Search NASA⌕ Search

SEARCH · Search NASA

Results for “Multivariate Analysis”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
DOE OSTI2015

Evaluation of the Risk of Grade 3 Oral and Pharyngeal Dysphagia Using Atlas-Based Method and Multivariate Analyses of Individual Patient Dose Distributions

Purpose: The study aimed to apply the atlas of complication incidence (ACI) method to patients receiving radical treatment for head and neck squamous cell carcinomas (HNSCC), to generate constraints based on dose-volume histograms (DVHs), and to identify clinical and dosimetric parameters that predict the risk of grade 3 oral mucositis (g3OM) and pharyngeal dysphagia (g3PD). Methods and Materials: Oral and pharyngeal mucosal DVHs were generated for 253 patients who received radiation (RT) or chemoradiation (CRT). They were used to produce ACI for g3OM and g3PD. Multivariate analysis (MVA) of the effect of dosimetry, clinical, and patient-related variables was performed using logistic regression and bootstrapping. Receiver operating curve (ROC) analysis was also performed, and the Youden index was used to find volume constraints that discriminated between volumes that predicted for toxicity. Results: We derived statistically significant dose-volume constraints for g3OM over the range v28 to v70. Only 3 statistically significant constraints were derived for g3PD v67, v68, and v69. On MVA, mean dose to the oral mucosa predicted for g3OM and concomitant chemotherapy and mean dose to the inferior constrictor (IC) predicted for g3PD. Conclusions: We have used the ACI method to evaluate incidences of g3OM and g3PD and ROC analysis to generate constraints to predict g3OM and g3PD derived from entire individual patient DVHs. On MVA, the strongest predictors were radiation dose (for g3OM) and concomitant chemotherapy (for g3PD).

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Macroscopic Hematuria After Conventional or Hypofractionated Radiation Therapy: Results From a Prospective Phase 3 Study

Purpose: To assess the macroscopic hematuria rates within a single-institution randomized phase 3 trial comparing dose-escalated, conventionally fractionated radiation therapy (CFRT) and moderately hypofractionated radiation therapy (MHRT) for localized prostate cancer. Methods and Materials: Patients with intermediate- to high-risk localized prostate cancer were treated with conformal RT and short-course androgen deprivation. Both the prostate and the entire seminal vesicles were treated to 80 Gy in 40 fractions over 8 weeks (CFRT) or 62 Gy in 20 fractions over 5 weeks (MHRT). The endpoint of the present study was the development of any episode or grade of macroscopic hematuria. The median follow-up period was 93 months (range 6-143). Results: Macroscopic hematuria was reported by 25 of 168 patients (14.9%). The actuarial estimate of hematuria at 8 years was 17.0% (95% confidence interval [CI] 10.7%-23.3%). The number of patients with hematuria was 6 and 19 in the CFRT and MHRT arms, respectively, for an actuarial 8-year estimate of 9.7% and 24.3%, respectively (hazard ratio 3.468, 95% CI 1.385-8.684; P=.008). Overall, 8 of 25 patients were found to have biopsy-proven urothelial carcinoma (3 in the CFRT arm and 5 in the MHRT arm; P=.27). Thus, the 8-year actuarial incidence of macroscopic hematuria (after censoring urothelial cancer–related episodes) was 4.1% and 18.2% after CFRT and MHRT, respectively (hazard ratio 4.961, 95% CI 1.426-17.263; P=.012). The results were confirmed by multivariate analysis after accounting for several patient-, treatment-, and tumor-related covariates. Conclusions: MHRT was associated with a statistically significant increased risk of macroscopic hematuria compared with CFRT.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Institutional, Retrospective Analysis of 777 Patients With Brain Metastases: Treatment Outcomes and Diagnosis-Specific Prognostic Factors

