Percutaneous Microwave Research Articles

Outcomes Following Percutaneous Microwave and Cryoablation of Lung Metastases from Adenoid Cystic Carcinoma of the Head and Neck: A Bi-Institutional Retrospective Cohort Study.

The aim of this study was to report outcomes following percutaneous microwave and cryoablation of lung metastases from adenoid cystic carcinoma (ACC) of the head and neck. This bi-institutional retrospective cohort study included 10 patients (6 females, median age 59 years [range 28-81]) who underwent 32 percutaneous ablation sessions (21 cryoablation, 11 microwave) of 60 lung metastases (median 3.5 tumors per patient [range 1-16]) from 2007 to 2019. Median tumor diameter was 16 mm [range 7-40], significantly larger for cryoablation (22 mm, p=0.002). A median of two tumors were treated per session [range 1-7]. Technical success, local control, complications, and overall survival were assessed. Primary technical success was achieved for 55/60 tumors (91.7%). Median follow-up was 40.6 months (clinical) and 32.5 months (imaging, per tumor). Local control at 1, 2, and 3years was 94.7%, 80.8%, and 76.4%, respectively, and did not differ between ablation modalities. Five of fifteen recurrent tumors underwent repeat ablation, and secondary technical success was achieved in four (80%). Assisted local tumor control at 1, 2, and 3years was 96.2%, 89.8%, and 84.9%, respectively. Complications occurred following 24/32 sessions (75.0%) and 57.2% Common Terminology Criteria for Adverse Events (CTCAE) lower than grade 3. Of 13 pneumothoraces, 7 required chest tube placements. Hemoptysis occurred after 7/21 cryoablation sessions, and bronchopleural fistula developed more frequently with microwave (p=0.037). Median length of hospital stay was 1 day [range 0-10], and median overall survival was 81.5 months (IQR 40.4-93.1). Percutaneous computed tomography-guided microwave and cryoablation can treat lung metastases from ACC of the head and neck. Complications are common but manageable, with full recovery expected.

Percutaneous microwave ablation of hepatocellular carcinoma

Percutaneous microwave ablation of hepatocellular carcinoma

Assessing ablation margins of FDG-avid liver tumors during PET/CT-guided thermal ablation procedures: a retrospective study

To retrospectively assess liver tumor ablation margins using intraprocedural PET/CT images from FDG PET/CT-guided microwave or cryoablation procedures and to correlate minimum margin measurements with local progression outcomes. Fifty-six patients (ages 36 to 85, median 62; 32 females) with 77 FDG-avid liver tumors underwent 60 FDG PET/CT guided, percutaneous microwave, or cryoablation procedures. Single breath-hold PET/CT images were used for intraprocedural assessment of the tumor ablation margin: liver tumors remained visible on PET immediately following ablation; microwave ablation zones were visible using contrast-enhanced CT; cryoablation zones (ice balls) were visible using unenhanced CT. Two readers retrospectively determined ablation margin assessability and measured the minimum ablation margin on intraprocedural PET/CT (n = 77) and postprocedural MRI (n = 56). Local tumor progression was assessed on all available follow-up imaging (1-49 months, mean 15). Local tumor progression was correlated with PET/CT minimum margin measurements using clustered survival models for 61 tumors. Minimum ablation margins were more often assessable using intraprocedural PET/CT (≥ 73/77 tumors, 95%) than postprocedural MRI (≤ 35/56 tumors, 63%). In 61 tumors with PET/CT-assessable margins (excluding tumors with overlapping ablations after PET/CT), there was a 6-fold increased risk of local tumor progression [hazard ratio (HR) 6.05; P = 0.004] for minimum ablation margins < 5 mm. Breath-hold PET/CT scans, during PET/CT-guided microwave or cryoablation procedures for FDG-avid liver tumors, enable reliable intraprocedural assessment of the entire tumor ablation margin; a minimum PET/CT ablation margin threshold of 5 mm correlates well with local tumor progression outcomes.

