HyperArc radiotherapy for recurrent synovial sarcoma of infratemporal fossa: a rare case report and review of the literature.

Background: Synovial sarcoma (SS), a malignant and uncommon soft tissue sarcoma, typically manifests in the extremities and trunk. However, its occurrence in the infratemporal fossa (ITF) of the head and neck is exceedingly rare. Patients afflicted with SS in this anatomical region pose considerable challenges, as radical surgery is often difficult to undertake, leading to a high rate of postoperative recurrence. Moreover, it is often difficult to effectively control the tumor when the cancer relapses. Much of our understanding regarding SS of ITF stems from limited case reports, with a lack of established clinical guidelines for its management. There exists a significant clinical need for effective therapeutic approaches. Case Description: This case report documents a patient with SS of ITF, experiencing repeated recurrences despite undergoing multiple surgeries and chemotherapy treatments. The patient underwent HyperArc (HA) radiotherapy (RT) in conjunction with concurrent chemotherapy utilizing cisplatin, resulting in a remarkable 3-year follow-up period devoid of recurrence. Conclusions: The primary objective of this case report is to disseminate knowledge regarding this rare manifestation of SS of ITF, detailing the successful treatment strategy employed. In this case, we employed a comprehensive treatment strategy involving concurrent chemoradiotherapy based on HA. Our findings demonstrate that this approach was effective in achieving disease control and improving patient outcomes.