A Minimally Invasive Surgery for Bone Metastases Using the Combination of Photodynamic Therapy and Hyperthermia Treatment

Abstract

<p class="MsoNormal" style="text-align:justify;"> <span lang="EN-US" style="font-family:Verdana;">Cancer patients with bone metastases in their extremities may require surgical intervention to prevent deterioration in their quality of life due to a pathological fracture or severe bone pain. However, curative surgical interventions sometimes have severe complications due to the status of the original cancers. To avoid the decreased quality of life caused by bone metastasis, minimally invasive surgery that avoids additional surgical morbidity is required. We have established two therapeutic treatments for bone metastasis, a photodynamic acridine orange treatment (AOT) and an electronic magnetic hyperthermia treatment (EMHT). </span><span lang="EN-GB" style="font-family:Verdana;">The present study investigated the clinical outcomes </span><span lang="EN-US"><span style="font-family:Verdana;">of combination therapy with EMHT and AOT for patients with bone metastases in their extremities. </span><b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> The study included 6 patients with 7 bone cancer metastasis locations. For bone metastases, all patients received intraregional tumor excision supported by AOT, in which photodynamic and radiodynamic therapy kills tumor cells during surgery with minimal damage to normal tissues. After the curettage, bone reconstruction was performed by using magnetic materials</span><span style="font-family:Verdana;">with calcium phosphate cement. EMHT was repeatedly performed after surgery. In EMHT, tumor cells are killed with an electric magnetic field generator, and bony union is promoted by electronic stimulation. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> The mean duration of follow-up was 14 months. During the follow-up period, only one patient experienced a local recurrence, and this recurrence occurred 14 months after surgery. Bony union occurred in 4 of 5 cases (80%), and the pain score was significantly reduced after surgery. </span><b><span style="font-family:Verdana;">Conclusions:</span></b><span style="font-family:Verdana;"> In the present study, AOT reduced the invasiveness of surgery. EMHT reduced the tumor growth without major complications and promoted bone formation after surgery. Our clinical results confirmed that EMHT and AOT combination therapy for bone metastasis can preserve limb function without local recurrence or bone absorption.</span></span><span lang="EN-US"><o:p></o:p></span> </p

Progress of photodynamic therapy applications in the treatment of musculoskeletal sarcoma (Review)

“…For example, there are several additional advantages of AO therapy combined with electronic magnetic hyperthermia treatment (EMHT): i) Visualization of the tumor cell by fluorescent microscopy during the surgery; ii) removal of the visualized target cell without damage to healthy tissues; and iii) residual AO-labeled tumor cells seated in deep areas are killed by low-dose radiation following surgery. With these advantages, the combination of AO therapy and EMHT has the ability to replace conventional tumor surgery and radiotherapy in certain cases ( 66 ). Therefore, it may strongly be suggested that PDT can be widely used in the diagnosis and treatment of bone and soft-tissue malignant tumors in the future.…”

Applications of Antimicrobial Photodynamic Therapy against Bacterial Biofilms

“…Other combination therapy studies include PDT with anticancer chemotherapy [ 24 ], photothermal hyperthermia therapy (PTT) for anticancer applications [ 25 ], antibacterial applications [ 26 ], and antifungal applications [ 27 ]. PDT has also been studied in combination with magnetic hyperthermia therapy (MHT) for various applications including hard-to-reach cancers such as brain cancer [ 28 ] and bone tissue cancers [ 29 ]. As a therapeutic technology, MHT involves the temperature elevation of tissues in which embedded magnetic nanoparticles are energized using a high frequency alternating magnetic field generated by an appropriate MHT applicator [ 30 ].…”