FDG-PET parameters as predictors of pathologic response and nodal clearance in patients with stage III non-small cell lung cancer receiving neoadjuvant chemoradiation and surgery

Machine Learning-Based Prediction of Pathological Responses and Prognosis After Neoadjuvant Chemotherapy for Non-Small-Cell Lung Cancer: A Retrospective Study

BACKGROUND

Neoadjuvant chemotherapy has variable efficacy in patients with non-small-cell lung cancer (NSCLC), yet reliable noninvasive predictive markers are lacking. This study aimed to develop a radiomics model predicting pathological complete response and postneoadjuvant chemotherapy survival in NSCLC.

MATERIALS AND METHODS

Retrospective data collection involved 130 patients with NSCLC who underwent neoadjuvant chemotherapy and surgery. Patients were randomly divided into training and independent testing sets. Nine radiomics features from prechemotherapy computed tomography (CT) images were extracted from intratumoral and peritumoral regions. An auto-encoder model was constructed, and its performance was evaluated. X-tile software classified patients into high and low-risk groups based on their predicted probabilities. survival of patients in different risk groups and the role of postoperative adjuvant chemotherapy were examined.

RESULTS

The model demonstrated area under the receiver operating characteristic (ROC) curve of 0.874 (training set) and 0.876 (testing set). The larger the area under curve (AUC), the better the model performance. Calibration curve and decision curve analysis indicated excellent model calibration (Hosmer-Lemeshow test, P = .763, the higher the P-value, the better the model fit) and potential clinical applicability. Survival analysis revealed significant differences in overall survival (P = .011) and disease-free survival (P = .017) between different risk groups. Adjuvant chemotherapy significantly improved survival in the low-risk group (P = .041) but not high-risk group (P = 0.56).

CONCLUSION

This study represents the first successful prediction of pathological complete response achievement after neoadjuvant chemotherapy for NSCLC, as well as the patients' survival, utilizing intratumoral and peritumoral radiomics features.

Four-dimensional quantitative analysis using FDG-PET in clinical oncology

Positron emission tomography (PET) with F-18 fluorodeoxyglucose (FDG) has been commonly used in many oncological areas. High-resolution PET permits a three-dimensional analysis of FDG distributions on various lesions in vivo, which can be applied for tissue characterization, risk analysis, and treatment monitoring after chemoradiotherapy and immunotherapy. Metabolic changes can be assessed using the tumor absolute FDG uptake as standardized uptake value (SUV) and metabolic tumor volume (MTV). In addition, tumor heterogeneity assessment can potentially estimate tumor aggressiveness and resistance to chemoradiotherapy. Attempts have been made to quantify intratumoral heterogeneity using radiomics. Recent reports have indicated the clinical feasibility of a dynamic FDG PET-computed tomography (CT) in pilot cohort studies of oncological cases. Dynamic imaging permits the assessment of temporal changes in FDG uptake after administration, which is particularly useful for differentiating pathological from physiological uptakes with high diagnostic accuracy. In addition, several new parameters have been introduced for the in vivo quantitative analysis of FDG metabolic processes. Thus, a four-dimensional FDG PET-CT is available for precise tissue characterization of various lesions. This review introduces various new techniques for the quantitative analysis of FDG distribution and glucose metabolism using a four-dimensional FDG analysis with PET-CT. This elegant study reveals the important role of tissue characterization and treatment strategies in oncology.

The predictive value of total-body PET/CT in non-small cell lung cancer for the PD-L1 high expression

Purpose

Total-body positron emission tomography/computed tomography (PET/CT) provides faster scanning speed, higher image quality, and lower injected dose. To compensate for the shortcomings of the maximum standard uptake value (SUVmax), we aimed to normalize the values of PET parameters using liver and blood pool SUV (SUR-L and SUR-BP) to predict programmed cell death-ligand 1 (PD-L1) expression in non-small cell lung cancer (NSCLC) patients.

