Could machine learning improve the prediction of pelvic nodal status of prostate cancer patients? Preliminary results of a pilot study.

We tested and compared performances of Roach formula, Partin tables and of three Machine Learning (ML) based algorithms based on decision trees in identifying N+ prostate cancer (PC). 1,555 cN0 and 50 cN+ PC were analyzed. Results were also verified on an independent population of 204 operated cN0 patients, with a known pN status (187 pN0, 17 pN1 patients). ML performed better, also when tested on the surgical population, with accuracy, specificity, and sensitivity ranging between 48-86%, 35-91%, and 17-79%, respectively. ML potentially allows better prediction of the nodal status of PC, potentially allowing a better tailoring of pelvic irradiation.

A mathematical approach for evaluating the influence of dose heterogeneity on TCP for prostate cancer brachytherapy treatment.

The low-dose-rate brachytherapy technique has proven suitable for the management of prostate cancer. However, published data generally report the clinical outcome and the minimum peripheral dose (mPD) to the target volume and not the actual dose distribution in patients. To this end, modern guidelines recommend the use of specific dose and volume indices describing dose distribution throughout the target. The introduction of a method, based on the standard linear quadratic model and Poisson statistics, entitled the F-factor allows the TCP from different DVHs to be calculated, by using the TCP from a uniform dose distribution as the reference. The F-factor sensitivity against radiobiological parameters and influence of the DVH were evaluated. We applied the F-formula on the post-plan DVHs of 58 patients treated with (125)I permanent seed implant brachytherapy for localized prostate cancer. F shows a strong correlation with dosimetric parameters already reported as significant predictors of the biochemical outcome.

Adjuvant hypofractionated radiation therapy for breast cancer after conserving surgery.

AIMS: To evaluate the incidence of locoregional recurrence (LRR) and the cosmetic results in a group of patients with breast cancer treated with a hypofractionated schedule of adjuvant radiotherapy after conservative surgery. MATERIALS AND METHODS: In total, 539 patients with pTis-pT1-pT2 breast cancer underwent radiotherapy treatment after conservative surgery at the University of Florence and at the Pistoia Hospital. The dose delivered was 44 Gy (2.75 Gy daily fraction). The tumour bed boost (10 Gy) was given by electrons. RESULTS: At the time of the analysis, 1.8% of patients (10/539) had breast relapse. No patients developed nodal recurrence (supraclavicular, axillary and internal mammary nodes). The 3- and 5-year actuarial rates for LRR were 1.2% (+/- 0.5% standard error) and 2.1% (+/- 0.6% standard error), respectively. Considering the late toxicity, we found that 412 (76.4%) patients had grade 0 or grade 1 late toxicity, 113 patients (20.9%) had grade 2 late toxicity and 14 patients (2.5%) had grade 3 late toxicity. No patients developed grade 4 toxicity. CONCLUSION: This type of approach resulted in an effective treatment in terms of local control in patients with negative or one to three positive axillary nodes and negative surgical margins. Patients treated with a hypofractionated schedule showed very good cosmesis.

Departmental libraries: why do they exist?

In response to an increasing concern on the part of the library staff over the role of the departmental libraries at The Milton S. Hershey Medical Center of The Pennsylvania State University, a questionnaire was developed by the George T. Harrel Library and sent to departmental libraries. From the analyzed responses, the authors were able to define the role of departmental libraries in a medical school/hospital situation, to analyze the Hershey Medical Center situation in an objective manner, to outline areas of possible cooperation between the main and departmental libraries, and to delineate some trends which appear to result from inadequate finding of a central library. Overall, the library found that departmental libraries at Hershey are currently maintaining collections consistent with the functional role of a departmental library.