx and 0% in skin and the recovery time was {<=} 9 weeks for all patients. Late toxicity was evaluated in patients in complete remission according to the RTOG/EORTC scale. No grade 3/4 late toxicity was observed. The 1-year locoregional progression-free survival was 50% and overall survival was 55%. Conclusion: HARTCIB (75 Gy in 5 weeks) is feasible for patients deemed unsuitable for chemoradiation. Acute toxicity was lower than predicted from radiobiological models; duration of dysphagia and confluent mucositis were particularly short. Better conformity of radiotherapy allows the use of more intensive altered fractionation schedules compared with older studies. These results suggest that further dose escalation might be possible when highly conformal techniques (e.g., stereotactic radiotherapy) are used.

  6. Advances in conformal radiotherapy using Monte Carlo Code to design new IMRT and IORT accelerators and interpret CT numbers

    Wysocka-Rabin, A

    2013-01-01

    The introductory chapter of this monograph, which follows this Preface, provides an overview of radiotherapy and treatment planning. The main chapters that follow describe in detail three significant aspects of radiotherapy on which the author has focused her research efforts. Chapter 2 presents studies the author worked on at the German National Cancer Institute (DKFZ) in Heidelberg. These studies applied the Monte Carlo technique to investigate the feasibility of performing Intensity Modulated Radiotherapy (IMRT) by scanning with a narrow photon beam. This approach represents an alternative to techniques that generate beam modulation by absorption, such as MLC, individually-manufactured compensators, and special tomotherapy modulators. The technical realization of this concept required investigation of the influence of various design parameters on the final small photon beam. The photon beam to be scanned should have a diameter of approximately 5 mm at Source Surface Distance (SSD) distance, and the penumbr...

  7. Quality of life assessment in advanced non-small-cell lung cancer patients undergoing an accelerated radiotherapy regimen: report of ECOG study 4593

    Purpose: To prospectively evaluate the quality of life (QOL) before, at completion, and after therapy for patients receiving an accelerated fractionation schedule of radiotherapy for advanced, unresectable non-small-cell lung cancer in a Phase II multi-institutional trial. Methods and Materials: The Functional Assessment of Cancer Therapy-Lung (FACT-L) patient questionnaire was used to score the QOL in patients enrolled in the Eastern Cooperative Oncology Group Phase II trial (ECOG 4593) of hyperfractionated accelerated radiotherapy in non-small-cell lung cancer. Radiotherapy (total dose 57.6 Gy in 36 fractions) was delivered during 15 days, with three radiation fractions given each treatment day. The protocol was activated in 1993, and 30 patients had accrued by November 1995. The FACT-L questionnaire was administered at study entry (baseline), on the last day of radiotherapy (assessment 2), and 4 weeks after therapy (assessment 3). The FACT-L includes scores for physical, functional, emotional, and social well-being (33 items), and a subscale of lung cancer symptoms (10 additional items). The summation of the physical, functional, and lung cancer symptom subscales (21 items) constitutes the Trial Outcome Index (TOI), considered the most clinically relevant outcome measure in lung cancer treatment trials. Results: The FACT-L completion rates at the designated study time points were as follows: baseline, 30 of 30 (100%); assessment 2, 29 (97%) of 30; and assessment 3, 24 (80%) of 30. At treatment completion, statistically significant declines in QOL scores were noted, compared with baseline for physical and functional well-being. Emotional well-being scores improved at both assessment 2 and assessment 3. The physical and functional scores returned approximately to baseline values at assessment 3. The change in TOI score was evaluated as a function of the clinical response to treatment, toxicity grade, and survival; no clear association was noted. A trend for the

  8. A Randomized Study of Accelerated Fractionation Radiotherapy with and Without Mitomycin C in the Treatment of Locally Advanced Head and Neck Cancer

    This single-institution study evaluates the feasibility of accelerated fractionation radiotherapy (AF) with and without mitomycin C (MMC) in thc treatment of locally advanced head and neck cancer. Patients and Methods: Between May 1998 and October 2001, sixty patients with locally advanced stage III and IV of head and neck cancer were randomized into three treatment arms: (I) conventional fractionation radiotherapy (CF) (5 fractions per week); (2) accelerated fractionation radiotherapy (AF) (6 fractions per week); and (3) AF plus Mitomycin C (MMC). The 2-year overall survival (OS) of the whole group was 21 %. The OS according to treatment arm was 23%, 20%. and 28% in CF. AF. and AF+MMC arms respectively (ρ<0. 19). The 2-year loco-regional control (LC) rate was 22% for the whole group of patients. The LC was 10%, 25%. and 30% for the CF, AF, and AF+MMC respectively (ρ=0.27). The only significant parameters for OS and LC were performance status and pre-treatment hemoglobin level. Mucositis grades 3 and 4 occurred in 70% and 90% of the patients in the AF and AF+MMC arm respectively compared to 55% of patients in the CF arm (ρ=0.04). However the addition of MMC did not significantly increase the incidence or severity of mucositis between AF and AF+MMC (ρ=0.13). Hematological toxicity grades 3 and 4 were significantly higher after MMC (occurred in 40% of patients versus 10% and 5% in CF and AF arms respectively, ρ=0.04). There was no statistically significant difference in the incidence of grade 3 dryness of mouth (ρ=0.06). fibrosis (ρ=0.6). or lymphoedema (ρ=0.39) among the three arms. There was a trend for improvement of LC and OS rates with the use or AF and the addition of MMC to AF compared to CF radiotherapy. although the difference was not statistically significant. The small number of the patients in each treatment arm and the inclusion or multiple tumor sites may contribute to these statistically insignificant results. Accordingly we advise to continue

  9. Normal tissue complication models for clinically relevant acute esophagitis (≥ grade 2) in patients treated with dose differentiated accelerated radiotherapy (DART-bid)

    One of the primary dose-limiting toxicities during thoracic irradiation is acute esophagitis (AE). The aim of this study is to investigate dosimetric and clinical predictors for AE grade ≥ 2 in patients treated with accelerated radiotherapy for locally advanced non-small cell lung cancer (NSCLC). 66 NSCLC patients were included in the present analysis: 4 stage II, 44 stage IIIA and 18 stage IIIB. All patients received induction chemotherapy followed by dose differentiated accelerated radiotherapy (DART-bid). Depending on size (mean of three perpendicular diameters) tumors were binned in four dose groups: <2.5 cm 73.8 Gy, 2.5–4.5 cm 79.2 Gy, 4.5–6 cm 84.6 Gy, >6 cm 90 Gy. Patients were treated in 3D target splitting technique. In order to estimate the normal tissue complication probability (NTCP), two Lyman models and the cutoff-logistic regression model were fitted to the data with AE ≥ grade 2 as statistical endpoint. Inter-model comparison was performed with the corrected Akaike information criterion (AICc), which calculates the model’s quality of fit (likelihood value) in relation to its complexity (i.e. number of variables in the model) corrected by the number of patients in the dataset. Toxicity was documented prospectively according to RTOG. The median follow up was 686 days (range 84–2921 days), 23/66 patients (35 %) experienced AE ≥ grade 2. The actuarial local control rates were 72.6 % and 59.4 % at 2 and 3 years, regional control was 91 % at both time points. The Lyman-MED model (D50 = 32.8 Gy, m = 0.48) and the cutoff dose model (Dc = 38 Gy) provide the most efficient fit to the current dataset. On multivariate analysis V38 (volume of the esophagus that receives 38 Gy or above, 95 %-CI 28.2–57.3) was the most significant predictor of AE ≥ grade 2 (HR = 1.05, CI 1.01–1.09, p = 0.007). Following high-dose accelerated radiotherapy the rate of AE ≥ grade 2 is slightly lower than reported for concomitant radio-chemotherapy with the

  10. Dosimetric Characteristics of Circular 6-MeV X-Ray Beams for Stereotactic Radiotherapy with a Linear Accelerator

    Wysocka, A.; Rostkowska, J.; Kania, M.; Bulski, W.; Fijuth, J.

    2000-01-01

    Dosimetric characteristics of 6 MeV circular X-ray beams of diameters ranging from 7.5 to 35.0 mm are reported. The 6-MeV X-ray beam from Clinac 2300CD was formed using additional cylindrical BrainLAB's collimators. The mechanical stability of the entire system was verified. Specific quantities measured include tissue maximum ratios (TMR), beam profiles (off-axis ratios OAR) and relative output factors. Measurements of these parameters were performed in a water phantom using small cylindrical ionization chambers and a diamond detector. Comparison of TMR values measured with the ionization chamber and the diamond detector showed no significant differences. It was shown that the latter yields more accurate results for beam profiles than ionization chambers. The mechanical and dosimetric characteristics of this radiotherapy unit are found to be suitable for stereotactic radiosurgery and radiotherapy.

  11. Breast cancer radiotherapy: controversies and prospectives

    YU Jin-ming; WANG Yong-sheng

    2008-01-01

    @@ Despite consensus on breast cancer radiotherapy, there are still some controversies over post-mastectomy radiotherapy (PMRT) in patients with 1-3 positive lymph nodes, accelerated partial breast irradiation (APBI), appropriate sequence of radiotherapy, chemotherapy and hormonal treatment, and radiotherapy after preoperative systemic therapy.

  12. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Kapanen, Mika [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Tenhunen, Mikko [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Haemaelaeinen, Tuomo [Department of Oncology, Helsinki University Central Hospital, Haartmaninkatu 4, 00029 Helsinki (Finland); Sipilae, Petri [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Parkkinen, Ritva [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland); Jaervinen, Hannu [Radiation and Nuclear Safety Authority (STUK), Laippatie 4, 00881 Helsinki (Finland)

    2006-07-21

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well ({<=}1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 {+-} 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control.

  13. Analysis of quality control data of eight modern radiotherapy linear accelerators: the short- and long-term behaviours of the outputs and the reproducibility of quality control measurements

    Quality control (QC) data of radiotherapy linear accelerators, collected by Helsinki University Central Hospital between the years 2000 and 2004, were analysed. The goal was to provide information for the evaluation and elaboration of QC of accelerator outputs and to propose a method for QC data analysis. Short- and long-term drifts in outputs were quantified by fitting empirical mathematical models to the QC measurements. Normally, long-term drifts were well (≤1%) modelled by either a straight line or a single-exponential function. A drift of 2% occurred in 18 ± 12 months. The shortest drift times of only 2-3 months were observed for some new accelerators just after the commissioning but they stabilized during the first 2-3 years. The short-term reproducibility and the long-term stability of local constancy checks, carried out with a sealed plane parallel ion chamber, were also estimated by fitting empirical models to the QC measurements. The reproducibility was 0.2-0.5% depending on the positioning practice of a device. Long-term instabilities of about 0.3%/month were observed for some checking devices. The reproducibility of local absorbed dose measurements was estimated to be about 0.5%. The proposed empirical model fitting of QC data facilitates the recognition of erroneous QC measurements and abnormal output behaviour, caused by malfunctions, offering a tool to improve dose control

  14. Three-dimensional conformal arc radiotherapy using a C-arm linear accelerator with a computed tomography on-rail system for prostate cancer: clinical outcomes

    We report the feasibility and treatment outcomes of image-guided three-dimensional conformal arc radiotherapy (3D-CART) using a C-arm linear accelerator with a computed tomography (CT) on-rail system for localized prostate cancer. Between 2006 and 2011, 282 consecutive patients with localized prostate cancer were treated with in-room CT-guided 3D-CART. Biochemical failure was defined as a rise of at least 2.0 ng/ml beyond the nadir prostate-specific antigen level. Toxicity was scored according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0. A total of 261 patients were analyzed retrospectively (median follow-up: 61.6 months). The median prescribed 3D-CART dose was 82 Gy (2 Gy/fraction, dose range: 78–86 Gy), and 193 of the patients additionally received hormonal therapy. The 5-year overall survival rate was 93.9 %. Among low-, intermediate-, and high-risk patients, 5-year rates of freedom from biochemical failure were 100, 91.5 and 90.3 %, respectively. Rates of grade 2–3 late gastrointestinal and genitourinary toxicities were 2.3 and 11.4 %, respectively. No patient experienced late grade 4 or higher toxicity. In-room CT-guided 3D-CART was feasible and effective for localized prostate cancer. Treatment outcomes were comparable to those previously reported for intensity-modulated radiotherapy

  15. In vivo cell kinetic measurements in a randomized trial of continuous hyperfractionated accelerated radiotherapy with or without mitomycin C in head-and-neck cancer

    Purpose: Tumor cell repopulation is still considered to be a major cause of failure in radiotherapy. In this study, we investigated the influence of cell kinetic parameters on the outcome of patients treated in a randomized trial of accelerated fractionation, with or without mitomycin C, vs. conventional fractionation. Methods and Materials: Sixty-two patients were studied using administration of bromodeoxyuridine (BrdUrd), and cell kinetic parameters were measured using flow cytometry. The patients were treated with either 70 Gy for 7 weeks or 55.3 Gy for 17 continuous days (V-CHART) with or without 20 mg/m2 mitomycin C on day 5. Results: The potential doubling time (Tpot) and labeling index (LI) failed to provide any prognostic information with regard to local control or survival. However, the duration of the S phase (Ts) revealed patients whose tumors had a long Ts had significantly worse local control (p = 0.028) and survival (p = 0.034) irrespective of treatment. A similar trend was evident within the different treatment arms particularly associated with overall survival. Conclusions: The Ts values of head-and-neck squamous cell cancers provided prognostic information that predicted clinical outcome irrespective of treatment schedule in this study. This neglected parameter of the Tpot method might provide information related to redistribution of cells during fractionated radiotherapy

  16. Commissioning and quality assurance of the X-ray volume Imaging system of an image-guided radiotherapy capable linear accelerator

    Muralidhar K

    2008-01-01

    Full Text Available An Image-Guided Radiotherapy-capable linear accelerator (Elekta Synergy was installed at our hospital, which is equipped with a kV x-ray volume imaging (XVI system and electronic portal imaging device (iViewGT. The objective of this presentation is to describe the results of commissioning measurements carried out on the XVI facility to verify the manufacturer′s specifications and also to evolve a QA schedule which can be used to test its performance routinely. The QA program consists of a series of tests (safety features, geometric accuracy, and image quality. These tests were found to be useful to assess the performance of the XVI system and also proved that XVI system is very suitable for image-guided high-precision radiation therapy.

  17. Locally advanced head and neck cancer treated with accelerated radiotherapy, the hypoxic modifier nimorazole and weekly cisplatin. Results from the DAHANCA 18 phase II study

    Bentzen, Jens; Toustrup, Kasper; Eriksen, Jesper Grau; Primdahl, Hanne; Andersen, Lisbeth Juhler; Overgaard, Jens

    2015-01-01

    150 oropharyngeal cancers. Of these, 112 (79%) were p16 pos and 29 (21%) were p16 neg. LRC for the p16 neg oropharyngeal cancers was poorer than for the p16 pos (74% vs. 91%; p = 0.02). Tube feeding during treatment was necessary for 146 (64%) patients. At 12 months this number was reduced to 6......%. CONCLUSION: The treatment was tolerable in this cohort of locally advanced HNSCC patients. Acute and late toxicity was comparable to similar studies of chemoradiotherapy, and the outcome superior to the data reported in the literature. This strongly indicates that RT of a......PURPOSE/OBJECTIVE: A phase II clinical trial evaluating the feasibility and outcome of treating locally advanced head and neck squamous cell carcinoma (HNSCC) with accelerated radiotherapy, the hypoxic modifier nimorazole and weekly cisplatin. MATERIAL AND METHODS: A total of 227 patients with...

  18. Accelerated hyperfractionated intensity-modulated radiotherapy for recurrent/unresectable rectal cancer in patients with previous pelvic irradiation: results of a phase II study

    This study was conducted to investigate the local effects and toxicity of accelerated hyperfractionated intensity-modulated radiotherapy for recurrent/unresectable rectal cancer in patients with previous pelvic irradiation. Twenty-two patients with recurrent/unresectable rectal cancer who previously received pelvic irradiation were enrolled in our single-center trial between January 2007 and August 2012. Reirradiation was scheduled for up to 39 Gy in 30 fractions using intensity-modulated radiotherapy plans. The dose was delivered via a hyperfractionation schedule of 1.3 Gy twice daily. Patient follow-up was performed by clinical examination, CT/MRI, or PET/CT every 3 months for the first 2 years and every 6 months thereafter. Tumor response was evaluated 1 month after reirradiation by CT/MRI based on the RECIST criteria. Adverse events were assessed using the National Cancer Institute (NCI) common toxicity criteria (version 3.0). The median time from the end of the initial radiation therapy to reirradiation was 30 months (range, 18-93 months). Overall local responses were observed in 9 patients (40.9%). None of the patients achieved a complete response (CR), and 9 patients (40.9%) had a partial response (PR). Thirteen patients failed to achieve a clinical response: 12 (54.5%) presented with stable disease (SD) and 1 (4.5%) with progressive disease (PD). Among all the patients who underwent reirradiation, partial or complete symptomatic relief was achieved in 6 patients (27.3%) and 13 patients (59.1%), respectively. Grade 4 acute toxicity and treatment-related deaths were not observed. The following grade 3 acute toxicities were observed: diarrhea (2 patients, 9.1%), cystitis (1 patient, 4.5%), dermatitis (1 patient, 4.5%), and intestinal obstruction (1 patient, 4.5%). Late toxicity was infrequent. Chronic severe diarrhea, small bowel obstruction, and dysuria were observed in 2 (9.1%), 1 (4.5%) and 2 (9.1%) of the patients, respectively. This study showed that

  19. Procedure to measure the neutrons spectrum around a lineal accelerator for radiotherapy; Procedimiento para medir el espectro de los neutrones en torno a un acelerador lineal para radioterapia

    Vega C, H. R.; Hernandez D, V. M.; Letechipia de L, C. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98060 Zacatecas (Mexico); Benites R, J. L. [Servicios de Salud de Nayarit, Centro Estatal de Cancerologia, Calzada de la Cruz 116 Sur, 63000 Tepic, Nayarit (Mexico); Salas L, M. A., E-mail: fermineutron@yahoo.com [Universidad Autonoma de Zacatecas, Unidad Academica de Agronomia, Apdo. Postal 336, 98000 Zacatecas (Mexico)

    2013-10-15

    An experimental procedure was developed, by means of Bonner spheres, to measure the neutrons spectrum around Linacs of medical use that only requires of a single shot of the accelerator; to this procedure we denominate Planetary or Isocentric method. One of the problems associated to the neutrons spectrum measurement in a radiotherapy room with lineal accelerator is because inside the room a mixed, intense and pulsed radiation field takes place affecting the detection systems based on active detector; this situation is solved using a passive detector. In the case of the Bonner spheres spectrometer the active detector has been substituted by activation detectors, trace detectors or thermoluminescent dosimeters. This spectrometer uses several spheres that are situated one at a time in the measurement point, this way to have the complete measurements group the accelerator should be operated, under the same conditions, so many times like spheres have the spectrometer, this activity can consume a long time and in occasions due to the work load of Linac to complicate the measurement process too. The procedure developed in this work consisted on to situate all the spectrometer spheres at the same time and to make the reading by means of a single shot, to be able to apply this procedure, is necessary that before the measurements two characteristics are evaluated: the cross-talking of the spheres and the symmetry conditions of the neutron field. This method has been applied to determine the photo-neutrons spectrum produced by a lineal accelerator of medical use Varian ix of 15 MV to 100 cm of the isocenter located to 5 cm of depth of a solid water mannequin of 30 x 30 x 15 cm. The spectrum was used to determine the total flow and the environmental dose equivalent. (Author)

  20. Monte Carlo simulation for the production of neutrons inside the labyrinth function rooms radiotherapy in head rotation of medical linear accelerator use and energy operation

    This work consists of an analysis, through computer simulation using the Monte Carlo method, the production of neutrons generated by the interaction of the beam with useful materials that are heavy in head-accelerated linear medical use. We developed a computer model of the head of the linear accelerator Varian, where there was the ambient dose equivalent due to the neutrons H*(10)n the plane of the patient and the region of the labyrinth bunker for several angles of operating at energies of 10, 15, 18 MV. It was found that production of neutrons in the plane of the patient has direct dependency with increasing beam energy useful, since the labyrinth it appears that besides energy the operating angle also has a direct influence on the production of neutrons in the region of the labyrinth, consequently the door. Therefore, a survey of H*(10)n at various angles with different operating ranges of energy contributes to better planning studies concerning shielding doors in rooms radiotherapy. (author)

  1. Intraoperative radiotherapy

    The potential benefit of intraoperative radiotherapy (IORT) was originally recognized years ago and has recently attracted renewed interest. Modern radiotherapeutic approaches may be more successful as a result of technical innovation, particularly in the use of electron beam accelerators. Preliminary studies, mainly uncontrolled and nonrandomized, have assessed the role of IORT for treatment of a variety of deep seated abdominal, retroperitoneal, and pelvic cancers. The results of some studies show much promise, but prospective trials are needed to scientifically validate these favorable initial observations. (Auth.)

  2. Accelerated Hyperfractionated Radiotherapy for Cervical Cancer: Multi-Institutional Prospective Study of Forum for Nuclear Cooperation in Asia Among Eight Asian Countries

    Purpose: To evaluate the toxicity and efficacy of accelerated hyperfractionated radiotherapy (RT) for locally advanced cervical cancer. Methods and Materials: A multi-institutional prospective single-arm study was conducted among eight Asian countries. Between 1999 and 2002, 120 patients (64 with Stage IIB and 56 with Stage IIIB) with squamous cell carcinoma of the cervix were treated with accelerated hyperfractionated RT. External beam RT consisted of 30 Gy to the whole pelvis, 1.5 Gy/fraction twice daily, followed by 20 Gy of pelvic RT with central shielding at a dose of 2-Gy fractions daily. A small bowel displacement device was used with the patient in the prone position. In addition to central shielding RT, intracavitary brachytherapy was started. Acute and late morbidities were graded according to the Radiation Therapy Oncology Group and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer criteria. Results: The median overall treatment time was 35 days. The median follow-up time for surviving patients was 4.7 years. The 5-year pelvic control and overall survival rate for all patients was 84% and 70%, respectively. The 5-year pelvic control and overall survival rate was 78% and 69% for tumors ≥6 cm in diameter, respectively. No treatment-related death occurred. Grade 3-4 late toxicities of the small intestine, large intestine, and bladder were observed in 1, 1, and 2 patients, respectively. The 5-year actuarial rate of Grade 3-4 late toxicity at any site was 5%. Conclusion: The results of our study have shown that accelerated hyperfractionated RT achieved sufficient pelvic control and survival without increasing severe toxicity. This treatment could be feasible in those Asian countries where chemoradiotherapy is not available

  3. Three-year outcomes of a once daily fractionation scheme for accelerated partial breast irradiation (APBI) using 3-D conformal radiotherapy (3D-CRT)

    The aim of this study was to report 3-year outcomes of toxicity, cosmesis, and local control using a once daily fractionation scheme (49.95 Gy in 3.33 Gy once daily fractions) for accelerated partial breast irradiation (APBI) using three-dimensional conformal radiotherapy (3D-CRT). Between July 2008 and August 2010, women aged ≥40 years with ductal carcinoma in situ or node-negative invasive breast cancer ≤3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study. Women were treated with APBI using 3–5 photon beams, delivering 49.95 Gy over 15 once daily fractions over 3 weeks. Patients were assessed for toxicities, cosmesis, and local control rates before APBI and at specified time points. Thirty-four patients (mean age 60 years) with Tis 0 (n = 9) and T1N0 (n = 25) breast cancer were treated and followed up for an average of 39 months. Only 3% (1/34) patients experienced a grade 3 subcutaneous fibrosis and breast edema and 97% of the patients had good/excellent cosmetic outcome at 3 years. The 3-year rate of ipsilateral breast tumor recurrence (IBTR) was 0% while the rate of contralateral breast events was 6%. The 3-year disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS) was 94%, 100%, and 100%, respectively. Our novel accelerated partial breast fractionation scheme of 15 once daily fractions of 3.33 Gy (49.95 Gy total) is a remarkably well-tolerated regimen of 3D-CRT-based APBI. A larger cohort of patients is needed to further ascertain the toxicity of this accelerated partial breast regimen

  4. Poster — Thur Eve — 28: Enabling trajectory-based radiotherapy on a TrueBeam accelerator with the Eclipse treatment planning system

    Mullins, J; Asiev, K; DeBlois, F; Morcos, M; Seuntjens, J; Syme, A [Department of Oncology, McGill University (Canada)

    2014-08-15

    The TrueBeam linear accelerator platform has a developer's mode which permits the user dynamic control over many of the machine's mechanical and radiation systems. Using this research tool, synchronous couch and gantry motion can be programmed to simulate isocentric treatment with a shortened SAD, with benefits such as smaller projected MLC leaf widths and an increased dose rate. In this work, water tank measurements were used to commission a virtual linear accelerator with an 85 cm SAD in Eclipse, from which several arc-based radiotherapy treatments were generated, including an inverse optimized VMAT delivery. For each plan, the pertinent treatment delivery information was extracted from control points specified in the Eclipse-exported DICOM files using the pydicom package in Python, allowing construction of an XML control file. The dimensions of the jaws and MLC positions, defined for an 85 cm SAD in Eclipse, were scaled for delivery on a conventional SAD linear accelerator, and translational couch motion was added as a function of gantry angle to simulate delivery at 85 cm SAD. Ionization chamber and Gafchromic film measurements were used to compare the radiation delivery to dose calculations in Eclipse. With the exception of the VMAT delivery, ionization chamber measurements agreed within 3.3% of the Eclipse calculations. For the VMAT delivery, the ionization chamber was located in an inhomogeneous region, but gamma evaluation of the Gafchromic film plane resulted in a 94.5% passing rate using criteria of 3 mm/3%. The results indicate that Eclipse calculation infrastructure can be used.

  5. Predicting the Effect of Accelerated Fractionation in Postoperative Radiotherapy for Head and Neck Cancer Based on Molecular Marker Profiles: Data From a Randomized Clinical Trial

    Purpose: To determine the prognostic and predictive values of molecular marker expression profiles based on data from a randomized clinical trial of postoperative conventional fractionation (p-CF) therapy versus 7-day-per-week postoperative continuous accelerated irradiation (p-CAIR) therapy for squamous cell cancer of the head and neck. Methods and Materials: Tumor samples from 148 patients (72 p-CF and 76 p-CAIR patients) were available for molecular studies. Immunohistochemistry was used to assess levels of EGFR, nm23, Ki-67, p-53, and cyclin D1 expression. To evaluate the effect of fractionation relative to the expression profiles, data for locoregional tumor control (LRC) were analyzed using the Cox proportional hazard regression model. Survival curves were compared using the Cox f test. Results: Patients who had tumors with low Ki-67, low p-53, and high EGFR expression levels and oral cavity/oropharyngeal primary cancer sites tended to benefit from p-CAIR. A joint score for the gain in LRC from p-CAIR based of these features was used to separate the patients into two groups: those who benefited significantly from p-CAIR with respect to LRC (n = 49 patients; 5-year LRC of 28% vs. 68%; p = 0.01) and those who did not benefit from p-CAIR (n = 99 patients; 5-year LRC of 72% vs. 66%; p = 0.38). The nm23 expression level appeared useful as a prognostic factor but not as a predictor of fractionation effect. Conclusions: These results support the studies that demonstrate the potential of molecular profiles to predict the benefit from accelerated radiotherapy. The molecular profile that favored accelerated treatment (low Ki-67, low p-53, and high EGFR expression) was in a good accordance with results provided by other investigators. Combining individual predictors in a joint score may improve their predictive potential.

  6. Poster — Thur Eve — 28: Enabling trajectory-based radiotherapy on a TrueBeam accelerator with the Eclipse treatment planning system

    The TrueBeam linear accelerator platform has a developer's mode which permits the user dynamic control over many of the machine's mechanical and radiation systems. Using this research tool, synchronous couch and gantry motion can be programmed to simulate isocentric treatment with a shortened SAD, with benefits such as smaller projected MLC leaf widths and an increased dose rate. In this work, water tank measurements were used to commission a virtual linear accelerator with an 85 cm SAD in Eclipse, from which several arc-based radiotherapy treatments were generated, including an inverse optimized VMAT delivery. For each plan, the pertinent treatment delivery information was extracted from control points specified in the Eclipse-exported DICOM files using the pydicom package in Python, allowing construction of an XML control file. The dimensions of the jaws and MLC positions, defined for an 85 cm SAD in Eclipse, were scaled for delivery on a conventional SAD linear accelerator, and translational couch motion was added as a function of gantry angle to simulate delivery at 85 cm SAD. Ionization chamber and Gafchromic film measurements were used to compare the radiation delivery to dose calculations in Eclipse. With the exception of the VMAT delivery, ionization chamber measurements agreed within 3.3% of the Eclipse calculations. For the VMAT delivery, the ionization chamber was located in an inhomogeneous region, but gamma evaluation of the Gafchromic film plane resulted in a 94.5% passing rate using criteria of 3 mm/3%. The results indicate that Eclipse calculation infrastructure can be used

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

    Tada, Takuhito, E-mail: tada@msic.med.osaka-cu.ac.jp [Department of Radiology, Osaka City University Graduate School of Medicine, Osaka (Japan); Department of Radiology, Izumi Municipal Hospital, Izumi (Japan); Chiba, Yasutaka [Department of Environmental Medicine and Behavioural Science, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Tsujino, Kayoko [Department of Radiation Oncology, Hyogo Cancer Center, Akashi (Japan); Fukuda, Haruyuki [Department of Radiology, Osaka Prefectural Medical Center for Respiratory and Allergic Diseases, Habikino (Japan); Nishimura, Yasumasa [Department of Radiation Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Kokubo, Masaki [Division of Radiation Oncology, Institute of Biomedical Research and Innovation, Kobe (Japan); Negoro, Shunichi [Department of Medical Oncology, Hyogo Cancer Center, Akashi (Japan); Kudoh, Shinzoh [Department of Respiratory Medicine, Osaka City University Graduate School of Medicine, Osaka (Japan); Fukuoka, Masahiro [Department of Medical Oncology, Izumi Municipal Hospital, Izumi (Japan); Nakagawa, Kazuhiko [Department of Medical Oncology, Kinki University Faculty of Medicine, Osaka-sayama (Japan); Nakanishi, Yoichi [Research Institute for Disease of the Chest, Graduate School of Medical Science, Kyusyu University, Fukuoka (Japan)

    2012-05-01

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

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

    Purpose: A Phase I study to determine a recommended dose of thoracic radiotherapy using accelerated hyperfractionation for unresectable non–small-cell lung cancer was conducted. Methods and Materials: Patients with unresectable Stage III non–small-cell lung cancer were treated intravenously with carboplatin (area under the concentration curve 2) and paclitaxel (40 mg/m2) on Days 1, 8, 15, and 22 with concurrent twice-daily thoracic radiotherapy (1.5 Gy per fraction) beginning on Day 1 followed by two cycles of consolidation chemotherapy using carboplatin (area under the concentration curve 5) and paclitaxel (200 mg/m2). Total doses were 54 Gy in 36 fractions, 60 Gy in 40 fractions, 66 Gy in 44 fractions, and 72 Gy in 48 fractions at Levels 1 to 4. The dose-limiting toxicity, defined as Grade ≥4 esophagitis and neutropenic fever and Grade ≥3 other nonhematologic toxicities, was monitored for 90 days. Results: Of 26 patients enrolled, 22 patients were assessable for response and toxicity. When 4 patients entered Level 4, enrollment was closed to avoid severe late toxicities. Dose-limiting toxicities occurred in 3 patients. They were Grade 3 neuropathy at Level 1 and Level 3 and Grade 3 infection at Level 1. However, the maximum tolerated dose was not reached. The median survival time was 28.6 months for all patients. Conclusions: The maximum tolerated dose was not reached, although the dose of radiation was escalated to 72 Gy in 48 fractions. However, a dose of 66 Gy in 44 fractions was adopted for this study because late toxicity data were insufficient.

  9. NSCLC: primary tumor size - radiation dose-related accelerated, twice daily radiotherapy by target splitting, preceded by 2 cycles of chemotherapy. First results of a prospective study

    Ensuing a phase I trial of accelerated, twice daily high dose radiotherapy showing good tolerability, a prospective study relating primary tumor size with radiation dose in non-operated patients with non-small cell lung cancer (NSCLC) was started. From 01/2004 until 12/2006 79 patients with 81 histologically/cytologically proven NSCLC tumors were treated, representing 94% of all referred non-operated NSCLC patients in stage Mo, malignant pleural effusions excluded. For the majority of patients the conformal target splitting technique has been employed. The target is split into a cranial and a caudal part; beam arrangements in the two parts are completely independent. In order to reduce internal margins slow planning CTs (4 sec./slice) were used, patients freely breathing, 7 mm margins from gross tumor volume to planning target volume. We formed 4 groups with primary tumor sizes (mean number of 3 perpendicular diameters) 6,0 cm (11/41/22/7 patients, respectively); tumor doses of 73,8, 79,2, 84,6 and 90,0 Gy (ICRU) were applied to the primary tumors of the patients in the respective groups. Single dose 1,8 Gy; twice daily, interval 11 h; 5 days/week; duration 33 days median (range 29-42). Macroscopically involved nodes 61,2 Gy median (range 54,0-75,6 Gy), nodes electively 45,0 Gy (to volume about 6 cm cranial to apparently involved nodes). In 62 patients chemotherapy before radiotherapy was given, 2 cycles median, generally a cisplatin or carboplatin containing doublet; no concurrent chemotherapy. Median follow-up of all patients 16,7 months, of patients alive 19,3 months. Until now 10 local failures (0/11, 3/41, 5/22, 2/7 in the respective groups) and 2 regional failures occured, resulting in an actuarial local and regional tumor control of 80,1% and 96% at 2 years, respectively. Local failures relate to the primary tumor site, regional failures to the regional node sites. Overall actuarial 1-, 2-year survival rate for all patients: 76%, 56%, respectively, median 26

  10. Tracking the dynamic seroma cavity using fiducial markers in patients treated with accelerated partial breast irradiation using 3D conformal radiotherapy

    Yue, Ning J.; Haffty, Bruce G.; Goyal, Sharad [Department of Radiation Oncology, Cancer Institute of New Jersey, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903 (United States); Kearney, Thomas; Kirstein, Laurie [Division of Surgical Oncology, Cancer Institute of New Jersey, UMDNJ/Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903 (United States); Chen Sining [Department of Biostatistics, Cancer Institute of New Jersey, UMDNJ/School of Public Health, New Brunswick, NJ 08901 (United States)

    2013-02-15

    Purpose: The purpose of the present study was to perform an analysis of the changes in the dynamic seroma cavity based on fiducial markers in early stage breast cancer patients treated with accelerated partial breast irradiation (APBI) using three-dimensional conformal external beam radiotherapy (3D-CRT). Methods: A prospective, single arm trial was designed to investigate the utility of gold fiducial markers in image guided APBI using 3D-CRT. At the time of lumpectomy, four to six suture-type gold fiducial markers were sutured to the walls of the cavity. Patients were treated with a fractionation scheme consisting of 15 fractions with a fractional dose of 333 cGy. Treatment design and planning followed NSABP/RTOG B-39 guidelines. During radiation treatment, daily kV imaging was performed and the markers were localized and tracked. The change in distance between fiducial markers was analyzed based on the planning CT and daily kV images. Results: Thirty-four patients were simulated at an average of 28 days after surgery, and started the treatment on an average of 39 days after surgery. The average intermarker distance (AiMD) between fiducial markers was strongly correlated to seroma volume. The average reduction in AiMD was 19.1% (range 0.0%-41.4%) and 10.8% (range 0.0%-35.6%) for all the patients between simulation and completion of radiotherapy, and between simulation and beginning of radiotherapy, respectively. The change of AiMD fits an exponential function with a half-life of seroma shrinkage. The average half-life for seroma shrinkage was 15 days. After accounting for the reduction which started to occur after surgery through CT simulation and treatment, radiation was found to have minimal impact on the distance change over the treatment course. Conclusions: Using the marker distance change as a surrogate for seroma volume, it appears that the seroma cavity experiences an exponential reduction in size. The change in seroma size has implications in the size of

  11. Neurocognitive outcome in brain metastases patients treated with accelerated-fractionation vs. accelerated-hyperfractionated radiotherapy: an analysis from Radiation Therapy Oncology Group Study 91-04

    Purpose: To evaluate neurocognitive outcome as measured by the Mini-Mental Status Examination (MMSE) among patients with unresectable brain metastases randomly assigned to accelerated fractionation (AF) vs. accelerated hyperfractionated (AH) whole-brain radiation therapy (WBRT). Methods and Materials: The Radiation Therapy Oncology Group (RTOG) accrued 445 patients with unresectable brain metastases to a Phase III comparison of AH (1.6 Gy b.i.d. to 54.4 Gy) vs. AF (3 Gy q.d. to 30 Gy). All had a KPS of ≥ 70 and a neurologic function status of 0-2. Three hundred fifty-nine patients had MMSEs performed and were eligible for this analysis. Changes in the MMSE were analyzed according to criteria previously defined in the literature. Results: The median survival was 4.5 months for both arms. The average change in MMSE at 2 and 3 months was a drop of 1.4 and 1.1, respectively, in the AF arm as compared to a drop of 0.7 and 1.3, respectively, in the AH arm (p=NS). Overall, 91 patients at 2 months and 23 patients at 3 months had both follow-up MMSE and computed tomography/magnetic resonance imaging documentation of the status of their brain metastases. When an analysis was performed taking into account control of brain metastases, a significant effect on MMSE was observed with time and associated proportional increase in uncontrolled brain metastases. At 2 months, the average change in MMSE score was a drop of 0.6 for those whose brain metastases were radiologically controlled as compared to a drop of 1.9 for those with uncontrolled brain metastases (p=0.47). At 3 months, the average change in MMSE score was a drop of 0.5 for those whose brain metastases were radiologically controlled as compared to a drop of 6.3 for those with uncontrolled brain metastases (p=0.02). Conclusion: Use of AH as compared to AF-WBRT was not associated with a significant difference in neurocognitive function as measured by MMSE in this patient population with unresectable brain metastases and

  12. Determination of the neutron spectra in the treatment room of a linear accelerator for radiotherapy; Determinacion de los espectros de neutrones en la sala de tratamiento de un acelerador lineal para radioterapia

    Vega C, H.R. [Universidad Autonoma de Zacatecas, Cuerpo Academico de Radiobiologia, A.P. 336, 98000 Zacatecas (Mexico); Barquero, R. [Hospital Universitario Rio Hortega, Valladolid (Spain); Mendez, R.; Iniguez, M.P. [Depto. de Fisica Teorica, Atomica, Molecular y Nuclear, Universidad de Valladolid, 47011 Valladolid (Spain)

    2003-07-01

    By means of a series of measures and Monte Carlo calculations the dosimetric characteristics of the photoneutrons have been determined that take place in volume to a linear accelerator of radiotherapy of 18 MV, LINAC, mark Siemens Mevatron model. The measures were carried out with thermoluminescent dosemeters TLD 600 and TLD 700 that were naked exposed and confined with cover of Cd and Sn, inside a sphere of paraffin and inside spheres Bonner. (Author)

  13. Clinical Experiences With Onboard Imager KV Images for Linear Accelerator-Based Stereotactic Radiosurgery and Radiotherapy Setup

    Purpose: To report our clinical experiences with on-board imager (OBI) kV image verification for cranial stereotactic radiosurgery (SRS) and radiotherapy (SRT) treatments. Methods and Materials: Between January 2007 and May 2008, 42 patients (57 lesions) were treated with SRS with head frame immobilization and 13 patients (14 lesions) were treated with SRT with face mask immobilization at our institution. No margin was added to the gross tumor for SRS patients, and a 3-mm three-dimensional margin was added to the gross tumor to create the planning target volume for SRT patients. After localizing the patient with stereotactic target positioner (TaPo), orthogonal kV images using OBI were taken and fused to planning digital reconstructed radiographs. Suggested couch shifts in vertical, longitudinal, and lateral directions were recorded. kV images were also taken immediately after treatment for 21 SRS patients and on a weekly basis for 6 SRT patients to assess any intrafraction changes. Results: For SRS patients, 57 pretreatment kV images were evaluated and the suggested shifts were all within 1 mm in any direction (i.e., within the accuracy of image fusion). For SRT patients, the suggested shifts were out of the 3-mm tolerance for 31 of 309 setups. Intrafraction motions were detected in 3 SRT patients. Conclusions: kV imaging provided a useful tool for SRS or SRT setups. For SRS setup with head frame, it provides radiographic confirmation of localization using the stereotactic target positioner. For SRT with mask, a 3-mm margin is adequate and feasible for routine setup when TaPo is combined with kV imaging

  14. Concurrent hyperfractionated accelerated radiotherapy with 5-FU and once weekly cisplatin in locally advanced head and neck cancer. The 10-year results of a prospective phase II trial

    In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m2 on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m2). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups. (orig.)

  15. Be aware of neutrons outside short mazes from 10-mv linear accelerators x-rays in radiotherapy facilities

    During the radiation survey of a reinstalled 10-MV linear accelerator in an old radiation treatment facility, high dose rates of neutrons were observed. The area outside the maze entrance is used as a waiting room where patients, their relatives and staff other than those involved in the actual treatment can freely pass. High fluence rates of neutrons would cause an unnecessary high effective dose to the staff working in the vicinity of such a system, and it can be several orders higher than the doses received due to X-rays at the same location. However, the common knowledge appears to have been that the effect of neutrons at 10-MV X-ray linear accelerator facilities is negligible and shielding calculations models seldom mention neutrons for this operating energy level. Although data are scarce, reports regarding this phenomenon are now emerging. For the future, it is advocated that contributions from neutrons are considered already during the planning stage of new or modified facilities aimed for 10 MV and that estimated dose levels are verified. (authors)

  16. Determination of attenuation of X-radiations in some selected materials using the linear accelerator for radiotherapy

    Radiation travelling through a medium could be attenuated in different ways depending on the type of medium. The research was done on the above basis and was carried out at the Medical Physics department of the National Hospital Abuja using the linear accelerator and an ionization chamber (farmer-type) which served as a radiation detector. The materials used for this research were: the Perspex, concrete, moulded clay (mud), wood, jean material, ordinary material (clothe), cardboard paper, ordinary paper and foam of which each was of (12 x 12 x 1)cm3 except for Perspex which was of (30 x 30 x 1)cm3. They were all beamed at one after the other using energy of 6MV photons from the linear accelerator. The chamber detected the radiation passing through each material and sent it (radiation) in minute current signals to an electrometer which read the signals in milligray. The results obtained indicated that Perspex would best attenuate radiation, but considering its cost, concrete is considered cheaper and next to Perspex from the results and would play a better role.

