Bone scanning in lung cancer
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《英国医生杂志》
EDITOR—Benamore et al assume that our incidence of bone metastases was high because of the unusually high proportion of patients with small cell lung cancer. The incidence of distant metastases is 30-50% at initial presentation of non-small cell lung cancer.1 The incidence of bone metastases was highest in the small cell variety at initial presentation but was identical at necropsy in the four main types.2 Many bone metastases are therefore likely to be missed at initial diagnosis of non-small cell lung cancer.
We used an extensive imaging algorithm to exclude bone metastases. In contrast to earlier clinical data and in agreement with results at necropsy,2 we found an almost identical incidence of bone metastases of 32.4% in non-small cell lung cancer and 33.3 % in small cell lung cancer (table).
Stage dependent (according to computed tomography criteria) distribution of patients with skeletal metastases. Values are numbers of patients (numbers of patients with skeletal metastases)
We assessed the reliability of symptoms in detecting bone metastases and hence did not evaluate the number of metastases incidentally detected on computed tomography. To exclude small metastases Benamore et al suggest using fluorodesoxyglucose positron emission tomography. This method, however, is currently not recommended by German and European professional societies for routine use in lung cancer.
We used magnetic resonance imaging to exclude bone metastases probably missed on bone scanning or computed tomography. We used data about the clinical course or at necropsy to decide finally whether a patient had bone metastases.
All patients in our series were questioned and examined by the doctors before bone scanning and the reference methods. This guaranteed that they were blinded to the stage of disease (table).
The study by Tanaka et al quoted by Benamore et al was a retrospective analysis and included patients between 1982 and 1996 but did not report whether the localisation of pain was identical with the site of bone metastases. Chronic back pain is reported by 80% of people aged 50-80,3 so the pretest probability for bone pain is generally high.
Conventional radiography was the standard technique used to confirm focal lesions identified in bone scans in early studies. Skeletal scintigraphy detects metastases several months before they become visible in conventional radiographs. Metastases not confirmed by conventional radiography were therefore regarded as false positive findings, giving a presumed low specificity of bone scintigraphy. Furthermore, only very large, potentially symptomatic metastases were considered true positives.
Martin Hetzel, consultant physician
martin.hetzel@medizin.uni-ulm.de, Department of Internal Medicine II, University of Ulm, D-89081 Ulm, Germany
Coskun Arslandemir, physician
Department of Internal Medicine II, University of Ulm, D-89081 Ulm, Germany
Holger Schirrmeister, consultant in nuclear medicine
Department of Nuclear Medicine, University of Ulm
The full version of this reply is available on bmj.com
Competing interests: None declared.
References
Vaporciyan AA, Nesbitt JC, Lee JS. Cancer of the lung. In: Holland JF, Frei E, eds. Cancer medicine. 5th ed. London: BC Decker, Hamilton, 2000: 1227-92.
Muggia FM, Chervu LR. Lung cancer: diagnosis in metastatic sites. Semin Oncol 1974;1: 217-28.
Deyo RA, Tsui-Wu Y-J. Descriptive epidemiology of low-back pain and its related medical care in the United States. Spine 1987;12: 264-8.
We used an extensive imaging algorithm to exclude bone metastases. In contrast to earlier clinical data and in agreement with results at necropsy,2 we found an almost identical incidence of bone metastases of 32.4% in non-small cell lung cancer and 33.3 % in small cell lung cancer (table).
Stage dependent (according to computed tomography criteria) distribution of patients with skeletal metastases. Values are numbers of patients (numbers of patients with skeletal metastases)
We assessed the reliability of symptoms in detecting bone metastases and hence did not evaluate the number of metastases incidentally detected on computed tomography. To exclude small metastases Benamore et al suggest using fluorodesoxyglucose positron emission tomography. This method, however, is currently not recommended by German and European professional societies for routine use in lung cancer.
We used magnetic resonance imaging to exclude bone metastases probably missed on bone scanning or computed tomography. We used data about the clinical course or at necropsy to decide finally whether a patient had bone metastases.
All patients in our series were questioned and examined by the doctors before bone scanning and the reference methods. This guaranteed that they were blinded to the stage of disease (table).
The study by Tanaka et al quoted by Benamore et al was a retrospective analysis and included patients between 1982 and 1996 but did not report whether the localisation of pain was identical with the site of bone metastases. Chronic back pain is reported by 80% of people aged 50-80,3 so the pretest probability for bone pain is generally high.
Conventional radiography was the standard technique used to confirm focal lesions identified in bone scans in early studies. Skeletal scintigraphy detects metastases several months before they become visible in conventional radiographs. Metastases not confirmed by conventional radiography were therefore regarded as false positive findings, giving a presumed low specificity of bone scintigraphy. Furthermore, only very large, potentially symptomatic metastases were considered true positives.
Martin Hetzel, consultant physician
martin.hetzel@medizin.uni-ulm.de, Department of Internal Medicine II, University of Ulm, D-89081 Ulm, Germany
Coskun Arslandemir, physician
Department of Internal Medicine II, University of Ulm, D-89081 Ulm, Germany
Holger Schirrmeister, consultant in nuclear medicine
Department of Nuclear Medicine, University of Ulm
The full version of this reply is available on bmj.com
Competing interests: None declared.
References
Vaporciyan AA, Nesbitt JC, Lee JS. Cancer of the lung. In: Holland JF, Frei E, eds. Cancer medicine. 5th ed. London: BC Decker, Hamilton, 2000: 1227-92.
Muggia FM, Chervu LR. Lung cancer: diagnosis in metastatic sites. Semin Oncol 1974;1: 217-28.
Deyo RA, Tsui-Wu Y-J. Descriptive epidemiology of low-back pain and its related medical care in the United States. Spine 1987;12: 264-8.