Pre-radiotherapy FDG PET for treatment planning in Hodgkin's lymphoma may lead to significant modification of the treatment strategy and the radiotherapy planning in patients with Stage I or II Hodgkin's disease, even in those who have undergone FDG PET as part of the pre-chemotherapy work-up, according to research published May 7 in the International Journal of Radiation Oncology Biology Physics.
The impact of pre-radiotherapy 18F-FDG PET on treatment strategy and radiotherapy planning was assessed in 137 patients (124 were available for analysis) with Stage I/II Hodgkin's disease in 11 centers between January 2004 and January 2006 in a large prospective multicenter study.
Conventional CT and FDG PET were performed just before the planned radiotherapy, wrote Pascal Pommier, MD, PhD, and colleagues at the department of radiation oncology, Lyon University-Centre Léon Bérard, Lyon, France.
The radiotherapy plan was first elaborated under blinded conditions for FDG PET data. The medical staffs were asked to confirm or not confirm the treatment strategy and, if appropriate, to modify the radiotherapy plan based on additional information from FDG PET, according to Pommier and colleagues.
Pre-chemotherapy work-up included FDG PET for 61 patients, and data were available for elaboration of the first radiotherapy plan. Based on preradiotherapy FDG-PET data, the radiotherapy was cancelled in six patients (4.8 percent), and treatment plan modifications occurred in 16 patients (12.9 percent), the researchers found.
Pommier and colleagues also demonstrated that the concordance between the treatment strategies with or without pre-radiotherapy FDG PET was 82.3 percent, while concordance results were not significantly different when pre-chemotherapy PET/CT information was available.