ESTRO 2024 - Abstract Book

S240

Brachytherapy - Gynaecology

ESTRO 2024

Conclusion:

MRI-based planning is superior to CT-based planning in P-ISBT. The ability of MRI to better define CTV and Organs at risk allows for smaller and more precise treatment volumes, with a tendency to achieve higher D90-CTV and lower rectal and bladder D2cc, and which therefore results in less events of late toxicity.

Keywords: Interstitial brachytherapy, MRI- based applicators

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Digital Poster

Improving cervical brachytherapy by better defining the contouring required for the rectum and bowel

Aspazia Spyrou 1 , Matthew Bolt 2 , Yu Kai Shing 3 , Adrian Franklin 1 , Alexandra Stewart 1

1 The Royal Surrey County NHS Trust, Clinical Oncology, Guildford, United Kingdom. 2 The Royal Surrey County NHS Trust, Radiotherapy Physics, Guildford, United Kingdom. 3 The Royal Surrey County NHS Trust, Research data manager, Guildford, United Kingdom

Purpose/Objective:

Cervical brachytherapy is a complex modality and a crucial part of the treatment algorithm for cervical cancer stages IB to IVa. It requires integration of many concepts such as 3D imaging, pathology, physics, clinical examination and systematic application in dose-volume parameters 1 . The main side effects include bleeding, ulceration, fibrosis, fistulation and necrosis. To some degree there may be urinary or bowel frequency, urgency and incontinence 2 . The aim is to deliver highly conformal radiotherapy to the high risk CTV (CTV HR ) defined as the