Making the Most Out of the Limited Context Length: Predictive Power Varies with Clinical Note Type and Note Section

Recent advances in large language models have led to renewed interest in natural language processing in healthcare using the free text of clinical notes. One distinguishing characteristic of clinical notes is their long time span over multiple long documents. The unique structure of clinical notes creates a new design choice: when the context length for a language model predictor is limited, which part of clinical notes should we choose as the input? Existing studies either choose the inputs with domain knowledge or simply truncate them. We propose a framework to analyze the sections with high predictive power. Using MIMIC-III, we show that: 1) predictive power distribution is different between nursing notes and discharge notes and 2) combining different types of notes could improve performance when the context length is large. Our findings suggest that a carefully selected sampling function could enable more efficient information extraction from clinical notes.Comment: Our code is publicly available on GitHub (https://github.com/nyuolab/EfficientTransformer

The Value of the History and Physical for Patients with Newly Diagnosed Brain Metastases Considering Radiosurgery

Background: For patients with brain metastases, systemic disease burden has historically been accepted as a major determinant of overall survival (OS). However, less research has focused on specific history and physical findings made by clinicians and how such findings pertain to patient outcomes at a given time point. The aim of this study is to determine how the initial clinical assessment of patients with brain metastases, as part of the history and physical at the time of consultation, correlates with patient prognosis.Methods: We evaluated a prospective, multi-institutional database of 1523 brain metastases in 507 patients who were treated with radiosurgery (Gamma Knife or CyberKnife) from 2001-2014. Relevant history of present illness (HPI) and past medical history (PMH) variables included comorbidities, Eastern Cooperative Oncology Group (ECOG) performance status, and seizure history. Physical exam findings included a sensory exam, motor exam, and cognitive function. Univariate and multivariate Cox regression analyses were used to identify predictors of OS.Results: 294 patients were included in the final analysis with a median OS of 10.8 months (95% C.I., 7.8-13.7 months). On univariate analysis, significant HPI predictors of OS included age, primary diagnosis, performance status, extracranial metastases, systemic disease status, and history of surgery. Significant predictors of OS from the PMH included cardiac, vascular, and infectious comorbidities. On a physical exam, findings consistent with cognitive deficits were predictive of worse OS. However, motor deficits or changes in vision were not predictive of worse OS. In the multivariate Cox regression analysis, predictors of worse OS were primary diagnosis (p=0.002), ECOG performance status (OR 1.73, p<0.001), and presence of extracranial metastases (OR 1.22, p=0.009).Conclusion: Neurologic deficits and systemic comorbidities noted at presentation are not associated with worse overall prognosis for patients with brain metastases undergoing radiosurgery. When encountering new patients with brain metastases, the most informative patient-related characteristics that determine prognosis remain performance status, primary diagnosis, and extent of extracranial disease

Five Fraction Image-Guided Radiosurgery for Primary and Recurrent Meningiomas

Purpose: Benign tumors that arise from the meninges can be difficult to treat due to their potentially large size and proximity to critical structures such as cranial nerves and sinuses. Single fraction radiosurgery may increase the risk of symptomatic peritumoral edema. In this study, we report our results on the efficacy and safety of five fraction image-guided radiosurgery for benign meningiomas. Materials/Methods: Clinical and radiographic data from 38 patients treated with five fraction radiosurgery were reviewed retrospectively. Mean tumor volume was 3.83mm3 (range, 1.08-20.79 mm3). Radiation was delivered using the CyberKnife, a frameless robotic image-guided radiosurgery system with a median total dose of 25 Gy (range, 25 Gy-35 Gy). Results: The median follow-up was 20 months. Acute toxicity was minimal with eight patients (21%) requiring a short course of steroids for headache at the end of treatment. Pre-treatment neurological symptoms were present in 24 patients (63.2%). Post treatment, neurological symptoms resolved completely in 14 patients (58.3%), and were persistent in eight patients (33.3%). There were no local failures, 24 tumors remained stable (64%) and 14 regressed (36%). Pre-treatment peritumoral edema was observed in five patients (13.2%). Post-treatment asymptomatic peritumoral edema developed in five additional patients (13.2%). On multivariate analysis, pre-treatment peritumoral edema and location adjacent to a large vein were significant risk factors for radiographic post-treatment edema (p = 0.001 and p = 0.026 respectively). Conclusions: These results suggest that five fraction image-guided radiosurgery is well tolerated with a response rate for neurologic symptoms that is similar to other standard treatment options. Rates of peritumoral edema and new cranial nerve deficits following five fraction radiosurgery were low. Longer follow-up is required to validate the safety and long-term effectiveness of this treatment approach

