American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer

External Beam Radiation Therapy for Liver Metastases

Stereotactic ablative radiotherapy (SABR) commonly is used for small liver metastases. Modern conformal radiotherapy techniques, including 3-dimensional conformal radiotherapy and intensity-modulated radiation therapy, enable the safe delivery of SABR to small liver volumes. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs, such as the stomach, duodenum, and large intestine. Controlling respiratory motion, the use of image guidance, and increasing the number of radiation fractions sometimes are necessary for the safe delivery of SABR in these situations.

Percutaneous radiofrequency ablation of liver metastases from colorectal cancer: Development of a prognostic score to predict overall survival

PURPOSE

To develop a model for pretreatment prediction of overall survival (OS) after radiofrequency ablation (RFA) for colorectal liver metastasis (CRLM).

METHOD

This retrospective study included 491 patients (median age, 61 years; 348 men) who underwent percutaneous RFA for CRLM between 2000 and 2021. The Kaplan-Meier method was used to estimate OS rates. Independent factors affecting OS were investigated using multivariable Cox regression analysis. Risk scores were assigned to the risk factors and pretreatment prediction models were created using the risk factors.

RESULTS

After RFA, the 5-, 10-, and 20-year OS rates were 44 %, 31 %, and 24 %, respectively, and the median OS was 46 months. Multivariate Cox regression analysis showed that a largest tumor size ≥ 2 cm (P<0.001), positive nodal status of primary tumor (P<0.001), carcinoembryonic antigen level > 30 ng/mL (P=0.049), multiple tumors (P=0.008), and T4 stage of the primary tumor (P=0.029) were independently associated with OS. In patients with a single CRLM, tumor diameter (P<0.001), positive nodal status of primary tumor (P=0.001), disease-free interval <12 months (P=0.045), and subcapsular location (P=0.03) were risk factors affecting OS. According to our prediction models, which included the aforementioned risk factors, OS rates progressively decreased as the risk scores increased, with significantly different OS rates between contiguous groups (P<0.001).

CONCLUSIONS

Our prediction models can be used as a prognostic stratification tool in patients with CRLM, and can help select those candidates who will benefit most from RFA.

Melatonin enhances the efficacy of anti-PD-L1 by improving hypoxia in residual tumors after insufficient radiofrequency ablation

The hypoxic microenvironment and inflammatory state of residual tumors caused by insufficient radiofrequency ablation (iRFA) are major reasons for rapid tumor progression and pose challenges for immunotherapy. We retrospectively analyzed the clinical data of patients with hepatocellular carcinoma (HCC) treated with RFA and observed that iRFA was associated with poor survival outcomes and progression-free survival. Using an orthotopic HCC mouse model and a colorectal liver metastasis model, we observed that treatment with melatonin after iRFA reduced tumor growth and metastasis and achieved the best outcomes when combined with anti-programmed death-ligand 1 (anti-PD-L1) therapy. In mechanism, melatonin inhibited the expression of epithelial-mesenchymal transitions, hypoxia-inducible factor (HIF)-1α, and PD-L1 in tumor cells after iRFA. Flow cytometry revealed that melatonin reduced the proportion of myeloid-derived suppressor cells and increased the proportion of CD8+ T cells. Transcriptomic analysis revealed an upregulation of immune-activated function-related genes in residual tumors. These findings demonstrated that melatonin can reverse hypoxia and iRFA-induced inflammation, thereby overcoming the immunosuppressive tumor microenvironment (TME) and enhancing the efficacy of immunotherapy.

Colorectal cancer

Despite decreased incidence rates in average-age onset patients in high-income economies, colorectal cancer is the third most diagnosed cancer in the world, with increasing rates in emerging economies. Furthermore, early onset colorectal cancer (age ≤50 years) is of increasing concern globally. Over the past decade, research advances have increased biological knowledge, treatment options, and overall survival rates. The increase in life expectancy is attributed to an increase in effective systemic therapy, improved treatment selection, and expanded locoregional surgical options. Ongoing developments are focused on the role of sphincter preservation, precision oncology for molecular alterations, use of circulating tumour DNA, analysis of the gut microbiome, as well as the role of locoregional strategies for colorectal cancer liver metastases. This overview is to provide a general multidisciplinary perspective of clinical advances in colorectal cancer.

Advancements in the Management of Synchronous Colorectal Liver Metastases: A Comprehensive Review of Surgical, Systemic, and Local Treatment Modalities

PURPOSE OF REVIEW

This review addresses the current landscape of colorectal cancer (CRC) with a focus on liver metastases, the third most common cancer globally. It explores recent findings in treatment strategies, emphasizing the dynamic interplay between surgery, systemic chemotherapy, and local therapies for synchronous colorectal liver metastases (CRLMs).

RECENT FINDINGS

Highlighting the role of advanced imaging, the review underscores the significance of contrast-enhanced MRI in surgical planning for CRLMs. Surgical resection remains a primary choice for resectable cases, with considerations for oncologic scoring systems and tumor biology. Perioperative systemic chemotherapy plays a pivotal role, especially in conversion therapy for initially unresectable CRLMs. The review also explores various local therapies, including radiofrequency ablation, microwave ablation, stereotactic body radiotherapy, hepatic arterial infusional chemotherapy, selective internal radiation therapy, and transarterial chemoembolization for unresectable cases. A comprehensive approach, integrating surgery, systemic chemotherapy, and local therapies, is crucial for managing synchronous CRLMs. Surgical resection and perioperative chemotherapy are key players, guided by considerations of tumor biology and scoring systems. For unresectable cases, local therapies offer viable alternatives, emphasizing the need for tailored treatments. Multidisciplinary collaboration among medical oncologists, surgeons, and radiologists is essential. Ongoing research will refine treatment approaches, while emerging technologies hold promise for further advancements in managing colorectal liver metastases.

A retrospective study comparing the efficacy of microwave ablation and stereotactic body radiotherapy in colorectal cancer lung metastases

The purpose of the present study was to assess and compare the efficacy of microwave ablation (MWA) and stereotactic body radiotherapy (SBRT) in the treatment of lung metastases from patients with colorectal cancer (CRC) and to identify the preferable treatment modality based on patient and tumor characteristics. Records of 118 patients with CRC with a total of 307 lung metastases who underwent SBRT or MWA between January 2015 and December 2022 were retrospectively analyzed, including the essential clinicopathological information on patients (age, sex and underlying diseases), diagnosis and treatment information [primary tumor site, levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9], imaging data [diameter of lung metastasis, location of the metastasis (i.e., whether or not the tumor was adjacent to the vessel or bronchus) and internal features] and follow-up data (postoperative therapy, complications or adverse effects and survival outcomes). For statistical analysis of the local tumor progression (LTP), disease-free survival and overall survival (OS) rates, Cox regression analysis, along with the Kaplan-Meier method adjusted using inverse probability of treatment weighting (IPTW), were performed. The median follow-up duration in the present study was 31.5 months. Multivariable Cox regression analysis revealed that the CEA level, metastasis diameter and internal features were independent predictors of OS. In the IPTW-adjusted analysis, no significant difference in the 1-year OS rate was observed between the SBRT and MWA groups (92.9 vs. 93.9%; P=0.483); however, a notable discrepancy in the treatment modalities was noted, leading to significant differences in the 2- and 3-year OS rates (65.9 vs. 57.6%, P=0.001, and 44.7 vs. 36.4%, P<0.001, respectively). A significant interaction effect for the treatment modality was observed for LTP (P=0.021). In conclusion, the present study revealed that SBRT and MWA have similar therapeutic effects in terms of prolonging the survival of patients with CRC with lung metastases; however, regarding the local control of lung metastases, MWA is associated with a number of significant advantages.

Circulating Tumor DNA Predicts Early Recurrence Following Locoregional Therapy for Oligometastatic Colorectal Cancer

(1) Background: Local therapies offer a potentially curative approach for patients with oligometastatic colorectal cancer (CRC). An evidence-based consensus recommendation for systemic therapy following definitive locoregional therapy is lacking. Tumor-informed circulating tumor DNA (ctDNA) might provide information to help guide management in this setting. (2) Methods: A multi-institutional retrospective study was conducted, including patients with CRC that underwent curative-intent locoregional therapy to an isolated site of metastatic disease, followed by tumor-informed ctDNA assessment. The Kaplan-Meier method and log-rank tests were used to compare disease-free survival based on ctDNA results. ctDNA test performance was compared to carcinoembryonic antigen (CEA) test results using McNemar's test. (3) Results: Our study cohort consisted of 87 patients treated with locoregional interventions who underwent ctDNA testing. The initial ctDNA test post-intervention was positive in 28 patients and negative in 59 patients. The median follow-up time was 14.0 months. Detectable ctDNA post-intervention was significantly associated with early disease recurrence, with a median disease-free survival (DFS) of 6.63 months compared to 21.30 months in ctDNA-negative patients (p < 0.001). ctDNA detected a numerically higher proportion of recurrences than CEA (p < 0.097). Post-intervention systemic therapy was not associated with improved DFS (p = 0.745). (4) Conclusions: ctDNA results are prognostically important in oligometastatic CRC, and further prospective studies are urgently needed to define its role in guiding clinical decisions.

