MRI Image Fusion for Helical Tomotherapy-based Image Guided Intensity Modulated Radiation Therapy

Volume 84  Number 3S  Supplement 2012 breast cancer patients. To improve dose coverage and uniformity in the axillary region and to reduce radiation therapy (RT) related lung injury using simple forward-planned intensity modulated RT; we have analyzed dosimetric and clinical outcomes. Materials/Methods: Simple forward-planned intensity modulated RT to the supraclavicular and axillary area was performed in 53 patients with breast cancer who presented axillary lymph node metastasis. Patients positioning and immobilization methods are identical with the conventional RT methods. Target volumes were defined including supraclavicular and axillary lymph nodes area. Total 50.4 Gy (28 fractions) were prescribed to CTV. Two to 6 segments of anterior/posterior oblique fields were used to optimize the radiation treatment plan. When there were macrometastases and extracapsular invasion, 9-14.4 Gy boost were delivered to the axillary tumor bed area using cone down plans. Dose volume parameters were calculated and compared with those from the conventional RT plans in the same patient. For the evaluation of lung injury, chest radiographs were serially analyzed during the follow up periods. Other clinical symptoms and late complications were analyzed. Results: Overall target coverage of CTV (e.g., the volume receiving 95% prescribed dose) for the patients with intensity modulated RT was superior to the conventional RT plan. Dose homogeneity of intensity modulated RT were better than conventional RT (e.g., stiffer dose volume histogram curve for the target). Lower lung dose regions were similar between two plans, but the volume of high dose regions were reduced in intensity modulated plans. V30-40 Gy were reduced w5% (range, 3.2-7.6%) of ipsilateral lung volume. During the median 24 months follow up period there were no significant aggravation of grade 2 lymph edema (pre-RT 15.1% vs. post-RT 17.0%) observed. Plan time was not significantly increased. There were radiographic lung changes in w13% patients. No patients had shown severe RT-induced pneumonitis. Conclusions: With the simple forward planned intensity modulated RT techniques, treatment for the axillary region can be further optimized to show the better target coverage and homogeneity without increasing normal lung injury. Long-term clinical impacts are necessary to show the actual clinical benefits. Author Disclosure: J. Nam: None. H. Jeon: None. W. Kim: None. Y. Ki: None. D. Park: None. D. Kim: None.

2118 Treatment Outcome, Relapse Patterns, and Prognostic Factors of Adult Medulloblastoma Patients S. Lai,1 J. Cheng,1 C. Wang,1 Y. Chen,1 and S. Kuo1,2; 1Division of Radiation Oncology, Department of Oncology, National Taiwan University Hospital, Taipei, Taiwan, 2Cancer Research Center, National Taiwan University College of Medicine, Taipei, Taiwan Purpose/Objective(s): In the present study, we investigated the clinical outcome and prognostic factors of adult medulloblastoma patients receiving multimodality treatment. Materials/Methods: We retrospectively reviewed the clinical manifestations, tumor characteristics, treatment variables, relapse patterns, and clinical outcome (disease-free survival [DFS], and overall survival [OS]) of all adult patients with medulloblastoma pathologically diagnosed at our institution between 1983 and 2009. Results: Sixteen (80%) of 20 patients received gross total resection and four (20%) of 20 patients received subtotal tumor resection (6 women and 14 men; median age: 22 years). Adjuvant chemotherapy was administered to six patients. Craniospinal irradiation (CSI) was given postoperatively using a 60 Co teletherapy machine or 6-MV linear accelerator or tomotherapy. The craniospinal axis received a median of 30 Gy/1.6e2 Gy/d (range: 23.4-39.6 Gy), and the tumor was boosted to receive a total median dose of 50 Gy (range: 50-55.25 Gy). After a median follow up of 36 months, the 3-year DFS and OS rates for all patients were 50% and 55%, respectively. In univariate analysis, Karnofsky Performance Scale (KPS) > 70 (p Z 0.037), neurologic symptoms duration 30 days (p Z 0.019), lateral tumor location (p Z 0.016), standard risk patients (p Z 0.029), no hydrocephalus (p Z 0.035), radiation therapy (RT)