  17. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico

    The helicoid tomo therapy is an external radiotherapy system of modulated intensity, guided by image, in which the radiation is imparted to the patient using a narrow radiation beam in helicoid form, in a similar way to the scanning process with a computerized tomography. The tomo therapy equipment (Tomo Therapy Hi-Art) consists in an electrons linear accelerator with acceleration voltages of 6 MV for treatment and 3.5 MV for image, coupled to a ring that turn around the patient as this is transferred through this ring in perpendicular sense to the radiation beam. The radiation beam is narrow because has the maximum size of 5 x 40 cm2 in the isocenter. The intensity modulation of the beam is carried out with a binary dynamic collimator of 64 crisscross sheets, and the guide by image though a system of megavoltage computerized tomography. Opposed to the radiation beam, also coupled to the rotational ring, a group of lead plates exists with a total thickness of 13 cm that acts as barrier of the primary radiation beam. The special configuration of the tomography equipment makes to have the following characteristics: 1) the presence of the lead barrier of the equipment reduces the intensity of the primary beam that reaches the bunker walls in considerable way, 2) the disperse and leakage radiations are increased with regard to a conventional accelerator due to the increase in the necessary irradiation time to produce modulated intensity fields by means of the narrow radiation beam. These special characteristics of the tomo therapy equipment make that particularities exist in the application of the formulations for structural shielding calculations that appears in the NCRP reports 49, NCRP 151 and IAEA-SRS-47. For this reason, several researches have development analytic models based on geometric considerations of continuous rotation of the equipment ring to determine the shielding requirements for the primary beam, the dispersed and leakage radiation in tomo therapy

  18. SU-E-T-190: First Integration of Steriotactic Radiotherapy Planning System Iplan with Elekta Linear Accelerator

    Purpose: For the first time in the world, BrainLAB has integrated its iPlan treatment planning system for clinical use with Elekta linear accelerator (Axesse with a Beam Modulator). The purpose of this study was to compare the calculated and measured doses with different chambers to establish the calculation accuracy of iPlan system. Methods: The iPlan has both Pencil beam (PB) and Monte Carlo (MC) calculation algorithms. Beam data include depth doses, profiles and output measurements for different field sizes. Collected data was verified by vendor and beam modelling was done. Further QA tests were carried out in our clinic. Dose calculation accuracy verified point, volumetric dose measurement using ion chambers of different volumes (0.01cc and 0.125cc). Planner dose verification was done using diode array. Plans were generated in iPlan and irradiated in Elekta Axesse linear accelerator. Results: Dose calculation accuracies verified using ion chamber for 6 and 10 MV beam were 3.5+/-0.33(PB), 1.7%+/-0.7(MC) and 3.9%+/-0.6(PB), 3.4%+/-0.6(MC) respectively. Using a pin point chamber, dose calculation accuracy for 6MV and 10MV was 3.8%+/-0.06(PB), 1.21%+/-0.2(MC) and 4.2%+/-0.6(PB), 3.1%+/-0.7(MC) respectively. The calculated planar dose distribution for 10.4×10.4 cm2 was verified using a diode array and the gamma analysis for 2%-2mm criteria yielded pass rates of 88 %(PB) and 98.8%(MC) respectively. 3mm-3% yields 100% passing for both MC and PB algorithm. Conclusion: Dose calculation accuracy was found to be within acceptable limits for MC for 6MV beam. PB for both beams and MC for 10 MV beam were found to be outside acceptable limits. The output measurements were done twice for conformation. The lower gamma matching was attributed to meager number of measured profiles (only two profiles for PB) and coarse measurement resolution for diagonal profile measurement (5mm). Based on these measurements we concluded that 6 MV MC algorithm is suitable for patient treatment

  19. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    Mozsa, Emoeke [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Landesklinikum Wiener Neustadt, Department of Radiooncology and Radiotherapy, Wiener Neustadt (Austria); Meszaros, Norbert; Major, Tibor; Froehlich, Georgina; Stelczer, Gabor; Fodor, Janos; Polgar, Csaba [National Institute of Oncology, Centre of Radiotherapy, Budapest (Hungary); Sulyok, Zoltan [National Institute of Oncology, Centre of Surgery, Budapest (Hungary)

    2014-05-15

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.) [German] Evaluation der 5-Jahres-Ergebnisse bezueglich Ueberleben, Tumorkontrolle, Nebenwirkungen und Kosmetik nach Teilbrustbestrahlung (APBI) mittels 3-D-konformaler, akzelerierter Radiotherapie (3D-CRT). Zwischen 2006 und 2011 wurden 44 Patienten mit Brustkrebs im Stadium I-II und niedrigem Risikoprofil brusterhaltend operiert. Die adjuvante, 3-D-konformale APBI wurde mittels 3-5 nonkoplanarer Feldern durchgefuehrt. Die Gesamtdosis betrug 36,9 Gy bei 9 -mal 4,1 Gy b.i.d.. Nach

  20. Main of probabilistic safety assessment (PSA) of the radiotherapy treatment process with a linear accelerator for medical purposes (linac)

    The radiation safety assessments traditionally have been based on analyzing the lessons you learn of new events that are becoming known. Although these methods are very valuable, their main limitation is that only cover known events and leave without consider other possible failures that have occurred or have not been published, This does not mean they can not occur. Other tools to analyze prospectively the safety, among which found Probabilistic Safety Assessment (PSA). This paper summarizes the project of American Forum of agencies radiological and nuclear regulators aimed at applying the methods of APS treatment process with a linear accelerator. We defined as unintended consequences accidental exposures both single patient and multiple patients. FMEA methodology was used to define events initiators of accidents and methods of event trees and trees failure to identify the accident sequences that may occur. A Once quantified the frequency of occurrence of accidental sequences Analyses of importance in determining the most recent events significant from the point of view of safety. We identified 158 of equipment failure modes and 295 errors human if they occurred would have the potential to cause the accidental exposures defined. We studied 118 of initiating events accident and 120 barriers. We studied 434 accident sequences. The accidental exposure of a single patient were 40 times likely that multiple patients. 100% of the total frequency of accidental exposures on a single patient is caused by human errors . 8% of the total frequency of accidental exposures on multiple patients initiating events may occur by equipment failure (Computerized tomography, treatment planning system, throttle linear) and 92% by human error. As part of the and recommendations of the study presents the events that are more contribution on the reduction of risk of accidental exposure. (author)

  1. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: effect of ion chamber calibration and long-term stability

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL 'dose intercomparison' for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy and uncertainities are within reported values. (author)

  2. Cost minimization analysis at the Hospital Mexico in the Caja Costarricense de Seguro Social for the accommodation of patients with radiotherapy with linear accelerator: shelter vs transfers

    Patients with oncological pathology have attended daily in sessions for several weeks in the linear accelerator radiation therapy. Persons subject to this intervention have moved to the Hospital Mexico of the social security of Costa Rica, place that centralizes this treatment. The Caja Costarricense de Seguro Social (CCSS) has considered two options depending on the place of origin of users: bear the costs of commuting from the area of habitual residence, or place them temporarily in a shelter provided by the institution; the CCSS has chosen the first alternative. This research has consisted of a cost-minimization analysis between these two alternatives. The study population are patients with oncological pathology attending sessions of radiotherapy with linear accelerator at the Hospital Mexico in the first half of 2009 using ambulances of Cruz Roja Costarricense. The size of the study population is 107 persons, the total number of transferred recorded in the Fondo Rotatorio de Operaciones of Hospital Mexico is 998. Patients came from five regions and twenty areas of health according to the geographical division of the CCSS. The variables included have been: cost per day by way of transfer, which involves the distance to the radiotherapy center of Hospital Mexico and the cost of the rate at Cruz Roja ambulance per Km (326.86 colons, according to the agreement CCSS-Cruz Roja in June 2009) estimated daily cost of lodging in a shelter, and the reason daily cost of relocation / daily cost of shelter. The cost of shelter includes food and were used data from the company International Medical Suppliers S. A. as a basis for estimating the daily cost, the price fixed by the company was 65 dollars a day, and the conversion into colons exchange rate as established by the Banco Central de Costa Rica; dated April 30, 2010, the amount has been 33.542.60 colons. The reason for each area of health was given by the ratio of the average daily cost in colons by way of ambulance of

  3. Induction Chemotherapy and Continuous Hyperfractionated Accelerated Radiotherapy (CHART) for Patients With Locally Advanced Inoperable Non-Small-Cell Lung Cancer: The MRC INCH Randomized Trial

    Purpose: Recent clinical trials and meta-analyses have shown that both CHART (continuous hyperfractionated accelerated radiation therapy) and induction chemotherapy offer a survival advantage over conventional radical radiotherapy for patients with inoperable non-small cell-lung cancer (NSCLC). This multicenter randomized controlled trial (INCH) was set up to assess the value of giving induction chemotherapy before CHART. Methods and Materials: Patients with histologically confirmed, inoperable, Stage I-III NSCLC were randomized to induction chemotherapy (ICT) (three cycles of cisplatin-based chemotherapy followed by CHART) or CHART alone. Results: Forty-six patients were randomized (23 in each treatment arm) from 9 UK centers. As a result of poor accrual, the trial was closed in December 2007. Twenty-eight patients were male, 28 had squamous cell histology, 34 were Stage IIIA or IIIB, and all baseline characteristics were well balanced between the two treatment arms. Seventeen (74%) of the 23 ICT patients completed the three cycles of chemotherapy. All 42 (22 CHART + 20 ICT) patients who received CHART completed the prescribed treatment. Median survival was 17 months in the CHART arm and 25 months in the ICT arm (hazard ratio of 0.60 [95% CI 0.31-1.16], p = 0.127). Grade 3 or 4 adverse events (mainly fatigue, dysphagia, breathlessness, and anorexia) were reported for 13 (57%) CHART and 13 (65%) ICT patients. Conclusions: This small randomized trial indicates that ICT followed by CHART is feasible and well tolerated. Despite closing early because of poor accrual, and so failing to show clear evidence of a survival benefit for the additional chemotherapy, the results suggest that CHART, and ICT before CHART, remain important options for the treatment of inoperable NSCLC and deserve further study.

  4. Dose volume histogram analysis of normal structures associated with accelerated partial breast irradiation delivered by high dose rate brachytherapy and comparison with whole breast external beam radiotherapy fields

    Mutyala Subhakar

    2008-11-01

    Full Text Available Abstract Purpose To assess the radiation dose delivered to the heart and ipsilateral lung during accelerated partial breast brachytherapy using a MammoSite™ applicator and compare to those produced by whole breast external beam radiotherapy (WBRT. Materials and methods Dosimetric analysis was conducted on patients receiving MammoSite breast brachytherapy following conservative surgery for invasive ductal carcinoma. Cardiac dose was evaluated for patients with left breast tumors with a CT scan encompassing the entire heart. Lung dose was evaluated for patients in whom the entire lung was scanned. The prescription dose of 3400 cGy was 1 cm from the balloon surface. MammoSite dosimetry was compared to simulated WBRT fields with and without radiobiological correction for the effects of dose and fractionation. Dose parameters such as the volume of the structure receiving 10 Gy or more (V10 and the dose received by 20 cc of the structure (D20, were calculated as well as the maximum and mean doses received. Results Fifteen patients were studied, five had complete lung data and six had left-sided tumors with complete cardiac data. Ipsilateral lung volumes ranged from 925–1380 cc. Cardiac volumes ranged from 337–551 cc. MammoSite resulted in a significantly lower percentage lung V30 and lung and cardiac V20 than the WBRT fields, with and without radiobiological correction. Conclusion This study gives low values for incidental radiation received by the heart and ipsilateral lung using the MammoSite applicator. The volume of heart and lung irradiated to clinically significant levels was significantly lower with the MammoSite applicator than using simulated WBRT fields of the same CT data sets. Trial registration Dana Farber Trial Registry number 03-179

  5. Accelerated partial breast irradiation with external beam three-dimensional conformal radiotherapy. Five-year results of a prospective phase II clinical study

    The aim of this study was to report the 5-year results of accelerated partial breast irradiation (APBI) using external beam three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2011, 44 patients with low-risk, stage I-II breast cancer underwent breast-conserving surgery. Postoperative APBI was given by means of 3D-CRT using three to five non-coplanar fields. The total dose of APBI was 36.9 Gy (nine fractions of 4.1 Gy b.i.d.). The mean follow-up time was 58.2 months for surviving patients. Survival results, side effects, and cosmetic results were assessed. One (2.3 %) local recurrence was observed, for a 5-year actuarial rate of 3.7 %. Neither regional nor distant failure was observed. Two patients died of internal disease. The 5-year disease-free, cancer-specific, and overall survival rates were 96.3, 100, and 95.1 %, respectively. Acute side effects included grade 1 (G1) erythema in 75 %, G1 parenchymal induration in 46 %, and G1 pain in 46 % of patients. No G2 or higher acute side effect occurred. Late side effects included G1, G2, and G3 fibrosis in 44, 7, and 2 % of patients, respectively, G1 skin pigmentation in 12 %, and G1 pain in 2 %. Asymptomatic fat necrosis occurred in 14 %. Cosmetic results were rated excellent or good in 86 % of cases by the patients themselves and 84 % by the physicians. The 5-year local tumor control, toxicity profile, and cosmetic results of APBI delivered with external beam 3D-CRT are encouraging and comparable to other APBI series. (orig.)

  6. Elective lymph node irradiation late course accelerated hyper-fractionated radiotherapy plus concurrent cisplatin-based chemotherapy for esophageal squamous cell carcinoma: a phase II study

    In this phase II study, we evaluated the efficacy, toxicity, and patterns of failure of elective lymph node irradiation (ENI) late course accelerated hyper-fractionated radiotherapy (LCAHRT) concurrently with cisplatin-based chemotherapy (CHT) for esophageal squamous cell carcinoma (ESCC). Patients with clinical stage II-IVa (T1-4N0-1M0 or M1a) ESCC were enrolled between 2004 and 2011. Radiation therapy (RT) comprised two courses: The first course of radiation covered the primary and metastatic regional tumors and high risk lymph nodal regions, given at 2 Gy per fraction for a dose of 40 Gy. In the second course, LCAHRT was delivered to the boost volume twice a day for an additional 19.6 Gy in 7 treatment days, using 1.4 Gy per fraction. Two cycles of CHT were given at the beginning of RT. The median age and Karnofsky performance status were 63 years and 80, respectively. The American Joint Committee on Cancer stage was II in 14 (20.6%) patients, III in 32 (47.1%), and IVa in 22 (32.3%). With a median follow-up of 18.5 months, the overall survival at 1-, 3-, 5-year were 75.5%, 46.5%, 22.7% for whole group patients, versus 78.6%, 49.4%, 39.9% for patients with stage II–III. The patterns of first failure from local recurrence, regional failure, and distant metastasis were seen in 20.6%, 17.6%, and 19.1%, respectively. The most frequent acute high-grade (≥ 3) toxicities were esophagitis and leucopenia, occurred in 26.4% and 32.4%. ENI LCAHRT concurrently with CHT was appeared to be an effective regimen for ESCC patient with a favorable and tolerated profile. Further observation with longer time and randomized phase III trial is currently underway.

  7. Long-term results of low dose daily cisplatin chemotherapy used concurrently with modestly accelerated radiotherapy in locally advanced squamous cell carcinomas of the head neck cancer region

    Pramod Kumar Gupta

    2014-01-01

    Full Text Available Introduction: Concurrent single agent cisplatin (CDDP with radiotherapy (RT improves outcomes in locally advanced squamous cell carcinomas of the head neck (LA-SCCHN. CDDP at 100 mg/m 2 at 3 weekly intervals raise compliance, hospitalization, and supportive care issues. Low dose daily CDDP was delivered with RT to evaluate its compliance, long-term safety and efficacy. Patients and Methods: During the period of month between November 2005 and May 2007, 52 patients of stage III/IV LA-SCCHN were given with conventional RT in a phased manner (dose-70 Gy/35 fractions/6 weeks along with daily CDDP (6 mg/m 2 ; capped 10 mg-30 cycles over 6 weeks. No hospitalization or antiemetic cover was planned. Compliance, acute and late toxicity were recorded as per Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer grading system and survival outcomes were evaluated. Results : The median follow-up was 63 months. 43 (83% cases complied with RT schedule and >28 cycles of CDDP was administered in 38 (73% cases. Confluent mucositis was seen in 65%, Grade III/IV dysphagia in 67%; 77% required enteral feed and hospitalization in 15%. There were four treatment related deaths. At 5 years, the loco-regional control was 25% (median-11 months and the overall survival was 31% (median-11 months. The 5 years actuarial rates of late Grade III/IV toxicity was 24%. Late swallowing difficulty/aspiration were seen in 17%; xerostomia-40%; ototoxicity-6%; nephrotoxicity-4%; and no second malignancy. Conclusion: Low dose cisplatin with moderately accelerated RT schedule appears feasible and logistically suitable "out-patient" option without increasing long-term toxicity in LA-SCCHN cancer region.

  8. Blood oxygenation level-dependent magnetic resonance imaging during carbogen breathing: differentiation between prostate cancer and benign prostate hyperplasia and correlation with vessel maturity

    Di, Ningning; Mao, Ning; Cheng, Wenna; Pang, Haopeng; Ren, Yan; Wang, Ning; Liu, Xinjiang; Wang, Bin

    2016-01-01

    Objective The aim of this study was to investigate whether the blood oxygenation level-dependent (BOLD) contrast magnetic resonance imaging (MRI) can evaluate tumor maturity and preoperatively differentiate prostate cancer (PCa) from benign prostate hyperplasia (BPH). Patients and methods BOLD MRI based on transverse relaxation time*-weighted echo planar imaging was performed to assess PCa (19) and BPH (22) responses to carbogen (95% O2 and 5% CO2). The average signal values of PCa and BPH before and after carbogen breathing and the relative increased signal values were computed, respectively. The endothelial-cell marker, CD31, and the pericyte marker, α-smooth muscle actin (mature vessels), were detected with immunofluorescence, and were assessed by microvessel density (MVD) and microvessel pericyte density (MPD). The microvessel pericyte coverage index (MPI) was used to evaluate the degree of vascular maturity. The changed signal from BOLD MRI was correlated with MVD, MPD, and MPI. Results After inhaling carbogen, both PCa and BPH showed an increased signal, but a lower slope was found in PCa than that in BPH (PMPI than BPH. The increased signal intensity was positively correlated with MPI in PCa and that in BPH (r=0.616, P=0.011; r=0.658, P=0.002); however, there was no correlation between the increased signal intensity and MPD or MVD in PCa than that in BPH (P>0.05). Conclusion Our results confirmed that the increased signal values induced by BOLD MRI well differentiated PCa from BPH and had a positive correlation with vessel maturity in both of them. BOLD MRI can be utilized as a surrogate marker for the noninvasive assessment of the degree of vessel maturity. PMID:27462169

  9. Accelerated hyperfractionated radiotherapy combined with induction and concomitant chemotherapy for inoperable non-small-cell lung cancer. Impact of total treatment time

    Tumour cell proliferation during conventionally fractionated radiotherapy (RT) can negatively influence the treatment outcome in patients with unresectable non-small-cell lung cancer (NSCLC). Accelerated and hyperfractionated RT may therefore have an advantage over conventional RT. Moreover, earlier studies have suggested improved survival with addition of cisplatin-based chemotherapy (CT). We present here the results of combined treatment with induction and concomitant CT and accelerated hyperfractionated RT in a retrospective series of patients with advanced NSCLS. Between August 1990 and August 1995, 90 consecutive patients, aged 42-77 years (median 63 years), with locally advanced unresectable or medically inoperable NSCLC and good performance status were referred for treatment: stage: I 23%, IIIa 37%, IIIb 40%. Patient histologies included: squamous cell carcinoma 52%, adenocarcinoma 34% and large cell carcinoma 13%. The treatment consisted of two courses of CT (cisplatin 100 mg/m2 day 1 and etoposide 100 mg/m2 day 1-3 i.v.), the second course given concomitantly with RT. The total RT dose was 61.2-64.6 Gy, with two daily fractions of 1.7 Gy. A one-week interval was introduced after 40.8 Gy to reduce acute toxicity, making the total treatment time 4.5 weeks. Concerning toxicity, 33 patients had febrile neutropenia, 10 patients suffered from grade III oesophagitis and 7 patients had grade III pneumonitis. There were two possible treatment-related deaths, one due to myocardial infarction and the other due to a pneumocystis carinii infection. The 1-, 2- and 3-year overall survival rates were 72%, 46% and 34%, respectively; median survival was 21.3 months. Fifty-nine patients had progressive disease: 21 failed locoregionally, 29 had distant metastases and 9 patients had a combination of these. Pretreatment weight loss was the only prognostic factor found, except for stage. However, the results for stage IIIb were no different from those for stage IIIa. We conclude

  10. Radiotherapy cure: safety

    In radiotherapy, a precisely measured dose of ionising radiation is directed at a limited tumour area so as not to damage healthy tissues. The most important form of therapy is external radiation therapy given by means of radiotherapy equipment. The bigger the tumour, the more cancer cells it contains and the higher the radiation dose that is needed to destroy the tumour. Different cancer types respond differently to radiation. Healthy tissues also respond in different ways to radiotherapy, e.g. the reaction may come during the treatment or later. The growth of some cancer types accelerates in two to four weeks after the initiation of the therapy. This information has brought about a reduction in treatment times so as to avoid cell growth that might endanger the treatment result. The radiotherapy that is given today by specialist doctors is safe because the side effects of the treatment are well under control. (orig.)

  11. Rapidly alternating combination of cisplatin-based chemotherapy and hyperfractionated accelerated radiotherapy in split course for Stage IIIA and Stage IIIB non-small cell lung cancer: results of a Phase I-II study by the GOTHA group

    Alberto, P.; Mermillod, B. [Hopital Cantonal Geneve, Geneva (Switzerland); Mirimanoff, R.O.; Leyvraz, S.; Nagy-Mignotte, H.; Bolla, M.; Wellmann, D.; Moro, D.; Brambilla, E. [Hopital Cantonal Universitaire, Lausanne (Switzerland)

    1995-08-01

    The prognosis of stage III non-small cell lung cancer (NSCLC) can be improved by a combination of radiotherapy (RT) and chemotherapy (CT). In this study, the GOTHA group evaluated the feasibility, tolerance, tumour response, pattern of failure and effect on survival of a combination alternating accelerated hyperfractionated (AH) RT and CT in patients with tumour stage III NSCLC. Toxic effects were leucopenia, nausea and vomiting, mucositis, diarrhoea, alopecia and peripheral neuropathy. Alternating CT and AHRT, as used in this study, were well tolerated and allowed full dose delivery within less than 12 weeks. Initial response was not predictive of survival. The survival curve is encouraging and the 5 year survival is superior to the 5% generally observed with conventionally fractionated radiotherapy. (author).

  12. Peripheral dose measurements with diode and thermoluminescence dosimeters for intensity modulated radiotherapy delivered with conventional and un-conventional linear accelerator

    Rajesh Kinhikar

    2013-01-01

    Full Text Available The objective of this paper was to measure the peripheral dose (PD with diode and thermoluminescence dosimeter (TLD for intensity modulated radiotherapy (IMRT with linear accelerator (conventional LINAC, and tomotherapy (novel LINAC. Ten patients each were selected from Trilogy dual-energy and from Hi-Art II tomotherapy. Two diodes were kept at 20 and 25 cm from treatment field edge. TLDs (LiF:MgTi were also kept at same distance. TLDs were also kept at 5, 10, and 15 cm from field edge. The TLDs were read with REXON reader. The readings at the respective distance were recorded for both diode and TLD. The PD was estimated by taking the ratio of measured dose at the particular distance to the prescription dose. PD was then compared with diode and TLD for LINAC and tomotherapy. Mean PD for LINAC with TLD and diode was 2.52 cGy (SD 0.69, 2.07 cGy (SD 0.88 at 20 cm, respectively, while at 25 cm, it was 1.94 cGy (SD 0.58 and 1.5 cGy (SD 0.75, respectively. Mean PD for tomotherapy with TLD and diode was 1.681 cGy SD 0.53 and 1.58 (SD 0.44 at 20 cm, respectively. The PD was 1.24 cGy (SD 0.42 and 1.088 cGy (SD 0.35 at 25 cm, respectively, for tomotherapy. Overall, PD from tomotherapy was found lower than LINAC by the factor of 1.2-1.5. PD measurement is essential to find out the potential of secondary cancer. PD for both (conventional LINAC and novel LINACs (tomotherapy were measured and compared with each other. The comparison of the values for PD presented in this work and those published in the literature is difficult because of the different experimental conditions. The diode and TLD readings were reproducible and both the detector readings were comparable.

  13. WE-G-BRE-09: Targeted Radiotherapy Enhancement During Accelerated Partial Breast Irradiation (ABPI) Using Controlled Release of Gold Nanoparticles (GNPs)

    Cifter, G; Ngwa, W [University of Massachusetts (United States); Harvard Medical School, Dana Farber Cancer Institute (United States); Chin, J; Cifter, F; Sajo, E [University of Massachusetts (United States); Sinha, N [Wentworth Institute of Technology, Boston, MA (United States); Bellon, J [Harvard Medical School, Dana Farber Cancer Institute (United States)

    2014-06-15

    Purpose: Several studies have demonstrated low rates of local recurrence with brachytherapy-based accelerated partial breast irradiation (APBI). However, long-term outcomes on toxicity (e.g. telangiectasia), and cosmesis remain a major concern. The purpose of this study is to investigate the dosimetric feasibility of using targeted non-toxic radiosensitizing gold nanoparticles (GNPs) for localized dose enhancement to the planning target volume (PTV) during APBI while reducing dose to normal tissue. Methods: Two approaches for administering the GNPs were considered. In one approach, GNPs are assumed to be incorporated in a micrometer-thick polymer film on the surface of routinely used mammosite balloon applicators, for sustained controlled in-situ release, and subsequent treatment using 50-kVp Xoft devices. In case two, GNPs are administered directly into the lumpectomy cavity e.g. via injection or using fiducials coated with the GNP-loaded polymer film. Recent studies have validated the use of fiducials for reducing the PTV margin during APBI with 6 MV beams. An experimentally determined diffusion coefficient was used to determine space-time customizable distribution of GNPs for feasible in-vivo concentrations of 43 mg/g. An analytic calculational approach from previously published work was employed to estimate the dose enhancement due to GNPs (2 and 10 nm) as a function of distance up to 1 cm from lumpectomy cavity. Results: Dose enhancement due to GNP was found to be about 130% for 50-kVp x-rays, and 110% for 6-MV external beam radiotherapy, 1 cm away from the lumpectomy cavity wall. Higher customizable dose enhancement could be achieved at other distances as a function of nanoparticle size. Conclusion: Our preliminary results suggest that significant dose enhancement can be achieved to residual tumor cells targeted with GNPs during APBI with electronic brachytherapy or external beam therapy. The findings provide a useful basis for developing nanoparticle

  14. WE-G-BRE-09: Targeted Radiotherapy Enhancement During Accelerated Partial Breast Irradiation (ABPI) Using Controlled Release of Gold Nanoparticles (GNPs)

    Purpose: Several studies have demonstrated low rates of local recurrence with brachytherapy-based accelerated partial breast irradiation (APBI). However, long-term outcomes on toxicity (e.g. telangiectasia), and cosmesis remain a major concern. The purpose of this study is to investigate the dosimetric feasibility of using targeted non-toxic radiosensitizing gold nanoparticles (GNPs) for localized dose enhancement to the planning target volume (PTV) during APBI while reducing dose to normal tissue. Methods: Two approaches for administering the GNPs were considered. In one approach, GNPs are assumed to be incorporated in a micrometer-thick polymer film on the surface of routinely used mammosite balloon applicators, for sustained controlled in-situ release, and subsequent treatment using 50-kVp Xoft devices. In case two, GNPs are administered directly into the lumpectomy cavity e.g. via injection or using fiducials coated with the GNP-loaded polymer film. Recent studies have validated the use of fiducials for reducing the PTV margin during APBI with 6 MV beams. An experimentally determined diffusion coefficient was used to determine space-time customizable distribution of GNPs for feasible in-vivo concentrations of 43 mg/g. An analytic calculational approach from previously published work was employed to estimate the dose enhancement due to GNPs (2 and 10 nm) as a function of distance up to 1 cm from lumpectomy cavity. Results: Dose enhancement due to GNP was found to be about 130% for 50-kVp x-rays, and 110% for 6-MV external beam radiotherapy, 1 cm away from the lumpectomy cavity wall. Higher customizable dose enhancement could be achieved at other distances as a function of nanoparticle size. Conclusion: Our preliminary results suggest that significant dose enhancement can be achieved to residual tumor cells targeted with GNPs during APBI with electronic brachytherapy or external beam therapy. The findings provide a useful basis for developing nanoparticle

  15. Modelling accelerated fractionation in radiotherapy

    This study was undertaken to investigate optimum treatment schedules for highly proliferative tumours. The linear quadratic model is used to predict the most effective fractionation regimes. It should be pointed out that greater early effects are associated with improved tumour control, as such these data should be treated as a useful guideline and should never be used out of context with clinical experience. The linear quadratic model with proliferation has been used to investigate the effect on cell survival and associated tumour control probability (TCP)

  16. Concurrent hyperfractionated accelerated radiotherapy with 5-FU and once weekly cisplatin in locally advanced head and neck cancer. The 10-year results of a prospective phase II trial

    Budach, V.; Boehmer, D.; Badakhshi, H.; Jahn, U.; Stromberger, C. [Campus Virchow Klinikum, Charite Universitaetsmedizin Berlin, Department for Radiooncology, Clinic for Radiooncology, Berlin (Germany); Becker, E.T. [Charite Universitaetsmedizin, Department of Otorhinolaryngology, Berlin (Germany); Wernecke, K.D. [Sostana Statistics GmbH, Charite Universitaetsmedizin Berlin, Berlin (Germany)

    2014-03-15

    In this study, the acute toxicity and long-term outcome of a hyperfractionated accelerated chemoradiation regimen with cisplatin/5-fluorouracil (5-FU) in patients with locally advanced squamous cell carcinomas of head and neck were evaluated. From 2000-2002, 38 patients with stage III (5.3 %) and stage IV (94.7 %) head and neck cancer were enrolled in a phase II study. Patients received hyperfractionated-accelerated radiotherapy with 72 Gy in 15 fractions of 2 Gy followed by 1.4 Gy twice daily with concurrent, continuous infusion 5-FU of 600 mg/m{sup 2} on days 1-5 and 6 cycles of weekly cisplatin (30 mg/m{sup 2}). Acute toxicities (CTCAEv2.0), locoregional control (LRC), metastases-free (MFS), and overall survival (OS) were analyzed and exploratively compared with the ARO 95-06 trial. Median follow-up was 11.4 years (95 % CI 8.6-14.2) and mean dose 71.6 Gy. Of the patients, 82 % had 6 (n = 15) or 5 (n = 16) cycles of cisplatin, 5 and 2 patients received 4 and 3 cycles, respectively. Grade 3 anemia, leukopenia, and thrombocytopenia were observed in 15.8, 15.8, and 2.6 %, respectively. Grade 3 mucositis in 50 %, grade 3 and 4 dysphagia in 55 and 13 %. The 2-, 5-, and 10-year LRC was 65, 53.6, and 48.2 %, the MFS was 77.5, 66.7, and 57.2 % and the OS 59.6, 29.2, and 15 %, respectively. Chemoradiation with 5-FU and cisplatin seems feasible and superior in terms of LRC and OS to the ARO 95-06C-HART arm at 2 years. However, this did not persist at the 5- and 10-year follow-ups. (orig.) [German] Untersuchung der Akuttoxizitaet und des Langzeitueberlebens einer hyperfraktioniert-akzelerierten simultanen Radiochemotherapie mit Cisplatin/5-Fluorouracil (5-FU) bei Patienten mit lokal fortgeschrittenen Kopf-Hals-Tumoren. Von 2000 bis 2002 wurden 38 Patienten mit Plattenepithelkarzinomen der Kopf-Hals-Region im Stadium III (5,3 %) und IV (94,7 %) eingeschlossen. Es erfolgte eine simultane hyperfraktionierte akzelerierte Radiochemotherapie mit 72 Gy in 15 Fraktionen a 2 Gy

  17. IAEA-HypoX. A randomized multicenter study of the hypoxic radiosensitizer nimorazole concomitant with accelerated radiotherapy in head and neck squamous cell carcinoma

    Purpose: To test the hypothesis that radiotherapy (RT) of head and neck squamous cell carcinoma (HNSCC) can be improved by hypoxic modification using nimorazole (NIM) in association with accelerated fractionation. Materials and methods: The protocol was activated in March 2012 as an international multicenter randomized trial in patients with HNSCC. Tumors were treated to a dose of 66–70 Gy, 33–35 fractions, 6 fractions per week. NIM was administered in a dose of 1.2 g per m2, 90 min before the first daily RT fraction. The primary endpoint was loco-regional failure. The trial was closed prematurely by June 2014 due to poor recruitment. An associated quality assurance program was performed to ensure the consistency of RT with the protocol guidelines. Results: The trial was dimensioned to include 600 patients in 3 years, but only 104 patients were randomized between March 2012 and May 2014 due to the inability to involve three major centers and the insufficient recruitment rate from the other participating centers. Twenty patients from two centers had to be excluded from the analysis due to the unavailability of the follow-up data. Among the remaining 84 patients, 82 patients were evaluable (39 and 43 patients in the RT + NIM and the RT-alone arms, respectively). The treatment compliance was good with only six patients not completing the full planned RT course, and 31 patients (79%) out of 39 allocated for NIM, achieving at least 90% of the prescribed drug dose. At the time of evaluation, 40 patients had failed to achieve persistent loco-regional tumor control, and a total of 45 patients had died. The use of NIM improved the loco-regional tumor control with an 18 month post-randomization cumulative failure rate of 33% versus 51% in the control arm, yielding a risk difference of 18% (CI −3% to 39%; P = 0.10). The corresponding values for overall death was 43% versus 62%, yielding a risk difference of 19% (CI −3% to 42%; P = 0.10). Sixteen patients, out of 55

  18. Quantitative analysis of results of quality control tests in linear accelerators used in radiotherapy; Analise quantitativa dos resultados de testes de controle de qualidade em aceleradores lineares usados em radioterapia

    Passaro, Bruno M.; Rodrigues, Laura N. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Videira, Heber S., E-mail: bruno.passaro@gmail.com [Universidade de Sao Paulo (HCFMRP/USP), Sao Paulo, SP (Brazil). Faculdade de Medicina. Hospital das Clinicas

    2013-04-15

    The aim of this study is to assess and analyze the stability of the calibration factor of three linear accelerators, as well as the other dosimetric parameters normally included in a program of quality control in radiotherapy. The average calibration factors of the accelerators for the period of approximately four years for the Clinac 600C and Clinac 6EX were (0.998±0.012) and (0.996±0.014), respectively. For the Clinac 2100CD 6 MV and 15 MV was (1.008±0.009) and (1.006±0.010), respectively, in a period of approximately four years. The data of the calibration factors were divided into four subgroups for a more detailed analysis of behavior over the years. Through statistical analysis of calibration factors, we found that for the 600C and Clinacs 2100CD, is an expected probability that more than 90% of cases the values are within acceptable ranges according to TG-142, while for the Clinac 6EX is expected around 85% since this had several exchanges of accelerator components. The values of TPR20,10 of three accelerators are practically constant and within acceptable limits according to the TG-142. It can be concluded that a detailed study of data from the calibration factor of the accelerators and TPR{sub 20},{sub 10} from a quantitative point of view, is extremely useful in a quality assurance program. (author)

  19. Dose escalation of accelerated hypofractionated three-dimensional conformal radiotherapy (at 3 Gy/fraction) with concurrent vinorelbine and carboplatin chemotherapy in unresectable stage III non-small-cell lung cancer: a phase I trial

    Accelerated hypofractionated radiotherapy can shorten total treatment time and overcome the accelerated repopulation of tumour cells during radiotherapy. This therapeutic approach has demonstrated good efficacy in the treatment of locally advanced non-small-cell lung cancer (NSCLC). However, the optimal fractionation scheme remains uncertain. The purpose of this phase I trial was to explore the maximum tolerated dose (MTD) of accelerated hypofractionated three-dimensional conformal radiotherapy (3-DCRT) (at 3 Gy/fraction) administered in combination with concurrent vinorelbine (NVB) and carboplatin (CBP) chemotherapy for unresectable stage III NSCLC. Previously untreated cases of unresectable stage III NSCLC received accelerated hypofractionated 3-DCRT, delivered at 3 Gy per fraction, once daily, with five fractions per week. The starting dose was 66 Gy and an increment of 3 Gy was utilized. Higher doses continued to be tested in patient groups until the emergence of dose-limiting toxicity (DLT). The MTD was regarded as the dose that was one step below the dose at which DLT occurred. Patients received at least one cycle of a concurrent two-drug chemotherapy regimen of NVB and CBP. A total of 13 patients were enrolled and progressed through three dose escalation groups: 66 Gy, 69 Gy, and 72 Gy. No treatment-related deaths occurred. The major adverse events included radiation oesophagitis, radiation pneumonitis, and neutropenia. Nausea, fatigue, and anorexia were commonly observed, although the magnitude of these events was typically relatively minor. Among the entire group, four instances of DLT were observed, including two cases of grade 3 radiation oesophagitis, one case of grade 3 radiation pneumonitis, and one case of grade 4 neutropenia. All of these cases of DLT occurred in the 72 Gy group. Therefore, 72 Gy was designated as the DLT dose level, and the lower dose of 69 Gy was regarded as the MTD. For unresectable stage III NSCLC 69 Gy (at 3 Gy/fraction) was

  20. Long-Term Outcome and Morbidity After Treatment With Accelerated Radiotherapy and Weekly Cisplatin for Locally Advanced Head-and-Neck Cancer: Results of a Multidisciplinary Late Morbidity Clinic

    Ruetten, Heidi, E-mail: h.rutten@rther.umcn.nl [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Pop, Lucas A.M.; Janssens, Geert O.R.J. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Takes, Robert P. [Department of Otorhinolaryngology and Head and Neck Surgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Knuijt, Simone [Department of Rehabilitation/Speech Pathology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Rooijakkers, Antoinette F. [Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Berg, Manon van den [Department of Gastroenterology-Dietetics, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Merkx, Matthias A. [Department of Oral and Maxillofacial Surgery, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Herpen, Carla M.L. van [Department of Medical Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands); Kaanders, Johannes H.A.M. [Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen (Netherlands)

    2011-11-15

    Purpose: To evaluate the long-term outcome and morbidity after intensified treatment for locally advanced head-and-neck cancer. Methods and Materials: Between May 2003 and December 2007, 77 patients with Stage III to IV head-and-neck cancer were treated with curative intent. Treatment consisted of accelerated radiotherapy to a dose of 68 Gy and concurrent cisplatin. Long-term survivors were invited to a multidisciplinary outpatient clinic for a comprehensive assessment of late morbidity with special emphasis on dysphagia, including radiological evaluation of swallowing function in all patients. Results: Compliance with the treatment protocol was high, with 87% of the patients receiving at least five cycles of cisplatin and all but 1 patient completing the radiotherapy as planned. The 5-year actuarial disease-free survival and overall survival rates were 40% and 47%, respectively. Locoregional recurrence-free survival at 5 years was 61%. The 5-year actuarial rates of overall late Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) Grade 3 and Grade 4 toxicity were 52% and 25% respectively. Radiologic evaluation after a median follow-up of 44 months demonstrated impaired swallowing in 57% of the patients, including 23% with silent aspiration. Subjective assessment using a systematic scoring system indicated normalcy of diet in only 15.6% of the patients. Conclusion: This regimen of accelerated radiotherapy with weekly cisplatin produced favorable tumor control rates and survival rates while compliance was high. However, comprehensive assessment by a multidisciplinary team of medical and paramedical specialists revealed significant long-term morbidity in the majority of the patients, with dysphagia being a major concern.

  1. Long-Term Outcome and Morbidity After Treatment With Accelerated Radiotherapy and Weekly Cisplatin for Locally Advanced Head-and-Neck Cancer: Results of a Multidisciplinary Late Morbidity Clinic

    Purpose: To evaluate the long-term outcome and morbidity after intensified treatment for locally advanced head-and-neck cancer. Methods and Materials: Between May 2003 and December 2007, 77 patients with Stage III to IV head-and-neck cancer were treated with curative intent. Treatment consisted of accelerated radiotherapy to a dose of 68 Gy and concurrent cisplatin. Long-term survivors were invited to a multidisciplinary outpatient clinic for a comprehensive assessment of late morbidity with special emphasis on dysphagia, including radiological evaluation of swallowing function in all patients. Results: Compliance with the treatment protocol was high, with 87% of the patients receiving at least five cycles of cisplatin and all but 1 patient completing the radiotherapy as planned. The 5-year actuarial disease-free survival and overall survival rates were 40% and 47%, respectively. Locoregional recurrence–free survival at 5 years was 61%. The 5-year actuarial rates of overall late Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) Grade 3 and Grade 4 toxicity were 52% and 25% respectively. Radiologic evaluation after a median follow-up of 44 months demonstrated impaired swallowing in 57% of the patients, including 23% with silent aspiration. Subjective assessment using a systematic scoring system indicated normalcy of diet in only 15.6% of the patients. Conclusion: This regimen of accelerated radiotherapy with weekly cisplatin produced favorable tumor control rates and survival rates while compliance was high. However, comprehensive assessment by a multidisciplinary team of medical and paramedical specialists revealed significant long-term morbidity in the majority of the patients, with dysphagia being a major concern.

  2. Aggressive simultaneous radiochemotherapy with cisplatin and paclitaxel in combination with accelerated hyperfractionated radiotherapy in locally advanced head and neck tumors. Results of a phase I-II trial

    Kuhnt, T.; Pigorsch, S.; Pelz, T.; Haensgen, G.; Dunst, J. [Dept. of Radiotherapy, Martin Luther Univ., Halle (Germany); Becker, A. [Dept. of Radiotherapy, Martin Luther Univ., Halle (Germany); Dept. of Radiotherapy, Municipial Hospital, Dessau (Germany); Bloching, M.; Passmann, M. [Dept. of Head and Neck Surgery, Martin Luther Univ., Halle (Germany); Lotterer, E. [Dept. of Internal Medicine I, Martin Luther Univ., Halle (Germany)

    2003-10-01

    We have tested a very aggressive combination protocol with cisplatin and escalated paclitaxel in combination with accelerated hyperfractionated radiotherapy to assess the maximum tolerated dose (MTD), dose-limiting toxicity (DLT), overall toxicity, and response rate. Patients and Methods: The trial recruited 24 patients (21 males, three females, mean age 57 years) treated at our department from 1998 through 2001. Irradiation was administered in daily doses of 2 Gy up to 30 Gy followed by 1.4 Gy twice daily up to 70.6 Gy to the primary tumor and involved nodes and 51 Gy to the clinically negative regional nodes. The chemotherapy schedule included cisplatin in a fixed dose of 20 mg/m{sup 2} on days 1-5 and 29-33 and paclitaxel at increasing dose levels of 20, 25, 30 mg/m{sup 2} twice weekly over the whole treatment time. Patients were recruited in cohorts of three to six, and the MTD was reached if two out of six patients in one cohort developed DLT. DLT was defined as any grade 4 toxicity or any grade 3 toxicity requiring treatment interruption or unplanned hospitalization or any grade 3 neurotoxicity. We recruited mainly patients with large tumors for this protocol; all patients were stage IV, and the mean tumor volume (primary + metastases) amounted to 72 {+-} 61 cm{sup 3}. The mean follow-up was 30 months (range 4-39 months). Results: One early death (peritonitis and sepsis a t day 10) occurred, and 23 patients were evaluable for acute toxicity and response. The MTD of paclitaxel was reached at the third dose level (30 mg/m{sup 2} paclitaxel twice weekly). The DLT was severe mucositis grade 3 (n = 1) and skin erythema grade 4 (n = 2). After determining the MTD, another 14 patients were treated at the recommended dose level of paclitaxel with 25 mg/m{sup 2} twice weekly. In summary, 13/23 patients (57%) developed grade 3 and 10/23 (43%) grade 2 mucositis. Two patients (9%) had grade 4, five (22%) grade 3, and 16 (69%) grade 2 dermatitis. One patient died at day 30

  3. Clinical application of AcMAR (accelerated multiple-arc radiotherapy) for head and neck tumors. Results of a randomized, two-dose study in Kitami Red-Cross General Hospital

    Enhanced acute mucositis is the limiting factor for accelerated, hyperfractionated radiotherapy in head and neck (H and N) squamous cell carcinomas (SCCs). We have developed a simple, new form of conformal radiotherapy, accelerated multiple arc radiotherapy (AcMAR), which covers the target volume by combined, segmental, and rotational arc fields. Two to three rotational fields were placed with CT guidance, each covering the primary tumor and lymph nodes separately. The optimal inter-isocenter distance was determined by 3D dose calculation. The surface area of oro-pharyngeal mucosa irradiated by more than a 50% dose by this method was reduced by 37-73% compared to that with a conventional parallel opposing technic. Dose searching, randomized two-dose study was initiated in Kitami Red-cross General Hospital (KRCGH) in January 1995, and 101 patients were registered and completed AcMAR in Oct 2000. All the patients were followed for up to 96 months (24-96 mo, median 48 mo) at the time of analysis. Fifty-one out of 101 patients were Stage III (17) and IV (34). Primary site of tumors were; 38 larynx, 25 oropharynx, 15 hypopharynx, 13 oral cavity, and 10 other miscellaneous sites. Patients were randomly allocated either to 60 Gy/24 fr/bid/3 wks to gross tumor volume (GTV) (Group A), or 66 Gy/33 fr/bid/4 wks to GTV (Group B). Forty Gy/16 fr/bid/2 wks was given to the volume of prophylactic'' irradiation in both groups of patients. Results were as follows: All the patients, except for one, completed AcMAR without treatment interruption. Acute mucositis at the site of high-dose irradiation was intense; 72% of Group A and 62.5% of Group B experienced World Health Organization (WHO) Grade 3 (confluent) mucositis focally. Fifty-one out of 53 in Group A and 48/48 in Group B, however, could maintain oral food intake (WHO Grade 1 or 2) even at the peak of their mucositis, because of the limited area of severe mucositis. With regard to late morbidity, however, 6/46 (followed >24 mo

  4. Evaluation of a combined respiratory-gating system comprising the TrueBeam linear accelerator and a new real-time tumor-tracking radiotherapy system: a preliminary study.

