Department of Oncology, Aarhus University Hospital, Aarhus, Denmark; Department of Medical Physics, McGill University Health Centre, Montreal, Canada.
Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
Brachytherapy. 2021 Jul-Aug;20(4):796-806. doi: 10.1016/j.brachy.2021.03.019. Epub 2021 May 14.
To characterize and report on dosimetric outcomes of image guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) applicators including oblique needles (O-needles) in locally advanced cervical cancer (LACC).
Twenty LACC patients treated with radio-chemotherapy and offered IC/IS-IGABT including O-needles were analyzed. An in-house 3D-printed vaginal template was used to steer the needles parallel and obliquely in relation to the tandem, supplemented with free-hand needles if needed. Implant characteristics and loading patterns were analyzed. Using the equivalent dose in 2Gy-fractions (EQD2) concept, cumulative (EBRT+BT) V85, V75, V60Gy, targets/OARs doses and high dose volumes (150%, 200% and 300% (100% = 85 Gy EQD2)) were evaluated.
Median(range) tumor width at diagnosis was 5.5(3.6; 7.5)cm; CTV volume was 45(23; 136)cm with maximum distance from tandem to CTV border of 3.4(2.5; 4.8)cm. T-stage distribution was IIB/III/IVA in 6(30%)/9(45%)/5(25%) of patients. At BT, 13(65%) patients had distal parametrial/pelvic wall infiltration. Median(range) number of needles per patient was 11(8-18). Average distribution of intrauterine, vaginal and interstitial dwell times were 31%, 25% and 44%, respectively. Median(range) dwell-time per dwell position was 11(2-127)% of average point-A based standard loading. Median V/V/V/V were 85(38; 171)/41(21; 93)/22(12; 41)/7(4; 19) cm; CTV D was 93(83; 97)Gy EQD2; bladder/rectum/sigmoid/bowel D were 78(64; 104)/65(52; 76)/59(53; 69)/61(47; 76)Gy EQD2.
The use of O-needles in patients with large and/or unfavorable tumors resulted in excellent target coverage and OARs sparing. Intrauterine and vaginal loadings were reduced compared to standard loading and almost half of the loading was shifted into IS needles. This was achieved with gentle loading in the majority of dwell positions.
描述并报告使用腔内和间质（IC/IS）施源器（包括斜针）进行局部晚期宫颈癌（LACC）图像引导自适应近距离治疗（IGABT）的剂量学结果。
分析了 20 例接受放化疗并接受 IC/IS-IGABT 治疗的 LACC 患者，包括斜针。使用内部 3D 打印的阴道模板引导针平行和倾斜放置于 tandem 中，如果需要，则补充自由放置的针。分析了植入物的特征和加载模式。使用等效剂量 2Gy 分数（EQD2）概念，评估了累积（EBRT+BT）V85、V75、V60Gy、靶区/OARs 剂量和高剂量体积（150%、200%和 300%（100%=85 Gy EQD2））。
诊断时肿瘤宽度的中位数（范围）为 5.5（3.6；7.5）cm；CTV 体积为 45（23；136）cm，tandem 与 CTV 边界的最大距离为 3.4（2.5；4.8）cm。T 期分布为 IIB/III/IVA 期的患者分别为 6（30%）/9（45%）/5（25%）例。在 BT 时，13（65%）例患者有远端宫旁/骨盆壁浸润。中位数（范围）每个患者的针数为 11（8-18）根。宫内、阴道和间质驻留时间的平均分布分别为 31%、25%和 44%。中位数（范围）每个驻留位置的驻留时间为基于平均点 A 的标准加载的 11（2-127）%。中位数 V/V/V/V 分别为 85（38；171）/41（21；93）/22（12；41）/7（4；19）cm；CTV D 为 93（83；97）Gy EQD2；膀胱/直肠/乙状结肠/肠 D 分别为 78（64；104）/65（52；76）/59（53；69）/61（47；76）Gy EQD2。
在大肿瘤或位置不佳的患者中使用斜针可实现优异的靶区覆盖和 OAR 保护。与标准加载相比，宫内和阴道的加载减少，几乎一半的加载转移到 IS 针中。这是通过在大多数驻留位置进行温和加载实现的。
