Multi-modality imaging parameters that predict rapid tumor regression in head and neck radiotherapy.

Background and purpose: Volume regression during radiotherapy can indicate patient-specific treatment response. We aimed to identify pre-treatment multimodality imaging (MMI) metrics from positron emission tomography (PET), magnetic resonance imaging (MRI), and computed tomography (CT) that predict rapid tumor regression during radiotherapy in human papilloma virus (HPV) associated oropharyngeal carcinoma. Materials and methods: Pre-treatment FDG PET-CT, diffusion-weighted MRI (DW-MRI), and intra-treatment (at 1, 2, and 3 weeks) MRI were acquired in 72 patients undergoing chemoradiation therapy for HPV+ oropharyngeal carcinoma. Nodal gross tumor volumes were delineated on longitudinal images to measure intra-treatment volume changes. Pre-treatment PET standardized uptake value (SUV), CT Hounsfield Unit (HU), and non-gaussian intravoxel incoherent motion DW-MRI metrics were computed and correlated with volume changes. Intercorrelations between MMI metrics were also assessed using network analysis. Validation was carried out on a separate cohort (N = 64) for FDG PET-CT. Results: Significant correlations with volume loss were observed for baseline FDG SUVmean (Spearman ρ = 0.46, p < 0.001), CT HUmean (ρ = 0.38, p = 0.001), and DW-MRI diffusion coefficient, Dmean (ρ = -0.39, p < 0.001). Network analysis revealed 41 intercorrelations between MMI and volume loss metrics, but SUVmean remained a statistically significant predictor of volume loss in multivariate linear regression (p = 0.01). Significant correlations were also observed for SUVmean in the validation cohort in both primary (ρ = 0.30, p = 0.02) and nodal (ρ = 0.31, p = 0.02) tumors. Conclusions: Multiple pre-treatment imaging metrics were correlated with rapid nodal gross tumor volume loss during radiotherapy. FDG-PET SUV in particular exhibited significant correlations with volume regression across the two cohorts and in multivariate analysis.

Noise robustness and metabolic load determine the principles of central dogma regulation.

The processes of gene expression are inherently stochastic, even for essential genes required for growth. How does the cell maximize fitness in light of noise? To answer this question, we build a mathematical model to explore the trade-off between metabolic load and growth robustness. The model predicts novel principles of central dogma regulation: Optimal protein expression levels for many genes are in vast overabundance. Essential genes are transcribed above a lower limit of one message per cell cycle. Gene expression is achieved by load balancing between transcription and translation. We present evidence that each of these novel regulatory principles is observed. These results reveal that robustness and metabolic load determine the global regulatory principles that govern central dogma processes, and these principles have broad implications for cellular function.

Auto-segmentation of neck nodal metastases using self-distilled masked image transformer on longitudinal MR images.

Objectives: Auto-segmentation promises greater speed and lower inter-reader variability than manual segmentations in radiation oncology clinical practice. This study aims to implement and evaluate the accuracy of the auto-segmentation algorithm, "Masked Image modeling using the vision Transformers (SMIT)," for neck nodal metastases on longitudinal T2-weighted (T2w) MR images in oropharyngeal squamous cell carcinoma (OPSCC) patients. Methods: This prospective clinical trial study included 123 human papillomaviruses (HPV-positive [+]) related OSPCC patients who received concurrent chemoradiotherapy. T2w MR images were acquired on 3 T at pre-treatment (Tx), week 0, and intra-Tx weeks (1-3). Manual delineations of metastatic neck nodes from 123 OPSCC patients were used for the SMIT auto-segmentation, and total tumor volumes were calculated. Standard statistical analyses compared contour volumes from SMIT vs manual segmentation (Wilcoxon signed-rank test [WSRT]), and Spearman's rank correlation coefficients (ρ) were computed. Segmentation accuracy was evaluated on the test data set using the dice similarity coefficient (DSC) metric value. P-values <0.05 were considered significant. Results: No significant difference in manual and SMIT delineated tumor volume at pre-Tx (8.68 ± 7.15 vs 8.38 ± 7.01 cm3, P = 0.26 [WSRT]), and the Bland-Altman method established the limits of agreement as -1.71 to 2.31 cm3, with a mean difference of 0.30 cm3. SMIT model and manually delineated tumor volume estimates were highly correlated (ρ = 0.84-0.96, P < 0.001). The mean DSC metric values were 0.86, 0.85, 0.77, and 0.79 at the pre-Tx and intra-Tx weeks (1-3), respectively. Conclusions: The SMIT algorithm provides sufficient segmentation accuracy for oncological applications in HPV+ OPSCC. Advances in knowledge: First evaluation of auto-segmentation with SMIT using longitudinal T2w MRI in HPV+ OPSCC.

