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.

Colorectal cancer treatment outcomes during the pandemic: Our experience of COVID-19 at a tertiary referral center.

BACKGROUNDS: The coronavirus disease 2019 (COVID-19) has led to major shifts in the management of colorectal cancer (CRC). This study aims to identify the impact and early outcomes of COVID-19 following CRC management at a tertiary referral center in Victoria, Australia. METHODS: This was a retrospective study, utilizing the Australian Comprehensive Cancer Outcomes and Research Database and inpatient records. Patients presenting for CRC management at our institution were identified coinciding with the first Victorian outbreak of COVID-19 (March 26 to September 26, 2020) (COVID). Management decisions including chemoradiotherapy utilization and surgical outcomes were analyzed within 6 months and compared with the corresponding period in 2019 (pre-COVID). RESULTS: A total of 276 patients were included in this study (147 pre-COVID period, 129 COVID period). During the COVID period, more patients (47.6% vs. 60.5%; p = 0.033) presented symptomatically and less for surveillance (10.9% vs. 2.3%; p < 0.01). Eighty-four pre-COVID and 69 COVID period patients proceeded to surgery. The average time from diagnosis date to surgery was 15.6 days less during the COVID period. There were no significant differences in postoperative utilization of higher care (p = 0.74), complications (p = 0.93), median hospital length of stay (p = 0.67), 30-day readmission (p = 0.50), or 30-day reoperation (p = 0.74). In 1.6% of cases, pandemic impacts resulted in a change in management. CONCLUSION: Presentation of patients with CRC varied, with a significant increase in symptomatic presentations and decreased numbers for surveillance. Through flexibility and change in practice, our institution helped improve access to surgical intervention and oncological therapies. Further prospective work is required to identify long-term outcomes and characterize the effects of ongoing disruptions.

Can sarcopenia predict survival in locally advanced rectal cancer patients?

BACKGROUND: There is mounting evidence that suggests sarcopenia can be used to predict survival outcomes in patients with colon cancer. However, the effect on locally advanced rectal cancer (LARC) is less clear. We sought to determine the association between sarcopenia on Overall Survival and Recurrence-free Survival (OS and RFS) in patients with LARC undergoing multimodal treatment. METHODS: A retrospective study was undertaken of all pre-treatment stage 2-3 rectal cancer patients who underwent neo-adjuvant treatment and surgery with curative intent between January 2010 and September 2016 at Western Health. Sarcopenia was measured on pre-treatment staging scans at the third lumbar vertebrae and defined using cohort-derived, sex-specific thresholds. Primary outcomes were OS and RFS. RESULTS: A total of 132 patients with LARC were analysed. Sarcopenia: Hazard ratio (HR) 3.71; 95% CI, 1.28-10.75, P = 0.016 was independently associated with worse Overall Survival following multivariate analysis. There was no significant relationship between sarcopenia and RFS: Time ratio (TR) 1.67; 95% CI 0.52-5.34, P = 0.386. CONCLUSION: Sarcopenia was found to be an independent risk factor for worse overall survival, but not recurrence free survival, in patients with locally advanced rectal cancer undergoing neo-adjuvant chemo-radiotherapy and surgery with curative intent.

Comparison of CT derived body composition at the thoracic T4 and T12 with lumbar L3 vertebral levels and their utility in patients with rectal cancer.

BACKGROUND: Computed tomography (CT) derived body composition measurements of sarcopenia are an emerging form of prognostication in many disease processes. Although the L3 vertebral level is commonly used to measure skeletal muscle mass, other studies have suggested the utilisation of other segments. This study was performed to assess the variation and reproducibility of skeletal muscle mass at vertebral levels T4, T12 and L3 in pre-operative rectal cancer patients. If thoracic measurements were equivalent to those at L3, it will allow for body composition comparisons in a larger range of cancers where lumbar CT images are not routinely measured. RESEARCH METHODS: Patients with stage I - III rectal cancer, undergoing curative resection from 2010 - 2014, were assessed. CT based quantification of skeletal muscle was used to determine skeletal muscle cross sectional area (CSA) and skeletal muscle index (SMI). Systematic differences between the measurements at L3 with T4 and T12 vertebral levels were evaluated by percentile rank differences to assess distribution of differences and ordinary least product regression (OLP) to detect and distinguish fixed and proportional bias. RESULTS: Eighty eligible adult patients were included. Distribution of differences between T12 SMI and L3 SMI were more marked than differences between T4 SMI and L3 SMI. There was no fix or proportional bias with T4 SMI, but proportional bias was detected with T12 SMI measurements. T4 CSA duplicate measurements had higher test-retest reliability: coefficient of repeatability was 34.10 cm2 for T4 CSA vs 76.00 cm2 for T12 CSA. Annotation time (minutes) with L3 as reference, the median difference was 0.85 for T4 measurements and -0.03 for T12 measurements. Thirty-seven patients (46%) had evidence of sarcopenia at the L3 vertebral level, with males exhibiting higher rates of sarcopenia. However, there was no association between sarcopenia and post-operative complications, recurrence or hospital LOS (length of stay) in patients undergoing curative resection. CONCLUSIONS: Quantifying skeletal muscle mass at the T4 vertebral level is comparable to measures achieved at L3 in patients with rectal cancer, notwithstanding annotation time for T4 measurements are longer.