Poster Viewing Abstracts S263 treatment field (CSI+ brain boost) (p Z 0.024), and CSI dose  30 Gy (p Z 0.032) were significantly associated with better DFS. Standard risk patients (p Z 0.045), RT treatment field (CSI+ brain boost) (p Z 0.038), and CSI dose  30 Gy (p Z 0.041) were also significantly associated with better OS. Conclusions: The combined modality treatment results in a favorable outcome for adult patients with medulloblastoma. Further investigation of the disease-related prognostic factors, radiation-related factors, and the role of systemic chemotherapy in this group of patients is needed. Author Disclosure: S. Lai: None. J. Cheng: None. C. Wang: None. Y. Chen: None. S. Kuo: None.

2119 Comparison of 2 Consecutive Prospective Series of Unresectable High-grade Glioma Patients Treated With or Without Neoadjuvant (NA) Chemotherapy Before Standard Radiochemotherapy and Adjuvant Temozolomide S. Villa,1 L. Capdevila,1 S. Cros,1 O. Etxaniz,1 S. Domenech,2 C. Hostalot,3 A. Manes,1 S. Comas,1 and C. Balana1; 1Catalan Institute of Oncology. HU Germans Trias, Badalona, Spain, 2Institut de Diagnostic per la Imatge. HU Germans Trias, Badalona, Spain, 3Neurosurgery. HU Germans Trias, Badalona, Spain Purpose/Objective(s): Standard treatment of HGG is based in CRT with TMZ. Neoadjuvant treatment before radiation therapy is not the standard of care. Materials/Methods: We analyzed 2 consecutive prospective series of nonresectable HGG patients treated with neoadjuvant chemotherapy (TMZ and cisplatin) before 2005 with those treated with TMZ and concurrent and adjuvant TMZ and radiation therapy (after 2005). Results: Forty-six patients, diagnosed between August 2003 and October 2010, were selected. Twenty-three patients received neoadjuvant therapy with TMZ and cisplatin followed by radiation therapy -60 Gy 6w(NA group), and the remaining 23 patients received EORTC schedule with concomitant TMZ and radiation therapy -60 Gy 6w- and adjuvant TMZ (CRT group). In the NA group, 87% of patients were 50 years, 43.5% were men, 65.2% had performance status (PS) <2, 38.4% had Barthel index <70. Histology: 78.3% were glioblastoma (GB). A total of 30.4% of patients had multifocal lesions, 43.5% had seizures at the diagnosis, and 95.7% of patients required dexamethasone. In the CRT group, 91.3% of patients were 50 years, 78.3% were men, PS was <2 in 60.9% and Barthel index <70 was seen in 21.7% of cases. Histology: 69.6% were GB, 26.1% patients had multifocal lesions, 26.1% had seizures at diagnosis, and 87% of patients required dexamethasone. All factors were uniformly distributed in the two groups. A total of 82.6% of patients completed the scheduled radiation therapy in NA group in front of 91.3% in the CRT group (p Z 0.66). PFS was 2.9 months (CI 95%: 0.5 - 5.5) in NA group versus 5.1m (CI 95%: 3.1 - 7.1) in the CRT group (p Z 0.62), OS was 8.5m (CI 95%: 4.0 - 12.9) vs 8.2m (CI 95%: 1.2 - 15.2), respectively (p Z 0.45). Conclusions: No advantages were seen using NA treatment in these patients. However, for busy Radiation Oncology Departments, NA treatment could be useful and do not deteriorate patients’ outcome. Our group has an ongoing trial focusing in NA treatment using bevacizumab basedtherapy. Author Disclosure: S. Villa: None. L. Capdevila: None. S. Cros: None. O. Etxaniz: None. S. Domenech: None. C. Hostalot: None. A. Manes: None. S. Comas: None. C. Balana: None.

