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Complications Associated with Brachytherapy Alone or with Laser in Lung Cancer
clinical investigations Complications Brachytherapy Cancer*
Associated with Alone or with Laser in Lung
Barbara Khanavkar, M.D.;t Petra Stem, M.D.;* Winfried Alberti, M.D.;* and john A. Nakhosteen, M.D., F.C.C.P.t
Relatively little has been reported about destruction through brachytherapy of mucosa-perforating and extraluminary tumors with probable large vessel involvement causing major hemorrhagic or fistular complications. We report 12 patients subjected to laser and brachytherapy for centrally occluding lung cancer, whom we have periodically followed up from June 1986 until they died. Although all laser procedures were free from complications, necrotic cavitation in five cases, two of which were accompanied by large bronchoesophageal fistulas, and massive fatal hemoptysis occurred in six. Minor complications included radiation mucositis (two), noncritical mucosal scarring (two), and
cough (four). Characteristics that will identify patients at risk of developing fatal hemoptysis and fistulas should be better defined by imaging and endoscopic techniques. In such cases, modifying the protocol or using alternative procedures should be considered. Minor complications, such as cough, can be avoided by using topical steroid therapy (eg, beclomethasone dipropionate).
Endobronchial brachytherapy alone or combined with laser vaporization is used increasingly for palliation in recurrent central lung tumors after exhaustion of all other therapeutic measures. 1"3 Shortterm results emphasizing symptomatic and lung function improvement are reported as good, and complications, relatively few. 4 •5 Patients are usually referred to pulmonary centers, and an indefinite number may be lost to follow-up. We report 12 patients treated with 192lr high-dose brachytherapy, five combined with laser resection, for their centrally occluding recurrent bronchial tumors seen in our department from June 1986, until December 1989 and whom we followed until they died.
took place at the pulmonary department at Augusta Teaching Hospital; irradiation treatment was conducted at the department for radiotherapy at the Kmpp Hospital. Following premedication with pethidine, 50 mg, and atropine, 0.5 mg, a flexible bronchoscope was introduced transorally under topical anesthesia and used to intubate a 9 mm endotracheal tube. The further procedure, reported in detail by Alberti et al,• is, in brief, as follows: a 4-mm blind catheter was introduced through the ETT and is positioned adjacent to the tumor ascertained using the bronchoscope. The guide tube then was anchored and its proximal end connected to the '"'lr source (initial activity: 370 GBq or 10 Ci resp, Gamma Med IIi, Isotopentechnik Dr. Sauerwein, Haan, FRG). Through this remote-controlled afterloading device, the 1112 lr capsule (diameter 1.1 mm) was advanced through the guide catheter and withdrawn stepwise in 5 mm increments over the desired distance, delivering a calculated dose of 8 Gy at a tissue depth of 5 mm in one 2 to 4 min session. Patients received two to eight sessions (average 5.5) timed at weekly or fortnightly intervals (average every ninth day); the average cumulative dose was 43.6 Gy. Details on total dose and length of irradiated bronchus are specified in Table 1. Previous laser therapy was performed Q.A.N .) with a neodymiumYAG laser using standard procedures.
PATIENTS AND METHODS
Twelve patients (ten men, two women, age 39 to 80 years) with centrally occluding bronchial tumors (ten squamous cell carcinomas, one adenosquamous carcinoma and one adenoid-cystic carcinoma) were selected for endobronchial irradiation. Tumor had recurred in 11 patients previously treated (percutaneous irradiation of 54 to 60 Gy 3 to 24 months prior) and had progressed in one patient with inoperable carcinoma and severe COLD not previously treated. Laser recanalization was performed in five patients prior to brachytherapy. Initial work-up, laser therapy, and posttreatment follow-up *From tAugusta Teaching Hospital, Bochum Germany; and :j:Kmpp von Bohlen und Halbach Teaching Hospital, Essen Germany. Manuscript received June 4; revision accepted October 18. Reprint requests: Dr: Naklwsteen, Bergstr 26, 4630 Bochum, Germany
1062
(Chest 1991; 99:1062-65) ETT =endotracheal tube; DSA =digital subtraction angiography
REsuLTS
Follow-up bronchoscopies showed good tumor regression in all patients until their time of death. Slow recurrence was seen in one patient seven months after therapy, and sustained tumor control persisted in a patient surviving for 24 months. Whereas eight patients reported improvement of symptoms (cough and dyspnea), objective improvement oflung function was inconsistent: FEV 1 and VC increased significantly (15 Brachytherapy and Laser in Lung Cancer (Khanavlcar at a/)
Table I-Dose and Irradiated Bronchial Length* Patients with Major Complications
23456789
Patients Without Major Complications
10
11 12
Radiation dose 48 64 32 32 56 16 16 56 64 48 32 48 at5mm tissue depth, Gy Length of 5466473343 .5 3 3 irradiated bronchus, em Average, Gy/cm 37.715.3 49.613.5 *Major complication appear more closely associated to lengths irradiated than to total dose.
