Low back pain in a child: a rare case of intramedullary schwannoma initially resembling juvenile spondyloarthritis.

BACKGROUND

Radiation-induced proctitis is a frequent adverse effect that negatively impacts the quality of life in rectal cancer patients receiving neoadjuvant chemoradiotherapy (nCRT). Identifying high-risk factors and predicting their occurrence are crucial for preventing acute radiation proctitis (ARP). The aim of this study was to identify potential risk factors and develop a nomogram to predict the risk of ARP.

METHODS

A total of 561 locally advanced rectal cancer (LARC) patients from January 1, 2019 to December 31, 2021 were collected. Patients were randomly allocated to the training and validation cohorts in a 7:3 ratio. Univariate and multivariate logistic regression analyses were conducted to determine potential predictive factors. A nomogram was created using predictive factors for ARP. The model's performance was assessed using the area under the receiver operating characteristic curve (AUC), calibration curves, and decision curve analysis (DCA).

RESULTS

Among 561 patients, 131 were diagnosed with ARP within 90 days after completion of radiotherapy. Multivariable analysis identified Body Mass Index (BMI), tumor volume (TV), and Prognostic Nutritional Index (PNI) as independent predictors for ARP. Their odds ratios (OR) and 95% confidence intervals (95% CI) were as follows: BMI (0.394, 0.230-0.675, P < 0.001), TV (2.242, 1.366-3.680, P = 0.001), and PNI (0.470, 0.279-0.790, P = 0.004). The nomogram showed moderate discriminative ability, with an AUC of 0.689 (95% CI [0.629-0.749]) in the training cohort and 0.725 (95% CI [0.636-0.815]) in the validation cohort. Calibration curves showed acceptable agreement between predicted and observed risks, and DCA suggested potential clinical usefulness within a range of threshold probabilities.

CONCLUSION

Lower BMI and PNI, and higher TV were independent predictors for ARP in LARC patients receiving nCRT.