Proceedings of the 52nd Annual ASTRO Meeting S291

patient had neurological or oropharyngeal deficits at initial presentation. PTV in 6/14 patients involved 1 vertebral body (VB); 3/14involved 2 contiguous VBs; 3/14 3 VBs; 1/14 4VBs and 1/14 5 VBs to a mean prescribed dose 15.1 Gy (range:12-16 Gy). Spinalcord, brachial plexus, larynx, trachea and esophagus were delineated as OAR on CT and MRI imaging in the actual treatment plansand dosimetrically evaluated.

Results: Patients were followed weekly for 1 month and every subsequent 3 months to assess treatment response and side effects oftherapy. Mean patient follow-up was 9.3 mos (range:1-33 mos). Mean cord dose was 6.1 Gy (max. 13.4 Gy) to a mean volumetreated (MVT) of 4.2 cc (range: 1.79-7.42 cc); mean brachial plexus dose 7.7 Gy (max 18.2 Gy) with a MVT of 15.46 cc (range:2.93-37.41 cc); mean laryngeal dose 4.9 Gy (max 18.1 Gy) with a MVT of 39.0 cc (range, 0-76.77 cc); mean tracheal dose 4.5 Gy(max 17.0 Gy) to a MVT of 12.55 cc (range, 0-37.37 cc); mean esophageal dose 5.8 Gy (max 18.6 Gy) to a MVT of 4.0 cc (range, 0-14.14 cc). For each OAR, dose to 0.1 cc, 1 cc, 2 cc, 5 cc and the volume receiving . 10 Gy will be presented at the meeting. Clin-ically, no patient developed hoarseness, dysphagia, strictures, esophagitis, or evidence of a brachial plexopathy. There was also nomyelopathy or radiculopathy documented.

Conclusions: Data exists evaluating the impact of radiation therapy on OARs in the cervico-thoracic region with conventionalfractionated regimens for head and neck, lung and breast cancer. To our knowledge this is the first published report evaluatingthe impact of single fraction spine radiosurgery on these same anatomic structures. From our analysis, the current SRS dosesused at our institution are safe and well tolerated. Although this preliminary data may not be surprising, it provides us withbench-mark OAR tolerances in the cervico-thoracic spinal region. As the field of SRS evolves toward dose escalation, larger studiesevaluating not only treatment responses, but also OAR dosimetry and clinical tolerance should be pursued.

Author Disclosure: G. Rahmathulla, None; T. Djemil, None; S. Chao, None; T. Emch, None; L. Angelov, Novalis, D. SpeakersBureau/Honoraria.

2195 Post-enucleation Orbital High Dose Rate Brachytherapy for Choroidal Melanoma with

Extrascleral Extension

P. D. Aridgides1,2, P. T. Finger1,3, L. B. Tena1,4

1St. Vincent’s Comprehensive Cancer Center, New York, NY, 2Upstate Medical University, Syracuse, NY, 3The New York EyeCancer Center, New York, NY, 4New York Medical College, Valhalla, NY

Purpose/Objective(s): Residual orbital melanoma (extrascleral extension) is associated with increased risk of metastasis and poorprognosis. Post-enucleation external beam radiation therapy (EBRT) has been employed to reduce local recurrence and improvesurvival. However, such orbital EBRT has been associated with eyelash loss, eyebrow loss, socket deformity and dry eye. Alter-natively, this study examines the results of a clinical case series of patients treated with iridium-192 high dose rate (HDR) brachy-therapy.

Materials/Methods: From February 2005 through January 2010, 6 patients were diagnosed with AJCC stage T4N0M0 choroidalmelanomas with extrascleral extension. Each was treated by primary enucleation. Histologic subtypes included: 1 spindle cell, 1epithelioid and 4 mixed cell type. All had a basal diameter .16 mm (pT4) and extrascleral extension. Metastatic surveys, includingtotal body PET/CT were negative. Seven to 11 brachytherapy catheters were inserted into the orbit using a bimanual techniqueunder general anesthesia. Medical epoxy was used to affix buttons to catheters that were sutured to the periorbital skin. Treatmentto a total dose of 32.9-34 Gy was delivered in 9 to 10 twice-daily fractions (over a 5-day course). The catheters were removed andpatients followed every 6 months for local control and metastatic disease.

Results: Local control has been 100%, with a median follow-up of 10.1 months (range, 2 to 35 months). Two patients (33%)expired from metastatic disease (5 and 14 months from brachytherapy). Cosmetic results include that 5 out of 6 patients devel-oped no eyebrow or eyelash loss. One patient experienced mild temporary eyebrow loss. Dry eye (66%) was the most commonside effect, which typically improved over time. There was no acute eyelid erythema, orbital infection or contracted dry sockets.All patients fit and maintained ocular prostheses. One patient developed bacterial conjunctivitis shortly after treatment that re-solved with antibiotics. Dosimetric review confirmed the following for all patients (maximum dose): contralateral eye \ 6Gy, contralateral lens \ 3.5 Gy, contralateral optic nerve \6 Gy, optic chiasm \ 8.5 Gy, and one-third of the normal brain\ 1.5 Gy.

Conclusions: HDR brachytherapy should be considered as an alternative method of treatment for choroidal melanoma with ex-trascleral extension. These first patients treated with this technique have experienced excellent local control and few side effectsas compared with our experience with orbital external beam radiation therapy.

Author Disclosure: P.D. Aridgides, None; P.T. Finger, None; L.B. Tena, None.

2196 Linac-based Stereotactic Radiosurgery for Brain Cavernomas

S. C. Blamek1, A. Idasiak1, D. Larysz2, A. Rudnik2, K. Ficek1, L. Miszczyk1, R. Tarnawski1

1Department of Radiotherapy, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Gliwice Branch,Gliwice, Poland, 2Department of Neurosurgery, Medical University of Silesia, Katowice, Poland

Purpose/Objective(s): Symptomatic cavernous malformations of the brain are usually treated surgically. Stereotactic radiosurgerycan be used in case of inoperable lesions or to treat patients unwilling a surgical procedure. Reported results of radiosurgical treat-ment however are relatively scarce and often conflicting. The aim of our study is to assess the outcome of patients treated withstereotactic radiosurgery for brain cavernomas.

Materials/Methods: Thirty patients; 16 men and 14 women, aged 15-65, mean and median age was 39.5 and 40.5 years, respec-tively. Eleven (36.7%) had previous clinically manifested hemorrhage, other symptoms were: epilepsy (26.7%), headaches(53.3%), dizziness (36.7%), paresis (26.7%), vision impairment (20%) and vomiting (20%). 5 patients were previously treated sur-gically, one had prior hypofractionated radiotherapy. All patients were irradiated with linac equipped with micro-multileaf colli-mator with doses ranging between 5 and 20 Gy, mean and median dose was 15.4 and 16 Gy, respectively. Mean and median follow-