High-Volume Hospital Had Lower Mortality of Severe Intracerebral Hemorrhage Patients.

Objective: Intracerebral hemorrhage (ICH) accompanies higher mortality rates than other type of stroke. This study aimed to investigate the association between hospital volume and mortality for cases of ICH. Methods: We used nationwide data from 2013 to 2018 to compare high-volume hospitals (≥32 admissions/year) and low-volume hospitals (<32 admissions/year). We tracked patients' survival at 3-month, 1-year, 2-year, and 4-year endpoints. The survival of ICH patients was analyzed at 3-month, 1-year, 2-year, and 4-year endpoints using Kaplan-Meier survival analysis. Multivariable logistic regression analysis and Cox regression analysis were performed to determine predictive factors of poor outcomes at discharge and death. Results: Among 9,086 ICH patients who admitted to hospital during 18-month period, 6,756 (74.4%) and 2,330 (25.6%) patients were admitted to high-volume and low-volume hospitals. The mortality of total ICH patients was 18.25%, 23.87%, 27.88%, and 35.74% at the 3-month, 1-year, 2-year, and 4-year, respectively. In multivariate logistic analysis, high-volume hospitals had lower poor functional outcome at discharge than low-volume hospitals (odds ratio, 0.80; 95% confidence interval, 0.72-0.91; p < 0.001). In the Cox analysis, high-volume hospitals had significantly lower 3-month, 1-year, 2-year, and 4-year mortality than low-volume hospitals (p < 0.05). Conclusion: The poor outcome at discharge, short- and long-term mortality in ICH patients differed according to hospital volume. High-volume hospitals showed lower rates of mortality for ICH patients, particularly those with severe clinical status.

Hypoxia-Directed Treatment of Human Papillomavirus-Related Oropharyngeal Carcinoma.

PURPOSE: Standard curative-intent chemoradiotherapy for human papillomavirus (HPV)-related oropharyngeal carcinoma results in significant toxicity. Since hypoxic tumors are radioresistant, we posited that the aerobic state of a tumor could identify patients eligible for de-escalation of chemoradiotherapy while maintaining treatment efficacy. METHODS: We enrolled patients with HPV-related oropharyngeal carcinoma to receive de-escalated definitive chemoradiotherapy in a phase II study (ClinicalTrials.gov identifier: NCT03323463). Patients first underwent surgical removal of disease at their primary site, but not of gross disease in the neck. A baseline 18F-fluoromisonidazole positron emission tomography scan was used to measure tumor hypoxia and was repeated 1-2 weeks intratreatment. Patients with nonhypoxic tumors received 30 Gy (3 weeks) with chemotherapy, whereas those with hypoxic tumors received standard chemoradiotherapy to 70 Gy (7 weeks). The primary objective was achieving a 2-year locoregional control (LRC) of 95% with a 7% noninferiority margin. RESULTS: One hundred fifty-eight patients with T0-2/N1-N2c were enrolled, of which 152 patients were eligible for analyses. Of these, 128 patients met criteria for 30 Gy and 24 patients received 70 Gy. The 2-year LRC was 94.7% (95% CI, 89.8 to 97.7), meeting our primary objective. With a median follow-up time of 38.3 (range, 22.1-58.4) months, the 2-year progression-free survival (PFS) and overall survival (OS) rates were 94% and 100%, respectively, for the 30-Gy cohort. The 70-Gy cohort had similar 2-year PFS and OS rates at 96% and 96%, respectively. Acute grade 3-4 adverse events were more common in 70 Gy versus 30 Gy (58.3% v 32%; P = .02). Late grade 3-4 adverse events only occurred in the 70-Gy cohort, in which 4.5% complained of late dysphagia. CONCLUSION: Tumor hypoxia is a promising approach to direct dosing of curative-intent chemoradiotherapy for HPV-related carcinomas with preserved efficacy and substantially reduced toxicity that requires further investigation.

Noise robustness and metabolic load determine the principles of central dogma regulation.

The processes of gene expression are inherently stochastic, even for essential genes required for growth. How does the cell maximize fitness in light of noise? To answer this question, we build a mathematical model to explore the trade-off between metabolic load and growth robustness. The model predicts novel principles of central dogma regulation: Optimal protein expression levels for many genes are in vast overabundance. Essential genes are transcribed above a lower limit of one message per cell cycle. Gene expression is achieved by load balancing between transcription and translation. We present evidence that each of these novel regulatory principles is observed. These results reveal that robustness and metabolic load determine the global regulatory principles that govern central dogma processes, and these principles have broad implications for cellular function.

