EP1191\u2005Recurrent vaginal mucosal melanoma treated with salvage hypofractionated external beam radiotherapy and interstitial brachytherapy

Abstract

Introduction/Background Malignant melanoma of the vagina is rare and portends a poor prognosis. Primary treatment for vaginal melanoma is oncologic resection.1 Systemic therapy has been utilized in the case of inoperable tumors.2 Postoperative adjuvant radiation therapy with or without chemotherapy has been utilized; however definitive radiation therapy for vaginal mucosal melanoma is rarely used.3–5 In this presentation, we discuss utilization of combination of external beam radiation therapy and interstitial brachytherapy as a salvage modality for recurrent vaginal mucosal melanoma. Methodology 62 year old treated with partial vaginectomy in Sept 2016 for vaginal cancer. Pathology showed a malignant melanoma with 6 mm thickness with positive deep margin. She had a completion radical vaginectomy and inguinal and pelvic node dissection in December 2016. PDL-1, BRAF V600, c-kit and N-ras were all negative. In Nov 2016, PET/CT was negative. In January 2017, MRI showed a 6.6 × 3.8 × 4.3 cm left vaginal mass and left inguinal lymphadenopathy. On March 9, 2017, she completed salvage radiation to the pelvic nodes, vaginal mass to a total of 62.1 gray with Simultaneous integrated boost, followed by interstitial brachytherapy in 4 fractions of 6.4 gray per fraction to a total of 26 Gy on April 24, 2017. Results She developed pulmonary metastasis. However, she refuses all systemic therapy. She enjoys excellent local control in the vaginal and inguinal nodes for 2 years. She complains of fatigue; she remains sexually active. She reports occasional pelvic discomfort. Abstract EP1191 Figure 1 Radiographic Images and Radiation Therapy plans (External Beam and Brachytherapy) Conclusion This presentation demonstrates that hypo-fractionated radiation therapy plus interstitial brachytherapy can offer excellent local control. Based on radiobiological principles, the use of high-dose-per treatment regimens for such relatively radioresistant tumor is understandable.6 We propose that radiation therapy should be considered for patients with unresectable melanoma. References Schmidt M, Honig A, Schwab M, Adam P, Dietl J. Primary vaginal melanoma: a case report and literature review. Eur J Gynaecol Oncol 2008;29:285–288 Baloglu A, Bezircioglu I, Cetinkaya B, Yavuzcan A. Primary malignant melanoma of the vagina. Arch Gynecol Obstet 2009;280:819–228. Lin LT, Liu CB, Chen SN, Chiang AJ, Liou WS, Yu KJ. Primary malignant melanoma of the vagina with repeated local recurrences and brain metastasis. J Chin Med Assoc 2011;74:376–379. Androutsopoulos G, Terzakis E, Ioannidou G, Tsamandas A, Decavalas G. Vaginal primary malignant melanoma: a rare and aggressive tumor. Case Rep Obstet Gynecol2013; 2013:137908. Kirschner AN, Kidd EA, Dewees T, Perkins SM. Treatment approach and outcomes of vaginal melanoma. Int J Gynecol Cancer. 2013;23:1484–1489. Rofstad EK. Radiation Biology of Malignant Melanoma. Acta Radiol Oncol 1986 Jan -Feb ; 25(1):1–10. Disclosure Nothing to disclose