S506 I. J. Radiation Oncology d Biology d Physics Volume 75, Number 3, Supplement, 2009

2720 Radiotherapy for the Patients with Metastases to the Spinal Column: A Review of 603 Patients in Terms of

Predictive Factors of Local Control and Survival

M. Mizumoto1,2, H. Harada2, H. Asakura2, T. Hashimoto1,2, K. Furutani2, H. Murata2, T. Takagi2, H. Katagiri2, M. Takahashi2,T. Nishimura2

1University of Tsukuba, Tsukuba, Japan, 2Shizuoka Cancer Center Hospital, Nagaizumi, Japan

Purpose/Objective(s): Long-course (30 Gy in 10 fractions or more) and short-course (8 Gy in one fraction, 20 Gy in five fractions)radiotherapy had a similar outcome for treatment effect of spinal metastases. Long-course is recommended for good predicted sur-vival to reduce the risk of in-field recurrence. On the other hands, short-course is recommended for poor predicted survival becausein-field recurrence is not different in the short term. To predict the prognosis of patients and probability of local control can be help-ful to select the optimal radiotherapy course. We analysed prognostic factors for survival and predictive factors for local control.

Materials/Methods: The subjects were 603 patients with spinal metastases who received radiotherapy at Shizuoka Cancer CenterHospital between September, 2002 and February, 2007. At our hospital, short-course was selected for patients with poor predictedsurvival, and long-course was selected for patients with good predicted survival. Prognostic factors for survival and predictive fac-tors for local control were retrospectively investigated by multivariate analyses using a Cox proportional hazard model to selectoptimal radiotherapy schedule. Local recurrence was defined as follows: 1. Re-growing within irradiated field diagnosed by CTor MRI. 2. Exacerbated symptoms such as pain and motor deficits in irradiated region. Patients were followed-up until deathby any cause.

Results: Of 603 patients, 555 (92%) were followed-up for a minimum of 12 months or until death. The overall survival rates after 6,12 and 24 months were 50%, 32%, and 19%, respectively (the median survival period was 6.2 months). The median survival pe-riods were 7.9 and 1.8 months for patients who underwent long-course and short-course, respectively. On multivariate analysis forsurvival, primary tumor site, good performance status, absence of previous chemotherapy, absence of visceral metastasis, singlebone metastases, younger age and non-hypercalcemia are associated with good survival. The local control rates after 6, 12, 24months were 91%, 79%, and 69%, respectively. On multivariate analysis for local control, non-mass-type tumor, breast cancerand absent of previous chemotherapy are associated with good local control.

Conclusions: This study showed that prognostic factors for survival were different from predictive factors for local control. Usingthese factors we could select short-course for poor predicted survival patients. Further investigation is needed to select optimalradiotherapy schedule according to risk factors of both local recurrence and survival.

Author Disclosure: M. Mizumoto, None; H. Harada, None; H. Asakura, None; T. Hashimoto, None; K. Furutani, None; H. Murata,None; T. Takagi, None; H. Katagiri, None; M. Takahashi, None; T. Nishimura, None.

2721 Validity of More Than 30 Gy Radiation Therapy for Long-surviving Patients with Painful Bone Metastases

E. Katayama1,2, H. Okada1, I. Asakawa2, T. Tamamoto2, C. Kajitani2, K. Furuichi1, A. Okura1, K. Ide1, S. Iwasaki1, M. Hasegawa2

1Higashi-Osaka General Hospital, Higashi-Osaka, Japan, 2Nara Medical University, Kashihara, Japan

Purpose/Objective(s): Radiation therapy (RT) of 8 Gy in a single fraction, 20 Gy in 5 fractions, or 30 Gy in 10 fractions is thecommon and standard palliative treatment for painful bone metastases. Re-irradiation is also suggested to be useful for recurrentpain in some long survivors, but the efficacy of the second RT is not always equal to that of the first. To determine whether RT ofmore than 30 Gy for painful bone metastasis is valid for patients who are suggested to be able to survive for 6 months or more, weanalyzed the actual survival of patients.