Feasibility and safety of fine positioning needle-mediated breathing control in CT-guided percutaneous puncture of small lung/liver nodules adjacent to diaphragm

To assess the efficacy, safety, and feasibility of a separate inserted positioning fine needle-mediated breathing-control technique applied to computed tomography (CT)-guided percutaneous puncture for biopsy or microwave ablation (MWA) of small lung/liver nodules near diaphragm. Total 46 patients with pulmonary/liver small nodules (≤ 3 cm in size) near diaphragm(nodule within 1 cm distance to the diaphragm)were undergone percutaneous biopsy ( n = 15) or MWA (n = 31) under the guidance of CT, and a separate positioning fine needle-mediated breathing-control technique was applied for the precise punctures. CT plain scan was performed to monitor the complications after the procedure. The patient baseline data, operation details, successful rate, major complications as well as radiation dose during the procedure were recorded and analyzed. With the assistance of a fine positioning needle insertion for controlling the breathing, the puncture success rate for biopsy or MWA reached 91.30% (42/46). For biopsy, the mean nodule diameter, nodule distance to the diaphragm, puncture time and radiation dose during CT scan were 2.27 cm ± 0.74, 0.61 cm ± 0.24, 18.67 min ± 6.23, 28.84 mSv ± 6.99, respectively; For MWA, the mean nodule diameter, nodule distance to the diaphragm, puncture time and CT radiation dose were 2.35 cm ± 0.64, 0.69 cm ± 0.23, 38.71 min ± 13.65, 33.02 mSv ± 8.77, respectively. Totally, there were three and four cases found minimal puncture-related hemoptysis and pneumothorax needed no additional treatments, respectively. We recently developed and verified a feasible, safe and highly effective puncture technique with reasonable radiation dose for CT-guided biopsy or MWA for small nodules abutting diaphragm, therefore worthy of extensive application to similar clinical situations.

Relationship of Antenna Work and Ablation Cavity Volume Following Percutaneous Microwave Ablation of Hepatic Tumors

PurposeTo formulate a statistical model relating ablation time, power, and work with posttreatment cavity volume following percutaneous microwave ablation of hepatic tumors in vivo. Materials and MethodsA retrospective review (October 2015 to October 2018) yielded 122 hepatic tumors treated with microwave ablation. Ablation cavity dimensions were measured at 1-month follow-up examination and calculated using an ellipsoid volume formula. The antenna manufacturer (Neuwave Medical, Madison, Wisconsin) provided the activation time and energy used to calculate the antenna work. Generalized estimating equations with ordinary least-squares regression models were obtained to relate tumor volume with cumulative antenna work. Coefficient of determination (R2) and mean square error were used as statistical measures of model prediction performance. ResultsThere is a logarithmic relationship between postablation cavity volume (cm3) and cumulative work (kJ), represented by the formula: log10 cm3 = −0.4583 + 0.9887 × cumulative work (log10 kJ) (R2 = 0.41, mean square error, 0.102). Ablation volumes were predicted as a function of antenna work, calculated using an antilog transformation. When a single antenna was used, ablation cavity volume was predicted using a generalized estimating equation ordinary least-squares regression model of power and time: log10cm3= −0.0546 + 0.0485 × total time (min) + 0.0107 × power (W) (R2 = 0.30; mean square error, 0.106). Using this model, a nomogram was developed to predict the postablation cavity volume based on total activation time and target power. ConclusionThere is a logarithmic relationship between the ablation work and posttreatment ablation cavity volume, which can be expressed in a nomogram when using a single probe.

Percutaneous Microwave Ablation of Desmoid Fibromatosis.

