Wilson Lydia J, Belko Sara, Gingold Eric, Wan Shuying, Monane Rachel, Pugliese Robert, Mourtada Firas
Department of Radiation Oncology, Thomas Jefferson University Hospital, Philadelphia, PA 19107, USA.
Health Design Lab, Thomas Jefferson University, Philadelphia, PA 19107, USA.
Pharmaceuticals (Basel). 2025 Apr 8;18(4):550. doi: 10.3390/ph18040550.
Accurate patient-specific dosimetry is essential for optimizing radiopharmaceutical therapy (RPT), but current tools lack validation in clinically realistic conditions. This work aimed to develop a workflow for designing and fabricating patient-derived, organ-realistic RPT phantoms and evaluate their feasibility for commissioning patient-specific RPT radioactivity quantification. We used computed tomographic (CT) and magnetic resonance (MR) imaging of representative patients, computer-aided design, and in-house 3D printing technology to design and fabricate anthropomorphic kidney and parotid phantoms with realistic organ spacing, anatomically correct orientation, and surrounding tissue heterogeneities. We evaluated the fabrication process via geometric verification (i.e., volume comparisons) and leak testing (i.e., dye penetration tests). Clinical feasibility testing involved injecting known radioactivities of Lu-PSMA-617 into the parotid and kidney cortex phantom chambers and acquiring SPECT/CT images. MIM SurePlan MRT SPECTRA Quant software (v7.1.2) reconstructed the acquired SPECT projections into a quantitative SPECT image and we evaluated the accuracy by region-based comparison to the known injected radioactivities and determined recovery coefficients for each organ phantom. Phantom fabrication costs totaled < USD 250 and required <84 h. Geometric verification showed a slight systematic expansion (<10%) from the representative patient anatomy and leak testing confirmed watertightness of fillable chambers. Quantitative SPECT imaging systematically underestimated the injected radioactivity (mean error: -17.0 MBq; -13.2%) with recovery coefficients ranging from 0.82 to 0.93 that were negatively correlated with the surface-area-to-volume ratio. Patient-derived, 3D-printed fillable phantoms are a feasible, cost-effective tool to support commissioning and quality assurance for patient-specific RPT dosimetry. The results of this work will support other centers and clinics implementing patient-specific RPT dosimetry by providing the tools needed to comprehensively evaluate accuracy in clinically relevant geometries. Looking forward, widespread accurate patient-specific RPT dosimetry will improve our understanding of RPT dose response and enable personalized RPT dosing to optimize patient outcomes.
准确的患者特异性剂量测定对于优化放射性药物治疗（RPT）至关重要，但目前的工具在临床实际情况下缺乏验证。这项工作旨在开发一种工作流程，用于设计和制造源自患者的、器官逼真的RPT体模，并评估其用于调试患者特异性RPT放射性活度定量的可行性。我们使用代表性患者的计算机断层扫描（CT）和磁共振（MR）成像、计算机辅助设计以及内部3D打印技术，设计并制造了具有逼真器官间距、解剖学正确取向和周围组织异质性的拟人化肾脏和腮腺体模。我们通过几何验证（即体积比较）和泄漏测试（即染料渗透测试）评估了制造过程。临床可行性测试包括将已知放射性活度的Lu-PSMA-617注入腮腺和肾脏皮质体模腔室，并获取SPECT/CT图像。MIM SurePlan MRT SPECTRA Quant软件（v7.1.2）将获取的SPECT投影重建为定量SPECT图像，我们通过与已知注入放射性活度进行基于区域的比较来评估准确性，并确定每个器官体模的回收系数。体模制造成本总计<250美元，所需时间<84小时。几何验证显示与代表性患者解剖结构相比有轻微的系统性膨胀（<10%），泄漏测试证实了可填充腔室的水密性。定量SPECT成像系统性地低估了注入的放射性活度（平均误差：-17.0 MBq；-13.2%），回收系数范围为0.82至0.93，且与表面积与体积比呈负相关。源自患者的3D打印可填充体模是一种可行的、具有成本效益的工具，可支持患者特异性RPT剂量测定的调试和质量保证。这项工作的结果将通过提供全面评估临床相关几何形状准确性所需的工具，支持其他中心和诊所实施患者特异性RPT剂量测定。展望未来，广泛准确的患者特异性RPT剂量测定将增进我们对RPT剂量反应的理解，并实现个性化RPT给药以优化患者治疗效果。
