Image-guided lung metastasis ablation: a literature review

Safety and Effectiveness of Track Cauterization for Lung Cryoablation

PURPOSE

To evaluate the safety and effectiveness of track cauterization for lung cryoablation through comparison of postprocedural adverse event (AE) rates.

MATERIALS AND METHODS

Fifty-nine patients who underwent 164 percutaneous lung cryoablation procedures between 2013 and 2018 were included in this retrospective study. The study cohort was subdivided by whether track cauterization was conducted or not at the end of the procedure. The study cohort was also subdivided by the number of probes (1-2 probes vs 3-4 probes). Postablation AE rates were assessed by immediate and delayed (at 1 month or later) AEs, pneumothorax, hemothorax, pleural effusion, and whether intervention was required. Univariate and multivariate logistic regression analyses were used to compare differences in AE rates.

RESULTS

Patients who underwent procedures with track cautery were 2.6 times less likely to exhibit pleural effusion (P = .017). Patients who underwent procedures conducted with a higher number of probes were 3.8 times more likely to receive interventions (P < .001), 1.6 times more likely to experience pneumothorax (P = .037), and 2.1 times more likely to experience pleural effusion (P = .003). History of lung surgery, increased number of probes, size of the probe, and absence of track cautery were noted to be significant predictors of AEs and need for interventions (all P < .05).

CONCLUSIONS

Track cauterization in lung cryoablation was proven to reduce pleural effusion, but no difference in pneumothorax or delayed AEs was noted. The use of fewer probes was associated with a lower rate of AEs.

Safety and efficacy of CT-guided percutaneous radiofrequency ablation for non-small cell lung cancer: a single-center, single-arm analysis

Non-small cell lung cancer (NSCLC) is a prevalent malignant tumor, and the commonly treatment modalities include surgery, radiotherapy, chemotherapy, etc. Currently, CT-guided percutaneous radiofrequency ablation (RFA) for the treatment of cancers has been widely performed. This study aimed to evaluate the safety and efficacy of this therapy in NSCLC patients. Thirty-five NSCLC patients were enrolled in this study and all received CT-guided percutaneous RFA therapy. The outcome measures included the changes in forced respiratory volume in the first second (FEV1), total lung volume (TLC), lesion size and computed tomography (CT) values of the region of interest (ROI) before and after treatment. The main efficacy measures comprised complete tumor ablation and local recurrence after initial treatment, as well as the objective response rate (ORR) and disease control rate (DCR) after 6 months of treatment. After receiving CT-guided percutaneous RFA therapy, the target lesion was effectively controlled and CT values gradually decreased. Besides, no significant changes were observed in the patient's lung function, postoperative complications were experienced by a total of 10 patients, primarily including pneumothorax, infection, lung hollowing. Fortunately, all these complications were successfully managed with appropriate treatment. Following the initial RFA treatment, 31 patients (88.57%) achieved complete ablation, while 6 patients experienced local recurrence. After 6 months of treatment, the ORR and DCR were found to be 68.57% and 82.86% respectively. CT-guided percutaneous RFA has demonstrated favorable safety and efficacy in the treatment of patients with NSCLC at different stages, which represented a promising therapeutic modality.

The Value of Magnetic Resonance Imaging in Assessing Immediate Efficacy After Microwave Ablation of Lung Malignancies

PURPOSE

To investigate the imaging performance and parametric analysis of magnetic resonance imaging (MRI) immediately after microwave ablation (MWA) of lung malignancies.

MATERIALS AND METHODS

We retrospectively analyzed the MRI performance immediately after MWA of 34 cases of lung malignancies. The ablation zone parameters of lung malignancies were measured, including the long diameter (L), short diameter (S), and safety margin of the ablation zone on plain computed tomography (CT), T1-weighted imaging (T1WI), and T2-weighted imaging (T2WI) after MWA. The study calculated the tumor volume (V0), the ablation zone volume (V1), and the ratio of V0 to V1 (V%). Statistical differences between the parameters were analyzed.

RESULTS

The ablation area of the lesion exhibited central low signal and peripheral high signal on T2WI, central high signal and peripheral equal or high signal on T1WI, and circumferential enhancement in the periphery. The safety margin measured on T2WI was greater than that measured on plain CT and T1WI. On plain CT, the L, S, and V1 were smaller in the effective treatment group than in the ineffective treatment group (P<0.05). On T1WI, the V% and safety margin were greater in the effective treatment group than in the ineffective treatment group (P=0.009 and P=0.016, respectively).

CONCLUSIONS

MRI may be a new, valuable method to assess immediate efficacy after MWA for lung malignancies using the ablation zone parameters V% on T1WI and safety margin on T2WI.

Continuous positive airway pressure is unsafe for radiofrequency ablation of lung cancer under sedation: a randomised controlled trial

OBJECTIVE

To evaluate the safety of a minimum continuous positive airway pressure of 4 cmH2O (CPAP + 4) during computed tomography (CT)-guided radiofrequency ablation (RFA) for lung malignancies under procedural sedation and analgesia (PSA).

METHODS

This was a prospective, randomised, single-blind, parallel-group, placebo-controlled trial with an open-label medical device conducted at a single tertiary university hospital in Barcelona, Spain. Forty-six patients over 18 years of age scheduled for CT-guided RFA of a malignant pulmonary tumour under PSA were randomised to receive either CPAP + 4 or a modified mask for placebo CPAP (Sham-CPAP). Exclusion criteria included contraindications for RFA, refusal to participate, inability to understand the procedure or tolerate the CPAP test, lung biopsy just prior to RFA, intercurrent diseases, or previous randomisation for additional pulmonary RFA. Primary outcomes were the percentage of patients reporting at least one serious adverse event (SAE), classification for complications from the Cardiovascular and Interventional Radiological Society of Europe (CIRSE), and Clavien-Dindo classifications for complications, hospital stay, and readmissions. Secondary outcomes included adverse events (AEs), respiratory parameters, airway management, and the local radiological efficacy of pulmonary ablation.

RESULTS

CPAP + 4 prolonged hospital stay (1.5 ± 1.1 vs. 1.0 ± 0 inpatient nights, p = 0.022) and increased the risk of AE post-RFA (odds ratio (95% CI): 4.250 (1.234 to 14.637), p = 0.021 with more pneumothorax cases (n = 5/22, 22.7% vs. n = 0/24, 0%, p = 0.019). Per-protocol analysis revealed more SAEs and CIRSE grade 3 complications in the CPAP + 4 group (23.5% vs. 0%, p = 0.036). No significant differences were found in the effectiveness of oxygenation, ventilation, or pulmonary ablation.

CONCLUSION

CPAP is unsafe during CT-guided RFA for lung cancer under PSA even at the lowest pressure setting.

TRIAL REGISTRATION

ClinicalTrials.Gov, ClinicalTrials.gov ID NCT02117908, Registered 11 April 2014, https://www.

CLINICALTRIALS

gov/study/NCT02117908 CRITICAL RELEVANCE STATEMENT: This study highlights the hazards of continuous positive airway pressure during radiofrequency ablation of lung cancer, even at minimal pressures, deeming it unsafe under procedural sedation and analgesia in pulmonary interventional procedures. Findings provide crucial insights to prioritise patient safety.

