Two-and-a-half-year clinical experience with the world's first magnetic resonance image guided radiation therapy system

Benjamin W Fischer-Valuck; Lauren Henke; Olga Green; Rojano Kashani; Sahaja Acharya; Jeffrey D Bradley; Clifford G Robinson; Maria Thomas; Imran Zoberi; Wade Thorstad; Hiram Gay; Jiayi Huang; Michael Roach; Vivian Rodriguez; Lakshmi Santanam; Harold Li; Hua Li; Jessika Contreras; Thomas Mazur; Dennis Hallahan; Jeffrey R Olsen; Parag Parikh; Sasa Mutic; Jeff Michalski

doi:10.1016/j.adro.2017.05.006

Two-and-a-half-year clinical experience with the world's first magnetic resonance image guided radiation therapy system

Adv Radiat Oncol. 2017 Jun 1;2(3):485-493. doi: 10.1016/j.adro.2017.05.006. eCollection 2017 Jul-Sep.

Authors

Benjamin W Fischer-Valuck¹, Lauren Henke¹, Olga Green¹, Rojano Kashani¹, Sahaja Acharya¹, Jeffrey D Bradley¹, Clifford G Robinson¹, Maria Thomas¹, Imran Zoberi¹, Wade Thorstad¹, Hiram Gay¹, Jiayi Huang¹, Michael Roach¹, Vivian Rodriguez¹, Lakshmi Santanam¹, Harold Li¹, Hua Li¹, Jessika Contreras¹, Thomas Mazur¹, Dennis Hallahan¹, Jeffrey R Olsen², Parag Parikh¹, Sasa Mutic¹, Jeff Michalski¹

Affiliations

¹ Washington University, Department of Radiation Oncology, St. Louis, Missouri.
² University of Colorado, Department of Radiation Oncology, Aurora, Colorado.

Abstract

Purpose: Magnetic resonance image guided radiation therapy (MR-IGRT) has been used at our institution since 2014. We report on more than 2 years of clinical experience in treating patients with the world's first MR-IGRT system.

Methods and materials: A clinical service was opened for MR-IGRT in January 2014 with an MR-IGRT system consisting of a split 0.35T magnetic resonance scanner that straddles a ring gantry with 3 multileaf collimator-equipped ⁶⁰Co heads. The service was expanded to include online adaptive radiation therapy (ART) MR-IGRT and cine gating after 6 and 9 months, respectively. Patients selected for MR-IGRT were enrolled in a prospective registry between January 2014 and June 2016. Patients were treated with a variety of radiation therapy techniques including intensity modulated radiation therapy and stereotactic body radiation therapy (SBRT). When applicable, online ART was performed and gating on sagittal 2-dimensional cine MR was used. The charts of patients treated with MR-IGRT were reviewed to report on the clinical and treatment characteristics of the initial patients who were treated with this novel technique.

Results: A total of 316 patients have been treated with the MR-IGRT system, which has been integrated into a high-volume clinic. The cases were most commonly selected for improved soft tissue visualization, ART, and cine gating. Seventy-six patients were treated with 3-dimensional conformal radiation therapy, 146 patients with intensity modulated radiation therapy, and 94 patients with SBRT. The most commonly treated disease sites were the abdomen (28%), breast (26%), pelvis (22%), thorax (19%), and head and neck (5%). Sixty-seven patients were treated with online ART over a total of 244 adapted fractions. Cine treatment gating was used for a total of 81 patients.

Conclusions: MR-IGRT has been successfully implemented in a high-volume radiation clinic and provides unique advantages in the treatment of a variety of malignancies. Additional clinical trials are in development to formally evaluate MR-IGRT in the treatment of multiple disease sites with techniques such as SBRT and ART.