Comprehensive and accurate genome analysis at scale using DRAGEN accelerated algorithms.

Research and medical genomics require comprehensive and scalable solutions to drive the discovery of novel disease targets, evolutionary drivers, and genetic markers with clinical significance. This necessitates a framework to identify all types of variants independent of their size (e.g., SNV/SV) or location (e.g., repeats). Here we present DRAGEN that utilizes novel methods based on multigenomes, hardware acceleration, and machine learning based variant detection to provide novel insights into individual genomes with ~30min computation time (from raw reads to variant detection). DRAGEN outperforms all other state-of-the-art methods in speed and accuracy across all variant types (SNV, indel, STR, SV, CNV) and further incorporates specialized methods to obtain key insights in medically relevant genes (e.g., HLA, SMN, GBA). We showcase DRAGEN across 3,202 genomes and demonstrate its scalability, accuracy, and innovations to further advance the integration of comprehensive genomics for research and medical applications.

Concurrent carboplatin and paclitaxel definitive radiation therapy for locally advanced head and neck cancer.

BACKGROUND: We report the outcomes of cisplatin-ineligible HNSCC patients treated with definitive chemoradiation and concurrent carboplatin and paclitaxel. MATERIALS AND METHODS: We included consecutive HNSCC patients treated from 2013 to 2021 that received definitive chemoradiation with carboplatin and paclitaxel. Locoregional recurrences (LRR) and distant metastases (DM) were estimated using cumulative incidence functions. Progression free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier methods. RESULTS: Sixty-five patients were identified with median age of 71 years (range 44-85). Median radiation dose was 70 Gy and the median doses of carboplatin and paclitaxel were AUC 1 and 40 mg/m2 , respectively. At a median follow-up of 29 (range 5-91) months, the 2-year rates of LRR, DM, PFS, and OS were 8.8%, 9.4%, 72.2%, and 88.7%, respectively. In total, there were 5 LRR, 7 DM, and 12 deaths. CONCLUSIONS: Chemoradiation with carboplatin and paclitaxel is an excellent option for cisplatin-ineligible HNSCC patients.

Proton Therapy Outcomes for Head and Neck Cutaneous Melanoma: Proton Collaborative Group Analysis.

Purpose: Reports of proton beam therapy (PBT) utilization for cutaneous melanoma of the head and neck (HN) region is virtually non-existent. This study reports on the efficacy and acute toxicities of PBT for primary HN cutaneous melanoma. Materials and Methods: We queried the prospectively collected, multi-institutional Proton Collaborative Group registry for all consecutive patients with HN cutaneous melanoma receiving PBT from May 2010 to December 2019. Kaplan-Meier methods were used to estimate overall survival (OS), progression free survival (PFS), and local regional recurrence free survival (LRFS). Toxicity was reported per CTCAE version 4.0. Results: A total of 8 patients were identified with a median age of 69 (range, 37-88). All patients (100%) underwent surgery followed with postoperative PBT. There were 3 patients (37.5%) with T3 or T4 disease and 4 (50%) with N2 or N3 disease. The median radiation dose was 46 GyRBE (range, 27-70) and median dose per fraction was 2.4 GyRBE (range, 2.0-6.0) with the most common dose fractionation being 44 or 48 GyRBE in 20 fractions (n = 4). At a median follow-up of 40.1 months (range, 1.6-62.4) the 1 and 3 year OS rates were 85.7% and 35.7%, respectively. The median PFS was 25.40 months (95% CI, 2.53-58.70) while PFS at 1 year and 3 years was 85.7% and 35.7%, respectively. LRFS was 100% at 1 year and 85.7% at 3 years. Five of the 8 patients developed distant metastases, of which 3 received immunotherapy. Acute G2+ and G3+ toxicities occurred in 5 of 8 patients and 2 of 8 patients, respectively. G3 toxicities included radiation dermatitis (n = 1) and immunotherapy-related rash (n = 1). No G4+ toxicities were reported. Conclusion: Single modality PBT for HN melanomas in the definitive setting provides effective and durable local control rates with tolerable acute toxicity. Distant failure remains the primary pattern of failure.

Change of mortality of patients with acute ischemic stroke before and after 2015.

