title: Combined approach of perioperative 18F-FDG PET/CT imaging and intraoperative 18F-FDG handheld gamma probe detection for tumor localization and verification of complete tumor resection in breast cancer.
abstract: BACKGROUND
  18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) has become an established method for detecting hypermetabolic sites of known and occult disease and is widely used in oncology surgical planning. Intraoperatively, it is often difficult to localize tumors and verify complete resection of tumors that have been previously detected on diagnostic PET/CT at the time of the original evaluation of the cancer patient. Therefore, we propose an innovative approach for intraoperative tumor localization and verification of complete tumor resection utilizing 18F-FDG for perioperative PET/CT imaging and intraoperative gamma probe detection.
  
  
  METHODS
  Two breast cancer patients were evaluated. 18F-FDG was administered and PET/CT was acquired immediately prior to surgery. Intraoperatively, tumors were localized and resected with the assistance of a handheld gamma probe. Resected tumors were scanned with specimen PET/CT prior to pathologic processing. Shortly after the surgical procedure, patients were re-imaged with PET/CT utilizing the same preoperatively administered 18F-FDG dose.
  
  
  RESULTS
  One patient had primary carcinoma of breast and a metastatic axillary lymph node. The second patient had a solitary metastatic liver lesion. In both cases, preoperative PET/CT verified these findings and demonstrated no additional suspicious hypermetabolic lesions. Furthermore, intraoperative gamma probe detection, specimen PET/CT, and postoperative PET/CT verified complete resection of the hypermetabolic lesions.
  
  
  CONCLUSIONS
  Immediate preoperative and postoperative PET/CT imaging, utilizing the same 18F-FDG injection dose, is feasible and image quality is acceptable. Such perioperative PET/CT imaging, along with intraoperative gamma probe detection and specimen PET/CT, can be used to verify complete tumor resection. This innovative approach demonstrates promise for assisting the oncologic surgeon in localizing and verifying resection of 18F-FDG positive tumors and may ultimately positively impact upon long-term patient outcomes.
authors.affiliation: Section of PET, Division of Nuclear Medicine, Department of Radiology, The Ohio State University, Columbus, OH, 43210, USA. nathan.hall@osumc.edu.
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Hall
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Povoski
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Murrey
authors.forename: Michael V
authors.initials: MV
authors.lastname: Knopp
authors.forename: Edward W
authors.initials: EW
authors.lastname: Martin