Total skin electron beam therapy in mycosis fungoides—a shift towards lower dose?
Cutaneous T-cell lymphoma is a rare group of malignancies characterized by the proliferation of CD4+ T-cells, of which mycosis fungoides (MF) is the predominant subtype. The neoplastic lymphocytes of MF are extremely radiosensitive and even low doses of radiation can produce excellent responses. As such, radiotherapy (RT) is considered to be the most efficacious single agent treatment option for MF. Total skin electron beam therapy (TSEBT) is a special RT technique that allows for homogenous irradiation of the entire skin. The effectiveness of conventional-dose (cd) TSEBT (30–36 Gy), particularly at inducing complete cutaneous responses, has been well documented over the years. Nonetheless, most patients eventually relapse. In these cases, cd-TSEBT is limited as RT toxicity is dose-dependent. Consequently, clinicians are moving towards low-dose (ld) TSEBT (10–12 Gy). Institutional studies and prospective trials have shown similar response rates, overall survival and symptomatic relief with this regimen, albeit at the cost of complete response. Advantages of ld-TSEBT include decreased treatment length, improved side effect profile, and the opportunity for multiple applications following disease recurrence. This comprehensive review evaluates TSEBT techniques, clinical outcomes, impact of different dose regimens, and toxicities in the treatment of MF. Future applications of TSEBT with newer systemic agents are also discussed.