For the treatment of bronchogenic carcinoma, surgery offers a considerably better chance of cure relative to radiation therapy. However, surgical resection is possible in only 20 to 25 percent of patients at presentation, and of these, five-year survivals following curative resection of 10 to 40 percent depend mainly on degree of lymph node involvement.
The overall five-year survival remains at 10 to 12 percent. Up to 90 percent of patients will require palliative therapy of the effects of their tumors. Many of these will have continuing symptoms due to the effects of the primary tumor on the airway, such as hemoptysis, dyspnea, or distal infection. External beam radiation is the mainstay of palliative therapy of these predominantly central tumors. However, the dose of external radiotherapy is limited by the tolerance of surrounding normal tissue and does not therefore lend itself to repeated use. Furthermore, while external beam radiation is effective in 84 percent of patients with hemoptysis, 61 percent with chest pain and 60 percent with dyspnea, resolution of atelectasis was achieved in only 23 percent of patients. We are reporting on a technique in use at this institution for management of the effects of the primary tumor on the airway. A 198Au radiation source is implanted into the tumor mass under local anesthesia via the fiberoptic bronchoscope (FOB). Repeated applications may be performed as indicated by clinical and roentgeno-graphic follow-up.
198Au was chosen as the radiation source as it has several favorable characteristics. These include intense continuous emission of gamma radiation with an energy of 412 kev with a short half life of 2.7 days; thus, the activity of the seed declines to near 0 in under two weeks. The gold “seeds” are cylindrical, measuring 2.6 mm in length and 0.8 mm in diameter and are thus eminently suited for placement via the suction channel of the FOB. X-ray dosimetry has revealed that most of the radiation is delivered to a sphere of 2 to 3 cm radius around the seed with minimal radiation of normal tissues, and thus, has the potential for repeated use. The typical freshly charged seed has a measured activity of 10 mCi which will deliver 10,000 rads to a sphere of 1 cm radius. The best treatment may be applied if you are examined by a wellexperienced doctor and take well-qualified drugs which may be ordered via Canadian Neighbor Pharmacy.
A bronchial biopsy forceps was modified by replacement of the tip with an unsheathed needle through which an ejector is passed. The 198Au seed is loaded into the introducer by the radiotherapist immediately prior to insertion. Routine fiberoptic bronchoscopy was performed using intramuscular meperidine and atropine for premedication and lidocaine or tetracaine applied topically to the mucosa for local anesthesia. Under direct vision, the introducer is passed through the bronchoscope biopsy channel and into the tumor mass, following which the ejector is used to deposit the seed. Correct seed placement was verified by fluoroscopy. More recently, we have begun to implant seeds into peripheral tumors via a transbronchial approach using a blunt introducer and fluoroscopic guidance.
The patients for this retrospective review were recruited by reviewing records of all patients undergoing this therapy over the period of 1979 to 1984. Adequate data were obtained on 54 cases. A further five patients were not analyzed as no follow-up data were obtainable; however, all five tolerated the procedure well and were routinely discharged from the hospital.