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The debt, the gap and crila: radiotherapy in Latin America
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I. J. Radiation Oncology 0 Biology 0 Physics
the parenchymal cells (3). In retrospect, we should expect a disease which manifests itself in damage to small blood vessels to place a patient at greater susceptibility to damage from radiation. Collagen vascular diseases thus join certain other diseases or conditions which merit enquiry in taking the history in that they increase the risk of incurring serious complications by irradiation: diabetes mellitus (4), hypertension (4), pelvic inflammatory disease (6), or prior abdominal surgery (5, 7). RICHARDH. MATTHEWS,PH.D., M.D. Phelps County Regional Medical Center 1000 West Tenth Street Rolla, MO 65401 I. Fleck, R. S.; McNeese, M. D.; Ellerbroek, N. A.; Hunter, T. A.:
2.
3. 4. 5.
6.
7.
8.
Montague, E. D. Complications of radiation therapy for breast cancer in women with preexisting collagen vascular disease. Int. J. Radiat. Oncol. Biol. Phys. lS(Suppl. 1):155; 1988. Gilliland, B. C.; Mannik, M. Progressive systemic sclerosis (diffuse scleroderma), In: Isselbacher, K. J., Adams, R. D., Braunwald, E., Petersdorf, R. G., Wilson, J. D., eds. Harrison’s principles of internal medicine, 9th edition. New York: McGraw-Hill; 1980. Hall, E. J. Radiobiology for the radiologist, 3rd edition. Philadelphia: Lippincott; 1988. Harwood, A. R.; Tierie, A. Radiotherapy of early glottic cancerII. Int. J. Radiat. Oncol. Biol. Phys. 5:477-482; 1979. Jampolis, S.; Martin, P.; Schroder, P.; Horiot, J. C. Treatment tolerance and early complications with extended field irradiation in gynaecological cancer. Br. J. Radiol. 50:195-199; 1977. O’Quinn, A. G.; Fletcher, G. H.; Wharton, J. T. Guidelines for conservative hysterectomy after irradiation. Gynecol. Oncol. 9:68-79; 1980. Pilepich, M. V.; Perez, C. A.; Walz, B. J.; Zivnuska, F. R. Complications of definitive radiotherapy for carcinoma of the prostate. Int. J. Radiat. Oncol. Biol. Phys. 7: 134 I- 1348; 198 1. Robinson, D. R. Scleroderma. In: Rubenstein, E., Federman, D. D., eds. Scientific american medicine, Vol. 15. New York: Scientific American Inc.; 1984:1-7.
THE DEBT, THE GAP AND CRILA: RADIOTHERAPY IN LATIN AMERICA To the Editor:The practice of radiotherapy in Latin American countries encounters many difficulties due to the high technological requirements of this medical field. The increasing economic problems of our nations, reflected in an oppressive external debt, have aggravated the situation. The social and cultural conditions of most of our patients certainly do not make this worrisome reality any better. Also, there is a significant difference in the incidence of the different types of cancer in the developing countries; for instance, cancer of the cervix and gastric cancer constitute the most frequent tumors with a high mortality rate in many areas (1). The many problems that confront the radiotherapist in Latin America gave origin to CRILA (Iberian Latin American Circle of Radiation Oncology) in 197 1 (3). This radiotherapy circle has been very active since its inception, and up to this time it has conducted six international meetings with the collaboration of many internationally known radiation oncologists. The cooperation of the Latin American colleagues who practice in the United States has been of special value. They are convinced of the necessity of creating a communication channel and establishing a technological bridge between the developed nations where they practice and their native countries. At the last CRILA meeting held in 1987 in Uruguay, we had the opportunity to share many ideas and experiences with our colleagues in the search of possible solutions to our common problems. The supervoltage unit most used in our countries is the wCo machine. Low energy linear accelerators (4-6 MeV) are available at some centers. Electron beam therapy exists in very few centers, and therapy with photons of higher energy and heavy particles is virtually nonexistent. Hyperthermia in association with radiation therapy is not practiced in any institution. Fortunately, the most frequent tumors that affect the population of our countries can be treated adequately with 6oCo gamma rays and brachytherapy with cesium using afterloading techniques. The medical personnel and radiation technologists are capable of administering radiotherapy with this equipment. Our efforts should be directed towards quality control of the specialty. We need help in the areas of radiation
