Feasibility, safety, and clinical outcomes analysis of dense-lattice radiation therapy in palliative care for cancer patients´

Abstract

Aim: The management of patients with advanced cancer, especially in the presence of bulky tumors, presents significant challenges for oncology practice, despite advances in conventional RT. Considering the dosimetry advantages of our dense-LRT protocol, we aimed for the first time to assess the safety and feasibility of the use of dense-LRT as exclusive radiation treatment for palliative care in locally advanced/metastatic cancer patients. Methods: Patients diagnosed with locally advanced and/or metastatic tumors and/or inoperable patients with a high burden of disease with cancers of different etiologies were included in this prospective study of dense-Lattice Radiotherapy from October-2022, until February-2025. The dense-LRT treatment characteristics have been already published. Our study aimed to analyze the use of dense-LRT as exclusive radiation treatment, which was designed as preplanned 3 patients’ cohorts in a 1:1:1 protocol. Cohort 1: 24 Gy-LRT + EBRT. Cohort 2: exclusive 24 Gy-LRT. Cohort 3: exclusive 36 Gy-LRT. The primary endpoints of the study were the feasibility and safety of the proposed treatment protocol. Results: The dense-LRT protocol was feasible and safe with no grade 3 acute or late toxicity reported. The 3 month CR and PR response rates were 2/20 (10%) and 14/20(70%), resulting in an objective response rate of 80%. The 1-year actuarial survival was 52.1%. The Hybrid and the accelerated cohorts showed better clinical response rates. The hybrid protocol showed a slightly increase in mild adverse effects. Conclusion: Our preliminary results could suggest that a high-dose accelerated LRT protocol (36 Gy/3fractions/5 days) is effective and a safe in the palliative treatment of bulky tumors. Further study is needed to define its role in palliative cancer care.