Commissioning and implementing a Quality Assurance program for dedicated radiation oncology MRI scanners.

PURPOSE: ACR and AAPM task group's guidelines addressing commissioning for dedicated MR simulators were recently published. The goal of the current paper is to present the authors' 2-year experience regarding the commissioning and introduction of a QA program based on these guidelines and an associated automated workflow. METHODS: All mandatory commissioning tests suggested by AAPM report 284 were performed and results are reported for two MRI scanners (MAGNETOM Sola and Aera). Visual inspection, vendor clinical or service platform, third-party software, or in-house python-based code were used. Automated QA and data analysis was performed via vendor, in-house or third-party software. QATrack+ was used for QA data logging and storage. 3D geometric distortion, B0 inhomogeneity, EPI, and parallel imaging performance were evaluated. RESULTS: Contrasting with AAPM report 284 recommendations, homogeneity and RF tests were performed monthly. The QA program allowed us to detect major failures over time (shimming, gradient calibration and RF interference). Automated QA, data analysis, and logging allowed fast ACR analysis daily and monthly QA to be performed in 3 h. On the Sola, the average distortion is 1 mm for imaging radii of 250 mm or less. For radii of up to 200 mm, the maximum, average (standard deviation) distortion is 1.2  and 0.4 mm (0.3 mm). Aera values are roughly double the Sola for radii up to 200 mm. EPI geometric distortion, ghosting ratio, and long-term stability were found to be under the maximum recommended values. Parallel imaging SNR ratio was stable and close to the theoretical value (ideal g-factor). No major failures were detected during commissioning. CONCLUSION: An automated workflow and enhanced QA program allowed to automatically track machine and environmental changes over time and to detect periodic failures and errors that might otherwise have gone unnoticed. The Sola is more geometrically accurate, with a more homogenous B0 field than the Aera.

Optimization of the reference region method for dual pharmacokinetic modeling using Gd-DTPA/MRI and (18) F-FDG/PET.

PURPOSE: The combination of MRI and positron emission tomography (PET) offers new possibilities for the development of novel methodologies. In pharmacokinetic image analysis, the blood concentration of the imaging compound as a function of time, [i.e., the arterial input function (AIF)] is required for MRI and PET. In this study, we tested whether an AIF extracted from a reference region (RR) in MRI can be used as a surrogate for the manually sampled (18) F-FDG AIF for pharmacokinetic modeling. METHODS: An MRI contrast agent, gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) and a radiotracer, (18) F-fluorodeoxyglucose ((18) F-FDG), were simultaneously injected in a F98 glioblastoma rat model. A correction to the RR AIF for Gd-DTPA is proposed to adequately represent the manually sampled AIF. A previously published conversion method was applied to convert this AIF into a (18) F-FDG AIF. RESULTS: The tumor metabolic rate of glucose (TMRGlc) calculated with the manually sampled (18) F-FDG AIF, the (18) F-FDG AIF converted from the RR AIF and the (18) F-FDG AIF converted from the corrected RR AIF were found not statistically different (P>0.05). CONCLUSION: An AIF derived from an RR in MRI can be accurately converted into a (18) F-FDG AIF and used in PET pharmacokinetic modeling.

Conversion of arterial input functions for dual pharmacokinetic modeling using Gd-DTPA/MRI and 18F-FDG/PET.

Reaching the full potential of magnetic resonance imaging (MRI)-positron emission tomography (PET) dual modality systems requires new methodologies in quantitative image analyses. In this study, methods are proposed to convert an arterial input function (AIF) derived from gadolinium-diethylenetriaminepentaacetic acid (Gd-DTPA) in MRI, into a (18)F-fluorodeoxyglucose ((18)F-FDG) AIF in PET, and vice versa. The AIFs from both modalities were obtained from manual blood sampling in a F98-Fisher glioblastoma rat model. They were well fitted by a convolution of a rectangular function with a biexponential clearance function. The parameters of the biexponential AIF model were found statistically different between MRI and PET. Pharmacokinetic MRI parameters such as the volume transfer constant (K(trans)), the extravascular-extracellular volume fraction (ν(e)), and the blood volume fraction (ν(p)) calculated with the Gd-DTPA AIF and the Gd-DTPA AIF converted from (18)F-FDG AIF normalized with or without blood sample were not statistically different. Similarly, the tumor metabolic rates of glucose (TMRGlc) calculated with (18) F-FDG AIF and with (18) F-FDG AIF obtained from Gd-DTPA AIF were also found not statistically different. In conclusion, only one accurate AIF would be needed for dual MRI-PET pharmacokinetic modeling in small animal models.

The myth of informed consent in rectal cancer surgery: what do patients retain?

BACKGROUND: Previous research in colorectal cancer has focused on survival, recurrence, and functional outcomes. Few have assessed the decisional needs of patients or the information patients are retaining from the informed consent process. OBJECTIVES: The aims of this study were to describe the decisional needs of adult patients with rectal cancer when deciding on the surgical treatment of their disease and to identify gaps in patients' recollection of the informed consent discussion. DESIGN: Face-to-face interviews were conducted with the use of a questionnaire based on the validated Ottawa Decision Support Framework Needs Assessment. SETTING: This study was performed at a university-based academic Cancer Assessment Center, in Ottawa, Ontario, Canada. PATIENTS: Adult patients with rectal cancer treated with low anterior resection or abdominoperineal resection were included. MAIN OUTCOME MEASURES: The primary outcomes measured were patients' knowledge and understanding of decision and their decisional needs. RESULTS: Thirty patients were interviewed between November 2009 and July 2010. Eighty percent were male, with a median age of 65. None of the patients perceived having a choice of surgical options. When questioned about the main outcomes of rectal cancer surgery, 47% could not recall a preoperative discussion of risks to bowel function, 47% could not recall a preoperative discussion of risks to sexual function, and 57% could not recall a preoperative discussion of risks to urinary function. Patients would like information regarding functional outcomes, body image, and the immediate postoperative period. A minority of patients desire information regarding cure rate, need for a second surgery, or the ability of surgery to treat their symptoms. Patients would like information that is portable and trusted by their health care team that they can review at their own time. LIMITATIONS: To avoid introducing decisional conflict before surgery, patients were interviewed at the first postoperative visit. Preoperative informed consent discussions were not standardized. CONCLUSION: Despite a comprehensive educational oncology pathway, patients retain little of the informed consent discussion. This study highlights the dichotomy between the outcomes that surgeons and patients value most. The results of this study will guide future efforts to improve informed consent.

Commissioning of GPU-based multi-criteria optimizer combined with plan navigation tools for high-dose-rate brachytherapy.

Purpose: Recently, our GPU-based multi-criteria optimization (gMCO) algorithm has been integrated in a graphical user interface (gMCO-GUI) that allows real-time plan navigation through a gMCO-generated set of Pareto-optimal plans for high-dose-rate (HDR) brachytherapy. This work reports on the commissioning of the gMCO algorithm into clinical workflow. Material and methods: Our MCO workflow was validated against Oncentra Prostate v. 4.2.2 (OcP) and Oncentra Brachy v. 4.6.0 (OcB). 40 HDR prostate brachytherapy patients (20 with OcP and 20 with OcB) were retrospectively re-planned with gMCO algorithm by generating 2,000 Pareto-optimal plans. A single gMCO treatment plan was exported using gMCO-GUI plan navigation tools. The optimized dwell positions and dwell times of gMCO plans were exported via DICOM RTPLAN files to OcP/OcB, where final dosimetry was calculated. TG43 implementation in gMCO was validated against the consensus data of flexisource. Five analytical shapes were used as the ground truth for volume calculations. Dose-volume histogram (DVH) curves generated by gMCO were compared with the ones generated by OcP/OcB. 3D dose distributions (and isodose lines) were validated against OcP/OcB using dice similarity coefficient (DSC), 95% undirected Hausdorff distance (95% HD), and γ analysis. Results: Differences between -0.4% and 0.3% were observed between gMCO calculated dose rates and the flexisource consensus data. gMCO volumes were within ±2% agreement in 3/5 volumes (deviations within -2.9% and 0.1%). For 9 key DVH indices, the differences between gMCO and OcP/OcB were within ±1.2%. Regarding the accuracy of key isodose lines, the mean DSC was greater than 0.98, and the mean 95% HD was below 0.4 mm. The fraction of voxels with γ ≤ 1 was greater than 99% for all cases with 1%/1 mm threshold. Conclusions: The GPU-based MCO workflow was successfully integrated into the clinical workflow and validated against OcP and OcB.

Catheters and dose optimization using a modified CVT algorithm and multi-criteria optimization in prostate HDR brachytherapy.