Purpose: To retrospectively evaluate the prognostic factors and survival of a series of 777 patients with brain metastases (BM) from a single institution. Methods and Materials: Patients were treated with surgery followed by whole-brain radiation therapy (WBRT) or with WBRT alone in 16.3% and 83.7% of the cases, respectively. The patients were RPA (recursive partitioning analysis) class I, II, and III in 11.2%, 69.6%, and 18.4% of the cases, respectively; RPA class II-a, II-b, and II-c in 8.3%, 24.8%, and 66.9% of the cases, respectively; and with GPA (graded prognostic assessment) scores of 0-1.0, 1.5-2.0, 2.5-3.0, and 3.5-4.0 in 35%, 27.5%, 18.2%, and 8.6% of the cases, respectively. Results: The median overall survival (OS) times according to RPA class I, II, and III were 20.1, 5.1, and 1.3 months, respectively (P<.0001); according to RPA class II-a, II-b, II-c: 9.1, 8.9, and 4.0 months, respectively (P<.0001); and according to GPA score 0-1.0, 1.5-2.0, 2.5-3.0, and 3.5-4.0: 2.5, 4.4, 9.0, and 19.1 months, respectively (P<.0001). By multivariate analysis, the favorable independent prognostic factors for survival were as follows: for gastrointestinal tumor, a high Karnofsky performance status (KPS) (P=.0003) and an absence of extracranial metastases (ECM) (P=.003); for kidney cancer, few BM (P=.002); for melanoma, few BM (P=.01), an absence of ECM (P=.002), and few ECM (P=.0002); for lung cancer, age (P=.007), a high KPS (P<.0001), an absence of ECM (P<.0001), few ECM and BM (P<.0001 and P=.0006, respectively), and control of the primary tumor (P=.004); and for breast cancer, age (P=.001), a high KPS (P=.007), control of the primary tumor (P=.05), and few ECM and BM (P=.01 and P=.0002, respectively). The triple-negative subtype was a significant unfavorable factor (P=.007). Conclusion: Prognostic factors varied by pathology. Our analysis confirms the strength of prognostic factors used to determine the GPA score, including the genetic subtype for breast cancer.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2011

Dose Constraint for Minimizing Grade 2 Rectal Bleeding Following Brachytherapy Combined With External Beam Radiotherapy for Localized Prostate Cancer: Rectal Dose-Volume Histogram Analysis of 457 Patients

Purpose: To determine the rectal tolerance to Grade 2 rectal bleeding after I-125 seed brachytherapy combined with external beam radiotherapy (EBRT), based on the rectal dose-volume histogram. Methods and Materials: A total of 458 consecutive patients with stages T1 to T3 prostate cancer received combined modality treatment consisting of I-125 seed implantation followed by EBRT to the prostate and seminal vesicles. The prescribed doses of brachytherapy and EBRT were 100 Gy and 45 Gy in 25 fractions, respectively. The rectal dosimetric factors were analyzed for rectal volumes receiving >100 Gy and >150 Gy (R100 and R150) during brachytherapy and for rectal volumes receiving >30 Gy to 40 Gy (V30-V40) during EBRT therapy in 373 patients for whom datasets were available. The patients were followed from 21 to 72 months (median, 45 months) after the I-125 seed implantation. Results: Forty-four patients (9.7%) developed Grade 2 rectal bleeding. On multivariate analysis, age (p = 0.014), R100 (p = 0.002), and V30 (p = 0.001) were identified as risk factors for Grade 2 rectal bleeding. The rectal bleeding rate increased as the R100 increased: 5.0% (2/40 patients) for 0 ml; 7.5% (20/267 patients) for >0 to 0.5 ml; 11.0% (11/100 patients) for >0.5 to 1 ml; 17.9% (5/28 patients) for >1 to 1.5 ml; and 27.3% (6/22 patients) for >1.5 ml (p = 0.014). Grade 2 rectal bleeding developed in 6.4% (12/188) of patients with a V30 {<=}35% and in 14.1% (26/185) of patients with a V30 >35% (p = 0.02). When these dose-volume parameters were considered in combination, the Grade 2 rectal bleeding rate was 4.2% (5/120 patients) for a R100 {<=}0.5 ml and a V30 {<=}35%, whereas it was 22.4% (13/58 patients) for R100 of >0.5 ml and V30 of >35%. Conclusion: The risk of rectal bleeding was found to be significantly volume-dependent in patients with prostate cancer who received combined modality treatment. Rectal dose-volume analysis is a practical method for predicting the risk of development of Grade 2 rectal bleeding.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Predisposing Factors of Liver Necrosis after Transcatheter Arterial Chemoembolization in Liver Metastases from Neuroendocrine Tumor