percent) in 5 of 12 patients, hypercapnea but not hypoxemia improved in three. Minimal complications included radiation mucositis in two patients and temporary increase of cough in four patients. Noncritical bronchial stenosis through scar formation in bronchial mucosa adjacent to the irradiated tumors constituted a minor late complication. Serious complications were observed in 7 of the 12 patients. Necrotic cavitation of the tumor developed in five patients, in two patients accompanied by a large bronchoesophageal fistula (Fig 1). Massive fatal hemoptysis occurred in six patients (one patient with a fistula died of a massive hemorrhage), 14 to 217 days after brachytherapy (Fig 2). Two of five patients with previous laser therapy developed major complications, and five of seven with brachytherapy alone showed either bronchoesophageal fistula or major hemorrhage. DISCUSSION
This more detailed follow-up of patients treated by endobronchial irradiation alone or with prior laser resection shows a higher complication rate than reported.4·5 The small number of patients studied precludes statistical analyses; nonetheless, the increased rate of major complications over what could be ex-
FIGURE 1. Tracheobronchoesophageal fistula following laser and brachytherapy in a 40-year old man with inoperable squamous cell cancer; esophageal prosthesis seen from trachea.
FIGURE 2. Post-mortem section of distal trachea and right upper lobe following fulminating hemorrhage from tumor-infiltrated pulmonary artery after brachytherapy; no laser previously. (Courtesy orProf. K.-M. Miiller, Bochum , FRG)
pected does seem remarkable; various possible explanations should be explored. Reports on the frequency of massive hemoptysis as cause of death in lung cancer as an inherent complication of the disease are rare. Miller and McGregor7 report on autopsies of 877 cases of lung cancer. They found an overall incidence of fatal hemoptysis in 29 of 877 cases (3.3 percent); predisposing factors were tumor type (squamous cell carcinoma 24 of 326, 7.4 percent), and tumor site (left main bronchus and right main bronchus 15 of 120, 12.5 percent). Percutaneous irradiation did not predispose to fatal hemoptysis in the examined population. In contrast to these results, the time of death in our patients is suggestive of a causal relationship with endobronchial irradiation, as with one exception hemoptysis occurred within four months after the completion of therapy. In addition, however, both conditions predisposing to hemorrhage are met in our patients: squamous cell carcinomas centrally located predominate. Although total irradiation dose did not correlate with frequency of complications, longer irradiated length in the patients with major complications indicated more advanced local CHEST I 99 I 5 I MAY. 1991
1063
FIGURE
3. DSA of right pulmonary tnmk shows amputation oflower pulmonary artery by tumor; patient not suitable for hrachytherapy.
Fl<:l' IIE 4. DSA of ri~ht pulmonary trunk shows indentation (arrowlu·m/) of proximal se~ment of lower artery throu~h tumor <.•>mpression . Patient selected for hrachytherapy, no hemorrha~e.
disease in this group at the outset of treatment. Fajardo and LeeH examined 11 cases of rupture of major nonpulmonary vessels after radiation. They concluded that a major factor resulting in vessel rupture is previous injury (surgery, inflammation) rather than radiation itself. Tumor involvement of the vessel wall can also be considered injurious in this sense. Pearlberg et al9 performed detailed roentgenographic investigations of tumor vicinities prior to laser therapy. They found major vessels located 1 to 3 mm away from bronchial tumors of the right and left main bronchus in four of ten patients, and hence, a very high rate ofbleeding complications might be expected. Kahn et al, 10 using DSA imaging, identified six patients with stenosis or occlusion of main pulmonary or lobar arteries out of a group of 16 potential candidates for afterloading brachytherapy; hemorrhage did not occur in the ten patients selected for brachytherapy. In our group of patients, we could not confirm the observation (personal communication, H. N. Macha, 1990) that previous laser therapy predisposes to major
complications following hrachytherapy. Fistulation or hemorrhage occurred in two of five laser plus brachytherapy patients and in five of seven hrachytherapy only patients. Minor complications such as radiation mucositis and temporary increase of cough were subsequently observed to respond favorably to inhaled steroid therapy (ie, heclomethasone dipropionate, 0 ..5 mg bd). The incidence of death from hemoptysis in patients treated with hrachytherapy is variably reported to be between 5.7 and 25 percent.~ · • A certain number may have heen lost to fi>llow-up, since many of these reports are from pulmonary referral centers with very large catchment areas. Although the relatively high rate of death from hemoptysis in our patients may be a chance occurrence, we nevertheless feel that characteristics that will identif): patients at risk of developing fatal hemoptysis (such as involvement of major arteries) and fistulas (eg , significant bronchial wall destruction and mediastinal invasion) should be better defined. Imaging techniques such as DSA (Fig 3 and 4), computer-assisted tomography, and nuclear magnetic resonance may prove invaluable for this purpose.