ObjectiveTo demonstrate the feasibility of percutaneous microwave ablation in desmoid fibromatosis with respect to tumor volume control and improvement in the quality of life.Materials and MethodsTwelve microwave ablations were performed in 9 patients with a histological diagnosis of desmoid fibromatosis between January 2010 and January 2019. The study population included 6 female and 3 male, with an age range of 21–76 years (mean = 46.6 years; standard deviation [SD] = 19.3 years). The mean major axis of the tumors was 10.9 cm (SD = 5.2 cm) and mean lesion volume was 212.7 cm3 (SD = 213 cm3). Their anatomical distribution was as follows: 3 lesions in the thigh, 2 in the gluteus, 2 in the leg and 2 in the periscapular region. We evaluated the reduction in tumor volume and improvement in the quality of life based on the Eastern Cooperative Oncology Group (ECOG) scale.ResultsAn average tumor volume reduction of 70.4% (SD = 24.9) was achieved, while the quality of life (ECOG scale) improved in 88.9% of patients.ConclusionPercutaneous microwave ablation may potentially be a safe, effective, and promising technique for controlling tumor volume and improving the quality of life in patients with desmoid fibromatosis.

Long-term outcomes of ultrasound-guided percutaneous microwave ablation versus resection for colorectal cancer liver metastases: a propensity-score matched study

Background and Aims Many previous studies comparing liver resection versus thermal ablation for colorectal cancer liver metastases (CRCLM) are subject to severe selection bias. This study aimed to compare the long-term clinical efficacy of ultrasonography-guided percutaneous microwave ablation (PMWA) with resection for CRCLM using propensity score analysis to reduce confounding by indication. Methods This retrospective study included 184 patients with CRCLM from January 2012 to June 2017. Treatment effect was estimated after propensity score matching, Descriptive, regression and survival statistics were applied. Results A lower American Society of Anesthesiologists classification score and higher performance status were found positively associated with resection (p < 0.05). After propensity score matching, the 1-, 2-, and 3-year local tumor progression free survival rates were found to be 60.3%, 19.1%, and 17.6% in the PMWA group, and 72.1%, 35.3%, 26.5% in the resection group, respectively (p = 0.049). The 1-, 3-, 5-, and 7-year overall survival rates in two groups were similar (p = 0.943). In the PMWA group and resection group, the median hospital stay was 1 (0–12) days and 7 (1–27) days (p = 0.005), respectively; major complications occurred in two patients (2%) and 11 patients (12.9%) (p = 0.009), respectively. Conclusions After adjusting for factors known to affect treatment choice, no significant difference in overall survival rates was shown after ultrasound-guided PMWA versus resection for CRCLM. The LTPFS rate of the resection group were better than those of the ultrasound-guided PMWA group. However, the ultrasound-guided PMWA group had fewer complications and shorter hospital stay.

A preliminary study on ultrasound-guided percutaneous microwave ablation for palliative treatment of advanced head and neck malignancies

Objective To evaluate the safety and efficacy of ultrasound (US)-guided percutaneous microwave ablation (UgPMWA) for palliative treatment of advanced head and neck malignancies. Materials and methods This study includes 18 consecutive patients with advanced head and neck malignancies (n = 24), who have undergone UgPMWA for palliative treatment at our institution from December 2016 to April 2020. The maximum diameter and volume of the tumor were assessed by US, CT or MRI before microwave ablation (MWA), 1, 3 and 6 months after MWA and every 6 months thereafter. The quality of life was clinically assessed by the University of Washington Head and Neck Quality of Life questionnaire (UW-QOl). Results The success rate of tumor-targeting microwave antenna placement was 100%. No nerve injury and serious complications or death occurred during the perioperative period. The follow-up duration varied from 1 month to 38 months (11.56 ± 10.23 months) among patients. By the last follow-up before submission, the value of maximum diameter (5.00 ± 2.90 vs 3.28 ± 2.11 cm. p < 0.05) and tumor volume decreased significantly（74.35 ± 46.88 vs 47.45 ± 24.08 cm3. p < 0.05）respectively after palliative treatment with UgPMWA. UW-QOl of the patients was improved (59.24 ± 11.51 vs 69.84 ± 8.12, p < 0.05). Conclusion UgPMWA is safe and effective for the palliative treatment of head and neck malignancies. Ultrasonic guidance can indicate an accurate location of the microwave antenna. It can also monitor the ablation area in real-time during the operation to avoid damage to surrounding normal tissues.

