UTHSC-H Home	People Directory	Maps	Calendar	University A - Z	Webmail

Radiation Injury to the Skin Caused by Fluoroscopic Procedures: Lessons on Radiation Management

T.R. Koenig, M.D.,Ph.D.; L.K. Wagner, Ph.D.; F. A. Mettler, M.D.1 and D. Wolff, M.D.2

The University of Texas  Health Science Center at Houston, TX

Scientific Exhibit Cum Laude

Annual Meeting of the Radiological Society of North America, 2000

---

INTRODUCTION

SKIN INJURIES

PROCEDURES CAUSING INJURIES

LESSONS TO BE LEARNED

REFERENCES

INTRODUCTION

The number and complexity of fluoroscopically guided interventional cardiologic and radiologic procedures has grown markedly in the last decade [1]. This trend is paralleled by a sharp increase in skin injuries. We reviewed more than 65 cases of skin injuries caused by fluoroscopic procedures [2]. Chronic ulceration and tissue necrosis were documented in about half of all cases. Our exhibit illustrates these injuries, discusses factors that contributed to the high radiation doses, and, on the basis of this information, makes recommendations on dose management and patient care.

SKIN  INJURIES

Radiation-induced skin injuries are typically observed after a characteristic latent period following the procedure. In our reviewed case material, this period ranged from a few hours to more than 3 years, but most frequently was about 2 weeks to 3 months. Table 1 lists radiation skin effects in order of their time of onset. Threshold doses required to cause the skin effects are given in Gy (1 Gy = 100 rad). The photographs illustrate examples of these injuries.

Table 1

Effect		Single-dose Threshold (Gy)		Onset		Example
Early transient erythema		2		hours
Main erythema		6		~ 10 d		Fig. 1
Temporary epilation		3		~ 3 wk		Fig. 2
Permanent epilation		7		~ 3 wk
Dry desquamation		14		~ 4 wk		Fig. 3
Moist desquamation		18		~ 4 wk
Secondary ulceration		24		> 6wk		Fig. 4, 6, 13
Late erythema		15		~ 8-10 wk
Ischemic dermal necrosis		18		> 10 wk		Fig. 5, 6, 7
Dermal atrophy (1st phase)		10		> 12 wk		Fig. 9
Dermal atrophy (2nd phase)		10		>   1 yr
Induration  (Invasive fibrosis)		10				Fig. 12
Telangiectasia		10		>   1 yr		Fig. 10
Late dermal necrosis		> 12?		>   1 yr		Fig. 11
Skin cancer		unknown		>   5 yr
Gy: gray;  d: day(s); wk:  week(s); yr:  year(s)
Table 1.  Threshold skin entrance doses for skin injuries [3, 4]

Figure 1. Erythema is an early sign of radiation damage, thought to be a response to depletion of cells in the basal layer of the skin. This patient’s elbow rested on the x-ray port during a cardiac ablation procedure (3 weeks after procedure). (Reproduced with permission from Ref.5)		Figure 2. Epilation results from the depletion of stem cells in hair follicles. The affected area (5 weeks after embolization of a dural AV-fistula) is the bald spot. The head was shaved before treatment with gamma knife surgery.

Figure 3 (Reproduced with permission from Ref. 6)		Figure 4 (Reproduced with permission from Ref. 7)		Figure 5 (Reproduced with permission from Ref.5)
Figures 3-5. Skin desquamation (Fig 3), secondary ulceration (Fig 4) and ischemic dermal necrosis (Fig 5) may arise between 4 and 10 weeks after the procedure. Areas of skin injury are usually well defined and occur in typical locations (see section 3.) Wound healing is typically prolonged (it may take months to more than a year) and less efficient due to microvascular radiation damage in the dermis [8]. Prophylaxis against local infection is necessary.

