Using a new artificial intelligence-aided method to assess body composition CT segmentation in colorectal cancer patients.

INTRODUCTION: This study aimed to evaluate the accuracy of our own artificial intelligence (AI)-generated model to assess automated segmentation and quantification of body composition-derived computed tomography (CT) slices from the lumber (L3) region in colorectal cancer (CRC) patients. METHODS: A total of 541 axial CT slices at the L3 vertebra were retrospectively collected from 319 patients with CRC diagnosed during 2012-2019 at a single Australian tertiary institution, Western Health in Melbourne. A two-dimensional U-Net convolutional network was trained on 338 slices to segment muscle, visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Manual reading of these same slices of muscle, VAT and SAT was created to serve as ground truth data. The Dice similarity coefficient was used to assess the U-Net-based segmentation performance on both a validation dataset (68 slices) and a test dataset (203 slices). The measurement of cross-sectional area and Hounsfield unit (HU) density of muscle, VAT and SAT were compared between two methods. RESULTS: The segmentation for muscle, VAT and SAT demonstrated excellent performance for both the validation (Dice similarity coefficients >0.98, respectively) and test (Dice similarity coefficients >0.97, respectively) datasets. There was a strong positive correlation between manual and AI segmentation measurements of body composition for both datasets (Spearman's correlation coefficients: 0.944-0.999, P < 0.001). CONCLUSIONS: Compared to the gold standard, this fully automated segmentation system exhibited a high accuracy for assessing segmentation and quantification of abdominal muscle and adipose tissues of CT slices at the L3 in CRC patients.

Body composition assessment by artificial intelligence can be a predictive tool for short-term postoperative complications in Hartmann's reversals.

BACKGROUND: Hartmann's reversal, a complex elective surgery, reverses and closes the colostomy in individuals who previously underwent a Hartmann's procedure due to colonic pathology like cancer or diverticulitis. It demands careful planning and patient optimisation to help reduce postoperative complications. Preoperative evaluation of body composition has been useful in identifying patients at high risk of short-term postoperative outcomes following colorectal cancer surgery. We sought to explore the use of our in-house derived Artificial Intelligence (AI) algorithm to measure body composition within patients undergoing Hartmann's reversal procedure in the prediction of short-term postoperative complications. METHODS: A retrospective study of all patients who underwent Hartmann's reversal within a single tertiary referral centre (Western) in Melbourne, Australia and who had a preoperative Computerised Tomography (CT) scan performed. Body composition was measured using our previously validated AI algorithm for body segmentation developed by the Department of Surgery, Western Precinct, University of Melbourne. Sarcopenia in our study was defined as a skeletal muscle index (SMI), calculated as Skeletal Muscle Area (SMA) /height2 < 38.5 cm2/m2 in women and < 52.4 cm2/m2 in men. RESULTS: Between 2010 and 2020, 47 patients (mean age 63.1 ± 12.3 years; male, n = 28 (59.6%) underwent body composition analysis. Twenty-one patients (44.7%) were sarcopenic, and 12 (25.5%) had evidence of sarcopenic obesity. The most common postoperative complication was surgical site infection (SSI) (n = 8, 17%). Sarcopenia (n = 7, 87.5%, p = 0.02) and sarcopenic obesity (n = 5, 62.5%, p = 0.02) were significantly associated with SSIs. The risks of developing an SSI were 8.7 times greater when sarcopenia was present. CONCLUSION: Sarcopenia and sarcopenic obesity were related to postoperative complications following Hartmann's reversal. Body composition measured by a validated AI algorithm may be a beneficial tool for predicting short-term surgical outcomes for these patients.

Chronic rectal anastomosis complications prior to ileostomy reversal: development of a pilot classification system and associated outcomes.

BACKGROUNDS: A loop ileostomy may reduce the severity of acute anastomotic complications after low rectal resection, but some patients have persistent rectal anastomotic problems. No consensus exists for the management of patients with a chronic low rectal anastomosis complication and a loop ileostomy. There is need for a standard description of these anastomotic complications and to determine whether it is safe to reverse the ileostomy. This study proposes a classification of chronic rectal anastomotic complications and to report the correlation with successful restoration of rectal continuity. METHODS: This was a retrospective project from a prospectively maintained database at a single colorectal unit in a large tertiary hospital in Metropolitan Melbourne. Patients with rectal anastomotic complications following rectal cancer resections between March 2012 and October 2019 were included. A classification of chronic rectal anastomotic complication was developed by reviewing the interval assessments of the rectal anastomosis. The classification categories were correlated with outcomes after stoma closure. RESULTS: Of the 149 patients, 20 patients had an anastomotic complication identified during work up prior to loop ileostomy reversal. Eleven patients had an anastomotic stenosis and nine had an anastomotic defect. Eighteen patients were eligible for stomal closure. The majority (11/12) of patients with a Type 1 stenosis or defect had no rectal complications after stoma closure. CONCLUSION: The classification system helps to describe chronic rectal anastomotic abnormalities and guide management. Although these patients may be a challenge, many can undergo successful ileostomy reversal.