Introduction: Advances in the diagnosis and management of acute ischemic stroke (AIS) and the increased use of mechanical thrombectomy (MT) have improved the quality of care and prognosis of patients with AIS since 2015. We investigated the changing trends in mortality of patients with AIS in Korea before and after 2015. Materials and methods: A retrospective cohort study was conducted using combined anonymized data from the Acute Stroke Assessment Registry of Korea and the Health Insurance Review & Assessment Service database. Patients with ischemic stroke with precise onset time and initial National Institute of Health Stroke Scale records were included. Results: Patients receiving MT treatment increased from 256 (2.7%) pre-2015 to 1,037 (3.9%) post-2015 (p < 0.001). Overall mortality significantly decreased from pre-2015 to post-2015. In pre-2015, intravenous thrombolysis (IVT) administered within 2 h significantly reduced 3-month mortality when compared with non-IVT. While, in post-2015, IVT administered within 2 h significantly reduced the 3-month, 1-year, 2-year, and 4-year mortality (p < 0.05). MT only reduced 1-year mortality pre-2015; however, MT significantly reduced the 3-month, 1-year, and 2-year mortality post-2015 (p < 0.05). Post-stroke antiplatelet and anticoagulant drugs significantly reduced the 3-month, 1-year, 2-year, and 4-year mortality post-2015. Discussion: Since 2015, faster IVT has significantly reduced the short- and long-term mortality in patients with AIS; MT reduced the 3-month, 1-year, and 2-year mortality. Post-stroke antithrombotic medication has significantly lowered the 2- and 4-year mortality since 2015. Conclusions: Changing trends in AIS management since 2015 have improved the prognosis of patients with AIS.

Epileptiform activity predicts epileptogenesis in cerebral hemorrhage.

This retrospective case-controlled study was performed to evaluate whether Epileptiform Activity, suspected clinical seizures, and/or 2HELPS2B/S after nontraumatic Intraparenchymal Hemorrhage or Subarachnoid Hemorrhage can predict Epilepsy. Hundred and thirty-two patients were included-29 (Epilepsy), 103 (Control Group). After matching, the average effect for all three risk factors was significant as follows: (1) Epileptiform Activity (p = 0.012, odds ratio 3.14), (2) suspected seizures (p = 0.021, odds ratio 3.78), and (3) 2HELPS2B/S score (p < 0.001, odds ratio 4.94). This study shows that Epileptiform Activity, suspected seizures, and particularly, the 2HELPS2B/S score in the acute phase are risk factors for the development of epilepsy after nontraumatic intraparenchymal and subarachnoid hemorrhage.

Short- and long-term mortality of subarachnoid hemorrhage according to hospital volume and severity using a nationwide multicenter registry study.

Introduction: Recent improvements in treatment for subarachnoid hemorrhage (SAH) have decreased the mortality rates; however, the outcomes of SAH management are dependent on many other factors. In this study, we used nationwide, large-scale, observational data to investigate short- and long-term mortality rates after SAH treatment and the influence of patient severity and hospital volume. Patients and methods: We selected patients with SAH treated with clipping and coiling from the South Korean Acute Stroke Assessment Registry. High- and low-volume hospitals performed ≥20 clipping and coiling procedures and <20 clipping and coiling procedures per year, respectively. Short- and long-term mortality were tracked using data from the Health Insurance Review and Assessment Service. Results: Among 2,634 patients treated using clipping and coiling, 1,544 (58.6%) and 1,090 (41.4%) were hospitalized in high- and low-volume hospitals, respectively, and 910 (34.5%) and 1,724 (65.5%) were treated with clipping and coiling, respectively. Mortality rates were 13.5, 14.4, 15.2, and 16.1% at 3 months, 1, 2, and 4 years, respectively. High-volume hospitals had a significantly lower 3-month mortality rate. Patients with mild clinical status had a significantly lower 3-month mortality rate in high-volume hospitals than in low-volume hospitals. Patients with severe clinical status had significantly lower 1- and 2-year mortality rates in high-volume hospitals than in low-volume hospitals. Conclusion: Short- and long-term mortality in patients with SAH differed according to hospital volume. In the modern endovascular era, clipping and coiling can lead to better outcomes in facilities with high stroke-care capabilities.

Hospital Lawsuits Over Unpaid Bills Increased By 37 Percent In Wisconsin From 2001 To 2018.

We analyzed Wisconsin court records from the period 2001-18 to document trends in hospital lawsuits to recover patients' unpaid medical bills. These lawsuits increased 37 percent during this period, from 1.12 per 1,000 residents in 2001 to 1.53 per 1,000 residents in 2018, with lawsuits being disproportionately directed at Black patients and patients living in poorer and less densely populated counties.

