Molecular Imaging with 11C-PD153035 PET/CT for Predicting and Monitoring Responsiveness of Non-small Cell Lung Cancer to EGFR-TKI

Abstract

Purpose/Objective(s)We have reported a preliminary result about the efficacy of 11C-PD153035 PET/CT as a non-invasive “molecular fingerprint” to the status of EGFR in NSCLC. In this study, we sought to determine whether this imaging was early predictive of the outcome of patients with advanced NSCLC who were treated with erlotinib.Materials/MethodsTwenty-one patients with pathologically proved advanced NSCLC were enrolled. A baseline 11C-PD153035 PET/CT was performed within 1 week before the initiation of treatment, and follow-up 11C-PD153035 PET/CT was performed at 1 to 2 weeks and 6 weeks after start of treatment with assessment of maximum standardized uptake values (SUVmax) for correlation with response. Treatment response was also expressed as CT results on the basis of traditional response evaluation criteria in solid tumors (RECIST). Patients were followed for survival until death.ResultsAll patients were registered for this study between July 2007 and January 2009. All of them underwent baseline 11C-PD153035 PETCT scan, three patients did not complete the follow-up PET/CT at 1 to 2 weeks and two patients did not complete the 6 weeks PET/CT. ROC curve analysis was performed using the clinical criteria of best response point to separate responders from those with PD. The area under the ROC curve was 0.813 ± 0.126, with a sensitivity of 87.5% and a specificity of 80.0%. The baseline maximum SUV (SUVmax) was 2.16 that served as the optimal threshold for treatment response. Tumor responders group had a higher baseline SUVmax than non-responders group (p = 0.042). 11C-PD153035 uptake change was no significant difference between baseline and the first follow-up scan (p = 0.142), and also similar between baseline and the second follow-up scan (p = 0.192). 16 patients had died and overall 12-month survival was 71.4% for all patients. Using various cutoff values, the maximum SUVs were significant predictors of patients' survival at baseline, 1 to 2 weeks (Kaplan-Meier log-rank p = 0.002, and p = 0.01, respectively).ConclusionsWe have developed a new radiotracer for the identification of tumors sensitive to erlotinib treatment. Our preliminary results suggest the 11C-PD153035 PET/CT can be used as a noninvasive and rapid method for predicting early treatment response of advanced NSCLC with erlotinib but cannot monitoring during treatment. Purpose/Objective(s)We have reported a preliminary result about the efficacy of 11C-PD153035 PET/CT as a non-invasive “molecular fingerprint” to the status of EGFR in NSCLC. In this study, we sought to determine whether this imaging was early predictive of the outcome of patients with advanced NSCLC who were treated with erlotinib. We have reported a preliminary result about the efficacy of 11C-PD153035 PET/CT as a non-invasive “molecular fingerprint” to the status of EGFR in NSCLC. In this study, we sought to determine whether this imaging was early predictive of the outcome of patients with advanced NSCLC who were treated with erlotinib. Materials/MethodsTwenty-one patients with pathologically proved advanced NSCLC were enrolled. A baseline 11C-PD153035 PET/CT was performed within 1 week before the initiation of treatment, and follow-up 11C-PD153035 PET/CT was performed at 1 to 2 weeks and 6 weeks after start of treatment with assessment of maximum standardized uptake values (SUVmax) for correlation with response. Treatment response was also expressed as CT results on the basis of traditional response evaluation criteria in solid tumors (RECIST). Patients were followed for survival until death. Twenty-one patients with pathologically proved advanced NSCLC were enrolled. A baseline 11C-PD153035 PET/CT was performed within 1 week before the initiation of treatment, and follow-up 11C-PD153035 PET/CT was performed at 1 to 2 weeks and 6 weeks after start of treatment with assessment of maximum standardized uptake values (SUVmax) for correlation with response. Treatment response was also expressed as CT results on the basis of traditional response evaluation criteria in solid tumors (RECIST). Patients were followed for survival until death. ResultsAll patients were registered for this study between July 2007 and January 2009. All of them underwent baseline 11C-PD153035 PETCT scan, three patients did not complete the follow-up PET/CT at 1 to 2 weeks and two patients did not complete the 6 weeks PET/CT. ROC curve analysis was performed using the clinical criteria of best response point to separate responders from those with PD. The area under the ROC curve was 0.813 ± 0.126, with a sensitivity of 87.5% and a specificity of 80.0%. The baseline maximum SUV (SUVmax) was 2.16 that served as the optimal threshold for treatment response. Tumor responders group had a higher baseline SUVmax than non-responders group (p = 0.042). 11C-PD153035 uptake change was no significant difference between baseline and the first follow-up scan (p = 0.142), and also similar between baseline and the second follow-up scan (p = 0.192). 16 patients had died and overall 12-month survival was 71.4% for all patients. Using various cutoff values, the maximum SUVs were significant predictors of patients' survival at baseline, 1 to 2 weeks (Kaplan-Meier log-rank p = 0.002, and p = 0.01, respectively). All patients were registered for this study between July 2007 and January 2009. All of them underwent baseline 11C-PD153035 PETCT scan, three patients did not complete the follow-up PET/CT at 1 to 2 weeks and two patients did not complete the 6 weeks PET/CT. ROC curve analysis was performed using the clinical criteria of best response point to separate responders from those with PD. The area under the ROC curve was 0.813 ± 0.126, with a sensitivity of 87.5% and a specificity of 80.0%. The baseline maximum SUV (SUVmax) was 2.16 that served as the optimal threshold for treatment response. Tumor responders group had a higher baseline SUVmax than non-responders group (p = 0.042). 11C-PD153035 uptake change was no significant difference between baseline and the first follow-up scan (p = 0.142), and also similar between baseline and the second follow-up scan (p = 0.192). 16 patients had died and overall 12-month survival was 71.4% for all patients. Using various cutoff values, the maximum SUVs were significant predictors of patients' survival at baseline, 1 to 2 weeks (Kaplan-Meier log-rank p = 0.002, and p = 0.01, respectively). ConclusionsWe have developed a new radiotracer for the identification of tumors sensitive to erlotinib treatment. Our preliminary results suggest the 11C-PD153035 PET/CT can be used as a noninvasive and rapid method for predicting early treatment response of advanced NSCLC with erlotinib but cannot monitoring during treatment. We have developed a new radiotracer for the identification of tumors sensitive to erlotinib treatment. Our preliminary results suggest the 11C-PD153035 PET/CT can be used as a noninvasive and rapid method for predicting early treatment response of advanced NSCLC with erlotinib but cannot monitoring during treatment.