Proceedings of the 49th Annual ASTRO Meeting S265

fossa, 3 in other regions. Eight patients were treated by proton beam therapy alone and the remaining 2 were treated by a combi-nation of surgery and postoperative proton beam therapy. Clinical target volume was defined as a volume encompassing gross tu-mor volume plus a 0–5 mm margin in all directions, and further 5 mm margin was added at irradiaion. The total dose ranged from51.0 Gy to 66.0 Gy with a median dose being 54.0 Gy.

Results: The overall survival at 10 years was 80.0% and the local control rate at 10.0 years was 100%. After the median follow-upperiod of 11.7 years (6–21 years), 2 patients are dead and 8 are alive at the end of March 2007. One patient died of myocardialinfarction and the other patient died or radiation necrosis 6.1 years after proton beam therapy. In this case, a petro-clival menin-gioma showed significant compression on the pons, and the brain stem necrosis became visible on MRI 1.7 years after proton beamtherapy. No acute treatment-related toxicity of grade 2 or more was detected, and no late treatment-related toxicity was foundexcept for the patient presented above.

Conclusions: It was indicated that proton beam therapy is beneficial to patients with meningioma from our long term observation.

Author Disclosure: Y. Hayashi, None; K. Tokuuye, None; A. Kanemoto, None; Y. Ooshiro, None; N. Fukumitsu, None;H. Nakayama, None; S. Sugahara, None; K. Oohara, None; K. Tsuboi, None.

2113 Single Fraction, Single Isocenter Intensity Modulated Radiosurgery (IMRS) for Multiple Brain

Metastases: Dosimetric and Early Clinical Experience

L. VanderSpek, J. Wang, J. Alksne, K. T. Murphy

Moores Cancer Center, University of California, San Diego (UCSD), San Diego, CA

Purpose/Objective(s): To present our early clinical experience using intensity-modulated radiosurgery (IMRS) for the treatmentof multiple ($3) brain metastases using a single isocenter, single fraction technique.

Materials/Methods: Ten patients with multiple brain metastases were treated between March 2006 and February 2007 on a VarianTrilogy linear accelerator equipped with a 120 leaf multi-leaf collimator. The median patient age was 59 (range, 36–82) years. Theprimary cancers were lung (5), breast (3), and melanoma (2). The median KPS was 75 (40–100). The median number of metastaseswas 6 (range, 3–12). Three patients received prior whole brain irradiation. Treatment was delivered using a frameless optically-guided immobilization approach in nine and a traditional frame-based approach in 1 patient. The median number of fields utilizedwas 9 (range, 8–14). Acute radiation toxicities were analyzed.

Results: The median total planning target volume (PTV) was 35.0 cm3 and the median prescribed dose was 16 (range, 14–18) Gy.The median integral dose to normal brain was 6.2 Gy-kg with a SD of 1.6 Gy-kg. The median dose to normal brain was 3.5 Gy witha SD of 1.3 Gy. The median maximum and minimum PTV coverage was 107% and 87%, respectively. Doses to normal structureswere minimal. One patient had an acute, medically reversible, grade 3 toxicity of confusion. One patient had grade 2 headache andleft lateral visual changes that improved with steroid administration. A third patient had grade 3 arm weakness prior to IMRS thathad worsened at first follow-up. At the time of last follow-up, 8 patients had either an improvement in their symptoms or reported nocomplications with IMRS.

For a comparison analysis, a patient with 6 lesions was re-planned using a 5 isocenter stereotactic radiosurgery (SRS) techniqueusing 20 arcs and multiple circular collimators. The prescribed dose was 18 Gy. The integral dose to normal brain was 1.6 Gy-kgand the median normal brain dose was 1.0 Gy, compared to 4.5 Gy-kg and 3.2 Gy, respectively, for the IMRS plan. Doses to criticalstructures were decreased compared to IMRS except for dose to the eyes.

Conclusions: Single fraction, single isocenter IMRS is a feasible and well-tolerated treatment of select patients with multiple brainmetastases. The SRS multiple isocenter plan had improved dosimetric parameters, however, the differences may not be clinicallysignificant. We are currently accruing patients to assess late toxicity and tumor control using this approach.

Author Disclosure: L. VanderSpek, None; J. Wang, None; J. Alksne, None; K.T. Murphy, None.

