Person: Nguyen, Paul
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Publication Variability in MRI vs. ultrasound measures of prostate volume and its impact on treatment recommendations for favorable-risk prostate cancer patients: a case series
(BioMed Central, 2014) Murciano-Goroff, Yonina; Wolfsberger, Luciant D; Parekh, Arti; Fennessy, Fiona; Tuncali, Kemal; Orio, Peter; Niedermayr, Thomas R; Suh, W Warren; Devlin, Phillip; Tempany, Clare Mary C; Sugar, Emily H Neubauer; O’Farrell, Desmond A; Steele, Graeme; O’Leary, Michael; Buzurovic, Ivan; Damato, Antonio L.; Cormack, Robert; Fedorov, Andriy; Nguyen, PaulBackground: Prostate volume can affect whether patients qualify for brachytherapy (desired size ≥20 mL and ≤60 mL) and/or active surveillance (desired PSA density ≤0.15 for very low risk disease). This study examines variability in prostate volume measurements depending on imaging modality used (ultrasound versus MRI) and volume calculation technique (contouring versus ellipsoid) and quantifies the impact of this variability on treatment recommendations for men with favorable-risk prostate cancer. Methods: We examined 70 patients who presented consecutively for consideration of brachytherapy for favorable-risk prostate cancer who had volume estimates by three methods: contoured axial ultrasound slices, ultrasound ellipsoid (height × width × length × 0.523) calculation, and endorectal coil MRI (erMRI) ellipsoid calculation. Results: Average gland size by the contoured ultrasound, ellipsoid ultrasound, and erMRI methods were 33.99, 37.16, and 39.62 mLs, respectively. All pairwise comparisons between methods were statistically significant (all p < 0.015). Of the 66 patients who volumetrically qualified for brachytherapy on ellipsoid ultrasound measures, 22 (33.33%) did not qualify on ellipsoid erMRI or contoured ultrasound measures. 38 patients (54.28%) had PSA density ≤0.15 ng/dl as calculated using ellipsoid ultrasound volumes, compared to 34 (48.57%) and 38 patients (54.28%) using contoured ultrasound and ellipsoid erMRI volumes, respectively. Conclusions: The ultrasound ellipsoid and erMRI ellipsoid methods appeared to overestimate ultrasound contoured volume by an average of 9.34% and 16.57% respectively. 33.33% of those who qualified for brachytherapy based on ellipsoid ultrasound volume would be disqualified based on ultrasound contoured and/or erMRI ellipsoid volume. As treatment recommendations increasingly rely on estimates of prostate size, clinicians must consider method of volume estimation.
Publication Disparities in selective referral for cancer surgeries: implications for the current healthcare delivery system
(BMJ Publishing Group, 2014) Sun, Maxine; Karakiewicz, Pierre I; Sammon, Jesse D; Sukumar, Shyam; Gervais, Mai-Kim; Nguyen, Paul; Choueiri, Toni; Menon, Mani; Trinh, Quoc-DienObjectives: Among considerable efforts to improve quality of surgical care, expedited measures such as a selective referral to high-volume institutions have been advocated. Our objective was to examine whether racial, insurance and/or socioeconomic disparities exist in the use of high-volume hospitals for complex surgical oncological procedures within the USA. Design, setting and participants Patients undergoing colectomy, cystectomy, oesophagectomy, gastrectomy, hysterectomy, lung resection, pancreatectomy or prostatectomy were identified retrospectively, using the Nationwide Inpatient Sample, between years 1999 and 2009. This resulted in a weighted estimate of 2 508 916 patients. Primary outcome measures Distribution of patients according to race, insurance and income characteristics was examined according to low-volume and high-volume hospitals (highest 20% of patients according to the procedure-specific mean annual volume). Generalised linear regression models for prediction of access to high-volume hospitals were performed. Results: Insurance providers and county income levels varied differently according to patients’ race. Most Caucasians resided in wealthier counties, regardless of insurance types (private/Medicare), while most African Americans resided in less wealthy counties (≤$24 999), despite being privately insured. In general, Caucasians, privately insured, and those residing in wealthier counties (≥$45 000) were more likely to receive surgery at high-volume hospitals, even after adjustment for all other patient-specific characteristics. Depending on the procedure, some disparities were more prominent, but the overall trend suggests a collinear effect for race, insurance type and county income levels. Conclusions: Prevailing disparities exist according to several patient and sociodemographic characteristics for utilisation of high-volume hospitals. Efforts should be made to directly reduce such disparities and ensure equal healthcare delivery.