PURPOSE: Currently, in high-dose rate (HDR) brachytherapy planning, the catheter's positions are often selected by the planner, which involves the planner's experience. The catheters are then inserted using a template that helps to guide the catheters. For certain applications, it is of interest to choose the optimal location and number of catheters needed for dose coverage and potential decrease of the treatment's toxicity. Hence, it is of great importance to develop patient-specific algorithms for catheters and dose optimization. METHODS: A modified Centroidal Voronoi tessellation (CVT) algorithm is implemented and merged with a graphics processing unit (GPU)-based multi-criteria optimization algorithm (gMCO). The CVT algorithm optimizes the catheters' positions, and the gMCO algorithm optimizes the dwell times and dwell positions. The CVT algorithm can be used simultaneously for insertion with or without a template. Some improvements to the CVT algorithm are presented such as a new way of considering the area that needs to be covered. One hundred eight previously treated prostates HDR cases using real-time ultrasound are used to evaluate the different optimization procedures. The plan robustness is evaluated using two types of errors: deviations (random) in the insertion and deviation (systematic) in the reconstruction of the catheters. RESULTS: Using gMCO on clinically inserted catheter increases the acceptance rate by 37% for Radiation Therapy Oncology Group (RTOG) criteria. Our results show that all the patients respect RTOG criteria with 11 catheters using CVT+gMCO with a template of 5 mm. The number of catheters needed for all patients to respect RTOG criteria with the freehand technique is 10 catheters using CVT+gMCO. When deviations are introduced, using a template, the acceptance rate goes to 85% with 3 mm deviations using 11 catheters. This decrease is less significant when the number of catheters is higher, decreasing by less than 5% with a 3 mm deviation using 13 catheters or more. In conclusion, it is feasible to decrease the number of catheters needed to treat most patients. CONCLUSIONS: Some cases still need a high number of catheters to reach the plan's criteria. Using gMCO allows an increase in the plan quality, while using CVT reduces the number of catheters. A higher number of catheters equates to plans that are more robust to deviations.

Inter-observer evaluation of a GPU-based multicriteria optimization algorithm combined with plan navigation tools for HDR brachytherapy.

PURPOSE: Recently, a GPU-based multicriteria optimization (gMCO) algorithm was integrated in a graphical user interface (gMCO-GUI) that allowed real-time plan navigation through a set of Pareto-optimal plans for high-dose-rate (HDR) brachytherapy. This work reports on the inter-observer evaluation of the gMCO algorithm into the clinical workflow. METHODS AND MATERIALS: Twenty HDR brachytherapy prostate cancer patients were retrospectively replanned with the gMCO algorithm. The reference clinical plans were each generated by experienced physicists using inverse planning followed by graphical optimization and approved by a radiation oncologist (RO). Each case was replanned with the gMCO algorithm by generating 2000 Pareto-optimal plans with four different objective functions. Two physicists were asked to rank the objective functions according to their preferences by choosing one preferred plan for each plans pool and ranking them using gMCO-GUI. The optimized dwell positions and dwell times of the gMCO plans that were ranked first were exported to Oncentra Prostate where a blinded comparison of the gMCO plans with the clinical plans was conducted by three ROs. RESULTS: The median planning time of the two physicists was 9 min. Both physicists preferred the objective function with target sub-regions to cover specific target regions. Regarding the blinded comparison, the gMCO plans were preferred 19, 17, and 12 times by the three ROs, in which eight gMCO plans were unanimously preferred compared with the clinical plans. CONCLUSIONS: The plan quality and the planning time were similar between the two physicists and within what is observed in the clinic. Moreover, the gMCO plans evaluated favorably by ROs compared to the reference clinical plans.

Advantages of TRUS-based delineation for high-dose-rate prostate brachytherapy planning.

