S582 I. J. Radiation Oncology d Biology d Physics Volume 78, Number 3, Supplement, 2010

Materials/Methods: The kyphoplasty conformed to standard procedure with minor modifications. For intraoperative radiotherapythe INTRABEAM system (Carl Zeiss Surgical, Oberkochen, Germany) was used. After choosing a bipendicular approach speciallydesigned metallic sleeves were inserted to guide the drift tube of the INTRABEAM system. Correct position of the sleeves wasverified using biplanar X-rays. Then the applicator (including the drift tube) was guided through the sleeve into the center ofthe metastasis. There a single dose of 8 Gy in 5 mm distance using 50 kV x-rays was delivered within 2 minutes. After removalof the INTRABEAM system the kyphoplasty balloon was inflated and PMMA cement was injected. The total treatment lasted lessthan 90 minutes.

Results: Since August 2009 14 lesions in 12 patients were treated. There were five males and seven female patients with a medianage of 65, 5 years. The primary histological diagnoses included: breast cancer (6), prostate cancer (2), rectum cancer, lung cancer,gastric cancer and hepatocellular carcinoma (respectively 1). No radiation induced skin reaction or neuropathy was seen. Therewere only a few procedure-related complications in two patients (asymptomatic extravertebral cement leak, asymptomatic pulmo-nary cement extravasation). Pain improved in all patients on day one. To date there have been no local failures with a medianfollow-up of two months (. 6 months in 2 patients).

Conclusions: The combination of kyphoplasty and IORT is technically feasible with high patient acceptance. As survival in pa-tients with cancer increases this new treatment method may become a valuable option for patients with spinal metastases providingimmediate stability and sterilization of the metastasis.

Author Disclosure: T. Reis, None; F. Schneider, None; B. Hermann, None; M. Bohrer, None; R. Schmitt, None; U. Obertacke,None; F. Wenz, None.

2847 Stereotactic Body Radiotherapy of Spine Metastasis

L. Sunyoung1 W. Chung2

1Konyang University Hospital of School, Daejon, Republic of Korea, 2East-West Neo Medical Cancer Center, Seoul, Republic ofKorea

Purpose/Objective(s): To report treatment outcomes in patients with spine metastases treated using the CyberKnife and to analyzethe factors associated with complete pain relief.

Materials/Methods: We retrospectively analyzed patients with pathologically confirmed malignant primary neoplasms who weretreated for spinal metastases with stereotactic body radiosurgery of median 24 Gy/3fractions between April 2007 and June 2009.Pain was assessed by verbal/visual analogue scale; from 0 to 10. Pain relief was defined as a decrease of at least three levels of thepain score without an increase in analgesic use. Complete relief was defined as no analgesics or score 0 or 1.

Results: Fifty-seven patients with 73 lesions have been reviewed. The median follow-up period was 6.8 months (range: 1-31). Themajority of patients had moderate to severe pain prior to treatment. Pain relief was seen in 88% of these patients, with completerelief in 51%. The median duration of pain relief was 3.2 months (range: 1-30). Of 6 patients with solitary bone metastasis, allexperienced pain relief; 5 of them were alive without evidence of disease at a median of 16 months. Radiologic studies of 50 lesionsrevealed pathologic fracture in the treated spine developing after radiosurgery in 1 patient and progressing in 2 patients. No radi-ation-induced myelopathy has occurred. Only performance status (p = 0.002) and the number of involved spine (p = 0.005) werepredictive of palliation for painful bone metastases by Cox analysis.

Conclusions: As previous studies have shown, our research shows that spinal radiosurgery is feasible, safe, and effective as analternative modality for the treatment of spinal metastasis. Further follow-up is needed to establish the long-term safety of spinalradiosurgery. Furthermore, a radiobiologic model suitable for radiosurgery is required to determine radiosurgery regimens in casesof re-treatment of spinal metastasis.

Author Disclosure: L. Sunyoung, None; W. Chung, None.

