e19069 Background: Early determination of therapeutic failure can potentially spare a pt ineffective and toxic treatment. We previously reported in a retrospective study the use of CT within 4 weeks of initiation of chemotherapy in advanced NSCLC to assess response and progression by RECIST (Bruzzi et al. JTO 2006). Here, we prospectively assess whether CT imaging after the first cycle of pemetrexed in advanced NSCLC has a role in evaluating response and management. Methods: We accrued pts with PS 2 or 3 advanced NSCLC receiving at least one dose of 1st or 2nd line pemetrexed. A repeat CT prior to a 2nd course was required. Pts with progression by RECIST were to come off study. CT scans were done using multislice CT technology (GE Lightspeed Plus), and images were reconstructed with slice thicknesses of 3.75mm or less. All images were reviewed using a PACs workstation (Stentor iSite) and measurements were done with electronic calipers. RECIST criteria: progression, an increase in the tumor's longest dimension by 20%, response, a decrease by 30%. Results: Thirty pts had a median age of 68 years (45 - 81). PS 2/3, 1st/2nd line, and F/M were 16/14, 17/13, and 12/18 respectively. Pts received 1–8 cycles (median 2). Twelve pts received only 1 course of whom 7 pts had f/u CTs at a median of 20 days (12–25) after 1st chemo dose. Of these pts, 5/7 had progression by RECIST and the other 2/7 pts had stable disease with 1 pt who came off due to serial PEs and 1 pt who opted off for reasons of travel. Two of the 5 pts who had progression by CT had no detectable change by CXR. Of 5/12 pts treated with only 1 course without f/u CT, 2 pts died, 2 pts had progression by CXR, and 1 pt stopped after treatment for pneumonia. All 18 pts receiving ≥2 cycles had a repeat CT prior to their 2nd course. Conclusions: The results of this prospective trial support earlier retrospective findings that short-term follow-up using CT in pts with advanced NSCLC can detect tumor progression and impact patient management. We will also present f/u CTs in pts who received ≥ 1course to determine whether early signs of progression predict later RECIST determined progression. [Table: see text]
Clinical outcomes of pembrolizumab therapy in advanced‐
NSCLC
patients with poor performance status (≥3) and high
PD‐L1
expression (
TPS
≥50%): A case series
