A prospective feasibility study evaluating the role of multimodality imaging and liquid biopsy for response assessment in locally advanced rectal carcinoma.

摘要: Colorectal cancer is a commonly encountered disease that poses several diagnostic and therapeutic challenges. The inherent heterogeneity of tumor biology propensity to relapse despite “curative” resection pose significant challenges with regard response assessment. Although MR imaging already plays key role in primary staging patients rectal carcinoma, its reliability restaging after neoadjuvant therapy debatable (Van der broek et al. Dis Colon Rectum 60(3):274–283, 2017). Therefore, there interest developing additional methods which may improve accuracy. This study aims evaluate the multimodality liquid biopsy Seventeen were enrolled into over span 24 months. All underwent hybrid PET-MRI CT-perfusion (CT-P), prior following for locally advanced carcinoma. Twelve 17 also biopsy, consisted blood sampling analysis circulating cells (CTCs) extracellular vesicles (EVs), including cell fragments microparticles (MPs), using Cell Search System (Menarini Silicon Biosystems). SUV, DWI, ADC calculated during PET-MRI, parameters evaluated CT-perfusion, including average perfusion, flow (BF), volume (BV), mean transit time (MTT), permeability-surface area product (PS), contrast extraction efficiency (E), K-trans (K). Changes observed pre- post-neoadjuvant each modality compared at histopathology modified Ryan regression grading system. Of included study, 14 classified as non-responders, 3 responders determined by Tumor Regression Grade (TRG) scoring system When combined, markers CT-P (mean K-trans, permeability-surface area (PS)) produced strongest models (p < 0.01). PET (SUV measurement) combined CT-P-derived marginally (p = 0.057) model predicting response. MRI-derived value did not provide prediction. A plus more accurately predicts than alone, or alone. These results suggest evaluation treatment response, could information functional modalities such should therefore be explored further trial larger sample size.