Purpose

Stereotactic radiosurgery (SRS) is an important management strategy for residual and recurrent craniopharyngiomas. The current study evaluated the factors which affected tumor control and complications in craniopharyngioma SRS.

Methods

This study includes 53 consecutive patients who underwent single-session SRS for recurrent or residual craniopharyngiomas. The median age was 41 years with 28 male and 25 females. The median tumor volume was 0.63 cm³ and median margin dose was 12 Gy (range 9–25 Gy).

Results

The overall 3-, 5-, and 10-year survival rates were 97.8%, 92.7% and 88.5%. The overall 3-, 5-, and 10-year tumor control rates were 81.0%, 72.1%, and 53.4%. In univariate analysis, ≥ 3 mm distance from optic structures (p = 0.002), only solid or cystic tumor type (p = 0.037), and ≥ 12 Gy to ≥ 85% of the tumor (p < 0.001) were significantly associated with improved tumor control. In multivariate analysis, only solid or cystic tumor type, (p = 0.034), and ≥ 85% of the tumor receiving ≥ 12 Gy (p = 0.004) were significantly associated with better tumor control. When ≥ 85% of the tumor received ≥ 12 Gy the tumor control rates at 3-, 5-, and 10-year were 100%, 93.3%, and 93.3%. Higher conformity index was not associated with better tumor control.

Conclusions

The tumor control rates after recurrent or residual craniopharyngiomas SRS were improved by ensuring that at least 85% of the tumor received ≥ 12 Gy even when the distance between the tumor and the optic system is < 3 mm. This concept refutes the conformity theory that a high conformity index is a critical feature of effective SRS.

中文翻译：

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优化复发性或残留颅咽管瘤患者的立体定向放射外科治疗

目的

立体定向放射外科（SRS）是治疗残留和复发颅咽管瘤的重要策略。目前的研究评估了影响颅咽管瘤 SRS 肿瘤控制和并发症的因素。

方法

这项研究包括 53 名连续接受单次 SRS 治疗复发或残留颅咽管瘤的患者。中位年龄为 41 岁，其中男性 28 人，女性 25 人。中位肿瘤体积为 0.63 cm ³，中位边缘剂量为 12 Gy（范围 9-25 Gy）。

结果

总体 3 年、5 年和 10 年生存率分别为 97.8%、92.7% 和 88.5%。总体 3 年、5 年和 10 年肿瘤控制率分别为 81.0%、72.1% 和 53.4%。在单变量分析中，距视结构 ≥ 3 mm 的距离 (p = 0.002)、仅实性或囊性肿瘤类型 (p = 0.037) 和 ≥ 12 Gy 至 ≥ 85% 的肿瘤 (p < 0.001) 与改善显着相关肿瘤控制。在多变量分析中，只有实体或囊性肿瘤类型 (p = 0.034) 和 ≥ 85% 的肿瘤接受 ≥ 12 Gy (p = 0.004) 与更好的肿瘤控制显着相关。当 ≥ 85% 的肿瘤接受 ≥ 12 Gy 时，3 年、5 年和 10 年的肿瘤控制率分别为 100%、93.3% 和 93.3%。较高的一致性指数与较好的肿瘤控制无关。

结论

通过确保至少 85% 的肿瘤接受 ≥ 12 Gy 的照射，即使肿瘤与光学系统之间的距离 < 3 mm，复发或残留颅咽管瘤 SRS 后的肿瘤控制率也有所提高。这一概念驳斥了一致性理论，即高一致性指数是有效 SRS 的关键特征。