title: PET CT imaging in patients undergoing sentinel node biopsy for melanoma.
abstract: OBJECTIVE
  Sentinel lymph node biopsy (SLNB) has been adopted in the surgical treatment of melanoma to reduce morbidity and enhance staging. Positron emission tomography with computerised tomography (PET/CT) has been utilised in the staging of patients with malignancy though the role of this imaging modality in early stage melanoma is unclear. This study examined the preoperative value of PET/CT in patients undergoing SLNB for malignant melanoma.
  
  
  METHODS
  Patients presenting with primary melanoma without evidence of either locoregional or systemic metastasis were considered candidates for SLNB. Selected patients underwent preoperative PET/CT followed by definitive surgical therapy including SLNB with regional lymphadenectomy, where indicated.
  
  
  RESULTS
  During a 12-month period 83 patients were identified as having undergone SLNB for melanoma, of which 37 (45%) had preoperative PET/CT. Mean melanoma thickness 1.9 mm and 2.4 mm (PET/CT vs. no PET/CT, p>0.05). 13 (15.6%) patients were found to have lymphatic metastasis at SLNB; nine of these patients underwent PET/CT, only two of these scans were suggestive of lymphatic metastasis (positive predictive value 24%, negative predictive value 76%). PET/CT revealed no unheralded metastatic disease but did identify a second occult malignancy in 4 (10.8%) patients undergoing therapy for melanoma.
  
  
  CONCLUSIONS
  The results of this study do not support the use of PET/CT in patients undergoing SLNB for melanoma. SLNB appears to be a more sensitive staging modality in the detection of lymphatic metastasis; however PET/CT may have a future role as a screening tool for malignancy.
authors.affiliation: Department of Surgical Oncology, Department of Surgery, Fox Chase Cancer Center, Philadelphia, PA 19111, USA. malcolm.kell@breastcheck.ie
authors.forename: M R
authors.initials: MR
authors.lastname: Kell
authors.forename: J A
authors.initials: JA
authors.lastname: Ridge
authors.forename: N
authors.initials: N
authors.lastname: Joseph
authors.forename: E R
authors.initials: ER
authors.lastname: Sigurdson
mesh_terms: D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy