- Email: [email protected]
In response to Drs. Kopelson et al
282
I. J. Radiation Oncology
● Biology ● Physics
IN RESPONSE TO DR. BEITLER To the Editor: We are grateful to Dr. Beitler for his generous comments about our work. We very much agree that traditional cervical cancer staging methods, especially the FIGO system, are inaccurate in determining the extent of disease and in assessing prognosis. PET scanning is, indeed, a standard and vital part of the workup of patients with advanced cervical cancer at our institution. Studies by our group (1, 2) and others (3–5) show that PET is far superior to conventional methods in identifying nodal and metastatic disease. We are now extending our work, recently reported in this journal on the assessment of prognosis (6). It may be possible to achieve similar or even superior prognostic information by a simple visual analysis of the PET images without the need for the specialized software used in Ref 6 (7). PET also seems to hold great promise in brachytherapy treatment planning (8, 9). After applicator placement and intravenous injection of the PET radiopharmaceutical F-18 fluorodeoxyglucose (FDG), a PET scan is performed with a tubing filled with FDG placed in the applicator, thus permitting accurate delineation of the three-dimensional distribution of the tumor in relation to the applicator. Our early work suggests that a substantial fraction of brachytherapy patients with large tumors receive an inadequate dose to part of their tumors. Further research in this area may lead to PET’s becoming an essential part of brachytherapy treatment planning. As PET continues its rapid expansion in the United States and throughout the developed world, we hope this imaging modality will become a routine part of the evaluation and treatment of patients with cervical cancer. TOM R. MILLER, M.D., PH.D. PERRY W. GRIGSBY, M.D. Mallinckrodt Institute of Radiology St. Louis, MO
PII S0360-3016(02)03824-5 1. Grigsby PW, Dehdashti F, and Siegel BA. FDG-PET evaluation of carcinoma of the cervix. Clin Positron Imag 1999;2:105–109. 2. Grigsby PW, Siegel BA, Dehdashti F. Lymph node staging by positron emission tomography in patients with carcinoma of the cervix. J Clin Oncol 2001;19:3745–3749. 3. Rose P, Adler L, Rodriguez M, et al. Positron emission tomography for evaluating para-aortic nodal metastasis in locally advanced cervical cancer before surgical staging: A surgicopathologic study. J Clin Oncol 1999;17:41– 45. 4. Sugawara Y, Eisbruch A, Kosuda S, et al. Evaluation of FDG-PET in patients with cervical cancer. J Nucl Med 1999;40:1125–1131. 5. Reinhardt M, Ehritt-Braun C, Vogelgesang D, et al. Metastatic lymph nodes in patients with cervical cancer: Detection with MR imaging and FDG PET. Radiology 2001;218:776 –782. 6. Miller TR, and Grigsby PW. Measurement of tumor volume by PET to evaluate prognosis in patients with advanced cervical cancer treated by radiation therapy. Int J Radiat Oncol Biol Phys 2002;53:353–359. 7. Miller T, Pinkus E, and Dehdashti F. Improved prognostic value of FDG-PET in patients with cervical cancer using a simple visual analysis of tumor characteristics (Abstr). J Nucl Med 2002;43:28P. 8. Mutic S, Grigsby PW, Low DA, et al. PET guided three-dimensional treatment planning of intracavitary gynecologic implants. Int J Radiat Oncol Biol Phys 2002;52:1104 –1110. 9. Malyapa RS, Mutic S, Low DA, et al. Physiologic FDG-PET three dimensional brachytherapy treatment planning for cervical cancer. Int J Radiat Oncol Biol Phys, in press. 2002.
IN RESPONSE TO DRS. SCHILD, WONG, AND NISI, IJROBP 2002;53:787 To the Editor: In a recent letter to the editor, Drs. Schild, Wong, and Nisi (1) were concerned that there might be no other dose–response data available in the literature for treating patients with spinal cord ependymo-
Volume 55, Number 1, 2003 mas. Please see such data that was published more than 20 years ago from the Massachusetts General Hospital, which provides this information (2). GENE KOPELSON, M.D. Trumbull Oncology Center Radiation Oncology of Southern Connecticut Trumbull, CT PII S0360-3016(02)03859-2 1. Schild SE, Wong W, Nisi K. In regard to the radiotherapy of myxopapillary ependymomas. Int J. Radiat Oncol Biol Phys 2002;53:787. 2. Kopelson G, Linggood RM, Kleinman GM, et al. Management of intramedullary spinal cord tumors. Radiology 1980;135:473– 479; Table V.
