Simultaneous treatment of two lung cancer lesions with stereotactic MR-guided adaptive radiation therapy - A case report

Sep 24, 2026

Lung cancer remains one of the most prevalent cancers globally, and stereotactic ablative radiotherapy (SABR) is an option for patients who are not suitable for surgery or who refuse operative treatment. The case describes a 46-year-old man with two recurrent lung cancer lesions treated simultaneously with magnetic resonance linear accelerator MR-guided adaptive radiotherapy. CT planning and MR simulation were performed using ViewRay MRIdian Linac, delivering 50 Gy in 4 fractions. Follow-up showed mild, resolving radiation-related pneumonitis and no FDG-avid recurrence, with survival beyond 18 months after SABR.

LanguageEnglish

CategoryHealthcare

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Abstract

Introduction

Background on lung cancer treatment

Role of SABR

MR-Linac rationale

® Clinical Case Report Simultaneous treatment of two lung cancer lesions with stereotactic MR-guided adaptive radiation therapy A case report Frank Chen, MDa , Yuan-Kai Cheng, MDa , Chen-Han Chianga , Tzu-Ying Lua , Chih-Jen Huang, PhDa,* | Abstract
Rationale: Lung cancer is 1 of the most prevalent cancers globally. Definitive stereotactic ablative radiotherapy (SABR) is suggested for those who are unfit for or refuse surgical intervention. Here we present a patient with 2 lung cancer lesions who received SABR simultaneously with magnetic resonance Linear accelerator (Linac)-magnetic resonance (MR) .
Patient concerns: A 46-years-old man had history of left lower lung cancer post lobectomy in 2018. Two recurrent tumors were found 2 years following, then became enlarged 4 months later.
Diagnoses: The recurrent tumors were found by computed tomography.
Interventions: SABR was indicated due to inoperability and small size. Simulation was done both by computed tomography and MR scan with ViewRay MRIdian Linac, with the prescription dose being 50 gray in 4 fractions performed every other day within 2 weeks. The 2 lesions were irradiated at the same time with a single isocenter with mean treatment time was 78 minutes. Outcomes: No acute side effect was noted. Follow-up chest computed tomography scan 14 months after SABR showed mild consolidation and pneumonitis over the upper irradiated site favoring radiation-related reasons, while pneumonitis was resolved over the lower irradiated site. Positron emission tomography showed no definite evidence of FDG-avid recurrence. The patient has survived over 18 months following SABR and more than 4 years from the first diagnosis of lung cancer without significant adverse effects.
Lessons: Simultaneous SABR for multiple lung lesions is quite challenging because tumor motion by breathing can increase the risk of missing the target. With help by MR-Linac, simultaneous SABR to multiple lung lesions can be performed safely with efficacy.
Abbreviations: CT = computed tomography, GTV = gross target volume, Gy = gray, ITV = internal target volume, Linac = linear accelerator, MR = magnetic resonance, MRI = magnetic resonance imaging, NSCLC = non-small cell lung cancer, OAR = Organs at risk OAR, PET = positron emission tomography, PTV = planning target volume, RT = radiotherapy, SABR = stereotactic ablative radiotherapy, VMAT = volumetric modulated arc therapy. | | --- | | Keywords: lung cancer, MR-linac, radiotherapy, SABR, simultaneously | 1. Introduction Lung cancer is 1 of the most prevalent cancers worldwide, and has been 1 of the leading causes of cancer-related deaths in men and women. [1] Recently, due to more prevalence of low-dose computed tomography (CT), more non-small-cell lung cancers (NSCLC) have been diagnosed. Surgery is the main treatment for operable tumors, and definitive radiotherapy (RT) is suggested for those unfit for or refusing surgical intervention. The authors have no funding and conflicts of interest to disclose. Data sharing not applicable to this article as no datasets were generated or analyzed during the current study. Ethical approval to report this case was obtained from Kaohsiung Medical University Hospital (KMUHIRB-E(I)-20220102). Written informed consent was obtained from the patient for his anonymized information to be published in this article. a Department of Radiation Oncology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan. * Correspondence: Chih-Jen Huang, Department of Radiation Oncology, Kaohsiung Medical University Hospital, 100 Tzyou 1st Road, Kaohsiung 807, Taiwan ([e-mail: ccjjhh@kmu.edu.tw](e-mail: ccjjhh@kmu.edu.tw)). Among all RT techniques, stereotactic ablative radiotherapy (SABR), also called stereotactic body radiotherapy is preferred than other techniques in treating lung lesions, since SABR could cause good local control[2] and better survival and lower rates o

FAQs

Why was SABR chosen for the patient in this case report?

SABR was indicated because the recurrent tumors were inoperable and small in size, making definitive stereotactic radiotherapy appropriate.

How was the SABR treatment planned and delivered?

Simulation was performed using computed tomography and MR scanning on a ViewRay MRIdian Linac. The prescription dose was 50 Gy delivered in 4 fractions every other day over 2 weeks using a single isocenter for both lesions.

What were the main outcomes and follow-up findings after treatment?

No acute side effects were noted. Chest CT 14 months after SABR showed mild consolidation and pneumonitis at the upper irradiated site with resolution at the lower site, and PET showed no definite FDG-avid recurrence.

Sep 24, 2026

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