Part II | Chapter 9 188 FS-HDR-BT MR-Linac Parameter Reference Median Range Median Range p-value Target coverage D95% CTV/PTV* ³ 19.0 Gy 18.8 Gy 14.0-21.7 19.0 Gy 15.5-21.7 0.053 D90% CTV/PTV* ³ 17.0 Gy 20.3 Gy 15.9-23.8 20.2 Gy 16.7-22.6 0.484 High-dose volumes V100% CTV/PTV* - 95% 73-99 95% 69-100 0.894 V150% CTV/PTV* - 55% 25-77 1% 0-38 < 0.001 V200% CTV/PTV* - 25% 9-54 0% - < 0.001 OAR dose D10% urethra < 17.7 Gy 16.0 Gy 6.7-18.2 17.5 Gy 8.2-17.7 < 0.001 D1cm3 rectum < 12.0 Gy 10.2 Gy 4.1-12.0 12.0 Gy 9.4-12.0 < 0.001 D2cm3 rectum - 8.6 Gy 1.6-10.8 10.7 Gy 8.4-11.3 < 0.001 D1cm3 bladder < 12.0 Gy 8.5 Gy 1.8-12.1 8.4 Gy 0.4-12.0 0.102 D2cm3 bladder - 7.0 Gy 1.6-10.8 6.6 Gy 0.5-11.1 0.090 FS-HDR-BT MR-Linac Location Near or between OARs? n Median D95 CTV (Gy) Range (Gy) Median D95 PTV (Gy) Range (Gy) Peripheral No 5 20.0 19.1-21.1 21.0 20.4-22.0 Central U 3 19.7 16.6-21.2 19.0 19.0-19.7 Peripheral U and R 3 19.1 17.5-19.1 19.0 18.1-19.2 Central U and R 4 18.4 17.7-18.7 18.5 17.4-19.3 Central U and B 3 15.2 14.0-21.7 17.7 17.0-20.7 Peripheral R 4 19.7 18.6-21.1 19.1 18.8-20.1 Seminal vesicles R and/or B 5 16.8 16.0-19.2 17.9 15.5-19.1 Base R and B 3 16.3 15.7-18.7 16.1 16.0-18.6 Table 2 – Dosimetric parameters for FS-HDR-BT plans and MR-Linac plans (n = 30) for a single, 19.0 Gy dose prescription to the Clinical Target Volume (CTV) and Planning Target Volume (PTV), respectively. *CTV for FS-HDR-BT plan and PTV for MR-Linac plan. Legend: DXX% = Dose to XX% of the volume. VXXX% = Volume receiving XXX% of the prescribed dose. OAR = Organ-at-risk. DXcm3 = Highest dose to X cm3 of the volume of interest. Table 3 – Median D95% coverage with ranges for the different tumour locations (both anatomical location and position with respect to organs-at-risk) for FS-HDR-BT and MR-Linac plans respectively. Legend: OARs = Organs-at-risk. D95 = Dose to 95% of the volume. CTV = Clinical Target Volume. U = Urethra. R = Rectum. B = Bladder.
RkJQdWJsaXNoZXIy MTk4NDMw