PURPOSE: To evaluate the variability of prostate contours delineated on computed tomography (CT) and transrectal ultrasound (TRUS). MATERIAL AND METHODS: A TRUS-based high-dose-rate (HDR) brachytherapy procedure was introduced in 2016 in our center. The first thirty patients were additionally imaged with CT immediately after the treatment. In 2018, four different radiation oncologists (ROs: 1, 2, 3, 4) contoured the prostate on both modalities. A volume comparison was performed between CT and TRUS imaging. Using prostate gold fiducial makers, a rigid registration between CT and TRUS was done in 20 of the 30 patients studied. Jaccard index (JI) was computed to evaluate the inter-observer volume delineation agreement. RESULTS: The ratio of TRUS/CT volumes was 0.82 (95% CI: 0.79-0.87%). The mean JI was 87% for CT and 92% for TRUS, when comparing all four ROs; CT and TRUS JIs were significantly different (p < 0.001). The mean JI for the prostate on CT was significantly more consistent (p < 0.001) when comparing RO1, 2, and 3 together (RO1-2, RO1-3, and RO2-3; mean = 89%) than when comparing RO4 (newest to clinical practice) to others (RO1-4, RO2-4, and RO3-4; mean = 85%). For TRUS planning, the mean JI was not significantly different (p > 0.05) when comparing all ROs. CONCLUSIONS: The inter-observer and intra-observer variability were statistically significantly smaller on TRUS compared to CT-based planning, despite varying ROs clinical experiences. The superior soft tissue contrast offered by TRUS obviates the effect of the ROs experience on prostate contour volumes and enables more reproducible prostate delineation.

Development and validation of limited sampling strategies for tacrolimus and mycophenolate in steroid-free renal transplant regimens.

PURPOSE: 1) To develop and validate limited sampling strategies (LSSs) for tacrolimus (TAC) and mycophenolic acid (MPA) in renal transplant recipients not receiving corticosteroids; and 2) to evaluate predictive performance of published LSSs (for steroid-based regimens) in a steroid-free population. METHODS: On administration of steady-state morning TAC and mycophenolate mofetil doses, 12-hour serial blood samples from 28 stable renal transplant recipients were collected and measured by validated high-performance liquid chromatography methods and area under the curve (AUC) by trapezoidal rule. TAC LSSs were developed and validated by multiple regression analysis by a two-group method (index n = 18; validation n = 10) and MPA LSSs by the jackknife method (n = 28). Potential LSSs were those with r ≥ .8 (TAC) or r ≥ 0.7 (MPA) and < 3 time points within 2 hours (TAC) or 4 hours (MPA) postdose. Predictive performance was calculated and other published TAC and MPA LSSs tested using preset criteria for bias and precision of within ± 15%. RESULTS: For TAC, three three-concentration, one two-concentration, and one one-concentration model met preset criteria. The best equations were: TAC AUC = 10.338 + 7.739C0 + 3.589C2 (r = 0.956, bias = -3.4%, precision = 4.7%) and TAC AUC = 29.479 + 5.016C2 (r = 0.862, bias = 3.2%, precision = 9.7%). For MPA, only one model was identified: MPA AUC = 9.328 + 1.311C1 + 1.455C2 + 2.901C4 (r = 0.838, bias = -3.8%, precision = 14.9%). One published TAC (and no MPA) LSS in renal transplant recipients on steroid-based regimens met criteria. CONCLUSIONS: To the authors' knowledge, these LSSs are the first to be developed and validated in steroid-free renal transplant recipients and can be used to accurately predict TAC and MPA AUCs for steroid-free regimens. Because the commonly used MPA LSS is based on a steroid regimen and not predictive for steroid-free patients, the newly derived MPA LSS is being applied at the authors' institution. Other renal transplant centers may also wish to validate this equation in their own patients.

Assessing the impact of a 2-day laparoscopic intestinal workshop.

BACKGROUND: Surgical educators have responded to the demand for increased skills in minimally invasive surgery by offering short technique-focused workshops at academic centres. The purpose of this study was to determine the impact of a comprehensive laparoscopic intestinal workshop for the adoption of laparoscopic colonic surgery. METHODS: A 2-day comprehensive laparoscopic intestinal surgery workshop included didactic teaching and supervised hands-on practice of numerous laparoscopic colon resections on a cadaveric model. Participants completed pre-, post- and 6-month postcourse questionnaires. RESULTS: The participants (n = 39) had been in practice for a mean of 10 (interquartile range 3-18) years. Fifty-one percent (n = 20) were already performing laparoscopic colectomies as part of their practices prior to the course. Regardless of whether they were performing laparoscopic colectomies prior to the course or not, attending the 2-day workshop improved their self-assessed preparedness to perform laparoscopic colectomies. Six months after the intestinal workshop, 10 of 16 respondents who were not performing laparoscopic colectomies prior to the course had performed at least 1 since the course. Seven of these individuals had a preceptor for their first case. Reasons cited for not performing a laparoscopic colectomy since the workshop included perceived inadequate surgical skill set, a lack of preceptor and the lack of an appropriate patient. CONCLUSION: A comprehensive laparoscopic intestinal workshop contributed to the perceived acquisition of advanced laparoscopic surgical skills. Local laparoscopic preceptorship was an important adjunct to the workshop for the incorporation of laparoscopic colorectal surgery into practice.

