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Irradiation of Pulmonary Tumor with Overlying Artificial Cardiac Pacemaker

1969; Radiological Society of North America; Volume: 92; Issue: 1 Linguagem: Inglês

10.1148/92.1.148

1527-1315

Frank J. Hildner, Joseph W. Linhart, Darrell O. Poole,

Wireless Body Area Networks

Permanent cardiac pacemakers are implanted so that the electrodes in contact with the heart are connected to a power source located elsewhere on the chest. This battery pack is usually placed in a subcutaneous pouch which overlies the right or left pectoral muscles. In this position it obscures the lung underlying the area when it is examined on a posteroanterior chest roentgenogram. Recently, an 80-year-old man who had previously had an artificial pacemaker implanted for complete heart block was found to have a malignant pulmonary tumor in this area (Fig. 1). The decision to use radiation as treatment for the tumor was complicated by the uncertain effect the radiation would have on the performance of the pacemaker. Pacemaker Radiation In order to determine the effect of radiation on similar pacemakers, two separate units were subjected to direct irradiation from a cobalt-60 teletherapy source. A ventricular demand type pacemaker2 was given a total dose of 10,000 rads, and a P-wave synchronous pacemaker3 (a far more complicated instrument) a total of 46,000 rads. Each pacemaker was irradiated separately at dose rates of 300 rads per minute and checked for performance after each 1,000 rads up to 10,000. The output of both units was observed on an oscilloscope4 after each irradiation, and the output-pulse rate, amplitude, and length were recorded. During the further irradiation of the P-wave synchronous pacemaker to an accumulated dose of 46,000 rads, the output-pulse was monitored remotely on the oscilloscope, and its rate, amplitude, and length were checked to ascertain any impairment of pacemaker operation. At no time during the irradiation of either pacemaker was there any detectable change in the output-pulse characteristics. Moreover, ninety days after the pacemakers were irradiated, no detectable change from preirradiation characteristics could be found. Clinical Course Since no immediate detrimental effects were induced in the pacemakers by the radiation, the patient was treated for presumptive carcinoma of the right upper lobe bronchus. This lesion was accompanied by destruction of the second rib, a right Horner syndrome, and recurrent laryngeal nerve palsy. The palliative treatment prescribed was a pair of 15 X 12ern, parallel opposed fields delivering 3,500 rads over a period of three weeks. No change in the patient's pacemaker function was noted during or immediately after therapy. Subsequent checks during the three-month period after therapy failed to reveal any obvious deterioration of the pacemaker. The patient tolerated the treatment well and obtained considerable relief from pain (Fig. 2). Summary Two artificial cardiac pacemakers were irradiated with cobalt-60 gamma rays. Doses in excess of those usually encountered in radiotherapeutic treatments failed to induce any obvious detrimental effects either immediately or after three months. A malignant tumor of the lung in an 80year-old man was treated with a therapeutic dose of radiation without ill effects to an overlying pacemaker.