Monitoring response to treatment in liver tumours

Multidisciplinary Taiwan consensus for the use of conventional TACE in hepatocellular carcinoma treatment

Developed in early 1980s, transarterial chemoembolization (TACE) with Lipiodol was adopted globally after large-scale randomized control trials and meta-analyses proving its effectiveness were completed. Also known as "conventional TACE" (cTACE), TACE is currently the first-line treatment for patients with unresectable intermediate stage hepatocellular carcinoma (HCC) and delivers both ischemic and cytotoxic effects to targeted tumors. Although new technology and clinical studies have contributed to a more comprehensive understanding of when and how to apply this widely-adopted therapeutic modality, some of these new findings and techniques have yet to be incorporated into a guideline appropriate for Taiwan. In addition, differences in the underlying liver pathologies and treatment practices for transcatheter embolization between Taiwan and other Asian or Western populations have not been adequately addressed, with significant variations in the cTACE protocols adopted in different parts of the world. These mainly revolve around the amount and type of chemotherapeutic agents used, the type of embolic materials, reliance on Lipiodol, and the degree of selectiveness in catheter positioning. Subsequently, interpreting and comparing results obtained from different centers in a systematic fashion remain difficult, even for experienced practitioners. To address these concerns, we convened a panel of experts specializing in different aspects of HCC treatment to devise modernized recommendations that reflect recent clinical experiences, as well as cTACE protocols which are tailored for use in Taiwan. The conclusions of this expert panel are described herein.

Treatment Response Evaluation and Follow-up in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the major causes of morbidity, mortality and healthcare expenditure in patients with chronic liver disease. The management of HCC is evolving because of recently introduced novel therapeutic approaches. Optimal outcome requires an early and accurate assessment of tumor response to therapy. Current imaging modalities, such as computed tomography (CT) and magnetic resonance (MR) imaging; provide reliable and reproducible anatomical data in order to demonstrate tumor burden changes. However, in the setting of novel targeted therapies and liver directed treatments, simple tumor anatomical changes can be less informative and usually appear later than biological changes. There has been a growing interest to monitor the therapeutic response, at an early phase of treatment, by measuring tumor viability and/or perfusion. Therefore the importance of tumor viability assessment is increasingly being recognized. The tumor viability measurement guidelines have recently been amended to include the measurement of only the longest diameter of the enhancing tumors to formally amend RECIST to modified RECIST (mRECIST). Viable tumor should be defined as uptake of contrast agent in the arterial phase. In this review, we discuss criteria of response evaluation in HCC and further follow-up of patients receiving curative and palliative treatment.

A comparison between ¹⁸F-FDG PET/CT imaging and biological and radiological findings in restaging of hepatoblastoma patients

BACKGROUND

In this study we retrospectively evaluated if ¹⁸F-FDG-PET/CT provided incremental diagnostic information over CI in a group of hepatoblastoma patients performing restaging.

PROCEDURE

Nine patients (mean age: 5.9 years; range: 3.1-12 years) surgically treated for hepatoblastoma were followed up by clinical examination, serum α-FP monitoring, and US. CI (CT or MRI) and PET/CT were performed in case of suspicion of relapse. Fine-needle aspiration biopsies (FNAB) were carried out for final confirmation if the results of CI, PET/CT, and/or α-FP levels were suggestive of relapse. PET/CT and CI findings were analyzed for comparison purposes, using FNAB as reference standard.

RESULTS

α-FP level was suggestive of disease recurrence in 8/9 patients. Biopsy was performed in 8/9 cases. CI and PET/CT resulted to be concordant in 5/9 patients (CI identified recurrence of disease, but ¹⁸F-FDG-PET/CT provided a better definition of disease extent); in 4/9 cases, CI diagnostic information resulted in negative findings, whereas PET/CT correctly detected recurrence of disease. ¹⁸F-FDG-PET/CT showed an agreement of 100% (8/8) with FNAB results.

CONCLUSIONS

¹⁸F-FDG-PET/CT scan seems to better assess HB patients with respect to CI and may provide incremental diagnostic value in the restaging of this group of patients.

