A Phase II Study of Salvage High-Dose-Rate Brachytherapy for the Treatment of Locally Recurrent Prostate Cancer after Definitive External Beam Radiotherapy

Abstract

PURPOSE-We report the toxicity and biochemical tumor control outcome of a prospective Phase II study using high-dose-rate brachytherapy (HDR) alone as a salvage therapy for recurrent disease after external beam radiotherapy (EBRT).METHODS-Forty-two patients with biopsy-proven recurrence were enrolled on a Phase II study of salvage HDR monotherapy using iridium-192. Median pretreatment EBRT dose was 8100 cGy (6840-8640 cGy) and the median time from completion of EBRT to salvage HDR was 73 months. The protocol prescription dose of 3200 cGy was delivered in four fractions over 30 hours in a single insertion. Median followup after salvage HDR was 36 months (6-67 months). RESULTS-The actuarial prostate-specific antigen biochemical relapse-free survival and distant metastases-free survival rates at 5 years were 68.5% and 81.5%, respectively. Cause-specific survival was 90.3%. Late genitourinary Grade 1and 2 toxicities were found in 38% and 48%, respectively, and one patient developed Grade 3 urinary incontinence. Late Grade 1 and 2 gastrointestinal toxicity was noted in 17% and 8% of patients, respectively. Three patients (7%) developed Grade 2 late urinary toxicity (urethral stricture), which were corrected with urethral dilatation, and one patient developed Grade 3 urinary incontinence. No Grade 4 toxicities were observed.CONCLUSIONS-Genitourinary toxicity was the most commonly encountered toxicity observed after salvage HDR but severe toxicities were uncommon. Salvage HDR is an effective and welltolerated modality for locally recurrent prostate cancer and should be considered even for patients who have previously been treated with ultra-high dose levels of EBRT.Open access under CC BY-NC-ND license.

High-dose-rate stereotactic body radiation therapy for postradiation therapy locally recurrent prostatic carcinoma: Preliminary prostate-specific antigen response, disease-free survival, and toxicity assessment

“…Excluding that case, and hence limiting the series only to the salvage of local failures after external beam RT, the grade 3 and higher GU toxicity rate shrinks to a rate of 4%-an incidence that compares favorably with the 2% to 16% incidence of ≥ grade 3 GU complications reported with HDR brachytherapy monotherapy in de novo and local recurrence prostate cancer cases. 14,15,17,29 This same adverse result was also reported in 1 HDR salvage series; 2 of 2 of the previous seed failure cases in that series developed incontinence with urethral necrosis. 16 In contradistinction, the University of California San Francisco group did not report any high-grade toxicity in patients with local failure after prior permanent source brachytherapy (both LDR and HDR salvage brachytherapy techniques were used in that series), so this specific topic remains unsettled but is still of a potential cautionary stance.…”

“…[10][11][12][13] Finally, high-dose-rate (HDR) brachytherapy has been used with reasonable intermediate-term success and a low reported incidence of serious complications. [14][15][16][17] Unfortunately, HDR prostate brachytherapy is an invasive and specialized procedure and, as such, is not widely used.…”

Retreatment for Local Recurrence of Prostatic Carcinoma After Prior Therapeutic Irradiation: Efficacy and Toxicity of HDR-Like SBRT

“…The 60% 5-year bRFS in this series is within the 45% to 78% range of reported 5-year salvage brachytherapy results. 12,[15][16][17][18][27][28][29][30][31][32][33] As previously described in great detail, the dose morphology in this protocol was designed to replicate that of HDR brachytherapy such that brachytherapy equivalence is expected and reasonably demonstrated herein. 19 We also report a biochemical relapse-free efficacy rate that appears at least comparable to that reported with salvage radical prostatectomy (RP); 60% 5-year bRFS in the present series versus 57% 3-year bRFS in a contemporary salvage RP series of similar size and similar median follow-up.…”

“…14 Lastly, high dose-rate (HDR) brachytherapy appears effective, although primarily performed at a few high volume tertiary centers and thus not widely available or practiced. [15][16][17][18] One institute with experience in LDR and HDR techniques reported a lower incidence of severe peak urinary symptoms with HDR brachytherapy, although recovery was typically seen by 3 years with both modalities. 18 Prostate stereotactic body radiation therapy (SBRT) is a more contemporary method, which may be made to effectively recapitulate "HDR-like" dose morphology, with the advantage of being noninvasive and increasingly available.…”

Reirradiation of Prostate Cancer Local Failures After Previous Curative Radiation Therapy: Long-Term Outcome and Tolerance

“…Most of the available data on reirradiation stem from retrospective studies using brachytherapy (BT) techniques (2)(3)(4)(5) owing to its optimal conformity and good rectal sparing. Preliminary results with salvage stereotactic body irradiation (SBRT) have been reported (6,7), although long-term data after salvage SBRT are lacking.…”