Publication Natural History of Untreated Prostate Specific Antigen Radiorecurrent Prostate Cancer in Men with Favorable Prognostic Indicators
(Hindawi Publishing Corporation, 2014) Martin, Neil; Chen, Ming-Hui; Beard, Clair; Nguyen, Paul; Loffredo, Marian J.; Renshaw, Andrew A.; Kantoff, Philip; D'Amico, AnthonyBackground and Purpose. Life expectancy data could identify men with favorable post-radiation prostate-specific antigen (PSA) failure kinetics unlikely to require androgen deprivation therapy (ADT). Materials and Methods. Of 206 men with unfavorable-risk prostate cancer in a randomized trial of radiation versus radiation and ADT, 53 experienced a PSA failure and were followed without salvage ADT. Comorbidity, age and established prognostic factors were assessed for relationship to death using Cox regression analyses. Results:. The median age at failure, interval to PSA failure, and PSA doubling time were 76.6 years (interquartile range [IQR]: 71.8–79.3), 49.1 months (IQR: 37.7–87.4), and 25 months (IQR: 13.1–42.8), respectively. After a median follow up of 4.0 years following PSA failure, 45% of men had died, none from prostate cancer and no one had developed metastases. Both increasing age at PSA failure (HR: 1.14; 95% CI: 1.03–1.25; P = 0.008) and the presence of moderate to severe comorbidity (HR: 12.5; 95% CI: 3.81–41.0; P < 0.001) were significantly associated with an increased risk of death. Conclusions:. Men over the age of 76 with significant comorbidity and a PSA doubling time >2 years following post-radiation PSA failure appear to be good candidates for observation without ADT intervention.
Publication Data on Medicare eligibility and cancer screening utilization
(Elsevier, 2016) Meyer, Christian P.; Allard, Christopher B.; Sammon, Jesse D.; Hanske, Julian; McNabb-Baltar, Julia; Goldberg, Joel E.; Reznor, Gally; Lipsitz, Stuart; Choueiri, Toni; Nguyen, Paul; Weissman, Joel; Trinh, Quoc-DienHealth insurance is associated with increased utilization of cancer screening services. Data on breast, prostate and colorectal cancer screening were abstracted from the 2012 Behavioral Risk Factor and Surveillance System. This data in brief includes two sets of analyses: (i) the use of cancer screening in individuals within the low-income bracket and (ii) determinants for each of the three approaches to colorectal cancer screening (fecal occult blood test, colonoscopy and sigmoidoscopy+fecal occult blood test). Covariates included education attainment, residency, and access to health care provider. The data supplement our original research article on the effect of Medicare eligibility on cancer screening utilization “The impact of Medicare eligibility on cancer screening behaviors” [1].
Publication Interfractional Variations in the Setup of Pelvic Bony Anatomy and Soft Tissue, and Their Implications on the Delivery of Proton Therapy for Localized Prostate Cancer
(Elsevier BV, 2011) Trofimov, Alexei; Nguyen, Paul; Efstathiou, Jason; Wang, Yi; Lu, Hsiao-Ming; Engelsman, Martijn; Merrick, Scott; Cheng, Chee-Wai; Wong, James R.; Zietman, AnthonyPurpose
To quantify daily variations in the anatomy of patients undergoing radiation therapy for prostate carcinoma, to estimate their effect on dose distribution, and to evaluate the effectiveness of current standard planning and set-up approaches employed in proton therapy.
Methods
We used series of CT data, which included the pre-treatment scan, and between 21 and 43 in-room scans acquired on different treatment days, from 10 patients treated with intensity-modulated radiation therapy at Morristown Memorial Hospital. Variations in femur rotation angles, thickness of subcutaneous adipose tissue, and physical depth to the distal surface of the prostate for lateral beam arrangement were recorded. Proton dose distributions were planned with the standard approach. Daily variations in the location of the prescription iso-dose were evaluated.
Results
In all 10 datasets, substantial variation was observed in the lateral tissue thickness (standard deviation of 1.7–3.6 mm for individual patients, variations of over 5 mm from the planning CT observed in all series), and femur rotation angle (standard deviation between 1.3–4.8°, with the maximum excursion exceeding 10° in 6 out of 10 datasets). Shifts in the position of treated volume (98% iso-dose) were correlated with the variations in the lateral tissue thickness.
