Cryotherapy in the treatment of liver metastases from colorectal cancer

Long-Term Results of a Phase 1 Dose-Escalation Trial and Subsequent Institutional Experience of Single-Fraction Stereotactic Ablative Radiation Therapy for Liver Metastases

PURPOSE

We report long-term outcomes from our phase 1 dose-escalation study to determine the maximum tolerated dose of single-fraction liver SABR pooled with our subsequent single institutional experience with patients treated postprotocol at the highest dose level (40 Gy) established from the phase 1 study.

METHODS AND MATERIALS

Patients with liver metastases from solid tumors located outside of the central liver zone were treated with single-fraction SABR on a phase 1 dose escalation trial. At least 700 cc of normal liver had to receive <9.1 Gy. Seven patients with 10 liver metastases received the initial prescription dose of 35 Gy, and dose was then escalated to 40 Gy for 7 more patients with 7 liver metastases. An additional 19 postprotocol patients with 22 liver metastases were treated to 40 Gy in a single fraction. Patients were followed for toxicity and underwent serial imaging to assess local control.

RESULTS

Median imaging follow-up for the combined cohort (n = 33, 39 lesions) was 25.9 months; 38.9 months for protocol patients and 20.2 months for postprotocol patients. Median lesion size was 2.0 cm (range, 0.5-5.0 cm). There were no dose-limiting toxicities observed for protocol patients, and only 3 grade 2 toxicities were observed in the entire cohort, with no grade ≥3 toxicities attributable to treatment. Four-year actuarial local control of irradiated lesions in the entire cohort was 96.6%, 100% in the protocol group and 92.9% in the subsequent patients. Two-year overall survival for all treated patients was 82.0%.

CONCLUSIONS

For selected patients with liver metastases, single-fraction SABR at doses of 35 and 40 Gy was safe and well-tolerated, and shows excellent local control with long-term follow-up; results in subsequent patients treated with single-fraction SABR doses of 40 Gy confirmed our earlier results.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.

Destruction of cancer cells by laser-induced shock waves: recent developments in experimental treatments and multiscale computer simulations

In this emerging area article we review recent progress in the mechanical destruction of cancer cells using laser-induced shock waves. The pure mechanical damaging and destruction of cancer cells associated with this technique possibly opens up a new route to tumor treatments and the corresponding therapies. At the same time progress in multiscale simulation techniques makes it possible to simulate mechanical properties of soft biological matter such as membranes, cytoskeletal networks and even whole cells and tissue. In this way an interdisciplinary approach to understanding key mechanisms in shock wave interactions with biological matter has become accessible. Mechanical properties of biological materials are also critical for many physiological processes and cover length scales ranging from the atomistic to the macroscopic scale. We argue that the latest developments and progress in experimentation enable the investigation of the shock wave interaction with cancer cells on multiple time- and length-scales. In this way the integrated use of experiment and simulation can address key challenges in this field. The exploration of the biological effects of laser-generated shock waves on a fundamental level constitutes an emerging multidisciplinary research area combining scientific methods from the areas of physics, biology, medicine and computer science.

Stereotactic ablative radiotherapy for oligometastatic disease in liver

Liver metastasis in solid tumors, including colorectal cancer, is the most frequent and lethal complication. The development of systemic therapy has led to prolonged survival. However, in selected patients with a finite number of discrete lesions in liver, defined as oligometastatic state, additional local therapies such as surgical resection, radiofrequency ablation, cryotherapy, and radiotherapy can lead to permanent local disease control and improve survival. Among these, an advance in radiation therapy made it possible to deliver high dose radiation to the tumor more accurately, without impairing the liver function. In recent years, the introduction of stereotactic ablative radiotherapy (SABR) has offered even more intensive tumor dose escalation in a few fractions with reduced dose to the adjacent normal liver. Many studies have shown that SABR for oligometastases is effective and safe, with local control rates widely ranging from 50% to 100% at one or two years. And actuarial survival at one and two years has been reported ranging from 72% to 94% and from 30% to 62%, respectively, without severe toxicities. In this paper, we described the definition and technical aspects of SABR, clinical outcomes including efficacy and toxicity, and related parameters after SABR in liver oligometastases from colorectal cancer.

Phase I dose-escalation study of stereotactic body radiotherapy in patients with hepatic metastases

PURPOSE

To identify a tolerable and effective dose for 5-fraction stereotactic body radiotherapy for hepatic metastases.

