Dedicated breast-PET-guided biopsy

Objectives Efforts to create dedicated Nuclear Medicine breast imaging scanners are maturing as they approach more routine clinical use. Since these techniques lack sufficient specificity for accurate diagnoses of breast cancer, a method for guiding biopsies with these new devices must be developed. In this investigation, the capabilities of our new dedicated breast PEM-PET system to guide biopsies was tested.

Methods The PEM-PET system has two pairs of rotating pixelated detectors to acquire data to produce tomographic images of the breast that can be used to direct the placement of a biopsy needle using a computer-controlled arm. The accuracy and precision of the placement of the biopsy needle was measured by the imaging of a phantom possessing multiple point-like source. The position of each source in the scanner's FOV was well known. Their locations were assessed using PET images of the phantom; the biopsy needle was moved to the the calculated positions. The accuracy and precision of needle positioning relative to the sources was measured from ten individual trials. Additionally, a "biopsy" was performed on a simulated breast contianing a 5mm-diameter "lesion".

Results The results from the positioning tests revealed that the system had very good accuracy and precision in all three axes. The maximum positioning error was ±0.27mm, sufficient to obtain samples from most lesions detected with PEM-PET. In addition, the simulated biopsy was performed successfully on a single attempt.

Conclusions This successful test demonstrates the ability of the PEM-PET system to guide the biopsy of suspicious lesions imaged with the PEM-PET scanner.

Research Support This work was supported in part by the National Cancer Institute (Grant Number R01 CA094196).