Power-law scaling in intratumoral microbiota of colorectal cancer.

It has recently been proposed that the study of microbial dynamics in humans may gain insights from island biogeographical theory. Here, we test whether the diversity of the intratumoral microbiota of colorectal cancer tumors (CRC) follows a power law with tumor size akin to the island species-area relationship. We confirm a direct correlation between the quantity of Amplicon Sequence Variants (ASVs) within CRC tumors and tumor sizes, following a (log)power model, explaining 47% of the variation. Understanding the processes involved, potentially through the analogy of tumors and islands, may ultimately contribute to future clinical and therapeutic strategies.

Saliva stress biomarkers in ERCP trainees before and after familiarisation with ERCP on a virtual simulator.

Background: Stress during the early ERCP learning curve may interfere with acquisition of skills during training. The purpose of this study was to compare stress biomarkers in the saliva of trainees before and after familiarisation with ERCP exercises on a virtual simulator. Methods: Altogether 26 endoscopists under training, 14 women and 12 men, completed the three phases of this study: Phase 1. Three different ERCP procedures were performed on the simulator. Saliva for α-amylase (sAA), Chromogranin A (sCgA), and Cortisol (sC) were collected before (baseline), halfway through the exercise (ex.), and 10 min after completion of the exercise (comp.); Phase 2. A three-week familiarisation period where at least 30 different cases were performed on the virtual ERCP simulator; and Phase 3. Identical to Phase 1 where saliva samples were once again collected at baseline, during, and after the exercise. Percentage differences in biomarker levels between baseline and exercise (Diffex) and between baseline and completion (Diffcomp) during Phase 1 and Phase 3 were calculated for each stress marker. Results: Mean % changes, Diffex and Diffcomp, were significantly positive (p < 0.05) for all markers in both Phase 1 and Phase 3. Diffex in Phase 1 was significantly greater than Diffex in Phase 3 (p < 0.05) for sAA and sCgA. Diffcomp for sAA in Phase 1 was significantly greater than Diffcomp in Phase 3 (p < 0.05). No significant differences were found in sC concentration between Phases 1 and 3. Conclusion: This study shows that familiarisation with the ERCP simulator greatly reduced stress as measured by the three saliva stress biomarkers used with sAA being the best. It also suggests that familiarisation with an ERCP simulator might reduce stress in the clinical setting.

Early-onset gastrointestinal cancer: An epidemiological reality with great significance and implications.

During the last few years, epidemiological data from many countries suggest that the incidence and prevalence of many cancers of the digestive system are shifting from the older to the younger ages, the so-called "early-onset cancer". This is particularly evident in colorectal cancer and secondarily in other malignant digestive neoplasms, mainly stomach and in a lesser degree pancreas, and biliary tract. It should be emphasized that data concerning digestive neoplasms, except for those referring to the colon and stomach, could be characterized as rather insufficient. The exact magnitude of the shift in younger ages is expected to become clearer shortly, as long as relevant epidemiological data from many parts of the world would be available. The most important question concerns the etiology of this phenomenon, since its magnitude cannot be explained solely by the better diagnostic methodology and the preventive programs applied in many countries. The existing data support the assumption that a number of environmental factors may play a primary role in influencing carcinogenesis, sometimes from childhood. Changes that have appeared in the last decades related mainly to eating habits, consistency of gut microbiome and an increase of obese people interacting with genetic factors, ultimately favor the process of carcinogenesis. Even these factors however, are not entirely sufficient to explain the age-related changes in the frequency of digestive neoplasms. Studies of the individual effect of each of the already known factors or factors likely to be involved in the etiology of this phenomenon and studies using state-of-the-art technologies to accurately determine the degree of the population exposure to these factors are required. In this article, we attempt to describe the epidemiological data supporting the age-shifting of digestive malignancies and their possible pathogenesis. Finally, we propose some measures regarding the attitude of the scientific community to this alarming phenomenon.

Perioperative nutritional assessment and management of patients undergoing gastrointestinal surgery.

