Persistently better treatment planning results of intensity-modulated (IMRT) over conformal radiotherapy (3D-CRT) in prostate cancer patients with significant variation of clinical target volume and/or organs-at-risk.

PURPOSE: To compare the dose coverage of planning and clinical target volume (PTV, CTV), and organs-at-risk (OAR) between intensity-modulated (3D-IMRT) and conventional conformal radiotherapy (3D-CRT) before and after internal organ variation in prostate cancer. METHODS AND MATERIALS: We selected 10 patients with clinically significant interfraction volume changes. Patients were treated with 3D-IMRT to 80 Gy (minimum PTV dose of 76 Gy, excluding rectum). Fictitious, equivalent 3D-CRT plans (80 Gy at isocenter, with 95% isodose (76 Gy) coverage of PTV, with rectal blocking above 76 Gy) were generated using the same planning CT data set ("CT planning"). The plans were then also applied to a verification CT scan ("CT verify") obtained at a different moment. PTV, CTV, and OAR dose coverage were compared using non-parametric tests statistics for V95, V90 (% of the volume receiving 95 or 90% of the dose) and D50 (dose to 50% of the volume). RESULTS: Mean V95 of the PTV for "CT planning" was 94.3% (range, 88-99) vs 89.1% (range, 84-94.5) for 3D-IMRT and 3D-CRT (p=0.005), respectively. Mean V95 of the CTV for "CT verify" was 97% for both 3D-IMRT and 3D-CRT. Mean D50 of the rectum for "CT planning" was 26.8 Gy (range, 22-35) vs 43.5 Gy (range, 33.5-50.5) for 3D-IMRT and 3D-CRT (p=0.0002), respectively. For "CT verify", this D50 was 31.1 Gy (range, 16.5-44) vs 44.2 Gy (range, 34-55) for 3D-IMRT and 3D-CRT (p=0.006), respectively. V95 of the rectum was 0% for both plans for "CT planning", and 2.3% (3D-IMRT) vs 2.1% (3D-CRT) for "CT verify" (p=non-sig.). CONCLUSION: Dose coverage of the PTV and OAR was better with 3D-IMRT for each patient and remained so after internal volume changes.

Three Years of Salvage IMRT for Prostate Cancer: Results of the Montpellier Cancer Center.

Background. To assess the feasibility of salvage intensity-modulated radiation Therapy (IMRT) and to examine clinical outcome. Patients and Methods. 57 patients were treated with salvage IMRT to the prostate bed in our center from January, 2007, to February, 2010. The mean prescription dose was 68 Gy in 34 fractions. Forty-four patients received concomitant androgen deprivation. Results. Doses to organs at risk were low without altering target volume coverage. Salvage IMRT was feasible without any grade 3 or 4 acute gastrointestinal or urinary toxicity. With a median follow-up of 21 months, one grade 2 urinary and 1 grade ≥2 rectal late toxicities were reported. Biological relapse-free survival was 96.5% (2.3% (1/44) relapsed with androgen suppression and 7.7% (1/13) without). Conclusion. Salvage IMRT is feasible and results in low acute and chronic side-effects. Longer follow-up is warranted to draw conclusions in terms of oncologic control.

Is there a role for pelvic irradiation in localized prostate adenocarcinoma? Preliminary results of GETUG-01.

PURPOSE: To assess the benefit and toxicity and quality-of-life (QOL) outcomes of pelvic nodes irradiation in nonmetastatic prostate carcinoma patients. PATIENTS AND METHODS: Between December 1998 and June 2004, 444 patients with T1b-T3, N0 pNx, M0 prostate carcinoma were randomly assigned to either pelvic and prostate radiotherapy or prostate radiotherapy only. Patients were stratified according to the prognostic factor of lymph node involvement (LNI). Short-term 6-month neoadjuvant and concomitant hormonal therapy was allowed only for patients in the high-risk group. The pelvic dose was 46 Gy. The total dose recommended to the prostate was changed during the course of the study from 66 Gy to 70 Gy. Criteria for progression-free survival (PFS) included biologic prostate-specific antigen recurrences or a local or metastatic evolution. Acute and late toxicities were recorded according to the Radiation Therapy Oncology Group and Late Effects in Normal Tissues Subjective, Objective, Management, and Analytic scales, respectively. The QOL outcome was recorded with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30, the International Prostatic Symptom Score, and the Sexual Function Index scales. RESULTS: With a 42.1-month median follow-up time, the 5-year PFS and overall survival were similar in the two treatment arms for the whole series and for each stratified group. On multivariate analysis, low LNI risk and hormonal therapy were statistically associated with increased PFS. However, subgroup analyses based on these factors did not show any benefit for pelvic irradiation. There were no significant differences in acute and late digestive toxicities and in QOL outcomes. CONCLUSION: Pelvic node irradiation was well tolerated but did not improve PFS.