F.W. George

Iridium-192 afterloaded implant in the retreatment of head and neck cancers

Abstract Retreatment of persistent (or “recurrent”) carcinoma of the head and neck by means of after-loading 192Ir techniques may prove quite satisfactory. A total of 64 patients were retreated by these techniques from February, 1974 to October, 1975 at the Los Angeles County—University of Southern California Medical Center and the Southern California Cancer Center. Follow-up periods, averaging only 24 months (18 to 36 months), are too short for statistically significant evaluation of survival, but the “response rate” has been gratifying. Only 11 of our 64 patients (17%) have shown no satisfactory response to re-irradiation by interstitial implant. Thirty-one of the 64 patients (49%) have had local control with “good palliation”. Twenty-two of the 64 (34%) had at least 50% regression of tumour with “fair” palliation. Thus 83% have had satisfactory response to retreatment. A considerable number of these have survived to the date of this report. Whereas 36 of the 64 (56%) are now dead, 28 of the 64 otherwis...

Persistent carcinoma of the oropharynx and oral cavity re-treated by after-loading interstitial 192Ir implant

After‐loading implantation techniques apparently offer an effective alternative in the management of persistent (or recurrent) oropharynx and oral cavity carcinoma postirradiation. A total of 29 patients with such lesions was treated from February 1974, to July 1975, in the LAC/USC Radiation Medicine Section, using after‐loading 192Ir implantation techniques. These patients all had extensive persistent cancer after “full tolerance” irradiation (with or without previous surgery) and were referred for palliation or for possible salvage. Additional doses administered ranged from 5000 to 7000 rads in three to five days. Eighteen of the 29 patients (63%) have had complete local control for 18 to 36 months. These patients have maintained a relatively satisfactory palliative status. Ten of the 29 are dead. Follow‐up periods are short, but early indications are that problem patients with persistent cancer after “full tolerance irradiation” can be salvaged, or at least satisfactorily palliated, with after‐loading interstitial implant techniques. Clinical details, sites of involvement, implantation techniques, dosimetry methodology, reactions and complications will be described.

Afterloading Interstitial Implant in the Treatment of Oral Cavity and Oropharyngeal Cancers1

(1) In all, 70 patients with carcinoma of the oral cavity and oropharynx have been treated utilizing one or more of several interstitial iridium-192 afterloading techniques. (2) After an 18-month minimum follow-up period, local control is still maintained in 9 of 10 patients with T1 and T2 lesions (UICC), in 17 of 22 patients with T3 lesions, and in 21 of 38 patients reirradiated for recurrent disease. The complication rate of 29% in the reirradiated patients, though high, is considered acceptable in these essentially hopeless cases. (3) This preliminary report is made to stimulate interest in the role of interstitial iridium-192 afterloading techniques. We feel they deserve evaluation in a controlled study of other head and neck cancer management techniques (including external irradiation, surgical resection and adjunctive chemotherapy).

USC-ABC ATMnet for radiation treatment planning

Three dimensional visualization of tumor and normal tissues are often valuable in precision treatment planning for radiation therapy of cancer. This is often not possible in many remote treatment facilities because of the high cost of imaging and computer equipment. At the University of Southern California, School of Medicine we are developing and testing a high speed, wide area, computer communications network to provide access to such resources from remote locations. In this paper, we present our concept of a Virtual Academic Medical Center, our network design and report on initial evaluations of effectiveness and clinical acceptability of 3D, CT simulation and treatment planning from a distance.