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Diagnostic imaging of post-irradiation changes in the chest
570
CORRESPONDENCE
:
Correspondence Letters are published at the discretion of the Editor. Opinions expressed by correspondents are not necessarily those of the Editor. Unduly long letters may be returned to the authors for shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be published in the same issue. Letters should be typed double spaced and should be signed by all authors personally. References should be given in the style specified in the Instruction to Authors at the front of the Journal.
DIAGNOSTIC IMAGING OF POST-IRRADIATION CHANGES IN THE CHEST
patients where the differentiation between radiation pneumonitis, recurrent tumour and other pathologies remains in doubt. R. GLYNNE-JONES
S m - The recent article on diagnostic imaging of post-irradiation changes in the chest by Bell et al. (1988) states that the chest radiograph is an insensitive indicator of post-irradiation change and hence of little value. Early radiation injury to the lung (radiation pneumonitis) is a welldescribed clinical entity characterised by cough, dyspnoea and low grade fever. Visible changes on chest radiographs subsequent to irradiation for breast cancer are common, and in some series have approached 70% (Bate and Guttman, 1957). However, radiological changes have not been shown to correlate either with symptomatic radiation pneumonitis (Chu et al., 1955) or later changes in respiratory function (Kaufman et al., 1986), emphasising the fact that radiation pneumonitis is in the main a clinical diagnosis. A study in the Professorial unit at this institution investigated all patients with primary breast cancer who received radical irradiation to the breast/chest wall between January 1984 and December 1987. One hundred and fifty-four consecutive unselected patients have been followed prospectively. Radiation pneumonitis was defined for the purpose of this study by the criteria of cough, dyspnoea and systemic upset occurring 4--24 weeks after radiotherapy is completed. Persistence of symptoms for more than 4 weeks and sufficient severity to require specific therapy in terms of corticosteroids/antibiotics/cough linctus were a necessary condition. To date radiation pneumonitis has been diagnosed in 18 of 154 patients (12%). All patients had chest radiographs performed at the time of symptoms, which showed abnormalities in 16 of 18 (dense apical shadowing in the majority). In two patients where the diagnosis was in doubt, lateral chest radiographs were obtained which confirmed consolidation of lung within the radiation fields by the diminution/loss of the retrosternal window. Arguably a lateral radiograph would have been of benefit in the case quoted by Bell et al (1988) on page 111 by showing the loss of the retrosternal window, and at a much cheaper price. Clearly, computed tomography (CT) can provide good qualitative and quantitative endpoints in the assessment of radiation-induced pulmonary damage (Mah and Van Dyk, 1988), and may provide better information for assembling dose-response relationships. However, it should be stressed that clinical post-irradiation follow-up with a careful search for signs and symptoms, complemented by a plain and lateral radiograph will define the majority of those patients who have developed symptomatic radiation pneumonitis. Early detection and treatment may be helpful in preventing progressive fibrosis. Computed tomography in the clinical setting can be reserved for the few
The Meyerstein Institute of Radiotherapy, The Middlesex and University College Hospitals, London W1.
References
Bate, D & Guttman, RJ (1957) Changes in lung and pleura following two million-volt therapy for carcinoma of the breast. Radiology, 69, 679-683. Chu, FCH, Phillips, R, Nickson, JJ & McPhee, JG (1955). Pneumonitis following radiation therapy of cancer of the breast by tangential technique. Radiology, 64, 642-653. Kaufman, J. Gunn, W, Hartz, AJ, Fischer, M, Hoffman, RG, Schlue~ter, DP, et al., (1986). The pathophysiologic and roentgenologic effects of Chest irradiation in breast carcinoma. International Journal of Radiation Oncology, Biology, Physics, 12, 887-893. Mah, K & Van Dyk, J (1988) Quantitative measurement of changes in human lung density following irradiation. Radiotherapy and Oncology, 11, 169-179. SIR- We are grateful to Dr Glynne-Jones for commenting on our paper as we welcome the opportunity to reply. Our aim in writing this paper was not to lay down guidelines for routine clinical follow-up but to discuss the abnormalities which may be missed by this. Some of these, particularly the functional abnormalities, are sufficiently extensive to warrant re-evaluation of the radiotherapy techniques which give rise to them. We pointed out that CT is not a suitable method to follow up patients after irradiation routinely. Indeed we have stressed the value of the chest radiograph and not simply dismissed it because of its lack of sensitivity in showing post-irradiation change. Dr Glynn-Jones' incomplete quotation of this passage is misleading. In view of its easy availability and relatively low cost, the chest radiograph is and will remain a first-line investigation in the follow-up of patients who have been irradiated. It should always be borne in mind however that post-irradiation changes may be more extensive than is evident from the chest radiograph. In the patient whose dyspnoea is out of proportion to the radiographic changes, CT or isotope scanning may well provide further useful information. E. RHYS DAVIES* P. R. G O D D A R D ? J. BELL§ J. A. BULLIMORE$
* University of Bristol Department of ~Radiodiagnosis and SRadiotherapy, Bristol Royal Infirmary §Radiology department Musgrove Park Hospital Taunton
CORRESPONDENCE
:
Correspondence Letters are published at the discretion of the Editor. Opinions expressed by correspondents are not necessarily those of the Editor. Unduly long letters may be returned to the authors for shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be published in the same issue. Letters should be typed double spaced and should be signed by all authors personally. References should be given in the style specified in the Instruction to Authors at the front of the Journal.
