Methods:
We retrospectively analyzed the DICOm Dose reports of fluoroscopically guided interventional (IR) and neuro-interventional (NIR) procedures performed between January 2016 and December 2018.
Procedures with a Cumulative Air Kerma at reference point (CAK) ≥4 Gy were considered to be a high dose procedures.
CAK >4 Gy triggers an automatic dose alert to a Medical Physics Expert and the operator.
In addition,
a web-based automatic dose monitoring software was used to identify all procedures exceeding 4 Gy CAK.
Skin dose and dose to critical organs was not calculated.
All cases met one or more criteria of SAFRAD (SAFety in RADiological procedures [1]) reporting system (in all 40 cases the fluoroscopy time was >40 minutes and Kerma-Air product (KAP) was >200 Gy.cm²,
in 15 out of 40 cases the CAK was >5 Gy).
Results:
40 (0,8%) out of 4964 procedures (IR and NIR procedures performed over the 3-year period) exceeded CAK of 4 Gy.
In this study,
26 (65%) male and 14 (35%) female patients with a median age of 68 years (56,5 – 74,7) and median Body Mass Index (BMI) of 29,6 kg/m² (26,6 – 34,0) (*BMI of 39 patients) were exposed to a high dose during the procedure (CAK >4 Gy).
BMI was slightly higher among cases with the total dose >5 Gy (median BMI 34,1 kg/m²) compared with the median BMI 28,9 kg/m² among cases with the total dose of 4 – 5 Gy,
though the difference was not statistically significant (Mann-Whitney U test p=0,155,
α=0,05).
Of 40 cases,
37 were interventions and 3 were diagnostic angiographies (intervention was not possible due to complexity of the case).
The most common IR procedures with a CAK >4 – 5 Gy were endovascular aortic repair (EVAR; 4 patients = 10%) and abdominal/pelvic embolisation (9 pts = 22,5%) procedures,
the most common NIR procedures with a CAK >4 – 5 Gy were coiling of an intracranial aneurysm (9 pts= 22,5%,
*ballon-assisted coiling = 2 pts,
stent-assisted coiling = 7 pts) and embolisation of an arteriovenous fistula (AVF) (2 pts= 5%).
Overall,
15 patients (37,5%) exceeded a CAK of >5 Gy,
among these cases 12 were within the IR group.
8 patients in the IR group were treated on an emergency basis for life threatening bleeding (3 retroperitoneal bleeding,
2 bleeding originating from HCC,
1 acute type-B aortic dissection,
1 traumatic pelvic bleeding,
1 bleeding after the removal of hip joint implant) and 4 patients were treated electively (2 endovascular aortic repair,
1 TACE by replaced left hepatic artery arising from the left gastric artery,
1 angiography of the pelvis without intervention (failed Implantation of a stent into an occluded A.
Iliaca interna prior to EVAR).
Within the NIR group only 3 cases exceeded >5 Gy,
these 3 patients were treated electively (1 stent-assisted coiling of an intracranial internal carotid artery aneurysm,
1 embolization of an intracranial arteriovenous malformation (AVM),
1 angiography of a spinal AVM without intervention (unsuccessful embolisation due to anatomical issues)).
There were no reported short term skin injuries.
Also,
a recent article has shown that radiation-induced skin reactions are uncommon (B.C.
Perry et al.
2018 [2]).
Long term effects to the skin (hair loss,
skin changes) are currently evaluated.
TABLE 1.
Dose
|
4 – 5 Gy
(n=25)
|
>5 Gy
(n=15)
|
Median age
|
68 (59 – 74)
|
69 (53 – 76)
|
Median BMI,
kg/m2
|
28,9 (26,1 – 31,5)
|
34,1 (26,7 – 37,1)
|
Median total dose,
Gy
|
4,5 (4,2 – 4,6)
|
5,9 (5,4 – 7,8)
|
Median FT,
hours
|
2,1 (1,2 – 3,7)
|
2,2 (1,0 – 3,3)
|
TABLE 2.
Dose
|
IR
n=24
|
NIR
n=16
|
Emergency procedures
n=18
|
Cases total dose,
≥ 5 (Gy)
|
12/24
|
3/16
|
8/18
|
Median total dose,
(Gy)
|
5,0 (4,5-6,0)
|
4,5 (4,3-4,7)
|
4,8 (4,5-5,4)
|
Median BMI,
kg/m2
|
32 (26,8 – 36,5)
|
28 (25,1 – 30,1)
|
30,4 (26,7 – 40)
|
Abbreviations: IR (interventional radiology),
NIR (neuro-interventional radiology),
CAK (Cumulative Air Kerma),
Kerma-Air product (KAP),
BMI (Body Mass Index),
TACE (transarterial chemoembolisation),
FT (fluoroscopy time).