Radiofrequency Ablation is a Valuable Therapeutic Option in the Treatment of Liver Metastases From Gastrointestinal Stromal Tumors

Abstract

We read with great interest the article entitled ‘‘A Role for Adjuvant RFA in Managing Hepatic Metastases from Gastrointestinal Stromal Tumors (GIST) After Treatment with Targeted Systemic Therapy Using Kinase Inhibitors’’ by Hakime et al. [1] indicating that radiofrequency ablation (RFA) in patients with GIST liver metastases, previously treated with tyrosine kinase inhibitor, has few complications and little toxicity and that the combination of RFA and imatinib seems to have improved progression-free survival rates compared with historical controls in similar patients treated with imatinib alone. These findings suggest that RFA is a potentially valuable therapeutic option in the treatment of GIST liver metastases. However, there are still some issues worthy of our deeper consideration. First, we fully agree with the author that ‘‘for primary and metastatic liver tumors of 3 cm or smaller, the rate of local control after radiofrequency ablation (RFA) has been found to be equivalent to that of resection . . . .’’ In fact, a growing number of recent studies have confirmed that RFA has been widely used for liver cancer as a rapid development of minimally invasive techniques [2–4]. Its advantages include convenient maneuvering, decreased open operation ratio, shorter hospital stays, precise curative effect, and relatively low cost. For patients with small hepatocellular carcinoma (tumors \3 cm in diameter), the long-term efficacy of RFA is similar to or even better than liver resection [2–4]. Although RFA for the treatment of GIST liver metastases has been rarely reported [1, 5], we can also learn, to some extent, from the experience of RFA in the treatment of colorectal liver metastases. Second, the essence of RFA treatment is to precisely inactivate tumor lesions entirely and minimize damage to normal liver tissue. Accurate identification of tumor-infiltrating scope and satellite lesions is the first premise. Therefore, great emphasis is placed on precise imaging before treatment. In recent years, contrast-enhanced ultrasound (CEUS) has played an important role in the RFA treatment of liver cancer and can help to confirm the actual size and shape of the tumor, the range of tumor infiltration, and the number of small tumors and satellite lesions, as well as provide a reliable reference for the development of RFA planning [6–8]. Combined with results from the existing literature [6–8] as well as our center’s experience, in addition to traditional US, computed tomography, and magnetic resonance imaging examinations, CEUS is worthy of being considered for RFA treatment of GIST liver metastases. Last, and most important, in April 2008, a National Institutes of Heath expert group re-discussed the risk stratification of primary GIST after resection and reached a new consensus: The original tumor site and tumor rupture can also serve as basic prognostic evaluation indicators [9]. Therefore, we should pay more attention to avoiding iatrogenic tumor rupture and seeding during surgery and preventing the probability of a higher postoperative recurrence and metastasis, whether in surgery or during other minimally invasive treatments, including RFA for the treatment of GIST. To achieve this goal, determining the location of tumor lesions should be especially focused. Based on our single-center experience, if the tumor is located in the liver parenchyma, the choice of RFA is feasible. However, if the tumor is located in the visceral surface of liver (especially greater than one-third of the Q.-K. Sun W. Wang (&) W.-D. Jia Department of Hepatic Surgery, Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, People’s Republic of China e-mail: whouwei@sina.com