Long-term MRI Follow-up of Hyaluronic Acid Dermal Filler.

We present a case report of hyaluronic acid (HA) injected in the subcutaneous fat of the lateral face, deep fat compartments of the mid-face, and a combination of deep and superficial injection of HA in the chin. MRI demonstrates longevity of HA in the lateral face and deep fat compartments of the mid-face versus almost complete degradation of HA in the chin 19 months from injection. The MRI signal demonstrated no migration of HA and persistence of HA at 27 months in the lateral face and mid-face.

Positive lateral pelvic lymph nodes in low rectal cancer: should we change our practice now?

BACKGROUND: The role of lateral lymph node dissection (LLND) in the treatment of patients with low rectal cancer with enlarged lateral lymph nodes (LLN+) is under investigation. Enthusiasm for LLND stems from a perceived reduction in local recurrence (LR). We aimed to compare the LR rate for LLN+ patients with LLN- patients, treated with neoadjuvant chemoradiotherapy (nCRT) and surgery, in a hospital that does not perform LLND. METHODS: A retrospective study of all patients with clinical stage 3 low rectal cancer who completed nCRT and surgery between 2008 and 2017 at Western Health was performed. Outcomes for LLN+ patients were compared with LLN- patients. The primary outcome was LR. Secondary outcomes included distant metastases, disease-free survival and overall survival. RESULTS: There were 110 patients treated for stage 3 low rectal cancer over 10 years. There was no significant difference in the LR rate, with one LR from 28 LLN+ patients and one LR from 82 LLN- patients (4% versus 1.2%, P = 0.44). There were no significant differences in median disease-free survival (41 versus 52 months, P = 0.19) or mean overall survival (62 versus 60 months, P = 0.80). Of all patients studied, 21% developed distant metastases. CONCLUSION: LR after nCRT and surgery in patients with stage 3 rectal cancer is rare, irrespective of lateral pelvic node status. These data, along with the uncertain benefit and known risks of LLND, supports the continued use of standard therapy in these patients. Strategies to address distant failure in these patients should be explored.

Hyaluronic Acid Filler Longevity and Localization: Magnetic Resonance Imaging Evidence.

SUMMARY: Hyaluronic acid is the most commonly used facial dermal filler in aesthetic medicine. Identification of placement, longevity, and localization of hyaluronic acid fillers are becoming increasingly important. This article proposes a practical approach to monitoring the location and longevity of hyaluronic acid, using magnetic resonance imaging. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Incidence of pulmonary embolism in patients with newly diagnosed colorectal cancer.

BACKGROUND: Studies have suggested a benefit from extended venous thromboprophylaxis post-operatively in colorectal cancer with an assumed base rate of zero venous thromboembolic events prior to treatment. We aim to establish the incidence of pulmonary embolism in patients with newly diagnosed stage III or IV colorectal cancer prior to any treatment. METHOD: Consecutive patients presenting to a single health service with a new diagnosis of stage III or IV colorectal cancer were identified from a prospective database, for the period between January 2011 and September 2014. Contemporaneous clinical data was reviewed. Included patients had a computerized tomography (CT) chest scan for pre-operative staging for cancer. The diagnosis of pulmonary emboli was made on chest CT. RESULTS: Of 330 patients identified, 224 had baseline CT chest imaging available for review, of which 107 (47.8%) were technically adequate scans. Pulmonary emboli were identified on five (4.7%) of these 107, including one of five patients (1.7%) with stage III and four of five patients (8.3%) with stage IV disease. None of the 107 patients with adequate scans had post-operative pulmonary emboli or deep vein thrombosis. CONCLUSION: There is a clinically significant baseline rate of asymptomatic pulmonary emboli in patients with stage III and IV colorectal cancer that can be demonstrated on the staging chest CT scan. Pulmonary emboli described as a post-operative event in previous series may have been present prior to surgery.