Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
Radiother Oncol. 2018 Mar;126(3):411-416. doi: 10.1016/j.radonc.2017.11.007. Epub 2017 Nov 29.
To analyse the clinical use of needles and examine the feasibility to meet the planning criteria in three fractions of cervical cancer brachytherapy. Furthermore, to investigate whether the needles with the largest discrepancy between application and loading are essential to treatment planning.
For 22 patients we analysed the applied and loaded needle patterns, and examined the dosimetric results for small (<30 cm) and large (≥30 cm) CTV. We removed from the clinical plans (CP) the needles applied most, but with the lowest loading frequency and intensity and re-optimized these plans (RP).
On average 5.8 needles were applied and 4.8 loaded per fraction, with average intensity 22% (17% for small, 29% for large CTV). Mid-lateral needles were applied and loaded most frequently and intensely. The average CTV D prescribed dose was 88.8 Gy (SD 4.2) EQD2, the average OAR [Formula: see text] limit was respected. Omitting the mid-ventral needles, minimal statistically significant differences were found in dose distributions between RP and CP.
Applying on average 5.8 needles per fraction it was possible to meet the planning criteria for targets and OARs in three BT fractions for both small and large CTV. The mid-ventral needles were not essential in treatment planning, unless situated in the vicinity of the GTV.
分析宫颈癌近距离放疗中三分割治疗的针的临床应用，并探讨能否满足规划标准。此外，还研究了在应用和加载之间存在最大差异的针对于治疗计划是否是必需的。
我们分析了 22 例患者的应用和加载的针模式，并检查了小（<30cm）和大（≥30cm）CTV 的剂量学结果。我们从临床计划（CP）中删除了应用最多但加载频率和强度最低的针，并对这些计划（RP）进行了重新优化。
平均每个部分应用 5.8 根针，加载 4.8 根针，平均强度为 22%（小 CTV 为 17%，大 CTV 为 29%）。中侧针应用和加载最频繁和强烈。CTV D 规定剂量的平均值为 88.8Gy（SD 4.2）EQD2，OAR[公式：见文本]限制得到尊重。省略中腹针后，RP 和 CP 之间的剂量分布差异具有统计学意义。
平均每个部分应用 5.8 根针，对于小和大 CTV，在三个 BT 部分中都可以满足目标和 OAR 的规划标准。除非位于 GTV 附近，否则中腹针对于治疗计划不是必需的。
