Current Opinion about Hepatocellular Carcinoma <10 mm

BACKGROUND

Early detection of hepatocellular carcinoma (HCC) is important. Advances in liver imaging techniques have facilitated the detection of HCC at an early stage. However, there is a controversial discussion on how to diagnose very small HCC by imaging. The aim of the current review is to present current published data on HCC ≤10 mm and discuss on how to best diagnose and treat such lesions.

SUMMARY

It is still challenging, however, to accurately characterize HCC <10 mm. The accuracy of contrast-enhanced ultrasound may be critical for early treatment decisions for cancer patients, particularly when CECT and/or CEMRI are inconclusive. Key Messages: The characterization of focal liver lesions <10 mm is frequently delayed until a follow-up imaging procedure demonstrates growth or stability. A repetition of ultrasound examination after 3 months for new nodules <1 cm should be recommended.

Tumor volume-adapted SUVN as an alternative to SUVpeak for quantification of small lesions in PET/CT imaging: a proof-of-concept study

PURPOSE

SUV_peak is a recommended quantification metric except for small lesions. We aimed to assess the averaged standard uptake value (SUV_N) as an alternative to SUV_peak for small-lesion quantification.

MATERIALS AND METHODS

NEMA-like phantom images were reconstructed using OSEM, OSEM + PSF, OSEM + TOF and OSEM + TOF + PSF with two post-smoothing Gaussian filters for different background activity levels. SUV_max, SUV_N (N = 5, 10, 15, 20, 25, 30, 35 or 40 hottest voxels), and SUV_peak, relative percent error, contrast recovery, and volume recovery coefficients were quantified and assessed.

RESULTS

SUV_N did not have the limitations of SUV_peak for smaller lesions. In the smallest insert at 2.68 kBq/ml, optimum N values for OSEM, OSEM + PSF, OSEM + TOF and OSEM + TOF + PSF were 10, 5, 15, and 10 for SUV_N, respectively. The same N values were obtained for metabolic tumor volumes (MTVs) for all reconstruction algorithms. At 5.30 kBq/ml, N = 5 was optimum for SUV_N and MTVs. For the larger inserts, the optimum N increased and tended towards the maximum (similar to SUV_peak).

CONCLUSIONS

SUV_N is more accurate than SUV_max or SUV_peak for small lesions, while being as accurate in larger ones. This harmonizing capacity of SUV_N can be beneficial for the quantitative analysis of small tumor volumes.

[Analysis of Percutaneous Biopsy of 41 Small Lung Lesions]

BACKGROUND

When lung cancer screening work extensively developed in recent years, more and more small lung lesions were found in clinic. The aim of this study is to analysis computed tomography (CT) guided percutaneous biopsy for lung small lesions (diameter<2 cm) on results, complications and prognosis.

METHODS

Choose CT guided percutaneous lung biopsy were performed in 41 cases of pulmonary peripheral lesions, single lesion in 39 cases, multiple lesions in 2 cases, 5-20 (13.1±5.2) mm in maximum diameter, depth from lung surface 1-45 (16.5±13.7) mm, ground-glass opacity (GGO) components 0%-100% (66.8%±35.2%).

RESULTS

41 patients and 43 biopsies successfully obtained pathological tissue. Atypical adenomatous hyperplasia in 3 cases, squamous carcinoma in 1 case, adenocarcinoma in 37 cases( carcinoma in situ in 7 cases, micro-invasive carcinoma in 5 cases, invasive adenocarcinoma in 25 cases, double primary lung cancer in 2 cases), inflammatory lesions in 2 cases. Except 2 cases of inflammatory lesions are in follow-up, biopsy and surgical pathology alignment (specificity) was 100%. 41 patients occurred complications related to percutaneous biopsy. Pneumothorax were in 22 cases, drainage required in 2 cases. There were 17 cases with hemoptysis, accounting for 39.5% incidence are self-limited. Intracranial air embolism occurred in 2 cases by 4.6% incidence. They were fully recovered.

CONCLUSIONS

For small lung lesions, CT guided percutaneous biopsy is technically feasible. However, for small lung lesions especially pure GGO biopsy, it is still need to be cautious.

MR visible localization device for radiographic-pathologic correlation of surgical specimens

PURPOSE

The detection of small parenchymal hepatic lesions identified by preoperative imaging remains a challenge for traditional pathologic methods in large specimens. We developed a magnetic resonance imaging (MRI) compatible localization device for imaging of surgical specimens aimed to improve identification and localization of hepatic lesions ex vivo.

MATERIALS AND METHODS

The device consists of two stationary and one removable MR-visible grids lined with silicone gel, creating an orthogonal 3D matrix for lesion localization. To test the device, five specimens of swine liver with a random number of lesions created by microwave ablation were imaged on a 3T MR scanner. Two readers independently evaluated lesion coordinates and size, which were then correlated with sectioning guided by MR imaging.

RESULTS

All lesions (n=38) were detected at/very close to the expected localization. Inter-reader agreement of lesion localization was almost perfect (0.92). The lesion size estimated by MRI matched macroscopic lesion size in cut specimen (±2mm) in 34 and 35, respectively, out of 38 lesions.

CONCLUSION

Use of this MR compatible device for ex vivo imaging proved feasible for detection and three-dimensional localization of liver lesions, and has potential to play an important role in the ex vivo examination of surgical specimens in which pathologic correlation is clinically important.