title: Volume and attenuation computed tomography measurements for interim evaluation of Hodgkin and follicular lymphoma as an additional surrogate parameter for more confident response monitoring: a pilot study.
abstract: OBJECTIVE
  To retrospectively determine the potential role of additional computed tomography (CT) attenuation measurements for interim response evaluation in residual masses of patients with Hodgkin disease (HD) and follicular non-Hodgkin lymphoma (NHL).
  
  
  METHODS
  In this retrospective study, 39 patients with HD and 35 patients with NHL presented with residual masses at mid-treatment CT (after 2-4 cycles of chemotherapy) and were assessed via contrast-enhanced CT at baseline, mid-treatment and post-treatment. Volume was recorded as whole-tumour volume. A tumour attenuation ratio (TAR) was calculated as the quotient of attenuation between tumour and muscle at the respective point in time versus baseline. The standard deviation of attenuation values within the tumour volume was recorded to estimate tumour heterogeneity. Results were correlated with relapse-free survival determined at a minimum of 12 months after end-treatment CT.
  
  
  RESULTS
  Tumour volume and TAR at interim versus baseline control were significantly reduced in responders compared with non-responders, even after controlling for age, stage, treatment regimen, and baseline tumour volume. No significant differences with respect to the standard deviation of attenuation values within the tumour volumes (tumour heterogeneity) were observed. The volume and attenuation CT (VACT) criteria yielded the highest sensitivities and specificities for the identification of non-response at a threshold of a >20% increase in volume and an increase in TAR at interim control, i.e. 88% (NHL 80%, HD 100%) and 98% (NHL 97%, HD 100%), respectively. The negative predictive values reached by VACT analysis were >=97%, according to both parameters.
  
  
  CONCLUSIONS
  Mid-treatment response assessment of residual masses in patients with HD and NHL using VACT may aid in the risk stratification as an additional surrogate parameter.
authors: Department of Diagnostic and Interventional Radiology, Eberhard-Karls-University, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany. daniel_spira@yahoo.de
authors: Daniel
authors: D
authors: Spira
authors: Martin
authors: M
authors: Sökler
authors: Wichard
authors: W
authors: Vogel
authors: Sarah
authors: S
authors: Löffler
authors: Sven Michael
authors: SM
authors: Spira
authors: Harald
authors: H
authors: Brodoefel
authors: Michael
authors: M
authors: Fenchel
authors: Marius
authors: M
authors: Horger
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006689:Hodgkin Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008224:Lymphoma, Follicular / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*