The Massachusetts Supreme Judicial Court unanimously ruled Monday that cigarette maker Philip Morris should pay for chest CT scans, in order for smokers to detect the early development of lung cancer.

The plaintiffs' complaint sought only present and future medical expenses for diagnostic low-dose CT scans to determine the onset of cancer at the “earliest practicable time for the purpose of maximizing the effective treatment of the disease.”

The judges based their ruling on “competent medical testimony” that medical monitoring is “necessary” to detect the potential onset of a serious illness or disease due to changes indicating a substantial increase in risk of harm from exposure to smoking. According to the court, injury and damage by the cigarette maker were proven and the cost of that monitoring is recoverable.

Writing the assent, Justice Francis X. Spina said that legal thinking needs to evolve to contemporary standards: “Our tort law developed in the late 19^th and early 20^th centuries...We must adapt to the growing recognition that exposure to toxic substances and radiation may cause substantial injury,” he wrote.

According to the court, Philip Morris’ “negligence caused the plaintiff to become exposed to a hazardous substance that produced, at least, subcellular changes that substantially increased the risk of serious disease, illness, or injury for which an effective medical test for reliable early detection exists, and early detection, combined with prompt and effective treatment, will significantly decrease the risk of death or the severity of the disease, illness or injury, and such diagnostic medical exams are reasonably (and periodically) necessary, conformably with the standard of care, and the present value of the reasonable cost of such tests and care.”

However, the court laid out the rules for statute of limitations for other smokers who may join the class action lawsuit, and every plaintiff will have the burden of proving each element of a negligence claim.

In response to the Mass. Supreme Court's ruling, the Richmond, Va.-based Philip Morris said the company is still trying to get the case removed from the U.S. District Court in Boston, and that federal and state courts have rejected this type of legal reasoning.