Low-Dose Total Skin Electron Beam Therapy as a Debulking Agent for Cutaneous T-Cell Lymphoma: An open-label prospective phase II study

Background:  Total skin electron beam therapy (TSEBT) is a powerful treatment for cutaneous T-cell lymphomas (CTCL). Based on the occurrence of relapses with low radiation doses, doses of 30-36 Gy are commonly used but most patients still eventually relapse and repeat treatment courses are limited due to the cumulative toxicity. Complete response rates are about 60-90% for T2-4 stages with a 5-year relapse-free survival of 10-25% for stages IB-III. Objectives:  To evaluate prospectively the efficacy of low-dose TSEBT (10 Gy) in terms of complete cutaneous response rate, overall response rate and response duration in CTCL. Methods:  Ten patients with stage IB-IV mycosis fungoides (MF) were treated in an open-label manner with 4 fractions of 1 Gy/week TSEB to a total skin dose of 10 Gy. Treatment responses were assessed at 1 and 3 months after treatment and subsequently at least every 6 months for a total period of 2 years or to disease relapse or progression. Results:  Patients achieved an overall response rate of 90%. The rate of the complete response (CR) or very good partial response (VGPR;