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Dive into the research topics where Gary R. Conrad is active.

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Featured researches published by Gary R. Conrad.


International Journal of Radiation Oncology Biology Physics | 2013

Stereotactic Body Radiation Therapy Can Be Used Safely to Boost Residual Disease in Locally Advanced Non-Small Cell Lung Cancer: A Prospective Study

Jonathan Feddock; Susanne M. Arnold; Brent J. Shelton; Partha Sinha; Gary R. Conrad; Li Chen; John J. Rinehart; Ronald C. McGarry

PURPOSE To report the results of a prospective, single-institution study evaluating the feasibility of conventional chemoradiation (CRT) followed by stereotactic body radiation therapy (SBRT) as a means of dose escalation for patients with stage II-III non-small cell lung cancer (NSCLC) with residual disease. METHODS AND MATERIALS Patients without metastatic disease and with radiologic evidence of limited residual disease (≤5 cm) within the site of the primary tumor and good or complete nodal responses after standard CRT to a target dose of 60 Gy were considered eligible. The SBRT boost was done to achieve a total combined dose biological equivalent dose >100 Gy to the residual primary tumor, consisting of 10 Gy × 2 fractions (20 Gy total) for peripheral tumors, and 6.5 Gy × 3 fractions (19.5 Gy total) for medial tumors using the Radiation Therapy Oncology Group protocol 0813 definitions. The primary endpoint was the development of grade ≥3 radiation pneumonitis (RP). RESULTS After a median follow-up of 13 months, 4 patients developed acute grade 3 RP, and 1 (2.9%) developed late and persistent grade 3 RP. No patients developed grade 4 or 5 RP. Mean lung dose, V2.5, V5, V10, and V20 values were calculated for the SBRT boost, and none were found to significantly predict for RP. Only advancing age (P=.0147), previous smoking status (P=.0505), and high CRT mean lung dose (P=.0295) were significantly associated with RP development. At the time of analysis, the actuarial local control rate at the primary tumor site was 82.9%, with only 6 patients demonstrating recurrence. CONCLUSIONS Linear accelerator-based SBRT for dose escalation of limited residual NSCLC after definitive CRT was feasible and did not increase the risk for toxicity above that for standard radiation therapy.


Clinical Nuclear Medicine | 1987

Ectopic Supernumerary Kidney Functional Assessment Using Radionuclide Imaging

Gary R. Conrad; Daniel J. Loes

A three-year old male presented with severe hydronephrosis secondary to posterior urethral valves; a pelvic supernumerary kidney was discovered postoperatively. Radionuclide imaging assisted in the management of this patient by providing estimates of relative renal function. A report of the case and a complete summary of the literature concerning this unusual duplication anomaly follows.


Clinical Nuclear Medicine | 2004

Perineural spread of skin carcinoma to the base of the skull: detection with FDG PET and CT fusion.

Gary R. Conrad; Partha Sinha; Markus Holzhauer

Abstract:A 66-year-old man underwent 2-F-18 fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) for evaluation of new-onset left jaw pain approximately 5 years after the diagnosis of squamous cell carcinoma of the lower lip. His initial surgery included a Mohs excision. As a result of


Seminars in Nuclear Medicine | 2012

Scintigraphic confirmation of brain death.

Partha Sinha; Gary R. Conrad

The concept of brain death has gained importance in the past few decades to prevent futile attempts to sustain ventilation and blood circulation when the brain has lost all function and to procure beneficial tissues or life-saving organs for transplantation. However, differences remain among professional societies and various study group recommendations, as well as among individual legal statutes, in how brain death is defined and the methodology for which the diagnosis is attained. Furthermore, reports have appeared both in the medical literature and the lay press concerning quality assurance measures in brain death documentation. Scintigraphy is a commonly used technique in the evaluation of brain death and can be performed with the use of either nonspecific tracers, such as Tc99m diethylene triamine pentaacetic acid, or brain-specific tracers, such as Tc99m hexamethylpropyleneamineoxime (HMPAO). Planar imaging, with or without radionuclide angiography, continues to be the mainstay for the scintigraphic confirmation of brain death. Flow with multiprojection static planar imaging with the use of Tc99m HMPAO can be used to evaluate the cerebral hemispheres, basal ganglia, thalamus, and cerebellum. Single-photon emission computed tomography (SPECT) can provide cross-sectional information but can be difficult to perform in the context of brain death. The current use of SPECT primarily is supplemental to help differentiate overlying scalp from intracerebral activity. The reliability of SPECT to exclude flow and metabolism in the brainstem remains to be scientifically validated.


Clinical Nuclear Medicine | 1988

Colonic localization of indium-111 labeled leukocytes in active Behcet's disease.

Raymond G. Harre; Gary R. Conrad; James E. Seabold

A patient with known Behcets disease demonstrated intense colonic localization of In-111 labeled leukocytes. Gastrointestinal involvement had not been previously manifested, but extensive colonic inflammation was documented by endoscopy. This case illustrates the utility of In-111 labeled leukocyte imaging for detecting active bowel disease in a debilitated patient with documented Behcets vasculitis.


