Glen Gejerman

Prospective study of quality of life of patients receiving treatment for prostate cancer.

Background: No research was found that compared quality of life (QOL) outcomes of prostate cancer patients receiving intensity-modulated radiation therapies with prostate cancer patients receiving radical prostatectomy. Objectives: To (a) describe differences in QOL before and after three types of treatment for prostate cancer: radical prostatectomy, intensity-modulated radiation therapy + seed implantation (permanent brachytherapy), or intensity-modulated radiation therapy + high dose rate radiotherapy (temporary brachytherapy); and (b) investigate demographic, physical, and psychosocial variables that impact QOL of men with prostate cancer. Methods: Data were collected on three occasions: baseline (prior to treatment), 1 month, and 3 months after beginning treatment. Measures included biographic data, physiological, and psychological measures. Analysis of variance and hierarchical regression were used to examine patterns, describe differences, and identify predictors of QOL in the three treatment groups. QOL was conceptualized as a multidimensional construct that included physical, psychological, social, and functional well-being and prostate cancer concerns. Results: Groups differed significantly in bowel and urinary symptom scores and prostate cancer concerns at baseline, and in urinary and depressive symptoms at 3 months. There were no significant group differences at 1 month. Discussion: Significant differences were found in QOL as measured with the Functional Assessment of Cancer Treatment-Prostate after treatment with radical prostatectomy, intensity-modulated radiation therapy + seed implantation, or intensity-modulated radiation therapy + high dose rate radiotherapy. Findings may provide healthcare providers with knowledge about treatment sequelae for prostate cancer, enable healthcare providers to educate patients about QOL outcomes of treatment for prostate cancer, and enable patients to make more informed treatment decisions.

An automated phantom-film QA procedure for intensity-modulated radiation therapy.

To verify that the calculated dose distribution is delivered accurately during intensity-modulated radiation therapy (IMRT), we have implemented an automated plan/film validation protocol. The cubic polystyrene film phantom provided with the Peacock IMRT system and the Radiation Imaging Technology (RIT) film dosimetry system were used to compare planned and delivered dose distributions. The calculated dose matrix from CORVUS was transferred to RIT and analyzed. The analysis included dose-difference histograms, dose comparison in low-gradient areas, distance to agreement in high-gradient areas, dose profiles, and isodose comparisons. Dose differences of up to 5% were commonly observed in the high-dose and low-gradient areas between verification films and treatment plans for prostate patients. The most prominent discrepancies were detected in the high-gradient areas of dose distributions. The automated protocol is an efficient technique that provides information about spatial differences between calculated and delivered doses.

The effects of edema on urethral dose following palladium-103 prostate brachytherapy

The effects of edema on urethral dose after interstitial prostate brachytherapy with palladium-103 (103Pd) were studied. Fifty patients underwent a 90-Gy 103Pd implant followed by dosimetric computed tomography (CT). Twenty-one days later, a Foley catheter was reinserted and a dosimetric CT was repeated. The mean reduction in prostate volume between day 0 and day 21 was 16%. Median prostate D90 on day 0 was 89.7 Gy (range 59.5 to 127) and 99.5 Gy (range 62.5 to 130) on day 21. Median prostate V100 was 90% (range 63 to 98%) on day 0 and 96% (range 66 to 99%) on day 21. Median V150 was 61% (range 31 to 85%) on day 0 and 75% (range 39 to 93%) on day 21. Median urethral D50 was 107 Gy (range 57 to 201) on day 0 and 126 Gy (range 64 to 193) on day 21. Regression analysis demonstrated a significant correlation between the decrease in the prostate volume and the increased urethral D50 (r 0.58, p < 0.05). Acute urinary toxicity was 32% grade 0, 38% grade 1, and 30% grade 2. The median urethral D50 increased by a mean of 18% with a correlation coefficient of 0.58 (p < 0.05). Catheterization of the urethra was well tolerated and was of value in better characterizing urethral dose after 103Pd brachytherapy.

Corrigendum: Incorrect Spelling of Author's Name: US Preventive Services Task Force prostate-specific antigen screening guidelines result in higher Gleason score diagnoses

[This corrects the article on p. 423 in vol. 58.].

