Impact of pretreatment whole-tumor perfusion computed tomography and 18F-fluorodeoxyglucose positron emission tomography/computed tomography measurements on local control of non–small cell lung cancer treated with stereotactic body radiotherapy

Abstract

This study aimed to investigate the correlation between the average iodine density (AID) detected by dual-energy computed tomography (DE-CT) and the maximum standardized uptake value (SUVmax) yielded by [18F] fluorodeoxyglucose positron emission tomography (18F-FDG PET) for non–small cell lung cancer (NSCLC) treated with stereotactic body radiotherapy (SBRT). Seventy-four patients with medically inoperable NSCLC who underwent both DE-CT and 18F-FDG PET/CT before SBRT (50‒60 Gy in 5‒6 fractions) were followed up after a median interval of 24.5 months. Kaplan–Meier analysis was used to determine associations between local control (LC) and variables, including AID, SUVmax, tumor size, histology, and prescribed dose. The median AID and SUVmax were 18.64 (range, 1.18–45.31) (100 µg/cm3) and 3.2 (range, 0.7–17.6), respectively. No correlation was observed between AID and SUVmax. Two-year LC rates were 96.2% vs 75.0% (P = 0.039) and 72.0% vs 96.2% (P = 0.002) for patients classified according to high vs low AID or SUVmax, respectively. Two-year LC rates for patients with adenocarcinoma vs squamous cell carcinoma vs unknown cancer were 96.4% vs 67.1% vs 92.9% (P = 0.008), respectively. Multivariate analysis identified SUVmax as a significant predictor of LC. The 2-year LC rate was only 48.5% in the subgroup of lower AID and higher SUVmax vs >90% (range, 94.4–100%) in other subgroups (P = 0.000). Despite the short follow-up period, a reduction in AID and subsequent increase in SUVmax correlated significantly with local failure in SBRT-treated NSCLC patients. Further studies involving larger populations and longer follow-up periods are needed to confirm these results.

Application of Dual-Energy Spectral Computed Tomography to Thoracic Oncology Imaging

“…The correlation between DESCT parameters and metabolic uptake in 18 F-fluorodeoxyglucose positron emission tomography (PET-CT) and association with tumor recurrence were also evaluated in several studies. Aoki et al (43,44) found strong correlations between IC and the maximum standardized uptake value (SUVmax) on PET-CT with local recurrence in NSCLC treated with stereotactic body radiotherapy (SBRT). Tumors with a lower IC and higher SUVmax showed significantly higher local recurrence rates, demonstrating an association of radioresistance with low tumor blood volume and a probable association with hypoxia.…”

Single-source Dual-energy CT as a Part of 18F-FDG PET/CT: Direct Comparison of Iodine-related and Metabolic Parameters in Non-small Cell Lung Cancer

“…In this respect, PET/CT is the recommended method for staging, however, it was recently demonstrated that level of FDG uptake has also a prognostic value determining the probability of successful therapy (3)(4)(5). At the same time, there is a presumption that the vascularization of lung tumors is related to their aggressiveness, that can be assessed by dynamic contrast-enhanced CT (DCE-CT) (6)(7)(8).…”

Tumour response in non‐small‐cell lung cancer patients treated with chemoradiotherapy – Can spectral CT predict recurrence?

“…Tumour hypoxia plays an important role in radioresistance as a negative predictive factor when radiation therapy is contemplated . Low iodine content in lung cancer detected by pretherapeutic dual‐energy CT indicates hypovascular tumours and could predict early recurrence after radiation therapy . Analogously, pretherapeutic iodine content could also predict the response of NSCLC to chemotherapy .…”