KEY POINTS

No prior randomised controlled trials on CPAP safety in percutaneous lung thermo-ablation. Standardised outcome measures are crucial for radiology research. CPAP during lung RFA raises hospital stay and the risk of complications. CPAP is unsafe during CT-guided RFA of lung cancer under procedural sedoanalgesia.

Combination of percutaneous thermal ablation and adoptive Th9 cell transfer therapy against non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is one of the predominant malignancies globally. Percutaneous thermal ablation (PTA) has gained widespread use among NSCLC patients, with the potential to elicit immune responses but limited therapeutic efficacies for advanced-stage disease. T-helper type 9 (Th9) cells are a subset of CD4+ effector T cells with robust and persistent anti-tumor effects. This study proposes to develop PTA-Th9 cell integrated therapy as a potential strategy for NSCLC treatment.

METHODS

The therapeutic efficacies were measured in mice models with subcutaneously transplanted, recurrence, or lung metastatic tumors. The tumor microenvironments (TMEs) were evaluated by flow cytometry. The cytokine levels were assessed by ELISA. The signaling molecules were determined by quantitative PCR and Western blotting. The translational potential was tested in the humanized NSCLC patient-derived xenograft (PDX) model.

RESULTS

We find that PTA combined with adoptive Th9 cell transfer therapy substantially suppresses tumor growth, recurrence, and lung metastasis, ultimately extending the survival of mice with NSCLC grafts, outperforming both PTA and Th9 cell transfer monotherapy. Analysis of TMEs indicates that combinatorial therapy significantly augments tumor-infiltrating Th9 cells, boosts anti-tumor effects of CD8+ T cells, and remodels tumor immunosuppressive microenvironments. Moreover, combinatorial therapy significantly strengthens the regional and circulation immune response of CD8+ T cells in mice with tumor lung metastasis and induces peripheral CD8+ T effector memory cells in mice with tumor recurrence. Mechanically, PTA reinforces the anti-tumor ability of Th9 cells primarily through upregulating interleukin (IL)-1β and subsequently activating the downstream STAT1/IRF1 pathway, which could be effectively blocked by intercepting IL-1β signaling. Finally, the enhanced therapeutic effect of combinatorial therapy is validated in humanized NSCLC PDX models.

CONCLUSIONS

Collectively, this study demonstrates that combinatorial therapy displays robust and durable anti-tumor efficacy and excellent translational potential, offering excellent prospects for translation and emerging as a promising approach for NSCLC treatment.

An Interventional Radiologist's Guide to Lung Cancer

Lung cancer continues to be the third leading cause of cancer and the leading cause of cancer deaths. As the field of interventional oncology continues to grow, interventional radiologists are increasingly treating lung cancer patients. Involvement begins with tissue diagnosis for which biomarkers and immunohistochemistry are used to guide selective and advanced medical therapies. An interventional radiologist must be aware of the rationale behind tissue diagnosis and techniques to minimize biopsy complications. Staging is an important part of tumor board conversations and drives treatment pathways. Surgical therapy remains the gold standard for early-stage disease but with an aging population the need for less invasive treatments such as radiation therapy and ablation continue to grow. The interventionalist must be aware of the indications, techniques, and pre- and posttherapy managements for percutaneous ablation. Endovascular therapy is broadly divided into therapeutic treatment of lung cancer, which is gaining traction, and treatment of lung cancer complications such as hemoptysis. This review aims to provide a good basis for interventional radiologists treating lung cancer patients.

Computed tomography-guided microwave ablation for right middle lobe pulmonary nodules: a retrospective, single-center, case-control study

PURPOSE

This retrospective, single-center, case-control study evaluated the safety and efficacy of Computed tomography (CT)-guided microwave ablation (MWA) for pulmonary nodules located in the right middle lobe (RML), a challenging location associated with a high frequency of complications.

METHODS

Between May 2020 and April 2022, 71 patients with 71 RML pulmonary nodules underwent 71 MWA sessions. To comparison, 142 patients with 142 pulmonary nodules in non-RML were selected using propensity score matching. The technical success, technique efficacy, complications, and associated factors were analyzed. The duration of the procedure and post-ablation hospital stay were also recorded.

RESULTS

Technical success was achieved in 100% of all patients. There were no significant differences in technique efficacy rates between the RML and non-RML groups (97.2% vs. 95.1%, p = 0.721). However, both major (47.9% vs. 19.7%, p < 0.001) and minor (26.8% vs. 11.3%, p = 0.004) pneumothorax were more common in the RML group than non-RML group. MWA for RML pulmonary nodules was identified as an independent risk factor for pneumothorax (p < 0.001). The duration of procedures (51.7 min vs. 35.3 min, p < 0.001) and post-ablation hospital stays (4.7 days vs. 2.8 days, p < 0.001) were longer in the RML group than non-RML group.

CONCLUSIONS

CT-guided MWA for RML pulmonary nodules showed comparable efficacy compared with other lobes, but posed a higher risk of pneumothorax complications, necessitating longer MWA procedure times and extended hospital stays.

Treatment strategies for malignant pulmonary nodule: beyond lobectomy. Point-counterpoint

PURPOSE OF REVIEW

Technological advancement in low-dose computed tomography resulted in an increased incidental discovery of early-stage lung cancer and multifocal ground glass opacity. The demand for parenchyma-preserving treatment strategies is greater now than ever. Pulmonary ablative therapy is a groundbreaking technique to offer local ablative treatment in a lung-sparing manner. It has become a promising technique in lung cancer management with its diverse applicability. In this article, we will review the current development of ablative therapy in lung and look into the future of this innovative technique.

RECENT FINDINGS

Current literature suggests that ablative therapy offers comparable local disease control to other local therapies and stereotactic body radiation therapy (SBRT), with a low risk of complications. In particular, bronchoscopic microwave ablation (BMWA) has considerably fewer pleural-based complications due to the avoidance of pleural puncture. BMWA can be considered in the multidisciplinary treatment pathway as it allows re-ablation and allows SBRT after BMWA.

SUMMARY

With the benefits which ablative therapy offers and its ability to incorporate into the multidisciplinary management pathway, we foresee ablative therapy, especially BMWA gaining significance in lung cancer treatment. Future directions on developing novel automated navigation platforms and the latest form of ablative energy would further enhance clinical outcomes for our patients.

Changes in the pulmonary function of CT-guided microwave ablation for patients with malignant lung tumors

PURPOSE

To investigate the changes in pulmonary function after computed tomography (CT)-guided microwave ablation (MWA) in patients with a malignant lung tumor.

MATERIALS AND METHODS

From June 2020 to January 2022, 133 patients with a malignant lung tumor who underwent CT-guided percutaneous MWA were included in the study. Pulmonary function tests (PFTs) were performed before (the baseline) and 1 month after the MWA. Vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1%, maximum mid-expiratory flow (MMEF), and diffusion capacity of the lung for carbon monoxide (DLCO-SB) at 1 month post MWA were compared with that at the baseline. The time of procedure and post-procedure length of hospital stay were also recorded.

