The therapeutic index of hyperfractionated radiotherapy is improved by concomitant cisplatin.

Background and Purpose:There is concern about the increase of radiation-induced malignancies with the application of modern radiation treatment techniques such as intensity-modulated radiotherapy (IMRT) and proton radiotherapy. Therefore, X-ray scatter and neutron radiation as well as the impact of the primary dose distribution on secondary cancer incidence are analyzed. Material and Methods: The organ equivalent dose (OED) concept with a linear-exponential and a plateau dose-response curve was applied to dose distributions of 30 patients who received radiation therapy of prostate cancer. Three-dimensional conformal radiotherapy was used in eleven patients, another eleven patients received IMRT with 6-MV photons, and eight patients were treated with spot-scanned protons. The treatment plans were recalculated with 15-MV and 18-MV photons. Secondary cancer risk was estimated based on the OED for the different treatment techniques. Results: A modest increase of 15% radiation-induced cancer results from IMRT using low energies (6 MV), compared to conventional four-field planning with 15-MV photons (plateau dose-response: 1%). The probability to develop a secondary cancer increases with IMRT of higher energies by 20% and 60% for 15 MV and 18 MV, respectively (plateau dose-response: 2% and 30%). The use of spot-scanned protons can reduce secondary cancer incidence as much as 50% (independent of dose-response). Conclusion: By including the primary dose distribution into the analysis of radiation-induced cancer incidence, the resulting increase in risk for secondary cancer using modern treatment techniques such as IMRT is not as dramatic as expected from earlier studies. By using 6-MV photons, only a moderate risk increase is expected. Spot-scanned protons are the treatment of choice in regard to secondary cancer incidence. um 60% für 18 MV an (2% bzw. 30% für eine Plateau-Dosis-Wirkungs-Beziehung). Verwendet man Protonentherapie ("spot-scanned") für die Behandlung, kann die Sekundärtumorinzidenz, unabhängig von der Dosis-Wirkungs-Beziehung, um 50% vermindert werden. Schlussfolgerung: Wird neben der Streu-und Neutronenstrahlung auch die primäre Dosisverteilung in die Analyse der Sekundärtumorinzidenz mit einbezogen, steigt das Risiko für einen Zweittumor beim Einsatz der IMRT nicht so dramatisch an, wie in früheren Studien vorhergesagt. Verwendet man ausschließlich 6-MV-Photonen für die IMRT, wird das Sekundärtumorrisiko nur leicht erhöht. Der Einsatz der Protonentherapie kann in Bezug auf die Entstehung von Zweittumoren gegenüber der Photonentherapie von Vorteil sein.Schlüsselwörter: Organäquivalentdosis · OED · Sekundärtumoren · Strahleninduzierter Krebs · IMRT · Protonentherapie

Purpose: A multi-centre study to assess the value of combined surgical resection and radiotherapy for the treatment of desmoid tumours. Patients and methods:One hundred and ten patients from several European countries qualified for this study. Pathology slides of all patients were reviewed by an independent pathologist. Sixty- eight patients received post-operative radiotherapy and 42 surgery only. Median follow-up was 6 years (1 to 44). The progression-free survival time (PFS) and prognostic factors were analysed. Results:The combined treatment with radiotherapy showed a significantly longer progressionfree survival than surgical resection alone (p smaller than 0.001). Extremities could be preserved in all patients treated with combined surgery and radiotherapy for tumours located in the limb, whereas amputation was necessary for 23% of patients treated with surgery alone. A comparison of PFS for tumour locations proved the abdominal wall to be a positive prognostic factor and a localization in the extremities to be a negative prognostic factor. Additional irradiation, a fraction size larger than or equal to 2 Gy and a total dose larger than 50 Gy to the tumour were found to be positive prognostic factors with a significantly lower risk for a recurrence in the univariate analysis. This analysis revealed radiotherapy at recurrence as a significantly worse prognostic factor compared with adjuvant radiotherapy. The addition of radiotherapy to the treatment concept was a positive prognostic factor in the multivariate analysis. Conclusion:Postoperative radiotherapy significantly improved the PFS compared to surgery alone. Therefore it should always be considered after a non-radical tumour resection and should be given preferably in an adjuvant setting. It is effective in limb preservation and for preserving the function of joints in situations where surgery alone would result in deficits, which is especially important in young patients.