1064
Brachytherapy and Laser in Lung Cancer {Khanavkar eta/)
Patients with major vessel involvement should be excluded from brachytherapy. In extensive bronchial wall destruction, laser recanalization should be done initially; brachytherapy, if subsequently applied, should be individual by adjusted doses with extended therapy-free intervals. Characteristics of tumor response to laser carbonization should be taken into account in planning brachytherapy. Finally, minor complications, such as cough or mucositis, can be avoided by initiating inhaled steroid therapy (eg, beclomethasone dipropionate, 2 puffs bd) one week prior to and continuing four weeks after therapy. REFERENCES 1 Moylan MD, Stmbler K, Unal A, Mohiuddin M, Ciampetro A, Boon R. Transbronchial brachytherapy of recurrent bronchogenic carcinoma: a new approach using the Rexible fiberoptic bronchosL~>pe. Radiology 1983; 147:253-54 2 Schumacher W, Koch K, Frost D, Michel L, Pluemecke M, Luebbert K, et al. Neue Moeglichkeiten der Strahlentherapie endobronchialerTumoren mit Hilfe des Afterloading-Verfahrens auch in Kombination mit der Lasertechnik. Strahlentherapie 1985; 161:663-68 3 Schray MF, McDougall J, Martinez A, Edmundson GK, Cortese DA. Management of malignant airway obstmction: clinical and dosimetric considerations using an iridium 192 afterloading technique in conjunction with the neodymium-YAG laser. lnt J
Radiation Oncol Bioi Phys 1985; 11:403-09 4 Macha H-N, Koch K, Stadler M, Schumacher W, Kmmmhaar D. New technique for treating occlusive and stenosing tumours of the trachea and main bronchi: endobronchial irradiation by high dose irridium-192 combined with laser canalization. Thorax 1987; 42:511-15 5 Schildge J, Freund U, Ortlieb H, Hasse J. Die Therapie inoperabler und nach Primaerbehandlung rezidivierender maligner Tumoren im zentralen Bronchialsystem durch endoskopische Laserabtragung und endobronchiale Kleinraumbestrahlung. Helv Chir Acta 1987; 54:303-09 6 Alberti W, Bauer PC, Busch M. The management of recurrent or obstmctive lung cancer with the Essen afterloading technique and the neodymium-YAG laser. Tumor-Diagnostik Therapie 1986; 7(suppl):22-25 7 Miller R, McGregor D. Haemorrhage from carcinoma of the lung. ~ancer 1980; 46:200-05 8 Fajardo LF, Lee A. Rupture of major vessels after radiation. Cancer 1975; 36:904-13 9 Pearlberg JL, Sandler MA, Kvale P, Bente GH, Madrazo BL. Computed-tomographic and conventional linear-tomographic evaluation of tracheobronchial lesions for laser photoresection. Radiology 1985; 154:759-62 10 Kahn T, Allgayer B, Munteanu J, Wackerle B, Henck A. Lasernod Afterloadingtherapie maligner Bronchusstenosen. Fortsch Rontgenstr 1986; 145:33~ 11 Seagren SL, Harrell JH, Horn RA. High dose rate intraluminal irradiation in recurrent endobronchial carcinoma. Chest 1985; 88:810-14
Diagnostic Imaging Update: MRI, CT, US, and lnterventional Stanford University Medical Center will present this course August 26-30 at the Hotel Vancouver, Vancouver, Canada. For information, contact Dawne Ryals, Ryals and Associates, PO Box 1925, Roswell, Georgia 30077-1925 (404:641-9773).
