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OBJECTIVE To analyse relapse patterns, toxicity and second malignancy in patients with stage I pure germ cell testicular tumours, treated in 1970–1999. PATIENTS AND METHODS In all, 487 patients received irradiation after surgery to the infra- (407, 83.5%) or infra- and supra-diaphragmatic volumes (80, 16.5%). Treatment-related toxicity was classified according to previous criteria and fertility investigated in 246 men. Second malignancies were identified by retrospective analysis of clinical records or telephone interviews in men who no longer needed a long-term follow-up. RESULTS The 10-year overall survival was 97% (98% and 96%, respectively, for the aortic nodes only, or aortic and iliac nodes, i.e. the ‘dog leg’ field) and disease-free survival was 94%. Twenty-one patients relapsed (five with a true ‘in-field’ recurrence, nine progressed to the mediastinum, and seven had disseminated disease). Acute toxicity was mainly gastrointestinal, with 7.6% classified as grade II. In all, 73 men achieved paternity after irradiation; nine did not but had normal sperm. Second malignancies were diagnosed in 16 (3.3%) men. CONCLUSION Para-aortic irradiation may be used safely in patients with stage I seminoma and undisturbed testicular drainage, with equivalent results to the ‘dog-leg’ group; these unrandomized data confirm the lower toxicity and equivalent survival rates of this treatment.

Purpose: To investigate the dosimetric properties of synthetic single crystal diamond based Schottky diodes under irradiation with therapeutic electron beams from linear accelerators. Methods: A single crystal diamond detector was fabricated and tested under 6, 8, 10, 12, and 15 MeV electron beams. The detector performances were evaluated using three types of commercial detectors as reference dosimeters: an Advanced Markus plane parallel ionization chamber, a Semiflex cylindrical ionization chamber, and a p-type silicon detector. Preirradiation, linearity with dose, dose rate dependence, output factors, lateral field profiles, and percentage depth dose profiles were investigated and discussed. Results: During preirradiation the diamond detector signal shows a weak decrease within 0.7% with respect to the plateau value and a final signal stability of 0.1% (1σ) is observed after about 5 Gy. A good linear behavior of the detector response as a function of the delivered dose is observed with deviations below ±0.3% in the dose range from 0.02 to 10 Gy. In addition, the detector response is dose rate independent, with deviations below 0.3% in the investigated dose rate range from 0.17 to 5.45 Gy/min. Percentage depth dose curves obtained from the diamond detector are in good agreement with the ones from the reference dosimeters. Lateral beam profile measurements show an overall good agreement among detectors, taking into account their respective geometrical features. The spatial resolution of solid state detectors is confirmed to be better than that of ionization chambers, being the one from the diamond detector comparable to that of the silicon diode. A good agreement within experimental uncertainties was also found in terms of output factor measurements between the diamond detector and reference dosimeters. Conclusions: The observed dosimetric properties indicate that the tested diamond detector is a suitable candidate for clinical electron beam dosimetry. © 2013 American Association of Physicists in Medicine .[ http://dx.doi.org/10.1118/1.4774360]