Surgical and Interventional Management of Liver Metastasis

Colorectal cancer is one of the most common cancers diagnosed worldwide. While the incidence of colorectal cancer has been declining since the adoption of screening colonoscopy, the findings of liver metastasis are still found in up to 25% of patients at diagnosis. The management of liver metastasis has evolved over the past two to three decades, and survival rates have improved secondary to improved systemic therapy, surgical options, and local therapies. In this article, we aim to review the available surgical and ablative options for management of colorectal liver metastasis, as well as appropriate imaging and patient selection.

Local Tumour Control Following Microwave Ablation: Protocol for the Prospective Observational CIEMAR Study

PURPOSE

Microwave ablation (MWA) is a treatment modality for colorectal liver metastases (CRLM). While potentially curative, more information is needed on factors that contribute to long-term local tumour control. The prospective multicentre observational study CIRSE Emprint Microwave Ablation Registry aims to prospectively collect real-world technical data and clinical outcomes on patients treated with MWA in CRLM.

METHODS

Eligible patients are adults with up to 9 local treatment naïve CRLM of ≤ 3 cm completely treatable with either MWA alone or MWA with resection and/or radiotherapy within 8 weeks. Data are collected, at baseline, every 3 months until 12 months, and thereafter every 6 months until the end of the study. The primary outcome measure is local tumour control. Secondary outcome measures are overall survival, (hepatic-) disease-free survival, time-to-progression untreatable by ablation, systemic therapy vacation, safety, and quality of life. Covariates related to the primary outcome measure will be assessed using a stratified log-rank test and an univariable Cox proportional hazard regression. A sample size of 500 patients with 750 lesions produces a two-sided 95% confidence interval with a precision equal to 0.057.

RESULTS

Between September 2019 and December 2022, 500 patients have been enrolled with at least 976 treated tumours.

CONCLUSION

The prospective observational CIEMAR study will provide valuable insights into the real-world use of MWA, helping in the future patient selection and clarifying factors that may contribute to long-term local tumour control.

TRIAL REGISTRATION

NCT03775980.

Optimizing Treatment Strategy for Oligometastases/Oligo-Recurrence of Colorectal Cancer

Colorectal cancer (CRC) is the third most common cancer, and nearly half of CRC patients experience metastases. Oligometastatic CRC represents a distinct clinical state characterized by limited metastatic involvement, demonstrating a less aggressive nature and potentially improved survival with multidisciplinary treatment. However, the varied clinical scenarios giving rise to oligometastases necessitate a precise definition, considering primary tumor status and oncological factors, to optimize treatment strategies. This review delineates the concepts of oligometastatic CRC, encompassing oligo-recurrence, where the primary tumor is under control, resulting in a more favorable prognosis. A comprehensive examination of multidisciplinary treatment with local treatments and systemic therapy is provided. The overarching objective in managing oligometastatic CRC is the complete eradication of metastases, offering prospects of a cure. Essential to this management approach are local treatments, with surgical resection serving as the standard of care. Percutaneous ablation and stereotactic body radiotherapy present less invasive alternatives for lesions unsuitable for surgery, demonstrating efficacy in select cases. Perioperative systemic therapy, aiming to control micrometastatic disease and enhance local treatment effectiveness, has shown improvements in progression-free survival through clinical trials. However, the extension of overall survival remains variable. The review emphasizes the need for further prospective trials to establish a cohesive definition and an optimized treatment strategy for oligometastatic CRC.

Hepatic arterial oxaliplatin plus intravenous 5-fluorouracil and cetuximab for first-line treatment of colorectal liver metastases: A multicenter phase II trial

BACKGROUND

The efficacy and tolerability of hepatic arterial infusion (HAI) oxaliplatin plus systemic 5-fluorouracil and cetuximab as frontline treatment in patients with colorectal liver metastases (CRLM) are unknown.

METHODS

In this multicenter, single-arm phase II study, patients with CRLM not amenable to curative-intent resection or requiring complex/major liver resection, and no prior chemotherapy for metastatic disease, received HAI oxaliplatin and intravenous 5-fluorouracil, leucovorin and cetuximab, every two weeks until disease progression, limiting toxicity or at least 3 months after complete response or curative-intent resection/ablation. The primary endpoint was overall response rate (ORR).

RESULTS

35 patients, mostly with bilateral (89%), multiple CRLM (>4, 86%; >10, 46%) were enrolled in eight centers. The ORR was 88% (95% CI, 71%-96%) among evaluable patients (n = 32), and 95% (95% CI 70-100%) among the 22 wild-type RAS/BRAF evaluable patients. After a median follow-up of 8.8 years (95% CI, 8.7-not reached), median progression-free survival was 17.9 months (95% CI, 15-23) and median overall survival (OS) was 46.3 months (95% CI, 40.0-not reached). 23 of the 35 patients (66%), including 22 (79%) of the 25 patients with wild-type RAS tumor, underwent curative-intent surgical resection and/or ablation of CRLM. HAI catheter remained patent in 86% of patients, allowing for a median of eight oxaliplatin infusions (range, 1-19). Treatment toxicity was manageable, without toxic death.

CONCLUSION

HAI oxaliplatin plus systemic 5-fluorouracil and cetuximab appears highly effective in the frontline treatment of patients with unresectable CRLM and should be investigated further.

Therapeutic Outcome of Stereotactic Body Radiotherapy for Small Hepatocellular Carcinoma Lesions - A Systematic Review and Network Meta-analysis

Surgical resection, stereotactic body radiotherapy (SBRT) and radiofrequency ablation (RFA) have seldom been compared for small hepatocellular carcinoma (HCC). We explored the treatment outcomes of SBRT for small HCC by conducting a network meta-analysis (NMA). We compared the efficacy and safety of surgical resection, RFA and SBRT for liver-confined small HCC (three or fewer lesions with a diameter ≤5 cm). The study endpoint included the odds ratios of the 1-, 3- and 5-year progression/recurrence/disease-free survival (disease progression-free survival; DPFS) and overall survival rates, as well as severe complications. Forty-five studies included 21 468 patients. In the NMA with comparable data, SBRT had comparable 1-, 3- and 5-year DPFS but significantly worse pooled long-term overall survival (3- and 5-year overall survival) than surgical resection (odds ratio 1.39, 95% confidential interval 1.3-1.89; odds ratio 1.33, 95% confidence interval 1.06-1.69, respectively). SBRT was associated with significantly better pooled 1-year DPFS compared with RFA (odds ratio 0.39, 95% confidence interval 0.15-0.97), with the remaining outcomes being comparable. SBRT had significantly less incidence of severe complications compared with surgical resection (odds ratio 0.62, 95% confidence interval 0.42-0.88) and RFA (odds ratio 0.2, 95% confidence interval 0.03-0.94). In conclusion, for small HCCs (≤5 cm) with one to three nodules, SBRT may be favourable to reduce the risks of severe complications. In terms of DPFS, SBRT may be recommended as an alternative first-line therapy for RFA and surgical resection. The results regarding overall survival should be interpreted with caution, considering the potentially uneliminated bias. There is a clear need for well-designed randomised trials to conclusively identify real differences in efficacy between these treatments, especially SBRT and surgical resection.

Management and pharmacotherapy of pediatric colorectal carcinoma: a review

INTRODUCTION

Colorectal carcinoma (CRC) is one of the most common tumors in adult, but is extremely rare in children. In childhood, CRC often presents unfavorable aggressive histotypes, advanced clinical stage at onset and a worse prognosis. Pediatric CRC series are limited and include few patients, therefore information about treatment strategy and pharmacotherapy is scarce. For this reason, management of these patients represents a real challenge for pediatric oncologists.

