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Resection Followed by Stereotactic Radiosurgery to the Resection Cavity for 1–4 Intracranial Metastases
Proceedings of the 49th Annual ASTRO Meeting procedures without further intervention in 5 patients, we documented one solid asymptomatic recurrence at 7 years and cystic progression of another for a tumor control rate of 93% (25/27). Of the 11 patients with formal pre-and post-treatment automated visual field testing, 8 had visual field defects prior to therapy. Of these, 6 patients improved, suggesting that the combined approach of surgery and post-operative FSR is beneficial to visual field status in patients with craniopharyngioma. Of 17 patients who had endocrine dysfunction prior to FSR, 14 had stable function that required no additional hormone replacement therapy, 2 had resolution of hypopituitarism, and one patient required further hormone replacement therapy. Conclusions: FSR for residual or recurrent craniopharyngiomas resulted in outcomes comparable to other radiotherapy modalities reported in the literature with low incidence of late sequelae. The combined modality of resection followed by initial planned postoperative radiation therapy also suggests improved visual and endocrine outcomes. Author Disclosure: A. Kaushal, None; J.J. Evans, None; S.H. Paek, None; M. Rosen, None; D. Heron, None; M. Gilbert, None; P. Savino, None; G. Bednarz, None; M. Werner-Wasik, None; W. Curran, None; D. Andrews, None.
2079
MRI PWI and CSI Imaging Studies of Brain for IMRT Treatment Planning Because of Differentiated Gliomas
R. Tarnawski, A. Idasiak, B. Bobek-Billewicz Centre of Oncology MSC Institute, Gliwice, Poland Purpose/Objective(s): To characterize correlation between metabolic CSI imaging of brain, PWI (Perfusion Weighted Images) MRI and early progression. Material/Methods: 43 patients with newly diagnosed differentiated gliomas (WHO grade II tumors) had MRI scans before radical radiotherapy treatment planning. 31 patients were irradiated postoperatively, 12 had biopsy. MR studies consisted of T1, T2 imaging without and with contrast enhancement, FLAIR, perfusion studies and CSI MRS using Siemens MAGNETOM AVANTO 1.5 T. Images were fused to treatment CT scans using Helios treatment planning system. All patients were treated with IMRT (both IMRT and 3D conformal plans were prepared for each patient but due to better normal tissue sparing IMRT treatment was selected for all patients) using 6 or 20 MV photons to total doses 54–60 Gy, 2 Gy/fx for PTV. Second MR study was done 0–3 days after the end of RT including all imaging and CSI MRS using the same localization and sequences as had been done for each patient before RT. MR scans were repeated every 6 months after radiotherapy. Volume of brain selected for CSI MRS was the biggest possible free from non-brain lipids artifacts. Relative intensities of the signals (choline, creatine [Cr] N-acetyl aspartate [NAA], lactate, and lipids) were obtained by automatic numeric integration of fitted signals in 3D array of 1 1 1 cm voxels. Total dimensions of registered arrays were 10 12 7 cm. PWI were registered according to standard procedures. Results: In majority of patients (30) decrease of NAA/Cr and increase of Cho/Cr ratio was registered in PTV, metabolic alterations decreased progressively with the distance from PTV borders. Alterations were registered up to 3 cm outside PTV borders. Strong lipids and lactate signals were registered for 8 patients. We did not observe correlation between PTV volume, mean radiation dose to brain and results of MRS. Results of MRS were not changed significantly after RT when compared to spectra registered before RT. Regions of increased perfusion were registered for 12 patients. After a median follow up of 13 months we observed radiologic progression for 9 patients, defined as increased regions of perfusion and increased regions of contrast enhancement. All patients with strong lactate signals had early progression up to 18 months after the end of radiotherapy. Conclusions: Lactate/lipids signals registered by 3D CSI MRS are indicators of aggressive disease, and may suggest malignant disease despite of the results of pathological examination of postoperative/biopsy material. Author Disclosure: R. Tarnawski, None; A. Idasiak, None; B. Bobek-Billewicz, None.
