Lung cancer screening with low-dose computed tomography: Experiences from a tertiary hospital in Taiwan.

BACKGROUND/PURPOSE: Lung cancer screening using low-dose computed tomography (CT) has been reported to reduce lung cancer-specific mortality for smokers at high risk. However, despite different characteristics of lung cancer in Asia, there are few data concerning this specific population for screening. We aim to analyze the performance of lung cancer screening with low-dose CT concurrent with chest radiography in Taiwan, with reference to international experience. METHODS: During the 1-year period from January 2012 to December 2012, we conducted a retrospective, single-center population-based screening program for lung cancer in the setting of annual medical examinations. Participants were asymptomatic adults without prior history of any cancer. Low-dose CT and chest radiography were offered to all individuals. Baseline CT evaluations were defined as positive if any noncalcified nodule≥4 mm in diameter, which were then classified as solid, pure ground-glass or partial ground-glass opacity. RESULTS: Of 3339 individuals, we detected 34 cancers, yielding an overall cancer detection rate of 1.02%. There was a particularly high cancer detection rate of 6.2% (8/129) in the high-risk group aged younger than 50 years with a positive family history of all types of cancers in first-degree relatives. Adenocarcinomas accounted for 88% (30/34) of cancers and 99% of them were early-stage (including carcinoma in situ and Stage I). The probability of cancers was significant higher in nodules with interval growth (odds ratio 257.89, p = 0.0002). There was no significant difference in the probability of cancers between ground glass opacity nodules and solid nodules (odds ratio 1.16, p=0.72). Of all screen-detected cancers, 61.76% (21/34) were chest radiographically occult. CONCLUSION: Low-dose CT is effective to detect early lung cancers. Further establishment of selection criteria for lung cancer screening, specifically for Asian individuals, is definitely warranted.

Predictive Value of 18F-FDG PET/CT for Vascular Invasion in Patients With Hepatocellular Carcinoma Before Liver Transplantation.

BACKGROUND: Positron emission tomography-computed tomography using F-fluorodeoxyglucose (F-FDG PET/CT) has been widely used in oncology. Vascular invasion of hepatocellular carcinoma (HCC) is associated with a high risk of tumor recurrence and low survival rates after liver transplantation (LT). This retrospective study determined the predictive value of F-FDG PET/CT for vascular invasion in patients with HCC before LT. METHODS: Sixty-five patients with HCC who underwent F-FDG PET/CT before LT were retrospectively included between January 2010 and July 2012. Volumes of interest (VOIs) were drawn for the tumors and normal liver tissues, and the standardized uptake value (SUV) in each VOI was measured. The maximal SUV (SUVmax) of the tumor, the ratio of tumor SUVmax to normal liver SUVmax (TSUVmax/LSUVmax), and the ratio of tumor SUVmax to normal liver SUVmean (TSUVmax/LSUVmean) were measured. The predictive value of metabolic parameters and conventional prognostic factors were analyzed. RESULTS: Vascular invasion was pathologically confirmed in 15 (23.08%) of 65 patients. Compared with patients without vascular invasion, patients with vascular invasion exhibited significantly higher serum alpha-fetoprotein (AFP) (P < 0.001), larger tumor size (P = 0.001), higher tumor number (P = 0.017), and higher SUVmax, TSUVmax/LSUVmax ratio, and higher TSUVmax/LSUVmean ratio (P = 0.008, P = 0.002, and P = 0.006, respectively). Univariate analysis revealed that SUVmax, TSUVmax/LSUVmax ratio, and TSUVmax/LSUVmean ratio of FDG PET/CT were significantly associated with vascular invasion in patients with HCC before LT (P = 0.019, P = 0.018, and P = 0.015, respectively). Multivariate analysis revealed that the TSUVmax/LSUVmean ratio of F-FDG PET/CT was a significant predictor of vascular invasion (P = 0.04) and that the TSUVmax/LSUVmax ratio of F-FDG PET/CT was an independent predictor of vascular invasion, although this finding demonstrated borderline statistical significance (P = 0.06) in patients with HCC before LT. CONCLUSIONS: According to the study results, the TSUVmax/LSUVmean ratio is an independent and significant predictor of vascular invasion, and the TSUVmax/LSUVmax ratio of F-FDG PET/CT is an independent predictor of vascular invasion, which is the main negative outcome after LT. Therefore, FDG PET/CT can provide vital information for determining prognosis and selecting an optimal candidate of LT for HCC.

Inaccuracy of lung adenocarcinoma subtyping using preoperative biopsy specimens.