Risk prediction of pneumothorax in lung malignancy patients treated with percutaneous microwave ablation: development of nomogram model

Objectives To develop effective nomograms for predicting pneumothorax and delayed pneumothorax after microwave ablation (MWA) in lung malignancy (LM) patients. Methods LM patients treated with MWA were randomly allocated to a training or validation cohort at a ratio of 7:3. The predictors of pneumothorax identified by univariate and multivariate analyses in the training cohort were used to develop a predictive nomogram. The C-statistic was used to evaluate predictive accuracy in both cohorts. A second nomogram for predicting delayed pneumothorax was developed and validated using identical methods. Results A total of 552 patients (training cohort: n = 402; validation cohort: n = 150) were included; of these patients, 27.9% (154/552) developed pneumothorax, with immediate and delayed pneumothorax occurring in 18.8% (104/552) and 9.1% (50/552), respectively. The predictors selected for the nomogram of pneumothorax were emphysema (hazard ratio [HR], 6.543; p < .001), history of lung ablation (HR, 7.841; p= .025), number of pleural punctures (HR, 1.416; p < .050), ablation zone encompassing pleura (HR, 10.225; p < .001) and pulmonary fissure traversed by needle (HR, 10.776; p < .001). The C-statistics showed good predictive performance in the training and validation cohorts (0.792 and 0.832, respectively). Another nomogram for delayed pneumothorax was developed based on emphysema (HR, 2.952; p= .005), ablation zone encompassing pleura (HR, 4.915; p < .001) and pulmonary fissure traversed by needle (HR, 4.348; p = .015). The C-statistics showed good predictive performance in the training cohort, and it had efficacy for prediction in the validation cohort (0.719 and 0.689, respectively). Conclusions The nomograms could effectively predict the risk of pneumothorax and delayed pneumothorax after MWA.

Efficacy and safety of CT-guided microwave ablation for stage T1a renal cell carcinoma in patients with a solitary kidney

Objective To retrospectively evaluate early clinical outcomes of percutaneous microwave ablation (MWA) for stage T1a renal cell carcinomas (RCCs) in solitary kidney patients. Materials and methods 15 solitary kidney patients with 16 stage T1a N0M0 biopsy-proved RCCs underwent CT-guided percutaneous microwave ablation between October 2016 and July 2020. The patients were followed up with contrast-enhanced computed tomography or magnetic resonance imaging at 1, 3, and 6 months and every 6 months thereafter. Serum creatinine levels of each patient pre MWA, 1 day after MWA and the most recent record were collected. Technical effectiveness, local recurrence, survival rates and complications were accessed. Results Complete ablation was achieved in all 16 tumors (100%) including 13 clear cell carcinomas and 3 papillary carcinomas. Within the follow-up time (median: 24 months) no tumor recurrence or major complication was detected. No significant change in serum creatinine level was noted. The cancer-specific survival rate was 100% (15 of 15), and 1-, 2-, and 3-year overall survival rates were 100%, 93.3%, and 93.3%, respectively. Conclusion Percutaneous MWA is an effective and safe treatment option for stage T1a RCCs in solitary kidney patients; it can achieve high complete ablation rate in selected lesions of appropriate size and location.