Malnutrition is a major issue in gastrointestinal perioperative situations, as only 40% of malnourished patients are finally treated. This literature review investigates the inconsistencies regarding the diagnostic approach to both preoperative and postoperative patients and the various underlying causes, as well as the efficiency of the various therapeutic regimens. A literature search was conducted until August 2023 in MEDLINE and Scopus. Clinical studies involving perioperative nutritional assessment in adult gastrointestinal surgery patients during the last 10 years were included in the present review. Finally, 19 articles were included in the study. Preoperative nutritional therapy is increasingly recognized as a key component of surgical care. Malnourished patients who are hospitalized and operated on, have significantly worse clinical results. Gastrointestinal postoperative malnutrition coexists with metabolic stress, as patients usually suffer from minor chronic inflammations; therefore, postoperative malnutrition is the result of a combination of the effects of inflammation and a lack of food intake. Postoperative malnutrition leads to prolonged hospitalizations and hospital complications and therefore the need to treat it is essential. There are many recognized tools for detecting malnutrition. However, all tools showed inconsistent results regarding their validity. Per os feeding after surgery, and dietary supplements when necessary, have been recommended. Therefore, it is very important to reduce malnutrition and define clear strategies towards that direction.

Validity of a virtual reality endoscopic retrograde cholangiopancreatography simulator: can it distinguish experts from novices?

Background: There is a lack of evidence regarding the effectiveness of virtual simulators as a means to acquire hands-on exposure to endoscopic retrograde cholangiopancreatography (ERCP). The present study aimed to assess the outcome and construct validity of virtual ERCP when training on the GI II Mentor simulator. Methods: A group of seven experienced endoscopists were compared with 31 novices. After a short introduction, they were requested to carry out three virtual ERCP procedures: diagnosing and removing a common bile duct (CBD) stone; diagnosing and taking brush cytology from a hilar stenosis; and, finally, diagnosing and treating a cystic leakage with a BD stent. For each task, the total time required to complete the task, time required to correctly view the papilla, total time of irradiation, time to deep cannulation, time to define diagnosis, time to complete sphincterotomy, and time to complete the respective intervention were measured. Cannulation of the BD, correct diagnosis, sphincterotomy, and time to complete intervention were assessed by an assessor blinded to the status of the endoscopist who performed the virtual ERCP. Results: The time required to visualize the papilla and to cannulate deeply when removing the BD stone was significantly shorter for the experts (both p < 0.05). The time to visualize the papilla, cannulate deeply, reach a diagnosis, complete sphincterotomy, and complete the intervention was significantly shorter for the experts when managing cystic leakage (all p < 0.05). In diagnosing and taking brush cytology from a hilar stenosis, there was only a trend toward the experts needing less time for the deep cannulation of the BD (p = 0.077). Conclusion: The performance differed between experts and novices, especially in the management of cystic leakage. This corroborates the construct validity of the GI II Mentor simulator.

The use of simulators to acquire ERCP skills: a systematic review.

Endoscopic retrograde cholangiopancreatography (ERCP) is a technically demanding diagnostic and therapeutic endoscopic procedure with a high risk for adverse events such as post-ERCP pancreatitis and bleeding. Since endoscopists with less experience have higher adverse event rates, the training of new residents on ERCP simulators has been suggested to improve the resident's technical skills necessary for ERCP. However, there is a lack of consensus on whether the training program should focus on a threshold number of procedures or be more tailored to the individual's performance. Furthermore, there is also disagreement on which form of simulator(s) should be used. Therefore, the primary outcome of this systematic review was to study the extent to which simulators used for ERCP training are correctly validated. Methods: In 2022, a systematic search of the literature was conducted on MEDLINE and SCOPUS under the guidance of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) 2020 protocol seeking articles with the MeSH terms 'Endoscopic Retrograde Cholangiopancreatography' OR 'ERCP' in combination with 'simulation' OR 'simulator'. Results: The search resulted in 41 references. A total of 19 articles met the inclusion criteria and were included in the qualitative analysis. Only one of the articles fulfilled the criteria of a robust validation study. Conclusions: Since only one of the 19 articles met the requirements for a thorough and correct validation, further studies with sufficient numbers of subjects, that evaluate complete preclinical training programs based on validated ERCP simulators are warranted.

5G in Healthcare: From COVID-19 to Future Challenges.

