Needleless Ablation of Osteoid Osteoma and Osteoblastoma: The Emergent Role of MRgFUS

Osteoblastoma (OB) and osteoid osteoma (OO) are benign bone-forming tumors, with nearly identical basic microscopic features. The main difference is dimension (OO has usually a nidus measuring <2 cm in diameter). In addition, OB is biologically more active than OO, with a tendency to grow in size. Historically, treatments have included surgical resection and analgesics, although invasiveness and poor tolerance have led to the current standard of care moving toward interventional radiology, where radiofrequency ablation (RFA) represents the most diffuse technique. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) has recently emerged as another innovative alternative treatment, providing tumor ablation through a needleless and ionizing radiation-free modality. In addition, this technique has the ability to guarantee a very precise and controlled increase in temperature, delivering small amounts of energy that can accurately destroy only the lesion, avoiding healthy surrounding tissues. The present review focuses on MRgFUS as the less invasive, safe, effective, and durable treatment option for the management of osteoid osteoma and osteoblastoma, including a description of technical details, indications and outcomes.

Focused Ultrasound Surgery Applications in Treating Vulvar Non-neoplastic Epithelial Disorders

: Vulvar intraepithelial neoplasia is a premalignant skin lesion of the vulva that often presents with severe vulvar pruritus, pain, and psychosexual disorders. The technology of non-invasive focused ultrasound surgery has improved over the years. Today its potential to treat these irritating diseases noninvasively is a relatively new area of clinical research interest. Increasing studies in China revealed that FUS treatment is effective and safe. This paper describes the preparation, technique, postoperative care, and results of this focused ultrasound surgery for treating vulvar non-neoplastic epithelial disease. Therefore it could be a future alternative treatment for benign vulvar diseases, replacing many invasive surgical treatments.

Continuum modeling perspectives of non-Fourier heat conduction in biological systems

The thermal modeling of biological systems is increasingly important in the development of more advanced and more precise techniques such as ultrasound surgery. One of the primary barriers is the complexity of biological materials: the geometrical, structural, and material properties vary in a wide range. In the present paper, we focus on the continuum modeling of heterogeneous materials of biological origin. There are numerous examples in the literature for non-Fourier thermal models. However, as we realized, they are associated with a few common misconceptions. Therefore, we first aim to clarify the basic concepts of non-Fourier thermal models. These concepts are demonstrated by revisiting two experiments from the literature in which the Cattaneo–Vernotte and the dual phase lag models are utilized. Our investigation revealed that these non-Fourier models are based on misinterpretations of the measured data, and the seeming deviation from Fourier’s law originates from the source terms and boundary conditions.

Magnetic Resonance-Guided Focused Ultrasound Surgery for Obsessive-Compulsive Disorders: Potential for use as a Novel Ablative Surgical Technique

Surgical treatment for psychiatric disorders, such as obsessive-compulsive disorder (OCD) and depression, using ablative techniques, such as cingulotomy and capsulotomy, have historically been controversial for a number of scientific, social, and ethical reasons. Recently, with the elucidation of anatomical and neurochemical substrates of brain function in healthy controls and patients with such disorders using various functional neuroimaging techniques, these criticisms are becoming less valid. Furthermore, by using new techniques, such as deep brain stimulation (DBS), and identifying more precise targets, beneficial effects and the lack of serious complications have been demonstrated in patients with psychiatric disorders. However, DBS also has many disadvantages. Currently, magnetic resonance-guided focused ultrasound surgery (MRgFUS) is used as a minimal-invasive surgical method for generating precisely placed focal thermal lesions in the brain. Here, we review surgical techniques and their potential complications, along with anterior limb of the internal capsule (ALIC) capsulotomy by radiofrequency lesioning and gamma knife radiosurgery, for the treatment of OCD and depression. We also discuss the limitations and technical issues related to ALIC capsulotomy with MRgFUS for medically refractory OCD and depression. Through this review we hope MRgFUS could be considered as a new treatment choice for refractory OCD.

Magnetic resonance-guided focused Ultrasound surgery for treatment of osteoid osteoma: How do we do it?

Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is an increasingly popular non-invasive technique for treatment of severe pain produced by soft tissue, solid or bone tumours. MRgFUS used targeted thermal ablation technique to control moderate to severe pain. Osteoid osteoma is a small benign, highly vascular tumour, composed of osteoid and woven bone, most commonly affect the appendicular skeleton. Bony spine involvement can produce painful scoliosis, while intra-articular joint involvement can cause irreversible joint damage. Clinical presentation is local bone pain which typically worsen at night and with increased activity. Conventional standard treatment of osteoid osteoma is analgesic or surgical intervention. Under conservative medical treatment, the patient needs to be on long term analgesic, e.g. salicylates, where well-known reported complications include renal tubular acidosis and gastric ulcer. The standard surgical treatment is curettage. However, this carry the risk of bleeding, infection and tissue damage. Minimally invasive radiofrequency ablation (RFA) or cryoablation which are the current treatment of choice also carry the risk of tumour rupture and bleeding. We present a case of severe bone pain from benign bone tumor (osteoid osteoma), successfully treated with noninvasive Magnetic MRgFUS.