3/11/2023 0 Comments Radium implantOne hundred and sixty-six patients with squamous cell carcinoma of the tongue were treated with radiation. No correlation exists between necrosis and tumor size or total dose. Minor or moderate soft tissue ulceration was observed in 12 patients, including 3 cases that progressed to osteonecrosis. For N0 patients definitive regional control is 97% and for N1-3 is 89%. A dose response effect was observed with local control of 79% (26/33) obtained with a combined dose greater than or equal to 75 Gy, but only 50% (4/8) for less than or equal to 70 Gy. Definitive local control for T1 lesions is 85% (11/13) and for T2 is 71% (25/35). Five-year crude disease-free survival is 50% with 35% of patients dying of recurrent disease. Seven tumors were treated exclusively by implantation to the base more » of tongue (mean: 63 Gy). This completed the treatment for the 30 node negative patients, but those with clinically positive nodes were managed by either an additional electron beam boost to the involved nodes or a neck dissection. Forty-one patients received moderate dose /sup 60/Co external beam irradiation (mean: 48.6 Gy) to the primary tumor and regional nodes, followed by an interstitial iridium-192 implant to the primary tumor (mean: 32 Gy). « lessįorty-eight patients with T1 or T2 epidermoid carcinomas of the base of tongue were treated at the Henri Mondor Hospital between 19. This treatment region is well tolerated and it preserves the functional and asthetic integrity in most patients. The salvage of neck failures and the local failures was feasible in 74% and 46% of the patients, respectively either by surgery or by re-irradiation using interstitial /sup 192/iridium implant alone. Treatment related complications such as soft tissue necrosis and/or osteoradionecrosis occurred in 8 of the 70 (11.4%) patients. An absolute 3-year disease-free survival of the entire group was 67.0%. Overall, local tumor control was observed in 58 of 70 (83%) patients at minimum follow-up of 2 years. The neck nodes were also separately implanted to deliver additional doses of 2000-4000 cGy in 50-80 hours. The doses of implant varied according to the stage of disease, that is, 2000-2500 cGy for T1 and T2 lesions, 3000-4000 cGy for T3 and T4 lesions, with typical dose rates of 50-60 cGy per hour. The primary site as well as the more » vallecula, epsilateral pharyngeal wall, glossopalatine sulcus, tonsillar bed, and pillars were routinely implanted to encompass contiguous spread of the disease. Interstitial volume implants were performed 2-3 weeks after completion of external irradiation. The dose of external irradiation was limited to 45-50 Gy over 4 1/2-5 1/2 weeks. All patients received a combination of external and interstitial irradiation. Fifty-one of the 70 (73%) patients had clinically palpable neck nodes at first presentation. Fifty-eight (83%) of these patients had locally advanced tumors (Stage T3, T4, N2, N3). =, number = ,Ī total of 70 patients with histologically proven diagnosis of carcinoma of the base of the tongue were treated with primary irradiation between May 1974 through April 1984. For a given volume, the incidence of necrosis was directly proportional to the degree of overdosage for a given dose, the incidence of necrosis was directly proportional to the degree of overdosage for a given dose, the incidence of necrosis was directly proportional to the volume receiving the dose. For lesions treated with implants plus external irradiation, greater local control was achieved when most of the dose was delivered through the interstitial implants. The optimal minimum tumor doses for local control vary with the size of the primary lesion: 6000 rads for T$sub 1$ lesions and 6,500 rads for T$sub 2$ lesions treated with interstitial radium implants in combination with external irradiation. In a retrospective computer dosimetry analysis of 58 patients with carcinoma of the oral tongue treated with interstitial radium implants alone or in combination with external irradiation, dose and volume appear to be the most important factors in both local control and the incidence of necrosis in the dose rate change commonly used in clinical interstitial radiotherapy, dose rate has no significant effect.
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