Materials and methods

A total of 138 (104 adenocarcinoma and 34 squamous cell carcinoma) primary diagnosed NSCLC patients who underwent ¹⁸F-FDG-PET/CT imaging were analyzed retrospectively. Immunohistochemistry (IHC) analysis was performed for PD-L1 expression on tumor cells and tumor-infiltrating immune cells with 22C3 antibody. Positive PD-L1 expression was defined as tumor cells no less than 50% or tumor-infiltrating immune cells no less than 10%. The relationships between PD-L1 expression and PET parameters (SUVmax, SUR-L, and SUR-BP) and clinical variables were analyzed. Statistical analysis included χ² test, receiver operating characteristic (ROC), and binary logistic regression.

Results

There were 36 patients (26%) expressing PD-L1 positively. Gender, smoking history, Ki-67, and histologic subtype were related factors. SUVmax, SUR-L, and SUR-BP were significantly higher in the positive subset than those in the negative subset. Among them, the area under the curve (AUC) of SUR-L on the ROC curve was the biggest one. In NSCLC patients, the best cutoff value of SUR-L for PD-L1-positive expression was 4.84 (AUC = 0.702, P = 0.000, sensitivity = 83.3%, specificity = 54.9%). Multivariate analysis confirmed that age and SUR-L were correlated factors in adenocarcinoma (ADC) patients.

Conclusion

SUVmax, SUR-L, and SUR-BP had utility in predicting PD-L1 high expression, and SUR-L was the most reliable parameter. PET/CT can offer reference to screen patients for first-line atezolizumab therapy.

Pathological nodal disease defines survival outcomes in patients with lung cancer with tumour major pathological response following neoadjuvant chemotherapy

OBJECTIVES

Major pathological response (MPR) is prognostic of outcomes for patients with non-small-cell lung cancer following neoadjuvant chemotherapy and is used as the primary end point in neoadjuvant immunotherapy trials. We studied the influence of pathological nodal disease on patterns and timing of recurrence among patients with MPR.

METHODS

Patients treated with neoadjuvant chemotherapy for stages I-III non-small-cell lung cancer were identified. Surgical specimens were histopathologically examined for tumour viability, categorized as ≤10% viability (MPR) or >10% (NoMPR). Overall survival and disease-free survival were evaluated with emphasis upon MPR and pathological nodal disease.

RESULTS

Among 307 patients, 58 (19%) had MPR within primary tumour and 42 (14%) had MPRypN0. In the MPR group, the frequency of cN0 and cN+ disease was 18 (31%) and 40 (69%); similarly, the frequency of ypN0, ypN1 and ypN2 was 72% (42/58), 16% (9/58) and 12% (7/58), respectively. When evaluating only those with MPR, recurrence rates among those with MPRypN0, MPRypN1 and MPRypN2 were 33% (14/42), 44% (4/9) and 71% (5/7) (P = 0.16). The median time-to-recurrence in MPRypN0, MPRypN1 and MPRypN2 was 40, 10 and 14 months (P = 0.006). Distant recurrences were less common among those with MPRypN0 [MPRypN0, 26% (11/42); MPRypN1, 44% (4/9); MPRypN2, 71% (5/7); P = 0.047]. Though the median disease-free survival was prolonged among those with MPR vs NoMPR (120 vs 25 months, P < 0.0001), only those with MPRypN0 had prolonged disease-free survival in comparison to other groups upon pairwise comparisons, while MPRypN+ experienced no benefit.

CONCLUSIONS

MPRypN0 represents the most favourable surrogate end point following neoadjuvant chemotherapy. Patients with ypN1-2 are at the risk of early recurrence regardless of primary tumour MPR, warranting intensive surveillance and consideration for additional adjuvant therapy. We highlight that MPRypN0 is the most rigorous end point and should be considered as a surrogate end point in future neoadjuvant trials.

Survival analysis of pathological complete response of locally advanced lung cancer after neoadjuvant treatment

AIM

The first aim is to determine the clinical and pathological characteristics and factors affecting survival in patients with pathological complete response (pCR) after neoadjuvant therapy, and the secondary aim is to investigate the effect of adjuvant therapy on survival in these patients.

