Local therapeutic approaches for the management of recurrent gynaecological cancer

Abstract

Surgery, radiotherapy and chemotherapy combinations are used to treat recurrent gynaecological malignancy. Stereotactic body radiotherapy (SBRT) delivered to the involved surgical margin could improve clinical outcomes after pelvic exenteration (PE). In radiation-naive recurrent gynaecological malignancy, SBRT and proton-beam therapy (PBT) allow tumour dose escalation while potentially offering reduced toxicity. Magnetic resonance guided high intensity focused ultrasound (MRgHIFU) has not been trialled in recurrent gynaecological malignancy. This work investigates the feasibility of SBRT, PBT and MRgHIFU to achieve local and symptom control in these patients. Chapter 2 describes patterns of relapse and determines histological prognostic factors affecting overall and disease-free survival and loco-regional control in patients after PE. Five-year loco-regional control was 66.7% for those with negative surgical margins compared to 35.0% for those with involved/close margins. It further demonstrates feasibility of post-operative SBRT to the involved/close margin regardless of exenteration type; doses to organs-at-risk were equivalent when planned to a narrow or high-risk target. Chapter 3 compares tumour dose escalation and dose to organs-at-risk using simultaneous integrated boost (SIB) intensity modulated radiotherapy, SBRT and PBT in radiation-naive central and pelvic side-wall recurrent gynaecological malignancy. SIB boosts of 55 Gy only were feasible for central disease compared to 65 Gy for side-wall disease. SBRT and PBT were dosimetrically deliverable for recurrences at both locations. Chapter 4 investigates HIFU for symptom palliation in recurrent gynaecological malignancy. It highlights the challenges when treating these patients and shows that pain and emotional functioning improve. Changes in imaging metrics were seen in extra-pelvic lesions. Finally, health economic evaluation indicated high costs for a single visit on the day of the procedure but with low costs for subsequent follow-up. Thus, this work demonstrates the feasibility and potential role of state-of-the-art local therapeutic approaches in curative and palliative management of recurrent gynaecological malignancy.