Newswire (Published: Monday, July 12, 2021, Received: Monday, July 12, 2021, 4:06:50 PM CDT)

Word Count: 673

2021 JUL 12 (NewsRx) -- By a News Reporter-Staff News Editor at NewsRx Drug Daily -- Researchers detail new data in Oncology - Prostate Cancer. According to news reporting out of Baltimore, Maryland, by NewsRx editors, research stated, “Major advances in delivery systems in recent years have turned radiotherapy (RT) into a more effective way to manage prostate cancer. Still, adjacency of organs at risk (OARs) can severely limit RT benefits.”

Financial support for this research came from National Institutes of Health (NIH) - USA.

Our news journalists obtained a quote from the research from the Johns Hopkins University School of Medicine, “Rectal spacer implant in recto-prostatic space provides sufficient separation between prostate and rectum, and therefore, the opportunity for potential dose escalation to the target and reduction of OAR dose. Pretreatment simulation of spacer placement can potentially provide decision support to reduce the risks and increase the efficacy of the spacer placement procedure. A novel finite element method-oriented spacer simulation algorithm, FEMOSSA, was developed in this study. We used the finite element (FE) method to model and predict the deformation of rectum and prostate wall, stemming from hydrogel injection. Ten cases of prostate cancer, which undergone hydrogel placement before the RT treatment, were included in this study. We used the pre-injection organ contours to create the FE model and post-injection spacer location to estimate the distribution of the virtual spacer. Material properties and boundary conditions specific to each patient’s anatomy were assigned. The FE analysis was then performed to determine the displacement vectors of regions of interest (ROIs), and the results were validated by comparing the virtually simulated contours with the real post-injection contours. To evaluate the different aspects of our method’s performance, we used three different figures of merit: dice similarity coefficient (DSC), nearest neighbor distance (NND), and overlapped volume histogram (OVH). Finally, to demonstrate a potential dosimetric application of FEMOSSA, the predicted rectal dose after virtual spacer placement was compared against the predicted post-injection rectal dose. Our simulation showed a realistic deformation of ROIs. The post-simulation (virtual spacer) created the same separation between prostate and rectal wall, as post-injection spacer. The average DSCs for prostate and rectum were 0.87 and 0.74, respectively. Moreover, there was a statistically significant increase in rectal contour similarity coefficient (P < 0.01). Histogram of NNDs showed the same overall shape and a noticeable shift from lower to higher values for both post-simulation and post-injection, indicative of the increase in distance between prostate and rectum. There was less than 2.2- and 2.1-mm averaged difference between the mean and fifth percentile NNDs. The difference between the OVH distances and the corresponding predicted rectal dose was, on average, less than 1 mm and 1.5 Gy, respectively. FEMOSSA provides a realistic simulation of the hydrogel injection process that can facilitate spacer placement planning and reduce the associated uncertainties.”

According to the news editors, the research concluded: “Consequently, it increases the robustness and success rate of spacer placement procedure that in turn improves prostate cancer RT quality.”

This research has been peer-reviewed.

For more information on this research see: Femossa: Patient-specific Finite Element Simulation of the Prostate-rectum Spacer Placement, a Predictive Model for Prostate Cancer Radiotherapy. Medical Physics, 2021. Medical Physics can be contacted at: Wiley, 111 River St, Hoboken 07030-5774, NJ, USA. (American Association of Physicists in Medicine -; Medical Physics -

Our news journalists report that additional information may be obtained by contacting Kai Ding, Johns Hopkins University School of Medicine, Dept. of Radiation Oncology and Molecular Radiation Sciences, Baltimore, MD 21205, United States. Additional authors for this research include Hamed Hooshangnejad, Sina Youssefian and James K. Guest.

The direct object identifier (DOI) for that additional information is: This DOI is a link to an online electronic document that is either free or for purchase, and can be your direct source for a journal article and its citation.

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