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A healthy 66 year-old man presented with a three-year history of a skin eruption, initially treated as psoriasis without response. A biopsy was subsequently performed that was consistent with mycosis fungoides (MF). This diagnosis was confirmed with a positive T-cell gene rearrangement. The patient was referred to our institution for management of tumor stage MF. This article is protected by copyright. All rights reserved.

Purpose: Mycosis fungoides is a common form of cutaneous T-cell lymphoma which generally affects the skin. A typical course of treatment may include fractionated total skin electron beam therapy. Given the difficulties in uniformly irradiating some regions of the body and the need for frequent visits within the context of a fractionated protocol, this study investigated the feasibility of delivering the dose using form-fitting cloth which contained phosphorous-32 as a source for beta particle irradiation. Methods: A piece of fabric (0.97 g) consisting of a blend of spandex and flame retardant material impregnated with phosphorus-31 (2000 ppm) was bombarded with neutrons to produce phosphorus-32. The cloth was then laid flat and a stack of radiochromic film placed on top. Sheets of film and tissue equivalent plastic were layered to form a stack measuring a total of 1 cm thickness and remained sandwiched for 77.3 hr. Results: The initial activity of the activated cloth was 44 μCi of P-32. The absorbed dose was uniform within planes parallel to the cloth and exponentially dependent on depth, delivering 560cGy at 0.3mm and falling to 20cGy at 3mm. Conclusion: The total dose prescribed for a typical course of TSET for mycosis fungoides is 36Gy delivered over 9 weeks and is expected to treat to at least 5mm depth. Therefore, the P-32 impregnated cloth may not be clinically indicated to treat this disease given the unfavorable depth-dose characteristics. However, a major advantage of using form-fitting cloth is the uniformity with which the dose could be delivered over the skin in areas which are not flat. Increasing the distance between cloth and skin could improve the depth-dose characteristics.

Purpose: Implement a dual six field electron beam treatment technique for treatment of Mycosis Fungoid patient with a cardiac pacemaker.Introduction: Total skin electron beam therapy for treatment of mycosis fungoids requires large size of treatment fields obtained at 4 to 5 meters distance (TG 30). A large field treatment with a cardiac pacemaker presents significant challenge for mycosis fungoid treatment. The Stanford technique with adequate shielding for pacemaker was implemented.Materials and Methods: A 82 year old gentleman with mycosis fungoid stage IB was planned for treatment with large field electron beams at extended distance. The standard Stanford technique of six dual fields was implemented on Varian Clinac iX. A custom made stand was designed to reproduce & support patient for daily treatment. A treatment distance of 4.8 meters using 6 MeV electrons was implemented. To achieve uniform dose delivery along patient height, a gantry angle of ±15° was finalized. A P‐11 parallel plate chamber was used for TG‐51 and profile measurements. The B factor concept from Stanford technique was used for absolute dose calculations. For the pacemaker 6 mm thick lead shield was used to reduce maximum dose < 2Gy during entire course of the treatment. Results: Patient received 20 Gy to entire skin surface in 20 fractions, followed by additional boost dose of 10 Gy to localized active lesions. During entire course of treatment nail bed and eyes were shielded. Patient tolerated entire course of treatment very well. Conclusions: The early response was promising. The functional evaluation by cardiologist did not indicate any radiation damage to the pacemaker.

Purpose: To commission and verify an Epson scanner for film dosimetry for total skin electron beam therapy (TSEB). Methods: Use data from an IBA PPC40 parallel‐plate ion chamber and Sun Nuclear QED skin diode detectors as standard; we have made comparisons to the film measurement using Kodak XV films. Hurter‐Driffield (HD) curve are established for 6 MeV total skin electron beams at a source‐to‐surface distance (SSD) of 5 m. Also HD curves are built for 6 MeV at a 100 cm SSD. Dose profiles for a series of oblique incident large electron fields are measured using the film for approximately 80 cGy dose delivered at the peak. The film is then scanned using two scanners, an Epson expression 10000 XL and a Vidar VXR‐16 Dosimetry Pro. The optimal scanning conditions (e.g., dot per pixel size, internal color correction scheme) are chosen for the Epson scanner. Matlab is then used to analyze the optical density (OD) of the scanned films. A transmission densitometer made by Tobias Associates transmission is used to analyze the films to give a classical standard. Results: The analysis of the Epson scanner is presented in two forms: one with and one without the HD correction from the established HD curve. The error analysis gives an uncertainty of 5% without the HD correction. An improved result of approximately 3% is found when an HD correction is applied to the analysis. Conclusions: A simple Epson scanner satisfies the commissioning standards for TSEB when an HD curve correction is applied.

Purpose: We are introducing a dosimetric system for calculation of dose distribution within patients from total skinelectron beam (TSEB) in order to avoid large dose variations and frequent setup changes for accurate and safe TSEB therapy of mycosis fundoides. Methods: Custom cylindrical phantoms were made of a set of buckets filled with water and wrapping with bolus outside. Films placed at depths of interest in the cylindrical phantoms and flat solid water phantom were irradiated using 6‐MeV high‐dose‐rate TSEB from an Elekta Synergy linear accelerator. Horizontal and vertical fluence profiles as well as depth‐dose curves were measured by positioning the flat phantom at various locations. Curvature factors were determined by the dose curves across the films in the cylindrical phantom and quantified as functions of the curvature radius and the angle between the TSEB and local surface norm. The off‐axis and curvature factors were used in calculation of the skin‐depth dose distribution in any body parts for individual beams. Sum of the doses from all beams provides the total skin dose distribution. The calculation requires only the toward beam body surfaces that can be captured with 3D cameras. Results: Repeated phantom experiments confirmed the dose calculation accuracy within 5%. Computer simulation for patients with different body shapes and treatment setup using the Stanford technique agreed with the results of in‐vivo dose measurements. Dose variation from different techniques including changes from 60 to 45 degree turntable angles for oblique beams in Stanford technique and rotation TSEB were simulated. Conclusions: This simple and accurate dosimetric system allows users to predict total skin dose distribution and distribution changes with different treatment techniques. Importantly, it allows users to plan and optimize TSEB treatment.

During the past eight years, 137 patients with mycosis fungoides were given total skin electron beam therapy (TSEB) using 2.5 to 4 MeV electrons. A single treatment delivers 400 rads to the entire skin surface, and patients are treated once a week for six to eight consecutive weeks. All have been followed for a median of 18 months (range 6-103 months). Although approximately 80 to 90% of the total population were in the advanced stages of the disease and had been previously treated elsewhere, cutaneous lesions and associated symptoms were effectively controlled. The remission lasted 6 to 103 months (median 19 months) after beginning the therapy for 109 mycosis fungoides patients, who were at risk for 12-103 months (median 24 months). Erythroderma and circulating Sezary cells adversely affected the duration of remission and indicate extracutaneous dissemination. Lymphocyte responsiveness to various mitogens and antigens correlated well with duration of the remission that was obtained from a course of TSEB.

Thirty-nine patients with mycosis fungoides were treated with total skin electron beam irradiation from 1971 to 1976, and all received minimum follow-up of 12 months. Details of treatment technique and dosimetry are given. Sixteen patients cleared completely. Seven patients are in long-term remission (1 1/2 to 4 1/2 years). Eleven patients died. Those who failed are now being treated with topical therapy with varying degrees of control. Some have been retreated with local irradiation. Most of the patients had extensive disease; for this group, total skin electron beam therapy was especially useful, as many of those who failed developed only minimal disease that was well controlled by topical measures.