S482 I. J. Radiation Oncology d Biology d Physics Volume 72, Number 1, Supplement, 2008

2700 An Increase in Medical Student Knowledge of Radiation Oncology: A Pre-post Examination Analysis of the

Oncology Education Initiative

A. E. Hirsch, P. Mulleady, P. J. Slanetz

Boston University School of Medicine, Boston, MA

Purpose/Objective(s): The Oncology Education Initiative was created to advance oncology and radiation oncology education byintegrating structured didactics into the existing core radiology clerkship. We set out to determine whether the addition of structureddidactics could lead to a significant increase in overall medical student knowledge about radiation oncology.

Materials/Methods: We conducted a pre and post test examining concepts in general radiation oncology, general oncology, andbreast and prostate cancer. The 15-question, multiple choice exam was administered before and after a 1.5 hour didactic lecturegiven by an attending physician in Radiation Oncology. The test was administered on the first and last day of the month long ro-tation. The questions on the pre and post exam were identical, with the exception of changes in the order of questions and answerchoices to sufficiently decrease recall bias. Individual question changes, overall student changes and overall categorical changeswere analyzed. All hypothesis tests were two-tailed with significance level 0.05.

Results: Of the 95 fourth-year students who have rotated through the radiology clerkship to date, all 95 (100%) have taken theexam. For the entire cohort, overall improvement was seen in all questions except those related to rates of cancer death and clinicalvignettes involving correct identification of TNM staging. Significant improvement (p # 0.03) was seen in questions regardingacute and late side effects of radiation, brachytherapy for prostate cancer, delivery of radiation treatment, and management ofearly-stage breast cancer. The average test grade improved from 62% to 72%, representing an absolute improvement of 10% (p= 0.007).

Conclusions: Addition of didactics in oncology and radiation oncology significantly improves medical students’ knowledge aboutthese topics. Of the questions that showed significant improvement, 80% were on radiation oncology. Despite perceived difficultyin not only teaching the advanced principles of this challenging topic but also the assumption that it is beyond the scope of reason-able knowledge for medical students, we have shown that even with one dedicated lecture in radiation oncology, students can learnand absorb general principles regarding radiation oncology.

Author Disclosure: A.E. Hirsch, None; P. Mulleady, None; P.J. Slanetz, None.

2701 Hormone use and Total Biological Equivalent Dose (BED) are Associated with Shorter PSA Doubling

Times in Prostate Cancer Patients Treated with Radiotherapy who Experience a PSA Failure

S. R. Blacksburg, C. A. Peters, N. N. Stone, J. A. Cesaretti, R. G. Stock

Mount Sinai Medical Center, New York, NY

Purpose/Objective(s): To investigate pre-treatment factors affecting PSA doubling time in prostate cancer patients treated withradiotherapy who have experienced a PSA failure.

Materials/Methods: A total of 1,955 consecutive patients treated with radiation therapy consisting of either low dose rate (LDR)brachytherapy alone or in combination with external beam radiation therapy (EBRT) were screened for PSA failure, with a min-imum follow-up time of 2 years. 181 (9.3%) patients experienced biochemical failure, defined by a nadir +2ng/ml Phoenix defi-nition. Post-failure PSA doubling times were calculated by a linear best-fit model. Gleason score, clinical stage, pre-treatment PSA,risk stratification, pre-failure hormone use, total BED (using an alpha beta value of 2), and race were analyzed to assess for doublingtimes greater than or less than 10 months. Median follow-up was 83.1 months (range 25.6 to 200).

Results: On univariate analysis, pre-failure hormone use, BED.180 Gy2, and Gleason scores of 6 and 7 were significantly asso-ciated with post-failure PSA doubling times\10 months (p180 (p\0.0001, [0.139, .560 95% CI]) were significantly associatedwith post-failure PSA doubling times 10 months. Clinical stage, pre-treatment PSA, and race did not predict post-failure doublingtime.

Conclusions: The relationship between pre-treatment factors and post-treatment PSA doubling time in patients with biochemicalfailure is interesting and needs to be further explored. In our analysis, use of hormones and high BED portended for shorter dou-bling time. One possible explanation is that the combination of high BED radiotherapy and hormone use leads to a highly ablativetreatment to the prostate gland, maximizing local control. In the small subsets of patients who fail this aggressive therapy, maximallocal control selects for those patients who will have metastatic disease.

Author Disclosure: S.R. Blacksburg, None; C.A. Peters, None; N.N. Stone, Prologics LLC, E. Ownership Interest; Nihon Medi-Physics, F. Consultant/Advisory Board; J.A. Cesaretti, CR Bard Lecturer, G. Other; R.G. Stock, CR Bard Lecturer, G. Other.

2702 Radiation Oncology Inpatient Co-morbidities and Complications over a 5 Year Period: A Review of

Hospital Patient Complexities and Outcomes

B. L. Brunet, P. Craighead, E. Kurien

Tom Baker Cancer Centre, Calgary, AB, Canada

Purpose/Objective(s): Canadian Radiation Oncologists traditionally admit and care for patients in hospital. A general observationhas been that many admitted patients tend to have multiple co-morbidities. Additionally, patient characteristics, reasons for admis-sion, and outcomes have seen only limited study. Also, the impact of complications and co-morbidities on length of stay and out-comes has been unclear.

Materials/Methods: We looked at all hospital discharges over a 5 year period where a Radiation Oncologist was the primary phy-sician. The data consisted of anonymous patient information including gender, age, main diagnosis, pre-existing co-morbidities,concurrent diseases, new diagnoses during admission, and procedures performed. Length of stay, hours in Special Care Unit(SCU), and complications were also included. Descriptive statistical methods were used for the analysis.