Utility of 3-year torso CT and head imaging in asymptomatic patients with high-risk melanoma.

Abstract

8594 Background: Patients (pts) with stage IIB to IIIC melanoma have a lifetime risk of melanoma related mortality of 30- 60%. By 3 years (yrs) from initial diagnosis, the risk of relapse in pts who remain disease free is decreased by 50%-75%. We sought to determine the utility and cost effectiveness of radiologic restaging of this pt population at the 3-yr follow-up (f/up) time point. Methods: In 2004, the BIDMC Cutaneous Oncology Program (COP) began obtaining torso CT scan and head imaging at the 3-yr f/up visit in all pts with stage IIB-IIIC melanoma who remained recurrence free. Chart review was performed on the 50 pts within the COP database who had undergone such restaging through 7/09. True positive (TP), false positive (FP) and normal scans were identified. Analysis of the cost of imaging and the cost of additional intervention for f/up of positive studies was performed, and a cost/diagnosis (TP) was calculated. Results: 25 head CT scans, 25 head MRIs, and 50 torso CTs were performed. One FP head CT and 5 abnormal torso CT scans (3 FP, 2 TP) were identified. FP and TP rates were 4/50 (8%); 2/50, (4%), respectively. The total cost including 3 yr f/up scans, additional imaging (1 repeat head CT, 2 chest CTs, 1 abdominal MRI) and diagnostic procedures (1 CT-guided lung biopsy (bx), one pelvic LN bx) was $600,406. The cost/diagnosis was $300,203. Both pts with TP scans developed symptomatic recurrence within weeks and died at 1 and 6.5 months after stage IV diagnosis. In the remaining 48 pts, at a median f/up of 14.5 months after the 3-yr f/up scan, 1 pt developed symptomatic stage IV disease and 1 developed local recurrence. Conclusions: In patients with stage IIB-IIIC melanoma who are asymptomatic and continuously disease free, extensive 3-yr f/up imaging appears to be of limited value. Two-thirds of abnormalities are FPs, and the cost of identifying a TP is > $300K/pt. Based on these findings, routine torso CT and head imaging of such pts is not recommended. Furthermore, given the low risk of recurrence beyond 3 yrs, it is likely that subsequent routine imaging would have similarly low utility. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Abraxis BioScience, Antigenics, Bayer, Genentech, Novartis, Onyx, Pfizer, Schering-Plough