ESTRO 2024 - Abstract Book

S1946

Clinical - Mixed sites, palliation

ESTRO 2024

Keywords: 4DMRI, 4DCT, respiratory motion

References:

1. Siemens. Siemens. [cited 2023 Jul 6]. 4D MRI – RT Respiratory Self-Gating. Available from: https://www.siemens healthineers.com/en-uk/magnetic-resonance-imaging/options-and-upgrades/clinical-applications/4d-mri

1773

Digital Poster

Deep hyperthermia and radiotherapy: workflow and thermometry results from a single-centre case serie

Francesco Martucci 1 , Lisa Milan 2 , Stefano Leva 1 , Giulia Borgonovo 1 , Deborah Daniele 1 , Domenico Santoro 1 , Rossella Cavicchiolo 1 , Letizia Deantonio 1,3 , Thomas Zilli 1,3 1 Oncology Institute of Southern Switzerland Bellinzona-Lugano, Ente Ospedaliero Cantonale, Radiation Oncology Clinic, Bellinzona, Switzerland. 2 Imaging Institute of Southern Switzerland, Medical Physics Division, Bellinzona, Switzerland. 3 Università della Svizzera Italiana, Radiation Oncology Clinic, Lugano, Switzerland

Purpose/Objective:

Combination of hyperthermia (HT) with radiotherapy (RT) is a validated treatment strategy to enhance the therapeutic ratio for several tumour sites. The time interval between RT and HT should ideally be of less than 4 hours, with the best sequencing between the two modalities not yet established (i.e. HT before or after a RT session). In the present study we evaluate the workflow optimization of this combined modality and the thermometry results of deep HT treatments performed in our clinic since the first installation of HT unit in December 2021.

Material/Methods:

One hundred and eleven sessions of deep HT sessions performed once or twice weekly in 28 consecutive patients from January 2022 to September 2023 were analysed. All patients were treated with external beam RT (median dose 36 Gy, range 30-50Gy) with a VMAT technique realized before the HT session. Deep HT was delivered with the 70 MHz loco-regional ALBA-4D system (Medlogix®). Thermo-radiotherapy was delivered in the definitive or palliative setting for different tumor sites: pelvic bone metastases (57%), pelvic primary tumors (i.e. anorectal, vagina, prostate and bladder) (11%), soft tissues/lymph-nodes metastases (22%), pancreatic lesions (7%), and retroperitoneal sarcomas (3%). Forty-four (40%) HT treatments were delivered without invasive thermometry, while in 67 (60%) treatments thermometry was evaluated with rectal probes or bladder catheters. The HT treatment planning was performed and adapted using the Plan2Heat system. Different treatments time intervals were evaluated and calculated: 1) the time interval between RT end (i.e. beam-off time) and start of deep HT delivery (RT HTtime); 2) the pre-heating time (pre-HTtime) defined as the time between the start of radiofrequency delivery and