METHODS

Between 2003 and 2015, there was 372 patients who underwent lung resection after neoadjuvant therapy with a diagnosis of locally advanced lung cancer. Sixty-eight patients who had pCRwere retrospectively analyzed. The odds ratios (OR) were calculated in regards of recurrence.

RESULTS

Overall 5-year survival rate was 65.1%. Recurrence was the risk factor affecting survival (78.2% vs 19.3%, p = 0.001) while neoadjuvant treatment type (p = 0.766), the reason of neodjuvant treatment (p = 0.581), and the type of operation (p = 0.860) did not affect survival. Postoperative adjuvant treatment had a positive effect on survival (71.1% versus 62.7%), although this difference was not significant (p = 0.561). Local or distant recurrence was detected in 15 patients (22%). In multivariate analysis, the independent risk factors affecting the recurrence were the time from the end of the neoadjuvant therapy to the surgery being less than eight weeks (OR = 6.49, p = 0.03), the type of neoadjuvant treatment (OR = 0.203, p = 0.03). In patients with a squamous cell carcinoma, there was a decreased trend toward in terms of recurrence (p = 0.06).

CONCLUSIONS

pCR after neoadjuvant therapy positively affects survival. Better survival may be detected in patients receiving adjuvant therapy. Due to unexpected the high recurrence rate, patients should be followed in the postoperative period closely.

PET-detected pneumonitis following curative-intent chemoradiation in non-small cell lung cancer (NSCLC): recognizing patterns and assessing the impact on the predictive ability of FDG-PET/CT response assessment

PURPOSE

Inflammatory FDG uptake in the lung (PET-pneumonitis) following curative-intent radiotherapy (RT)/chemo-RT (CRT) in non-small cell lung cancer (NSCLC) can pose a challenge in FDG-PET/CT response assessment. The aim of this study is to describe different patterns of PET-pneumonitis to guide the interpretation of FDG-PET/CT and investigate its association with tumor response and overall survival (OS).

METHODS

Retrospective analysis was performed on 87 NSCLC patients in three prospective trials who were treated with radical RT (n = 7) or CRT (n = 80), with baseline and post-treatment FDG-PET/CT. Visual criteria were performed for post-treatment FDG-PET/CT response assessment. The grading of PET-pneumonitis was based on relative lung uptake intensity compared to organs of reference and classified as per Deauville score from grade 1-5. Distribution patterns of PET-pneumonitis were defined as follows: A) patchy/sub-pleural; B) diffuse (involving more than a segment); and C) peripheral (diffusely surrounding a photopenic region).

RESULTS

Follow-up FDG-PET/CT scans were performed approximately 3 months (median, 89 days; interquartile range, 79-93) after RT. Overall, PET-pneumonitis was present in 62/87 (71%) of patients, with Deauville 2 or 3 in 12/62 (19%) and 4 or 5 in 50/62 (81%) of patients. The frequency of patterns A, B and C of PET-pneumonitis was 19/62 (31%), 20/62 (32%) and 23/62 (37%), respectively. No association was found between grade or pattern of PET-pneumonitis and overall response at follow-up PET/CT (p = 0.27 and p = 0.56, respectively). There was also no significant association between PET-pneumonitis and OS (hazard ratio [HR], 1.3; 95% confidence interval [CI], 0.6-2.5; p = 0.45). Early FDG-PET/CT response assessment, however, was prognostic for OS (HR, 1.7; 95% CI, 1.2-2.2; p < 0.001).

CONCLUSION

PET-pneumonitis is common in early post-CRT/RT, but pattern recognition may assist in response assessment by FDG-PET/CT. While FDG-PET/CT is a powerful tool for response assessment and prognostication, PET-pneumonitis does not appear to confound early response assessment or to independently predict OS.

What 18F-FDG PET Response-Assessment Method Best Predicts Survival After Curative-Intent Chemoradiation in Non-Small Cell Lung Cancer: EORTC, PERCIST, Peter Mac Criteria, or Deauville Criteria?

