The role of [(18)F]FDG-PET/CT in staging and treatment planning for volumetric modulated Rapidarc radiotherapy in cervical cancer: experience of the European Institute of Oncology, Milan, Italy.

Rationale: to evaluate the role of 18F-fluorodeoxyglucose positron emission tomography ([(18)F]FDG-PET) integrated with computer tomography (CT) scan [(18)F]FDG-PET/CT in the staging and target volume definition in Intensity Modulated RapidarcTM Delivery (RA-IMRT) in cervical cancer.

Methods: From June 2010 to December 2011, 66 patients affected by cervical cancer, candidates for definitive or adjuvant radiochemotherapy, underwent standard staging with CT and magnetic resonance imaging (MRI). All patients underwent [(18)F]FDG-PET/CT in order to exclude distant metastases and to define gross tumor volume (GTV). 40 and 26 patients received exclusive and adjuvant radiotherapy, respectively. RA-IMRT with simultaneous integrated boost (SIB) to the positive disease technique was employed.

Results: [(18)F]FDG-PET/CT has changed the stage, and radiotherapy treatment planning was modified in 25% and 7.7 % of patients that received definitive and adjuvant radiotherapy, respectively. Particularly [(18)F]FDG-PET/CT imaging showed metabolically active tumor in lymph nodes area, therefore the stage and the treatment planning changed for these patients.

Conclusions: [(18)F]FDG-PET/CT leads to a better staging and definition of disease and has the potential of showing lymph-node metastasis not only within the pelvis but also in the para-aortic area. In addition, [(18)F]FDG-PET/CT is useful for better definition of the target volume and to produce a 'dose painted' treatment. This might also open the field for escalation dose regimens.