A novel hyperthermia treatment for bone metastases using magnetic materials

Abstract

Patients with bone metastases in the extremities sometimes require surgical intervention to prevent deterioration of quality of life due to a pathological fracture. The use of localized radiotherapy combined with surgical reinforcement has been a gold standard for the treatment of bone metastases. However, radiotherapy sometimes induces soft tissue damage, including muscle induration and joint contracture. Moreover, cancer cells are not always radiosensitive. Hyperthermia has been studied since the 1940s using an experimental animal model to treat various types of advanced cancer, and studies have now reached the stage of clinical application, especially in conjunction with radiotherapy or chemotherapy. Nevertheless, bone metastases have several special properties which discourage oncologists from developing hyperthermic therapeutic strategies. First, the bone is located deep in the body, and has low thermal conductivity due to the thickness of cortical bone and the highly vascularized medulla. To address these issues, we developed new hyperthermic strategies which generate heat using magnetic materials under an alternating electromagnetic field, and started clinical application of this treatment modality. The purpose of this review is to summarize the latest studies on hyperthermic treatment in the field of musculoskeletal tumors, and to introduce the treatment strategy employing our novel hyperthermia approach.

Antitumor Immunity by Magnetic Nanoparticle-Mediated Hyperthermia

“…Matsumine et al reported a novel MNHT system for patients with bone metastases in their extremities [85]. They used a calcium phosphate cement containing MNPs.…”

“…The development of AMF applicators is also an important issue for applying MNHT to various forms of cancers with different sizes, shapes and locations. While significant progress has been made[23,78,85,87], more sophisticated applicators may still need to be developed. In addition, the development of noninvasive thermometry that accurately measures or estimates the temperature distribution in situ within and outside tumor tissues during MNHT treatment also needs to be developed, as reviewed byKaddi et al …”

In vitro apatite formation and drug loading/release of porous TiO2 microspheres prepared by sol–gel processing with different SiO2 nanoparticle contents

“…Firstly, the cancer-affected region is extirpated by surgery and the excision site is sometimes filled with injectable calcium phosphate cement in order to achieve early postoperative ambulation [2][3][4]. After the surgical operation, chemotherapy is performed in order to prevent cancer recurrence and metastasis.…”

Magnetic Nanoparticle-Mediated Hyperthermia and Induction of Anti-Tumor Immune Responses

“…Matsumine et al [65] developed an injectable calcium phosphate cement containing MNPs for patients with bone metastases in the extremities. Calcium phosphate cement containing MNPs was injected to fill the bone defect following resection of bone tumors, and AMF was applied totally 10 times from day 8 to day 29 after surgical operation for 23 patients with 25 bone metastases.…”