Dose escalation with high-dose 3D-conformal radiotherapy (HD-3D-CRT) or low-dose 3D-conformal radiotherapy plus HDR brachytherapy (LD-3D-CRT+HDR-B) for intermediate- or high-risk prostate cancer: Higher PSA control with lower toxicity.

Abstract

82 Background: To report early and late toxicity and preliminary biochemical outcome in in a prospective serie of 445 patients with intermediate- or high-risk clinically localized prostate cancer treated with either HD-3D-CRT or with LD-3D-CRT+HDR-B. Methods: Between 12/1999 and 10/2005, 445 patients (pts) with PSA >10, Gleason score > 6 and/or T2b-T3 N0 M0 prostate cancer entered the study. Pts were prospevtively assigned to one of the two treatment groups: 76 Gy HD-3D-CRT to the prostate in 38 fractions (group 1; 223 patients) or 46 Gy LD-3D-CRT+ 16 Gy HDR-B given in 2 fractions of 8 Gy (group 2, 222 patients), limiting the maximum rectal dose to 85% of the prescribed dose. Both groups were well balanced taking into account patient’s as well as tumors’ characteristics. Toxicities were scored by the EORTC /RTOG morbidity grading scales. Special attention to local, regional or distant recurrence, survival, late effects, PSA and testosterone levels and quality of life was done. Results: All pts completed treatment. None pts included in the group 1 or 2 experienced grade 3 rectal toxicity. 28 pts of group 1 (12.5%) and 6 pts of group 2 (2.7%) developed grade 2 rectal toxicity (rectal bleeding or urgency). 15 pts in group 1 (6.7%) and 3 pts in group 2 (1.3%) developed grade 1 rectal bleeding (less than 2 times/week). In group 1 and 2, 81.8%and 95,9% of pts were free from rectal reactions respectively (p<0.005). Free from failure survival at 5-year was 82.3% and 98.1% respectively (p<0.05) Conclusions: High-dose 3D-EBRT + HDR brachytherapy was a safe and effective method of escalating the dose to the prostate without increasing the risk of late effects. Acute as well as late rectal complications were significantly reduced with the combined treatment, compared with what was observed with high-dose conventional, 3D-conformal radiotherapy. Short-term PSA control rates tends to be better with in the HDR-boosted patients as spected by higher effective dose. No significant financial relationships to disclose.

The effectiveness and side effects of conformal external beam radiotherapy combined with high-dose-rate brachytherapy boost compared to conformal external beam radiotherapy alone in patients with prostate cancer

“…However, we noted that the total dose applied in EBRT alone schedule [ 10 , 11 , 14 - 16 ] was lower (66–70 Gy) than recommended by the current guidelines. The adequate dose of 76 Gy in EBRT alone group was applied only in the study by Guix et al [ 12 , 13 ] (Table 4 ).…”

“…According to the published studies, acute GU reactions were more intense in the combined scheme groups [ 8 , 14 , 16 ]. By contrast, late GI reactions more often appeared in EBRT alone groups [ 12 , 13 ]. Late GU side effects were comparable in both groups [ 10 - 13 , 15 ].…”