Validation of a commercial software dose calculation for Y-90 microspheres.

PURPOSE: Several new commercial software packages have become available that can calculate the tumor and normal tissue dose distributions from post-treatment PET-CT scans for Y-90 microsphere treatments of liver lesions. This work seeks to validate the MIM SurePlan Liver Y90 software by comparing its results to a previously developed Monte Carlo derived voxel dose kernel calculation method. METHODS: We analyzed 10 patients who had treatments for metastatic liver cancer and created contours on post Y-90 treatment PET-CT images. We then performed dose calculations using three methods and compared the results. The first two methods calculated the dose using MIM SurePlan Liver Y90's LDM (Local Deposition Method) and the VSV (Voxel S Value) algorithms. The third method calculated the dose using a publicly available Fluka Monte Carlo-derived dose kernel (MCK) calculation (used as ground truth). We investigated 3D Gamma passing rates and several dosimetric parameters. RESULTS: A total of 3%/3 mm 3D gamma passing rates averaged 99.3% for the VSV and 78.9% for LDM. Compared to the MCK distribution, the differences for combined target GTV V70Gy and normal liver and/or lobe mean doses were small. Larger differences were seen in GTV mean doses and D95, likely due to large dose gradients in the treated regions combined with differences in dose kernel, dose grid and finite volume effects. CONCLUSIONS: The MIM SurePlan Liver Y90 VSV algorithm agreed well with the MCK calculation for patients treated with Y-90 microspheres based on the gamma analysis and several dosimetric parameters. Larger dosimetric differences in lesion mean doses and D95 suggests that these metrics are less robust to changes in calculation grid location and finite volume effects for small lesions.

Phenotypic characterisation of Meatmaster sheep using quantitative and qualitative trait analysis.

A phenotypic analysis of the Meatmaster breed was done, using linear body measurements, qualitative assessment, slaughter data and pedigree performance data. The linear body measurements and pedigree performance data were collected from 187 rams and 222 ewes of all age categories. The following means were recorded in rams and ewes respectively: Body weight (kg) (80.47±13.33; 57.51±12.43), head length (cm) (23.93±1.55; 22.68±2.05), neck length (cm) (28.35±5.16; 29.61±3.82), chest girth (cm) (102.45±8.42; 92.95±8.08), tail length (cm) (38.24±4.88; 36.64±4.70), wither height (cm) (63.91±4.04; 58.99±4.86), chest depth (cm) (37.51±2.97; 34.47±2.97), chest width (cm) (23.47±2.56; 21.24±2.85), body length (cm) (78.95±5.59; 72.67±6.06), rump length (cm) (21.82±3.29; 20.77±1.93), rump width (cm) (23.87±2.82; 21.36±3.15), skin thickness (mm) (2.846±0.5; 2.805±0.5), pelvic length (cm) (7.66±.98), pelvic width (cm) (7.66±.90), pelvic area (cm2) (46.69±10.62) and scrotal circumference (cm) (35.12±3.03). The pedigree performance data of 177 ewes showed the following means: age at first lambing (15.242±3.8 months), number of times lambed (3.33±1.8), number of lambs born (4.36±3.4), number of lambs weaned (3.44±2.5) and average inter-lambing period (258.64±151.3 days). Slaughter data was compiled from 2251 animals of different genders and ages; the means are as follows: measured in (kg): A-grade carcass (16.77±4.1), AB-grade carcass (24.039±13.8), B-grade carcass (26.904±13.3) and C-grade carcass (24.88±4.9). A predictive value of R2= 0.140 was observed between wither height and average inter-lambing period as well as a R2= 0.154 between the wither height and number of lambs born. This seems to be a characteristic of the Afro-type breeds which have a higher wither height and also have a higher tendency to birth multiple lambs per lambing opportunity.

Risk factors for return with a second trigger digit.

The purpose of this study was to determine predictors of return to the same practice with a second idiopathic trigger digit. A total of 2234 patients with Quinnell grade 2 or greater (objective triggering) of one or more digits were retrospectively analysed. A total of 490 of 2234 (22%) patients returned to the same practice with a second trigger digit, with an average follow-up time of 2.1 years (range, 7 days to 10 years). Predictors of return with a second trigger digit included carpal tunnel syndrome, Type 1 diabetes mellitus and duration of follow-up in years. Patients diagnosed with idiopathic trigger digit can be advised that about one in five will return to the same practice with another trigger digit, with approximately double the risk in patients that have carpal tunnel syndrome or Type 1 diabetes.

Evaluation of the scratch collapse test for the diagnosis of carpal tunnel syndrome.

This prospective study measured and compared the diagnostic performance characteristics of various clinical signs and physical examination manoeuvres for carpal tunnel syndrome (CTS), including the scratch collapse test. Eighty-eight adult patients that were prescribed electrophysiological testing to diagnose CTS were enrolled in the study. Attending surgeons documented symptoms and results of standard clinical manoeuvres. The scratch collapse test had a sensitivity of 31%, which was significantly lower than the sensitivity of Phalen's test (67%), Durkan's test (77%), Tinel's test (43%), CTS-6 lax (88%), and CTS-6 stringent (54%). The scratch test had a specificity of 61%, which was significantly lower than the specificity of thenar atrophy (96%) and significantly higher than the specificity of Durkan's test (18%) and CTS-6 lax (13%). The sensitivity of the scratch collapse test was not superior to other clinical signs and physical examination manoeuvers for CTS, and the specificity of the scratch collapse test was superior to that of Durkan's test and CTS-6 lax. Further studies should seek to limit the influence of a patient's clinical presentation on scratch test performance and assess the scratch test's inter-rater reliability.

