Radiomics in pancreatic neuroendocrine tumors: methodological issues and clinical significance

PURPOSE

To present the state-of-art of radiomics in the context of pancreatic neuroendocrine tumors (PanNETs), with a focus on the methodological and technical approaches used, to support the search of guidelines for optimal applications. Furthermore, an up-to-date overview of the current clinical applications of radiomics in the field of PanNETs is provided.

METHODS

Original articles were searched on PubMed and Science Direct with specific keywords. Evaluations of the selected studies have been focused mainly on (i) the general radiomic workflow and the assessment of radiomic features robustness/reproducibility, as well as on the major clinical applications and investigations accomplished so far with radiomics in the field of PanNETs: (ii) grade prediction, (iii) differential diagnosis from other neoplasms, (iv) assessment of tumor behavior and aggressiveness, and (v) treatment response prediction.

RESULTS

Thirty-one articles involving PanNETs radiomic-related objectives were selected. In regard to the grade differentiation task, yielded AUCs are currently in the range of 0.7-0.9. For differential diagnosis, the majority of studies are still focused on the preliminary identification of discriminative radiomic features. Limited information is known on the prediction of tumors aggressiveness and of treatment response.

CONCLUSIONS

Radiomics is recently expanding in the setting of PanNETs. From the analysis of the published data, it is emerging how, prior to clinical application, further validations are necessary and methodological implementations require optimization. Nevertheless, this new discipline might have the potential in assisting the current urgent need of improving the management strategies in PanNETs patients.

[Indications and surgical treatment of acute complicated diverticulitis]

Although the surgical treatment of acute and complicated diverticulitis has been refined over the years, discussion is still ongoing about whether a single or two stage procedure (Hartmann's procedure) should be performed in patients with peritonitis from perforation of a colonic diverticulum. A retrospective review was completed for patients undergoing surgery for acute complicated diverticulitis from 1980 to 1997. All patients were categorized according to Hinchey classification. Of the 186 patients treated, emergency operation was performed in 52 (28 per cent; group I) and an elective operation in 134 (72 per cent; group II). All patients had a resection of the involved colon and anastomosis was performed using CEEA staplers. In the group I, 50 patients underwent resection with immediate reconstruction with or without colostomy and two an Hartmann's procedure. Among the group II, primary anastomosis with or without proximal diversion was performed in 132 patients; two patients underwent an Hartmann's procedure. Post-operative mortality was of 5.76% in the group I and 2.9% in the group II. Nine anastomotic leaks occurred in the group I and 18 in the group II. Comparing these results with the recent literature, we have concluded that primary resection is virtually always possible in acute and complicated diverticulitis. Primary anastomosis with or without colostomy, in expert hands, is a safe procedure for patients in stage I of Hinchey's classification or II, but should be considered on an individual basis in presence of peritonitis. In case of fecal peritonitis, persistent hypotension, ascites, severe immune compromise and extreme malnutrition the Hartmann procedure represent the procedure of choice.

[Angiodysplasia of the large intestine: unusual rectal localization]

The authors report a case of lower gastrointestinal hemorrhage in a 69-year-old male, in which the sequence colonoscopy-angiography identified the source of bleeding as a rare Angiodysplasia (AD) of the rectum. Such vascular abnormalities are one of the most common causes of major lower gastrointestinal tract bleeding in the elderly and usually occurs predominantly in the right side of the colon. The clinical presentation of Angiodysplasia is varied and accurate diagnosis usually requires a combination of diagnostic techniques such as colonoscopy and angiography. The optimal management is uncertain and should be individualized for each patient depending on severity and rate of rebleeding. A conservative medical approach is indicated for many patients, while endoscopic treatment does not seem modify the risk of recurrent bleeding. In case of massive hemorrhage or recurrent bleeding surgery still represents the definitive treatment for Angiodysplasia. However the risk of rebleeding following surgery is a considerable problem and varies in literature from 5% to 30%.

[Lesions of the main bile duct: combined percutaneous-endoscopic treatment]

The authors report their experience in "minimally invasive" treatment of benign biliary lesions. More than 80% of them occur after injury to the bile ducts during cholecystectomy. The clinical experience reported in this work concerns three patients managed with a coordinated--percutaneous and endoscopic--approach. In all patients an ERCP with biliary sphincterectomy has been performed at first, followed by percutaneous biliary drainage with external-internal catheters. All drainage catheters have been removed after one year. No patient has evidence of recurrence after a mean follow up of 18 months. Only in a patient a recurrent cholangitis treated with antibiotic therapy has been observed. This preliminary study suggests that the "rendez-vous" technique may be useful for the initial management of biliary strictures in most patients. This association improves the success rate and can avoid surgery. The role of surgery is reserved to few selected cases and particularly to lesions which are detected at the time of the operation.

[Non visible carcinoma of the gallbladder. A strategic problem after video laparoscopic cholecystectomy]

A formal contraindication to laparoscopic cholecystectomy is gallbladder cancer. Sometimes its first appearance is intraoperative finding or microscopic examination of gallbladder removed for presumed benign disease. These patients with "inapparent carcinoma" may be long-term survivors if definitive and curative therapy is performed. We present the case of 56 y. woman which presented a T2 unsuspected carcinoma that was reoperated and cured by wedge liver resection, extended lymph node dissection and large excision of tissue of trocar wounds.