Entity

Time filter

Source Type

Raleigh, NC, United States

Richards A.L.,North Carolina State University | Kleinstreuer C.,North Carolina State University | Kennedy A.S.,Cancer Centers of North Carolina | Childress E.,North Carolina State University | Buckner G.D.,North Carolina State University
IEEE Transactions on Biomedical Engineering | Year: 2012

Recent work employing the computational fluid-particle modeling of the hepatic arteries has identified a correlation between particle release position and downstream branch distribution for direct tumor-targeting in radioembolization procedures. An experimental model has been constructed to evaluate the underlying simulation theory and determine its feasibility for future clinical use. A scaled model of a generalized hepatic system with a single inlet and five outlet branches was fabricated to replicate the fluid dynamics in the hepatic arteries of diseased livers. Assuming steady flow, neutrally buoyant microspheres were released from controlled locations within the inlet of the model and the resulting output distributions were recorded. Fluid and particle transport simulations were conducted with identical parameters. The resulting experimentally and simulation-derived microsphere distributions were compared. The experimental microsphere distribution exhibited a clear dependence on injection location that correlated very strongly with the computationally predicted results. Individual branch targeting was possible for each of the five outputs. The experimental results validate the simulation methodology for achieving targeted microsphere distributions in a known geometry under constant flow conditions. © 2011 IEEE. Source


Regan M.M.,Dana-Farber Cancer Institute | O'Donnell E.K.,Beth Israel Deaconess Medical Center | Kelly W.K.,Yale University | Halabi S.,Duke University | And 5 more authors.
Annals of Oncology | Year: 2010

Background: Docetaxel is associated with prolonged survival in castration-resistant prostate cancer (CRPC). Platinum compounds have modest but distinct single-agent activity. Carboplatin may have greatest potential for benefit when combined with taxanes. We investigated whether there is a subset of patients with CRPC for whom the efficacy of combination taxane-estramustine-carboplatin (TEC) chemotherapy may be greatest. Patients and methods: Individual patient data (n = 310) were obtained from seven trials using TEC chemotherapy. Prostate-specific antigen (PSA) response was defined as ‡50% post-therapy decline from baseline. Overall survival was defined from baseline to death from any cause. Logistic and Cox regression were used to investigate heterogeneity in outcome to TEC by patient and disease characteristics. Predicted survival probabilities were calculated from the Halabi Cancer and Leukemia Group B (CALGB) nomogram. Results: The pooled PSA response proportion was 69% [95% confidence interval (CI) 56% to 80%]. There was no evidence of differential PSA response by disease characteristics. Established prognostic factors were associated with survival. The pooled 12-month survival estimate of 79% (95% CI 71% to 84%) was higher than the median 59% 12-month nomogram-predicted survival. Conclusions: TEC chemotherapy has significant clinical activity in CRPC. A randomized, controlled trial evaluating the addition of carboplatin to taxane-based chemotherapy is needed to elucidate the value of carboplatin in CRPC. © The Author 2009. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. Source


Gibbons J.P.,Mary Bird Perkins Cancer Center | Antolak J.A.,Mayo Medical School | Followill D.S.,University of Texas M. D. Anderson Cancer Center | Huq M.S.,University of Pittsburgh | And 6 more authors.
Medical Physics | Year: 2014

A protocol is presented for the calculation of monitor units (MU) for photon and electron beams, delivered with and without beam modifiers, for constant source-surface distance (SSD) and source-axis distance (SAD) setups. This protocol was written by Task Group 71 of the Therapy Physics Committee of the American Association of Physicists in Medicine (AAPM) and has been formally approved by the AAPM for clinical use. The protocol defines the nomenclature for the dosimetric quantities used in these calculations, along with instructions for their determination and measurement. Calculations are made using the dose per MU under normalization conditions, D0', that is determined for each user's photon and electron beams. For electron beams, the depth of normalization is taken to be the depth of maximum dose along the central axis for the same field incident on a water phantom at the same SSD, where D 0' = 1 cGy/MU. For photon beams, this task group recommends that a normalization depth of 10 cm be selected, where an energy-dependent D 0' ≤ 1 cGy/MU is required. This recommendation differs from the more common approach of a normalization depth of dm, with D 0' = 1 cGy/MU, although both systems are acceptable within the current protocol. For photon beams, the formalism includes the use of blocked fields, physical or dynamic wedges, and (static) multileaf collimation. No formalism is provided for intensity modulated radiation therapy calculations, although some general considerations and a review of current calculation techniques are included. For electron beams, the formalism provides for calculations at the standard and extended SSDs using either an effective SSD or an air-gap correction factor. Example tables and problems are included to illustrate the basic concepts within the presented formalism. © 2014 American Association of Physicists in Medicine. Source