Laparoscopic colostomy reversal after a Hartmann procedure: a prospective series, literature review and an argument against laparotomy as the primary approach.

BACKGROUND: Open restoration of bowel continuity after a Hartmann procedure has been associated with significant morbidity, including anastomotic leak, incisional hernia, wound infections and inability to re-establish intestinal continuity. Few studies have examined the role of laparoscopy in performing a Hartmann reversal. The aim of this study was to review our laparoscopic Hartmann reversal (LHR) experience with an emphasis on intra- and postoperative adverse events. METHODS: A prospectively collected laparoscopic colorectal database involving 3 surgeons in 4 academic centres between 1991 and 2008 was reviewed. Factors evaluated were patient demographics, diagnosis, duration of surgery, intra- and postoperative complications, recovery of bowel function and length of stay in hospital. RESULTS: Twenty-eight consecutive patients (13 men, 15 women) with a mean age of 61.1 (standard deviation [SD] 15.3) years and a mean weight of 72.3 (SD 20.1) kg underwent LHR. The diagnosis at initial surgery was complicated diverticulitis in 19 patients (67.9%), cancer in 6 patients (21.4%) and "other" in 3 patients (10.7%). The median duration of surgery was 166.2 (SD 74.4) minutes. There were no conversions. There was 1 major intraoperative complication (bleeding; 3.6%). There were 3 postoperative complications (10.7%): 1 abscess, 1 prolonged ileus and 1 wound hematoma. Only 1 patient with an abscess required readmission. There were no observed clinical anastomotic leaks. All patients underwent successful reanastomosis. The median time to return of bowel function was 4 (interquartile range [IQR] 3-4) days. The median length of stay in hospital was 5 (IQR 3-6) days. There was no mortality. CONCLUSION: Laparoscopic colostomy reversal after a Hartmann procedure is safe and feasible in experienced hands. It is associated with low morbidity, quick return of bowel function and short stay in hospital.

In-line cosmetic end-point detection of batch coating processes for colored tablets using multivariate image analysis.

In this study, an in-line Process Analytical Technology (PAT) for cosmetic (non-functional) coating unit operations is developed using images of the tablet bed acquired in real-time by an inexpensive industrial camera and lighting system. The cosmetic end-point of multiple batches, run under different operating conditions, is automatically computed from these images using a Multivariate Image Analysis (MIA) methodology in conjunction with a stability determination strategy. The end-points detected by the algorithm differed, on average, by 3% in terms of total batch time from those identified visually by a trained operator. Since traditional practice typically relies on a coating overage to ensure full batch aspect homogeneity in the face of disturbances, the current in-line method can be used to reduce coating material and processing time (over 40% for the operating policy adopted in this work). Additionally, monitoring of the color features calculated by the algorithm allowed the identification of abnormal process conditions affecting visible coating uniformity. This work also addresses practical challenges related to image acquisition in the harsh environment of a pan coater, bringing this tool closer to a state of maturity for implementation in production units and opening the path for their optimization, monitoring, and automatic control.

Resident training in minimally invasive surgery: a survey of Canadian department and division chairs.

BACKGROUND: This study aimed to seek the opinions of academic surgical chairs on minimally invasive surgery (MIS) education for general surgery residents and to identify perceived gaps and trends in educational strategies. METHODS: A national survey on attitudes toward MIS was sent to the chairs of departments of surgery and divisions of general surgery across the 16 Canadian academic centers. The survey contained 34 questions consisting of Likert scales, single answers, and multiple-choice questions. Nonresponders were contacted directly. At the time of the survey, two department chair positions were vacant. RESULTS: The response rate was 87% (26/30). The majority of the centers used early operating room exposure to basic MIS cases (92%) and animal labs (85%). Two-thirds of the institutions used early operating room exposure to advanced MIS cases (69%) and didactic lectures (65%). Half of the academic centers used MIS video (54%) and the laparoscopic virtual reality simulator (54%). The least used method was computer software (19%). The surgical division and department chairs believed the most effective teaching method was early operating room exposure to basic MIS cases (100%), followed by the laparoscopic virtual reality simulator (91%) and animal labs (88%). Computer software was considered 42% useful, and the least useful method was didactic lectures (16%). In the next 5 years, 62% of academic centers plan to add laparoscopic virtual reality simulators to their MIS curriculum. CONCLUSION: The chairs' opinion on the most effective MIS teaching method for residents is basic MIS cases followed by laparoscopic virtual reality simulators. The majority of academic institutions plan to add laparoscopic virtual reality simulators to the curriculum in the next 5 years.

