SELECTED CASE EXPERIENCES
Case 1: Melanoma was removed from foot of patient five years ago. Recent PET scan showed hot spot in groin. Operation was performed for suspected metastatic melanoma. Patient was injected with FDG before surgery. Intraoperative use of the PET Probe assisted in localizing an inguinal lymph node that was cancerous. Node located by PET probe was 6 cm away from location measured on PET scan in Radiology.
Case 2: Patient was operated on to rule-out recurrent Hodgkin’s lymphoma. PET scan before surgery showed suspected hot spot in axilla. PET Probe used during surgery localized a cancerous sub-pectoral tumor positioned very medially to the axilla. Cancer was confirmed by Pathology.
Denise Johnson, M.D.
Director, Melanoma Program
Stanford University Medical Center, Palo Alto, CA
In a study to evaluate the ability of the PET Probe for intraoperative localization of recurrent melanoma to enable complete tumor resection and improved patient outcome, the PET Probe results yielded a sensitivity of 89% and specificity of 100%. In three out of five cases, PET Probe allowed the identification of non-visualized and non-palpable tumor foci that were later confirmed pathologic.
Stanley Leong, M.D.
UCSF Comprehensive Cancer Center, San Francisco
Two hot spots appeared on the PET scan image near the axilla of a breast cancer patient. Patient was injected with FDG before surgery. During surgery, the lesions were not readily visualized since they were under the pectoral muscle. The PET Probe accurately localized both hot spots for excision, which were confirmed by pathology as cancerous lymph nodes, and saved time in surgery.
Janet Ihde, M.D.
Desert Comprehensive Breast Center, Palm Springs, CA
In a prospective, diagnostic phase II study, 40 patients underwent surgical exploration using PET-probe. 6 patients were selected for therapeutic excisions and four for diagnostic excisions for recurrent or metastatic disease. Patients underwent a PET scan or MRI scan to detect tumor sites and to guide surgical decisions. A second dose of FDG was administered between one and four hours before surgery. In all patients, the PET Probe was able to detect tumors seen with the preoperative PET or MRI scan. The probe localized four lesions that were not palpable and found two lesions that were not on the preoperative scan.
Seza Gulec, M.D.
Center for Cancer Care, Goshen, IN
Patient was evaluated for recurrent lymphoma. A hot spot was detected in the axilla on the PET scan image. Guided by the PET Probe, an incision was made. Two cm into the axilla an enlarged lymph node was visualized, but ex-vivo counts showed no radioactivity. Further dissection revealed a second enlarged lymph node that was excised, again with no ex-vivo radioactivity. The PET Probe was inserted into the cavity and, directed by high counts, a deeper dissection led to a third lymph node that was excised. This node showed high counts ex-vivo and was confirmed as the cancer. Without PET Probe, the diagnosis would have been missed and treatment delayed.
Vijay Trisal, M.D.
City of Hope Medical Center, Duarte, CA
A staging CT scan on a 44 year-old woman with breast cancer suggested a possible metastasis in the retroperitoneum adjacent to the duodenum. The lesion was positive on a whole-body PET scan. During an exploratory laparotomy the lesion was palpable and also had a positive uptake with the hand-held PET Probe. In-vivo and ex-vivo measurements with the hand-held PET Probe provided concordance with the preoperative images and assured us that the correct lesion had been successfully excised. The final pathology report showed a paraganglioma.
Jay K. Harness, MD
St. Joseph Hospital Comprehensive Breast Center, Orange, CA