The technical limitations of x-rays in detecting lung cancer do not come into the radiologist’s defense in court cases, according to an article published July 20 in Academic Radiology.
The conclusion is from an analysis by Sagar Kulkarni, MD, of the University of Washington, and colleagues, who reviewed a broad range of medicolegal cases of missed lung cancer to assess how courts have viewed the standard of care of physicians when using this “imperfect test.”
“The technical limitations of the radiograph in detecting lung cancer, its limited sensitivity and specificity, do not come into the radiologist’s defense because they are numbers derived from populations, and may not apply to the specific patient,” the group wrote.
Study findings have shown that up to 25% of cancers go undetected by chest x-rays and that screening with chest x-rays does not affect lung cancer mortality, Kulkarni and colleagues explained. This should absolve the radiologist, who may miss the cancer, of negligence, as the cancer may not have been discovered early enough for any treatment provided to offer a differential mortality benefit, they added.
Yet medicolegal cases involving cancer usually involve a fight over whether the plaintiff had a “lost chance” at a better outcome due to the defendant’s negligence, the authors wrote.
For instance, in a case in 1996, a 29-year-old woman undergoing surgical treatment for endometriosis in Louisiana had a small lung mass noted by a radiologist on a routine preoperative chest x-ray, but the finding was not communicated to the patient. Later that year, the woman presented again, this time with seizures, which unbeknownst to her were caused by a 2-cm brain metastasis, implying stage IV lung cancer. The patient died one year later.
The radiologist was sued for failing to communicate the finding to the patient, which led to a five-month delay in the treatment, the authors noted. During the trial, the plaintiff’s expert witnesses opined that the tumor on the x-ray was a stage I or stage II tumor, and ultimately, the jury sided with the plaintiff on the grounds that the five-month delay represented a lost chance of survival.
In this case, an evidence-based approach might have favored the defendant, the authors wrote. Increasing tumor size correlates with improved detection on chest x-ray, with only 29% of primary tumors sized less than 10 mm being detected, and metastatic potential correlates with size — patients with primary tumors larger than 3 cm likely have brain metastases.
“However, specific evidence for the conjectures was neither furnished nor sought,” the group wrote.
In this case, it was unknown whether the tumor was metastatic or not at the time of diagnosis. The only thing known with certainty was that there was a five-month delay, with the lost chance doctrine favoring the plaintiff, the authors wrote.
At present, there is no formal, universally accepted methodology of using radiology-specific evidence-based medicine in courts, and this is a gap which professional societies can bridge, the group suggested.
“Coupled with the fact that the physicians, aware of the limitations of the chest radiograph, are also aware that they have no idea of the biological severity of the potential diagnosis, one can understand why so many chest CTs are requested by clinicians and recommended by the radiologists,” they concluded.
The full article is available here.