Predicting the coagulation volume induced by microwave ablation of hepatocellular carcinoma: the role of deposited energy, ex-vivo bovine liver charts and central hyperdense area on post-treatment CT

Purpose To study the correlation between the overall coagulation zone (A) attained in percutaneous microwave ablation (MWA) of hepatocellular carcinomas (HCC) and: (1) the hyperdense zone (C) visible in the central part of zone A on post-treatment unenhanced CT scans; (2) the deposited energy; (3) the coagulation zones observed on ex-vivo bovine liver. Materials and methods The post-procedural computed tomography (CT) scans of HCCs treated with a single energy deployment through the same 2450 MHz MWA system were retrospectively analyzed, retrieving the dimensions of A and C zones and the deposited energy (E). Ex-vivo bovine liver MWA with the same system were performed and analyzed to determine the same quantities by gross-pathologic examination and CT imaging. Results A total of 101 HCC treatments were analyzed. The average coagulation volumes increased linearly with deposited energy (1.11 cc/kJ, R 2 = 0.90, 4.2 kJ ≤ E ≤ 48 kJ), similarly to ex-vivo findings (1.38 cc/kJ, R 2 =0.97, 7.2 kJ ≤ E ≤ 144 kJ). The long axis (L) and short axis (D) of zones A and C held a fairly constant ratio both in-vivo (LC/LA=0.43 ± 0.13; DC/DA=0.42 ± 0.10) and ex-vivo (LC/LA = 0.49 ± 0.07; DC/DA = 0.28 ± 0.06). Conclusions The average dimensions of the ablation zone induced by the considered system on HCC increase linearly with the deposited energy and are fairly well predicted by the corresponding ex-vivo dimensions. The ratio between each linear dimension of A and C zones was found to be roughly constant over a large deposited energy span, both ex-vivo and in-vivo.

Minimally Invasive Microwave Ablation of Colorectal Cancer Liver Metastases: A Single Institution Experience with 135 Surgical Ablations

Background: Percutaneous Microwave Ablation (MWA) is an effective therapy for non-resectable colorectal liver metastases (CRLM), but many are not percutaneously treatable. We report one of the largest single-institution experiences with laparoscopic, ultrasound-guided MWA of 135 unresectable CRLM. Methods: We performed a retrospective review of ablated CRLM from 2009-2018. Demographics, disease and treatment characteristics were abstracted. Kaplan-Meier modeling was performed. Results: We ablated 135 CRLM in 36 patients. Median age was 52 years and 58% of patients were male. The primary tumor was of colonic origin in 26 patients (72%), and the remainder (28%) were rectal cancer metastases. All patients received systemic chemotherapy. Non-resectability was due to inadequate future remnant in 25 cases (69%), physiologic frailty in 8 (22%), and complexity of concurrent rectal resection in 3 cases (8%). Ablation was combined with colon or rectal resection in 15 (38%) patients. Median number of ablations per patient was 2 (IQR 1-5, range 1-15). Median diameter of ablated lesions was 1.9 cm (IQR 1.3-2.3). During follow up, 18 patients experienced recurrence. Six had local recurrence (treatment failure), 11 had intra-hepatic recurrence, and 1 had systemic recurrence. Median follow up of the study was 28 months. Median disease-free survival was not reached. Of the 135 lesions ablated, the per-lesion local recurrence rate was 6/135 (4.4%). Median overall survival for the cohort was 81 months. Conclusions: Surgical ablation of CRLM provides excellent local control and long-term survival outcomes in patients who may otherwise not be candidates for other liver-directed therapies.

Risk prediction of pleural effusion in lung malignancy patients treated with CT-guided percutaneous microwave ablation: a nomogram and artificial neural network model