2080
Resection Followed by Stereotactic Radiosurgery to the Resection Cavity for 1–4 Intracranial Metastases
L. Do1, R. D. Pezner2, E. Radany2, A. Liu2, C. Staud2, B. Badie2 1
UCI Medical Center, Orange, CA, 2City of Hope Medical Center, Duarte, CA
Purpose/Objective: In patients who have resection of CNS metastases, whole brain radiotherapy (WBRT) is added to reduce rates of recurrence and neurological death. However, the risk of late neurotoxicity has led many patients to decline WBRT. We have offered adjuvant stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) as an alternative to select patients with resected brain metastases. Materials/Methods: We performed a retrospective review of patients who underwent resection of brain metastases followed by SRS/SRT instead of WBRT. Additional unresected lesions were treated with SRS/SRT alone. WBRT was administered only as salvage treatment. Dose range was 15–18 Gy for SRS and 22–27.5 Gy in 4–6 fractions for SRT. Target margins were typically expanded by 1–1.5 mm for rigid immobilization and 3 mm for mask immobilization. SRT was usually reserved for large target volumes. Dose was prescribed to the 80–90% isodose lines. SRS/SRT involved use of Linac radiosurgery via IMRT on Varian 21EX or the Helical TomoTherapy unit. Kaplan-Meier life table analyses were performed with statistical inferences on the actuarial curves made with log rank tests. Results: From 12/99–1/07, 30 patients diagnosed with intracranial metastases were treated with resection followed by SRS or SRT to the resection cavity. Primary sites of disease included lung in 14 patients; breast in 6; melanoma in 6; and renal, prostate, colon and endometrial in 1 patient each. Patients had 1–4 brain metastases including 13 patients with single metastases, 10 patients with 2 metastases, 5 patients with 3 metastases, and 2 patients with 4 metastases. SRS was used in 22 cases and SRT in 8. Four of 30 (13.3%) patients recurred in the resection cavity site. Fourteen (46.6%) patients developed recurrences in new intracranial sites. Actuarial 12-month survival rates were 78% for local recurrence-free survival, 36% for freedom from new brain metastases, 63% for neurological deficit-free survival, and 48% for overall survival. Salvage WBRT was performed in 11 (36.6%) of the 30 patients. Median follow up time was 10 months and ranged between 1–37 months (Figs.).
S247
I. J. Radiation Oncology d Biology d Physics
S248
Volume 69, Number 3, Supplement, 2007
Conclusions: Many patients have not required WBRT during their clinical course and so were not at risk of neurocognitive toxicity of WBRT. Our study suggests that postoperative SRS/SRT may be a viable option for patients who have undergone resection of brain metastases. WBRT can be reserved as salvage with acceptable neurological deficit-free survival rates.
Author Disclosure: L. Do, None; R.D. Pezner, None; E. Radany, None; A. Liu, None; C. Staud, None; B. Badie, None.
2081
Clinical Experience With Radiation Therapy in the Management of Neurofibromatosis-Associated Central Nervous System Tumors
S. Wentworth, T. L. Ellis, S. Glazier, K. P. McMullen, V. W. Stieber, S. B. Tatter, E. G. Shaw Wake Forest University, Winston-Salem, NC Purpose/Objective(s): Patients with neurofibromatosis (NF) frequently develop tumors of the central nervous system (CNS). Radiation therapy (RT) is sometimes used in treating these lesions. To better define the efficacy of RT in controlling NF-associated CNS tumors, we reviewed our 20 year experience. Patients/Methods: Seventy-four lesions in 16 patients with NF were treated with RT from 1986–2006. One third of patients had NF1, two thirds NF2. Median follow up was 36 months. Progression was defined as tumor growth or recurrence in an irradiated lesion on serial imaging. Progression free survival was measured from date of treatment to date of last imaging follow up. The actuarial rates of progression free survival were calculated according to the Kaplan Meier method. Results: On average, 5 lesions were treated per patient. The most common indication for treatment was growth on serial imaging. Median age at time of treatment was 24.1 years (range: 4.3–57.1). The treated lesions included acoustic neuromas (9%), ependymomas (7%), low grade gliomas (12%), meningiomas (62%), and non-acoustic schwanommas/neurofibromas (8%). Most patients (62%) received stereotactic radiosurgery. The others received fractionated external beam RT. Overall survival at 5 years for all patients was 94%. Five year progression free survival was 100% (acoustic neuromas), 75% (ependymomas), 100% (low grade gliomas), 86% (meningiomas) and 100% (non-acoustic schwannomas). Most patients with acoustic neuromas were deaf prior to treatment. In those patients with pre-treatment useful hearing, the hearing preservation rate was 0% (Fig.). Conclusions: This is the largest published experience on the results of RT in NF patients with CNS tumors. The progression free survival rates herein are similar or superior to those published for non-NF patients treated with RT. RT should be considered in NF patients with CNS tumors.
