Case Serie of Hybrid Brachytherapy followed by Intensity Modulated Radiation Therapy (HyBIRT) Technique for the Definitive Management of Tongue Squamous Cell Carcinoma (TSCC)

Abstract Introduction The Hy brid B rachytherapy followed by I ntensity Modulated R adiation T herapy (HyBIRT) technique reverses the commonly used sequence by delivering high dose rate interstitial brachytherapy (HDRIBT) first followed by IMRT in the management of tongue squamous cell carcinomas (TSCC). Materials and methods Eleven patients treated with 20Gy in 5 fractions HDRIBT to TSCC followed by definitive IMRT to 69.96Gy to the involved nodes; 61.71Gy to the high risk volume and 56.1Gy to the low risk volume over 33 fractions in a single institution were analyzed retrospectively. Results All 11 patients achieved clinical complete response (cCR) and 9 patients with available radiological imaging achieved radiological complete response (rCR) at the primary site. One year locoregional progression-free survival was 90% (95% CI: 73.2% − 100%) and 18-month disease-free survival (DFS) for 8 patients who achieved rCR was 66.7% (95% CI: 30% − 100%). Median times to cCR and rCR at the primary site were 3.91 months and 4.34 months, respectively. Seven out of 8 patients with nodal disease achieved rCR of the nodes with a median time for rCR of 4.58 months. Two patients had persistent ulcer at 8 months and 11 months of follow-up. Discussion HyBIRT technique has the advantage of easy tumor identification during HDRIBT applicator insertion, ability to maneuver the subsequent IMRT plan and reduced the overall treatment time (OTT) while delivering tumoricidal dose to gross disease. Studies with larger sample size are needed to further confirm the efficacy of this organ sparring technique.