DIAGNOSTIC IMAGING OF POST-IRRADIATION CHANGES IN THE CHEST
patients where the differentiation between radiation pneumonitis, recurrent tumour and other pathologies remains in doubt. R. GLYNNE-JONES
S m - The recent article on diagnostic imaging of post-irradiation changes in the chest by Bell et al. (1988) states that the chest radiograph is an insensitive indicator of post-irradiation change and hence of little value. Early radiation injury to the lung (radiation pneumonitis) is a welldescribed clinical entity characterised by cough, dyspnoea and low grade fever. Visible changes on chest radiographs subsequent to irradiation for breast cancer are common, and in some series have approached 70% (Bate and Guttman, 1957). However, radiological changes have not been shown to correlate either with symptomatic radiation pneumonitis (Chu et al., 1955) or later changes in respiratory function (Kaufman et al., 1986), emphasising the fact that radiation pneumonitis is in the main a clinical diagnosis. A study in the Professorial unit at this institution investigated all patients with primary breast cancer who received radical irradiation to the breast/chest wall between January 1984 and December 1987. One hundred and fifty-four consecutive unselected patients have been followed prospectively. Radiation pneumonitis was defined for the purpose of this study by the criteria of cough, dyspnoea and systemic upset occurring 4--24 weeks after radiotherapy is completed. Persistence of symptoms for more than 4 weeks and sufficient severity to require specific therapy in terms of corticosteroids/antibiotics/cough linctus were a necessary condition. To date radiation pneumonitis has been diagnosed in 18 of 154 patients (12%). All patients had chest radiographs performed at the time of symptoms, which showed abnormalities in 16 of 18 (dense apical shadowing in the majority). In two patients where the diagnosis was in doubt, lateral chest radiographs were obtained which confirmed consolidation of lung within the radiation fields by the diminution/loss of the retrosternal window. Arguably a lateral radiograph would have been of benefit in the case quoted by Bell et al (1988) on page 111 by showing the loss of the retrosternal window, and at a much cheaper price. Clearly, computed tomography (CT) can provide good qualitative and quantitative endpoints in the assessment of radiation-induced pulmonary damage (Mah and Van Dyk, 1988), and may provide better information for assembling dose-response relationships. However, it should be stressed that clinical post-irradiation follow-up with a careful search for signs and symptoms, complemented by a plain and lateral radiograph will define the majority of those patients who have developed symptomatic radiation pneumonitis. Early detection and treatment may be helpful in preventing progressive fibrosis. Computed tomography in the clinical setting can be reserved for the few
The Meyerstein Institute of Radiotherapy, The Middlesex and University College Hospitals, London W1.
References
Bate, D & Guttman, RJ (1957) Changes in lung and pleura following two million-volt therapy for carcinoma of the breast. Radiology, 69, 679-683. Chu, FCH, Phillips, R, Nickson, JJ & McPhee, JG (1955). Pneumonitis following radiation therapy of cancer of the breast by tangential technique. Radiology, 64, 642-653. Kaufman, J. Gunn, W, Hartz, AJ, Fischer, M, Hoffman, RG, Schlue~ter, DP, et al., (1986). The pathophysiologic and roentgenologic effects of Chest irradiation in breast carcinoma. International Journal of Radiation Oncology, Biology, Physics, 12, 887-893. Mah, K & Van Dyk, J (1988) Quantitative measurement of changes in human lung density following irradiation. Radiotherapy and Oncology, 11, 169-179. SIR- We are grateful to Dr Glynne-Jones for commenting on our paper as we welcome the opportunity to reply. Our aim in writing this paper was not to lay down guidelines for routine clinical follow-up but to discuss the abnormalities which may be missed by this. Some of these, particularly the functional abnormalities, are sufficiently extensive to warrant re-evaluation of the radiotherapy techniques which give rise to them. We pointed out that CT is not a suitable method to follow up patients after irradiation routinely. Indeed we have stressed the value of the chest radiograph and not simply dismissed it because of its lack of sensitivity in showing post-irradiation change. Dr Glynn-Jones' incomplete quotation of this passage is misleading. In view of its easy availability and relatively low cost, the chest radiograph is and will remain a first-line investigation in the follow-up of patients who have been irradiated. It should always be borne in mind however that post-irradiation changes may be more extensive than is evident from the chest radiograph. In the patient whose dyspnoea is out of proportion to the radiographic changes, CT or isotope scanning may well provide further useful information. E. RHYS DAVIES* P. R. G O D D A R D ? J. BELL§ J. A. BULLIMORE$
* University of Bristol Department of ~Radiodiagnosis and SRadiotherapy, Bristol Royal Infirmary §Radiology department Musgrove Park Hospital Taunton