Time, Dose and Volume Factors in Interstitial Radium Implants of Carcinoma of the Oral Tongue

Abstract

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 range commonly used in clinical interstitial radiotherapy, dose rate has no significant effect. The optimal minimum tumor doses for local control vary with the size of the primary lesion: 6,000 rads for T1 lesions and 6,500 rads for T2 lesions treated with interstitial radium implants alone and 7,500 rads for lesions treated with interstitial radium implants in combination with external irradiation. For lesions treated with implants plus external irradiation, greater local control was achieved when most of the dose was delivered through the interstitial implants. 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 volume receiving the dose.

Interstitial‐implant radiotherapy in upperaerodigestive‐tract malignancy

“…The largest series is that of Pierquin et al,17 who have evaluated local control of lesions up t o 4 cm in size, reporting in 153 patients an astonishing 95% local control at six months and at four years (metastatic disease limited the overall four-year survival to 50%). Also satisfactory is a control rate of 76% in 50 patients with lesions of less than 4 cm, and an overall control rate of 71% in 58 patients, reported by Fu et al 7 Delclos et a13 have reported 82% (28/34) local control with lesions of less than 4 cm, and 80% (37/46) overall control. At the University of Southern California (USC) Medical Center, a total of 21 patients with oral-cavity lesions were treated and followed for a minimum of two years; 87% (7/8) of these patients with lesions smaller than 4 cm are living without tumor, and 71% (10/14) with lesions larger than 4 cm are controlled at two years.…”

Definitive Radiotherapy for Carcinoma of the Oral Tongue

“…Although Korb et al (29) found no difference in local control rate between patients with TI -2 lesions treated with versus without implant, a majority of authors have reported that a high dose brachytherapy is necessary for securing a good local control (3,7,9,30). For patients treated with combined external and interstitial irradiation.…”

Evaluation of Local Control, Survival and Pattern of Failure with Radiotherapy in Cancer of the Tongue

“…Results of radiation therapy for carcinoma of the tongue are related to the size of the primary lesion and [4,[6][7][8][9][10]. Many patients with advanced tumours are unable to tolerate radical attempts at cure by any modality.…”