European Journal of Nuclear Medicine and Molecular Imaging | 2016

A simple method for determining split renal function from dynamic (99m)Tc-MAG3 scintigraphic data.

Michal J. Wesolowski; Gary R. Conrad; Martin Šámal; Gage Watson; Surajith N. Wanasundara; Paul Babyn; Carl A. Wesolowski

PurposeCommonly used methods for determining split renal function (SRF) from dynamic scintigraphic data require extrarenal background subtraction and additional correction for intrarenal vascular activity. The use of these additional regions of interest (ROIs) can produce inaccurate results and be challenging, e.g. if the heart is out of the camera field of view. The purpose of this study was to evaluate a new method for determining SRF called the blood pool compensation (BPC) technique, which is simple to implement, does not require extrarenal background correction and intrinsically corrects for intrarenal vascular activity.MethodsIn the BPC method SRF is derived from a parametric plot of the curves generated by one blood-pool and two renal ROIs. Data from 107 patients who underwent 99mTc-MAG3 scintigraphy were used to determine SRF values. Values calculated using the BPC method were compared to those obtained with the integral (IN) and Patlak-Rutland (PR) techniques using Bland-Altman plotting and Passing-Bablok regression. The interobserver variability of the BPC technique was also assessed for two observers.ResultsThe SRF values obtained with the BPC method did not differ significantly from those obtained with the PR method and showed no consistent bias, while SRF values obtained with the IN method showed significant differences with some bias in comparison to those obtained with either the PR or BPC method. No significant interobserver variability was found between two observers calculating SRF using the BPC method.ConclusionThe BPC method requires only three ROIs to produce reliable estimates of SRF, was simple to implement, and in this study yielded statistically equivalent results to the PR method with appreciable interobserver agreement. As such, it adds a new reliable method for quality control of monitoring relative kidney function.


Clinical Nuclear Medicine | 2011

FDG PET/CT findings of a glomangiopericytoma.

Gary R. Conrad; Partha Sinha; Kimberly J. Absher

Glomangiopericytoma (GPC) is a rare vascular neoplasm that arises almost exclusively from the nasal cavity or paranasal sinuses. GPC is also called sinonasal-type hemangiopericytoma, although current nomenclature, as well as classification in a group with myopericytomas, better emphasizes the relatively indolent behavior of this tumor. The authors present the FDG PET/CT findings of GPC in a 53-year-old with symptoms of nasal congestion and facial pressure. CT and MRI showed a nasal mass to extend along the sphenoid ridge from the posterior nasal cavity into the posterior nasopharynx. PET showed the mass to have uniformly low-grade FDG hypermetabolism. Pathologic examination of the surgical specimen showed classic features of GPC.


Clinical Nuclear Medicine | 1997

Solitary adenocarcinoma metastasis mimicking sarcomatous degeneration in Paget's disease.

Gary R. Conrad; Alex W. Johnson

A rare case of mucinous adenocarcinoma presented as a solitary, metastatic deposit to a region of Pagets disease within the peripheral skeleton. Historical, physical, radiographic, and scintigraphic findings were indistinguishable from those of sarcomatous degeneration arising from pagetoid bone. This case supports the idea that when a painful, osteolytic lesion is discovered within a region of Pagets disease, bone scintigraphy has greater value of disclosing potential multifocal or multicentric disease than for providing etiologic specificity for the principal lesion.


Clinical Nuclear Medicine | 2010

FDG PET of alveolar soft part sarcoma.

Justin R. Montgomery; Gary R. Conrad; Partha Sinha; Kimberly J. Absher

Alveolar soft part sarcoma (ASPS) is a very rare, but distinctive type of soft tissue sarcoma, whose name is derived from the pseudoalveolar appearance of its histology. In this report, the FDG PET/CT findings of ASPS are described in a 17-year-old asthmatic female who presented with worsening respiratory symptoms and a pelvic mass. The staging PET showed heterogeneous intense incorporation of FDG within the mass and variable FDG incorporation within the multiple lung nodules. In concordance with other soft tissue sarcomas, PET/CT helped to confirm the anatomic origin of the ASPS, to direct its biopsy, and to assess the distribution of disease.


Clinical Nuclear Medicine | 2002

Incidental detection of a falx meningioma on post-therapy radioiodide whole-body imaging.

Partha Sinha; Gary R. Conrad; Markus Holzhauer

An angiomatous meningioma was discovered incidentally on post-therapy whole-body imaging after 1-131 administration for papillary carcinoma of the thyroid. The patient had no neurologic signs or symptoms. He was treated for an increasing serum thyroglobulin level, and findings of previous pretherapy 1-131 and TI-201 whole-body images were negative. The mechanism for radioiodide localization within the meningioma is uncertain, although the vascularity of the tumor might be a significant factor. Primary neoplasia should be considered when intracranial localization of I-131 occurs with low to moderate intensity.

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Carl A. Wesolowski

Memorial University of Newfoundland

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