2114 The Effect of Timing and Dose Fractionation on Stereotactic Radiation Therapy for Lung Cancer

Metastatic to the Brain

J. Kelley1, B. Cameron1, S. Benedict2, W. Broaddus1, T. Chung1

1MCV Hospitals VCUHS, Richmond, VA, 2University of Virginia Medical Center, Charlottesville, VA

Purpose/Objective(s): Stereotactic radiation therapy has been shown to increase local tumor control and improve survival in selectlung cancer patients with brain metastases. The optimal timing and most effective dose scheme for stereotactic therapy have notbeen determined. In this study we evaluate the effect of stereotactic dose fractionation and the timing of stereotactic radiation ther-apy on clinical outcomes in patients with lung cancer metastatic to the brain.

Materials/Methods: Between 1995 and 2005 a series of 114 patients were identified with primary lung carcinoma metastatic to thebrain. These patients were treated with whole brain radiation alone (n = 25) or in combination with stereotactic therapy (n = 89).Patients were treated for single or multiple brain metastases with the number of treated isocenters ranging from 1 to 10. We eval-uated the effect of dose fractionation between single fraction stereotactic radiosurgery (SRS) and hypofractionated stereotactic ra-diotherapy (SRT) on patient outcome. We also examined the timing of stereotactic therapy by treating one patient cohort withimmediate adjuvant stereotactic radiation (n = 28) and reserving stereotactic treatment for salvage therapy at time of intracranialdisease progression in other patients (n = 51). Patients were retrospectively analyzed with the primary outcome of survival. Sec-ondary outcomes were treatment related toxicity, tumor response, intracranial recurrence, sites of distant failure, and cause of death.

Results: Stereotactic radiation therapy was well tolerated in this study. Mild headache and ataxia were the most frequently reportedcomplications from therapy. There was no increase in late effect toxicity noted in stereotactic treated patients. The addition of ste-reotactic therapy to whole brain radiation dramatically increased the median survival time from 8.9 months to 41.2 months. Thedose fractionation scheme did not significantly alter outcomes with SRS and SRT treatment groups demonstrating median survivaltimes of 41.1 and 42.4 months respectively. However, the timing of stereotactic therapy demonstrated a significant impact on

S266 I. J. Radiation Oncology d Biology d Physics Volume 69, Number 3, Supplement, 2007

patient outcome. Salvage stereotactic treatment was superior to immediate adjuvant therapy with median survival times of 49 and26 months.

Conclusions: Stereotactic radiation therapy dramatically improves survival in metastatic lung cancer. Dose fractionation studiessuggest that SRS is equivalent to hypofractionated SRT. These results suggest that survival is most improved by delaying SRStreatment until salvage at the time of tumor progression.

Author Disclosure: J. Kelley, None; B. Cameron, None; S. Benedict, None; W. Broaddus, None; T. Chung, None.

2115 Linac-Stereotactic Radiosurgery (LSRS) in the Management of Trigeminal Neuralgia:

A Report of 51 Cases

S. J. Gurley1, R. J. Mark1,2, P. J. Anderson1, T. R. Neumann1, M. Nair1, R. S. Akins3, D. White1

1Joe Arrington Cancer Center, Lubbock, TX, 2Texas Tech University, Lubbock, TX, 3University of Miami, Miami, FL

Purpose/Objective(s): Stereotactic Radiosurgery (SRS) with the Gamma Knife (GK) has been used successfully in the treatmentof Trigeminal Neuralgia (TN). Results have been comparable to open surgery. There have been few reports with the use LSRS inthe management of TN. We report our updated results with LSRS in the treatment of TN.

Materials/Methods: Between 2000 and 2007, 51 patients with medically refractory TN were treated with LSRS. Prior neurosur-gical intervention had been performed in 39 patients. Twenty two patients had one procedure, 14 patients two, and 5 patients threeinterventions. All patients had typical TN. LSRS was given to the cranial nerve V entry root zone into the brainstem. Targeting wasdefined by CT and MRI Scans, and CT Cisternogram, utilizing axial and coronal images. Treatment planning was accomplishedthru Radionics Treatment Planning System. The dose was 87 Gy to Dm, in one fraction using the 5 mm collimator and 6 arcs withthe 20% Isodose line just touching the brainstem. This dosimetry is similar to Gamma Knife. The dose rate was 400 MU/min.Average Arc length was 130 degrees. Response to treatment was defined as excellent (no pain, off analgesics), good (no pain,with analgesics), and poor (continued pain despite analgesics).

