Rate of local tumor progression following radiofrequency ablation of pathologically early hepatocellular carcinoma

AIM To evaluate whether pathologically early hepatocellular carcinoma(HCC) exhibited local tumor progression after radiofrequency ablation(RFA) less often than typical HCC.METHODS Fifty pathologically early HCCs [tumor diameter(mm): mean, 15.8; range, 10-23; follow-up days after RFA: median, 1213; range, 216-2137] and 187 typical HCCs [tumor diameter(mm): mean, 15.6; range, 6-30; follow-up days after RFA: median, 1116; range, 190-2328] were enrolled in this retrospective study. The presence of stromal invasion(namely, tumor cell invasion into the intratumoral portal tracts) was considered to be the most important pathologic finding for the diagnosis of early HCCs. Typical HCC was defined as the presence of a hyper-vascular lesion accompanied by delayed washout using contrastenhanced computed tomography or contrast-enhanced magnetic resonance imaging. Follow-up examinations were performed at 3-mo intervals to monitor for signs of local tumor progression. The local tumor progression rates of pathologically early HCCs and typical HCCs were then determined using the Kaplan-Meier method.RESULTS During the follow-up period for the 50 pathologically early HCCs, 49(98%) of the nodules did not exhibit local tumor progression. However, 1 nodule(2%) was associated with a local tumor progression found 636 d after RFA. For the 187 typical HCCs, 46(24.6%) of the nodules exhibited local recurrence after RFA. The follow-up period until the local tumor progression of typical HCC was a median of 605 d, ranging from 181 to 1741 d. Among the cases with typical HCCs, local tumor progression had occurred in 7.0%(7/187), 16.0%(30/187), 21.9%(41/187) and 24.6%(46/187) of the cases at 1, 2, 3 and 4 years, respectively. Pathologically early HCC was statistically associated with a lower rate of local tumor progression, compared with typical HCC, when evaluated using a log-rank test(P = 0.002). CONCLUSION The rate of local tumor progression for pathologically early HCCs after RFA was significantly lower than that for typical HCCs.

Lenvatinib for large hepatocellular carcinomas with portal trunk invasion:Two case reports

BACKGROUND In a phase III trial of lenvatinib as first-line treatment for advanced unresectable hepatocellular carcinoma(uHCC),the drug proved non-inferior to sorafenib in terms of the overall survival,but offered better progression-free survival.However,the effects of lenvatinib in uHCC patients with a tumor thrombus in the main portal vein and/or a high tumor burden(tumor occupancy more than 50%of the total liver volume),remain unclear,because these were set as exclusion criteria in the aforementioned trial.CASE SUMMARY A 53-year-old man(case 1)and 66-year-old woman(case 2)with uHCC presented to us with a tumor thrombus in both the main portal vein and inferior vena cava,a high tumor burden accompanied by a tumor diameter greater than>100 mm,and distant metastasis,with the residual liver function classified as grade 2A according to the modified Albumin–Bilirubin grading.We started both patients on lenvatinib.The therapeutic effect,as evaluated by the modified Response Evaluation Criteria in Solid Tumors,was rated as partial response in both case 1 and case 2(at 8 wk and 4 wk after the start of lenvatinib administration,respectively).The therapeutic effect was sustained for 6 mo in case 1 and 20 mo in case 2.Fever occurred as an adverse event in both case 1 and 2,and hyperthyroidism and thrombocytopenia in only case 2,neither of which,however,necessitated treatment discontinuation.CONCLUSION Even in hepatocellular carcinoma patients with poor prognostic factors,if the liver function is well-preserved,lenvatinib is effective and safe.

钢材表面状态对喷雾冷却特性的影响

本文研究了钢材表面状态（即表面铁皮层厚度和表面粗糙度）对喷雾冷却和空气喷射冷却特性的影响。试样为20mm厚的SUS304不锈钢。试样表面的铁皮层采用Al2O3粉末热喷涂制成。A1203层的厚度范围是50um-210um。本文还研究了无铁皮层的试样，在这种情况下，试样表面用喷丸打磨，使表面粗糙度达到20umRa。研究结果表明，在喷雾冷却和空气喷射冷却过程中，钢材表面的铁皮层具有热阻作用。喷雾冷却的冷却效果取决于表面温度、膜状沸腾的冷却速度、表面淬火温度。表面粗糙度提高了膜状沸腾的冷砷速度，进而提高了淬火温度。在空气喷射冷却过程中，热通量随表面粗糙度的增大而增大。但这种趋势只能在较大的流速时才能看到。表面粗糙度对喷雾冷却过程中的热通量具有重大影响。尽管平均热通量并不大。本研究得出，水滴冲击过程中的热通量比空气喷射冷却过程中的热通量大得多，这就解释了表面粗糙度对两种冷却方式的冷却特性具有不同的影响。