Image-Guided Microtherapy for Tumor Ablation: From Thermal Coagulation to Advanced Irradiation Techniques

Image-Guided Local Treatment for Unresectable Intrahepatic Cholangiocarcinoma-Role of Interventional Radiology

Intrahepatic cholangiocarcinoma is a highly aggressive malignancy with an increasing incidence in recent years. Prognosis is poor and most patients are not eligible for resection at the time of initial diagnosis due to the anatomic location, inadequate hepatic reserve, limiting comorbidities or metastatic disease. Several locoregional therapies from the field of interventional radiology exist for patients who are not amenable for surgery, or in case of local recurrence as a single treatment modality or combined with systemic treatment. To date, evidence is limited, with most conclusions drawn from single-center studies with small patient cohorts, often treated in the salvage situation or for local recurrence after initial resection. Nevertheless, the results are promising and suggest a survival benefit in selected patients. This narrative review focuses on the use of different locoregional treatment options for intrahepatic cholangiocarcinoma.

Current State of Multidisciplinary Treatment in Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignancy, and its incidence seems to be increasing over the last years. Given the high rate of irresectability at the time of initial diagnosis, new treatment approaches are important to achieve better patient outcomes. Our review provides an overview of current multimodal therapy options across different specialties of gastroenterology/oncology, surgery, and interventional radiology.

SUMMARY

CCA is subdivided into clinically and molecularly distinct phenotypes. Surgical treatment currently is the only potentially curative therapy, but unfortunately, the majority of all patients are not eligible for resection at the time of initial diagnosis due to anatomic location, inadequate hepatic reserve, metastatic disease, or limiting comorbidities. However, multimodal treatment options are available to prolong survival, relieve symptoms, and maintain life quality.

KEY MESSAGES

The treatment of CCA is complex and requires close interdisciplinary collaboration and individualized treatment planning to ensure optimal patient care at specialized centers. Molecular profiling of patients and inclusion into clinical trials is highly recommended.

Extensive Use of Interventional Therapies Improves Survival in Unresectable or Recurrent Intrahepatic Cholangiocarcinoma

Aim. To assess the outcomes of patients with unresectable intrahepatic cholangiocellular carcinoma (ICC) treated by a tailored therapeutic approach, combining systemic with advanced image-guided local or locoregional therapies. Materials and Methods. Treatment followed an algorithm established by a multidisciplinary GI-tumor team. Treatment options comprised ablation (RFA, CT-guided brachytherapy) or locoregional techniques (TACE, radioembolization, i.a. chemotherapy). Results. Median survival was 33.1 months from time of diagnosis and 16.0 months from first therapy. UICC stage analysis showed a median survival of 15.9 months for stage I, 9 months for IIIa, 18.4 months for IIIc, and 13 months for IV. Only the number of lesions, baseline serum CEA and serum CA19-9, and objective response (RECIST) were independently associated with survival. Extrahepatic metastases had no influence. Conclusion. Patients with unresectable ICC may benefit from hepatic tumor control provided by local or locoregional therapies. Future prospective study formats should focus on supplementing systemic therapy by classes of interventions (“toolbox”) rather than specific techniques, that is, local ablation leading to complete tumor destruction (such as RFA) or locoregional treatment leading to partial remission (such as radioembolization). This trial is registered with German Clinical Trials Registry (Deutsche Register Klinischer Studien), DRKS-ID: DRKS00006237.

Drug-eluting polymer implants in cancer therapy

BACKGROUND

Drug-eluting polymer implants present a compelling parenteral route of administration for cancer chemotherapy. With potential for minimally invasive, image-guided placement and highly localized drug release, these delivery systems are playing an increasingly important role in cancer management. This is particularly true as the use of labile proteins and other bioactive molecules is likely to increase in the upcoming years.

OBJECTIVE

In this review, we present the current trends in the application of Pre-formed and in situ-forming systems as drug-eluting implants for cancer chemotherapy.

METHODS

We outline the clinically available options as well as up-and-coming technologies and their advantages and challenges. We also describe ongoing related innovations with image-guided drug delivery, mathematical modeling of implanted delivery systems and implanted drug delivery in combination with other therapies.

RESULTS/CONCLUSION

Whether used alone or combined with other minimally invasive procedures, drug-eluting polymeric implants will play a significant role in the future of cancer management.

Brachytherapy of liver metastases

Brachytherapy for the treatment of liver metastases is a novel approach. In this procedure, techniques of locally ablative treatment in interventional radiology and radiation therapy are combined. After computed tomography (CT)-guided percutaneous implantation of catheters into the hepatic tumor, the irradiation is performed in an afterloading technique. This minimally invasive procedure offers circumscriptive high-dose rate irradiation of the lesion to treat in a single session, irrespective of breathing motion or potential cooling effects of neighboring vessels. Good local control rates have been achieved in several tumor entities, including both secondary and primary malignancies of the liver. This article gives an overview of the application technique, possible adverse events, and outcome with special attention to the pancreatic cancer scenario.