    Shiinoki, Takehiro; Kawamura, Shinji; Uehara, Takuya; Yuasa, Yuki; Fujimoto, Koya; Koike, Masahiro; Sera, Tatsuhiro; Emoto, Yuki; Hanazawa, Hideki; Shibuya, Keiko

    2016-01-01

    A combined system comprising the TrueBeam linear accelerator and a new real-time, tumor-tracking radiotherapy system, SyncTraX, was installed in our institution. The goals of this study were to assess the capability of SyncTraX in measuring the position of a fiducial marker using color fluoroscopic images, and to evaluate the dosimetric and geometric accuracy of respiratory-gated radiotherapy using this combined system for the simple geometry. For the fundamental evaluation of respiratory-gated radiotherapy using SyncTraX, the following were performed:1) determination of dosimetric and positional characteristics of sinusoidal patterns using a motor-driven base for several gating windows; 2) measurement of time delay using an oscilloscope; 3) positional verification of sinusoidal patterns and the pattern in the case of a lung cancer patient; 4) measurement of the half-value layer (HVL in mm AL), effective kVp, and air kerma, using a solid-state detector for each fluoroscopic condition, to determine the patient dose. The dose profile in a moving phantom with gated radiotherapy having a gating window ≤ 4 mm was in good agreement with that under static conditions for each photon beam. The total time delay between TrueBeam and SyncTraX was lung cancer patient. The air-kerma rates from one fluoroscopy direction were 1.93 ± 0.01, 2.86 ± 0.01, 3.92 ± 0.04, 5.28 ± 0.03, and 6.60 ± 0.05 mGy/min for 70, 80, 90, 100, and 110 kV X-ray beams at 80 mA, respectively. The combined system comprising TrueBeam and SyncTraX could track the motion of the fiducial marker and control radiation delivery with reasonable accuracy; therefore, this system provides significant dosimetric improvement. However, patient exposure dose from fluoroscopy was not clinically negligible. PMID:27455483

  5. Construction of a remote radiotherapy planning system

    We constructed a remote radiotherapy planning system, and we examined the usefulness of and faults in our system in this study. Two identical radiotherapy planning systems, one installed at our institution and the other installed at an affiliated hospital, were used for radiotherapy planning. The two systems were connected by a wide area network (WAN), using a leased line. Beam data for the linear accelerator at the affiliated hospital were installed in the two systems. During the period from December 2001 to December 2002, 43 remote radiotherapy plans were made using this system. Data were transmitted using a file transfer protocol (FTP) software program. The 43 radiotherapy plans examined in this study consisted of 13 ordinary radiotherapy plans, 28 radiotherapy plans sent to provide assistance for medical residents, and 2 radiotherapy plans for emergency cases. There were ten minor planning changes made in radiotherapy plans sent to provide assistance for medical residents. Our remote radiotherapy planning system based on WAN using a leased line is useful for remote radiotherapy, with advantages for both radiation oncologists and medical residents. (author)

  6. Radiotherapy: yesterday, today and tomorrow

    The inaugural lecture starts with a brief history of the discovery of x-rays and the development of radiotherapy. In a modern radiotherapy department, cancer is diagnosed and mostly treated non-surgically. The modern treatment of many cancers is complex and involves a choice between at least 3 modalities; namely surgery, radiotherapy and cancer chemotherapy. One or a combination of these can be used. A discussion is given of a radiotherapy department as it functions at the University of Cape Town. At the University, cancer is not managed by any one treatment modality, but by a group of specialists who have a major intersest in a particular field. The personnel of the radiotherapy department consists of various people such as a radiographer, radiotherapist, radiobiologist and others, who are all experts in a particular area. Together they form the radiotherapy team. An individual treatment plan is drawn up for each patient. An indication is given of the cost of a major linear accelerator and the patient treatment cost on such an accelerator. Cancer chemotherapy comprises an important part in any radiotherapy department and is used to prevent the appearance of microscopic disease or to reduce and even cure established disease. A summary is given of the cost attached to chemotherapy. An indication of cure rates with the present methods of treatment is given. The reason why oxygen is necessary in the radiation of tumours is discussed. The radiobiologist plays an important role in this respect. A look is also taken at the future prospects of radiotherapy

  7. Preliminary Experience in Treatment of Papillary and Macular Retinoblastoma: Evaluation of Local Control and Local Complications After Treatment With Linear Accelerator-Based Stereotactic Radiotherapy With Micromultileaf Collimator as Second-Line or Salvage Treatment After Chemotherapy

    Purpose: To determine the local control and complication rates for children with papillary and/or macular retinoblastoma progressing after chemotherapy and undergoing stereotactic radiotherapy (SRT) with a micromultileaf collimator. Methods and Materials: Between 2004 and 2008, 11 children (15 eyes) with macular and/or papillary retinoblastoma were treated with SRT. The mean age was 19 months (range, 2–111). Of the 15 eyes, 7, 6, and 2 were classified as International Classification of Intraocular Retinoblastoma Group B, C, and E, respectively. The delivered dose of SRT was 50.4 Gy in 28 fractions using a dedicated micromultileaf collimator linear accelerator. Results: The median follow-up was 20 months (range, 13–39). Local control was achieved in 13 eyes (87%). The actuarial 1- and 2-year local control rates were both 82%. SRT was well tolerated. Late adverse events were reported in 4 patients. Of the 4 patients, 2 had developed focal microangiopathy 20 months after SRT; 1 had developed a transient recurrence of retinal detachment; and 1 had developed bilateral cataracts. No optic neuropathy was observed. Conclusions: Linear accelerator-based SRT for papillary and/or macular retinoblastoma in children resulted in excellent tumor control rates with acceptable toxicity. Additional research regarding SRT and its intrinsic organ-at-risk sparing capability is justified in the framework of prospective trials.

  8. Preliminary Experience in Treatment of Papillary and Macular Retinoblastoma: Evaluation of Local Control and Local Complications After Treatment With Linear Accelerator-Based Stereotactic Radiotherapy With Micromultileaf Collimator as Second-Line or Salvage Treatment After Chemotherapy

    Pica, Alessia, E-mail: Alessia.Pica@chuv.ch [Department of Radiation Oncology, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Moeckli, Raphael [University Institute for Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Balmer, Aubin [Department of Radiation Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland); Beck-Popovic, Maja [Unit of Pediatric Oncology, University of Lausanne, Lausanne (Switzerland); Chollet-Rivier, Madeleine [Department of Anesthesiology, University of Lausanne, Lausanne (Switzerland); Do, Huu-Phuoc [University Institute for Radiation Physics, Centre Hospitalier Universitaire Vaudois, Lausanne (Switzerland); Weber, Damien C. [Department of Radiation Oncology, Geneva University Hospital, University of Geneva, Geneva (Switzerland); Munier, Francis L. [Department of Radiation Oncology, Jules Gonin Eye Hospital, Lausanne (Switzerland)

    2011-12-01

    Purpose: To determine the local control and complication rates for children with papillary and/or macular retinoblastoma progressing after chemotherapy and undergoing stereotactic radiotherapy (SRT) with a micromultileaf collimator. Methods and Materials: Between 2004 and 2008, 11 children (15 eyes) with macular and/or papillary retinoblastoma were treated with SRT. The mean age was 19 months (range, 2-111). Of the 15 eyes, 7, 6, and 2 were classified as International Classification of Intraocular Retinoblastoma Group B, C, and E, respectively. The delivered dose of SRT was 50.4 Gy in 28 fractions using a dedicated micromultileaf collimator linear accelerator. Results: The median follow-up was 20 months (range, 13-39). Local control was achieved in 13 eyes (87%). The actuarial 1- and 2-year local control rates were both 82%. SRT was well tolerated. Late adverse events were reported in 4 patients. Of the 4 patients, 2 had developed focal microangiopathy 20 months after SRT; 1 had developed a transient recurrence of retinal detachment; and 1 had developed bilateral cataracts. No optic neuropathy was observed. Conclusions: Linear accelerator-based SRT for papillary and/or macular retinoblastoma in children resulted in excellent tumor control rates with acceptable toxicity. Additional research regarding SRT and its intrinsic organ-at-risk sparing capability is justified in the framework of prospective trials.

  9. Solid state tuneable power RF source for S-band klystron used in the indigenous development of medical linear accelerator for radiotherapy

    Medical Linear Accelerators (LINAC) are being widely used in the treatment of the cancer patients. The requirement of the energy and the particle type depends on the tumour site and its volume. Hence, it is a necessary to design and develop the multiple energy electron medical accelerators. We have successfully indigenously developed, installed and commissioned the 4 MV (Jeevan-Jyoti) and 6 MV (Siddarth) machines for this purpose. The said machines have been type approved by Atomic Energy Regulatory Board (AERB), Mumbai for the treatment of cancer patient. After this achievement we have taken up the project to design and develop the dual mode (Photon and Electron) multiple energy Medical Accelerator. This LINAC will deliver the two photon energies of 6 and 10 MV, whereas five electron energies viz. 6, 9, 12, 15 and 18 MeV. The system has various sub system such as Linear accelerator (radiation source), High power Modulator, Microwave system based on Klystron, Gantry, Patient Support Assembly, Dosimetry, Beam limiting system, control console, etc. In conclusion, we have successfully achieved the precise variation of RF power using this RF source which will be input to klystron amplifier and the accelerator will produce the different energies as per the treatment requirement using the FPGA based control system

  10. Accelerated high-dose radiotherapy alone or combined with either concomitant or sequential chemotherapy; treatments of choice in patients with Non-Small Cell Lung Cancer

    Results of high-dose chemo-radiotherapy (CRT), using the treatment schedules of EORTC study 08972/22973 or radiotherapy (RT) alone were analyzed among all patients (pts) with Non Small Cell Lung Cancer (NSCLC) treated with curative intent in our department from 1995–2004. Included are 131 pts with medically inoperable or with irresectable NSCLC (TNM stage I:15 pts, IIB:15 pts, IIIA:57 pts, IIIB:43 pts, X:1 pt). Group I: Concomitant CRT: 66 Gy/2.75 Gy/24 fractions (fx)/33 days combined with daily administration of cisplatin 6 mg/m2: 56 pts (standard). Group II: Sequential CRT: two courses of a 21-day schedule of chemotherapy (gemcitabin 1250 mg/m2 d1, cisplatin 75 mg/m2 d2) followed by 66 Gy/2.75 Gy/24 fx/33 days without daily cisplatin: 26 pts. Group III: RT: 66 Gy/2.75 Gy/24 fx/33 days or 60 Gy/3 Gy/20 fx/26 days: 49 pts. The 1, 2, and 5 year actuarial overall survival (OS) were 46%, 24%, and 15%, respectively. At multivariate analysis the only factor with a significantly positive influence on OS was treatment with chemo-radiation (P = 0.024) (1-, 2-, and 5-yr OS 56%, 30% and 22% respectively). The incidence of local recurrence was 36%, the incidence of distant metastases 46%. Late complications grade 3 were seen in 21 pts and grade 4 in 4 patients. One patient had a lethal complication (oesophageal). For 32 patients insufficient data were available to assess late complications. In this study we were able to reproduce the results of EORTC trial 08972/22973 in a non-selected patient population outside of the setting of a randomised trial. Radiotherapy (66 Gy/24 fx/33 days) combined with either concomitant daily low dose cisplatin or with two neo-adjuvant courses of gemcitabin and cisplatin are effective treatments for patients with locally advanced Non-Small Cell Lung Cancer. The concomitant schedule is also suitable for elderly people with co-morbidity

  11. A strategy for the use of image-guided radiotherapy (IGRT) on linear accelerators and its impact on treatment margins for prostate cancer patients

    In external beam radiotherapy of prostate cancer, the consideration of various systematic error types leads to wide treatment margins compromising normal tissue tolerance. We investigated if systematic set-up errors can be reduced by a set of initial image-guided radiotherapy (IGRT) sessions. 27 patients received daily IGRT resulting in a set of 882 cone-beam computed tomographies (CBCTs). After matching to bony structures, we analyzed the dimensions of remaining systematic errors from zero up to six initial IGRT sessions and aimed at a restriction of daily IGRT for 10% of all patients. For threshold definition, we determined the standard deviations (SD) of the shift corrections and selected patients out of this range for daily image guidance. To calculate total treatment margins, we demanded for a cumulative clinical target volume (CTV) coverage of at least 95% of the specified dose in 90% of all patients. The gain of accuracy was largest during the first three IGRTs. In order to match precision and workload criteria, thresholds for the SD of the corrections of 3.5 mm, 2.0 mm and 4.5 mm in the left-right (L-R), cranial-caudal (C-C), and anterior-posterior (A-P) direction, respectively, were identified. Including all other error types, the total margins added to the CTV amounted to 8.6 mm in L-R, 10.4 mm in C-C, and 14.4 mm in A-P direction. Only initially performed IGRT might be helpful for eliminating gross systematic errors especially after virtual simulation. However, even with daily IGRT performance, a substantial PTV margin reduction is only achievable by matching internal markers instead of bony anatomical structures. (orig.)

  12. How Do the ASTRO Consensus Statement Guidelines for the Application of Accelerated Partial Breast Irradiation Fit Intraoperative Radiotherapy? A Retrospective Analysis of Patients Treated at the European Institute of Oncology

    Purpose: To verify how the classification according to the American Society for Therapeutic Radiation Oncology (ASTRO) consensus statement (CS) for the application of accelerated partial breast irradiation (APBI) fits patients treated with intraoperative radiotherapy with electrons (ELIOT) at a single institution. Methods and Materials: The study included 1,822 patients treated with ELIOT as the sole radiation modality outside of a clinical trial at the European Institute of Oncology after breast-conserving surgery for invasive breast cancer, who were classified into CS groups of suitable, cautionary, and unsuitable. The outcome in terms of ipsilateral breast recurrence, regional node relapse, distant metastases, progression free-survival, cause-specific survival, and overall survival were assessed. Results: All the 1,822 cases except for 25 could be classified according to ASTRO CS: 294 patients met the criteria for inclusion into the suitable group, 691 patients into the cautionary group, and 812 patients into the unsuitable group. The 5-year rate of ipsilateral breast recurrence for suitable, cautionary, and unsuitable groups were 1.5%, 4.4%, and 8.8%, respectively (p = 0.0003). Whereas the regional node relapse showed no difference, the rate of distant metastases was significantly different in the unsuitable group compared with the suitable and cautionary groups, having a significant impact on survival. Conclusion: In the context of patients treated with ELIOT, the ASTRO guidelines identify well the groups for whom APBI might be considered as an effective alternative to whole breast radiotherapy and also identify groups for whom APBI is not indicated.

  13. Final results of the randomized phase III CHARTWEL-trial (ARO 97-1) comparing hyperfractionated-accelerated versus conventionally fractionated radiotherapy in non-small cell lung cancer (NSCLC)

    Background: Continuous hyperfractionated accelerated radiotherapy (CHART) counteracts repopulation and may significantly improve outcome of patients with non-small-cell lung cancer (NSCLC). Nevertheless high local failure rates call for radiation dose escalation. We report here the final results of the multicentric CHARTWEL trial (CHART weekend less, ARO 97-1). Patients and methods: Four hundred and six patients with NSCLC were stratified according to stage, histology, neoadjuvant chemotherapy and centre and were randomized to receive 3D-planned radiotherapy to 60 Gy/40 fractions/2.5 weeks (CHARTWEL) or 66 Gy/33 fractions/6.5 weeks (conventional fractionation, CF). Results: Overall survival (OS, primary endpoint) at 2, 3 and 5 yr was not significantly different after CHARTWEL (31%, 22% and 11%) versus CF (32%, 18% and 7%; HR 0.92, 95% CI 0.75-1.13, p = 0.43). Also local tumour control rates and distant metastases did not significantly differ. Acute dysphagia and radiological pneumonitis were more pronounced after CHARTWEL, without differences in clinical signs of pneumopathy. Exploratory analysis revealed a significant trend for improved LC after CHARTWEL versus CF with increasing UICC, T or N stage (p = 0.006-0.025) and after neoadjuvant chemotherapy (HR 0.48, 0.26-0.89, p = 0.019). Conclusions: Overall, outcome after CHARTWEL or CF was not different. The lower total dose in the CHARTWEL arm was compensated by the shorter overall treatment time, confirming a time factor for NSCLC. The higher efficacy of CHARTWEL versus CF in advanced stages and after chemotherapy provides a basis for further trials on treatment intensification for locally advanced NSCLC.

  14. Determination of radiation levels by neutrons in an accelerator for radiotherapy; Determinacion de niveles de radiacion por neutrones en un acelerador para radioterapia

    Paredes G, L.; Salazar B, M.A. [Instituto Nacional de Investigaciones Nucleares, Apdo. Postal 18-1027, 11801 Mexico D.F. (Mexico); Genis S, R. [Fundacion Clinica Medica Sur, Puente de Piedra 150, Col. Torriello Guerra, Tlalpan 14050, Mexico D.F. (Mexico)

    1998-12-31

    It was determined the radiation levels by neutrons due to photonuclear reactions ({gamma}, n) which occur in the target, levelling filter, collimators and the small pillow blinding of a medical accelerator Varian Clinac 2100C of 18 MeV, using thermoluminescent dosemeters UD-802AS and US-809AS. The experimental values were presented for the patient level, inside and outside of the radiation field, as well as for the small pillow. (Author)

  15. State of accelerator for therapy

    Maruhashi, A

    2002-01-01

    21 facilities carry out particle radiotherapy in the world and 6 facilities will start in the next year. They are shown in the table. 6 facilities of them exist in Japan. Small accelerator for proton therapy is developed. The area of them becomes smaller than 100 m sup 2. 5 makers, form, kinds of accelerator, length of track, beam energy of them are shown. States of particle radiotherapy in 4 facilities in Japan are explained by the kinds of particle, energy, beam intensity, time structure and radiation room. The important problems are reconsideration of building and compact rotating gantry. The problems of radiotherapy are explained. (S.Y.)

  16. Treatment machines for external beam radiotherapy

    Since the inception of radiotherapy soon after the discovery of X rays by Roentgen in 1895, the technology of X ray production has first been aimed towards ever higher photon and electron beam energies and intensities, and more recently towards computerization and intensity modulated beam delivery. During the first 50 years of radiotherapy the technological progress was relatively slow and mainly based on X ray tubes, van de Graaff generators and betatrons. The invention of the 60Co teletherapy unit by H.E. Johns in Canada in the early 1950s provided a tremendous boost in the quest for higher photon energies and placed the cobalt unit at the forefront of radiotherapy for a number of years. The concurrently developed medical linacs, however, soon eclipsed cobalt units, moved through five increasingly sophisticated generations and became the most widely used radiation source in modern radiotherapy. With its compact and efficient design, the linac offers excellent versatility for use in radiotherapy through isocentric mounting and provides either electron or megavoltage X ray therapy with a wide range of energies. In addition to linacs, electron and X ray radiotherapy is also carried out with other types of accelerator, such as betatrons and microtrons. More exotic particles, such as protons, neutrons, heavy ions and negative p mesons, all produced by special accelerators, are also sometimes used for radiotherapy; however, most contemporary radiotherapy is carried out with linacs or teletherapy cobalt units

  17. The spanish radiotherapy park: past and present

    The present article has as objective to provide a general overview on the spanish radiotherapy park, presenting how was its start and evolution until the current state. Considering only the units of teletherapy and the accelerators. Actually in Spain there is 28 units of Cobalt therapy, in functioning during the last two decades, being advised a rapid substitution to accelerators

  18. Radiotherapy; Strahlentherapie

    Wannenmacher, M. [Heidelberg Univ., Mannheim (Germany). Abt. fuer Klinische Radiologie; Debus, J. [Univ. Heidelberg (Germany). Abt. Radioonkologie und Strahlentherapie; Wenz, F. (eds.) [Universitaetsklinikum Mannheim (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2006-07-01

    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.

  19. Accelerated split-course radiotherapy and simultaneous cis-dichlorodiammine-platinum and 5-fluorouracil chemotherapy with folinic acid enhancement for unresectable carcinoma of the head and neck

    Thirty-four (6 stage III, 28 stage IV) patients with advanced squamous cell carcinoma of the head and neck were treated by simultaneous radio-chemotherapy. Treatment was divided into three cycles. Chemotherapy consisted of cis-diamminedichloroplatinum(II) (cis-DDP) 60 mg/sqm i.v., 5-fluorouracil (5-FU) 350 mg/sqm i.v. and folinic acid (FA)-50 mg/sqm i.v. on day 2 and 5-FU 350 mg/sqm per 24 h and FA 100 mg/sqm/24 h on days 2-5. Radiotherapy consisted of 23.4 Gy/9 days divided in 13 fractions of 1.8 Gy delivered twice a day from day 3 through day 11. This regimen was repeated on days 22 and 44. Total radiation dose amounted to 70.2 Gy/51 days. Mean follow-up of surviving patients was 21 (14-34) months. 28/32 patients achieved complete response, 4/32 partial response. Actuarial one and two years survival were 88 and 58% including two early deaths from tumour bleeding. Local control rates at one and two years were 87 and 81%, respectively. This protocol produces excellent palliation and the chance of improved long term tumour control. Two patients developed distant metastases. Overall toxicity was tolerable. Since the treatment breaks were inserted after low radiation doses, acute mucositis healed rapidly and was not a limiting factor. 39 refs.; 3 figs.; 3 tabs

  20. Radiotherapy for recurrent breast cancer

    Clinico-radiobiological characteristics of radiotherapy for relapsed breast cancer were studied. Adequate choice of tissue mass to be exposed appeared much more important than any change in focal dose within 50-80 Gy, to achieve higher frequency of locoregional therapeutic effect. However, recurrent tumors more than 3 large lower radiosensitivity involving a sharp rise in the likelihood of dissemination. Radiotherapy for primary tumor did not affect the radiosensitivity of recurrent malignancies but slowed down the rate of its growth. Also, it might promote the dissemination acceleration

  1. Biological and medical research with accelerated heavy ions at the Bevalac, 1974--1977. [Planning for use for radiotherapy and as radiation source for diagnostic radiography

    Elam, S. (ed.)

    1977-04-01

    The Bevalac, a versatile high-energy heavy-ion accelerator complex, has been in operation for less than two years. A major purpose for which the Bevalac was constructed was to explore the possibility of heavy-ion teams for therapy for certain forms of cancer. Significant progress has been made in this direction. The National Cancer Institute has recognized the advantages that these and other accelerated particles offer, and heavy ions have been included in a long-term plan for particle therapy that will assess by means of controlled therapeutic tests the value of various modalities. Since accelerated heavy ions became available, the possibility of other contributions, not planned, became apparent. We are developig a new diagnostic method known as heavy-ion radiography that has greatly increased sensitivity for soft-tissue detail and that may become a powerful tool for localizing early tumors and metastases. We have discovered that radioactive beams are formed from fragmentation of stable deflected beams. Use of these autoradioactive beams is just beginning; however, we know that these beams will be helpful in localizing the region in the body where therapy is being delivered. In addition, it has been demonstrated that instant implantation of the radioactive beam allows direct measurements of blood perfusion rates in inaccessible parts of the body, and such a technique may become a new tool for the study of fast hot atom reactions in biochemistry, tracer biology and nuclear medicine. The Bevalac will also be useful for the continuation of previously developed methods for the control of acromegaly, Cushing's disease and, on a research basis, advanced diabetes mellitus with vascular disease. The ability to make small bloodless lesions in the brain and elsewhere with heavy-ion beams has great potential for nervous-system studies and perhaps later for radioneurosurgery.

  2. Accelerated intensity-modulated radiotherapy plus temozolomide in patients with glioblastoma. A phase I dose-escalation study (ISIDE-BT-1)

    We performed a dose-escalation trial to determine the maximum tolerated dose (MTD) of intensity-modulated radiotherapy (IMRT) with standard concurrent and sequential-dose temozolomide (TMZ) in patients with glioblastoma multiforme. Histologically proven glioblastoma patients underwent IMRT dose escalation. IMRT was delivered over 5 weeks with the simultaneous integrated boost (SIB) technique to the two planning target volumes (PTVs) defined by adding 5-mm margin to the respective clinical target volumes (CTVs). CTV1 was the tumor bed plus the enhancing lesion with 10-mm margin; CTV2 was the area of perifocal edema with 20-mm margin. Only the PTV1 dose was escalated (planned dose escalation: 60, 62.5, 65, 67.5, 70 Gy) while the PTV2 dose remained the same (45 Gy). Forty consecutive glioblastoma patients were treated. While no dose-limiting toxicity (DLT) was recorded during the dose escalation up to 67.5/2.7 Gy, two out of the first six consecutively enrolled patients on the highest dose level (70/2.8 Gy) experienced a DLT, and therefore a cohort expansion was required. 3/14 patients experienced a DLT on the highest planned dose level, and therefore the MTD was not exceeded. After a median follow-up time of 25 months no grade >2 late neurological toxicity was recorded. By using a SIB IMRT technique, a radiation dose of 70 Gy in 25 fractions (biological effective dose-BED-of 92.8 Gy) can be delivered with concurrent and sequential standard dose TMZ, without unacceptable acute toxicity in patients with glioblastoma. (author)

  3. Cosmetic Outcomes for Accelerated Partial Breast Irradiation Before Surgical Excision of Early-Stage Breast Cancer Using Single-Dose Intraoperative Radiotherapy

    Purpose: Determine cosmetic outcome and toxicity profile of intraoperative radiation delivered before tumor excision for patients with early-stage breast cancer. Methods and Materials: Patients age 48 or older with ultrasound-visible invasive ductal cancers <3 cm and clinically negative lymph nodes were eligible for treatment on this institutional review board-approved Phase II clinical trial. Treatment planning ultrasound was used to select an electron energy and cone size sufficient to cover the tumor plus a 1.5- to 2.0-cm circumferential margin laterally and a 1-cm-deep margin with the 90% isodose line. The dose was prescribed to a nominal 15 Gy and delivered using a Mobetron electron irradiator before tumor excision by segmental mastectomy. Physician- and patient-assessed cosmetic outcome and patient satisfaction were determined by questionnaire. Results: From March 2003 to July 2007, 71 patients were treated with intraoperative radiation therapy. Of those, 56 patients were evaluable, with a median follow-up of 3.1 years (minimum 1 year). Physician and patient assessment of cosmesis was 'good or excellent' (Radiation Therapy Oncology Group cosmesis scale) in 45/56 (80%) and 32/42 (76%) of all patients, respectively. Eleven patients who received additional whole breast radiation had similar rates of good or excellent cosmesis: 40/48 (83%) and 29/36 (81%), respectively). Grade 1 or 2 acute toxicities were seen in 4/71 (6%) patients. No Grade 3 or 4 toxicities or serious adverse events have been seen. Conclusion: Intraoperative radiotherapy delivered to an in situ tumor is feasible with acceptable acute tolerance. Patient and physician assessment of the cosmetic outcome is good to excellent.

  4. Five-Year Results From a Scandinavian Sarcoma Group Study (SSG XIII) of Adjuvant Chemotherapy Combined With Accelerated Radiotherapy in High-Risk Soft Tissue Sarcoma of Extremities and Trunk Wall

    Jebsen, Nina L. [Department of Surgical Sciences, University of Bergen Faculty of Medicine, Bergen, Norway and Department of Oncology, Haukeland University Hospital, Bergen (Norway); Bruland, Oyvind S. [Cancer Clinic, Norwegian Radium Hospital, Oslo University Hospital and University of Oslo Faculty Division, Clinical Medicine, Oslo (Norway); Eriksson, Mikael; Engellau, Jacob [Department of Oncology, Skane University Hospital, Lund (Sweden); Turesson, Ingela [Department of Oncology, Uppsala University Hospital, Uppsala (Sweden); Folin, Annika [Department of Oncology, Karolinska Hospital, Stockholm (Sweden); Trovik, Clement S. [Departments of Oncology and of Orthopedics, Haukeland University Hospital, Bergen (Norway); Hall, Kirsten Sundby [Cancer Clinic, Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway)

    2011-12-01

    Purpose: To evaluate adjuvant chemotherapy and interpolated accelerated radiotherapy (RT) for adult patients with high-risk soft tissue sarcoma in the extremities or trunk wall. Methods and Materials: High-risk soft tissue sarcoma was defined as high-grade malignancy and at least two of the following criteria: size {>=}8 cm, vascular invasion, or necrosis. Six cycles of doxorubicin and ifosfamide were prescribed for all patients. RT to a total dose of 36 Gy (1.8 Gy twice daily) was inserted between two chemotherapy cycles after marginal margin resection regardless of tumor depth or after wide-margin resection for deep-seated tumors. RT was boosted to 45 Gy in a split-course design in the case of intralesional margin resection. Results: A total of 119 patients were eligible, with a median follow-up of 5 years. The 5-year estimate of the local recurrence, metastasis-free survival, and overall survival rate was 12%, 59%, and 68%, respectively. The group receiving RT to 36 Gy had a local recurrence rate of 10%. In contrast, the local recurrence rate was 29% in the group treated with RT to 45 Gy. The presence of vascular invasion and low chemotherapy dose intensity had a negative effect on metastasis-free and overall survival. Toxicity was moderate after both the chemotherapy and the RT. Conclusions: Accelerated RT interposed between chemotherapy cycles in a selected population of patients with high-risk soft tissue sarcoma resulted in good local and distant disease control, with acceptable treatment-related morbidity. The greater radiation dose administered after intralesional surgery was not sufficient to compensate for the poorer surgical margin. Vascular invasion was the most important prognostic factor for metastasis-free and overall survival.

  5. Five-Year Results From a Scandinavian Sarcoma Group Study (SSG XIII) of Adjuvant Chemotherapy Combined With Accelerated Radiotherapy in High-Risk Soft Tissue Sarcoma of Extremities and Trunk Wall

    Purpose: To evaluate adjuvant chemotherapy and interpolated accelerated radiotherapy (RT) for adult patients with high-risk soft tissue sarcoma in the extremities or trunk wall. Methods and Materials: High-risk soft tissue sarcoma was defined as high-grade malignancy and at least two of the following criteria: size ≥8 cm, vascular invasion, or necrosis. Six cycles of doxorubicin and ifosfamide were prescribed for all patients. RT to a total dose of 36 Gy (1.8 Gy twice daily) was inserted between two chemotherapy cycles after marginal margin resection regardless of tumor depth or after wide-margin resection for deep-seated tumors. RT was boosted to 45 Gy in a split-course design in the case of intralesional margin resection. Results: A total of 119 patients were eligible, with a median follow-up of 5 years. The 5-year estimate of the local recurrence, metastasis-free survival, and overall survival rate was 12%, 59%, and 68%, respectively. The group receiving RT to 36 Gy had a local recurrence rate of 10%. In contrast, the local recurrence rate was 29% in the group treated with RT to 45 Gy. The presence of vascular invasion and low chemotherapy dose intensity had a negative effect on metastasis-free and overall survival. Toxicity was moderate after both the chemotherapy and the RT. Conclusions: Accelerated RT interposed between chemotherapy cycles in a selected population of patients with high-risk soft tissue sarcoma resulted in good local and distant disease control, with acceptable treatment-related morbidity. The greater radiation dose administered after intralesional surgery was not sufficient to compensate for the poorer surgical margin. Vascular invasion was the most important prognostic factor for metastasis-free and overall survival.

  6. Efficacy of intensified hyperfractionated and accelerated radiotherapy and concurrent chemotherapy with carboplatin and 5-fluorouracil: Updated results of a randomized multicentric trial in advanced head-and-neck cancer

    Purpose: To prove an expected benefit of concurrent radiochemotherapy (RCT), a two-arm randomized multicentric study was performed. In a subgroup analysis the influence of pretherapeutical hemoglobin level (p-Hb) on survival under locoregional control (SLC) was tested. Patients and Methods: The study included primarily untreated Stage III/IV (International Union Against Cancer [UICC]) oropharyngeal and hypopharyngeal carcinomas. Patients were randomized to receive either hyperfractionated (hf) and accelerated (acc) RCT with two cycles 5-fluorouracil (600 mg/m2/day) and carboplatin (70 mg/m2/day) on Days 1-5 and 29-33 or hf-acc radiotherapy (RT) alone. Total RT dose in both arms was 69.9 Gy in 38 days in concomitant boost technique. Results: After a median follow-up time of 57 months, SLC is significantly better in RCT than in RT (p = 0.01), with median SLC of 17 months and 11 months, respectively. Also overall survival (OS) shows a benefit for RCT (p 0.016), with a median survival of 23 months for RCT and 16 months for RT. However, the benefit in SLC and OS is not seen in hypopharyngeal carcinomas. In a multivariate analysis of oropharyngeal cancer patients, p-Hb levels lower than 12.7 g/dL resulted in lower SLC compared with higher p-Hb levels up to 13.8 g/dL. P-Hb levels >13.8 g/dL did not further improve SLC. Conclusions: Hyperfractionated-accelerated RCT is superior to hf-acc RT in oropharyngeal carcinomas. P-Hb levels >13.8 g/dL do not further improve SLC

  7. Natural history of intracranial meningioma after radiotherapy

    The author examined the natural history of intracranial meningioma after radiotherapy using CT or MR imaging. Twenty patients with intracranial meningioma received radiotherapy from a high-energy linear accelerator (4-10 MV X rays) from 1980 to 1996. The total doses were 50 Gy to the tumor bed in single doses of 2 Gy in 5 weekly fractions. Meningiomas in 10 of 20 patients were reduced within 1 to 38 months after radiotherapy, the average being 11 months. The tumors were controlled for a median of 60 months after radiotherapy (range 19-126 months). Four other patients have shown no change in tumor size after radiotherapy. The tumors were controlled for a median of 70 months after radiotherapy (range 37-127 months). The other six patients have shown tumor growth within 3 to 25 months after radiotherapy, after which the tumors stopped growing for a median of 71 months (range 2-181 months). Neither tumor size nor histological type was related to response. The growth of tumors was controlled by radiotherapy for a median duration of 43 months in the meningothelial type, 52 months in the fibroblastic type, and 61 months in the transitional type. The median duration for all benign tumors was 52 months. A moderate correlation was noted between tumor response and functional outcome after radiotherapy in 9 patients with neurological deficits. The natural histories of intracranial meningiomas after radiotherapy were grouped into three categories. Some tumors showed no change in size over a long period. This was a characteristic response after radiotherapy that differed from that of other brain tumors. The results of this study provide important information for the follow-up of intracranial meningiomas after radiotherapy. (author)

  8. Accelerated radiotherapy and concomitant high dose chemotherapy in non resectable stage IV locally advanced HNSCC: Results of a GORTEC randomized trial

    Background: The objective was to evaluate the efficacy of a strong increase of the dose-intensity of concomitant radio-chemotherapy (RT-CT) in patients with far advanced non metastatic HNSCC. Methods: Eligible patients had N3 disease (UICC 1997) and the primary tumor and/or the node(s) had to be strictly unresectable. Patients with palpable N2B-C were also eligible if massive nodal involvement was present. 109 patients were included, with 53 randomized to RT-CT and 56 to accelerated RT. In the RT-CT arm, the RT regimen consisted of 64 Gy in 5 weeks and the CT regimen consisted of synchronous CDDP 100 mg/m2 on days 2, 16, and 30 and 5FU 1000 mg/m2 on days1-5 and 29-33 of the RT course. After RT-CT, two adjuvant cycles of CDDP-5FU were delivered in good responders. A control arm was using a very accelerated RT, delivering 64 Gy in 3 weeks. Results: The most common tumor sites were oropharynx and hypopharynx. Most of the patients had T4 disease (70%) and 100% had a massive nodal involvement (mainly N3 with a mean nodal size >7 cm in both arms). A significant difference was observed in favor of the RT-CT arm (p = 0.005) in terms of cumulative incidence of local regional failure or distant metastases. However, the overall survival and event free survival rates were not significantly different between the two arms (p = 0.70 and 0.16, respectively). The lack of survival benefit in favor of the RT-CT was partly due to an excess of initial early treatment related death in the RT-CT arm. Conclusion: The very intense RT-CT schedule was more efficient on disease control, but was also more toxic than accelerated RT alone, pointing out that there was no clear improvement of the therapeutic index. This study shows the limits of dose-intensification, with regard to concomitant RT-CT.

  9. Feasibility Study of Moderately Accelerated Intensity-Modulated Radiotherapy Plus Concurrent Weekly Cisplatin After Induction Chemotherapy in Locally Advanced Head-and Neck Cancer

    Purpose: To evaluate the feasibility and efficacy of moderately accelerated intensity-modulated radiation therapy (IMRT) along with weekly cisplatin, after induction chemotherapy, in patients with locally advanced unresectable head and neck cancer (HNC). Methods and Materials: Patients with Stage III or IV locally advanced HNC, without progressive disease after three courses of induction chemotherapy, received concurrent chemo-IMRT (weekly cisplatin 30 mg/m2 plus simultaneous integrated boost IMRT). A total of 67.5 Gy in 30 fractions were delivered to primary tumor and involved nodes, 60 Gy in 30 fractions to high-risk nodal areas, and 55.5 Gy in 30 fractions to low-risk nodal areas. Results: In all, 36 patients (median age, 56 years) with International Union Against Cancer (UICC) Stage III (n = 5) and IV (n = 31) were included. Of the 36 patients, 17 had received CF (cisplatin and 5-fluorouracil (CF) and 19 had received docetaxel cisplatin and 5-fluorouracil (DCF). During concurrent chemoradiation, 11 of 36 patients (30.5%) experienced Grade III mucositis (CF, 47%; DCF, 15%; p < 0.04). Grade III pharyngeal-esophageal toxicity was observed in 5 of 19 patients (26.3%; CF, 0.0%; DCF, 26.3%; p = 0.02). Two patients died of complications (5.5%). After chemoradiation, the complete response rate was 63.8%. Two-year local control was 88.7%. Two-year progression free survival and overall survival were 74.5% and 60.9%, respectively. Conclusions: In our experience, a moderately accelerated chemo-IMRT was feasible after induction chemotherapy. However, a noteworthy early death rate of 5.5% was observed. Intensive supportive care strategies should be defined to better manage radiation-induced toxic effects. Longer follow-up is required to determine the incidence of late radiation toxicities and tumor control rates.

  10. Continuous accelerated 7-days-a-week radiotherapy for head-and-neck cancer: Long-term results of Phase III clinical trial

    Purpose: To update 5-year results of a previously published study on special 7-days-a-week fractionation continuous accelerated irradiation (CAIR) for head-and-neck cancer patients. Methods and Materials: One hundred patients with squamous cell carcinoma of head and neck in Stage T2-4N0-1M were randomized between two definitive radiation treatments: accelerated fractionation 7 days a week including weekends (CAIR) and conventional 5 days a week (control). Hence the overall treatment time was 2 weeks shorter in CAIR. Results: Five-year local tumor control was 75% in the CAIR group and 33% in the control arm (p < 0.00004). Tumor-cure benefit corresponded with significant improvement in disease-free survival and overall survival rates. Confluent mucositis was the main acute toxicity, with the incidence significantly higher in CAIR patients than in control (respectively, 94% vs. 53%). When 2.0-Gy fractions were used, radiation necrosis developed in 5 patients (22%) in the CAIR group as a consequential late effect (CLE), but when fraction size was reduced to 1.8 Gy no more CLE occurred. Actuarial 5-year morbidity-free survival rate was similar for both treatments. Conclusions: Selected head-and-neck cancer patients could be treated very effectively with 7-days-a-week radiation schedule with no compromise of total dose and with slight 10% reduction of fraction dose (2 Gy-1.8 Gy), which article gives 1 week reduction of overall treatment time compared with standard 70 Gy in 35 fractions over 47-49 days. Although this report is based on the relatively small group of patients, its results have encouraged us to use CAIR fractionation in a standard radiation treatment for moderately advanced head-and-neck cancer patients

  11. Palliative Radiotherapy

    Palliative care does not attempt to prolong survival but to the achieve the highest quality of life both for the patient and their family covering their physical, psychological, social and spiritual needs. Radiotherapy (RT), one of the most important therapeutic modalities, has a great significance in palliative medicine for cancer since it attempts to reduce as much as possible the acute reaction associated with the treatment for the patient. (Author)

  12. Dosimetric comparison on tissue interfaces with TLD dosimeters, L-alanine, EDR2 films and Penelope simulation for a Co-60 source and linear accelerator in radiotherapy

    Percentage depth dose curves were obtained with TLD-100 dosimeters, EDR2 films and Penelope simulation at the interfaces in an inhomogeneous mannequin, composed by equivalent materials to the human body built for this study, consisting of cylindrical plates of solid water-bone-lung-bone-solid water of 15 cm in diameter and 1 cm in height; plates were placed in descending way (4-2-8-2-4). Irradiated with Co-60 source (Theratron Equinox-100) for small radiation fields 3 x 3 cm2 and 1 x 1 cm2 at a surface source distance of 100 cm from mannequin. The TLD-100 dosimeters were placed in the center of each plate of mannequin irradiated at 10 Gy. The results were compared between these measurement techniques, giving good agreement in interfaces better than 97%. This study was compared with the same characteristics of another study realized with other equivalent materials to human body not homogeneous acrylic-bone-cork-bone-acrylic. The percentage depth dose curves were obtained with mini-dosimeters L-alanine of 1 mm in diameter and 3 mm in height and 3.5 to 4.0 mg of mass with spectrometer band K (EPR). The mini-dosimeters were irradiated with a lineal accelerator PRIMUS Siemens 6 MV. The results of percentage depth dose of L-alanine mini-dosimeters show a good agreement with the percentage depth dose curves of Penelope code, better than 97.7% in interfaces of tissues. (Author)

  13. Linear Correlation Between Patient Survival and Decreased Percentage of Tumor [18F]Fluorodeoxyglucose Uptake for Late-Course Accelerated Hyperfractionated Radiotherapy for Esophageal Cancer

    Purpose: The aims of this trial were to study whether a decreased percentage of tumor fluorodeoxyglucose (FDG) uptake (%DeltaSUVmax) correlated with overall survival and local control times for patients with esophageal cancer and which patients would benefit from a late-course accelerated hyperfractionated (LCHF) radiation scheme. Methods and Materials: A total of 50 eligible patients with squamous esophageal cancer received positron-emission tomography examinations three times and were treated with the LCHF radiation scheme, with a dose of 68.4 Gy/41 fractions in 6.5 weeks. A %DeltaSUVmax value was calculated, and patients were stratified as highly radiosensitive (HR), moderately radiosensitive (MR), and low radiosensitivity (LR) according to %DeltaSUVmax values in the conventional fraction (CF) scheme. Then, a linear correlation was calculated between patients’ survival time and %DeltaSUVmax. Local control and overall survival rates were compared after stratification. Results: In the MR subgroup, there was no linear correlation between %DeltaSUVmax and the CF and LCHF schemes (correlation coefficient, R 0.05). In the other subgroups (HR and LR), %DeltaSUVmax values between the CF and LCHF schemes were correlated. Also, in the HR and LR subgroups, %DeltaSUVmax after radiation correlated with overall survival or local control rates (correlation coefficient, R >0.5, and p < 0.05). Three-year local control rates in the HR, MR, and LR subgroups were 100%, 81.5%, and 0%, respectively (p < 0.001). Also, 3-year overall survival rates were 92.4%, 58.8%, and 0% for HR, MR, and LR subgroups, respectively (p < 0.001). Conclusions: Postradiation %DeltaSUVmax was positively correlated with survival time for patients’ with esophageal cancer. Patients who benefited from LCHF schedules were those with a decrease of 30% to 60% in tumor FDG uptake after the completion of CF radiation.

