Robin L Albert, M.D.

Radiation doses in interventional radiology procedures: the RAD-IR Study. Part III: Dosimetric performance of the interventional fluoroscopy units
Balter, Stephen; Schueler, Beth A; Miller, Donald L; Cole, Patricia E; Lu, Hollington T; Berenstein, Alejandro; Albert, Robin; Georgia, Jeffrey D; Noonan, Patrick T; Russell, Eric J; Malisch, Tim W; Vogelzang, Robert L; Geisinger, Michael; Cardella, John F; St George, James; Miller, George L 3rd; Anderson, Jon
2004 Sep;15(9):919-926, Journal of vascular & interventional radiology
PURPOSE: To present the physics data supporting the validity of the clinical dose data from the RAD-IR study and to document the performance of dosimetry-components of these systems over time. MATERIALS AND METHODS: Sites at seven academic medical centers in the United States prospectively contributed data for each of 12 fluoroscopic units. All units were compatible with International Electrotechnical Commission (IEC) standard 60601-2-43. Comprehensive evaluations and periodic consistency checks were performed to verify the performance of each unit's dosimeter. Comprehensive evaluations compared system performance against calibrated ionization chambers under nine combinations of operating conditions. Consistency checks provided more frequent dosimetry data, with use of each unit's built-in dosimetry equipment and a standard water phantom. RESULTS: During the 3-year study, data were collected for 48 comprehensive evaluations and 581 consistency checks. For the comprehensive evaluations, the mean (95% confidence interval range) ratio of system to external measurements was 1.03 (1.00-1.05) for fluoroscopy and 0.93 (0.90-0.96) for acquisition. The expected ratio was 0.93 for both. For consistency checks, the values were 1.00 (0.98-1.02) for fluoroscopy and 1.00 (0.98-1.02) for acquisition. Each system was compared across time to its own mean value. Overall uncertainty was estimated by adding the standard deviations of the comprehensive and consistency measurements in quadrature. The authors estimate that the overall error in clinical cumulative dose measurements reported in RAD-IR is 24%. CONCLUSION: Dosimetric accuracy was well within the tolerances established by IEC standard 60601-2-43. The clinical dose data reported in the RAD-IR study are valid
— id: 66506, year: 2004, vol: 15, page: 919, stat: Journal Article,

Radiation doses in interventional radiology procedures: the RAD-IR study: part II: skin dose
Miller, Donald L; Balter, Stephen; Cole, Patricia E; Lu, Hollington T; Berenstein, Alejandro; Albert, Robin; Schueler, Beth A; Georgia, Jeffrey D; Noonan, Patrick T; Russell, Eric J; Malisch, Tim W; Vogelzang, Robert L; Geisinger, Michael; Cardella, John F; George, James St; Miller, George L 3rd; Anderson, Jon
2003 Aug;14(8):977-990, Journal of vascular & interventional radiology
PURPOSE: To determine peak skin dose (PSD), a measure of the likelihood of radiation-induced skin effects, for a variety of common interventional radiology and interventional neuroradiology procedures, and to identify procedures associated with a PSD greater than 2 Gy. MATERIALS AND METHODS: An observational study was conducted at seven academic medical centers in the United States. Sites prospectively contributed demographic and radiation dose data for subjects undergoing 21 specific procedures in a fluoroscopic suite equipped with built-in dosimetry capability. Comprehensive physics evaluations and periodic consistency checks were performed on each unit to verify the stability and consistency of the dosimeter. Seven of 12 fluoroscopic suites in the study were equipped with skin dose mapping software. RESULTS: Over a 3-year period, skin dose data were recorded for 800 instances of 21 interventional radiology procedures. Wide variation in PSD was observed for different instances of the same procedure. Some instances of each procedure we studied resulted in a PSD greater than 2 Gy, except for nephrostomy, pulmonary angiography, and inferior vena cava filter placement. Some instances of transjugular intrahepatic portosystemic shunt (TIPS) creation, renal/visceral angioplasty, and angiographic diagnosis and therapy of gastrointestinal hemorrhage produced PSDs greater than 3 Gy. Some instances of hepatic chemoembolization, other tumor embolization, and neuroembolization procedures in the head and spine produced PSDs greater than 5 Gy. In a subset of 709 instances of higher-dose procedures, there was good overall correlation between PSD and cumulative dose (r = 0.86; P <.000001) and between PSD and dose-area-product (r = 0.85, P <.000001), but there was wide variation in these relationships for individual instances. CONCLUSIONS: There are substantial variations in PSD among instances of the same procedure and among different procedure types. Most of the procedures observed may produce a PSD sufficient to cause deterministic effects in skin. It is suggested that dose data be recorded routinely for TIPS creation, angioplasty in the abdomen or pelvis, all embolization procedures, and especially for head and spine embolization procedures. Measurement or estimation of PSD is the best method for determining the likelihood of radiation-induced skin effects. Skin dose mapping is preferable to a single-point measurement of PSD
— id: 38813, year: 2003, vol: 14, page: 977, stat: Journal Article,