METHODS

Patients were enrolled onto three dose-escalation cohorts: 30 Gy in 3 fractions, 50 Gy in 5 fractions, and 60 Gy in 5 fractions. Eligible patients had one to five hepatic metastases, ability to spare a critical hepatic volume (volume receiving <21 Gy) of 700 ml, adequate baseline hepatic function, no concurrent antineoplastic therapy, and a Karnofsky performance score of ≥60. Dose-limiting toxicity included treatment-related grade 3 toxicity in the gastrointestinal, hepatobiliary/pancreas, and metabolic/laboratory categories. Any grade 4 or 5 event attributable to therapy was defined as a dose-limiting toxicity. Local control (LC) and complete plus partial response rates were assessed.

RESULTS

Twenty-seven patients, 9 in each cohort, with 37 lesions were enrolled and treated: 17 men and 11 women; median age 62 (range 48-86) years; most common site of primary disease, colorectal (44.4%). Median follow-up was 20 (range 4-53) months. There was no grade 4 or 5 toxicity or treatment-related grade 3 toxicity. Actuarial 24-month LC rates for the 30-, 50-, and 60-Gy cohorts were 56%, 89%, and 100%, respectively. There was a statistically significant difference for LC between the 60- and 30-Gy cohorts (P = 0.009) but not between the 60- and 50-Gy cohorts (P = 0.56) or the 50- and 30-Gy cohorts (P = 0.091). The maximum tolerated dose was not reached.

CONCLUSIONS

A dose of 60 Gy in 5 fractions can be safely delivered to selected patients with hepatic metastases as long as the critical liver volume is respected. A dose of 60 Gy in 5 fractions yields an excellent level of LC.

Radiofrequency ablation of unresectable liver tumors: factors associated with incomplete ablation or local recurrence

BACKGROUND

Radiofrequency ablation (RFA) of liver tumors is associated with a risk of incomplete ablation or local recurrence.

METHODS

One hundred sixty-eight patients with 311 unresectable liver tumors were included. Effects of different variables on incomplete ablation and local recurrence were analyzed.

RESULTS

There were 132 hepatocellular carcinomas and 179 liver metastases. Tumor size was 24 (±13) mm. Two hundred twenty-six tumors were treated percutaneously, and 85 through open approach (associated with liver resection in 42 cases). There was no mortality. Major morbidity rate was 7%. Incomplete ablation and local recurrence rates were 14% and 18.6%. Follow-up was 29 months. On multivariate analysis, factors associated with incomplete ablation were tumor size (>30 mm vs ≤30 mm, P = .004) and approach (percutaneous vs open, P = .0001). Factors associated with local recurrence were tumor size (>30 mm vs ≤30 mm, P = .02) and patient age (>65 years vs ≤65 years, P = .05).

CONCLUSIONS

RFA is effective to treat unresectable liver tumors. However, there is a risk of incomplete ablation when percutaneously treating tumors >30 mm. When tumor ablation is completely achieved, the main factor associated with local recurrence is tumor size >30 mm.

Optimizing electrode placement using finite-element models in radiofrequency ablation treatment planning

Conventional radiofrequency ablation (RFA) planning methods for identifying suitable electrode placements typically use geometric shapes to model ablation outcomes. A method is presented for searching electrode placements that couples finite-element models (FEMs) of RFA together with a novel optimization strategy. The method was designed to reduce the need for model solutions per local search step. The optimization strategy was tested against scenarios requiring single and multiple ablations. In particular, for a scenario requiring multiple ablations, a domain decomposition strategy was described to minimize the complexity of simultaneously searching multiple electrode placements. The effects of nearby vasculature on optimal electrode placement were also studied. Compared with geometric planning approaches, FEMs could potentially deliver electrode placement plans that provide more physically meaningful predictions of therapeutic outcomes.

Bilobar colorectal liver metastases: treatment options

Although prospective, randomized clinical trials never have been conducted, retrospective and comparative studies strongly indicate that hepatic resection is the only available treatment that allows long-term survival in colorectal carcinoma that has metastasized to the liver. Unfortunately, curative resection can be performed in less than 25% of the patients. Ten years ago, hepatic resection was contraindicated in case of multiple or bilobar nodules. Currently, the trend is to be more aggressive and to increase the indications for surgical resection with the development of new strategies using a multidisciplinary approach.