AREAS COVERED

The authors provide an overview of the general features and management strategies of pediatric CRC with specific attention to systemic treatment. Literature data regarding pharmacotherapy in published pediatric series are summarized and analyzed in detail, according to adult treatment standards.

EXPERT OPINION

In the absence of specific recommendations for pediatric CRC, the general therapeutic strategy should follow the same principles as for adults and should be the result of a multidisciplinary discussion. Patient access to optimal treatment is difficult due to the lack of new drugs approved for the pediatric age group and non-availability of clinical trials. Collaboration between pediatric and adult oncologists is considered crucial in order to overcome these issues and find solutions to increase knowledge and improve the outcome of such a rare disease in children.

Risk and prognostic factors in patients with colon cancer with liver metastasis

OBJECTIVE

The most common site of metastasis in patients with colon cancer is the liver. This study aimed to identify patients with colon cancer at high risk of developing liver metastasis and to explore their prognosis.

METHODS

The clinical characteristics, treatment methods and survival outcomes of patients diagnosed with colon cancer from 2010 to 2015 were identified from the Surveillance, Epidemiology and End Results (SEER) database. Patients were divided into two groups according to the presence of liver metastasis, and multivariate logistic and Cox regression models were used to identify risk and prognostic factors.

RESULTS

A total of 60,018 patients with colon cancer were selected from the SEER database. The incidence of liver metastasis was 9.2%. African American ethnicity, poor differentiation, higher tumor stage, higher lymph node ratio, and lung metastases were common factors associated with both liver metastasis risk and prognosis.

CONCLUSIONS

Metastasectomy might improve survival among patients with colon cancer with resectable liver metastasis lesions and no other organ involvement.

Different power modes of microwave ablation for hepatocellular carcinoma: Evaluation of recurrence rate and factors related to recurrence

PURPOSE

To evaluate the safety and efficacy of different power modes(constant power and variable power) percutaneous microwave ablation (MWA) for treating hepatocellular carcinoma (HCC) and to predict the risk factors of recurrence after MWA.

MATERIALS AND METHODS

In this retrospective study, a total of 112 patients with solitary HCC were included from January 2015 to January 2021. All patients received MWA through a percutaneous approach that was guided by ultrasound, 45 patients received variable power MWA, and the remaining 67 were treated with constant power MWA. The complete ablation rates, local recurrence rates, complications, and short-term survival were analyzed. Possible risk factors for tumor recurrence were analyzed.

RESULTS

The complete ablation rates were 95.9% for the first ablation and 100% for the second ablation for ≤3 cm lesions. The complete ablation rates were 84.2%(95.9% versus 84.2%, p = 0.039) for the first ablation and 94.7% (100% versus 94.7%, p = 0.113) for the second ablation for 3-5 cm lesions. Local and distant recurrence rates were 18.7%(21/112) and 14.3%(16/112). The 1-, 2-year survival rates were 86.3 and 66.3%, respectively. Subgroup analysis showed that 1-, 2-year survival rates were 91.1% and 78.5% in ≤3 cm group, and were 74.4% and 40.9% in 3-5 cm group, respectively. Univariate analysis revealed that a positive correlation existed between the HBV DNA replication(p = 0.007), AFP level of pre-MWA(p = 0.001) and post-MWA(p<0.001), tumor diameter(p<0.001), irregular shape(p = 0.014), proximity to the risk location(p = 0.008), poor differentiation(p = 0.003), constant power(p = 0.028), length(p<0.001) and width of ablation zone(p = 0.001), and present complication(p<0.001), and early recurrence. Multivariate analysis identified HBV DNA replication(OR = 0.266, p = 0.036), AFP level of pre-MWA (OR = 4.001, p = 0.036), tumor diameter (OR = 2.153, p = 0.042), tumor location (OR = 0.910, p = 0.046), and width of ablation zone(OR = 2.530, p = 0.044) were independent prognosis factors causing postoperative HCC recurrence.

CONCLUSION

Variable power MWA of HCC appears to be a safe and effective treatment. HBV DNA, AFP level of pre-MWA, tumor diameter, tumor location, and width of ablation range appear to be independent predictors of tumor recurrence.

Predictive Factors of Local Recurrence after Colorectal Cancer Liver Metastases Thermal Ablation

Background: Identify risk factors for local recurrence (LR) after radiofrequency (RFA) and microwave (MWA) thermoablations (TA) of colorectal cancer liver metastases (CCLM). Methods: Uni- (Pearson’s Chi2 test, Fisher’s exact test, Wilcoxon test) and multivariate analyses (LASSO logistic regressions) of every patient treated with MWA or RFA (percutaneously and surgically) from January 2015 to April 2021 in Centre Georges François Leclerc in Dijon, France. Results: Fifty-four patients were treated with TA for 177 CCLM (159 surgically, 18 percutaneously). LR rate was 17.5% of treated lesions. Univariate analyses by lesion showed factors associated with LR: sizes of the lesion (OR = 1.14), size of nearby vessel (OR = 1.27), treatment of a previous TA site LR (OR = 5.03), and non-ovoid TA site shape (OR = 4.25). Multivariate analyses showed that the size of the nearby vessel (OR = 1.17) and the lesion (OR = 1.09) remained significant risk factors of LR. Conclusions: The size of lesions to treat and vessel proximity are LR risk factors that need to be considered when making the decision of thermoablative treatments. TA of an LR on a previous TA site should be reserved to specific situations, as there is an important risk of another LR. An additional TA procedure can be discussed when TA site shape is non-ovoid on control imaging, given the risk of LR.

Laparoscopic microwave ablation versus percutaneous microwave ablation of hepatic malignancies: Efficacy and recurrence-free survival outcomes in patients

BACKGROUND

Hepatic thermal ablation has been found to be effective and equivalent to resection in certain liver histologies. Of the 16,000 annual liver ablations performed in the United States, only 13% (2,080 ablations) are performed laparoscopically. The laparoscopic technique remains underused even with the benefits of improved staging and better access to tumors. The purpose of this study is to compare laparoscopic microwave ablation versus percutaneous microwave ablation in terms of efficacy and recurrence-free survival outcomes in patients with hepatic malignancies.

METHODS

A comparative analysis was performed on 275 patients (289 ablation procedures) who underwent laparoscopic microwave ablation or percutaneous microwave ablation between February 2011 and May 2021. Ablation success was confirmed postprocedure and recurrence was monitored at follow-up via contrast-enhanced computed tomography/magnetic resonance imaging and/or computed tomography/positron emission tomography.

RESULTS

The groups were similar for sex, age, body mass index, location of tumor, size of tumor, and number of tumors. Ablation success was 100% in both groups. Local recurrence was significant (5%: laparoscopic microwave ablation vs 22%: percutaneous microwave ablation, P = .002) and same-lobe recurrence (21%: laparoscopic microwave ablation vs 24%: percutaneous microwave ablation) was lower in the laparoscopic microwave ablation group. Median recurrence-free survival was 15.8 months for the laparoscopic microwave ablation group and 5.6 months for the percutaneous microwave ablation group (P = .0002). Overall, 90-day complications were lower in the laparoscopic microwave ablation group (11%) compared with the percutaneous microwave ablation group (21%) (P = .11).

CONCLUSION

Laparoscopic surgical ablation is a critical surgical skill that must be taught in fellowship. Laparoscopic microwave ablation leads to better tumor specific outcomes and oncologic outcomes demonstrating clinical efficacy in the treatment of hepatic malignancies compared with percutaneous microwave ablation.

Safety of High-Frequency Jet Ventilation During Image-Guided Thermal Ablation Procedures

RATIONALE AND OBJECTIVE

Percutaneous thermal ablative technique is a common radiological procedure for malignant lesions treatment. Controlled assisted ventilation during general anesthesia is the usual mode of ventilation, but high-frequency jet ventilation (HFJV) can be a helpful alternative for the operator. The objective was to evaluate the safety of HFJV during thermal ablation procedures.

MATERIALS AND METHODS

This monocentric prospective analysis included adult patients undergoing percutaneous thermal ablation procedures for abdominal tumor performed under HFJV. Procedures with a transpulmonary path were excluded. The primary outcome was the incidence of respiratory complications. Secondary outcomes included gas exchange modifications (hypercapnia, hypoxemia, pulmonary atelectasis) and the incidence of barotrauma.

RESULTS

Sixty patients were included during the study period. The mean duration time was 88 min. All procedures went according to the protocol and there was no respiratory complication. There was no barotrauma event. Three patients had an exhaled capnia above 45 mmHg at the end of the procedure which normalized within 10 min of conventional ventilation.