CHEST I 99 I 5 I MAY, 1991
1085
Associated with Alone or with Laser in Lung
Barbara Khanavkar, M.D.;t Petra Stem, M.D.;* Winfried Alberti, M.D.;* and john A. Nakhosteen, M.D., F.C.C.P.t
Relatively little has been reported about destruction through brachytherapy of mucosa-perforating and extraluminary tumors with probable large vessel involvement causing major hemorrhagic or fistular complications. We report 12 patients subjected to laser and brachytherapy for centrally occluding lung cancer, whom we have periodically followed up from June 1986 until they died. Although all laser procedures were free from complications, necrotic cavitation in five cases, two of which were accompanied by large bronchoesophageal fistulas, and massive fatal hemoptysis occurred in six. Minor complications included radiation mucositis (two), noncritical mucosal scarring (two), and
cough (four). Characteristics that will identify patients at risk of developing fatal hemoptysis and fistulas should be better defined by imaging and endoscopic techniques. In such cases, modifying the protocol or using alternative procedures should be considered. Minor complications, such as cough, can be avoided by using topical steroid therapy (eg, beclomethasone dipropionate).
Endobronchial brachytherapy alone or combined with laser vaporization is used increasingly for palliation in recurrent central lung tumors after exhaustion of all other therapeutic measures. 1"3 Shortterm results emphasizing symptomatic and lung function improvement are reported as good, and complications, relatively few. 4 •5 Patients are usually referred to pulmonary centers, and an indefinite number may be lost to follow-up. We report 12 patients treated with 192lr high-dose brachytherapy, five combined with laser resection, for their centrally occluding recurrent bronchial tumors seen in our department from June 1986, until December 1989 and whom we followed until they died.
took place at the pulmonary department at Augusta Teaching Hospital; irradiation treatment was conducted at the department for radiotherapy at the Kmpp Hospital. Following premedication with pethidine, 50 mg, and atropine, 0.5 mg, a flexible bronchoscope was introduced transorally under topical anesthesia and used to intubate a 9 mm endotracheal tube. The further procedure, reported in detail by Alberti et al,• is, in brief, as follows: a 4-mm blind catheter was introduced through the ETT and is positioned adjacent to the tumor ascertained using the bronchoscope. The guide tube then was anchored and its proximal end connected to the '"'lr source (initial activity: 370 GBq or 10 Ci resp, Gamma Med IIi, Isotopentechnik Dr. Sauerwein, Haan, FRG). Through this remote-controlled afterloading device, the 1112 lr capsule (diameter 1.1 mm) was advanced through the guide catheter and withdrawn stepwise in 5 mm increments over the desired distance, delivering a calculated dose of 8 Gy at a tissue depth of 5 mm in one 2 to 4 min session. Patients received two to eight sessions (average 5.5) timed at weekly or fortnightly intervals (average every ninth day); the average cumulative dose was 43.6 Gy. Details on total dose and length of irradiated bronchus are specified in Table 1. Previous laser therapy was performed Q.A.N .) with a neodymiumYAG laser using standard procedures.
PATIENTS AND METHODS
Twelve patients (ten men, two women, age 39 to 80 years) with centrally occluding bronchial tumors (ten squamous cell carcinomas, one adenosquamous carcinoma and one adenoid-cystic carcinoma) were selected for endobronchial irradiation. Tumor had recurred in 11 patients previously treated (percutaneous irradiation of 54 to 60 Gy 3 to 24 months prior) and had progressed in one patient with inoperable carcinoma and severe COLD not previously treated. Laser recanalization was performed in five patients prior to brachytherapy. Initial work-up, laser therapy, and posttreatment follow-up *From tAugusta Teaching Hospital, Bochum Germany; and :j:Kmpp von Bohlen und Halbach Teaching Hospital, Essen Germany. Manuscript received June 4; revision accepted October 18. Reprint requests: Dr: Naklwsteen, Bergstr 26, 4630 Bochum, Germany
1062
(Chest 1991; 99:1062-65) ETT =endotracheal tube; DSA =digital subtraction angiography
REsuLTS
Follow-up bronchoscopies showed good tumor regression in all patients until their time of death. Slow recurrence was seen in one patient seven months after therapy, and sustained tumor control persisted in a patient surviving for 24 months. Whereas eight patients reported improvement of symptoms (cough and dyspnea), objective improvement oflung function was inconsistent: FEV 1 and VC increased significantly (15 Brachytherapy and Laser in Lung Cancer (Khanavlcar at a/)
Table I-Dose and Irradiated Bronchial Length* Patients with Major Complications
23456789
Patients Without Major Complications
10
11 12
Radiation dose 48 64 32 32 56 16 16 56 64 48 32 48 at5mm tissue depth, Gy Length of 5466473343 .5 3 3 irradiated bronchus, em Average, Gy/cm 37.715.3 49.613.5 *Major complication appear more closely associated to lengths irradiated than to total dose.