RESULTS

The mean VC, FVC, FEV1, FEV1%, MMEF, and DLCO-SB at the baseline and 1 month post MWA were 3.23 ± 0.75 and 3.22 ± 0.77 (P = 0.926), 3.20 ± 0.75 and 3.21 ± 0.77 (P = 0.702), 2.35 ± 0.70 and 2.35 ± 0.71 (P = 0.992), 91.97 ± 23.14 and 91.87 ± 23.16 (P = 0.837), 1.83 ± 0.93 and 1.81 ± 0.95 (P = 0.476), and 6.38 ± 1.67 and 6.32 ± 1.62 (P = 0.389), respectively. There was no significant difference in the PFT results before and 1 month post MWA. The mean time of procedure and post-MWA length of hospital stay were 33 min and 2.5 days, respectively.

CONCLUSIONS

MWA is a lung parenchyma-sparing local treatment, and pulmonary function at 1 month post MWA was not statistically different from the baseline, indicating that MWA may not affect pulmonary function.

Image-guided percutaneous cryoablation of a solitary subpleural lung metastasis from breast cancer

This case presents CT-guided percutaneous cryoablation as a treatment option in a patient with oligometastatic breast cancer who previously had received standard-of-care treatment for metastatic breast cancer. Before cryoablation, the patient received two systemic lines of therapy, several surgeries and radiotherapy for oligometastatic disease. The cryoablation was performed in a single 7 mm subpleural oligometastatic lesion 42 months after diagnosis of metastatic breast cancer. It was performed without complications, and the patient experienced no complaints or discomfort after the procedure. A 3-month, 6-month, 9-month and 12-month follow-up fluorodeoxyglucose-positron emission tomography/CT scans showed no sign of disease progression.

Microwave ablation with a blunt-tip antenna for pulmonary ground-glass nodules: a retrospective, multicenter, case-control study

PURPOSE

A previous small-sample study verified that a blunt-tip antenna reduced hemorrhage during microwave ablation. We conducted this large-sample, multicenter, case-control study to further verify the efficacy and safety of microwave ablation with a blunt-tip antenna for ground-glass nodules.

MATERIALS AND METHODS

Patients with pulmonary ground-glass nodules were treated with either a sharp-tip (Group A) or blunt-tip antenna (Group B). A total of 147 and 150 patients were retrospectively allocated to Groups A and Group B, respectively. Group A patients underwent 151 procedures, and Group B patients underwent 153 procedures. We assessed the technical success, technique efficacy, and complications.

RESULTS

Technical success and overall technique efficacy were achieved in all patients (100%). Major complications of pneumothorax were more commonly observed in Group A than in Group B (19.7% vs. 2.0%, p < 0.001). Minor complications, such as intrapulmonary hemorrhage (2.0% vs. 9.5%, p = 0.005) and hemothorax (0.0% vs. 2.7%, p = 0.049), occurred less frequently in Group B compared to Group A.

CONCLUSION

In the treatment of ground-glass nodules, microwave ablation with a blunt-tip antenna had equal efficacy compared to microwave ablation with a sharp-tip antenna but had a decreased number of hemorrhage and hemothorax complications.

Primary and Metastatic Lung Cancer: Rationale, Indications, and Outcomes of Thermal Ablation

The widespread use of imaging as well as the efforts conducted through screening campaigns has dramatically increased the early detection rate of lung cancer. Historically, the management of lung cancer has heavily relied on surgery. However, the increased proportion of patients with comorbidities has given significance to less invasive therapeutic options like minimally invasive surgery and image-guided thermal ablation, which could precisely target the tumor without requiring general anesthesia or a thoracotomy. Thermal ablation is considered low-risk for lung tumors smaller than 3 cm that are located in peripheral lung and do not involve major blood vessels or airways. The rationale for ablative therapies relies on the fact that focused delivery of energy induces cell death and pathologic necrosis. Image-guided percutaneous thermal ablation therapies are established techniques in the local treatment of hepatic, renal, bone, thyroid and uterine lesions. In the lung, and specifically in the setting of metastatic disease, the 3 main indications for lung ablation are to serve as (1) curative intent, (2) as a strategy to achieve a chemo-holiday in oligometastatic disease, and (3) in oligoprogressive disease. Following these premises, the current paper aims to review the rationale, indications, and outcomes of thermal ablation as a form of local therapy in the treatment of primary and metastatic lung disease.

Local thermal ablative therapies for extracranial oligometastatic disease of non-small-cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer. Clinically, 40-50% of patients with NSCLC are found to have systemic metastasis at the initial diagnosis. Meanwhile, 30-75% of patients with lung cancer who have undergone radical surgical resection have local recurrence and distant metastases. However, not all distant metastases are multiple, and some are potentially curable. In this study, among the patients with NSCLC having distant organ metastasis, approximately 7% showed extrapulmonary solitary metastasis and remained in this relatively stable state for a long time. This form of metastasis is known as NSCLC oligometastases. This review describes the concept and classification of oligometastases, as well as the local treatment and prognosis of extracranial oligometastases.

SPACES: Our team's experience in lung tumor microwave ablation

The standard treatment of stage I nonsmall cell lung cancer is lobectomy with systematic mediastinal lymph node evaluation. Unfortunately, up to 25% of patients with stage I nonsmall cell lung cancer are not candidates for surgery due to severe medical comorbidities (poor cardiopulmonary function). Image-guided thermal ablation is an alternative for those patients, includes radiofrequency ablation, microwave ablation (MWA), cryoablation, and laser ablation. Compared to them, MWA is a relatively new technique with some potential advantages, such as faster heating times, higher intralesional temperatures, larger ablation zones, less procedural pain, relative insensitivity to "heat sinks," and less sensitivity to tissue types. However, some advantages of MWA mentioned above (such as higher intralesional temperatures, larger ablation zones) also have potential risks and problems, and an innovative and standardized guidance system is needed to avoid and solve these risks and problems. This article combs our team's clinical experience over the past decade, summarizes a systematic and standardized guidance system, and names it SPACES (Selection, Procedure, Assessment, Complication, Evaluation, Systemic therapy). Both primary and metastatic pulmonary tumors can be efficiently treated with image-guided thermal ablation in selected candidates. The selection and use of ablation techniques should consider the size and location of the target tumor, the risk of complications, and the expertise and skills of the professionals, among which the size of the target tumor (<3 mm) is a major factor determining the success of ablation.

Synchronous computed tomography-guided percutaneous biopsy and microwave ablation for highly suspicious malignant lung ground-glass opacities adjacent to mediastinum

BACKGROUND

This retrospective study aimed to assess the safety and efficacy of synchronous biopsy and microwave ablation (MWA) for highly suspected malignant lung ground-glass opacities (GGOs) adjacent to the mediastinum (distance ≤10 mm).

MATERIALS AND METHODS

Ninety patients with 98 GGOs (diameter range, 6-30 mm), located within 10 mm of the mediastinum, underwent synchronous biopsy and MWA at a single institution from 1 May 2020, to 31 October 2021 and were enrolled in this study. Synchronous biopsy and MWA involving the completion of the biopsy and MWA in a single procedure was performed. Safety, technical success rate, and local progression-free survival (LPFS) were evaluated. The risk factors for local progression were calculated using the Mann-Whitney U test.