Conclusions
Analysis suggests that, combined with image-guided set-up verification, the range compensator expansion technique prevents loss of dose to target due to femur rotation and soft tissue deformation, in the majority of cases. Anatomic changes coupled with the uncertainties of particle penetration in tissue restrict possibilities for margin reduction in proton therapy of prostate cancer.
Publication Conditional cancer-specific mortality in T4, N1, or M1 prostate cancer: implications for long-term prognosis
(Springer Science + Business Media, 2015) Muralidhar, Vinayak; Mahal, Brandon; Nguyen, PaulBackground: The risk of prostate cancer-specific mortality (PCSM) following a diagnosis of prostate cancer may improve after patients have survived a number of years after diagnosis. We sought to determine long-term conditional PCSM for patients with stage T4, N1, or M1 prostate cancer. Methods: We identified 66,817 patients diagnosed with stage IV (T4N0M0, N1M0, or M1) prostate cancer between 1973 and 2011 using the Surveillance, Epidemiology, and End Results (SEER) database. Conditional five-year PCSM was evaluated for each group of patients at 5, 10, and 15 years of survival according to the Fine & Gray model for competing risks after adjusting for tumor grade, age, income level, and marital status. Race-stratified analyses were also performed. Results: There were 13,345 patients with T4 disease, 12,450 patients with N1 disease, and 41,022 patients with M1 disease. Median follow-up among survivors in the three groups was 123 months (range: 0-382 months), 61 months (range: 0-410 months), and 30 months (range: 0-370 months), respectively. Conditional PCSM improved in all three groups over time. Among patients with T4 disease, 5-year PCSM improved from 13.9% at diagnosis to 11.2%, 8.1%, and 6.5% conditioned on 5, 10, or 15 years of survival, respectively (p < 0.001 in all cases). In patients with N1 disease, 5-year PCSM increased within the first five years and decreased thereafter, from 18.9% at diagnosis to 21.4% (p < 0.001), 17.6% (p = 0.055), and 13.8% (p <0.001), respectively. In patients with metastatic disease, 5-year PCSM improved from 57.2% at diagnosis to 41.1%, 28.8%, and 20.8%, respectively (p < 0.001). White race was associated with Conditional mortality after T4, N1, or M1 prostate cancer--2 a greater increase in conditional survival compared to non-white race among those with T4 or N1 disease. Conclusions: While patients with T4, N1, or M1 prostate cancer are never “cured,” their odds of cancer-specific survival increase substantially after they have survived for 5 or more years. Physicians who take care of patients with prostate cancer can use this data to guide follow-up decisions and to counsel newly diagnosed patients and survivors regarding their long-term prognosis.
Publication Advanced nodal stage predicts venous thromboembolism in patients with locally advanced non-small cell lung cancer
(Elsevier BV, 2016) Li, Richard Jay; Hermann, Gretchen; Baldini, Elizabeth; Chen, Aileen; Jackman, David M; Kozono, David; Nguyen, Paul; Nohria, Anju; Powell, Graham; Mak, RaymondObjectives: Patients with non-small cell lung cancer (NSCLC) are known to be at high risk for venous thromboembolism (VTE), but previous studies have not specifically analyzed locally advanced disease. We performed a retrospective VTE risk analysis in a cohort of locally advanced NSCLC treated with definitive intent including radiation therapy. Materials and Methods: The cohort consisted of 629 patients with stage II-III NSCLC treated at a single institution from January 2003 to December 2012. All patients received treatment with curative intent, including radiation therapy. Fine and Gray’s competing-risks regression model, accounting for death and distant metastasis as competing risks, was used to identify significant predictors of VTE risk, and cumulative incidence estimates were generated using the competing-risks model. Results and Conclusion: At a median follow-up of 31 months, 127 patients developed a VTE, with 80% of events occurring in the first year after treatment initiation. 1-year and 3-year overall cumulative incidence estimates were 13.5% and 15.4%, respectively. On univariate analysis, stage IIIB and N3 nodal disease were associated with increased VTE risk. In the final multivariable model, N3 nodal disease was associated with increased VTE risk (Hazard ratio 1.64; 95% CI 1.06-2.54; p=0.027). In conclusion, patients with locally advanced NSCLC are at high risk for VTE, especially in the first year after treatment initiation, with a 1-year cumulative incidence of 13.5%. N3 nodal staging was associated with significantly higher VTE risk compared to N0-N2 staging.
Publication Prostate Cancer – Local Treatment after Radiorecurrence: Surgery - Back to the future?
(Sociedade Brasileira de Urologia, 2018) Reis, Leonardo O.; Nguyen, Paul