Abstract
The most common malignancy for women in New Zealand is breast cancer. As part of their treatment regimen the majority of these women will receive radiation therapy. A significant number of patients will experience severe acute radiation-induced skin reactions. At the time of writing, there is no evidence-based standard treatment for these reactions, the most extreme of which is moist desquamation which has a severe effect on patient comfort and psychological well-being.
Previous studies in our department had shown that Mepilex Lite, an adhesive soft silicon dressing (Mölnlycke Health Care AB, Gothenburg, Sweden), reduced the severity of acute radiation-induced skin reaction by 40% when used to treat existing erythema. It is theorised that these soft silicone dressings prevent further mechanical damage to the radiation-damaged basal layer of the skin, allowing time for repair. Mepitel Film is another soft silicone dressing from the same company. This Film is fully breathable, transparent, very thin and with no clinically significant bolus effect; it can be left on during radiation therapy and can therefore be used prophylactically. We hypothesized that Mepitel Film would be more successful in minimizing acute radiation induced skin reactions when used in this way.
In order to test the hypothesis we conducted an intra-individual randomised controlled trial (n=80) which investigated whether the prophylactic use of Mepitel Film would be superior to aqueous cream in reducing both the incidence of moist desquamation and the severity of radiation-induced skin reactions in breast cancer patients.
The skin area to be irradiated was divided into a medial half and lateral half (which included the axilla). These two halves were then randomised to Mepitel Film (trial area) or aqueous cream (control area) from the start of radiation treatment. This trial was carried out by the author and one other radiation therapist researcher (RTR) at the Dunedin Radiation Oncology Centre (DROC) in New Zealand. Modified RTOG as well as the modified Radiation-Induced Skin Reaction Assessment Scale (RISRAS) was used to assess the visible signs (researcher component) and symptoms (patient component) of the skin reactions. Patients were reviewed three times a week during radiation therapy treatment, then once a week post-treatment for four weeks or until reactions had completely resolved. All patients filled out an Exit Questionnaire after completion of treatment.
This thesis analyses the results of the first 10 mastectomy patients and the first 10 non-mastectomy patients who completed the trial. The results of this 20 patient cohort demonstrated that Mepitel Film, when used prophylactically, completely prevented the occurrence of moist desquamation and decreased the severity of radiation-induced skin reactions by more than 90%.
A major limitation of this trial was the fact that neither the researcher nor the patient could be blinded as it was very clear where the film was and it was important that the film remained in place for as long as possible (up to several weeks).
In conclusion, the results of this study show that using Mepitel Film prophylactically reduces the incidence and severity of radiation-induced moist desquamation in breast cancer patients.