title: Predictive and prognostic value of FDG-PET/CT imaging and different response evaluation criteria after primary systemic therapy of breast cancer.
abstract: OBJECTIVE
  (1) To predict pathological complete remission (pCR) and survival after primary systemic therapy (PST) in patients diagnosed with breast cancer by using two different PET/CT based scores: a simplified PERCIST-based PET/CT score (Method 1) and a combined PET/CT score supplemented with the morphological results of the RECIST system (Method 2) and (2) to assess the effect of different breast carcinoma subtypes on tumor response and its evaluation.
  
  
  METHODS
  Eighty-eight patients were enrolled in the study who underwent PET/CT imaging before and after PST. PET/CTs were evaluated by changes in maximum Standardized Uptake Value (SUVmax) and tumor size. Method 1 and 2 were applied to predict pathological complete remission (pCR). Kaplan-Meier analyses for survival were performed. Classification into biological subtypes was performed based on the pre-therapeutic tumor characteristics.
  
  
  RESULTS
  A total of 30/88 patients showed pCR (34.1 %). Comparing pCR/non-pCR patient groups, significant differences were detected by changes in SUVmax (p < 0.001) and tumor size (p < 0.001) regarding the primary breast lesions. To predict pCR, Method 2 had higher sensitivity (72.4 % vs. 44.8 %) and negative predictive value (57.9 % vs. 45.8 %) with lower false negativity rate (16 vs. 32) than Method 1. pCR rate was higher in Her2-positive and triple negative tumors. Despite the significant differences detected between the biological subtypes regarding changes in primary tumor SUVmax (p = 0.007) and size (p = 0.015), the subtypes only had significant impact on response evaluation with Method 2 and not with Method 1. In our study, neither clinical nor pathological CR were predictors of longer progression-free survival.
  
  
  CONCLUSIONS
  Our results suggest that combined PET/CT criteria are more predictive of pCR. The effect of biological subtypes is significant on pCR rate as well as on the changes in FDG-uptake and morphological tumor response. Response evaluation with combined criteria was also able to reflect the differences between the biological behavior of breast tumor subtypes.
authors.affiliation: Oncological Division, 1st Department of Internal Medicine, Semmelweis University, Tömő utca 25-29, 4th floor, Budapest, 1083, Hungary.
authors.forename: Tímea
authors.initials: T
authors.lastname: Tőkés
authors.affiliation: Pozitron PET/CT Center, Hunyadi J. út 9, Budapest, 1117, Hungary.
authors.forename: Kornélia
authors.initials: K
authors.lastname: Kajáry
authors.affiliation: Oncological Division, 1st Department of Internal Medicine, Semmelweis University, Tömő utca 25-29, 4th floor, Budapest, 1083, Hungary.
authors.forename: Gyöngyvér
authors.initials: G
authors.lastname: Szentmártoni
authors.affiliation: Pozitron PET/CT Center, Hunyadi J. út 9, Budapest, 1117, Hungary.
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Lengyel
authors.affiliation: Department of Nuclear Medicine, Semmelweis University, Üllői út 78/A, Budapest, 1082, Hungary.|Scanomed Ltd, Laky Adolf utca 44, Budapest, 1145, Hungary.
authors.forename: Tamás
authors.initials: T
authors.lastname: Györke
authors.affiliation: Oncological Division, 1st Department of Internal Medicine, Semmelweis University, Tömő utca 25-29, 4th floor, Budapest, 1083, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Torgyík
authors.affiliation: Surgical Division of the St Margaret Hospital, Bécsi út 132, Budapest, 1032, Hungary.
authors.forename: Krisztián
authors.initials: K
authors.lastname: Somlai
authors.affiliation: MTA-SE Tumor Progression Research Group, 2nd Department of Pathology, Üllői út 93, Budapest, 1091, Hungary.|2nd Department of Pathology, Semmelweis University, Üllői út 93, Budapest, 1091, Hungary.
authors.forename: Anna-Mária
authors.initials: AM
authors.lastname: Tőkés
authors.affiliation: MTA-SE Tumor Progression Research Group, 2nd Department of Pathology, Üllői út 93, Budapest, 1091, Hungary.|2nd Department of Pathology, Semmelweis University, Üllői út 93, Budapest, 1091, Hungary.
authors.forename: Janina
authors.initials: J
authors.lastname: Kulka
authors.affiliation: Oncological Division, 1st Department of Internal Medicine, Semmelweis University, Tömő utca 25-29, 4th floor, Budapest, 1083, Hungary. phd.se.oncology@gmail.com.
authors.forename: Magdolna
authors.initials: M
authors.lastname: Dank
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D003430:Cross-Sectional Studies; D018572:Disease-Free Survival; D005188:False Negative Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008408:Mastectomy; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D011379:Prognosis; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Breast cancer; FDG-PET/CT; PERCIST; Primary systemic therapy; RECIST