November 1989, Volume 17, Number 5 physics and dosimetry, and there is a great need to install new equipment, such as computers for treatment planning, and simulators. These are our basic needs, since the scientific knowledge of the radiotherapists in Spain and Latin America has been maintained due in great part to the efforts of the members of CRILA who have contributed to the success of our periodic meetings. The recommendations and conclusions that emanate from the CRILA meetings should be conveyed to the public authorities, who have to be adequately informed of the radiotherapy situation in each country. In a recent survey conducted in Venezuela (2), all the public radiotherapy centers were visited and specific recommendations to improve the quality of the specialty were made. The next CRILA meeting will be held in 1989 in Venezuela (Barcelona) where CRILA was founded in 197 1. We want to extend a cordial invitation to all the members of ASTRO to visit us during that important event, and to bring new ideas to better the practice of radiotherapy in our countries. Our local office in Caracas can furnish further information: Dr. Raul Vera Vera, Apartado 600.006, Zona Postal 1061, Caracas, Venezuela. DR. RAUL VERA VERA Dept. of Radiotherapy, Oncology and Nuclear Medicine Instituto Medico La Floresta Central University Caracas Venezuela DR. NELSONURDANETA Dept. of Therapeutic Radiology Yale University School of Medicine 333 Cedar St. New Haven. CT 065 10 1. Avilan, R. J. Mortalidad por cancer en Venezuela. In: Vera, R., Palacios, L. E., Urdaneta, N., Scannone, F., eds. Cancer al dia, Vol 1. 2nd edition. Caracas: S.A. 1.0. Fundacancer: 1982:1-6. 2. crdaneta, N.; Millan, R.; Rodriquez, A. I. Es&do a&al de la radioterapia en Venezuela (In press). 3. Vera, R. Why CRILA? Int. J. Radiat. Oncol. Biol. Phys. 4525-526; 1978. LINAC PERFORMANCE DURING SHORT IRRADIATIONS To the Editor: In the October issue of this journal, Ohara et al. (2) describe how a lung tumor may move up and down with respiration thus occupying a greater volume than if it were stationary. Instead of using a field that is large enough to cover the tumor throughout its range of travel, they suggest gating the patient’s respiration to the Linac in such a way as to turn the radiation on and off so that the tumor is irradiated only when it is positioned in the center of a somewhat smaller field. There are two issues which should be examined in a critical analysis of this paper. First, is the reduction by a few centimeters in the field length of a patient with a lung tumor of sufficient clinical significance to justify the complexity (and expense) of their system? As a physicist, it would be presumptuous of me to answer this question. Second, can operating a medical Linac by turning it off and on in this way lead to significant errors in dose delivery compared with the usual sort of irradiation? The authors report that the variation in beam flatness for their accelerator could be +-4.5% with 3 mu dose fractions. A 9% variation across the tumor volume might be more problematic for the patient than using a field 2 cm larger. In fairness, not all accelerators have such problems in short irradiations. It is the purpose of this letter to serve as a reminder that operating a Linac for only a few monitor units, whether for this purpose, for film dosimetry, or for compensator construction requires special attention to the performance of the machine during short irradiations. ROBERTJ. BARISH,PH.D. Division of Radiation Oncology New York University Medical Center New York, NY 10016 1. Barish, R. J.; Fleischman, R. C.; Pipman, Y. M. Teletherapy beam characteristics: the first second. Med. Phys. 14657-66 1; 1987. 2. Ohara, K.; Okumara, T.; Akisada, M.; Inada, T.; Mori, T.; Yokota, H.; Calaguas, M. J. B. Irradiation synchronized with respiration gate. Int. J. Radiat. Oncol. Biol. Phys. 17:OOOO-0000;1989.
