Abstract
Local treatment of squamous cell carcinoma of the esophagus is only modestly successful. To increase local control, we have developed a procedure to inject a boost dose of radiation into the tumor bed after completion of external beam radiotherapy. The boost dose is given with 32P, a readily available radiocolloid. 32P is a pure emitter and poses no significant radiation hazards. It can penetrate 10-15 mm into the tumor mass and has a half-life of 14.3 days. After determination of the volume to be treated, the colloid is injected with endoscopic guidance using the same technique as used in injection sclerotherapy of esophageal varices. We use the Pentax FG 34 JA operating gastroscope and a Bard disposable 0.5 cm 25 Ga retractable injection sclerotherapy needle. We deliver 150-200 microCurie of 32P colloid diluted to 20 ml with normal saline at 10 to 20 injection sites. This boosts the radiotherapy dose of 5, 500-6, 000 cGy to the range of 7, 500-8, 000 cGy. We have treated five patients so far, with length of follow-up ranging from 8-28 months. Local control and survival results have been excellent and no complications have been associated with the procedure. A combination of external beam radiotherapy and interstitial boost treatment with colloidal 32P appears to be a safe and effective method of managing squamous cell carcinoma of the esophagus.