IN RESPONSE TO DRS. KOPELSON ET AL. To the Editor: Dr. Kopelson has kindly identified his dose–response data for all subtypes and grades of spinal ependymomas in a 1980 study (1). His study included 12 patients with ependymomas, and of these, 6 had myxopapillary ependymomas. The dose–response was evaluated in the 8 ependymoma patients with a minimum follow-up of 5 years. Of the 3 patients who received a time– dose fraction (TDF) of ⬍55, 2 were locally controlled. Of the 3 patients who received a TDF 55– 65, 2 were locally controlled. Of the 2 patients who received a TDF of ⬎65, both were locally controlled. There are other examples of dose–response relationships published in the literature for ependymomas (2, 3). The letter published in IJROBP that he responded to was specifically addressing the uncommon subtype “myxopapillary ependymomas” (4). Myxopapillary ependymomas are distinct from other ependymomas in their histologic appearance and behavior. Myxopapillary ependymomas are uniformly low-grade tumors found in the cauda equina region, where most arise from the filum terminale. The most characteristic histologic feature is the abundance of intercellular and perivascular mucin. Myxopapillary ependymomas have a significantly better prognosis than other ependymomas. The 5-year survival rate was 100% for patients with myxopapillary ependymomas as compared to 76% for those with other ependymomas ( p ⫽ 0.02) (5). Myxopapillary ependymomas are quite rare, and in our 1998 series, they made up only 12 of the 80 (15%) total ependymomas and 12 of the 19 (63%) ependymomas occurring in the lumbar spine. There seemed to be an association between local control and dose for patients with myxopapillary ependymomas. The 5-year local control rates were 100% with doses exceeding 50 Gy and 67% with lesser doses (p ⫽ 0.08, log-rank test). Unfortunately, because myxopapillary ependymomas are quite rare, there may be no other dose–response data available in the literature for this histologic variant of ependymoma. STEVEN SCHILD, M.D. WILLIAM WONG, M.D. KURT NISI, M.D. Department of Radiation Oncology Mayo Clinic Scottsdale, AZ PII S0360-3016(02)03860-9 1. Kopelson G, Linggood RM, Kleinman GM, et al. Management of intramedullary spinal cord tumors. Radiology 1980;135:473– 479. 2. Garrett PG, Simpson WJ. Ependymomas: Results of radiation treatment. Int J Radiat Oncol Biol Phys 1983;9:1121–1124. 3. Stuben G, Stuschke M, Kroll M, et al. Postoperative radio-therapy of spinal and intracranial ependymomas: Analysis of prognostic factors. Radiother Oncol 1997;45:3–10. 4. Schild SE, Wong W, Nisi K. In regard to the radiotherapy of myxopapillary ependymomas. Int J Radiat Oncol Biol Phys 2002;53:787. 5. Schild SE, Nisi K, Scheithauer BW, et al. The results of radiotherapy for ependymomas: The Mayo Clinic experience. Int J Radiat Oncol Biol Phys 1998;42(5):953–958.
I. J. Radiation Oncology
● Biology ● Physics
IN RESPONSE TO DR. BEITLER To the Editor: We are grateful to Dr. Beitler for his generous comments about our work. We very much agree that traditional cervical cancer staging methods, especially the FIGO system, are inaccurate in determining the extent of disease and in assessing prognosis. PET scanning is, indeed, a standard and vital part of the workup of patients with advanced cervical cancer at our institution. Studies by our group (1, 2) and others (3–5) show that PET is far superior to conventional methods in identifying nodal and metastatic disease. We are now extending our work, recently reported in this journal on the assessment of prognosis (6). It may be possible to achieve similar or even superior prognostic information by a simple visual analysis of the PET images without the need for the specialized software used in Ref 6 (7). PET also seems to hold great promise in brachytherapy treatment planning (8, 9). After applicator placement and intravenous injection of the PET radiopharmaceutical F-18 fluorodeoxyglucose (FDG), a PET scan is performed with a tubing filled with FDG placed in the applicator, thus permitting accurate delineation of the three-dimensional distribution of the tumor in relation to the applicator. Our early work suggests that a substantial fraction of brachytherapy patients with large tumors receive an inadequate dose to part of their tumors. Further research in this area may lead to PET’s becoming an essential part of brachytherapy treatment planning. As PET continues its rapid expansion in the United States and throughout the developed world, we hope this imaging modality will become a routine part of the evaluation and treatment of patients with cervical cancer. TOM R. MILLER, M.D., PH.D. PERRY W. GRIGSBY, M.D. Mallinckrodt Institute of Radiology St. Louis, MO
PII S0360-3016(02)03824-5 1. Grigsby PW, Dehdashti F, and Siegel BA. FDG-PET evaluation of carcinoma of the cervix. Clin Positron Imag 1999;2:105–109. 2. Grigsby PW, Siegel BA, Dehdashti F. Lymph node staging by positron emission tomography in patients with carcinoma of the cervix. J Clin Oncol 2001;19:3745–3749. 3. Rose P, Adler L, Rodriguez M, et al. Positron emission tomography for evaluating para-aortic nodal metastasis in locally advanced cervical cancer before surgical staging: A surgicopathologic study. J Clin Oncol 1999;17:41– 45. 4. Sugawara Y, Eisbruch A, Kosuda S, et al. Evaluation of FDG-PET in patients with cervical cancer. J Nucl Med 1999;40:1125–1131. 5. Reinhardt M, Ehritt-Braun C, Vogelgesang D, et al. Metastatic lymph nodes in patients with cervical cancer: Detection with MR imaging and FDG PET. Radiology 2001;218:776 –782. 6. Miller TR, and Grigsby PW. Measurement of tumor volume by PET to evaluate prognosis in patients with advanced cervical cancer treated by radiation therapy. Int J Radiat Oncol Biol Phys 2002;53:353–359. 7. Miller T, Pinkus E, and Dehdashti F. Improved prognostic value of FDG-PET in patients with cervical cancer using a simple visual analysis of tumor characteristics (Abstr). J Nucl Med 2002;43:28P. 8. Mutic S, Grigsby PW, Low DA, et al. PET guided three-dimensional treatment planning of intracavitary gynecologic implants. Int J Radiat Oncol Biol Phys 2002;52:1104 –1110. 9. Malyapa RS, Mutic S, Low DA, et al. Physiologic FDG-PET three dimensional brachytherapy treatment planning for cervical cancer. Int J Radiat Oncol Biol Phys, in press. 2002.
