Image-guided vulvovaginal interstitial brachytherapy in the treatment of primary and recurrent gynecological malignancies.

PURPOSE: Evaluation of interstitial high-dose-rate brachytherapy (HDRB) to the vulvovaginal region both alone and in combination with external beam radiotherapy (EBRT) for primary or recurrent gynecological malignancy. METHODS AND MATERIALS: From 1998 to 2009, 37 women with a mean age of 68 years were treated with transperineal interstitial HDRB. Fifteen patients (40.5%) were treated for primary disease, whereas 22 (59.5%) patients were treated for recurrent disease. Median time to local recurrence was 31 months (2-312 months). Primary sites included endometrium (12), vulva (11), vagina (10), vulvovagina (1), cervix (1), and bladder (2). Thirty-one patients (83.7%) in this series were treated with radical intent, whereas 6 (16.3%) were treated with palliative intent. Radically treated patients received between 45 and 60Gy (median, 45Gy) of EBRT. The median number of days from EBRT to HDR boost was 5 days (1-35 days). The HDRB doses ranged from 11Gy in two fractions to 42Gy in six fractions (dose per fraction varied from 4 to 8.5Gy) and fractions were given at least 6-8h apart.
RESULTS: Eight of the 31 patients (26%) treated with radical intent relapsed locally. Eleven of 37 patients (30%) treated with either radical or palliative intent recurred locally. The 2- and 5-year local progression-free survival was 74% and 63.4%, respectively. The total progression-free survival, which includes local, locoregional/nodal, and distant recurrence, at 2 and 5 years, was 73.6% and 45.6%, respectively. With a mean follow-up of 27 months (3.8-111.9 months), the median survival for the patient group was 16.6 months with a 2- and 5-year overall survival of 47.7% and 36.4%, respectively. Acute Grade 3 toxicity was seen in 13 (35%) of the 37 patients (skin: 10, urinary: 2, genital: 2, gastrointestinal: 0). No acute Grade 4 toxicities were seen. A total of 10 of the 37 patients (27%) developed late Grade 3 toxicities. Five of the 22 patients (22%) treated for recurrent disease with radical intent developed Grade 3 toxicity (skin: 4, urinary: 2, genital: 1, radiation-induced fracture of acetabulum: 1, and gastrointestinal: 0), whereas 1 of the 6 patients treated with palliative intent had Grade 3 toxicity affecting skin. No late Grade 4 toxicities were seen.
CONCLUSION: This retrospective series suggests that interstitial perineal HDRB is a safe and effective treatment option for primary or locally recurrent gynecological malignancies. It is a valuable option in patients who have received previous EBRT to the pelvis, achieving good local control with acceptable late treatment-related side effects.