Starting at square one
The first mobile CT scanner was launched in Nagano Prefecture, a rural area in Japan, in 1996. Since then, mobile screening units, primarily mounted on tractor trailers, have brought screening to centralized areas, such as shopping mall parking lots. The Levine Cancer Institute in Charlotte, North Carolina, also has a mobile CT-screening unit mounted in a modified box truck.
For Headrick and colleagues the goal was not to reinvent the wheel, but to see if a mobile lung cancer screening program could improve access and also pay for itself in a time of parsimonious support for preventive medicine.
Their first challenge was the mobile unit itself.
“CT scanners are sensitive, complex electrical machines that require climate control and a level environment to operate. Historically, they have been placed in tractor trailers and parked on level concrete slabs connected to external power supplies. We needed mobility, self-leveling, independent power, climate control, patient comfort, and drivability,” they wrote.
They assembled a team of engineers from CT and vehicle makers, and input was also provided by a thoracic surgeon, pulmonologist, radiologist, CT technician, and driver with a commercial driver’s license. Together, they designed and built the bus over 8 months. Funds for the total cost of the prototype vehicle ($650,000) came from two local nonprofit foundations. The estimated cost for a commercial version of the same vehicle was $850,000.
The Breathe Easy pilot began operation in early 2018, with the initial plan to drive the bus within a 2-hour radius of CHI Memorial Hospital, Chattanooga, Tennessee, to avoid overnight trips. The radius was later shortened to 1.5 hours when operators realized it was a burden for patients with significant screening findings to travel to as much as 4 hours (round trip) to Chattanooga for further testing.
Each screening visit takes about 15 minutes.
Cancer and other significant findings
As noted before, the bus traveled to 104 sites over 10 months, and 548 patients with a mean age of 62 were screened. Five lung cancers were identified, including two stage 1A, one stage 1A2, one stage 1B, and one stage 3A.
Two patients with early stage disease underwent stereotactic body radiation therapy, and two underwent minimally invasive surgery (a segmentectomy and a lobectomy). The patient with stage 3A disease underwent curative chemotherapy and radiation therapy. One patient with a type B1 thymoma underwent robotic-assisted thoracoscopic resection with en bloc pericardial resection and reconstruction.
A total of 51 patients had a significant pulmonary finding of Lung CT Screening Reporting and Data System (Lung-RADS) 3 or 4 and were advised to follow up with further testing, but 17 patients in this group did not pursue further testing. Of these 17 patients, 15 had been screened in a health clinic for the homeless at a rural site.
Significant nonpulmonary findings included moderate to severe coronary artery disease in 101 patients, abdominal findings in 15, thyroid abnormalities in 14, other thoracic findings in 10, and ascending aortic dilatation in 9. Of the 152 patients with nonpulmonary findings, only 13 required further testing and none required treatment.