Probabilities for secondary cancer incidence have been estimated for a patient with Hodgkin's disease for whom treatment has been planned with different radiation modalities using photons and protons. The ICRP calculation scheme has been used to calculate cancer incidence from dose distributions. For this purpose, target volumes as well as critical structures have been outlined in the CT set of a patient with Hodgkin's disease. Dose distributions have been calculated using conventional as well as intensity-modulated treatment techniques using photon and proton radiation. The cancer incidence has been derived from the mean doses for each organ. The results of this work are: (a) Intensity-modulated treatment of Hodgkin's disease using nine photon fields (15 MV) results in nearly the same cancer incidence as treating with two opposed photon fields (6 MV). (b) Intensity-modulated treatment using nine proton fields (maximum energy 177.25 MeV) results in nearly the same cancer incidence as treating with one proton field (160 MeV). (c) Irradiation with protons using the spot scanning technique decreases the avoidable cancer incidence compared to photon treatment by a factor of about two. This result is independent of the number of beams used. Our work suggests that there are radiotherapy indications in which intensity-modulated treatments will result in little or no reduction of cancer incidence compared to conventional treatments. However, proton treatment can result in a lower cancer incidence than photon treatment.

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The mean velocity of respiration-induced organ motion in cranio-caudal direction is of the same magnitude as the velocity of the moving jaw during a treatment with an enhanced dynamic wedge. Therefore, if organ motion is present during collimator movement, the resulting dose distribution in wedge direction may differ from that obtained for the static case, i.e., without organ motion. The position as a function of time of the moving jaw has been derived from a log-file generated during each treatment. Parameters for the respiratory cycle and information about respiration-induced motion for organs in the upper abdomen were taken from the literature. Both movements were superimposed and the resulting monitor unit distribution has been calculated in the intrinsic coordinate system of the organ. The deviations from the static case have been studied as a function of wedge angle, amplitude of organ motion, respiratory rate, asymmetry of the respiratory cycle, beam energy, and the dose rate. If an amplitude of 30 mm and a respiratory rate of 10 min(-1) are assumed, the maximum deviation in monitor units is 2.5% for a 10 degees wedge, 7% for a 30 degrees wedge, and 16% for a 60 degrees wedge. Furthermore, a dose distribution for an organ undergoing respiration-induced motion has been generated and we found dose deviations of the same magnitude as calculated with the monitor unit distribution.

Purpose Radiochemotherapy is the standard treatment for anal carcinoma (ACa). Intensity-modulated radiotherapy (IMRT) has been introduced, allowing focused irradiation of the tumor area. Whether physical benefits of IMRT translate to clinical benefits has not been sufficiently demonstrated. Methods We retrospectively reviewed data from 82 patients with newly diagnosed ACa. Patients treated with IMRT were compared with previous patients treated with conventional three-dimensional computational radiotherapy (3D-CRT). The influence of IMRT on complete remission and acute and chronic side effects was analyzed in univariate and multivariate analyses. Results 39/40 patients treated with IMRT were in complete remission after 1 year compared to 31/39 patients treated with 3D-CRT (p = 0.014). Multivariate analysis confirmed tumor T stage as well as lack of IMRT treatment as risk factors for persistent tumor at 6 months. No significant benefits of IMRT were apparent at later timepoints (median follow up 52 months, IQR: 31.5-71.8 months). Patients treated with IMRT had a significantly lower degree of skin toxicity (median 2 vs. 3 in a scale ranging from 0 to 3, p = 0.00092). Rates of hematological toxicity/proctitis were not reduced and rates of acute diarrhea increased (p = 0.034). Median length of hospitalization tended to be shorter in patients treated with IMRT (n. s.). ConclusionWe present a real-world experience of shifting radiation technique from conventional 3D-CRT to IMRT. IMRT patients had better tumor control at 1 year and lower degrees of skin toxicity. Our data indicate that IMRT can enable therapies with lower side effects with equal or better oncological results for patients with ACa.

We report on 3 females with breast cancer who developed morphea at the site of post-surgery radiotherapy. One was suffering from other autoimmune skin diseases before the diagnosis and treatment of breast cancer. Postirradiation morphea is a potential complication after radiotherapy, particularly radiotherapy for cancer. This troublesome skin disease can occur months to years after treatment, and is associated with remarkable morbidity and pain, and also cosmetic aspects. Therefore, it is crucial to be aware of this condition, and to try to identify patients who might be at an increased risk of developing morphea.