PurposeTo investigate predictive factors for liver necrosis after transcatheter arterial chemoembolization (TACE) of neuroendocrine liver metastases.MethodsA total of 164 patients receiving 374 TACE were reviewed retrospectively to analyze predictive factors of liver necrosis. We analyzed patient age and sex; metastasis number and location; percentage of liver involvement; baseline liver function test; and pretreatment imaging abnormalities such as bile duct dilatation (BDD), portal vein narrowing (PVN), and portal vein thrombosis (PVT). We analyzed TACE technique such as Lipiodol or drug-eluting beads (DEB) as the drug’s vector; dose of chemotherapy; diameter of DEB; and number, frequency, and selectivity of TACE.ResultsLiver necrosis developed after 23 (6.1 %) of 374 TACE. In multivariate analysis, DEB > 300 μm in size induced more liver necrosis compared to Lipiodol (odds ratio [OR] 35.20; p < 0.0001) or with DEB < 300 μm in size (OR 19.95; p < 0.010). Pretreatment BDD (OR 119.64; p < 0.0001) and PVT (OR 9.83; p = 0.030) were predictive of liver necrosis. BDD or PVT responsible for liver necrosis were present before TACE in 59 % (13 of 22) and were induced by a previous TACE in 41 % (9 of 22) of cases.ConclusionDEB > 300 μm in size, BDD, and PVT are responsible for increased rate of liver necrosis after TACE. Careful analysis of BDD or PVT on pretreatment images as well as images taken between two courses can help avoid TACE complications.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2015

Prognostic Relevance of HPV Infection and p16 Overexpression in Squamous Cell Anal Cancer

Purpose: Human papillomavirus (HPV) DNA and p16 status have both been reported as prognostic factors in anal cancer, but the prognostic relevance of combined detection and particularly HPV−/p16+ and HPV+/p16− signatures is unknown. We evaluated combined HPV DNA and p16 status as a prognostic factor of treatment response in anal cancer. Methods: 106 patients treated with radiochemotherapy (RCT+5-FU/MMC) with available paraffin-embedded tumor tissue specimens were evaluated regarding local control (LC) and overall survival (OS) at 5 years. In addition to HPV DNA/p16 status, the influence of age, gender, previous surgery, initial recurrence, T stage, N status, and tumor localization was analyzed. Results: 63 patients were HPV+/p16+, 9 were HPV+/p16−, 11 were HPV−/p16+, and 23 were HPV−/p16−. In univariate analysis, LC was significantly better in patients with T1/2 stage, female gender, and HPV/p16 status. HPV+/p16+ was associated with significantly better LC (88.1%; 95% confidence interval [CI]: 78.89-97.31) compared with HPV−/p16+ (63.6%; 95% CI: 35.18-92.02; P=.021) and especially HPV−/p16− (55.8%; 95% CI: 33.46-78.14; P=.002) but not with HPV+/p16− (77.8%; 95% CI: 50.56-105.04; P=.270). OS was influenced by T stage and LC. HPV+/p16+ patients showed a trend toward better OS compared with HPV−/p16− patients (HPV+/p16+: 81.1%; 95% CI: 70.12-92.08 vs HPV−/p16−: 68.8%; 95%CI: 47.44-90.16; P=.138). On multivariate analysis, T3/4 stage and HPV/p16 status (HPV−/p16+, HPV−/p16− vs HPV+/p16+) predicted poorer LC (T3/4: 50.3% vs T1/2: 86.6%, hazard ratio [HR] 0.22; 95% CI: 0.09-0.53; P<.001; HPV+/p16+ vs HPV−/p16+: HR 4.73; 95% CI: 1.33-16.82; P=.016, and HPV+/p16+ vs HPV−/p16−: HR 6.40; 95% CI: 2.23-18.35; P<.001), whereas local relapse dramatically influenced OS. Conclusion: Our data suggest that HPV/p16 signature determines prognosis. HPV+/p16+ patients had the best prognosis, and HPV−/p16+ and HPV−/p16− patients showed the worst outcome and therefore require therapy optimization, particularly given that LC is the most important factor for OS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

A Dose–Response Analysis of Biochemical Control Outcomes After {sup 125}I Monotherapy for Patients With Favorable-Risk Prostate Cancer