CONCLUSION

HFJV during thermal ablation procedures is safe regarding gas exchange and barotrauma. This technique could be an interesting alternative to conventional ventilation during image-guided thermal ablation procedures. Clinical Trials database This study was registered in Clinical Trials database (NCT04209608).

Stereotactic Ablative Radiation Therapy for Colorectal Liver Metastases

INTRODUCTION

Stereotactic Ablative Radiation Therapy (SABR) is a therapeutic option for patients with inoperable oligometastatic colorectal carcinoma (CRC). Given the scarcity of prospective data on outcomes of SABR for metastatic CRC, this study aims to review SABR outcomes and determine predictive factors of local control (LC) and survival in patients with liver metastases from CRC.

MATERIALS AND METHODS

A retrospective review of SABR for CRC liver metastases between 2011 and 2019 was undertaken. Endpoints included LC, overall survival (OS), progression-free survival (PFS) and time to restarting systemic therapy. Univariate (UVA) and multivariable analyses (MVA) were performed to identify predictive factors.

RESULTS

Forty-eight patients were identified. The total number of tumors treated was 58. Median follow-up was 26.6 months. LC at 1, 2 and 3 years was 92.7%, 80.0%, and 61.2% respectively. Median time to local failure was 40.0 months (95% CI 31.8-76.1 months). Median OS was 31.9 months (95% CI 20.6-40.0 months). OS at 1, 2, and 3 years was 79.2%, 61.7%, and 44.9% respectively. Thirty-three patients (69%) restarted systemic therapy after completion of SABR. Median time to restarting chemotherapy was 11.0 months (95% CI 7.1-17.6 months). Systemic therapy free survival at 1, 2, and 3 years was 45.7%, 29.6%, and 22.6% respectively. On MVA, inferior LC was influenced by GTV volume ≥40 cm³ (HR: 3.805, 95% CI 1.376-10.521, P = .01) and PTV D100% BED <100 Gy₁₀ (HR 2.971, 95% CI 1.110-7.953; P = .03). Inferior OS was associated with PTV volume ≥200 cm³ (HR 5.679, 95% CI 2.339-13.755; P < .001).

CONCLUSION

SABR is an effective therapeutic option for selected patients with CRC liver metastases providing acceptable LC within the first 2 years. In many cases, it provides meaningful chemotherapy-free intervals. Higher biological effective doses are required to enhance LC.

Multimodality liver directed treatment for colorectal liver metastasis: Array of complementary options can improve outcomes - A single centre experience from India

AIM

Complimentary use of Liver directed therapies (LDTs) with systemic chemotherapy has improved oncologic outcomes in colorectal liver metastasis (CRLM). We analysed institutional results of multimodality management.

Methods

Retrospective analysis of prospectively maintained database of CRLM patients managed with LDT including surgical resection, Ablation, Transarterial chemoembolization (TACE) or Transarterial radioembolization (TARE) between November 2011 to March 2020. Management plan was decided in multidisciplinary meeting. Resectable tumours underwent surgical resection or ablation or both in some cases. Borderline resectable or unresectable disease was treated with down staging chemotherapy or TACE/TARE followed by resection or ablation. All patients received adjuvant chemotherapy. Factors influencing survival were analysed.

Results

Out of total 375 patients, surgery alone was done in 191 (50.93%) patients while surgery with other LDT in 26 patients (6.93%). Ablation alone was done in 100 (26.66%) whereas TACE/TARE were done as standalone treatment in 21 (5.6%) and 7 (1.86%) patients respectively. TACE + ablation was done in 28 (7.46%) and TARE + ablation was done in 2(0.53%) patients.5-year Overall Survival(OS) was 49.8% while Event free survival(EFS) was 21.4%. The median OS and EFS for surgical group was significantly better than non-surgical group (78 V/s 39 months; p<0.05 and 20 V/s 15 months p <0.005). The resectable (78 months) group had better median OS as compared to borderline resectable and Unresectable group (39 months and 29 months). Male gender, resectable disease and surgical intervention were associated with improved OS.

Conclusion

Although surgery remains the mainstay of treatment, complementary use of non-surgical LDT with systemic therapy offers possibility of good outcomes in advanced liver limited disease. Our experience highlights the impact of multidisciplinary care in optimizing CRLM treatment.

Predictive Factors for Local Recurrence after Intraoperative Microwave Ablation for Colorectal Liver Metastases

This study aimed to clarify local recurrence (LR) predictive factors following intraoperative microwave ablation (MWA) for colorectal liver metastases. The data from 195 patients with 1392 CRLM lesions, who were preoperatively diagnosed by gadolinium-enhanced MRI with diffusion-weighted imaging and dynamic CT and treated with intraoperative MWA (2450 MHz) with or without hepatectomy, from January 2005 to December 2019, were retrospectively reviewed and analyzed using logistic regression. In addition, the margins were measured on contrast-enhanced CT 6 weeks post-ablation. Overall, 1066 lesions were ablated. The LRs occurred in 44 lesions (4.1%) among 39 patients (20.0%). The multivariate analysis per patient showed that tumor size > 20 mm and ablation margin < 5 mm were significant predictors for LR. Furthermore, multivariate analysis per lesion revealed that segments 1, 7, and 8 and tumor size > 15 mm, ablation margin < 5 mm, tumor size > 20 mm, and proximity to the Glisson were significant LR predictors. Finally, the outcome of this study may help determine indications for MWA.

Neoadjuvant Chemotherapy Followed by Radiofrequency Ablation May Be a New Treatment Modality for Colorectal Liver Metastasis: A Propensity Score Matching Comparative Study

Background: Most colorectal liver metastases (CRLM) are not candidates for liver resection. Radiofrequency ablation (RFA) plays a key role in selected CRLM patients. Neoadjuvant chemotherapy (NAC) followed by liver resection has been widely used for resectable CRLM. Whether NAC followed by radiofrequency ablation (RFA) can achieve a similar prognosis to NAC followed by hepatectomy remains is unclear. The present study aimed to provide a new treatment modality for CRLM patients. Methods: This comparative retrospective research selected CRLM patients from 2009 to 2022. They were divided into NAC + RFA group and NAC + hepatectomy group. The propensity score matching (PSM) was used to reduce bias. We used multivariate cox proportional hazards regression analysis to explore independent factors affecting prognosis. The primary study endpoint was the difference in the progression-free survival (PFS) between the two groups. Results: A total of 190 locally curable CRLM patients were in line with the inclusion criteria. A slight bias was detected in the comparison of basic clinical characteristics between the two groups. RFA showed a significant advantage in the length of hospital stay (median; 2 days vs. 7 days; p < 0.001). The 1- and 3-year PFS in the liver resection and the RFA groups was 57.4% vs. 86.9% (p < 0.001) and 38.8% vs. 55.3% (p = 0.035), respectively. The 1-year and 3-year OS in the liver resection and RFA groups was 100% vs. 96.7% (p = 0.191) and 73.8% vs. 73.6% (p = 0.660), respectively. Conclusions: NAC followed by RFA has rapid postoperative recovery, fewer complications, and better prognosis.

A comparative study on computational models of multi-electrode radiofrequency ablation of large liver tumors

PURPOSE

Thermal ablation of liver tumors has emerged as a first-line curative treatment for single small tumors (diameter < 2.5 cm) due to similar overall survival rates as surgical resection. Moreover, it is far less invasive, has lower complication rates, a superior cost-effectiveness, and an extremely low treatment-associated mortality. However, in many cases, complete tumor coverage cannot be achieved only with a single electrode and several electrodes are used to create overlapping ablations. Multi-electrode planning is a challenging 3D task with many contradictive constraints to consider, a dimensionality difficult to assess even for experts. It requires extremely long planning time since it is mostly performed mentally by clinicians looking at 2D CT views. An accurate and reliable prediction of the ablation zone would help to turn thermal ablation into a first-line curative treatment also for large liver tumors treated with multiple electrodes. In order to determine the level of model simplification that can be acceptable, we compared three computational models, a simple spherical model, a biophysics-based model and an Eikonal model.

METHODS

RF ablation electrodes were virtually placed at a desired position in the patient pre-operative CT image and the models predicted the ablation zone generated by multiple electrodes. The last two models are patient-specific. In these cases, hepatic structures were automatically segmented from the pre-operative CT images to predict a patient-specific ablation zone.

