C a se Report Respiration 1992:59:181-184
Pulmonary Department, Army General Hospital, Athens; University of Crete Medical School, Heraklion, Crete, Greece
Mediastinal Fibrosis and Radiofrequency Radiation Exposure: Is There an Association?
Key Words
Abstract
Idiopathic mediastinal fibrosis Fibrosing mediastinitis Sclerosing mediastinitis Radiofrequcncy radiation Microwave radiation
A 45-year-old officer, working for a period of 18 years at a military radar base, presented with progressive exertional dyspnea, dry cough, and hemoptysis. Subsequent evaluation demonstrated a left pulmonary artery occlusion as well as a left upper lobe bronchus stenosis, due to a dense fibrotic mediastinal mass. Histologically, this proved to be idiopathic mediastinal fibrosis (IMF). The development of IMF in a man exposed for a long period to radio-fre quency radiation (RFR) is unique in the literature in English. The possible association of radiation exposure with IMF is discussed.
Idiopathic mediastinal fibrosis (IMF) is a very rare con dition characterized by formation of a dense fibrotic mass within the mediastinum. This condition results in a multi tude of clinical syndromes due to entrapment and erosion of mediastinal vital structures. We describe a patient who presented with IMF after long-term exposure to radiofre quency radiation (RFR) from radar antennas and associ ated equipment. This case appears to be unique in the lit erature in English.
Case Report A 45-year-old officer was admitted to our hospital with mild he moptysis and abnormal chest X-rays. He had a 5-month history of progressive exertional dyspnea, dry cough, and wheezing. His past medical history included diplopia in 1973. treated with corticoste roids and cured I year later. He is a smoker (24 pack years) and has worked at a military radar base for the last 18 years. On physical ex amination he was dyspneic. with decreased breath sounds in the left hemithorax. A chest roentgenogram showed left hilar enlargement
Received: June 28.1991 Accepted after revision: January 30.1992
with lingular collapse and elevation of the left hemidiaphragm (fig. 1). Routine hematologic and urinary studies, as well as electro cardiographic and echocardiographic findings, were normal. Ra test, Le cells, antinuclear antibodies, and anti-DNA were negative. Mul tiple sputum cytologic studies, special stains, and cultures for acidfast bacilli and various fungi were negative. R. Mantoux PPD RT 23 (2 IU) was positive (45 mm). Arterial blood gas analysis (FiO , 21%) showed a P(), of 86 mm Hg, P((), 40 mm Hg, and a pH of 7.46. Pulmonary function studies disclosed a mild obstructive defect: FVC 3,300 ml (78% predicted). FEV /FV C 0.70 (predicted 0.82), TLC 5.6(H) ml (90% predicted), RV/TLC 0.41 (predicted 0.31), DLCOs„ 8.2 mmol/M • KPA (predicted 10.3), airway resistance (shut ter method) 0.38 KPA • S/L (normal 0.15-0.30). Fiberoptic bronchoscopy showed narrowing of the left upper lobe bronchus (> 50%) and a broadening of the secondary Carina between the left upper and lower bronchi by an extrabronchial process. Cy tologic, histologic, and microbiologic studies of bronchoscopic speci mens were negative. Repeated bronchoscopy failed to reveal any ad ditional information. Evaluation by computed tomography showed narrowing of the left upper lobe bronchus, with segmental densities extending to the left hilum (fig. 2). Magnetic resonance imaging confirmed the com puted tomography findings and also revealed a narrowing of the left
L. Papandreou, MD Asteriou 2. Goudi 157 73 Athens (Greece)
© 1992S. Karger AG. Basel 0025-7931/92.3)50.^-0! Hl $ 2.75/0
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
L. Papandreow' P. Panagoua D. Bouros3h
Fig. 3. Magnetic resonance imaging. Narrowing of the left pulmo nary artery (arrow).
Fig. 2. Computed tomography. Segmental densities of the left up per lobe, extending to the left hilum, and lingular collapse.
182
Fig. 4. Digital subtraction angiography. Significant occlusion of the left pulmonary artery (arrow) with poor perfusion of the left lung.