Purpose: To define the optimal dose for {sup 125}I prostate implants by correlating postimplantation dosimetry findings with biochemical failure and toxicity. Methods and Materials: Between 2003 and 2009, 683 patients with prostate cancer were treated with {sup 125}I prostate brachytherapy without supplemental external beam radiation therapy and were followed up for a median time of 80 months. Implant dose was defined as the D90 (the minimal dose received by 90% of the prostate) on postoperative day 1 and 1 month after implantation. Therefore, 2 dosimetric variables (day 1 D90 and day 30 D90) were analyzed for each patient. We investigated the dose effects on biochemical control and toxicity. Results: The 7-year biochemical failure-free survival (BFFS) rate for the group overall was 96.4% according to the Phoenix definition. A multivariate analysis found day 1 D90 and day 30 D90 to be the most significant factors affecting BFFS. The cutoff points for day 1 D90 and day 30 D90, calculated from ROC curves, were 163 Gy and 175 Gy, respectively. By use of univariate analysis, various dosimetric cutoff points for day 30 D90 were tested. We found that day 30 D90 cutoff points from 130 to 180 Gy appeared to be good for the entire cohort. Greater D90s were associated with an increase in late genitourinary or gastrointestinal toxicity ≥ grade 2, but the increase was not statistically significant. Conclusions: Improvements in BFFS rates were seen with increasing D90 levels. Day 30 D90 doses of 130 to 180 Gy were found to serve as cutoff levels. For low-risk and low-tier intermediate-risk prostate cancer patients, high prostate D90s, even with doses exceeding 180 Gy, achieve better treatment results and are feasible.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2012

Primary Tumor Volume Is an Important Predictor of Clinical Outcomes Among Patients With Locally Advanced Squamous Cell Cancer of the Head and Neck Treated With Definitive Chemoradiotherapy

Purpose: The tumor volume has been established as a significant predictor of outcomes among patients with head-and-neck cancer undergoing radiotherapy alone. The present study attempted to add to the existing data on tumor volume as a prognostic factor among patients undergoing chemoradiotherapy. Methods and Materials: A total of 78 patients who had undergone definitive chemoradiotherapy for Stage III-IV squamous cell cancer of the hypopharynx, oropharynx, and larynx were identified. The primary tumor volumes were calculated from the treatment planning computed tomography scans, and these were correlated to the survival and tumor control data obtained from the retrospective analysis. Results: The interval to progression correlated with the primary tumor volume (p = .007). The critical cutoff point for the tumor volume was identified as 35 cm{sup 3}, and patients with a tumor volume <35 cm{sup 3} had a significantly better prognosis than those with a tumor volume >35 cm{sup 3} at 5 years (43% vs. 71%, p = .010). Longer survival was also correlated with smaller primary tumor volumes (p = .022). Similarly, patients with a primary tumor volume <35 cm{sup 3} had a better prognosis in terms of both progression-free survival (61% vs. 33%, p = .004) and overall survival (84% vs. 41%, p = < .001). On multivariate analysis, the primary tumor volume was the best predictor of recurrence (hazard ratio 4.7, 95% confidence interval 1.9-11.6; p = .001) and survival (hazard ratio 10.0, 95% confidence interval 2.9-35.1; p = < .001). In contrast, the T stage and N stage were not significant factors. Analysis of variance revealed that tumors with locoregional failure were on average 21.6 cm{sup 3} larger than tumors without locoregional failure (p = .028) and 27.1-cm{sup 3} larger than tumors that recurred as distant metastases (p = .020). Conclusion: The results of our study have shown that the primary tumor volume is a significant prognostic factor in patients with advanced cancer of the head and neck undergoing definitive chemoradiotherapy and correlated with the treatment outcomes better than the T or N stage.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Local Control and Toxicity in a Large Cohort of Central Lung Tumors Treated With Stereotactic Body Radiation Therapy

