Impact of a lead glass screen on scatter radiation to eyes and hands in interventional cardiologists

Abstract

The objective of this study was to assess the impact of a transparent lead glass screen (TLGS) on scatter radiation to the eyes and the hands in interventional cardiologists and to compare the results to the recommended annual threshold values of 150 and 500 mSv, respectively. Local radiation doses to the left eye and the ring finger of the left hand of three operators (A, B, C) were assessed by thermoluminiscence dosimeters during 813 coronary angiographies (CAs), including 190 ad hoc percutaneous coronary interventions (PCIs) either with a TLGS placed between patient and operator [615 CAs including 138 ad hoc PCIs; dose-area product (DAP) = 84.9 +/- 71.3 Gy x cm(2)], or without (198 CAs including 52 PCIs; DAP = 85.7 +/- 61.5 Gy x cm(2)). To determine the efficacy of the TLGS, average DAP-normalized local doses were calculated. Using a TLGS, operator A, B, and C performed 259 (in 9 months), 211 (in 8 months), and 145 CAs (in 8 months) with TLGS and acquired cumulative eye lens doses of 5.5, 1.5, and 1.0 mSv corresponding to extrapolated annual doses of 7.3, 2.3, and 1.5 mSv. The cumulative finger doses were 9.6, 10.3, and 6.4 mSv, resulting in extrapolated annual doses of 12.8, 15.5, and 9.6 mSv. Compared to 139 (in 5 months), 36 (in 2 months), and 23 CAs (in 2 months) without TLGS, the use of a TLGS reduced the DAP-normalized eye dose by a factor of 19 (with TLGS 0.153 vs. without TLGS 2.924 microSv/Gy x cm(2)), whereas only a weak effect on the dose to the hands was observed (with TLGS 0.504 vs. without TLGS 0.578 microSv/Gy x cm(2)). The consequent use of a TLGS efficiently reduces scatter radiation to the operator's eyes in daily practice, but has only minimal effects on the dose to the hands.

Evaluation of a Suspended Personal Radiation Protection System vs. Conventional Apron and Shields in Clinical Interventional Procedures

“…Since the mobile suspended lead-acrylic shield was used in 100% of LAS procedures and 0% of Zgrav procedures in the wrist group (Table 1), this suggests ineffectiveness of the ancillary shields for reducing hand exposures, and that their omission does not increase exposures. These results were consistent with other reports [20,22,23]. When standardized to Total DAP (instead of fluoroscopic DAP), wrist exposure for all procedures in Phase II = 0.39 uSv/Gycm².…”

“…Although phantom studies provide preliminary information, application to clinical practice is problematic due to many dynamic factors including large patients, interference with operator's hands or arms from accessory shields, and inability to use shielding in certain image receptor obliquities or operator stances. Results with phantoms showing significantly reduced eye exposures using shields are not fully corroborated by clinical studies using the same shielding, with one study documenting high clinical eye doses and recommending protective eyewear in addition to the suspended shield [20][21][22][23][27][28][29]. A feasibility study of an earlier prototype of the suspended personal radiation protection system using phantoms showed 16 -78 fold decreases in exposure to various body areas compared to a lead apron due to thicker lead and greater surface area covered [30].…”

“…DAP Standardized wrist exposures were similar to other reports. Absence of significant difference between LAS and Zgrav was unsurprising since neither Zgrav nor the mobile suspended lead-acrylic shield protect the hands or forearms [20,22,23]. In keeping with ALARA, we perform 100% of procedures without ever placing the fingers in the direct beam.…”

¿Es suficiente la protección otorgada por gafas plomadas en cardiología intervencionista?

“…En este estudio se observó que las dosis equivalentes del cristalino de los cardiólogos intervencionistas medidas delante de las gafas plomadas exceden el límite anual actualmente sugerido por la ICRP con un valor promedio anual de 78 mSv, lo que es levemente superior a lo publicado el año 2006 por Maeder M, 2006 15 , quien reportó un promedio anual de 66,1 mSv. Todos los demás estamentos permanecieron bajo el umbral de 50 mSv.…”

“…La dosis promedio por examen observada en los cardiólogos intervencionistas fue la mayor, con un valor de 33 µSv en el dosímetro ubicado entre el vidrio plomado y el tubo de rayos X. Este valor se encuentra dentro del rango de valores observados en otros estudios [15][16][17][18] que reportaron los siguientes valores promedio por examen: 13, 13, 44 y 294 µSv respectivamente. El último valor se escapa significativamente de los valores reportados.…”