Outcomes of perineal reconstruction with inferior gluteal artery myocutaneous flaps and primary closure following abdominoperineal resection.

BACKGROUND: Perineal wound morbidity following abdominoperineal resection (APR) is a significant challenge. Myocutaneous flap-based techniques have been developed to overcome morbidity associated with perineal reconstruction. We reviewed outcomes for patients undergoing APR in a hospital that performs inferior gluteal artery myocutaneous (IGAM) island transposition flaps and primary closure (PC) for perineal reconstruction. METHODS: A retrospective study of patients who underwent APR for malignancy between January 2012 and March 2020 was performed and outcomes between IGAM reconstruction and PC compared. Primary outcomes were wound infection and dehiscence. Secondary outcomes included return to theatre, operative time, length of stay, flap loss and perineal hernia incidence. RESULTS: One-hundred and two patients underwent APR, with 50 (49%) who had PC and 52 (51%) had IGAM flap reconstructions. There were no differences between each group with regards to wound infection (23 vs. 22%, P = 0.55) or wound dehiscence (25 vs. 24%, P = 0.92). Thirteen (25%) IGAM patients required a return to theatre compared to three PC patients (6%) (P = 0.008). IGAM procedures required twice the overall operative time (506 vs. 240 min, P = 0.001) with no differences between groups when comparing the APR component (250 vs. 240 min, P = 0.225). The IGAM group had a longer length of stay (median 13 days vs. 9 days, P = 0.001). Only one IGAM flap was lost and no symptomatic hernias were identified. CONCLUSION: Perineal closure technique did not affect the incidence of wound infection or dehiscence. Closure technique should be tailored to underlying patient characteristics and surgical pathology.

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.

The effect of smoking, obesity and diabetes on recurrence-free and overall survival in patients with stage III colon cancer receiving adjuvant chemotherapy.

BACKGROUND: The association between smoking, diabetes and obesity and oncological outcomes in patients with stage III colon cancer treated with surgery and adjuvant chemotherapy is unclear. AIM: To evaluate whether smoking, obesity and diabetes are associated with the disease-free survival and overall survival rates of patients with stage III colon cancer who have received adjuvant chemotherapy. METHODS: Patients were selected from the prospectively maintained Australian Cancer Outcomes and Research Database (ACCORD). All stage III colon cancer patients who received adjuvant chemotherapy between January 2003 to December 2015 were retrospectively analyzed. The three primary exposures of interest were smoking status, body mass index (BMI) and diabetic (DM) status. The primary outcomes of interest were disease-free survival (DFS) and overall survival (OS). RESULTS: A total of 785 patients between 2003 and 2015 were included for analysis. Using Kaplan-Meier survivorship curves, there was no association between OS and smoking (P = .71), BMI (P = .3) or DM (P = .72). Similarly, DFS did not reveal an association with smoking (P = .34), BMI (P = .2) and DM (P = .34). Controlling for other covariates the results did not reach statistical significance in adjusted multiple regression models. CONCLUSION: Smoking, obesity and DM were not shown to influence DFS or OS for patients with stage III colon cancer who have received adjuvant chemotherapy.

A Pipeline for Generating Interactive, Schematic 3D Surgical Anatomy Models.

