ESTRO 2025 - Abstract Book

S1710

Clinical - Sarcoma & skin cancer & malignant melanoma

ESTRO 2025

Material/Methods:

High-risk disease was defined by the presence of at least one of the following: histological grade 2-3, tumour size >5 cm, deep-seated tumour, or a lesion at high risk of incomplete resection. Staging included total body computed tomography (CT) and magnetic resonance imaging (MRI) both before and after treatment. RT was delivered using the VMAT technique with a prescribed dose of 50 Gy in 25 fractions. Gross tumour volume (GTV) was defined as the macroscopic disease on the planning CT, merged with MRI, and included peri-lesional oedema. The clinical target volume (CTV) was defined as an extension of the GTV by 1.5 cm transversely and 4 cm longitudinally. The planning target volume (PTV) extended the CTV by 0.5 cm in all directions, taking into account daily cone beam computed tomography (CBCT) imaging. HT was performed twice weekly, immediately after RT, using a radiative system with manual temperature monitoring using at least two skin probes. Patients with the highest risk of distant recurrence based on the Sarculator Nomogram score, received systemic anthracycline-based chemotherapy prior to RT and HT. Complete pathological response (pCR) was defined as the absence of tumour cells.