Purpose: Poor sensitivity and accuracy have been reported using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in the detection of ductal carcinoma in situ (DCIS), yet no reference to the use of 18F-fluoromethylcholine (FCH) PET can be identified in the in situ breast cancer literature. This study determined the tumour to background ratio for cases where both FDG and FCH-PET were used to detect DCIS.

Methods: Patients with newly diagnosed DCIS were recruited from the Breast Assessment Centre at a Western Australian teaching hospital. During the 16 month recruitment period, two patients consented to participate in the study. Each underwent a FDG-PET and a FCH-PET scan. The activity within the tumour was measured against the activity in the contralateral breast to obtain the tumour-to-background ratio.

Results: The DCIS lesions were visualised on the FDG and FCH-PET scans in both patients. The tumour to background ratios were 1.49:1 and 1.47:1 for the FDG-PET scan, compared to 1.49:1 and 1.20:1 for the FCH-PET scan. Both patients had comedo/ solid unifocal DCIS, with intermediate and high nuclear grade.

Conclusions: FDG-PET gave a higher tumour to background ratio than FCH-PET in the detection of DCIS and hence appeared to be the preferred radiopharmaceutical for imaging and hand-held PET technology in in situ breast cancer management.