Papandrcou/Panagou/Bouros
Mediastinal Fibrosis and Radiofrcquency Radiation Exposure
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
main pulmonary artery (fig. 3). A vcntilation/perfusion lung scan demonstrated a significant reduction of the left lung perfusion matched to ventilation. Digital subtraction angiography revealed a remarkable occlusion of the left main pulmonary artery with poor perfusion of the left lung (fig. 4.). An explorative left thoracotomy revealed external compression and erosion of left main pulmonary artery, left upper lobe bronchus, pericardium, and aorta by a mediastinal mass of dense fibrotic tissue. Histologically, this mass was composed of intervening and thick bun dles of dense collagen infiltrated by a large number of plasma cells, some lymphocytes, and occasional eosinophils and histiocytes. Tissue stains and cultures were negative for acid-fast bacilli and fungi.
Discussion IMF is a very rare benign disease characterized by for mation of a remarkably dense fibrous tissue within the mediastinum. Symptoms result from compression and erosion of mediastinal vital structures, such as superior vena cava, pulmonary arteries and veins, bronchi, pericar dium, and esophagus. The most frequent initial com plaints are cough, dyspnea, and hemoptysis, as in our pa tient. Pleuritic chest pain, recurrent pulmonary infections, fever, wheezing, weight loss, superior vena cava syndrome, and dysphagia are less common. The chest radiographic manifestations are mediastinal widening and/or hilar enlargement and, less commonly, pulmonary infiltrates, atelectasis, pleural effusion, and Kerley B lines. Computed tomography usually shows bronchial narrowing and also reveals calcifications that are not apparent on conventional X-rays [1]. Magnetic res onance imaging demonstrates the relationship of the ma jor vascular structures to the fibrosing process [2], Ventilation/perfusion lung scanning usually discloses large perfu sion defects. The pulmonary angiogram may mimic thrombotic obstruction. To establish the diagnosis, open biopsy is indicated. Histologically, the fibrotic mass is composed of hypoceliular collagenous fibrous tissue infiltrated by a large number of plasma cells and smaller numbers of lymphocytes and histiocytes [3,4], Owing to the small number of cases, no controlled trials exist for medical therapy in IMF. Since there is no evi dence of active infection, treatment with antibiotics or an tifungal agents is not indicated. Corticosteroid therapy does not appear to be of any benefit. Radiotherapy is con traindicated, as it may promote a further fibrotic reaction. Surgical treatm ent is generally unsuccessful, because it is technically difficult and hazardous. Therefore, surgery is recommended only when there is a risk to life from pres sure on involved mediastinal structures. A few cases of successful operations have been reported [5, 6], The clinical, radiologic, and histologic features of IMF are similar to those of ‘secondary mediastinal fibrosis’. This latter entity is more common and develops as a reac tion to certain infections (in most cases histoplasmosis, but also tuberculosis, aspergillosis, and syphilis) [7], How
ever, the presence of organisms was histologically demon strated only in 2 out of 6 cases by Dunn et al. [6], in 39 out of 71 cases by Loyd et al. [7], and in 3 out of 77 ca ses by Schowengerdt et al. [8]. The etiology of IMF, as reflected in the term ‘idio pathic’, is unknown. Various factors have been implicated, such as chronic infection, repeated trauma, methysergide, certain malignancies, and autoimmune processes [3], An abnormal immune response or hypersensitivity to an un known antigen seems to be the most probable hypothesis. The great similarity of IMF to other idiopathic forms of fi brosis (such as retroperitoneal fibrosis, Riedel’s thyroid itis, and sclerosing cholangitis) and the coincindence of two or more of these rare conditions in 1patient [9,10] sug gest that they all may be different manifestations of a sin gle disease. Involvement of more than one organ has been termed ‘multifocal fibrosclerosis’ [9], The search for other organ involvement in our patient was negative. RFR is nonionizing electromagnetic energy at frequen cies between 0 and 3 *1012 Hz. (Frequencies from 300 MHz to 300 GHz are called microwaves.) Radiofrequencies from 500 kHz to 100 GHz are generated by sources such as radio and television broadcast antennas, radar antennas, mobile and hand-held radio transmitters, and satellite communication facilities [11]. At sufficiently high intensities (> 1 mW/cm2), exposure to RFR can produce a variety of adverse health effects, such as cataracts of the eye, overloading of the thermoreg ulatory response, thermal injury, convulsions, altered be havioral patterns, and decreased endurance [12]. The sci entific and medical literature does not contain plentiful data about the clinical histories of those linked with expo sure to RFR, because such a case history may be recog nized but not published. Besides, no relationship is estab lished between pathology and RFR exposure [13], Only a few cases of injuries resulting from exposure to RFR have been reported [13—15]. A possible association of IMF with radiation exposure has never been reported in the literature in English. Our patient was frequently, and without protection, exposed for a 18-year period to RFR from radar antennas (im proved high-powered illuminator radar) and associated equipment. It is known that RFR is not cumulative, al though it can be hazardous. A power intensity of at least 1 mW/cm2 (which is the maximum permissible exposure lev el for personnel) is present along the axis of the above an tenna, for a distance of 111.5 m. This distance is based on calculations and actual measurements and may be used as a guide to prevent RFR damage. Although personnel are restricted from entering the area on top of the radars in
183
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
The diagnosis of IMF was made which was also confirmed at the Flinders Medical Center. South Australia (Dr. Douglas W. Hender son). F'urther evaluation for retroperitoneal fibrosis, sclerosing cholangiitis. and Riedel’s thyroiditis was negative.
