# Radiation Oncology/Esthesioneuroblastoma

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Esthesioneuroblastoma

## Overview

* Also known as olofactory neuroblastoma
* Originating from the olofactory epithelium in the roof of the nasal cavity
** Exact cell of origin controversial
** Data suggest ENB is derived from immature olofactory neurons of neuroectodermal origin
* Lines superior one third of nasal septum, cribriform plate, and superior turbinate
** Tumor typically occurs in the vault of nasal cavity or lateral wall adjacent to ethymoid sinuses
* Estimated to be 3-5% of nasal malignant tumors
* Bimodal age distribution
** 10-20 years
** 40-60 years
* Clinical presentation
** Unilateral symptoms: nasal obstruction, epistaxis
* Nodal spread
** Rare in early stage (<10%)
** More common in advanced stage (30-50%)

## Staging

Kadish System
* Kadish A: confined to nasal cavity (18%)
* Kadish B: extends to paranasal sinuses (32%)
* Kadish C: extends beyond nasal cavity and paranasal sinuses (49%)
* Kadish D: lymph node or distant metastases
TNM Staging
* As per Nasal Cavity and Paranasal Sinuses staging

## Outcome

* Survival
** Kadish A: 83%
** Kadish B: 49%
** Kadish C: 39%
** Kadish D: 13%
* Predictors of survival
** Kadish stage
** Treatment modality
** Age at diagnosis

## Treatment

* Rare disease, so most studies are small, single institution, retrospective
* Surgery frequently primary modality
* Some evidence that postop RT improves local control, particularly for more advanced disease
* Some evidence that concurrent chemo-RT may be beneficial
* Elective nodal irradiation controversial, particularly if chemo-RT used for primary disease
* Treatment recommendations (Hansen, 2nd ed)
** Small, low grade tumors: surgery or RT alone (65-70 Gy)
** Large tumors: consider preop RT (50 Gy), surgery, or postop chemo-RT (60 Gy)
* Ulsan University, Korea; 2011 (1996-2007) PMID 20421144 -- "Radiotherapy for esthesioneuroblastoma: is elective nodal irradiation warranted in the multimodality treatment approach?" (Noh OK, Int J Radiat Oncol Biol Phys. 2011 Feb 1;79(2):443-9. Epub 2010 Apr 24.)
** Retrospective. 14 patients, various combinations of modalities, elective nodal irradiation 4 patients. Median F/U 2.2 years
** Outcome: 3-year OS 73%. LR 21%, regional recurrence 21%, distant failure 14%. No nodal failure in patients treated with chemo-RT, regardless of ENI
** Conclusion: Elective nodal irradiation may play a limited role, if patients treated with chemo-RT
* Chiba; 2007 (1999-2005) PMID 17398027 -- "Proton-beam therapy for olfactory neuroblastoma." (Nishimura H, Int J Radiat Oncol Biol Phys. 2007 Jul 1;68(3):758-62. Epub 2007 Mar 29.)
** Retrospective. 14 patients (Kadish A 2/14, Kadish B 5/14, Kadish C 7/14). Dose 65 GyE in 2.5 Gy/fx. Median F/U 3.3 years
** Outcome: 5-year LC 84%, 5-year RFS 71%, 5-year OS 93%
** Toxicity: Liquorrhea 1 patient, no other Grade 3+
** Conclusion: Excellent local control and survival outcome, without serious side effects
* Harvard; 2002 (1992-1998) PMID 12173330 -- "Neuroendocrine tumors of the sinonasal tract. Results of a prospective study incorporating chemotherapy, surgery, and combined proton-photon radiotherapy." (Fitzek MM, Cancer. 2002 May 15;94(10):2623-34.)
** Prospective. 19 patients with olofactory neuroblastoma or neuroendocrine carcinoma. Kadish Stage B 4/19, Kadish Stage C 15/19. Induction cisplatin/etoposide x2 cycles, then proton/photon RT to 69.2 CGE concomitant boost. If response, further 2 cycles of chemo. Median F/U 3.7 years
** Outcome: 5-year OS 74%; 5-year LC 88%
** Toxicity: 1 patient unilateral vision loss after induction chemo. 4 patients frontal/temporal lobe damage by MRI. 2 patients soft tissue/bone necrosis. No radiation-induced visual loss
** Conclusion: This approach is successful, with radical surgery reserved for nonresponders