HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Miller, D. L. Articles by Georgia, J. D. Search for Related Content PubMed PubMed Citation Articles by Miller, D. L. Articles by Georgia, J. D.

Minimizing Radiation-induced Skin Injury in Interventional Radiology Procedures¹

¹ From the Department of Radiology, National Naval Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889-5600 (D.L.M., P.T.N., J.D.G.); Department of Radiology and Nuclear Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Md (D.L.M., J.D.G.); Medical Oncology Clinical Research Unit, Center for Cancer Research, National Cancer Institute, Bethesda, Md (D.L.M.); and Department of Medicine, Lenox Hill Hospital, New York, NY (S.B.). Received August 20, 2001; revision requested October 11; revision received November 8; accepted December 11. Address correspondence to D.L.M. (e-mail: dm72v@nih.gov).

View larger version (28K): [in a new window]   Figure 1a. Diagrams of a C-arm fluoroscopic unit. (a) Location of the DAP meter ionization chamber and the interventional reference point (IRP) () are shown. The DAP meter measures x-ray flux across the entire beam. The small central volume is used to measure dose along the central ray. (b) Note that the relationship of IRP () to skin surface changes with gantry angulation. This relationship also varies with changes in table height.

View larger version (23K): [in a new window]   Figure 1b. Diagrams of a C-arm fluoroscopic unit. (a) Location of the DAP meter ionization chamber and the interventional reference point (IRP) () are shown. The DAP meter measures x-ray flux across the entire beam. The small central volume is used to measure dose along the central ray. (b) Note that the relationship of IRP () to skin surface changes with gantry angulation. This relationship also varies with changes in table height.

View larger version (80K): [in a new window]   Figure 2. Skin-dose map display obtained during spinal arteriography. A map of the skin-dose distribution is shown. The map is displayed as if the skin surface were cut along the midline anteriorly and reflected laterally, as shown in the diagram at the bottom of the figure. As skin dose increases, the color of the corresponding portion of the skin map changes from white through yellow and orange to red. Note the region of skin dose (arrowheads) due to arteriography in the lateral plane. The current radiation field is indicated by the blue rectangle, and the current value of peak skin dose within this field is displayed in blue (1223, long arrow). The current value of peak skin dose for the entire skin surface is displayed in green (1457, short arrow). The display also indicates, in tabular form (not shown), cumulative dose, DAP, fluoroscopy time, peak skin dose, and 95% area load.

View larger version (129K): [in a new window]   Figure 3a. (a) Right internal carotid arteriogram obtained in the frontal plane before treatment with detachable coils of an internal carotid bifurcation aneurysm (arrow). The skin-dose maps obtained (b) early in the procedure and (c) at the conclusion of the procedure are also shown. The procedure was performed in a biplane room. (b) The midline octagon (long arrow) indicates the radiation field from the frontal plane, and the lateral octagon (short arrow) indicates the radiation field from the lateral plane. The cumulative dose for the procedure was 2,458 mGy, and the peak skin dose was 2,098 mGy. (c) The red color on the skin-dose map indicates that the skin dose to this area exceeded 2,000 mGy. The dose index was 0.85, and the 95% area load was 46.3 cm2.

View larger version (76K): [in a new window]   Figure 3b. (a) Right internal carotid arteriogram obtained in the frontal plane before treatment with detachable coils of an internal carotid bifurcation aneurysm (arrow). The skin-dose maps obtained (b) early in the procedure and (c) at the conclusion of the procedure are also shown. The procedure was performed in a biplane room. (b) The midline octagon (long arrow) indicates the radiation field from the frontal plane, and the lateral octagon (short arrow) indicates the radiation field from the lateral plane. The cumulative dose for the procedure was 2,458 mGy, and the peak skin dose was 2,098 mGy. (c) The red color on the skin-dose map indicates that the skin dose to this area exceeded 2,000 mGy. The dose index was 0.85, and the 95% area load was 46.3 cm2.

View larger version (85K): [in a new window]   Figure 3c. (a) Right internal carotid arteriogram obtained in the frontal plane before treatment with detachable coils of an internal carotid bifurcation aneurysm (arrow). The skin-dose maps obtained (b) early in the procedure and (c) at the conclusion of the procedure are also shown. The procedure was performed in a biplane room. (b) The midline octagon (long arrow) indicates the radiation field from the frontal plane, and the lateral octagon (short arrow) indicates the radiation field from the lateral plane. The cumulative dose for the procedure was 2,458 mGy, and the peak skin dose was 2,098 mGy. (c) The red color on the skin-dose map indicates that the skin dose to this area exceeded 2,000 mGy. The dose index was 0.85, and the 95% area load was 46.3 cm2.