Diagnosis and treatment of metastatic disease to the liver

A number of cancers present with synchronous or metachronous hepatic metastases. Historically, many of these patients were considered unresectable and were treated with either systemic chemotherapy or supportive care. Today, a variety of options exist for the management of hepatic metastases. Newer agents for systemic therapy continue to be introduced and are providing improved progression-free and overall survival and increased resectability of liver metastases. However, complete surgical resection of isolated hepatic metastases remains the optimal management for these patients. Surgical interventions can be offered to patients with hepatic-only metastases. Hepatic artery chemotherapy represents an adjunct for those patients undergoing resection and can improve survival. This benefit may be even more pronounced when combined with systemic chemotherapy. Newer generation biologic agents can improve results. New therapeutic modalities to treat lesions that are unresectable include ablative techniques such as radiofrequency ablation (RFA) and cryoablation. This article will examine modalities of diagnosis of hepatic metastases and highlight the data regarding hepatic resection for metastases of several types of primary cancers, the rationale for, and efficacy of, hepatic arterial chemotherapy, in both the postoperative adjuvant setting and in unresectable liver disease, and review the current literature for ablative techniques in the treatment of liver metastases.

Eotaxin-2 and colorectal cancer: a potential target for immune therapy

PURPOSE

To study the production of chemokines by colorectal hepatic metastases.

EXPERIMENTAL DESIGN

Biopsies of resected colorectal hepatic metastases and nonneoplastic adjacent liver tissue were screened for chemokines using protein arrays and results were confirmed by ELISA and immunohistochemistry.

RESULTS

Two chemokines, eotaxin-2 and MCP-1, were found at elevated levels within the tumor biopsy compared with adjacent liver. The relative increase in expression from tumor was much higher for eotaxin-2 than MCP-1, with 10 of 25 donors having a >100-fold increase in expression compared with 0 of 24 donors for MCP-1. In a parallel analysis, eotaxin-2 was also found at elevated levels in the tumor region of primary colorectal cancer biopsies. Immunohistochemical staining indicated that carcinoembryonic antigen-positive tumor cells stained strongly for eotaxin-2, implicating these cells as the predominant source of the chemokine. In vitro studies confirmed that several colorectal tumor lines produce eotaxin-2 and that secretion of this chemokine could be depressed by IFN-gamma and enhanced by the Th2-type cytokines interleukin-4 and interleukin-13. Jurkat T cells were engineered to express the receptor for eotaxin-2 (CCR3). These cells effectively migrated in response to eotaxin-2 protein, suggesting that immune cells gene modified to express a chemokine receptor may have improved abilities to home to tumor.

CONCLUSIONS

Taken together, these observations confirm eotaxin-2 as a chemokine strongly associated with primary and metastatic tumors of colorectal origin. Furthermore, the importance of this result may be a useful tool in the development of targeted therapeutic approaches to colorectal tumors.

Concepts and preliminary data toward the realization of image-guided liver surgery

Image-guided surgery provides navigational assistance to the surgeon by displaying the surgical probe position on a set of preoperative tomograms in real time. In this study, the feasibility of implementing image-guided surgery concepts into liver surgery was examined during eight hepatic resection procedures. Preoperative tomographic image data were acquired and processed. Accompanying intraoperative data on liver shape and position were obtained through optically tracked probes and laser range scanning technology. The preoperative and intraoperative representations of the liver surface were aligned using the iterative closest point surface matching algorithm. Surface registrations resulted in mean residual errors from 2 to 6 mm, with errors of target surface regions being below a stated goal of 1 cm. Issues affecting registration accuracy include liver motion due to respiration, the quality of the intraoperative surface data, and intraoperative organ deformation. Respiratory motion was quantified during the procedures as cyclical, primarily along the cranial-caudal direction. The resulting registrations were more robust and accurate when using laser range scanning to rapidly acquire thousands of points on the liver surface and when capturing unique geometric regions on the liver surface, such as the inferior edge. Finally, finite element models recovered much of the observed intraoperative deformation, further decreasing errors in the registration. Image-guided liver surgery has shown the potential to provide surgeons with important navigation aids that could increase the accuracy of targeting lesions and the number of patients eligible for surgical resection.

