Role of Radiation Therapy in the Management of Mycosis Fungoides

Abstract

Cutaneous T-cell lymphoma (CTCL) consists of spectrum of diseases of which Mycosis Fungoides and Sézary's syndrome are most common. Mycosis Fungoides (MF) is a low-grade, chronic lymphoproliferative disorder affecting skin caused by abnormal proliferation of CD4 + T-cells. The incidence of MF is showing an increasing trend all over the world. Also, it is seen twice as often in males as in females (2:1) and mostly it occurs after fourth decade of life. The clinical stages of MF usually progress through distinct phases namely pre-mycotic, patches plaque, tumor and erythroderma. The diagnosis may be confirmed by histopathology of skin biopsy, immunophenotyping and genotyping. Fine needle aspiration cytology from any suspected organ is a suitable procedure to establish the organ involvement. The imaging techniques like X-ray, ultrasonogram, CT scan, MRI and PET scan, etc., are helpful to know the exact extent of disease, visceral as well as lymph node involvement. Radiation therapy is the most effective modality of treatment for MF which offers cure in limited-stage disease and desirable palliation in advanced-stage disease. The radiation dose-fractionation schedule for the treatment of MF varies widely across the world. Treating entire skin having many curved surfaces and folds with radiation dose is the real challenge for the radiation oncologist. Many techniques, dose schedules and modifications in total skin electron beam therapy (TSEBT) have been tried since1950s. Radiotherapy treatment is time-consuming and inconvenient to both patient as well as the oncologist. Therefore, this treatment is performed with high dose rate (HDR) mode in some centers. The advantage of treating with HDR mode is to bring down the treatment time of a single patient every day from two-and-a-half hours to 15 minutes which increases patient compliance and at the same time saves machine time. TSEBT is performed with 4 MeV electrons with a daily fraction size of 120 cGy to a total dose of 36 Gy. At the end of 36 Gy, a booster dose of 10–15 Gy is delivered to self-shielding regions like sole, scalp and perineum. Where the energy is more than 4 MeV, a polysterene screen is inserted in between the patient and gantry to degrade the energy of electrons from 6 to 4 MeV. The most common radiation-related morbidities are erythema, skin blisters, various degrees of desquamations, swelling of joints (especially small joints), etc., which are controlled by treatment interruptions and conservative measures. To reduce these radiation toxicities, many dose schedule modifications are being practiced at many centers. In the present article, we have tried to review various literatures on this topic. As a conclusion, we can submit that TSEBT is an excellent therapeutic modality for the patients with MF, both curative as well as palliative.

Key words: Mycosis fungoides, radiotherapy, total skin electron beam therapy