RT Journal Article
SR Electronic
T1 An <sup>18</sup>F-FDG PET/CT and Mean Lung Dose Model to Predict Early Radiation Pneumonitis in Stage III Non–Small Cell Lung Cancer Patients Treated with Chemoradiation and Immunotherapy
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 520
OP 526
DO 10.2967/jnumed.123.266965
VO 65
IS 4
A1 Thor, Maria
A1 Lee, Chen
A1 Sun, Lian
A1 Patel, Purvi
A1 Apte, Aditya
A1 Grkovski, Milan
A1 Shepherd, Annemarie F.
A1 Gelblum, Daphna Y.
A1 Wu, Abraham J.
A1 Simone, Charles B.
A1 Chaft, Jamie E.
A1 Rimner, Andreas
A1 Gomez, Daniel R.
A1 Deasy, Joseph O.
A1 Shaverdian, Narek
YR 2024
UL http://jnm.snmjournals.org/content/65/4/520.abstract
AB Radiation pneumonitis (RP) that develops early (i.e., within 3 mo) (RPEarly) after completion of concurrent chemoradiation (cCRT) leads to treatment discontinuation and poorer survival for patients with stage III non–small cell lung cancer. Since no RPEarly risk model exists, we explored whether published RP models and pretreatment 18F-FDG PET/CT–derived features predict RPEarly. Methods: One hundred sixty patients with stage III non–small cell lung cancer treated with cCRT and consolidative immunotherapy were analyzed for RPEarly. Three published RP models that included the mean lung dose (MLD) and patient characteristics were examined. Pretreatment 18F-FDG PET/CT normal-lung SUV featured included the following: 10th percentile of SUV (SUVP10), 90th percentile of SUV (SUVP90), SUVmax, SUVmean, minimum SUV, and SD. Associations between models/features and RPEarly were assessed using area under the receiver-operating characteristic curve (AUC), P values, and the Hosmer–Lemeshow test (pHL). The cohort was randomly split, with similar RPEarly rates, into a 70%/30% derivation/internal validation subset. Results: Twenty (13%) patients developed RPEarly. Predictors for RPEarly were MLD alone (AUC, 0.72; P = 0.02; pHL, 0.87), SUVP10, SUVP90, and SUVmean (AUC, 0.70–0.74; P = 0.003–0.006; pHL, 0.67–0.70). The combined MLD and SUVP90 model generalized in the validation subset and was deemed the final RPEarly model (RPEarly risk = 1/[1+e(−x)]; x = −6.08 + [0.17 × MLD] + [1.63 × SUVP90]). The final model refitted in the 160 patients indicated improvement over the published MLD-alone model (AUC, 0.77 vs. 0.72; P = 0.0001 vs. 0.02; pHL, 0.65 vs. 0.87). Conclusion: Patients at risk for RPEarly can be detected with high certainty by combining the normal lung’s MLD and pretreatment 18F-FDG PET/CT SUVP90. This refined model can be used to identify patients at an elevated risk for premature immunotherapy discontinuation due to RPEarly and could allow for interventions to improve treatment outcomes.