title: Prediction of positron emission tomography/computed tomography (PET/CT) positivity in patients with high-risk primary melanoma.
abstract: Positron emission tomography/computed tomography (PET/CT) is an important tool to identify occult melanoma metastasis. To date, it is controversial which patients with primary cutaneous melanoma should have staging PET/CT. In this retrospective analysis of more than 800 consecutive patients with cutaneous melanoma, we sought to identify factors predictive of PET/CT positivity in the setting of newly-diagnosed high-risk primary melanoma to determine those patients most appropriate to undergo a PET/CT scan as part of their diagnostic work up. 167 patients with newly-diagnosed high-risk primary cutaneous melanoma underwent a PET/CT scan performed as part of their initial staging. Clinical and histologic factors were evaluated as possible predictors of melanoma metastasis identified on PET/CT scanning using both univariate and multivariate logistic regression. In all, 32 patients (19.2%) had a positive PET/CT finding of metastatic melanoma. In more than half of these patients (56.3%), PET/CT scanning identified disease that was not detectable on clinical examination. Mitotic rate, tumor thickness, lymphadenopathy, and bleeding were significantly predictive of PET/CT positivity. A combinatorial index constructed from these factors revealed a significant association between number of high-risk factors observed and prevalence of PET/CT positivity, which increased from 5.8% (with the presence of 0-2 factors) to 100.0%, when all four factors were present. These results indicate that combining clinical and histologic prognostic factors enables the identification of patients with a higher likelihood of a positive PET/CT scan.
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research InstituteSan Francisco, California 95107, USA; University of CopenhagenCopenhagen, Denmark.
authors.forename: Maria
authors.initials: M
authors.lastname: Danielsen
authors.affiliation: Department of Clinical Physiology, Nuclear Medicine and PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen Copenhagen, Denmark.
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjaer
authors.affiliation: Department of Nuclear Medicine and Radiology, California Pacific Medical Center San Francisco, California 95107, USA.
authors.forename: Max
authors.initials: M
authors.lastname: Wu
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: Lea
authors.initials: L
authors.lastname: Martineau
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Nosrati
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: Stanley Pl
authors.initials: SP
authors.lastname: Leong
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: Richard W
authors.initials: RW
authors.lastname: Sagebiel
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: James R
authors.initials: JR
authors.lastname: Miller
authors.affiliation: Center for Melanoma Research and Treatment, California Pacific Medical Center Research Institute San Francisco, California 95107, USA.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Kashani-Sabet
keywords: FDG; Melanoma; PET; PET/CT; molecular imaging; nuclear medicine; skin cancer; staging