Automatic genetic planning for volumetric modulated arc therapy: A large multi-centre validation for prostate cancer.

PURPOSE: The first clinical genetic autoplanning algorithm (Genetic Planning Solution, GPS) was validated in ten radiotherapy centres for prostate cancer VMAT by comparison with manual planning (Manual). METHODS: Although there were large differences among centres in planning protocol, GPS was tuned with the data of a single centre and then applied everywhere without any centre-specific fine-tuning. For each centre, ten Manual plans were compared with autoGPS plans, considering dosimetric plan parameters and the Clinical Blind Score (CBS) resulting from blind clinician plan comparisons. AutoGPS plans were used as is, i.e. there was no patient-specific fine-tuning. RESULTS: For nine centres, all ten plans were clinically acceptable. In the remaining centre, only one plan was acceptable. For the 91% acceptable plans, differences between Manual and AutoGPS in target coverage were negligible. OAR doses were significantly lower in AutoGPS plans (p < 0.05); rectum D15% and Dmean were reduced by 8.1% and 17.9%, bladder D25% and Dmean by 5.9% and 10.3%. According to clinicians, 69% of the acceptable AutoGPS plans were superior to the corresponding Manual plan. In case of preferred Manual plans (31%), perceived advantages compared to autoGPS were minor. QA measurements demonstrated that autoGPS plans were deliverable. A quick configuration adjustment in the centre with unacceptable plans rendered 100% of plans acceptable. CONCLUSION: A novel, clinically applied genetic autoplanning algorithm was validated in 10 centres for in total 100 prostate cancer patients. High quality plans could be generated at different centres without centre-specific algorithm tuning.

Low dose rate brachytherapy (LDR-BT) as monotherapy for early stage prostate cancer in Italy: practice and outcome analysis in a series of 2237 patients from 11 institutions.

OBJECTIVE: Low-dose-rate brachytherapy (LDR-BT) in localized prostate cancer is available since 15 years in Italy. We realized the first national multicentre and multidisciplinary data collection to evaluate LDR-BT practice, given as monotherapy, and outcome in terms of biochemical failure. METHODS: Between May 1998 and December 2011, 2237 patients with early-stage prostate cancer from 11 Italian community and academic hospitals were treated with iodine-125 ((125)I) or palladium-103 LDR-BT as monotherapy and followed up for at least 2 years. (125)I seeds were implanted in 97.7% of the patients: the mean dose received by 90% of target volume was 145 Gy; the mean target volume receiving 100% of prescribed dose (V100) was 91.1%. Biochemical failure-free survival (BFFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method. Log-rank test and multivariable Cox regression were used to evaluate the relationship of covariates with outcomes. RESULTS: Median follow-up time was 65 months. 5- and 7-year DSS, OS and BFFS were 99 and 98%, 94 and 89%, and 92 and 88%, respectively. At multivariate analysis, the National Comprehensive Cancer Network score (p < 0.0001) and V100 (p = 0.09) were correlated with BFFS, with V100 effect significantly different between patients at low risk and those at intermediate/high risk (p = 0.04). Short follow-up and lack of toxicity data represent the main limitations for a global evaluation of LDR-BT. CONCLUSION: This first multicentre Italian report confirms LDR-BT as an excellent curative modality for low-/intermediate-risk prostate cancer. ADVANCES IN KNOWLEDGE: Multidisciplinary teams may help to select adequately patients to be treated with brachytherapy, with a direct impact on the implant quality and, possibly, on outcome.

Twenty years of radiobiology in clinical practice: the Italian contribution.

AIMS AND BACKGROUND: To present the Italian state-of-the-art contribution to radiobiology of external beam radiotherapy, brachytherapy, and radionuclide radiotherapy. METHODS AND STUDY DESIGN: A survey of the literature was carried out, using PubMed, by some independent researchers of the Italian group of radiobiology. Each paper was reviewed by researchers of centers not comprising its authors. The survey was limited to papers in English published over the last 20 years, written by Italian investigators or in Italian institutions, excluding review articles. RESULTS: A total of 135 papers have been published in journals with an impact factor, with an increase in the number of published papers over time, for external beam radiotherapy rather than radionuclide radiotherapy. The quantity and quality of the papers researched constitutes a proof of the enduring interest in clinical radiobiology among Italian investigators. CONCLUSIONS: The survey could be useful to individuate expert partners for an Italian network on clinical radiobiology, addressing future collaborative investigations.

Preoperative radiation treatment for rectal cancer: comparison of target coverage and small bowel NTCP in conventional vs. 3D-conformal planning.

A prospective study was undertaken to evaluate the improvement in rectal cancer radiation treatment achieved with the implementation of target delineation for conformal radiotherapy, replacing conventional technique using standard radiological anatomy for target volume definition. In 10 patients receiving preoperative pelvic irradiation for rectal cancer, a 3-field technique was designed by a 3-dimensional (3D) planning system. Two plans were simulated for each patient, one with the fields designed in the conventional way based on radiological anatomy, and the other with the fields designed on the basis of a computed tomography (CT) delineated planning target volume (PTV). A total dose of 45 Gy in 25-daily fractions of 1.8 Gy in 5 weeks was planned. Dose-volume histograms (DVHs) of PTV, small bowel, anal sphincter, and urinary bladder were analyzed to compare plans. The minimum, maximum, and mean dose in the PTV and in critical organs were also evaluated. The inhomogeneity coefficient (IC) and the target coverage (TC) were calculated. The normal tissue complication probability (NTCP) for each organ at risk (OAR) was determined. NTCP for small bowel and urinary bladder was not statistically different, while the PTV coverage was significantly lower with conventional treatment relative to conformal treatment (median IC=7.2, median TC=0.91 vs. median IC=0.14 and median TC=1, p<0.005). The 3D conformal treatment plan in preoperative radiotherapy for rectal cancer improves target coverage without significantly affecting small bowel and urinary bladder NTCP.