Worldwide up to May 2022 there have been 515 million cases of COVID-19 infection and over 6 million deaths. The World Health Organization estimated that 115,000 healthcare workers died from COVID-19 from January 2020 to May 2021. This toll on human lives prompted this review on 5G based networking primarily on major components of healthcare delivery: diagnosis, patient monitoring, contact tracing, diagnostic imaging tests, vaccines distribution, emergency medical services, telesurgery and robot-assisted tele-ultrasound. The positive impact of 5G as core technology for COVID-19 applications enabled exchange of huge data sets in fangcang (cabin) hospitals and real-time contact tracing, while the low latency enhanced robot-assisted tele-ultrasound, and telementoring during ophthalmic surgery. In other instances, 5G provided a supportive technology for applications related to COVID-19, e.g., patient monitoring. The feasibility of 5G telesurgery was proven, albeit by a few studies on real patients, in very low samples size in most instances. The important future applications of 5G in healthcare include surveillance of elderly people, the immunosuppressed, and nano- oncology for Internet of Nano Things (IoNT). Issues remain and these require resolution before routine clinical adoption. These include infrastructure and coverage; health risks; security and privacy protection of patients' data; 5G implementation with artificial intelligence, blockchain, and IoT; validation, patient acceptance and training of end-users on these technologies.

Gut microbiome: Linking together obesity, bariatric surgery and associated clinical outcomes under a single focus.

Obesity is increasingly prevalent in the post-industrial era, with increased mortality rates. The gut microbiota has a central role in immunological, nutritional and metabolism mediated functions, and due to its multiplexity, it is considered an independent organ. Modern high-throughput sequencing techniques have allowed phylogenetic exploration and quantitative analyses of gut microbiome and improved our current understanding of the gut microbiota in health and disease. Its role in obesity and its changes following bariatric surgery have been highlighted in several studies. According to current literature, obesity is linked to a particular microbiota profile that grants the host an augmented potential for calorie release, while limited diversity of gut microbiome has also been observed. Moreover, bariatric surgery procedures represent effective interventions for sustained weight loss and restore a healthier microbiota, contributing to the observed fat mass reduction and lean mass increase. However, newer evidence has shown that gut microbiota is only partially recovered following bariatric surgery. Moreover, several targets including FGF15/19 (a gut-derived peptide), could be responsible for the favorable metabolic changes of bariatric surgery. More randomized controlled trials and larger prospective studies that include well-defined cohorts are required to better identify associations between gut microbiota, obesity, and bariatric surgery.

Breaking down the silos of artificial intelligence in surgery: glossary of terms.

BACKGROUND: The literature on artificial intelligence (AI) in surgery has advanced rapidly during the past few years. However, the published studies on AI are mostly reported by computer scientists using their own jargon which is unfamiliar to surgeons. METHODS: A literature search was conducted in using PubMed following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. The primary outcome of this review is to provide a glossary with definitions of the commonly used AI terms in surgery to improve their understanding by surgeons. RESULTS: One hundred ninety-five studies were included in this review, and 38 AI terms related to surgery were retrieved. Convolutional neural networks were the most frequently culled term by the search, accounting for 74 studies on AI in surgery, followed by classification task (n = 62), artificial neural networks (n = 53), and regression (n = 49). Then, the most frequent expressions were supervised learning (reported in 24 articles), support vector machine (SVM) in 21, and logistic regression in 16. The rest of the 38 terms was seldom mentioned. CONCLUSIONS: The proposed glossary can be used by several stakeholders. First and foremost, by residents and attending consultant surgeons, both having to understand the fundamentals of AI when reading such articles. Secondly, junior researchers at the start of their career in Surgical Data Science and thirdly experts working in the regulatory sections of companies involved in the AI Business Software as a Medical Device (SaMD) preparing documents for submission to the Food and Drug Administration (FDA) or other agencies for approval.

Comparison of Postoperative and Oncologic Outcomes in Laparoscopic and Open Right Colectomy for Colon Cancer: A 5-year Experience.

