[en] The reproducibility of 3-dimensional (3D) conformal therapy in localized prostate cancer was studied in 14 patients, based on retrospective analysis of 196 anteroposterior-posteroanterior (AP/PA) and lateral portal images. The patients were treated supine without rigid immobilization using six isocentric coplanar conformal fields. Three different observers independently compared the portal and simulation images, determining the deviation of each portal film from the corresponding simulation film. No significant deviations were observed in the cephalo-caudal or lateral axes (0 mm median values). However, a systematic median shift of 5 mm (0 to +10, range) was observed in the anteroposterior direction, presumably as a consequence of a sagging in the treatment couch under the patient's weight. After modification of the treatment couch, no further systematic anteroposterior shifts have been observed. These results demonstrate that the daily setup of conformal prostate irradiation fields can be performed with acceptable reproducibility without the use of special immobilization devices

[en] The treatment of large cerebral arteriovenous malformations is a surgical challenge, especially for deep seated brain locations. Furthermore, these lesions are unfit for radiosurgical approaches due to a high risk of complications secondary to high radiation doses to large brain volumes. Fractionated precision radiotherapy can potentially deliver high, uniform, target-contoured dose distributions optimizing the dose reduction to the critical surrounding brain. The results of a study are presented in such a way that dose distributions achievable with proton beams are compared to those with 10 MV x-rays; and the potential improvements with protons evaluated, relying heavily on dose-volume histograms to examine the coverage of the lesion as well as the dose to the normal brain, brain-stem, and optic chiasm

[en] Short communication

[en] Purpose: To evaluate the influence of different shielding conditions and field geometry on the scatter dose to the remaining testicle during postoperative radiotherapy (RT) in seminoma.Materials and methods: Testicular dose measurements were made with LiF thermoluminescent dosimeters (TLD) in 29 patients with stage I and IIA seminoma. The target volume consisted of para-aortic (PA) and para-aortic and homolateral iliac (PAI) lymph nodes in 14 and 15 patients, respectively. All patients had a scrotal shield as well as an additional block extending 7 cm inferiorly from the caudal field edge to shield the testicle from external scatter and collimator leakage. Doses with and without testicular blocks were measured for all patients. In seven patients treated exclusively to the PA region the gonadal dose was assessed according to four different shielding conditions: without any protection, with a gonadal shield alone, with the addition of an inferior field border block to the gonadal shield, and with the field border block alone.Results: For patients treated with PAI fields the mean testicular doses per fraction were 3.89 cGy (S.D.±1.44) and 1.48 cGy (S.D.±0.51) without and with gonadal shielding, respectively (P-value <0.001); the corresponding values for PA fields were 1.86 cGy (S.D.±0.86) and 0.65 cGy (S.D.±0.35). For the patients treated to the PA region and assessed according to the four different shielding conditions, the additional external block to the testicular shield did not reduce significantly the measured dose on the testis.Conclusions: These results suggest a benefit of gonadal shielding even in seminoma patients undergoing radiotherapy limited to the para-aortic region. (Copyright (c) Elsevier Science B.V., Amsterdam. All rights reserved.)

[en] A prospective trial was performed to better assess the risk of nausea and vomiting and the rescue value of tropisetron (TRO), a 5-HT₃ receptor antagonist, in 88 patients undergoing fractionated radiotherapy to the abdomen or to large supradiaphragmatic fields and failing a first anti-emetic trial with metoclopramide (MET). Nausea was graded 0 (absent), 1 (mild), 2 (moderate) and 3 (severe). Nausea requiring anti-emetics (≥ grade 2) was present in 64% of the patients. MET was able to control nausea (≤ grade 1) in 26 of 58 patients (45%) who developed ≥ grade 2 nausea during radiation treatment (2 patients vomiting without nausea included). 34 patients required TRO, and 31 experienced immediate relief. However, nausea (≥ grade 2) recurred in 7 patients from 1 to 3 weeks after starting TRO. Sex, age, field type and field size (cm²) did not influence the incidence and severity of nausea and vomiting. Only 24/88 patients vomited after starting radiotherapy. MET helped to eliminate emesis in one third of these patients. TRO helped to control vomiting in 73% of the salvaged patients. Constipation was observed in 8 patients on TRO and was a reason to stop the medication in 4 cases. (author)