I. J. Radiation Oncology 0 Biology 0 Physics
the parenchymal cells (3). In retrospect, we should expect a disease which manifests itself in damage to small blood vessels to place a patient at greater susceptibility to damage from radiation. Collagen vascular diseases thus join certain other diseases or conditions which merit enquiry in taking the history in that they increase the risk of incurring serious complications by irradiation: diabetes mellitus (4), hypertension (4), pelvic inflammatory disease (6), or prior abdominal surgery (5, 7). RICHARDH. MATTHEWS,PH.D., M.D. Phelps County Regional Medical Center 1000 West Tenth Street Rolla, MO 65401 I. Fleck, R. S.; McNeese, M. D.; Ellerbroek, N. A.; Hunter, T. A.:
2.
3. 4. 5.
6.
7.
8.
Montague, E. D. Complications of radiation therapy for breast cancer in women with preexisting collagen vascular disease. Int. J. Radiat. Oncol. Biol. Phys. lS(Suppl. 1):155; 1988. Gilliland, B. C.; Mannik, M. Progressive systemic sclerosis (diffuse scleroderma), In: Isselbacher, K. J., Adams, R. D., Braunwald, E., Petersdorf, R. G., Wilson, J. D., eds. Harrison’s principles of internal medicine, 9th edition. New York: McGraw-Hill; 1980. Hall, E. J. Radiobiology for the radiologist, 3rd edition. Philadelphia: Lippincott; 1988. Harwood, A. R.; Tierie, A. Radiotherapy of early glottic cancerII. Int. J. Radiat. Oncol. Biol. Phys. 5:477-482; 1979. Jampolis, S.; Martin, P.; Schroder, P.; Horiot, J. C. Treatment tolerance and early complications with extended field irradiation in gynaecological cancer. Br. J. Radiol. 50:195-199; 1977. O’Quinn, A. G.; Fletcher, G. H.; Wharton, J. T. Guidelines for conservative hysterectomy after irradiation. Gynecol. Oncol. 9:68-79; 1980. Pilepich, M. V.; Perez, C. A.; Walz, B. J.; Zivnuska, F. R. Complications of definitive radiotherapy for carcinoma of the prostate. Int. J. Radiat. Oncol. Biol. Phys. 7: 134 I- 1348; 198 1. Robinson, D. R. Scleroderma. In: Rubenstein, E., Federman, D. D., eds. Scientific american medicine, Vol. 15. New York: Scientific American Inc.; 1984:1-7.
THE DEBT, THE GAP AND CRILA: RADIOTHERAPY IN LATIN AMERICA To the Editor:The practice of radiotherapy in Latin American countries encounters many difficulties due to the high technological requirements of this medical field. The increasing economic problems of our nations, reflected in an oppressive external debt, have aggravated the situation. The social and cultural conditions of most of our patients certainly do not make this worrisome reality any better. Also, there is a significant difference in the incidence of the different types of cancer in the developing countries; for instance, cancer of the cervix and gastric cancer constitute the most frequent tumors with a high mortality rate in many areas (1). The many problems that confront the radiotherapist in Latin America gave origin to CRILA (Iberian Latin American Circle of Radiation Oncology) in 197 1 (3). This radiotherapy circle has been very active since its inception, and up to this time it has conducted six international meetings with the collaboration of many internationally known radiation oncologists. The cooperation of the Latin American colleagues who practice in the United States has been of special value. They are convinced of the necessity of creating a communication channel and establishing a technological bridge between the developed nations where they practice and their native countries. At the last CRILA meeting held in 1987 in Uruguay, we had the opportunity to share many ideas and experiences with our colleagues in the search of possible solutions to our common problems. The supervoltage unit most used in our countries is the wCo machine. Low energy linear accelerators (4-6 MeV) are available at some centers. Electron beam therapy exists in very few centers, and therapy with photons of higher energy and heavy particles is virtually nonexistent. Hyperthermia in association with radiation therapy is not practiced in any institution. Fortunately, the most frequent tumors that affect the population of our countries can be treated adequately with 6oCo gamma rays and brachytherapy with cesium using afterloading techniques. The medical personnel and radiation technologists are capable of administering radiotherapy with this equipment. Our efforts should be directed towards quality control of the specialty. We need help in the areas of radiation