Materials/Methods: Between February 2007 and August 2008, 169 patients with painful bone metastasis were treated with ra-diotherapy in 2 hospitals (77 patients in H and 92 patients in N) according to the protocol as follows: If patients with painfulbone metastasis are suggested to be able to survive for 6 months or more, fractionated RT more than 30 Gy (37.5 Gy in 15 fractions,40 Gy in 20 fractions, 50 Gy in 25 fractions, etc.) was performed (Group L). The other patients were treated with the standard RT 30Gy in 10 fractions or RT less than 30 Gy (Group S). After follow-up of 6 months or more, patients of Group L and Group S werecompared to evaluate the validity of the protocol. Survival analyses were performed according to the Kaplan-Meier method and thelog–rank test.

Results: Median follow-up time of the all patients and the survivors was 6.6 months and 9.7 months, respectively. Median survivaltime overall was 2.4 months and 7.5 months for Group S and Group L, respectively (p\0.01); 3.4 months and 7.5 months in H, and1.2 months and 7.5 months in N, respectively. Furthermore, median survival time for patients with lung cancer was 3.4 months forGroup S and 6.9 months for Group L (p\0.01); however, there was no significant difference of survival time between Group S andGroup L for patients with prostate cancer and breast cancer, respectively. In both groups of the two cancers, median survival timewas more than 6 months.

Conclusions: Except for prostate cancer and breast cancer, the patient group that received more than 30 Gy for painful bone me-tastasis survived significantly longer than the other group. This result suggests that more intense RT than the standard RT may beuseful for some limited groups of patients with bone metastasis.

Author Disclosure: E. Katayama, None; H. Okada, None; I. Asakawa, None; T. Tamamoto, None; C. Kajitani, None; K. Furuichi,None; A. Okura, None; K. Ide, None; S. Iwasaki, None; M. Hasegawa, None.

2722 Response of Pediatric Low-grade Glioma to Conformal Radiation Therapy

M. Naik, L. P. Berle, T. E. Merchant

St. Jude Children’s Research Hospital, Memphis, TN

Purpose/Objective(s): Asymptomatic changes in tumor size, patterns of enhancement and cyst formation are commonly noted byMRI when monitoring pediatric low-grade glioma (LGG) after radiation therapy. The purpose of this study was to quantitativelyand qualitatively describe the imaging changes after conformal radiation therapy (CRT).

Proceedings of the 51st Annual ASTRO Meeting S507

Materials/Methods: A total of 82 lesions in 78 patients (median age 8.9 years) who received CRT between 8/1997 and 08/2006were evaluated using MRI performed before, during (Weeks 3 and 5) and every 3–6 months after CRT (54 Gy) through five years.A total of 1196 MRI studies contributed to this report. Lesions were serially assessed for characteristics of enhancement, cyst for-mation or expansion and measured in 3 dimensions (anterior-posterior, transverse and superior-inferior). The imaging sequencethat best demonstrated the tumor at the time of the initial evaluation was used throughout the study. Increasing and decreasing en-hancement was recorded and the composition of the lesion was described according to the development or change in cystic com-ponents.

Results: Patients were followed for a median of 60.1 months (range, 8.8–65.2 months). Enhancement at the initiation of CRTwas noted in 89% (73 of 82) of the lesions and decreased in 67.1% (55 of 82) with a median time of 7.2 months (range, 0.5–36.20 months) after CRT. An increase in the 3-dimensional volume of the tumor complex was noted in 25 lesions duringtreatment. Increasing cystic components were noted in 46.3% (38 of 82) of lesions with a median time of 4.2 months (range,0.2–24 months); 71.1% (27 of 38) of these lesions eventually decreased in size. Approximately 40.2% (33 of 82) of lesionsdid not change; 75.8% (25 of 33) enhanced prior to CRT. Local tumor progression occurred in 9 patients (median 54.1months, range, 17.2 – 83.9). Four failures occurred due to increasing tumor size, 1 due to increasing enhancement, and 4due to increasing size and enhancement. Thirty-one lesions in 30 patients had a median maximum increase in tumor volumeof 24.4% (range, 1.1–332.7), at a median time of 4.9 months (range, 0.2–15.27 months) without developing progressivedisease.

Conclusions: Decreasing enhancement and increasing cyst formation characterize the response of pediatric LGG to CRT. Thesechanges occur predictably in the majority of cases. Because cyst formation or change in tumor volume may occur during CRT, werecommend MRI during treatment to identify changes that would affect tumor coverage. Serial evaluation is required to documenttumor progression. Increasing tumor size during the first year of CRT is common. Most patients who experience local tumor pro-gression have changes in tumor volume or enhancement more than one year after treatment.

