Mepitel Film for the Prevention of Acute Radiation Dermatitis in Breast Cancer: A Randomized Multicenter Open-Label Phase III Trial.

PURPOSE: Radiation dermatitis (RD) is common in patients undergoing breast radiotherapy. Mepitel film (MF) can reduce RD, but the results from two randomized controlled trials are conflicting. We aimed to conduct a confirmatory randomized controlled trial in patients at risk of RD. METHODS: Patients were randomly assigned to receive MF or standard care (2:1 ratio). Patients with large breasts after lumpectomy (bra size ≥ 36 inches or cup size ≥ C) or after mastectomy were eligible. Stratification factors included surgery type, dose fractionation, and administration of boost/bolus. The primary end point was grade (G) 2 or 3 RD using the Common Terminology Criteria for Adverse Events v5.0. Secondary end points included patient- and clinician-reported outcomes. RESULTS: Between January 2020 and May 2022, 376 patients were included in the modified intention-to-treat analysis. The incidence of G2 or 3 RD was significantly lower in MF patients compared with standard care (n = 39/251, 15.5%; 95% CI, 11.3 to 20.6% v n = 57/125, 45.6%; 95% CI, 36.7 to 54.8% respectively, odds ratio (OR): 0.20, P < .0001). Benefits of MF remained significant in patients who developed G 3 RD (n = 7, 2.8%; 95% CI, 1.1 to 5.7% v n = 17, 13.6%; 95% CI, 8.1 to 20.9%, OR: 0.19) and moist desquamation (n = 20, 8.0%; 95% CI, 4.9 to 12.0% v n = 24, 19.2%; 95% CI, 12.7 to 27.1%, OR: 0.36). When evaluating the combined patient and health care provider score using Radiation-Induced Skin Reaction Assessment Scale, the MF arm had significantly lower scores (P < .0001). Individual items on the Radiation-Induced Skin Reaction Assessment Scale also favored the MF for both patient- and clinician-reported outcomes. Blistering/peeling, erythema, pigmentation, and edema were significantly reduced in the MF arm. Three patients removed the film prematurely because of rash (n = 2) and excessive pruritus (n = 1). CONCLUSION: MF significantly reduces RD in patients undergoing breast radiotherapy.

A Feasibility Study of Mepitel Film for the Prevention of Breast Radiation Dermatitis in a Canadian Center.

PURPOSE: Severe radiation dermatitis (RD) is distressing and may have adverse long-term effects including fibrosis and telangiectasia. Treatment interruptions due to severe RD may increase the risk of recurrence. Two randomized trials of Mepitel film demonstrated efficacy in preventing severe RD in breast cancer, but this product has not been widely adopted in North America. We aimed to assess the feasibility and efficacy of Mepitel film for prevention of breast RD at a Canadian center. METHODS AND MATERIALS: Patients were stratified based on breast size and receipt of postmastectomy radiation therapy. The primary outcome was RD grade using the Common Terminology Criteria for Adverse Events. Secondary outcomes included moist desquamation, patient- and clinician-reported symptoms of skin toxicity, and cosmetic outcomes. RESULTS: Thirty patients receiving external beam radiation therapy to the breast or chest wall were enrolled. Two patients (6.7%) discontinued use of the Mepitel film before completing radiation therapy. No patients developed grade 3 RD or higher. Five patients (17.9%) developed grade 2 RD: 3 (10.7%) had moist desquamation, and 2 (7.1%) had brisk erythema without moist desquamation. CONCLUSIONS: Mepitel film completely prevented grade 3 RD. Rates of moist desquamation and grade 2 RD were lower with Mepitel film than in studies using aqueous cream, but unlike previous trials of Mepitel film we did not achieve complete prevention of moist desquamation. Further research is needed to confirm the efficacy of Mepitel film versus standard prophylaxis for RD and identify the patients who will benefit the most from the film.

The effect of prone and supine treatment positions for the pre-operative treatment of rectal cancer on organ-at-risk sparing and setup reproducibility using volumetric modulated arc therapy.

BACKGROUND AND PURPOSE: To compare organ-at-risk doses and setup reproducibility using the prone and supine orientations in volumetric modulated arc therapy (VMAT) for rectal cancer. MATERIALS AND METHODS: Seventeen consecutive rectal cancer patients undergoing preoperative radiation were selected and setup in either the prone (N = 8) or supine (N = 9) position. All patients were treated using posteriorly-applied VMAT. Bladder and small bowel dose and cone beam CT (CBCT) reproducibility metrics were retrospectively collected. RESULTS: Dose metrics for bladder and small bowel did not show significant differences between the prone and supine orientations. The prone data had a trend for smaller irradiated volumes than supine for the small bowel at lower doses-V20 (prone: 135 ± 99 cm3; supine: 201 ± 162 cm3) and V30 (prone: 78 ± 71 cm3; supine: 105 ± 106 cm3). At higher doses, the trend reversed as exemplified by the small bowel V50.4 (prone: 20 ± 28 cm3; supine: 10 ± 14 cm3). CBCT data showed that rotational errors in pitch and roll were significantly larger for the prone vs. supine orientation (pitch: 2.0° ± 1.3° vs. 0.8° ± 1.1° p < 0.001; roll: 1.0° ± 0.9° vs. 0.3° ± 0.5°, p < 0.001). CONCLUSIONS: Bladder and small bowel doses were not significantly different when comparing VMAT plans developed for the prone and supine orientations. The supine orientation demonstrated improved setup reproducibility.