  14. Quality assurance (QA) and implementation of intensity modulated radiotherapy (IMRT) with dynamic multileaf collimator (DMLC) on 2100 C/D linear accelerator

    Intensity Modulated Radiation Therapy (IMRT) involves the modulation of radiation beam intensities in order to conform the target volumes and spare surrounding critical structures and normal tissues. IMRT can improve the dose distribution to a large extent compared to conventional 3DCRT. The purpose of this article is to discuss the methodology adopted in the Quality Assurance (QA) program for the implementation of IMRT on 2100 C/D linear accelerator at our center. QA of Multi-Leaf Collimator (MLC) including mechanical tests, radiation tests, dynamic MLC tests and patient specific QA of the final IMRT plan has been described here in detail. The average transmission values were found to be 1.31% and 1.40% for A bank and B bank, respectively, for 6 MV photon beam measured with the parallel plate chamber. From film measurements we got the maximum interleaf transmission value of 1.88%. The speed of the MLC leaves was found to be within the specification of the manufacturer. The MLC positional accuracy with the methods mentioned gave a precision of 1 mm, irrespective of the gantry positions. The absolute dose for 6 and 15 MV photons was estimated for the Dynamic MLC (DMLC) field periodically and was found to be consistent. The inverse-planning algorithm produced satisfactory dose distribution and adequate Planning Target Volume (PTV) coverage with critical organ dose-volume parameters, within the respective tolerances. The percentage deviation between the measured and the calculated absolute dose for the Intensity Modulated (IM) fields is found to be less than 3%. The clinical implementation of inverse planning and treatment delivery with DMLC is extremely complex and involves a substantial developmental effort. The dose delivery in DMLC mode needs a confirmation using established QA program that is both stringent and efficient. However, a comprehensive QA is mandatory to ensure the safe and accurate dose delivery. (author)

  15. Postmastectomy radiotherapy

    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.)

  16. Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings

    The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

  17. The development of radiotherapy in Slovenia

    The historical data on the development of radiotherapy in Slovenia are presented from its first use in this county in 1902 until the present. The Institute of Oncology in Ljubljana was established in 1938 with the intention of providing a sound development of radium and roentgen cancer treatment. After World War II, the development of radiotherapy was dynamic, which is evident from the data on new radiation sources in external beam therapy (accelerators, telecobalt units), in brachytherapy (various sealed radioisotopes) as well as in the introduction of therapy with unsealed radioisotopes. In 1947, a Chair of Oncology and Radiotherapy was instituted at the Medical Faculty of the University of Ljubljana (with the seat at the Institute of Oncology). In 1955, radiotherapy and oncology were officially recognized as separate branches of medicine requiring special obligatory postgraduate residency training. Within the Medical Society of Slovenia, the Section for Radiotherapy was established in 1987. The following year, the Section for Radiotherapy of Slovenia became a member of the European Society for Therapeutic Radiology and Oncology. Considering the size of population of Slovenia (nearly 2 million), it was reasonable that by this time radiotherapy became almost completely concentrated in one central institution, the Institute of Oncology, whose core and cohesive activity were represented in the multidisciplinary cancer treatment approach

  18. Palliative radiotherapy in developing countries

    Full text: The International Agency for Research on Cancer predicts that cancer incidence in developing countries will increase dramatically in the first two decades of this millennium. Already some 80% of cancer patients in developing countries present with incurable disease. [n many cases pain is a severe problem and palliation is needed to improve quality of life as well as extending survival. This paper will consider the physical and clinical aspects of palliative radiotherapy (PRT), choice of radiation modality, alternative approaches to imaging and therapy and cost-benefit considerations. The potential benefits of a dedicated palliative centre include lower cost and therefore more centres, enabling more patients access to regional palliative care. Whilst there is an obvious need for palliative radiotherapy, simple curative treatments could also be managed. C060 radiotherapy has important advantages in developing countries, because of the higher initial cost of a linear accelerator, as well as the need for reliable power supply and the level of skill required by linac technicians and physicists. The beam characteristics of both C060 units and low energy linacs are compared and both are found to be acceptable for palliation. The concept of telemedicine is also discussed, using mobile phones and internet communication to allow rural clinics to receive support from specialists based in the cities, to send images for remote diagnosis and remote dose planning for radiotherapy. (author)

  19. High-energy accelerators in medicine

    Mandrillon, Pierre

    1992-01-01

    The treatment of tumours with charged particles, ranging from protons to "light ions" ( Carbon, Oxygen, Neon) has many advantages, but up to now has been little used because of the absence of facilities. After the successful pioneering work carried out with accelerators built for physics research, machines dedicated to this new radiotherapy are planned or already in construction. The rationale for this new radiotherapy, the high energy accelerators and the beam delivery systems are presented in these two lectures.

  20. Overview of radiotherapy resources in Beijing in 2010

    Objective: To investigate and analyze the resources of radiotherapy in Beijing, in order to provide reference for the subject development, resources allocation and professional training of radiotherapy. Methods: A questionnaire survey was conducted by on-site inspection, supplemented by telephone or e-mail investigation among the 33 hospitals with radiotherapy facilities to know the current status of distribution of radiotherapy institutions, radiotherapy facilities, human resources and number of patients treated. Results: There were 52 linear accelerators, 1 spiral CT machine, and 2 intraoperative radiotherapy machines in these 33 hospitals up to June 2010. Three-dimensional conformal or stereotactic radiotherapy was carried out in 31 hospitals, intensity modulated radiation therapy (IMRT) in 19, image guided radiation therapy (IGRT) in 6, and volumetric modulated arc therapy (VMRT) in 2. The number of professional personnel (except nurses) was 495, including 214 radiation oncologists, 78 radiotherapy physicists, and 203 radiotherapy technologists, and those with senior professional titles accounted for 52.3%, 17.9%, and 1.5%, respectively. Conclusions: Compared to the national level, the radiotherapy resources level is higher in Beijing, but the distribution of resources is imbalanced. The resource allocation should be optimized and training of the personnel should be strengthened so as to meet the growing needs of patients. (authors)

  1. Radiotherapy in paediatric oncology

    Full text: Radiation therapy has always been one of the most powerful tools in the fight against childhood cancer. Since the middle of the last century, we have known that most paediatric tumours are exquisitely sensitive to radiation. The early application of radiotherapy alone led to the first cures of retinoblastoma, Hodgkin lymphoma, as well as certain sarcomas and brain tumours. The generous application of radiation in conjunction with chemotherapy led to further extraordinary increases in survival rates for leukemias, Wilms tumour, sarcomas, and other paediatric malignancies. Over the past 40 years, the overall cure rate for childhood cancer has climbed from 25% to 75% in the USA. With this success, however, came the knowledge that radiation can be associated with significant late effects. We now have a much better understanding of both the benefits and risks of using radiation to treat children as we seek to optimize and refine its role in curative therapy. Leukemias constitute approximately one third of paediatric cancer diagnoses and most of these patients are successfully treated with chemotherapy alone. Central nervous system (CNS) radiation is still recommended for patients at highest risk of CNS failure and total body radiation is useful for the small percentage of patients who require bone marrow transplant. Brain tumours also make up almost one-third of paediatric neoplasms and children with most kinds of brain tumours will require high dose radiotherapy. Many of the other types of paediatric tumours (Wilms, neuroblastoma, sarcomas, etc.) also require radiotherapy as part of curative treatment. There have been considerable advances in radiation technology including three dimensional planning, intensity modulated radiation therapy, and protons. Individual paediatric patients may or may not benefit from advanced technologies based on numerous patient and disease related factors. Examples will be illustrated. We must also be mindful of economic and

  2. Status of Radiotherapy in Kenya: The Milestones and Challenges

    According to Gobacan 2012, seventy eight (78) Kenyans die daily of cancer related complications. Ratiotherapy is the treatment of cancer using high energy radiation targeting the tumour cells. The three main modalities used in treatment are radiotherapy, chemotherapy and surgery. More than 50% of cases are treated using radiotherapy. Radiotherapy is divided into two brad categoeis, namely external beam radiotherapy (EBRT) or teletherapy and internal radiotherapy (Brachytherapy). In Kenya, the machines available for EBRT are Cobalt-60 and linear accelerators. Co-60 source emits gamma-ray with energy of 1.25 MV while linear accelerators available locally emit photons (x-rays) and electrons ranging between 6 to 8MV. Until 2010, there was only one (public) radiotherapy facility using the co-60. Currently, four private facilities using linear accelerations have joined the fray. Two more public institutions are at different stages of putting up radiotherapy facilities. Owing to the high energy range, a lot of radiation safety considerations are made prior to installation, during acceptance testing and commissioning and during the operation. These include, but not limited to shielding integrity checks, Dosimetry checks, mechanical checks and emergency procedures check. In view of these, a lot of capacity building still needs to be done in term of skilled staff development as well as equipment

  3. Project of compact accelerator for cancer proton therapy

    The status of the sub-projetc 'Compact Accelerator' in the framework of the Hadrontherapy Project leaded by Prof. Amaldi is described. Emphasis is given to the reasons of the use of protons for radiotherapy applications, to the results of the preliminary design studies of four types of accelerators as possible radiotherapy dedicated 'Compact Accelerator' and to the scenario of the fonts of financial resources

  4. The application of accelerator for medical therapy in Indonesia

    The study of the application of accelerator for medical therapy in Indonesia was carried out. Accelerator that used for therapy is an electron lintier accelerator (Linac) which can radiate electron beam and X-ray. This study shows that there are 8 unit of Linac distributed at 6 big hospitals in Indonesia, especially in Jakarta. This study also shows that radiotherapy facilities in Indonesia is un sufficient of. Therefore, providing radiotherapy facilities for hospitals, especially the big hospitals in Indonesia is necessary

  5. Present status of radiotherapy in Venezuela

    The purpose of the work was to discover the conditions obtaining in the practice of radiotherapy in Venezuela; 15 public radiotherapy centres were visited, evaluated and information obtained on physical environment, treatment units, intracavitary radiotherapy groups, medical and para-medical personnel, recording of clinical data and number of patients. In the groups it was observed that: only one of 17 voltage stabilizing units was operating; the four linear accelerators can only be operated irregularly and there are 17 60Co units operating, but the majority of those are antiquated and worn out. One centre has a simulator and another has a computer. In intracavitary radiotherapy, approximately 50% of the centres do not carry out utero-vaginal implants in proper conditions. There are sufficient radiotherapists, but their working conditions cannot be compared with those in developed countries. There is a lack of auxiliary personnel, radiation physicists and dosimetrists. There is no training for radiotherapy technicians and there are not enough of them. In 50% of the centres, no treatment plans are made; one-third do not have any devices for immobilization. Four hospitals do not use radiotherapy histories or treatment graphics, and in four institutions no tumour record is used. The conclusion is that oncological radiotherapy is not adequate in most of the centres and it is recommended that: the damaged equipment should be repaired; the 60Co units with inadequate source-axis distances should be replaced; new sources should be acquired for the equipment with source-axis distances of 80 cm; maintenance should be constant; simulators should be provided; damaged intracavitary radiotherapy equipment and sources should be replaced; the numbers and training of technical personnel should be increased; physicists and dosimetrists should be trained; a national radiation physics centre should be set up, and the recording of clinical information should be improved. (author)

  6. Radiotherapy for Hodgkin lymphoma

    Specht, Lena [Rigshospitalet Copenhagen Univ. (Denmark). Depts. of Oncology and Haematology; Yahalom, Joachim (eds.) [Memorial Sloan-Kettering Cancer, New York, NY (United States). Dept. of Radiation Oncology

    2011-07-01

    This book deals in detail with all aspects of the best practice in modern radiotherapy for Hodgkin lymphoma. It provides the background and rationale for the inclusion of radiotherapy in today's combined-modality approach, including special clinical situations such as Hodgkin lymphoma in children, in the pregnant patient, and in the elderly. Radiotherapy planning using state-of-the-art imaging, target definition, planning software, and treatment equipment is expounded in detail. Acute and long-term side effects of radiotherapy are analyzed, and the implications for modern radiotherapy approaches in Hodgkin lymphomas are explained. (orig.)

  7. Radiotherapy for Hodgkin lymphoma

    This book deals in detail with all aspects of the best practice in modern radiotherapy for Hodgkin lymphoma. It provides the background and rationale for the inclusion of radiotherapy in today's combined-modality approach, including special clinical situations such as Hodgkin lymphoma in children, in the pregnant patient, and in the elderly. Radiotherapy planning using state-of-the-art imaging, target definition, planning software, and treatment equipment is expounded in detail. Acute and long-term side effects of radiotherapy are analyzed, and the implications for modern radiotherapy approaches in Hodgkin lymphomas are explained. (orig.)

  8. Radiotherapy gel dosimetry

    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

  9. Quality control programme for radiotherapy

    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

  10. Outline of the dose calculation system imagine for radiotherapy

    The dose calculation system IMAGINE is under development for supporting X-ray radiotherapy by rapidly providing the accurate dose distribution in a patient body utilizing precise models of the patient body and accelerator assembly incorporated with Monte Carlo calculations. The system will be used for the quality assurance of the current radiotherapy widely carried out at present, and further for promoting the prevalence of advanced therapy. The system is scheduled to be completed in 2007 after the five-year project. (author)

  11. Establishment Of An External Audit Group For Radiotherapy In Israel

    A national external audit group (EAG) was set up in Israel in 1997 in the framework of the IAEA Q A network for radiotherapy dosimetry. The members of the group were drawn from the Israeli SSDL, the Soreq Nuclear Research Center and the Soroka Medical Center. Ashen fully operational, the EAG will serve 8 hospitals in which 15 linear accelerators and 4 cobalt units are installed. The distribution of radiotherapy machines in Israel at the present time is shown in Table 1

  12. IART® (Intra-Operative Avidination for Radionuclide Therapy) for accelerated radiotherapy in breast cancer patients. Technical aspects and preliminary results of a phase II study with 90Y-labelled biotin

    Paganelli, G.; De Cicco, C; M. E. Ferrari; McVie, G.; Pagani, G; Leonardi, M C; Cremonesi, M.; Ferrari, A.; Pacifici, M.; Di Dia, A; Botta, F; De Santis, R; Galimberti, V.; Luini, A.; Orecchia, R.

    2010-01-01

    Background: Breast conserving surgery (BCS) plus external beam radiotherapy (EBRT) is considered the standard treatment for early breast cancer. We have investigated the possibility of irradiating the residual gland, using an innovative nuclear medicine approach named IART® (Intra-operative Avidination for Radionuclide Therapy). Aim: The objective of this study was to determine the optimal dose of avidin with a fixed activity (3.7 GBq) of 90Y-biotin, in order to provide a boost of 20 Gy, foll...

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

    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

  14. The study of aging change of normal prostate using carbogen-breathing BOLI-fMRI%吸入混合气BOLD-fMRI对正常前列腺组织加龄性变化的研究

    焦自梅; 王锡臻; 胡娜; 刘金刚; 王滨; 王光彬; 李莉莉

    2013-01-01

    目的 通过比较正常前列腺志愿者吸入carbogen气体后不同年龄组正常中央腺区(CZ)和周围带(PZ)的相对信号强度平均增加率,探讨正常前列腺不同组织SI-TC的加龄性变化特征.方法 本研究纳入正常前列腺志愿者32例,按年龄分为<30岁,30~50岁和>50岁三组.吸入carbogen气体状态下行BOLD-fMRI成像.分别记录吸入carbogen气体前、后的CZ和PZ的平均信号强度值,计算吸入carbogen气体后相对信号强度平均增加率;比较不同年龄段CZ和PZ相对信号强度平均增加率之间的差别.结果 <30岁年龄组的CZ相对信号强度平均增加率高于>50岁年龄组(P =0.014);<30岁年龄组的PZ相对信号强度平均增加率高于30~50岁年龄组和>50岁年龄组,差异均具有统计学意义(P =0.015;P=0.007).结论 吸入carbogen气体状态下BOLD-fMRI信号改变能反映正常前列腺组织的加龄性变化规律,可为前列腺疾病发生机制的研究提供新的手段.%Objective The relative increase signal average rate in normal prostate central zone tissue (CZ), peripheral zone tissue (PZ) using blood oxygen level-dependent (BOLD) induced by carbogen (95% O2/ 5% CO2) breathing were analyzed. The objective of this study was to explore the changes of signal intensity-time curve (SI-TC) in CZ and PZ of different age. Methods BOLD-fMRI was performed using a 3. 0 Tesla superconducting magnetic scanner (GE) in 32 healthy volunteers and the volunteers were divided into three groups according to the age: under 30 years old, 30 — 50 years old and above 50 years old. The average signal values of CZ and PZ before/after carbogen breathing and the relative increase signal average rate were computed. Results There was statistical significance between every two groups. The relative increase signal average rate of CZ under 30 years old was higher than that of above 50 years old ( P =0. 014). The relative increase signal average rate of PZ under 30

  15. Heavy-ion radiography applied to charged particle radiotherapy

    The objectives of the heavy-ion radiography research program applied to the clinical cancer research program of charged particle radiotherapy have a twofold purpose: (1) to explore the manner in which heavy-ion radiography and CT reconstruction can provide improved tumor localization, treatment planning, and beam delivery for radiotherapy with accelerated heavy charged particles; and (2) to explore the usefulness of heavy-ion radiography in detecting, localizing, and sizing soft tissue cancers in the human body. The techniques and procedures developed for heavy-ion radiography should prove successful in support of charged particle radiotherapy

  16. Japanese structure survey of high-precision radiotherapy in 2012 based on institutional questionnaire about the patterns of care

    The purpose of this study was to clarify operational situations, treatment planning and processes, quality assurance and quality control with relevance to stereotactic radiotherapy, intensity-modulated radiotherapy and image-guided radiotherapy in Japan. We adopted 109 items as the quality indicators of high-precision radiotherapy to prepare a questionnaire. In April 2012, we started to publicly open the questionnaire on the website, requesting every institution with radiotherapy machines for response. The response ratio was 62.1% (490 out of 789 institutions responded). Two or more radiotherapy technologists per linear accelerator managed linear accelerator operation in ∼90% of the responded institutions while medical physicists/radiotherapy quality managers were engaged in the operation in only 64.9% of the institutions. Radiotherapy certified nurses also worked in only 18.4% of the institutions. The ratios of the institutions equipped for stereotactic radiotherapy of lung tumor, intensity-modulated radiotherapy and image-guided radiotherapy were 43.3, 32.6 and 46.8%, respectively. In intensity-modulated radiotherapy planning, radiation oncologists were usually responsible for delineation while medical physicists/radiotherapy quality managers or radiotherapy technologists set up beam in 33.3% of the institutions. The median time required for quality assurance of intensity-modulated radiotherapy at any site of brain, head and neck and prostate was 4 h. Intensity-modulated radiotherapy quality assurance activity had to be started after clinical hours in > 60% of the institutions. This study clarified one major issue in the current high-precision radiotherapy in Japan. A manpower shortage should be corrected for high-precision radiotherapy, especially in the area relevant to quality assurance/quality control. (author)

  17. Carbon ion radiotherapy for pancreatic cancer

    The Heavy Ion Medical Accelerator in Chiba (HIMAC) is the world's first heavy ion accelerator complex dedicated to medical use in a hospital environment. Carbon ion therapy offers the potential advantages of improved dose localization and enhanced biological effects. It has been suggested that carbon ion therapy is effective against radioresistant pancreatic cancer. In April 2000, clinical studies examining the treatment of pancreatic cancer with carbon ions were begun at the HIMAC. As of February 2010, 48 patients treated with preoperative carbon ion radiotherapy and 89 patients treated for locally advanced pancreatic cancer were enrolled into the clinical trials. Both protocols are still ongoing. The interim results of these clinical trials suggest that carbon ion radiotherapy provides good local control and offers a survival advantage for patients with otherwise hard to cure pancreatic cancer, without unacceptable morbidity. (author)

  18. Radiotherapy of anal carcinomas

    Report is given on radiotherapy of anal carcinomas. Own experiences and a review of the recent literature are presented. Prior to surgery radiotherapy with high energy electrons in combination with chemotherapy is in the foreground. Especially in cloacogenous carcinoma no residual tumor was found after preliminary irradiation. Our recommended conception of post-operative radiotherapy of the regional lymphatic draining vessels is outlined. (orig./MG)

  19. Quality Assurance in Radiotherapy

    Mckenzie, Alan

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

  20. Radiotherapy of Cervical Cancer.

    Vordermark, Dirk

    2016-01-01

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

  1. Radiotherapy status in 2007. Key figures from the radiotherapy observatory 2006-2007

    This document briefly comments graphs and tables of data concerning the activity, the equipment and the human resources of French radiotherapy centres: numbers of public and private centres, numbers, types and age of installed accelerators, expected evolution of this stock, techniques used in external radiotherapy, numbers of the different involved professionals in the private sector or public sector. It indicates the status of these centres with respect to the different agreement criteria. The second part gives graphs and tables of data concerning the curie-therapy activity: curietherapy centres, medical treatment activities, used isotopes, types of curietherapy (high, low and pulsed rate)

  2. A New Cancer Radiotherapy System Using Multi Robotic Manipulators

    The CyberKnife system is state-of-the-art cancer treatment equipment that combines an image tracking technique, artificial intelligence software, robot technology, accelerator technology, and treatment simulation technology. The current CyberKnife System has significant shortcomings. The biggest problem is that it takes a longer time to treat a tumor. A long treatment time gives stress to patients. Furthermore it makes the patients uncomfortable with radiation and thus it is difficult to measure the exact radiation dose rate to the tumor in the processing. Linear accelerators for radiation treatment are dependent on imports, and demand high maintenance cost. This also makes the treatment cost higher and prevents the popularization of radiation. To solve the disadvantages of the existing CyberKnife, a radiation treatment robot system applied to several articulated robots is suggested. Essential element techniques for new radiotherapy robot system are investigated and some problems of similar existing systems are analyzed. This paper presents a general configuration of a new radiation robot treatment system including with a quantitative goal of the requirement techniques. This paper described a new radiotherapy robot system to track the tumor using multiple articulated robots in real time. The existing CyberKnife system using a single robot arm has disadvantages of a long radiotherapy time, high medical fee, and inaccurate measurement of the radiotherapy dose. So a new radiotherapy robot system for tumors has been proposed to solve the above problems of conventional CyberKnife systems. Necessary technologies to configure new the radiotherapy robot system have been identified. Quantitative targets of each technology have been established. Multiple robot arms are adopted to decrease the radiotherapy time. The results of this research are provided as a requisite technology for a domestic radiotherapy system and are expected to be the foundation of new technology. The

  3. A New Cancer Radiotherapy System Using Multi Robotic Manipulators

    Kim, Seung Ho; Lee, Nam Ho; Lee, Byung Chul; Jeung, Kyung Min; Lee, Seong Uk; Bae, Yeong Geol; Na, Hyun Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The CyberKnife system is state-of-the-art cancer treatment equipment that combines an image tracking technique, artificial intelligence software, robot technology, accelerator technology, and treatment simulation technology. The current CyberKnife System has significant shortcomings. The biggest problem is that it takes a longer time to treat a tumor. A long treatment time gives stress to patients. Furthermore it makes the patients uncomfortable with radiation and thus it is difficult to measure the exact radiation dose rate to the tumor in the processing. Linear accelerators for radiation treatment are dependent on imports, and demand high maintenance cost. This also makes the treatment cost higher and prevents the popularization of radiation. To solve the disadvantages of the existing CyberKnife, a radiation treatment robot system applied to several articulated robots is suggested. Essential element techniques for new radiotherapy robot system are investigated and some problems of similar existing systems are analyzed. This paper presents a general configuration of a new radiation robot treatment system including with a quantitative goal of the requirement techniques. This paper described a new radiotherapy robot system to track the tumor using multiple articulated robots in real time. The existing CyberKnife system using a single robot arm has disadvantages of a long radiotherapy time, high medical fee, and inaccurate measurement of the radiotherapy dose. So a new radiotherapy robot system for tumors has been proposed to solve the above problems of conventional CyberKnife systems. Necessary technologies to configure new the radiotherapy robot system have been identified. Quantitative targets of each technology have been established. Multiple robot arms are adopted to decrease the radiotherapy time. The results of this research are provided as a requisite technology for a domestic radiotherapy system and are expected to be the foundation of new technology. The

  4. Can Accelerators Accelerate Learning?

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ)[1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  5. 3.4 Radiotherapy

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

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

  6. Training logbook for radiotherapy.

    Hunter, R.; Maciejewski, B.; Leer, J.W.H.; Kinay, M.; Heeren, G.

    2004-01-01

    AIM: To develop a structured logbook for trainees in the medical specialty of radiotherapy with Europe that records the increasing experience throughout their training period. MATERIAL AND METHODS: A working party appointed by the European Board of Radiotherapy developed a draft version of a Europea

  7. Antitumor radiotherapy in children

    The philosophy is outlined of the therapy of malignant tumors in children, including Hodgkin type lymphomas and non-Hodgkin tumors, such as Wilm's tumor. The role of radiotherapy is defined and discussed in the comprehensive management of children using a combined radiotherapy-chemotherapy system. (L.O.). 5 refs

  8. [Radiotherapy of skin cancers].

    Hennequin, C; Rio, E; Mahé, M-A

    2016-09-01

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

  9. To understand radiotherapy

    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

  10. Mucosal regeneration during radiotherapy

    Background and purpose: Regeneration of the aerodigestive mucosa is known to occur during conventionally fractionated radiotherapy. The circumstances surrounding its time of onset and magnitude are not well understood, however. Material and methods: Mucosal reactions were observed in 100 patients undergoing conventionally fractionated treatment at 2 Gy/day over 7 weeks and 88 receiving accelerated treatment at 1.8 Gy twice daily over 3(1(2)) weeks on the Trans Tasman Radiation Oncology Group head and neck cancer trials. Similar observations in 61 patients treated palliatively at dose rates between 0.8 and 240 Gy/h using ten 3.0-4.2 Gy fractions over 2 weeks are compared. Results: Several findings emerged from these studies: 1. Reactions evolved more quickly at oropharyngeal sites than in the hypopharynx. 2. Reactions at both sites evolved more rapidly at greater rates of dose accumulation. 3. The timing of reactions suggested the presence of a strong regenerative mucosal response that started before the manifestation of 'patchy' (grade II) mucosal reactions. 4. The regenerative response was strong enough to 'make good' damage accumulated at a rate of 2 Gy/day in over a third of cases. 5. The linear quadratic model without time correction failed to provide an adequate prediction of the frequency or intensity of mucosal reactions produced by any of the regimes. A simple model of the regenerative response is presented. Conclusions: This study suggests that the timing and magnitude of the regenerative response vary between sites and individuals but are linked to the amount of epithelial cellular depletion occurring during treatment

  11. Plasma accelerators

    Recently attention has focused on charged particle acceleration in a plasma by a fast, large amplitude, longitudinal electron plasma wave. The plasma beat wave and plasma wakefield accelerators are two efficient ways of producing ultra-high accelerating gradients. Starting with the plasma beat wave accelerator (PBWA) and laser wakefield accelerator (LWFA) schemes and the plasma wakefield accelerator (PWFA) steady progress has been made in theory, simulations and experiments. Computations are presented for the study of LWFA. (author)

  12. Advances of Precise Radiotherapy for Lung Cancer

    Xin WANG; Xu, Feng; Wei, Yuquan

    2011-01-01

    At present lung tumor radiation therapy has entered the accurate radiotherapy era. Precise radiotherapy includes intensity modulated radiotherapy (IMRT), image-guided radiotherapy (IGRT) and stereotactic body radiotherapy (SBRT). During the process of implementing precise radiotherapy, these problems should be fully considered to ensure executing precise radiotherapy accurately: patient positioning, controlling of the lung tumor motion, selecting of image techniques, PTV margin, dose prescrip...

  13. Linear Accelerators

    Vretenar, M

    2014-01-01

    The main features of radio-frequency linear accelerators are introduced, reviewing the different types of accelerating structures and presenting the main characteristics aspects of linac beam dynamics.

  14. Advanced medical accelerator design

    This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described

  15. Experimental radiotherapy and clinical radiobiology. Vol. 20. Proceedings; Experimentelle Strahlentherapie und Klinische Strahlenbiologie. Bd. 20. Proceedings

    Baumann, Michael; Dahm-Daphi, Jochen; Dikomey, Ekkehard; Petersen, Cordula; Rodemannn, Hans-Peter; Zips, Daniel (eds.)

    2011-07-01

    The proceedings include contributions on the following issues: laser driven proton accelerators on the way for radiotherapy, radiobiological evaluation of new radiations; molecular factors of radiation response; biological targeting; EGFR epidermal growth factor receptor/targeting - combined internal and external irradiation, radiobiology of normal tissues; dose-volume histograms for the radiotherapy: curves without radiobiological relevance or important information for the therapy planning; HPV (human papilloma virus) and radiation sensitivity of HNSCC (head and neck squamous cell carcinomas): evidence, radiobiological mechanism, clinical consequences and perspectives; mechanisms of action and intertumoral heterogeneity of response to EGFR inhibition in radiotherapy of solid tumors; evaluation of biomarkers for radiotherapy.

  16. DICOM in Radiotherapy

    A. Nikfarjam

    2007-08-01

    Full Text Available Noticeable development in achieving data from patients is acquired by means of designing a system that connects these systems: imaging, archive and monitoring systems. When several imaging devices work based on DICOM standard; they can connect to each other without any interface. There are many applications for DICOM standard in radiotherapy; however its main usage is in imaging. It has other applications such as RT Structure Set, RT Dose, RT Plan and RT Brachy Treatment. "nNow DICOM is a complete and widespread standard to use in radiotherapy. Most of the radiotherapy machines have ability to use DICOM. Before installing a new Linac, it is necessary to predict all aspects of DICOM standard in this device. Therefore, as regards to entrance of 12 Linac to Iran, it is important to have enough knowledge about it. This article is a review about development of DICOM in radiotherapy. We try to stress on DICOM applications and abstain from technological agenda.

  17. Debate about breast cancer: 'Cons: Intraoperative radiotherapy'; Debats autour du cancer du sein: 'contre' la radiotherapie peroperatoire

    Bourgier, C.; Heymann, S.; Verstraet, R.; Biron, B.; Marsiglia, H. [Departement de radiotherapie, institut Gustave-Roussy, 114, rue edouard-Vaillant, 94800 Villejuif (France)

    2011-10-15

    Early breast cancer incidence increases owing to mammography screening. Hypo-fractionated radiotherapy is more and more proposed in women with low local relapse risk breast cancer, especially accelerated partial breast irradiation. Various irradiation modalities have been reported: brachytherapy, intraoperative irradiation, 3D-conformal accelerated partial breast irradiation. We describe limitations of intraoperative irradiation and the advantages of alternative techniques. (authors)

  18. Quality assurance methods for intensity modulated radiotherapy

    Aydın ÇAKIR

    2013-06-01

    Full Text Available Intensity modulated radiation therapy (IMRT, based on the use of non-uniform radiation beam intensity of a new step in conformal radiotherapy. Was able to get the optimal dose distributions with IMRT can improve the clinical results. In case of inadequate use of IMRT, the result may be worse than conventional treatments. Multiple sub-areas the accuracy of IMRT dose used in these fields depends on the performance of linear accelerator quality control tests. Multileaf collimator (MLC positioning accuracy, table movement, gantry and collimator indicators, with a gantry rotation speed and a lot of parameters such as rates of MLC. Linear accelerators used for IMRT in the treatment of pre-defined quality control program within the mechanical and dosimetric tests should be done periodically. In this study, linear accelerators capable of IMRT and IMRT plans for quality controls were investigated in the literature.

  19. Chemoradiation for Advanced Head and Neck Cancer: Potential for Improving Results to Match Those of Current Treatment Modalities for Early-Stage Tumors-Long-Term Results of Hyperfractionated Chemoradiation With Carbogen Breathing and Anemia Correction With Erythropoietin

    Purpose: To attempt to improve results of chemoradiation for head and neck cancer. Methods and Materials: From March 1996 to April 2007, 98 patients with head and neck cancer (15 Stage III and 83 Stage IV) were treated with a twice-daily hyperfractionated schedule. Eleven patients presented with N0, 11 with N1, 13 with N2A, 17 with N2B, 24 with N2C, and 22 with N3. Each fraction of treatment consisted of 5 mg/m2 of carboplatin plus 115 cGy with carbogen breathing. Treatment was given 5 days per week up to total doses of 350 mg/m2 of carboplatin plus 8050 cGy in 7 weeks. Anemia was corrected with erythropoietin. Results: Ninety-six patients tolerated the treatment as scheduled. All patients tolerated the planned radiation dose. Local toxicity remained at the level expected with irradiation alone. Chemotherapy toxicity was moderate. Ninety-seven complete responses were achieved. After 11 years of follow-up (median, 81 months), actuarial locoregional control, cause-specific survival, overall survival, and nodal control rates at 5 and 10 years were, respectively, 83% and 83%, 68% and 68%, 57% and 55%, and 100% and 100%. Median follow-up of disease-free survivors was 80 months. No significant differences in survival were observed between the different subsites or between the pretreatment node status groups (N0 vs. N+, N0 vs. N1, N0 vs. N2A, N0 vs. N2B, N0 vs. N2C, and N0 vs. N3). Conclusions: Improving results of chemoradiation for advanced head and neck cancer up to the level obtained with current treatments for early-stage tumors is a potentially reachable goal

  20. Intraoperative radiotherapy in the theatre room with electron beams: technical and dosimetric description of Sordina LIAC accelerator; Radioterapia intraoperatoria en quirofano con haces de electrones: descripcion tecnica y dosimetrica del acelerador dedicado Sordina LIAC

    Sendon del Rio, J. R.; Ayala Lazaro, R.; Gomez Cores, S.; Garcia Hernandez, M. J.; Polo Cezon, R.; Jimenez Rojas, R.; Lopez Bote, M. A.

    2015-05-01

    n this work we show our experience during the commissioning of a mobile electron-beam accelerator dedicated to intraoperative radiation therapy in the theatre room. The linac is a Sordina LIAC 12 MeV model with a hard-docking applicator system. We describe the linac, the measurement methods and the specific dosimetry. The dosimetric behavior is also discussed. Differences with other applicator systems can be explained from the particular head design of the linac. (Author)

  1. Booster linear accelerators for proton therapy

    Radiotherapy using proton beams of energies of order 200 MeV is now accepted as a feasible cancer treatment technique whose widespread use has so far been limited by the high costs of proposed facilities. AEA Technology have identified a low-cost solution using a linear accelerator to boost existing hospital cyclotrons. The present project status and the design of the booster linear accelerator are discussed. (Author) 4 tabs., 2 figs., 2 refs

  2. Present status of radiotherapy in Zimbabwe

    Radiotherapy departments are one of the most expensive health facilities to equip, maintain and run efficiently. In Zimbabwe, there are two radiotherapy centres, at Parirenyatwa Central Hospital in Harare and at Mpilo Central Hospital in Bulawayo. Both these centres have nuclear imaging facilities. The radiotherapy services also cater for patients from neighbouring states. A referral system for consultation and prescription by the radiotherapist is in use. Administration of most cytotoxics is done in the radiotherapy department. Zimbabwe's population is over 8 million. Of this, yearly averages of 400 to 500 and over 700 new patients are seen at the Bulawayo and Harare centres respectively. So far 159 new cervical cancer patients have been seen this year at the Bulawayo centre. To cater for this and other malignancies, facilities ranging from the supervoltage therapy to a linear accelerator are available as well as limited brachytherapy facilities. The funding of these has been from the government, charity organisations and international aid agreements. Servicing and maintenance of the units is done by the private sector. Treatment planning is done mostly by radiographers but the more complex techniques are not done due to lack of qualified medical physicists. This shortage also affects the calibration of and other routine checks of the equipment. Progress in these services has been hampered by the lack of local radiotherapists. Improvements are expected with the WHO radiotherapist training programme due to start in 1990. If the cancer awareness programme is stepped up, the demands on the radiotherapy services will increase, necessitating review and updating of the present facilities and staffing levels. (author). 1 fig., 5 tabs

  3. Future accelerators (?)

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made

  4. Future accelerators (?)

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  5. International symposium on utilization of accelerators. Book of extended synopses

    Papers presented at this meeting were devoted to accelerator facilities design, improvements, for electron, neutron, or ion beams applications in radiotherapy, industry, material testing, isotope production. A number of presentations were dealing with accelerator driven systems as a possible power production device

  6. Accelerated partial breast irradiation using intensity-modulated radiotherapy technique compared to whole breast irradiation for patients aged 70 years or older: subgroup analysis from a randomized phase 3 trial

    Meattini, Icro; Saieva, Calogero; Marrazzo, Livia; Di Brina, Lucia; Pallotta, Stefania; Mangoni, Monica; Meacci, Fiammetta; Bendinelli, Benedetta; Francolini, Giulio; Desideri, Isacco; De Luca Cardillo, Carla; Scotti, Vieri; Furfaro, Ilaria Francesca; Rossi, Francesca; Greto, Daniela

    2015-01-01

    The purpose of this study was to report the efficacy and the safety profile on the subset of selected early breast cancer (BC) patients aged 70 years or older from a single-center phase 3 trial comparing whole breast irradiation (WBI) to accelerated partial breast irradiation (APBI) using intensity-modulated radiation therapy technique. Between 2005 and 2013, 520 patients aged more than 40 years old were enrolled and randomly assigned to receive either WBI or APBI in a 1:1 ratio. Eligible pat...

  7. Experimental determination of tissue maximum ratios (TMR) and of off-center ratios (OCR) of the 8MV Mel Philips linear accelerator at the Radiotherapy Center-Hospital Sirio-Libanes, Sao Paulo-Brazil

    Tissue maximum ratio-TMR-and off center ratio-OCR-using Baldwin Farmer ion chamber are measured for radiation field of MEL Philips 8MV Linac for a depth in a water phantom varying between 4 to 30cm. These data are compared with the values, obtained from percentage depth dose for 8MV accelerator (cf.Suppl.11, Brit.Jour.Read.). These data when used in EXTREP Computer Program yields isodose for any fields. The treatment plannings are 2-dimensional but encompass a wide variety of radiation therapy techniques including rotating beams wedged fields, tangential rotation and any number of stationary fields of different field sizes

  8. Accelerating Value Creation with Accelerators

    Jonsson, Eythor Ivar

    2015-01-01

    accelerator programs. Microsoft runs accelerators in seven different countries. Accelerators have grown out of the infancy stage and are now an accepted approach to develop new ventures based on cutting-edge technology like the internet of things, mobile technology, big data and virtual reality. It is also......Accelerators can help to accelerate value creation. Accelerators are short-term programs that have the objective of creating innovative and fast growing ventures. They have gained attraction as larger corporations like Microsoft, Barclays bank and Nordea bank have initiated and sponsored...

  9. Phase II, two-arm RTOG trial (94-11) of bischloroethyl-nitrosourea plus accelerated hyperfractionated radiotherapy (64.0 or 70.4 Gy) based on tumor volume (> 20 or ≤ 20 cm2, respectively) in the treatment of newly-diagnosed radiosurgery-ineligible glioblastoma multiforme patients

    Purpose: To compare survivorship, and acute and delayed toxicities following radiation therapy (RT) of radiosurgery-ineligible glioblastoma multiforme (GBM) patients treated with tumor volume-influenced, high-dose accelerated, hyperfractionated RT plus bischloroethyl-nitrosourea (BCNU), using prior RTOG malignant glioblastoma patients as historical controls. Methods and Materials: One hundred four of 108 patients accrued from June 1994 through May 1995 from 26 institutions were analyzable. Patients were histologically confirmed with GBM, and previously untreated. Treatment assignment (52 patients/arm) was based on tumor mass (TM), defined as the product of the maximum diameter and greatest perpendicular dimension of the titanium-gadolinium-enhanced postoperative MRI: Arm A, 64 Gy, TM > 20 cm2; or Arm B, 70.4 Gy, TM ≤ 20 cm2. Both Arms A and B received BCNU (80 mg/m2, under hyperhydration) days 1-3, 56-58, then 4 cycles, each 8 weeks, for a total of 6 treatment series. Results: During the 24 months immediately post-treatment, the overall median survival was 9.1 months in Arm A (64 Gy) and 11.0 months in Arm B (70.4 Gy). Median survival in recursive partitioning analysis (RPA) Class III/IV was 10.4 months in Arm A and 12.2 months in Arm B, while RPA Class V/VI was 7.6 months in Arm A and 6.1 months in Arm B. There were no grade 4 neurological toxicities in Arm A; 2 grade 4 neurological toxicities were observed in Arm B (1 motor deficit, 1 necrosis at 157 days post-treatment). Conclusion: This strategy of high-dose, accelerated hyperfractionated radiotherapy shortens overall RT treatment times while allowing dose escalation, and it provides the potential for combination with currently available, as well as newer, chemotherapy agents. Survival is comparable with previously published RTOG data, and toxicities are within acceptable limits.

  10. Conformal accelerated partial breast irradiation: State of the art

    Breast conserving treatment (breast conserving surgery followed by whole breast irradiation) has commonly been used in early breast cancer since many years. New radiation modalities have been recently developed in early breast cancers, particularly accelerated partial breast irradiation. Three-dimensional conformal accelerated partial breast irradiation is the most commonly used modality of radiotherapy. Other techniques are currently being developed, such as intensity-modulated radiotherapy, arc-therapy, and tomo-therapy. The present article reviews the indications, treatment modalities and side effects of accelerated partial breast irradiation. (authors)

  11. Advice concerning radiotherapy

    Dutch National cancer incidence figures were calculated by using the reliable data on cancer incidence in the Eindhoven area and population forecasts and information obtained from the Central Bureau of Statistics. Several radiotherapy departments suffer from under capacity (a lack of resources and understaffing). Data have also shown that 35% of cancer patients receive radiotherapy, instead of 50%. Calculations have been made by the committee on the present and future needs with regard to equipment and staff. In 1983, the number of megavoltage therapy units amounted to 38, but should have been 65. It should be 80 in 1990 and 90 in 2000. Since building and installing such equipment is a lengthy process a considerable effort is needed to make up for the arrears. The committee advocates the extension of the system of regional cooperation in cancer care (comprehensive cancer centres), in which radiotherapy departments play a crucial role. Working parties from the committee provided a comprehensive description of current radiotherapy practice with reference to physical, technical, clinical and management aspects. Another working party assessed the results of cancer treatment with regard to many different tumour sites. Recent and expected developments were analysed or indicated. The Radiotherapy Committee commissioned an external team to conduct a project to achieve a picture of future developments using methods different to those of the committee's. An interim advice has been added on this subject. (Auth.)

  12. Image-guided radiotherapy (IGRT) and four dimensional radiotherapy (4DRT)

    Since the development of conformation radiotherapy in the 1960s by Takahashi, et al., diagnostic and localization accuracy have been the main concerns. With increasing improvement in imaging techniques and multileaf collimators, three dimensional conformal radiotherapy (3D CRT) and intensity modulated radiotherapy (IMRT) have prevailed to produce highly conformal dose distribution. Image guided radiotherapy (IGRT), in which diagnostic imaging techniques are equipped in the treatment room, has been paid more attention than before to increase localization accuracy in the use of complex fields in clinical radiotherapy. Setup error has been shown to be reduced by using stereotactic frames for intracranial diseases, diagnostic X ray imagers, ultrasound, or computed tomography in the treatment room for relatively static organs. Planning target volume (PTV) margin for the clinical target volume (CTV) can be reduced by using these IGRT techniques. However, for mobile tumours such as those in the liver or lung, it is still difficult to use a 'tight' margin because of difficulty focusing radiation beams exactly on the moving tumour. Planning target volume for these mobile or moving tumours has generally been determined with a large PTV margin in the direction of tumour movement. A respiration gated radiotherapy system was developed in an attempt to reduce the PTV margin. However, it remained impossible to neglect the possibility that the tumour might be dislocated by depth of breath or setup error. A more accurate method is required to determine the 3D coordinates of a moving tumour during radiotherapy. The relative relationship between the tumour and the surrounding normal structure may change due to tumour mobility, thus a more accurate treatment planning method is also required accounting for temporal changes of anatomy. We have developed a linear accelerator synchronized with a fluoroscopic real time tumour tracking radiotherapy system (RTRT) by which the 3D location of

  13. Cardiac dose sparing and avoidance techniques in breast cancer radiotherapy

    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

  14. Saliva in relation to dental erosion before and after radiotherapy

    Jensdottir, Thorbjorg; von Buchwald, Christian; Nauntofte, Birgitte;

    2013-01-01

    Abstract Objective. Low saliva flow and abnormal saliva composition are common conditions after radiotherapy for oral cavity and pharyngeal cancer. Both conditions increase the susceptibility to dental caries and erosion, which may be further accelerated by changes in food preferences. The aim of...... this study was to determine changes in saliva flow and susceptibility to erosive challenges in pharyngeal cancer patients before and after radiotherapy to the head and neck. Materials and methods: The erosive potential of sucking acidic candies with and without calcium was determined in nine patients...

