Re-irradiation using Permanent Interstitial Brachytherapy (PIB) : A Potentially Durable Technique for Salvaging Recurrent Pelvic Malignancies
Menée auprès de 42 patientes atteintes d'une tumeur pelvienne récidivante (durée médiane de suivi : 16,3 mois), cette étude évalue la faisabilité d'une curiethérapie interstitielle permanente, en combinaison ou non avec une radiothérapie de courte durée, dans le cadre d'un traitement de sauvetage
Purpose : Women who develop recurrence of malignancy in a previously irradiated pelvis are often considered incurable. Permanent interstitial brachytherapy (PIB) is an under-utilized but well-tolerated and safe treatment option with significant curative potential when utilized in well-selected patients. Materials and methods : Forty-two previously irradiated patients received curative or palliative intent PIB for a recurrent pelvic malignancy between January 2009 and August 2016. Minimum follow-up was 6 months following the PIB procedure. All patients had a biopsy-proven recurrence and were treated using PIB alone (n=32) or in combination with a short course of additional radiation therapy (n=10). Competing risk analyses were performed to assess the risk of failures in the presence of death without failure. Exploratory analyses were performed for factors related to failure using competing risk analyses and the Gray statistic. Results : A total of 61 PIB implants were performed among 42 patients with a median follow up of 16.3 months. Fifty-two implants were performed as the first salvage re-irradiation to a solitary recurrence (8 patients had more than one lesion), and the success rate for initial re-irradiation using PIB was 73% (38 cases out of 52), and the median TTF was not reached. Nine patients underwent a second repeat PIB to the same recurrence as a form of salvage – 3 (33%) remain without evidence of recurrence. The median TTF after second salvage was 7.7 months. Even with the limited sample size, prolonged TTF was marginally associated with definitive intent (p=0.07) and the extent of disease at the time of PIB (p=0.08). Grade 3+ toxicities were seen in 8 patients (16.7%). Conclusions : Permanent interstitial brachytherapy is a feasible and potentially durable treatment modality that can be used to curatively salvage selected recurrent pelvic malignancies in a previously irradiated field.