When cancer patients undergo chemotherapy, the dose of most drugs is calculated based on the patient’s body surface area. This is estimated by plugging the patient’s height and weight into an equation, dating to 1916, that was formulated from data on just nine patients.

This simplistic dosing doesn’t take into account other factors and can lead to patients receiving either too much or too little of a drug. As a result, some patients likely experience avoidable toxicity or insufficient benefit from the chemotherapy they receive.

To make chemotherapy dosing more accurate, MIT engineers have come up with an alternative approach that can enable the dose to be personalized to the patient. Their system measures how much drug is in the patient’s system, and these measurements are fed into a controller that can adjust the infusion rate accordingly.

This approach could help to compensate for differences in drug pharmacokinetics caused by body composition, genetic makeup, chemotherapy-induced toxicity of the organs that metabolize the drugs, interactions with other medications being taken and foods consumed, and circadian fluctuations in the enzymes responsible for breaking down chemotherapy drugs, the researchers say.

“Recognizing the advances in our understanding of how drugs are metabolized, and applying engineering tools to facilitate personalized dosing, we believe, can help transform the safety and efficacy of many drugs,” says Giovanni Traverso, an associate professor of mechanical engineering at MIT, a gastroenterologist at Brigham and Women’s Hospital, and the senior author of the study.

Louis DeRidder, an MIT graduate student, is the lead author of the paper, which appears today in the journal Med.