[en] Purpose: In this study factors are analyzed that may potentially influence the site of failure in medulloblastoma children. Patient, disease, and treatment related variables are analyzed with a special focus on radiotherapy (RT) time-dose and technical factors. Methods and Materials: Eighty-six children and adolescents with a diagnosis of medulloblastoma were treated in Switzerland during the period 1972-1991. Postoperative megavoltage RT was delivered to all patients. Simulation and portal films of the whole brain irradiation (WBI) fields were retrospectively reviewed in 77 patients. The distance from the field margin to the cribiform plate and to the floor of the temporal fossa were carefully assessed and correlated with supratentorial failure-free survival. Fields were considered acceptable if the portal limits surrounded the basal portion of the brain with at least 5 mm margin for x-rays and 10 mm margin for Co-60. A marginal miss was concluded if the margins were 1-4 mm for x-rays or 4-9 mm for Co-60, while a major miss was considered to exist if the margins were ≤0 mm (field limit inside the target) for x-rays, or ≤3 mm for Co-60. The above mentioned limits were chosen on the assumption that the field margins associated with a marginal miss and with a major miss would underdose the excessively shielded regions by at least 25-50% and 50-75%, respectively. The correctness of the field margins around the convexity was also assessed. Field limits inside the brain convexity were considered unacceptable. In 19 children the spine was treated with high-energy electron beams the reminder with megavoltage photons. Simulation and port films of the posterior fossa fields were also reviewed in 72 patients. The surface of the treatment region was calculated to evaluate the potential relationship between field size and posterior fossa failure. The median field size was 72 cm² (40-234, range). In addition to field size, a technique was judged to be acceptable only if the anterior field limit reached the posterior clinoids and the inferior limit included C1 (first cervical vertebra). The field size and the field limits were evaluated and correlated with posterior fossa failure-free survival. Results: Five- and 10-year overall survival was 57% and 39%, respectively. The median follow-up for the surviving patients was 8.6 years (3.1-16.8, range). Forty-nine patients failed either locally or distantly. Twenty-four patients failed in the posterior fossa with or without distant failure. Twelve patients failed in the supratentorial region only. The lower portion of the frontal and/or temporal lobes was the site of failure in 8 cases. The supratentorial irradiation technique was considered acceptable in 13 patients (17%). A marginal miss was concluded in 28 patients (36%), while a major miss was observed in 36 patients (47%). Twelve patients failed in the supratentorial region and 9 of these patients belonged to the group of 36 children in whom the inferior portion of the brain had been clearly underdosed. On multivariate analysis only base of skull field correctness was retained as being significantly correlated with supratentorial failure-free survival (p=0.049). Fields were judged too tight around the convexity (i.e., field limits inside the brain convexity) in 7 patients (5 with an additional major miss of the base of skull). None recurred in the supratentorium. Neither the total dose to the spinal theca nor the treatment technique (electron versus photon beams) were significantly correlated with outcome. Posterior fossa failure-free survival was not influenced by total dose, overall treatment time, field size, or field margin correctness. Conclusion: A correlation between WBI field correctness and supratentorial failure-free survival was observed. Underdosage of the basal brain portion was a frequent event among the patients in this series. This, and a gravity-related sanctuary effect may explain why the meningeal region close to the base of skull (in addition to the ventricles) is at higher risk for relapse. Treating the spine with electron beams was not deletereous. A significant correlation between local control and other technical factors was not observed, including those relating to posterior fossa treatment

[en] An attempt to retrospectively quantify the risk of acute toxicity (peak scores) with field size was undertaken in 286 patients irradiated for unresected head and neck tumors with or without chemotherapy, and with or without accelerated radiotherapy between 1979 and 1990. A Grade-3 to -4 acute toxicity score (RTOG) and >5% weight loss were chosen as endpoints. For Grade-3 to -4 toxicity, the risk increased from 0.06 for 5x5 cm² to 0.68 for 17x17 cm² fields and conventional radiotherapy, and from 0.33 for 5x5 cm² to 0.94 for 17x17 cm² and multiple daily fractionation. For >5% weight loss, the risk ranged from 0.07 for 5x5 cm² to 0.94 for 17x17 cm² fields. The size of the cervical fields receiving the first 50 Gy was an indicator for severe acute toxicity and weight loss. Taking these data into account may help to improve preventive and treatment measures. (orig.)

