Neoadjuvant Chemoradiotherapy

This study is testing new imaging and analysis methods to improve how doctors predict treatment response in rectal cancer patients receiving chemoradiotherapy. Current MRI scans sometimes miss complete tumor response, which can lead to unnecessary surgery. To address this, researchers will use a special MRI technique called hyperpolarized carbon-13 MRI, along with blood and tissue analysis (metabolomics) and advanced image feature analysis (radiomics). These tools can track how cancer cells use energy and how metabolism changes during treatment. The study will follow 30 rectal cancer patients at Chang Gung Memorial Hospital over 3 years. Patients will undergo standard MRI, colonoscopy, and advanced metabolic imaging before and after treatment. Results will compare patients whose tumors completely respond to therapy with those who do not. The goal is to see if metabolic changes detected by hyperpolarized MRI and metabolomics can predict treatment outcomes earlier and more accurately. This may help doctors avoid unnecessary surgery and provide more personalized care for rectal cancer patients.

Neoadjuvant chemoradiation therapy (nCRT) is the standard treatment modality for locally advanced rectal cancer (LARC), and patients achieving complete response (CR) generally have improved local control, metastasis-free survival, and overall survival. The aim of this clinical trial is to investigate the impact of radiotherapy dose escalation in rectal cancer by identifying poor responders during treatment using the Early Tumor Regression Index (ERI). Patients are treated using magnetic resonance-guided radiotherapy (MRgRT). ERI is calculated at fraction 10. Patients with an ERI value below 13.1 continue the standard treatment schedule, whereas patients with an ERI value above 13.1 undergo adaptive replanning with dose escalation up to 60.1 Gy to the residual tumor volume. Concomitant chemotherapy consists of fluoropyrimidine-based treatment, with oxaliplatin permitted in patients at high risk of recurrence. In selected high-risk patients, consolidation chemotherapy with three cycles of FOLFOX may be administered during the interval before surgery. Following protocol amendments, the study was expanded to include a total planned enrollment of 179 patients. Additional blood samples for circulating tumor DNA (ctDNA) analysis and stool samples for gut microbiome profiling are collected at predefined time points. These longitudinal multi-omics data are integrated with magnetic resonance imaging-based delta-radiomics features to develop composite biomarker models for prediction of treatment response. The primary outcome measures are complete response, defined as ypT0N0 after Total Mesorectal Excision (TME), ypT0 ycN0 after Local Excision (LE), or ycT0N0 in patients managed with Watch and Wait, and the prospective validation of the magnetic resonance-guided radiotherapy delta-radiomics predictive model.

A prospective, single-arm clinical trial is conducted to investigate the role of oral immunonutrion in reducing acute toxicity after neoadjuvant chemoradiotherapy among pancreatic cancer patients.