Correlation Between Metabolic Information and Tumor Volume for Astrocytic Brain Tumors Before and During Radiation Therapy

Volume 93  Number 3S  Supplement 2015 Jefferson University, Philadelphia, PA, 2University of Maryland School of Medicine, Baltimore, MD Purpose/Objective(s): Glioblastoma is the most common malignant brain tumor in adults and predominantly occurs in the sixth and 7thdecades of life. The optimal treatment paradigm for elderly patients is not well established. We sampled current worldwide management strategies for elderly patients with newly diagnosed glioblastoma. Materials/Methods: A web-based survey was developed and distributed to 168 radiation oncologists (RO), neuro-oncologists (NO) and neurosurgeons (NS) identified through the United Council for Neurologic Subspecialties and the CNS/scientific committees for the Asian Society of Neuro-Oncology (ASNO), National Cancer Institute of Canada (NCIC), European Organization for Research and Treatment of Cancer (EORTC) and the NSABP/RTOG/GOG (NRG). Questions addressed the influence of molecular information, age, and patient comorbidities on treatment recommendations in order to determine whether management consensus exists in this patient subset. Results: There were 53 (35%) respondents (49% NO, 4% NS and 49% RO) with 70% having more than 10 years’ experience, 89% from academic institutions, and 57% with a large volume of GBM patients yearly (>50). Eighteen individuals were excluded due to duplicate emails or they opted out of the survey. Across respondents, the most important factors directing treatment were KPS (92%), MGMT methylation status (71%), and comorbidity index (31%). Only 43% of respondents factor in age when making treatment recommendations with 62% defining elderly as greater than 70 years-old. The most common treatment recommendations for MGMT-methylated elderly patients with KPS>70 were as follows: standard chemoRT (58%), temozolomide alone (28%), and short course RT (26%). The most common treatment recommendations for MGMTunmethylated patients with KPS>70 were as follows: standard chemoRT (47%), short course RT alone (43%), and short course chemoRT (20%). Treatment recommendations for patients with KPS<50 were short course RT alone (52%), best supportive care (50%), or TMZ alone (22%). NovoTTF is or will soon be available as a treatment option in 59% of institutions. The majority (86%) of institutions do not have a clinical trial open for enrollment of elderly patients with GBM, although 94% of institutions would be willing to participate in such a trial. Nearly all (98%) of respondents would be willing to randomize MGMT-unmethylated elderly patients to an arm without TMZ. Over 90% of respondents are willing to use short course RT as the standard RT for elderly patients. Conclusion: Worldwide treatment recommendations for elderly patients with newly diagnosed GBM vary widely. Further randomized studies are needed to elucidate the optimal treatment strategy for this subset of patients. Author Disclosure: J.D. Palmer: None. M.P. Mehta: Leads CNS group and develops clinical trials; RTOG. N.L. Williams: None. A.P. Dicker: Develops roles of translational medicine in clinical trials for oncology; RTOG. M. Werner-Wasik: Guides the publication process for RTOG trials; RTOG. W. Shi: None.

Poster Viewing Session Poster Viewing Abstracts 2167; Table 1 and volume at different times