Metastatic Testicular Embryonal Carcinoma Presenting as Gastrointestinal Hemorrhage.

Testicular cancer is the most common malignancy in men aged 20-35 years, usually presenting with painless scrotal swelling. Metastases, should they occur, frequently involve retroperitoneal lymph nodes, which drain the testes. Gastrointestinal (GI) metastases are rare, and metastatic disease may not initially be considered in a young man presenting with GI hemorrhage. This case demonstrates the importance of evaluating for a primary underlying malignancy, especially if other causes of GI hemorrhage have been ruled out. Testicular primary should additionally be considered in men because early intervention may often lead to improved clinical outcomes.

Optimal surgical timing and radiotherapy dose for trimodality therapy in locally advanced non-small cell lung cancer.

PURPOSE/OBJECTIVES: Data are conflicting on the effects of time interval from neoadjuvant chemoradiation (NCRT) to surgery for locally advanced non-small-cell lung cancer (LA-NSCLC). This study investigated the impact of surgical timing after NCRT and radiation dose on postoperative mortality and overall survival (OS). MATERIALS AND METHODS: Using the National Cancer Database, we identified 3489 LA-NSCLC patients treated with NCRT and surgery. Multivariate Cox proportional hazards analysis (MVA) was used to examine the effects of surgery >7 weeks from NCRT completion on OS. Propensity score (PS)-matched survival analysis for surgery ≤7 and >7 weeks was performed. Postoperative mortality was assessed. RESULTS: Median OS for surgery ≤7 weeks and >7 weeks after NCRT were 56.9 versus 45.6 months (hazard ratio, HR 1.18 [1.07-1.30]; p < 0.001). Surgery >7 weeks correlated with decreased OS on MVA (HR 1.15 [1.04-1.27]; p = 0.009) and PS matching (HR 1.16 [1.049-1.29]; p = 0.004). Time as a continuous variable correlated with OS on MVA (HR 1.003 [1.001-1.006]; p = 0.0056) and PS matching (HR 1.004 [1.001-1.006]; p = 0.004). Among 2902 lobectomy patients, the mortality rate for surgery ≤66 days was 5.2% versus 8.1% for >66 days (MVA HR 1.59 [1.02-2.49]; p = 0.04). Higher neoadjuvant radiotherapy dose correlated with surgery >7 weeks and lobectomy >66 days on MVA. CONCLUSIONS: Increased interval >7 weeks from NCRT to surgery for LA-NSCLC is correlated with worse OS and lobectomy ≤66 days correlated with improved OS. Surgery ≤7weeks may improve tumor control, whereas higher mortality for surgery >66 days may relate to late NCRT manifestations. Neoadjuvant doses of 44-50.4 Gy may minimize risks of radiation-induced lung injury and surgical complications and facilitate surgery within the optimal 7-week interval.

Interactions Between Enhanced Polygenic Risk Scores and Lifestyle for Cardiovascular Disease, Diabetes, and Lipid Levels.

BACKGROUND: Both lifestyle and genetic factors confer risk for cardiovascular diseases, type 2 diabetes, and dyslipidemia. However, the interactions between these 2 groups of risk factors were not comprehensively understood due to previous poor estimation of genetic risk. Here we set out to develop enhanced polygenic risk scores (PRS) and systematically investigate multiplicative and additive interactions between PRS and lifestyle for coronary artery disease, atrial fibrillation, type 2 diabetes, total cholesterol, triglyceride, and LDL-cholesterol. METHODS: Our study included 276 096 unrelated White British participants from the UK Biobank. We investigated several PRS methods (P+T, LDpred, PRS continuous shrinkage, and AnnoPred) and showed that AnnoPred achieved consistently improved prediction accuracy for all 6 diseases/traits. With enhanced PRS and combined lifestyle status categorized by smoking, body mass index, physical activity, and diet, we investigated both multiplicative and additive interactions between PRS and lifestyle using regression models. RESULTS: We observed that healthy lifestyle reduced disease incidence by similar multiplicative magnitude across different PRS groups. The absolute risk reduction from lifestyle adherence was, however, significantly greater in individuals with higher PRS. Specifically, for type 2 diabetes, the absolute risk reduction from lifestyle adherence was 12.4% (95% CI, 10.0%-14.9%) in the top 1% PRS versus 2.8% (95% CI, 2.3%-3.3%) in the bottom PRS decile, leading to a ratio of >4.4. We also observed a significant interaction effect between PRS and lifestyle on triglyceride level. CONCLUSIONS: By leveraging functional annotations, AnnoPred outperforms state-of-the-art methods on quantifying genetic risk through PRS. Our analyses based on enhanced PRS suggest that individuals with high genetic risk may derive similar relative but greater absolute benefit from lifestyle adherence.

