Dynamic tumor-tracking stereotactic body radiotherapy with real-time monitoring of liver tumors using a gimbal-mounted linac: A multi-institutional phase II study. (March 2023)

• Record Type: Journal Article
• Authors: Iizuka, Yusuke; Hiraoka, Masahiro; Kokubo, Masaki; Sakamoto, Takashi; Karasawa, Katsuyuki; Murofushi, Keiko; Nakamura, Mitsuhiro; Matsuo, Yukinori; Morita, Satoshi; Inokuchi, Haruo; Mizowaki, Takashi
• Is Part Of: Clinical and translational radiation oncology. Volume 39(2023)
• Publication Date: 2023-03
• Subjects: Liver -- Malignant neoplasms -- Metastasis -- Stereotactic body radiotherapy -- Dynamic tumor tracking; DTT dynamic tumor tracking -- SBRT stereotactic body radiotherapy -- LC local control -- OS overall survival -- PFS progression-free survival -- HCC hepatocellular carcinoma -- RFA radiofrequency ablation -- CT computed tomography -- 4D four-dimensional -- TV target volume -- GTV gross tumor volume -- CTV clinical target volume -- PTV planning target volume -- OAR organs at risk -- IR infrared; Cancer -- Radiotherapy -- Periodicals; Oncology -- Periodicals; Cancer -- Radiotherapy; Oncology; Radiation Oncology; Neoplasms -- radiotherapy; Translational Medical Research; Periodicals; Electronic journals; Periodicals; 616.9940642
• DOI: 10.1016/j.ctro.2023.100591
• Languages: English
• ISSNs: 2405-6308

Abstract

Graphical abstract: Highlights: We evaluated DTT-SBRT for liver tumors using a gimbal-mounted system. DTT-SBRT was successfully with a median treatment time of 28 min/fraction. The 2-year LC, OS, and PFS rates were 98.0%, 88.8%, and 55.1%, respectively. No grade 4 or 5 treatment-related toxicity was observed. DTT-SBRT for liver tumors has excellent LC with acceptable adverse-event incidence. Abstract: Background and purpose: This prospective multicenter phase II study aimed to evaluate the safety and efficacy of dynamic tumor tracking (DTT) stereotactic body radiotherapy (SBRT) with real-time monitoring of liver tumors using a gimbal-mounted system. Materials and methods: Patients with < 4 primary or metastatic liver tumors with diameters ≤ 50 mm and expected to have a respiratory motion of ≥ 10 mm were eligible. The prescribed dose was 40 Gy in five fractions. The primary endpoint was local control (LC) at 2 years. The secondary endpoints were overall survival (OS), progression-free survival (PFS), treatment-related toxicity, and tracking accuracy. Results: Between September 2015 and March 2019, 48 patients (48 lesions) with a median age of 74 years were enrolled from four institutions. Of these, 39 were diagnosed with hepatocellular carcinoma and nine with metastatic liver cancer. The median tumor diameter was 17.5 mm. DTT-SBRT was successfully performed in all patients; the median treatment time was 28 min/fraction. The median follow-up period was 36.5 months. The 2-year LC, OS, and PFS rates were 98.0 %, 88.8 %, and 55.1 %, respectively. Disease progression was observed in 33 (68.8 %) patients. One patient (0.2 %) had local recurrence, 31 (64.6 %) developed new hepatic lesions outside the irradiation field, and nine (18.8 %) had distant metastases (including overlap). Grade 3 late adverse events were observed in seven patients (14.5 %). No grade 4 or 5 treatment-related toxicity was observed. The median tracking accuracy was 2.9 mm. Conclusion: Employing DTT-SBRT to treat liver tumors results in excellent LC with acceptable adverse-event incidence.