The optimal methodology for defining response with ¹⁸F-FDG PET after curative-intent chemoradiation for non-small cell lung cancer (NSCLC) is unknown. We compared survival outcomes according to the criteria of the European Organization for Research and Treatment of Cancer (EORTC), PERCIST 1.0, the Peter Mac metabolic visual criteria, and the Deauville criteria, respectively. Methods: Three prospective trials of chemoradiation for NSCLC, involving baseline and posttreatment ¹⁸F-FDG PET/CT imaging, were conducted between 2004 and 2016. Responses were categorized as complete metabolic response (CMR), partial metabolic response, stable metabolic disease, or progressive metabolic disease. Cox proportional-hazards models and log-rank tests assessed the impact of each response on overall survival (OS). Results: Eighty-seven patients underwent ¹⁸F-FDG PET/CT before and after radical chemoradiation for NSCLC. Follow-up ¹⁸F-FDG PET/CT scans were performed at a median of 89 d (interquartile range, 79-93 d) after radiotherapy. Median follow-up and OS after PET response imaging were 49 and 28 mo, respectively. Interobserver agreements for EORTC, PERCIST, Peter Mac, and Deauville had κ values of 0.76, 0.76, 0.87, and 0.84, respectively. All 4 response criteria were significantly associated with OS. Peter Mac and Deauville showed better fit than EORTC and PERCIST and distinguished better between CMR and non-CMR. Conclusion: All 4 response criteria were highly predictive of OS, but visual criteria showed greater interobserver agreement and stronger discrimination between CMR and non-CMR, highlighting the importance of visual assessment to recognize radiation pneumonitis, changes in lung configuration, and patterns of response.

Pathologic complete response after induction therapy-the role of surgery in stage IIIA/B locally advanced non-small cell lung cancer

Background

Pathologic complete response (pCR) is dominant prognostic factor determining favorable outcome in locally advanced non-small cell lung cancer (NSCLC) after induction therapy (IT). There is no non-operative diagnostics that adequately estimates the pCR. Aim of this retrospective study was to assess the correlation between clinical and pathological factors in patients with pCR.

Methods

Twenty-five patients with pCR after curative lung resection following IT were assessed using univariate and multivariate Cox regression and descriptive analysis. The survival rate was estimated by Kaplan-Meier method.

Results

The IT included chemoradiation with median doses of 50.4 Gy (range, 45-59.4 Gy) combined with platinum-based chemotherapy in 23 patients (92%) and induction platinum-based chemotherapy in 2 patients (8%). Clinical tumor stage before IT was IIIA in 21, IIIB in 4 patients. Mean interval between IT and surgery was 8.1±3.0 weeks. Perioperative morbidity and 30-day mortality was 32% and 4%, respectively. There was no significant correlation of pCR and different clinical and pathological factors. The estimated 5-year long-term survival (LTS) and progressive-free survival (PFS) was 57% and 54%, respectively. The median LTS and PFS was not reached.

Conclusions

pCR in patients with locally advanced NSCLC following IT is an independent prognostic factor, without correlation with pathological and clinical factors. Non-operative accurate assessment of pCR is currently impossible. Surgical resection enables secure identification of pCR and might improve the patient stratification for additive therapy.

Neoadjuvant Chemoradiotherapy for Stage III Non-Small Cell Lung Cancer

The local management of stage III non-small cell lung cancer is controversial. Although definitive chemoradiotherapy (CRT) is considered a standard-of-care in the curative management of the disease, inadequate local control outcomes have led to various treatment strategies that incorporate surgical resection. Surgery alone has long been recognized as insufficient for this stage, and thus neoadjuvant strategies have been developed to treat micrometastatic disease and increase the probability of a complete resection. The optimal induction strategy has not yet been defined, however, with arguments favoring either preoperative chemotherapy or CRT. In this article, the data supporting the use of neoadjuvant CRT and the randomized literature comparing the two approaches will be reviewed. The article will conclude with summary comparisons of these induction paradigms.