2079
MRI PWI and CSI Imaging Studies of Brain for IMRT Treatment Planning Because of Differentiated Gliomas
R. Tarnawski, A. Idasiak, B. Bobek-Billewicz Centre of Oncology MSC Institute, Gliwice, Poland Purpose/Objective(s): To characterize correlation between metabolic CSI imaging of brain, PWI (Perfusion Weighted Images) MRI and early progression. Material/Methods: 43 patients with newly diagnosed differentiated gliomas (WHO grade II tumors) had MRI scans before radical radiotherapy treatment planning. 31 patients were irradiated postoperatively, 12 had biopsy. MR studies consisted of T1, T2 imaging without and with contrast enhancement, FLAIR, perfusion studies and CSI MRS using Siemens MAGNETOM AVANTO 1.5 T. Images were fused to treatment CT scans using Helios treatment planning system. All patients were treated with IMRT (both IMRT and 3D conformal plans were prepared for each patient but due to better normal tissue sparing IMRT treatment was selected for all patients) using 6 or 20 MV photons to total doses 54–60 Gy, 2 Gy/fx for PTV. Second MR study was done 0–3 days after the end of RT including all imaging and CSI MRS using the same localization and sequences as had been done for each patient before RT. MR scans were repeated every 6 months after radiotherapy. Volume of brain selected for CSI MRS was the biggest possible free from non-brain lipids artifacts. Relative intensities of the signals (choline, creatine [Cr] N-acetyl aspartate [NAA], lactate, and lipids) were obtained by automatic numeric integration of fitted signals in 3D array of 1 1 1 cm voxels. Total dimensions of registered arrays were 10 12 7 cm. PWI were registered according to standard procedures. Results: In majority of patients (30) decrease of NAA/Cr and increase of Cho/Cr ratio was registered in PTV, metabolic alterations decreased progressively with the distance from PTV borders. Alterations were registered up to 3 cm outside PTV borders. Strong lipids and lactate signals were registered for 8 patients. We did not observe correlation between PTV volume, mean radiation dose to brain and results of MRS. Results of MRS were not changed significantly after RT when compared to spectra registered before RT. Regions of increased perfusion were registered for 12 patients. After a median follow up of 13 months we observed radiologic progression for 9 patients, defined as increased regions of perfusion and increased regions of contrast enhancement. All patients with strong lactate signals had early progression up to 18 months after the end of radiotherapy. Conclusions: Lactate/lipids signals registered by 3D CSI MRS are indicators of aggressive disease, and may suggest malignant disease despite of the results of pathological examination of postoperative/biopsy material. Author Disclosure: R. Tarnawski, None; A. Idasiak, None; B. Bobek-Billewicz, None.