Purpose: Stereotactic body radiation therapy (SBRT) in central lung tumors has been associated with higher rates of severe toxicity. We sought to evaluate toxicity and local control in a large cohort and to identify predictive dosimetric parameters. Methods and Materials: We identified patients who received SBRT for central tumors according to either of 2 definitions. Local failure (LF) was estimated using a competing risks model, and multivariate analysis (MVA) was used to assess factors associated with LF. We reviewed patient toxicity and applied Cox proportional hazard analysis and log-rank tests to assess whether dose-volume metrics of normal structures correlated with pulmonary toxicity. Results: One hundred twenty-five patients received SBRT for non-small cell lung cancer (n=103) or metastatic lesions (n=22), using intensity modulated radiation therapy. The most common dose was 45 Gy in 5 fractions. Median follow-up was 17.4 months. Incidence of toxicity ≥ grade 3 was 8.0%, including 5.6% pulmonary toxicity. Sixteen patients (12.8%) experienced esophageal toxicity ≥ grade 2, including 50% of patients in whom PTV overlapped the esophagus. There were 2 treatment-related deaths. Among patients receiving biologically effective dose (BED) ≥80 Gy (n=108), 2-year LF was 21%. On MVA, gross tumor volume (GTV) was significantly associated with LF. None of the studied dose-volume metrics of the lungs, heart, proximal bronchial tree (PBT), or 2 cm expansion of the PBT (“no-fly-zone” [NFZ]) correlated with pulmonary toxicity ≥grade 2. There were no differences in pulmonary toxicity between central tumors located inside the NFZ and those outside the NFZ but with planning target volume (PTV) intersecting the mediastinum. Conclusions: Using moderate doses, SBRT for central lung tumors achieves acceptable local control with low rates of severe toxicity. Dosimetric analysis showed no significant correlation between dose to the lungs, heart, or NFZ and severe pulmonary toxicity. Esophageal toxicity may be an underappreciated risk, particularly when PTV overlaps the esophagus.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

MPC-1 expression in myeloma cells is associated with the efficacy of bortezomib therapy

The use of bortezomib in the clinic has significantly improved outcomes for patients with multiple myeloma (MM), even those harboring high-risk cytogenetic abnormalities or those classified in the high-risk category according to the International Staging System (ISS). In this study, we analyzed the association between immunophenotyping on myeloma cells and the clinical outcomes of patients who received bortezomib-based regimens as first-line therapy. Immunophenotypic analysis before bortezomib therapy was performed by flow cytometry, and whether the immunophenotyping results influenced the clinical outcomes of the patients was investigated. Seventy-four newly diagnosed patients with MM were included in this study. We found that the expression of MPC-1 significantly predicted the time to next therapy (TNT), with a longer TNT in the MPC-1 positive group (p = 0.005), whereas it did not affect overall survival (OS; p = 0.773). In addition, we found that CD45-positivity was associated with shorter TNT (p = 0.0432). Following ISS assessment at treatment initiation, patients who were classified as stage I showed a slightly longer OS compared to those at stage II or III; however, these results were not significant (p = 0.0987). Furthermore, multivariate analysis revealed the prognostic significance of MPC-1 expression, as MPC-1-negativity was associated with a worse TNT. The combination of MPC-1 and CD45 status more sensibly predicted the TNT for bortezomib therapy. Our results demonstrate the clinical importance of immunophenotyping on myeloma cells to determine patient prognoses in this era of novel therapeutic agents.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2017

Analysis of Factors Affecting Successful Clinical Trial Enrollment in the Context of Three Prospective, Randomized, Controlled Trials

Purpose: Challenges can arise when attempting to maximize patient enrollment in clinical trials. There have been limited studies focusing on the barriers to enrollment and the efficacy of alternative study design to improve accrual. We analyzed barriers to clinical trial enrollment, particularly the influence of timing, in context of three prospective, randomized oncology trials where one arm was considered more aggressive than the other. Methods and Materials: From June 2011 to March 2015, patients who were enrolled on 3 prospective institutional protocols (an oligometastatic non-small cell lung cancer [NSCLC] trial and 2 proton vs intensity modulated radiation therapy trials in NSCLC and esophageal cancer) were screened for protocol eligibility. Eligible candidates were approached about trial participation, and patient characteristics (age, sex, T/N categorization) were recorded along with details surrounding trial presentation (appointment number). Fisher's exact test, Student's t tests, and multivariate analysis were performed to assess differences between enrolled and refusal patients. Results: A total of 309 eligible patients were approached about trial enrollment. The enrollment success rate during this time span was 52% (n=160 patients). Enrolled patients were more likely to be presented trial information at an earlier appointment (oligometastatic protocol: 5 vs 3 appointments [P<.001]; NSCLC protocol: 4 vs 3 appointments [P=.0018]; esophageal protocol: 3 vs 2 appointments [P=.0086]). No other factors or patient characteristics significantly affected enrollment success rate. Conclusion: Improvement in enrollment rates for randomized control trials is possible, even in difficult accrual settings. Earlier presentation of trial information to patients is the most influential factor for success and may help overcome accrual barriers without compromising trial design.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Prognostic Importance of Gleason 7 Disease Among Patients Treated With External Beam Radiation Therapy for Prostate Cancer: Results of a Detailed Biopsy Core Analysis

