Postchemotherapy tumor volume as a prognostic indicator in Wilms tumor: A single-center experience from South India.

BACKGROUND: Optimal risk stratification is the key to minimizing relapse and toxicity in children with Wilms tumor (WT). The study evaluated poor tumor volume response to chemotherapy as a risk factor that predicts relapse. PROCEDURE: Children with WT who were treated between 2005 and 2020 at the center were analyzed. Tumor volumes at the time of diagnosis and after preoperative chemotherapy were calculated from cross-sectional imaging. The International Society of Paediatric Oncology (SIOP)-WT-2001 protocol was used for treatment. The area under a receiver operating characteristic curve was estimated to ascertain the ability of tumor volume to predict relapse. RESULTS: Ninety-five patients with a median age of 40 months were included. A postchemotherapy tumor volume cutoff of 270 ml was ascertained to have the best predictive value for relapse. Patients with a tumor volume of <270 ml following preoperative chemotherapy had a better 3-year event-free survival (EFS) than those with a tumor volume of ≥270 ml (89.8% ± 4.0% vs. 57.4% ± 12.5%, p = .001). The data demonstrated that a tumor volume of ≥270 ml after chemotherapy was associated with an increased risk of relapse (hazard ratio [HR]: 5.3, p = .006). The EFS in patients with an epithelial or stromal type of histopathology was not affected by the tumor volume response (p = .437). Conversely, patients with other types of intermediate-risk histopathology who had a poor tumor volume response had an inferior survival (3-year EFS 51.4% ± 18.7%, p = .001). CONCLUSION: A postchemotherapy tumor volume cutoff of ≥270 ml emerged as a strong predictor of relapse in a low- and middle-income country (LMIC) center study of WT treated with the SIOP protocol.

Ultrasound and magnetic resonance imaging for the detection of blood: An ex-vivo study.

OBJECTIVES: Early detection of bleeding into a joint is crucial in patients with haemophilia. This study was designed to evaluate the sensitivity of ultrasonography (USG) and magnetic resonance imaging (MRI) to detect the presence of blood in small concentrations in a simulated model to mimic joint bleeding. MATERIALS AND METHODS: Different concentrations of blood in plasma, varying from 0.1% to 45%, were collected in 10-ml plastic syringes and imaged using 12 and 18 MHz USG transducers and with 1.5T and 3T MRI scanners, at different intervals of time following dilution. The images were scored for the presence of blood by four experienced radiologists who were blinded to the concentration of blood. RESULTS: Within the first 2 h, the 18 MHz transducer was able to detect blood consistently up to 0.5%, whereas the 12 MHz transducer could consistently identify blood up to 1.4%. After the first 12 h, both transducers were able to detect blood up to 0.5% concentration. However, at concentrations below 0.5%, there was discordance in the ability to detect blood, with both transducers. There was no correlation between the signal intensities of MRI images and concentration of blood, at different time intervals, irrespective of the magnetic field strength. CONCLUSIONS: Detection of blood using the USG is dependent on variables such as the concentration of blood, frequency of the transducer used and timing of the imaging. As the concentration of blood decreases below 0.5%, the discordance between the observers increases, implying that the detection limit of USG affects its reliability at lower concentrations of blood. Caution is urged while interpreting USG imaging studies for the detection of blood in symptomatic joints.

MRI predictors of infectious etiology in patients with unilateral sacroiliitis.

BACKGROUND: Unilateral presentation of sacroiliitis is a diagnostic dilemma, especially between infection and inflammatory sacroiliitis associated with spondyloarthritis, requiring an early and accurate diagnosis. OBJECTIVE: To assess the utility of magnetic resonance imaging (MRI) in differentiating infective versus inflammatory etiology in unilateral sacroiliitis. MATERIALS AND METHODS: Retrospective review of the MRI of 90 patients with unilateral sacroiliitis, having an established final diagnosis. MR images were evaluated for various bone and soft tissue changes using predefined criteria and analyzed using univariate and multivariate regression analysis. RESULTS: Among the 90 patients, infective etiology was diagnosed in 66 (73.3%) and inflammatory etiology in 24 (26.7%). Large erosions, both iliac and sacral-sided edema, joint space involvement with effusion or synovitis, soft tissue edema, elevated ESR/CRP, and absence of capsulitis and enthesitis were associated with infection (p < .001). The independently differentiating variables favoring infection on multivariate analysis were-both iliac and sacral-sided edema (OR 4.79, 95% CI: 0.96-23.81, p = .05), large erosions (OR 17.96, 95% CI: 2.66-121.02, p = .003), and joint space involvement (OR 9.9, 95% CI: 1.36-72.06, p = .02). Exclusive features of infection were osteomyelitis, sequestra, abscesses, sinus tracts, large erosions, and multifocality. All infective cases had soft tissue edema, joint space involvement, elevated ESR, and no capsulitis. CONCLUSION: MRI evaluation for the presence and pattern of bone and joint space involvement, soft tissue involvement, and careful attention to certain exclusive features will aid in differentiating infectious sacroiliitis from inflammatory sacroiliitis.