RESULTS

The technical success rate was 97.96% (96/98 patients). The LPFS rates at 3, 6, and 12 months were 95.0%, 90.0%, and 82.0%, respectively. The diagnostic rate of biopsy-proven malignancy was 72.45% (n = 71/98). Invasion of lesions into the mediastinum was a risk factor for local progression (p = 0.0077). The 30-day mortality rate was 0. The major complications were pneumothorax (13.27%), ventricular arrhythmias (3.06%), pleural effusion (1.02%), hemoptysis (1.02%), and infection (1.02%). Minor complications included pneumothorax (30.61%), pleural effusion (24.49%), hemoptysis (18.37%), ventricular arrhythmias (11.22%), structural changes in adjacent organs (3.06%), and infection (3.06%).

CONCLUSIONS

Synchronous biopsy and MWA was effective for treating GGOs adjacent to the mediastinum without severe complications (Society of Interventional Radiology classification E or F). Invasion of lesions into the mediastinum was identified as a risk factor for local progression.

An ultra-low-dose protocol for computed tomography-guided lung radiofrequency ablations

To evaluate the safety and efficacy of ultra-low-dose (ULD) protocol for computed tomography (CT)-guided lung radiofrequency ablation (RFA). Patients who had undergone lung RFA between November 2017 and January 2021 were consecutively and retrospectively included. Thirty patients were treated using a conventional standard protocol (SP), including helical acquisitions with mA automatic adjustment and sequential CT at 80 kVp; and 31, with a ULD protocol defined with helical acquisitions with fixed mA and sequential series at 100 kVp. These parameters were selected from those used for a diagnostic lung low-dose CT scanner. Patient characteristics, dose indicators, technical efficacy (minimal margin [MM], recurrence during follow-up), and complications (pneumothorax, alveolar haemorrhage, and haemoptysis) were recorded. We included 61 patients (median age, 65 [54-73] and 33 women), with no significant differences according to the type of protocol, except for the type of anaesthesia. Even if the number of helical acquisitions did not significantly change, all dose indicators significantly decreased by 1.5-fold-3-fold. The median dose-length-product and effective dose, with their ranges, respectively, were 465 mGy cm (315-554) and 6.5 mSv (4.4-7.8) in the SP group versus 178 mGy cm (154-267) and 2.5 mSv (2.2-3.7) in the ULD group, (p< 001). The ULD group exhibited lower intraoperator variability and better interoperator alignment than those of the SP group. The MM was not significantly different between the two groups (4.6 mm versus 5 mm,p= 16). One local recurrence was observed in each group at 8 months in the SP and at one year in the ULD group (p= 1). The complication rates did not differ significantly. Implementing an ULD protocol during lung RFA may provide similar efficacy, a reduction of dose indicators, and intra- and interoperator variability, without increasing complication rates, compared to those associated with an SP.

Cytoreductive Surgical Treatment of Pleural Mesothelioma in a Porcine Model Using Magnetic-Resonance-Guided Focused Ultrasound Surgery (MRgFUS) and Radiofrequency Ablation (RFA)

A combination of surgery and chemotherapy is the most effective treatment available for Malignant Pleural Mesothelioma (MPM). However, both cause significant collateral damage and cannot eliminate residual microscopic disease. This investigation aimed to compare and determine the feasibility of utilizing Radiofrequency Ablation (RFA) and Magnetic-Resonance-guided Focused Ultrasound Surgery (MRgFUS) as alternative treatments for MPM. A large animal tumor model was developed in 13 Yorkshire female pigs using the MSTO211H cell line. Two pigs were initially used to determine the cyclosporine dose required for immunosuppression and tumor development. Subsequently, 11 other pigs underwent tumor development. Of these 11, 2 died during cell inoculation. Small tumor masses and adhesions were present in the other 9, indicating mesothelioma development. Five pigs then received RFA treatment, and 4 pigs received MRgFUS treatment. Tumor model development and effect of the two treatments were examined using MRI and by necropsy. RFA and MRgFUS both successfully ablated approximately the same sized area in the same treatment time. This study demonstrates that RFA and MRgFUS are feasible for tumor debulking, and while MRgFUS requires more pretreatment planning compared to RFA, MRgFUS is a completely noninvasive procedure.

Different effects of intravenous and local anesthesia in patients undergoing ultrasound-guided radiofrequency ablation of thyroid nodules: a prospective cohort study

PURPOSE

To compare the efficacy and safety of intravenous anesthesia (IV) with local anesthesia (LA) in patients undergoing ultrasound (US)-guided radiofrequency ablation (RFA) of thyroid nodules.

METHODS

50 patients with American Society of Anesthesiologists classification grades I-II undergoing US-guided thyroid RFA were enrolled and randomly (1:1) divided into IV (conscious sedation with Ramsay Sedation Scale [RSS] scores of 2-3 with an anesthesiologist) and LA (subcutaneous anesthesia with lidocaine without an anesthesiologist) groups. Pre-, intra- and post-procedural blood pressure (BP) (SBP₀/DBP₀, SBP₁/DBP₁, and SBP₂/DBP₂), intra- and post-procedural pain (NRS₁ and NRS₂), ablated area volume, treatment time and adverse events were analyzed and compared.

RESULTS

Age, sex, weight, number, nature, volume of nodules, and SBP₀/DBP₀ showed no difference between both groups. 11 and 0 patients' SBP₁/DBP₁ were elevated in the LA and IV groups. NRS₁ differed between both groups. 6 patients in the LA group had moderate or severe pain, but none in the IV group. No between-group difference in SBP₂/DBP₂, NRS₂, ablation completion rate and ablated volume was noted. The median procedure duration differed from 1109 (176) s in IV group and 723 (227) s in LA groups. There was no increased incidence of adverse events in IV group.

CONCLUSIONS

IV with RSS scores of 2-3 maintained intra-procedural BP and relieved intra-procedural pain better, without affecting the ablation efficacy and increasing complications. Despite increased treatment time, IV is a potential option for patients undergoing US-guided RFA of thyroid nodules.

Current trends in image-guided chest interventions

Interventional radiology (IR) is a rapidly expanding medical subspecialty and refers to a range of image‐guided procedural techniques. The image guidance allows real‐time visualization and precision placement of a needle, catheter, wire and device to deep body structures through small incisions. Advantages include reduced risks, faster recovery and shorter hospital stays, lower costs and less patient discomfort. The range of chest interventional procedures keeps on expanding due to improved imaging facilities, better percutaneous assess devices and advancing ablation and embolization techniques. These advances permit procedures to be undertaken safely, simultaneously and effectively, hence escalating the role of IR in the treatment of chest disorders. This review article aims to cover the latest developments in some image‐guided techniques of the chest, including thermal ablation therapy of lung malignancy, targeted therapy of pulmonary embolism, angioplasty and stenting of mediastinal venous/superior vena cava occlusion, pulmonary arteriovenous malformation treatment and bronchial artery embolization for haemoptysis.

Comparison of expected imaging findings following percutaneous microwave and cryoablation of pulmonary tumors: ablation zones and thoracic lymph nodes

OBJECTIVE

To compare temporal changes of ablation zones and lymph nodes following lung microwave ablation (MWA) and cryoablation.

METHODS

This retrospective cohort study compared lung ablation zones and thoracic lymph nodes following MWA and cryoablation performed 2006-2020. In the ablation zone cohort, ablation zone volumes were measured on serial CT for 12 months. In the lymph node cohort, the sum of bidimensional products of lymph node diameters was measured before (baseline) and up to 6 months following ablation. Cumulative incidence curves estimated the time to 75% ablation zone reduction and linear mixed-effects regression models compared the temporal distribution of ablation zones and lymph node sizes between modalities.

