Positron emission tomography is superior to computed tomography for metastatic detection in melanoma patients.
BACKGROUND
Whole-body positron emission tomography (PET) provides diagnostic information not currently available with traditional imaging and may improve the accuracy of staging melanoma patients.


METHODS
A retrospective cohort review was performed of 104 patients with primary or recurrent melanoma who underwent PET to determine sensitivity/specificity for metastatic detection compared with body computed tomography (CT). One hundred fifty-seven PET and 70 CT scans were analyzed, with a median patient follow-up of 24 months. Metastases were confirmed with positive histology (87.5%) or documented disease progression (12.5%). Fifty-three patients prospectively underwent consecutive studies within a mean 3-week interval for direct comparative analysis.


RESULTS
PET demonstrated 84% sensitivity (95% confidence interval [CI],.78 to.89) and 97% specificity (95% CI,.91 to.99), whereas CT showed 58% sensitivity (95% CI,.49 to.66) and 70% specificity (95% CI,.51 to.84). Exclusion of areas not evaluated on CT (head, neck/supraclavicular, extremities) increased CT sensitivity to 69% (95% CI,.59 to.77). Sixty-six consecutive PET and CT scans were performed with 81% and 57% of metastases detected, respectively.


CONCLUSIONS
PET is more sensitive and specific than CT for detection of melanoma metastasis and should be considered the primary staging study for recurrent disease. PET shows greater ability to detect soft tissue, small-bowel, and lymph node metastasis that do not meet criteria designated as abnormal by CT. PET is superior to CT even when sites not routinely evaluated by CT are excluded from comparative analysis.
Swetter
Susan M
SM
Dermatology (SMS) and Nuclear Medicine (GMS) Services, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA. sswetter@stanford.edu
Carroll
Lisa A
LA
Johnson
Denise L
DL
Segall
George M
GM
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000000981:diagnostic imaging*; D009367:Neoplasm Staging; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D014055:Tomography, Emission-Computed; D014057:Tomography, X-Ray Computed