For MIA and AIS, patients have an approximately 100% 5-year survival rate following resection, no statistically significant differences for disease-free survival (DFS) and overall survival (OS). For IADC stage IA1, OS rate is insignificant compared to MIA but 10-20% IADC relapse. [4]
Low dose CT lung screens enable detection of early lung cancers and early surgery. Artificial intelligence aids in early detection both by improving imaging with deep learning algorithms (DLA) and with computer aided detection (CAD) of lung nodules. Improved scanners with filters and DLA as well as new detectors such as in Siemens Photon Counting CT (PCCT) have resulted in ultra-low dose CT lung screens, with doses as low as the equivalent of less than 2 CXRs.
In the Parkway Radiology group which services the four largest private hospitals in Singapore, ultralow dose lung CTs are performed on the Canon Aquilion One, Prism edition and the Siemens Naeotom PCCT; both with similar ultralow doses achieved.
The use of AI in CAD reduces the reading time and increases the detection rate of lung nodules, functioning either as a concurrent or second-reader. [5], [8]
In our group, we are the first in the country to use a Health Sciences Authority (HSA) AI system in reporting our CT lung screens. Initially, we employed AI to check our reports, but of late, it has become the other way around; AI detects the nodules and our radiologists review these.
Once detected, we employ either the Fleischner Society 2017 [6] or the ACR’s Lung Rads v 2022 [7] criteria for follow-up and management.
The large GGOs and the semisolid GGOs are then surgically resected. As these are sometimes extremely small, radiological localization is routinely performed. In our practice, CT guided tattooing of the nodule with methylene blue is performed half an hour before the surgery. The surgeon then resects the blue spot. This is also useful for the pathologist, as they often are unable to find the lesion and they have to be advised to cut on the blue.
Should the patient be unfit for surgery, cryoablation of the GGO is performed; with good local control and low recurrence rates. [9], [10]