253 N Broadway St Apt 407
Portland OR 97227
Medical School: Other - Unknown
Accepts Medicare: No
Participates In eRX: No
Participates In PQRS: No
Participates In EHR: No
License #: D8574
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Radiation exposure in patients with subarachnoid hemorrhage: a quality improvement target. - Journal of neurosurgery
The care of patients with subarachnoid hemorrhage (SAH) has improved dramatically over the last decades. These gains are the result of improved microsurgical, endovascular, and medical management techniques. This intensive management subjects patients to multiple radiographic studies and thus increased radiation exposure. As greater understanding of the risks of radiation exposure develops, physicians must be better equipped to balance the need for optimal SAH management with the minimization of patient exposure to radiation from imaging studies. The goal in the current study was to determine if there is an opportunity for a reduction in radiation dose without a change in the quality of treatment in patients with SAH.A retrospective chart review of all patients hospitalized for SAH at the Brigham and Women's Hospital in the period from January 1, 2009, to August 31, 2010, was performed. The authors calculated cumulative and imaging study-specific radiation doses, determined the time of day that imaging studies were performed, and surveyed neurosurgeons regarding issues surrounding imaging-related radiation exposure.The data for 77 patients were analyzed. The mean cumulative radiation dose during hospitalization was 2.76 Gy per patient (range 0.46-8.32 Gy). The mean radiation exposure from each CT, CT angiography (CTA), and angiography study was 0.08, 0.29, and 0.77 Gy (ranges 0.02-0.40, 0.15-0.99, and 0.11-4.36 Gy, respectively). Subgroup analysis of the top quartile of patients in terms of total radiation dose revealed a mean cumulative radiation dose of 4.78 Gy (range 3.42-8.32 Gy), mean cumulative number of CT and CTA scans of 14, and mean CT or CTA scan per day of 0.5 (maximum 0.8). Seventeen percent of the noncontrast head CT studies were performed just prior to morning rounds, more than double the 8% expected rate at random. Thirty-four percent of the repeat noncontrast head CTs did not show any change between scans, as documented on radiology reports. When surveyed, a majority of neurosurgeons incorrectly estimated the radiation dose typically received from CT, CTA, and angiography studies, and 65% asserted that radiation exposure is "not important" or only "somewhat important" when considering whether to order an imaging study.Study findings suggested that patients with SAH have significant imaging-related exposure to radiation. The authors believe it is possible to continue the current improved outcomes in SAH with a significant reduction in radiation exposure from imaging studies. This analysis highlights the significance of accurate assessment of radiation exposure as a quality improvement target.
Polymethylmethacrylate and radioisotopes in vertebral augmentation: an explanation of underlying principles. - Pain physician
We recently reported a novel concept for combining radioactive isotope technology with polymethylmethacrylate (PMMA) cement used for vertebral augmentation and have advocated that pain physicians become aware of this new concept when treating malignant compression fractures. The use of vertebral augmentation for malignant compression fractures is steadily increasing, and the goal of this novel approach would be to stabilize the fractured vertebral body while also controlling proliferation of the tumor cells in the vertebral body that caused the vertebral fracture. This approach would therefore provide mechanical stabilization of the fractured vertebral body at the same time as direct targeting of the cancer cells causing the fracture. For our analysis, we investigated six specific radioisotopes with regard to physical and biologic properties as they would interact with PMMA and local bone metastatic disease, taking into consideration anatomical, biological and physical characteristics. The radioisotopes investigated include beta emitting (plus and minus) sources, as well as low energy and mid-energy photon sources and are: P-32, Ho-166, Y-90, I-125, F-18, and Tc-99m. We review the advantages and disadvantages of each radioisotope. In addition, this paper serves to provide pain physicians with a basic background of the biologic principles (Biologically Effective Dose) and statistical modeling (Monte Carlo method) used in that analysis. We also review the potential complications when using radioactive sources in a clinical setting. Understanding the methodologies employed in determining isotope selection empowers the practitioner by fostering understanding of this presently theoretical treatment option. We believe that embedding radioisotopes in PMMA is merely a first step in the road of local treatment for symptomatic local lesions in the setting of systemic disease.
Radioisotopes and vertebral augmentation: dosimetric analysis of a novel approach for the treatment of malignant compression fractures. - Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology
Vertebral compression fractures (VCFs), a major cause of morbidity and debilitating pain, often results from secondary tumor metastases to the skeleton. Vertebral augmentation is a palliative technique developed to treat VCFs and involves the injection of polymethyl methacrylate (PMMA) to augment the fractured vertebral body. The authors investigate the feasibility of radionuclide therapy coupled with vertebral augmentation to treat both the tumor metastases and VCFs. Six therapeutic radioisotopes, uniformly mixed in a PMMA bolus, were investigated for their dosimetric properties.The MCNP5 Monte Carlo computer code was used to characterize the therapeutic dosimetric distribution within a cortical bone phantom for a 1 mm radial bolus of isotope-infused PMMA. Based on these data, the minimum activity required for a therapeutic treatment was calculated.The dosimetry from beta emitting Y-90, P-32, and Ho-166 decreased to 10% of its maximum therapeutic dose (R10%) after traveling 1.20 mm, 1.03 mm, and 0.97 mm, respectively, through cortical bone. Low photon energy I-125 had a slightly larger calculated R10% of 1.32 mm. Although F-18 and Tc-99m exhibited a more uniform distribution (R10%=1.72 mm and 1.94 mm, respectively), the lower dosimetric gradients resulted in significantly greater therapeutic implant activities relative to the other isotopes studied in this report.Radionuclide therapy coupled with vertebral augmentation is shown to be a feasible technique for the treatment of secondary skeletal metastases and its resulting side effects. Future studies will include a full clinical investigation to determine optimal treatment isotope(s).
How does time-dependent dental unit waterline flushing affect planktonic bacteria levels? - Journal of dental education
The purpose of this study was to evaluate how time-dependent waterline flushing affects the presence of biofilm in otherwise-untreated dental unit waterlines (DUWLs). Water samples were obtained from twelve highspeed handpiece DUWLs located in the undergraduate treatment clinic at the University of Missouri-Kansas City, School of Dentistry. Baseline water samples (50 cc) were collected prior to the start of continuous flushing. Additional 50 cc samples were collected after two-, three-, and four-minute flushing intervals from the baseline. The levels of planktonic bacteria in DUWLs were quantified by counting colony forming units (CFUs). In addition, segments of water tubing from each of the highspeed handpiece waterlines were examined by scanning electron microscopy, which confirmed the presence of a residual biofilm in the lumen of each dental unit waterline. A one-factor repeated measures ANOVA showed a statistically significant (p<0.01) reduction in CFUs at all intervals compared to baseline and between each successive time interval. Indeed, after four minutes of continuous flushing, all waterlines still harbored CFU levels that exceed current American Dental Association (ADA) recommendations. It was concluded that water flushing of DUWLs produced a statistically significant reduction in planktonic bacteria at each time interval compared to the baseline and between each successive time interval. However, the level of CFUs after four minutes of continuous water flushing still exceeds the current ADA recommendations for acceptable levels of microorganisms.
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253 N Broadway St Apt 407 Portland, OR 97227
2800 N Vancouver Ave Suite 230
2801 N Gantenbein Ave
3620 N Interstate Ave
3600 N Interstate Ave Department Of Physical Medicine
2801 N Gantenbein Ave
300 N Graham St Suite 420