[Place and technical aspects of external beam radiation therapy in the treatment of adult soft tissue sarcomas]. / Place et techniques de radiothérapie dans le traitement des sarcomes des tissus mous de l'adulte.

ABSTRACT

In soft tissue sarcoma, surgical resection remains the cornerstone of therapy for localized disease. Quality of margins is very important to evaluate. In case of marginal or incomplete resection, a new enlarged surgical resection should always be discussed before administration of any adjuvant treatments. Many retrospective studies and 2 randomized studies (one of adjuvant brachytherapy and one of external beam radiotherapy) have shown that adjuvant radiotherapy after complete surgery reduces significantly the risk of local recurrence in extremity soft tissue sarcomas. Combination of surgery and pre- or postoperative radiotherapy has therefore become the standard treatment with a local recurrence rate amputations. A recent randomized study has compared pre-op to postoperative radiotherapy. The results in terms of local control are similar in both arms (93 and 92% at 5 years) but the risk of early complications is higher in the preoperative arm and the risk of late sequela is higher in the postoperative arm. Surgical resection without radiotherapy may be considered after discussion at best within a multidisciplinary meeting, if surgical margins are considered satisfactory, in superficial, small tumours and low-grade. In retroperitoneal sarcomas, adjuvant radiotherapy is not a standard. It may decrease the risk of local recurrence but at the price of an increased gastro-intestinal toxicity. A randomized trial is warranted. Because of its rarity, and the risk of recurrence both local and metastatic, treatment should preferentially be discussed with a multimodality specialized approach.