percent) in 5 of 12 patients, hypercapnea but not hypoxemia improved in three. Minimal complications included radiation mucositis in two patients and temporary increase of cough in four patients. Noncritical bronchial stenosis through scar formation in bronchial mucosa adjacent to the irradiated tumors constituted a minor late complication. Serious complications were observed in 7 of the 12 patients. Necrotic cavitation of the tumor developed in five patients, in two patients accompanied by a large bronchoesophageal fistula (Fig 1). Massive fatal hemoptysis occurred in six patients (one patient with a fistula died of a massive hemorrhage), 14 to 217 days after brachytherapy (Fig 2). Two of five patients with previous laser therapy developed major complications, and five of seven with brachytherapy alone showed either bronchoesophageal fistula or major hemorrhage. DISCUSSION
This more detailed follow-up of patients treated by endobronchial irradiation alone or with prior laser resection shows a higher complication rate than reported.4·5 The small number of patients studied precludes statistical analyses; nonetheless, the increased rate of major complications over what could be ex-
FIGURE 1. Tracheobronchoesophageal fistula following laser and brachytherapy in a 40-year old man with inoperable squamous cell cancer; esophageal prosthesis seen from trachea.
FIGURE 2. Post-mortem section of distal trachea and right upper lobe following fulminating hemorrhage from tumor-infiltrated pulmonary artery after brachytherapy; no laser previously. (Courtesy orProf. K.-M. Miiller, Bochum , FRG)
pected does seem remarkable; various possible explanations should be explored. Reports on the frequency of massive hemoptysis as cause of death in lung cancer as an inherent complication of the disease are rare. Miller and McGregor7 report on autopsies of 877 cases of lung cancer. They found an overall incidence of fatal hemoptysis in 29 of 877 cases (3.3 percent); predisposing factors were tumor type (squamous cell carcinoma 24 of 326, 7.4 percent), and tumor site (left main bronchus and right main bronchus 15 of 120, 12.5 percent). Percutaneous irradiation did not predispose to fatal hemoptysis in the examined population. In contrast to these results, the time of death in our patients is suggestive of a causal relationship with endobronchial irradiation, as with one exception hemoptysis occurred within four months after the completion of therapy. In addition, however, both conditions predisposing to hemorrhage are met in our patients: squamous cell carcinomas centrally located predominate. Although total irradiation dose did not correlate with frequency of complications, longer irradiated length in the patients with major complications indicated more advanced local CHEST I 99 I 5 I MAY. 1991
1063
FIGURE
3. DSA of right pulmonary tnmk shows amputation oflower pulmonary artery by tumor; patient not suitable for hrachytherapy.
Fl<:l' IIE 4. DSA of ri~ht pulmonary trunk shows indentation (arrowlu·m/) of proximal se~ment of lower artery throu~h tumor <.•>mpression . Patient selected for hrachytherapy, no hemorrha~e.
disease in this group at the outset of treatment. Fajardo and LeeH examined 11 cases of rupture of major nonpulmonary vessels after radiation. They concluded that a major factor resulting in vessel rupture is previous injury (surgery, inflammation) rather than radiation itself. Tumor involvement of the vessel wall can also be considered injurious in this sense. Pearlberg et al9 performed detailed roentgenographic investigations of tumor vicinities prior to laser therapy. They found major vessels located 1 to 3 mm away from bronchial tumors of the right and left main bronchus in four of ten patients, and hence, a very high rate ofbleeding complications might be expected. Kahn et al, 10 using DSA imaging, identified six patients with stenosis or occlusion of main pulmonary or lobar arteries out of a group of 16 potential candidates for afterloading brachytherapy; hemorrhage did not occur in the ten patients selected for brachytherapy. In our group of patients, we could not confirm the observation (personal communication, H. N. Macha, 1990) that previous laser therapy predisposes to major
complications following hrachytherapy. Fistulation or hemorrhage occurred in two of five laser plus brachytherapy patients and in five of seven hrachytherapy only patients. Minor complications such as radiation mucositis and temporary increase of cough were subsequently observed to respond favorably to inhaled steroid therapy (ie, heclomethasone dipropionate, 0 ..5 mg bd). The incidence of death from hemoptysis in patients treated with hrachytherapy is variably reported to be between 5.7 and 25 percent.~ · • A certain number may have heen lost to fi>llow-up, since many of these reports are from pulmonary referral centers with very large catchment areas. Although the relatively high rate of death from hemoptysis in our patients may be a chance occurrence, we nevertheless feel that characteristics that will identif): patients at risk of developing fatal hemoptysis (such as involvement of major arteries) and fistulas (eg , significant bronchial wall destruction and mediastinal invasion) should be better defined. Imaging techniques such as DSA (Fig 3 and 4), computer-assisted tomography, and nuclear magnetic resonance may prove invaluable for this purpose.