2848 Hypofractionated Image Guided Radiotherapy for Large Volume Oligometastases

K. S. Corbin, M. C. Ranck, M. Hasselle, D. W. Golden, J. Partouche, T. Wu, R. R. Weichselbaum, J. K. Salama

University of Chicago, Chicago, IL

Purpose/Objective(s): Hypofractionated image-guided RT (HIGRT) is increasingly used for oligometastatic disease. Reportedstudies have treated small volume tumors (median GTVs: 4-14cc, (Rusthoven, 2009, Milano, 2006)). Recently, we have treatedlarger volume oligometastases with HIGRT. Here we report the toxicity and outcomes of consecutively treated large volumeoligometastases.

Materials/Methods: HIGRT patients treated from 10/2005-3/2010 were reviewed. Metastases were considered large volume iflargest PTV exceeded 50 cc. Patients underwent CT simulation using 4DCT and gating as appropriate. GTVs were delineatedon each CT slice with a 5-7 mm expansion to create the PTV. 3D CRT was used for radiation planning. RT was typically prescribedto the 85% isodose line. Patients were treated with either ten fraction regimen (4-5Gy/fraction) or 3-5 fraction regimen (8-14 Gy/fraction). PTV volume was obtained from planning software. Toxicity was obtained from both prospectively collected databasesand retrospectively from patient charts. Statistical analysis was performed using JMP (v8).

Results: A total of 68 patients with 93 treated lesions . 50 cc were identified. Median age: 63 (30-91). Median PTV volume was119 cc (50.1-1222.1). The median # of lesions was 1 (r: 1-7); A maximum of 3 large volume lesions were treated in a single patient.Primary tumors were mostly lung (40%), renal (19%), breast (10%), colorectal (9%), and head and neck (7%).Treated sites in-cluded lung (n = 32, 34%), mediastinal (n = 14, 15%) and abdominal lymph nodes (n = 6, 6%), bone (n = 18, 19%), adrenal(n = 9, 10%), liver (n = 5, 5%), visceral structures (n = 5, 5%), and musculoskeletal sites (n = 4, 4%). The most frequent dosefractionation was 50 Gy/5 Gy fractions (n = 45, 48%). Grade 3 acute toxicity was reported in 3 patients (4.4%) consisting of fatigue(2), and skin (1) toxicity. Five patients experienced late toxicity including 3 with Grade 3 pulmonary toxicity, and one Grade 4 GI

Proceedings of the 52nd Annual ASTRO Meeting S583

toxicity in a patient with history of IBD treated to a lesion adjacent to bowel. One pathologic fracture was noted after treatment toa bony lesion. At mean follow-up of 13 months, crude lesion control was 85%. 12 Month actuarial lesion control was 83% [95% CI:70.4-90.6%]. BEDs \ 50 Gy negatively impacted local control. Twelve month local control of 90% [77-96%] was achieved forBED . 50, compared with 30% [4-63%] for 12 patients treated to BED\50, p = 0.002. There was no statistical difference in localcontrol by lesion size less than or greater than median volume. The predominant pattern of first failure was distant only, occurring in53% of patients. Among 53 patients with $6 months follow-up, 12 (22%) are alive without progression of disease.

Conclusions: HIGRT to large volume oligometastatic disease is tolerable and feasible with promising tumor control.

Author Disclosure: K.S. Corbin, None; M.C. Ranck, None; M. Hasselle, None; D.W. Golden, None; J. Partouche, None; T. Wu,None; R.R. Weichselbaum, None; J.K. Salama, None.

2849 Single Dose vs. Fractionated Stereotactic Radiotherapy for Brain Metastases

Y. Kim1, K. Cho2, J. Kim2, Y. Lim2, H. Min2, S. Lee2, H. Kim2, H. Gwak2, H. Yoo2, S. Lee2

1Seoul National University Hospital, Seoul, Republic of Korea, 2Research Institute and Hospital, National Cancer Center,Goyang, Republic of Korea

Purpose/Objective(s): To evaluate the efficacy of stereotactic radiotherapy in patients with brain metastases by comparing twodifferent regimens, single-dose radiosurgery (SRS) versus fractionated stereotactic radiotherapy (FSRT).

Materials/Methods: Between November 2003 and December 2008, 98 patients with brain metastases were included. Fifty-eightpatients were treated with SRS and 40 patients were treated with FSRT. FSRT was used for the lesions in large size or located nearthe eloquent structures. The median doses were 20 Gy for the SRS group and 36 Gy in 6 fractions for the FSRT group.