2120 Reirradiation of Recurrent Glioblastoma Multiform Using Amino Acid PET/CT/MRI Image Fusion for Helical Tomotherapy-based Image Guided Intensity Modulated Radiation Therapy K. Miwa,1 J. Shinoda,1 H. Yano,2 and T. Iwama2; 1Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Kizawa Memorial Hospital, Minokamo, Japan, 2Department of Neurosurgery, Gifu University School of Medicine, Gifu, Japan

S264

International Journal of Radiation Oncology  Biology  Physics

Purpose/Objective(s): To develop a valid treatment strategy for recurrent glioblastoma multiforme (GBM) using helical tomotherapy (HT)-based image-guided intensity-modulated radiation therapy (IMRT) based on biologic imaging by 11C-methionine positron emission tomography (MET-PET). Materials/Methods: The trial included a total of 17 patients with recurrent GBM after previous surgery and postoperative conventional radiation therapy chemotherapy. For fractionated stereotactic radiation therapy by HT-based IMRT treatment planning, the gross tumor volume (GTV) was defined by MET-PET/computed tomography (CT)/magnetic resonance imaging (MRI) fusion in all of the patients. GTV included the complete region of increased amino acid tracer uptake. The planning target volume (PTV) encompassed the GTV plus 3-mm margin. Treatment was performed with a total dose of 25-35 Gy, given as 5-7 Gy daily continually over 5 days. This dose was prescribed to the 95% isodose line, which covered the PTV. In 10 of 17 patients (59%), chemotherapy with temozolomide (TMZ) (150-200 mg/m2 body surface/day) was continued after HT-based IMRT treatment. All patients were evaluated in follow-up by clinical investigators and MRI or MET-PET every 2 months after HT-based IMRT until death. Results: The median tumor volume was 27.4 cm3. With a median followup of 10 months, the overall survival time was 9 months from the date of HT-based IMRT treatment, with 6-month and 1- year survival rate of 64.7% and 20.2%, respectively. The clinicoradiological progression-free survival time was 6 months from the date of HT-based IMRT treatment, with 6-month and 1- year survival rate of 52.9% and 17.6%, respectively. Median survival time was 12 months for patients who received TMZ after HT-based IMRT and significantly lower, 5 months for patients without TMZ after HT-based IMRT (p Z 0.004, log rank). The most important prognostic factor in univariate analysis was Karnofsky performance statuses (KPS) on the date of HT-based IMRT treatment (p < 0.0001, logrank). In the multivariate model, KPS remained statistically significant (p < 0.038). No hematologic toxicity Grade 3 or higher was observed. Two patients experienced Grade 3/4 radiation necrosis, and necrotomy was required in one patient. Conclusion: This is the first study of biologic imaging optimized HT-based IMRT using MET-PET/CT/MRI image fusion in recurrent GBM. It demonstrates the feasibility and safety of this approach. Univariate analysis confirmed a significant survival benefit from multimodal treatment (i.e., addition of TMZ), despite the limited number of patients. Whether treatment planning with MET-PET independently influences survival has to be studied in a larger series of patients. Author Disclosure: K. Miwa: None. J. Shinoda: None. H. Yano: None. T. Iwama: None.

years (range, 13-81); 37 patients with glioblastoma, 27 with WHO Grade III glioma; 15 patients underwent reirradiation, 49 did not. At recurrence, 4 patients underwent both surgery and reirradiation, while 42 patients underwent neither of them. The median initial treatment dose was 60 Gy (35-70 Gy). As for reirradiation, one received 20 Gy stereotactic radiosurgery; 3 hypofractionated stereotactic radiation therapy (25-35 Gy in 5 fractions); 5 conventional stereotactic radiation therapy (40-50 Gy in 20-25 fractions); 6 three-dimensional conformal radiation therapy (30-60 Gy in 15-30 fractions). Reirradiation volumes overlapped previously irradiated field in 12 patients. Results: At the time of recurrence, median Karnofsky Performance Score (KPS) was 70% (range, 40-100) in reirradiated patients, and 60% (20-100%) in the patients without reirradiation. Median follow-up from recurrence was 6.2 months (range, 0-57.2 months). Median overall survival (OS) from recurrence was 11.8 months (95% confidence interval [CI], 4.9-18.7 months) for the reirradiated patients, and 5.0 months (3.7-6.3 months) for those without reirradiation (p Z 0.01). A subgroup with KPS >60% showed OS of 18 months (95% CI, 9.326.7 months) for the reirradiated patients and 8.1 months (6.1-10.1 months) for the patients without reirradiation (p Z 0.07). No severe acute or late complications arose due to reirradiation, and all patients completed radiation therapy. Conclusions: Our results suggest that reirradiation is a feasible and effective option as palliative therapy for patients with recurrent high-grade glioma. Author Disclosure: Y. Tsutsumi: None. H. Harada: None. N. Hirasawa: None. H. Ogawa: None. H. Asakura: None. H. Fuji: None. S. Murayama: None. K. Mitsuya: None. Y. Nakasu: None. T. Nishimura: None.