Purpose: To analyze the effect of primary Gleason (pG) grade among a large cohort of Gleason 7 prostate cancer patients treated with external beam radiation therapy (EBRT). Methods and Materials: From May 1989 to January 2011, 1190 Gleason 7 patients with localized prostate cancer were treated with EBRT at a single institution. Of these patients, 613 had a Gleason 7 with a minimum of a sextant biopsy with nonfragmented cores and full biopsy core details available, including number of cores of cancer involved, percentage individual core involvement, location of disease, bilaterality, and presence of perineural invasion. Median follow-up was 6 years (range, 1-16 years). The prognostic implication for the following outcomes was analyzed: biochemical recurrence-free survival (bRFS), distant metastasis-free survival (DMFS), and prostate cancer-specific mortality (PCSM). Results: The 8-year bRFS rate for pG3 versus pG4 was 77.6% versus 61.3% (P<.0001), DMFS was 96.8% versus 84.3% (P<.0001), and PCSM was 3.7% versus 8.1% (P=.002). On multivariate analysis, pG4 predicted for significantly worse outcome in all parameters. Location of disease (apex, base, mid-gland), perineural involvement, maximum individual core involvement, and the number of Gleason 3+3, 3+4, or 4+3 cores did not predict for distant metastases. Conclusions: Primary Gleason grade 4 independently predicts for worse bRFS, DMFS, and PCSM among Gleason 7 patients. Using complete core information can allow clinicians to utilize pG grade as a prognostic factor, despite not having the full pathologic details from a prostatectomy specimen. Future staging and risk grouping should investigate the incorporation of primary Gleason grade when complete biopsy core information is used.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Validating a Local Failure Risk Stratification for Use in Prospective Studies of Adjuvant Radiation Therapy for Bladder Cancer

Purpose: To inform prospective trials of adjuvant radiation therapy (adj-RT) for bladder cancer after radical cystectomy, a locoregional failure (LF) risk stratification was proposed. This stratification was developed and validated using surgical databases that may not reflect the outcomes expected in prospective trials. Our purpose was to assess sources of bias that may affect the stratification model's validity or alter the LF risk estimates for each subgroup: time bias due to evolving surgical techniques; trial accrual bias due to inclusion of patients who would be ineligible for adj-RT trials because of early disease progression, death, or loss to follow-up shortly after cystectomy; bias due to different statistical methods to estimate LF; and subgrouping bias due to different definitions of the LF subgroups. Methods and Materials: The LF risk stratification was developed using a single-institution cohort (n=442, 1990-2008) and the multi-institutional SWOG 8710 cohort (n=264, 1987-1998) treated with radical cystectomy with or without chemotherapy. We evaluated the sensitivity of the stratification to sources of bias using Fine-Gray regression and Kaplan-Meier analyses. Results: Year of radical cystectomy was not associated with LF risk on univariate or multivariate analysis after controlling for risk group. By use of more stringent inclusion criteria, 26 SWOG patients (10%) and 60 patients from the single-institution cohort (14%) were excluded. Analysis of the remaining patients confirmed 3 subgroups with significantly different LF risks with 3-year rates of 7%, 17%, and 36%, respectively (P<.01), nearly identical to the rates without correcting for trial accrual bias. Kaplan-Meier techniques estimated higher subgroup LF rates than competing risk analysis. The subgroup definitions used in the NRG-GU001 adj-RT trial were validated. Conclusions: These sources of bias did not invalidate the LF risk stratification or substantially change the model's LF estimates.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2016