RESULTS

The three models were used to simulate multiple electrode ablations on 12 large tumors from 11 patients for which the procedure information was available. Biophysics-based simulations approximate better the post-operative ablation zone in term of Hausdorff distance, Dice Similarity Coefficient, radius, and volume compared to two other methods. It also predicts better the coverage percentage and thus the tumor ablation margin.

CONCLUSION

The results obtained with the biophysics-based model indicate that it could improve ablation planning by accurately predicting the ablation zone, avoiding over or under-treatment. This is particularly beneficial for multi-electrode radiofrequency ablation of larger liver tumors where the planning phase is particularly challenging.

Percutaneous Ablation of Hepatic Tumors at the Hepatocaval Confluence Using Irreversible Electroporation: A Preliminary Study

Background: Tumors at the hepatocaval confluence are difficult to treat, either surgically or ablatively. Methods: A retrospective longitudinal study on patients ineligible for thermal ablation who underwent computed tomography-guided IRE for hepatic tumors at the hepatocaval confluence was conducted. Factors analyzed included patient and tumor characteristics, IRE procedure details, treatment-related complications, and prognosis. Results: Between 2017 and 2021, 21 patients at our institute received percutaneous IRE. Of the 38 lesions, 21 were at the hepatocaval confluence. Complete ablation was achieved in all cases. Local and distant recurrence was observed in 4.8% (1/21) and 42.6% (9/21) of the ablated tumors, respectively. All postcava remained perfused at follow-up, except for 1 (4.8%) hepatic vein near the lesion found to be temporarily occluded and restored within 1 month. The ratio of the maximum diameter of ablation area at 1, 3, and 6 months post procedure compared to that immediately after IRE was 0.68 (0.50–0.84), 0.49 (0.27–0.61), and 0.38 (0.25–0.59), respectively. Progression-free survival of the patients with recurrence was 121 (range, 25–566) days. Four (19.0%) patients died at the end of follow-up with median overall survival of 451.5 (range, 25–716) days. Conclusions: IRE could be a safe and effective treatment for hepatic tumors at the hepatocaval confluence. This article provides valuable prognostic data; further clinical research is needed for better prognosis.

Neoadjuvant Chemotherapy Followed by Radiofrequency Ablation Prolongs Survival for Ablatable Colorectal Liver Metastasis: A Propensity Score Matching Comparative Study

Background

Typically, colorectal liver metastasis (CRLM) is not a candidate for hepatectomy. Radiofrequency ablation (RFA) plays a critical role in unresectable CRLM patients. Nevertheless, high local tumor progression (LTP) and distant metastasis limit the development and further adoption and use of RFA. Neoadjuvant chemotherapy (NAC) has been widely used in resectable CRLM and is recommended by the guidelines. There are no studies on whether NAC can improve the prognosis in ablatable CRLM patients. The present study aimed to determine the feasibility and effectiveness of RFA plus NAC.

Methods

This retrospective cohort included CRLM patients from Zhejiang Cancer Hospital records, who received RFA from January 2009 to June 2020 and were divided into two groups according to the presence or absence of NAC. The Kaplan–Meier method was used to evaluate the 3-year local tumor progression-free survival (LTPFS), progression-free survival (PFS), and overall survival (OS) of the two groups. The propensity score matching was used to reduce bias when assessing survival. Multivariate Cox proportional hazards regression analysis was used to study the independent factors affecting LTPFS, PFS, and OS.

Results

A total of 149 CRLM patients (88 in the RFA alone group and 61 in the plus NAC group) fulfilled the inclusion criteria. Post-RFA complications were 3.4% in the RFA alone group and 16.4% in the plus NAC group. The 3-year LTPFS, PFS, and OS of the RFA only group were 60.9%, 17.7%, and 46.2%, respectively. The 3-year LTPF, PFS, and OS of the plus NAC group were 84.9%, 46.0%, and 73.6%, respectively. In the 29 pairs of propensity score matching cohorts, the 3-year LTPFS, PFS, and OS in the plus NAC group were longer than those in the RFA group (P < 0.05). NAC was an independent protective factor for LTPFS, PFS, and OS (P < 0.05).

Conclusions

For ablatable CRLM patients, RFA plus NAC obtained a better prognosis than RFA alone. Based on the current results, the application of NAC before RFA may become the standard treatment.

Radiofrequency Ablation versus Stereotactic Body Radiation Therapy in the Treatment of Colorectal Cancer Liver Metastases

Purpose

This study aimed to compare the treatment outcomes of radiofrequency ablation (RFA) and stereotactic body radiation therapy (SBRT) for colorectal cancer liver metastases (CRLM) and to determine the favorable treatment modality according to tumor characteristics.

Materials and Methods

We retrospectively analyzed the records of 222 colorectal cancer patients with 330 CRLM who underwent RFA (268 tumors in 178 patients) or SBRT (62 tumors in 44 patients) between 2007 and 2014. Kaplan-Meier method and Cox models were used by adjusting with inverse probability of treatment weighting (IPTW).

Results

The median follow-up duration was 30.5 months. The median tumor size was significantly smaller in the RFA group than in the SBRT group (1.5 cm vs 2.3 cm, p < 0.001). In IPTW-adjusted analysis, difference in treatment modality was not associated with significant differences in 1-year and 3-year recurrence-free survival (35% vs. 43%, 22% vs. 23%; p=0.198), overall survival (96% vs. 91%, 58% vs. 56%; p=0.508), and freedom from local progression (FFLP; 90% vs. 72%, 78% vs. 60%; p=0.106). Significant interaction effect between the treatment modality and tumor size was observed for FFLP (p=0.001). In IPTW-adjusted subgroup analysis of patients with tumor size > 2 cm, the SBRT group had a higher FFLP compared with the RFA group (hazard ratio, 0.153; p < 0.001).

Conclusion

SBRT and RFA showed similar local control in the treatment of patients with CRLM. Tumor size was an independent prognostic factor for local control and SBRT may be preferred for larger tumors.

Microwave ablation for colorectal cancer metastasis to the liver: a single-center retrospective analysis

Background

The purpose of this study is to evaluate the safety and intermediate-term efficacy of percutaneous microwave (MW) ablation for the treatment of colorectal liver metastases (CRLM) at a single institution.

Methods

A retrospective review was performed of all CRLM treated with MW ablation from 3/2011 to 7/2020 (102 tumors; 72 procedures; 57 patients). Mean age was 60 years (range, 36-88) and mean tumor size was 1.8 cm (range, 0.5-5.0 cm). The patient population included 19 patients with extra-hepatic disease. Chemotherapy (pre- and/or post-ablation) was given in 98% of patients. Forty-five sessions were preceded by other focal CRLM treatments including resection, ablation, radiation, and radioembolization. Kaplan-Meier curves were used to estimate local tumor progression-free survival (LTPFS), disease-free survival (DFS), and overall survival (OS) and multivariate analysis (Cox Proportional Hazards model) was used to test predictors of OS.

Results

Technical success (complete ablation) was 100% and median follow-up was 42 months (range, 1-112). There was a 4% major complication rate and an overall complication rate of 8%. Local tumor progression (LTP) rate during the entire study period was 4/98 (4%), in which 2 were retreated with MW ablation for a secondary LTP-rate of 2%. LTP-free survival at 1, 3, and 5 years was 93%, 58%, and 39% and median LTP-free survival was 48 months. OS at 1, 3, and 5 years was 96%, 66%, 47% and median OS was 52 months. There were no statistically significant predictors of OS.

Conclusions

MW ablation of hepatic colorectal liver metastases appears safe with excellent local tumor control and prolonged survival compared to historical controls in selected patients. Further comparative studies with other local treatment strategies appear indicated.

Protective Effect of Nerium Oleander Distillate and Tarantula Cubensis Alcoholic Extract on Cancer Biomarkers on Colon and Liver Tissues of Rats with Experimental Colon Cancer

BACKGROUND

Colon cancers are among the three major cancer types that result in death. The research for effective treatment continues.

OBJECTIVE

The aim of this study is to determine the effects of Tarantula cubensis alcoholic extract (TCAE) and Nerium oleander (NO) distillate on the levels of midkine, TGF-β, VEGF, AFP, COX-2, IGF and caspase 3 in liver and colon tissues of experimentally induced colon cancer in rats.

METHOD

The liver and colon tissues of the rats were divided into Control, Colon Cancer (AZM), AZM+TCAE and AZM+NO groups and they were homogenized. The levels of midkine, TGF-β, VEGF, AFP, COX-2, IGF and caspase 3 in the colon and liver tissues were measured by ELISA kits.

