The utilization of a 3-dimensional noncoplanar treatment plan to avoid pacemaker complications

Treatment planning of thoracic patients having upper lobe lesions and a pacemaker presents quite a challenge. It is necessary to avoid the pacemaker as well as other critical structures in order to deliver the prescribed dose for local control. This case demonstrates the utilization of noncoplanar beams and asymmetric fields to limit the radiation dose to the pacemaker. The dose to the pacemaker was quantified by the information represented in the dose-volume histogram (DVH) of the computerized tomography (CT)-based treatment plan. The delivered dose was verified utilizing thermoluminescent dosimeters (TLDs) placed on the patient. Measurements of the daily dose from all of the treatment fields to include the open jaws during portal imaging were taken to sum the total possible dose the pacemaker may receive. The allowable dose to the pacemaker is dependent upon individual manufacturers. It was found that with proper treatment planning and appropriate precautions, a patient is able to receive full-prescribed dose with no risks of interfering with the pacemaker function.