Embolization of an unusual metastatic site of hepatocellular carcinoma in the humerus

Current Overview of Treatment for Metastatic Bone Disease

The number of patients with bone metastasis increases as medical management and surgery improve the overall survival of patients with cancer. Bone metastasis can cause skeletal complications, including bone pain, pathological fractures, spinal cord or nerve root compression, and hypercalcemia. Before initiation of treatment for bone metastasis, it is important to exclude primary bone malignancy, which would require a completely different therapeutic approach. It is essential to select surgical methods considering the patient’s prognosis, quality of life, postoperative function, and risk of postoperative complications. Therefore, bone metastasis treatment requires a multidisciplinary team approach, including radiologists, oncologists, and orthopedic surgeons. Recently, many novel palliative treatment options have emerged for bone metastases, such as stereotactic body radiation therapy, radiopharmaceuticals, vertebroplasty, minimally invasive spine stabilization with percutaneous pedicle screws, acetabuloplasty, embolization, thermal ablation techniques, electrochemotherapy, and high-intensity focused ultrasound. These techniques are beneficial for patients who may not benefit from surgery or radiotherapy.

Hepatocellular Carcinoma: First Manifestation as Solitary Humeral Bone Metastasis

Hepatocellular carcinoma (HCC) most commonly presents with abdominal pain or mass, fever of unknown etiology, weight loss, and decompensation of known liver disease or at an asymptomatic stage through surveillance. Rarely, presenting symptoms can be exclusively related to extrahepatic metastases. Herein, we write a case of a patient with no known liver disease, presenting with a pathological fracture of the proximal humerus bone secondary to a massive solitary metastasis from HCC. This case represents an unusual appendicular skeletal metastasis in a patient with unknown primary HCC, successfully treated with sorafenib. The prognosis of HCC patients with extrahepatic metastasis is poor, and in the presence of bone metastases, the mean survival rate is severely reduced. However, the multikinase inhibitor sorafenib has been the standard of treatment. Recently, there has been developments of other therapeutic class of drugs (i.e., immune check inhibitors), which have shown promising benefits and better side effect profiles. Still, there is a need for further studies, owing to challenges in recognizing cellular and molecular markers.

Preoperative transarterial Embolisation in bone tumors

Bone tumors include a variety of lesions, both primary and metastatic. The treatment modalities for bone tumors vary with the individual lesion, but in general surgical excision is the treatment of choice with other adjunctive therapies. However, surgery for many bone tumors is complex due to several factors including tumor bulk, vascularity, vicinity to vital structures and potentially inaccessible location of the lesion. Transarterial Embolisation (TAE) is one of the important adjuvant treatment modalities and in some cases it may be the primary and curative treatment. Preoperative TAE has proved to be effective in both primary and metastatic bone tumors. It reduces tumor vascularity and intraoperative blood loss, the need for blood transfusion and associated complications, allows better definition of tissue planes at surgery affording more complete excision, and hence reduced recurrence. Preoperative chemoEmbolisation has also been shown to increase the sensitivity of some tumors to subsequent chemotherapy and radiotherapy. There are several techniques and embolic agents available for this purpose, but the ultimate aim is to achieve tumor devascularization. In this review, we discuss the techniques including the choice of embolic agent, application to individual lesions and potential complications.

Embolization of musculoskeletal bone tumors

Bone tumors may present as incidental findings, with pain or loss of function, or as fractures. There is a broad range of indications for transarterial embolization (TAE) in primary or metastatic bone tumors: to reduce operative hemorrhagic risks, to simplify or allow more definitive surgery, or in the context of pain palliation, fever, bleeding, or hypercalcemic and other rheological factors. Embolization may also increase tumor sensitivity to chemotherapy or radiation therapy. The procedure itself is often complex with significant risk to adjacent structures and is usually part of a wider treatment strategy. There are many options of embolic agent, techniques, and end points but all aim to devascularize the tumor. Catheter angiography at the time of TAE is used to determine the correct embolic agent and technique with care taken to isolate at risk structures. Many factors determine the best choice of embolic material, probably the most important of which is operator experience. In life-threatening situations or in preoperative embolizations of metastatic tumors, many operators opt for a combination of particulate emboli and stainless steel or platinum coils. Agents discussed include polyvinyl alcohol particles, trisacryl microspheres, gelatin sponge, liquid embolic agents, and embolization coils. Tumor types treated include vascular metastatic lesions, commonly renal cell or thyroid, particularly in locations prone to fracture; giant cell tumors; aneurysmal bone cysts; vertebral hemangiomas, osteosarcomas; arteriovenous malformations; and osteoblastomas. TAE should be considered in the treatment algorithm of primary or secondary bone tumors. Specific benefit is present where there is a high risk of bleeding at surgery, where there is spinal involvement and neural encroachment, where active bleeding is present or in awkward surgical locations where prolonged surgery is anticipated.

