Table 2.
Comparison of the dosimetric parameters, ADS and CTVHR for a single IGABT session between IGABT plans with and without HGI
| Parameters | IGABT plans without HGI (number of plans = 18) | IGABT plans with HGI (number of plans = 32) | P-value |
|---|---|---|---|
| CTVHRD90% (GyEQD2) | |||
| Median (IQR) | 7.88 (7.43–8.41) | 8.33 (7.99–8.85) | 0.049 |
| CTVHRV100% (%) | |||
| Median (IQR) | 100.0 (99.9–100.0) | 100.0 (100.0–100.0) | 0.042 |
| D2.0 cm3 of the rectum (GyEQD2) | |||
| Median (IQR) | 4.27 (3.06–4.93) | 3.68 (2.62–4.92) | 0.363 |
| D2.0 cm3 of the bladder (GyEQD2) | |||
| Median (IQR) | 5.78 (5.58–6.27) | 5.23 (4.31–6.00) | 0.037 |
| D2.0 cm3 of the sigmoid colon (GyEQD2) | |||
| Median (IQR) | 4.52 (4.12–5.00) | 4.60 (4.24–4.94) | 0.746 |
| D2.0 cm3 of the small intestine (GyEQD2) | |||
| Median (IQR) | 3.02 (2.41–4.30) | 2.59 (1.85–3.71) | 0.169 |
| ADS | |||
| Median (IQR) | 2.70 (2.46–2.99) | 2.37 (2.17–2.52) | 0.001 |
| CTVHR (cm3) | |||
| Median (IQR) | 29.77 (16.86–51.47) | 18.88 (16.48–43.41) | 0.461 |
ADS, adjusted dose score; CTVHR, high-risk clinical target volume; IGABT, image-guided adaptive brachytherapy; HGI, hyaluronate gel injection; CTVHRD90%, the minimum dose covering 90% of the CTVHR; EQD2, the equivalent dose in 2 Gy fractions; CTVHRV100%, the percentage of CTVHR receiving 100% of the prescription dose; D2.0 cm3, the most exposed 2.0 cm3; IQR, interquartile range.