  15. Dosimetric evaluation of Radiotherapy units wit 60Co

    The SSDL network of the IAEA performs, every year, quality audit tests for radiotherapy services (60 Co units and linear accelerators), and for national SSDL as well. Because of the SSDL-Mexico results in these tests and due to our enthusiasm and confidence in our work, a parallel test has been done , which is described in this talk as well as the results. Nowadays, a second parallel test goes up, which could confirm our optimism and open the possibility to our country to start a national dosimetric audit of 60 Co radiotherapy units. (Author)

  16. Laser driven particle acceleration

    This dissertation summarizes the last ten years of research at the Laboratory of Applied Optics on laser-plasma based electron acceleration. The main result consists of the development and study of a relativistic electron source with unique properties: high energy (100-300 MeV) in short distances (few millimeters), mono-energetic, ultra-short (few fs), stable and tunable. The manuscript describes the steps that led to understanding the physics, and then mastering it in order to produce this new electron source. Non linear propagation of the laser pulse in the plasma is first presented, with phenomena such as non linear wakefield excitation, relativistic and ponderomotive self-focusing in the short pulse regime, self-compression. Acceleration and injection of electrons are then reviewed from a theoretical perspective. Experimental demonstrations of self-injection in the bubble regime and then colliding pulse injection are then presented. These experiments were among the first to produce monoenergetic, high quality, stable and tunable electron beams from a laser-plasma accelerator. The last two chapters are dedicated to the characterization of the electron beam using transition radiation and to its applications to gamma radiography and radiotherapy. Finally, the perspectives of this research are presented in the conclusion. Scaling laws are used to determine the parameters that the electron beams will reach using peta-watt laser systems currently under construction. (author)

  17. Chemical modifiers of radiotherapy

    Only two groups, anticancer drugs and radiosensitizers are discussed among many groups of chemical modifiers. In combined radiotherapy (RT) with chemotherapy (CT), sequential administration seems to be superior to concomitant administration, because simultaneous use enhances intensively normal tissue damage. In sequential administration, interruption of CT during RT causes growth of distant metastases. So, alternating scheme of RT and CT is proposed and evaluated clinically. Hypoxic cell sensitizers including well-known misonidazole and PLDR inhibitors (Ara-A etc.) are promising in radiotherapy. They should be used intermittently two or three times during RT in order to avoid neurotoxicity of misonidazole. (author) 70 refs

  18. Xerostomia induced by radiotherapy

    Alimi D

    2015-08-01

    Full Text Available David Alimi Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USAWe read with great interest the excellent review on xerostomia induced by radiotherapy, by Pinna et al.1 The authors should be congratulated for a very detailed review of the physiopathology, clinical symptoms, and therapeutic management of an extremely difficult condition. Although we agree that the use of anticholinergic medication represents treatment, it requires the patient to have residual salivary gland function. Unfortunately, it is well established that in most cases radiotherapy destroys most of the salivary gland and associated salivary secretions.     

  19. Prospective study of accelerated postoperative radiation therapy in patients with squamous-cell carcinoma of the head and neck; Radiotherapie externe acceleree postoperatoire des carcinomes epidermoides localement evolues de la sphere ORL: etude prospective de phase 2

    Zouhair, A.; Coucke, P.A.; Azria, D.; Moeckli, R.; Mirimanoff, R.O.; Ozsahin, M. [Centre Hospitalier Universitaire Vaudois CHUV, Service de Radio-Oncologie, Lausanne (Switzerland); Azria, D. [Centre Regional de Lutte Contre le Cancer Val-d' Aurelle-Paul-Lamarque, Dept. d' Oncologie- Radiotherapie, 34 - Montpellier (France); Pache, P. [Centre Hospitalier Universitaire Vaudois CHUV, Service d' ORL, Lausanne (Switzerland); Stupp, R. [Centre hospitalier Universitaire Vaudois CHUV, Centre Pluridisciplinaire d' Oncologie Medicale, Lausanne (Switzerland)

    2003-08-01

    Purpose. - To assess the feasibility and efficacy of accelerated postoperative radiation therapy (RT) in patients with squamous-cell carcinoma of the head and neck (SCCHN). Patients and methods. - Between December 1997 and July 2001, 68 patients (male to female ratio: 52/16; median age: 60-years (range: 43-81)) with pT1-pT4 and/or pN0-pN3 SCCHN (24 oropharynx, 19 oral cavity, 13 hypopharynx, 5 larynx, 3 unknown primary, 2 maxillary sinus, and 2 salivary gland) were included in this prospective study. Postoperative RT was indicated because extra-capsular infiltration (ECT) was observed in 20 (29%), positive surgical margins (PSM) in 20 (29%) or both in 23 patients (34%). Treatment consisted of external beam R 66 Gy in 5 weeks and 3 days. Median follow-up was 15 months. Results. -According to CTC 2.0, acute morbidity was acceptable: grade 3 mucositis was observed in 15 (22%) patients, grade 3 dysphagia in 19 (28%) patients, grade 3 skin erythema in 21 (31%) patients with a median weight loss of 3.1 kg (range: 0-16). No grade 4 toxicity wa observed. Median time to relapse was 13 months; we observed only three (4%) local and four (6%) regional relapses, whereas eight (12%) patients developed distant metastases without any evidence of locoregional recurrence. The 2 years overall-, disease-free survival, an actuarial locoregional control rates were 85, 73 and 83% respectively. Conclusion.- The reduction of the overall treatment time using postoperative accelerated RT with weekly concomitant boost (six fraction per week) is feasible with local control rates comparable to that of published data. Acute RT related morbidity is acceptable. (author)

  20. Calculation of the structural shielding of the radiotherapy treatment room equipped with a linear accelerator type Tomo therapy Hi-Art in the Oncology Center of Chihuahua, Mexico; Calculo del blindaje estructural de la sala de tratamiento de radioterapia equipada con un acelerador lineal del tipo Tomotherapy Hi-Art en el Centro Oncologico de Chihuahua, Mexico

    Caballero G, C. A. [Southwest Oncology Centers, North Civic Center Plaza No. 2926, Scottsdale, Arizona (United States); Plascencia, J. C. [Centro Oncologico Louis and Lucille Grado, Republica del Peru No. 102-5, Col. Americas, Aguascalientes (Mexico); Vargas V, M. X.; Toledo J, P., E-mail: cabshm@msn.co [Centro Oncologico de Chihuahua, Hacienda de la Esperanza No. 6304, Fracc. Cima Comercial, Chihuahua (Mexico)

    2010-09-15

    The helicoid tomo therapy is an external radiotherapy system of modulated intensity, guided by image, in which the radiation is imparted to the patient using a narrow radiation beam in helicoid form, in a similar way to the scanning process with a computerized tomography. The tomo therapy equipment (Tomo Therapy Hi-Art) consists in an electrons linear accelerator with acceleration voltages of 6 MV for treatment and 3.5 MV for image, coupled to a ring that turn around the patient as this is transferred through this ring in perpendicular sense to the radiation beam. The radiation beam is narrow because has the maximum size of 5 x 40 cm{sup 2} in the isocenter. The intensity modulation of the beam is carried out with a binary dynamic collimator of 64 crisscross sheets, and the guide by image though a system of megavoltage computerized tomography. Opposed to the radiation beam, also coupled to the rotational ring, a group of lead plates exists with a total thickness of 13 cm that acts as barrier of the primary radiation beam. The special configuration of the tomography equipment makes to have the following characteristics: 1) the presence of the lead barrier of the equipment reduces the intensity of the primary beam that reaches the bunker walls in considerable way, 2) the disperse and leakage radiations are increased with regard to a conventional accelerator due to the increase in the necessary irradiation time to produce modulated intensity fields by means of the narrow radiation beam. These special characteristics of the tomo therapy equipment make that particularities exist in the application of the formulations for structural shielding calculations that appears in the NCRP reports 49, NCRP 151 and IAEA-SRS-47. For this reason, several researches have development analytic models based on geometric considerations of continuous rotation of the equipment ring to determine the shielding requirements for the primary beam, the dispersed and leakage radiation in tomo

  1. Concomitant boost radiotherapy in oropharynx carcinomas

    Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)

  2. Concomitant boost radiotherapy in oropharynx carcinomas

    Bieri, S.; Allal, A.S.; Kurtz, J.M. [Ospedale San Giovanni, Bellinzona (Switzerland). Dept. of Radiation Oncology; Dulguerov, P.; Lehmann, W. [Geneva Univ. Hospital (Switzerland). Div. of Head and Neck Surgery

    1998-12-31

    Fifty-five patients with resectable and unresectable oropharynx carcinomas were treated with concomitant boost radiotherapy. Forty-two of the patients (76%) had stages III-IV disease. Although none of the patients had undergone major surgery to the primary tumor, 11 had neck dissections prior to radiotherapy, and 19 (35%) received chemotherapy. The planned total tumor dose was 69.9 Gy, delivered over 5.5 weeks. During the last 3.5 weeks, a boost to the initial gross disease was delivered in 13 fractions of 1.5 Gy each, as a second daily fraction in a progressively accelerated schedule; the prescribed dose outside the boost volume thus was 50.4 Gy. Median follow-up for surviving patients was 31.5 months (range: 16-65 months). All patients but one completed the planned radiotherapy schedule. According to the RTOG scoring system, 48 patients (88%) presented with grades 3-4 acute toxicity. The rate of grades 3-4 late complications was 12%. At three years the actuarial locoregional control rate was 69.5% and overall survival was 60%. We conclude that this concomitant boost schedule is feasible and does not seem to be associated with an excess risk of late complications. Acute toxicity was higher in association with chemotherapy, but remained manageable. Although the oncological results appear encouraging, evaluation of the efficacy of concomitant boost schedules compared with conventionally fractionated irradiation with or without concomitant chemotherapy requires prospective randomized trials. (orig.)

  3. Contemporary Breast Radiotherapy and Cardiac Toxicity.

    Yeboa, Debra Nana; Evans, Suzanne Buckley

    2016-01-01

    Long-term cardiac effects are an important component of survivorship after breast radiotherapy. The pathophysiology of cardiotoxicity, history of breast radiotherapy, current methods of cardiac avoidance, modern outcomes, context of historical outcomes, quantifying cardiac effects, and future directions are reviewed in this article. Radiation-induced oxidative stress induces proinflammatory cytokines and is a process that potentiates late effects of fibrosis and intimal proliferation in endothelial vasculature. Breast radiation therapy has changed substantially in recent decades. Several modern technologies exist to improve cardiac avoidance such as deep inspiration breath hold, gating, accelerated partial breast irradiation, and use of modern 3-dimensional planning. Modern outcomes may vary notably from historical long-term cardiac outcomes given the differences in cardiac dose with modern techniques. Methods of quantifying radiation-related cardiotoxicity that correlate with future cardiac risks are needed with current data exploring techniques such as measuring computed tomography coronary artery calcium score, single-photon emission computed tomography imaging, and biomarkers. Placing historical data, dosimetric correlations, and relative cardiac risk in context are key when weighing the benefits of radiotherapy in breast cancer control and survival. Estimating present day cardiac risk in the modern treatment era includes challenges in length of follow-up and the use of confounding cardiotoxic agents such as evolving systemic chemotherapy and targeted therapies. Future directions in both multidisciplinary management and advancing technology in radiation oncology may provide further improvements in patient risk reduction and breast cancer survivorship. PMID:26617212

  4. Recent innovations in carbon-ion radiotherapy

    In the last few years, hospital-based facilities for carbon-ion radiotherapy are being constructed and proposed in Europe and Asia. During the next few years, several new facilities will be opened for carbon-ion radiotherapy in the world. These facilities in operation or under construction are categorized in two types by the beam shaping method used. One is the passive beam shaping method that is mainly improved and systematized for routine clinical use at Heavy Ion Medical Accelerator in Chiba (HIMAC), Japan. The other method is active beam shaping which is also known as beam scanning adopted at Gesellschaft fur Schwerionenforschung (GSI)/Heidelberg Ion Therapy Center (HIT), Germany. In this paper an overview of some technical aspects for beam shaping is reported. The technique of passive beam shaping is established for stable clinical application and has clinical result of over 4000 patients in HIMAC. In contrast, clinical experience of active beam shaping is about 400 patients, and there is no clinical experience to respiratory moving target. A great advantage of the active beam shaping method is patient-specific collimator-less and compensator-less treatment. This may be an interesting potential for adaptive radiotherapy. (author)

  5. Advances of Precise Radiotherapy for Lung Cancer

    Xin WANG

    2011-11-01

    Full Text Available At present lung tumor radiation therapy has entered the accurate radiotherapy era. Precise radiotherapy includes intensity modulated radiotherapy (IMRT, image-guided radiotherapy (IGRT and stereotactic body radiotherapy (SBRT. During the process of implementing precise radiotherapy, these problems should be fully considered to ensure executing precise radiotherapy accurately: patient positioning, controlling of the lung tumor motion, selecting of image techniques, PTV margin, dose prescription and reporting, arrangement of beams, controlling of dose volume and treatment delivering.

  6. Combined modality treatment of the rhabdomyosarcoma R1H of the rat: tumor and normal tissue response after cisplatin and conventional or accelerated irradiation treatment

    Purpose: To test the importance of the sequence of cisplatin and irradiation, either conventional or accelerated fractionated. Methods and Materials: 30 fractions of 2 Gy were given in 6 or 3 weeks preceded or followed by (time interval between cisplatin and radiotherapy: 3 days) a single IP dose of 5 mg/kg cisplatin in the rhabdomyosarcoma R1H of the rat. Survival curves were generated, and comparisons were made by the log-rank test. Results: After 60 Gy in 6 weeks, no local tumor controls were observed. If cisplatin was injected 3 days before start of 60 Gy/6 weeks, 11 ± 10% (mean ± SE) of the tumors were controlled. Cisplatin after radiotherapy resulted in 50 ± 14% local controls. The difference was significant (p 0.01) for cisplatin after radiotherapy in comparison to radiotherapy alone where no local controls were observed. After accelerated fractionation, 57 ± 19% of the animals were cured with or without cisplatin before radiotherapy. If the drug was injected after end of 60 Gy/3 weeks, 86 ± 13% survived recurrence free. The difference to accelerated radiotherapy alone was not significant. Accelerated radiotherapy produced significantly higher control rates than conventional radiotherapy (p < 0.001). Conclusions: Accelerated radiotherapy resulted in higher local tumor control rates as compared to conventional fractionated irradiation. Cisplatin combined with radiotherapy showed significantly better results if given after but not before irradiation, either conventional or accelerated fractionated

  7. Erythropoietin and radiotherapy; Erythropoietine et radiotherapie

    Le Fur, E.; Albarghach, M.N.; Pradier, O. [CHU de Morvan, Dept. de radiotherapie, 29 - Brest (France)

    2010-01-15

    Erythropoietin (E.P.O.) is a glycoprotein hormone. This hormone is a growth factor for red blood cells precursors in the bone marrow. The decrease of oxygen partial pressure, a reduced number of erythrocytes caused by bleeding or excessive destruction, or increased tissues oxygen requirements lead to increased secretion of E.P.O.. Its action takes place on bone marrow erythroblastic cells through specific receptors. E.P.O. stimulates the proliferation of red cell precursors stem cells in the bone marrow, thus increasing their production in one to two weeks. The effectiveness of E.P.O. at increasing haemoglobin and improving patients quality of life has been demonstrated by several studies. However, its use in radiotherapy remains controversial. While tumour hypoxia caused by anaemia is a factor of radio resistance and thus a source of local failure, tumour expression of E.P.O. receptors presents a significant risk for tumour progression and neo-angiogenesis, which would be increased during the administration of E.P.O.. The purpose of this article is to answer the question: is there a place for E.P.O. in combination with radiotherapy in the management of cancer?

  8. External Beam Accelerated Partial Breast Irradiation Yields Favorable Outcomes in Patients with Prior Breast Augmentation

    RachelYi-FengLei; CharlesELeonard; JaneMKercher; TereseKaske

    2014-01-01

    Purpose: To report outcomes in breast cancer patients with prior breast augmentation treated with external beam accelerated partial breast irradiation (EB-APBI) utilizing intensity modulated radiotherapy (IMRT) or 3-dimensional conformal radiotherapy (3D-CRT), both with image-guided radiotherapy (IGRT).Methods and Materials: 16 stage 0/I breast cancer patients with previous elective bilateral augmentation were treated post-lumpectomy on institutional EB-APBI trials (01185132 and 01185145 on c...

  9. Quality indicators in radiotherapy

    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

  10. Bowel disease after radiotherapy

    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. (author)

  11. Nanoparticle-guided radiotherapy

    2012-01-01

    The present invention relates to a method and nano-sized particles for image guided radiotherapy (IGRT) of a target tissue. More specifically, the invention relates to nano-sized particles comprising X-ray-imaging contrast agents in solid form with the ability to block x-rays, allowing for simult...

  12. Radiotherapy treatment planning

    A teaching text on external beam radiotherapy treatment planning is presented. Chapters are included on machines, radiation units, the physics of a single radiation field, the multiple-field isodose curve pattern, electron beam therapy, manual addition of isodose curves and dose calculation methods. (U.K.)

  13. Radiotherapy equipment for conformal radiotherapy and IMRT in the Czech Republic

    The development of the equipment of radiotherapy departments in the Czech Republic is presented here. The data from the special questionnaire from 14 workplaces with linear accelerators with multi-leaf collimators (MLC) and electronic portal imaging device (EPID) are included. They show not only the equipment specification but also the application methods, the quality control, plans for future etc. In the Czech Republic, a great extension of modem irradiation techniques and accessories occurs at present. Together with it, it is necessary to develop quality assurance of the whole process of dose delivery to the patient. It is also necessary to assure further education and training of hospital staff. Modern radiotherapy techniques demand sufficient amount of all sources including personal sources. (authors)

  14. Laser accelerator

    Vigil, Ricardo

    2014-01-01

    Approved for public release; distribution is unlimited In 1979,W. B. Colson and S. K. Ride proposed a new kind of electron accelerator using a uniform magnetic field in combination with a circularly-polarized laser field. A key concept is to couple the oscillating electric field to the electron’s motion so that acceleration is sustained. This dissertation investigates the performance of the proposed laser accelerator using modern high powered lasers and mag-netic fields that are significan...

  15. Quality assurance in radiotherapy

    Good radiotherapy results and safety of treatment require the radiation to be optimally applied to a specified target area and the correct dose. According to international recommendations, the average uncertainty in therapeutic dose should not exceed 5%. The need for high precision in therapeutic dose requires quality assurance covering the entire radiotherapy process. Besides the physical and technical characteristics of the therapy equipment, quality assurance must include all radiotherapy equipment and procedures that are significant for the correct magnitude and precision of application of the therapeutic dose. The duties and responsibilities pertaining to various stages of treatment must also be precisely defined. These requirements may be best implemented through a quality system. The general requirements for supervision and quality assurance of medical radiation apparatus are prescribed in section 40 of the Radiation Act (592/1991, amendment 1142/1998) and in sections 18 and 32 of the Decree of the Ministry of Social Affairs and Health on the medical use of radiation (423/2000). Guide ST 2.2 imposes requirements on structural radiation shielding of radiotherapy equipment and the premises in which it is used, and on warning and safety arrangements. Guide ST 1.1 sets out the general safety principles for radiation practices and regulatory control procedure for the use of radiation. Guide ST 1.6 provides general requirements for operational measures in the use of radiation. This Guide sets out the duties of responsible parties (the party running a radiation practice) in respect of arranging and maintaining radiotherapy quality assurance. The principles set out in this Guide and Guide ST 6.3 may be applied to radionuclide therapy

  16. The physics of radiotherapy X-rays and electrons

    Metcalfe, Peter; Hoban, Peter

    2012-01-01

    The Physics of Radiotherapy X-Rays and Electrons is an updated successor to The Physics of Radiotherapy X-Rays from Linear Accelerators published in 1997. This new volume includes a significant amount of new material, including new chapters on electrons in radiotherapy and IMRT, IGRT, and tomotherapy, which have become key developments in radiation therapy. Also updated from the earlier edition are the physics beam modeling chapters, including Monte Carlo methods, adding those mysterious electrons, as well as discourse on radiobiological modeling including TCP, NTCP, and EUD and the impact of these concepts on plan analysis and inverse planning. This book is intended as a standard reference text for postgraduate radiation oncology medical physics students. It will also be of interest to radiation oncology registrars and residents, dosimetrists, and radiation therapists. The new text contains review questions at the end of each chapter and full bibliographic entries. Fully indexed. Selected questions and ans...

  17. Prostaglandin inhibitor and radiotherapy in advanced head and neck cancers

    Radiotherapy is the usual mode of treatment for unresectable head and neck cancer. To improve cure rates, extend survival, and reduce morbidity, we use accelerated hyperfractionation radiotherapy and an adjuvant drug to inhibit prostaglandin synthesis. In this study, 19 patients received 300 rad/day of radiotherapy in two equally divided doses to a total dose averaging 6,200 rad. Either indomethacin, 25 mg, or placebo was given four times a day in a double-blind fashion during therapy. Radiation mucositis was graded as 0 to 4+; pain, nutritional status, and tumor status were monitored daily and recorded biweekly. Evaluation of the data showed delayed mucositis in the experimental group for grades 1 to 3, with a significant difference at grade 3 compared with controls. The significance of a long-term comparison of cure rates would be doubtful considering the heterogeneity of the primary sites and regional disease in this group coupled with the small size of our study

  18. Quality assurance status on radiotherapy in Vietnam

    Vietnam was one of the first countries, which early applied ionizing radiation in medicine. Dr. Marie Curie herself certificated supplying radium sources to Hanoi Cancer Hospital (today name is the K Hospital) for cancer treatment since 1923. In spite of early application of radiation in medicine, Vietnam is now facing to problem of deficiency of radiotherapy facilities. 13 cobalt units and 7 Linear Accelerators (linac) per 84 millions population are working in the whole country, meanwhile about 100,000 patients suffered by cancer and tumor disease per year and only 10 percent of these are treated by radiation. The deficiency of the facilities leads to an ugly overloading with patients in the cancer centers and hospitals. The problem could be resolved by increasing the number of Cobalt therapy units and introducing of more effective tools for treatment as linear electron accelerators and other related equipment and by close cooperation and effort of physicists and physicians in the field of application of ionizing radiation in medicine to effectively use of facilities and ensure QA/QC in radiotherapy. (author)

  19. Accelerated partial breast irradiation using intensity-modulated radiotherapy technique compared to whole breast irradiation for patients aged 70 years or older: subgroup analysis from a randomized phase 3 trial.

    Meattini, Icro; Saieva, Calogero; Marrazzo, Livia; Di Brina, Lucia; Pallotta, Stefania; Mangoni, Monica; Meacci, Fiammetta; Bendinelli, Benedetta; Francolini, Giulio; Desideri, Isacco; De Luca Cardillo, Carla; Scotti, Vieri; Furfaro, Ilaria Francesca; Rossi, Francesca; Greto, Daniela; Bonomo, Pierluigi; Casella, Donato; Bernini, Marco; Sanchez, Luis; Orzalesi, Lorenzo; Simoncini, Roberta; Nori, Jacopo; Bianchi, Simonetta; Livi, Lorenzo

    2015-10-01

    The purpose of this study was to report the efficacy and the safety profile on the subset of selected early breast cancer (BC) patients aged 70 years or older from a single-center phase 3 trial comparing whole breast irradiation (WBI) to accelerated partial breast irradiation (APBI) using intensity-modulated radiation therapy technique. Between 2005 and 2013, 520 patients aged more than 40 years old were enrolled and randomly assigned to receive either WBI or APBI in a 1:1 ratio. Eligible patients were women with early BC (maximum diameter 2.5 cm) suitable for breast conserving surgery. This study is registered with ClinicalTrials.gov, NCT02104895. A total of 117 patients aged 70 years or more were analyzed (58 in the WBI arm, 59 in the APBI arm). At a median follow-up of 5-years (range 3.4-7.0), the ipsilateral breast tumor recurrence (IBTR) rate was 1.9 % in both groups. No significant difference between the two groups was identified (log-rank test p = 0.96). The 5-year disease-free survival (DFS) rates in the WBI group and APBI group were 6.1 and 1.9 %, respectively (p = 0.33). The APBI group presented significantly better results in terms of acute skin toxicity, considering both any grade (p = 0.0001) and grade 2 or higher (p = 0.0001). Our subgroup analyses showed a very low rate and no significant difference in terms of IBTR, using both WBI and APBI. A significant impact on patients compliance in terms of acute and early late toxicity was shown, which could translate in a consistent improvement of overall quality of life. PMID:26350524

  20. Interim Cosmetic Results and Toxicity Using 3D Conformal External Beam Radiotherapy to Deliver Accelerated Partial Breast Irradiation in Patients With Early-Stage Breast Cancer Treated With Breast-Conserving Therapy

    Purpose: We present our ongoing clinical experience utilizing three-dimensional (3D)-conformal radiation therapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer treated with breast-conserving therapy. Methods and Materials: Ninety-one consecutive patients were treated with APBI using our previously reported 3D-CRT technique. The clinical target volume consisted of the lumpectomy cavity plus a 10- to 15 -mm margin. The prescribed dose was 34 or 38.5 Gy in 10 fractions given over 5 consecutive days. The median follow-up was 24 months. Twelve patients have been followed for ≥4 years, 20 for ≥3.5 years, 29 for >3.0 years, 33 for ≥2.5 years, and 46 for ≥2.0 years. Results: No local recurrences developed. Cosmetic results were rated as good/excellent in 100% of evaluable patients at ≥ 6 months (n = 47), 93% at 1 year (n = 43), 91% at 2 years (n = 21), and in 90% at ≥3 years (n = 10). Erythema, hyperpigmentation, breast edema, breast pain, telangiectasias, fibrosis, and fat necrosis were evaluated at 6, 24, and 36 months after treatment. All factors stabilized by 3 years posttreatment with grade I or II rates of 0%, 0%, 0%, 0%, 9%, 18%, and 9%, respectively. Only 2 patients (3%) developed grade III toxicity (breast pain), which resolved with time. Conclusions: Delivery of APBI with 3D-CRT resulted in minimal chronic (≥6 months) toxicity to date with good/excellent cosmetic results. Additional follow-up is needed to assess the long-term efficacy of this form of APBI

  1. Project of compact accelerator for cancer proton therapy; Progetto di acceleratore compatto per terapia oncologica con protoni (TOP)

    Picardi, L.; Ronsivalle, C.; Vignati, A. [ENEA, Cntro Ricerche Frascati, Rome (Italy). Dip. Innovazione

    1995-04-01

    The status of the sub-project `Compact Accelerator` in the framework of the Hadrontherapy Project leaded by Prof. Amaldi is described. Emphasis is given to the reasons of the use of protons for radiotherapy applications, to the results of the preliminary design studies of four types of accelerators as possible radiotherapy dedicated `Compact Accelerator` and to the scenario of the fonts of financial resources.

  2. LIBO accelerates

    2002-01-01

    The prototype module of LIBO, a linear accelerator project designed for cancer therapy, has passed its first proton-beam acceleration test. In parallel a new version - LIBO-30 - is being developed, which promises to open up even more interesting avenues.

  3. Measurements of the Photonuclear Neutron Yield During Radiotherapy Using Bubble Detectors and Thermoluminescence Detectors

    Stokkevåg, Camilla Hanquist

    2010-01-01

    Medical linear accelerators (linacs) used for radiotherapy with photons produce an undesirable neutron contribution as treatment energies exceed the (γ,n) threshold of the high-Z constituents of the linac. Secondary neutrons in radiotherapy can contribute to an additional dose outside the treatment volume in the patient. Treatment techniques o ering improved con nement of the dose to the target volume are rapidly evolving and will contribute di erently to the production of n...

  4. Induction accelerators

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  5. Radiotherapy of bronco-pulmonary cancer; Radiotherapie des cancers brochopulmonaires

    Bourry, N.; Millardet, C.; Lapeyre, M.; Verrelle, P.; Gross, E.; Champeaux-Orange, E.; Lahbabi, K.; Galland, S.; Chomy, F.; Lagarde, P.; Blanchard, P

    2007-11-15

    Six oral communications as follow: tomography by positron emission with {sup 18}F-FDG and target volume determination in the non at small cells bronchi cancers: interest and limit; adjuvant radiotherapy in the non at small cells pulmonary cancers; pulmonary stereotaxic radiotherapy; the chemoradiotherapy of locally evolved bronco-pulmonary cancers; the mesothelioma: place of radiotherapy; predictive factors of the toxicity and the care of complications of thorax irradiation. (N.C.)

  6. Dosimetry at the location of secondary tumors after radiotherapy

    Baas, H.W.; Davelaar, J.J.; Broerse, J.J.; Noordijk, E.M. [University Hospital, Leiden (Netherlands). Dept. of Clinical Oncology

    1995-12-01

    After a latency period of many years the incidence of a secondary tumor is considered a serious late effect of radiotherapy. Analysis of about 200 patients, treated by radiotherapy for Hodgkin`s disease in our hospital, shows an actuarial risk for the incidence of a secondary tumor of about 7% after 10 years. The chance of tumor induction depends on the dose at the location of the tumor and therefore a good dose estimation is mandatory. Radiotherapy was given with Co-60 in the early years and with linear accelerators thereafter, exposing the target areas to 36 - 40 Gy. For dose estimations at the penumbra and outside the beam, where tumor incidence is expected to be high, we used a.o. Monte Carlo calculations. We developed an EGS4 computer simulation for a treatment beam from a linear accelerator irradiating a mathematical phantom representing the patient geometry (GSF ADAM phantom). The isodose curves at certain energies were obtained for a water phantom and fitted quite well with measurements. In addition to Monte Carlo calculations we also used existing treatment planning systems. The dose estimations of a number of patients and the derived risk per unit of dose, which is important for both radiotherapy as well as radiation protection in general, is discussed.

  7. Experimental radiotherapy unit to be established at GSI in Darmstadt

    The Radiologische Universitaetsklinik, Heidelberg, the Gesellschaft fuer Schwerionenforschung, GSI, Darmstadt, and the Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, have filed an application for a joint project intended to study the feasibility and methodology of an enhancement of radiotherapy by way of application of heavy ions and novel irradiation techniques. The experimental radiotherapy unit is to be installed at the heavy ion synchrotron of GSI. It is planned to have about 70 patients a year taking part in the clinical study extending over a period of five years. The results obtained shall be analysed to answer the following questions: - Is the technique developed suitable for clinical routine? - Are the improved dose distributions obtained with the charged particles more effective for local tumor healing than the radiation applied for conventional radiotherapy? - Can an additional clinical effect be attributed to the high-LET properties of the heavy charged particles? - Do the results indicate novel applications of the high-precision radiotherapy using heavy ions? The project is also intended to yield baseline data for defining the concept and technical conditions of heavy-ion radiotherapy as a clinical routine method and therefore also encompasses a design study for a heavy-ion accelerator exclusively for clinical applications. (orig./MG)

  8. Configuration control based on risk matrix for radiotherapy treatment

    The incorporation of the science and technique breakthroughs in the application of the radiotherapy represents a challenge so that, the appearance of equipment failure or human mistakes that triggers unfavorable consequences for patients, public, or the occupationally exposed workers; it is also diversified forcing to incorporate besides, as part of the efforts, new techniques for the evaluation of risk and the detection of the weak points that can lead to these consequences. In order to evaluate the risks of the radiotherapy practices there is the SEVRRA code, based on the method of Risk Matrix. The system SEVRRA is the most frequently used code in the applications of risk studies in radiotherapy treatment. On the other hand, starting from the development of tools to control the dangerous configurations in nuclear power plants, it has been developed the SECURE code, which in its application variant of Risk Matrix, has gain a comfortable interface man-machine to make risk analyses to the radiotherapy treatment, molding in this way a lot of combinations of scenarios. These capacities outstandingly facilitate the studies and risk optimization applications in these practices. In the system SECURE-Risk Matrix are incorporated graphic and analytical capacities, which make more flexible the analyses and the subsequent documentation of all the results. The paper shows the the application of the proposed system to an integral risk study for the process of radiotherapy treatment with linear accelerator. (Author)

  9. External audit in radiotherapy dosimetry

    Quality audit forms an essential part of any comprehensive quality assurance programme. This is true in radiotherapy generally and in specific areas such as radiotherapy dosimetry. Quality audit can independently test the effectiveness of the quality system and in so doing can identify problem areas and minimize their possible consequences. Some general points concerning quality audit applied to radiotherapy are followed by specific discussion of its practical role in radiotherapy dosimetry, following its evolution from dosimetric intercomparison exercises to routine measurement-based on-going audit in the various developing audit networks both in the UK and internationally. Specific examples of methods and results are given from some of these, including the Scottish+ audit group. Quality audit in radiotherapy dosimetry is now well proven and participation by individual centres is strongly recommended. Similar audit approaches are to be encouraged in other areas of the radiotherapy process. (author)

  10. Radiotherapy of hemangiomas

    Gauwerky, F.

    1982-10-11

    The findings about the regular, spontaneous and complete regression of cavernous skin hemangiomas occurring in infants and those findings about the damaging effects due to ionising radiation - here particularly local growth disturbances - led to the development of very cautious diagnostic methods and to a considerate individual dosage and radiotherapy, which always takes into consideration the spontaneous regression tendency of the hemangiomas. However, a function-impairing localisation at the orifices, fulminant macrosomia, tendency to hemorrhages and poly-infection with superficial ulceration and even thrombopenic syndromes of the Kasabach-Merritt type may become necessary, urgent and also vital indications for a particular radiotherapy. For the sake of the patients, irradiation methods, which do not provoke any risk of radiation hazards, have to be preserved and applied in practice. Certainly further research and the nosologic nature of hemangiomas is required. A general non-treatment of hemangiomas is refused.

  11. Nutrition and radiotherapy

    Full text: Radiation is a common method of treating large tumours, however one of the major problems in radiation therapy is the severe side effects that may limit its efficacy. Utilising nutrients can assist in the control of these side effects which will greatly enhance the quality of life of the patient plus improve the effectiveness of the radiation. Another controversial point regarding radiation and nutrition is the concurrent use of antioxidants and radiotherapy. The science literature is in agreement that supplementing with antioxidants after radiation is essential. In addition, most studies now show that antioxidants do not interfere with the efficacy of radiotherapy. These issues and suggestions for nutrients to assist during and after radiation will be discussed

  12. Radiotherapy for aggressive fibromatosis

    Purpose/Objective: To evaluate local control with radiotherapy for aggressive fibromatosis. Materials and Methods: Fifty-three patients with histologically confirmed aggressive fibromatosis were treated with radiotherapy at the University of Florida between March 1975 and June 1992. The minimum length of follow-up was 2 years; 88% of patients had follow-up for at least 5 years. Thirty-nine patients had lesions in an extremity and 14 patients had lesions in the trunk. Twenty-nine patients were treated for gross disease. Patients were treated with total doses between 35 Gy and 70 Gy; 83% of patients received 50 Gy to 60 Gy. Results: Local control was achieved in 23 of 29 patients (79%) treated for postoperative microscopic residual disease. Local control was achieved in 21 of 24 patients (88%) treated for gross disease; gross disease was controlled in 8 of 8 patients with previously untreated lesions, and in 13 of 16 patients treated for postoperative gross residual and recurrent disease. Overall, aggressive fibromatosis was locally controlled in 83% of treated patients. All 9 treatment failures occurred with extremity lesions 4 to 68 months after initiation of treatment. Of the 9 recurrences, 4 were out-of-field, 3 were in-field, and 4 occurred at the margin of the irradiated field. Salvage was successful in 8 of 9 patients in whom salvage was attempted with surgery alone or combined with postoperative radiotherapy. A functional limb was maintained in 38 of 39 patients with extremity or limb girdle lesions. The most serious complication of treatment was pathologic fracture, which occurred in 3 of 53 treated patients; all 3 fractures healed with conservative management. Conclusion: Radiotherapy is a valuable adjunct to surgery in the management of aggressive fibromatosis and can be used alone in patients with unresectable or inoperable disease

  13. Conformal radiotherapy: a glossary

    Most of the concepts and terms related to conformal radiotherapy were produced by English-speaking authors and eventually validated by international groups of experts, whose working language was also English. Therefore, a significant part of this literature is poorly accessible to the French-speaking radiation oncology community. The present paper gathers the 'official' definitions already published in French, along with propositions for the remaining terms which should be submitted to a more formal and representative validation process. (author)

  14. DICOM in Radiotherapy

    A. Nikfarjam; E Ganjalikhan Hakemi; E. Negahbani; MR. Khajeaminian

    2007-01-01

    Noticeable development in achieving data from patients is acquired by means of designing a system that connects these systems: imaging, archive and monitoring systems. When several imaging devices work based on DICOM standard; they can connect to each other without any interface. There are many applications for DICOM standard in radiotherapy; however its main usage is in imaging. It has other applications such as RT Structure Set, RT Dose, RT Plan and RT Brachy Treatment. "nNow DICOM is ...

  15. Xerostomia induced by radiotherapy

    Alimi, David

    2015-01-01

    David Alimi Department of Anesthesiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USAWe read with great interest the excellent review on xerostomia induced by radiotherapy, by Pinna et al.1 The authors should be congratulated for a very detailed review of the physiopathology, clinical symptoms, and therapeutic management of an extremely difficult condition. Although we agree that the use of anticholinergic medication represents treatment, it requires the patient to have resi...

  16. Technologies for Delivery of Proton and Ion Beams for Radiotherapy

    Owen, Hywel; Alonso, Jose; MacKay, Ranald

    2013-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  17. TECHNOLOGIES FOR DELIVERY OF PROTON AND ION BEAMS FOR RADIOTHERAPY

    Owen, H; Alonso, J; Mackay, R

    2014-01-01

    Recent developments for the delivery of proton and ion beam therapy have been significant, and a number of technological solutions now exist for the creation and utilisation of these particles for the treatment of cancer. In this paper we review the historical development of particle accelerators used for external beam radiotherapy and discuss the more recent progress towards more capable and cost-effective sources of particles.

  18. Characteristic evaluation of photoneutron in radiotherapy room using MCNPX

    Linear accelerators are now playing a pivotal role in radiotherapy and high energy photon beams of a strength exceeding 8 MV have recently been mainly used. However, when using high energy photons, neutron contamination due to photonuclear reaction develops. This study focused on the dose distribution of photoneutrons emitted from a linear accelerator using Monte Carlo MCNPX code. MCNPX was used to simulate transportation of photoneutrons in the linear accelerator and the entire space of the radiotherapy room and is useful for calculating the flux, spectrum and absorbed dose. As result of the simulation, we could know that the neutron absorbed dose was as less as negligible when comparing to the photon absorbed dose in radiotherapy room. And it was found that the photoneutron flux increased substantially starting from 10 MV while the absorbed dose rose sharply between 10 MV and 12 MV. It was observed that although the ratio of thermal neutrons to fast neutrons was not altered as the energy increased, it was found that as the distance from the source increased the ratio of thermal neutrons rose markedly

  19. Fractionated stereotactic radiotherapy for recurrent small cell lung cancer brain metastases after whole brain radiotherapy

    Objective: Evaluation the Fractionated Stereotactic Radiotherapy (FSRT) for the patients with small-cell lung cancer (SCLC) after the whole brain radiotherapy (WBRT) failure. Methods: We retrospectively analyzed 35 patients with brain metastases from small-cell lung cancer treated with linear accelerator FSRT after the WBRT failure. Multivariate analysis was used to determine significant prognostic factor related to survival. Results: The following-up rate was 100%. The median following-up time was 11 months. The median over-all survival (OS) time was 10.3(1 -30) months after FSRT. Controlled extra cranial disease was the only identified significant predictor of increased median OS time (χ2 =4.02, P =0.045 ). The median OS time from the diagnosis of brain metastasis was 22 (6 - 134 ) months. 14 patients died from brain metastasis, 14 from extra-cranial progression, 1 from leptomeningeal metastases, and 3 from other causes. Local control at 6 months and 12 months was 91% and 76%, respectively. No significant late complications. New brain metastases outside of the treated area developed in 17% of patients at a median time of 4(2 -20) months; all patients had received previous WBRT. Conclusions: Fractionated stereotactic radiotherapy was safe and effective treatment for recurrent small-cell lung carcinoma brain metastases. (authors)

  20. Decommissioning of Radiotherapy Facilities

    Radiotherapy units containing high activity sealed radioactive sources of 60Co or 137Cs are mainly use for medical, research or calibration applications. After several half-lives of decay, the radionuclide source has to be changed or the unit is decommissioned if no longer required. Before starting a decommissioning project it is very important to look for documents relating to any sources held or installed in equipment. In general this should be no problem because the recommended working life of such sealed radioactive sources is limited to 10 or a maximum of 15 years. These time periods are short in comparison with other facilities like research laboratories or small reactors. These documents (source certificates) will be very helpful to plan the decommissioning because they say everything about the original activity of the source at a reference date, the type of the source and the manufacturer. The next step may be to contact the machine supplier or the source manufacturer, but be aware that neither may still be in existence or may have changed their type of business. In such cases, it is recommended to contact national or international sealed source manufacturers or suppliers for help. Sometimes it is also helpful to contact colleagues in other hospitals or research centres to ask for information about specialists in this topic. In general it is not useful, and even very dangerous, to try to decommission such a unit without expert help It is essential to have specialist tools and shielded containers to recover the source out of the unit. It is strongly recommended to invite the source removal specialist for a site visit to review the situation before starting any decommissioning process. A further problem can occur, if the source must be transported to a national storage centre or even an international storage facility, as the source must be packaged to meet international transport requirements. The end state of such a project should be an empty room where the

  1. Radiotherapy of presenile spinal osteoporosis

    Painfull conditions of presenile spinal osteoporosis may no longer respond to medication or physical therapy. Analgesic radiotherapy coupled with mild physical therapy and if necessary supported by orthopedic measures frequently results in pain relief and physical stability. Fifty-two cases of osteoporosis and osteoporotic spinal fractures illustrate how better longterm results are achieved by increasing the customary dosage and speeding up radiotherapy. (orig.)

  2. Tandem accelerators

    After the installation of Ti-acceleration tubes and substantial modifications and additions to the EN tandem accelerator the performance of the machine has stabilized. The voltage behaviour of the tubes obviously improves as conditioning times necessary to run up to 6 MV decrease. A gridded lens has been added at the entrance of the first acceleration tube, and a second foil stripper is now installed in the short dead section between the high-energy tubes. The MP tandem also has been running stably during most of the year. However, beam instabilities originating from the last tube section and wear problems at the low-energy set of pelletron-chains caused some loss of beam time. During the fall, one set of pelletron charging chains has to be replaced after 49,000 hours of operation. In the course of the year, the MP and the EN tandem accelerators finished their 100,000th and 150,000th hours of operations, respectively. Preparations for the installation of the 3 MV negative heavy ion injector for the MP are progressing steadily. External beam transport, terminal ion optics, and data acquisition and control systems are to a major extent completed; the integration of the terminal power supplies has started. After the final assembly of the accelerator column structure, first voltage runs can be performed. (orig.)

