Reproducibility and Repeatability of CBCT-Derived Radiomics Features

PurposeThis study was conducted in order to determine the reproducibility and repeatability of cone-beam computed tomography (CBCT) radiomics features.MethodsThe first-, second-, and fifth-day CBCT images from 10 head and neck (H&N) cancer patients and 10 pelvic cancer patients were retrospectively collected for this study. Eighteen common radiomics features were extracted from the longitudinal CBCT images using two radiomics packages. The reproducibility of CBCT-derived radiomics features was assessed using the first-day image as input and compared across the two software packages. The site-specific intraclass correlation coefficient (ICC) was used to quantitatively assess the agreement between packages. The repeatability of CBCT-based radiomics features was evaluated by comparing the following days of CBCT to the first-day image and quantified using site-specific concordance correlation coefficient (CCC). Furthermore, the correlation with volume for all the features was assessed with linear regression and R2 as correlation parameters.ResultsThe first-order histogram-based features such as skewness and entropy showed good agreement computed in either software package (ICCs ≥ 0.80), while the kurtosis measurements were consistent in H&N patients between the two software tools but not in pelvic cases. The ICCs for GLCM-based features showed good agreement (ICCs ≥ 0.80) between packages in both H&N and pelvic groups except for the GLCM-correction. The GLRLM-based texture features were overall less consistent as calculated by the two different software packages compared with the GLCM-based features. The CCC values of all first-order and second-order GLCM features (except GLCM-energy) were all above 0.80 from the 2-day part test–retest set, while the CCC values all dropped below the cutoff after 5-day treatment scans. All first-order histogram-based and GLCM-texture-based features were not highly correlated with volume, while two GLRLM features, in both H&N and pelvic cohorts, showed R2 ≥0.8, meaning a high correlation with volume.ConclusionThe reproducibility and repeatability of CBCT-based radiomics features were assessed and compared for the first time on both H&N and pelvic sites. There were overlaps of stable features in both disease sites, yet the overall stability of radiomics features may be disease-/protocol-specific and a function of time between scans.

Devastated Bladder Outlet in Pelvic Cancer Survivors: Issues on Surgical Reconstruction and Quality of Life

Bladder outlet obstruction following treatment of pelvic cancer, predominantly prostate cancer, occurs in 1–8% of patients. The high incidence of prostate cancer combined with the long-life expectancy after treatment has increased concerns with cancer survivorship care. However, despite increased oncological cure rates, these adverse events do occur, compromising patients’ quality of life. Non-traumatic obstruction of the posterior urethra and bladder neck include membranous and prostatic urethral stenosis and bladder neck stenosis (also known as contracture). The devastated bladder outlet can result from benign conditions, such as neurogenic dysfunction, trauma, iatrogenic causes, or more frequently from complications of oncologic treatment, such as prostate, bladder and rectum. Most posterior urethral stenoses may respond to endoluminal treatments such as dilatation, direct vision internal urethrotomy, and occasionally urethral stents. Although surgical reconstruction offers the best chance of durable success, these reconstructive options are fraught with severe complications and, therefore, are far from being ideal. In patients with prior RT, failed reconstruction, densely fibrotic and/or necrotic and calcified posterior urethra, refractory incontinence or severe comorbidities, reconstruction may not be either feasible or recommended. In these cases, urinary diversion with or without cystectomy is usually required. This review aims to discuss the diagnostic evaluation and treatment options for patients with bladder outlet obstruction with a special emphasis on patients unsuitable for reconstruction of the posterior urethra and requiring urinary diversion.

Altered Gut Microbiota Associated With Hemorrhage in Chronic Radiation Proctitis

Pelvic cancer radiotherapy may cause chronic radiation proctitis (CRP) that adversely affects patient’s quality of life, especially in patients with prolonged hematochezia. However, previous studies of radiation enteropathy mainly focused on acute irradiation hazards, and the detailed pathogenesis process and mechanism of prolonged hematochezia associated with radiation-induced toxicity remain unclear. In this study, we characterized the gut microbiota of 32 female CRP patients with or without hematochezia. Differential patterns of dysbiosis were observed. The abundance of Peptostreptococcaceae, Eubacterium, and Allisonella was significantly higher in CRP patients with hematochezia, while the compositions of the Lachnospiraceae, Megasphera, Megamonas, and Ruminococcaceae were lower in the microbiota of non-hematochezia patients. Functional prediction suggested significant difference in the expression of mineral absorption and the arachidonic acid metabolism proteins between hematochezia and non-hematochezia patients, possibly interdependent on radiation-induced inflammation. This study provides new insight into the altered composition and function of gut microbiota in patients with hematochezia, implying the potential use of probiotics and prebiotics for assessment and treatment of CRP.

Adverse Features of Rectourethral Fistula Requiring Extirpative Surgery and Permanent Dual Diversion: Our Experience and Recommendations

Introduction: To report a series of men with a rectourethral fistula (RUF) resulting from pelvic cancer treatments and explore their therapeutic differences and impact on the functional outcomes and quality of life highlighting the adverse features that should determine permanent urinary or dual diversion. Methods: A retrospective database search was performed in four centers to identify patients with RUF resulting from pelvic cancer treatment. Medical records were analyzed for the demographics, comorbidities, diagnostic evaluation, fistula characteristics, surgical approaches and outcomes. The endpoints analyzed included a successful fistula closure following a repair and the impact of the potential adverse features on outcomes. Results: Twenty-three patients, aged 57–79 years (median 68), underwent an RUF reconstruction. The median follow-up (FU) was 54 months (range 18–115). The patients were divided into two groups according to the etiology: radiation/energy-ablation treatments with or without surgery (G1, n = 10) and surgery only (G2, n = 13). All of the patients underwent a temporary diverting colostomy and suprapubic cystostomy. Overall, a successful RUF closure was achieved in 18 (78%) patients. An interposition flap was used in six (60%) patients and one (7.7%) patient in groups G1 and G2, respectively (p = 0.019). The RUF was managed successfully in all 13 patients in group G2 as opposed to 5/10 (50%) in group G1 (p = 0.008). The patients in the radiation/energy-ablation group were more likely to require permanent dual diversion (50% vs. 0%, p < 0.0075). Conclusion: Radiation/energy-ablation therapies are associated with a more severe RUF and more complex reconstructions. Most of these patients require an abdominoperineal approach and flap interposition. The failure of an RUF repair with the need for permanent dual diversion, eventually combined with extirpative surgery, is higher after previous radiation/energy-ablation treatment. Therefore, permanent dual diversion as the primary treatment should always be included in the decision-making process as reconstruction may be futile in specific settings.

A study of bladder filling consistency before and during the radiotherapy for pelvic cancer

The full text of this preprint has been withdrawn by the authors because preprints are not widely accepted in China. Therefore, the authors do not wish this work to be cited as a reference. Questions should be directed to the corresponding author.