Pretreatment and Posttreatment Tumor Metabolic Activity Assessed by FDG-PET/CT as Predictors of Tumor Recurrence and Survival Outcomes in Early-Stage Non-Small Cell Lung Cancer Treated With Stereotactic Body Radiation Therapy

Saarang R Deshpande; Tarun K Podder; William Grubb; Yuxia Zhang; Yiran Zheng; Christopher Towe; Philip Linden; Norbert Avril; Tithi Biswas

doi:10.1016/j.adro.2023.101313

Pretreatment and Posttreatment Tumor Metabolic Activity Assessed by FDG-PET/CT as Predictors of Tumor Recurrence and Survival Outcomes in Early-Stage Non-Small Cell Lung Cancer Treated With Stereotactic Body Radiation Therapy

Adv Radiat Oncol. 2023 Jul 9;9(1):101313. doi: 10.1016/j.adro.2023.101313. eCollection 2024 Jan.

Authors

Saarang R Deshpande^{1

2

3}, Tarun K Podder^{1

2}, William Grubb⁴, Yuxia Zhang¹, Yiran Zheng¹, Christopher Towe^{2

5}, Philip Linden^{2

5}, Norbert Avril^{2

6}, Tithi Biswas^{1

2}

Affiliations

¹ Department of Radiation Oncology, University Hospitals, Seidman Cancer Center, Cleveland, Ohio.
² School of Medicine, Case Western Reserve University, Cleveland, Ohio.
³ Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania.
⁴ Department of Radiation Oncology, Medical College of Georgia, Augusta, Georgia.
⁵ Division of Cardiothoracic Surgery, University Hospitals Cleveland Medical Center, Seidman Cancer Center, Cleveland, Ohio.
⁶ Department of Radiology, Nuclear Medicine, University Hospitals, Cleveland, Ohio.

Abstract

Purpose: Stereotactic body radiation therapy (SBRT) is considered the standard of care for medically inoperable early-stage non-small cell lung cancer. There is mixed evidence on the prognostic significance of tumor metabolic activity assessed by positron emission tomography combined with computed tomography (PET/CT) using F-18 fluorodeoxyglucose (FDG). The objectives of this study were to evaluate the maximum standardized uptake value (SUV_max) pretreatment and at 3 and 6 months after SBRT for prediction of tumor control and survival outcomes.

Methods and materials: Consecutive patients from a single institution with T12N0M0 non-small cell lung cancer receiving primary treatment with SBRT with pretreatment FDG-PET/CT (n = 163) and follow-up FDG-PET/CT at 3 or 6 months (n = 71) were included. Receiver operator characteristic analysis was performed to dichotomize variables for Kaplan-Meier survival analysis. Multivariate analysis was performed with Cox proportional hazards regression.

Results: Median follow-up was 19 months. For the whole cohort, 1-year and 2-year local control, progression-free survival (PFS), and overall survival (OS) were 95.0% and 80.3%, 87.1% and 75.4%, and 67.0% and 49.6% respectively. The following pre-SBRT SUV_max cutoffs were significant: SUV > 4.0 for distant failure-free survival (adjusted hazard ratio [aHR], 3.33, P = .006), >12.3 for PFS (aHR, 2.80, P = .011), and >12.6 for OS (aHR, 3.00, P = .003). SUV_max decreases of at least 45% at 3 months (aHR, 0.15, P = .018), and 53% at 6 months (aHR, 0.12, P = .046) were associated with improved local failure-free survival.

Conclusions: Pre-SBRT SUV_max cutoffs can predict distant failure, PFS, and OS. At both 3 and 6 months after SBRT, cutoffs for percentage change in SUV_max can potentially stratify risk of local recurrence.