Figure 6A		Figure 6B		Figure 6C
(Reprinted with permission from the American Journal of Roentgenology)		(Reprinted with permission from the American Journal of Roentgenology)		(Reprinted with permission from the American Journal of Roentgenology)
		Figures 6A-E. Progression of secondary ulceration. This patient had 3 TIPS procedures within one week. (a) at 6 months after last procedure, (b) at 7.5 months, (c) at 10 months,  (d) at 22 months, e) at 23 months with musculocutaneous skin graft. (From [2])
Figure 6D				Figure 6E
(Reprinted with permission from the American Journal of Roentgenology)				(Reprinted with permission from the American Journal of Roentgenology)

Despite all treatment, radiation ulcers can increase in size and depth to involve muscles, bones or even extend to the pleura. Ulcers that have slowly healed over an extended course have a tendency to recur, often provoked by trivial trauma. Pain can be difficult to control. In 23% of the reviewed cases, musculocutaneous skin grafting had to be performed. In a few cases, the initial graft failed probably due to the compromised vascular supply.

Figure 7

Figure 7. Deep ulceration on the back 13 months after TIPS procedure. Previous attempts at skin grafting failed. G = graft, R = exposed rib. This patient was thought to be abnormally sensitive to radiation due to his collagen vascular disease and diabetes mellitus. ((Reproduced with permission from Ref.9)

Figure 8		Figure 9		Figure 10
(Reproduced with permission from the American Journal of Roentgenology)		(Reproduced with permission from the American Journal of Roentgenology)		(Reproduced with permission from the American Journal of Roentgenology)
Figures 8-10. Hyperpigmentation (Fig 8), localized dermal atrophy (Fig 9) and telangiectasia (Fig 10) are permanent changes which occur between 3 months and more than a year. All patients had prior coronary angioplasties.(Reproduced with permission from Ref.9)

		Figure 11. Skin necrosis on posterior chest wall 3 years after coronary interventions. (Reproduced with permission from Ref.10)
Figure 11
		Figure 12. Subcutaneous fibrotic induration resulted in limitation of arm movement in this 17-year-old girl who had two cardiac ablation procedures two years earlier. Radiation induced skin injuries at the female breast also indicate high radiation doses  to breast tissue. This will increase, especially in adolescents, the statistical risk for breast cancer in the future. (Reproduced with permission from Ref.11)
Figure 12
		Figure 13. Chronic ulceration progressing into ischemic necrosis, surrounded by well demarcated erythema. Injury at approximately 3 to 4 months after coronary intervention .
Figure 13

WHICH  PROCEDURES  CAN  CAUSE  SKIN  INJURIES?

The majority of the cases of fluoroscopic skin injuries (63%) was caused by coronary procedures (PTCA, stent placement, atherectomy and diagnostic angiography). A smaller number of skin injuries was related to cardiac catheter radiofrequency ablation (17%), transjugular intrahepatic portosystemic shunt (TIPS) placement (10%), neuroradiological interventions (4%) and other abdominal or chest interventions (6%). The site of the injury corresponds to the site of the entrance beam and reflects the beam orientation predominately used during the procedure. Coronary procedures caused injuries at the right or left scapular or subscapular area, right lateral chest below axilla, midback, and right anterolateral chest. Cardiac ablation procedures lead to injuries at the back and arm, TIPS procedures at the right midback.

LESSONS  TO  BE  LEARNED  ON  DOSE  REDUCTION  AND  PATIENT  MANAGEMENT

• A good quality control program should be established to assure high standards in dose reduction and image quality.
  
• Prior to a procedure, the patient should be asked about previous fluoroscopic interventions. If the patient had a prior procedure, a brief skin inspection should follow.  Radiation exposure to pre-damaged skin should be avoided.
  
• Connective tissue diseases (e.g. scleroderma, lupus erythematosus, mixed connective tissue disease), diabetes mellitus, hyperthyroidism and the homozygous form of ataxia telangiectasia have been associated with an increased sensitivity to radiation [9].  Some chemotherapy agents are also known to increase radiation effects [8].  The history should include these risk factors. The patient should be advised about the potential higher risk .
  
• To avoid injuries when using an oblique or lateral beam projection, the patient's arm must be secured away from the primary beam.  Direct exposure of the female breast, especially en trance-beam exposure, must also be avoided.

B.  During the procedure:

 General rules of dose reduction must be followed, e.g. the image intensifier as close to the patient as possible, and a large distance between x-ray tube and patient.  If big air gaps between the patient and image intensifier cannot be avoided, the grid should be removed, if possible.

