Aims: The existing clinical guidelines do not describe a clear indication for adjuvant radiotherapy (RT) in the treatment of superficial soft tissue sarcomas (STSs). We aimed to determine the efficacy of adjuvant RT for superficial STSs.
Methods: We retrospectively studied 304 patients with superficial STS of the limbs and trunk who underwent surgical resection at a tertiary sarcoma centre. The efficacy of RT was investigated according to the tumour size and grade: group 1, ≤ 5 cm, low grade; group 2, ≤ 5cm, high grade; group 3, > 5 cm, low grade; group 4, > 5 cm, high grade.
Results: The five- and ten-year local recurrence-free survival (LRFS) for all patients was 88% and 81%, respectively. While the efficacy of adjuvant RT was not proven in local control of all patients (five-year LRFS; RT+, 90% versus RT-, 83%; p = 0.074), the LRFS was significantly improved by adjuvant RT in group 2 (five-year LRFS; RT+, 96% versus RT-, 82%; p = 0.019), and group 4 (five-year LRFS; RT+, 87% versus RT-, 73%; p = 0.027). In groups 2 and 4, adjuvant RT significantly reduced the LR risk if the resection margin was clear but less than 5 mm; the LR rate was 7% with adjuvant RT compared with 26% with surgery alone (p = 0.003). There was no statistical relationship with the use of adjuvant RT and survival in every group.
Conclusion: Adjuvant RT reduces the risk of local recurrence in patients with superficial high-grade STS regardless of tumour size, especially when resection margin is less than 5 mm. Cite this article: Bone Joint J 2020;102-B(8):1088-1094.
Keywords: Margin; Outcome; Radiotherapy; Soft-tissue sarcoma; Superficial; Surgery.