BACKGROUND: The prognostic significance of the new classification of lung adenocarcinoma proposed in the 2015 World Health Organization guideline has been validated. This study aimed to compare the preoperative classification of the adenocarcinoma subtype based on computed tomography-guided 18-gauge core needle biopsy (CTNB) or radial probe endobronchial ultrasound (R-EBUS) specimens, with the postoperative classification based on the resected specimens. METHODS: We retrospectively analyzed a consecutive series of 128 patients (60 CTNB and 68 R-EBUS) who underwent surgery for preoperatively confirmed lung adenocarcinoma between 2010 and 2014. Comprehensive histological subtyping was performed according to the 2015 World Health Organization classification system. Diagnostic concordance of subtypes between small biopsy and resection specimens was assessed. RESULTS: Concordant subtyping of adenocarcinomas between the predominant pattern on resections and biopsy sections was observed in 58.6% of cases (75 of 128; 95% confidence interval [CI], 49.9%-66.8%). Preoperative subtyping was accurate in only 30% of samples (3 of 10) with a predominance of solid patterns. None of the 5 micropapillary predominant cases was detected by CTNB or R-EBUS. For the concordance of the presence or absence of micropapillary/solid component, the sensitivity was as low as 16.5% (95% CI, 9.1%-26.5%). The detection rate by CTNB/R-EBUS increased with the increase in the percentage of micropapillary/solid component; however, even in the ≥40% micropapillary/solid group, only 24% of cases were detected by CTNB/R-EBUS. CONCLUSIONS: The accuracy of the estimation of adenocarcinoma histological subtype based on preoperative biopsy sections was unsatisfactory.

False Suggestion of Malignant Transformation of Benign Bone Tumor by 18F-FDG PET/CT: A Potential Pitfall.

A 68-year-old man underwent serial F-FDG PET/CT scan follow-up for lung cancer. Then 5.5 years after the initial F-FDG PET/CT scan, the presumed benign bone tumor in the left clavicle showed markedly increased FDG uptake during follow-up; in contrast, the Tc-MDP bone scan paradoxically exhibited no apparent interval change since last bone scan 5.5 years earlier. He underwent a CT-guided biopsy, and the pathological diagnosis was benign fibrous histiocytoma. The result was consistent with the lack of progression in Tc-MDP bone scan, whereas the F-FDG PET/CT scan gave a false-positive impression of malignant transformation.

Pituitary macroadenoma on 99mTc-TRODAT-1 brain SPECT.

Dopamine transporter (DAT) radiopharmaceuticals are capable of binding to the DAT with high selectivity, especially in the corpora striata, and have been widely used to evaluate parkinsonian disorder. However, only a few reports have mentioned about the extrastriatal pathologic DAT uptake. Herein we present an interesting case about the incidental discovery of pituitary macroadenoma with intense uptake of 99mTc-TRODAT-1.

Intramural metastases of rectum from carcinosarcoma (malignant müllerian mixed tumor) of uterine cervix.

A 25-year-old woman had carcinosarcoma of uterine cervix after definitive treatment. One year later, local recurrent disease was found in the right posterior pelvis on FDG PET/CT. FDG PET/CT also disclosed an incidental intramural hypermetabolic lesion in the rectum, which seemed separate from the right pelvic lesion on contrast-enhanced CT. The rectal lesion was confirmed as metastatic carcinosarcoma from uterine cervix after endoscopic biopsy.

Computed tomographic imaging in determining the need of embolization for high-grade blunt renal injury.

BACKGROUND: It is well documented that transarterial embolization (TAE) can successfully stop bleeding in renal trauma patients and reduce the failure rate of conservation treatment. However, there is no consensus on the indications for TAE. The aim of this study was to evaluate the criteria for computed tomography (CT) to predict the need for TAE for patients with high-grade blunt renal trauma. METHODS: Of the 137 patients with blunt renal trauma between 2005 and 2010, 81 had a high-grade injury (grade ≥ 3) with stable hemodynamics, who were treated conservatively, were included in the study. CT criteria included contrast extravasation (CE), perirenal hematoma rim distance (PRD), and extent of hematoma. The patients were divided into two groups according to the extent of hematoma on CT, as either Group 1 with localized hematomas or Group 2 with extensive hematomas. We compared the CT and angiographic findings and examined the correlation between patient management and outcome. The CT criteria, alone or in combination, for predicting the subsequent requirement for TAE were evaluated. RESULTS: Of the 81 patients, 35 were in Group 1 and 46 were in Group 2, with 35 having CE. The 22 patients who received TAE were all in Group 2 and had CE. Mean PRD was larger for the patients who received TAE than for those who did not. CE, extent of hematoma, and PRD correlated significantly with the need for TAE (all p < 0.001). Overall, the combination of CT criteria for CE and extent of hematoma showed the highest accuracy for predicting the need for TAE. CONCLUSION: CE, extent of hematoma, and PRD were simple and sensitive indicators of patients who required TAE. The combination of CE criteria and extent of hematoma markedly increased the predictive value for predicting the need for TAE. LEVEL OF EVIDENCE: Prognostic study, level III; therapeutic study, level IV.