Metabolic tumour and nodal response to neoadjuvant chemotherapy on FDG PET-CT as a predictor of pathological response and survival in patients with oesophageal adenocarcinoma

Abstract

Objectives 2-deoxy-2[18F]Fluoro-d-glucose (FDG) PET-CT has an emerging role in assessing response to neoadjuvant therapy in oesophageal cancer. This study evaluated FDG PET-CT in predicting pathological tumour response (pTR), pathological nodal response (pNR) and survival. Methods Cohort study of 75 patients with oesophageal or oesophago-gastric junction (GOJ) adenocarcinoma treated with neoadjuvant chemotherapy then surgery at Guy’s and St Thomas’ NHS Foundation Trust, London (2017–2020). Standardised uptake value (SUV) metrics on pre- and post-treatment FDG PET-CT in the primary tumour (mTR) and loco-regional lymph nodes (mNR) were derived. Optimum SUVmax thresholds for predicting pathological response were identified using receiver operating characteristic analysis. Predictive accuracy was compared to PERCIST (30% SUVmax reduction) and MUNICON (35%) criteria. Survival was assessed using Cox regression. Results Optimum tumour SUVmax decrease for predicting pTR was 51.2%. A 50% cut-off predicted pTR with 73.5% sensitivity, 69.2% specificity and greater accuracy than PERCIST or MUNICON (area under the curve [AUC] 0.714, PERCIST 0.631, MUNICON 0.659). Using a 30% SUVmax threshold, mNR predicted pNR with high sensitivity but low specificity (AUC 0.749, sensitivity 92.6%, specificity 57.1%, p = 0.010). pTR, mTR, pNR and mNR were independent predictive factors for survival (pTR hazard ratio [HR] 0.10 95% confidence interval [CI] 0.03–0.34; mTR HR 0.17 95% CI 0.06–0.48; pNR HR 0.17 95% CI 0.06–0.54; mNR HR 0.13 95% CI 0.02–0.66). Conclusions Metabolic tumour and nodal response predicted pTR and pNR, respectively, in patients with oesophageal or GOJ adenocarcinoma. However, currently utilised response criteria may not be optimal. pTR, mTR, pNR and mNR were independent predictors of survival. Key Points • FDG PET-CT has an emerging role in evaluating response to neoadjuvant therapy in patients with oesophageal cancer. • Prospective cohort study demonstrated that metabolic response in the primary tumour and lymph nodes was predictive of pathological response in a cohort of patients with adenocarcinoma of the oesophagus or oesophago-gastric junction treated with neoadjuvant chemotherapy followed by surgical resection. • Patients who demonstrated a response to neoadjuvant chemotherapy in the primary tumour or lymph nodes on FDG PET-CT demonstrated better survival and reduced rates of tumour recurrence.

Pre‐ and post‐treatment FDG PET‐CT as a predictor of patient outcomes in anal squamous cell carcinoma: A systematic review and meta‐analysis

“…Taking homogenous metrics for meta‐analysis left two studies examining SUV max as a positive predictor of OS and PFS. While underpowered, this meta‐analysis serves to highlight the potential future use of SUV max for patient prognostic use, which also appears to have a predictive role in other disease processes 31,32 . Of note, some studies reported differing interpretations of the same metric, for example, Cardenas reported a HR considering a reduction in SUV max greater or less than 62.3%, 28 while Duimering et al .…”

“…While underpowered, this meta-analysis serves to highlight the potential future use of SUV max for patient prognostic use, which also appears to have a predictive role in other disease processes. 31,32 Of note, some studies reported differing interpretations of the same metric, for example, Cardenas reported a HR considering a reduction in SUV max greater or less than 62.3%, 28 while Duimering et al reported HRs relating to an MTV greater or less than 35cm 3 . 27 Further study to standardise values to enable consistent reporting which would better allow for inter-study comparison may be prudent.…”

18F-FDG PET/CT metabolism multi-parameter prediction of chemotherapy efficacy in locally progressive gastric cancer

“…Active therapeutic monitoring has a pivotal role in NAC for gastric cancer, with the primary goals being assessment of tumor responsiveness to chemotherapy, determining the appropriate course of chemotherapy, and determining the optimal timing of surgery. Previous studies on PET/CT-based response assessments associated with early metabolic changes in esophagogastric junction cancer have shown significant but inconclusive results and have had an emerging role in the response to neoadjuvant treatments [ 14 , 15 ]. In the present study, we assessed patients with locally progressive gastric adenocarcinomas.…”

18F-FDG PET/CT metabolism multi-parameter prediction of chemotherapy efficacy in locally progressive gastric cancer

“…Active therapeutic monitoring has a pivotal role in NAC for gastric cancer, with the primary goals being assessment of tumor responsiveness to chemotherapy, determining the appropriate course of chemotherapy, and determining the optimal timing of surgery. Previous studies on PET/CT-based response assessments associated with early metabolic changes in esophagogastric junction cancer have shown signi cant but inconclusive results and have had an emerging role in the response to neoadjuvant treatments [14,15] . In the present study, we assessed patients with locally progressive gastric adenocarcinomas.…”