??Original Contribution RADIATION PNEUMONITIS: EXPERIENCE FOLLOWING A LARGE SINGLE DOSE OF RADIATION C. J. H. FRYER,L.R.C.P., M.R.C.S., F.R.C.P.(C),t P. J. FITZPATRICK, M.B., B.S., F.R.C.P.(C), F.R.C.R.,S W. D. RIDER,M.B., B.Ch., F.R.C.P.(C), F.R.C.R.§ and P. POON,M.B., B.S., F.R.C.P.(C)* Princess Margaret Hospital, University of Toronto, Canada The acute radiation pneumonitis syndrome of increasing cough with dyspnea and characteristii radiographic changes deve-iopedin 44 of 245 patients (17.5%) who were treated with a single large dose of radiation. The median onset was 100 days and proved fatal within 2 weeks in 84% of patients. Because these patients with advanced cancer had a median survival of 126 days, the fncidence was cakufated by the actuariaf method. This was 83.5% and 29% for single uncorrected doses of 1000 and 800 rad: the two standard deviations were 20% and 14%. The risk increased with previous h-radiation or intrathorack tumor. Steroids had no obvious protective effect, but in three patients withdrawal of the drug apparently precipitatad tbe syndrome. Vigorous supportive treatment with antibiotks and predoisone reversed the process in three cases. Radiotolerance of tbe lung is the liiiting factor in using radiation as a systematk treatment for cancer. Radiotherapy, Wide field, Radiation pneumonitis. a diffuse or nodular pattern (Fig. la and lb). Symptoms increase rapidly and death nearly always

in INTRODUCTION

Widefield irradiation with a total or half-body technique is an attempt to use radiation as a systemic treatment for cancer. In the program at the Princess Margaret Hospital. a large single dose of radiation is given to the entire lung: this practice has afforded a unique opportunity to study this organ’s radiation tolerance. Radiation damage to the lung results from microvascular endarteritis and alveolar cell damage. Four types of radiation injury with specific syndromes are the hyperacute syndrome, acute recognized: syndrome, subclinical pneumonitis and chronic pulmonary fibrosis. The hyperacute syndrome which develops during a course of radiotherapy was not observed.‘” Acute radiation pneumonitis presents about 16 weeks following treatment with the rapid onset of cough and dyspnea. Chest radiographs show opacities tResearch Fellow. Radiation Oncology. Present Address: Cancer Control Agency of British Columbia. 2656 Heather St.. Vancouver, British Columbia, Canada V5Z 353. *Radiation Oncologist, Associate Professor of Radiology. Khief. Radiation Oncology, Professor of Radiology. *Radiologist. Lecturer in Radiology. Reprint requests to: P. J. Fitzpatrick, M.B.. 500 Sher-

ensues within 2-3 weeks. An asymptomatic subclinical detected on routine X-ray:

pneumonitis this usually

may

be

resolves without treatment or sequelae. Chronic pulmonary fibrosis develops insidiously and may follow a previous reaction. This paper describes the acute radiation pneumonitis syndrome. METHODS AND MATERIALS

Between 1960 and 1976, 245 patients received whole lung irradiation in a single exposure: doses ranged from 200 to 1OOOrad (Fig. 2). Treatment was given mainly to relieve the pain of advanced cancer using the upper half-body irradiation (UHBI) technique.’ The series also includes patients treated by total body irradiation (TBI) as adjuvant therapy for Ewing’s tumor and those in the leukemia bone marrow transplant program.‘.‘4 Patients were irradiated bourne St., Toronto. Ontario, Canada M4X lK9. Acknowledgements-We appreciate our secretarial help, the statistical help of Joan Reid and Theresa Chua. and the advice of Dr. J. Carruthers of the Pathology Department. the co-operation of the Defense Research Establishment. Ottawa. is also gratefully acknowledged. Accepted for publication 29 July 1978.

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Radiation Oncology 0 Biology 0 Physics

November-December

1978. Vol. 4, No.

I I and No. I2

TOTAL LUNG IRRADIATION 1960

245 Patients

4

1976 Breast - Lung - Prostate - Ewngs - Myeloma - Lymphoma Other

Median Survival

98 30 ?8 27 16 9 37

4 Months

Rad 11 TX

No_

loo0

?3

300

149

600

24