Objectives To develop an effective nomogram and artificial neural network (ANN) model for predicting pleural effusion after percutaneous microwave ablation (MWA) in lung malignancy (LM) patients. Methods LM patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (7:3). The predictors of pleural effusion identified by univariable and multivariable analyses in the training cohort were used to develop a nomogram and ANN model. The C-statistic was used to evaluate the predictive accuracy in both the training and validation cohorts. Results A total of 496 patients (training cohort: n = 357; validation cohort: n = 139) were enrolled in this study. The predictors selected into the nomogram for pleural effusion included the maximum power (hazard ratio [HR], 1.060; 95% confidence interval [CI], 1.022–1.100, p = 0.002), the number of pleural punctures (HR, 2.280; 95% CI, 1.103–4.722; p = 0.026) and the minimum distance from needle to pleura (HR, 0.840; 95% CI, 0.775–0.899; p < 0.001). The C-statistic showed good predictive performance in both cohorts, with a C-statistic of 0.866 (95% CI, 0.787–0.945) internally and 0.782 (95% CI, 0.644–0.920) externally (training cohort and validation cohort, respectively). The optimal cutoff value for the risk of pleural effusion was 0.16. Conclusions Maximum power, number of pleural punctures and minimum distance from needle to pleura were predictors of pleural effusion after MWA in LM patients. The nomogram and ANN model could effectively predict the risk of pleural effusion after MWA. Patients showing a high risk (>0.16) on the nomogram should be monitored for pleural effusion.

Is Stereotactic Microwave Ablation of Resectable Colorectal Liver Metastasis an Alternative for Liver Resection in Covid19 Pandemic?

Purpose: Recent studies showed no difference in overall survival between microwave ablation (MWA) and resection of colorectal liver metastasis (CRLM) ≤ 3cm. Percutaneous MWA (pMWA) under CT guidance is less invasive than surgical ablation but less accurate due to “free-hand” puncture, resulting in higher rates of incomplete ablation and local recurrence. Moreover, lesions in segments 1, 2, 4A, 7, 8 are difficult to reach by “free-hand” approach. Stereotactic navigation allows accurate puncture in all liver segments.

Modified percutaneous ethanol injection method combined with microwave ablation for the treatment of symptomatic, predominantly cystic, benign thyroid nodules: a retrospective study of 201 cases

Objective Percutaneous ethanol injection (PEI) and microwave ablation (MWA) are both important methods used in treating benign thyroid nodules. This study aimed to investigate the efficacy and safety of a modified PEI method combined with MWA for the treatment of symptomatic, predominantly cystic and benign thyroid nodules. Materials and methods This study included 201 patients who underwent treatment in our department between April 2015 and August 2018. Predominantly cystic thyroid nodules were treated by the modified PEI procedure, which included short-term boiling ethanol ablation (STBEA) and was combined with MWA. Complications, the volume reduction ratio (VRR), symptoms and cosmetic scores were recorded at 1, 3, 6 and 12 months after treatment and every 6 months thereafter. Results No major complications were observed during or after the treatment. Ten patients (4.8%) experienced temporary voice change, which resolved within 3 months. Of 200 (97.6%) out of 205 nodules showed significant volume reduction at the final follow-up. Recurrence occurred for only 5 (2.4%) nodules. The mean thyroid nodule volume decreased from 17.40 ± 3.21 mL at baseline to 1.17 ± 0.37 mL at 12 months. The greatest VRR was observed within the first 3 months after treatment. Conclusions The modified PEI method combined with MWA is safe and effective for the treatment of predominantly cystic benign thyroid nodules and provides a shorter operating time and lower recurrence rate than traditional treatments.

MRI-guided percutaneous thermoablation as first-line treatment of recurrent hepatic malignancies following hepatic resection: single center long-term experience

