Ultra-low-dose intraoperative X-ray imager for minimally invasive surgery: a pilot imaging study

Abstract

Background: With advances in surgical technology, thoracic surgeons have widely adopted minimally invasive limited-resection techniques to preserve normal tissues. However, it remains difficult to achieve in situ localization of invisible pulmonary nodules during surgery. Therefore, we proposed an in situ ultralow-dose X-ray imaging device for intraoperative pulmonary nodule localization during minimally invasive surgeries. Methods:The proposed device features a hand-held type and consists of a carbon nanotube-based X-ray source and an intraoral dental sensor. In a preclinical study, we created pseudo pulmonary nodules using ex vivo pig lungs. Subsequently, its clinical feasibility was evaluated using ex vivo lung cancer specimens from patients with cancer who had undergone minimally invasive surgery.Results: Using the proposed device, we successfully differentiated normal and abnormal tissues from X-ray images of resected lung specimens. In addition, our proposed device only yielded an average radiation dose of 90.9 nGy for a single acquisition of X-ray images and demonstrated excellent temperature stability under consecutive X-ray irradiations. The radiation exposure of our proposed device (0.1±0.0006 μSv/h) was significantly lower than that of conventional C-arm fluoroscopy (41.5±51.8 μSv/h). In both preclinical and clinical studies, the margin of nodule shadows was clearly visualized using the proposed device. Conclusions:The proposed device substantially reduced radiation exposure to staff and patients and may allow in situ localization of pulmonary nodules. Our proposed device clearly revealed the margins of lung nodules with radiocontrast injection and showed the potential to identify solid nodules without the use of radiocontrast agents.

Imaging skins: stretchable and conformable on-organ beta particle detectors for radioguided surgery

“…In minimally invasive surgery (MIS), the challenge deepens since access through the incision port limits visual inspection and restricts direct finger palpation and indirect palpation through a medical instrument. Besides, these methods are rarely sufficient to assess the location of the resection margins or they are still at the experimental stage [12,13].…”

“…What would be the potential benefits of integrating these concepts into radiation detectors that are directly attached to the organs? In the specific application of nuclear imaging, we hypothesise that bringing a radiation detector closer to the source would improve the signal-to-noise ratio (SNR), thereby reducing the radiation dose required to obtain high-quality images [13,20]. This would also extend the imaging while providing instantaneous feedback during surgery.…”

Will the ultra-low-dose intraoperative X-ray imager change thoracoscopic surgery?

“…Park et al described the use of an ultra-low-dose X-ray imager to identify lung nodules intraoperatively (16). This device is a hand-held, clamp-shaped endoscopic instrument that employs a carbon nanotube, which allows a compact design.…”

“…The second issue with the ultra-low-dose X-ray imager is that Park et al identified lesions containing contrast media (16). In clinical practice, the insertion of a contrast agent into a lesion involves an extra procedure, which involves additional radiation exposure and procedural risks.…”