CIRSE Standards of Practice on Conducting Meetings on Morbidity and Mortality.

This CIRSE Standards of Practice document is developed by an expert writing group under the guidance of the CIRSE Standards of Practice Committee. It aims to assist Interventional Radiologists in their daily practice by providing best practices for conducting meetings on morbidity and mortality.

Non-invasive classification of non-small cell lung cancer: a comparison between random forest models utilising radiomic and semantic features.

OBJECTIVE: Non-invasive distinction between squamous cell carcinoma and adenocarcinoma subtypes of non-small-cell lung cancer (NSCLC) may be beneficial to patients unfit for invasive diagnostic procedures or when tissue is insufficient for diagnosis. The purpose of our study was to compare the performance of random forest algorithms utilizing CT radiomics and/or semantic features in classifying NSCLC. METHODS: Two thoracic radiologists scored 11 semantic features on CT scans of 106 patients with NSCLC. A set of 115 radiomics features was extracted from the CT scans. Random forest models were developed from semantic (RM-sem), radiomics (RM-rad), and all features combined (RM-all). External validation of models was performed using an independent test data set (n = 100) of CT scans. Model performance was measured with out-of-bag error and area under curve (AUC), and compared using receiver-operating characteristics curve analysis on the test data set. RESULTS: The median (interquartile-range) error rates of the models were: RF-sem 24.5 % (22.6 - 37.5 %), RF-rad 35.8 % (34.9 - 38.7 %), and RM-all 37.7 % (37.7 - 37.7). On training data, both RF-rad and RF-all gave perfect discrimination (AUC = 1), which was significantly higher than that achieved by RF-sem (AUC = 0.78; p < 0.0001). On test data, however, RM-sem model (AUC = 0.82) out-performed RM-rad and RM-all (AUC = 0.5 and AUC = 0.56; p < 0.0001), neither of which was significantly different from random guess ( p = 0.9 and 0.6 respectively). CONCLUSION: Non-invasive classification of NSCLC can be done accurately using random forest classification models based on well-known CT-derived descriptive features. However, radiomics-based classification models performed poorly in this scenario when tested on independent data and should be used with caution, due to their possible lack of generalizability to new data. ADVANCES IN KNOWLEDGE: Our study describes novel CT-derived random forest models based on radiologist-interpretation of CT scans (semantic features) that can assist NSCLC classification when histopathology is equivocal or when histopathological sampling is not possible. It also shows that random forest models based on semantic features may be more useful than those built from computational radiomic features.

Stenting the Upper/Cervical Oesophagus with a Proximal Deployment Cervical Oesophageal Stent: Technique and Outcomes.

INTRODUCTION: Proximal oesophageal stent deployment continues to provide challenges due to the proximity of the upper oesophageal sphincter and the associated subsequent complications such as globus sensation and stent migration. Patients with cervical oesophageal cancer have previously had limited stenting options available to them with a paucity of the literature describing the radiological technique for successfully placing these high-risk stents. In this paper, we present our experience using the Taewoong Niti-S CERVICAL Oesophageal Stent. MATERIALS AND METHODS: We describe our method for stent deployment highlighting the importance of pre-procedural planning in ensuring an adequate proximal landing zone for the short proximal flare of the stent. Furthermore, we outline how we have adapted our placement technique to incorporate a routine pre-dilatation stage which has optimised retrieval of the proximal to distal deployment system. RESULTS: We have placed eight cervical oesophageal stents within our institution. Contrast swallows in all the patients following stent deployment have demonstrated free flow of contrast to the stomach with all patients reporting symptomatic relief and no foreign body/globus sensation. There has been one episode of stent migration but no incidence of oesophageal perforation or haemorrhage. DISCUSSION: Evolution of stenting technique and the properties of the stents themselves are improving accuracy of stent placement in relation to the important landmark of the upper oesophageal sphincter. CONCLUSION: Stenting of cervical oesophageal malignancy has proved successful in our institution and provided symptom relief for a subset of palliative patients who were previously unable to benefit from oesophageal stenting.

Percutaneous Antegrade Colonic Stent Insertion Using a Proximal Trans-peritoneal Colopexy Technique.

INTRODUCTION: Conventionally, colonic stents are inserted with a retrograde trans-anal approach-however, stenting of right-sided or proximal transverse colon lesions may pose a challenge due to tortuosity or long distances. We report three successful cases of percutaneous antegrade colonic stenting in patients using a proximal trans-peritoneal colopexy technique. MATERIALS AND METHODS: Three patients underwent a proximal trans-peritoneal colopexy technique for antegrade colonic stent placement. The patients included three males, ages 89, 92 and 55, who were unsuitable for conventional methods. All patients had a colopexy with the aid of three gastropexy sutures performed under CT or fluoroscopic guidance and subsequent colonic access, followed by the crossing lesion and subsequent deployment of an uncovered colonic stent. A 10-Fr pigtail catheter was exchanged for the sheath, capped and left in place along with the colopexy suture anchors. RESULTS: Percutaneous antegrade colonic stent placement was technically successful in all patients with no complications. Follow-up at 10 days, a tubogram confirmed stent patency. The pigtail drain and suture anchors were subsequently removed. CONCLUSION: Antegrade colonic stenting with the use of a three point colopexy is a straightforward well-tolerated procedure and is a useful technique in a cohort of patients in whom conventional stenting has failed/is unsuitable. Additionally, we believe we have reported the first two cases involving transverse colon access for stenting.

Ultrasound-guided percutaneous retrieval of a dropped gallstone following laparoscopic cholecystectomy.

Removal of intraabdominal dropped gallstones remains a challenging problem for both surgeon and radiologist. We describe in this report a novel, minimally invasive technique to successfully remove a dropped gallstone, causing recurrent intra-abdominal infection, from a patient who had undergone laparoscopic cholecystectomy.