View larger version (169K): [in a new window]   Figure 4a. (a) Posterior fossa arteriogram obtained in the lateral plane before embolization of a cerebellar arteriovenous malformation (arrows). (b) Skin-dose map obtained at the conclusion of the procedure. The yellow color is a visual indicator that skin dose was less than 1,600 mGy. The cumulative dose was 3,481 mGy; peak skin dose, 1,465 mGy; dose index, 0.42; and 95% area load, 24.5 cm2.

View larger version (61K): [in a new window]   Figure 4b. (a) Posterior fossa arteriogram obtained in the lateral plane before embolization of a cerebellar arteriovenous malformation (arrows). (b) Skin-dose map obtained at the conclusion of the procedure. The yellow color is a visual indicator that skin dose was less than 1,600 mGy. The cumulative dose was 3,481 mGy; peak skin dose, 1,465 mGy; dose index, 0.42; and 95% area load, 24.5 cm2.

View larger version (73K): [in a new window]   Figure 5a. Skin-dose maps obtained during and after occlusion with detachable coils of a basilar artery tip aneurysm. (a) Skin-dose map obtained approximately one-third of the way through the procedure, with 19.6-minute fluoroscopy time and a cumulative dose of 1,213 mGy. At this time, the peak skin dose was 886 mGy. The darker yellow color indicates a skin dose of between 1,000 and 1,200 mGy, and the paler yellow color indicates a region of lower skin dose. The skin map demonstrates that the dose has been spread over a larger skin surface than the radiation field (indicated by the blue rectangle). Compare this skin-dose map with those in with Figure 3. (b) Skin-dose map obtained at the conclusion of the procedure, with 3,493-mGy cumulative dose, 2,281-mGy peak skin dose, dose index of 0.65, and 95% area load of 10.5 cm2. The 95% area load was minimized with the use of table movement and gantry angulation. As indicated by the zone of yellow and orange colors, which represent doses of 1,200-2,000 mGy, the dose has been spread over a larger area of skin. As a result, the red area (skin dose > 2 Gy) is smaller than the radiation field. Compare with Figure 3.

View larger version (58K): [in a new window]   Figure 5b. Skin-dose maps obtained during and after occlusion with detachable coils of a basilar artery tip aneurysm. (a) Skin-dose map obtained approximately one-third of the way through the procedure, with 19.6-minute fluoroscopy time and a cumulative dose of 1,213 mGy. At this time, the peak skin dose was 886 mGy. The darker yellow color indicates a skin dose of between 1,000 and 1,200 mGy, and the paler yellow color indicates a region of lower skin dose. The skin map demonstrates that the dose has been spread over a larger skin surface than the radiation field (indicated by the blue rectangle). Compare this skin-dose map with those in with Figure 3. (b) Skin-dose map obtained at the conclusion of the procedure, with 3,493-mGy cumulative dose, 2,281-mGy peak skin dose, dose index of 0.65, and 95% area load of 10.5 cm2. The 95% area load was minimized with the use of table movement and gantry angulation. As indicated by the zone of yellow and orange colors, which represent doses of 1,200-2,000 mGy, the dose has been spread over a larger area of skin. As a result, the red area (skin dose > 2 Gy) is smaller than the radiation field. Compare with Figure 3.

View larger version (151K): [in a new window]   Figure 6a. Coil embolization of an internal iliac artery aneurysm. (a) Pelvic arteriogram obtained in the frontal plane after embolization demonstrates multiple coils (arrows) within the aneurysm. (b) Skin-dose map obtained at the end of the procedure demonstrates the effect of gantry angulation during the procedure, with 3,449-mGy cumulative dose, 1,143-mGy peak skin dose, dose index of 0.33, and 95% area load of 13.3 cm2. The skin-dose map demonstrates the skin doses from all of the radiation fields as a series of overlapping squares and octagons. The light yellow color indicates that skin dose in most of these fields was less than 800 mGy. The blue outline indicates the radiation field at the conclusion of the procedure.