Sonpavde G.,Texas Oncology And Us Oncology Research | Matveev V.,Russian Academy of Medical Sciences | Burke J.M.,Rocky Mountain Cancer Centers | Caton J.R.,Willamette Valley Cancer Center | And 9 more authors.
Annals of Oncology | Year: 2012

Background: AT-101 (A), a small molecule oral inhibitor of the Bcl-2 family, has activity alone and in combination with docetaxel (Taxotere) and prednisone (DP) in metastatic castration-resistant prostate cancer (mCRPC). A randomized, double-blind, placebo-controlled phase II trial compared DP combined with either AT-101 (A) or placebo in chemonaive mCRPC.Patients and methods: Men with progressive mCRPC despite androgen deprivation were eligible and randomized 1 1. Patients received docetaxel (75 mg/m 2 day 1) and prednisone 5 mg orally twice daily every 21 days with either AT-101 (40 mg) or placebo twice daily orally on days 1-3. The primary end point was overall survival (OS).Results: Two hundred and twenty-one patients were randomly assigned. Median OS for AT-101 plus docetaxel-prednisone (ADP) and placebo-DP was 18.1 versus 17.8 months [hazard ratio (HR) 1.07, 95% confidence interval 0.72-1.55, P = 0.63]. Secondary end points were also not statistically different. Grade 3/4 toxic effects for ADP versus placebo-DP were cardiac events (5% versus 2%), lymphopenia (23% versus 16%), neutropenia (47% versus 40%), ileus (2% versus 0%) and pulmonary embolism (6% versus 2%). In a subgroup of high-risk mCRPC (n = 34), outcomes appeared to favor ADP (median OS 19 versus 14 months).Conclusions: AT-101 was tolerable but did not extend OS when combined with DP in mCRPC; a potential benefit was observed in high-risk patients. © The Author 2011. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. Source


Sonpavde G.,Baylor College of Medicine | Pond G.R.,McMaster University | Berry W.R.,Cancer Centers of North Carolina | De Wit R.,Erasmus Medical Center | And 3 more authors.
Cancer | Year: 2011

Background: In men with metastatic castration-resistant prostate cancer (CRPC), the association of measurable tumor responses with overall survival (OS) is unknown. The authors retrospectively evaluated the TAX327 phase 3 trial to study this relation. Methods: Eligible patients for this analysis included those with World Health Organization (WHO)-defined measurable metastatic disease randomized to receive either docetaxel or mitoxantrone. OS was estimated by using the Kaplan-Meier method, and the prognostic relation of WHO-defined radiologic response with OS was performed by using Cox proportional hazards regression. Landmark analyses evaluated survival from baseline and at 2, 3, 4, and 6 months after baseline. Results: Four hundred twelve patients enrolled on the TAX327 trial had measurable tumors. Thirty-seven patients exhibited a complete or partial objective response (CR/PR, 9.0%), 116 had stable disease (SD, 28.2%), 99 had progressive disease (PD, 24%) and 160 (38.8%) did not have a after-baseline objective assessment. Partial responders demonstrated longer median OS (29.0 months) than patients with SD (22.1 months) or those with PD (10.8 months) or those who were not assessed (12.7 months). These results remained after landmark analysis. The authors found a significant association between ≥30% prostate-specific antigen (PSA) declines and radiologic response, with ≥30% PSA declines occurring in all patients with CR/PR, 79.8% of patients with SD, and 34.4% with PD. Radiologic response remained a significant but modest post-treatment prognostic factor for OS after adjusting for treatment, pain response, and ≥30% PSA decline (P =.009). Conclusions: In men with metastatic CRPC and measurable disease receiving chemotherapy, objective tumor response was prognostic for OS and appeared to complement PSA assessment. © 2011 American Cancer Society. Source

Discover hidden collaborations