Short-term toxicity assessments of an antibiotic metabolite in Wistar rats and its metabonomics analysis by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

4-Epi-oxytetracycline (4-EOTC), one of main oxytetracycline (OTC) metabolites, can be commonly detected in food and environment. The toxicity and effects of OTC on animals have been well characterized; however, its metabolites have never been studied systemically. This study aims to investigate 15-day oral dose toxicity and urine metabonomics changes of 4-EOTC after repeated administration in Wistar rats at daily doses of 0.5, 5.0 and 50.0 mg/kg bw (bodyweight). Hematology and clinical chemistry parameters, including white blood cell count, red blood cell count, total protein, globulin and albumin/globulin, were obviously altered in rats of 5.0 and 50.0 mg/kg bw. Histopathology changes of kidney and liver tissues were also observed in high-dose groups. Urinary metabolites from all groups were analyzed using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Seventeen metabolites contributing to the clusters were identified as potential biomarkers from multivariate analysis, including aminoadipic acid, 6-phosphogluconate, sebacic acid, pipecolic acid, etc. The significant changes of these biomarkers demonstrated metabonomic variations in treated rats, especially lysine and purine metabolism. For the first time in this paper, we combined the results of toxicity and metabonomics induced by 4-EOTC for the serious reconsideration of the safety and potential risks of antibiotics and its degradation metabolites. - Highlights: • 4-Epioxytetracycline (4-EOTC) induced damages in liver and kidney. • Metabonomics changes especially amino acid and purine metabolism were observed. • Security of OTC metabolite 4-EOTC should be taken into serious reconsideration.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Rectal Toxicity After Proton Therapy For Prostate Cancer: An Analysis of Outcomes of Prospective Studies Conducted at the University of Florida Proton Therapy Institute

Purpose: Study goals were to characterize gastrointestinal effects of proton therapy (PT) in a large cohort of patients treated for prostate cancer, identify factors associated with rectal bleeding (RB), and compare RB between patients receiving investigational protocols versus those in outcome-tracking protocols. Methods and Materials: A total of 1285 consecutive patients were treated with PT between August 2006 and May 2010. Potential pre-existing clinical and treatment-related risk factors for rectal toxicity were recorded. Common Terminology Criteria for Adverse Events version 3.0 was used to score toxicity. Results: Transient RB was the predominant grade 2 or higher (GR2+) toxicity after PT, accounting for 95% of gastrointestinal events. GR1 RB occurred in 217 patients (16.9%), GR2 RB in 187 patients (14.5%), and GR3 in 11 (0.9%) patients. There were no GR4 or GR5 events. Univariate analyses showed correlations between GR2+ RB and anticoagulation therapy (P=.008) and rectal and rectal wall dose-volume histogram (DVH) parameters (P<.001). On multivariate analysis, anticoagulation therapy (P=.0034), relative volume of rectum receiving 75 Gy (V75; P=.0102), and relative rectal wall V75 (P=.0017) were significant predictors for G2+ RB. Patients treated with investigational protocols had toxicity rates similar to those receiving outcome-tracking protocols. Conclusions: PT was associated with a low rate of GR2+ gastrointestinal toxicity, predominantly transient RB, which was highly correlated with anticoagulation and rectal DVH parameters. Techniques that limit rectal exposure should be used when possible.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2013

Pattern of Retained Contrast on Immediate Postprocedure Computed tomography (CT) After Particle Embolization of Liver Tumors Predicts Subsequent Treatment Response

