Feasibility of electromagnetic transponder use to monitor inter- and intrafractional motion in locally advanced pancreatic cancer patients.

PURPOSE: The primary objective of this study was to determine the feasibility of electromagnetic transponder implantation in patients with locally advanced unresectable pancreatic cancer. Secondarily, the use of transponders to monitor inter- and intrafractional motion, and the efficacy of breath holding for limiting target motion, were examined. METHODS AND MATERIALS: During routine screening laparoscopy, 5 patients without metastatic disease were implanted with transponders peri-tumorally. The Calypso System's localization and tracking modes were used to monitor inter- and intrafractional motion, respectively. Intrafractional motion, with and without breath holding, was also examined using Calypso tracking mode. RESULTS: Transponder implantation was well tolerated in all patients, with minimal migration, aside from 1 patient who expulsed a single transponder. Interfractional motion based on mean shifts from setup using tattoos/orthogonal imaging to transponder based localization from 164 treatments was significant in all dimensions. Mean shift (in millimeters), followed by the standard deviation and p value, were as follows: X-axis: 4.5 mm (1.0, p = 0.01); Y axis: 6.4 mm (1.9, p = 0.03); and Z-axis 3.9 mm (0.6, p = 0.002). Mean intrafractional motion was also found to be significant in all directions: superior, 7.2 mm (0.9, p = 0.01); inferior, 11.9 mm (0.9, p < 0.01); anterior: 4.9 mm (0.5, p = 0.01); posterior, 2.9 mm (0.5, p = 0.02); left, 2.2 mm (0.4, p = 0.02); and right, 3.1 mm (0.6, p = 0.04). Breath holding during treatment significantly decreased tumor motion in all directions. CONCLUSIONS: Electromagnetic transponder implantation appears to be safe and effective for monitoring inter- and intrafractional motion. Based on these results a larger clinical trial is underway.

Prevention of surgical resident attrition by a novel selection strategy.

OBJECTIVE(S): We modified the resident selection strategy in an attempt to reduce resident attrition (RA). SUMMARY BACKGROUND DATA: Despite implementation of the Accreditation Council for Graduate Medical Education work rules, lifestyle and generational priorities have fostered a persistent and relatively high attrition rate for surgical trainees. METHODS: An independent external review of residents who left the training program and a detailed analysis of the resident selection strategy were performed by an organizational management expert. Modifications implemented in 2005 (the intervention) included standardization of the screening and interview format. Applicants were required to submit a 500 words essay related to stress management, organizational skills, future aspirations, and prioritization abilities. Their responses formed the basis of an extended, personalized, and structured interview script. Candidate characteristics and RA were compared for the 5 years before and after the intervention, using Fisher exact test or chi2. RESULTS: Age, sex, birthplace, medical school ranking, step 1 score, and American Board of Surgey In-Training Examination performance were not significantly different between the selection strategy groups. Risk factors for RA included ABSITE performance and gender. Resident performance and subsequent RA were significantly affected by the resident selection strategy. CONCLUSIONS: RA was dramatically reduced following the intervention. A custom designed process to identify candidates most likely to succeed substantially improved resident retention in a demanding academic training program.