title: Size and attenuation CT (SACT) of residual masses in patients with follicular non-Hodgkin lymphoma: more than a status quo?
abstract: OBJECTIVE
  To evaluate CT-attenuation ratio of residual masses in patients with follicular Non-Hodgkin lymphoma (FL) at end-treatment compared to baseline mass density and determine its potential prognostic relevance.
  
  
  METHODS
  52 consecutive patients with FL presenting with residual masses after chemotherapy receiving whole-body-CECT at baseline, end-treatment, and post-treatment were identified retrospectively by a search of our electronic medical record database from 2002 through 2010. An attenuation ratio (AR), defined as the quotient of CT-attenuation [HU] between tumor and muscle was measured. Size was recorded as the product of long- and short-axis diameter of masses. In 38/52 patients a follow-up period of ≥ 2 years was available to correlate results with relapse-free survival.
  
  
  RESULTS
  AR and tumor size of masses significantly decreased in responders when baseline was compared to end-treatment (n = 70; p < 0.05, respectively). An increase in both, AR and size was recorded in case of relapse (n = 14; p < 0.05, respectively). 12/53 masses initially responded to therapy but relapsed within the consecutive 2-year period. The mean time to relapse was 13.5 months (range 5-24 months). AR measured at the time of end-control was significantly lower in masses remaining stable for ≥ 2 years (n = 41) compared to masses with relapse during 2-year follow-up (n = 12; p < 0.05). At a threshold of an AR>1 at end-control the specificity and sensitivity for relapsing disease within 2 years reached 83% and 75%, respectively.
  
  
  CONCLUSIONS
  CT-attenuation measurements of residual masses in patients with FL at end-control may aid in the risk stratification of early (≤ 2 years) relapsing disease.
authors: Department of Diagnostic Radiology, Eberhard-Karls-University, Hoppe-Seyler-Str 3, 72076 Tübingen, Germany. daniel.spira@med.uni-tuebingen.de
authors: Daniel
authors: D
authors: Spira
authors: Wichard
authors: W
authors: Vogel
authors: Martin
authors: M
authors: Sökler
authors: Sarah
authors: S
authors: Löffler
authors: Alexander
authors: A
authors: Sauter
authors: Maximilian
authors: M
authors: Schulze
authors: Marius
authors: M
authors: Horger
mesh_terms: D000328:Adult; D000368:Aged; D003287:Contrast Media; D005260:Female; D006801:Humans; D007472:Iohexol / Q000031:analogs & derivatives; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D018365:Neoplasm, Residual / Q000000981:diagnostic imaging* / Q000473:pathology; D011379:Prognosis; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D051598:Whole Body Imaging
chemical_list: D003287:Contrast Media; D007472:Iohexol; C038192:iopromide