Papanikolaou Panos, Swanson Gregory, Stathakis Sotirios, Mavroidis Panayiotis
Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
Department of Radiation Oncology, Baylor Scott & White Health, Temple, Texas.
Adv Radiat Oncol. 2023 Oct 21;9(3):101393. doi: 10.1016/j.adro.2023.101393. eCollection 2024 Mar.
Our purpose was to determine and model the dose-response relations of different parts of the pelvis regarding the endpoint of hematocrit level drop after pelvic radiation therapy (RT).
Two hundred and twenty-one patients treated with RT for prostate adenocarcinoma between 2014 and 2016 were included. All patients had complete blood counts collected at baseline and 3 months post-RT. The net difference of hematocrit level post-RT versus baseline was calculated, and the level of the 15th percentiles defined the thresholds of response in each case. The doses to 8 different pelvic structures were derived and fitted to the hematocrit levels using the relative seriality normal tissue complication probability model and the biologically equivalent uniform dose ().
Pelvic structures that correlated with significant decreases in hematocrit were the os coxae bilaterally superior to the acetabulum (OCUB), the total os coxae bilaterally, and the bone volume of the whole pelvis. The structure showing the highest correlation was OCUB with a maximum area under the curve (AUC) of 0.74. For V20 Gy < 30% the odds ratio was 9.8 with 95% CI of 2.9 to 32.9. For mean dose (D) to OCUB, an AUC of 0.73 was observed where the dose threshold was 23 Gy and the odds ratio was 2.7 and 95% CI 1.3 to 5.6. The values for the D50, γ, and s parameters of the relative seriality model were 26.9 Gy (25.9-27.9), 1.3 (1.2-2.2), and 0.12 (0.10-0.83), respectively. The AUC of was 0.73 and patients with to OCUB ≥ 27 Gy had 8.2 times higher rate of significant hematocrit drop versus <27 Gy.
These findings confirm the association of radiation-induced damage to pelvic bone marrow with a drop in hematocrit. A threshold of V20 Gy < 30%, D < 23 Gy, or < 27 Gy to OCUB may significantly reduce the risk for this endpoint.
我们的目的是确定盆腔放疗（RT）后血细胞比容水平下降这一终点时骨盆不同部位的剂量反应关系并建立模型。
纳入2014年至2016年间接受前列腺腺癌放疗的221例患者。所有患者在基线和放疗后3个月采集全血细胞计数。计算放疗后与基线时血细胞比容水平的净差异，每组中第15百分位数水平定义反应阈值。利用相对串联性正常组织并发症概率模型和生物等效均匀剂量（ ）得出8个不同盆腔结构的剂量，并将其与血细胞比容水平进行拟合。
与血细胞比容显著降低相关的盆腔结构为双侧髋臼上方的髋骨（OCUB）、双侧髋骨整体以及整个骨盆的骨体积。相关性最高的结构是OCUB，曲线下面积（AUC）最大值为0.74。当V20 Gy < 30%时，优势比为9.8，95%置信区间为2.9至32.9。对于OCUB的平均剂量（D），观察到AUC为0.73，剂量阈值为23 Gy，优势比为2.7，95%置信区间为1.3至5.6。相对串联性模型的D50、γ和s参数值分别为26.9 Gy（25.9 - 27.9）、1.3（1.2 - 2.2）和0.12（0.10 - 0.83）。 的AUC为0.73，OCUB的 ≥ 27 Gy的患者与<27 Gy的患者相比，血细胞比容显著下降的发生率高8.2倍。
这些发现证实了辐射诱导的盆腔骨髓损伤与血细胞比容下降之间的关联。V20 Gy < 30%、D < 23 Gy或OCUB的 < 27 Gy这一阈值可能显著降低该终点事件的风险。