front of the antenna when radiating, our patient fre quently entered it. It is possible that there is a relationship between IMF and RFR. Further studies on persons exposed to RFR, as well as on patients with IMF, are needed to examine if such a relationship exists.
Acknowledgment We are indebted to Dr. Douglas W. Henderson, Associate Profes sor and Chief of the Department of Pathology, Flinders Medical Center, Adelaide, South Australia, for reviewing the histological slides.
1 Weinstein JB. Aronberg DJ. Sagel SS: CT of fi brosing mediastinitis: Findings and their utility. AJR 1983;141:247-251. 2 Rholl KS, Levitt RG. Glazcr HS: Magnetic res onance imaging of fibrosing mediastinitis. AJR 1985;145:255-259. 3 Light AM: Idiopathic fibrosis of mediastinum: A discussion of three cases and review of the literature. J Clin Pathol 1978;31:78-88. 4 Sobrinho-Simocs MA, Vaz Salciro J. Wagenvoort CA: Mediastinal and hilar fibrosis. Histopathology 1981:5:53-60. 5 Mitchell IM, Saunders NR. Maher O, Lennox SC, Walker DR: Surgical treatment of idio pathic mediastinal fibrosis: Report of fivecases. Thorax 1986;41:210-214. 6 Dunn EJ, Ulicny KS. Wright CB. Cottcsman L: Surgical implications of sclerosing mediasti nitis: A report of six cases and review of the lit erature. Chest 1990;97:338-346.
7 Loyd JE, Tillman BF. Atkinson JB, Des Prez RM: Mediastinal fibrosis complicating histo plasmosis. Medicine (Baltimore) 1988:67:295310. 8 Schowengerdt CG. Suyemoto R. Main FB: Granulomatous and fibrous mediastinitis: A review and analysis of 180 cases. J Thorac Cardiovasc Surg 1969;57:365-379. 9 Comings DE, Skubi KB. Van Eyes J. Motulsv AG: Familial multifocal fibrosclerosis. Ann In tern Med 1967;66:884-892. 10 Hanley PC. Shub C. Lie JT: Constrictive peri carditis associated with combined idiopathic and mediastinal fibrosis. Mayo Clin Proc 1984; 59:300-304. 11 Elder JA: Radiofrequency radiation activities and issues: A 1986 perspective. Health Phys 1987;53:607-611.
12 1RPA/INIRC: Guidelines on limits of exposure to radiofrequency electromagnetic fields in the frequency range from 100 kHz to 300 GHz. Health Phys 1988;54:115-123. 13 Servantie B: Damage criteria for determining microwave exposure. Health Phys 1989;56:781786. 14 McLaughlin JT: Tissue destruction and death from microwave radiation (radar). Calif Med 1957,86:336-339. 15 Castillo M. Quencer RM: Sublethal exposure to microwave radar. JAMA 1988:259:355.
