In this pilot study, we report that chemosensitivity assays using liquid biopsy-derived metastatic melanoma (MM) CTCs, from 7 patients with stage IIIC, BRAF wild-type metastatic melanomas, localized exclusively to the pelvic region, un-eligible for immunotherapy and treated with melphalan hypoxic pelvic perfusion (HPP), is both feasible and useful in predicting response to therapy. Here, BRAF is linked to Miyoshi myopathy.