Selective arterial embolisation for bone tumours: experience of 454 cases

PURPOSE

The authors present the experience of a single institution with selective arterial embolisation for primary and metastatic bone tumours.

MATERIALS AND METHODS

A total of 365 patients were treated with 454 embolisation procedures from December 2002 to April 2010. Embolisation was the primary treatment for benign bone tumours, adjuvant treatment to surgery for benign and malignant bone tumours and palliative treatment for bone sarcomas and metastases. Indications for repeat embolisation included pain or imaging evidence of progressive disease: 105 patients had repeat embolisation at the same location at an interval of 1-3 months; 260 patients had one embolisation, 78 had two and 29 had three or more. In all patients, N-2-butyl cyanoacrylate (NBCA) in 33% lipiodol was the embolic agent used.

RESULTS

A total of 419 of the 454 embolisations (93%) were technically successful. In 35 cases, embolisation was not feasible because of poor lesion vascularisation (21 patients with bone metastases and two with aneurysmal bone cysts), origin of the Adamkiewicz artery in the embolisation field (four patients with bone metastases and one with aneurysmal bone cyst), atheromatosis and arteriosclerosis (five patients with bone metastases) and anatomical and technical problems such as small-calibre vessels, many branches and acute vessel angles (two patients with bone metastases). A clinical response was achieved in 406 of the 419 procedures (97%), and no response in 13 procedures in patients with pelvis and sacrum tumours. Complications included postembolisation syndrome in 81 patients (22%), transient paraesthesias in 41 (11%), skin breakdown and subcutaneous necrosis at the shoulder and pelvis in five (1.4%) and paresis of the sciatic nerve in one (0.3%).

CONCLUSIONS

We recommend embolisation as primary or palliative treatment or an adjunct to surgery for tumours of variable histology. Strict adherence to the principles of transcatheter embolisation is important. Arteries feeding the tumour and collaterals must be evaluated carefully and catheterised superselectively to protect the normal tissues. NBCA is considered the most appropriate embolic agent for small-vessel occlusion without major complications.

Selective embolization with N-butyl cyanoacrylate for metastatic bone disease

PURPOSE

To evaluate the clinical and imaging effect of selective embolization using N-butyl cyanoacrylate (NBCA) as palliation for bone metastases.

MATERIALS AND METHODS

The procedures and effect of 309 embolizations performed in 243 patients were retrospectively analyzed; 56 patients had repeat embolization at the same location at 1-3 months; 197 patients had embolization for progressive bone metastases after radiation therapy. The mean tumor diameter before embolization was 7.8 cm (range 5-30 cm). In all patients, embolizations were performed under local anesthesia through transfemoral catheterization using NBCA in 33% ethiodized oil. The technical success of embolization was evaluated by angiography after completion of the procedure. The clinical and imaging effect was evaluated at follow-up examinations with a pain score scale and use of analgesics, hypoattenuating areas, tumor size, and ossification.

RESULTS

In all 309 embolizations, postprocedural angiography showed complete occlusion of metastatic blood supply and greater than 80% devascularization of the lesions. Greater than 50% reduction of pain score and analgesic doses was achieved in 97% of procedures. The mean duration of pain relief was 8.1 months (range 1-12 months). The mean maximal tumor diameter after embolization was 5.5 cm (range 2-20 cm). Variable ossification appeared in 65 patients. Postembolization syndrome, ischemic pain at the site of embolization, paresthesias, skin breakdown, and subcutaneous necrosis were observed in 87 patients.

CONCLUSIONS

Selective embolization with NBCA is a safe and effective palliative treatment for metastatic bone lesions of various primary cancers; pain relief is temporary.