Radiotherapy and Oncology, 24 (1992) 155- 162 0 1992 Elsevier Science Publishers B.V. All rights reserved. 0167-8140/92/$05.00 155 RADION 00999 Clinical experience with a single field rotational total skin electron irradiation technique for cutaneous T-cell lymphoma C. R. Freeman”, S. Suissab, G. Shenoudaa, T. bonga, L. Souhami”, M. Pla”, E. B. Podgorsak” and C. Pla” a Department of Oncology (Division of Radiation Oncology), and b Department of Epidemiology and Biostatistics, McGill University, Montreal, Q uebec, Canada (Received 23 July 1991, revision received 27 January 1992, accepted 19 February 1992) Key words: Cutaneous T-cell lymphoma; Total skin electron irradiation; Radiotherapy Summary Between October 1981 and December 1989,44 patients with cutaneous T-cell lymphoma (CTCL) were treated with a single field rotational total skin electron irradiation (RTSEI) technique developed in the McGill University, Department of Radiation Oncology. Only 11 (25%) of the 44 patients had received 110 prior treatment Three-quarters (33/44). had advanced (Ts or T4) disease. Complete responses were seen in 32/44 (73%) of patients (91% T,, 71% T, and 58% T4), but only 3/11 (27%) of pa- tients with T, disease and 3/z (14%) of patients with T, disease remain in continuous complete remission in the skin, after median intervals of 58 and 35 months, respectively. Median cause-specific survival for the whole group is 43 months and survival at 5 years is 38%. Survival was significantly better for patients with T, disease than for patients with T, disease (relative risk 4.3; 95% CI 1.4-13.2) and patients with T, disease (relative risk 3.1; 95% CI 0.8-12.1). The RTSEI technique used at McGill has depth-dose characteristics and photon caWimmat&n similar to other commonly used TSEI techniques_ It is relatively simple and provides a homogenous dose distribution over the entire skin surface in a short treatment time. Results of treatment are similar to those obtained with other techniques. For T, disease, TSEI is an effective treatment modality with a possibility of long-term tumor control. For more advanced disease, more aggressive treatment, which may include TSEI, is necessary. Cutaneous T-cell lymphoma (CTCL) is an uncommon clinical problem, with an estimated annual incidence in North America of 2-3 cases per million population. The onset is usually insidious. The early lesions in the skin are easily misinterpreted as one of a variety of other skin disorders, and even once a histological diag- nosis is made, the clinical course is variable. Treatment is, in general, quite unsatisfactory. While the majority of patients in early stages of the disease will achieve complete responses with the use of S-methoxypsoralen with UV light (PUVA) [4,5,20], or with topical application of nitrogen mustard (HN,) [4,8,25], most patients will subsequently develop pro- gressive disease, and the curative potential of both of these two approaches appears to be low. Total skin electron irradiation (TSEI), on the other hand, is re- ported to result in complete disappearance of cutane- ous disease in 70-100% of patients, and may be cur- ative in a substantial proportion of patients with early- stage disease [7,16,23]. Requirements for TSEI, which include a large field size of the order of 200 x 60 cm2, dose uniformity over this area of approximately & 5%, and an electron dose rate at the skin surface of approximately 20 cGy/min, are not easily met. Most TSEI techniques are complex and time-consuming, and even then may not produce a satisfactory dose distribution over the entire skin sur- face. Addressfor correspondence: C. R. Freeman, M.B., B.S., Department of Radiation Oncology, Montreal General Hospital, 1650 Cedar Avenue, Montreal, Quebec H3G lA4, Canada.