Search

Introduction: Accurate identification of patients with pathologic complete response (pCR) following neoadjuvant radiochemotherapy (RCT) for locally advanced rectal cancer (LARC) is essential. 18-FDG PET/MRI provides metabolic information that complements the morphological assessment of standard MRI, potentially enhancing the differentiation between fibrotic and tumorous tissues post-treatment. This study aims to evaluate the performance of 18-FDG PET/MRI in assessing treatment response compared to standard MRI., Materials and Methods: A prospective study was conducted at HM Sanchinarro University Hospital, Madrid, from 2018 to 2021. Patients with LARC undergoing RCT were included and staged at diagnosis and restaged 8-12 weeks post-neoadjuvant treatment using 18-FDG PET/MRI. The primary outcome was to compare the performance of PET/MRI and standard MRI in detecting pCR and tumor regression grade (TRG) confirmed via histopathological examination. Quantitative analysis assessed the apparent diffusion coefficient (ADC) and standardized uptake value (SUV). A secondary outcome included survival analysis using the Kaplan-Meier method and Cox regression analysis for radiological and pathological prognostic markers., Results: Among 33 patients, pCR was observed in 45% (14/33). PET/MRI demonstrated sensitivity, specificity, and accuracy values of 0.88, 0.80, and 0.84, respectively, for detecting pCR, compared to 0.82, 0.50, and 0.67 for standard MRI (p < 0.001). PET/MRI accurately identified TRG stages in 72% of cases, compared to 50% for standard MRI. Post-SUV, post-ADC, and delta-ADC were the most precise PET/MRI predictors for pCR, with AUC values of 0.81, 0.75, and 0.55, respectively. Patients with mrEMVI and mrTRG showed worse disease-free survival (DFS)., Conclusion: 18-FDG PET/MRI emerges as a promising imaging tool for predicting response to neoadjuvant treatment in rectal cancer, with superior diagnostic accuracy compared to standard MRI. Radiological findings, such as EMVI, can identify high-risk patients, offering valuable prognostic insights., Competing Interests: Declarations. Ethics approval and consent to participate: This study was approved by the Ethics Committee of the Sanchinarro Hospital. All experiments were performed in accordance with relevant guidelines and regulations (such as the Declaration of Helsinki). Informed consent was obtained from all participants in the study. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

Background: The watch-and-wait (WW) strategy is a potential option for patients with rectal cancer who obtain a complete clinic response after neoadjuvant therapy. The aim of this study is to analyze the long-term oncological outcomes and perform a cost-effectiveness analysis in patients undergoing this strategy for rectal cancer., Material and Methods: The data of patients treated with the WW strategy were prospectively collected from January 2015 to January 2020. A control group was created, matched 1:1 from a pool of 480 patients undergoing total mesorectal excision. An independent company carried out the financial analysis. Clinical and oncological outcomes were analyzed in both groups. Outcome parameters included surgical and follow-up costs, quality-adjusted life years (QALYs), and the incremental cost per QALY gained or the incremental cost-effectiveness ratio (ICER)., Results: Forty patients were included in the WW group, with 40 patients in the surgical group. During a median follow-up period of 36 months, metastasis-free survival (MFS) and overall survival (OS) were similar in the two groups. In the WW group, nine (22%) local regrowths were detected in the first 2 years. The permanent stoma rate was slightly higher after salvage surgery in the WW group compared to the surgical group (48.5% vs 20%, p < 0.01). The cost-effectiveness analysis was slightly better for the WW group, especially for low rectal cancer compared to medium-high rectal cancer (ICER =  - 108,642.1 vs ICER =  - 42,423)., Conclusions: The WW strategy in locally advanced rectal cancer offers similar oncological outcomes with respect to the surgical group and excellent results in quality of life and cost outcomes, especially for low rectal cancer. Nonetheless, the complex surgical field during salvage surgery can lead to a high permanent stoma rate; therefore, the careful selection of patients is mandatory., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objectives: Neoadjuvant chemoradiation (nCRT) is universally considered to be a valid treatment to achieve downstaging, to improve local disease control and to obtain better resectability in locally advanced rectal cancer (LARC). The aim of this study is to correlate the change in the tumour 18F-FDG PET-CT standardized uptake value (SUV) before and after nCRT, in order to obtain an early prediction of the pathologic response (pR) achieved in patients with LARC., Data Description: We performed a retrospective analysis of patients with LARC diagnosis who underwent curative resection. All patients underwent a baseline 18F-FDG PET-CT scan within the week prior to the initiation of the treatment (PET-CT SUV1) and a second scan (PET-CT SUV2) within 6 weeks of the completion of nCRT. We evaluated the prognostic value of 18F-FDG PET-CT in terms of disease-free survival (DFS) and overall survival (OS) in patients with LARC.A total of 133 patients with LARC were included in the study. Patients were divided in two groups according to the TRG (tumour regression grade): 107 (80%) as the responders group (TRG0-TRG1) and 26 (25%) as the no-responders group (TRG2-TRG3). We obtained a significant difference in Δ%SUV between the two different groups; responders versus no-responders (p < 0.012). The results of this analysis show that 18F-FDG PET-CT may be an indicator to evaluate the pR to nCRT in patients with LARC. The decrease in 18F-FDG PET-CT uptake in the primary tumour may offer important information in order for an early identification of those patients more likely to obtain a pCR to nCRT and to predict those who are unlikely to significantly regress., (© 2021. The Author(s).)