Thomas T. Zacharia MD, Presenter: Nothing to Disclose

Govind Chavhan MD, Abstract Co-Author: Nothing to Disclose

Brad Dean PhD, Abstract Co-Author: Nothing to Disclose

Elkan F. Halpern PhD, Abstract Co-Author: Nothing to Disclose

Sanjay S. Saini MD, Abstract Co-Author: Nothing to Disclose

James E Sumner, Abstract Co-Author: Nothing to Disclose

We sought to define whether measurement of more target lesions lead to more accurate patient response evaluation in patients undergoing chemotherapy for colon cancer

Thirty consecutive patients were recruited for the purpose of this study. Patients were part of a multisite, randomized, double arm, phase 3 clinical trial that undergo chemotherapy with an investigational drug for metastatic colon cancer. Patients were recruited from US and international sites. Our study included CT measurements of hepatic metastases.All these patients (n=30) had a minimum of 5 target lesions in the liver, target lesion size defined by RECIST criteria.We calculated the patient response at 2 months and 4 months (Complete Response, Partial Response, Stable disease and Progressive disease) using RECIST. Patient response was calculated based on the percentage increase or decrease at two and four months in the greatest diameter of the single largest lesion, two large lesions, three large lesions, four lesions and five lesions respectively. The concordance between five target lesion measurements and lesser number of lesions were analyzed using kappa statistics (using StatView 5.0 (SAS Institute, Cary, NC)

In 94% patients (n=28) there was agreement on patient response, irrespective of the number of measurements made on CT. Out of these 30 patients, 47% had partial response (n=14/30), 43% had stable disease (n=13/30) and 10% had progressive disease at 2 months (n=3/30),43% had partial response (n=13/30), 47% had stable disease (n=14/30) and 10% had progressive disease at 4 months (n=3/30). Agreement in response evaluation between lesion groups for multiple measurements was high, with values of 1.0 for multiple lesion measurements and 0.88 for single lesion measurement at 2 months. The values were 0.96 and 0.84 respectively at 4 months.

Response evaluation based on single largest diameter as the sole criterion gives the same results comparable to multiple lesion measurements upto five target lesions in 94% patients. This information has significant implications in the design of clinical trials, can provide more efficient, less tedious and cost effective radiological analysis

Zacharia, T, Chavhan, G, Dean, B, Halpern, E, Saini, S, Sumner, J, CT Measurement of Colon Cancer Metastases to Liver by Modified Recist Criteria: Does Measurement of More Lesions Provide Better Response Evaluation?.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4402943.html