No abstract

Purpose: The purpose of this study was to evaluate the predictive value of 2-deoxy-2- [F-18] fluoro-D-glucose-positron emission tomography (FDG-PET) following concurrent chemoradiotherapy (CRT) on survival in patients with carcinoma of the oropharynx (OPC). Methods: Eighteen patients with primary OPC who underwent PET pre-and post-CRT were evaluated prospectively for survival. The prognostic performance of post-CRT PET and CT for recurrence was compared. Results: Patients with positive post-CRT PET exhibited significantly lower 2-year cause-specific survival and disease-free survival (50% vs. 91%, PG0.05 and 0% vs. 83%, PG0.0001); however, patients with positive post-CRT CT did not exhibit any significant difference (67% vs. 83%, P= 0.416 and 50% vs. 75%, P=0.070). Other factors, such as clinical and pre-CRT PET variables, also did not indicate any significant difference. The accuracy of prediction of residual and local recurrence for post-CRT PET and CT (local%/regional%) was 83%/94% and 83%/78%, respectively. Conclusion: OPC patients with positive post-CRT PET exhibit poor survival. The prognostic accuracy of post-CRT PET is superior to that of CT. The results of post-CRT FDG-PET should be included in the management of the OPC patients.

FDG-PET can be used to detect MALT lymphoma when it forms mass lesions, whereas it is difficult to detect non-massive MALT lymphoma of gastrointestinal origin.

High SUV values (early SUV > 4.5) suggest the presence of high-risk tumors. A very high SUV value (early SUV > 7.1) is useful for the differentiation of thymic carcinomas from other types of tumors. The delayed SUV values were higher than the early SUV values in all types of tumors.

Chronic expanding hematoma is a rare presentation of a hematoma characterized by a persistent increase in size for more than a month after the initial hemorrhage. We present a 65-year-old man with a chronic expanding hematoma in his ilium who was receiving anticoagulant treatment. The patient had a delayed manifestation of a femoral neuropathy with massive bone destruction. 2-Deoxy-[18F]fluoro-D: -glucose (FDG) positron emission tomography (PET) imaging revealed an increased uptake in the rim of the mass in images acquired 1 h after FDG injection. FDG-PET scans were performed using a dedicated PET scanner (HeadtomeV/SET2400 W, Shimadzu, Kyoto, Japan), and the PET data for the most metabolically active region of interest (ROI) were analyzed. The maximum standardized uptake value (SUVmax) was set to a cut-off point of 3.0 to distinguish between benign and malignant lesions. The SUVmax of the patient's lesion was 3.10, suggesting a malignant lesion. The characteristics of FDG-PET images of chronic expanding hematomas, including the uptake of FDG in the peripheral rim of the mass as a result of inflammation, should be recognized as a potential interpretive pitfall in mimicking a sarcoma.