Salvage low-dose-rate brachytherapy for local recurrences after prostatectomy and adjuvant or salvage external beam irradiation: Feasibility study on five patients and literature review

Abstract

PURPOSE: To assess the feasibility and tumor outcome of re-irradiation with low-dose-rate brachytherapy for macroscopic local recurrences after radical prostatectomy (RP) followed by adjuvant or salvage external beam radiation therapy (EBRT). METHODS AND MATERIALS: Between 2011 and 2018, five men with histologically proven local failure within the prostate (4) or seminal vesicle bed (1) after RP and adjuvant or salvage EBRT (median dose: 67.5 Gy) underwent a salvage brachytherapy (S-BT). The median delay after EBRT was 86 months (range 75e234). Two patients were castration-resistant at the time of S-BT. The gross tumor volume was defined on a multiparametric MRI and transrectal US imaging. Echoguided transperineal implants of Iodine-125 seeds were optimized with a per-operative dosimetry and delivered with the seed-selectron. RESULTS: A high conformity was achieved with a high dose to the CTV (D 95% O 145 Gy in all but one) and very low dose to the rectum, urethra, and bladder. With a median followup of 21 months, all but one patient experienced nodes and/or bone metastases. Local control was achieved in 3/4 of evaluable patients (local failure distant to the treated volume in one). To date, no Grade 2 or more late toxicities were observed. CONCLUSION: For selected patients, focal local recurrence brachytherapy after PR and EBRT appears technically feasible and safe, but the efficacy remains uncertain as the majority of patients quickly relapsed at other sites. Large prospective studies are still required to better select patients who will benefit from this strategy.

Stereotactic Re-Irradiation for Local Recurrence after Radical Prostatectomy and Radiation Therapy: A Retrospective Multicenter Study

“…For instance, one study assessed the feasibility of salvage surgery, with a comparable median of biochemical recurrence-free survival of 23.7 months [29]. Another study reported the feasibility of brachytherapy with five patients, which is not enough to make conclusions on efficacy and safety [30].…”

REPAIR_GETUG P16 - Relapse in previously irradiated Prostate bed: a phase I/II study of stereotactic Ablative reirradiation potentiated by Metformine study protocol

“…With a median follow-up of 21 months, local control was achieved in 3/4 of evaluable patients. No grade 3 acute toxicity and Grade 2 or more late toxicities were observed (12).…”

“…Palliative androgen deprivation therapy (ADT) (continuous or intermittent) is the salvage treatment proposed in most cases (9,10). Curative strategies including surgery, brachytherapy, HIFU or cryotherapy are feasible, but lack a good level of evidence (11)(12)(13). More recently, salvage stereotactic prostate bed radiotherapy was shown to be feasible with acceptable toxicity and encouraging e cacy results in retrospective studies (5,14).…”

Salvage high-dose-rate interventional radiotherapy (brachytherapy) for locally relapsed prostate cancer after radical prostatectomy and subsequent external irradiation

“…In majority of patients, this method was used as a boost combined with EBRT, except for one recent study [9][10][11][12]. On the contrary, salvage low-dose-rate (LDR) seeds were mostly used without EBRT [13][14][15][16][17][18]. Following RP and EBRT as adjuvant or salvage treatment, it is challenging to choose a further local treatment.…”