PurposeTo determine if the pattern of retained contrast on immediate postprocedure computed tomography (CT) after particle embolization of hepatic tumors predicts modified Response Evaluation Criteria in Solid Tumors (mRECIST) response.Materials and MethodsThis study was approved by the Institutional Review Board with a waiver of authorization. One hundred four liver tumors were embolized with spherical embolic agents (Embospheres, Bead Block, LC Bead) and polyvinyl alcohol. Noncontrast CT was performed immediately after embolization to assess contrast retention in the targeted tumors, and treatment response was assessed by mRECIST criteria on follow-up CT (average time 9.0 {+-} 7.7 weeks after embolization). Tumor contrast retention (TCR) was determined based on change in Hounsfield units (HUs) of the index tumors between the preprocedure and immediate postprocedure scans; vascular contrast retention (VCR) was rated; and defects in contrast retention (DCR) were also documented. The morphology of residual enhancing tumor on follow-up CT was described as partial, circumferential, or total. Association between TCR variables and tumor response were assessed using multivariate logistic regression.ResultsOf 104 hepatic tumors, 51 (49 %) tumors had complete response (CR) by mRECIST criteria; 23 (22.1 %) had partial response (PR); 21 (20.2 %) had stable disease (SD); and 9 (8.7 %) had progressive disease (PD). By multivariate analysis, TCR, VCR, and tumor size are independent predictors of CR (p = 0.02, 0.05, and 0.005 respectively). In 75 tumors, DCR was found to be an independent predictor of failure to achieve complete response (p < 0.0001) by imaging criteria.ConclusionTCR, VCR, and DCR on immediate posttreatment CT are independent predictors of CR by mRECIST criteria.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2014

Prospective Coronary Heart Disease Screening in Asymptomatic Hodgkin Lymphoma Patients Using Coronary Computed Tomography Angiography: Results and Risk Factor Analysis

Purpose: To prospectively investigate the coronary artery status using coronary CT angiography (CCTA) in patients with Hodgkin lymphoma treated with combined modalities and mediastinal irradiation. Methods and Materials: All consecutive asymptomatic patients with Hodgkin lymphoma entered the study during follow-up, from August 2007 to May 2012. Coronary CT angiography was performed, and risk factors were recorded along with leukocyte telomere length (LTL) measurements. Results: One hundred seventy-nine patients entered the 5-year study. The median follow-up was 11.6 years (range, 2.1-40.2 years), and the median interval between treatment and the CCTA was 9.5 years (range, 0.5-40 years). Coronary artery abnormalities were demonstrated in 46 patients (26%). Coronary CT angiography abnormalities were detected in nearly 15% of the patients within the first 5 years after treatment. A significant increase (34%) occurred 10 years after treatment (P=.05). Stenoses were mostly nonostial. Severe stenoses were observed in 12 (6.7%) of the patients, entailing surgery with either angioplasty with stent placement or bypass grafting in 10 of them (5.5%). A multivariate analysis demonstrated that age at treatment, hypertension, and hypercholesterolemia, as well as radiation dose to the coronary artery origins, were prognostic factors. In the group of patients with LTL measurements, hypertension and LTL were the only independent risk factors. Conclusions: The findings suggest that CCTA can identify asymptomatic individuals at risk of acute coronary artery disease who might require either preventive or curative measures. Conventional risk factors and the radiation dose to coronary artery origins were independent prognostic factors. The prognostic value of LTL needs further investigation.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Safety and Prognosis of Transarterial Chemoembolization for Octogenarians with Hepatocellular Carcinoma

Purpose: The global population of the aged is escalating. The need of transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC) in patients older than 80 years is on the rise. The aim of this study was to retrospectively evaluate the safety and the prognosis of TACE in octogenarians with HCC. Materials and Methods: From January 2007 to January 2018, 86 octogenarians with HCC initially treated with TACE, who were treatment naïve or had a recurrence after surgery and/or radiofrequency ablation, were enrolled in this study. The adverse events were evaluated. The overall survival (OS) after TACE and causes of death were investigated. The prognostic factors for OS were analyzed using Cox proportional hazard models. Results: Grade 4 adverse events (according to the Common Terminology Criteria for Adverse Event version 4.0) of AST, ALT and tumor rupture were found in 8, 4 and 1 patients, respectively. There were no treatment-related deaths. The 1-, 3- and 5-year overall survival rates were 84.1%, 61.1% and 27.6%, respectively. The overall median survival time was 38.3 months (HR 2.854, 95% CI 32.7–43.8). 56.9% causes of death were HCC or liver dysfunction. Multivariate analysis revealed that performance status (ECOG: 0) was an independent prognostic significant factor (95% CI 1.103–4.573; P = .026). Conclusions: TACE is safe and could improve survival of octogenarians with HCC. Performance status is an important prognosis factor predicting the OS.

62 RADIOLOGY AND NUCLEAR MEDICINE↗