OBJECTIVE: We describe a pipeline for creating and publishing online schematic 3D anatomical models, that requires minimal resources and facilitates an intuitive understanding of complex surgical structures, using the inguinal canal as an example. DESIGN: The open source 3D modeling software Blender1 was used to generate the inguinal canal model. With screen recording enabled, the model was annotated within a 3D space and the resultant video tutorial uploaded to YouTube. The 3D model was also exported to an online web portal that students could navigate independently. Feedback was collated from YouTube and the online platform over two years via video comments and an online form for platform visitors. SETTING: Department of Surgery, Western Precinct, University of Melbourne, Melbourne, Australia. PARTICIPANTS: A total of 5,438 students utilized the online platform over the past 24 months. Video tutorials depicting the inguinal canal model were viewed a total of 162,181 times across the same period. RESULTS: Feedback was uniformly positive with a predominant theme of faster comprehension times that were attributed to the visuospatial feedback complementing traditional resources. CONCLUSIONS: The development of online 3D schematic models is achievable with the use of free and readily accessible computer software. These models allow students to "walk through" complex anatomical areas, which may enable them to better orientate and understand previously difficult to teach surgical concepts.

Laparoscopic Management of Abdominal Apoplexy.

Abdominal apoplexy, otherwise known as intraperitoneal idiopathic spontaneous haemorrhage, is a rare condition that presents as a diagnostic dilemma and is associated with high mortality. Symptoms and signs typically are similar to other conditions presenting with upper abdominal peritonitis. Intraabdominal haemorrhage can occur from many different causes, including trauma, iatrogenic, ruptured aneurysm, gynaecological conditions, malignancy, and inflammatory or autoimmune processes. Spontaneous or idiopathic causes are much rarer. Prompt diagnosis and ligation of the bleeding vessel usually result in a good outcome. Most cases described involve males in the fifth and sixth decade of life who present in the setting of hypertension and known atherosclerotic disease and are managed with laparotomy or are diagnosed at autopsy. We present a case of abdominal apoplexy managed laparoscopically in a healthy 20-year-old male with no pre-existing medical conditions. This case highlights the importance to consider abdominal apoplexy in any demographic.

Emergency appendicectomy in Australia: findings from a multicentre, prospective study.

BACKGROUND: Emergency appendicectomy is the most common emergency surgical procedure performed in Australia. Despite this frequency, there is a relative paucity of contemporary, broad-based, local data that examine how emergency appendicectomies are currently performed and what are the outcomes from these operations. METHODS: A multicentre, prospective, observational study was performed. Patients were recruited by local investigators for a period of 2 months with 30-day follow-up. Patients were eligible for study inclusion if they underwent an emergency appendicectomy for suspected acute appendicitis. The primary outcome of the study was the negative appendicectomy rate (NAR), with secondary outcomes including 30-day complication rates, method of operation and conversion rates. RESULTS: A total of 1189 patients were recruited across 27 centres. The NAR across all centres was 19.0%. 98.2% of appendicectomies were performed with a laparoscopic-first approach. The rate of conversion from laparoscopy to open operation was 2.4%. 9.4% of patients were recorded as having one or more of the following complications: readmission (6.6%), surgical site infection (1.9%), intra-abdominal abscess (2.7%) or further intervention (1.5%). Patients who had an open operation had higher rates of readmission and surgical site infection. CONCLUSION: The NAR found in this study is within the traditional measures of acceptance; however, this rate is high when measured against modern international benchmarks.

Primary cutaneous mucoepidermoid carcinoma: a case study with a review of the literature.

Mucoepidermoid carcinoma (MEC) of the skin is a rare neoplasm with few cases reported in the medical literature. We report a case of MEC of the skin in a 76-year-old man who presented with an infiltrative multinodular lesion on his right cheek. Histological description showed a multilobulated nodulocystic tumor extending throughout the dermis exhibiting glandular and squamoid differentiation. Cribiform nests of epidermoid cells contained glandular spaces with mucin. The nuclei were mildly atypical and contained scattered mitotic figures. A small focus of perineural invasion was evident within the tumor not extending beyond the deep margin with no lymphovascular invasion. There was no overlying intraepidermal carcinoma. Immunohistochemical analysis revealed staining for EMA, PanCK, and p63 whereas CK7, CK20, and CEA were negative. It is important to differentiate primary cutaneous MEC from cutaneous adenosquamous carcinoma, direct extension from an underlying primary salivary gland MEC, or metastasis of MEC from another site. We conclude that primary MEC of the skin is a low-grade neoplasm that should be differentiated from adenosquamous carcinoma. Immunohistochemical staining for p63 has proven to be helpful in differentiating primary epidermal or adnexal tumours and metastatic neoplasms to the skin.