Dados do Trabalho

Título

Intraoperative radiotherapy with low energy X-rays for soft-tissue and bone sarcomas: A single-center retrospective study

Introdução

Soft-tissues sarcomas (STS) and Bone Sarcomas (BS) are rare neoplasms. They account for 4.902 to 8090 new cases/year in Brazil. Local control can be accomplished by surgery and radiotherapy. Electronic intraoperative radiotherapy with low energy photons (e-IORT) has proven to be safe and efficient in several tumor entities, however there are scarce data on its use in sarcoma treatment. We conducted the first retrospective analysis on e-IORT in STS and BS from Brazil.

Objetivo

Evaluate Progression-free survival (PFS), local recurrence in the primary site and distant metastasis of patients diagnosed with STS and BS treated with e-IORT.

Método

Electronic medical records of 10 patients with primary or recurrent STS/BS treated between April, 2017 and December, 2020 at our institution were retrospectively analyzed. All patients underwent surgery after computed tomography (CT) and magnetic resonance (MR) staging diagnosis.Patients were treated with e-IORT during resection. Depending on the surgery extension, the dose was prescribed to depth (flat applicators) or applicator surface (spherical applicators).

Resultados

The study included 10 patients. Mean age was 54,2 years (29 – 87).Mean follow-up was 22 months (SD=16). Mean tumor size was 6,09 cm (1.3 – 12.9).Seven patients had newly STS with no prior treatment and 3 presented recurrent disease after previous treatment (surgery and/or external beam radiotherapy). Resection status was R0 in 8 (80%) and R1 in 2 (20%) patients. Five patients had extremities sarcoma, 3 had pelvic and abdominal tumors, 1 had thoracic sarcoma and 1 head and neck tumors. The median PFS was 38 months for both primary and recurrent tumors. Distant metastasis events were recorded in 1 recurrent STS patient and 1 primary STS patient after 38 and 29 months respectively. No local recurrence in the primary setting occurred during the period. No serious complications were observed, except one patient had moderate local infection.

Conclusão

Despite limited sample and non-randomized nature of this analysis, our data are in accordance with the only study using e-IORT in STS. Results seem to be superior in comparison to historical series, generating hypothesis of greater effectiveness of e-IORT with low toxicity associated. Additional collaborative studies are needed to confirm this hypothesis.

Palavras-chave

sarcoma , radiotherapy , e-IORT