TACE versus TAE as therapy for hepatocellular carcinoma

Transarterial chemoembolization (TACE) improves survival in cirrhotic patients with hepatocellular carcinoma (HCC). The optimal schedule, best anticancer agent and best technique are still unclear. TACE may not be better than transarterial embolization (TAE). HCC is very chemoresistant, thus embolization may be more important than chemotherapy. Lipiodol cannot be considered as an embolic agent and there are no data to show that it can release chemotherapeutic agents slowly. It can mask residual vascularity on CT imaging and its use is not recommended. Both TACE and TAE result in hypoxia, which stimulates angiogenesis, promoting tumor growth; thus combination of TACE with antiangiogenic agents may improve current results. To date, there is no evidence that TACE pre-liver transplantation or resection helps to expand current selection criteria for patients with HCC, nor results in less recurrence after surgery. Combination with other techniques, such as radiofrequency ablation and drugs, may enhance the effect of TACE. New trials are being conducted to clarify these issues.

Evaluation of the role of CT in the assessment of response to selective internal radiation therapy in patients with colorectal liver metastases

Selective internal radiation therapy (SIRT) is a relatively new method for treating non-resectable liver tumours. There is reason to believe that conventional assessments of response by CT scan may underestimate the efficacy of this treatment. A study was undertaken in 54 patients to evaluate CT changes after SIRT for advanced colorectal cancer and to compare these with tumour marker (carcinoembryonic antigen (CEA)) changes to determine how best to assess whether a response has occurred. Computed tomography scans were carried out before treatment and at 3-monthly intervals thereafter. Serial CEA measurements were undertaken at 4-weekly intervals. Index lesions were identified and their size was assessed on serial scans by three independent, blinded investigators. Per cent changes in CEA levels after SIRT were calculated for all patients. Disappearance of all index lesions was noted in five patients (9.3%). A decrease in the size was seen in a further 41 patients (76%), no change was seen in five (9.3%), and an increase in size was noted in three (5.4%). The time taken for the maximum decrease in size to occur ranged from 3 to 21 months (median 12 months). Carcinoembryonic antigen changes were more dramatic, with a reduction of more than 75% within 2 months in 35 of 50 patients (70%) and a rise in only 3 of 50 patients (6%). Early assessment of response by CT scan may be misleading because of the time taken for size reduction to occur. Response to SIRT is more accurately judged in the early stages by tumour marker data.

Transarterial therapy for hepatocellular carcinoma: which technique is more effective? A systematic review of cohort and randomized studies

BACKGROUND

Chemoembolization (TACE) improves survival in cirrhotic patients with hepatocellular carcinoma (HCC). The optimal schedule, or whether embolization (TAE) alone gives the same survival advantage, is not known.

PURPOSE

To evaluate whether specific patient characteristics and/or radiological transarterial techniques result in better outcomes.

METHOD

A PubMed search was carried out for cohort and randomized trials (n = 175) testing transarterial therapies; meta-analysis was performed where appropriate.

RESULTS

Anticancer drugs were used as sole agent in 75% of cases (double 15% and triple 6%): doxorubicin (36%), cisplatin (31%), epirubicin (12%), mitoxantrone (8%), mitomycin (8%), and SMANCS (5%). Embolizing agents used were: gelatin sponge particles (71%), polyvinyl alcohol (PVA) particles (8%), degradable starch microspheres (DSM) (4%), and embospheres (4%). Sessions per patient were 2.5 +/- 1.5 (interval: 2 months). Objective response was 40 +/- 20%; survival rates at 1, 2, 3, and 5 years were: 62 +/- 20%, 42 +/- 17%, 30 +/- 15%, and 19 +/- 16%, respectively, and survival time was 18 +/- 9.5 months. The post-TACE complications were: acute liver failure, 7.5% (range 0-49%); acute renal failure, 1.8% (0-13%); encephalopathy, 1.8% (0-16%); ascites, 8.3% (0-52%); upper gastrointestinal bleeding; 3% (0-22%); and hepatic or splenic abscess, 1.3% (0-2.5%). Treatment-related mortality was 2.4% (0-9.5%), mainly due to acute liver failure. Our meta-analysis of nine randomized controlled trials (RCTs) confirmed that TACE improves survival; but a meta-analysis of TACE versus TAE alone (3 RCTs, 412 patients) demonstrated no survival difference.

CONCLUSIONS

No chemotherapeutic agent appears better than any other. There is no evidence for benefit with lipiodol. Gelatin sponge is the most used embolic agent, but PVA particles may be better. TAE appears as effective as TACE. New strategies to reduce the risk of post-TACE complications are required.