Prediction of Tumor Control in 90Y Radioembolization by Logit Models with PET/CT-Based Dose Metrics

• DOI: 10.2967/jnumed.119.226472
• Publication Date: 2019-05-31T02:45:12Z
• Authors: Yuni K. Dewaraja; Theresa Devasia; Ravi K. Kaza; Justin K. Mikell; Dawn Owen; Peter L. Roberson; Matthew J. Schipper
• Keywords: Carcinoma, Hepatocellular; Phantoms, Imaging; Radiotherapy Planning, Computer-Assisted; Brachytherapy; Liver Neoplasms; Normal Distribution; Embolization, Therapeutic; Microspheres; 3. Good health; 03 medical and health sciences; Logistic Models; 0302 clinical medicine; Liver; Area Under Curve; Positron Emission Tomography Computed Tomography; Humans; Regression Analysis; Yttrium Radioisotopes; Neoplasm Metastasis; Radiometry; Monte Carlo Method

The aim of this work was to develop models for tumor control probability (TCP) in radioembolization with ⁹⁰Y PET/CT–derived radiobiologic dose metrics. <b>Methods:</b> Patients primary liver cancer or metastases who underwent glass microspheres were imaged PET/CT voxel-level dosimetry determine lesion absorbed (AD) metrics, biological effective (BED) equivalent uniform dose, and BED 28 treatments (89 lesions). dose–shrinkage correlation assessed on the basis RECIST and, when available, modified (mRECIST) at first follow-up. For a subset mRECIST, logit regression TCP fit via maximum likelihood relate lesion-level binary response As an exploratory analysis, nontumoral dose–toxicity relationship also evaluated. <b>Results:</b> Lesion analysis showed that there no significant differences between model parameters metastatic subgroups coefficients superior mRECIST. Therefore, subsequent performed combined group using mRECIST only. overall rate 57%. AD metrics yielding 50% 292 441 Gy, respectively. All considered modeling, including mean AD, significantly associated response, high areas under curve (0.87–0.90, <i>P</i> &lt; 0.0001) sensitivity (&gt;0.75) specificity (&gt;0.83) calculated threshold corresponding TCP. Because nonuniform deposition by cannot be determined PET microscopic scale, radiosensitivity values extracted here fitting clinical data substantially lower than reported vitro cell cultures external-beam radiotherapy studies. There toxicity measures. <b>Conclusion:</b> Despite heterogeneous patient cohort, logistic strong association various response. performance comparable involve more complex calculations. These results demonstrate importance considering treatment planning radioembolization.