Results: With median follow-up of 7 months, median survival was 7 months for all patients with 6 months for the SRS group and 8months for the FSRT group (p = 0.89). Local progression free survival (LPFS) rates at 6 months and 1 year were 81% and 71% forthe SRS group and 97% and 69% for the FSRT group, respectively (p = 0.31) Despite FSRT was used for the lesions in adverselocation and size, LPFS was not inferior to that after SRS. Toxicities were more prevalent in the SRS group than in the FSRT group(17% vs. 5%, p = 0.05).

Conclusions: Given that patients treated with FSRT, despite FSRT was used for the lesions in adverse location and size, showeda similar survival and LPFS with lower risks of toxicity compared with those treated with SRS, FSRT can be particularly beneficialfor patients with lesions in large size or located near the eloquent structures.

Author Disclosure: Y. Kim, None; K. Cho, None; J. Kim, None; Y. Lim, None; H. Min, None; S. Lee, None; H. Kim, None; H.Gwak, None; H. Yoo, None; S. Lee, None.

2850 Re-treatment of Spinal Metastases with Volumetric Modulated Arc Therapy: Feasibility and First

Clinical Outcomes

P. Navarria1, P. Mancosu1, F. Tancioni1, S. Castiglioni1, A. Tozzi1, A. Fogliata2, L. Cozzi2, A. Santoro1, R. Rodriquez Y Baena1,

M. Scorsetti1

1Istituto Clinico Humanitas, Rozzano, Italy, 2Oncology Institute of Southern Switzerland, Bellinzona, Switzerland

Purpose/Objective(s): To evaluate the effect of re-irradiating patients with in-field metastatic epidural spinal cord compression(MESCC) relapse by means of volumetric modulated arc therapy (VMAT). Feasibility, acute toxicity, clinical improvement, localcontrol, and survival were the parameters considered.

Materials/Methods: Ten consecutive patients (pts) with in-field MESCC were enrolled between February 2009 and December2009. The treatment was performed with RapidArc technique optimizing a single volumetric modulated arc of 6 MV. The medianage was 65 years (range, 51-80 years). The primary cancers were: 4 pts with NSCLC, 2 pts with prostate, and 1 pt with multiplemyeloma, HCC, chordoma and thyroid cancer. The median time of recurrence from previous irradiation was 18 months (range,3-106 months). At the time of re-irradiation 8 patients had other site of metastases. The treated levels were cervical in 3, thoracicin 6 and lumbar in 1 pts. In order to define the clinical target volume (CTV), the whole vertebrae with reoccurrence (1-4 vertebrae)were considered, excluding the central spinal cord canal. From CTV to PTV a 5mm margin in the three directions was applied,avoiding the internal portion. The dose to PTV was defined so as to have a total biological equivalent dose (BED) to the spinalcord lower than 100 Gy2. EORTC-RTOG scale for toxicity, visual analog scale (VAS) for pain, Frankel Scale for neurologicaldeficit and magnetic resonance imaging or computed tomography scan were considered to assess the clinical outcome. Allpatients had back pain before treatment (VAS $7), whereas major or minor preoperative neurological deficit was present in 7patients.

Results: No significant acute toxicity was recorded. Clinical remission of pain was obtained in 9/10 patients (VAS\2), withmedian time of 6 months (3-10 months). Improvement of neurological deficit was observed in 6 patients. At the last follow-up(13 months from the start of the first patient) no local recurrence occurred; median survival was 6 months (range, 3-10 months);5 patients are alive and 5 dead.

Conclusions: In this study the feasibility of re-irradiation of in-field MESCC relapse patients has been assessed and clinicalbenefits for a high percentage of patients were observed. In this preliminary communication late toxicities are not evaluated. Furtherprospective studies are necessary to define the better re-irradiation treatment in terms of volume of irradiation, total dose andfractionation.

Author Disclosure: P. Navarria, None; P. Mancosu, None; F. Tancioni, None; S. Castiglioni, None; A. Tozzi, None; A. Fogliata, Herhusband acts as advisor for Varian Medical System, F. Consultant/Advisory Board; L. Cozzi, He acts as advisor to Varian MedicalSystem, F. Consultant/Advisory Board; A. Santoro, None; R. Rodriquez Y Baena, None; M. Scorsetti, None.