RESULTS

Ablation zones of 59 tumors treated in 45 sessions (16 MWA, 29 cryoablation) in 36 patients were evaluated. Differences in the time to 75% volume reduction between modalities were not detected. Following MWA, half of the ablation zones required an estimated time of 340 days to achieve a 75% volume reduction compared to 214 days following cryoablation (p = .30). Thoracic lymph node sizes after 33 sessions (13 MWA, 20 cryoablation) differed between modalities (baseline-32 days, p = .01; 32-123 days, p = .001). Following MWA, lymph nodes increased on average by 38 mm² (95%CI, 5.0-70.7; p = .02) from baseline to 32 days, followed by an estimated decrease of 50 mm² (32-123 days; p = .001). Following cryoablation, changes in lymph nodes were not detected (baseline-32 days, p = .33).

CONCLUSION

The rate of ablation zone volume reduction did not differ between MWA and cryoablation. Thoracic lymph nodes enlarged transiently after MWA but not after cryoablation.

KEY POINTS

• Contrary to current belief, the rate of lung ablation zone volume reduction did not differ between microwave and cryoablation. • Transient enlargement of thoracic lymph nodes after microwave ablation was not associated with regional tumor spread and decreased within six months following ablation. • No significant thoracic lymph node enlargement was observed following cryoablation.

Expanding the role of interventional oncology for advancing precision immunotherapy of solid tumors

Adoptive cell therapy with chimeric antigen receptors (CAR) T cells has proven effective for hematologic malignancies, but success in solid tumors has been impeded by poor intratumoral infiltration, exhaustion of effector cells from antigen burden, and an immunosuppressive tumor microenvironment. Results from recent clinical trials and preclinical studies lend promising evidence of locoregional approaches for CAR T cell delivery, priming the tumor microenvironment, and performing adjuvant therapies that sustain T cell activity. Interventional oncology is a subspeciality of interventional radiology where imaging guidance is used to perform percutaneous and catheter-directed procedures for localized, non-surgical therapy or interrogation of solid tumors. Interventional oncology provides unique synergies with immunotherapy, which has been well-studied to improve treatment efficacy while reducing toxicities associated with systemic treatment. Besides aiding in CAR T cell delivery, priming, or the stimulation of the tumor microenvironment to promote effector survival and function, interventional oncology can also aid in the monitoring of treatment response through selective, multiplex tumor sampling and catheter-based venous sampling. This review presents an overview of interventional oncology, its various procedures, and its potential for advancing CAR T cell immunotherapy of solid tumors.

Risk factors for the recurrence of early hepatocellular carcinoma treated by percutaneous radiofrequency ablation with a multiple-electrode switching system: a multicenter prospective study

PURPOSE

To investigate the long-term efficacy of radiofrequency ablation (RFA) with a multiple-electrode switching system (MESS) in the treatment of early hepatocellular carcinoma (HCC) and evaluate the patterns and risk factors of intrahepatic recurrence of HCC after RFA.

METHODS

In total, 139 patients with early HCC who underwent RFA with MESS as primary treatment at multiple centers were prospectively enrolled according to the inclusion criteria. We evaluated the local tumor progression (LTP), intrahepatic distant recurrence (IDR), the incidence of cumulative disease-free survival (DFS), LTP-free survival, IDR-free survival, and overall survival. We also analyzed the associated risk factors.

RESULTS

A total of 139 patients were included in the study and the median follow-up time was 64 months, ranging from 11 to 72 months. The complete ablation rate was 98.56%. Sixty-nine (49.64%) were found to have intrahepatic recurrence (LTP, n = 15; IDR, n = 55) during follow-up. The 1-year, 3-year and 5-year cumulative DFS, LTP-free survival, and IDR-free survival rates were 74.82, 94.46 and 78.75%; 54.68, 88.03 and 61.79%; and 51.80, 85.67 and 60.17%, respectively. In the multivariable analysis, tumor size > 4 cm was the only important risk factor for LTP. The alkaline phosphatase (ALP) level and the number of tumors were independent risk factors for IDR; α-fetoprotein (AFP) level > 400 µg/L and recurrence interval were risk factors for the overall survival period.

CONCLUSIONS

The MESS-RFA is an effective method for local control of tumors in early HCC. Early HCC with multiple high-ALP tumors has a higher rate of recurrence, which mainly occurs in an IDR pattern. Early HCC with high AFP levels and a shorter initial recurrence interval resulted in a poorer prognosis. Thus, treatments such as liver transplantation or surgical resection may be a good strategy in those cases.

CLINICALTRIALS.GOV ID

NCT02046356.

Cryoablation in Locoregional Management of Complex Unresectable Chest Neoplasms

RATIONALE AND OBJECTIVES

The aim of our retrospective study was to assess the safety and feasibility of cryoablation in high-risk patients with complex chest neoplastic lesions.

MATERIALS AND METHODS

Twenty patients with complex chest malignancies, both primary and secondary, located in the mediastinum, lung, and chest wall, underwent percutaneous CT-guided cryoablation treatments. Procedural success as well as complications were evaluated.

RESULTS

A total of 24 neoplastic lesions were treated (mean diameter: 27 mm; range: 7-54 mm). Technical success was obtained in all patients, without major complications or intraprocedural death. A pneumothorax not requiring a drainage tube placement was registered in 50% of patients, while 3/24 patients had a grade 3 pneumothorax requiring a chest tube placement.

CONCLUSION

Percutaneous CT-guided cryoablation seems a safe and feasible treatment for complex thoracic lesions.

Role of surgical resection and its alternative local therapy for pulmonary metastasis of colorectal cancer

We reviewed surgical and alternative treatments for pulmonary metastasis of colorectal cancer, focusing on recent reports. The standard treatment for pulmonary metastasis of colorectal cancer is pulmonary resection, if resectable, despite the fact that the metastasis is hematogenous to distant organs. Guidelines in several countries, including Japan, have described pulmonary resection as a useful option because of the favorable long-term prognosis reported in various studies pertaining to pulmonary resection. The indications for pulmonary resection have been reviewed in several studies; additionally, the number of metastases, pretreatment carcinoembryonic antigen value, and disease-free interval from the primary resection to pulmonary recurrence have been proposed. However, no consensus has been reached to date. Contrastingly, recent advances in chemotherapy have remarkably improved the outcome of distant metastases, indicating that it is time to reconsider the significance of local treatment, including pulmonary resection. In addition to surgical resection, minimally invasive therapies, such as stereotactic body radiation therapy and radiofrequency ablation have been developed as local treatments for pulmonary metastases, and their long-term results have been reported. Prospective controlled trials and large-scale data analyses are needed to determine the best local treatment for pulmonary metastases and to find the appropriate indication for each treatment.

