ESTR
O 2
01
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Poster presented at:
Olfactory neuroblastoma – 10-year experience with
volumetric modulated arc therapy
Ariyaratne H1, Ward A2, Bhudia P2, Lund V2, Carnell D2
1Royal Free London NHS Foundation Trust, 2University College London Hospitals NHS Foundation Trust
Email: [email protected]
Purpose
Olfactory neuroblastoma is an unusual head and neck tumour arising
from neuroectodermal cells. Localized disease is best managed with
combined modality treatment with surgical resection and radiotherapy
(1). Treatment is challenging due to the proximity of organs at risk.
The majority of previously reported series of patients have been treated
with conformal radiotherapy (2,3). We report our experience in using
volumetric modulated arc therapy (VMAT) with concurrent chemotherapy
in the treatment of olfactory neuroblastoma.
Methods
We retrospectively reviewed the records of patients with olfactory
neuroblastoma treated at University College London Hospital from Aug
2006 - June 2016.
Radiotherapy was inverse-planned and delivered using RapidarcTM
VMAT (Varian Medical Systems Inc, CA). A dose of 60 – 65 Gy in 30
fractions was delivered to the planning target volume. The radiotherapy
planning constraints for organs at risk were:
Fig. 1. Dose distribution achieved with VMAT after resection of olfactory
neuroblastoma with positive margins near left orbit.
Induction chemotherapy was used for bulky disease. Concurrent
platinum-based chemotherapy was administered during radiotherapy
using cisplatin 35 mg/m2 weekly. Acute toxicity was assessed using the
CTCAE grading system. Kaplan-Meier survival analysis was used for the
whole group..
Conclusion
VMAT radiotherapy with concurrent chemotherapy for olfactory
neuroblastoma is well-tolerated. Overall survival for patients with
olfactory neuroblastoma is very good after multi-modality treatment.
References
1. Lund VJ, Howard D, Wei W, Spittle M. Olfactory Neuroblastoma: Past, Present, and Future?
The Laryngoscope. 2003;113(3):502-7.
2. Castelnuovo P, Bignami M, Delù G, Battaglia P, Bignardi M, Dallan I. Endonasal endoscopic
resection and radiotherapy in olfactory neuroblastoma: Our experience. Head & Neck.
2007;29(9):845-50.
3. Zappia JJ, Carroll WR, Wolf GT, Thornton AF, Ho L, Krause CJ. Olfactory neuroblastoma:
The results of modern treatment approaches at the University of Michigan. Head & Neck.
1993;15(3):190-6.
4. Kadish S, Goodman M, Wang C. Olfactory neuroblastoma—A clinical analysis of 17 cases.
Cancer. 1976;37(3):1571-6.
Results
17 consecutive patients treated with VMAT radiotherapy were included.
Median follow-up of patients was 43 months. Median age was 57 years
(range 22 – 75 years). 53% were male. The Kadish (4) staging of
patients is shown below:
13 patients had endoscopic surgery and 3 patients had open craniofacial
resection. One patient had unresectable disease. Even with inverse-
planned treatment, there were minor deviations from radiotherapy
constraints for the optic apparatus in some patients, due to the proximity
to the target volume (Fig. 1).
There was no acute grade 3/4 toxicity, and no long-term visual or
neurological toxicity during the period of follow-up. 5-year overall survival
of patients in this series was 83%. (Fig.2 below)
Kadish Stage No. ofpatients
%
A 4 23.5
B 3 17.6
C 7 41.2
D 3 17.6
Total 17 100.0
Organ at risk Parameter Constraint
Spinal cord Max 46 Gy
D0.1cc 44 Gy
Spinal cord PRV Max 50 Gy
D0.1cc 48 Gy
Brainstem Max 55 Gy
D0.1cc 54 Gy
Brainstem PRV Max 59 Gy
D0.1cc 55 Gy
Parotid Mean 24 Gy
Optic nerve PRV Max 50 Gy
Optic chiasm PRV Max 50 Gy
Lens Max 6 Gy
Cochlea Mean 48 Gy
EP-1042Hemal Ariyaratne DOI: 10.3252/pso.eu.ESTRO36.2017
Clinical track: Head and Neck