IN RESPONSE TO DRS. SCHILD, WONG, AND NISI, IJROBP 2002;53:787 To the Editor: In a recent letter to the editor, Drs. Schild, Wong, and Nisi (1) were concerned that there might be no other dose–response data available in the literature for treating patients with spinal cord ependymo-
Volume 55, Number 1, 2003 mas. Please see such data that was published more than 20 years ago from the Massachusetts General Hospital, which provides this information (2). GENE KOPELSON, M.D. Trumbull Oncology Center Radiation Oncology of Southern Connecticut Trumbull, CT PII S0360-3016(02)03859-2 1. Schild SE, Wong W, Nisi K. In regard to the radiotherapy of myxopapillary ependymomas. Int J. Radiat Oncol Biol Phys 2002;53:787. 2. Kopelson G, Linggood RM, Kleinman GM, et al. Management of intramedullary spinal cord tumors. Radiology 1980;135:473– 479; Table V.
IN RESPONSE TO DRS. KOPELSON ET AL. To the Editor: Dr. Kopelson has kindly identified his dose–response data for all subtypes and grades of spinal ependymomas in a 1980 study (1). His study included 12 patients with ependymomas, and of these, 6 had myxopapillary ependymomas. The dose–response was evaluated in the 8 ependymoma patients with a minimum follow-up of 5 years. Of the 3 patients who received a time– dose fraction (TDF) of ⬍55, 2 were locally controlled. Of the 3 patients who received a TDF 55– 65, 2 were locally controlled. Of the 2 patients who received a TDF of ⬎65, both were locally controlled. There are other examples of dose–response relationships published in the literature for ependymomas (2, 3). The letter published in IJROBP that he responded to was specifically addressing the uncommon subtype “myxopapillary ependymomas” (4). Myxopapillary ependymomas are distinct from other ependymomas in their histologic appearance and behavior. Myxopapillary ependymomas are uniformly low-grade tumors found in the cauda equina region, where most arise from the filum terminale. The most characteristic histologic feature is the abundance of intercellular and perivascular mucin. Myxopapillary ependymomas have a significantly better prognosis than other ependymomas. The 5-year survival rate was 100% for patients with myxopapillary ependymomas as compared to 76% for those with other ependymomas ( p ⫽ 0.02) (5). Myxopapillary ependymomas are quite rare, and in our 1998 series, they made up only 12 of the 80 (15%) total ependymomas and 12 of the 19 (63%) ependymomas occurring in the lumbar spine. There seemed to be an association between local control and dose for patients with myxopapillary ependymomas. The 5-year local control rates were 100% with doses exceeding 50 Gy and 67% with lesser doses (p ⫽ 0.08, log-rank test). Unfortunately, because myxopapillary ependymomas are quite rare, there may be no other dose–response data available in the literature for this histologic variant of ependymoma. STEVEN SCHILD, M.D. WILLIAM WONG, M.D. KURT NISI, M.D. Department of Radiation Oncology Mayo Clinic Scottsdale, AZ PII S0360-3016(02)03860-9 1. Kopelson G, Linggood RM, Kleinman GM, et al. Management of intramedullary spinal cord tumors. Radiology 1980;135:473– 479. 2. Garrett PG, Simpson WJ. Ependymomas: Results of radiation treatment. Int J Radiat Oncol Biol Phys 1983;9:1121–1124. 3. Stuben G, Stuschke M, Kroll M, et al. Postoperative radio-therapy of spinal and intracranial ependymomas: Analysis of prognostic factors. Radiother Oncol 1997;45:3–10. 4. Schild SE, Wong W, Nisi K. In regard to the radiotherapy of myxopapillary ependymomas. Int J Radiat Oncol Biol Phys 2002;53:787. 5. Schild SE, Nisi K, Scheithauer BW, et al. The results of radiotherapy for ependymomas: The Mayo Clinic experience. Int J Radiat Oncol Biol Phys 1998;42(5):953–958.