PII S0360-3016(00)01550-9 CLINICAL INVESTIGATION Head and Neck METHODS OF BOLUSING THE TRACHEOSTOMY STOMA JONATHAN J. BEITLER, M.D., M.B.A.,* ² RAVINDRA YAPARPALVI, M.S.,* CESAR DELLA BIANCIA, M.S.,* AND DORACY P. FONTENLA,PH.D.* ² Departments of *Radiation Oncology and ² Otolaryngology, Montefiore Medical Center, Bronx, NY Purpose: The tracheostomy stoma is a potential site of recurrence for patients who have subglottic cancer or subglottic spread of cancer. In these patients, it is important that the anterior supraclavicular field does not underdose the posterior wall of the tracheostomy stoma when using a 6-MV anterior photon field. Convention- ally, this problem is surmounted with placement of a plastic tracheostomy tube, which is uncomfortable for the patient, potentially traumatic, and can interfere with vocalization via a tracheal esophageal puncture. Our study was designed to investigate the dosimetry of this region and see if alternate methods would be effective. Methods and Materials: A phantom was constructed using a No. 6 tracheostomy tube as the model for the tracheostomy curvature and size. Using the water-equivalent phantom, film dosimetry, and films oriented parallel to the en face field, we investigated the dose at the depth of the surface of the posterior wall of the phantom’s tracheostomy stoma. Dose was measured both in space and at the tissue interface by scanning points of interest both horizontally and vertically. We measured doses with a No. 6 and No. 8 plastic tracheostomy tube, either 0.5 cm and 1.0 cm of bolus (1-cm airhole) with no tracheostomy tube, as well as 0.3 cm and 0.6 cm tissue-equivalent Aquaplast (Med-Tec Co., Orange City, Iowa) over the tracheostomy. Dosimetry at the posterior interface was confirmed using thermoluminescent dosimeters. Results: Three mm and 6 mm of Aquaplast produced a posterior tracheal dose of 93% and 100%. Conclusion: There is no need for these patients to wear a temporary plastic tracheostomy tube during their external radiation therapy. Aquaplast should allow better position reproducibility, reduce trauma, not interfere with patient respiratory efforts, and be compatible with vocalization via a tracheal esophageal puncture. © 2001 Elsevier Science Inc. Tracheostomy, Subglottic, Subglottic extension, Tracheostomy bolus, Laryngectomy. INTRODUCTION Total laryngectomy is still necessary for patients who fail to respond to nonsurgical therapy. For those patients with subglottic extension who require a total laryngectomy, the tracheal stoma is at risk for local recurrence according to prominent textbooks (1–3). Wang agrees that postoperative radiation to the tracheal stoma is indicated for subglottic extension but also feels that routine postoperative radiation to the neck and tracheostomy stoma are indicated for post- operative advanced glottic and supraglottic cancers if mul- tiple nodes are present (3). Million and Cassisi (2) point out that, “The most frequent sites of local failure after total laryngectomy are around the tracheal stoma, in the base of the tongue, and in the neck lymph nodes.” The tracheostomy geometry ensures that the posterior mucosal wall is directly exposed to anterior supraclavicular field photons, and due to lack of build-up, it was feared that the mucosal surface of the tracheostomy stoma would be underdosed. Conventionally, this problem is surmounted with place- ment of a plastic tracheostomy tube, which is uncomfortable for the patient, potentially traumatic, and can interfere with vocalization via a tracheal esophageal puncture. We con- centrated on the area of the posterior tracheal wall, which by virtue of geometry of the tracheal stoma had no “natural” bolus. Our study was designed to investigate the dosimetry of this region and see if alternate methods would be effec- tive. METHODS AND MATERIALS A polystyrene water-equivalent phantom (see Figs. 1–3) was constructed using a No. 6 tracheostomy tube as the model for the tracheostomy curvature and size. The trachea Correspondence: Dr. Jonathan J. Beitler, Department of Radia- tion Oncology, Montefiore Medical Center, 111 East 210th Street, Bronx, NY 10467-2490. E-mail: JBeitler92@alumni.gsb. columbia.edu Present address for C. D. Biancia, Department of Medical Phys- ics, Memorial Sloan–Kettering Cancer Center, New York, NY. Present address for D. P. Fontenla, Department of Radiation Oncology, Long Island Jewish Hospital, New Hyde Park, NY. Presented at 82nd Annual Meeting of the American Radium Society, London, England, April 4, 2000. Acknowledgment—The authors would like to acknowledge the expert secretarial assistance of Ms. Liza Estevez. Accepted for publication 3 November 2000. Int. J. Radiation Oncology Biol. Phys., Vol. 50, No. 1, pp. 69 –74, 2001 Copyright © 2001 Elsevier Science Inc. Printed in the USA. All rights reserved 0360-3016/01/$–see front matter 69