[Interventional Radiology in Oncology - Update 2021]

Interventional radiology plays a crucial role in oncology. The most common interventional treatments are transarterial embolisation as well as percutaneous thermal ablations. Transarterial embolisation, such as transarterial chemoembolization (TACE) or selective internal radiation therapy (SIRT) are well established, usually palliatively intended treatment options for primary and secondary hepatic malignancies. Embolisation is usually well tolerated under conscious sedation and can be repeated several times. Percutaneous thermoablation is a local ablative, usually curatively intended treatment for hepatic, renal and pulmonary tumors. As a minimally invasive technique, it competes against surgery and radiation therapy. There are different types of thermoablation, most commonly used are radiofrequency ablation (RFA), microwave ablation (MWA) and cryo-ablation. Ablation is usually performed in general anesthesia, less common in conscious sedation. New interventional treatments are high intensity focused ultrasound (HIFU) and irreversible electroporation (IRE). HIFU allows a non-invasive, imaging-guided thermoablation that is currently certified for uterine myoma, prostate cancer and bone tumors. IRE is a minimal invasive non-thermal ablation that is especially established for locally advanced tumors that show a close relationship to large vessels, for example pancreatic cancer.

Society of Interventional Radiology Multidisciplinary Position Statement on Percutaneous Ablation of Non-small Cell Lung Cancer and Metastatic Disease to the Lungs: Endorsed by the Canadian Association for Interventional Radiology, the Cardiovascular and Interventional Radiological Society of Europe, and the Society of Interventional Oncology

PURPOSE

To state the Society of Interventional Radiology's position on the use of image-guided thermal ablation for the treatment of early stage non-small cell lung cancer, recurrent lung cancer, and metastatic disease to the lung.

MATERIALS AND METHODS

A multidisciplinary writing group, with expertise in treating lung cancer, conducted a comprehensive literature search to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 63 studies, including existing systematic reviews and meta-analysis, retrospective cohort studies, and single-arm trials were identified. The expert writing group developed and agreed on 7 recommendations on the use of image-guided thermal ablation in the lung.

CONCLUSION

SIR considers image-guided thermal ablation to be an acceptable treatment option for patients with inoperable Stage I NSCLC, those with recurrent NSCLC, as well as patients with metastatic lung disease.

Acoustically Detonated Microbubbles Coupled with Low Frequency Insonation: Multiparameter Evaluation of Low Energy Mechanical Ablation

Noninvasive ultrasound surgery can be achieved using focused ultrasound to locally affect the targeted site without damaging intervening tissues. Mechanical ablation and histotripsy use short and intense acoustic pulses to destroy the tissue via a purely mechanical effect. Here, we show that coupled with low-frequency excitation, targeted microbubbles can serve as mechanical therapeutic warheads that trigger potent mechanical effects in tumors using focused ultrasound. Upon low frequency excitation (250 kHz and below), high amplitude microbubble oscillations occur at substantially lower pressures as compared to higher MHz ultrasonic frequencies. For example, inertial cavitation was initiated at a pressure of 75 kPa for a center frequency of 80 kHz. Low frequency insonation of targeted microbubbles was then used to achieve low energy tumor cell fractionation at pressures below a mechanical index of 1.9, and in accordance with the Food and Drug Administration guidelines. We demonstrate these capabilities in vitro and in vivo. In cell cultures, cell viability was reduced to 16% at a peak negative pressure of 800 kPa at the 250 kHz frequency (mechanical index of 1.6) and to 10% at a peak negative pressure of 250 kPa at a frequency of 80 kHz (mechanical index of 0.9). Following an intratumoral injection of targeted microbubbles into tumor-bearing mice, and coupled with low frequency ultrasound application, significant tumor debulking and cancer cell death was observed. Our findings suggest that reducing the center frequency enhances microbubble-mediated mechanical ablation; thus, this technology provides a unique theranostic platform for safe low energy tumor fractionation, while reducing off-target effects.

Local ablative therapy in oncogenic-driven oligometastatic non-small cell lung cancer: present and ongoing strategies-a narrative review

Oligometastatic (OM) disease is defined by a low metastatic tumor spread. OM non-small cell lung cancer (NSCLC) treatment aims to improve the patient's prognosis and quality of life, in an attempt-to-cure objective. Oncogenic-driven metastatic NSCLC accounts for about 20-25% of NSCLCs, with an ever-increasing number of potentially druggable molecular alterations. Due to specific targeted therapy, the care and prognosis of mutated NSCLC is quite different from non-oncogenic-driven NSCLC. However, OM-NSCLC treatment guidelines do not specifically discuss oncogenic-driven OM-NSCLC patients. We conducted a narrative review regarding retrospective and prospective studies published from inception to May 2020 dealing with oncogenic-driven OM-NSCLC in order to: (I) describe the specific patterns of metastatic spread of oncogenic-driven NSCLC (i.e., bone and pleural tropism in EGFR mutated NSCLC and serous and brain metastases in ALK NSCLC); (II) review the low level of current evidence for local ablative therapy (LAT) strategies in patients with oncogenic-driven OM-NSCLC, focusing on the benefit/risk of tyrosine kinase inhibitors (TKI) and LATs combination and (III) present strategies to help to select the best candidate for an attempt-to-cure approach. Finally, the optimal strategy may be to introduce a targeted therapy, then treat all tumor sites with LAT, and finally continue TKI for unknown prolonged duration in an attempt to prolong progression free survival in most patients, improve overall survival for some patients, and potentially lead to a cancer cure for a few patients.

Assessment of safety margin after microwave ablation of stage I NSCLC with three-dimensional reconstruction technique using CT imaging

Objective

To assess the ablative margin of microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) using a three-dimensional (3D) reconstruction technique.

Materials and methods

We retrospectively analyzed 36 patients with stage I NSCLC lesions undergoing MWA and analyzed the relationship between minimal ablative margin and the local tumor progression (LTP) interval, the distant metastasis interval and disease-free survival (DFS). The minimal ablative margin was measured using the fusion of 3D computed tomography reconstruction technique.

Results

Univariate and multivariate analyses indicated that tumor size (hazard ratio [HR] = 1.91, P < 0.01; HR = 2.41, P = 0.01) and minimal ablative margin (HR = 0.13, P < 0.01; HR = 0.11, P < 0.01) were independent prognostic factors for the LTP interval. Tumor size (HR = 1.96, P < 0.01; HR = 2.35, P < 0.01) and minimal ablative margin (HR = 0.17, P < 0.01; HR = 0.13, P < 0.01) were independent prognostic factors for DFS by univariate and multivariate analyses. In the group with a minimal ablative margin < 5 mm, the 1-year and 2-year local progression-free rates were 35.7% and 15.9%, respectively. The 1-year and 2-year distant metastasis-free rates were 75.6% and 75.6%, respectively; the 1-year and 2-year disease-free survival rates were 16.7% and 11.1%, respectively. In the group with a minimal ablative margin ≥ 5 mm, the 1-year and 2-year local progression-free rates were 88.9% and 69.4%, respectively. The 1-year and 2-year distant metastasis-free rates were 94.4% and 86.6%, respectively; the 1-year and 2-year disease-free survival rates were 88.9% and 63.7%, respectively. The feasibility of 3D quantitative analysis of the ablative margins after MWA for NSCLC has been validated.

Conclusions

The minimal ablative margin is an independent factor of NSCLC relapse after MWA, and the fusion of 3D reconstruction technique can feasibly assess the minimal ablative margin.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12880-021-00626-z.

