The potential use of intensity-modulated radiation therapy in the management of early-stage gynaecologic malignancies

Introduction A literature review was conducted to establish if intensity modulated radiation therapy (IMRT) planning and treatment enhances current whole pelvic radiation therapy (WPRT) practices for early-stage gynaecological malignancies. Our purpose was to determine if IMRT implementation at a small radiation therapy centre is feasible, and warranted, given the issues of potentially small patient numbers and limited resources. Method A literature review was undertaken to identify relevant articles that dealt with the advantages and disadvantages of IMRT for gynaecological malignancies, and accessed through online journal search engines. Early stage gynaecological malignancy patients, treated in 2006, were identified through Varian (Palo Alto, CA, USA) Varis Vision database. Patients undertaking WPRT with brachytherapy (BT) regime were the only patients considered as suitable candidates for IMRT. Results IMRT reduces toxicity to relevant organs at risk (OAR) such as small bowel (40-70%), rectum (10-66%), bladder (30–46%) and bone marrow (50–60%), but uncertainties exist in the ability to accurately delineate gross tumour volume (GTV) and OAR. Sixteen patients, 1.6% of all patients seen in 2006 at W P Holman Clinic Hobart, Tasmania received treatment to the primary gynaecological tumour alone. Out of this sixteen, seven (0.9%) patients received radical external beam radiation therapy only, four (0.5%) received further dose-escalation treatment with BT. One patient, due to co-morbidities was unable to undergo BT. Therefore, five (0.6%) of the patients were potential candidates for IM-WPRT. Conclusion IMRT planning for early-stage gynaecological malignancies enhances IM-WPRT technique and reduces dose to OAR, therefore increasing the therapeutic ratio. At present, IMRT planning and treatment does not consider daily OAR motion and GTV shrinkage for these patients. Multiple imaging modalities provide such valuable information. IMRT implementation for early-stage gynaecological malignancies in a small radiation therapy centre, of two linear accelerators, is hindered by limited imaging modalities. From the data collected in this study, gynaecological patient numbers are not sufficient to warrant purchase of all required imaging modalities.