Presenter(s)
Y. Tang1, H. S. M. Park1, H. Liu2, C. Shi3, Y. H. Chang1, M. Lee1, D. Han1, E. Draeger1, R. Tummala1, J. J. Kim1, L. Tressel1, Z. Chen1, D. J. Carlson1, and H. Chen1; 1Department of Therapeutic Radiology, Yale School of Medicine, New Haven, CT, 2Department of Radiation Oncology, University of Southern California, Los Angeles, CA, 3Department of Radiation Oncology, Orange County Lennar Foundation Cancer Hospital, Irvine, CA
Purpose/Objective(s): Biology-guided radiotherapy (BgRT) introduces unique planning and delivery considerations by integrating Positron Emission Tomography (PET) signal guidance into treatment workflows. The clinical and technical complexity of BgRT, particularly for systems such as RefleXion X1, underscores the urgent need for a structured and efficient patient screening process. This study aims to develop an APP-based, standardized BgRT clinical pocket checklist for patient eligibility assessment, along with an integrated software platform to streamline the checklist-based evaluation.
Materials/Methods: An in-house clinical pocket checklist was created to assess key clinical criteria in BgRT patient screening and treatment planning, including geometry integrity (target, organ-at-risk (OAR), Biological Tracking Zone (BTZ) contouring, target-OAR separation), dosimetry acceptability (target coverage and OAR constraints), imaging tracer validation (PET/CT image registration, PET signals) and motion range (Table 1). Additionally, a MATLAB APP-based software platform was developed. After clinical staff (physicians or others) entered patient- and plan-specific information, the platform automatically generated eligibility results using a red-yellow-green indicator system to denote ineligible, cautionary, or acceptable conditions, respectively.
Results: The BgRT checklist demonstrated high sensitivity in identifying patient eligibility concerns and planning deficiencies, detecting relevant geometric and imaging-related inadequacies. The APP-based eligibility platform provided rapid, user-friendly, and intuitive visualization of patient suitability and planning readiness, facilitating early identification of potential limitations prior to treatment delivery, improving overall efficiency of BgRT implementation.
Conclusion: The BgRT clinical pocket checklist, combined with an automated eligibility screening platform delivered via APP interface, provides an efficient and clinically practical framework for assessing patient suitability for BgRT treatments. This approach timely supplements emerging new treatment technologies for which commercial quality control software is not yet available and directly addresses current clinical needs. Continued refinement and multi-institutional validation may further strengthen screening consistency across diverse practice settings and platforms.
Table 1. RefleXion BgRT plan clinical pocket checklist inputs| Tumor-related input | GTV size (cm) |
| PTV size (cm) | |
| Motion range (cm) | |
| Biological Tracking Zone (BTZ) | |
| Other Factors relative to planning | Distance between GTV to OAR (cm) |
| SUVmax (diagnostic PET) | |
| Activity Concentration (AC) (kBq/ml) | |
| Normal Tissue Signal (NTS) | |
| Dose shaping (CI and Dmax) | |
| Dose per fraction (Gy) | |
| Number of fraction |