Purpose:Radiation oncology departments are uniquely susceptible to additional challenges when transitioning from paper to electronic chart recording systems. The Gamma Knife stereotactic radiation therapy system has additional complexities stemming from limited network connectivity to other computer systems used within the department. The goal of this project is to transition from paper charting to completely electronic charting. Methods:To accomplish the digital transformation, our department created a detailed mapping of the paper workflow, converted all documents digitally, implemented a paperless printing solution, and established a digital platform for document processing. Throughout each step, we intended to preserve the integrity of the high-quality treatment workflow in our department by focusing on (1) enhancing the multidisciplinary aspects of the treatment workflow; (2) ensuring protected health information security; and (3) maintaining efficient patient care. Results:Electronic signature software and a digital printer were installed to overcome technical hurdles. All paper documents, such as the written directive, stereotactic radiosurgery-frame measurements, and physics consult, were converted to electronic documents mainly using spreadsheet applications. Based on clinical implementation and practice, all goals were met which enhanced the treatment workflow by allowing less time spent on documentation and more time with the patients. Conclusions:With technical planning and coordination from all team members, we demonstrated that the implementation of electronic chart recording systems can be achieved for Gamma Knife radiosurgery treatments that enhance the treatment workflow, provide flexibility for staff, and allow for greater multidisciplinary communication.

Purpose/Objective(s) This prospective observational study investigates mechanisms behind neurocognitive function (NCF) decline after partial-brain irradiation in malignant glioma patients. We aim to use resting-state functional MRI (RS-fMRI) to identify the dominant network-level disturbances post-radiation therapy (RT) that correlate with NCF changes. Materials/Methods Adult patients with IDH-wildtype or IDH-mutant gliomas underwent NCF test using the NIH Toolbox Cognitive Function Battery at baseline and 6 months post RT. The battery includes fluid cognition tests: dimension change card sort test (executive function), flanker test (attention), picture sequence test (episodic memory), list sorting test (working memory), and pattern comparison test (processing speed). The five test scores were then combined into an age-normalized composite score, from which the percent change of composite (PCC) was calculated relative to the baseline. To determine a potential correlation between NCF and changes in brain functional connectivity (FC), we used seed-based FC analysis from a 12-minute RS-fMRI scan. A split-sample approach was used for analysis, with a 26-patient training set and a 6-patient validation set, iterated 200 times. Within each run, connectivity-regression analysis within the training set was first used to identify which intra- or inter-network FC change was most significantly associated with PCC, and a linear regression was used to predict FC change of the selected networks using the validation set. Permutation test was used to evaluate the significance of network selection, and R2 value was used to evaluate the predictive performance. Results From September 2020 to December 2023, there were 43 patients who had baseline data, while 32 patients completed 6-month follow-ups and were evaluable. The mean NCF composite changed from 88.8 (±16.2) at baseline to 91.1 (±19.4) at 6 months. The mean PCC was 2.9 (±13.7), including 12 patients with negative PCC (Decline cohort) and 20 patients with positive PCC (Non-decline cohort). The clinical, treatment, and dosimetric characteristics between two cohorts were not significantly different among 24 variables examined. The mean R2 was 0.36 (±0.27). The most significant correlations with PCC were consistently observed in the inter-network FC changes between Default Mode Network to Medial Temporal Lobe (DMN-MTL, P = 0.005) and Parietal Memory Network to MTL (PMN-MTL, P = 0.02). Sensitivity analyses using only FC maps from the contra-lateral side of the tumor confirmed the same finding. Conclusion RS-fMRI changes post RT correlated with NCF decline, suggesting its potential as an imaging biomarker. Specifically, disruption of inter-network FC between DMN-MTL and PMN-MTL may be key mechanism underlying RT-induced NCF decline, warranting further investigation.

AbstractCurrent available secondary dose calculation software for Gamma Knife radiosurgery falls short in situations where the target is shallow in depth or when the patient is positioned with a gamma angle other than 90°. In this work, we evaluate a new secondary calculation software which utilizes an innovative method to handle nonstandard gamma angles and image thresholding to render the skull for dose calculation. 800 treatment targets previously treated with our GammaKnife Icon system were imported from our treatment planning system (GammaPlan 11.0.3) and a secondary dose calculation was conducted. The agreement between the new calculations and the TPS were recorded and compared to the original secondary dose calculation agreement with the TPS using a Wilcoxon Signed Rank Test. Further comparisons using a Mann‐Whitney test were made for targets treated at a 90° gamma angle against those treated with either a 70 or 110 gamma angle for both the new and commercial secondary dose calculation systems. Correlations between dose deviations from the treatment planning system against average target depth were evaluated using a Kendall’s Tau correlation test for both programs. The Wilcoxon Signed Rank Test indicated a significant difference in the agreement between the two secondary calculations and the TPS, with a P‐value < 0.0001. With respect to patients treated at nonstandard gamma angles, the new software was largely independent of patient setup, while the commercial software showed a significant dependence (P‐value < 0.0001). The new secondary dose calculation software showed a moderate correlation with calculation depth, while the commercial software showed a weak correlation (Tau = −.322 and Tau = −.217 respectively). Overall, the new secondary software has better agreement with the TPS than the commercially available secondary calculation software over a range of diverse treatment geometries.

Functional MRI (fMRI) utilizes fluctuations in the ratio of oxyhemoglobin to deoxyhemoglobin to map the cortical networks of the brain. In particular, resting-state fMRI (rs-fMRI) can be used to map the cortical networks of the brain using endogenous brain activity, and thus can be acquired independent of patient participation. This independence is beneficial in patients with altered cognitive status, making it advantageous in patients with brain tumors. The purpose of this study is to investigate changes to cortical networks due to the presence of tumors, with the ultimate goal of studying the effects of radiation on these networks, and potentially tailoring radiation therapy treatment planning to minimize changes post-radiation treatment. Seven patients undergoing surgical resection of brain tumors participated in this study, and an additional 21 patients have been identified as having rs-fMRI data acquired both pre and post-radiation therapy. rs-fMRI correlation maps were generated using an artificial neural network known as a multilayer perceptron, with the output representing an estimate of each voxel belonging to each of seven resting state networks: language network, somatomotor network, visual network, dorsal attention network, ventral attention network, frontoparietal control, and default mode network. The efficacy of the multilayer perceptron was confirmed through comparison with motor and language networks as identified with direct electrocortical stimulation performed during resection. rs-fMRI mapping of tumor subjects reveals network distortion in the presence of tumors, with significant anisotropy across the midline seen in networks present in areas near the tumor. Interestingly, there were areas within the tumor that continued to display network connectivity. Additional study is needed to determine the effects of radiation on the cortical networks. The rs-fMRI provides insight into the brain’s organizational structure through identification of cortical networks. Though distorted, these networks are preserved in the presence of tumors, and further study is required to determine the effect of radiation on them.