PET can play a useful diagnostic role for patients with vulvar carcinoma, researchers said at the Society of Gynecologic Oncologists (SGO) 41st Annual Meeting on Women's Cancer.

PET using fluorodeoxyglucose (FDG) as a tracer (FDG-PET) is widely used in clinical oncology, including cervical, endometrial, and ovarian cancer. But its use in vulvar carcinoma was unknown.

Akila Viswanathan, MD, Dana Farber Cancer Institute, Boston, Massachusetts, and colleagues used retrospective data to identify 57 women seen at Brigham and Women's Hospital, Dana Farber Cancer Institute, and Massachusetts General Hospital, Boston, Massachusetts, with vulvar malignancies between January 2002 and December 2008, who also had an FDG-PET scan as part of their staging workup.

Data collection for all of the women in the study included patient characteristics such as age, smoking, and symptoms at the time of diagnosis. Tumour and treatment characteristics recorded included tumour size, histology, whether patients had received preoperative or postoperative PET scans, and their subsequent management (ie, radiation treatment and surgery, radiation treatment without surgery, surgery alone, or chemotherapy).

The median age was 69 years and the group was roughly divided between never-smokers and current or former smokers.

The most common presenting symptoms were vulvar lesions and irritation. Within the group, 41 women (72%) had squamous cell histology, 6 (11%) had melanoma, 5 (9%) had adenocarcinoma, and 2 had adenosquamous carcinoma, 1 had non-Hodgkin's lymphoma, 1 had Paget's Disease, and 1 had Synovial sarcoma.

The positive predictive value of FDG-PET scans was 95% for squamous cell carcinoma and 71% for adenosquamous carcinoma and adenocarcinomas combined.

In order to determine the impact of PET on management, patients were divided into 3 groups: preoperative scans (16; 31%), postoperative scans (19; 37%), and inoperable based on PET imaging (16; 31%).

Of the 16 preop scans, 14 (88%) were positive for the primary and 6 (38%) were positive for inguinal lymph nodes. All 14 women with positive primaries had surgery to the primary. Of the 6 positive for inguinal lymph nodes, 5 had nodal surgery with disease identified. The 2 women with negative positron emission tomography ( PET ) scans both had disease on surgery.

Of the 19 postop scans, 16 (84%) had positive scans. In 13 (68%) of these patients, the vulva had residual disease. Within this group, 4 women had surgery followed by radiation, 1 had surgery alone, 1 declined surgery, and 7 had radiation alone.

PET results changed management in 18 of these 19 patients. Eight (44%) patients received radiotherapy instead of surgery due to more extensive disease than anticipated. Four (22%) patients received more extensive surgery than planned, including 2 lymph node dissections, 1 with involvement of lymph node and primary, and 1 with a more extensive primary tumour. Five (28%) patients had additional radiotherapy and surgery, including >=4 extensive primary disease and 1 for more extensive primary plus lymph node involvement. One (6%) patient refused treatment.

The authors concluded that these updated results demonstrate the utility of FDG-PET imaging. It is particularly helpful in identifying patients with node-positive disease that may be clinically nonpalpable at presentation. PET imaging may also influence clinical management, including modification of both radiation and surgical interventions.

Source: SGO

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