  3. Radiotherapy for eyelid cancer

    Saika, Kazumi [Yokohama City Univ. (Japan). School of Medicine

    2001-05-01

    Some studies on radiotherapy for eyelid cancer have been reported, but the optimal radiation doses for different histological types and tumor sizes have not been detailed. So I studied the optimal radiation doses in radiotherapy for eyelid cancer. The patients were fourteen and histological diagnoses were made on the basis of biopsies or surgery before radiotherapy. Surgical cut margins were positive in 10 cases. In 5 of these cases, tumors were visible. There were 9 sebaceous adenocarcinomas (SAC), 4 squamous cell carcinomas (SCC), and 1 basal cell carcinoma (BCC). In 13 of 14 cases, radiation was applied to eyelids in which tumor-surgical cut margin distances were 3 mm or less. The eyeballs were covered with lead or tungsten shields, and the eyelids were irradiated with a total dose of 50 to 66.6 Gy. In 5 cases, radiation was applied prophylactically for ipsilateral pre-auricle lymph node areas. 11 of 13 cases were locally controlled. I gave greater radiation doses for SAC than for SCC or BCC. I also gave greater doses for in visible tumors than for invisible ones. In the acute phase dermatitis, inflammation of the cornea, conjunctivitis, etc. occurred but they were mild. Later reactions were decreased cilia, dry eye, inflammation of cornea, conjunctivitis, discomfort of the scar, etc. Cataracts were also seen, but they were of senile origen. Because 81.8% of the tumors were controlled, this radiation method was useful with salvage therapies to select an optimal radiation dose according to the differences among histological types and tumor sizes. 60% of visible tumors were also controlled so I think that radical therapy using radiation alone is possible. (author)

  4. Radiotherapy of benign diseases

    Still today radiotherapy is of decisive relevance for several benign diseases. The following ones are briefly described in this introductory article: 1. Certain inflammatory and degenerative diseases as furuncles in the face, acute thrombophlebitis, recurrent sudoriparous abscesses, degenerative skeletal diseases, cervical syndrome and others; 2. rheumatic joint diseases; 3. Bechterew's disease; 4. primary presenile osteoporosis; 5. synringomyelia; 6. endocrine ophthalmopathy; 7. hypertrophic processes of the connective tissue; 8. hemangiomas. A detailed discussion and a profit-risk analysis is provided in the individual chapters of the magazine. (MG)

  5. Clinical treatment of lumbodorsal radiotherapy ulcers

    Objective: To summarize our experience in the treatment of 12 cases of severe lumbodorsal radio-therapy ulcers. Methods: Of the 12 cases, 4 were male and 8 female. The youngest patient was 29 and the oldest was 67 years old. Their injuries were mainly resulted from radiotherapy for costal metastasis of breast cancer, carcinoma of uterus and dorsal skin carcinoma or scar induced by 60Co γ-rays, deep X-rays or superficial accelerator electrons. Their local accumulative dose was 60-120 Gy. Palliative debridement was performed with partial excision of the ribs and spinous process. And then the defects were repaired with local skin flap in 2 cases, parascapular skin flap in 1 case and island musculocutaneous flap of latissimus dorsi muscle in 9 cases. Results: All the skin flaps and musculocutaneous flaps grafted on the wounds of the 12 cases survived (100%). Grade A healing was achieved in 11 cases of ulcer (91.7%) and grade B healing in 1 cases (8.3%). All the skin flaps and musculocutaneous flaps grafted survived and the ulcers never recurred. Conclusion: Severe lumbodorsal radiotherapy injury often results in complications. The authors performed palliative excision and repaired by transferring an axial skin flap or a musculocutaneous flap with good blood circulation selected in accordance with the principles of plastic surgery, which can effectively improve blood circulation and promote wound healing. Reverse musculocutaneous flap of latissimus dorsi muscle is an especially good material for reconstruction. It has axial blood vessel and proper thickness. It is broad and can be rotated with great range and the donor site can be sutured directly

  6. Problems of clinical dosimetry in Russian radiotherapy centers

    Due to the general catastrophic situation of radiation oncology in Russia, its outdated equipment and shortage of medical physicists, the clinical dosimetry is also in a very poor state and doesn't meet the modern requirements of the quality assurance in radiotherapy. In Russia there are 140 radiotherapy departments, 100 medical accelerators and 250 gamma apparatus but only 150 clinical dosimeters and 75 dose field analyzers, 90% of which are morally and physically obsolete and do not meet the requirements of the quality assurance. Ten percent of the radiotherapy departments are not equipped with clinical dosimeters at all. There is no national program of quality assurance in radiotherapy. Service for dosimetry equipment calibration is lacking. The national standards and protocols of clinical dosimetry haven't been elaborated. Two-hundred-and-sixty medical physicists work in radiotherapy, 90% of whom have insufficient experience and qualification. Ten percent of radiotherapy departments do not have medical physicists in its staff at all and the rest of the departments face a shortage of medical physicists. The number of medical physicists is not enough to provide the full medical physics service. Qualified medical physicists do not stay long in clinics because of the small salary. As a result of these drawbacks the accuracy of the therapeutic dose delivery to the tumour often achieves 30% instead of the 5% admissible error. This situation leads to high radiation risks, particularly for radiation overdosage or underdosage during the patient's treatment. However, there are no radiation accident statistics in Russia; therefore it's impossible to evaluate them in terms of quantity. Unfortunately, this is the outcome of the lack of the state policy in this field. Neither the Health Ministry nor the Rosatom is concerned about this problem. The only thing that the Health Ministry is undertaking now is the purchase of the new equipment, dosimetry equipment included, for

  7. Performance of different radiotherapy workload models

    Purpose: The purpose of this study was to evaluate the performance of different radiotherapy workload models using a prospectively collected dataset of patient and treatment information from a single center. Methods and Materials: Information about all individual radiotherapy treatments was collected for 2 weeks from the three linear accelerators (linacs) in our department. This information included diagnosis code, treatment site, treatment unit, treatment time, fields per fraction, technique, beam type, blocks, wedges, junctions, port films, and Eastern Cooperative Oncology Group (ECOG) performance status. We evaluated the accuracy and precision of the original and revised basic treatment equivalent (BTE) model, the simple and complex Addenbrooke models, the equivalent simple treatment visit (ESTV) model, fields per hour, and two local standards of workload measurement. Results: Data were collected for 2 weeks in June 2001. During this time, 151 patients were treated with 857 fractions. The revised BTE model performed better than the other models with a mean vertical bar observed - predicted vertical bar of 2.62 (2.44-2.80). It estimated 88.0% of treatment times within 5 min, which is similar to the previously reported accuracy of the model. Conclusion: The revised BTE model had similar accuracy and precision for data collected in our center as it did for the original dataset and performed the best of the models assessed. This model would have uses for patient scheduling, and describing workloads and case complexity

  8. A scintillating fiber dosimeter for radiotherapy

    Bartesaghi, G. [Universita degli Studi di Milano and INFN sezione di Milano (Italy)], E-mail: giacomo.bartesaghi@gmail.com; Conti, V. [Universita degli Studi di Milano and INFN sezione di Milano (Italy); Bolognini, D.; Grigioni, S.; Mascagna, V.; Prest, M.; Scazzi, S. [Universita dell' Insubria, Como and INFN sezione di Milano (Italy); Mozzanica, A. [Universita degli Studi di Brescia and INFN sezione di Pavia (Italy); Cappelletti, P.; Frigerio, M.; Gelosa, S.; Monti, A.; Ostinelli, A. [Fisica Sanitaria, Ospedale S. Anna di Como (Italy); Giannini, G.; Vallazza, E. [INFN sezione di Trieste and Universita degli Studi di Trieste (Italy)

    2007-10-21

    Radiotherapy, together with chemotherapy and surgery, is one of the main methods applied in the fight against cancer; in order to increase the chances of a successful radiotherapy treatment the dose delivery to the tumor and the surrounding normal tissues has to be computed with high accuracy. Traditional dosimeters are accurate but single channel (ionization chambers and diodes) or non real-time (radiographic films) devices. At present there is no device water equivalent that can perform real-time and bidimensional measurements of a dose distribution. This article describes the development of a real-time dosimeter based on scintillating fibers for photon and electron beams; the fibers are made of polystyrene, that is water equivalent and thus tissue equivalent, allowing a direct dose calculation. Three prototypes (single and multichannel) have been assembled, consisting in small scintillators coupled to white fibers that carry the light to photomultiplier tubes. In this article the prototypes and the readout electronics are described, together with the results of the measurements with electron and photon beams with energy up to 20 MeV (produced by linear accelerators Varian Clinac 1800 and 2100CD)

  9. A scintillating fiber dosimeter for radiotherapy

    Radiotherapy, together with chemotherapy and surgery, is one of the main methods applied in the fight against cancer; in order to increase the chances of a successful radiotherapy treatment the dose delivery to the tumor and the surrounding normal tissues has to be computed with high accuracy. Traditional dosimeters are accurate but single channel (ionization chambers and diodes) or non real-time (radiographic films) devices. At present there is no device water equivalent that can perform real-time and bidimensional measurements of a dose distribution. This article describes the development of a real-time dosimeter based on scintillating fibers for photon and electron beams; the fibers are made of polystyrene, that is water equivalent and thus tissue equivalent, allowing a direct dose calculation. Three prototypes (single and multichannel) have been assembled, consisting in small scintillators coupled to white fibers that carry the light to photomultiplier tubes. In this article the prototypes and the readout electronics are described, together with the results of the measurements with electron and photon beams with energy up to 20 MeV (produced by linear accelerators Varian Clinac 1800 and 2100CD)

  10. Transverse tomography and radiotherapy

    This study was intended to delineate the indications for radiotherapy treatment-planning with the help of computerized axial tomography (C.T.) and transverse analog tomography (T.A.T.). Radiotherapy localisation procedures with the conventional method (simulator), with the CT-scanner and with the transverse analog tomograph (T.A.T., Simtomix, Oldelft) were compared. As criterium for evaluation differences in reconstruction drawing based on these methods were used. A certain method was judged ''superior'' to another if the delineation of the target volume was more accurate, if a better impression was gained of the site of (for irradiation) organs at risk, or if the localisation could only be performed with that method. The selected group of patients consisted of 120 patients for whom a reconstruction drawing in the transverse plane was made according to the treatment philosophy. In this group CT-assisted localisation was judged on 68 occasions superior to the conventional method. In a number of cases it was found that a ''standard'' change in a standard target volume, on the base of augmented anatomical knowledge, made the conventional method sufficient. The use of CT-scanner for treatment planning was estimated. For ca. 270/1000 new patients a CT-scan is helpful (diagnostic scan), for 140 of them the scan is necessary (planning scan). The quality of the anatomical information obtained with the T.A.T. does not yet fall within acceptable limits, but progress has been made. (Auth.)

  11. Imaging in radiotherapy

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

  12. Pregnancy and radiotherapy : management options for minimising risk, case series and comprehensive literature review

    Full text: This article reviews the efficacy and safety of radiotherapy in patients with cancer who are pregnant. Our review provided extended follow-up results in nine cases, presents a technical discussion on measures taken to minimise foetal radiation exposure and provides a comprehensive summary of the literature. Nine patients who received radiotherapy while pregnant are described. The clinical presentation and outcomes of these and 100 additional cases identified on a systematic literature review are presented. Comparisons of scattered radiation doses from three linear accelerators are presented. The average maternal follow-up in our series was 8.9 years with one patient having a recurrence of their astrocytoma. In terms of foetal outcome, there were one death in utero, one elective termination of pregnancy and one on which no data were available. Six children, on whom long-term follow-up (average 10.3 years) was obtainable, were in good health. Overall, there had been 109 cases of radiotherapy in pregnancy that met our search criteria with 13 adverse outcomes and a median follow-up of 37 months. Comparisons of three linear accelerators demonstrated significant differences in the amount of scattered radiation to the abdominal surface. In summary radiotherapy during pregnancy can be associated with a significant number of adverse outcomes. While it may be difficult for a patient not to attribute these effects to radiotherapy, it is also difficult to define the mechanisms by which radiotherapy would have caused them, if that were the case.

  13. Advanced Accelerator Applications in Medicine

    besides the original purpose on development of particle acceleratora as research tools in nuclear and high-energy physics, there are large variety of accelerators used in various fileds from fundamental research to industrial usesand applications chemistry, biology and medicine. Pratical accelators used in various field of medical applications since serveral decades. Even through, a large fraction of applications is emphasized on cancer therappy, the number of accelerators used in midicine for other diagnostics and treatments has increased steady over the years. Several types of accelerated particles are used including electron, proton, neutron and ions. Presently, relativistic electron beams and radiation from linear accelerators (linas) are widely used. A combination of positron emission tomography (PRT) and radiotherapy is an example of excellent invention early detection and treat of cancer tumors. The most developments for proton and heavy ion therapy as well as a modern boron neutron capture therapy (BNCT) are also great incoming effective systems. This talk will focus on developments of the accelrator systems as well as overview on biophysical properties and medical aspects of the diacnostics and treatments.

  14. Advances in radiotherapy

    Radiation therapy is in the midst of a rebirth largely driven by the use of computers for treatment planning and beam delivery. The first edge of this renaissance was the advent of three-dimensional conformal radiation therapy (3-D CRT). This was enabled by the widespread availability and utilization of three-dimensional imaging such as computed tomography and magnetic resonance scanning, themselves products of the computer revolution. For the first time this allowed radiation oncologists to segment and visualize the tumor in association with it neighboring sensitive soft-tissue structures. Software tools to visualize the beam paths through the body enabled the beam directions and beam shapes to be manually optimized. Simultaneously, improved dose calculations utilizing the CT images of the patient anatomy produced more accurate distributions of dose. The dose was delivered with custom-shaped blocks or recently collimators with multiple leaves that allow complex shaped fields to be delivered without the need for block fabrication. In the last couple of decades new treatment delivery methodologies have emerged. The first has been stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) which is the purview of neurosurgeons (who call it SRS) as well as radiation oncologists (who usually call it SRT). SRS and SRT are premised on multiple beams focusing on one location typically with circular aperture collimators but increasingly with fields shaped by multi-leaved collimators. Often only a single treatment session (the usual for SRS) is used when the treatment volume is small, but for larger lesions several treatment sessions, or fractions, are used (most often for SRT) to allow for normal tissue repair. The new equipment market for SRS and SRT is about 10% of the total for radiation therapy. Intensity-modulated radiation therapy (IMRT) is the latest treatment methodology and its adoption has been extremely rapid, particularly in the United States. IMRT uses

  15. Stereotactic radiotherapy (SRT) for acoustic neuroma by linear accelerator

    Sakamoto, Tooru; Shirato, Hiroki; Fukuda, Satoshi [Hokkaido Univ., Sapporo (Japan). School of Medicine] [and others

    1997-10-01

    We analyzed forty one patients with acoustic neuroma treated by SRT giving 36 Gy in 20 fractions to 48 Gy in 23 fractions during 1991 and 1997, and found a sterilization of tumor size in 97.6%. Twenty-six patients had measurable hearing before and after SRT and 43.5% of patients showed change in pure tone average less than 10 dB, 82.6% less than 20 dB at the last follow-up examination. Facial and trigeminal nerve function was evaluated in 41 patients. Transient facial weakness developed in 4.8% and trigeminal neuropathy in 9.6% of irradiated cases. We consider that SRT complications are less than that of gamma-knife, although the longer follow-up period should be needed. (author)

  16. Particle acceleration

    Vlahos, L.; Machado, M. E.; Ramaty, R.; Murphy, R. J.; Alissandrakis, C.; Bai, T.; Batchelor, D.; Benz, A. O.; Chupp, E.; Ellison, D.

    1986-01-01

    Data is compiled from Solar Maximum Mission and Hinothori satellites, particle detectors in several satellites, ground based instruments, and balloon flights in order to answer fundamental questions relating to: (1) the requirements for the coronal magnetic field structure in the vicinity of the energization source; (2) the height (above the photosphere) of the energization source; (3) the time of energization; (4) transistion between coronal heating and flares; (5) evidence for purely thermal, purely nonthermal and hybrid type flares; (6) the time characteristics of the energization source; (7) whether every flare accelerates protons; (8) the location of the interaction site of the ions and relativistic electrons; (9) the energy spectra for ions and relativistic electrons; (10) the relationship between particles at the Sun and interplanetary space; (11) evidence for more than one acceleration mechanism; (12) whether there is single mechanism that will accelerate particles to all energies and also heat the plasma; and (13) how fast the existing mechanisms accelerate electrons up to several MeV and ions to 1 GeV.

  17. Accelerator design

    The feasibility of constructing a TeV region electron-positron linear collider in Japan is discussed. The design target of the collider is given as follows: Energy, 1 TeV + 1 TeV; luminosity, 1032-1033/cm2/s; total length, 25km; electric power, 250MW; energy dispersion, 1%-10%; the start of the first experiment, early 1990s. For realizing the above target, the following research and developmental works are necessary. (a) Development of an acceleration tube with short filling time and high shunt resistance. (b) Short pulse microwave source with high peak power. (c) High current, single bunch linac. (d) Beam dynamics. As for the acceleration tube, some possibility is considered: For example, the use of DAW (Disk and Washer) which is being developed for TRISTAN as a traveling-wave tube; and the Jungle Gym-type acceleration tube. As a promising candidate for the microwave source, the Lasertron has been studied. The total cost of the collider construction is estimated to be about 310 billion yen, of which 120 billion yen is for the tunnel and buildings, and 190 billion yen for the accelerator facilities. The operation cost is estimated to be about 3 billion yen per month. (Aoki, K.)

  18. Accelerator operations

    This section is concerned with the operation of both the tandem-linac system and the Dynamitron, two accelerators that are used for entirely different research. Developmental activities associated with the tandem and the Dynamitron are also treated here, but developmental activities associated with the superconducting linac are covered separately because this work is a program of technology development in its own right

  19. Advanced accelerators

    This report discusses the suitability of four novel particle acceleration technologies for multi-TeV particle physics machines: laser driven linear accelerators (linac), plasma beat-wave devices, plasma wakefield devices, and switched power and cavity wakefield linacs. The report begins with the derivation of beam parameters practical for multi-TeV devices. Electromagnetic field breakdown of materials is reviewed. The two-beam accelerator scheme for using a free electron laser as the driver is discussed. The options recommended and the conclusions reached reflect the importance of cost. We recommend that more effort be invested in achieving a self-consistent range of TeV accelerator design parameters. Beat-wave devices have promise for 1-100 GeV applications and, while not directly scalable to TeV designs, the current generation of ideas are encouraging for the TeV regime. In particular, surfatrons, finite-angle optical mixing devices, plasma grating accelerator, and the Raman forward cascade schemes all deserve more complete analysis. The exploitation of standard linac geometry operated in an unconventional mode is in a phase of rapid evolution. While conceptual projects abound, there are no complete designs. We recommend that a fraction of sponsored research be devoted to this approach. Wakefield devices offer a great deal of potential; trades among their benefits and constraints are derived and discussed herein. The study of field limitation processes has received inadequate attention; this limits experiment designers. The costs of future experiments are such that investment in understanding these processes is prudent. 34 refs., 12 figs., 3 tabs

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

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

    2016-01-01

    Purpose 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. Methods and materials Ten consecutive patients with inoperable chest wall de...

  1. Radiotherapy in a public health

    The aim of our publication is to evaluate the state of radiotherapy, its role and place in oncology and in the public health system, in order to plan necessities. The cost and economical effectiveness are objectives of the current evaluation. Radiotherapy is strongly dependant of introducing new technologies and the need of gross capital investments. However, their relative cost is reduced due to their long-term use. Because of the serious delay of Bulgaria from the world standards in radiotherapy, the analysis is based on the data published in the scientific literature. The main tendencies and ideas for development are based on the analysis of The Swedish Council on Technology Assessment in Health Care (SBU) and the ESTRO QUARTS project. We use Swedish model for estimating the expenses, having in mind the conditions in Bulgaria (salary, management, patient cares). The main conclusions are: 1) Radiotherapy is basic curative and palliative method in oncology; 2) Bulgarian radiotherapy is at one of the last places in Europe (therapeutic units are 30 years old average, despite their recommended exploitation of 12-20 years); 3) In contradiction to the world tendencies delay grows during the last 10 years; 4) In countries with low or average GDP radiotherapy should be prioritized, due to its low cost in comparison to the other treatment methods in oncology; 5) The need of radiotherapy will continue to grow, this necessitate not only replacement of the old machines but increasing their number 3 times during the next few years; 6) It is necessary to form a modern radiotherapy centers, equipped with at least two compatible units, based on the currently existing radiotherapy departments. (authors)

  2. MedLinac2: a GEANT4 based software package for radiotherapy

    Barbara Caccia

    2010-06-01

    Full Text Available Dose distribution evaluation in oncological radiotherapy treatments is an outstanding problem that requires sophisticated computing technologies to optimize the clinical results (i.e. increase the dose to the tumour and reduce the dose to the healthy tissues. Nowdays, dose calculation algorithms based on the Monte Carlo method are generally regarded as the most accurate tools for radiotherapy. The flexibility of the GEANT4 (GEometry ANd Tracking Monte Carlo particle transport simulation code allows a wide range of applications, from high-energy to medical physics. In order to disseminate and encourage the use of Monte Carlo method in oncological radiotherapy, a software package based on the GEANT4 Monte Carlo toolkit has been developed. The developed package (MedLinac2 allows to simulate in an adequate flexible way a linear accelerator for radiotherapy and to evaluate the dose distributions.

  3. Successful Application of Neutron Bubble Detectors in Neutron Dose Monitoring for Primus-M Election Linear Accelerators

    2008-01-01

    <正>Neutrons produced by 10 MeV medical electronic linear accelerators used for radiotherapy treatments may be harmful for medical personnel and patients. These neutrons are generated by the photon-induced

  4. Experiences with intraoperative radiotherapy in gastric cancer (Berlin method)

    The aim of our pilot study is to determine whether intraoperative radiotherapy in gastric cancer cannot only prevent a local relapse but also improve the survival rate. Since November 1987, 26 patients with resectable gastric cancer were irradiated intraoperatively with the linear accelerator using fast electrons (single dose: 12 to 16 Gy). Percutaneous radiotherapy was performed postoperatively with 24 to 38 Gy (4x2 Gy per week). For intraoperative and percutaneous radiotherapy the target absorbed dose was selected in a way that their combined effect on the tumor was approximately equivalent to that of a total dose of 60 Gy in the usual fractionating. Up to now, the median survival time for stage III patients (UICC 1987) has been twelve months. In five patients who died of a relapse or of peritoneal carcinosis, histologic evaluation revealed in every case a diffuse tumor type according to Lauren-classification. All relapses occurred within the first eight months. The two-year survival rate according to Kaplan-Meier is 67% for stage III. Advanced resectable gastric cancer of the intestinal tumor type seems to profit from adjuvant intraoperative radiotherapy. The results warrant further research within the framework of a prospective randomized multicenter study. (orig.)

  5. Palliative and low cost radiotherapy in developing countries

    Full text: The International Agency for Research on Cancer predicts that cancer incidence in developing countries will increase dramatically in the first two decades of this millennium. Already some 80% of cancer patients in developing countries present with incurable disease. In many cases pain is a severe problem and palliation is needed to improve quality of life as well as extending survival. This paper will consider the physical and clinical aspects of palliative radiotherapy (PRT), choice of radiation modality, alternative approaches to imaging and therapy and cost-benefit considerations. The potential benefits of a dedicated palliative care centre include lower cost and therefore more centres, enabling more patients access to regional palliative care. Simple curative treatments could also be managed. Co60 radiotherapy has important advantages in developing countries, because of the higher initial cost of a linear accelerator, as well as the need for reliable power supply and the level of skill required by linac technicians and physicists. The beam characteristics of both Co60 units and low energy linacs are compared and both are found to be acceptable for palliation. The role of palliative and low cost radiotherapy in Bangladesh is reviewed. The concept of telemedicine is also discussed, using mobile phones and internet communication to allow rural clinics to receive support from specialists based in the cities, to send images for remote diagnosis and remote dose planning for radiotherapy.

  6. Intercomparison of quality control procedures in radiotherapy in the Netherlands

    A grant was received from the Dutch government to accomplish the development and implementation of guidelines for quality control (QC) of radiotherapy equipment in The Netherlands. QC of electron accelerators, simulators, CT scanners, mould room equipment, dosimetry equipment and treatment planning systems will be considered in this project. The project started in September 1994 with an investigation of QC of medical electron accelerators as performed in all 21 radiotherapy institutions in The Netherlands. An extensive questionnaire on QC procedures of electron accelerators was sent to all centres with items related to safety systems, mechanical aspects, radiation leakage, beam data and dosimetry equipment (in total about 60 questions). From the answers the following conclusions can be drawn: There is a large variation in time spent on QC; This QC time strongly depends on the complexity of the linear accelerator; There is a large variation in frequency and tolerance levels of the various tests; The way QC of an item is performed differs considerably (extensive-comprehensive). From these data recommendations specific for the situation in The Netherlands are being prepared and compared with other existing national and international reports. Similar procedures are underway for CT scanners and simulators while for the other equipment minimum guidelines still have to be developed. (author)

  7. Adaptive Motion Compensation in Radiotherapy

    Murphy, Martin J

    2011-01-01

    External-beam radiotherapy has long been challenged by the simple fact that patients can (and do) move during the delivery of radiation. Recent advances in imaging and beam delivery technologies have made the solution--adapting delivery to natural movement--a practical reality. Adaptive Motion Compensation in Radiotherapy provides the first detailed treatment of online interventional techniques for motion compensation radiotherapy. This authoritative book discusses: Each of the contributing elements of a motion-adaptive system, including target detection and tracking, beam adaptation, and pati

  8. Development of targeted radiotherapy systems

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

  9. Future directions for radiotherapy: Gray or Blue perspective?

    Over the past 20 years radiobiological and clinical rationale for altered radiotherapy were defined. Better understanding of the importance of dose per fraction, ovetrall treatment time, time interval between fractions, and tumor and normal tissue repair mechanisms have contributed to the studies on accelerated (AF) and hyperfractionated (HF) radiotherapy. The results of these studies lead to development of combined AF-HF schedules. Among numerous pilot and randomized studies the only few were recognized as important. Hyperfractionation was found to be advantageous in advanced oropharyngeal cancers, and CHART increased therapeutic gain in advanced laryngeal cancer. Accelerated hyperfractionation (AF-FH) improves local control and/or permits a lower total dose for the same rate of control. Better tumor control has always involved increased severity of acute mucosal reactions. The results of clinical trials which improved effectiveness of radiotherapy are discussed. A variety of physical parameters used in altered fractionation makes difficult the comparison of biological effect of different fractionation regimens based on doses in Grays. A new concept of Biological Units of effectiveness - BLUE, proposed by Withers is presented. It is interesting complex system of biological dosimetry which might supplement the Gray doses. Basic assumption of this concept and practical example are presented. (author)

  10. European organization for research on treatment of cancer trials using radiotherapy with multiple fractions per day

    During the past decade (1976-1986), radiotherapy with altered fractionation schemes using multiple fractions per day (MFD) was the major field of the clinical research undertaken in the EORTC Cooperative Group of Radiotherapy. Some of its participating institutions (Portsmouth, Dijon, Leuven, Amsterdam, Rome) performed pilot studies in the midseventies in more than 400 patients. Then largely based upon the previous institutional experiences, EORTC-labelled phase II and III were activated: 1,678 patients have been entered in 8 trials during the period 1978-1987. In order to summarize these clinical experiments covering various fields of tumor pathology, radiotherapy schemes are divided according to the type of altered fractionation: pure hyperfractionation, accelerated fractionation and mixed hyprfractionated and accelerated schemes

  11. 前列腺疾病吸入5%二氧化碳混合气体BOLD-MRI与微血管特征的对照研究%The correlative study of carbogen breathing BOLD-MRI and features of micro-vascular of prostatic disease

    陈化峰; 焦自梅; 高珊珊; 胡娜; 王锡臻; 刘金刚; 李莉莉; 王滨

    2015-01-01

    Objective To investigate the relationship between micro-vascular features and carbogen breathing BOLD-MRI in be-nign prostatic hyperplasia (BPH)and prostate cancer (PCa).Methods Carbogen breathing BOLD-fMRI was performed using a 3.0 Tesla superconducting magnetic scanner (GE)equipped with a phased-array multi-coil.The regions of interest (ROI)of central zone (CZ),peripheral zone (PZ),BPH and PCa were drawn.The relative increase signal rates and time signal intensity curve (TIC) were recorded.The average diameter,area,circumference and special shape index of micro-vascular were analyzed using immunohis-tochemical stain.The relationship between micro-vascular features and BOLD-MRI was analyzed using SPSS 1 1 .5 .Results The sig-nal intensities of CZ,PZ,BPH and PCa during carbogen breathing were higher than those during air breathing (P<0.05).The rela-tive increasing rate of TIC of CZ,PZ,BPH and PCa after carbogen breathing were (5.07±1.08)%,(2.78±1.13)%,(6.44± 2.02)% and (1.77±0.40)% (P<0.05).The mean MVD of BPH and PCa were 12.32±3.14/field and 30.22±11.19/field (P<0.05).The average diameter,area,circumference and special-shape index of PCa were lower than those of BPH (P<0.05).Conclu-sion Carbogen inhaling BOLD-MRI is related with the micro-vascular structures in BPH and PCa,which will have potential to eval-uate the function and maturity of micro-vascular.%目的:探讨吸入5%二氧化碳混合气体BOLD-MRI与前列腺增生(BPH)和前列腺癌(PCa)中微血管特征的对应关系。方法采用美国 GE Signa Excite HD 3.0T超导型磁共振成像仪和腹部相控阵线圈,在吸入5%二氧化碳混合气体行 BOLD-MRI。画取正常前列腺外周带(PZ)、中央腺区(CZ)、BPH 和PCa感兴趣区(ROI),记录时间-信号强度曲线(TIC)和信号强度平均增加率。免疫组化分析BPH 和PCa微血管形态学特征:平均直径、平均面积、平均周长及异型指数。结果 CZ、PZ、BPH 及 PCa 区信号强度于吸入混合气体

  12. [Hepatic tumors and radiotherapy].

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

    2016-09-01

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

  13. Radiotherapy for bone metastases

    Between December 1986 and January 1978, 68 patients with bone metastases were analyzed to evaluate the effect of radiation for the relief of pain. The 68 patients, who had a total of 97 lesions, complained of pain caused by their bone metastasis. The good, fair, and poor responses were found to be 18%, 60%, and 22%, respectively. With reference to the primary neoplasms, the effective response rate was 73% in lung cancer, 100% in breast cancer, 75% in gastric cancer, 100% in hepatic cancer, 100% in bladder cancer, 25% in epipharyngeal cancer, and 70% in the other neoplasms. Depending on the cell types of the lung cancer, the effective response rate was 80% for small cell carcinomas, 72% for adenocarcinomas and 40% for squamous cell carcinomas. Our results suggest that radiotherapy for bone metastases is to be recommended, since the effective response rate was 78% for the relief of pain. (author)

  14. Radiotherapy in pancreatic cancer

    Purpose and approach: to summarize the current knowledge on the role of radiotherapy in the treatment of pancreatic ductal adenocarcinoma (PDAC). The results of meta-analyses, phase III-studies, and phase II-studies using chemoradiation (CRT) and chemotherapy for resectable and non-resectable PDAC are reviewed. Results and conclusion: the role of CRT is undefined in the adjuvant setting but there may be a role as additive treatment after R1 resection. Locally advanced borderline resectable tumors may shrink down and be subject to potentially curative resections. In locally advanced clearly unresectable cancers the effect of CRT as well as chemotherapy is poorly defined and the sequence of chemotherapy and CRT should be re-evaluated. Patients with PDAC should always be treated within studies to identify optimal treatment results. (orig.)

  15. Tumours following retinoblastoma radiotherapy

    Radioinduced tumours in young patients irradiated in childhood for retinoblastoma take on a particularly deadly aspect. The onset of this true clinical entity characterized by a long post-irradiation latency period induced by a dose above 6000 rads is a real tragedy. The vast majority of patients then enter into a long martyrdom ending in death. The only cure is surgical, but seldom possible. Treatment is limited to palliative radiotherapy, effective for a while, and chemiotherapy as a last resort but often difficult to prescribe. Prevention alone is the answer. The quality and reliability of the radiotherapeutic treatment depend not only on the personal talent of the radiotherapist but above all on the standard of the equipment. A strong reduction in the doses employed as well as recent technological progress improving the material, its precision and reproducibility appear already to have lowered the frequency curve of these fatal radioinduced tumours

  16. Anatomical imaging for radiotherapy

    Evans, Philip M [Joint Physics Department, Institute of Cancer Research and Royal Marsden NHS Foundation Trust, Downs Road, Sutton, Surrey SM2 5PT (United Kingdom)], E-mail: phil.evans@icr.ac.uk

    2008-06-21

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  17. MRI assisted radiotherapy planning

    To obtain the optimal radiation field, an MR simulation system (MRSS) has been developed. The system consists of an MR unit, a work station and a laser marking system. Phantom study concerned geographic distortion and the total accuracy of MRSS, the former revealed the result lesser than 1 mm within 90 mm-distance between MR slices and Center of magnetic field, the latter showed maximal errors 2 mm in the field size, and 3 mm in the iso-center. This system was applied to 15 patients with intracranial or head and neck lesions and all procedures were smoothly performed. To evaluate the usefulness of MRSS, 6 radiation oncologists compared the difference between MRSS and CT simulation system in setting radiation field. The results were satisfactory especially in cases with lesions the extent of which was unclear on CT images. It was considered that this system could support the radiotherapy planning for intracranial or head and neck lesions. (author)

  18. Image guided multibeam radiotherapy

    This paper provides an outlook of the status of the first development stages for an updated design of radiotherapy conformal system based on tumor 3D images obtained as an output the last generation imaging machines as PET, CT and MR which offer a very valuable output in cancer diagnosis. Prospective evaluation of current software codes and acquisition of useful experience in surgical planning involves a multidisciplinary process as an initial and unavoidable stage to develop an expert software and user skills which assures the delivery of the radiation dose is done correctly in geometry and value in each voxel as a radiation protection basic condition. The validation of the images obtained has been done by the production of anatomical models of interest regions by rapid prototyping of the 3D segmented images and its evaluation by contrasting with the real regions during surgical procedures. (author)

  19. Image guided multibeam radiotherapy

    This paper provides an outlook of the status of the first development stages for an updated design of radiotherapy conformal system based on tumor 3D images obtained as an output the last generation imaging machines as PET, CT and MR which offer a very valuable output in cancer diagnosis. Prospective evaluation of current software codes and acquisition of useful experience in surgical planning involves a multidisciplinary process as an initial and unavoidable stage to develop an expert software and user skills which assures the delivery of the radiation dose is done correctly in geometry and value in each voxel as a radiation protection basic condition. The validation of the images obtained has been done by the production of anatomical models of interest regions by rapid proto typing of the 3D segmented images and its evaluation by contrasting with the real regions during surgical procedures. (author)

  20. Anatomical imaging for radiotherapy

    The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of

  1. MUON ACCELERATION

    BERG,S.J.

    2003-11-18

    One of the major motivations driving recent interest in FFAGs is their use for the cost-effective acceleration of muons. This paper summarizes the progress in this area that was achieved leading up to and at the FFAG workshop at KEK from July 7-12, 2003. Much of the relevant background and references are also given here, to give a context to the progress we have made.

  2. KEKB accelerator

    KEKB, the B-Factory at High Energy Accelerator Research Organization (KEK) recently achieved the luminosity of 1 x 1034 cm-2s-1. This luminosity is two orders higher than the world's level at 1990 when the design of KEKB started. This unprecedented result was made possible by KEKB's innovative design and technology in three aspects - beam focusing optics, high current storage, and beam - beam interaction. Now KEKB is leading the luminosity frontier of the colliders in the world. (author)

  3. Accelerating networks

    Evolving out-of-equilibrium networks have been under intense scrutiny recently. In many real-world settings the number of links added per new node is not constant but depends on the time at which the node is introduced in the system. This simple idea gives rise to the concept of accelerating networks, for which we review an existing definition and-after finding it somewhat constrictive-offer a new definition. The new definition provided here views network acceleration as a time dependent property of a given system as opposed to being a property of the specific algorithm applied to grow the network. The definition also covers both unweighted and weighted networks. As time-stamped network data becomes increasingly available, the proposed measures may be easily applied to such empirical datasets. As a simple case study we apply the concepts to study the evolution of three different instances of Wikipedia, namely, those in English, German, and Japanese, and find that the networks undergo different acceleration regimes in their evolution

  4. Radiotherapy in the Hodgkin's disease

    An up-to-date summary of Hodgkin's disease is presented taking into account its natural history, dissemination patterns, history, staging and therapeutic sugestions, with special regard to radiotherapy. (Author)

  5. Fetal dose determination in patients with breast cancer submitted to radiotherapy

    The exposure that the fetus receive during radiotherapy treatment for patients with breast cancer submitted to cobalt 60 and linear accelerator of 6 MV is studied. Measurements with a rando-Alderson Phantom and ionization chamber for each individualized irradiation field, at the body level where the fetus is localized during the several stages of pregnancy, are made. (M.A.C.)

  6. Improved internal iliac artery chemotherapy combined with radiotherapy for the treatment of stage Ⅲ-Ⅳa cervical cancers

    Objective: To investigate the efficacy of modified internal iliac artery chemotherapy combined with radiotherapy for the treatment of stage Ⅲ-Ⅳa cervical cancers. Methods: A total of 70 patients with stage Ⅲ-Ⅳa cervical cancer, who were admitted to the authors' hospital (Department of Obstetric and Gynecology, Oncology) during the period from May 2005 to August 2009, were enrolled in this study. The clinical data were retrospectively analyzed. Modified internal iliac artery chemotherapy combined with radiotherapy was carried out in 32 patients (study group), and simple radiotherapy was adopted in 38 patients (control group). For patients in study group, puncturing of right femoral artery using Seldinger's technique was performed, which was followed by right uterine artery chemoembolization and subsequent super-selective left iliac artery chemotherapy, which lasted for three days. The chemotherapeutic drugs included cisplatin and fluorouracil. Distance external beam linear accelerator was used for radiotherapy together with 192 Ir high dose rate brachytherapy. For patients in control group, only distance external beam linear accelerator radiotherapy with 192 Ir high dose rate brachytherapy was employed, with the radioactive dose being a little bit smaller than that used in the study group. Results: The one-year survival rate for the study group and the control group was 78.1% and 55.3%, respectively (P0.05). The difference in the occurrence of radiotherapy-related complications was not significant between the two groups (P>0.05). Conclusion: For the treatment of stage Ⅲ-Ⅳa cervical cancers, modified internal iliac artery chemotherapy combined with radiotherapy is more effective than that of simple radiotherapy for a short-term period. The living quality of the patients can be markedly improved. Nevertheless, the five-year survival rate of chemotherapy combined with radiotherapy is not statistically difference from that of simple radiotherapy. (authors)

  7. Contact radiotherapy. Report of technological assessment

    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

  8. Radiotherapy with linear accelerator in a patient with permanent pacemaker, methodology and results of dose determination in a case in vivo; Radioterapia con Linac en un paciente con marcapasos permanente, metodologia y resultados de determinacion de dosis en un caso in vivo

    Diaz A, P.; Dominguez O, X.; Toledo B, V.; Nungaray, H.; Zazueta L, F., E-mail: pdiaz@hospitalsanjavier.co [Hospital San Javier, Pablo Casals No. 640, Col. Prados Providencia, 44670 Guadalajara, Jalisco (Mexico)

    2010-09-15

    This work presents the methodology used by the radiotherapy department of the Hospital San Javier in the patients handling with pacemaker. By means of dosimetry to the implant area of the pacemaker together with electrocardiography measurements during the radiotherapy sessions, the pacemaker performance is evaluated with the objective of detecting any anomaly to the same caused by electromagnetic interference and/or accumulated dose. It is necessary to follow specific protocols in these patients type that guarantee their security during the exposition to ionizing radiation since a definitive consent that allows to calculate the failure probability of pacemaker in this therapeutic condition does not exist. (Author)

  9. Indications for Salivary Gland Radiotherapy.

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

    2016-01-01

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

  10. Education in physics of radiotherapy

    Radiotherapy is the clinical application which requires the highest precision in dose delivery because of the very high doses administrated to patients, taking into account that new diagnostic methods and new modalities and treatment machines give greater possibilities of dose escalation. These higher doses may also produce serious side effects if not accurately administered. High qualified personnel is therefore needed for dealing with these new complex modalities, assuring that dose prescribed is correctly administered and providing adequate radiation protection to patients, public and staff. Education in Physics of Radiotherapy aims to provide students with solid theoretical and practical basis in order to be able to work with great responsibility and understanding in a Radiotherapy Department and assure that appropriate radiation protection to patients, public and staff. Since 1964 the National Atomic Energy Commission (CNEA) gives course related to Radiotherapy and since 2002, due to a collaborative project, these courses are given at the Oncology Institute 'Angel H. Roffo' (IOAR) which belongs to the University of Buenos Aires (UBA). The IOAR is well equipped in Radiotherapy and new techniques are continuously introduced. That is why, being a University Institution and having highly specialized staff, it is the ideal hospital for teaching Radiotherapy in Buenos Aires, not only for regular courses but also for implementing workshops, seminars and updating courses as well. Continuous education helps to create and increase awareness of the importance of radiation protection in patients as well as in public and staff. (author)

  11. Carbon Beam Radio-Therapy and Research Activities at HIMAC

    Radio-therapy with carbon ion beam has been carried out since 1994 at HIMAC (Heavy Ion Medical Accelerator in Chiba) in NIRS (National Institute of Radiological Sciences). Now, many types of tumors can be treated with carbon beam with excellent local controls of the tumors. Stimulated with good clinical results, requirement of the dedicated compact facility for carbon beam radio-therapy is increased. To realize this requirement, design study of the facility and the R and D's of the key components in this design are promoted by NIRS. According successful results of these activities, the dedicated compact facility will be realized in Gunma University. In this facility, the established irradiation method is expected to use, which is passive irradiation method with wobbler magnets and ridge filter. In this presentation, above R and D's will be presented together with clinical results and basic research activities at HIMAC

  12. Conformal radiotherapy by intensity modulation of pediatrics tumors

    The objective of this study is to take stock on the validated and potential indications of the conformal radiotherapy with intensity modulation ( intensity modulated radiotherapy I.M.R.T.) in pediatrics and to propose recommendations for its use as well as the adapted dose constraints. About 40 to 50% of children treated for a cancer are irradiated. The I.M.R.T., by linear accelerator or helical tomo-therapy has for aim to give a homogenous dose to the target volume and to save organs at risk. Its use in pediatrics seems particularly interesting because of the complexity of target volumes and the closeness of organs at risk. In compensation for these positive elements, the importance of low doses irradiation given in big volumes makes fear event consequences on growth and an increased incidence of secondary cancers in children suffering from tumors with high cure rates and long life expectancy. (N.C.)

  13. Radiotherapy of Langerhans' cell histiocytosis. Results and Implications of a national patterns-of-care study

    Purpose: This patterns-of-care study was performed to define the current clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany and to define open questions resulting from this study. Material and Methods: A standardized questionnaire was sent to 198 German radiotherapy institutions. Data about patient characteristics, stage of disease, practice and fractionation of radiotherapy, outcome of therapy, etc. were systematically evaluated. 123 of 198 institutions answered the complete questionnaire (62.1%). Results: Only 23 of the 123 institutions (18.7%) reported experience with radiotherapy of Langerhans' cell histiocytosis of adults. 18 institutions with 98 patients were evaluable. The majority of patients (72 of 98) was treated on a linear accelerator. The median single dose of radiotherapy was 2 Gy, while the median total dose was 24 Gy. 81 of 89 evaluable patients (91%) reached a local control of the treated lesion(s), 69 of those had a complete remission. Eight of 89 patients (9%) developed an in-field recurrence. 87.8% of patients experienced no acute and 97% of patients no late side effects of radiotherapy. Conclusion: Clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany is still very limited. Nevertheless, the clinical results - with high remission and local control rates - confirm the effectiveness of radiotherapy in the multidisciplinary treatment of this disease. Due to the small number of patients in this study despite higher incidence rates, the knowledge of this disease has to be multiplied in Germany. Future patients should be systematically included into a prospective radiotherapy registry. (orig.)

