A New Method To Predict The Pathological Progression Of Ground Glass Nodules In Lung Adenocarcinoma

Objective: Low-dose chest CT has led to the detection of more early-stage lung adenocarcinomas,allowing more patients with lung cancer access to radical treatment.Lung adenocarcinoma develops in the order of atypical aneurysmal hyperplasia(AAH),carcinoma in situ(AIS),microinvasive adenocarcinoma(MIA),and invasive adenocarcinoma(IAC).Many imaging measures are available to predict the aggressiveness of ground glass nodules,but these methods remain controversial.We have devised a new method,the CT value ratio,for the practical radiological assessment of the nature of ground glass nodules.This paper focuses on the correlation between the CT value ratio and the pathological progression of lung adenocarcinoma.Methods: We retrieved CT images of 400 pulmonary ground glass nodules(GGN)that had been surgically resected from 2017-2022 and their pathological diagnostic reports.The pathologies of the 400 GGNs were atypical verrucous hyperplasia(AAH)in 100 cases,carcinoma in situ(AIS)in 100 cases,microinvasive adenocarcinoma(MIA)in100 cases,and invasive adenocarcinoma(IAC)in 100 cases.We randomly selected three cross-sections of ground glass nodules on CT and recorded the highest CT value of ground glass nodules on each cross-section.The average of the highest CT values of the three cross-sections was taken as the highest CT value of the ground glass nodule and its ratio to the CT value of the normal lung tissue of the patient was calculated and recorded as HLR.The ratio of the lowest CT value to the CT value of the normal lung tissue,LLR,was recorded in the same way.The collected data were analyzed using SPSS(version 26.0).Result: We found that the overall trend of HLR and LLR was decreasing with the advancement of tumor pathology,implying that when the HLR and LLR were smaller,the more advanced the type of pathology was.Meanwhile,LLR was significantly different between AAH and AIS(p < 0.01),with a cut-off value of 0.77(sensitivity 77%;specificity 78%).This implies that when LLR > 0.77,the likelihood of a ground glass nodule being AAH is high.In contrast,there was a significant difference in HLR between AIS and MIA,MIA and IAC(p < 0.01),with cut-off values of 0.35(sensitivity89%;specificity 64%)and 0.18(sensitivity 75%;specificity 88%),respectively.This indicates that when HLR ≤ 0.77 and LLR > 0.35,the ground glass nodule is probably AIS,when LLR ≤ 0.35,the ground glass nodule is probably MIA,and when LLR ≤0.18,the ground glass nodule is probably IAC.Anatomic lobectomy should be performed in patients with pathological type of IAC,and the prognosis of such patients will also be worse than non-IAC.Therefore,a careful distinction should be made between IAC and non-IAC.Therefore,we further found by univariate logistic regression analysis to be predictive of IAC when HLR ≤ 0.18(p < 0.001,OR: 22.7,95%CI: 8.656-59.653).Conclusions: The LLR and HLR gradually decreased with the advancement of lung adenocarcinoma pathology.LLR between AAH and AIS was statistically significant with an LLR cut-off value of 0.77.HLR between AIS and MIA,and MIA and IAC were statistically significant with HLR cut-off values of 0.35 and 0.18,respectively.Univariate logistic regression demonstrated that HLR ≤0.18 predicted invasive lung adenocarcinoma.Also,the use of the CT value ratio was more stable than the application of CT value alone.