Results: With a median follow-up of 46 months (range 6–84 months), 74.5% (38/51) of patients have reported an excellent or goodresult after LSRS. One patient has sustained permanent ipsilateral facial numbness.

Conclusions: LSRS offers comparable results to Gamma Knife SRS in the management of TN.

Author Disclosure: S.J. Gurley, None; R.J. Mark, None; P.J. Anderson, None; T.R. Neumann, None; M. Nair, None; R.S. Akins,None; D. White, None.

2116 Proton Therapy and Carbon Ion Therapy for Patients With Hepatocellular Carcinoma:

The Hyogo Ion Beam Medical Center Experience

S. Komatsu1, M. Murakami2, T. Fukumoto1, M. Tominaga1, T. Iwasaki1, D. Miyawaki2, H. Nishimura1, R. Sasaki1,

Y. Ku1, Y. Hishikawa2

1Kobe University Graduate School of Medicine, Kobe, Japan, 2Hyogo Ion Beam Medical Center, Tatsuno, Japan

Purpose/Objective(s): Particle therapy is a raising treatment option for hepatocellular carcinoma and other malignancies. Hepa-tocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. The disease is well known to originate inthe virus-associated (hepatitis C and hepatitis B) liver cirrhosis, and its incidence has increased dramatically in the United Statesbecause of the spread of hepatitis C virus infection and is expected to increase for the next 2 decades. Prognosis of HCC is depen-dent not only upon the tumor stage, but also upon underlying liver function. Particle therapies are sophisticated treatment modalitieswith excellent dose localization to the tumor, being able to avoid surrounding normal tissue damage. In Hyogo Ion Beam MedicalCenter, both proton therapy and carbon ion therapy have been used for the treatment of HCC since 2001. The aims of this retro-spective study are to evaluate efficacy of proton therapy and carbon ion therapy for patients with HCC and to elucidate significantprognostic factors in those patients.

Materials/Methods: From 2001 to February 2006, 99 patients (M/F: 72/27) aged 42–83 (median, 69) with HCC were treated withthe proton therapy (92 patients) or carbon ion therapy (7 patients). Clinical stage was evaluated with using TNM classification(UICC), resulting in stage I (13 patients), II (48), III (24), IVA (10), and IVB (4). Tumor sizes were classified into 4 groups(\3 cm/3.1–5 cm/5.1–10 cm/>10.1 cm: 40/26/28/5 patients). Among them, 63 (64%) patients were associated with hepatitis Cinfection, 16 (16%) patients with hepatitis B infection, and 20 patients with neither of them. Liver function was classified withtwo categories: one is the Child-Pugh Grade (A/B/C: 78/20/1 patients), and the other is the ICG Score (\10/10–20/20–30/>30%: 20/33/20/19 patients except for 7 patients whose data unavailable). Eighty-eight patients were treated by the curative reg-imen, and other 11 patients were treated by the palliative policies. Two protocols for proton therapy (76 GyE in 20 fractions and60 GyE in 10 fractions using 150, 190, or 210 MeV proton beam), and one protocol for carbon ion therapy (52.8 GyE in 8 fractionsusing 250, or 320 MeV carbon ion beam) were employed in the period. Overall survival (OS) and local control (LC) rates werecalculated by Kaplan-Meier estimates and evaluated by log-rank test.

Results: The median follow-up period for all patients was 25 months (range: 14–69 months). Three-year OS was 59%. Prognosticsignificance for OS was detected in the clinical stage (p = 0.002; 50% survival of stage I: 28 months, stage II: 64, stage III: 48, IVA:6, and IVB: 6), and the Child-Pugh Grade (p\0.0001; 50% survival of Grade A: 64 months, Grade B: 12, and Grade C: 2). Three-year LC was 88%. Clinical stage also showed prognostic significance for LS (p = 0.006; 50% survival of stage I: 28 months, stageII: 33, stage III: 33, IVA: 3, and IVB: 16).

Conclusions: Particle therapy using proton beam or carbon ion beam showed excellent local tumor controllability in patients withHCC. Because the clinical stage and the liver function affected outcomes of the treatment, eligible cases should be carefully de-termined in the future.

Author Disclosure: S. Komatsu, None; M. Murakami, None; T. Fukumoto, None; M. Tominaga, None; T. Iwasaki, None;D. Miyawaki, None; H. Nishimura, None; R. Sasaki, None; Y. Ku, None; Y. Hishikawa, None.