Evaluating the Use of 18F-FDG PET CT for External Beam Radiotherapy Planning in Gynaecological Malignancies

Abstract

Our review confirms that the incorporation of 18F-FDG PET CT during radiotherapy planning may decrease inter-observer variability during target delineation. It can also provide useful functional information regarding the tumour, which may facilitate the development of techniques for dose escalation and 'dose painting' not only for primary disease, especially in cervical cancer, but also nodal metastasis. The utilisation of this functional modality in external beam radiotherapy planning, particularly in locally advanced cervical malignancy, is an exciting topic that warrants further prospective research. Perhaps the most valuable role may be the potential to deliver dose escalation to 18F-FDG PET CT avid targets previously limited by organ at risk constraints, now that we have significantly more advanced radiotherapy planning tools at our disposal.

Impact of suboptimal dosimetric coverage of pretherapeutic 18F-FDG PET/CT hotspots on outcome in patients with locally advanced cervical cancer treated with chemoradiotherapy followed by brachytherapy

“…For brachytherapy, a residual gross tumor volume (GTV), a high-risk clinical target volume (CTV-HR) and an intermediate-risk clinical target volume (CTV-IR) are defined according to (i) gynecological examination and (ii) MRI at diagnosis and at the time of brachytherapy [6]. However, the role of PET in radiotherapy planning and particularly in volume delineation has been poorly studied in patients with CC [7][8][9][10][11][12].…”

Use of Baseline 18F-FDG PET/CT to Identify Initial Sub-Volumes Associated With Local Failure After Concomitant Chemoradiotherapy in Locally Advanced Cervical Cancer

“…The intensity of 18 F-FDG uptake may also constitute a potential diagnostic and prognostic factor: pre-treatment maximum standardized uptake value (SUV max ) has been shown to be significantly associated with the presence of synchronous lymph nodes metastasis, and to be independently correlated with recurrence and survival in a retrospective monocentric cohort of 149 patients (8). However, the role of PET for the radiotherapy planning and particularly for volume delineation has not been as extensively investigated in patients with CC as in other sites such as head and neck (9)(10)(11)(12)(13). Currently the determination of the gross tumor volume (GTV, corresponding to the primary tumor) and the clinical target volume (CTV) are based on magnetic resonance imaging (MRI) only.…”