Friedrich D. Knollmann MD, PhD, Presenter: Nothing to Disclose

Rohan Kumthekar MS, Abstract Co-Author: Nothing to Disclose

Iclal Ocak MD, Abstract Co-Author: Nothing to Disclose

With the introduction of multidetector CT, volumetric measurements of tumor size have become feasible. We set out to investigate if the greater accuracy of volumetric tumor measurements allows for a more accurate prediction of treatment response, as measured by patient survival, in patients with advanced non small cell lung cancer (NSCLC).

Patients with non resectable NSCLC (stages III or IV, n=100) who were repeatedly evaluated for treatment response by CT were included. Tumor response was measured by comparing tumor dimensions using response evaluation criteria for solid tumors (RECIST), and comparing tumor volumes over time (Vitrea, Vital Images). Patient survival was compared with the size criteria for treatment response using Kaplan Meier survival statistics and Cox regression analysis.

Median overall patient survival was 760 days (std. error: 186 days), for stage IIIA: 853 days, IIIB: 826 days, IV: 587 days. There was substantial overlap of survival between the stages, and the survival difference was not statistically significant (p=0.4). Using RECIST, 5 patients demonstrated complete response, 41 partial response, 47 stable disease, and 7 progressive disease. Patient survival was not significantly associated with RECIST class (p=0.47), nor the change of the sum of tumor diameters (p=0.47), or the change of the sum of volumetric tumor dimensions (p=0.45).

In a group of 100 patients with advanced NSCLC, CT measurements of tumor size did not significantly predict patient survival, and the use of the geometrically more accurate volumetric measurements did not improve the predictive powers. These observations are in accordance with some earlier data from the literature, and suggest that the size response to treatment may not be a useful parameter to drive treatment decisions in individual patients.

Volumetric CT measurements are not significantly associated with patient survival in patients with adavnced non small cell lung cancer.

Knollmann, F, Kumthekar, R, Ocak, I, Measuring Treatment Response in Lung Cancer: Does Volumetric CT Allow for a Better Prediction?.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12020809.html