Liver-directed therapies for patients with primary liver cancer and hepatic metastases

Liver cancer, whether primary or metastatic, is a major cause of death throughout the world. The surgical management of these diseases varies according to the extent of disease and the overall health of the patient. Surgical resection of hepatic disease remains the only chance for cure. However, a large proportion of patients with liver cancer are unable to undergo a complete surgical resection. These patients are often treated with liver-directed therapies. Although not as effective as surgical resection, these approaches can help to improve the survival of patients. In patients with primary liver cancer, underlying liver disease often prohibits surgical intervention. However, survival advantages have been gained with the application of percutaneous alcohol injection and radiofrequency ablation (RFA). In patients with hepatic metastases, the number of metastases is often what prevents surgical resection. In these patients, RFA, cryoablation, and hepatic artery infusional therapy have all aided in prolonging survival. As chemotherapeutic agents improve and targeted therapies are developed, more patients will be able to undergo surgical management of their liver cancer, primary or metastatic.

The safety and feasibility of extracorporeal high-intensity focused ultrasound (HIFU) for the treatment of liver and kidney tumours in a Western population

High-intensity focused ultrasound (HIFU) provides a potential noninvasive alternative to conventional therapies. We report our preliminary experience from clinical trials designed to evaluate the safety and feasibility of a novel, extracorporeal HIFU device for the treatment of liver and kidney tumours in a Western population. The extracorporeal, ultrasound-guided Model-JC Tumor Therapy System (HAIFU Technology Company, China) has been used to treat 30 patients according to four trial protocols. Patients with hepatic or renal tumours underwent a single therapeutic HIFU session under general anaesthesia. Magnetic resonance imaging 12 days after treatment provided assessment of response. The patients were subdivided into those followed up with further imaging alone or those undergoing surgical resection of their tumours, which enabled both radiological and histological assessment. HIFU exposure resulted in discrete zones of ablation in 25 of 27 evaluable patients (93%). Ablation of liver tumours was achieved more consistently than for kidney tumours (100 vs 67%, assessed radiologically). The adverse event profile was favourable when compared to more invasive techniques. HIFU treatment of liver and kidney tumours in a Western population is both safe and feasible. These findings have significant implications for future noninvasive image-guided tumour ablation.

Short- and-long term results of intraoperative radiofrequency ablation of liver metastases

BACKGROUND

Surgical resection is the only therapeutic option with curative effect on malignant liver tumours, but in over 70% of cases, this is not a feasible option. A prospective study was performed to assess the short- and long-term effects of intraoperative radiofrequency ablation on unresectable liver metastases.

PATIENTS

Between 1997 and 2001, 57 patients (mean age 61.9 years; range 31-83 years) with 297 unresectable liver metastases (colorectal adenocarcinoma, n=38; carcinoid tumour, n=4; malignant melanoma, n=3; other metastases, n=12) underwent intraoperative radiofrequency ablation.

RESULTS

No mortality was observed in patients managed solely with radiofrequency ablation. Eight postoperative complications occurred in eight patients (14%). Three occurred when radiofrequency ablation was combined with resection. Of the 33 patients completely ablated, 30 patients are still alive and 21 are disease-free after a median follow-up of 18.1 months (range 2-43). Ten patients underwent more than one intraoperative radiofrequency ablation episode. Overall survival was 72.5% at 1 year and 52.5% at 3 years. Complete ablation and the number of lesions were significant independent prognostic factors for survival, with p<0.001 and p<0.0001, respectively.

CONCLUSION

Radiofrequency ablation is a safe and effective option for patients with inoperable liver metastases without extra hepatic disease. Prospective controlled trials comparing the results of different treatments are required to assess which patients will benefit best from this emerging new treatment.

High-intensity focused ultrasound in the treatment of solid tumours

Traditionally, surgery has been the only cure for many solid tumours. Technological advances have catalysed a shift from open surgery towards less invasive techniques. Laparoscopic surgery and minimally invasive techniques continue to evolve, but for decades high-intensity focused ultrasound has promised to deliver the ultimate objective - truly non-invasive tumour ablation. Only now, however, with recent improvements in imaging, has this objective finally emerged as a real clinical possibility.

Prevention and therapy of colorectal cancer

Colorectal cancer is expected to affect more than 146,000 and kill more than 57,000 Americans in 2004. Increased understanding of carcinogenesis is transforming clinical approaches to all stages of this disease. During the last 5 years, four new drugs have been approved for colorectal cancer treatment, and substantial progress has been made in identifying and developing agents that prevent or delay carcinogenesis. These advances substantiate target-driven approaches to cancer prevention and treatment, and provide fruitful opportunities for future investigations.

