title: Multicentric study on ¹⁸F-FDG-PET/CT breast incidental uptake in patients studied for non-breast malignant purposes.
abstract: OBJECTIVE
  Our study has aimed to establish the prevalence and pathological nature of fluorine-18-fluorodeoxyglucose ((18)F-FDG) breast incidental uptake (BIU) in patients studied for non-malignant breast tumours and then to compare our data obtained in three Italian nuclear medicine centres with those available in literature.
  
  
  METHODS
  We retrospectively evaluated 42,927 (18)F-FDG-PET/CT scans performed on patients studied in three Italian Nuclear Medicine Centres. All patients underwent (18)F-FDG-PET/CT for oncologic purposes not related to breast disease.
  
  
  RESULTS
  Among 42,927 scans, a BIU was identified in 79 (0.18%) patients, 75 (95%) female and 4 (5%) male with an average age of 62 ± 17 years. Twenty-five out of 35 (71.5%) BIUs were malignant and 10/35 (28.5%) benign. Among the 25/35 incidentalomas that were malignant, 12/25 (48%) were infiltrating ductal carcinoma, 5/25 (20%) ductal carcinoma (infiltrating and in situ), 4/25 (16%) lobular carcinoma, 2/25 (8%) ductal carcinoma in situ and 2/25 (8%) were metastases from the primary tumour under investigation. Of the 10 BIUs that were benign in the histological examination, after further investigations it was found that 9/10 (90%) were fibroadenomas and 1/10 (10%) was a benign lesion not better specified. The lesion to liver or to blood-pool SUVmax ratio in malignant lesions is significantly higher than in benign ones.
  
  
  CONCLUSIONS
  Our multicenter study demonstrates that, although they are uncommon, BIUs show a high percentage of malignancy and therefore requires further research.
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, Brescia, Italy. Electronic address: francesco.bertagna@spedalicivili.brescia.it.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bertagna
authors.affiliation: Radiotherapy and Nuclear Medicine Unit, Istituto Oncologico Veneto IOV-IRCCS, Padova, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Evangelista
authors.affiliation: Department of Nuclear Medicine, Ospedali Galliera, Genoa, Italy.
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Piccardo
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Mattia
authors.initials: M
authors.lastname: Bertoli
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Bosio
authors.affiliation: Nuclear Medicine, University of Brescia and Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: Giubbini
authors.affiliation: Department of Radiology, Spedali Civili di Brescia, Brescia, Italy.
authors.forename: Emanuela
authors.initials: E
authors.lastname: Orlando
authors.affiliation: Department of Nuclear Medicine and PET/CT Center, Oncology Institute of Southern Switzerland, Bellinzona, Switzerland.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Treglia
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001941:Breast Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology; D001943:Breast Neoplasms / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000556:secondary; D018567:Breast Neoplasms, Male / Q000000981:diagnostic imaging / Q000453:epidemiology; D018270:Carcinoma, Ductal, Breast / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000737:chemistry / Q000000981:diagnostic imaging / Q000453:epidemiology; D018275:Carcinoma, Lobular / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005260:Female; D018226:Fibroadenoma / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000453:epidemiology; D005462:Fluorine Radioisotopes / Q000493:pharmacokinetics*; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D033162:Incidental Findings; D007558:Italy; D008297:Male; D008875:Middle Aged; D009378:Neoplasms, Multiple Primary / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000453:epidemiology; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D012189:Retrospective Studies; D014018:Tissue Distribution
chemical_list: D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: (18)F-FDG; Breast; Incidentaloma; Mama; PET/CT; PET/TAC