title: Locoregional lymph node involvement on 18F-FDG PET/CT in breast cancer patients scheduled for neoadjuvant chemotherapy.
abstract: The optimal method for locoregional staging in patients treated with neoadjuvant chemotherapy (NAC), usually ultrasound (US) and pre- or post-chemotherapy sentinel lymph node biopsy (SLNB), remains subject of debate. The aim of this study was to assess the value of 18F-FDG PET/CT for detecting locoregional lymph node metastases in primary breast cancer patients scheduled for NAC. 311 breast cancer patients, scheduled for NAC, underwent PET/CT of the thorax in prone position with hanging breasts. A panel of four experienced reviewers examined PET/CT images, blinded for other diagnostic procedures. FDG uptake in locoregional nodes was determined qualitatively using a 4-point scale (0 = negative, 1 = questionable, 2 = moderately intense, and 3 = very intense). Results were compared with pathology obtained by US-guided fine needle aspiration or SLNB prior to NAC. All FDG-avid extra-axillary nodes were considered metastatic, based on the previously reported high positive predictive value of the technique. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of FDG-avid nodes for the detection of axillary metastases (score 2 or 3) were 82, 92, 98, 53, and 84 %, respectively. Of 28 patients with questionable axillary FDG uptake (score 1), 23 (82 %) were node-positive. Occult lymph node metastases in the internal mammary chain and periclavicular area were detected in 26 (8 %) and 32 (10 %) patients, respectively, resulting in changed regional radiotherapy planning in 50 (16 %) patients. In breast cancer patients scheduled for NAC, PET/CT renders pre-chemotherapy SLNB unnecessary in case of an FDG-avid axillary node, enables axillary response monitoring during or after NAC, and leads to changes in radiotherapy for a substantial number of patients because of detection of occult N3-disease. Based on these results, we recommend a PET/CT as a standard staging procedure in breast cancer patients scheduled for NAC.
authors.affiliation: Department of Nuclear Medicine, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
authors.forename: Bas B
authors.initials: BB
authors.lastname: Koolen
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés Olmos
authors.forename: Paula H M
authors.initials: PH
authors.lastname: Elkhuizen
authors.forename: Wouter V
authors.initials: WV
authors.lastname: Vogel
authors.forename: Marie-Jeanne T F D
authors.initials: MJ
authors.lastname: Vrancken Peeters
authors.forename: Sjoerd
authors.initials: S
authors.lastname: Rodenhuis
authors.forename: Emiel J Th
authors.initials: EJ
authors.lastname: Rutgers
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008875:Middle Aged; D064847:Multimodal Imaging; D020360:Neoadjuvant Therapy; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D021701:Sentinel Lymph Node Biopsy; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18