When is a biopsy-proven diagnosis necessary before stereotactic ablative radiotherapy for lung cancer?: A decision analysis.
BACKGROUND
The practice of treating a solitary pulmonary nodule (SPN) suspicious for stage I non-small cell lung cancer (NSCLC) with stereotactic ablative radiotherapy (SABR) in the absence of pathology is growing. In the absence of randomized evidence, the appropriate prior probability threshold of lung cancer of when such a strategy is warranted can be informed using decision analysis.


METHODS
A decision tree and Markov model were constructed to evaluate the relative merits of surveillance, a PET scan-directed SABR strategy (without pathology), or a PET scan-biopsy-SABR strategy, when faced with an SPN at different prior probabilities for lung cancer. Diagnostic characteristics, as well as disease, treatment, and toxicity parameters, were extracted from the literature. Deterministic analysis and probabilistic sensitivity analyses were performed to inform the appropriate lung cancer prior probability threshold between treatment strategies.


RESULTS
In the reference case analysis, the prior probability threshold between surveillance and PET scan-biopsy-SABR was 17.0%; between PET scan-directed SABR and PET scan-biopsy-SABR, the threshold was 85.0%. The latter finding was confirmed on probabilistic sensitivity analysis (85.2%; 95% CI, 80.0% to 87.2%). This predicted lung cancer prior probability threshold was most sensitive to the diagnostic sensitivity of transthoracic biopsy (range, 77.2% to 94.0%) and the detection rate of false negatives on CT scan surveillance (range, 82.4% to 92.3%).


CONCLUSIONS
This model suggests that if there are concerns about morbidity related to biopsy for an SPN, a PET scan-directed SABR strategy is warranted when the prior probability of lung cancer exceeds a point estimate of 85%.
The Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands; The Department of Radiation Oncology, London Regional Cancer Program, London, ON, Canada; The Department of Epidemiology, Harvard School of Public Health, Boston, MA. Electronic address: Dr.alexlouie@gmail.com.
Alexander V
AV
Louie
The Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands.
Suresh
S
Senan
The Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
Pretesh
P
Patel
The Department of Epidemiology, Harvard School of Public Health, Boston, MA; The Department of Epidemiology and Biostatistics, Erasmus MC, Rotterdam, The Netherlands.
Bart S
BS
Ferket
The Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands.
Frank J
FJ
Lagerwaard
The Department of Radiation Oncology, London Regional Cancer Program, London, ON, Canada.
George B
GB
Rodrigues
The Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
Joseph K
JK
Salama
The Department of Radiation Oncology, Duke University Medical Center, Durham, NC.
Christopher
C
Kelsey
The Department of Radiation Oncology, London Regional Cancer Program, London, ON, Canada.
David A
DA
Palma
The Department of Epidemiology, Harvard School of Public Health, Boston, MA; The Department of Epidemiology and Biostatistics, Erasmus MC, Rotterdam, The Netherlands.
Myriam G
MG
Hunink
D001706:Biopsy / Q000379:methods*; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000601:surgery; D003661:Decision Support Techniques; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000601:surgery; D049268:Positron-Emission Tomography; D016634:Radiosurgery / Q000379:methods*; D012680:Sensitivity and Specificity; D003074:Solitary Pulmonary Nodule / Q000175:diagnosis* / Q000601:surgery; D016896:Treatment Outcome