A review of antenna designs for percutaneous microwave ablation

Microwave (MW) antenna is a key element in microwave ablation (MWA) treatments as the means that energy is delivered in a focused manner to the tumor and its surrounding area. The energy delivered results in a rise in temperature to a lethal level, resulting in cell death in the ablation zone. The delivery of energy and hence the success of MWA is closely dependent on the structure of the antennas. Therefore, three design criteria, such as expected ablation zone pattern, efficiency of energy delivery, and minimization of the diameter of the antennas have been the focus along the evolution of the MW antenna. To further improve the performance of MWA in the treatment of various tumors through inventing novel antennas, this article reviews the state-of-the-art and summarizes the development of MW antenna designs regarding the three design criteria.

Non-surgical Treatments for Lung Metastases in Patients with Soft Tissue Sarcoma: Stereotactic Body Radiation Therapy (SBRT) and Radiofrequency Ablation (RFA)

BACKGROUND

Radio-frequency ablation (RFA) and Stereotactic Body Radiation Therapy (SBRT) are two emerging therapies for lung metastases.

INTRODUCTION

Aliterature review was performed to evaluate the outcomes and complications of these procedures in patients with lung metastases from soft tissue sarcoma (STS).

METHODS

After selection, seven studies were included for each treatment encompassing a total of 424 patients: 218 in the SBRT group and 206 in the RFA group.

RESULTS

The mean age ranged from 47.9 to 64 years in the SBRT group and from 48 to 62.7 years in the RFA group. The most common histologic subtype was, in both groups, leiomyosarcoma. In the SBRT group, median overall survival ranged from 25.2 to 69 months and median disease- free interval was from 8.4 to 45 months. Two out of seven studies reported G3 and one G3 toxicity, respectively. In RFA patients, overall survival ranged from 15 to 50 months. The most frequent complication was pneumothorax. Local control showed a high percentage for both procedures.

CONCLUSION

SBRT is recommended in patients unsuitable to surgery, in synchronous bilateral pulmonary metastases, in case of deep lesions and patients receiving high-risk systemic therapies. RFA is indicated in case of a long disease-free interval, in oligometastatic disease, when only the lung is involved, in small size lesions far from large vessels. Further large randomized studies are necessary to establish whether these treatments may also represent a reliable alternative to surgery.

Efficacy of Tract Embolization After Percutaneous Pulmonary Radiofrequency Ablation

PURPOSE

To evaluate the efficacy of tract embolization technique using gelatin sponge slurry with iodinated contrast medium (GSSI) to reduce the incidence of pneumothorax and chest tube placement after computed tomography-guided lung radiofrequency ablation (RFA).

MATERIALS AND METHODS

In this single-institute retrospective study, we examined all patients with metastatic cancer treated from January 2016 to December 2019 by interventional radiologists with computed tomography-guided lung RFA. Since 2017 in our institution, we have applied a tract embolization technique using GSSI for all RFA. Patients were included into those who underwent lung RFA performed either with GSSI (Group A) or without GSSI (Group B). Univariate and multivariate analyses were performed between the two groups to identify risk factors for pneumothorax and chest tube placement, including patient demographics and lesion characteristics.

RESULTS

This study included 116 patients (54 men, 62 women; mean age, 65 ± 11 years) who underwent RFA. Group A comprised 71 patients and Group B comprised 45 patients. Patients who underwent tract embolization had a significantly lower incidence of pneumothorax (Group A, 34% vs. Group B, 62%; p < 0.001) and chest tube insertion (Group A, 10% vs. Group B, 29%; p < 0.01). No embolic complications occurred. The hospitalization stay was significantly shorter in patients who underwent tract embolization (mean, 1.04 ± 0.2 days; p = 0.02).

CONCLUSION

Tract embolization after percutaneous lung RFA significantly reduced the rate of post-RFA pneumothorax and chest tube placement and was safer than the standard lung RFA technique.

In situ terahertz monitoring of an ice ball formation during tissue cryosurgery: a feasibility test

SIGNIFICANCE

Uncontrolled cryoablation of tissues is a strong reason limiting the wide application of cryosurgery and cryotherapy due to the certain risks of unpredicted damaging of healthy tissues. The existing guiding techniques are unable to be applied in situ or provide insufficient spatial resolution. Terahertz (THz) pulsed spectroscopy (TPS) based on sensitivity of THz time-domain signal to changes of tissue properties caused by freezing could form the basis of an instrument for observation of the ice ball formation.

AIM

The ability of TPS for in situ monitoring of tissue freezing depth is studied experimentally.

APPROACH

A THz pulsed spectrometer operated in reflection mode and equipped with a cooled sample holder and ex vivo samples of bovine visceral adipose tissue is applied. Signal spectrograms are used to analyze the changes of THz time-domain signals caused by the interface between frozen and unfrozen tissue parts.

RESULTS

Experimental observation of TPS signals reflected from freezing tissue demonstrates the feasibility of TPS to detect ice ball formation up to 657-μm depth.

CONCLUSIONS

TPS could become the promising instrument for in situ control of cryoablation, enabling observation of the freezing front propagation, which could find applications in various fields of oncology, regenerative medicine, and THz biophotonics.

Image guided thermal ablation in lung cancer treatment

Lung ablation has been introduced into lung cancer treatment for about two decades. Currently, 3 main choices of thermal energy for lung ablation are radiofrequency ablation (RFA), microwave ablation (MWA), and cryoablation. As a mostly palliative, occasionally curative intent local treatment, the feasibility and safety of lung ablation have been validated in small size lung cancer treatment, especially in lung tumor ≤3 cm. Improved techniques and experience in recent years help render outcomes much better than before for lung cancer patients who are medically inoperable with early stage primary lung cancer, and patients with oligometastasis or local recurrence. For stage IA non-small cell lung cancer (NSCLC) patients underwent RFA, 1- and 2-year overall survival rate were reported as 86.3% and 69.8%. And 1- and 2-year local recurrence rate were reported as 68.9% and 59.8%. Limitations, including heat sink, skin burn, and inconsistent heat conduction, are observed in the first applied ablation technique, RFA. MWA and cryoablation are developed to overcome these limitations and achieve the goal of less morbidity. Generally, imaged guided thermal ablation has a good safety profile, with pneumothorax as the most common morbidity. This article will mainly discuss the current features and application of these ablation techniques in lung cancer treatment.

Standardizing percutaneous Microwave Ablation in the treatment of Lung Tumors: a prospective multicenter trial (MALT study)

OBJECTIVES

To prospectively assess reproducibility, safety, and efficacy of microwave ablation (MWA) in the treatment of unresectable primary and secondary pulmonary tumors.

METHODS

Patients with unresectable primary and metastatic lung tumors up to 4 cm were enrolled in a multicenter prospective clinical trial and underwent CT-guided MWA. Treatments were delivered using pre-defined MW power and duration settings, based on target tumor size and histology classifications. Patients were followed for up to 24 months. Treatment safety, efficacy, and reproducibility were assessed. Ablation volumes were measured at CT scan and compared with ablation volumes obtained on ex vivo bovine liver using equal treatment settings.

RESULTS

From September 2015 to September 2017, 69 MWAs were performed in 54 patients, achieving technical success in all cases and treatment completion without deviations from the standardized protocol in 61 procedures (88.4%). Immediate post-MWA CT scans showed ablation dimensions smaller by about 25% than in the ex vivo model; however, a remarkable volumetric increase (40%) of the treated area was observed at 1 month post-ablation. No treatment-related deaths nor complications were recorded. Treatments of equal power and duration yielded fairly reproducible ablation dimensions at 48-h post-MWA scans. In comparison with the ex vivo liver model, in vivo ablation sizes were systematically smaller, by about 25%. Overall LPR was 24.7%, with an average TLP of 8.1 months. OS rates at 12 and 24 months were 98.0% and 71.3%, respectively.