  14. Accelerators and the Accelerator Community

    Malamud, Ernest; Sessler, Andrew

    2008-06-01

    In this paper, standing back--looking from afar--and adopting a historical perspective, the field of accelerator science is examined. How it grew, what are the forces that made it what it is, where it is now, and what it is likely to be in the future are the subjects explored. Clearly, a great deal of personal opinion is invoked in this process.

  15. Workshop on the accelerator for particle therapy

    A two-day workshop on the accelerator for particle therapy was held on August 22-23, 1990, with the aim of mutual understanding of medical accelerators among investigators. The state-of-the-art facilities in Japan and medical proton accelerators in Japan and other countries were introduced. This is a compilation of papers presented at the workshop: (1) particle radiotherapy at the National Institute of Radiological Sciences (NIRS); (2) proton therapy; (3) treatment planning, especially for photon and electron therapies; (4) heavy ion synchrotron project at the NIRS; (5) medical proton accelerator project of Tsukuba University and recent status of Loma Linda University Medical Center Proton Beam Facility; (6) inspection report on the Loma Linda University Medical Center Proton Beam Facility; (7) accelerator project of Kyoto University; (8) actual conditions of the 7 MeV proton linear accelerator; (9) design study of superconducting compact cyclotron prototype model; (10) medical superconducting prototype cyclotron; (11) RCNP cyclotron cascade project; (12) beam extraction from synchrotron; (13) radiation safety design in high energy particle accelerator facilities. (N.K.)

  16. Gene therapy and radiotherapy in malignant tumor

    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)

  17. Film dosimetry in conformal radiotherapy

    Danciu, C.; Proimos, B.S. [Patras Univ. (Greece). Dept. of Medical Physics

    1995-12-01

    Dosimetry, through a film sandwiched in a transverse cross-section of a solid phantom, is a method of choice in Conformal Radiotherapy because: (a) the blackness (density) of the film at each point offers a measure of the total dose received at that point, and (b) the film is easily calibrated by exposing a film strip in the same cross-section, through a stationary field. The film must therefore have the following properties: (a) it must be slow, in order not to be overexposed, even at a therapeutic dose of 200 cGy, and (b) the response of the film (density versus dose curve) must be independent of the photon energy spectrum. A few slow films were compared. It was found that the Kodak X-Omat V for therapy verification was the best choice. To investigate whether the film response was independent of the photon energy, response curves for six depths, starting from the depth of maximum dose to the depth of 25 cm, in solid phantom were derived. The vertical beam was perpendicular to the anterior surface of the phantom, which was at the distance of 100 cm from the source and the field was 15x15 cm at that distance. This procedure was repeated for photon beams emitted by a Cobalt-60 unit, two 6 MV and 15 MV Linear Accelerators, as well as a 45 MV Betatron. For each of those four different beams the film response was the same for all six depths. The results, as shown in the diagrams, are very satisfactory. The response curve under a geometry similar to that actually applied, when the film is irradiated in a transverse cross-section of the phantom, was derived. The horizontal beam was almost parallel (angle of 85) to the plane of the film. The same was repeated with the central ray parallel to the film (angle 90) and at a distance of 1.5 cm from the horizontal film. The field size was again 15x15 at the lateral entrance surface of the beam. The response curves remained the same, as when the beam was perpendicular to the films.

  18. Methodology for shielding design and evaluation in radiotherapy facilities

    The Government of the Republic of Cuba has decided to carry out a wide programme concerning the purchase of more than a dozen dual linear accelerators and, also; more than a dozen cobalt-60 units. Due to the lack of a national methodology for the design and calculation of shielding enclosures for radiotherapy units, the medical physicists from different hospitals began to use different methodologies, e.g. those in: a) Medical Physics Publishing. Shielding Techniques for Radiation Oncology Facilities. Patton H. McGinley. 1998.; b) National Council on Radiation Protection and Measurements, Structural shielding design and evaluation for medical use of X-rays and gamma-rays of energies up to 10 MeV, Report No. 49, NCRP, Washington, DC (1976).; c) National Council on Radiation Protection and Measurements, Radiation Protection Guidelines for 0.1 - 100 MeV Particle Accelerator Facilities, Report No. 51, NCRP, Washington, DC (1977). In some cases this caused the overestimation of the shielding thickness, when applying the values of dose constraints required by the Cuban regulations. The objective of the present work is to provide the medical physicists, the Radiation Safety Officers and other related professionals with a consistent methodology for the design and remodelation of bunkers hosting radiotherapy units but not using shielding doors. This work shows the validity of the above mentioned methodology, and the feasibility of designing door less bunkers for radiotherapy purposes. This methodology is considered to be self consistent and therefore no other complementary materials for its application are required. The experience so far confirms that; entry of realistic input data, and adequate application of sound engineering concepts when using this methodology leads to the achievement of enclosure shielding designs for radiotherapy units that comply with the dose constraints established by the Cuban regulations. Radiation shielding is attained having no over expenses on

  19. accelerating cavity

    On the inside of the cavitytThere is a layer of niobium. Operating at 4.2 degrees above absolute zero, the niobium is superconducting and carries an accelerating field of 6 million volts per metre with negligible losses. Each cavity has a surface of 6 m2. The niobium layer is only 1.2 microns thick, ten times thinner than a hair. Such a large area had never been coated to such a high accuracy. A speck of dust could ruin the performance of the whole cavity so the work had to be done in an extremely clean environment.

  20. Radioprotectors in Radiotherapy

    Nair, C.K.K. [Bhabha Atomic Research Centre, Mumbai (India); Parida, D.K.; Nomura, Taisei

    2001-03-01

    This review article focuses on clinically relevant radioprotectors and their mechanisms of radioprotection. Radiotherapy is the most common modality of human cancer therapy. Obtaining optimal results requires a judicious balance between the total dose of radiotherapy delivered and the threshold limit of critical surrounding normal tissues, and the normal tissues need to be protected against radiation injury to obtain better tumor control by using a higher dose. For this reason, radiation-protective agents play an important role in clinical radiotherapy. Radiation-protective agents can be classified into three groups: radioprotectors, adaptogens, and absorbents. The first group generally consists of sulfhydryl compounds and other antioxidants. They include several myelo-, entero-, and cerebro-protectors. Adaptogens act as promotors of radioresistance. They are natural protectors that offer chemical protection against low levels of ionizing radiation. Absorbents protect organs from internal radiation and chemicals. They include drugs that prevent incorporation of radioiodine by the thyroid gland and absorption of radionuclides. This article thoroughly describes the properties, mechanisms of action, and perspectives on clinical application of the following categories of radioprotectors: sulfhydryl compounds (e.g., cysteine, cysteamine, glutathione, AET, WR 2127, and other WR-compounds), antioxidants (e.g., tempace, Hoechst 33342, vitamin A, E, and C, TMG, melatonin), angiotensin-converting enzyme (ACE) inhibitors (e.g., captopril, elanopril, penicillamine, pentoxifylline, L-158, 809), cytoprotective agents (mesna, dexrazoxane, and amifostin), metalloelements (e.g., manganese chloride, cadmium salts, bismuth subnitrate), immunomodulators (gamma-interferon, polysaccharides AM5, AM218, heat-killed lactobacillus cells, broncho-vaxom, trehalose dicorynomycolate, and AS101), lipopolysaccharides and prostaglandins, plant extracts and compounds isolated from plants (curcmin

  1. Study on the possibility of using a 60 Co therapeutical unity in Intensity Modulated Radiotherapy (IMRT)

    With the increasing advances in complex treatment techniques, there is a tendency to obtain more sophisticated equipment to deliver the dose. The use of 3D conformal radiotherapy is now routine in many radiotherapy facilities as well as the utilization of intensity modulated radiotherapy (IMRT). Both are usually implemented using linear accelerators equipped with multi leaves collimators, which create the conformity and the fluence distributions required. However, the complexity of increasingly sophisticated equipment, such as linear accelerators, requires a frequent quality control of their operation, as well as a detailed and constant maintenance. Even carrying out these procedures, the accelerators may present technical problems interrupting for a long time a treatment using the IMRT technique. Despite the clear practical and technological advantages that linear accelerators have on 60Co irradiators, these devices occupy an important place in radiotherapy, mainly due to the low cost of equipment installation and maintenance when compared to those required by accelerators. Many radiotherapy facilities that work with IMRT have tele therapeutic isocentric 60Co units. In principle, such equipment would be able to be used for treatment with IMRT using compensating blocks to modulate the beam. This study investigates this possibility and shows that it is feasible. The comparison of treatment plans of a head-and-neck cancer and other of a cancer of the central nervous system, based on a 60Co irradiator and a Linac 2300 C/D, presented advantages for the 60Co irradiator. Furthermore; the delivery of dose obtained with the two systems showed themselves equivalent when compared to their respective plans. (author)

  2. Clinical outcome of concurrent chemo-radiotherapy for patients with stage IV non-small cell lung cancer

    Objective: To analyze the clinical outcome of concurrent chemo-radiotherapy in stage IV non-small cell lung cancer(NSCLC). Methods: From Jan. 1997 to Dec. 2006, 214 patients with pathologically or cytologically proven stage IV NSCLC were included in this analysis. Of those patients, 98 received radiotherapy concurrently with 3-week cycle chemotherapy (group A), 18 received radiotherapy concurrently with weekly chemotherapy( group B), 44 received chemotherapy alone, 37 received radiotherapy alone and 13 received sequential chemo-radiotherapy. The primary tumor was treated by three-dimensional conformal radiotherapy(3DCRT) or conventional radiotherapy with conventional fractionation or late-course accelerated hyperfraction (LAHRT). Group A received 21-28 days cycle cisplatin-based chemotherapy (cisplatin combined with PTX, DTY, NVB or Vp-16), and group B received weekly DDP combined with PTX or toptecon for 4-6 weeks. Results: The follow-up rate was 99%. The 1- and 2-year overall survival rates of group A, group B, chemotherapy alone, radiotherapy alone and sequential chemo-radiotherapy were 41% and 11%, 16% and 0, 31% and 7%, 34% and 10%, 26% and 3%, respectively(χ2=11.18, P=0.025). The patients with concurrent 3DCRT, LAHRT and radiotherapy dose ≥70 Gy had better survival in group A than those in chemotherapy alone group. Patients who received ≥2 cycles chemotherapy with concurrent radio-therapy had longer survival time than those who had ≥2 cycles chemotherapy alone. Conclusions: Concurrent chemotherapy and 3 DCRT, LAHRT with the dose ≥70 Gy can improve the overall survival of patients with stage IV non-small cell lung cancer. (authors)

  3. Gonadal doses from radiotherapy

    The method of calculation of gonadal doses arising from different radiotherapeutic procedures is described. The measurement of scatter factors to the gonads from superficial and deep therapy is detailed and the analytic fits to the experimental data, as a function of field position, field size and beam energy are given. The data used to calculate the gonadal doses from treatments using linear accelerators, teletherapy and sealed sources are described and the analytic fits to the data given

  4. Electron Accelerator Facilities

    Lecture presents main aspects of progress in development of industrial accelerators: adaptation of accelerators primary built for scientific experiments, electron energy and beam power increase in certain accelerator constructions, computer control system managing accelerator start-up, routine operation and technological process, maintenance (diagnostics), accelerator technology perfection (electrical efficiency, operation cost), compact and more efficient accelerator constructions, reliability improvement according to industrial standards, accelerators for MW power levels and accelerators tailored for specific use

  5. Voice following radiotherapy

    This study was undertaken to provide information on the voice of patients following radiotherapy for glottic cancer. Part I presents findings from questionnaires returned by 227 of 235 patients successfully irradiated for glottic cancer from 1960 through 1971. Part II presents preliminary findings on the speaking fundamental frequencies of 22 irradiated patients. Normal to near-normal voice was reported by 83 percent of the 227 patients; however, 80 percent did indicate persisting vocal difficulties such as fatiguing of voice with much usage, inability to sing, reduced loudness, hoarse voice quality and inability to shout. Amount of talking during treatments appeared to affect length of time for voice to recover following treatments in those cases where it took from nine to 26 weeks; also, with increasing years since treatment, patients rated their voices more favorably. Smoking habits following treatments improved significantly with only 27 percent smoking heavily as compared with 65 percent prior to radiation therapy. No correlation was found between smoking (during or after treatments) and vocal ratings or between smoking and length of time for voice to recover. There was no relationship found between reported vocal ratings and stage of the disease

  6. Margins in radiotherapy

    As part of the treatment prescription procedure, one has to prescribe in anatomical terms any GTV (Gross Tumor Volume) according to the general TNM-rules as well as any other tissues that are to be treated for presumed subclinical diseases. These prescriptions of one or several Clinical Target Volumes (CTVs) are based on general oncological principles, and are not related to the treatment modality. If external beam radiotherapy is being used, one has to consider special problems related to different geometric inaccuracies and uncertainties, which can be both intrafractional and interfractional. Such inaccuracies and uncertainties are due to either the position, shape and size of the patient/tissues in relation to a fix point, or to variations in beam geometry. The two different types of variations may or may not co-variate. A margin or margins for these uncertainties has to be included in the dose planning procedure, which then will evaluate a static situation, representing the CTV(s) plus geometric ''safety'' margin(s) (Planning Target Volume, PTV) and in fact not the true clinical situation. The dose distribution arrived at for this static representation will however have to be considered as representative for the CTV. This presents of course a dilemma, but one has to accept a reasonable compromise. There is no general rule on the size of the different geometric uncertainties or how they should be added up. Individual evaluations are needed. (author)

  7. Automatization in radiotherapy

    Data-processing in external radiotherapy has to be adapted to each local situation, taking into account the patients to be treated, the irradiation equipment, the data-processing centers available locally, regionally, and nationally, and the rentability of the data-processing system required. It should be recalled that most dosimetric methods used today can be treated manually, and the question of rentability has to be kept in mind when deciding to buy a data-processing system. The radiotherapist should, therefore, prepare a list of costs for each situation, and verify the validity of each programme proposed by the supplier. It is difficult to make a definite choice between the presently available systems. The radiotherapist has to choose in relation to his activity, his availability and the systems available to him. It can sometimes be more advantageous to have a terminal linked to a large computer, rather than to readapt a series of programmes for a data-processing system available locally: many such solutions, though original, cannot be 'exported'. It should be recalled that a large number of dosimetries can be obtained manually, and on the rare occasions when the aid of a computer is essential, the assistance of better equipped neighbouring centers can be obtained. The decision as to whether a data-processing system needs to be acquired has to take all these imperatives into account

  8. Radiation Protection in the Design of Radiotherapy Facilities

    The incidence of cancer throughout the world is increasing with the prolonged life expectancy that has resulted from improvements in standards of living. About half of all cancer patients receive radiotherapy, either as part of their primary treatment or in connection with recurrences or palliation. The IAEA has estimated that approximately 2500 teletherapy machines were in use in 1998 in developing countries and that 10 000 such machines may be needed by 2015. This Safety Report was initiated as a result of an expected increase in the construction of radiotherapy facilities, and in response to Member States that have requested practical guidance regarding the design and shielding of such facilities. The objective of this report is to elaborate on the requirements for the design and shielding of radiotherapy facilities prescribed in Appendix IV of the International Basic Safety Standards for Protection against Ionizing Radiation and for the Safety of Radiation, Safety Series No. 115. This report gives guidance on the design of radiotherapy facilities and describes how the required structural shielding should be determined. Methods for determining the necessary structural shielding for external beam units (60Co units, linear accelerators, superficial and orthovoltage units and simulators) are given as well as shielding for brachytherapy units. Data used for determining the structural shielding necessary for all types of radiotherapy facilities are reproduced in this report, and example calculations are provided for each type of facility. The design of facilities so that security objectives for radioactive sources can be met is also addressed in this publication. This Safety Report is intended to be used primarily by health physicists, medical physicists and other radiation protection professionals in the planning and design of new radiotherapy facilities and in the remodelling of existing facilities. Sections of the report will also be of interest to architects

  9. Special procedures and techniques in radiotherapy

    In addition to the routine conventional radiotherapy techniques used in standard radiotherapy departments and clinics, several specialized techniques are known and used for special procedures, be it in dose delivery or target localization. These techniques deal with specific problems that usually require equipment modifications, special quality assurance procedures and heavy involvement and support from clinical physicists. Owing to their increased complexity, these specialized techniques are usually available only in larger, regional centres. The radiotherapy techniques that currently fall into the specialized category are listed below; the first six are special dose delivery techniques, the last three are special target localization techniques: Stereotactic irradiation; Total body irradiation (TBI) with photon beams; Total skin electron irradiation (TSEI); Intraoperative radiotherapy (IORT); Endorectal irradiation; Conformal radiotherapy and intensity modulated radiotherapy (IMRT); Image guided radiotherapy (IGRT); Respiratory gated radiotherapy; Positron emission tomography (PET)/computed tomography (CT) fused images

  10. Small animal radiotherapy research platforms

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research. (topical review)

  11. Small animal radiotherapy research platforms

    Verhaegen, Frank; Granton, Patrick; Tryggestad, Erik

    2011-06-01

    Advances in conformal radiation therapy and advancements in pre-clinical radiotherapy research have recently stimulated the development of precise micro-irradiators for small animals such as mice and rats. These devices are often kilovolt x-ray radiation sources combined with high-resolution CT imaging equipment for image guidance, as the latter allows precise and accurate beam positioning. This is similar to modern human radiotherapy practice. These devices are considered a major step forward compared to the current standard of animal experimentation in cancer radiobiology research. The availability of this novel equipment enables a wide variety of pre-clinical experiments on the synergy of radiation with other therapies, complex radiation schemes, sub-target boost studies, hypofractionated radiotherapy, contrast-enhanced radiotherapy and studies of relative biological effectiveness, to name just a few examples. In this review we discuss the required irradiation and imaging capabilities of small animal radiation research platforms. We describe the need for improved small animal radiotherapy research and highlight pioneering efforts, some of which led recently to commercially available prototypes. From this, it will be clear that much further development is still needed, on both the irradiation side and imaging side. We discuss at length the need for improved treatment planning tools for small animal platforms, and the current lack of a standard therein. Finally, we mention some recent experimental work using the early animal radiation research platforms, and the potential they offer for advancing radiobiology research.

  12. Protection of patient In radiotherapy

    The purpose of this project is to clarify some aspects about protection of patient in radiotherapy. Therefore, some basic information about how the use of ionizing radiation in medicine has brought tremendous health benefits to the population globally, the requirement of radiation protection (Justification of practices, Dose limitation and Optimization of protection), and the deterministic and stochastic effects of radiation are presented. The aim of radiotherapy is to use ionizing radiation to cure diseases or make the symptoms of a disease less severe. Also presented are layout of a radiotherapy facility (controlled areas, supervised areas, mazes, door and interlocks, patient observation and communication, and warning sign and lights), radionuclides commonly used for radiation therapy and their main emissions, equipment and devices used in radiotherapy, aspect of protection of patient in radiotherapy such as: leakage test, source on/off, emergency buttons, radiation oncology team, treatment planning, room monitoring, equipment or for protection and Cobalt-60 unit stuck source. The advantages of brachytherapy, leakage from the treatment head and radiation incidents resulting from incorrect dose calibration are discussed. The importance of minimization dose exposure, by considering the basic principles of: time, distance and shielding are also stated. These principles prevent deterministic effects and limit stochastic effects of radiation. (author)

  13. Accelerator system and method of accelerating particles

    Wirz, Richard E. (Inventor)

    2010-01-01

    An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

  14. Technological advances in radiotherapy for esophageal cancer

    Milan; Vosmik; Jiri; Petera; Igor; Sirak; Miroslav; Hodek; Petr; Paluska; Jiri; Dolezal; Marcela; Kopacova

    2010-01-01

    Radiotherapy with concurrent chemotherapy and surgery represent the main treatment modalities in esophageal cancer.The goal of modern radiotherapy approaches,based on recent technological advances,is to minimize post-treatment complications by improving the gross tumor volume definition (positron emission tomography-based planning),reducing interfraction motion (image-guided radiotherapy) and intrafraction motion (respiratory-gated radiotherapy),and by better dose delivery to the precisely defined planning ...

  15. Components of quality assurance of radiotherapy process - Setup in the Czech Republic

    Full text: Quality assurance (QA) of radiotherapy process consists of many components. It includes a system of internal tests of radiotherapy equipment (acceptance tests, status tests, constancy tests), external tests of radiotherapy equipment (on site audits, TLD postal audits), clinical audits, and inspections. Definitions of these items are presented, as well as description of their aim, content, range, methodology, facture (who performs, how often, budget), acquisition, impact on practice, implementation, etc. Advantages and disadvantages, and related difficulties are described and compared. Legislation, guidelines, recommendations, and standards (international, European, national, ESTRO, IAEA) serve as the bases for QA implementation. According to these documents workplaces introduce QA system, set up QA manual, quality control (QC) procedures, local standards for radiotherapy procedures, and other documents. Particular QA system implementation depends on the national procedures. Actual situation and impact of QA implementation on radiotherapy in the Czech Republic is described as an example. Comparison of all on-site audits of teleradiotherapy equipment performed in 1996-2000 and after 2000 is presented. Selected results of audits of linear accelerators with MLC used for IMRT are given. Experiences from clinical audits of radiotherapy workplaces in the Czech Republic - pilot study - are discussed. (author)

  16. Probabilistic safety analysis of radiation treatments with linear accelerator (Spanish Ed.)

    This publication addresses the issue of accidental exposures of radiotherapy patients and how to avoid them. More proactive approaches are required to anticipate and thus avoid situations that could lead to accidental exposures. In this context, the International Atomic Energy Agency (IAEA) and the Ibero American Forum of Radiation and Nuclear and Safety Regulatory Agencies (the FORO) have applied proactive methods, such as probabilistic safety assessment to radiotherapy treatments with accelerators. The methodology and results of this exercise are described in this publication.

  17. INEEL Advanced Radiotherapy Research Program Annual Report 2001

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

  18. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    Venhuizen, James R.

    2002-04-30

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

  19. INEEL Advanced Radiotherapy Research Program Annual Report 2001

    Venhuizen, James Robert

    2002-04-01

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

  20. What is the Radiotherapy Quality Program of the Instituto Nacional do Cancer - INCa?

    The Radiotherapy Quality Program (PQRT) of Cancer National Institute (INCA) has been functioning since 1999 as a pilot program with only 33 participant institutions. Due to the optimal obtained results the program becomes a part of the INCA National Programs and his activities were extended to all radiotherapy services which attend the Health Unique Systems (SUS), approximately 130 institutions corresponding to 90 percent of the radiotherapy services available in Brazil. The PQRT main objective is to make the radiotherapy to be evaluated as planned, in accordance with quality assurance international standards. The principal activities of the PQRT are: local evaluation, TLD postal evaluation under reference and non-reference conditions, and training and development of research projects. The Local Evaluation System has already evaluated 85 teletherapy equipment (38 Co-60 and 47 linear accelerators), executing dosimetric, electric, mechanic and safety tests. The TLD postal system used for the 33 participants until 2002 was the International Atomic Energy Agency (IAEA) for reference conditions. Five evaluations has already been performed with this simply system. Since 2003, the postal evaluation of the PQRT is using his own system, developed for reference and non-reference conditions, applied to 58 beams (18 Co-60 and 40 linear accelerators). The PQRT ras already performed 400 evaluations under reference conditions (190 Co-60 and 210 linear accelerators). 18 courses have been provided for the participants, covering his main practical problems. In addition, some studies and research has been performed

  1. Dosimetry in radiotherapy. V.1

    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

  2. Computerised tomography in radiotherapy planning

    This study evaluates the effectiveness of computed tomography as an adjunct to radiotherapy planning. Until recently, acquisition of accurate data concerning tumour anatomy lagged behind other developments in radiotherapy. With the advent of computer-tomography (CT), these data can be displayed and transmitted to a treatment planning computer. It is concluded that the greatest inaccuracies in the radiation treatment of patients are to be found in both the inadequate delineation of the target volume within the patient and changes in body outline relative to the target volume over the length of the irradiated volume. The technique was useful in various subgroups (pelvic, intra-thoracic and chest-wall tumours) and for those patients being treated palliatively. With an estimated improvement in cure rate of 4.5% and cost-effective factors of between 3.3 and 5, CT-assisted radiotherapy planning appears to be a worthwhile procedure. (orig.)

  3. Dosimetry in radiotherapy. V.2

    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

  4. Hyperthermia and radiotherapy

    Combined hyperthermia (HT 45 min once or twice per week) and low dose radiotherapy (LDRT 30-34.5 Gy in 2-3 weeks) have been given to 182 locally recurrent or metastatic superficial tumours in 133 patients. Tumour response was analysed in 137 tumours in 100 patients. The overall complete response (CR) was 50% with a median duration (DCR) of 13±3 months. When mammary carcinoma, representing 62% of the treated tumours, were analysed, CR was 62% with a DCR of 14±4 months. In a comparative, non-randomized study, on 34 matched tumour pairs in 24 patients, treatment was given with LDRT+HT to the larger and the same LDRT to the smaller tumour, the patients acting as their own control. A significant difference in CR was obtained in favour of the combined treatment (p=0.0013 all diagnosis and p=0.0027 mammary carcinoma). There was no significant difference in DCR between the two modalities. No significant difference in CR was seen when tumours were randomely treated with HT once (CR 56%) or twice (CR 69%) per week combined with the same LDRT. Predictive factors for CR, multivariately analysed (15 parameters), in mammary carcinoma recurring in earlier irradiated regions, were; the present LDRT absorbed dose (p=0.02) and the average minimum temperature in the best HT session (p=0.03). Significant skin toxicity was seen in 28% of all the 182 heated regions. Prognostic factors for skin damage, multivariately analysed, were; the extension of the heated region (p=0.007) and the highest average maximum temperature in any of the HT sessions (p=0.04). Pain was in some way correlated to severe toxicity but was not considered to be an optimal monitor for HT as many patients with severe and moderate pain were without any serious skin reactions, while slight or no pain sometimes were associated with severe reactions. 401 refs

  5. Analysis of quality control protocol implementation of equipment in radiotherapy services

    Considering the importance of the Quality Assurance in the radiotherapy services, there was an interest to make tests' evaluation for a Quality Control for the cobalt equipment, linear accelerator and simulator as a classification and comparison. The work proposed is a suggestion that can serve as tool for medical physicists that are starting to work in the radiotherapy area and for the most experts. The discussions were made by the gathering of local tests and official protocols, resulting in a minimum protocol as a suggestion for a routine work, emphasizing the periodicity and level of tolerance of each one of the tests. (author)

  6. Phase-space database for external beam radiotherapy. Summary report of a consultants' meeting

    A summary is given of a Consultants' Meeting assembled to discuss and recommend actions and activities to prepare a Phase-space Database for External Beam Radiotherapy. The new database should serve to disseminate phase-space data of those accelerators and 60Co units used in radiotherapy through the compilation of existing data that have been properly validated. Both the technical discussions and the resulting work plan are described, along with the detailed recommendations for implementation. The meeting was jointly organized by NAPC-Nuclear Data Section and NAHU-Dosimetry and Medical Radiation Physics Section. (author)

  7. Should radiotherapy be used routinely in the management of benign parotid tumours

    The authors review the literature and compare the manner in which evidence accumulated that radioactivity is oncogenic to the thyroid, with the existing situation concerning the parotid gland. They conclude that there is a strong case that radiotherapy does accelerate or cause the development of malignant salivary tumours and that it favours the development of tumours in the 'minor' salivary glands. Also, leaving aside the possibility of tumour induction by radiotherapy, radionecrosis of the cervical vertebrae, transverse myelitis of the cervical spinal cord and epilepsy from cerebral irradiation damage have all been reported as causing late morbidity. (author)

  8. Should radiotherapy be used routinely in the management of benign parotid tumours

    Watkin, G.T.; Hobsley, M.

    1986-08-01

    The authors review the literature and compare the manner in which evidence accumulated that radioactivity is oncogenic to the thyroid, with the existing situation concerning the parotid gland. They conclude that there is a strong case that radiotherapy does accelerate or cause the development of malignant salivary tumours and that it favours the development of tumours in the minor salivary glands. Also, leaving aside the possibility of tumour induction by radiotherapy, radionecrosis of the cervical vertebrae, transverse myelitis of the cervical spinal cord and epilepsy from cerebral irradiation damage have all been reported as causing late morbidity.

  9. Who risk profile in radiotherapy

    The different steps of a treatment in radiotherapy are: patient evaluation, decision to treat, prescription of the treatment protocol, positioning and immobilization, simulation, imaging and volume determination, planning and implementation of materials and software, transfer of treatment data, patient positioning, treatment realisation, treatment checking and follow-up. It exist processes of safety for any step of a radiotherapy realisation: patient identification, accreditation of equipment and processes, evaluation of the personnel competencies, quality assurance of equipment and management of the processes quality, redundancy during the data transfer, control of processes, errors reports and quality improvement, external controls, appropriateness of the workforce. (N.C.)

  10. Combined chemotherapy and radiotherapy: Cyclophosphamide

    Compared to the other chemotherapeutic preparations discussed today, cyclophosphamide in combination with radiotherapy is a relatively unproblematic substance. Despite the great number of experimental and clinical data, the evaluation does not prove an advantage of the combined therapy with cyclophosphamide and irradiation as against radiotherapy alone in local tumor treatment. This should give occasion to further experimental investigations in adequate models. On the other hand, the practice of combined treatment with irradiation and preparations containing cyclophosphamide should be reconsidered for those cases where local control of a tumor is the principal therapeutic aim. (orig.)

  11. QA of conformal radiotherapy for multi-centre radiotherapy trials in Australasia

    The precision available in dose delivery in radiotherapy allows patient doses to be prescribed and delivered very accurately. Increasingly, the dose prescription is based on data extracted from multi-centre clinical trials. The optimal prescription extracted from trial data will be blurred by any inconsistencies in treatment delivery across all patients across all treating centres participating in the trial. These inconsistencies, together with treatment errors, will reduce the dose effect being observed in the clinical trial. Inconsistencies in treatment delivery in a multi-centre trial can arise from a variety of sources including errors in protocol interpretation, protocol violations, variation in radiographic, treatment planning and irradiation techniques, treatment delivery errors and variations in the reporting of dose delivery. One way to overcome and/or quantify inconsistencies in a radiotherapy clinical trial is to undertake quality assurance (QA) procedures aimed at identifying errors. Programmes for undertaking such QA have been developed by international collaborative trials dosimetry groups, e.g. EQUAL (Europe) and RPC (USA). A method of quantifying treatment inconsistencies in Australasia using an anthropomorphic phantom was trialed for specific rectal and prostate radiotherapy trials, with design of the phantom and study protocol based on a set of recommendations from a previous study. Treatment of this phantom at multiple Australasian sites was undertaken, involving collection of digital and physical dosimetric information for evaluation of multiple steps of the treatment process. Specifically, the study involved determining the variation across participating centres of: Absolute linear accelerator output; Quality of radiography for treatment planning; Treatment planning techniques including outlining of structures; Treatment delivery strategies; Calculation of dose-volume parameters; Assessment of patient setup at treatment; Final treatment

  12. Department of Accelerator Physics and Technology: Overview

    Full text: As presented at the overview seminar held on December 98, the activities of the Department were shared among several directions of accelerator applications, as well as research and development works on new accelerator techniques and technologies. In the group of proton and ion accelerators, two main tasks were advanced. The first was a further step in the optimization of operational parameters of multicusp ion-source, prepared for axial injection system in C-30 cyclotron. Another one is the participation in important modifications of r.f. acceleration system in heavy-ion accelerator C-200 of Warsaw University. In the broad field of electron accelerators our main attention was directed at medical applications. Most important of them was the designing and construction of a full scale technological model of a high-gradient accelerating structure for low-energy radiotherapy unit CO-LINE 1000. Microwave measurements, and tuning were accomplished, and the technical documentation for construction of radiation unit completed. This work was supported by the State Committee for Scientific Research. Preparatory work was continued to undertake in the year 1999 the design of two new medical accelerators. First is a new generation radiotherapy unit, with 15 MeV electron beam and two selected energies of X-ray photons. This accelerator should in future replace the existing Neptun 10 MeV units. The work will be executed in the frame of the Project-Ordered commissioned by the State Committee for Scientific Research. The next type of accelerators in preparation is the mobile, self-shielded electron-beam unit for inter operative irradiation. The specification of parameters was completed and study of possible solutions advanced. The programme of medical accelerator development is critically dependent on the existence of a metrological and experimental basis. Therefore the building of a former proton linear accelerator was adopted to the new function as electron accelerators

  13. Department of Accelerator Physics and Technology: Overview

    Pachan, M. [The Andrzej Soltan Institute for Nuclear Studies, Otwock-Swierk (Poland)

    1999-10-01

    Full text: As presented at the overview seminar held on December 98, the activities of the Department were shared among several directions of accelerator applications, as well as research and development works on new accelerator techniques and technologies. In the group of proton and ion accelerators, two main tasks were advanced. The first was a further step in the optimization of operational parameters of multicusp ion-source, prepared for axial injection system in C-30 cyclotron. Another one is the participation in important modifications of r.f. acceleration system in heavy-ion accelerator C-200 of Warsaw University. In the broad field of electron accelerators our main attention was directed at medical applications. Most important of them was the designing and construction of a full scale technological model of a high-gradient accelerating structure for low-energy radiotherapy unit CO-LINE 1000. Microwave measurements, and tuning were accomplished, and the technical documentation for construction of radiation unit completed. This work was supported by the State Committee for Scientific Research. Preparatory work was continued to undertake in the year 1999 the design of two new medical accelerators. First is a new generation radiotherapy unit, with 15 MeV electron beam and two selected energies of X-ray photons. This accelerator should in future replace the existing Neptun 10 MeV units. The work will be executed in the frame of the Project-Ordered commissioned by the State Committee for Scientific Research. The next type of accelerators in preparation is the mobile, self-shielded electron-beam unit for inter operative irradiation. The specification of parameters was completed and study of possible solutions advanced. The programme of medical accelerator development is critically dependent on the existence of a metrological and experimental basis. Therefore the building of a former proton linear accelerator was adopted to the new function as electron accelerators

  14. CyberKnife radiotherapy for pediatric recurrent gliomas and medulloblastomas

    CyberKnife (CK), the linear accelerator mounted on the robot arm, is a novel stereotactic irradiation system. Children with recurrent tumors including 6 low-grade and 4 high-grade gliomas and 3 medulloblastomas were treated with hypofractionated stereotactic radiotherapy using with the CK. The patient ages were 4-15 years, with average of 10.3 years. The tumor sizes were 0.11-28.5 cm3. Marginal doses were set at 17.2-31.1 Gy. When the total dose was over 20 Gy, the treatment was divided into 2-5 fractions. Among 6 patients with low grade-glima, 2 patients were controlled and others required further therapies. Four patients followed over 2 years were still alive. Six out of 7 patients with high-grade glioma or medulloblastoma survived between 11 and 48 months after the CK radiotherapy. No treatment complication was observed. The safety and less invasiveness indicate that the CK is a useful tool when it adds to the standard tumor treatments. However, long period of tumor control was not achieved. Indication and application of the CK radiotherapy for these invasion tumors should be explored. (author)

  15. Quantitative analysis of results for quality assurance in radiotherapy

    The linear accelerators represent the most important, practical and versatile source of ionizing radiation in radiotherapy. These functional characteristics influence the geometric and dosimetric accuracy of therapeutic doses applied to patients. The performance of this equipment may vary due to electronic defects, component failures or mechanical breakdowns, or may vary due to the deterioration and aging of components. Maintaining the quality of care depends on the stability of the accelerators and quality control of the institutions to monitor deviations in the parameters of the beam. The aim of this study is to assess and analyze the stability of the calibration factor of linear accelerators, as well as the other dosimetric parameters normally included in a program of quality control in radiotherapy. The average calibration factors of the accelerators for the period of approximately four years for the Clinac 600C and Clinac 6EX were (0,998 ± 0,012) and (0,996 ± 0,014), respectively. For the Clinac 2100CD 6 MV and 15 MV was (1,008 ± 0,009) and (1,006 ± 0,010), respectively, in a period of approximately four years. Statistical analysis of the three linear accelerators was found that the coefficient of variation of calibration factors had values below 2% which shows a consistency in the data. By calculating the normal distribution of calibration factors, we found that for the Clinac 600C and Clinac 2100CD, is an expected probability that more than 90% of cases the values are within acceptable limits according to the TG-142, while for the Clinac 6EX is expected around 85% since this had several exchanges of accelerator components. The values of TPR20,10 of three accelerators are practically constant and within acceptable limits according to the TG-142. It can be concluded that a detailed study of data from the calibration factor of the accelerators and TPR20,10 from a quantitative point of view, is extremely useful in a quality assurance program. (author)

  16. Proton beams in radiotherapy

    Khoroshkov, V.S.; Minakova, E.I. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

    1998-11-01

    A branch of radiology, proton therapy employs fast protons as a tool for the treatment of various, mainly oncological, diseases. The features of tissue ionization by protons (Bragg peak) facilitate a further step towards solving the principal challenge in radiology: to deliver a sufficiently high and homogeneous dose to virtually any tumour, while sparing healthy neighbouring tissues, organs and structures. The state of the art of proton therapy is described, as well as the main technical, physics and clinical results gained since the 1950s at high-energy physics centres worldwide. The future of proton therapy is connected with the construction of hospital-based facilities with dedicated medical accelerators and modern technical instrumentation. (author)

  17. Radiotherapy - past present and future

    The beginnings of therapeutic applications of x-rays are far less known and surrounded by acrimonious controversy. The past, present and future of radiotherapy are briefly reviewed. The major challenges for hospital physicists is in educating staff members and monitoring the ever broadening use of ionising radiation

  18. Radiotherapy of bile duct carcinoma

    Twenty-six patients with cholangiocarcinoma and nineteen patients with carcinoma of the gallbladder treated with external radiotherapy were analyzed. Of the twenty-six patients, eighteen had cancer of the hepatic hilus (Klatskin), four intrahepatic and the remaining four extrahepatic cholangiocarcinoma. All but two of the patients had advanced disease. Thirty-three patients received primary irradiation for unresectable tumors, ten patients adjuvant irradiation after non-curative gross tumor resection, and two patients preoperative radiotherapy. Patients with cholangiocarcinoma who underwent radiotherapy with relatively small radiation field tolerated the treatment well, but there was no significant difference in survival according to field size or radiation doses (TDF). On the other hand, patients with carcinoma of gallbladder were treated with larger field size and lower dose. In the patients without gross tumor resection, those receiving radiation doses≥90 TDF had significantly longer survival than 2) had longer survival (p=0.07). The patients with gross tumor resection had significantly longer survival than that without resection in both cholangiocarcinoma and carcinoma of gallbladder. Postmortem examination revealed tumor recurrence even in the patients with gross tumor resection, but widespread distant metastases were present simultaneously. Cholangitis and liver abscess were special and lethal conditions related to these carcinomas, and intensive therapy must be developed for these conditions. External radiotherapy may be effective in the treatment of bile duct carcinoma in terms of palliation and survival. (author)

  19. Radiotherapy T1 glottic carcinoma

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

    1989-11-01

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

  20. Thalassaemic osteoarthropathy treated with radiotherapy

    Davies, A.N. (King' s Coll. Hospital, London (United Kingdom))

    1993-11-01

    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).

  1. Computerised tomography in radiotherapy planning

    P.C. Badcock (Peter)

    1983-01-01

    textabstractSuccessful radiotherapy practice depends on the irradiation of tumours such that their destruction follows without unacceptable damage of the surrounding normal tissues. Until recently the accurate acquisition of data concerning the tumour anatomy lagged behind other developments in radi

  2. Mathematical representation of photon beam out-put factors for tele-isotopic machines and linear accelerators

    An attempt had been made to generalise the concepts involved in the dose output measurement of tele cobalt machines and linear accelerators. In India, cobalt therapy machines are in mainstay for use in radiotherapy and problems in exposure rate measurement are immense. The paper analyses the output factors for different models of cobalt machines and accelerators. (author)

  3. Clinical utility of RapidArcTM radiotherapy technology

    Infusino E

    2015-11-01

    Full Text Available Erminia Infusino Department of Radiotherapy, Campus Bio-Medico University Hospital, Rome, Italy Abstract: RapidArcTM is a radiation technique that delivers highly conformal dose distributions through the complete rotation (360° and speed variation of the linear accelerator gantry. This technique, called volumetric modulated arc therapy (VMAT, compared with conventional radiotherapy techniques, can achieve high-target volume coverage and sparing damage to normal tissues. RapidArc delivers precise dose distribution and conformity similar to or greater than intensity-modulated radiation therapy in a short time, generally a few minutes, to which image-guided radiation therapy is added. RapidArc has become a currently used technology in many centers, which use RapidArc technology to treat a large number of patients. Large and small hospitals use it to treat the most challenging cases, but more and more frequently for the most common cancers. The clinical use of RapidArc and VMAT technology is constantly growing. At present, a limited number of clinical data are published, mostly concerning planning and feasibility studies. Clinical outcome data are increasing for a few tumor sites, even if only a little. The purpose of this work is to discuss the current status of VMAT techniques in clinical use through a review of the published data of planning systems and clinical outcomes in several tumor sites. The study consisted of a systematic review based on analysis of manuscripts retrieved from the PubMed, BioMed Central, and Scopus databases by searching for the keywords "RapidArc", "Volumetric modulated arc radiotherapy", and "Intensity-modulated radiotherapy". Keywords: IMRT, VMAT, SBRT, SRS, treatment planning software 

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

    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.)

  5. Obstruction of the esophagus 5 months after radiotherapy for a central lung cancer

    Dysphagia after radiotherapy of thoracic tumors may be caused by recurrences or by radiation damage to the esophagus. Case Report: A 75-year-old patient presented with a complete obstruction of the esophagus 5 months after CHARTWEL radiotherapy for a non-small cell lung cancer. During the last week of radiotherapy mild dysphagia (Grade 1 EORTC/RTOG, Grade 2 MRC-CHART-Score) occurred that persisted over the following months. X-ray and endoscopic investigations revealed an easily removable food bolus without evidence of esophageal stricture or ulceration. Conclusion: The case report describes a mild but prolonged early radiation reaction of the esophagus. In comparison with conventional fractionation the incidence of dysphagia is higher after accelerated fractionation schedules. The pathophysiologic mechanisms underlying persistent dysphagia are currently unknown. Beside of recurrences, radiation effects to the esophagus should be considered if dysphagia after irradiation of thoracic tumors occurs, because, as in this case, therapy may rapidly improve the symptoms. (orig.)

  6. National Observatory of Radiotherapy. Survey report: situation at the end of 2012 and evolution since 2007

    This report presents and discusses the results of a survey on French radiotherapy centres to assess the condition of radiotherapy equipment, on the activity of these centres, on the composition of their medical and paramedical radiotherapy staff. After a presentation of the survey organisation and implementation, and of its methodology, results are presented and discussed, generally illustrated by tables and graphs. These results concern technical platforms and equipment (structure of the linear accelerator stock, additional equipment, operation planning and duration, procedures in case of machine stoppage, treatment preparation, equipment for treatment quality control), the activity (number of treated patients, numbers of treatments and sessions, treatment preparation, applied techniques and tumour locations), and the staff (evolution of the numbers of oncologists radiotherapists, medical physicists, technicians, and dosimetry technicians)

  7. EPR dosimetry for actual and suspected overexposures during radiotherapy treatments in Poland

    EPR dosimetry on bone samples was recently used for actual and suspected overexposures during radiotherapy treatments performed in Poland. In 2001 five breast-cancer patients undergoing radiotherapy in the Bialystok Oncology Center, Poland, were overexposed. The overexposure was due to a defective safety interlock and an obsolete safety system of the linear accelerator. For the three most exposed patients, pieces of rib bones removed during surgical reconstruction of the chest wall and skin transplantation allowed an estimation of the accident doses by electron paramagnetic resonance (EPR) spectrometry. The doses delivered during the accident were as high as 60-80 Gy. In 2005, a patient treated in Kielce Holy Cross Cancer Center exhibited similar deep necroses of the chest wall but 6 years following a 'standard upper mantel fields' radiotherapy for Hodgkin's disease. In order to investigate the possible late effect of an overexposure as necrosis origin, the delivered dose was afterward estimated by EPR dosimetry performed on a rib sample

  8. Pulsed DC accelerator for laser wakefield accelerator

    For the acceleration of ultra-short, high-brightness electron bunches, a pulsed DC accelerator was constructed. The pulser produced megavolt pulses of 1 ns duration in a vacuum diode. Results are presented from field emission of electrons in the diode. The results indicate that the accelerating gradient in the diode is approximately 1.5 GV/m

  9. Linear Accelerator (LINAC)

    ... News Physician Resources Professions Site Index A-Z Linear Accelerator A linear accelerator (LINAC) customizes high energy x-rays to ... ensured? What is this equipment used for? A linear accelerator (LINAC) is the device most commonly used ...