184
Papandreou/Panagou/Bouros
Mediastinal Fibrosis and Radiofrcqucncy Radiation Exposure
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
References
Pulmonary Department, Army General Hospital, Athens; University of Crete Medical School, Heraklion, Crete, Greece
Mediastinal Fibrosis and Radiofrequency Radiation Exposure: Is There an Association?
Key Words
Abstract
Idiopathic mediastinal fibrosis Fibrosing mediastinitis Sclerosing mediastinitis Radiofrequcncy radiation Microwave radiation
A 45-year-old officer, working for a period of 18 years at a military radar base, presented with progressive exertional dyspnea, dry cough, and hemoptysis. Subsequent evaluation demonstrated a left pulmonary artery occlusion as well as a left upper lobe bronchus stenosis, due to a dense fibrotic mediastinal mass. Histologically, this proved to be idiopathic mediastinal fibrosis (IMF). The development of IMF in a man exposed for a long period to radio-fre quency radiation (RFR) is unique in the literature in English. The possible association of radiation exposure with IMF is discussed.
Idiopathic mediastinal fibrosis (IMF) is a very rare con dition characterized by formation of a dense fibrotic mass within the mediastinum. This condition results in a multi tude of clinical syndromes due to entrapment and erosion of mediastinal vital structures. We describe a patient who presented with IMF after long-term exposure to radiofre quency radiation (RFR) from radar antennas and associ ated equipment. This case appears to be unique in the lit erature in English.
Case Report A 45-year-old officer was admitted to our hospital with mild he moptysis and abnormal chest X-rays. He had a 5-month history of progressive exertional dyspnea, dry cough, and wheezing. His past medical history included diplopia in 1973. treated with corticoste roids and cured I year later. He is a smoker (24 pack years) and has worked at a military radar base for the last 18 years. On physical ex amination he was dyspneic. with decreased breath sounds in the left hemithorax. A chest roentgenogram showed left hilar enlargement
Received: June 28.1991 Accepted after revision: January 30.1992
with lingular collapse and elevation of the left hemidiaphragm (fig. 1). Routine hematologic and urinary studies, as well as electro cardiographic and echocardiographic findings, were normal. Ra test, Le cells, antinuclear antibodies, and anti-DNA were negative. Mul tiple sputum cytologic studies, special stains, and cultures for acidfast bacilli and various fungi were negative. R. Mantoux PPD RT 23 (2 IU) was positive (45 mm). Arterial blood gas analysis (FiO , 21%) showed a P(), of 86 mm Hg, P((), 40 mm Hg, and a pH of 7.46. Pulmonary function studies disclosed a mild obstructive defect: FVC 3,300 ml (78% predicted). FEV /FV C 0.70 (predicted 0.82), TLC 5.6(H) ml (90% predicted), RV/TLC 0.41 (predicted 0.31), DLCOs„ 8.2 mmol/M • KPA (predicted 10.3), airway resistance (shut ter method) 0.38 KPA • S/L (normal 0.15-0.30). Fiberoptic bronchoscopy showed narrowing of the left upper lobe bronchus (> 50%) and a broadening of the secondary Carina between the left upper and lower bronchi by an extrabronchial process. Cy tologic, histologic, and microbiologic studies of bronchoscopic speci mens were negative. Repeated bronchoscopy failed to reveal any ad ditional information. Evaluation by computed tomography showed narrowing of the left upper lobe bronchus, with segmental densities extending to the left hilum (fig. 2). Magnetic resonance imaging confirmed the com puted tomography findings and also revealed a narrowing of the left
L. Papandreou, MD Asteriou 2. Goudi 157 73 Athens (Greece)
© 1992S. Karger AG. Basel 0025-7931/92.3)50.^-0! Hl $ 2.75/0
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
L. Papandreow' P. Panagoua D. Bouros3h
Fig. 3. Magnetic resonance imaging. Narrowing of the left pulmo nary artery (arrow).
Fig. 2. Computed tomography. Segmental densities of the left up per lobe, extending to the left hilum, and lingular collapse.
182
Fig. 4. Digital subtraction angiography. Significant occlusion of the left pulmonary artery (arrow) with poor perfusion of the left lung.