BACKGROUND/AIM: Laparoscopic colectomy is a procedure which is being performed for three decades and is gaining popularity continuously over the traditional open colectomy. This study was conducted in order to compare postoperative and oncologic results based on several factors in laparoscopic and open right colectomy for right colon cancer. PATIENTS AND METHODS: This is a retrospective study of right colectomy at a single institution from 2015 until 2020. The factors that were studied included postoperative values of C-reactive protein (CRP), lactate dehydrogenase (LDH), creatine phosphokinase (CPK), the number of excised lymph nodes, the use of postoperative analgesics and the length of hospital stay. RESULTS: We collected data from 21 open and 17 laparoscopic right colectomies through a 5-year period. Measurements on the second postoperative day revealed mean CRP and CPK values significantly lower in the laparoscopic group compared to the open group, while LDH levels did not affirm major differences between the two groups. The mean number of lymph nodes excised during the open procedure was superior to those harvested in the laparoscopic group. The use of analgesics throughout the entire hospital stay was a combination of pethidine and tramadol for the first three postoperative days in open procedures, while paracetamol and, occasionally, tramadol were administered upon patient request following laparoscopic procedures. The mean hospital stay was substantially shorter in the laparoscopic group compared to the open surgery group. CONCLUSION: Laparoscopic right colectomy is superior compared to open right colectomy with regards to postoperative analgesia and length of hospital stay, but also in certain postoperative laboratory values. Despite these there was no supremacy considering oncologic clearance.

Intraoperative cholangiography 2020: Quo vadis? A systematic review of the literature.

BACKGROUND: There are few randomized controlled trials with sufficient statistical power to assess the effectiveness of intraoperative cholangiography (IOC) in the detection and treatment of common bile duct injury (BDI) or retained stones during cholecystectomy. The best evidence so far regarding IOC and reduced morbidity related to BDI and retained common bile duct stones was derived from large population-based cohort studies. Population-based studies also have the advantage of reflecting the outcome of the procedure as it is practiced in the community at large. However, the outcomes of these population-based studies are conflicting. DATA SOURCES: A systematic literature search was conducted in 2020 to search for articles that contained the terms "bile duct injury", "critical view of safety", "bile duct imaging" or "retained stones" in combination with IOC. All identified references were screened to select population-based studies and observational studies from large centers where socioeconomic or geographical selections were assumed not to cause selection bias. RESULTS: The search revealed 273 references. A total of 30 articles fulfilled the criteria for a large observational study with minimal risk for selection bias. The majority suggested that IOC reduces morbidity associated with BDI and retained common bile duct stones. In the short term, IOC increases the cost of surgery. However, this is offset by reduced costs in the long run since BDI or retained stones detected during surgery are managed immediately. CONCLUSIONS: IOC reduces morbidity associated with BDI and retained common bile duct stones. The reports reviewed are derived from large, unselected populations, thereby providing a high external validity. However, more studies on routine and selective IOC with well-defined outcome measures and sufficient statistical power are needed.

Gut Microbiota in Lung Cancer: Where Do We Stand?

The gut microbiota (GM) is considered to constitute a powerful "organ" capable of influencing the majority of the metabolic, nutritional, physiological, and immunological processes of the human body. To date, five microbial-mediated mechanisms have been revealed that either endorse or inhibit tumorigenesis. Although the gastrointestinal and respiratory tracts are distant physically, they have common embryonic origin and similarity in structure. The lung microbiota is far less understood, and it is suggested that the crosslink between the human microbiome and lung cancer is a complex, multifactorial relationship. Several pathways linking their respective microbiota have reinforced the existence of a gut-lung axis (GLA). Regarding implications of specific GM in lung cancer therapy, a few studies showed that the GM considerably affects immune checkpoint inhibitor (ICI) therapy by altering the differentiation of regulatory T cells and thus resulting in changes in immunomodulation mechanisms, as discovered by assessing drug metabolism directly and by assessing the host immune modulation response. Additionally, the GM may increase the efficacy of chemotherapeutic treatment in lung cancer. The mechanism underlying the role of the GLA in the pathogenesis and progression of lung cancer and its capability for diagnosis, manipulation, and treatment need to be further explored.

A systematic review on artificial intelligence in robot-assisted surgery.

