Local Tumor Control and Long-Term Overall Survival in 51 Patients with Anterior Skull Base Tumors Treated with Intraoperative Radiation Therapy

Abstract

In order to achieve local Tumor control in advanced Primary and recurrent Tumors at the skull base, interdisciplinary cooperation is the perquisition the last nineteen years we have investigated, if intraoperative Radiotherapy in the complex anatomical area of the skull base is possible and if the Addition of this therapy can lead to improvement in local control and survival After local tumor excision at the anterior skull base intraoperative radiotherapy was applied to 51 patients. There were 31 treatments for primary tumors, 20 times the reason for the procedure was tumor recurrence. A maximum dose of 10 Gy (range 8-10 Gy) was given. Electrons between 4 and 6 MeV and perplex tubes of 4 and 5 centimeters were used. Thirty-seven (37) patients also received adjuvant radiotherapy. The anatomical area most often involved were the paranasal sinuses (26 Primaries, 5 recurrent Tumors) followed by nasal cavity (7), Nasopharynx (2), buccal mucosa (3), Oropharynx (2), Orbita (3), parotid Gland (1), recurrence of thyroid cancer and recurrence of unknown H/N CUP. 40 male and 11 female patients between 35 and 73 years of age were treated. The histology consisted of squamous cell carcinoma (18x), Adenocarcinoma (14), undifferentiated (4), adenoid cystic carcinoma (3), Olfactorius neuroblastoma (3), Mucoepidermoid Ca., Melanoma (each 2), Leiomyosarcoma, Basalioma, transitional cell Carcinoma, sebaceous Gland carcinoma and papillary thyroid cancer (each 1). With a median follow up of 6.2 years (0.1-19 years) 13 of 31 patients with advanced Primaries and 8 of 20 patients with recurrent Tumors are alive, from them 14 patients with a survival of at least 136 months with local and distant control. Four further patients are controlled locally without distant disease at 102,80,18 and 7 months, three patients are locally controlled at 96,32 and 3 months, but show distant metastases. The cohort of 51 patients with intraoperative radiotherapy at the anterior skull base establish the biggest Group of patients treated with this procedure at that anatomical area in the literature with Long term follow up so far. We could show that including intraoperative radiotherapy in the interdisciplinary treatment of this patients with advanced Primaries and recurrent tumors lead to a Long time Tumor control in one third of the patients in good Quality of life and without side effects from the procedure