Long-term Outcomes of Neoadjuvant Radiotherapy Versus Adjuvant Radiotherapy for Malignant Lacrimal Sac Tumors (A Multicenter Randomized Controlled Trial)

The treatment for malignant lacrimal sac tumors is difficult and the prognosis is poor. The conventional strategy is surgical resection followed by adjuvant radiotherapy with or without concurrent chemotherapy. This approach has many drawbacks including positive surgical margins due to large tumor size, distant metastasis due to intraoperative squeeze, and implant exposure due to high doses of radiation. In previous research, the investigators innovatively adopted neoadjuvant radiotherapy (or chemoradiotherapy) and withdrew radiotherapy after surgery. Preoperative radiotherapy can effectively reduce the tumor size and encapsulate the tumor in a fibrotic cyst, and therefore enables en-bloc excision of the tumor and simultaneous orbital reconstruction. This multidisciplinary approach can reduce the risk of recurrence and metastasis, lower the dose of radiation, and avoid implant exposure after reconstruction.

In order to compare the long-term outcomes between neoadjuvant radiotherapy and conventional treatment approach, the investigators will prospectively recruit 94 patients with malignant lacrimal sac tumors and randomly assign these subjects into the study group (neoadjuvant radiotherapy, 47 cases) and the control group (conventional treatment, 47 cases). The primary outcomes include overall survival, disease-free survival, distant metastasis-free survival, and locoregional control at 2-year, 5-year and 10-year intervals. The secondary outcomes include ocular functions (visual acuity and diplopia, tear film stability and tear secretion, globe dystopia and motility, and corneal topography), acute and chronic radiation-related toxicity, cosmesis (medial canthal tendon dystopia and eyelid retraction), and assessment of quality of life.