title: Prospective analysis of 18F-FDG PET/CT predictive value in patients with low rectal cancer treated with neoadjuvant chemoradiotherapy and conservative surgery.
abstract: This study prospectively assessed (18)F-FDG PET/CT in predicting the response of locally advanced low rectal cancer (LRC) to neoadjuvant chemoradiation (nCRT).
  
  
  METHODS
  56 patients treated with chemoradiation underwent two (18)F-FDG PET/CT scans (baseline and 5-6 weeks post-nCRT). (18)F-FDG uptake (SUVmax and SUVmean) and differences between baseline (SUV1) and post-nCRT (SUV2) scans (ΔSUV and RI%) were evaluated. Results were related to the Mandard's TRG and (y)pTNM.
  
  
  RESULTS
  (18)F-FDG PET/CT sensitivity, specificity, accuracy, PPV and NPV resulted in 88.6%, 66.7%, 83.92%, 90.7%, and 61.5%. SUV2 resulted in better than SUV1 to predict nCRT response by TRG, with no significant statistical difference between the SUVmax2 and SUVmean2 AUC (0.737 versus 0.736; P = 0.928). The same applies to the (y)pTNM (0.798 versus 0.782; P = 0.192). In relation to the TRG, RI values had a higher AUC than ΔSUV, with no significant difference between RImax and RImean (0.672 versus 0.695; P = 0.292). The same applied to the (y)pTNM (0.742 versus 0.741; P = 0.940). In both cases ΔSUV does not appear to be a good predictive tool. Logistic regression confirmed the better predictive role of SUVmax2 for the (y)pTNM (odds ratio = 1.58) and SUVmean2 for the TRG (odds ratio = 1.87).
  
  
  CONCLUSIONS
  (18)F-FDG PET/CT can evaluate response to nCRT in LRC, even if more studies are required to define the most significant parameter for predicting pathologic tumor changes.
authors.affiliation: Nuclear Medicine Unit, DIM, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
authors.forename: Artor
authors.initials: A
authors.lastname: Niccoli-Asabella
authors.affiliation: Nuclear Medicine Unit, DIM, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
authors.forename: Corinna
authors.initials: C
authors.lastname: Altini
authors.affiliation: Department of Surgical Oncology, Istituto Tumori "G. Paolo II", Viale Orazio Flacco 65, 70124 Bari, Italy.
authors.forename: Raffaele
authors.initials: R
authors.lastname: De Luca
authors.affiliation: Nuclear Medicine Unit, DIM, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
authors.forename: Margherita
authors.identifier: 0000-0002-0128-9745
authors.initials: M
authors.lastname: Fanelli
authors.affiliation: Nuclear Medicine Unit, DIM, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubini
authors.affiliation: Department of Surgical Oncology, Istituto Tumori "G. Paolo II", Viale Orazio Flacco 65, 70124 Bari, Italy.
authors.forename: Cosimo
authors.initials: C
authors.lastname: Caliandro
authors.affiliation: Department of Surgical Oncology, Istituto Tumori "G. Paolo II", Viale Orazio Flacco 65, 70124 Bari, Italy.
authors.forename: Severino
authors.initials: S
authors.lastname: Montemurro
authors.affiliation: Nuclear Medicine Unit, DIM, University of Bari "Aldo Moro", Piazza G. Cesare 11, 70124 Bari, Italy.
authors.forename: Giuseppe
authors.identifier: 0000-0003-1972-3308
authors.initials: G
authors.lastname: Rubini
mesh_terms: D000230:Adenocarcinoma / Q000000981:diagnostic imaging / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D012004:Rectal Neoplasms / Q000000981:diagnostic imaging / Q000628:therapy
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18