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1.  Randomized study evaluating testosterone recovery using short-versus long-acting luteinizing hormone releasing hormone agonists 
We sought to compare the rate of return of testosterone levels and sexual function in men with prostate cancer receiving longer acting, 3-month preparation of luteinizing hormone-releasing hormone agonist (L-LHRH-A) versus shorter acting, 1-month preparation of luteinizing hormone-releasing hormone agonist (S-LHRH-A).
Methods and Materials:
Men with low to intermediate risk localized prostate cancer were randomized to either L-LHRH-A (2–3 month duration LHRH-A) or S-LHRH-A (6-1 month duration LHRH-A) of androgen suppression therapy (AST) and prostate brachytherapy using iodine-125 radioisotopes. Serum total testosterone levels and PSA were recorded every 2 months for 2 years.
A planned target sample size of 100 was not achieved due to insufficient accrual. A total of 55 patients were randomized and 46 were used for analysis. The median time to recovery of testosterone to baseline levels (calculated from end of AST) was 8 and 4 months in the L-LHRH-A and S-LHRH-A arms, respectively (p = 0.268). The median time to testosterone recovery to lower limit of reference range was 4 and 2 months respectively (p = 0.087).
This randomized study, which failed to reach accrual target, showed a trend towards more rapid recovery of testosterone levels using shorter acting LHRH-A. Another randomized study would be required to validate these findings. Currently, there is insufficient evidence to recommend the use of shorter acting LHRH-A as a means of providing more rapid recovery of testosterone levels.
PMCID: PMC3114026  PMID: 21672478
2.  Consistency in electronic portal imaging registration in prostate cancer radiation treatment verification 
A protocol of electronic portal imaging (EPI) registration for the verification of radiation treatment fields has been implemented at our institution. A template is generated using the reference images, which is then registered with the EPI for treatment verification. This study examines interobserver consistency among trained radiation therapists in the registration and verification of external beam radiotherapy (EBRT) for patients with prostate cancer.
Materials and methods
20 consecutive patients with prostate cancer undergoing EBRT were analyzed. The EPIs from the initial 10 fractions were registered independently by 6 trained radiation therapist observers. For each fraction, an anterior-posterior (AP or PA) and left lateral (Lat) EPIs were generated and registered with the reference images. Two measures of displacement for the AP EPI in the superior-inferior (SI) and right left (RL) directions and two measures of displacement for the Lat EPI in the AP and SI directions were prospectively recorded. A total of 2400 images and 4800 measures were analyzed. Means and standard deviations, as well as systematic and random errors were calculated for each observer. Differences between observers were compared using the chi-square test. Variance components analysis was used to evaluate how much variance is attributed to the observers. Time trends were estimated using repeated measures analysis.
Inter-observer variation expressed as the standard deviation of the six observers' measurements within each image were 0.7, 1.0, 1.7 and 1.4 mm for APLR, APSI, LatAP and LatSI respectively. Variance components analysis showed that the variation attributed to the observers was small compared to variation due to the images. On repeated measure analysis, time trends were apparent only for the APLR and LatSI measurements. Their magnitude however was small.
No clinically important systematic observer effect or time trends were identified in the registration of EPI by the radiation therapist observers in this study. These findings are useful in the documentation of consistency and reliability in the quality assurance of treatment verification of EBRT for prostate cancer.
PMCID: PMC1592498  PMID: 16984655

Results 1-2 (2)