1064
Brachytherapy and Laser in Lung Cancer {Khanavkar eta/)
Patients with major vessel involvement should be excluded from brachytherapy. In extensive bronchial wall destruction, laser recanalization should be done initially; brachytherapy, if subsequently applied, should be individual by adjusted doses with extended therapy-free intervals. Characteristics of tumor response to laser carbonization should be taken into account in planning brachytherapy. Finally, minor complications, such as cough or mucositis, can be avoided by initiating inhaled steroid therapy (eg, beclomethasone dipropionate, 2 puffs bd) one week prior to and continuing four weeks after therapy. REFERENCES 1 Moylan MD, Stmbler K, Unal A, Mohiuddin M, Ciampetro A, Boon R. Transbronchial brachytherapy of recurrent bronchogenic carcinoma: a new approach using the Rexible fiberoptic bronchosL~>pe. Radiology 1983; 147:253-54 2 Schumacher W, Koch K, Frost D, Michel L, Pluemecke M, Luebbert K, et al. Neue Moeglichkeiten der Strahlentherapie endobronchialerTumoren mit Hilfe des Afterloading-Verfahrens auch in Kombination mit der Lasertechnik. Strahlentherapie 1985; 161:663-68 3 Schray MF, McDougall J, Martinez A, Edmundson GK, Cortese DA. Management of malignant airway obstmction: clinical and dosimetric considerations using an iridium 192 afterloading technique in conjunction with the neodymium-YAG laser. lnt J
Radiation Oncol Bioi Phys 1985; 11:403-09 4 Macha H-N, Koch K, Stadler M, Schumacher W, Kmmmhaar D. New technique for treating occlusive and stenosing tumours of the trachea and main bronchi: endobronchial irradiation by high dose irridium-192 combined with laser canalization. Thorax 1987; 42:511-15 5 Schildge J, Freund U, Ortlieb H, Hasse J. Die Therapie inoperabler und nach Primaerbehandlung rezidivierender maligner Tumoren im zentralen Bronchialsystem durch endoskopische Laserabtragung und endobronchiale Kleinraumbestrahlung. Helv Chir Acta 1987; 54:303-09 6 Alberti W, Bauer PC, Busch M. The management of recurrent or obstmctive lung cancer with the Essen afterloading technique and the neodymium-YAG laser. Tumor-Diagnostik Therapie 1986; 7(suppl):22-25 7 Miller R, McGregor D. Haemorrhage from carcinoma of the lung. ~ancer 1980; 46:200-05 8 Fajardo LF, Lee A. Rupture of major vessels after radiation. Cancer 1975; 36:904-13 9 Pearlberg JL, Sandler MA, Kvale P, Bente GH, Madrazo BL. Computed-tomographic and conventional linear-tomographic evaluation of tracheobronchial lesions for laser photoresection. Radiology 1985; 154:759-62 10 Kahn T, Allgayer B, Munteanu J, Wackerle B, Henck A. Lasernod Afterloadingtherapie maligner Bronchusstenosen. Fortsch Rontgenstr 1986; 145:33~ 11 Seagren SL, Harrell JH, Horn RA. High dose rate intraluminal irradiation in recurrent endobronchial carcinoma. Chest 1985; 88:810-14
Diagnostic Imaging Update: MRI, CT, US, and lnterventional Stanford University Medical Center will present this course August 26-30 at the Hotel Vancouver, Vancouver, Canada. For information, contact Dawne Ryals, Ryals and Associates, PO Box 1925, Roswell, Georgia 30077-1925 (404:641-9773).
CHEST I 99 I 5 I MAY, 1991
1085