Brachytherapy in soft tissue tumours: an interdisciplinary challenge

Interdisciplinary work including surgery and additive radiotherapy is often needed for the therapy of tumours. Beneath this, brachytherapy is an important part of the radiotherapy. It was first used over 100 years ago and is in regular use after the development of afterload technology in the early 1970s. Today it is often used in different tumour therapies, for example in soft tissue sarcoma or breast tumours, in order to decrease the risk of local recurrence. Concerning its benefits, higher doses could be used because of the localized effect with equivalent local control rate and less toxicity of treatment. Moreover, brachytherapy can also shorten the treatment time from 5-7 weeks to some days and is better reconcilable due to its localized effects, thus reducing side effects, as radiation-induced reactions, teleangiectasia and brosis. Precondition for application of brachytherapy is the need of a good soft tissue coverage and wound healing. Therefore, good interdisciplinary cooperation between plastic surgery and radiotherapy is important. After wide surgical resection reconstruction with different kind of flaps are often required, for achieving early wound healing and fast start of radiotherapy. Between 2011 and 2017 we applied brachytherapy to 13 patients with soft tissue sarcomas and other tumours like merkel-cell-carcinoma, schwannoma, and breast cancer. The treatment consisted of tumour resection, intraoperative insertion of brachytherapy catheters and after that brachytherapy alone or in combination with external beam radiotherapy. In half of the patients a reconstruction with different flaps was required, including pedicled trapezius flap, musculus latissimus dorsi flap and radial forearm flap; in some cases nerve and tendon reconstruction for better function and faster wound healing and so faster start of postoperative brachytherapy was also needed. The mean age of the patients was 55 years (±19) and we could start brachytherapy after 3-21 days after the operation, with a mean start on day 8±5 postoperatively. Three patients received additional percutaneous radiotherapy. The patients who received only brachytherapy got a dose of 2, 5 or 3Gy twice daily, with a mean total dose of 31±3Gy. Multidisciplinary work, including surgery as the main procedure and radiotherapy additionally, is needed for a successful treatment of soft tissue tumours. Depending on the type and the stadium of tumour plastic and reconstructive surgery provides soft tissue cove