BACKGROUND: Despite the extensive published literature on the significant potential of artificial intelligence (AI) there are no reports on its efficacy in improving patient safety in robot-assisted surgery (RAS). The purposes of this work are to systematically review the published literature on AI in RAS, and to identify and discuss current limitations and challenges. MATERIALS AND METHODS: A literature search was conducted on PubMed, Web of Science, Scopus, and IEEExplore according to PRISMA 2020 statement. Eligible articles were peer-review studies published in English language from January 1, 2016 to December 31, 2020. Amstar 2 was used for quality assessment. Risk of bias was evaluated with the Newcastle Ottawa Quality assessment tool. Data of the studies were visually presented in tables using SPIDER tool. RESULTS: Thirty-five publications, representing 3436 patients, met the search criteria and were included in the analysis. The selected reports concern: motion analysis (n = 17), urology (n = 12), gynecology (n = 1), other specialties (n = 1), training (n = 3), and tissue retraction (n = 1). Precision for surgical tools detection varied from 76.0% to 90.6%. Mean absolute error on prediction of urinary continence after robot-assisted radical prostatectomy (RARP) ranged from 85.9 to 134.7 days. Accuracy on prediction of length of stay after RARP was 88.5%. Accuracy on recognition of the next surgical task during robot-assisted partial nephrectomy (RAPN) achieved 75.7%. CONCLUSION: The reviewed studies were of low quality. The findings are limited by the small size of the datasets. Comparison between studies on the same topic was restricted due to algorithms and datasets heterogeneity. There is no proof that currently AI can identify the critical tasks of RAS operations, which determine patient outcome. There is an urgent need for studies on large datasets and external validation of the AI algorithms used. Furthermore, the results should be transparent and meaningful to surgeons, enabling them to inform patients in layman's words. REGISTRATION: Review Registry Unique Identifying Number: reviewregistry1225.

Use of saliva stress biomarkers to estimate novice male endoscopist's stress during training in a high-end simulator.

OBJECTIVE: Simulated endoscopic training can be challenging and stressful for the novice trainee. The absence of a reliable stress detection method during simulated endoscopic training makes estimating trainees' mental stress difficult to quantify. This study concomitantly measures the responses of four saliva stress biomarkers and compares them to the video score (VS) achieved by novice endoscopists in a reproducibly stressful simulation environment. METHODS: Thirty-six male endoscopy naïve surgery residents were enrolled. After an orientation phase, a saliva specimen was collected for cortisol (sC), alpha-amylase (sAA), Chromogranin A (sCgA), and immunoglobulin A (sIgA) measurements (baseline phase, BL). Thereafter, the simulation exercise phase (E) started, practicing in the Fundamentals of Endoscopic Surgery Skills module (GI-Bronch Mentor). Immediately after, a second saliva sample for measuring the above-cited biomarkers was collected. The whole experiment was videotaped, and the VS was calculated. The percentage (E-BL)diff of each of the four saliva biomarkers was calculated and examined for correlation to VS. RESULTS: sCgAdiff showed the best correlation with VS, followed by sAAdiff. CONCLUSIONS: sCgA and sAA, are saliva stress biomarkers that are easy to collect non-invasively and showed the best correlation with novice endoscopist's performance in our simulation setting, and therefore, they could be used for monitoring stress.

Open versus endovascular repair for extracranial carotid aneurysms.

BACKGROUND: Extracranial carotid artery aneurysms (ECCAs) are rare; however, they are associated with a high risk of stroke and mortality if untreated. In the present review, we compared the major outcomes between open and endovascular repair of ECCAs. METHODS: We systematically searched PubMed, Embase, Scopus, and the Cochrane Library for clinical studies reported online up to September 2020 that had evaluated major outcomes after both open and endovascular repair of ECCAs. Eligible studies were required to have evaluated at least the 30-day mortality or stroke and/or transient ischemic attack rates. The quality of the studies was also evaluated. RESULTS: Overall, seven studies (three high quality, two medium quality, and two low quality) with 374 patients and 383 ECCAs were eligible. All the studies had been reported from 2004 to 2020. In total, 220 open repairs were compared with 81 endovascular repairs. The open and endovascular treatments showed similar 30-day mortality rates (4% vs 0%; pooled odds ratio [OR], 2.67; 95% confidence interval [CI], 0.291-24.451) and stroke and transient ischemic attack rates (5.5% vs 1.2%; pooled OR, 1.42; 95% CI, 0.412-4.886). Open repair was associated in six studies with a greater incidence of cranial nerve injury compared with endovascular repair (14.5% vs 0%; OR, 3.98; 95% CI, 1.178-13.471). The hematoma or bleeding rate was also similar between the two methods in six studies (5.2% vs 0%; OR, 1.92; 95% CI, 0.518-7.094). CONCLUSIONS: Open and endovascular repair of ECCAs is associated with similarly low early mortality and cerebrovascular event rates, although open repair showed a greater risk of cranial nerve injuries. An endovascular approach could be more appropriate when the aneurysm is located distally or requires extensive dissection. More studies are needed with standardized follow-up durations to evaluate late outcomes.

