Prognostic factors for in-transit metastasis in patients with malignant melanoma.

Background and aims: Malignant melanoma represents an aggressive and unpredictable malignancy, with high locoregional recurrence rates, regardless of tumor stage and therapeutic management. This study aims to identify the main histopathological prognostic factors involved in the development of in-transit metastasis in patients with malignant melanoma. Methods: The study includes only patients that were diagnosed with malignant melanoma and with histologically confirmed in-transit metastasis who were treated in a comprehensive cancer center between 2010-2021. Histopathological parameters were investigated, univariate and multivariate analysis was performed. Results: A total of 26 patients were included in the analysis. On univariate and multivariate analysis, only primary cutaneous melanomas located on the thorax correlated with the risk of developing in-transit metastasis, whereas clinicopathological factors such as an increased Breslow thickness and Clark level, the presence of ulceration, positive lymph nodes, a non-brisk TIL density, a high mitotic rate, a nodular subtype, and age >50 years may represent risk factors, even though we could not find any correlations. Conclusions: Primary cutaneous melanomas that arise on the thorax present a high risk for the occurrence of locoregional disease, whereas other clinicopathological characteristics could not be used to predict local recurrence. However, prospective and more extensive cohort studies are needed in order to validate these important prognostic factors.

Ablation therapy of non-colorectal cancer lung metastases: retrospective analysis of tumour response post-laser-induced interstitial thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA).

PURPOSE: To retrospectively compare the local tumour response and survival rates in patients with non-colorectal cancer lung metastases post-ablation therapy using laser-induced thermotherapy (LITT), radiofrequency ablation (RFA) and microwave ablation (MWA). MATERIAL AND METHODS: Retrospective analysis of 175 computed tomography (CT)-guided ablation sessions performed on 109 patients (43 males and 66 females, mean age: 56.6 years). Seventeen patients with 22 lesions underwent LITT treatment (tumour size: 1.2-4.8 cm), 29 patients with 49 lesions underwent RFA (tumour size: 0.8-4.5 cm) and 63 patients with 104 lesions underwent MWA treatment (tumour size: 0.6-5 cm). CT scans were performed 24-h post-therapy and on follow-up at 3, 6, 12, 18 and 24 months. RESULTS: The overall-survival rates at 1-, 2-, 3- and 4-year were 93.8, 56.3, 50.0 and 31.3% for patients treated with LITT; 81.5, 50.0, 45.5 and 24.2% for patients treated with RFA and 97.6, 79.9, 62.3 and 45.4% for patients treated with MWA, respectively. The mean survival time was 34.14 months for MWA, 34.79 months for RFA and 35.32 months for LITT. In paired comparison, a significant difference could be detected between MWA versus RFA (p = 0.032). The progression-free survival showed a median of 23.49 ± 0.62 months for MWA,19.88 ± 2.17 months for LITT and 16.66 ± 0.66 months for RFA (p = 0.048). The lowest recurrence rate was detected in lesions ablated with MWA (7.7%; 8 of 104 lesions) followed by RFA (20.4%; 10 of 49 lesions) and LITT (27.3%; 6 of 22 lesions) p value of 0.012. Pneumothorax was detected in 22.16% of MWA ablations, 22.73% of LITT ablations and 14.23% of RFA ablations. CONCLUSION: LITT, RFA and MWA may provide an effective therapeutic option for non-colorectal cancer lung metastases with an advantage for MWA regarding local tumour control and progression-free survival rate.

Thermal Ablation of Lung Tumors: Focus on Microwave Ablation.

Background Image-guided thermal ablation can be used for the treatment of medically inoperable primary and metastatic lung cancer. These techniques are based on the heating up or freezing (cryoablation) of a volume of tissue around a percutaneous applicator that induces necrosis of the tumor. Method The English-language literature concerning thermal ablation of the lung was reviewed. Radiofrequency ablation (RFA) is the most widely performed and investigated of these techniques. Microwave ablation (MWA) represents a relatively new alternative that shares the same indications and is conducted in a very similar fashion as RFA. It has been experimentally and clinically shown that MWA produces larger, more spherical ablation zones over shorter periods of time compared to RFA. Seven different MWA systems are available in Europe and the USA with significant differences in the size and shape of the produced ablation zones. Results The types of complications caused by MWA and their rates of occurrence are very similar to those caused by RFA. The local progression rates after MWA of lung malignancies vary between 0 % and 34 % and are similar to those in the RFA literature. Conclusion Despite technical improvements, the current generation of MWA systems has comparable clinical outcomes to those of RFA. Key Points · MWA is a safe technique that should be considered one of the treatment options for medically inoperable lung tumors. · As thermal ablations of lung tumors are becoming more frequent, radiologists should be acquainted with the post-ablation imaging characteristics. · Although MWA has some theoretical advantages over RFA, the clinical outcomes are similar. Citation Format · Vogl TJ, Nour-Eldin NA, Albrecht MH et al. Thermal Ablation of Lung Tumors: Focus on Microwave Ablation. Fortschr Röntgenstr 2017; 189: 828 - 843.