Bath Psoralen-ultraviolet A and Narrowband Ultraviolet B Phototherapy as Initial Therapy for Early-stage Mycosis Fungoides: A Retrospective Cohort of 267 Cases at the University of Toronto

Phototherapy is one of the mainstay treatments for early stages mycosis fungoides (MF). Response rates are not statistically different when utilizing either bath PUVA or nbUVB in early stage MF. However, longer remission is achieved with bath PUVA therapy. Background: Phototherapy is used frequently to treat early-stage mycosis fungoides (MF). The effectiveness of bath psoralen-ultraviolet A (bath PUVA) and narrowband ultraviolet B (nbUVB) in MF is well established. However, evidence is limited comparing the effectiveness of the 2 modalities for early-stage MF. The objective of the present study was to compare the responses between the study participants receiving bath PUVA versus nbUVB phototherapy. Patients and Methods: The study included a retrospective cohort of stage 1A and 1B MF patients treated with bath PUVA or nbUVB at their initial presentation. The primary outcome was the response to treatment. The secondary outcome was disease-free survival. Results: The cohort included 267 patients (158 treated with bath PUVA and 109 treated with nbUVB) with a mean age of 45.22 years. The mean follow-up period was 59.58 months for bath PUVA and 22.27 months for nbUVB. Overall, 88.61% of the bath PUVA group and 88.07% of the nbUVB group had complete responses (P = .89). The median number of treatments to achieve a complete response was 55 for bath PUVA and 55.5 for nbUVB (P = .63). The median disease-free survival was 43.25 months for bath PUVA and 14.9 months for nbUVB (P <.0001). The study was limited by its retrospective nature. Conclusion: Bath PUVA and nbUVB are both effective treatments. The use of bath PUVA resulted in significantly greater disease-free survival.