[en] The objective of the study is to evaluate the feasibility and the dosimetry contribution of an intensity modulated radiotherapy (I.M.R.T.) using a simple two beams technique, compared to a seven beams technique, in the unilateral irradiation to cure cancers of the ear-nose-throat area. Compared to multiple beams I.M.R.T., the two beams I.M.R.T. is a simple method giving an excellent coverage of target volumes and an optimal preservation of organs at risk and allowing to reduce the complete dose and the treatment time. (N.C.)

[en] Total body irradiation (T.B.I.) has an established role as preparative regimen for bone-marrow transplantation in the treatment of hematological malignancies. Many randomized trials demonstrated that the clinical outcomes obtained from the association of T.B.I. and cyclophosphamide are equivalent, or, sometimes, better than those based on chemotherapeutic agents. Despite the therapeutic progress of the last years, and the consequent improvement in the overall survival, this preparative regimen remains always associated with a relatively high rate of acute and late toxicity. In this article, we review the actual indications of T.B.I. in clinical practice, and analyze the technological progress in this domain. We focus on the hypothesis that a selective irradiation of the hematopoietic or lymphoid organs is actually possible with intensity-modulated radiotherapy. Technical limits and preliminary results in terms of acute and late toxicities of intensity-modulated T.B.I. are analyzed. With these new technologies, treatment-related toxicity is not anymore a major limiting factor in the preparative regimens for bone-marrow transplantation, allowing for a larger spectrum of T.B.I. indications, a possible extension to patients older than 50 years, or a dose escalation. Preliminary results warrant, however, further evaluation in clinical trials to better assess the impact of this new approach on disease control and the long-term toxicity. (authors)

[en] Aim of the present study was to evaluate the usefulness of 11C-choline PET/CT for detecting lymphatic or haematogenous spread and for planning radiotherapy in patients with medium-to-high risk prostate cancer. We have included 61 consecutive patients recently diagnosed with cancer prostate by biopsy. All patients were classified as medium-to-high risk: Gleason: 7-9; PSA: 6.3-30.4 ng/mL; stage T2c (N.=20) or stage T3 (N.=41). Image acquisition began 5 min after intravenous injection of 11C-choline (656+119 MBq), starting at the pelvis and continuing craniocaudally. Images were interpreted visually to evaluate uptake by the prostate gland. Lymph nodes with 11C-choline uptake were considered invaded, regardless of their size. Bone lesions were considered positive when they showed greater focal uptake than the surrounding bone. In patients with evidence of lymph-node invasion or bone metastases (15 patients), disease was classified as locoregional, oligo metastatic, or multi metastatic. All patients had prostate gland uptake (20 focal, 8 bifocal, and 33 multifocal). Extra prostatic disease was present in 15 patients (24.6%), as follows: 9 (60%) in a single location: in an infra diaphragmatic lymph node (N.=6), in a supra diaphragmatic lymph node (N.=1), and in bone (M1) (N.=2). Six (40%) as multifocal invasion: with both infra- and supra diaphragmatic lymph node involvement (N.=2); with infra diaphragmatic lymph node involvement and M1 bone metastases (N.=3); and infra- and supra diaphragmatic lymph node involvement plus M1 bone metastases (N.=1). Disease was classified as locoregional (N.=6), oligo metastatic (N.=5), and multi metastatic (N.=4). The 11 (73.3%) patients with locoregional and oligo metastatic disease were selected to undergo intensity-modulated radiation therapy with dose escalation based on the PET findings. Our results suggest that 11C-choline PET/CT is a useful one-stop diagnostic procedure for evaluating patients with medium/high risk prostate cancer scheduled for radical treatment. 11C-choline PET/CT can reliably rule out lymph node involvement and remote metastases, allowing to select candidates for radiotherapy and to plan their treatment.