SMART-TOMO (SINGLE-SETUP MULTI TARGET ACCURATE RADIATION THERAPY BY HELICAL TOMO IN OLIGOMETASTASIS)

Abstract

Background: The management of oligometastatic disease has evolved substantially following randomized trials including SABR-COMET, ORIOLE, STOMP, and EXTEND, which demonstrated that comprehensive metastasis-directed stereotactic body radiotherapy (SBRT) improves progression-free survival, delays systemic therapy, and, in selected patients, improves overall survival. Consequently, an increasing number of patients are referred for SBRT to multiple metastatic lesions. However, treatment delivery remains technically challenging because conventional linear accelerator (LINAC)-based approaches generally require multiple isocenters, repeated patient repositioning, independent treatment plans, and sequential image-guided irradiation of each lesion, resulting in prolonged treatment times and increasing workflow complexity. Purpose: To describe SMART (Single-Setup Multi-Target Accurate Radiation Therapy), a standardized workflow for single-setup multi-target stereotactic radiotherapy using Helical TomoTherapy, including its technical rationale, implementation, and potential clinical applications. Technical Report: SMART is a standardized workflow for single-setup, multi-target stereotactic radiotherapy using Helical TomoTherapy. It integrates all treatable metastatic lesions into a single simulation, one inverse-optimized treatment plan, one MVCT-guided setup, and one continuous helical treatment session. By eliminating multiple isocenters and repeated patient repositioning, SMART streamlines treatment delivery, reduces cumulative setup uncertainty, improves workflow efficiency, and maintains highly conformal dose distributions with optimal organ-at-risk sparing for patients with oligometastatic disease. Conclusions: SMART represents a practical technical evolution of image-guided stereotactic radiotherapy using Helical TomoTherapy. By standardizing the complete treatment pathway from simulation to delivery, SMART provides a reproducible framework for comprehensive multi-target radiotherapy simplifying the delivery of technically complex multi-target stereotactic radiotherapy. Prospective clinical studies are warranted to evaluate its impact on treatment efficiency, dosimetric quality, toxicity, patient-reported outcomes, resource utilization, and long-term oncological outcomes.