Association between homeobox protein transcript antisense intergenic ribonucleic acid genetic polymorphisms and cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) represents a rare but highly aggressive malignancy that is often challenging to diagnose, especially in early stages. The role of existing tumor biomarkers for CCA diagnosis, remains controversial due to their low sensitivity and specificity. Increasing evidence has implicated long non-coding ribonucleic acid polymorphisms with cancer susceptibility in a variety of tumor types. The association between long non-coding ribonucleic acid homeobox protein transcript antisense intergenic ribonucleic acid (HOTAIR) polymorphisms and CCA risk has not been reported yet. AIM: To investigate the influence of HOTAIR variants on the risk of CCA development. METHODS: We conducted a case-control study in which three HOTAIR single nucleotide polymorphisms (rs920778, rs4759314 and rs7958904) were genotyped in a Greek cohort. Our study population included 122 CCA patients (80 males and 42 females) and 165 healthy controls. The polymorphisms under investigation were examined in peripheral blood samples. RESULTS: HOTAIR rs4759314 AG and GG genotypes were associated with a significantly increased CCA risk [P = 0.004, odds ratio: 3.13; 95% confidence interval: 1.65-5.91 and P = 0.005, odds ratio: 12.31; 95% confidence interval: 1.48-101.87, respectively]. However, no significant associations of HOTAIR rs920778, and rs7958904 were detected. Similarly, we found no significant associations between rs4759314 AA genotype and CCA susceptibility. CONCLUSION: HOTAIR rs4759314 AG and GG genotypes may be implicated with CCA development and may serve as a potential diagnostic biomarker.

Place of hyperthermic intraperitoneal chemotherapy in the armament against pancreatic adenocarcinoma: A survival, mortality and morbidity systematic review.

Pancreatic adenocarcinoma is one of the deadliest types of cancer worldwide, with a 5-year survival rate of 8% despite recent treatment advancements. The present systematic review aimed to investigate the role of hyperthermic intraperitoneal chemotherapy (HIPEC) following surgical resection for pancreatic adenocarcinoma, with or without peritoneal carcinomatosis. A systematic search of the MEDLINE and SCOPUS electronic databases was performed according to PRISMA guidelines. All possible relevant articles published between January 1980 and May 2019 were retrieved using multiple search terms associated with HIPEC and pancreatic adenocarcinoma. The initial search resulted in 1,244 reports, which condensed to 41 reports following screening of titles and abstracts, and subsequently to four reports following full-text thorough examination. The four reports included involved a prospective cohort study of HIPEC use in resectable pancreatic adenocarcinoma, and three retrospective studies of HIPEC use following cytoreductive surgery for peritoneal carcinomatosis due to pancreatic adenocarcinoma, resulting in a total of 47 patients. The overall survival ranged between 2 and 62 months, and the hospital mortality rate was 8.5%. Morbidity (34%) was mainly attributed to anastomotic leak or respiratory failure. Due to the small sample size and low quality of evidence of the included studies, no valid conclusions could be drawn. Therefore, further studies are required to justify the use of HIPEC as an adjuvant therapy in resectable pancreatic adenocarcinoma, while cytoreductive surgery and HIPEC in peritoneal carcinomatosis of pancreatic origin seems not only not useful but also unsafe at this level of evidence.

Baseline characteristics in laparoscopic simulator performance: The impact of personal computer (PC)-gaming experience and visuospatial ability.

