What happened, in summary

An 81-year-old woman was diagnosed with adenocarcinoma in the left lower lobe of the lung. The tumor was Stage I and was planned for stereotactic body radiotherapy.

She also had a leadless pacemaker in the right ventricle because of complete atrioventricular block. The device was not recognized during the initial radiation-planning process, and the first plan would have exposed it to a relatively high radiation dose. Once the pacemaker was identified, the radiation team redesigned treatment using fixed beams to avoid direct exposure to the device.

Pacemaker checks were performed before and after treatment. No device abnormalities were detected, and the stereotactic radiotherapy course was completed without complications.