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Proton Therapy of Cancers of the Nasal Cavity and Paranasal Sinuses
Reporter: J. Taylor Whaley, MD
The Abramson Cancer Center of the University of Pennsylvania
Presenter: Robert Malyapa
Presenter's Institution: University of Florida Proton Center
- Nasal cavity and paranasal sinuses cancers are rare tumors and compose 3-4% of all head and neck cancers. Approximately 2000 people are diagnosed each year in the United States.
- The typical age range at the time of diagnosis is middle age to elderly individuals.
- Although the most common histology for tumors in this region are squamous cell carcinomas, a variety of tumors, including adenoid cystic, esthesioneuroblastoma, sinonasal undifferentiated carcinomas, and sarcomas, can be found here.
- Historically, the majority of patients with sinonasal carcinomas presented with locally advanced disease. Because of the tendency for late presentations with intracranial and intraorbital invasion, many tumors are unresectable due to the complex anatomy and nearby critical structures, including the brain stem and optic chiasm.
- Due to the frequent inability to achieve adequate resections, local recurrences occur approximately 50% of the time. With the risk of recurrence significant, post-operative radiation is generally employed to improve local control.
- Due to the lack of exit radiation associated with proton therapy, significant dosimetric advantages can be seen compared to patients who were historically treated with photon therapy. Proton therapy offers the potential for similar target coverage while sparing many nearby critical structures.
- The purpose of this study report the initial experience in the treatment outcomes in patients with cancers of the nasal cavity and paranasal sinuses treated with proton beam therapy at the University of Florida.
- Since 2007, University of Florida has treated 72 patients with nasal cavity and paranasal sinuses cancers with proton therapy. 49 patients completed therapy with more than one year of follow up.
- Of the 49 patients, 43 patients had prior surgery- generally endoscopic surgery and bifrontal craniotomy for intracranial extension. 23 patients had close or positive margins, 20 patients had negative margins, and 6 patients underwent only a biopsy. Sinonasal cavity was the most common location.
- The majority of patients were locally advanced with 69% of patients noted to have intracranial invasion.
- Median age at the time of diagnosis was 58 years (Range 16-82 years).
- All patients were treated with a hyperfractionated regimen at 1.2 GyE twice daily. Total prescription doses were 64.8-69.6 for post-op negative margins and 74.4 GyE for positive margins and gross disease.
- 5-8 fields were used with each field treated daily. The regional nodes in the neck were treated with a photon matched plan using half-beam block to 50 Gy in 2 Gy/fraction regimen.
- Median follow up was 2 years for all patients (Range 0.4 to 4 years).
- Despite aggressive histologies and locally advanced presentations in most patients, 1-year Overall Survival was 94% with 2-year OS 73%.
- 1-year local control was 86% with 2-year local control 86% as well.
- Of 2 patients with in-field recurrence, one subsequently died of disease.
- Six patients who were inoperable succumbed to their disease in 6-20 months.
- The most common site of failure was distant failure. Five patients who underwent post-operative proton therapy died of distant disease with no signs of local recurrence.
- Most patients developed significant acute skin and mucosal reactions during treatment.
- No severe CNS or ocular toxicities observed
- Medial retinopathy occurred in a single patient. This was treated successfully with intraocular Avastin and vision was maintained.
- In patients with locally advanced cancers of the nasal cavity and paranasal sinuses, high-dose post-operative and definitive proton beam radiation is feasible and beneficial with avoidance of normal structures.
- Patients who underwent surgical resection had better outcomes than patients who under biopsy alone.
- Further follow up is required to evaluate potential late side effects of proton therapy.
- The authors present their experience with proton radiotherapy locally advanced cancers of the nasal cavity and paranasal sinuses. The presentation is certainly a valuable contribution to the standing body of literature.
- Due to the small number of cases of cancers of the nasal cavity and paranasal sinuses diagnosed in the United States annually, prospective trials are difficult to perform. The majority of literature involves retrospective reports from single institutions.
- Proton therapy offers potential dosimetric advantages for cancers near the base of skull, and the acute toxicity appears to be acceptable. Due to the rapidly evolving techniques surrounding proton therapy, this very difficult and debilitating disease could be effectively treated with fewer side effects than previously seen.
- Information on late effects and long term outcomes associated with this treatment remains will certainly contribute to the literature when longer follow-up permits analysis of quality of life and disease control following proton beam radiotherapy.