  10. The evaluation of neutron and gamma ray dose equivalent distributions in patients and the effectiveness of shield materials for high energy photons radiotherapy facilities

    Ghassoun, J., E-mail: ghassoun@ucam.ac.ma [EPRA, Department of Physics, Faculty of Sciences Semlalia, PO Box: 2390, 40000 Marrakech (Morocco); Senhou, N. [EPRA, Department of Physics, Faculty of Sciences Semlalia, PO Box: 2390, 40000 Marrakech (Morocco)

    2012-04-15

    In this study, the MCNP5 code was used to model radiotherapy room of a medical linear accelerator operating at 18 MV and to evaluate the neutron and the secondary gamma ray fluences, the energy spectra and the dose equivalent distributions inside a liquid tissue-equivalent (TE) phantom. The obtained results were compared with measured data published in the literature. Moreover, the shielding effects of various neutron material shields on the radiotherapy room wall were also investigated. Our simulation results showed that paraffin wax containing boron carbide presents enough effectiveness to reduce both neutron and secondary gamma ray doses. - Highlights: Black-Right-Pointing-Pointer The Monte Carlo method has been used to model radiotherapy room of a 18 MV linear accelerator. Black-Right-Pointing-Pointer The neutron and the gamma ray dose equivalent distributions inside a liquid (TE) phantom were evaluated. Black-Right-Pointing-Pointer The radiotherapy room shielding performance has been also investigated.

  11. The evaluation of neutron and gamma ray dose equivalent distributions in patients and the effectiveness of shield materials for high energy photons radiotherapy facilities

    In this study, the MCNP5 code was used to model radiotherapy room of a medical linear accelerator operating at 18 MV and to evaluate the neutron and the secondary gamma ray fluences, the energy spectra and the dose equivalent distributions inside a liquid tissue-equivalent (TE) phantom. The obtained results were compared with measured data published in the literature. Moreover, the shielding effects of various neutron material shields on the radiotherapy room wall were also investigated. Our simulation results showed that paraffin wax containing boron carbide presents enough effectiveness to reduce both neutron and secondary gamma ray doses. - Highlights: ► The Monte Carlo method has been used to model radiotherapy room of a 18 MV linear accelerator. ► The neutron and the gamma ray dose equivalent distributions inside a liquid (TE) phantom were evaluated. ► The radiotherapy room shielding performance has been also investigated.

  12. Particle radiotherapy for patients with H and N malignant tumor

    Particle beams have a characteristic called the Bragg peak, which is a peak formed at a fixed depth in the body depending on the acceleration energy. Utilizing this property, a high dose can be concentrated in the target tumor while minimizing damage to surrounding normal tissues. Proton and carbon ion beams have a higher linear energy transfer (LET) than X-rays. The relative biological effectiveness of proton and carbon ion beams compared with X-rays (=1) is estimated to be 1.1 and 3.0, respectively. Therefore, we can expect particle radiotherapy to be effective for patients with radio-resistant tumors such as malignant melanoma, adenoidcystic carcinoma and adenocarcinoma. As of the end of July 2011, there were 9 particle institutes operating in Japan; the Hyogo Ion Beam Medical Center was established in May 2001 as a leading project of the ''Hyogo Cancer Strategy''. One major characteristic is that the Center can generate both proton and carbon ion beams. Locally advanced nasal, paranasal or salivary gland cell tumors are good candidates for particle radiotherapy. Downsizing of the accelerator, price reduction of the machine, broad use of particle therapy in the field of clinical oncology, and intensity modulated particle therapy are future challenges. (author)

  13. Audit of 3D conformal radiotherapy treatment planning systems

    finally the complex multi-field arrangements are applied.The clinical test case setup conditions are carried out using a treatment machine, and the doses to specific points in the phantom are directly measured with an ionization chamber. These checks are primarily aimed at confirming that the doses calculated by TPS agree with those determined by measurement, within predefined acceptance criteria. The audit process takes about 15 hours for one accelerator (considering two photon beams and up to three TPS algorithms). In practice it requires two working days. On the first day CT scanning and test case planning is performed. CT scanning requires approximately 45 minutes of scanner time including time necessary for data transfer. The first scan is performed to verify the HU/ED conversion curve used by TPS, and the second scan is performed for treatment planning purposes. The planning of test cases and transfer of the data to the accelerator record and verify system requires approximately 6 hours. On the second day the irradiation of the phantom will take place, which will require up to 5 hours of accelerator time for a dual photon energy machine. Analyses of the data would require an additional 2 hours. Audit in the Baltic States. The audit was carried out in the 5 largest radiotherapy departments of the region. It was the same auditor who visited all the radiotherapy departments and ensured that the procedure of IAEA-TECDOC-1583 was followed. The performance of seven TPSs have been evaluated and the measurements were conducted on seven treatment units. Altogether, there were 28 different combinations of photon beams and TPS algorithms/ inhomogeneity correction methods tested. All TPSs tested had a satisfactory performance with deviations less than 3% in the majority of clinical test cases, with the exception of dose measurements at points located in the lung equivalent material. The deviations of up to 19.2% between measured and calculated doses were discovered for these

  14. Accelerated repopulation as a cause of radiation treatment failure in non-small cell lung cancer: review of current data and future clinical strategies.

    Yom, Sue S

    2015-04-01

    Despite convincing evidence that the principles of accelerated repopulation would open up additional therapeutic opportunities in the treatment of advanced-stage non-small cell lung cancer, this strategy has been generally underexplored. The implementation of accelerated radiotherapy schedules has been hampered by logistical barriers, concerns about acute toxicity, and the prioritization of integrating concurrent chemotherapy into the standard treatment platform. At present, it is unclear to what extent accelerated fractionation will influence future treatment paradigms in non-small cell lung cancer, although technical advances in radiotherapy, allowing higher dose delivery with reduced toxicity, could permit the development of more convenient and tolerable forms of accelerated schedules. PMID:25771413

  15. Accelerated partial breast irradiation trials: Diversity in rationale and design

    Seven randomised trials are currently testing accelerated partial breast irradiation against whole breast radiotherapy after breast conservation surgery. The trials are varied in the techniques used to deliver partial breast radiotherapy, reflecting the range of opportunities offered by advanced brachytherapy and teletherapy modalities. Dose schedules also vary between trials, but the most important point of difference between them reflects alternative concepts of clinical and planning target volumes. These are based mainly on the spatial pattern of relapse in retrospective and prospective studies, which report the majority of first local relapses close to the primary tumour site, and on the assumption that radiotherapy does not prevent the development of new primary tumours developing elsewhere in the breast. However, the pattern of ipsilateral breast tumour relapse is not accurately defined in the clinical literature and does not correspond closely to pathological findings. In addition, published data are consistent with a significant reduction in the rate of other quadrant relapse after whole breast radiotherapy. Regardless of the biological model of local tumour relapse and responsiveness to radiation, the ongoing trials will generate level I evidence for or against accelerated partial breast irradiation, provided patients are followed up long enough before the first reporting of results.

  16. Running radiotherapy services in a limited resource setting

    treatment is similarly affected, resulting in poor documentation of outcomes of treatment. This has a large impact on quality control as measured by outcomes of therapy. Similarly, defaulters are difficult to trace. The choice of equipment for the centre can be very difficult based on what is deemed suitable in an environment such as ours. Machine downtime occasionally gets to a level that compromises treatment credibility and sometimes denies patients the chance of ever getting the treatment at all. In our centre we have had the experience of using Co-60 as well as linear accelerators. Whilst the Co-60 unit has been hailed as the appropriate treatment machine for the economically constrained environment, the linear accelerator has proven to be of value in our setting where it has been used for the past 22 years. The role of the linear accelerator in the provision of a good radiotherapy service even in resource-poor settings is pivotal. All its advantages such as varying photon energies, better skin sparing, better beam shaping and electrons become even more important in a setting where the side effects of treatment, both early and late may be difficult to follow up. If evidence based practice is the goal, this equipment becomes indispensable as most current evidence on radiotherapy treatment is decreasingly based on Co-60 treatments as the general worldwide trend is towards linear accelerators. Technological advances cannot be ignored even in our setting as information on which to base guidelines for patient management becomes inapplicable where there is a lag in technological advancement. What may be a relatively longer downtime for a linear accelerator in our setting is not only attributable to operational conditions such as housing, staff training and experience. The lack of supportive services, not only at the institutional level but also by the equipment providers themselves plays a large role in this. The training of radiation oncologists and radiographers has been

  17. Irradiation Accidents in Radiotherapy Analyze, Manage, Prevent

    Why do errors occur? How to minimize them? In a context of widely publicized major incidents, of accelerated technological advances in radiotherapy planning and delivery, and of global communication and information resources, this critical issue had to be addressed by the professionals of the field, and so did most national and international organizations. The ISMP, aware of its responsibility, decided as well to put an emphasis on the topic at the occasion of its annual meeting. In this frame, potential errors in terms of scenarios, pathways of occurrence, and dosimetry, will first be examined. The goal being to prioritize error prevention according to likelihood of events and their dosimetric impact. Then, case study of three incidents will be detailed: Epinal, Glasgow and Detroit. For each one, a description of the incident and the way it was reported, its investigation, and the lessons that can be learnt will be presented. Finally, the implementation of practical measures at different levels, intra- and inter institutions, like teaching, QA procedures enforcement or voluntary incident reporting, will be discussed

  18. Palliative radiotherapy: current status and future directions.

    Sharma, Sonam; Hertan, Lauren; Jones, Joshua

    2014-12-01

    For nearly 100 years, palliative radiotherapy has been a time-efficient, effective treatment for patients with metastatic or advanced cancer in any area where local tumors are causing symptoms. Short courses including a single fraction of radiotherapy may be effective for symptom relief with minimal side effects and maximization of convenience for patient and family. With recent advances in imaging, surgery, and other local therapies as well as systemic cancer therapies, palliative radiotherapy has been used frequently in patients who may not yet have symptoms of advanced or metastatic cancer. In this setting, more prolonged radiotherapy courses and advanced radiotherapy techniques including intensity-modulated radiotherapy (IMRT) or stereotactic radiotherapy (SRT) may be useful in obtaining local control and durable palliative responses. This review will explore the use of radiotherapy across the spectrum of patients with advanced and metastatic cancer and delineate an updated, rational approach for the use of palliative radiotherapy that incorporates symptoms, prognosis, and other factors into the delivery of palliative radiotherapy. PMID:25499634

  19. The evaluation of results and complications of radiotherapy in children treated for orbital rhabdomyosarcoma

    To analyse treatment results and late complications of radiotherapy in children treated for orbital rhabdomyosarcoma. Between the years 1980 and 2000 34 children (median age 7 yrs. range: 1-15) with orbital RMS, were treated in the 1st Department of the MCCMCC in Warsaw. All but two of the patients received induction chemotherapy; 3 children were treated after ablative surgery (exenteration); 6 children were irradiated due to recurrence after chemotherapy. All the children were treated with megavoltage radiotherapy from a Co-60 unit or linear accelerator. We applied individual lens and lacrimal apparatus shielding in 16 patients. Five children, treated between 1996-2000, received conformal radiotherapy, with CT and 3-D treatment planning system.To obtain information about late side effects, we developed a questionnaire, including questions about the status of the affected eye, appearance of the orbit and facial structures.Thirty one patients (91%) are still living (between 24 and 264 months - median 138 mos) after completion of radiotherapy and 28 (82%) with no recurrence. In six patients treated due to recurrent tumour OS and DFS was 80% and 60%, respectively. Late complications were evaluated in 24 patients. We observed lacrimal duct stenosis in 33%, cataract in 29%, enophtalmos in 20% of patients. Retinopathy developed in 2 children, glaucoma in 2 pts, and facial asymmetry in 3 pts. In one case enucleation of blind eye was performed. Thirteen children have preserved adequate vision in the treated eye. In children treated with conformal radiotherapy we did not observe any late complications. Radiotherapy in orbital RMS allows to obtain good local control and excellent survival rate. Late complications could be limited with the application of individual treatment planning and conformal radiotherapy. (author)

  20. Dosimetric comparison of linear accelerator-based stereotactic radiosurgery systems

    Sharma S; Kumar Sudhir; Dagaonkar S; Bisht Geetika; Dayanand S; Devi Reena; Deshpande S; Chaudhary S; Bhatt B; Kannan S

    2007-01-01

    Stereotactic radiosurgery (SRS) is a special radiotherapy technique used to irradiate intracranial lesions by 3-D arrangements of narrow photon beams eliminating the needs of invasive surgery. Three different tertiary collimators, namely BrainLab and Radionics circular cones and BrainLab micro multileaf collimator (mMLC), are used for linear accelerator-based SRS systems (X-Knife). Output factor (St), tissue maximum ratio (TMR) and off axis ratio (OAR) of these three SRS systems were measured...

  1. A cost-minimising analysis of standard radiotherapy and two experimental therapies in glioblastoma

    Background and purpose: Accelerated radiotherapy (ART) and intracavity brachytherapy (ICBT) have been introduced in the primary treatment of glioblastoma. Our objective was to determine total treatment costs, hospitalisation time, and treatment outcome in these two experimental therapies compared to standard treatment. Materials and methods: In the time period 1985 to 1st May 1999, a total of 174 patients with histologically confirmed glioblastoma multiforme were given postoperative radiotherapy according to three different treatment schedules at three different time intervals. A conventional regime of external radiotherapy (54 Gy/30 fractions) was given to 58 patients (group I), 75 patients were treated with ART (48 Gy/twice daily 30 fractions) (group II), and 41 patients were given ICBT (60 Gy/ten fractions) (group III). Treatment costs including surgery, hospital stay, hospital hotel stay, and radiotherapy were calculated. Results: The total mean costs employing the three treatment alternatives were calculated to $25,618 (group I), $23,442 (group II), and $14,534 (group III). Total mean stay in hospital for the whole primary treatment was 48.8, 41.6, and 19 days for groups I, II, and III respectively. Median survival figures were 16, 14, and 13 months for groups I, II, and III, respectively. Conclusions: The total cost of postoperative radiotherapy in glioblastoma is comparable to other health care services. ART did not improve the total treatment cost or influence the need for hospitalisation compared to standard treatment. ICBT seemed to have economic benefits with less need for hospitalisation

  2. Accelerated hyperfractionation plus temozolomide in glioblastoma

    Hyperfractionated (HFRT) or accelerated hyperfractionated radiotherapy (AHFRT) have been discussed as a potential treatment for glioblastoma based on a hypothesized reduction of late radiation injury and prevention of repopulation. HFRT and AHFRT have been examined extensively in the pre-Temozolomide era with inconclusive results. In this study we examined the role of accelerated hyperfractionation in the Temozolomide era. Sixty-four patients who underwent AHFRT (62 of which received Temozolomide) were compared to 67 patients who underwent normofractionated radiotherapy (NFRT) (64 of which received TMZ) between 02/2009 and 10/2014. Follow-up data were analyzed until 01/2015. Median progression-free survival (PFS) was 6 months for the entire cohort. For patients treated with NFRT median PFS was 7 months, for patients treated with AHFRT median PFS was 6 months. Median overall survival (OS) was 13 months for all patients. For patients treated with NFRT median OS was 15 months, for patients treated with AHFRT median OS was 10 months. The fractionation regimen was not a predictor of PFS or OS in univariable- or multivariable analysis. There was no difference in acute toxicity profiles between the two treatment groups. Univariable and multivariable analysis did not show significant differences between NFRT and AHFRT fractionation regimens in terms of PFS or OS. The benefits are immanent: the regimen does significantly shorten hospitalization time in a patient collective with highly impaired life expectancy. We propose that the role of AHFRT + TMZ should be further examined in future prospective trials

  3. Psychosocial effects of radiotherapy after mastectomy

    Psychosocial morbidity was measured in 47 patients who received postoperative radiotherapy and in 38 who received no further treatment after mastectomy. Roughly one third of all patients experienced depression or anxiety. One month after operation, before radiotherapy, there were no significant differences between the two groups in any of the measures of psychosocial morbidity. Knowledge of impending treatment did not seem to influence morbidity. At three months patients who had completed radiotherapy had significantly more somatic symptoms and social dysfunction than those not so treated. At six months the radiotherapy group continued to show more somatic symptoms, but a year after operation there were no significant differences between the groups. Although several patients who received radiotherapy were upset by their treatment, the study failed to confirm that depression and anxiety were commoner among those given radiotherapy than among patients given no further treatment. (author)

  4. Radiotherapy of Langerhans' cell histiocytosis. Results and Implications of a national patterns-of-care study

    Seegenschmiedt, M.H. [Alfried Krupp Krankenhaus, Essen (Germany). Dept. of Radiation Oncology and Radiotherapy; Olschewski, T.

    2006-11-15

    Purpose: This patterns-of-care study was performed to define the current clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany and to define open questions resulting from this study. Material and Methods: A standardized questionnaire was sent to 198 German radiotherapy institutions. Data about patient characteristics, stage of disease, practice and fractionation of radiotherapy, outcome of therapy, etc. were systematically evaluated. 123 of 198 institutions answered the complete questionnaire (62.1%). Results: Only 23 of the 123 institutions (18.7%) reported experience with radiotherapy of Langerhans' cell histiocytosis of adults. 18 institutions with 98 patients were evaluable. The majority of patients (72 of 98) was treated on a linear accelerator. The median single dose of radiotherapy was 2 Gy, while the median total dose was 24 Gy. 81 of 89 evaluable patients (91%) reached a local control of the treated lesion(s), 69 of those had a complete remission. Eight of 89 patients (9%) developed an in-field recurrence. 87.8% of patients experienced no acute and 97% of patients no late side effects of radiotherapy. Conclusion: Clinical experience with radiotherapy of Langerhans' cell histiocytosis in adults in Germany is still very limited. Nevertheless, the clinical results - with high remission and local control rates - confirm the effectiveness of radiotherapy in the multidisciplinary treatment of this disease. Due to the small number of patients in this study despite higher incidence rates, the knowledge of this disease has to be multiplied in Germany. Future patients should be systematically included into a prospective radiotherapy registry. (orig.)

  5. A New Beam and Delivery System for Radiotherapy

    The new beam delivery system consists of an electron accelerator and a system of magnets (one or more). Introducing a transverse magnetic field in and near the tumor, causes the electrons to spiral in this region, thereby producing an effective peak in the depth dose distribution, within the tumor volume. Although the basic idea is not new, we suggest here for the first time, a viable as well as a workable, magnetic field configuration, which in addition to focusing the beam does not interfere with its propagation to the target. Prototypes were successfully tested by means of computer simulation. The electron accelerator : can be a linear accelerator or any other type electron accelerator, capable of producing different electron energies for different depths and dose absorptionaccumulation . The Field size can be as small as a pencil beam and as big as any of the other standard field sizes that are used in radiotherapy. The scatter filter can be used or removed. The dose rate accumulation can be as higher as possible. The magnets are able to produce magnetic fields. The order, direction, width, place, shape and number of the magnetic fields define the shape and the Percentage Depth Dose (PDD) curve of the electron beam.

  6. Gel dosimetry for conformal radiotherapy

    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)

  7. Proton Radiotherapy for Pediatric Sarcoma

    Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas

  8. Radiotherapy for symptomatic vertebral hemangioma

    Purpose: Assessment of treatment results of symptomatic vertebral hemangiomas and review of the literature. Patients and Methods: Ten patients treated between 1974 to 1997 were retrospectively analyzed. Efficacy of treatment was determined according to improvement of pain and/or neurological symptoms. Results: Improvement was achieved in 8 of 10 patients. The initially existing neurological symptoms of 3 patients disappeared completely in 2 cases and improved in 1 case. Acute side effects were slight. Late side effects were not seen. A dose-effect relationship could not be assessed. There was no relapse. Conclusion: Radiotherapy with 30 Gy for symptomatic vertebral angioma as primary therapy is indicated. In case of neurological symptoms a radiotherapy after operative therapy is recommendable even if the patient is free of symptoms to prevent progress or relapse. (orig.)

  9. Stereotactic radiotherapy for vestibular schwannoma

    Muzevic, Dario; Legcevic, Jelena; Splavski, Bruno;

    2014-01-01

    BACKGROUND: Vestibular schwannomas (acoustic neuromas) are common benign tumours that arise from the Schwann cells of the vestibular nerve. Management options include observation with neuroradiological follow-up, microsurgical resection and stereotactic radiotherapy. OBJECTIVES: To assess...... the effect of stereotactic radiotherapy compared to observation, microsurgical resection, any other treatment modality, or a combination of two or more of the above approaches for vestibular schwannoma. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials; PubMed; EMBASE; CINAHL...... resection or any other possible treatment or combination of treatments in patients with a cerebellopontine angle tumour up to 3 cm in diameter, presumed to be a vestibular schwannoma. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by The Cochrane Collaboration. MAIN...

  10. Radiotherapy in osseous metastasizing carcinoid

    In an 51-year old patient with a disseminately metastasizing bronchus carcinoid, percutaneous radiotherapy was employed as a palliative measure against most severe pain in the region of bone metastases. In all irradiated regions (entire vertebral column and both shoulders) good pain relief was achieved in 2 weeks, lasting until the end of the follow-up period (18 months after irradiation), by application of 30 Gy photon radiation. Correlated with the subjective pain relief was a reduction of the required quantity of analgesics, a reduction of the greatly increased activity of alkaline phosphatase in the serum, and roentgenological sclerosing of the metastatic bone lesions. This case report is intended to point to the possibility of employing radiotherapy in similar cases where medication has finally proved futile, since the rare reports in literature are mostly negative. (orig.)

  11. Proton Radiotherapy for Pediatric Sarcoma

    Ladra, Matthew M.; Yock, Torunn I., E-mail: tyock@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114 (United States)

    2014-01-14

    Pediatric sarcomas represent a distinct group of pathologies, with approximately 900 new cases per year in the United States alone. Radiotherapy plays an integral role in the local control of these tumors, which often arise adjacent to critical structures and growing organs. The physical properties of proton beam radiotherapy provide a distinct advantage over standard photon radiation by eliminating excess dose deposited beyond the target volume, thereby reducing both the dose of radiation delivered to non-target structures as well as the total radiation dose delivered to a patient. Dosimetric studies comparing proton plans to IMRT and 3D conformal radiation have demonstrated the superiority of protons in numerous pediatric malignancies and data on long-term clinical outcomes and toxicity is emerging. In this article, we review the existing clinical and dosimetric data regarding the use of proton beam radiation in malignant bone and soft tissue sarcomas.

  12. Fingerprints identification of radiotherapy patients

    The identification of patient plays a key role in the quality and safety of radiotherapy. It does impact on all professional staff and on patients. After the regulatory authority approval (Cnil), a pilot study has been performed on 1901 patients. Acceptance has been very high (> 93%) with a low risk of mis-identification (< 0.1%). The next step will be to implement and test a bimodal system in order to improve registration capacity and sensitivity. (authors)

  13. Experiment on radiotherapy of postnatal mastitis

    The results of radiotherapy of postnatal mastitis in 78 women are presented. It is shown that the radiotherapy is the method of choice. Application of radiotherapy at different stages of disease promotes either complete resolution of infiltration (1-2 irradiations) or stipulates the decrease in temperature, abatement of pains and improvement of general state (at the presence of purulent fusion of mammary tissue). X-ray therapy of postnatal mastitis has does not affect the lactational function of mammary gland

  14. Single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients: comparative effectiveness

    External beam radiotherapy (EBRT) is an effective treatment for symptomatic bone metastases from a variety of primary malignancies. Previous meta-analyses and systematic reviews have reported on the efficacy of EBRT on bone metastases from multiple primaries. This review is focused on the comparative effectiveness of single fraction radiotherapy versus multiple fraction radiotherapy for bone metastases in prostate cancer patients

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

    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....

  16. Radiological safety aspects of the operation of proton accelerators

    Particle accelerators are finding increased application in both the fundamental and applied sciences and in industry around the world. Positive ion accelerators are being applied in a host of fields, including radiation damage studies, induced activation and dating measurements, radiography, radiotherapy and fusion research. Because these devices can be potent sources of neutrons, it is important that information concerning their safe operation be widely available. This report is conceived as a source book providing authoritative guidance in radioprotection from an important category of radiation sources. It thus supplements other manuals of the IAEA related to the planning and implementation of radiation protection programmes. Refs, figs and tabs

  17. Patient Radiation Protection in Radiotherapy

    The Role of Radiotherapy is treatment modalities for cancer which is generally assumed that 50 to 60% of cancer patients will benefit from radiotherapy. It constitutes a peaceful application of ionizing radiation and an essential part of cancer management. The two aims of radiation protection Prevention is of deterministic effect and Reduction of the probability of stochastic effects. The Shielding fundamentals is to limit radiation exposure of staff, patients, visitors and the public to acceptable levels it also optimize protection of patients, staff and the public. Diagnosis is important for target design and the dose required for cure or palliation while Simulator is often used twice in the radiotherapy process where Patient data acquisition - target localization, contours, outlines and Verification. The Prescription is the responsibility of individual clinicians, depending on the patient’s condition, equipment available, experience and training. An ultimate check of the actual treatment given can only be made by using in vivo dosimetry. Treatment records must be kept of all relevant aspects of the treatment – including Session and Summary Record information, Records all treatment parameters, Dose Calculations and Dose Measurements

  18. Immediate side effects of large fraction radiotherapy

    Devereux, S.; Hatton, M.Q.F.; Macbeth, F.R. [Glasgow Western Infirmary (United Kingdom)

    1997-09-01

    The use of hypofractionated radiotherapy regiments is becoming more widely recognized in the palliation of non-small cell lung carcinoma (NSCLC). Anecdoctal reports of chest pain, rigors and fevers in the hours that follow radiotherapy led us to perform a survey estimating the frequency and severity of these symptoms following treatment to the thorax. We conclude that patients receiving palliative radiotherapy for bronchial carcinoma often develop significant symptoms in the hours following treatment. The timing and duration suggest a relationship with the radiotherapy, and we feel that patients should be warned of the possible occurrence of these symptoms. (author).

  19. Targeting IAP proteins in combination with radiotherapy

    The efficacy of radiotherapy critically depends on the activation of intrinsic cell death programs in cancer cells. This implies that evasion of cell death, a hallmark of human cancers, can contribute to radioresistance. Therefore, novel strategies to reactivate cell death programs in cancer cells are required in order to overcome resistance to radiotherapy. Since Inhibitor of Apoptosis (IAP) proteins are expressed at high levels in multiple cancers and block cell death induction at a central point, therapeutic targeting of IAP proteins represents a promising approach to potentiate the efficacy of radiotherapy. The current review discusses the concept of targeting IAP proteins in combination with radiotherapy

  20. Otologic disorders following radiotherapy for nasopharyngeal carcinoma

    Radiotherapy is widely accepted as the first choice for nasopharyngeal carcinoma. Delayed otitis of both external and middle ears is sometimes seen as a complication after radiotherapy for head and neck cancer, especially for nasopharyngeal carcinoma. They are usually hard to manage and some produces cochlear damages, finally resulting in a sensorineural hearing loss. However, these otologic disorders are tends to be overlooked, because physicians pay less attention to them than the concerning for cancer recurrence. Therefore, studies on the otologic disorders following radiotherapy are lacking. In this study, we analyzed 24 nasopharyngeal carcinoma cases retrospectively to clarify the incidence of otologic disorders induced by radiotherapy. (author)

  1. Guide of external radiotherapy procedures 2007

    This work aims at participating in the permanent optimization of the returned medical service and the ratio profit-risk. This first version of the guide of external radiotherapy procedures 2007 processes only techniques of external radiotherapy, by opposition to the techniques of brachytherapy which use radioactive sources (iridium192, iodine125, cesium137) placed in the contact of the tumor to be irradiated. Only, also, will be considered the irradiations of the most frequent cunning(malignant) tumors with the exception of the radiotherapy of the mild pathologies and the re-irradiations after a first radiotherapy. The first part is shared in eight chapters as follow: introduction, the steps of a treatment by radiotherapy, infrastructure, equipment and human resources, radiobiology mechanism of action of ionising radiations in radiotherapy, dose in radiotherapy, quality of treatment and radiation protection of patients in radiotherapy, prevention and risk management in radiotherapy, quality assurance and radiation protection for the pediatrics cancers and the case of pregnant women. The second part gives the tumoral localizations and the procedures; the third part is a glossary and different annexes such regulations and legislative texts. (N.C.)

  2. The role of radiotherapy in hospice care

    The aim of palliative radiotherapy for the terminally ill is to improve the quality of the remaining span of life. From November 1982 to September 1987, 69 patients in the Seirei Hospice have been treated with such radiotherapy, and symptomatic relief was obtained in 64% of these patients. Radiotherapy also proved useful in achieving an improvement in their performance status. While the aim of hospice care is not directed towards treatment of the underlying disease, the use of radiotherapy is considered to have an important role in hospice care. (author)

  3. Role of radiotherapy in hospice care

    Nishimura, Tetsuo; Sugiyama, Akira; Shimizu, Teppei; Ichinohe, Kenji; Teshima, Takeshi; Kaneko, Masao; Hara, Yoshio; Chihara, Satoshi.

    1989-01-01

    The aim of palliative radiotherapy for the terminally ill is to improve the quality of the remaining span of life. From November 1982 to September 1987, 69 patients in the Seirei Hospice have been treated with such radiotherapy, and symptomatic relief was obtained in 64% of these patients. Radiotherapy also proved useful in achieving an improvement in their performance status. While the aim of hospice care is not directed towards treatment of the underlying disease, the use of radiotherapy is considered to have an important role in hospice care.

  4. Every second cancer patient receives radiotherapy

    Radiotherapy to treat cancer was given for the first time exactly one hundred years ago. Today, radiotherapy and surgery are the two main modes of treating cancer. One in two cancer patients receives radiotherapy at some point during the course of treatment for the disease. Radiotherapy is applied most commonly in cases where surgery is not possible. Moreover, these two modes of treatment are often used together to supplement each other. About half of new cancer cases detected today can be ordered. The estimate given by the EU for cancers cured is 45 per cent, which is divided between the various treatment modes as follows: surgery 22 %, radiotherapy 12 %, surgery plus radiotherapy 6 %, and drug therapy 6 %. In addition to curative treatment, radiotherapy plays a crucial role in palliative treatment, i.e. treatment that alleviates symptoms. The sensitivity of malignant tumours to radiotherapy varies over a wide range; the same is true for healthy tissues. Radiotherapy can only be used to cure a tumour that is more sensitive to radiation than the surrounding healthy tissue. The tumour must also be sufficiently small in size and limited to a relatively small area. (orig.)

  5. Department of Accelerator Physics and Technology: Overview

    Full text: The principal Department's duties in 1999 have not changed and were consequently directed on development in the area of electron and ion accelerators and their applications in science, medicine and technology. Two important events dominated the current and future orientation of R and D activity. The first was finalizing of long time efforts for preparing of the ordered research project granted by the State Committee of Scientific Research and devoted to elaboration and design of a new electron accelerator for radiotherapy, with two energies of X-ray photon beams. This project was formally approved in March 1999 and due to organisatory procedures set in operation after few months. In the second half of 1999, an important progress was done in advancing the project. The second mentioned event is foundation by the government of a Multiyear Research Programme - called ''Isotopes and Accelerators''. This programme formulates a broad spectrum of important tasks oriented on application of isotopes and accelerator techniques in many branches of science and national economy. The expected participation of the Department in this programme comprises following subjects: medical interoperative accelerator, high power electron accelerator for radiation technology, and upgrading of cyclotron for isotopes production. In course of 1999, preparatory studies in these subjects were carried out. Some of the results were presented on conferences and seminars. An interesting experience was the expertise done on technical status of Eindhoven isochronous cyclotron and its possible transfer to Swierk as a professional tool for isotopes production. In the group of medical applications, three subjects were continued during 1999 and brought important results: - completion of microwave measurements of high gradient acceleration structure for low energy accelerators; such structure will be very useful solution for Co-Line and interoperative accelerator; - evaluation of design data and

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

    Schreiber, Eric C.; Chang, Sha X.

    2012-01-01

    Purpose: Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on ca...

  7. Prescription dose and fractionation predict improved survival after stereotactic radiotherapy for brainstem metastases

    Leeman Jonathan E; Clump David A; Wegner Rodney E; Heron Dwight E; Burton Steven A; Mintz Arlan H

    2012-01-01

    Abstract Background Brainstem metastases represent an uncommon clinical presentation that is associated with a poor prognosis. Treatment options are limited given the unacceptable risks associated with surgical resection in this location. However, without local control, symptoms including progressive cranial nerve dysfunction are frequently observed. The objective of this study was to determine the outcomes associated with linear accelerator-based stereotactic radiotherapy or radiosurgery (SR...

  8. The clinical outcome of intracranial hemangioblastomas treated with linac-based stereotactic radiosurgery and radiotherapy

    Puataweepong, Putipun; Dhanachai, Mantana; Hansasuta, Ake; Dangprasert, Somjai; Sitathanee, Chomporn; Puddhikarant, Parmon; Jiarpinitnun, Chuleeporn; Ruangkanchanasetr, Rawee; Dechsupa, Patchareporn; Pairat, Kumutinee

    2014-01-01

    Recent publications have reported stereotactic radiosurgery as an effective and safe treatment for intracranial hemangioblastomas. However, because of the low incidence of these particular tumors, reports on large patient number studies have not yet been available. The objective of this study was to analyze the clinical results of 14 patients with 56 intracranial hemangioblastomas treated with linear accelerator (linac)-based stereotactic radiosurgery (SRS) and radiotherapy (SRT) in the same ...

  9. Quality assurance in stereotactic radiosurgery/radiotherapy according to DIN 6875-1

    Mack, A.; Mack, G.; Scheib, S.; Czempiel, H; Kreiner, H. J.; Lomax, N J; Gianolini, S.; Rieker, M.; Weltz, D.; Wolff, R.; Muacevic, A.; Wowra, B.; Böttcher, H. D.; Seifert, V

    2004-01-01

    The new DIN (' Deutsche Industrie- Norm') 6875- 1, which is currently being finalised, deals with quality assurance ( QA) criteria and tests methods for linear accelerator and Gamma Knife stereotactic radiosurgery/ radiotherapy including treatment planning, stereotactic frame and stereotactic imaging and a system test to check the whole chain of uncertainties. Our existing QA program, based on dedicated phantoms and test procedures, has been refined to fulfill the demands of this new DIN. The...

  10. Acceleration without Horizons

    Doria, Alaric; Munoz, Gerardo

    2015-01-01

    We derive the metric of an accelerating observer moving with non-constant proper acceleration in flat spacetime. With the exception of a limiting case representing a Rindler observer, there are no horizons. In our solution, observers can accelerate to any desired terminal speed $v_{\\infty} < c$. The motion of the accelerating observer is completely determined by the distance of closest approach and terminal velocity or, equivalently, by an acceleration parameter and terminal velocity.

  11. Conformal three dimensional radiotherapy treatment planning in Lund

    Knoos, T.; Nilsson, P. [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A. [Lund Univ. (Sweden). Dept. of Oncology

    1995-12-01

    The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

  12. Conformal three dimensional radiotherapy treatment planning in Lund

    The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam's eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam's eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment

  13. Prism: a new approach to radiotherapy planning software

    Purpose: We describe the capabilities and performance of Prism, an innovative new radiotherapy planning system with unusual features and design. The design and implementation strategies are intended to assure high quality and clinical acceptability. The features include Artificial Intelligence tools and special support for multileaf collimator (MLC) systems. The design provides unusual flexibility of operation and ease of expansion. Methods and Materials: We have implemented Prism, a three-dimensional (3D) radiotherapy treatment-planning system on standard commercial workstations with the widely available X window system. The design and implementation use ideas taken from recent software engineering research, for example, the use of behavioral entity-relationship modeling and the 'Mediator Method' instead of ad-hoc programming. The Prism system includes the usual features of a 3D planning system, including Beam's Eye View and the ability to simulate any treatment geometry possible with any standard radiotherapy accelerator. It includes a rule-based expert system for automated generation of the planning target volume as defined in ICRU Report 50. In addition, it provides special support for planning treatments with a multileaf collimator (MLC). We also implemented a Radiotherapy Treatment Planning Tools Foundation for Prism, so that we are able to use software tools from other institutions without any source code modification. Results: The Prism system has been in clinical operation at the University of Washington since July 1994 and has been installed at several other clinics. The system is run simultaneously by several users, each with their own workstation operating from a common networked database and software. In addition to the dosimetrists, the system is used by radiation oncologists to define tumor and target volumes and by radiation therapists to select treatment setups to load into a computer controlled accelerator. Conclusions: Experience with the

  14. Principles of laser-plasma accelerators

    The continuing development of powerful laser systems has permitted to extend the interaction of laser beams with matter far into the relativistic domain in which extremely high electric and magnetic fields are generated. Thanks to these tremendous fields, that only plasma can support and sustain, new and compact approaches for producing energetic particle beams have been recently achieved (for example the bubble regime and the colliding laser pulses scheme). The incredible progress of these laser-plasma accelerators has allowed physicists to produce high quality beams of energetic radiation and particles. These beams have interesting properties such as shortness, brightness and spatial quality, and could lend themselves to applications in many fields, including medicine (radiotherapy, proton therapy, imaging), radiation biology (short-time-scale), chemistry (radiolysis), physics and material science (radiography, electron and photon diffraction), security (material inspection), and of course accelerator science. Stimulated by the advent of compact and powerful lasers, with moderate costs and high repetition rate, this research field has witnessed considerable growth in the past few years, and the promises of laser-plasma accelerators are in tremendous progress. The recent years in particular have seen spectacular progress in the acceleration of electrons and of ions, both in terms of energy and in terms of quality of the beams. (authors)

  15. The use of low energy, ion induced nuclear reactions for proton radiotherapy applications

    Horn, K.M.; Doyle, B. [Sandia National Labs., Albuquerque, NM (United States); Segal, M.N. [Univ. of New Mexico Medical School, Albuquerque, NM (United States). Dept. of Otolaryngology; Hamm, R.W. [Accsys Technology Inc., Pleasanton, CA (United States); Adler, R.J. [North Star Research Corp., Albuquerque, NM (United States); Glatstein, E. [Univ. of Texas Southwest Medical Center, Dallas, TX (United States)

    1995-04-01

    Medical radiotherapy has traditionally relied upon the use of external photon beams and internally implanted radioisotopes as the chief means of irradiating tumors. However, advances in accelerator technology and the exploitation of novel means of producing radiation may provide useful alternatives to some current modes of medical radiation delivery with reduced total dose to surrounding healthy tissue, reduced expense, or increased treatment accessibility. This paper will briefly overview currently established modes of radiation therapy, techniques still considered experimental but in clinical use, innovative concepts under study that may enable new forms of treatment or enhance existing ones. The potential role of low energy, ion-induced nuclear reactions in radiotherapy applications is examined specifically for the 650 keV d({sup 3}He,p){sup 4}He nuclear reaction. This examination will describe the basic physics associated with this reaction`s production of 17.4 MeV protons and the processes used to fabricate the necessary materials used in the technique. Calculations of the delivered radiation dose, heat generation, and required exposure times are presented. Experimental data are also presented validating the dose calculations. The design of small, lower cost ion accelerators, as embodied in `nested`-tandem and radio frequency quadrupole accelerators is examined, as is the potential use of high-output {sup 3}He and deuterium ion sources. Finally, potential clinical applications are discussed in terms of the advantages and disadvantages of this technique with respect to current radiotherapy methods and equipment.

  16. The use of low energy, ion induced nuclear reactions for proton radiotherapy applications

    Medical radiotherapy has traditionally relied upon the use of external photon beams and internally implanted radioisotopes as the chief means of irradiating tumors. However, advances in accelerator technology and the exploitation of novel means of producing radiation may provide useful alternatives to some current modes of medical radiation delivery with reduced total dose to surrounding healthy tissue, reduced expense, or increased treatment accessibility. This paper will briefly overview currently established modes of radiation therapy, techniques still considered experimental but in clinical use, innovative concepts under study that may enable new forms of treatment or enhance existing ones. The potential role of low energy, ion-induced nuclear reactions in radiotherapy applications is examined specifically for the 650 keV d(3He,p)4He nuclear reaction. This examination will describe the basic physics associated with this reaction's production of 17.4 MeV protons and the processes used to fabricate the necessary materials used in the technique. Calculations of the delivered radiation dose, heat generation, and required exposure times are presented. Experimental data are also presented validating the dose calculations. The design of small, lower cost ion accelerators, as embodied in 'nested'-tandem and radio frequency quadrupole accelerators is examined, as is the potential use of high-output 3He and deuterium ion sources. Finally, potential clinical applications are discussed in terms of the advantages and disadvantages of this technique with respect to current radiotherapy methods and equipment

  17. The incidence of bladder cancer recurrences and metastases after radical radiotherapy

    The authors compare the incidence of bladder carcinoma recurrences and dissemination after long-distance gamma-beam therapy, carried out according to a traditional method, and in an accelerated hyperfractionation mode combined with metronidazole therapy. The recurrences were most frequently detected at the site of the primary tumor (62-67 % of cases) in 6 to 18 months after the treatment. They come to a conclusion that accelerated hyperfractionation and local metronidazole radiomodification were conductive to a reduction of the incidence of recurrences from 45 to 28 % as against the traditional split radiotherapy course in the classical fractionation mode

  18. Changes in serum and salivary amylase during radiotherapy for head and neck cancer; A comparison of conventionally fractionated radiotherapy with CHART

    Leslie, M.D.; Dische, S. (Mount Vernon Hospital, Northwood (United Kingdom))

    1992-05-01

    The changes in serum amylase that occur when radiotherapy is given in the treatment of head and neck cancer has been studied in 41 patients, 29 treated by CHART and 12 by conventionally fractionated radiotherapy. The peak rise in serum amylase following the start of treatment is seen earlier and is greater in the patients receiving continuous hyperfractionated accelerated radiotherapy (CHART). The serum amylase returns to normal earlier in the CHART patients so that the area under the curve is the same for both groups. The difference probably reflects the more rapid delivery of treatment to the patients receiving CHART. A close correlation between the peak rise in serum amylase and the amount of parotid tissue in the treatment volume is demonstrated. For six patients the total amount of amylase secreted by the parotid gland during CHART was measured and found to decline rapidly within a few days of the start of radiotherapy. The rise in serum amylase that results from the irradiation of salivary tissue provides a unique biochemical measure of an early radiation effect in a normal tissue. This probably reflects the interphase cell death of serous salivary cells. Although these immediate changes are of considerable interest they may not relate to the late effects of radiation on salivary gland function. (author). 13 refs.; 4 figs.

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

    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.

  20. Radiotherapy and Brachytherapy : Proceedings of the NATO Advanced Study Institute on Physics of Modern Radiotherapy & Brachytherapy

    Lemoigne, Yves

    2009-01-01

    This volume collects a series of lectures presented at the tenth ESI School held at Archamps (FR) in November 2007 and dedicated to radiotherapy and brachytherapy. The lectures focus on the multiple facets of radiotherapy in general, including external radiotherapy (often called teletherapy) as well as internal radiotherapy (called brachytherapy). Radiotherapy strategy and dose management as well as the decisive role of digital imaging in the associated clinical practice are developed in several articles. Grouped under the discipline of Conformal Radiotherapy (CRT), numerous modern techniques, from Multi-Leaf Collimators (MLC) to Intensity Modulated RadioTherapy (IMRT), are explained in detail. The importance of treatment planning based upon patient data from digital imaging (Computed Tomography) is also underlined. Finally, despite the quasi- totality of patients being presently treated with gamma and X-rays, novel powerful tools are emerging using proton and light ions (like carbon ions) beams, bound to bec...