Radiation doses in interventional radiology procedures: the RAD-IR study: part I: overall measures of dose
Miller, Donald L; Balter, Stephen; Cole, Patricia E; Lu, Hollington T; Schueler, Beth A; Geisinger, Michael; Berenstein, Alejandro; Albert, Robin; Georgia, Jeffrey D; Noonan, Patrick T; Cardella, John F; St George, James; Russell, Eric J; Malisch, Tim W; Vogelzang, Robert L; Miller, George L 3rd; Anderson, Jon
2003 Jun;14(6):711-727, Journal of vascular & interventional radiology
PURPOSE: To determine patient radiation doses for interventional radiology and neuroradiology procedures, to identify procedures associated with higher radiation doses, and to determine the effects of various parameters on patient doses. MATERIALS AND METHODS: A prospective observational study was performed at seven academic medical centers. Each site contributed demographic and radiation dose data for subjects undergoing specific procedures in fluoroscopic suites equipped with built-in cumulative dose (CD) and dose-area-product (DAP) measurement capability compliant with International Electrotechnical Commission standard 60601-2-43. The accuracy of the dosimetry was confirmed by comprehensive measurements and by frequent consistency checks performed over the course of the study. RESULTS: Data were collected on 2,142 instances of interventional radiology procedures, 48 comprehensive physics evaluations, and 581 periodic consistency checks from the 12 fluoroscopic units in the study. There were wide variations in dose and statistically significant differences in fluoroscopy time, number of images, DAP, and CD for different instances of the same procedure, depending on the nature of the lesion, its anatomic location, and the complexity of the procedure. For the 2,142 instances, observed CD and DAP correlate well overall (r = 0.83, P <.000001), but correlation in individual instances is poor. The same is true for the correlation between fluoroscopy time and CD (r = 0.79, P <.000001). The correlation between fluoroscopy time and DAP (r = 0.60, P <.000001) is not as good. In 6% of instances (128 of 2,142), which were principally embolization procedures, transjugular intrahepatic portosystemic shunt (TIPS) procedures, and renal/visceral artery stent placements, CD was greater than 5 Gy. CONCLUSIONS: Most procedures studied can result in clinically significant radiation dose to the patient, even when performed by trained operators with use of dose-reducing technology and modern fluoroscopic equipment. Embolization procedures, TIPS creation, and renal/visceral artery stent placement are associated with a substantial likelihood of clinically significant patient dose. At minimum, patient dose data should be recorded in the medical record for these three types of procedures. These data should include indicators of the risk of deterministic effects as well as the risk of stochastic effects
— id: 38814, year: 2003, vol: 14, page: 711, stat: Journal Article,

Approach to risk assessment for genotoxic carcinogens based on data from the mouse skin initiation-promotion model
Burns, F; Albert, R; Altshuler, B; Morris, E
1983 Apr;50:309-320, Environmental health perspectives
Tumor induction data in the mouse skin initiation-promotion system were found to be consistent with a quadratic function where the coefficient of the linear term depended on the dose of the promoter. The model implies that the existence of promoters may be more important at low doses of the carcinogen than at high doses where most testing is performed. Experiments are described showing that the initiating effect of carcinogenic chemicals, such as benzo(a)pyrene, 7,12-dimethyl-benz(a)anthracene, nitroquinoline oxide and beta-propiolactone, accumulates in a linear, irreversible manner at low doses. Even when 7,12-dimethylbenz(a)anthracene was applied intragastrically to pregnant females, initiating activity was found in the skins of exposed offspring about in proportion to dose applied and number of cells at risk. The initiated cells essentially represent a potential for cancer that has a high probability for expression in the presence of a promoter. Risk then can be interpreted in terms of the accumulated dose of initiator which alone presents a small risk of cancer. However, a promoter may substantially expand the overall risk, possibly by clonally expanding the initiated cells. Promotion needs to be sustained since there is a reduction of cancer risk if promotion is ended early. Some tissues, such as mouse bladder, may be intrinsically promoted more than others so that comparisons between tissues and between species are best made when the combination of intrinsic promotion and response to extrinsic promotion are comparable
— id: 123141, year: 1983, vol: 50, page: 309, stat: Journal Article,

Dose-dependent size increases of aortic lesions following chronic exposure to 7,12-dimethylbenz(a)anthracene
Penn, A; Batastini, G; Soloman, J; Burns, F; Albert, R
1981 Feb;41(2):588-592, Cancer research
The prevalence, size, and patterns of distribution of arterial lesions (plaques) were investigated in cockerels exposed chronically to 7,12-dimethylbenz(a)anthracene (DMBA). Animals, from 5 to 20 weeks of age, received weekly i.m. injections of 5, 10, or 20 mg of DMBA per kg, dissolved in dimethyl sulfoxide. Control animals received weekly injections of dimethyl sulfoxide. All animals were sacrificed at 21 weeks of age. The entire aorta from each animal was cut transversely into 5-mm segments starting at the iliac trifurcation. The cross-sectional area of plaques was determined by light microscopic analysis of sections taken from the face of each segment. Plaque frequency was similar in DMBA-treated and control groups. However, mean plaque cross-sectional area was 7- to 11-fold higher for the treatment groups than for the controls. The distribution of plaque areas in both treated animals and controls was consistent with a log normal distribution. Median cross-sectional area and plaque volume index each increased in a linear fashion with DMBA dose. Small plaques were present in all groups. Large plaques were present only in DMBA-treated animals. Labeling indices of plaques, although low, were 2.3- to 26-fold higher than for underlying medial smooth muscle cells. The data indicate that the primary response to chronic DMBA exposure is a dose-dependent size increase of spontaneous aortic lesions and not the induction of new lesions
— id: 123140, year: 1981, vol: 41, page: 588, stat: Journal Article,