Delaying Post-Operative Radiation in Low Grade Esthesioneuroblastoma: Is it Worth the Wait?

 

Introduction: Esthesioneuroblastoma (ENB) is a very rare, malignant tumor that originates from the olfactory epithelium. Due to the low incidence of this tumor, and sparse literature on treatment outcomes, there is no accepted standard of care in regards to the exact timing of surgery, chemotherapy, and/or radiotherapy. In particular, it is unclear in patients with surgically resected ENB after a gross-total resection with negative margins and a low Hyams grade if holding radiotherapy until recurrence is an effective management strategy.

Methods: A retrospective review at one institution of 109 consecutive esthesioneuroblastoma patients. A search for those presenting for primary resection with Kadish Stage B or C and Hyams grade 1–4 was conducted. Forty-five patients were subsequently found that met the above criteria and records were reviewed for relevant data including patient characteristics, surgical approach and margins, radiotherapy administration, and complications. Patients were divided into two groups: those that underwent planned immediate postoperative adjuvant radiotherapy (AR group) and those that did not receive adjuvant radiotherapy (NAR group).

Results: In the AR group, there were 22 (48.9%) patients with a mean age 48.3 ± 11.3 (28 – 80) years. Eleven (50%) were female. One (4.5%) was Kadish Stage B, while the remaining 21 were Stage C. Fourteen (63.6%) had negative margins at surgery. Two were Hyams grade 1, 7 were grade 2, 11 were grade 3, and 2 were grade 4. One patient developed an exposed dura and meningocele in the ethmoid cavity and underwent endoscopic repair. One patient developed a right frontal mucocele that is undergoing observation. One patient developed chronic sinus symptoms. Mean follow-up was 103.4 ± 60.3 (8 – 194) months. Nine patients were not alive at last follow-up, 7 died secondary to ENB. Of the remaining 13 patients, 8 were free of disease, 3 were not, and 2 had unknown disease status. In the NAR group, there were nine patients with a mean age of 42.6 ± 12.6 (21 – 61) years. Five were female. Five (55.6%) patients were Kadish Stage B, while 4 (44.4%) were Stage C. All patients had negative margins at surgery. Eight (88.9%) were Hyams grade 2 and 1 was Hyams grade 3. 5 (55.6%) patients developed recurrence and underwent radiotherapy at a mean of 50.8 ± 51.9 (7 – 141) months. After salvage radiotherapy, one patient developed wound break down requiring revision surgery. Two patients developed chronic sinus symptoms. Mean follow-up was 111.9 ± 64.7 (35 – 224) months. All patients were alive at last follow-up; 6 free of disease.

Conclusions: Results from this study show good outcomes in patients with ENB with long-term follow-up. In our series, there appeared to be little toxicity incurred by immediate radiotherapy. However, in those with delayed radiotherapy performed at the time of salvage surgery, all patients were successfully salvaged with no further local recurrence and were alive at last follow up.