Changes in treatment plan for carpal tunnel syndrome based on electrodiagnostic test results.

This study evaluated how often the treatment plan for carpal tunnel syndrome (CTS) changed based on electrodiagnostic test results. Secondly, we assessed factors associated with a change in the treatment plan for CTS. One-hundred-and-thirty English-speaking adult patients underwent electrodiagnostic testing in a prospective cohort study. Treatment plan was recorded before and after testing. Treatment plan changed in 25 patients (19%) based on electrodiagnostic test results. The plan for operative treatment before testing decreased significantly after testing (83% versus 72%). The best logistic regression model for no change in treatment plan included a prolonged or non-recordable median distal sensory latency (normal, prolonged, or non-recordable), and explained 24% of the variation. For surgeons that manage CTS on the basis of objective pathophysiology rather than symptoms, electrodiagnostic test results often lead to changes in recommended treatment.

A prospective randomized comparison of neoprene vs thermoplast hand-based thumb spica splinting for trapeziometacarpal arthrosis.

OBJECTIVE: In patients with trapeziometacarpal arthrosis, we tested the hypothesis that there is no difference in arm-specific disability 5-15 weeks after prescription of a pre-fabricated neoprene or a custom-made thermoplast hand-based thumb spica splint with the metacarpophalangeal joint included and the first interphalangeal joint free. METHOD: One hundred nineteen patients with a diagnosis of trapeziometacarpal arthrosis were prospectively randomized to wear either a neoprene or a thermoplast hand-based thumb spica splint. At enrollment, patients completed a set of validated questionnaires. An average of 9 weeks later, patients returned for a second visit. Bivariable analyses assessed factors associated with disability, pain and satisfaction. Analysis was by intention-to-treat. RESULTS: Sixty-two patients (32 with a neoprene and 30 with a thermoplast splint) completed the study, 51 patients (43%) did not return for the second visit, and six did not complete the protocol for other reasons. Non-completers were significantly younger than completers (P < 0.00044). On average completers rated the neoprene splint as more comfortable (P = 0.048), but there were no detectable differences in Disabilities of the Arm, Shoulder and Hand (DASH), change in DASH, pain, satisfaction, pinch or grip strength between the two splint types in our sample. CONCLUSION: When compared to custom-made thermoplast splints, pre-fabricated neoprene hand-based thumb spica splints are, on average, more comfortable, less expensive, and as effective in treating trapeziometacarpal arthrosis. This trial was registered at Clinicaltrials.gov (NCT00438763).

SU-E-T-548: Case Study of HDR Vs IMRT in Pediatric Sarcomas.

PURPOSE: To compare the dose to critical structures using HDR brachytherapy versus IMRT in pediatric tumors. METHOD: Two sarcoma cases, for which both HDR and IMRT could be options, were selected for this case study. Case 1 targeted a volume on the posterior neck/upper back with an HDR prescription of 600cGy × 5 fractions, 3000cGy total. The IMRT prescription used was 180cGy × 25 fractions, 4500cGy total with a boost of 180cGy × 6 fractions, 1080cGy. The IMRT PTV used was a 0.5cmexpansion of the HDR PTV; the boost PTV was identical to the HDR treatment plan. Case 2 targeted a volume on the palette of the mouth with an HDR prescription of 300cGy × 12 fractions, 3600cGy total. The IMRT prescription used was 180cGy × 28 fractions, 5040cGy total. A 0.5cm expansion of the HDR PTV was used for the IMRT PTV. In both cases, for both HDR and IMRT, at least 95% of the PTV received 100% prescription dose, following Children's Oncology Group protocols. RESULTS: Case 1 : the mean doses to the body, brachial plexus, esophagus, spinal cord and thyroid were higher using IMRT than HDR. Integral dose was 6.6 times higher using IMRT than HDR. Case 2: the mean doses to the body, mandible, and parotids were higher using IMRT than HDR. Integral dose was 2.9 times higher using IMRT than HDR. CONCLUSION: This study shows the potential benefit of treating with HDR compared to IMRT in select pediatric cases. These results suggest that HDR can be superior to IMRT in the sparing of critical structures and in delivering less integral dose to the patient while still achieving adequate target coverage. However, lower mean doses to critical structures must also be weighed against the possibility of complications from HDR's very high hotspots.

Fractures of the proximal tibial epiphysis.

Fractures of the upper tibial epiphysis are rare. We report on three cases classified according to the Salter and Harris method. Case one, a Type III injury, was associated with a neurovascular lesion. Case two, a Type II injury, was associated with rupture of the medial collateral ligament of the knee, which was treated by internal fixation of the fracture and repair of the ligament. Case three was an unusual fracture, which has not previously been reported in the literature, a Type II injury with an accompanying fracture of the tibial tubercle.