Laparoscopic colectomy for complex diverticular disease: a justifiable choice?

BACKGROUND: Surgery is increasingly reserved for complicated diverticulitis. The role of laparoscopy in this context is ill defined. This study aimed to evaluate the safety, feasibility, and outcomes associated with the application of laparoscopy to an unrestricted spectrum of diverticular pathologies, with an emphasis on complicated disease. METHODS: Consecutive patients who underwent elective, urgent, or emergent laparoscopic colectomy for diverticular disease from 1991 to 2007 were analyzed from a prospectively collected database. Laparoscopy was offered to all patients presenting for surgical attention, thus minimizing selection bias. Complicated cases had abscesses, perforations, fistulas, or strictures. Uncomplicated cases had chronic or recurrent diverticulitis. Summary statistics and univariate comparisons were generated. RESULTS: A total of 183 patients were analyzed, including 39 complicated cases. The complicated cohort included 12 abscesses or perforations (31%), 18 fistulas (46%), and 11 strictures (28%). Intraoperative complications were comparable between the two groups (7.7 vs. 9.7%), although the complicated cases resulted in more conversions (23 vs. 4.2%; p = 0.0007). More than 79% of the complicated patients and 96% of the uncomplicated patients underwent unprotected primary anastomosis. Medical (23 vs. 1.4%; p < 0.0001) and surgical (28 vs. 14%; p = 0.035) complications were more frequent in the complicated group. Leak rates were acceptably low (6.5 vs. 2.2%; p = 0.23). There were no recorded deaths. Finally, the time until discharge from hospital was significantly longer in the complicated group by a median of 1 day. CONCLUSIONS: The laparoscopic management of complicated diverticular disease is feasible and appears to be safe in the hands of experts. Despite a high rate of conversion to open surgery, laparoscopy was the sole operative intervention for the majority of patients with complicated diverticular disease. Further studies are needed to allow rigorous comparison with an open control group.

Hand assisted laparoscopic surgery versus conventional laparoscopy for colorectal surgery.

BACKGROUND: Laparoscopic surgery for colon disease has been shown to have advantages over the open approach in the perioperative period in terms of shorter hospital stay, decreased analgesic use and a more rapid return of bowel function but provides these benefits at the expense of increased technical difficulty and operative time. Hand assisted surgery which a is a hybrid of open surgery and laparoscopic surgery may offer patients the perioperative advantages of minimally invasive surgery without the technical difficulty and increased operative time associated with the conventional laparoscopic approach. This review compares the benefits and harms of laparoscopic and hand assisted laparoscopic surgery for colon disease. OBJECTIVES: To estimate the perioperative outcomes of hand assisted laparoscopic surgery compared to conventional laparoscopic surgery in adult patients requiring colorectal resections. SEARCH STRATEGY: We searched EMBASE (1980- Feb 2010), Medline (1966- Feb 2010) and the Cochrane Central Register of Controlled Trials (CENTRAL, 2010 issue 1), references of included studies, relevant review articles and conference abstracts. SELECTION CRITERIA: Randomised controlled trials (RCTs) in which adult patients were allocated to either receive hand-assisted laparoscopic surgery or conventional laparoscopic colorectal resection for benign or malignant colorectal disease. Studies were not restricted by language of publication. DATA COLLECTION AND ANALYSIS: Reports of potentially relevant articles were retrieved in full text, and two reviewers independently assessed the eligibility of these studies. Data abstraction was performed independently by two reviewers. Meta-analysis of perioperative outcome measures was carried out using a random effects model.  MAIN RESULTS: Three randomised controlled studies met the inclusion criteria (n=189). One study focused exclusively on malignant pathology, the second study focused mostly on benign pathology and the third trial had a mixed variety of pathology with approximately a third representing malignant pathology. Conversion rates were significantly decreased in patients undergoing hand assisted surgery but there was no statistically significant difference in operative time or complication rates when comparing hand assisted surgery to conventional laparoscopy.  All studies were associated with methodological limitations.    AUTHORS' CONCLUSIONS: Despite the limited number of trials performed, meta-analysis demonstrated a statistically significant decrease in conversion rates among the hand assisted group. There was no difference in operating time or perioperative complication rates.  Additional adequately powered and methodologically sound trials are needed to determine if there is a clinically important difference in perioperative outcomes.  Due to significant costs associated with the use of hand-assist devices, economic analyses are also warranted. 

