¹²⁵I seed implantation brachytherapy for glottic carcinoma: an experimental and clinical study

¹²⁵I seed implantation brachytherapy (ISIB) is the preferred treatment for prostate cancer. Is ISIB technically suitable for glottic carcinoma (GC)? This question has not been answered in the literature; thus, the present study was carried out to evaluate the feasibility and effect of ISIB on GC in animal and clinical studies. An animal model of Tu-212 cell laryngeal carcinoma xenografts (n = 20 animals) underwent ISIB treatments [experimental group (EG) using 0.8-mCi/seed, control group (CG) using 0-mCi/seed]; at 4 weeks, haematoxylin-eosin (HE) staining was performed, and the mRNA and protein expression of Bax, Bcl-2 and PCNA was analysed. Moreover, thirty healthy beagle dogs underwent ISIB under CT guidance (EG, 0.8 mCi/seed, CG, 0 mCi/seed), and injuries to the normal tissue were analysed by HE and Masson staining at 2, 4, and 8 weeks. Finally, twenty-one GC patients (T2-3N0M0) underwent percutaneous ISIB at a mean prescription dose of 116.8 Gy; the technical success, complications, local tumour response, voice quality, local progression and overall survival were analysed. The results showed that the xenograft tumours were significantly inhibited in the EG. The Bax protein levels were significantly increased in this group (P<0.05), while the Bcl-2 and PCNA protein levels were decreased (P<0.05). Moreover, the glottic injury scores increased with the dose accumulation (P<0.05), while the adjacent tissue did not show pathohistological injury, and the routine blood tests showed no change between the pre-treatment baseline levels and the levels 2, 4, or 8 weeks later (P>0.05). The clinical study found that the rate of technical success was 100% with no procedure-related complications; furthermore, complete response was achieved in all patients, and no local progression occurred. All patients survived and showed improvements in their voice quality (P<0.05) during the follow-up period (median 23.5 months). The results show that ISIB is a safe and effective treatment for GC; randomized controlled trials are needed to further evaluate its clinical efficacy.