Cryoablation of colorectal liver metastases: minimally invasive tumour control

BACKGROUND

Freezing is used for in situ destruction (ablation) of liver tumours not eligible for resection. The procedure is typically done during laparotomy. The objective of this report was to study tumour control at the site of freezing and a minimally invasive approach to cryoablation of colorectal liver metastases.

METHODS

A prospective study of 19 patients was conducted between 1999 and 2003. Twenty-five tumours were ablated during 24 procedures (i.e. 5 reablations). Sixteen procedures were performed percutaneously, 5 during laparotomy and 3 laparoscopically. Magnetic resonance imaging (MRI) was used for intraprocedural monitoring during most procedures. Nine patients had concomitant liver resections performed (5 during laparoscopy, 4 during laparotomy).

RESULTS

Out of 25 ablations, 18 (72%) were assumed adequate. Total ice-ball volume during percutaneous procedures was median 62 cm (range 32-114). Excellent imaging of the extent of freezing was achieved using MRI. Hospital stay for patients treated percutaneously was median 4 days (range 3-30). No perioperative mortality occurred. Tumour recurrence at the site of ablation occurred in 8 of 18 (44%) tumours adequately ablated. Actuarial 2-year tumour-free survival at site of ablation was 48%. At the time of analyses 12 out of 13 (92%) patients assumed to be adequately ablated were alive. Of all patients, 14 out of 19 (74%) survived.

CONCLUSIONS

Short-term tumour control can be achieved following cryoablation of colorectal liver metastases. A minimally invasive approach is feasible but the diameter of metastases considered for percutaneous cryoablation should not exceed 3 cm.

High intensity focused ultrasound: surgery of the future?

For 50 years, high intensity focused ultrasound (HIFU) has been a subject of interest for medical research. HIFU causes selective tissue necrosis in a very well defined volume, at a variable distance from the transducer, through heating or cavitation. Over the past decade, the use of HIFU has been investigated in many clinical settings. This literature review aims to summarize recent advances made in the field. A Medline-based literature search (1965-2002) was conducted using the keywords "HIFU" and "high intensity focused ultrasound". Additional literature was obtained from original papers and published meeting abstracts. The most abundant clinical trial data comes from studies investigating its use in the treatment of prostatic disease, although early research looked at applications in neurosurgery. More recently horizons have been broadened, and the potential of HIFU as a non-invasive surgical tool has been demonstrated in many settings including the treatment of tumours of the liver, kidney, breast, bone, uterus and pancreas, as well as conduction defects in the heart, for surgical haemostasis, and the relief of chronic pain of malignant origin. Further clinical evaluation will follow, but recent technological development suggests that HIFU is likely to play a significant role in future surgical practice.

Strategies to increase the resectability of liver metastases from colorectal cancer

Liver resection can provide long-term survival and cure for patients with colorectal liver metastases but is feasible in only 15-25% of patients. In the last few years several major developments have contributed to increase this resectability rate. Neo-adjuvant chemotherapy can provide response rates as high as 50%, allowing surgery in about 10-15% of patients initially deemed unresectable. Patients requiring extensive liver resections with an anticipated small residual liver volume can undergo portal vein embolization to reduce the risk of postoperative liver failure by inducing hypertrophy of the remnant liver. Extensive bilobar disease can be treated by two-stage hepatectomy, with an interval to allow liver regeneration. Ablation techniques can be combined with hepatic resection to reduce local recurrence from incomplete surgical resection margins or to destroy contralateral tumor deposits. Finally, for patients with tumors involving the inferior vena cava or the hepatic veins, in which conventional resection is not feasible, in situ hypothermia or bench resection with reimplantation are suitable for very selected patients. Downstaging strategies may increase the resectability rate of colorectal liver metastases by over 20%.

