Deintensification of radiotherapy for HPV positive oropharyngeal squamous cell carcinoma through biological responsebased adaptation

Hargreaves, Sarah 2022. Deintensification of radiotherapy for HPV positive oropharyngeal squamous cell carcinoma through biological responsebased adaptation. MD Thesis, Cardiff University. Item availability restricted.

Preview	PDF (MD Thesis) - Accepted Post-Print Version Download (6MB) | Preview
	PDF (Cardiff University Electronic Publication Form) - Supplemental Material Restricted to Repository staff only Download (163kB)
Preview	PDF - Supplemental Material Download (2MB) | Preview
Preview	PDF - Supplemental Material Download (2MB) | Preview
Preview	PDF - Supplemental Material Download (8MB) | Preview
Preview	PDF - Supplemental Material Download (101kB) | Preview

Abstract

Human Papillomavirus associated Oropharyngeal Squamous Cell Carcinoma (HPV positive OPSCC) tends to affect younger and fitter patients and has a superior prognosis compared to the HPV negative OPSCC. Treatment of OPSCC can be surgical and/or non-surgical, and both modalities are associated with high levels of toxicity in the acute and chronic setting. Given the improved survival in a younger and healthier population of patients, contemporaneous HPV positive OPSCC research has largely focused on methods of de-intensifying treatment whilst retaining high cure rates with the aim of reducing the rate of long-term toxicity.As part of my thesis, I wrote a study protocol for a novel PET-based adaptive radiotherapy trial, PEARL. This is a phase 2 feasibility study for HPV positive OPSCC patients. It aims to look at the dosimetric advantages of adapting radiotherapy plans based upon primary tumour response after 2 weeks of concurrent chemoradiotherapy seen on Fluorodeoxyglucose Positron Emission Tomography CT (FDG PET-CT) scans. In my thesis I show the dosimetric impact of adaptation in a pilot study and the re-working of the initial planning method to improve the adaptive planning process. In addition, I look at whether Proton Beam Therapy - based radiotherapy offers an additional dosimetric advantage in this cohort of patients. Finally, I investigate whether more can be done to refine the Planning Target Volume (PTV) margins implemented for set-up error by exploring the relationship between the position of the hyoid bone and primary tumour volume as seen on verification imaging.

Item Type:	Thesis (MD)
Date Type:	Completion
Status:	Unpublished
Schools:	Medicine
Date of First Compliant Deposit:	26 July 2023
Last Modified:	25 Jul 2024 01:30
URI:	https://orca.cardiff.ac.uk/id/eprint/161259

Actions (repository staff only)

Edit Item