Department of Urology, University of Alabama Birmingham, United States of America.
Department of Radiology, University of Alabama Birmingham, United States of America.
J Pediatr Urol. 2024 Aug;20(4):745.e1-745.e6. doi: 10.1016/j.jpurol.2024.06.003. Epub 2024 Jun 7.
Children with spina bifida (SB) undergo a videourodynamic study (VUDS) or urodynamic study and voiding cystourethrogram (VCUG). A standardized protocol for imaging during a pediatric VUDS has not been established. Our aim is to quantify radiation exposure and establish a baseline for children with spina bifida (SB) undergoing VUDS in current practice at our institution.
This is a retrospective study from 2013 to 2020 of consecutive pediatric SB patients undergoing VUDS by a single provider. Patients were categorized into three groups based on age; group 1 (0-2 YR), group 2 (2-10 YR), group 3 (>10 YR). Radiation data was reported as mean air kerma (AK), dose area product (DAP) and exposure time (seconds). Effective dose (ED) was calculated based on radiation quantity (Air Kerma, AK) and organ sensitivity. The lifetime attributable risk (LAR) was calculated based on AK and a risk coefficient. Data points calculated for patients undergoing VUDS were then compared to age matched institutional VCUG data in the same age groups.
398 patients undergoing VUDS met inclusion criteria and 262 independent patients underwent VCUG. ED increased with age in both VUDS and VCUG. All VCUG groups were found to have a higher ED than VUDS. The LAR for VUDS groups 1-3 was 0.001, 0.002, and 0.006, respectively. Reported in percentages, there is a 0.1%, 0.2%, and 0.6% chance, respectively, of age groups 1, 2 and 3 developing cancer as a result of the radiation exposure from a VUDS.
Our study found that ED was low across all age groups for VUDS, comparing favorably to the VCUG groups. VCUG was selected as a benchmark comparison for its diagnostic similarities and, at times, overlapping indications. Few studies have described ED with respect to VUDS or extrapolate the ED of VUDS into LAR in the pediatric population. We recognize that we have not determined the true ED of the gonads and bladder, rather we have overestimated, as the data is based on an international reference point proximal to the exposed individual. However, LAR was calculated for each age group and revealed that patients are at a negligible increased risk of developing malignancy secondary to exposure compared to the general population.
Our current practice for pediatric VUDS has exhibited consistently low radiation exposure amongst all age groups. Moving forward, we have the foundation and flexibility to create an imaging protocol for pediatric VUDS, while taking more calculated steps toward incorporating ALARA, as low as reasonably achievable, principles. A protocol adhering to the ALARA principle could provide consistency across institutions and aid in multi-institutional studies.
患有脊柱裂（SB）的儿童会进行尿动力学研究（VUDS）或尿动力学研究和排尿膀胱尿道造影（VCUG）。目前尚未为儿科 VUDS 制定成像标准协议。我们的目的是量化辐射暴露，并为在我们机构接受 VUDS 的脊柱裂（SB）儿童建立基线。
这是 2013 年至 2020 年期间由一名医生对连续的儿科 SB 患者进行的回顾性研究。根据年龄将患者分为三组；第 1 组（0-2 岁）、第 2 组（2-10 岁）和第 3 组（>10 岁）。辐射数据以平均空气比释动能（AK）、剂量面积乘积（DAP）和曝光时间（秒）表示。有效剂量（ED）根据辐射量（空气比释动能，AK）和器官敏感性计算。基于 AK 和风险系数计算终生归因风险（LAR）。对接受 VUDS 的患者进行计算的数据点然后与相同年龄组的机构 VCUG 数据进行比较。
398 名接受 VUDS 的患者符合纳入标准，262 名患者接受了独立的 VCUG。在 VUDS 和 VCUG 中，ED 随年龄增长而增加。所有 VCUG 组的 ED 均高于 VUDS。VUDS 组 1-3 的 LAR 分别为 0.001、0.002 和 0.006。以百分比表示，1、2 和 3 组分别有 0.1%、0.2%和 0.6%的几率因 VUDS 辐射而患上癌症。
我们的研究发现，VUDS 所有年龄段的 ED 均较低，与 VCUG 组相比具有优势。选择 VCUG 作为基准比较，是因为它具有相似的诊断功能，并且有时具有重叠的适应症。很少有研究描述过 VUDS 的 ED，或者将 VUDS 的 ED 外推到儿科人群中的 LAR。我们认识到，我们没有确定性腺和膀胱的真实 ED，而是进行了高估，因为数据是基于靠近暴露个体的国际参考点。然而，为每个年龄组计算了 LAR，并揭示了与一般人群相比，患者因暴露而患恶性肿瘤的风险增加可以忽略不计。
我们目前对儿科 VUDS 的做法在所有年龄段都表现出一致的低辐射暴露。展望未来，我们为儿科 VUDS 制定成像协议奠定了基础和灵活性，同时朝着采用可合理达到的尽量低的原则（ALARA）采取更具计算性的步骤。遵守 ALARA 原则的协议可以在机构之间提供一致性，并有助于多机构研究。