Purpose Hepatic recurrence of liver malignancies is a leading problem in patients after liver resection with curative intention. Thermoablation is a promising treatment approach for patients after hepatic resection, especially in liver-limited conditions. This study aimed to investigate safety, survival, and local tumor control rates of MRI-guided percutaneous thermoablation of recurrent hepatic malignancies following hepatic resection. Material and methods Data from patients with primary or secondary hepatic malignancies treated between 2004 and 2018 with MRI-guided percutaneous thermoablation of hepatic recurrence after prior hepatic resection were retrospectively analyzed. Disease-free survival and overall survival rates were calculated using the Kaplan-Meier method. Results A total of 57 patients with hepatic recurrence (mean tumor size = 18.9 ± 9.1 mm) of colorectal cancer liver metastases (n = 27), hepatocellular carcinoma (n = 17), intrahepatic recurrence of cholangiocellular carcinoma (n = 9), or other primary malignant tumor entities (n = 4) were treated once or several times with MR-guided percutaneous radiofrequency (n = 52) or microwave ablation (n = 5) (range: 1–4 times). Disease progression occurred due to local recurrence at the ablation site in nine patients (15.8%), non-local hepatic recurrence in 33 patients (57.9%), and distant malignancy in 18 patients (31.6%). The median overall survival for the total cohort was 40 months and 49 months for the colorectal cancer group, with a 5-year overall survival rate of 40.7 and 42.5%, respectively. The median disease-free survival was 10 months for both the total cohort and the colorectal cancer group with a 5-year disease-free survival rate of 15.1 and 14.8%, respectively. The mean follow-up time was 39.6 ± 35.7 months. Conclusion MR-guided thermoablation is an effective and safe approach in the treatment of hepatic recurrences in liver-limited conditions and can achieve long-term survival.

Survival prediction for non-small cell lung cancer patients treated with CT-guided microwave ablation: development of a prognostic nomogram

Objectives To explore the outcomes of CT-guided percutaneous microwave ablation (MWA) in non-small cell lung cancer (NSCLC) patients, and then develop an effective nomogram to predict the survival. Methods NSCLC patients treated with MWA were randomly allocated to either the training cohort or the validation cohort (3:1). The primary outcome measurement was overall survival (OS), whose predictors were identified by univariate and multivariate analyses in the training cohort. Then, a predictive nomogram was developed to predict the OS, with the predictive accuracy evaluated by C-statistic and receiver operating characteristic in both the training and validation cohorts. Results A total of 234 patients (training cohort: n = 176; validation cohort: n = 58) and 271 tumors with a median OS of 17.0 ± 12.2 months were included. The predictors selected into the nomogram included tumor diameter (hazard ratio [HR], 2.12; 95% confidence interval [CI], 1.37-3.30; p < 0.001), extrapulmonary metastases (HR, 1.77; 95% CI, 1.06–2.95; p = 0.030), tumor stage (HR, 1.38; 95% CI, 1.07–1.79; p = 0.013), tumor type (HR, 2.00; 95% CI, 1.48–2.72; p < 0.001) and post-MWA TKIs (HR, 0.55; 95% CI, 0.34–0.89; p < 0.001), based on the results of univariate and multivariate analyses. The C-statistic showed good predictive performance, with a C-statistic of 0.838 (95% CI, 0.779–0.897) internally and 0.808 (95% CI, 0.695–0.920) externally (training cohort and validation cohort, respectively). Conclusions The nomogram was effective in predicting the OS in NSCLC patients treated with MWA, and could be applied to identify patients who may benefit most from MWA and be helpful for clinical decision making.

Microwave ablation versus parathyroidectomy for severe secondary hyperparathyroidism in patients on hemodialysis: a retrospective multicenter study

Background Microwave ablation is effective for severe secondary hyperparathyroidism, but the difference in efficacy between microwave ablation and parathyroidectomy remains unclear. In this multicenter retrospective cohort study, we compared the long-term clinical efficacy of microwave ablation and parathyroidectomy for severe secondary hyperparathyroidism undergoing hemodialysis. Materials and methods The patients were divided into microwave ablation and parathyroidectomy groups. The primary endpoint was the proportion of patients with intact parathyroid hormone (iPTH) concentrations within the target range (100–600 pg/mL) during the efficacy assessment phase. The secondary endpoints were (i) differences in iPTH concentrations over time between the two groups, and (ii) decreases in iPTH concentrations over time in the two groups. Results Microwave ablation was performed in 47/92 patients and parathyroidectomy in 45/92. Primary endpoint: iPTH concentrations within the target range were achieved during the efficacy assessment phase in 26/47 patients (55.3%) and in 14/45 (31.1%) patients in the microwave ablation and parathyroidectomy groups, respectively (p = .02). Secondary endpoints: (i) Mean iPTH concentrations during the efficacy assessment phase were significantly higher in the microwave ablation versus parathyroidectomy groups (649 ± 519 pg/mL versus 136 ± 228 pg/mL, respectively; p < .01). (ii) Mean decrease in iPTH concentration from baseline was 725 ± 605 pg/mL versus 1369 ± 478 pg/mL in the MWA versus parathyroidectomy groups, respectively (p < .01). Conclusions Ultrasound-guided percutaneous microwave ablation provides higher iPTH target-achieving rates than parathyroidectomy in patients with severe secondary hyperparathyroidism undergoing hemodialysis.

