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Dose Escalation of Three-Dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomized Study
S154
I. J. Radiation Oncology
● Biology ● Physics
Volume 63, Number 2, Supplement, 2005
Conclusions: First, neither the pretreatment SUV, nor the changes of SUV before and after treatment was a significant predictor for local response. Second, SUV at three months after completion of CCRT was a significant determinate for local response. Third, the cutoff of 4.0 for SUV at three months after completion of CCRT was useful for determination local responders v non-responders.
1013
Dose Escalation of Three-Dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomized Study
J. Li,1,3 C. Hu,1 G. Jiang,1 N.A. Mayr,2 J.Z. Wang,2 X. He,1 Y. Wu1 1
Department of Radiation Oncology, Affiliated Cancer Hospital, Fudan University, Shanghai, China, 2Department of Radiation Medicine, Ohio State University, Columbus, OH, 3Department of Radiation Oncology, University of Maryland, Baltimore, MD Purpose/Objective: To investigate the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma in a prospective randomized study. Materials/Methods: Thirty-six patients with locally recurrent nasopharyngeal carcinoma after prior radical radiotherapy underwent re-irradiation. Eligibility criteria included (1) interval between first radiation and local recurrence of ⬎6 month, (2) no cervical lymph node involvement and (3) no distant metastasis. Patients were treated with conformal small-field externalbeam radiotherapy to 54 Gy/27 fractions/5.4 weeks. This was followed by a 3D-CRT boost to the gross tumor region, randomized to three boost dose levels: 16 Gy (4 Gy ⫻ 4 fractions) for Group I; 20 Gy (4 G y x5 fractions) for Group II; and 24 Gy (4 Gy ⫻ 6 fractions) for Group III. All boost doses were delivered as 3 fractions per week. Median follow-up was 27 months (range: 14 – 44 months). Results: Overall 3-year survival rate was 65%, 3-year local recurrence-free survival rate 45%, and 3-year distant metastasis rate 10%. Local-recurrence-free survival at 3 years was significantly higher (80%) for the high-dose Group III compared with Groups I and II (30% and 28%, respectively, p⫽0.047). The 3-year distant metastases rates were 17%, 0% and 18% for Group I, II, III, respectively (p ⫽ 0.35). There was no significant difference in the 3-year overall survival rate among groups I, II and III (72%, 59%, and 82%, respectively, p ⫽ 0.60). Skull base invasion (p⫽0.017) and histology (p⫽0.0006) were significant prognostic factors for overall survival rate in univariate analysis. Toxicity was acceptable: grade 3 oral mucositis occurred in 17%, 17%, 0%, and nasopharyngeal mucositis in 25%, 17%, 17% of patients in groups I, II and III, respectively (p ⫽ NS). Conclusions: Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent nasopharyngeal carcinoma. Dose escalation to the boost volume to 78 Gy (54 Gy ⫹ 24 Gy boost) results in improved recurrence-free survival compared to lower doses.