RESULTS

All parameters levels of colon and liver tissues in the AZM group were generally higher (p<0.05) than the Control group. TCAE and NO prevented (p<0.05) the increases in midkine, TGF-β, VEGF, AFP, COX-2, IGF and caspase-3 levels in the colon. NO prevented increase of all parameters except for IGF level, while TCAE prevented (p<0.05) the increase of all values apart from COX-2 and IGF levels in the liver.

CONCLUSION

NO and TCAE may prevented at the specified marker levels of colon in the AZM induced colon cancer. The increases the level of parameters in the liver are not as severe as in the colon, due to the 18-week study period may not be sufficient for liver metastasis formationIn the future molecular studies should be done to determine the mechanisms and pathways of them more clearly.

Multielectrode Radiofrequency Ablation for Resectable Metachronous Liver Metastasis from Colorectal Cancer

The outcome of radiofrequency ablation (RFA) for liver metastases from colorectal cancer (CRLM) has been thought to be inferior to metastasectomy. However, the recent development of multielectrode RFA (multi-RFA) systems has made the ablation zone larger and more complete. Thus, we assessed the survival benefits of this modality in cases of metachronous CRLM. This retrospective study assessed patients diagnosed with resectable metachronous CRLM between 2013 and 2016; 132 patients were categorized by treatment for liver metastases: multi-RFA (n = 68), hepatectomy (n = 34), or systemic treatment only (n = 30). Therapeutic effectiveness, outcomes, and intervention-related complications were compared between groups. Median overall survival (OS), recurrence-free survival (RFS), and intrahepatic recurrence-free survival (IHRFS) were 69.8, 85.2, and 59.7 months for the hepatectomy group; 53.4, 41.3, and 32.3 months for the multi-RFA group; and 19.1, 7.1, and 7.1 months for the systemic treatment group. No significant differences were observed between the multi-RFA and hepatectomy groups after a median follow-up of 59.8 months. This study demonstrated that multi-RFA and hepatectomy provide similar survival benefits for patients with resectable CRLM. Multi-RFA may represent a reliable treatment option for the management of resectable liver metastases.

Recurrence and survival following microwave, radiofrequency ablation, and hepatic resection of colorectal liver metastases: A systematic review and network meta-analysis

BACKGROUND

Gold standard for colorectal liver metastases (CRLM) remains hepatic resection (HR). However, patients with severe comorbidities, unresectable or deep-situated resectable CRLM are candidates for ablation. The aim of the study was to compare recurrence rate and survival benefit of the microwave ablation (MWA), radiofrequency ablation (RFA) and HR by conducting the first network meta-analysis.

DATA SOURCES

Systematic search of the literature was conducted in the electronic databases. Both updated traditional and network meta-analyses were conducted and the results were compared between them.

RESULTS

HR cohort demonstrated significantly less local recurrence rate and better 3- and 5-year disease-free (DFS) and overall survival (OS) compared to MWA and RFA cohorts. HR cohort included significantly younger patients and with significantly lower preoperative carcinoembryonic antigen (CEA) by 10.28 ng/mL compared to RFA cohort. Subgroup analysis of local recurrence and OS of solitary and ≤ 3 cm CRLMs did not demonstrate any discrepancies when compared with the whole sample.

CONCLUSIONS

For resectable CRLM the treatment of choice still remains HR. MWA and RFA can be used as a single or adjunct treatment in patients with unresectable CRLM and/or prohibitive comorbidities.

What is the difference in ablation zone of multi-bipolar radiofrequency ablation between liver cirrhosis and normal liver background? - a prospective clinical study

PURPOSE

To explore the differences in ablation zone between liver cirrhosis and normal liver background and investigate the effect of hepatic blood flow on ablation zone of RFA.

METHODS

Between 2017 and 2019, 203 patients who had liver malignancies and underwent percutaneous RFA with Celon bipolar electrodes enrolled into this study. There were 90 patients had liver cirrhosis and 113 patients had normal liver background. They were 63 females and 140 males with average age of 59.0 ± 10.9 years old. Contrast-enhanced CT/MRI was used to evaluate the ablation zone in one month after RFA. The hepatic flow measurements on CDFI and CEUS were performed before RFA. Correlations between ablation zone versus hepatic flow were assessed using multiple linear regression analysis.

RESULTS

The average ablation zone in cirrhotic liver was significantly larger than those in normal liver background with 3 cm tip of RF electrodes (length 3.5 ± 0.5 vs 3.1 ± 0.4 cm, p = 0.001; width 2.6 ± 0.3 vs 2.2 ± 0.3 cm, p < 0.001; thickness 2.5 ± 0.3 vs 2.0 ± 0.2 cm, p < 0.001). The similar result was found with three 4 cm tip of RF electrodes (width 3.6 ± 0.5 vs 3.1 ± 0.5 cm, p = 0.019; thickness 3.3 ± 0.5 vs 2.7 ± 0.5 cm, p = 0.002). The multiple linear regression analysis showed arrive time of hepatic vein and portal vein was statistically associated with ablation zone with 3 cm electrodes (p < 0.001, p = 0.001), but explained part of the variance (Adjusted R²=0.294, adjusted R²=0.212).

CONCLUSION

The ablation zones of RFA with multi-bipolar electrodes in liver cirrhosis were significantly larger than those in normal liver background, being up to 6 mm in thickness. The hepatic flow parameters partly contributed to the ablation zone.

The learning curve of laparoscopic ablation of liver tumors: A technically demanding procedure requiring dedicated training

BACKGROUND

Laparoscopic ablation (LA) of liver tumors is an increasingly performed procedure. However, LA is technically demanding, with inherent difficulties making LA more complex than percutaneous and open surgery ablations. This study aimed to characterize the learning curve (LC) of LAs.

METHODS

All consecutive LAs of malignant liver tumors performed with curative intent by a single surgeon were identified from a prospective database. A risk-adjusted cumulative summative (RA-CUSUM) analysis was used for evaluating the LC of LAs. Incomplete ablation (IA) was the outcomes measure. Performance trends were analyzed using broken-line modeling.

RESULTS

From June 2007 to February 2018, 241 lesions underwent LA during 151 procedures. RA-CUSUM analysis demonstrated an LC of 93 LAs (p < 0.001), with an IA rate decreasing from 12.9% to 4.7% (p = 0.027). Lesions in the posterosuperior segment and those in cirrhotic livers showed an LC of 34 and 45 tumor ablations, respectively (p=<0.001 each). Open ablations performed during the same period showed steady outcomes, indicating already acquired proficiency.

CONCLUSION

Completion of a steep LC is needed to gain proficiency in LAs. Dedicated training should be warranted to novices to smooth the LC and decrease LA failures.

Software-based planning of ultrasound and CT-guided percutaneous radiofrequency ablation in hepatic tumors

Objectives

Radiofrequency ablation (RFA) can be associated with local recurrences in the treatment of liver tumors. Data obtained at our center for an earlier multinational multicenter trial regarding an in-house developed simulation software were re-evaluated in order to analyze whether the software was able to predict local recurrences.

Methods

Twenty-seven RFA ablations for either primary or secondary hepatic tumors were included. Colorectal liver metastases were shown in 14 patients and hepatocellular carcinoma in 13 patients. Overlap of the simulated volume and the tumor volume was automatically generated and defined as positive predictive value (PPV) and additionally visually assessed. Local recurrence during follow-up was defined as gold standard. Sensitivity and specificity were calculated using the visual assessment and gold standard.

Results

Mean tumor size was 18 mm (95% CI 15–21 mm). Local recurrence occurred in 5 patients. The PPV of the simulation showed a mean of 0.89 (0.84–0.93 95% CI). After visual assessment, 9 incomplete ablations were observed, of which 4 true positives and 5 false positives for the detection of an incomplete ablation. The sensitivity and specificity were, respectively, 80% and 77% with a correct prediction in 78% of cases. No significant correlation was found between size of the tumor and PPV (Pearson Correlation 0.10; p = 0.62) or between PPV and recurrence rates (Pearson Correlation 0.28; p = 0.16).

Conclusions

The simulation software shows promise in estimating the completeness of liver RFA treatment and predicting local recurrence rates, but could not be performed real-time. Future improvements in the field of registration could improve results and provide a possibility for real-time implementation.

