Positron emission tomography (PET): evaluation of chronic periaortitis.

OBJECTIVE: To evaluate the presence and extent of large-vessel inflammation in patients with chronic periaortitis (CP) using (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET). METHODS: A consecutive case series consisting of 7 patients with CP seen over a 3-year period and a control group of 14 patients with malignancy were evaluated with FDG-PET. For every case we selected 2 age- and sex-matched controls who underwent PET imaging for malignancy. The diagnosis of CP was made by means of computed tomography. PET imaging was performed at diagnosis before therapy was started. Measurement of vascular uptake was graded using a 4-point semiquantitative scale. RESULTS: All patients had evidence of grade 2+ or 3+ vascular uptake in the abdominal aorta and/or iliac artery. No controls showed vascular uptake greater than 1+. Vascular uptake in the thoracic aorta and/or in its branches was seen in 3 (43%) of 7 patients. Vascular uptake in abdominal aorta and/or iliac artery was observed in patients with CP but not in controls (100% versus 0%). There was also a significantly more frequent FDG uptake in the large thoracic arteries in case-patients compared with controls (43% versus 0%; P = 0.03). CONCLUSION: FDG-PET scan shows in patients with CP the presence of a large-vessel vasculitis involving abdominal aorta and common iliac arteries, which in some patients is also extended to thoracic aorta and/or its branches.

The impact of 18F-deoxyglucose positron emission tomography on tumor staging, treatment strategy and treatment planning for radiotherapy in a department of radiation oncology.

AIMS AND BACKGROUND: The study analyzed the potential contribution of positron emission tomography (PET) in patient selection for radiotherapy and in radiation therapy planning. METHODS: Eighty-seven patients with a histological cancer diagnosis were accrued for the study from December 2000 to December 2001. Demographic characteristics included a median age of 54 years and male/female ratio of 51/36. All patients staged by conventional workup who were candidates for radiotherapy had PET imaging and were allocated to a conventional "pre/post-PET stage". The treatment protocol and the shape and/or size of the portals was directly related to PET results. We examined 26 lung cancers, 15 gastrointestinal tumors, 22 genitourinary cancers and 24 hematologic malignancies. RESULTS: In the lung cancer group, the stage was modified in 10/26 patients (38.5%) by PET, with a change in management in 13 (50%) and a change in radiotherapy planning in 6 (23.1%). In the hematological group, stage was modified by PET in 8/24 cases (33.3%), with a change in treatment strategy in 9 (37.5%) and a change in radiotherapy planning in 3 (12.5%). In the gastrointestinal group, the stage was modified by PET in 2/15 cases (13.4%), with a change inn treatment strategy in 4 (26.7%) and a change in the decision for radiotherapy in 8 (no radiotherapy in 53.3%). In the mixed group (genitourinary, breast and other), the stage was modified by PET in 6/22 cases (27.3%), with a change in treatment strategy in 11 (50%) and a very low rate of change in radiotherapy planning. CONCLUSIONS: PET contributed to a modification of stage in 26/87 patients (30%), to a changing in treatment strategy in 37/87 (42.5%), and to a substantial change of the shape and/or size of radiotherapy portals in 13/43 (30%) who underwent radiotherapy.