gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Proton Radiation Therapy for Unresectable Sinonasal Squamous Cell Carcinoma

Meeting Abstract

  • J. J. Wang - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • J. A. Adams - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • N. J. Liebsch - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • J. F. McIntyre - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • J. R. Clark - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA
  • A. Chan - Dept. of Radiation Oncology, Massachusetts General Hospital, Boston, USA

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog219

DOI: 10.3205/09ptcog219, URN: urn:nbn:de:0183-09ptcog2194

Published: September 24, 2009

© 2009 Wang et al.
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Outline

Text

Background: Due to the anatomical location of sinonasal malignancies, conventional radiation therapy results in very poor local control rate and is associated with significant treatment-related toxicity. The treatment outcome of unresectable squamous cell carcinoma of the paranasal sinus results in even lower survival rates, since tumor resection prior to radiotherapy has been shown to offer the best overall survival and local control rates.

Intensity-modulated radiation therapy, though initially promising, has not been shown to improve the local control or survival for patients with unresectable sinonasal malignancies, although they have reduced toxicity. Proton radiation therapy with its superior dose distribution properties allows the delivery of higher doses to the tumor and lower doses to the surrounding normal tissues. The purpose of this study was to assess the treatment outcome and prognostic factors in patients with unresectable sinonasal squamous cell carcinoma treated with proton beam therapy.

Methods and materials: Between 1991 and 2008, 20 patients with locally advanced unresectable squamous cell carcinoma of the sinonasal malignancy received 3-dimensional conformal proton beam therapy at the Massachusetts General Hospital (MGH). The distribution of the staging was 1 T3 and 19 T4b. There were 12 males and 8 females, with a median age of 51 (range 17–78). The primary tumor epicenter included the ethmoid sinus in 1, maxillary in 5, nasal cavity in 1, sphenoid sinus in 12, and other in 1 patient. All patients underwent biopsy alone before radiation. The median gross tumor volume (GTV) was 78cc (range 19–318). The median total dose to the GTV was 76 Gray-Equivalent (range 67.8–76.5). Patients after 2002 were treated with concurrent chemotherapy, refined radiation schema and techniques, and with gantry-based technique at the hospitalbased proton facility instead of fixed beams at the Harvard Cyclotron Laboratory.

Results: With a median follow-up of 22 months for all patients, 3 patients developed local, 2 regional, and 5 distant metastasis as the first site of failure. The 2-year actuarial rates of local control, regional control, and freedom from distant metastasis were 79%, 86%, and 71%, respectively. The disease-specific survival and overall survival rates at 2 years were 71%, and 55%, respectively. In multivariate analysis, treatment after 2002 was predictive of improved overall survival rate (p=0.03, adjusted HR = 0.27, 95% CI=1.2, 12.1). The overall survival at 2 years was 100% for patients treated after 2002 and 11% for patients treated before 2002 (p=0.01). There was no radiation-related grade 3 or higher ocular-visual or auditory toxicity. Radiographic brain change was observed in 2 patients after radiation; both were grade 1 asymptomatic without treatment.

Conclusions: Proton beam therapy results in promising local control and survival rates in patients with unresectable sinonasal squamous cell carcinoma. Prospective multi-institutional studies are necessary to further study the use of proton beam therapy with chemotherapy in the treatment of this rare and aggressive malignancy.