Prognostic Significance of Standardized Uptake Value of Lymph Nodes on Survival for Stage III Non-small Cell Lung Cancer Treated With Definitive Concurrent Chemoradiotherapy

Virtual clinical trials: A tool for predicting patients who may benefit from treatment beyond progression with pembrolizumab in non-small cell lung cancer

Enrolling patients in immunotherapy clinical trials is becoming increasingly competitive. Virtual clinical trials can help investigators answer key questions despite this. For example, pembrolizumab is the recommended first-line treatment for non-small cell lung cancer (NSCLC) with no driver alterations and a programmed death ligand 1 (PD-L1) Tumor Proportion Score ≥50%. Salvage therapies for relapsed/refractory patients are limited. Retrospective studies suggest that a subset of patients may benefit from pembrolizumab beyond progression; these results have not been validated in a prospective study. We constructed digital twins of patients and simulated clinical trials to predict the best salvage therapy after progressive disease (PD) on pembrolizumab. Response dynamics were evaluated at the lesion level to represent patients who experience systemic PD while individual lesions continue shrinking. With >25,000 radiographic lesion measurements from >500 patients, we simulated responses to pembrolizumab, chemotherapy, and PD on pembrolizumab followed by either pembrolizumab beyond progression or salvage chemotherapy. Switching all progressors to salvage chemotherapy was suboptimal. Virtual trials predicted progression-free survival (PFS) from pembrolizumab beyond progression to be comparable with salvage chemotherapy in patients whose PD was due to nontarget progression. A PFS-optimized regimen may improve disease control rates ≥15%. Pembrolizumab beyond progression may benefit a subset of patients with PD-L1-high, driver alteration-free NSCLC, but prospective studies are warranted.

Concurrent chemoradiotherapy for stage III non-small-cell lung cancer: recent progress and future perspectives (a narrative review)

Concurrent chemoradiotherapy (CHRT) remains the therapeutic standard for locally advanced inoperable non-small-cell lung cancer (NSCLC). The median overall survival (OS) with this approach is in the range of 20–30 months, with five-year survival of approximately 30%. These outcomes have recently been further improved by supplementing CHRT with maintenance durvalumab, a monoclonal anti-PD-L1 agent. The progress in treatment outcomes of locally advanced NSCLC before the era of immunotherapy has been achieved mainly by virtue of developments in diagnostics and radiotherapy techniques. Routine implementation of endoscopic and endobronchial ultrasonography for mediastinal lymph nodes assessment, positron emission tomography/computed tomography and magnetic resonance imaging of the brain allows for more accurate staging of NSCLC and for optimizing treatment strategy. Thorough staging and respiratory motion control allows for higher conformity of radiotherapy and reduction of radiotherapy related toxicity. Dose escalation with prolonged overall treatment time does not improve treatment outcomes of CHRT. In consequence, 60 Gy in 2 Gy fractions or equivalent biological dose remains the standard dose for definitive CHRT in locally advanced NSCLC. However, owing to increased toxicity of CHRT, this option may not be applicable in a proportion of elderly or frail patients. This article summarizes recent developments in curative CHRT for inoperable stage III NSCLC, and presents perspectives for further improvements of this strategy

Can we define any marker associated with brain failure in patients with locally advanced non-small cell lung cancer?

PURPOSE

To define the factors which may be related to brain metastasis (BM) in patients with locally advanced non-small cell lung cancer (LA-NSCLC) who developed brain metastases after definitive treatment.

PATIENTS AND METHODS

A total of 208 patients with LA-NSCLC, without BM who received definitive radiotherapy (RT) or RT+chemotherapy (CT) between January 2005 and January 2016 were evaluated retrospectively. Platelet, neutrophil, lymphocyte counts, LDH, CRP, Hb levels, neutrophil-to-lymphocyte radio (NLR), platelet-to-lymphocyte radio (PLR), advanced lung cancer inflammation index (ALI) and FDG-PET/CT parameters (SUVmax of the primary tumor and mediastinal lymph nodes), and patient characteristics were evaluated for brain metastasis free survival (BMFS).

RESULTS

Median follow-up duration was 25 months (range: 3-130months). Cut-off values for platelet, NLR, PLR, LDH, CRP, and Hb were 290×103/μL, 2.6, 198, 468 IU/L, 2.5mg/dL, and 11.5g/dl. We defined each parameter as low or high according to the cut-off values. 56 patients (26.9%) developed brain metastases during follow-up. In univariate analysis, high NLR (P=0.001), PLR (P=0.037), LDH (P=0.028), CRP (P=0.002) values, value ≥7.5 for lymph nodes (P=0.005) and low ALI value (P=0.002) were poor prognostic factors for BMFS. In multivariate analysis, high NLR (P=0.022), PLR (P=0.017), CRP (P=0.006), stage ≥IIIB disease (P<0.001), multi-stational N2 disease (P=0.036), adenocarcinoma histology (P<0.001) and SUVmax value ≥7.5 (P=0.035) were poor prognostic factors for BMFS.

CONCLUSIONS

High NLR, PLR, LDH, CRP values, SUVmax values for lymph nodes, and low ALI which indicates high tumor burden were additional prognostic factors besides stage, histology, and lymph node status.