2121 Efficacy of Reirradiation for Patients With Recurrent High-grade Glioma Y. Tsutsumi,1 H. Harada,1 N. Hirasawa,1 H. Ogawa,1 H. Asakura,1 H. Fuji,2 S. Murayama,2 K. Mitsuya,3 Y. Nakasu,3 and T. Nishimura1; 1 Division of Radiation Oncology, Shizuoka Cancer Center, Shizuoka, Japan, 2Division of Proton Therapy, Shizuoka Cancer Center, Shizuoka, Japan, 3Division of Neurosurgery, Shizuoka Cancer Center, Shizuoka, Japan Purpose/Objective(s): To evaluate the efficacy of reirradiation in patients with high-grade glioma. Materials/Methods: A retrospective analysis was performed of 64 patients with recurrent high-grade gliomas diagnosed as intracranial recurrence at Shizuoka Cancer Center from September 2002 to February 2012. All treatment decisions were based on interdisciplinary conference. The gross tumor volume (GTV) was defined as the area of contrast enhancement on T1-weighted MRI sequences; the planning target volume included GTV, adding a safety margin depending on radiation therapy techniques. Survival time was calculated using the Kaplan-Meier method and compared univariately using the log-rank test. Characteristics of the 64 patients diagnosed were as follows: 35 men, 29 women; median age, 60

2122 Fractionated Stereotactic Radiation Therapy With Intensity Modulation as an Optic Nerve and Chiasm Sparing Technique in High Grade Gliomas H. Koh,1 C. Kim,2 J. Han,2 Y. Kim,2 N. Jang,2 J. Kim,2 and I. Kim2; 1Seoul National University Hospital, Seoul, Republic of Korea, 2Seoul National University Bundang Hospital, Seongnam, Republic of Korea Purpose/Objective(s): Fractionated Stereotactic Radiation Therapy (FSRT) is known as a safe option for brain tumors, which has close proximity to critical normal structures due to its submillimeter set-up accuracy. Higher dose conformality with homogeneity inside of the tumor and sharp falloff outside of the target volume is characteristic of intensity modulated plans, which allows for better normal tissue sparing effect. In current study, we tried to evaluate the potential advantage of FSRT with intensity modulation as an optic nerve and chiasm sparing technique in the management of anaplastic astrocytoma (AA) or glioblastoma (GBM). Materials/Methods: Clinical data from 16 patients with High-grade gliomas who underwent three dimensional conformal radiation therapy (3D-CRT) followed by FSRT boost or FSRT only from November 2006 to October 2010 was collected. The median follow-up duration was 16.5 months (range, 4.5-46.9). All patients had contrast-enhanced computed tomography (CT) plus magnetic resonance imaging (MRI) fusion images for treatment planning. In case of 3D-CRT, the head of the patient was immobilized in an individual Aquaplast head mask and the Pinnacle RT system was used. In the case of FSRT, a BrainLaB thermoplastic mask tightly attached to the stereotactic frame was used as an immobilization device, and BrainSCAN was used as a plan system. Results: There were 9 men and 7 women, and the median age was 56.6 years (range, 14-74.8). Twelve patients underwent 3D-CRT followed by FSRT boost and 4 patients underwent FSRT only. Nine patients (56%) had GBM and 7 patients (44%) had AA. The median survival was 22.3 months and the 2-year overall survival (OS) was 42%. The estimated maximum optic nerve and chiasm dose in this group were 38.116.6 Gy (range, 5-58.6) and 48.65.0 Gy (range, 34.2-55.9), respectively. When