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Fractionated Stereotactic Radiotherapy of Paraspinal Tumors
I. J. Radiation Oncology d Biology d Physics
S248
Volume 75, Number 3, Supplement, 2009
edema. In one other patient an uncomplicated intracerebral hemorrhage with short time hemianopia happened 24 months after treatment. No secondary malignancies were observed and none of the patients died during follow-up. Conclusions: Stereotactic reirradiation in not completely obliterated AVM is an effective treatment option to control intracranial bleeding risk with only few treatment related complications. This thesis should be further evaluated in prospective trials with larger patient numbers. Author Disclosure: S.H. Hauswald, None; F. Sterzing, None; N. Pfaendner, None; S. Milker-Zabel, None; W. Schlegel, None; J. Debus, None; A. Zabel-du Bois, None.
2149
The Results of Radiotherapy for Ependymoma in 110 Patients: The Christie Hospital Experience
N. Ghosal, A. Britten, R. Swindell, R. Gattamaneni The Christie Hospital, Manchester, United Kingdom Purpose/Objective(s): Ependymoma is a rare neuroectodermal tumour and there are few randomized controlled trials to optimize management. The extent of resection and histological grade are significant prognostic factors. Most chemotherapy (CT) related trials were done on children. We present our experience at the Christie Hospital. Materials/Methods: The case notes of patients with ependymoma, subependymoma, myxopapillary ependymoma and anaplastic ependymoma treated at the Christie Hospital between 1982 and 2008 were reviewed retrospectively with a median follow up of 13 years. We present the demographics and survival statistics. Results: A total of 110 patients, 69 males and 41 females, between the ages of 6 months to 80 years (mean 31.2 yrs) were treated. There were 35 children (\16 years) and 75 adults. Supratentorial (ST), infratentorial (IT), and spinal primary (SP) were noted in 20, 52 and 38 patients respectively. Seven patients (2 SP, 1 ST and 4 IT primaries) had metastases at presentation. There were 19 total resections, 86 incomplete resections and 5 biopsies only. Ninety nine patients were treated with primary surgery followed by radiotherapy (XRT). CT was part of primary treatment in 15 patients. Eleven patients did not receive XRT including 5 aged less than four. Twenty six patients received craniospinal irradiation (CSI) plus tumour bed boost (CSI+B), and 73 had local XRT. The doses used for CSI varied between 35-55Gy in 22-34 fractions with a median CSI dose of 30Gy in 20 fractions and a boost dose of 20 Gy in 10 fractions. The local treatment doses were 35-55Gy in 15-30 fractions with common dose being 42.5Gy in 15 fractions and 54Gy in 30 fractions. A univariate analysis was done looking at age, site of presentation (ST, IT and SP), completeness of resection, type of XRT (CSI+B vs. local XRT) and dose to the primary site. Overall survival (OS) at 5 years was 81% and 71% at 10 years. Children less than 4 years had the worst prognosis with a 5 and 10 year survival of 51% and 41% respectively. The 5 and 10 year survival for adults was 84% and 72% respectively. The site specific 5 and 10 year survival was ST 80% and 70%; IT 70% and 63% and Spinal 97% and 85% respectively. The 5 and 10 year survival for CSI was 89% and 84% and for the local XRT was 83% and 71% respectively. Conclusions: We report the largest single institution series of ependymoma. The majority of our patients had incomplete resections. Our results are similar to the other large single institutional and multicenter series. Very young children who did not receive XRT had a poor prognosis. There is no difference in survival between local XRT and CSI. The majority of patients had local recurrences. The pattern of treatment failure, dose effect to the primary and histological association with survival will be presented at the time of the meeting. Author Disclosure: N. Ghosal, None; A. Britten, None; R. Swindell, None; R. Gattamaneni, None.
