INTRODUCTION: To describe the technique of injecting Lipiodol in the submucosa of the urinary bladder wall as a novel modality to improve localization of muscle-invasive bladder tumors before image-guided radiation therapy.
TECHNICAL CONSIDERATIONS: Eight patients underwent submucosal Lipiodol injections at transurethral bladder tumor reresection. A rigid cystoscope with a working port was used to inject Lipiodol into bladder submucosa circumferentially around the tumor bed (2-3 mm from margin of resection). Approximately 20-30 injections were used to demarcate the tumor bed for external beam radiation therapy, which was used as part of a bladder-sparing approach. All patients were diagnosed with clinically localized, high-grade, muscle-invasive carcinoma and were deemed nonsurgical candidates or were unwilling to undergo radical cystectomy. Five of the 8 patients received radiation at our institution. Lipiodol injections (95%) were visible on treatment planning computed tomographic scans and kilovoltage portal images throughout the 7-week course of image-guided radiation therapy. In 2 of 5 patients, the tumor bed based on Lipiodol extended outside a planning target volume that would have been treated with radiation therapy based on cystoscopy reports and computed tomographic scans without Lipiodol. There were no adverse events or treatment-related toxicities secondary to Lipiodol injection.
CONCLUSION: Intravesical Lipiodol injection is an easy-to-perform technique that is safe and effective. Lipiodol serves as a fiducial marker that improves tumor bed localization for radiation therapy, thereby reducing the likelihood of missing the tumor.
Written by:
Baumgarten AS, Emtage JB, Wilder RB, Biagioli MC, Gupta S, Spiess PE. Are you the author?
Department of Genitourinary Oncology, Moffitt Cancer Center, Tampa, FL; Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL.
Reference: Urology. 2014 Jan 4. pii: S0090-4295(13)01421-0.
doi: 10.1016/j.urology.2013.09.058
PubMed Abstract
PMID: 24397940
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