Predicting tumor responses and patient survival in chemoradiotherapy-treated patients with non-small-cell lung cancer using dynamic contrast-enhanced integrated magnetic resonance-positron-emission tomography.

PURPOSE

We investigated whether radiologic parameters by dynamic contrast-enhanced (DCE) integrated magnetic resonance-positron-emission tomography (MR-PET) predicts tumor response to treatment and survival in non-metastatic non-small-cell lung cancer (NSCLC) patients receiving chemoradiotherapy (CRT).

METHODS

Patients underwent DCE integrated MR-PET imaging 1 week before CRT. The following parameters were analyzed: primary tumor size, gross tumor volume, maximal standardized uptake value (SUV), total lesion glycolysis (TLG), apparent diffusion coefficient (ADC), volume transfer constant (K), reverse reflux rate constant (k), extracellular extravascular volume fraction (v), blood plasma volume fraction (v), and initial area under the time-concentration curve defined over the first 60 s post-enhancement (iAUC). CRT responses were defined using the revised Response Evaluation Criteria in Solid Tumors (RECIST) guideline (version 1.1).

RESULTS

Thirty patients were included. Non-responders demonstrated higher baseline TLG (p = 0.012), and lower baseline K (p = 0.020) and iAUC (p = 0.016) compared to responders, indicating the usefulness of DCE integrated MR-PET to predict treatment responses. Receiver operating characteristic curve indicated that TLG has the best differentiation capability to predict responders. By setting the threshold of TLG to 277, the sensitivity, specificity, and accuracy were 66.7%, 83.3%, and 75.0%, respectively, with an area under the curve of 0.776. The median follow-up time was 19.6 (range 7.8-32.0) months. In univariate analyses, baseline TLG >277 (p = 0.005) and baseline K <254 (10 min; p = 0.015) correlated with poor survival after CRT. In multivariate analysis, baseline TLG >277 remained the significant factor in predicting progression (p = 0.012) and death (p = 0.031).

CONCLUSIONS

The radiologic parameters derived from DCE integrated MR-PET scans are useful for predicting treatment response in NSCLC patients treated with CRT; furthermore, these parameters are correlated with clinical and survival outcomes including tumor progression and death.