2150
Fractionated Stereotactic Radiotherapy of Paraspinal Tumors
K. A. Wharton1, B. Stea1, L. Thomas2, A. C. Gruessner1 1
University of Arizona Health Science Center, Tucson, AZ, 2University of Arizona, Tucson, AZ
Purpose/Objective(s): Stereotactic radiotherapy of paraspinal tumors has safely achieved pain control in a growing number of clinical reports. The majority of these have used a single fraction. The efficacy, optimal dose, and toxicities of fractionated treatment largely remain to be defined. We present our experience with fractionated, image-guided intensity modulated radiotherapy (IG-IMRT) to the paraspinal region. Materials/Methods: We conducted a retrospective review of patient charts and imaging. The median follow-up was 9.26 months. Between 2004 and 2009, 54 patients were treated with IG-IMRT to 47 metastatic lesions and 7 primary spine tumors. Fifteen patients had previous treatment with a median dose of 30 Gy. Fourteen patients received 3D conformal radiation prior to a planned IMRT boost. Patient immobilization was frameless and consisted of a vacuum cushion or thermoplastic mask. The biological effective dose (BED) was calculated for the spinal cord and tumor to equate various fractionation schedules using the formula of BED= (nd) x (1 + d/(a/b)) with an a/b ratio of 2 for the spinal cord and 10 for tumor. Results: The mean total prescribed tumor dose was 33.43 Gy with a fraction size of 3.10 Gy. The mean maximum spinal cord dose was 36.67 Gy (3.1-70.3 Gy), which corresponded to a mean spinal cord BED of 91.4 Gy2 (42.9-155.3 Gy2) to the maximum dose point and 71 Gy2 (5.6-150.6 Gy2) to the 10% volume. The mean survival from the start of treatment was 15.8 ± 2.33 months. Seven patients had diffuse spinal metastasis prior to treatment. Of the remaining patients, 10 had radiographic evidence of tumor recurrence in the spine; 5 recurred in the SBRT field, 4 recurred out of field and one patient recurred in both. The mean time to recurrence was 11.3 months. Two patients recurred within one vertebral body of the area treated. The median BED for metastatic lesions that recurred in-field was 28 Gy10, versus 39 Gy10 for those with no recurrence. Pain was reported as stable or improved in 30% and 68% respectively, with 7.4% of patients reporting a recurrence of pain at a mean of 2.25 months. There were eight patients who experienced grade 2 esophagitis, 3 patients with grade 2 diarrhea, and one case of possible radiation pneumonitis. There were no cases of myelitis or RTOG grade 3 or 4 toxicity. Conclusions: Fractionated IG-IMRT to paraspinal tumors can be delivered with a low risk of toxicity and a reasonable expectation of a durable reduction in pain symptoms. The incidence of in-field failure was low and was uncommon in patients receiving more than 40 Gy10. The probability of an isolated recurrence in an adjacent vertebral body was \5%. In comparison to radiosurgery, this technique may allow for similar rates of tumor control with less morbidity. Author Disclosure: K.A. Wharton, None; B. Stea, None; L. Thomas, None; A.C. Gruessner, None.
S248
Volume 75, Number 3, Supplement, 2009
edema. In one other patient an uncomplicated intracerebral hemorrhage with short time hemianopia happened 24 months after treatment. No secondary malignancies were observed and none of the patients died during follow-up. Conclusions: Stereotactic reirradiation in not completely obliterated AVM is an effective treatment option to control intracranial bleeding risk with only few treatment related complications. This thesis should be further evaluated in prospective trials with larger patient numbers. Author Disclosure: S.H. Hauswald, None; F. Sterzing, None; N. Pfaendner, None; S. Milker-Zabel, None; W. Schlegel, None; J. Debus, None; A. Zabel-du Bois, None.
2149
The Results of Radiotherapy for Ependymoma in 110 Patients: The Christie Hospital Experience
N. Ghosal, A. Britten, R. Swindell, R. Gattamaneni The Christie Hospital, Manchester, United Kingdom Purpose/Objective(s): Ependymoma is a rare neuroectodermal tumour and there are few randomized controlled trials to optimize management. The extent of resection and histological grade are significant prognostic factors. Most chemotherapy (CT) related trials were done on children. We present our experience at the Christie Hospital. Materials/Methods: The case notes of patients with ependymoma, subependymoma, myxopapillary ependymoma and anaplastic ependymoma treated at the Christie Hospital between 1982 and 2008 were reviewed retrospectively with a median follow up of 13 years. We present the demographics and survival statistics. Results: A total of 110 patients, 69 males and 41 females, between the ages of 6 months to 80 years (mean 31.2 yrs) were treated. There were 35 children (\16 years) and 75 adults. Supratentorial (ST), infratentorial (IT), and spinal primary (SP) were noted in 20, 52 and 38 patients respectively. Seven patients (2 SP, 1 ST and 4 IT primaries) had metastases at presentation. There were 19 