Brachytherapy of the head and neck: An University of California Los Angeles guide to morbidity reduction.

The head and neck (H&N) region is among the most intricate and functional part of our anatomy. Major functional nerves and blood vessels with importance that affect the entire body emanate from the base of skull. Brachytherapy plays an important role as a single modality therapy in early cancer of the lip and oral cavity and a supplemental role in the pharynx or in advanced or recurrent disease. Morbidity in the H&N is intensely personal and disabling. Its avoidance is critical in determining the success or failure of a treatment program, and it is essential to preservation of quality of life. This article summarizes the current literature regarding morbidity related to H&N brachytherapy to aid patients and physicians to achieve optimal outcomes.

Oral IBGard™ Before Colonoscopy: A Single-Center Double-Blinded, Randomized, Placebo-Controlled Trial.

BACKGROUND: Peppermint oil is well known to inhibit smooth muscle contractions, and its topical administration during colonoscopy is reported to reduce colonic spasms. AIMS: We aimed to assess whether oral administration of IBGard™, a sustained-release peppermint oil formulation, before colonoscopy reduces spasms and improves adenoma detection rate (ADR).  METHODS: We performed a single-center randomized, double-blinded, placebo-controlled trial. Patients undergoing screening or surveillance colonoscopies were randomized to receive IBGard™ or placebo. The endoscopist graded spasms during insertion, inspection, and polypectomy. Bowel preparation, procedure time, and time of drug administration were documented. Statistical analysis was performed using the Student's t test and Wilcoxon rank-sum test. RESULTS: There was no significant difference in baseline characteristics or dose-timing distribution between IBGard™ and placebo groups. Similarly, there was no difference in ADR (IBGard™ = 47.8%, placebo = 43.1%, p = 0.51), intubation spasm score (1.23 vs 1.2, p = 0.9), withdrawal spasm score (1.3 vs 1.23, p = 0.72), or polypectomy spasm score (0.52 vs 0.46, p = 0.69). Limiting the analysis to patients who received the drug more than 60 min prior to the start of the procedure did not produce any significant differences in these endpoints. CONCLUSIONS: This randomized controlled trial failed to show benefit of orally administered IBGard™ prior to colonoscopy on the presence of colonic spasms or ADR. Because of its low barrier to widespread adoption, the use of appropriately formulated and timed oral peppermint oil warrants further study to determine its efficacy in reducing colonic spasms and improving colonoscopy quality.

Treatment interruptions affect biochemical failure rates in prostate cancer patients treated with proton beam therapy: Report from the multi-institutional proton collaborative group registry.

INTRODUCTION: To date, no studies examining the effect of treatment interruptions (TI) with proton beam therapy (PBT) have been published. The goal of our study was to determine the predictors of TI amongst patients with prostate cancer (PCa) treated with PBT and to determine whether TI are associated with biochemical failure (BF). We hypothesized that any correlation between TI and biochemical control would be more pronounced in high risk groups. METHODS: Data for 4278 patients with PCa was obtained from the prospectively collected Proton Collaborative Group (PCG) data registry. Univariate and multivariate logistic regression analysis (MVA) was used to model possible predictors of BF. A subset analysis was performed for high risk patients treated with ADT and PBT. Finally, propensity score (PS) analysis was performed to account for any indication bias caused by lack of randomization. RESULTS: Total treatment duration (OR, 1.05 [1.04-1.06]; p < 0.001) increased the likelihood of TI on MVA. TI did not have a statistically significant correlation with BF (OR, 1.44 [0.86-2.39]; p = 0.162) amongst PS matched patients. However, on subset analyses of high risk group patients with PS matching, there was a trend towards worse BF in patients with TI (OR 3.85; 95%CI (0.96-15.44); p = 0.057). CONCLUSION: In the first analysis of its kind, the results suggest that TI in high risk PCa patients treated with PBT and ADT have worse BF rates. Interventions such as increased patient education, proper maintenance of proton facilities, and decreasing total treatment duration with alternative fractionation schedules may help avoid the unintended negative effects on tumor control due to TI. However, future analyses on a larger patient population is needed.