Magnetic Resonance Imaging-Guided Adaptive Radiotherapy for Colorectal Liver Metastases

Technological advances have enabled well tolerated and effective radiation treatment for small liver metastases. Stereotactic ablative radiation therapy (SABR) refers to ablative dose delivery (>100 Gy BED) in five fractions or fewer. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs such as the stomach, duodenum, and large intestine. In addition to stereotactic treatment delivery, controlling respiratory motion, the use of image guidance, adaptive planning and increasing the number of radiation fractions are sometimes necessary for the safe delivery of SABR in these situations. Magnetic Resonance (MR) image-guided adaptive radiation therapy (MRgART) is a new and rapidly evolving treatment paradigm. MR imaging before, during and after treatment delivery facilitates direct visualization of both the tumor target and the adjacent normal healthy organs as well as potential intrafraction motion. Real time MR imaging facilitates non-invasive tumor tracking and treatment gating. While daily adaptive re-planning permits treatment plans to be adjusted based on the anatomy of the day. MRgART therapy is a promising radiation technology advance that can overcome many of the challenges of liver SABR and may facilitate the safe tumor dose escalation of colorectal liver metastases.

Radiotherapeutic treatment options for oligotopic malignant liver lesions

Background

Several radiotherapeutic approaches for patients with oligotopic malignant liver lesions unfit for surgical resection exist. The most advanced competitive techniques are high-dose-rate (HDR) brachytherapy, Cyberknife, volume-modulated-arc therapy (VMAT) and Tomotherapy. We evaluated the optimal technique by a planning study for a single ablative dose with different lesion sizes.

Methods

We compared dose distributions of HDR-brachytherapy with stereotactic ablative radiotherapy using the Cyberknife, VMAT or Tomotherapy. Tumor-control-probabilities (TCP), normal-tissue-complication-probabilities (NTCP) were determined in a theoretical framework applying a single dose of 20 Gy (demanding 95% coverage) for intrahepatic lesions of 1–5 cm in size. We evaluated therapeutic ratios by TCP (mean dose in the lesion) relative to high-dose (conformality) or low-dose liver exposition in dependency on the lesion size for each technique. In addition, we considered treatment times and accuracy (clinical target volume vs planning target volume).

Results

HDR-brachtherapy has the highest therapeutic ratios with respect to high-dose as well as low-dose liver exposition even for extended lesions, and the Cyberknife being suited second best. However, for lesions ≥ 3 cm diameter the therapeutic ratios of all ablative techniques are increasingly converging, and better tolerance and shorter treatment times of noninvasive external techniques become more important. On the other hand, mean tumor doses of HDR-brachytherapy of near 60 Gy are unattainable by the other techniques gaining only 22–34 Gy, and the conformality of HDR-brachytherapy is still rather good for lesions ≥ 3 cm diameter.

Conclusions

HDR-brachytherapy is by far the most effective technique to treat intrahepatic lesions by a single fraction, but sparing of the surroundings declines with increasing lesion size and approaches the benchmarks of external beam radiosurgery techniques. External beam radiotherapy has the advantage to use suitable fractionation schedules.

Long-term results of percutaneous microwave ablation for colorectal liver metastases

BACKGROUND

Radiofrequency ablation (RFA) has been used for therapy of colorectal liver metastases (CRLMs) several years, with considerable data confirming its safety and efficacy. However, there are few studies focusing on the long-term results of percrtaneous microwave ablation (PMWA) for CRLMs. The aim of this study was to evaluate the long-term survival and prognostic factors in patients with CRLMs undergoing PMWA.

METHODS

We retrospectively analyzed treatment and survival parameters of 210 patients with CRLMs who had received PMWA in a single center from January 2010 to December 2017. Prognostic factors for survival were evaluated by means of univariate and multivariate analyses.

RESULTS

The median follow-up time after PMWA was 48 months. The median overall survival (OS) time were 40.0 months (95% CI, 31.4 to 48.5 months), with 1-, 2, 3-, 4, and 5-year cumulative survival rates of 98.6%, 73.3%, 53.3%, 42.2%, and 32.9%, respectively. Tumor number (P = 0.004; HR: 1.838; CI: 1.213- 2.784), main tumor size (P = 0.017; HR: 1.631; CI: 1.093- 2.436), and serum CEA level (P = 0.032; HR: 1.559; CI: 1.039-2.340) were found as independent predictors of OS. The median OS time for patients with resectable lesions was 60.91 months (95% CI, 51.36 to 70.47 months), with 5-year cumulative survival rates of 53.5%.

CONCLUSION

PMWA is a safe and effective treatment for CRLMs, with a favorable long-term outcome. Multiple lesions, main tumor diameter>3 cm, and serum CEA >30 ng/ml have a significant negative effect on OS.

Interventional Treatment of Hepatic Metastases from Colorectal Cancer

Modern systemic therapies provide a significant survival benefit in metastatic colorectal cancer. Despite these advances, the durability of response remains limited and nearly all patients progress on systemic treatment. Colorectal liver metastases (CLM) develop in approximately half of patients with metastatic disease and contribute to mortality in most patients. In selected patients, surgical resection of hepatic metastases prolongs survival, indicating the benefits of the targeted treatment of CLM through alternate means. Minimally invasive interventional treatments offer the promise of treating CLM in a wider range of patients than those eligible for surgical resection. Thermal ablation and intra-arterial therapies, including chemoembolization and radioembolization, are commonly used in the treatment of CLM. Each of these treatment modalities will be discussed in detail with an emphasis on the available clinical data for each interventional treatment for CLM.

Interventional Oncology Approach to Hepatic Metastases

Metastatic liver disease is one of the major causes of cancer-related morbidity and mortality. Locoregional therapies offered by interventional oncologists alleviate cancer-related morbidity and in some cases improve survival. Locoregional therapies are often palliative in nature but occasionally can be used with curative intent. This review will discuss important factors to consider prior to palliative and curative intent treatment of metastatic liver disease with locoregional therapy. These factors include those specific to the tumor, liver function, liver reserve, differences between treatment modalities, and patient-specific considerations.

Factors Associated With Local Tumor Control and Complications After Thermal Ablation of Colorectal Cancer Liver Metastases: A 15-year Retrospective Cohort Study

INTRODUCTION

The purpose of this study was to identify risk factors associated with local tumor progression-free survival (LTPFS) and complications after colorectal liver metastases (CLM) thermal ablation (TA).

PATIENTS AND METHODS

This retrospective analysis included 286 patients with 415 CLM undergoing TA (radiofrequency and microwave ablation) in 378 procedures from January 2003 to July 2017. Prior hepatic artery infusion (HAI), bevacizumab, pre-existing biliary dilatation, ablation modality, minimal ablation margin (MM), prior hepatectomy, CLM number, and size were analyzed as factors influencing complications and LTPFS. Statistical analysis included the Kaplan-Meier method, Cox proportional hazards model, competing risk analysis, univariate/multivariate logistic/exact logistic regressions, and the Fisher exact test. Complications were reported according to modified Society of Interventional Radiology guidelines.

RESULTS

The median follow-up was 31 months. There was no LTP for MM > 10 mm. Smaller tumor size, increased MM, and prior hepatectomy correlated with longer LTPFS. The major complications occurred following 28 (7%) of 378 procedures. There were no biliary complications in HAI-naive patients, versus 11% in HAI patients (P < .001), of which 7% were major. Biliary complications predictors in HAI patients included biliary dilatation, bevacizumab, and MM > 10 mm. In HAI patients, ablation with 6 to 10 mm and > 10 mm MM resulted in major biliary complication rates of 4% and 21% (P = .0011), with corresponding LTP rates of 24% and 0% (P = .0033). In HAI-naive patients, the LTP rates for 6 to 10 mm and > 10 mm MM were 27% and 0%, respectively.

CONCLUSIONS

No LTP was seen for MM > 10 mm. Biliary complications occurred only in HAI patients, especially in those with biliary dilatation, bevacizumab, and MM > 10 mm. In HAI patients, MM of 6 to 10 mm resulted in 76% local tumor control and 4% major biliary complications incidence.

External Beam Radiation Therapy for Liver Metastases

Stereotactic ablative radiotherapy (SABR) commonly is used for small liver metastases. Modern conformal radiotherapy techniques, including 3-dimensional conformal radiotherapy and intensity-modulated radiation therapy, enable the safe delivery of SABR to small liver volumes. For larger tumors, the safe delivery of SABR can be challenging due to a more limited volume of healthy normal liver parenchyma and the proximity of the tumor to radiosensitive organs, such as the stomach, duodenum, and large intestine. Controlling respiratory motion, the use of image guidance, and increasing the number of radiation fractions sometimes are necessary for the safe delivery of SABR in these situations.