US Preventive Services Task Force prostate-specific antigen screening guidelines result in higher Gleason score diagnoses

Purpose To evaluate the impact that the 2012 US Preventive Services Task Force (USPSTF) prostate-specific antigen (PSA) screening guidelines have had on the diagnosis of prostate cancer, we compared the incidence and distribution of new cases diagnosed in 2011-before the USPSTF PSA screening recommendations versus 2014 at which time the guidelines were widely adopted. Materials and Methods We identified all prostate biopsies performed by a large urology group practice utilizing a centralized pathology lab. We examined total biopsies performed, percentage of positive biopsies, and for those with positive biopsies examined for differences in patient age, PSA, and Gleason score. Results A total of 4,178 biopsies were identified – 2,513 in 2011 and 1,665 in 2014. The percentage of positive biopsies was 27% in 2011 versus 34% in 2014 (p<0.0001). Among patients with positive biopsies, we found statistically significant differences between the 2 cohorts in the median ages and Gleason scores. Patients were about 1 year younger in 2014 compared to 2011 (t-test; p=0.043). High Gleason scores (8–10) were diagnosed in 19% of the 2014 positive biopsies versus 9% in the 2011 positive biopsies (chi square; p<0.0001). Conclusions After the widespread implementation of the 2011 USPTF PSA screening guidelines, 34% fewer biopsies were performed with a 29% increase in positive biopsy rates. We found a significantly higher incidence of high grade disease in 2014 compared with 2011. The percentage of patients with positive biopsies having Gleason scores 8–10 more than doubled in 2014. The higher incidence of these more aggressive cancers must be part of the discussion regarding PSA screening.

SU‐FF‐T‐86: Rapid (<15 Minutes) Automated Tangential Breast IMRT Treatment Planning With Cutplane Evaluation

Purpose: To develop an automated, dose-based IMRT planning technique for tangential breast irradiation and to introduce a novel technique for efficient plan evaluation in three-dimensions. Method and Materials: Patients were CT-simulated using an isocentric SAD technique with the medial and lateral tangents designed to encompass the breast tissue. The CT data and the beam information were transferred to the treatment planning system (TPS). The dose was then calculated for standard open equally weighted split beams. The planar dose rate matrix for a beams-eye-view plane was calculated and exported to a PC. An in-house program was developed to rescale this matrix and automatically create a series of dose-based MLC segments. Creation of the MLC segments took less than a minute. The MLC segments were imported back into the TPS where utilities were used to determine the optimal segment weights. An efficient plan evaluation tool was developed that presented the dose distributions in only three or less cutplanes parallel to the plane formed by the posterior beam border. The mathematical formalism for determining the cutplane orientation will be demonstrated. The planning and evaluation tools were tested on three representative case studies and compared to wedged tangent plans. To ensure unbiased comparison all plans were normalized to identical ICRU Reference Points. Results: The entire planning process, from CT import to plan completion, took approximately 15 minutes. For all cases studied the IMRT plans demonstrated superior coverage and dose homogeneity as determined by both isodose coverage and the ICRU Conformity Index. Cutplanes through the lung, mid breast, and apex were found to be the most clinically useful. Conclusion: The automated procedure is able to consistently produce optimized IMRT breast treatment plans within a few minutes. Isodose distributions in three cutplanes parallel to the posterior border are an effective tool for rapid plan evaluation.

Chapter 42 – Radiation Therapy for Early-stage Prostate Cancer – Could It Parallel Prostatectomy?

The introduction of 3D imaging modalities, such as computed tomography (CT) and magnetic resonance imaging scans, coupled with the increased availability of sophisticated computer systems has helped move radiation oncology into the era of 3D conformal therapy (3D-CRT). 3D-CRT is a method of irradiating a target volume with multiple X-ray beams of uniform intensity whose direction and boundaries are individually determined based on 3D anatomical information. Conformal radiotherapy allows for a more accurate delineation of the tumor that ensures more consistent dosimetric coverage. Reports of post-radiotherapy persistent local disease and high failure rates in the pre-prostate specific antigen (PSA) era led some to conclude that radiotherapy is an inadequate treatment for prostate cancer. Improvements in anatomic imaging, treatment planning software, and dose-delivery systems make it possible to maximize the radiation dose to the prostate gland while minimizing dose to the contiguous bladder and rectum. Conformal radiotherapy has allowed dose escalation to the prostate target volume with a resultant improvement in tumor eradication.