Evaluating the impact of real-time multicriteria optimizers integrated with interactive plan navigation tools for HDR brachytherapy.

PURPOSE: Currently in high-dose-rate (HDR) brachytherapy planning, manual fine-tuning of an objective function is a common practice. Furthermore, automated planning approaches such as multicriteria optimization (MCO) are still limited to the automatic generation of a single treatment plan. This study aims to quantify planning efficiency gains when using a graphics processing unit-based MCO (gMCO) algorithm combined with a novel graphical user interface (gMCO-GUI) that integrates efficient automated and interactive plan navigation tools. METHODS AND MATERIALS: The gMCO algorithm was used to generate 1000 Pareto optimal plans per case for 379 prostate cases. gMCO-GUI was developed to allow plan navigation through all plans. gMCO-GUI integrates interactive parameter selection tools directly with the optimization algorithm to allow plan navigation. The quality of each plan was evaluated based on the Radiation Treatment Oncology Group 0924 protocol and a more stringent institutional protocol (INSTp). gMCO-GUI allows real-time time display of the dose-volume histogram indices, the dose-volume histogram curves, and the isodose lines during the plan navigation. RESULTS: Over the 379 cases, the fraction of Radiation Treatment Oncology Group 0924 protocol valid plans with target coverage greater than 95% was 90.8%, compared with 66.0% for clinical plans. The fraction of INSTp valid plans with target coverage greater than 95% was 81.8%, compared with 62.3% for clinical plans. The average time to compute 1000 deliverable plans with gMCO was 12.5 s, including the full computation of the 3D dose distributions. CONCLUSIONS: Combining the gMCO algorithm with automated and interactive plan navigation tools resulted in simultaneous gains in both plan quality and planning efficiency.

Laparoscopic colon surgery: does operative time matter?

PURPOSE: The purpose was to determine if the perioperative benefits associated with laparoscopic colectomies are maintained as operative time increases. METHODS: A retrospective review was performed of a database that was prospectively collected from April 1991 to May 2005. Since operative time distributions were different, patients were divided into three groups: laparoscopic right colectomy or ileocecal resection, sigmoid resection, and total abdominal colectomy. The following outcomes were assessed: intraoperative and postoperative complications, days to surgical diet, length of stay, 30-day mortality, and the presence of a learning curve. RESULTS: Following exclusions, there were 231 right colon and ileocecal resections, 210 sigmoid colectomies, and 46 total abdominal colectomies. With increasing operative time in both right/ileocecal and sigmoid resections, logistic regression demonstrated no significant association between intraoperative and postoperative complications, days to surgical diet, or length of stay. Weight was significantly correlated with increasing operative time in the right/ileocecal and sigmoid resection groups. In the total abdominal colectomy group, significant relationships between increased operative time and postoperative complications (P = 0.04), days to surgical diet (P = 0.02), and hospital stay (P = 0.03) were found. An operative time cut-point was determined in the total abdominal colectomy group. Patients with operative times >270 minutes were more likely to have postoperative complications (P = 0.024), longer ileus (five vs. three median days to surgical diet, P = 0.003), and longer length of stay (seven vs. five days, P = 0.04). This increased risk remained significant after adjusting for weight and diagnosis. No significant learning curve was identified. CONCLUSION: Increasing operative time does not appear to adversely affect perioperative outcomes in segmental colectomies. Total abdominal colectomies lasting more than 270 minutes were associated with increased postoperative complications, days to surgical diet, and length of stay.

Impact of incision length on the short-term outcomes of laparoscopic colorectal surgery.

