An evaluation of 20-year survival of radiofrequency ablation for hepatocellular carcinoma as first-line treatment.

OBJECTIVES: To evaluate the changes in clinical characteristics, overall survival (OS), and progression-free survival (PFS) by investigating a 20-year cohort of patients with HCC who underwent RFA treatment. METHODS: From 2000 to 2020, 505 consecutive patients with HCC underwent ultrasound-guided percutaneous RFA as first-line therapy at a tertiary cancer hospital. We divided the cohort according to the time when hepatitis-B antiviral therapy was covered by national medical insurance coverage (early 2011), including the first decade (2000-2010) and second decade (2011-2020). The prognostic factors for OS were analyzed by the Cox proportional hazard model. OS and PFS in different groups were compared using the Kaplan-Meier method. To reduce selection bias, matched groups of patients were selected using the propensity score matching (PSM) method. RESULTS: In total, 726 RFA sessions were performed to treat 867 HCC lesions. Patients treated in the second decade were younger (p =.047), had smaller tumors (p <.001), had lower Child-Pugh scores (p <.001), and had a higher proportion of antiviral treatment (p <.001). A total of 96.0% of patients achieved technical efficacy from the initial RFA. After PSM analysis, improved PFS was found for the second decade (median, 68 vs. 49 months, p =.003), but no significant difference in OS was observed between the two groups (median, 71 vs. 65 months, p =.20). CONCLUSIONS: This study demonstrated that improved PFS was achieved in patients with HCC receiving RFA as first-line treatment in the second decade. However, long-term OS was not significantly increased compared to the first decade suggesting that while RFA treatment has improved, it still might not substantially affect OS results.

Low monoenergetic DECT detection of pyelonephritis extent.

OBJECTIVES: To determine whether contrast enhanced DECT low monoenergetic can improve diagnostic conspicuity of inflamed kidney foci in acute pyelonephritis compared to conventional images. MATERIALS AND METHODS: A retrospective study of 45 patients with clinical signs of acute pyelonephritis undergoing contrast-enhanced exams on a single source-DECT was conducted. Representative conventional and monoenergetic images were randomized and presented to four abdominal radiologists to determine their preference for inflamed kidney foci detection, and to determine the number of foci identified. Clinical impact of monoenergetic images was assessed using multivariant analysis. Contrast and signal to noise ratios were compared between the images using paired t-tests. RESULTS: A greater number of foci were detected on the low energetic images for each patient (6.4 ± 5.3 vs. 4.2 ± 3.8, p < 0.02). Additionally, a consistent linear increase in the number of detected foci on the monoenergetic compared to the conventional images was seen (y = 0.10X + 0.36 R2 = 0.76). Most notably, in 16% of kidneys a clearly definable focus was detected only on monoenergetic images. SNR and CNR were increased by 2 and 1.5 fold for monoenergetic compared to conventional images (p < 0.001). Monoenergetic images were preferred by all readers for detecting inflamed foci (162/180 reads, P < 0.05), with 79% interreader reliability. CONCLUSION: Low monoenergetic images enable increased detection of inflamed kidney parenchyma, and permit identification of pathologic foci some of which were not seen on the conventional images. Along with the strong preference of radiologists, these images should be considered beneficial for evaluating acute pyelonephritis.

Significance of enhanced cerebral gray-white matter contrast at 80 kVp compared to conventional 120 kVp CT scan in the evaluation of acute stroke.

We aimed to determine whether 80 kVp conventional nonenhanced head CT scans have better gray-white matter contrast than standard 120 kVp scans performed on the same patients. Thirty head CT scans acquired at 80 kVp (CT dose index [CTDI]vol 46) were compared to prior studies in the same patients performed at 120 kVp (CTDIvol 59). Signal (Hounsfield units [HU]), noise (sd HU), and contrast-to-noise ratio per dose (CNRD) were assessed in multiple cerebral gray and white matter regions of interest. A noise correction factor was used to compensate for scanning at different CTDIvol values. Average gray matter signal at 80 kVp and 120 kVP was 33.9 ± 3.5 HU and 29 ± 4.6 HU, respectively (p<0.0001); the averages for white matter were 22.5 ± 3.1 HU and 21.6 ± 4.6 HU, respectively (p=0.11). Corrected noise was 3 ± 0.6 and 2.7 ± 0.6, respectively, for gray matter (p=0.0001), and 2.8 ± 0.6 and 2.6 ± 0.5, respectively, for white matter (p=0.00001). The gray-white matter CNRD was 4.0 ± 1.2 at 80 kVp and 2.8 ± 1 at 120 kVp (p<0.00001). Cerebral gray-white matter CNRD is increased by 40% at 80 kVp compared to conventional 120 kVp CT scans. These findings justify further clinical evaluation in the acute stroke setting.

Vacuum-assisted resection of malignant tumors with and without subsequent radiofrequency ablation: feasibility of complete tumor treatment tested in an animal model.

PURPOSE: To evaluate the feasibility of vacuum-assisted tumor excision with and without RF ablation for the minimally invasive treatment of small tumors. MATERIALS AND METHODS: Twenty VX2 tumors were implanted bilaterally into the spine muscle of 10 rabbits. Tumor excision was performed after tumor sizes reached 10 mm (12-27 d incubation) with use of a vacuum-assisted biopsy device. Three or four directed vacuum-assisted biopsies were performed in angle steps of 30 degrees. In 10 tumors, ultrasound (US)-guided radiofrequency (RF) ablation (8 min, 60 W) was subsequently performed with use of a cooled-tip electrode system. Follow-up US was performed at 3-4-day intervals for as long as 3 weeks after excision/RF ablation. Autopsy and histopathologic analysis were performed. RESULTS: The duration of vacuum excision ranged from 12 to 45 minutes (25 min +/- 7). Histologically tumor-free margins in the outer round of the core biopsy specimens were found in only four of 20 cases (20%). Maximum lesion sizes during RF ablation ranged from 18 to 25 mm (20 mm +/- 2.6). Histologic examination of the excision specimens documented tumor-free margins in only three tumors (30%) among the excision-only group and only one (10%) among the combined excision/ablation group. Local recurrences occurred in eight of 10 cases (80%) after vacuum excision alone, whereas recurrence after combined excision and RF ablation occurred only in two of 10 cases (20%; P <.05). CONCLUSIONS: Local tumor resection with use of vacuum-assisted biopsy is feasible and promising as a minimally invasive therapy for the treatment of small focal breast neoplasms. Combined excision and RF ablation techniques may reduce the rate of local recurrence considerably.