Therapy of the lateral pelvic nodes in cervical carcinoma

Abstract

T HE importance of adequate therapy to the lymphatics of the lateral pelvic wall in patients wit,h carcinoma of the uterine cervix has long been acknowledged. During the decades covered by Dr. Kosmak’s editorship many studies have reconfirmed this1 and many techniques have been proposed to achieve control of the spreading carcinoma in the nodes of the lateral pelvis.? Taussig” employed surgical dissection of the lateral nodes together with radiation therapy for the central lesion, a suggestion which has been made again more recently by Kimbrough.4 The addition of lateral pelvic x-ray ports to provide increased side-wall dosage of irracliation has been tried hut is associated with an increased incidence of spontaneous fracture of the neck of the femur.” Transvaginally placed interstitial needles69 7 are intended to increase the dosage to these nodes by placing the sources of radioactivity in the neighborhood of the lateral wall. Sherman and his co-workers8 have proposed reaching this area by the paracervical injection into the tissues of colloidal suspensions of radioactive gold. The present paper discusses another approach to this problem. In 1951 Morton alld his associates” proposed the use of fine Nylon tubing as a carrier for multiple weak sources of radioactive cobalt. Such a unit constitutes a plastic and pliable “needle” which possesses unique characteristics as a container for radiation sources in interstitial therapy.l”j I1 This tubing can be so attenuated that it can be threaded into a surgical needle for sewing directly into the area to be treated. More recently, these Nylon “threads” with radioactive portions have become available commercially. While their application in this particular field has not been extensive, and no five-year results are available, the technical details of their use merit discussion as a potential approach to the therapy of the lateral pelvic nodes in carcinoma of t,he cervix. The Threads.-Fine cobalt wire (0.5 mm. diameter) is cut into lengths of one-third centimeter and activated so that each such .piece has a strength of 0.2 mc. These cobalt pieces, with aluminum spacers of the same size, are placed in Nylon tubing of 1.75 mm. outside diameter. When the active sections of such “threads” are placed parallel and at an interval of 1.0 cm. from each other a fielcl is created which yields about 1,000 gamma roentgens per day to the immediate area. Since the strength of such a field results from the cross-firing of multiple sources which are individually weak, it falls off