The Significance of Microwave Ablation in the Treatment of Primary and Metastatic Liver Cancer

Extensive liver resection is the main method of treating patients with primary and metastatic liver cancer, which allows to achieve a significant prolongation of life. In patients with a reduced functional reserve of the liver or an insufficient volume of the remaining liver parenchyma, the applying of these interventions becomes impossible due to the increased risk of post-resection acute liver failure. One of the most modern and promising ways to overcome this obstacle is the use of minimally invasive methods of tumor destruction. We present clinical observations of the use of the microwave ablator: liver resection and percutaneous microwave ablation of colorectal cancer metastases to the liver. The presented experience demonstrates the justification for the use of microwave destruction of metastatic malignant tumors of the liver and demonstrates the possibilities of microwave thermal ablation therapy in patients who cannot be performed radical surgical treatment.

Laparoscopic and percutaneous microwave ablation to treat liver metastasis from colon cancer. A tool for long-term iterative strategy: results from a high volume center

Introduction: Colorectal cancer is the third most common tumor worldwide. The liver is involved in 20-30% of cases, which strongly affects the long-term outcome. Liver resection and systemic chemotherapy are the current standard of care for colorectal liver metastasis (CRLMs), but microwave thermal ablation (MWA) is emerging as a viable option in non resectable patients or to achieve treatment with parenchymal spearing approach. Purpose: Verify safety and efficacy of MWA to treat CRLMs. Methods: Retrospective analysis of a prospective database of patient with CRLMs below maximum diameter of 3cm, treated with laparoscopic or percutaneous MWA from 2009 to 2019. Patients were not suitable for liver resection (tumor in critical position near major hepatic structures, insufficient future liver remnant after resection, comorbidity). Efficacy of the MWA was evaluated according to mRECIST criteria. Statistical analysis was performed to identify safety profile, overall survival and recurrence rate. Results: A total of 79 nodules were treated with 55 ablation procedures in 51 patients. Thirty-one nodules were treated by percutaneous approach; 48 nodules by laparoscopy approach. A single nodule was treated in 69% of procedures. The median tumour size was 18 mm (range, 8-30 mm). At 6 months complete response (100% of necrosis) was obtained in 85% of nodules treated, partial response in 11.3% and a progression disease in 3.7%. With a median follow up of 18 months (9,9-26), the overall recurrence rate in all organs was 64.7% (33 patients), with a local tumour progression (LTP) of 27.4% (14 patients), an intrasegmental recurrence (ISR) of 25.4% (13 patients), a intrahepatic recurrence (IHR) of 17.6% (9 patients), an extrahepatic recurrence (EHR) of 5.8% (3 patients) with a disease free rate of 35.2% (18 patients). Perioperative mortality was 0%. Overall morbidity was 18%, with Dindo-Clavien complications ≥3 in 2%. The median length of stay was 1 day. Overall 1-, 3-, and 5-year survival rates were 92.5%, 55.9% and 43.2%. Conclusion: In this mono-centric study MWA appears safe and effective to treat CRLMs when resection is not feasible or a major hepatectomy in fragile patients is necessary. Considering the low morbidity and repeatability of this procedure, it can be a viable option to treat patients with recurrent disease in the era of effective chemotherapy and multimodal treatments.