Superselective intra-arterial cisplatin infusion and concomitant radiotherapy (RADPLAT) for maxillary sinus squamous cell carcinoma: an institutional experience of 118 cases

<title>Abstract</title> <p>Background Surgery combined with radiotherapy is a standard treatment for resectable maxillary sinus squamous cell carcinoma (MS-SCC), but radical surgery can cause substantial cosmetic and functional morbidity. While intravenous chemoradiotherapy has limitations, superselective intra-arterial (IA) infusion of high-dose cisplatin with concomitant radiotherapy (RADPLAT) has been incorporated into Japanese clinical practice guidelines as a treatment option for selected patients with cT4aN0 MS-SCC. Methods We retrospectively analyzed 118 consecutive patients with MS-SCC who underwent RADPLAT as an initial treatment at Hokkaido University Hospital between 1999 and 2021 to evaluate clinical outcomes and toxicities. Results The 5-year overall survival (OS) and local event-free survival (LEFS) rates were 69.5% and 59.4%. Patients without lymph node metastases had significantly better OS (P &lt; 0.01) and LEFS (P = 0.02). Acute Grade ≥ 3 adverse events occurred in 53.4% of patients. Multivariate analysis identified younger age, absence of nodal metastasis, and increased number of cycles of IA chemotherapy as significant favorable prognostic factors. Conclusion RADPLAT demonstrated favorable long-term outcomes and acceptable toxicity profiles in patients with MS-SCC. These findings suggest that RADPLAT may represent a promising treatment option for selected patients; however, further prospective comparative studies are warranted to clarify its role among multimodal treatment strategies.</p>