Author Disclosure: M. Naik, None; L.P. Berle, None; T.E. Merchant, None.

2723 Radiotherapy for Pediatric and Young Adult Soft Tissue Sarcoma: The University of Florida Experience

K. B. Smith1, D. J. Indelicato1,2, J. A. Knapik3, C. G. Morris1, J. Kirwan1, R. A. Zlotecki1, M. T. Scarborough3, C. Gibbs3,R. B. Marcus2

1University of Florida Shands Cancer Center, Gainesville, FL, 2University of Florida Proton Therapy Institute, Jacksonville, FL,3University of Florida, Gainesville, FL

Purpose/Objective(s): Pediatric and young adult soft tissue sarcomas are a rare and heterogeneous group of tumors. This studyevaluated prognostic factors, outcomes, and complications in patients under 30 years old with nonrhabdomyosarcoma soft tissuesarcoma (NRSTS) treated at the University of Florida with radiotherapy over a 36-year period.

Materials/Methods: One hundred twenty-two patients under 30 years old with NRSTS were treated with curative intent at theUniversity of Florida between 1972 and 2008. The most common histological tumor subtypes were synovial sarcoma (25 patients),malignant fibrous histiocytoma (21 patients), and malignant peripheral nerve sheath tumor (15 patients). The mean age at radio-therapy was 22 years (range, 2 to 30 years). Ninety-three patients had high-grade tumors. Forty-nine, 51, and 22 patients receivedpreoperative, postoperative, and definitive RT, respectively. Prognostic factors for survival, local recurrence, and distant recurrencewere analyzed.

Results: The median followup was 5.5 years (range, 0.3–30.4 years). The actuarial estimates of 5-year overall survival and disease-free survival (DFS) were 59% and 73%. Ninety-three percent of all deaths were disease related. Early AJCC stage, early IntergroupRhabdomyosarcoma Study (IRS) group, microscopically negative margins, tumor\8 cm, absence of neurovascular invasion, andlow/intermediate-grade histology were associated with superior DFS. The actuarial 5-year local control rate was 80%. Early IRSgroup, absence of neurovascular or bone invasion, extremity site, resectability, and microscopically negative margins were asso-ciated with superior local control. Although 70% of local recurrences initially occurred in the absence of metastases, all patientswith a local failure ultimately died of their disease. The rate of NCI Common Toxicity Criteria (CTCAE v3) Grade 3–5 treatmentcomplication was 7%. No secondary malignancies were observed.

Conclusions: In this large single-institution study, we found unresectable tumors and involvement of vital structures to be poorprognostic factors for both local progression and survival. This study helps characterize the therapeutic ratio of radiotherapy inpediatric and young adult sarcoma patients. Our data suggests that local relapse compromises survival and provides a basis foridentifying high-risk patients in whom treatment intensification may be justified.

Author Disclosure: K.B. Smith, None; D.J. Indelicato, None; J.A. Knapik, None; C.G. Morris, None; J. Kirwan, None; R.A. Zlo-tecki, None; M.T. Scarborough, None; C. Gibbs, None; R.B. Marcus, None.

2724 Patterns of Failure after Craniospinal Irradiation, Intensity Modulated Radiation Therapy (IMRT) Boost

and Chemotherapy for Medulloblastoma

A. Paulino1,2, A. Mazloom3, M. South1, B. Teh1, F. Okcu3,2, J. Su3,2, E. Butler1, M. Chintagumpala3,2

1The Methodist Hospital, Houston, TX, 2Texas Children’s Hospital, Houston, TX, 3Baylor College of Medicine, Houston, TX

Purpose/Objective(s): Intensity modulated radiation therapy (IMRT) has been used to minimize high doses of radiation (RT) tonormal surrounding tissues such as the cochlea. Concern has been raised regarding failure patterns after IMRT boost as "marginalmisses" may be more frequent with "tightening" of the high dose region. The purpose of this study is to determine the patterns offailure after craniospinal irradiation (CSI), IMRT boost and chemotherapy for medulloblastoma.

Materials/Methods: From January 1997 to December 2006, 60 patients with a median age of 7.8 years (range, 2.8 to 18 years)and medulloblastoma underwent resection, RT and chemotherapy. There were 42 boys and 18 girls; risk category was standard-risk(SR) in 40 and high-risk (HR) in 20. For SR patients, CSI dose was 18.0–23.4 Gy followed either by (1) IMRT posterior fossa (PF)