Locoregional strategies for colorectal hepatic metastases

Hepatic colorectal metastases present a challenging problem in patients with recurrent colorectal cancer. Twenty percent of patients with recurrence will have liver metastases as a component of their disease, and only 10% of these patients will have isolated liver metastases that are resectable. Although systemic chemotherapy alone has not proven efficacious in the treatment of liver metastases, a number of options exist in managing these lesions. For those that are resectable, surgery remains the optimal treatment, with an expected 5-year survival rate of 33%-39% based on several large series. Hepatic artery chemotherapy is another adjunct treatment in patients undergoing resection and may further improve survival. This benefit may be even more pronounced when combined with systemic chemotherapy. Newer-generation agents are likely to further improve results. More recently, new therapeutic modalities have been used to treat unresectable lesions. These include hepatic artery chemotherapy and ablative techniques such as radiofrequency ablation and cryoablation. This article will highlight the data regarding hepatic resection for colorectal metastases, describe the rationale for and efficacy of hepatic arterial chemotherapy in the postoperative adjuvant setting and in unresectable liver disease, and review the current literature describing ablative techniques in the treatment of liver metastases.

Endoscopic cryotherapy for the treatment of bleeding mucosal vascular lesions of the GI tract: a pilot study

BACKGROUND

Thermal therapy is the cornerstone of endoscopic treatment of bleeding mucosal lesions of the GI tract. However, there is a 20% failure rate and contact devices may be cumbersome in the treatment of large bleeding areas. A pilot study was conducted to evaluate the safety and efficacy of endoscopic cryotherapy for bleeding mucosal vascular lesions.

METHODS

Patients with recurrent bleeding from diffuse mucosal vascular lesions were treated with cryotherapy and had endoscopic and clinical follow-up.

RESULTS

Twenty-six patients with gastric and duodenal arteriovenous malformations (n = 7), watermelon stomach (n = 7), radiation-induced gastritis (n = 5), and radiation-induced proctitis (n = 7) were treated with mean of 3.4 (1.6) sessions. The best results were achieved in patients with radiation-induced proctitis, with cessation of bleeding in all 7 patients. Cryotherapy was also effective in patients with multiple arteriovenous malformations (86%) and watermelon stomach (71%). It was less effective in patients with radiation-induced damage to stomach and duodenum, although all patients in this group were debilitated because of disseminated malignancy.

CONCLUSIONS

Cryotherapy is a safe and effective treatment for bleeding from diffuse mucosal lesions of the GI tract. Bleeding from radiation-induced proctitis and multiple arteriovenous malformations is particularly responsive to endoscopic cryotherapy.

Angiography for diagnosis and treatment of colorectal cancer

AIM: To evaluate the role of preoperative angiography in the diagnosis and treatment of colorectal cancer.

METHODS: The authors performed selective arterial cannulation by Seldinger's method in 47 patients to locate the primary cancer and to diagnose metastasis to the liver. Each patient was then given intra-arterial regional chemotherapy, and received 5-fluorouracil (5-Fu, 1000 mg), mitomycin C (MMC, 20 mg), and cisplatinum (CDDP, 80 mg).

RESULTS: The location and shape of each tumor were observed, including metastatic tumors in the liver, in 42 of the 47 (89.4%) patients. The site of the primary tumor was difficult to identify in 5 cases because the patients had a recurrence of cancer. Arterial chemotherapy was performed successfully in all patients. The authors recorded no partial or significant morbidity resulted from angiography. The only incident was bleeding from the artery puncture site in one patient, which was successfully stopped by general medication.

CONCLUSION: Preoperative selective arterial angiography can help the diagnosis and locate primary tumors and to detect liver metastasis. At the same time, regional arterial chemotherapy can be an important form of preoperative therapy.

Current treatment for liver metastases from colorectal cancer

The liver is the commonest site of distant metastasis of colorectal cancer and nearly half of the patients with colorectal cancer ultimately develop liver involved during the course of their diseases. Surgery is the only therapy that offers the possibility of cure for patients with hepatic metastatic diseases. Five-year survival rates after resection of all detectable liver metastases can be up to 40%. Unfortunately, only 25% of patients with colorectal liver metastases are candidates for liver resection, while the others are not amenable to surgical resection. Regional therapies such as radiofrequency ablation and cryotherapy may be offered to patients with isolated unresectable metastases but no extrahepatic diseases. Hepatic artery catheter chemotherapy and chemoembolization and portal vein embolization are often used for the patients with extensive liver metastases but without extrahepatic diseases, which are not suitable for regional ablation. For the patients with metastatic colorectal cancer beyond the liver, systemic chemotherapy is a more appropriate choice. Immunotherapy is also a good option when other therapies are used in combination to enhance the efficacy. Selective internal radiation therapy is a new radiation method which can be used in patients given other routine therapies without effects.

