ESTRO 2024 - Abstract Book

S5541

RTT - Patient care, preparation, immobilisation and IGRT verification protocols

ESTRO 2024

conformal radical head and neck radiotherapy, therefore further investigation into improvement in patient immobilisation is essential. Customised head rests used in conjunction with the shoulder shells should be considered.

Future work should also include evaluating the PRR more inferiorly away from the high dose volumes to determine if PRR is significantly reduced and could improve coverage of long nodal volumes typically seen in HNSCC radiotherapy.

Keywords: Head and neck, CBCT

References:

1. The Royal College of Radiologists (2022) Head and neck cancer RCR consensus statements

2. On Target 2: Ensuring geometric accuracy in radiotherapy. The Royal College of Radiologists, 2021

1394

Digital Poster

Introduction of kV corrective imaging protocol for breast radiotherapy

Harikrishnan Nair Venugopalan, Syed Moinuddin, Rita Simoes, Sairanne Wickers

University College London Hospitals, Radiotherapy, London, United Kingdom

Purpose/Objective:

Traditional treatment verification for breast cancer patients using mega voltage (MV) images (taken at the treatment angle) lacked corrective capabilities also resulted in higher concomitant radiation doses to patients. This study aimed to introduce a corrective kilo voltage (kV) imaging protocol to improve imaging quality, enhance treatment precision and to reduce patient imaging exposure for breast cancer radiotherapy.

Material/Methods:

The imaging protocol transitioned from single non-corrective MV images (Cohort 1) to single non-corrective kV images (Beams Eye Views) initially (Cohort 2). Subsequently, a corrective kV imaging (Cohort 3) approach was implemented, involving the acquisition of orthogonal kV images (anterior/posterior and lateral) to address positional variations. Data were collected for all three patient cohorts; 20 patients were included from each cohort. The study assessed positional variations (systematic and random errors) and treatment duration, measured from the first image to treatment beam switch-off.

Results: