Figure 1
Cone-Beam CT-guidance procedure on a 59-years-old male with a suspected mass in the hilum of the right kidney. Histopathological result revealed a small cell neuroendocrine carcinoma for which this patient underwent a nephrectomy. (A) Entrypoint (EP) geometric configuration of the C-arm, looking ‘down-the-barrel’ (with arrow). (B) shows the common geometric configuration of the C-arm in the Progress view (PV). This clearly shows the close position of the operator to the radiation beam.
Figure 2
The disposable lead drape armor (Pb equivalent of 0.25 mm) as positioned during the model measurement with a Rando-phantom®.
Figure 3
The rotation (A) and angulation (B) of the C-arm used during the model measurements of scatter radiation for the operator. Dose measurement was performed in every combination of rotation projections between -120 degrees to +120 degrees at an interval of 30 degrees and in every angulation projection with an interval of 20 degrees in a range between -40 degrees to +40 degrees.
Table 1
Overview of the characteristics used for the model and during the clinical cases.
| Thorax | Abdomen | total | ||
|---|---|---|---|---|
| Scatter radiation model | N | 47 | 66 | 113 |
| Sex | 19 women / 19 men | 28 women / 47 men | 47 women/ 66 abdomen | |
| Mean age (y) | 62.1 (range 24–85) | 63.9 (range 32–83) | 63.3 (range 24–85) | |
| Mean target size (mm) | 31.0 (95% CI 24.3–37.6) | 25.1 (95% CI 20.1–30.1) | 27.8 (95% CI 23.8–31.8) | |
| Mean BMI (kg/m2) | 23.9 (95% CI 23.5–24.3) | 23.9 (95% CI 23.5–24.3) | 23.9 (95% CI 23.8–24.0) | |
| Clinical cases | N | 17 | 20 | 37 |
| Sex | 5 women / 12 men | 8 women / 12 men | 13 women / 24 men | |
| Mean age (y) | 67.3 (range 35–83) | 62.6 (range 35–83) | 64.7 (range 35–83) | |
| Mean length size (mm) | 23.7 (95% CI 19.8–30.1) | 22.9 (95% CI 17.7–27.5) | 23.3 (95% CI 20.5–27.2) | |
| Mean BMI (kg/m2) | 24.4 (95% CI 23.4–25.5) | 24.0 (95% CI 22.9–25.0) | 24.2 (95% CI 23.5–24.9) |
Table 2
Overview of the data in entrypoint view, progress view and in total. Data is based on the clinical setting and used for the scatter radiation model.
| Entrypoint | Progress View | Total | ||||
|---|---|---|---|---|---|---|
| Thorax | Abdomen | Thorax | Abdomen | Thorax | Abdomen | |
| Fluoroscopy time (s); median (95% CI) | 74.4 (64.6–84.3) | 68.3 (62.4–74.1) | 137.9 (124.8–150.9) | 111.4 (103.9–118.8) | 212.3 (192.7–231.9) | 179.7 (168.7–190.6) |
| kV; median (95% CI) | 91.9 (90.4–93.3) | 98.6 (97.2–100.1) | 103.3 (101.2–105.3) | 117.7 (117.0–118.4) | ||
| mAs; median (95% CI) | 13.5 (13.3–13.7) | 14.7 (14.5–14.8) | 14.9 (14.6–15.1) | 15.4 (15.3–15.6) | ||
| Field Diameter (cm) ; median (95% CI) | 27.7 (25.3–30.1) | 28.0 (26.0–30.0) | 27.7 (25.6–29.7) | 31.1 (29.5–32.8) | ||
| Angulation; median (95% CI) | –3° (–8°–+2°) | 11° (7°–15.0°) | 0° (–0°–0°) | 0° (0°–0°) | ||
| Rotation; median (95% CI) | –4° (–12°–+5°) | –4.0° (–10°–+2°) | –22° (–44°–1°) | –25° (–45°– –6°) | ||
| Dose Hand (µSv); median (95% CI) | 10.7 (8.2–13.1) | 17.9 (13.2–22.6) | 23.5 (17.4–29.7) | 36.7 (30.9–42.6) | 34.2 (26.9–41.5) | 54.6 (46.9–62.4) |
| Dose Thyroid region (µSv); median (95% CI) | 68.6 (–3.4–140.5) | 42.6 (9.1–76.1) | 13.8 (9.2–18.4) | 23.6 (17.7–29.5) | 83.2 (11.1–155.3) | 66.2 (31.4–100.9) |
| Dose Gonads region (µSv); median (95% CI) | 17.8 (11.1–24.4) | 20.8 (17.2–24.4) | 16.1 (11.6–20.7) | 26.4 (20.9–32.0) | 34.3 (26.0–42.7) | 47.2 (39.9–54.5) |
| Dose Thyroid Shielding (µSv); median (95% CI) | 1.7 (–0.1–3.4) | 0.7 (0.2–1.2) | 0.5 (0.3–0.6) | 1.0 (0.7–1.3) | 2.2 (0.4–3.9) | 1.7 (1.1–2.3) |
| Dose Gonads Shielding (µSv); median (95% CI) | 1.3 (0.9–1.7) | 1.5 (1.2–1.8) | 1.3 (0.9–1.7) | 2.1 (1.6–2.6) | 2.6 (2.0–3.2) | 3.6 (2.9–4.2) |
| Dose Hand Drape (µSv); median (95% CI) | 3.3 (2.4–4.2) | 7.1 (4.1–10.0) | 4.6 (3.5––5.8) | 10.5 (6.3–14.8) | 7.9 (6.1–9.8) | 17.6 (11.9–23.4) |
| Dose Thyroid Drape (µSv); median (95% CI) | 94.7 (–22.1–211.6) | 76.8 (14.4–139.3) | 16.7 (8.7–24.7) | 21.8 (18.3–25.3) | 111.4 (–5.9–228.7) | 98.6 (35–161.4) |
| Dose Gonads Drape (µSv); median (95% CI) | 33.8 (19.2–48.5) | 34.3 (26.9–41.8) | 26.4 (9.3–33.5) | 37.8 (29.6–46.0) | 60.2 (43.9–76.5) | 72.1 (59.2–85.0) |
| Dose Thyroid Both (µSv); median (95% CI) | 0.06 (0.00–0.14) | 0.05 (0.03–0.08) | 0.02 (0.01–0.02) | 0.13 (0.05–0.21) | 0.08 (0.01–0.16) | 0.18 (0.08–0.28) |
| Dose Gonads Both (µSv); median (95% CI) | 0.06 (0.00–0.13) | 0.05 (0.02–0.08) | 0.18 (0.12–0.25) | 0.40 (0.24–0.56) | 0.37 (0.28–0.46) | 0.84 (0.55–1.13) |
Table 3
Thorax group.
| Couch/Ceiling Shielding | Lead drape Shielding | Couch/Ceiling and Lead drape Shielding | ||
|---|---|---|---|---|
| Hand | Entrypoint | No difference | –68.9% | No difference compared to lead drape shielding |
| Progress View | –80.4% | |||
| Total | –76.8% | |||
| Thyroid region | Entrypoint | –97.5% | +38.4% | –99.8% |
| Progress View | –96.6% | +13.8% | –99.5% | |
| Total | –97.4% | +33.9%* | –99.7% | |
| Gonad region | Entrypoint | –93.2% | +90.3% | –97.9% |
| Progress View | –91.6% | +59.3% | –98.4% | |
| Total | –92.4% | +75.3% | –98.2% |
Percentages of dose difference compared to the setting without any radiation shielding in the scatter radiation model. All percentages represent significant (p<0.05) changes expect the one marked with an asterix (*; p=0.31).
Table 4
Abdominal group.
| Couch/Ceiling Shielding | Lead drape Shielding | Couch/Ceiling and Lead drape Shielding | ||
|---|---|---|---|---|
| Hand | Entrypoint | No difference | –60.4% | No difference compared to lead drape shielding |
| Progress View | –71.3% | |||
| Total | –67.8% | |||
| Thyroid region | Entrypoint | –98.4% | +80.5% | –99.9% |
| Progress View | –95.8% | –7.7%* | –99.8% | |
| Total | –97.4% | +49.0% | –99.8% | |
| Gonad region | Entrypoint | –92.8% | +65.2% | –98.9% |
| Progress View | –92.0% | +42.9% | –98.7% | |
| Total | –92.4% | +52.8% | –98.9% |
Percentages of dose difference compared to the setting without any radiation shielding in the scatter radiation model. All percentages represent significant (p<0.05) changes expect the one marked with an asterix (*; p=0.43).