Predicting per-lesion local recurrence in locally advanced non-small cell lung cancer following definitive radiation therapy using pre- and mid-treatment metabolic tumor volume

Abstract

Background We evaluated whether pre- and mid-treatment metabolic tumor volume (MTV) predicts per lesion local recurrence (LR) in patients treated with definitive radiation therapy (RT, dose≥60 Gy) for locally advanced non-small cell lung cancer (NSCLC). Methods We retrospectively reviewed records of patients with stage III NSCLC treated from 2006 to 2018 with pre- and mid-RT PET-CT. We measured the MTV of treated lesions on the pre-RT (MTVpre) and mid-RT (MTVmid) PET-CT. LR was defined per lesion as recurrence within the planning target volume. Receiver operating characteristic (ROC) curves, cumulative incidence rates, and uni- and multivariable (MVA) competing risk regressions were used to evaluate the association between MTV and LR. Results We identified 111 patients with 387 lesions (112 lung tumors and 275 lymph nodes). Median age was 68 years, 69.4% were male, 46.8% had adenocarcinoma, 39.6% had squamous cell carcinoma, and 95.5% received concurrent chemotherapy. Median follow-up was 38.7 months. 3-year overall survival was 42.3%. 3-year cumulative incidence of LR was 26.8% per patient and 11.9% per lesion. Both MTVpre and MTVmid were predictive of LR by ROC (AUC = 0.71 and 0.76, respectively) and were significantly associated with LR on MVA (P = 0.004 and P = 7.1e-5, respectively). Among lesions at lower risk of LR based on MTVpre, higher MTVmid was associated with LR (P = 0.001). Conclusion Per-lesion, larger MTVpre and MTVmid predicted for increased risk of LR. MTVmid was more highly predictive of LR than MTVpre and if validated may allow for further discrimination of high-risk lesions at mid-RT informing dose painting strategies.

Selective Personalized RadioImmunotherapy for Locally Advanced Non–Small-Cell Lung Cancer Trial (SPRINT)

“…9,19,20 As response to induction therapy seems to predict long-term clinical outcomes, strategies to escalate or de-escalate treatment intensity on the basis of early response assessments may be considered.Thoracic radiotherapy is delivered using a deintensified, risk-adapted approach. Data from several institutions suggest that in-field disease progression after definitive radiotherapy for LA-NSCLC occurs almost exclusively at sites of bulky disease involvement 11,12 and modest radiotherapy doses may be sufficient to control small tumors and lymph nodes in the setting of active systemic therapy. 13 We therefore used a relatively low radiotherapy dose (48 Gy) to treat small tumors and lymph nodes in this trial.…”

“…Hypermetabolic pulmonary tumors and involved lymph nodes were delineated on postinduction PET using a commercial semiautomatic contouring tool (MIMvista Corp, Cleveland, OH). 10 On the basis of patternsof-failure analyses and previous trials suggesting that small NSCLC lesions can be controlled with modest radiotherapy doses, [11][12][13] tumors and lymph nodes with the metabolic tumor volume under 20 cc received a radiotherapy dose of 48 Gy, whereas larger lesions received a dose of 55 Gy, all delivered in 20 daily fractions over 4 weeks. All patients were treated with photon radiotherapy, and standard dosimetric constraints for the brachial plexus, esophagus, heart, lungs, and spinal cord were applied.…”

Recurrence patterns are significantly associated with the 18F‑FDG PET/CT radiomic features of patients with locally advanced non‑small cell lung cancer treated with chemoradiotherapy

“…Previous studies showed that the MTVs of the primary tumor and regional metastatic lymph nodes displayed by 18 F-FDG PET pre-and mid-radiotherapy are significantly associated with the recurrence patterns of patients with LA-NSCLC who receive chemoradiotherapy (11). The AUC values of pre-and mid-radiotherapy MTVs for predicting LR are 0.71 and 0.76, ------------------------------------ respectively (11).…”

“…Previous studies showed that the MTVs of the primary tumor and regional metastatic lymph nodes displayed by 18 F-FDG PET pre-and mid-radiotherapy are significantly associated with the recurrence patterns of patients with LA-NSCLC who receive chemoradiotherapy (11). The AUC values of pre-and mid-radiotherapy MTVs for predicting LR are 0.71 and 0.76, ------------------------------------ respectively (11). A previous study demonstrated that patients with LA-NSCLC and a tumor volume >50 cm 3 are more prone to primary tumor recurrence after chemoradiotherapy compared with those with a tumor volume ≤50 cm 3 (9).…”

“…Therefore, tumors with a volume of >50 cm 3 are more prone to recurrence compared with those with a volume of ≤50 cm 3 . Another study demonstrated that the total MTV of the primary tumor and regional metastatic lymph nodes, analyzed by pre-and mid-radiotherapy 18 F-FDG PET, are significantly associated with local recurrence in patients with LA-NSCLC (11). Therefore, it has been hypothesized that the deep learning model constructed based on the features of CT radiomics can be used to predict the recurrence pattern of chemoradiotherapy-treated patients with LA-NSCLC (12).…”