Bladder spatial-dose descriptors correlate with acute urinary toxicity after radiation therapy for prostate cancer.

PURPOSE: To assess bladder spatial-dose parameters predicting acute urinary toxicity after radiotherapy for prostate cancer (PCa) through a pixel-wise method for analysis of bladder dose-surface maps (DSMs). MATERIALS & METHODS: The final cohort of a multi-institutional study, consisting of 539 patients with PCa treated with conventionally (CONV:1.8-2Gy/fr) or moderately hypo-fractionated radiotherapy (HYPO:2.2-2.7Gy/fr) was considered. Urinary toxicity was evaluated through the International Prostate Symptoms Score (IPSS) administered before and after radiotherapy. IPSS increases ⩾10 and 15 points at the end of radiotherapy (ΔIPSS⩾10 and ΔIPSS⩾15) were chosen as endpoints. Average DSMs (corrected into 2Gy-equivalent doses) of patients with/without toxicity were compared through a pixel-wise method. This allowed the extraction of selected spatial descriptors discriminating between patients with/without toxicity. Previously logistic models based on dose-surface histograms (DSH) were considered and replaced with DSM descriptors. Discrimination power, calibration and log-likelihood were considered to evaluate the impact of the inclusion of spatial descriptors. RESULTS: Data of 375/539 patients were available. ΔIPSS⩾10 was recorded in 76/375 (20%) patients, while 30/375 (8%) experienced ΔIPSS⩾15. The posterior dose at 12mm from the bladder base (roughly corresponding to the trigone region) resulted significantly associated to toxicity in the whole/HYPO populations. The cranial extension of the 75Gy isodose along the bladder central axis was the best DSM-based predictor in CONV patients. Multi-variable models including DSM descriptors showed better discrimination (AUC=0.66-0.77) when compared to DSH-based models (AUC=0.58-0.71) and higher log-likelihoods. CONCLUSION: DSMs are correlated with the risk of acute GU toxicity. The incorporation of spatial descriptors improves discrimination and log-likelihood of multi-variable models including dosimetric and clinical parameters.

[High-dose-rate brachytherapy. The indications, technic and preliminary results]. / La brachiterapia ad alto rateo di dose. Indicazioni, tecnica e risultati preliminari.

The authors report their experience of high dose brachytherapy technique (HDR), relative to the first period of work, especially regarding treatment indications and preliminary clinical results. Twenty eight patients were examined, 12 of them with esophageal carcinoma, 7 biliary tract carcinoma, 6 skin of the face and 3 head and neck carcinoma. HDR brachytherapy was the first treatment in 20 cases; the other 8 cases were recurrences after previous irradiation. The HDR treatment had a curative purpose in 15 patients and was palliative in the other 13. Brachytherapy doses ranged from 20 to 30 Gy for curative treatments, with 4-8 fractions; 1 fraction was used for palliative radiotherapy, with doses from 5 to 10 Gy. The results were satisfactory. Local control was achieved in 5/6 patients affected with cholangiocarcinoma of the biliary tract and in 6/6 patients with skin neoplasia. In esophageal cancer, 9/12 patients treated with palliative, disobstructive purpose, showed dysphagia remission in 89% of the cases; the remission was maintained in 7 patients (78%), with 9 months median follow-up. HDR brachytherapy was then proved, during this first period of clinical application, as a valid and safe therapeutic method. It also allowed to extend the application field of brachytherapy, with new indications, as in esophageal neoplasias and biliary tract carcinomas.

[Prognostic factors in the treatment of carcinoma of the cervix uteri in IB-IIA stage. Retrospective study]. / Fattori prognostici nel trattamento del carcinoma del collo dell'utero negli stadi IB-IIA. Studio retrospettivo.

January, 1977, to December, 1990, 311 patients with stage IB-IIA cervix carcinoma were treated at the Radiotherapy Department of the University of Turin. The distribution by stage was: 232 T1b (74.6%) and 79 T2a (25.4%). One hundred and eighty-nine patients (77% T1b-23% T2a) underwent preoperative radiotherapy, 63 patients (58% T1b-42% T2a) radiotherapy alone and 59 (85% T1b-15% T2a) postoperative radiotherapy. The first group of patients was treated according to three treatment protocols, based on different surgical procedures. During the median follow-up period of 86 months (82.6% of the patients underwent a minimum 3-year follow-up), 55 locoregional relapses (17%) and 21 extrapelvic metastases (7%) were observed. The 5-year NED survival rate and local control was 80%. The prognostic factors which significantly influenced survival in the univariate analysis, were: disease stage (p < .01), age (p < .05), the period between first symptom and therapy (p = .01), treatment protocols (radiotherapy combined with surgery versus radiation therapy alone: p < .05), residual disease after brachytherapy (p < .01), nodal status (p < .00001). In the radiotherapy alone group, the total dose influence on survival was not statistically significant (p = .12). In our series, histology and surgical procedures did not seem to influence prognosis. In the multivariate analysis, treatment protocol, age and residual disease after brachytherapy did not influence the prognosis, whereas the total dose of radiotherapy, pain (as first symptom) and Wertheim-Meigs surgery approach are prognostic factors. Severe late-effects were 17: 13 in the radiotherapy plus surgery protocol and 4 in the radiotherapy alone protocol. The incidence of major complications seems to correlate with surgical impact.