CONCLUSIONS

Percutaneous CT-guided MWA is a reproducible, safe, and effective treatment for malignant lung tumors up to 4 cm in size.

KEY POINTS

• Percutaneous MWA treatment of primary and secondary lung tumors is a repeatable, safe, and effective therapeutic option. • It provides a fairly reproducible performance on both the long and short axis of the ablation zone. • When using pre-defined treatment duration and power settings according to tumor histology and size, LPR does not increase with increasing tumor size (up to 4 cm) for both primary and metastatic tumors.

The evolution of interventional oncology in the 21st century

Interventional oncology (IO) has proven to be highly efficient in the local therapy of numerous malignant tumors in addition to surgery, chemotherapy, and radiotherapy. Due to the advent of immune-oncology with the possibility of tumor control at the molecular and cellular levels, a system change is currently emerging. This will significantly rule oncology in the coming decades. Therefore, one cannot think about IO in the 21st century without considering immunology. For IO, this means paying much more attention to the immunomodulatory effects of the interventional techniques, which have so far been neglected, and to explore the synergistic possibilities with immuno-oncology. It can be expected that the combined use of IO and immuno-oncology will help to overcome the limitations of the latter, such as limited local effects and a high rate of side-effects. To do this, however, sectoral boundaries must be removed and interdisciplinary research efforts must be strengthened. In case of success, IO will face an exciting future.

A Clinical Study on Microwave Ablation in Combination with Chemotherapy in Treating Peripheral IIIB-IV Nonsmall Cell Lung Cancer

Background: This study investigated the efficacy and complications of microwave ablation in combination with chemotherapy in treating peripheral IIIB-IV nonsmall cell lung cancer (NSCLC). Materials and Methods: A total of 100 patients with peripheral IIIB-IV NSCLC were randomly divided into two groups: combination group (n = 52) and chemotherapy group (n = 48). Patients in the combination group were treated with microwave ablation, radiotherapy, and chemotherapy, whereas the patients in the chemotherapy group were treated with pemetrexed disodium or gemcitabine hydrochloride, cisplatin chemotherapy, and conventional radiotherapy. Results: The effectiveness and disease control rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). The second- and third-year survival rates were significantly higher in the combination group than in the chemotherapy group (p < 0.05). However, patients in the combination group had no serious complications, and there were no intraoperative and perioperative deaths. Conclusions: Microwave ablation is safe and effective. Combination chemotherapy is superior to chemotherapy in treating peripheral IIIB-IV NSCLC in terms of effectiveness rate, disease control rate, and extended patient survival time.

Salvage treatment of NSCLC recurrence after first-line chemotherapy failure: Iodine-125 seed brachytherapy or microwave ablation?

Background

Salvage treatments for recurrent NSCLC after first‐line chemotherapy remain challenging. This study was conducted to evaluate the clinical value of microwave ablation (MWA) and iodine‐125 brachytherapy, including overall survival (OS), disease free survival (DFS), local control, hospital stay, and health economics.

Methods

The data of 51 and 32 patients who were treated with MWA and brachytherapy was retrospectively analyzed. The number of lesions was limited up to two, with a diameter <4 cm and patients diagnosed with unilateral lung disease. Peripheral tumors were treated with MWA, while lesions close to the hilum were treated with brachytherapy. Contrast‐enhanced CT, blood cell count, coagulation function, liver & kidney function and tumor markers were performed for two years, with complications calculated. OS, DFS, local control rate, toxicity, hospital stay and expense were recorded.

Results

The one and two‐year OS rates were 96.08% and 92.16% versus 96.88% and 90.62% in the MWA and brachytherapy groups, respectively. The one and two‐year DFS rates were 92.16% and 76.47% versus 93.75% and 78.13%, respectively. No significant differences were observed in log‐rank analysis between the groups. Local control rates at six and 12 months were 100% and 96.08% versus 100% and 96.88%, while incidences of pleural effusion were 3.92% and 3.13%, respectively (P < 0.05). Medical cost was 3356.73 ± 206.87 and 6714.28 ± 35.43 U.S. dollars (P = 0.014).

Conclusion

MWA and brachytherapy are effective and safe options for the treatment of NSCLC recurrence after first‐line chemotherapy. Which modality should be considered is dependent upon tumor location, tumor size and experience of specialists.

Independent prognostic value of HIF-1α expression in radiofrequency ablation of lung cancer

Radiofrequency ablation (RFA) is widely used in the treatment of lung cancer. Hypoxia-inducible factor-1α (HIF-1α) is a crucial transcription factor regulating oxygen homeostasis that is involved in tumor cell metastasis. The present study investigated the impact of HIF-1α expression and other factors, such as postoperative blood CD4⁺/CD8⁺ ratio, on the prognosis of patients with lung cancer who had received RFA treatment. A total of 80 patients with lung cancer were recruited between January 2011 and October 2016 at The Shenzhen People's Hospital. Lung cancer was confirmed following pathological or histological examination. All patients underwent RFA treatment. Patients were followed up for 6–66 months. HIF-1α expression in lung cancer tissues was assessed by immunohistochemistry. Multivariate survival analysis was performed using Cox proportional hazards model. The results demonstrated that HIF-1α level was low in 36 patients and overexpressed in 44 patients with lung cancer. Kaplan-Meier (KM) curve analysis demonstrated that the overall survival time of patients with high HIF-1α expression was significantly shorter compared with patients with low HIF-1α expression (P<0.05). Furthermore, the results from the KM model and log-rank test revealed that age, Union for International Cancer Control stage, primary or metastatic cancer, chemotherapy, postoperative blood CD4⁺/CD8⁺ ratio, Eastern Cooperative Oncology Group performance status and HIF-1α expression had significant effects on overall survival of patients with lung cancer. The results from Cox analysis demonstrated that high HIF-1α expression, advanced age, clinical staging and chemotherapy were independent risk factors for the prognosis of lung cancer following RFA treatment, and that high HIF-1α expression was associated with the increased risk (5.91-fold) of mortality. In conclusion, the present study demonstrated that HIF-1α expression was increased in lung cancer tissues and was associated with the prognosis of patients with lung cancer who were treated with RFA. These findings suggest that HIF-1α expression may be considered as a marker for evaluating the prognosis of these patients.

The Yin and Yang of PDT and PTT

In Chinese philosophy, yin and yang ("dark-bright," "negative-positive") describe how seemingly opposite or contrary forces may actually be complementary, interconnected and interdependent. This paper provides this perspective on photodynamic and photothermal therapies, with a focus on the treatment of solid tumors. The relative strengths and weaknesses of each modality, both current and emerging, are considered with respect to the underlying biophysics, the required technologies, the biological effects, their translation into clinical practice and the realized or potential clinical outcomes. For each specific clinical application, one or the other modality may be clearly preferred, or both are effectively equivalent in terms of the various scientific/technological/practical/clinical trade-offs involved. Alternatively, a combination may the best approach. Such combined approaches may be facilitated by the use of multifunctional nanoparticles. It is important to understand the many factors that go into the selection of the optimal approach and the objective of this paper is to provide guidance on this.