Prognostic importance of 18F-fluorodeoxyglucose uptake by positron emission tomography for stage III non-small cell lung cancer treated with definitive chemoradiotherapy

OBJECTIVES

Survival heterogeneity exists among patients with non-small cell lung cancer (NSCLC), even within the same stage. We aimed to evaluate the prognostic role of pre-treatment maximum standardized uptake value (SUV_max) in patients treated with definitive concurrent chemoradiotherapy for stage III NSCLC.

MATERIALS AND METHODS

Between 2010 and 2017, 103 patients with stage III NSCLC who underwent ¹⁸F-FDG PET/CT at the time of diagnosis were included in the study.

RESULTS

Higher tumor stages were correlated with higher pre-treatment SUV_max of lymph nodes (LNs) (p=0.005) but were not correlated with higher SUV_max of primary tumor (p=0.2). The median SUV_max of LNs was 2.84, 8.06, and 11.11 in stage IIIa, IIIb and IIIc, respectively. Higher nodal stage was also correlated with higher SUV_max of LNs (p=0.01). According to ROC analysis, there was no significant cut-off value of SUV_max observed for primary tumor, therefore continuous variables were used for survival analyses. The best SUV_max cut-off was 3.5 for the LNs, therefore the SUV_max of LNs was evaluated as both a dichotomous and a continuous variable. Pre-treatment SUV_max of primary tumor did not predict survival outcomes but both the continuous and dichotomous variables of SUV_max of LNs predicted recurrence free survival and overall survival. Nodal stage (N0-2 vs. N3) and AJCC stage (IIIa vs IIIb vs. IIIc) were the other prognostic factors.

CONCLUSIONS

Pre-treatment SUV_max of LNs had prognostic value in patients treated with definitive concurrent chemoradiotherapy for stage III NSCLC. In future trials, pre-treatment SUV_max of the LNs would serve as a guide for patients who might benefit from more aggressive treatments.

Rationale and Protocol for a Canadian Multicenter Phase II Randomized Trial Assessing Selective Metabolically Adaptive Radiation Dose Escalation in Locally Advanced Non-small-cell Lung Cancer (NCT02788461)

We explain the rationale for metabolically adaptive radiation dose escalation in stage III non-small-cell lung cancer and describe the design of a Canadian phase II randomized trial investigating this approach. In the trial, patients are randomized to either conventional chemoradiation treatment (60 Gy in 30 fractions) or metabolically adaptive chemoradiation, where fluorodeoxyglucose-avid tumor sub-volumes receive an integrated boost dose to a maximum of 85 Gy in 30 fractions. The trial sample size is 78 patients, and the target population is patients with newly diagnosed, inoperable stage III non-small-cell lung cancer treated with radical intent chemoradiation. The primary objective of the trial is to determine if dose escalation to metabolically active sub-volumes will reduce 2-year local-regional failure rate from 42.3% to 22.3%, when compared with standard treatment. The secondary objectives are to determine the effect of dose escalation on overall survival, progression-free survival, quality of life, and rate of grade 3 to 5 toxicities.

Current Methods to Define Metabolic Tumor Volume in Positron Emission Tomography: Which One is Better?

Numerous methods to segment tumors using ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET) have been introduced. Metabolic tumor volume (MTV) refers to the metabolically active volume of the tumor segmented using FDG PET, and has been shown to be useful in predicting patient outcome and in assessing treatment response. Also, tumor segmentation using FDG PET has useful applications in radiotherapy treatment planning. Despite extensive research on MTV showing promising results, MTV is not used in standard clinical practice yet, mainly because there is no consensus on the optimal method to segment tumors in FDG PET images. In this review, we discuss currently available methods to measure MTV using FDG PET, and assess the advantages and disadvantages of the methods.

The value of nodal information in predicting lung cancer relapse using 4DPET/4DCT

PURPOSE

There is evidence that computed tomography (CT) and positron emission tomography (PET) imaging metrics are prognostic and predictive in nonsmall cell lung cancer (NSCLC) treatment outcomes. However, few studies have explored the use of standardized uptake value (SUV)-based image features of nodal regions as predictive features. The authors investigated and compared the use of tumor and node image features extracted from the radiotherapy target volumes to predict relapse in a cohort of NSCLC patients undergoing chemoradiation treatment.

METHODS

A prospective cohort of 25 patients with locally advanced NSCLC underwent 4DPET/4DCT imaging for radiation planning. Thirty-seven image features were derived from the CT-defined volumes and SUVs of the PET image from both the tumor and nodal target regions. The machine learning methods of logistic regression and repeated stratified five-fold cross-validation (CV) were used to predict local and overall relapses in 2 yr. The authors used well-known feature selection methods (Spearman's rank correlation, recursive feature elimination) within each fold of CV. Classifiers were ranked on their Matthew's correlation coefficient (MCC) after CV. Area under the curve, sensitivity, and specificity values are also presented.

RESULTS

For predicting local relapse, the best classifier found had a mean MCC of 0.07 and was composed of eight tumor features. For predicting overall relapse, the best classifier found had a mean MCC of 0.29 and was composed of a single feature: the volume greater than 0.5 times the maximum SUV (N).

CONCLUSIONS

The best classifier for predicting local relapse had only tumor features. In contrast, the best classifier for predicting overall relapse included a node feature. Overall, the methods showed that nodes add value in predicting overall relapse but not local relapse.