View larger version (58K): [in a new window]   Figure 6b. Coil embolization of an internal iliac artery aneurysm. (a) Pelvic arteriogram obtained in the frontal plane after embolization demonstrates multiple coils (arrows) within the aneurysm. (b) Skin-dose map obtained at the end of the procedure demonstrates the effect of gantry angulation during the procedure, with 3,449-mGy cumulative dose, 1,143-mGy peak skin dose, dose index of 0.33, and 95% area load of 13.3 cm2. The skin-dose map demonstrates the skin doses from all of the radiation fields as a series of overlapping squares and octagons. The light yellow color indicates that skin dose in most of these fields was less than 800 mGy. The blue outline indicates the radiation field at the conclusion of the procedure.

View larger version (18K): [in a new window]   Figure 7. Diagram demonstrates result of gantry angulation with overlapping radiation fields. The skin surface in the overlap area (arrows) receives radiation in both gantry positions. This can often be avoided with a greater degree of collimation.

View larger version (80K): [in a new window]   Figure 8a. Skin-dose maps obtained at the start of an embolization procedure for treatment of a cerebral arteriovenous malformation. (a) Initial collimation of the frontal and lateral fluoroscopic radiation fields resulted in an area of overlap on the skin of the posterolateral right side of the neck and head, indicated only by position of the radiation fields on the skin-dose map. (b) After review of the skin-dose map, the collimation of both radiation fields was adjusted. No useful information was lost, and the overlap disappeared.

View larger version (99K): [in a new window]   Figure 8b. Skin-dose maps obtained at the start of an embolization procedure for treatment of a cerebral arteriovenous malformation. (a) Initial collimation of the frontal and lateral fluoroscopic radiation fields resulted in an area of overlap on the skin of the posterolateral right side of the neck and head, indicated only by position of the radiation fields on the skin-dose map. (b) After review of the skin-dose map, the collimation of both radiation fields was adjusted. No useful information was lost, and the overlap disappeared.

View larger version (88K): [in a new window]   Figure 9a. Skin-dose maps obtained (a) during and (b) at the conclusion of uterine artery embolization. Note that the irradiated field (blue outline) is relatively large and extends across the midline. At the conclusion of the procedure, the peak skin dose was located in the patient’s midline as a result of bilateral overlapping radiation fields. The skin-dose map shows a central orange region representing skin doses of 1,200-1,400 mGy surrounded by lighter yellow areas representing regions of progressively lower skin dose. Cumulative dose was 2,875 mGy; peak skin dose, 1,374 mGy; dose index, 0.48; and 95% area load, 26.5 cm2.

View larger version (84K): [in a new window]   Figure 9b. Skin-dose maps obtained (a) during and (b) at the conclusion of uterine artery embolization. Note that the irradiated field (blue outline) is relatively large and extends across the midline. At the conclusion of the procedure, the peak skin dose was located in the patient’s midline as a result of bilateral overlapping radiation fields. The skin-dose map shows a central orange region representing skin doses of 1,200-1,400 mGy surrounded by lighter yellow areas representing regions of progressively lower skin dose. Cumulative dose was 2,875 mGy; peak skin dose, 1,374 mGy; dose index, 0.48; and 95% area load, 26.5 cm2.

View larger version (103K): [in a new window]   Figure 10a. Skin-dose maps obtained (a) during and (b) at the conclusion of uterine artery embolization performed with careful attention to collimation and dose spreading. (a) Note the relatively small size of the irradiated field (blue rectangle). This image was recorded during embolization of the right uterine artery. Bilateral fields of this size do not overlap. (b) At the conclusion of the procedure, the skin-dose distribution was bilobed and spared the midline. The region of maximum skin dose is indicated by the darker yellow zone, which indicates a skin dose of 800-1,000 mGy. The rest of the pelvis contains only zones of light yellow, indicating regions with skin doses less than 600 mGy. The cumulative dose was 3,022 mGy; peak skin dose, 939 mGy; dose index, 0.31; and 95% area load, 12.8 cm2.

View larger version (100K): [in a new window]   Figure 10b. Skin-dose maps obtained (a) during and (b) at the conclusion of uterine artery embolization performed with careful attention to collimation and dose spreading. (a) Note the relatively small size of the irradiated field (blue rectangle). This image was recorded during embolization of the right uterine artery. Bilateral fields of this size do not overlap. (b) At the conclusion of the procedure, the skin-dose distribution was bilobed and spared the midline. The region of maximum skin dose is indicated by the darker yellow zone, which indicates a skin dose of 800-1,000 mGy. The rest of the pelvis contains only zones of light yellow, indicating regions with skin doses less than 600 mGy. The cumulative dose was 3,022 mGy; peak skin dose, 939 mGy; dose index, 0.31; and 95% area load, 12.8 cm2.