Papandrcou/Panagou/Bouros
Mediastinal Fibrosis and Radiofrcquency Radiation Exposure
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
main pulmonary artery (fig. 3). A vcntilation/perfusion lung scan demonstrated a significant reduction of the left lung perfusion matched to ventilation. Digital subtraction angiography revealed a remarkable occlusion of the left main pulmonary artery with poor perfusion of the left lung (fig. 4.). An explorative left thoracotomy revealed external compression and erosion of left main pulmonary artery, left upper lobe bronchus, pericardium, and aorta by a mediastinal mass of dense fibrotic tissue. Histologically, this mass was composed of intervening and thick bun dles of dense collagen infiltrated by a large number of plasma cells, some lymphocytes, and occasional eosinophils and histiocytes. Tissue stains and cultures were negative for acid-fast bacilli and fungi.
Discussion IMF is a very rare benign disease characterized by for mation of a remarkably dense fibrous tissue within the mediastinum. Symptoms result from compression and erosion of mediastinal vital structures, such as superior vena cava, pulmonary arteries and veins, bronchi, pericar dium, and esophagus. The most frequent initial com plaints are cough, dyspnea, and hemoptysis, as in our pa tient. Pleuritic chest pain, recurrent pulmonary infections, fever, wheezing, weight loss, superior vena cava syndrome, and dysphagia are less common. The chest radiographic manifestations are mediastinal widening and/or hilar enlargement and, less commonly, pulmonary infiltrates, atelectasis, pleural effusion, and Kerley B lines. Computed tomography usually shows bronchial narrowing and also reveals calcifications that are not apparent on conventional X-rays [1]. Magnetic res onance imaging demonstrates the relationship of the ma jor vascular structures to the fibrosing process [2], Ventilation/perfusion lung scanning usually discloses large perfu sion defects. The pulmonary angiogram may mimic thrombotic obstruction. To establish the diagnosis, open biopsy is indicated. Histologically, the fibrotic mass is composed of hypoceliular collagenous fibrous tissue infiltrated by a large number of plasma cells and smaller numbers of lymphocytes and histiocytes [3,4], Owing to the small number of cases, no controlled trials exist for medical therapy in IMF. Since there is no evi dence of active infection, treatment with antibiotics or an tifungal agents is not indicated. Corticosteroid therapy does not appear to be of any benefit. Radiotherapy is con traindicated, as it may promote a further fibrotic reaction. Surgical treatm ent is generally unsuccessful, because it is technically difficult and hazardous. Therefore, surgery is recommended only when there is a risk to life from pres sure on involved mediastinal structures. A few cases of successful operations have been reported [5, 6], The clinical, radiologic, and histologic features of IMF are similar to those of ‘secondary mediastinal fibrosis’. This latter entity is more common and develops as a reac tion to certain infections (in most cases histoplasmosis, but also tuberculosis, aspergillosis, and syphilis) [7], How
ever, the presence of organisms was histologically demon strated only in 2 out of 6 cases by Dunn et al. [6], in 39 out of 71 cases by Loyd et al. [7], and in 3 out of 77 ca ses by Schowengerdt et al. [8]. The etiology of IMF, as reflected in the term ‘idio pathic’, is unknown. Various factors have been implicated, such as chronic infection, repeated trauma, methysergide, certain malignancies, and autoimmune processes [3], An abnormal immune response or hypersensitivity to an un known antigen seems to be the most probable hypothesis. The great similarity of IMF to other idiopathic forms of fi brosis (such as retroperitoneal fibrosis, Riedel’s thyroid itis, and sclerosing cholangitis) and the coincindence of two or more of these rare conditions in 1patient [9,10] sug gest that they all may be different manifestations of a sin gle disease. Involvement of more than one organ has been termed ‘multifocal fibrosclerosis’ [9], The search for other organ involvement in our patient was negative. RFR is nonionizing electromagnetic energy at frequen cies between 0 and 3 *1012 Hz. (Frequencies from 300 MHz to 300 GHz are called microwaves.) Radiofrequencies from 500 kHz to 100 GHz are generated by sources such as radio and television broadcast antennas, radar antennas, mobile and hand-held radio transmitters, and satellite communication facilities [11]. At sufficiently high intensities (> 1 mW/cm2), exposure to RFR can produce a variety of adverse health effects, such as cataracts of the eye, overloading of the thermoreg ulatory response, thermal injury, convulsions, altered be havioral patterns, and decreased endurance [12]. The sci entific and medical literature does not contain plentiful data about the clinical histories of those linked with expo sure to RFR, because such a case history may be recog nized but not published. Besides, no relationship is estab lished between pathology and RFR exposure [13], Only a few cases of injuries resulting from exposure to RFR have been reported [13—15]. A possible association of IMF with radiation exposure has never been reported in the literature in English. Our patient was frequently, and without protection, exposed for a 18-year period to RFR from radar antennas (im proved high-powered illuminator radar) and associated equipment. It is known that RFR is not cumulative, al though it can be hazardous. A power intensity of at least 1 mW/cm2 (which is the maximum permissible exposure lev el for personnel) is present along the axis of the above an tenna, for a distance of 111.5 m. This distance is based on calculations and actual measurements and may be used as a guide to prevent RFR damage. Although personnel are restricted from entering the area on top of the radars in
183
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
The diagnosis of IMF was made which was also confirmed at the Flinders Medical Center. South Australia (Dr. Douglas W. Hender son). F'urther evaluation for retroperitoneal fibrosis, sclerosing cholangiitis. and Riedel’s thyroiditis was negative.