2080
Resection Followed by Stereotactic Radiosurgery to the Resection Cavity for 1–4 Intracranial Metastases
L. Do1, R. D. Pezner2, E. Radany2, A. Liu2, C. Staud2, B. Badie2 1
UCI Medical Center, Orange, CA, 2City of Hope Medical Center, Duarte, CA
Purpose/Objective: In patients who have resection of CNS metastases, whole brain radiotherapy (WBRT) is added to reduce rates of recurrence and neurological death. However, the risk of late neurotoxicity has led many patients to decline WBRT. We have offered adjuvant stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) as an alternative to select patients with resected brain metastases. Materials/Methods: We performed a retrospective review of patients who underwent resection of brain metastases followed by SRS/SRT instead of WBRT. Additional unresected lesions were treated with SRS/SRT alone. WBRT was administered only as salvage treatment. Dose range was 15–18 Gy for SRS and 22–27.5 Gy in 4–6 fractions for SRT. Target margins were typically expanded by 1–1.5 mm for rigid immobilization and 3 mm for mask immobilization. SRT was usually reserved for large target volumes. Dose was prescribed to the 80–90% isodose lines. SRS/SRT involved use of Linac radiosurgery via IMRT on Varian 21EX or the Helical TomoTherapy unit. Kaplan-Meier life table analyses were performed with statistical inferences on the actuarial curves made with log rank tests. Results: From 12/99–1/07, 30 patients diagnosed with intracranial metastases were treated with resection followed by SRS or SRT to the resection cavity. Primary sites of disease included lung in 14 patients; breast in 6; melanoma in 6; and renal, prostate, colon and endometrial in 1 patient each. Patients had 1–4 brain metastases including 13 patients with single metastases, 10 patients with 2 metastases, 5 patients with 3 metastases, and 2 patients with 4 metastases. SRS was used in 22 cases and SRT in 8. Four of 30 (13.3%) patients recurred in the resection cavity site. Fourteen (46.6%) patients developed recurrences in new intracranial sites. Actuarial 12-month survival rates were 78% for local recurrence-free survival, 36% for freedom from new brain metastases, 63% for neurological deficit-free survival, and 48% for overall survival. Salvage WBRT was performed in 11 (36.6%) of the 30 patients. Median follow up time was 10 months and ranged between 1–37 months (Figs.).
S247
I. J. Radiation Oncology d Biology d Physics
S248
Volume 69, Number 3, Supplement, 2007
Conclusions: Many patients have not required WBRT during their clinical course and so were not at risk of neurocognitive toxicity of WBRT. Our study suggests that postoperative SRS/SRT may be a viable option for patients who have undergone resection of brain metastases. WBRT can be reserved as salvage with acceptable neurological deficit-free survival rates.
Author Disclosure: L. Do, None; R.D. Pezner, None; E. Radany, None; A. Liu, None; C. Staud, None; B. Badie, None.
2081
Clinical Experience With Radiation Therapy in the Management of Neurofibromatosis-Associated Central Nervous System Tumors
S. Wentworth, T. L. Ellis, S. Glazier, K. P. McMullen, V. W. Stieber, S. B. Tatter, E. G. Shaw Wake Forest University, Winston-Salem, NC Purpose/Objective(s): Patients with neurofibromatosis (NF) frequently develop tumors of the central nervous system (CNS). Radiation therapy (RT) is sometimes used in treating these lesions. To better define the efficacy of RT in controlling NF-associated CNS tumors, we reviewed our 20 year experience. Patients/Methods: Seventy-four lesions in 16 patients with NF were treated with RT from 1986–2006. One third of patients had NF1, two thirds NF2. Median follow up was 36 months. Progression was defined as tumor growth or recurrence in an irradiated lesion on serial imaging. Progression free survival was measured from date of treatment to date of last imaging follow up. The actuarial rates of progression free survival were calculated according to the Kaplan Meier method. Results: On average, 5 lesions were treated per patient. The most common indication for treatment was growth on serial imaging. Median age at time of treatment was 24.1 years (range: 4.3–57.1). The treated lesions included acoustic neuromas (9%), ependymomas (7%), low grade gliomas (12%), meningiomas (62%), and non-acoustic schwanommas/neurofibromas (8%). Most patients (62%) received stereotactic radiosurgery. The others received fractionated external beam RT. Overall survival at 5 years for all patients was 94%. Five year progression free survival was 100% (acoustic neuromas), 75% (ependymomas), 100% (low grade gliomas), 86% (meningiomas) and 100% (non-acoustic schwannomas). Most patients with acoustic neuromas were deaf prior to treatment. In those patients with pre-treatment useful hearing, the hearing preservation rate was 0% (Fig.). Conclusions: This is the largest published experience on the results of RT in NF patients with CNS tumors. The progression free survival rates herein are similar or superior to those published for non-NF patients treated with RT. RT should be considered in NF patients with CNS tumors.