• Long exposure time was the primary factor related to injuries in our review. In addition the the simplistic rule for frugal use of fluoroscopy on-time and fluorographic imaging, fluoroscopists must also know how to reduce beam on-time by using dose-reducing variable pulsed fluoroscopy and employing minimal fluorographic frame rates.  Pulsed fluoroscopy can reduce the radiation dose by 50-70% without perceivable loss in image quality [12].  In long procedures, the incident beam angel should be varied to expose different areas of skin.  This will be effective only if the field of view is minimized by collimation.
  
• Irradiation through thick body masses (i.e. large patients and/or steep beam angulation) was a common factor related to injuries.  Physicians must realize that thick body masses exponentially decrease the penetrability of x-rays and cause the skin to be positioned closer  to the x-ray port.  Large patients result in poorer image quality, potentially increasing procedure difficulty and duration.  These factors serve to greatly increase the risk for injury when procedures are long.  Steep beam angulations should be used sparingly.
  
• Image magnification and high-detail mode should be used judiciously and sparingly.
  
• Real-time dose monitoring is recommended, as it enables the interventionalist re recognize high dose levels.  The interventionalist can take action to lessen the dose rate early, if the dose monitor indicates high radiation levels.  Normal values for the accumulated radiation dose exceeds a certain limit, consultation with more experienced staff should be sought. Dose monitoring will also detect increased output due to equipment malfunction.

C.  After the procedure:

Patients who receive a high skin dose (e.g., in excess of 3 Gy) should be counseled and advised on examining their skin.  If any skin changes are observed, the patient should contact the physician who performed the procedure.  This will facilitate patient care and serve as quality management information.

REFERENCES

[1] Owings, MF, Kozak, LJ. Ambulatory and Inpatient Procedures in the United States, 1996. National Center for Health Statistics. Vital Health Stat 1998;13

[2] Submitted and accepted for publication by the American Journal of Roentgenology (with permission of RadioGraphics)

[3] Wagner LK. Perspectives on radiation risks to skin and other tissues in fluoroscopy. In: Proceedings of the Thirty-Fifth Annual Meeting of the National Council on Radiation Protection and Measurements, No. 21; Arlington, Virginia; April 7-8, 1999;361-375

[4] John Hopewell, oral communication, 1999

[5] Wagner LK, Archer BR. Minimizing Risks from Fluoroscopic X Rays: Bioeffects, Instrumentation, and Examination, 3rd edition; Houston, TX; R. M. Partnership, 2000

[6] Stone MS, Robson KJ, LeBoit PE. Subacute radiation dermatitis from fluoroscopy during coronary artery stenting: evidence for cytotoxic lymphocyte mediated apoptosis. J Am Acad Dermatol 1998;38:333-336

[7] Granel F, Barbaud A, Gillet-Terver MN, et al. Radiodermites chroniques après cathétérisme interventionnel cardiaque. Quatre observations. Ann Dermatol Venereol 1998;125:405-407

[8] Trott K, Kummermehr J. Radiation effects in skin. In: Scherer E, Streffer C, Trott K, eds. Radiopathology of organs and tissues. Berlin: Springer-Verlag, 1991;33-66

[9] Wagner LK, McNesse MD, Marx MV, Siegel EL. Severe skin reactions from interventional fluoroscopy: case report and review of literature. Radiology 1999;213:773-776

[10] Dandurand M, Huet P, Guillot B. Radiodermites secondaires aux explorations endovasculaires : 5 observations. Ann Dermatol Venereol 1999;126:413-417

[11] Vañó E, Arranz L, Sastre JM, et al. Dosimetric and radiation protection considerations based on some cases of patient skin injuries in interventional cardiology. Br J Radiol 1998;71:510-516

[12] Wagner LK, Archer BR, Cohen AM. Management of patient skin dose in fluoroscopically guided interventional procedures. JVIR 2000;11:25-33

¹University of New Mexico-School of Medicine, ²Krefeld, Germany

 

Copyright 2002-Present | The Dept. of Diagnostic and Interventional Imaging The University of Texas Health Science Center at Houston Site Policies | State of Texas  |  Contact Us  | Site Publisher

The Dept. of Diagnostic and Interventional Imaging 6431 Fannin Street, MSB 2.132 Houston, Texas 77030 Phone: 713-500-7632   Fax: 713-500-7639

Last Modified June 25, 2007