BACKGROUND: Learning via simulators is under constant development, and it is important to further optimize simulator training curricula. This study investigates the impact of personal computer-gaming experience, visuospatial skills, and repetitive training on laparoscopic simulator performance and specifically on the constituent parameters of the simulator score. METHODS: Forty-seven medical students completed 3 consecutive Minimally Invasive Surgical Trainer-Virtual Reality simulator trials. Previously, they performed a visuospatial test and completed a questionnaire regarding baseline characteristics and personal computer-gaming experience. Linear regression was used to analyze the relationship between simulator performance and type of personal computer-gaming experience and visuospatial ability. RESULTS: During the first 2 Minimally Invasive Surgical Trainer-Virtual Reality simulation tasks, there was an association between personal computer-gaming experience and the coordination parameters of the score (eg, EconDiath task 1: P = .0047; EconDiath task 2: P = .0102; EconDiath task 3: P = .0836). The type of game category played seemed to have an impact on the coordination parameters (eg, EconDiath task 1-3 for sport games versus no-sport games: P = .01, P = .0013, and P = .01, respectively). In the first Minimally Invasive Surgical Trainer task, visuospatial ability correlated with Minimally Invasive Surgical Trainer simulator performance but was abolished with repetitive training (overall Minimally Invasive Surgical Trainer score task 1-3: P = .0122, P = .0991, and P = .3506, respectively). Sex-specific differences were noted initially but were abolished with training. CONCLUSION: Sport games versus no-sport games demonstrated a significantly better Minimally Invasive Surgical Trainer performance. Furthermore, repetitive laparoscopic simulator training may compensate for a previous lack of personal computer-gaming experience, low visuospatial ability, and sex differences.

Photon beam energy dependent single-arc volumetric modulated arc optimization.

PURPOSE: The purpose of this work was to present a new single-arc mixed photon (6&18MV) VMAT (SAMP) optimization framework that concurrently optimizes for two photon energies with corresponding partial arc lengths. METHODS AND MATERIALS: Owing to simultaneous optimization of energy dependent intensity maps and corresponding arc locations, the proposed model poses nonlinearity. Unique relaxation constraints based on McCormick approximations were introduced for linearization. Energy dependent intensity maps were then decomposed to generate apertures. Feasibility of the proposed framework was tested on a sample of ten prostate cancer cases with lateral separation ranging from 34 cm (case no.1) to 52 cm (case no.6). The SAMP plans were compared against single energy (6MV) VMAT (SE) plans through dose volume histograms (DVHs) and radiobiological parameters including normal tissue complication probability (NTCP) and equivalent uniform dose (EUD). RESULTS: The contribution of higher energy photon beam optimized by the algorithm demonstrated an increase for cases with a lateral separation >40 cm. SAMP-VMAT notably improved bladder and rectum sparing in large size cases. Compared to single energy, SAMP-VMAT plans reduced bladder and rectum NTCP in cases with large lateral separation. With the exception of one case, SAMP-VMAT either improved or maintained femoral heads compared to SE-VMAT. SAMP-VMAT reduced the nontarget tissue integral dose in all ten cases. CONCLUSIONS: A single-arc VMAT optimization framework comprising mixed photon energy partial arcs was presented. Overall results underline the feasibility and potential of the proposed approach for improving OAR sparing in large size patients without compromising the target homogeneity and coverage.

Effect of video games playing on surgical simulation training: a systematic review.

INTRODUCTION: Video games have a positive impact on the skills required for laparoscopic surgery. Several studies have assessed the impact of video games on laparoscopic skills. AIM: This study aims to systematically review the existing evidence. MATERIALS AND METHODS: A search strategy was implemented to retrieve relevant articles from MEDLINE and SCOPUS databases. The retrieved articles were reviewed for further evaluation according to the predetermined inclusion/exclusion criteria. RESULTS: Twenty-six studies were included in this systematic review. These included prospective (n=9), retrospective (n=5) and interventional (n=12). Other review papers were cited in the discussion section. Studies with positive outcomes significantly outweighed the negative ones (21 vs. 5, respectively). CONCLUSIONS: Although there is some evidence that video game experience could give some advantage in laparoscopy no firm conclusions could be drawn yet. The reasons for that lay in the various aims, approaches and results of different study reports. Gaming could be used as a daily warm-up or as a tool to speed-up mastering new skills. A standardized protocol is needed for answering the different questions regarding the impact of video game exposure to laparoscopic skills development and progression.