1014
Partial Volume Tolerance of Human Spinal Cord to Single Dose Radiosurgery: Accumulated Experience of 211 Procedures
S. Ryu,1 J. Jin,1 S. Yoo,1 K. Faber,1 J. Rock,2 B. Movsas,1 M. Ajlouni,1 J. Kim1 1
Radiation Oncology, Henry Ford Hospital, Detroit, MI, 2Neurosurgery, Henry Ford Hospital, Detroit, MI
Purpose/Objective: Single dose radiosurgery for spinal tumors achieved a rapid relief of pain and neurologic improvement. The critical organ at risk in the spinal radiosurgery is the spinal cord. Since there is a rapid dose fall-off of radiation to a portion of the spinal cord, tolerance of the partial volume of spinal cord may determine the clinical application of spinal radiosurgery. The purpose of this analysis is to determine the partial volume tolerance dose of human spinal cord to a single dose of radiation after spinal radiosurgery by clinical and radiologic evaluation, and to determine the radiobiological and physical factors that may affect the spinal cord dose in spinal radiosurgery. Materials/Methods: Total of 211 lesions in 158 patients received radiosurgery of the involved spine or spinal cord with a single radiation dose of 10 –18 Gy at Henry Ford Hospital between 3/01 and 12/04, using BrainLab Novalis radiosurgery unit. Most patients were treated for primary and metastatic tumors to the spine and/or cord. The radiation dose was prescribed to the 90% isodose line which encompassed the target volume. The endpoints were clinical and neurological status, and radiologic studies during the follow-up period of 6 – 42 months. Results: Precision of spinal radiosurgery was 1.36 ⫾ 0.11 mm. Dosimetric distance from 90% to 50% isodose line was 5.24 ⫾ 0.92 mm. The average tumor volume was 57.0 ⫾ 34.1 cc with length 49.1 ⫾ 15.3 mm and width 45.5 ⫾ 10.7 mm. The spinal cord volume at the treated spinal level was 5.9 ⫾ 2.2 cc. In the accumulated DVH of all patients, single mean dose of 10 Gy was given to 10% volume of the spinal cord at the involved spinal segment. The maximum doses to 20%, 10% and 0.1% of spinal cord volumes were 13.2 Gy, 14.0 Gy and 17.1 Gy respectively. There were no clinical/neurological and radiological abnormalities that might be secondary of radiation damage to the spinal cord for a longest follow-up period of 42 months. Conclusions: Single dose 10 Gy delivered to 10% volume partial volume of the spinal cord was well tolerated. The maximum tolerance dose is still not known. However, the result shows that single dose radiosurgery is safe and can be used clinically for spine/cord tumors. Since the position of the cord is variable within the spinal canal, special effort to reduce the spinal cord is needed in individual case.
I. J. Radiation Oncology
● Biology ● Physics
Volume 63, Number 2, Supplement, 2005
Conclusions: First, neither the pretreatment SUV, nor the changes of SUV before and after treatment was a significant predictor for local response. Second, SUV at three months after completion of CCRT was a significant determinate for local response. Third, the cutoff of 4.0 for SUV at three months after completion of CCRT was useful for determination local responders v non-responders.
1013
Dose Escalation of Three-Dimensional Conformal Radiotherapy for Locally Recurrent Nasopharyngeal Carcinoma: A Prospective Randomized Study
J. Li,1,3 C. Hu,1 G. Jiang,1 N.A. Mayr,2 J.Z. Wang,2 X. He,1 Y. Wu1 1
Department of Radiation Oncology, Affiliated Cancer Hospital, Fudan University, Shanghai, China, 2Department of Radiation Medicine, Ohio State University, Columbus, OH, 3Department of Radiation Oncology, University of Maryland, Baltimore, MD Purpose/Objective: To investigate the feasibility and efficacy of dose escalation using three-dimensional conformal radiotherapy (3D-CRT) boost technique for locally recurrent nasopharyngeal carcinoma in a prospective randomized study. Materials/Methods: Thirty-six patients with locally recurrent nasopharyngeal carcinoma after prior radical radiotherapy underwent re-irradiation. Eligibility criteria included (1) interval between first radiation and local recurrence of ⬎6 month, (2) no cervical lymph node involvement and (3) no distant metastasis. Patients were treated with conformal small-field externalbeam radiotherapy to 54 Gy/27 fractions/5.4 weeks. This was followed by a 3D-CRT boost to the gross tumor region, randomized to three boost dose levels: 16 Gy (4 Gy ⫻ 4 fractions) for Group I; 20 Gy (4 G y x5 fractions) for Group II; and 24 Gy (4 Gy ⫻ 6 fractions) for Group III. All boost doses were delivered as 3 fractions per week. Median follow-up was 27 months (range: 14 – 44 months). Results: Overall 3-year survival rate was 65%, 3-year local recurrence-free survival rate 45%, and 3-year distant metastasis rate 10%. Local-recurrence-free survival at 3 years was significantly higher (80%) for the high-dose Group III compared with Groups I and II (30% and 28%, respectively, p⫽0.047). The 3-year distant metastases rates were 17%, 0% and 18% for Group I, II, III, respectively (p ⫽ 0.35). There was no significant difference in the 3-year overall survival rate among groups I, II and III (72%, 59%, and 82%, respectively, p ⫽ 0.60). Skull base invasion (p⫽0.017) and histology (p⫽0.0006) were significant prognostic factors for overall survival rate in univariate analysis. Toxicity was acceptable: grade 3 oral mucositis occurred in 17%, 17%, 0%, and nasopharyngeal mucositis in 25%, 17%, 17% of patients in groups I, II and III, respectively (p ⫽ NS). Conclusions: Re-irradiation with high-dose 3D-CRT boost technique results in high local control rate and acceptable toxicity in patients with recurrent nasopharyngeal carcinoma. Dose escalation to the boost volume to 78 Gy (54 Gy ⫹ 24 Gy boost) results in improved recurrence-free survival compared to lower doses.