Oncological outcomes and predictors of radiofrequency ablation of colorectal cancer liver metastases

BACKGROUND

Surgical resection is considered the standard treatment option for long-term survival in colorectal cancer liver metastasis (CRLM) patients, but only a small number of patients are suitable for resection following diagnosis. Radiofrequency ablation (RFA) is an accepted alternative therapy for CRLM patients who are not suitable for resection. However, the relatively high rate of local tumor progression (LTP) is an obstacle to the more widespread use of RFA.

AIM

To determine the oncological outcomes and predictors of RFA in CRLM patients.

METHODS

A retrospective analyze was performed on the clinical data of 85 consecutive CRLM patients with a combined total of 138 liver metastases, who had received percutaneous RFA treatment at our institution from January 2013 to December 2018. Contrast-enhanced computed tomography was performed the first month after RFA to assess the technique effectiveness of the RFA and to serve as a baseline for subsequent evaluations. The Kaplan-Meier method was used to calculate overall survival (OS) and LTP-free survival (LTPFS). The log-rank test and Cox regression model were used for univariate and multivariate analyses to determine the predictors of the oncological outcomes.

RESULTS

There were no RFA procedure-related deaths, and the technique effectiveness of the treatment was 89.1% (123/138). The median follow-up time was 30 mo. The LTP rate was 32.6% (45/138), and the median OS was 36 mo. The 1-, 3-, and 5-year OS rates were 90.6%, 45.6%, and 22.9%, respectively. Univariate analysis revealed that tumor size and ablative margin were the factors influencing LTPFS, while extrahepatic disease (EHD), tumor number, and tumor size were the factors influencing OS. Multivariate analysis showed that tumor size larger than 3 cm and ablative margin of 5 mm or smaller were the independent predictors of shorter LTPFS, while tumor number greater than 1, size larger than 3 cm, and presence of EHD were the independent predictors of shorter OS.

CONCLUSION

RFA is a safe and effective treatment method for CRLM. Tumor size and ablative margin are the important factors affecting LTPFS. Tumor number, tumor size, and EHD are also critical factors for OS.

Irreversible electroporation ablation against subcutaneously implanted VX2 tumors in rabbits: findings of shearwave ultrasound elastography

PURPOSE

This study aimed to evaluate stiffness changes of rabbit subcutaneous VX₂ tumors before and after irreversible electroporation (IRE) ablationby shearwave ultrasound elastography (SWE).

METHODS

IRE was performed on 20 subcutaneously implanted VX₂ tumors in rabbits (R-SIVX₂). Tumor stiffness was measured by SWE at different time points (before IRE,120minutes after IRE,7 days after IRE and 14 days after IRE).

RESULTS

Before IRE, the mean stiffness (E_mean) of tumors was (10.45 ± 1.07) KPa. 120 minutes after I RE, the E_mean of tumors obviously rose to (70.53 ± 9.87) KPa. 7 days after IRE, the E_mean of tumors decreased to (40.22 ± 9.01) KPa. 14 days after IRE, the E_mean of tumors was (15.17 ± 1.00) KPa. A clear boundary was observed between the ablation area and the normal tissues in the pathological results.

CONCLUSIONS

The stiffness of the VX₂ tumors experienced a first rise process and tend to be normal in the procedure of IRE. SWE could provide tissue stiffness information of different IRE ablation period as a non-invasive method.

Taiwan Society of Colon and Rectal Surgeons (TSCRS) Consensus for Cytoreduction Selection in Metastatic Colorectal Cancer

BACKGROUND

Taiwan has witnessed a surge in the incidence of colorectal cancer (CRC), of which 40-60% metastasize. Continuous updating of cytoreductive strategies in metastatic CRC (mCRC) has contributed to median overall survival reaching 40 months. In this changing scenario, to standardize the approaches across Taiwan, a group of experts from the Taiwan Society of Colon and Rectal Surgeons (TSCRS) convened to establish evidence- and opinion-based recommendations for defining the criteria of "resectability" in mCRC.

METHODS

Over the course of one-on-one consultations, lasting 30-40 min each, with 30 medical specialists (19 colorectal surgeons, 4 general surgeons, and 7 medical oncologists) from 16 hospitals in Taiwan followed by a 2-h meeting with 8 physician experts (3 general surgeons, 4 colorectal surgeons, and 1 thoracic surgeon), 12 key questions on cytoreduction were addressed. This was further contextualized based on published literature.

RESULTS

The final consensus includes eight recommendations regarding the criteria for metastasis resection, role of local control treatment in liver potentially resectable patients, management of synchronous liver metastases, approach for peritoneal metastasis, place for resection in multiple-organ metastasis, and general criteria for resectability.

CONCLUSIONS

mCRC patients undergoing R0 resection have the greatest survival advantage following surgery. Our role as a multidisciplinary team (MDT) should be to treat potentially resectable mCRC patients as rapidly and safely as possible, and achieve R0 resection as far as possible and for as long as possible (continuum of care). This TSCRS consensus statement aims to help build clinical capacity within the MDTs, while making better use of existing healthcare resources.

Follow-Up 18F-FDG PET/CT versus Contrast-Enhanced CT after Ablation of Liver Metastases of Colorectal Carcinoma-A Cost-Effectiveness Analysis

PURPOSE

After a percutaneous ablation of colorectal liver metastases (CRLM), follow-up investigations to evaluate potential tumor recurrence are necessary. The aim of this study was to analyze whether a combined 18F-Fluordesoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scan is cost-effective compared to a contrast-enhanced computed tomography (CE-CT) scan for detecting local tumor progression.

MATERIALS AND METHODS

A decision model based on Markov simulations that estimated lifetime costs and quality-adjusted life years (QALYs) was developed. Model input parameters were obtained from the recent literature. Deterministic sensitivity analysis of diagnostic parameters based on a Monte-Carlo simulation with 30,000 iterations was performed. The willingness-to-pay (WTP) was set to $100,000/QALY.

RESULTS

In the base-case scenario, CE-CT resulted in total costs of $28,625.08 and an efficacy of 0.755 QALYs, whereas 18F-FDG PET/CT resulted in total costs of $29,239.97 with an efficacy of 0.767. Therefore, the corresponding incremental cost-effectiveness ratio (ICER) of 18F-FDG PET/CT was $50,338.96 per QALY indicating cost-effectiveness based on the WTP threshold set above. The results were stable in deterministic and probabilistic sensitivity analyses.

CONCLUSION

Based on our model, 18F-FDG PET/CT can be considered as a cost-effective imaging alternative for follow-up investigations after percutaneous ablation of colorectal liver metastases.

In situ thermal ablation augments antitumor efficacy of adoptive T cell therapy

Purpose: The aim of this study is to investigate whether radiofrequency ablation (RFA) improves the efficacy of adoptive T cell immunotherapy in preclinical mouse cancer models.Method: Mice implanted subcutaneously (sc) with syngeneic colon adenocarcinoma or melanoma were treated with sub-curative in situ RFA (90 °C, 1 min). Trafficking of T cells to lymph nodes (LN) or tumors was quantified by homing assays and intravital microscopy (IVM) after sham procedure or RFA. Expression of trafficking molecules (CCL21 and intercellular adhesion molecule-1 [ICAM-1]) on high endothelial venules (HEV) in LN and tumor vessels was evaluated by immunofluorescence microscopy. Tumor-bearing mice were pretreated with RFA to investigate the therapeutic benefit when combined with adoptive transfer of in vitro-activated tumor-specific CD8⁺ T cells.Results: RFA increased trafficking of naïve CD8⁺ T cells to tumor-draining LN (TdLN). A corresponding increase in expression of ICAM-1 and CCL21 was detected on HEV in TdLN but not in contralateral (c)LN. IVM revealed that RFA substantially enhanced secondary firm arrest of lymphocytes selectively in HEV in TdLN. Furthermore, strong induction of ICAM-1 in tumor vessels was associated with significantly augmented trafficking of adoptively transferred in vitro-activated CD8⁺ T cells to tumors after RFA. Finally, preconditioning tumors with RFA augmented CD8⁺ T cell-mediated apoptosis of tumor targets and delayed growth of established tumors when combined with adoptive T cell transfer immunotherapy.Conclusions: These studies suggest that in addition to its role as a palliative therapeutic modality, RFA may have clinical potential as an immune-adjuvant therapy by augmenting the efficacy of adoptive T cell therapy.