total resections, 86 incomplete resections and 5 biopsies only. Ninety nine patients were treated with primary surgery followed by radiotherapy (XRT). CT was part of primary treatment in 15 patients. Eleven patients did not receive XRT including 5 aged less than four. Twenty six patients received craniospinal irradiation (CSI) plus tumour bed boost (CSI+B), and 73 had local XRT. The doses used for CSI varied between 35-55Gy in 22-34 fractions with a median CSI dose of 30Gy in 20 fractions and a boost dose of 20 Gy in 10 fractions. The local treatment doses were 35-55Gy in 15-30 fractions with common dose being 42.5Gy in 15 fractions and 54Gy in 30 fractions. A univariate analysis was done looking at age, site of presentation (ST, IT and SP), completeness of resection, type of XRT (CSI+B vs. local XRT) and dose to the primary site. Overall survival (OS) at 5 years was 81% and 71% at 10 years. Children less than 4 years had the worst prognosis with a 5 and 10 year survival of 51% and 41% respectively. The 5 and 10 year survival for adults was 84% and 72% respectively. The site specific 5 and 10 year survival was ST 80% and 70%; IT 70% and 63% and Spinal 97% and 85% respectively. The 5 and 10 year survival for CSI was 89% and 84% and for the local XRT was 83% and 71% respectively. Conclusions: We report the largest single institution series of ependymoma. The majority of our patients had incomplete resections. Our results are similar to the other large single institutional and multicenter series. Very young children who did not receive XRT had a poor prognosis. There is no difference in survival between local XRT and CSI. The majority of patients had local recurrences. The pattern of treatment failure, dose effect to the primary and histological association with survival will be presented at the time of the meeting. Author Disclosure: N. Ghosal, None; A. Britten, None; R. Swindell, None; R. Gattamaneni, None.
2150
Fractionated Stereotactic Radiotherapy of Paraspinal Tumors
K. A. Wharton1, B. Stea1, L. Thomas2, A. C. Gruessner1 1
University of Arizona Health Science Center, Tucson, AZ, 2University of Arizona, Tucson, AZ
Purpose/Objective(s): Stereotactic radiotherapy of paraspinal tumors has safely achieved pain control in a growing number of clinical reports. The majority of these have used a single fraction. The efficacy, optimal dose, and toxicities of fractionated treatment largely remain to be defined. We present our experience with fractionated, image-guided intensity modulated radiotherapy (IG-IMRT) to the paraspinal region. Materials/Methods: We conducted a retrospective review of patient charts and imaging. The median follow-up was 9.26 months. Between 2004 and 2009, 54 patients were treated with IG-IMRT to 47 metastatic lesions and 7 primary spine tumors. Fifteen patients had previous treatment with a median dose of 30 Gy. Fourteen patients received 3D conformal radiation prior to a planned IMRT boost. Patient immobilization was frameless and consisted of a vacuum cushion or thermoplastic mask. The biological effective dose (BED) was calculated for the spinal cord and tumor to equate various fractionation schedules using the formula of BED= (nd) x (1 + d/(a/b)) with an a/b ratio of 2 for the spinal cord and 10 for tumor. Results: The mean total prescribed tumor dose was 33.43 Gy with a fraction size of 3.10 Gy. The mean maximum spinal cord dose was 36.67 Gy (3.1-70.3 Gy), which corresponded to a mean spinal cord BED of 91.4 Gy2 (42.9-155.3 Gy2) to the maximum dose point and 71 Gy2 (5.6-150.6 Gy2) to the 10% volume. The mean survival from the start of treatment was 15.8 ± 2.33 months. Seven patients had diffuse spinal metastasis prior to treatment. Of the remaining patients, 10 had radiographic evidence of tumor recurrence in the spine; 5 recurred in the SBRT field, 4 recurred out of field and one patient recurred in both. The mean time to recurrence was 11.3 months. Two patients recurred within one vertebral body of the area treated. The median BED for metastatic lesions that recurred in-field was 28 Gy10, versus 39 Gy10 for those with no recurrence. Pain was reported as stable or improved in 30% and 68% respectively, with 7.4% of patients reporting a recurrence of pain at a mean of 2.25 months. There were eight patients who experienced grade 2 esophagitis, 3 patients with grade 2 diarrhea, and one case of possible radiation pneumonitis. There were no cases of myelitis or RTOG grade 3 or 4 toxicity. Conclusions: Fractionated IG-IMRT to paraspinal tumors can be delivered with a low risk of toxicity and a reasonable expectation of a durable reduction in pain symptoms. The incidence of in-field failure was low and was uncommon in patients receiving more than 40 Gy10. The probability of an isolated recurrence in an adjacent vertebral body was \5%. In comparison to radiosurgery, this technique may allow for similar rates of tumor control with less morbidity. Author Disclosure: K.A. Wharton, None; B. Stea, None; L. Thomas, None; A.C. Gruessner, None.