Chapter 4: Case Studies of Radiation Injury
Non-Symptomatic Skin Reactions
Minor skin reactions caused by X-rays can be easily misattributed
to other causes (e.g. sun exposure or rashes). Also, since these skin reactions
are delayed effects, they typically would not be be seen in the clinic.
Thus, patients and caregivers may not be aware of skin changes that can be caused
by lengthy fluoroscopic procedures (Wagner 1999). The following case study
is a useful example:
- Physical examination one year following coronary angioplasty identified a 1 x 2.5
cm-depigmented area with telangiectasia on the patient’s left shoulder. Total fluoroscopy time: 34 minutes.
-
One year after PTCA involving 66 minutes of fluoroscopy, a 10-cm diameter hyperpigmented area
with telangiectasia was evident on the patient’s right shoulder.
The above skin changes were in areas not visible to the patients and were only identified upon physical
examination.
Symptomatic Skin Reactions
The circumstances leading to symptomatic radiation induced changes are varied. Case reports are grouped
according to common factors in order to identify the reasons for radiation-induced effects.
PA Fluoroscopy
The posteroanterior (PA) orientation of the fluoroscope, when properly configured with the image
intensifier down close to the patient, is probably the least problematic with regard to
Entrance Skin Exposure (ESE) rate.
However, extended fluoroscopy usage has resulted in reports of skin damage. The following case study,
which did not occur at Henry Ford Health System, illustrates this effect (Shope 1995).
On March 29, 1990, a 40-year-old male underwent coronary angiography, coronary angioplasty and a second angiography procedure (due to
complications) followed by a coronary artery by-pass graft. Total fluoroscopy time estimated to be > 120 minutes.
Figure 4-1 shows the area
of injury six to eight weeks following the procedures. The injury was described as "turning red about one month after the procedure and peeling a
week later." In mid-May 1990, it had the appearance of a second-degree burn.
Figure 4-1: 6-8 Weeks Post Procedure
Courtesy of Wagner, 1999
Note the square pattern of the injury.
Figure 4-2 shows the appearance of skin injury approximately 16 to 21 weeks following the
procedures with small ulcerated area present.
Figure 4-2: 16-21 Weeks Post Procedure
Courtesy of Wagner, 1999
Appearance of skin injury approximately 18 to 21 months following procedures,
evidencing tissue necrosis:
Figure 4-3: 18-21 months Weeks Post Procedure
Courtesy of Wagner, 1999
Figure 4-4 shows a close-up of injury area at 18-21 months:
Figure 4-4: 18-21 Months Post Procedure
Courtesy of Wagner, 1999
Two additional reported cases of radiation-induced injury (Wagner 1999):
-
Following a transjugular intrahepatic portosystemic shunt (TIPS) procedure involving 90 minutes of
fluoroscopy, a discharged patient developed erythema and discoloration on his back. One year after
the TIPS procedure an ulcer developed, which did not heal, and two years later it was 4-cm in size.
A split thickness skin graft from the right buttock was performed.
- Following a TIPS procedure lasting 6 hours and 30 minutes (no indication of total fluoroscopy time),
a 16- x 18-cm hyperpigmented area developed on the patient’s back and progressed over a period
of several months into a central area with ulceration. After 14 months a split thickness skin graft
was performed leaving a depressed scar at the surgical sight.
These case studies indicate that extensive use of fluoroscopy can induce severe skin damage, even
under the most favorable geometries.
Steep Fluoroscopic Angles
When the fluoroscope is oriented at a lateral or an oblique angle, two factors combine to increase the
patient’s ESE rate. The first is that a thicker mass of body tissue must be penetrated. The second is that the
skin of the patient is closer to the source because of the wider span of anatomy (Wagner 1999). Example
cases are given below:
-
A PA oblique angle using a C-arm involved 57 minutes of fluoroscopy. Twenty-four hours later the
patient reported a stabbing pain in his right thorax. Three days later an erythema developed which
evolved into a superficial ulcer. At two and half months after the procedure the area was
approximately 12-cm x 6.5-cm and described as a brownish pigmented area with
telangiectasia, central infiltration and hyperkeratosis.
- A PA oblique angle was employed during a catheter ablation procedure involving 190 minutes of
fluoroscopy. A symptomatic discoloration was noted several days after the procedure on the
patient’s left upper back. In the next few weeks the area had become painful and was draining. At
seven weeks the area was approximately 7- x14-cm in size and described as a rectangular erythema
with ulcers. After treatment, there was a gradual lessening of tenderness with
reepitherlialization, leaving a mottled slightly depressed plaque.
- A steep PA oblique angle through the right shoulder was employed involving 51 minutes of
fluoroscopy. Fourteen days after the procedure, an erythema appeared on the right shoulder that
progressed into moist superficial ulcer with poor healing. This degenerated into a deep muscular
ulcer requiring a myocutaneous skin graft approximately 14 months after the procedure.
The temporal progressions of these effects are consistent with high levels of acute exposure to x-ray
radiation. The temporal differences in the responses are due in part to the levels of radiation
received, but are also likely due to variations in radiation sensitivity amongst the patients.
Multiple Procedures
Although intervals between procedures should permit the skin to recover, healing might not be complete.
This may lower the tolerance of the skin for further procedures (Wagner
1999). Example cases are given below:
-
A patient underwent two PTCA procedures about one year apart. Skin changes appeared
approximately three weeks after the second procedure. At seven weeks a cutaneous ulcer had
developed over the right scapula and healed without grafting.
- A patient underwent two unsuccessful cardiac ablations involving approximately 100 minutes of
fluoroscopy in a lateral oblique orientation. Approximately 12 hours after the second attempt, an
erythema developed in the right axilla. At one month the area was red and blistering. At two years
the area was described as a 10 x 5cm atrophic indurated plaque with lineal edges, hyper- and
hypopigmentation, and telangiectasia. The patient was described as having difficulty raising her right
arm.
-
Three PTCAs were performed on the patient, the last two completed on the same day
approximately 6 months after the first procedure. The total fluoroscopy time was approximately 51
minutes. Erythema was noted immediately after the last procedure. This progressed from a
prolonged erythema with poor healing into a deep dermal necrosis. The patient underwent a
successful split thickness skin graft two years after the last procedure.
-
Past treatment of pulmonary tuberculosis often resulted in many patients undergoing extensive
exposure to fluoroscopy. These patients had a demonstrated high incidence of breast cancer.
Previous procedures can lower the skin’s tolerance for future irradiation. Prior to commencing any
lengthy fluoroscopic procedure, the patient’s medical history should be reviewed. The skin of the patient
should be examined to ascertain if any skin damage is apparent should the patient have a history of lengthy
fluoroscopic examinations. Direct irradiation of damaged areas should be avoided when possible.
Positions of arms
Keeping arms out of the x-ray beam during some procedures can be a difficult. Careful attention
must be given to providing the arms with a resting position that will not restrict circulation but will at the
same time maintain the arms in an area that is outside the radiation field (Archer 2000).
A middle-aged woman had a history of progressively worsening episodes of arrhythmia. A
radiofrequency electrophysiological cardiac catheter ablation was scheduled to treat the condition.
The procedure employed 20 min of beam-on time for each plane of a bi-plane fluoroscope. Prior
to the procedure the separator or spacer cone was removed so that the fluoroscopic c-arms could be
easily rotated around the patient. The spacer cone is a spacer attached to the tube housing
designed to keep the patient at a reasonable distance from the x-ray source. This is done
specifically to avoid the high skin-dose rates that can be encountered near the tube port.
The patient’s arms were originally placed at the patient’s side but the right
arm later fell into a lower position directly in front of this x-ray tube. However, personnel were not aware of this change because sterile covers
were draped over the patient and did not correctly interpret the image (Figure
4-4). The right humerus was directly in the beam at the port. Because the separator cones were removed, the arm was only
about 20–30 cm from the focal spot. With the soft tissue and bone of the arm directly in the beam, the automatic brightness control drove the output to high levels at the surface
of the arm. The cumulative dose probably exceeded 25 Gy (2500 rad).
This procedure was not performed at Henry Ford Health System.
Figure 4-4: Image of Arm resting on X-ray Tube Port
Courtesy of Archer, 2000
The patient was released from the hospital the day after the procedure. At the
time there were no complaints regarding her arm and no indication of
erythema. About three weeks after the procedure, a bright erythema was
demonstrated (Figure 4-5).
Figure 4-5: Three weeks Post Procedure
Courtesy of Archer, 2000
The condition worsened and at five months a large ulcer the size of the
collimated x-ray port developed.
Figure 4-6: Five Months Post Procedure
Courtesy of Archer, 2000
The separator or spacer cone ensures that a minimal distance between the X-ray source and the patient is
maintained (inverse square law effects). For some X-ray machines, the spacer cone is designed to be
removable in order to provide more flexibility in positioning for some special surgical procedures (e.g.,
portable C-arms). There is a risk of very high dose rates to the skin surface when it is removed.
Skin Sensitivity
Some patients may be hypersensitive to radiation due to pre-existing health conditions (Wagner 1999).
Erythema developed after diagnostic angiography and liver biopsy. Skin necrosis requiring rib
resection evolved in the same patient after a TIPS procedure. The wound remained open for five
years before a successful cover was put in place. Investigation into the events revealed that the
patient suffered from multiple problems, including Sjøgren’s syndrome and mixed connective tissue
disease.
Injuries to personnel
The following are modern-day examples of how improper use of the fluoroscope can lead to injuries in
personnel (Wagner 1999).
-
Hands of physicians have incurred physiologic changes indicative of high cumulative doses of chronic
low-dose-rate irradiation. Brown finger nails and epidermal degeneration are typical signs. These
changes were the result of years of inserting hands into the x-ray field with the x-ray tube above the
patient.
-
Four cases of radiation-induced cataract have been reported in personnel from procedures utilizing
the x-ray tube above the patient orientation.
Doses accumulated to hands and eyes from frequently using the fluoroscope with the tube above
the patient can be extremely high. Only routine application of proper radiation management
techniques will be effective at avoiding such high doses.
Go to Chapter 5: Protection Methods
