title: [Quantitative and qualitative evaluation of the interim PET/CT in lymphoma treatment in the prediction of complete metabolic response].
abstract: OBJECTIVE
  To compare two different methods for the interpretation of interim PET/CT (PET/CT-i) in lymphomas, and to establish which one best predicts a complete metabolic response (CMR) in the PET/CT study at the end of treatment (PET/CT-et).
  
  
  METHODS
  Retrospective longitudinal analysis of the PET/CT studies for staging (PET/CT-s), PET/CT-i and PET/CT-et of 65 patients, 35 Hodgkin's lymphoma (HL) and 30 Non-HL. The PET/CT-i was performed between the second and fourth chemotherapy cycle. It was interpreted using two different criteria: qualitative criteria (5 point visual scale), semiquantitative criteria (percentage difference between the lesion with more SUVmax in the PET/CT-s and PET/CT-i). We analyzed the likelihood of obtaining a CMR in the PET/CT-et according to the results obtained on the PET/CT-i with these two criteria.
  
  
  RESULTS
  We obtained sensitivity (S), specificity (Sp), positive predictive values (PPV), negative predictive values (NPV) and likelihood ratio (LR) for the qualitative/semiquantitative method of 91%/80%, 76.2%/67%, 88.9%/83.3%, 80%/60.9% and 32%/7.8%, respectively, to predict a CMR in the PET/CT-et. There were no statistically significant differences between the LR of both methods (p=0.1942).
  
  
  CONCLUSIONS
  We found clear differences in S, Sp, PPV and NPV between both interpretation criteria for the PET/CT-i to predict a CMR in the PET/CT-et. Nevertheless, we cannot confirm the superiority of the qualitative method over the semiqualitative method for this purpose as no statistically significance differences were found in their LR in our study.
authors: Servicio de Medicina Nuclear, Hospital General Universitario de Ciudad Real, Ciudad Real, España. patrick_pilkington@yahoo.com
authors: J P
authors: JP
authors: Pilkington Woll
authors: A M
authors: AM
authors: García Vicente
authors: M P
authors: MP
authors: Talavera Rubio
authors: A M
authors: AM
authors: Palomar Muñoz
authors: G
authors: G
authors: Jiménez Londoño
authors: A
authors: A
authors: León Martín
authors: C
authors: C
authors: Calle Primo
authors: A M
authors: AM
authors: Soriano Castejón
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005069:Evaluation Studies as Topic; D005260:Female; D006689:Hodgkin Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D006801:Humans; D008137:Longitudinal Studies; D008228:Lymphoma, Non-Hodgkin / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012074:Remission Induction; D015203:Reproducibility of Results; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult