The Primary Tumor Characteristics of Non-Small Cell Lung Cancer on Pet/Ct

Objective: To explore the location, tumor diameter and SUVmax on PET/CT of primary tumor in non-small cell lung cancer. Subjects and Methods: Patients diagnosed with non-small cell lung cancer based on pathology results were retrospective analyzed at Oncology and Nuclear Medicine Department - Bach Mai Hospital, from November 2015 to October 2018. They were underwent 18F-FDG PET-CT scans before the treatment. The variables include location, tumor diameter, SUVmax of the primary tumor. Results:


Introduction
Lung cancer is a fairly common malignancy of the respiratory system, the most common cause of cancer death in Europe in 2006 (about 334,800 deaths), after prostate cancer and is the most common type of cancer in men. The morbidity and mortality rates in 2006 were 75. 3  In recent years, the role of PET / CT in diagnosing and assessing the stage of non-small cell lung cancer has been increasingly confirmed. However, in our country, there is no research to mention the role of PET / CT in assessing stage of non-small cell lung cancer.

Materials and Methods
The subjects selected were patients with Non-small cell lung cancer diagnosed by pathological anatomy and were taken PET / CT according to the method selected in the study.
Place: performed at the Department of Oncology and Nuclear  (Tables 1-3). Total 318 100,0 The smallest, the biggest medium The smallest: 0.9 cm; The largest: 15.9 cm Average: 4.77 ± 2.41 cm Note: Primary tumors were found at all sizes with equal ratio, the smallest tumor was 0.9 cm, the largest was 15.9 cm; Average 4.77 ± 2.41 cm. Note: The tumor is present in all the pulmonary lobes, in which the upper lobe accounts for the highest proportion (36.8%), the lower lobe (29.2%), the original bronchus (12.9%). SUV is a semi-quantitative indicator that assesses the tumor's FDG uptake. On that basis, collect metabolic assessment information [4]. However, some studies show that SUVs are not an independent prognostic factor when compared to the period [6].
In Park SB et al. [4], SUVmax was not an independent prognostic factor with survival time on univariate analysis (P = 0.168). This author's result is also consistent with previous reports that have found that SUVmax is not an independent prognostic factor for survival time [6]. This can be partly explained by the influence of the partial volume and the dependence of SUVmax on tumor size. SUV is a unique voxel measurement, with the points with the highest radioactive concentration in the Volume of Interest (VOI).
So. may not reflect the heterogeneous nature of the tumor and it is easily affected by noise interferences in statistics and voxel size [5].
Difference of SUVmax is only representative for single voxel. In the meanwhile, MTV and TLG represent the extent of FDG uptake of the whole tumor and have been considered as a better predictor of index than SUVmax, giving good applicability in clinical practice in the survey. types of malignancies [7]. The clinical signs and symptoms of lung cancer are often vague or nonspecific, including cough, chest pain, hoarseness, recurrent pneumonia and coughing up blood. Conventional X-rays help find lung nodules or tumors, but often produce false-negative results, especially in early-stage disease [8]. In a study of 396 lung radiographs of proven lung cancer patients from 1992-1995, nearly 20% of lung cancer was undetectable, usually with nodules less than 1.6 cm in diameter [9].
Many cases were not detected on radiographs, until lesions were detected relatively large in size [8]. Computerized tomography has greatly improved compared to pulmonary X-ray in detecting small lesions [10].
For non-small cell lung cancer, PET / CT is better than computerized tomography for distinguishing benign and malignant lesions and is far more valuable in the evaluation of invasive lymphadenopathy and distant metastases. Other officials [11].
Research by Antoch et al. [12] shows that the superior detection of PET / CT scans compared with PET scans or computed tomography in evaluating T-stage small cell non-small cell lung cancer (accuracy 94 % with PET / CT versus 75% of PET or computerized tomography, stage N (93% accuracy with PET / CT and 63% for computerized tomography and 89% for PET alone). PET / CT is also better at detecting distant metastases than CT or PET alone. Although the accuracy of PET / CT is higher than that of computerized tomography in lung cancer assessment. However, in some cases of non-malignant lesions such as inflammation, granulomatosis (mycobacterial infection, sarcoidosis), recent surgery may have a false positive result with FDG uptake [13].

Conclusion
The smallest tumor is 0.9 cm, the largest is 15.9 cm Average 4.77 ± 2.41 cm. The tumor was present in all hydro-lung, in which the upper lobe accounted for the highest proportion (36.8%), followed by the lower lobe (29.2%), and the original bronchus