Salvage prostate re-irradiation using high-dose-rate brachytherapy or focal stereotactic body radiotherapy for local recurrence after definitive radiation therapy

Abstract

BackgroundOptimal management of locally recurrent prostate cancer after definitive radiation therapy is still challenging. With the development of highly accurate radiotherapy devices, prostate salvage re-irradiation might generate lower toxicity rates than classical salvage therapies. We retrospectively evaluated the toxicity and the feasibility of a prostate re-irradiation after definitive radiation therapy failure. Two modalities were investigated: high-dose-rate brachytherapy (HDRB) on whole prostate gland and focal stereotactic radiotherapy (SBRT) using CyberKnife® linac.MethodsBetween 2011 and 2015, 28 patients with imaged and/or biopsy-proven intra-prostatic recurrence of cancer after definitive radiation therapy underwent a salvage re-irradiation using HDRB (n = 10) or focal SBRT (n = 18). The schedule of re-irradiation was 35 Gy in 5 fractions.Biological response (defined as post-salvage radiation PSA variation) and biochemical no-evidence of disease (bNED) were evaluated in the whole cohort. For patients who had a positive biological response after salvage radiation, biochemical recurrence (BCR) and survival after salvage radiotherapy were evaluated. Post-salvage toxicities were assessed according to the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 and were compared to baseline status.ResultsWithin a median follow-up of 22.5 months (IQR = 8–42), 9 (90%) patients experienced a positive biological response after salvage HDRB and 5 (50%) remained bNED at the end of the follow-up. Among patients who initially responded to salvage HDRB, the BCR rate was 44.4% after a median interval of 19.5 months (IQR = 11.5–26). Only one patient experienced a transient grade 3 urinary complication.In the SBRT group, the median follow-up was 14.5 months (IQR = 7–23) and 10 (55.6%) out of the 18 patients remained bNED. Among the 15 patients who initially responded to salvage SBRT, 5 (33.3%) experienced a BCR. One patient experienced a transient grade 4 urinary complication.At the end of the follow-up, all evaluated patients had a urinary status grade variation ≤ +1 grade. No grade 3–4 digestive toxicity was observed.ConclusionsSalvage prostate re-irradiation for locally recurrent cancer is feasible and generate low toxicities rates when using with HDRB or focal SBRT. However, further investigations are necessary to confirm these findings and to determine predictive features for patients who might benefit from such an approach.

Reirradiation for isolated local recurrence of prostate cancer: Mono-institutional series of 64 patients treated with salvage stereotactic body radiotherapy (SBRT)

“…Since toxicity our series was very low despite the inclusion of numerous patients with comorbidities, we do believe that BED >130 Gy should be considered in all patients undergoing salvage SBRT (re-EBRT). Higher doses were employed by some investigators15,17,20,21,23,24,26 still maintaining acceptable toxicity level and somehow higher tumor control when compared to our findings. We do believe that these somehow suboptimal tumor control might be explained both by inclusion of patients with aggressive disease (high PSA and Gleason score at the first diagnosis and at the diagnosis of recurrent cancer) and relatively low doses prescribed in our series.…”

“…The efficacy of salvage reirradiation for locally recurrent PCa has been evaluated by several investigations. [14][15][16][17][18][19][22][23][24][25][26][28][29][30][31][32][33][34] The first report on re-EBRT by Vavassori et al 15 including six cases treated by CyberKnife, showed the feasibility of reirradiation with an acceptable rate of acute and early chronic toxicity (median follow-up was 11.3 months). These preliminary findings were then confirmed by the successive series.…”

“…14,[16][17][18][19][28][29][30][31][32][33][34] All but one report concluded that salvage re-EBRT is safe. [14][15][16][17][18][19][20][21][23][24][25][26][27] Zilli et al 22 published the data of 14 patients treated with whole prostate reirradiation, with the median follow-up of 94 months, showing low acute but very high late GU and GI toxicity rates (29% of patients experienced combined Grade 4 GU/GI injury). Contrarily to the Zilli's series, we observed only 1 Grade 3 GU event among 20 males with follow-up >36 months.…”

“…7,12 As far as reirradiation is concerned, the vast majority of patient series were treated with brachytherapy (BRT). In the last years, along with the improvement in radiotherapy (RT) planning and delivery technology, several reports on salvage EBRT have been published [14][15][16][17][18][19][20][21][22][23][24][25][26][27] (Table 1).…”

Feasibility and safety of focal irreversible electroporation as salvage treatment for localized radio‐recurrent prostate cancer

“…In a recent systematic review on focal salvage therapy for radio‐recurrent PCa, the 5‐year biochemical disease‐free survival rate was 46.5–54.5% . Feasibility trials have been performed with HIFU, cryosurgery, iodine‐125 brachytherapy and HDR brachytherapy . For whole‐gland salvage HIFU and cryosurgery, biochemical failure occurred in 3–79% of patients, and rates of preserved urinary continence and potency ranged from 10% to 93% and 15% to 56%, respectively .…”