E67

Correlation between metabolites

Correlated with volume at different time points p-value

Before RT

4th day after RT

10th day after RT

14th day after RT

20th day after RT

Cho/Cr Cho/NAA NAA/Cr Lip/Cr Lip1.3/Cr Glx/Cr MI/Cr

0.148 0.197 0.019 0.001 0.001 0.435 0.427

0.040 0.488 0.034 0.021 0.008 0.042 0.215

0.041 0.415 0.020 0.010 0.0003 0.182 0.027

0.127 0.754 0.199 0.996 0.063 0.004 0.089

0.025 0.010 0.222 0.021 0.516 0.420 0.513

1

Yu TG, Feng Y, Feng XY, Dai JZ, Qian HJ, Huang Z. Prognostic factor from MR spectroscopy in rat with astrocytic tumor during radiation therapy. Br J Radiol 2015;88:20140418. brain tumors using magnetic resonance spectroscopy (MRS) during radiation therapy (RT). Materials/Methods: Twelve healthy male Sprague-Dawley rats were used and C6 tumor cells were injected into the right caudate nuclei of the rats. Tumor model was created successfully until tumors grew for 18 days after the injection. MRS was performed with 2-D multi-voxel PRESS sequence using a GE Signa VH/i 3.0T MR scanner equipped with ratspecial coil. RT was given at the 19th day with dose of 4Gy in one single fraction. The metabolic information was obtained through image examinations performed before RT, and on the 4th, 10th, 14th, and 20th days after treatment, respectively. GE Functool software package was used for post-processing of spectrum. Pearson correlations were performed to check the relationship between tumor volume change and metabolic ratios. Results: The metabolic information included choline-containing components (Cho), creatine and creatine phosphate (Cr), N-acetyl aspartate (NAA), lipid and lactate (LL) levels, and glutamate plus glutamine (Glx). It was interesting to find that the correlation between metabolic ratios of serial MRS with the tumor volume varied with time after RT. As shown in the Table 1, NAA/Cr, Lip/Cr and Lip1.3/Cr were significantly correlated with tumor volume before RT and the strong correlation remained until the 10th day after RT and again on the 20th day after RT. Cho/Cr was significantly correlated with tumor volume on the 4th, 10th and 20th day after RT. Cho/NAA became significantly correlated with tumor volume on the 20th day after RT. Glx/Cr was significantly correlated with tumor volume on the 4th and 14th day after RT. MI/Cr only correlated with tumor volume on the 10thday after RT. Conclusion: All metabolic ratios would provide useful information and could be prognostic factors depending on which stage the tumor regression is. Author Disclosure: Z. Huang: None. Y. Feng: None. S.S. Lo: None. N.A. Mayr: None. W. Yuh: None. T.G. Yu: None. X.Y. Feng: None. J.Z. Dai: None. H.J. Qian: None.

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Correlation Between Metabolic Information and Tumor Volume for Astrocytic Brain Tumors Before and During Radiation Therapy Z. Huang,1 Y. Feng,1 S.S. Lo,2 N.A. Mayr,3 W. Yuh,4 T.G. Yu,5 X.Y. Feng,5 J.Z. Dai,5 and H.J. Qian5; 1East Carolina University Brody School of Medicine, Greenville, NC, 2University Hospitals Case Medical Center, Cleveland, OH, 3University of Washington Medical Center, Seattle, WA, 4University of Washington, Seattle, WA, 5 Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China

Detailed Spinal Axis Patterns of Failure Following SBRT for Metastatic Spinal Sarcoma J.E. Leeman,1 M. Bilsky,1 I. Laufer,1 M.R. Folkert,2 N.K. Taunk,3 J.R. Osborne,1 J. Zatcky,4 K.M. Alektiar,3 Y. Yamada,3 and D.E. Spratt3; 1 Memorial Sloan-Kettering Cancer Center, New York, NY, 2University of Texas Southwestern Medical Center, Dallas, TX, 3Memorial Sloan Kettering Cancer Center, New York, NY, 4Memorial Sloan Kettering Cancer Center, New York, NY

Purpose/Objective(s): Both the primary tumor volume and the Ki-67 labeling index (LI) are prognostic factors for clinical outcome. We previously found a linear relationship between the metabolic ratio (Cho/Cr) and the Ki-67 LI1. In this study we investigated the relationship between the temporal change in the tumor volume and metabolic ratios of astrocytic

Purpose/Objective(s): Local control following SBRT to spinal lesions is excellent; however, patterns of failure along the spinal axis have not been reported. Herein, we report a detailed analysis of patterns of failure within the spinal axis of patients treated with stereotactic body radiation therapy (SBRT) for sarcoma metastatic to the osseous spine. Materials/Methods: Between 2005 and 2012, 88 consecutive patients with metastatic sarcoma were treated to 120 spinal lesions with SBRT to doses