Clinical Nuclear Medicine

68 Ga-Pentixafor PET/MRI for Treatment Response Assessment in Mantle Cell Lymphoma: Comparison Between Changes in Lesion CXCR4 Expression on PET and Lesion Size and Diffusivity on MRI
Evaluation of 11 C-Choline PET/CT for T Staging and Tumor Volume Delineation in Nasopharyngeal Cancer Patients in Comparison to 18 F-FDG PET/CT
67 Ga-PSMA I&T for Radioguided Surgery of Lymph Node Metastases in Patients With Biochemical Recurrence of Prostate Cancer
Incidental Finding of Intervertebral Disc Herniation With Increased 18 F-FAPI-04 Uptake in a Healthy Volunteer
FDG PET/CT in Primary Retroperitoneal Serous Carcinoma
Frontal Hypoperfusion and Cerebellar Hyperperfusion in Transient Alcoholic Cerebellar Degeneration
FDG PET/CT Imaging of Severe Polymyalgia Rheumatica
Assessment of Microglial Activation in Alzheimer Disease Using 18 F-PBR06 PET

Editor's Note

This month's Editor's favorite is Li and colleagues' Evaluation of 11C-Choline PET/CT for T Staging and Tumor Volume Delineation in Nasopharyngeal Cancer Patients in Comparison to 18F-FDG PET/CT.

18F-FDG PET/CT is limited by the high physiological uptake in the surrounding brain tissue. 11C-choline PET/CT is known to accumulate in nasopharyngeal cancer (NPC). The authors investigated if 11C-choline could improve the accuracy of T staging and tumor volume delineation in 39 patients with pathologically confirmed NPC. Primary tumor extension was evaluated by 11C-choline PET/CT, 18F-FDG PET/CT, and contrast-enhanced MRI. PET/CT-based tumor volume (VPET) was measured by 3 threshold methods, including the threshold of SUV 2.5 (Th2.5), 40% of maximal SUV (Th40%), and relative background-dependent threshold (Thbgd).

Tumor volume and Dice similarity coefficient were compared among VPET with different segmentation methods and VMR.

Thirty-three patients with treatment-naive NPC and 6 patients with suspicious recurrent disease were enrolled. The NPC lesions were avid for both 11C-choline and 18F-FDG. Visual analysis showed that 11C-choline PET/CT had better contrast and higher discernability than 18F-FDG PET/ CT for intracranial, skull base, and orbital involvement. 11C-choline PET/ CT also exhibited advantage over MRI for differentiation between local recurrence and radiation-induced alterations. For the tumor delineated, the VMR was larger than VPET in general, except for 18F-FDG PET/CT with Th2.5 threshold. For all 3 threshold methods, 11C-choline PET/CT produced more consistent and comparable tumor volume to MRI than 18F-FDG PET/CT. 11C-choline PET/CT with Thbgd threshold showed the closest tumor volume and highest similarity to MRI.

The investigators concluded that 11C-choline PET/CT provides a higher accuracy than 18F-FDG PET/CT in mapping tumor extension in locally advanced NPC and may be a promising complement to MRI in delineating the primary tumor.