BACKGROUND: The recent introduction of hand-assist devices in laparoscopic colorectal surgery has renewed interest in the influence of incision length. This study aimed to define the impact of extraction incision length on the postoperative outcomes of laparoscopic left-sided colon and rectal resections. METHODS: Consecutive patients undergoing laparoscopic left-sided colorectal resection from 1991 to 2007 were retrieved from a prospectively collected database. The association between incision length and patient characteristics, diagnosis, and perioperative outcomes were analyzed using logistic regression, Spearman correlation, Wilcoxon test, and chi-square test. RESULTS: A total of 494 laparoscopic colorectal resections (left, sigmoid, anterior, and low anterior resections) were retrieved. Patients with conversions to open surgery (n = 59) and missing data (n = 53) were excluded. As a result, 382 cases were included in the study. A slight majority of the patients had malignant disease (n = 202, 53%). The median incision length was 5 cm (interquartile range, 4-6 cm). Increasing weight was positively correlated with incision length (p = 0.0001). Male patients had modestly larger mean incisions than female patients (5.5 vs. 5.0 cm; p = 0.0075). Age, previous surgery, diagnosis, days to resumption of normal diet, and days to discharge from hospital showed no significant relationship with incision length. No association was observed between the incision length and intraoperative or postoperative complications. CONCLUSIONS: Patients undergoing laparoscopic colorectal surgery appear to achieve the same perioperative outcomes irrespective of their extraction incision lengths. To maintain the short-term benefits of laparoscopy, surgeons should consider pursuing a minimally invasive technique, even when a larger extraction incision will ultimately be required.

Does experience with laparoscopic colorectal surgery influence intraoperative outcomes?

BACKGROUND: This study aimed to define the management and risk factors for intraoperative complications (IOC) and conversion in laparoscopic colorectal surgery, and to assess whether surgeon experience influences intraoperative outcomes. METHODS: Consecutive patients undergoing laparoscopic colorectal procedures from 1991 to 2005 were analyzed from a longitudinal prospectively collected database. All patients referred to the four surgeons involved in this study were offered a minimally invasive approach. Patient characteristics, perioperative variables, and surgeon experience data were analyzed and compared. RESULTS: A total of 991 consecutive laparoscopic colorectal procedures were studied. The majority of operations were performed for malignant disease (n=526, 53%), and most frequently consisted of segmental colonic resections (n=718, 72%). A total of 85 patients (8.6%) had an IOC. Patients experiencing an IOC had a significantly higher median body weight (75 versus 68 kg, p=0.0047) and had a higher proportion of previous abdominal surgery (31% versus 20%, p=0.029). Only 39% of patients suffering an IOC required conversion to open surgery. A total of 126 (13%) cases were converted to open surgery. On multivariable analysis, previous abdominal surgery [odds ratio (OR) 3.40, 95% confidence interval (CI) 1.39-8.35, p=0.0076] was independently associated with having an IOC and a conversion to open within the same procedure. With increasing experience, individual surgeons were found to operate on heavier patients (p=0.025), and on patients who had a higher rate of previous intra-abdominal surgery (p<0.0001). Despite these risk factors, the early and late experience demonstrated no significant difference in terms of IOCs (p=0.54) and conversion to open surgery (p=0.40). CONCLUSIONS: The majority of IOCs can be managed laparoscopically. With increasing experience surgeons can perform laparoscopic colorectal surgery on a patient population with a greater proportion of previous abdominal surgery and a higher mean body weight without adversely affecting their rates of intraoperative complications or conversion.

The adoption of laparoscopic colorectal surgery: a national survey of general surgeons.

BACKGROUND: Laparoscopic surgery may become the standard of care for the treatment of colorectal disease. Little is known regarding North American patterns of practice or the limiting factors and strategies for adoption among surgeons. METHODS: We sent a 28-item questionnaire to all general surgeon members of the Royal College of Physicians and Surgeons of Canada. We derived descriptive and correlative information using chi(2), Wilcoxon rank sum and Student t tests and multivariate logistic regression. RESULTS: The return rate was 55% (694/1266). A total of 67% (462/694; 95% confidence interval 63%-70%) of respondents perform colorectal surgery. Of these, 54% perform laparoscopic colorectal surgery. Multivariate logistic regression identified 5 factors related to performing laparoscopic colorectal surgery: fewer years in practice (p < 0.001), male sex (p = 0.015), practising in the province of Quebec (p = 0.005), university-hospital affiliation (p = 0.034) and minimally invasive surgery fellowship training (p = 0.023). Lack of adequate operating time and formal training were the main reasons cited by surgeons not offering laparoscopic colon resections. Most surgeons (67%) felt that site visits from a minimally invasive surgeon would represent the most effective training method for acquiring advanced laparoscopic skills. CONCLUSION: About half of Canadian general surgeons offer laparoscopic colorectal resections. Recent graduation, male sex, practice location, university-hospital affiliation and minimally invasive surgery training are significant predictors for offering a laparoscopic approach. Lack of operative time and formal training are the main barriers to adoption of the technique. Site visits by trained laparoscopic surgeons is the preferred method of acquiring advanced skills.