1014
Partial Volume Tolerance of Human Spinal Cord to Single Dose Radiosurgery: Accumulated Experience of 211 Procedures
S. Ryu,1 J. Jin,1 S. Yoo,1 K. Faber,1 J. Rock,2 B. Movsas,1 M. Ajlouni,1 J. Kim1 1
Radiation Oncology, Henry Ford Hospital, Detroit, MI, 2Neurosurgery, Henry Ford Hospital, Detroit, MI
Purpose/Objective: Single dose radiosurgery for spinal tumors achieved a rapid relief of pain and neurologic improvement. The critical organ at risk in the spinal radiosurgery is the spinal cord. Since there is a rapid dose fall-off of radiation to a portion of the spinal cord, tolerance of the partial volume of spinal cord may determine the clinical application of spinal radiosurgery. The purpose of this analysis is to determine the partial volume tolerance dose of human spinal cord to a single dose of radiation after spinal radiosurgery by clinical and radiologic evaluation, and to determine the radiobiological and physical factors that may affect the spinal cord dose in spinal radiosurgery. Materials/Methods: Total of 211 lesions in 158 patients received radiosurgery of the involved spine or spinal cord with a single radiation dose of 10 –18 Gy at Henry Ford Hospital between 3/01 and 12/04, using BrainLab Novalis radiosurgery unit. Most patients were treated for primary and metastatic tumors to the spine and/or cord. The radiation dose was prescribed to the 90% isodose line which encompassed the target volume. The endpoints were clinical and neurological status, and radiologic studies during the follow-up period of 6 – 42 months. Results: Precision of spinal radiosurgery was 1.36 ⫾ 0.11 mm. Dosimetric distance from 90% to 50% isodose line was 5.24 ⫾ 0.92 mm. The average tumor volume was 57.0 ⫾ 34.1 cc with length 49.1 ⫾ 15.3 mm and width 45.5 ⫾ 10.7 mm. The spinal cord volume at the treated spinal level was 5.9 ⫾ 2.2 cc. In the accumulated DVH of all patients, single mean dose of 10 Gy was given to 10% volume of the spinal cord at the involved spinal segment. The maximum doses to 20%, 10% and 0.1% of spinal cord volumes were 13.2 Gy, 14.0 Gy and 17.1 Gy respectively. There were no clinical/neurological and radiological abnormalities that might be secondary of radiation damage to the spinal cord for a longest follow-up period of 42 months. Conclusions: Single dose 10 Gy delivered to 10% volume partial volume of the spinal cord was well tolerated. The maximum tolerance dose is still not known. However, the result shows that single dose radiosurgery is safe and can be used clinically for spine/cord tumors. Since the position of the cord is variable within the spinal canal, special effort to reduce the spinal cord is needed in individual case.