Clinical characteristics and management of late urinary symptom flare following stereotactic body radiation therapy for prostate cancer

Purpose: Stereotactic body radiotherapy (SBRT) is increasingly utilized as primary treatment for localized prostate cancer (PCa). The late GU toxicity of SBRT has not been fully described. We characterize the clinical features of late urinary symptom flare (LUSF) and recommend conservative management approaches.Methods: Between Feb.08-Aug.11, 216 men with PCa were treated definitively with SBRT at GUH. Treatment was delivered using the CyberKnife (35 Gy-36.25 Gy in 5 fractions). The prevalence of CTC-graded toxicities and medication usage were assessed at each follow-up visit. Patient-reported symptoms were assessed using the AUA symptom score and the EPIC-26 at 1, 3, 6, 9, 12, 18 and 24 months. LUSF was defined as an increase in the AUA score of ≥ 5 points above baseline with a degree of severity in the moderate to severe range. The relationship between the occurrence of flare and pretreatment characteristics were examined.Results: Of the 216 patients, 29 (13.4%) experienced a late transient increase in the AUA score that met the criteria for LUSF. Among flare patients, median age was 66 yrs compared to 70 for those without flare (p = 0.007). In patients who experienced flare, CTC toxicities peaked at 9-18 months, and alpha-antagonist utilization peaked at 18 months (85%) before decreasing at 24 months. The EPIC urinary summary score of flare patients transiently declined between 6 months and 18 months before returning to baseline at two years post-SBRT. Clinically significant increases in frequency, weak stream and dysuria were seen at 12 months post-SBRT. Among flare patients, 42.9% felt that urination was a moderate to big problem at 12 months following SBRT.Conclusions: In this study, we characterize LUSF following SBRT. LUSF is a constellation of symptoms including frequency/urgency, weak stream and dysuria that transiently occurs 6-18 months post-SBRT. The maintenance of prophylactic alpha-antagonists may limit the bother associated with this syndrome

Five fraction image-guided radiosurgery for primary and recurrent meningiomas.

PURPOSE: Benign tumors that arise from the meninges can be difficult to treat due to their potentially large size and proximity to critical structures such as cranial nerves and sinuses. Single fraction radiosurgery may increase the risk of symptomatic peritumoral edema. In this study, we report our results on the efficacy and safety of five fraction image-guided radiosurgery for benign meningiomas. MATERIALS/METHODS: Clinical and radiographic data from 38 patients treated with five fraction radiosurgery were reviewed retrospectively. Mean tumor volume was 3.83 mm(3) (range, 1.08-20.79 mm(3)). Radiation was delivered using the CyberKnife, a frameless robotic image-guided radiosurgery system with a median total dose of 25 Gy (range, 25-35 Gy). RESULTS: The median follow-up was 20 months. Acute toxicity was minimal with eight patients (21%) requiring a short course of steroids for headache at the end of treatment. Pre-treatment neurological symptoms were present in 24 patients (63.2%). Post treatment, neurological symptoms resolved completely in 14 patients (58.3%), and were persistent in eight patients (33.3%). There were no local failures, 24 tumors remained stable (64%) and 14 regressed (36%). Pre-treatment peritumoral edema was observed in five patients (13.2%). Post-treatment asymptomatic peritumoral edema developed in five additional patients (13.2%). On multivariate analysis, pre-treatment peritumoral edema and location adjacent to a large vein were significant risk factors for radiographic post-treatment edema (p = 0.001 and p = 0.026 respectively). CONCLUSION: These results suggest that five fraction image-guided radiosurgery is well tolerated with a response rate for neurologic symptoms that is similar to other standard treatment options. Rates of peritumoral edema and new cranial nerve deficits following five fraction radiosurgery were low. Longer follow-up is required to validate the safety and long-term effectiveness of this treatment approach