November 1989, Volume 17, Number 5 physics and dosimetry, and there is a great need to install new equipment, such as computers for treatment planning, and simulators. These are our basic needs, since the scientific knowledge of the radiotherapists in Spain and Latin America has been maintained due in great part to the efforts of the members of CRILA who have contributed to the success of our periodic meetings. The recommendations and conclusions that emanate from the CRILA meetings should be conveyed to the public authorities, who have to be adequately informed of the radiotherapy situation in each country. In a recent survey conducted in Venezuela (2), all the public radiotherapy centers were visited and specific recommendations to improve the quality of the specialty were made. The next CRILA meeting will be held in 1989 in Venezuela (Barcelona) where CRILA was founded in 197 1. We want to extend a cordial invitation to all the members of ASTRO to visit us during that important event, and to bring new ideas to better the practice of radiotherapy in our countries. Our local office in Caracas can furnish further information: Dr. Raul Vera Vera, Apartado 600.006, Zona Postal 1061, Caracas, Venezuela. DR. RAUL VERA VERA Dept. of Radiotherapy, Oncology and Nuclear Medicine Instituto Medico La Floresta Central University Caracas Venezuela DR. NELSONURDANETA Dept. of Therapeutic Radiology Yale University School of Medicine 333 Cedar St. New Haven. CT 065 10 1. Avilan, R. J. Mortalidad por cancer en Venezuela. In: Vera, R., Palacios, L. E., Urdaneta, N., Scannone, F., eds. Cancer al dia, Vol 1. 2nd edition. Caracas: S.A. 1.0. Fundacancer: 1982:1-6. 2. crdaneta, N.; Millan, R.; Rodriquez, A. I. Es&do a&al de la radioterapia en Venezuela (In press). 3. Vera, R. Why CRILA? Int. J. Radiat. Oncol. Biol. Phys. 4525-526; 1978. LINAC PERFORMANCE DURING SHORT IRRADIATIONS To the Editor: In the October issue of this journal, Ohara et al. (2) describe how a lung tumor may move up and down with respiration thus occupying a greater volume than if it were stationary. Instead of using a field that is large enough to cover the tumor throughout its range of travel, they suggest gating the patient’s respiration to the Linac in such a way as to turn the radiation on and off so that the tumor is irradiated only when it is positioned in the center of a somewhat smaller field. There are two issues which should be examined in a critical analysis of this paper. First, is the reduction by a few centimeters in the field length of a patient with a lung tumor of sufficient clinical significance to justify the complexity (and expense) of their system? As a physicist, it would be presumptuous of me to answer this question. Second, can operating a medical Linac by turning it off and on in this way lead to significant errors in dose delivery compared with the usual sort of irradiation? The authors report that the variation in beam flatness for their accelerator could be +-4.5% with 3 mu dose fractions. A 9% variation across the tumor volume might be more problematic for the patient than using a field 2 cm larger. In fairness, not all accelerators have such problems in short irradiations. It is the purpose of this letter to serve as a reminder that operating a Linac for only a few monitor units, whether for this purpose, for film dosimetry, or for compensator construction requires special attention to the performance of the machine during short irradiations. ROBERTJ. BARISH,PH.D. Division of Radiation Oncology New York University Medical Center New York, NY 10016 1. Barish, R. J.; Fleischman, R. C.; Pipman, Y. M. Teletherapy beam characteristics: the first second. Med. Phys. 14657-66 1; 1987. 2. Ohara, K.; Okumara, T.; Akisada, M.; Inada, T.; Mori, T.; Yokota, H.; Calaguas, M. J. B. Irradiation synchronized with respiration gate. Int. J. Radiat. Oncol. Biol. Phys. 17:OOOO-0000;1989.