front of the antenna when radiating, our patient fre quently entered it. It is possible that there is a relationship between IMF and RFR. Further studies on persons exposed to RFR, as well as on patients with IMF, are needed to examine if such a relationship exists.
Acknowledgment We are indebted to Dr. Douglas W. Henderson, Associate Profes sor and Chief of the Department of Pathology, Flinders Medical Center, Adelaide, South Australia, for reviewing the histological slides.
1 Weinstein JB. Aronberg DJ. Sagel SS: CT of fi brosing mediastinitis: Findings and their utility. AJR 1983;141:247-251. 2 Rholl KS, Levitt RG. Glazcr HS: Magnetic res onance imaging of fibrosing mediastinitis. AJR 1985;145:255-259. 3 Light AM: Idiopathic fibrosis of mediastinum: A discussion of three cases and review of the literature. J Clin Pathol 1978;31:78-88. 4 Sobrinho-Simocs MA, Vaz Salciro J. Wagenvoort CA: Mediastinal and hilar fibrosis. Histopathology 1981:5:53-60. 5 Mitchell IM, Saunders NR. Maher O, Lennox SC, Walker DR: Surgical treatment of idio pathic mediastinal fibrosis: Report of fivecases. Thorax 1986;41:210-214. 6 Dunn EJ, Ulicny KS. Wright CB. Cottcsman L: Surgical implications of sclerosing mediasti nitis: A report of six cases and review of the lit erature. Chest 1990;97:338-346.
7 Loyd JE, Tillman BF. Atkinson JB, Des Prez RM: Mediastinal fibrosis complicating histo plasmosis. Medicine (Baltimore) 1988:67:295310. 8 Schowengerdt CG. Suyemoto R. Main FB: Granulomatous and fibrous mediastinitis: A review and analysis of 180 cases. J Thorac Cardiovasc Surg 1969;57:365-379. 9 Comings DE, Skubi KB. Van Eyes J. Motulsv AG: Familial multifocal fibrosclerosis. Ann In tern Med 1967;66:884-892. 10 Hanley PC. Shub C. Lie JT: Constrictive peri carditis associated with combined idiopathic and mediastinal fibrosis. Mayo Clin Proc 1984; 59:300-304. 11 Elder JA: Radiofrequency radiation activities and issues: A 1986 perspective. Health Phys 1987;53:607-611.
12 1RPA/INIRC: Guidelines on limits of exposure to radiofrequency electromagnetic fields in the frequency range from 100 kHz to 300 GHz. Health Phys 1988;54:115-123. 13 Servantie B: Damage criteria for determining microwave exposure. Health Phys 1989;56:781786. 14 McLaughlin JT: Tissue destruction and death from microwave radiation (radar). Calif Med 1957,86:336-339. 15 Castillo M. Quencer RM: Sublethal exposure to microwave radar. JAMA 1988:259:355.
184
Papandreou/Panagou/Bouros
Mediastinal Fibrosis and Radiofrcqucncy Radiation Exposure
Downloaded by: UCL 144.82.238.225 - 5/6/2018 8:22:31 AM
References