Cryotherapeutic ablation of liver tumours

BACKGROUND

This paper reports a 7-year experience of cryoablation for colorectal and non-colorectal liver metastases.

METHODS

A retrospective review was undertaken of patients treated in two adjacent UK centres in the north-west of England.

RESULTS

Over a 7-year period (1993-2000), 57 patients underwent cryotherapy for malignant hepatic tumours (41 colorectal, 16 non-colorectal). In the patients with colorectal metastases, preoperative carcinoembryonic antigen (CEA) levels fell significantly, from a mean of 444.1 to 6.22 micro g/l (P = 0.002). One patient died, two developed cryoshock and six had cardiorespiratory complications. All patients with colorectal metastases subsequently received 5-fluorouracil-based chemotherapy. The remaining 16 patients with non-colorectal tumours (seven neuroendocrine metastases, five hepatocellular carcinomas, three sarcomas, one cholangiocarcinoma) all received cryotherapy alone, with no major complications. The median survival for patients with non-colorectal metastases was 37 months, compared with 22 months for those with colorectal metastases (P = 0.005).

CONCLUSION

Hepatic cryotherapy is effective and safe, as demonstrated by the significant reduction in postoperative CEA concentration and the low risk of complications. However, this initial short-term success was not reflected in 5-year survival rates. Cryotherapy for non-colorectal metastases had a greater long-term survival benefit and is a useful means of controlling symptoms.

Arterial chemotherapy of 5-fluorouracil and mitomycin C in the treatment of liver metastases of colorectal cancer

AIM: Regional chemotherapy using hepatic artery catheters is a good method of treating patients with colorectal cancer liver metastases. We investigated the survival of patients with liver metastases from colorectal cancer using 5-fluorouracil (5-FU) and mitomycin C Cthrough implantable hepatic arterial infusion port.

METHODS: Seventy-five patients with inoperable liver metastases from colorectal cancer were included between March, 1992 and November, 2001. We placed implantable hepatic arterial catheter (HAC) port by laparotomy.5-FU, 1000 mg/m²/d continuous infusion for five days every four weeks, was delivered in the hepatic arterial catheter through the port. Mitomycin C, 30 mg/m²/d infusion in the first day every cycle through the port. Response to the treatment was evaluated by serial determinations of plasma CEA and imaging techniques consisting of computerized tomography and sonography of liver.

RESULTS: Sixty-eight were performed hepatic artery chemotherapy and fifty-six were followed up among seventy-five HAC patients. Twenty-six patients (46.4%) have responded and 4 complete remission were achieved. Eight patients (14.3%) had stable liver metastases. Twenty-two patients (39.3%) were progressed with increased tumor size and number. Twenty-nine patients (51.8%) had a decreased serum CEA level, while 10 patients (17.9%) were stable and 17 patients (30.4%) had an increased serum CEA level. There were no operative death in this series. Complications, which occurred in 18 patients (32.1%), were as followed: hepatic artery thrombosis in 11, Upper gastric and intestinal bleeding in 3, liver abscess in 1, pocket infection in 1, cholangitis in 1, and hepatic artery pseudo-aneurysm in one patient.

CONCLUSION: Combined infusion of 5-FU and mitomycin C by hepatic artery catheter port is an effective treatment for liver metastases from colorectal cancer. The high response and lower complication rates prove the adjuvant treatment of colorectal cancer with this treatment.

Radiofrequence ablation of liver cancers

Primary and secondary malignant liver cancers are some of most common malignant tumors in the world. Chemotherapy and radiotherapy are not very effective against them. Surgical resection has been considered the only potentially curtive option, but the majority of patients are not candidates for resection because of tumor size, location near major intrahepatic blood vessels and bile ducts, precluding a margin-negative resection, cirrhotic, hepatitis virus infection or multifocial. Radiofrequence ablation (RFA), which is a new evolving effective and minimally invasive technique, can produce coagulative necrosis of malignant tumors. RFA should be used percutaneously, laparscopically, or during the open laparotomy under the guidance of ultrasound, CT scan and MRI. RFA has lots of advantages superior to other local therapies including lower complications, reduced costs and hospital stays, and the possibility of repeated treatment. In general, RFA is a safe, effective treatment for unresectable malignant liver tumors less than 7.0 cm in diameter. We review the principle, mechanism, procedures and experience with RFA for treating malignant liver tumors.