Factors influencing MR changes associated with sacral injury after high-intensity focused ultrasound ablation of uterine fibroids.

PURPOSE: We investigated the risk factors influencing MR changes associated with sacral injury from ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation for uterine fibroids. METHODS: We retrospectively analyzed a total of 346 patients with symptomatic uterine fibroids who received USgHIFU ablation. All of the patients underwent contrast-enhanced magnetic resonance imaging (CE-MRI) before and after treatment. Injury to the sacrum was set as the dependent variable, while fibroid features and the treatment parameters were set as independent variables. These variables were used to assess respectively their correlation with sacral injury by using univariate and multivariate analyses. RESULTS: The results of univariate analysis revealed that the volume, distance from the fibroid to the skin, maximal diameter, distance from the fibroid to the sacrum, fibroid types, degree of enhancement, therapeutic dosimetry (TD), energy efficiency factor (EEF) and non-perfused volume (NPV) ratio manifested significant correlations with the sacral injury (p < .05). Multivariate analysis showed that the degree of enhancement, TD and EEF were independent risk factors for sacral injury (p < .05), while the distance from fibroid to sacrum and intramural or subserosal types were protective factors (p < .05). The incidence of sacral tail pain and leg pain showed a significant positive correlation with sacral injury (p < .05). CONCLUSION: As important affecting factors, the degree of enhancement, distance from fibroid to sacrum and fibroid types all possess significant correlations with MR changes associated with sacral injury.

Thermal effect of percutaneous radiofrequency ablation with a clustered electrode for vertebral tumors: In vitro and vivo experiments and clinical application.

PURPOSE: To investigate effects and heat distribution of radiofrequency ablation (RFA) on vertebral tumors in vitro and in vivo swine experiments and its clinical application. MATERIALS AND METHODS: RFA was performed on the swine spine in vitro and in vivo for 20 min at 90 °C at the electrode tip, and the temperature at the electrode tip and surrounding tissues were recorded. Clinical application of ablation combined with vertebroplasty was subsequently performed in 4 patients with spinal tumors. RESULTS: In the in vitro study, the mean temperature at the front and ventral wall of the spinal canal was 50.8 °C and 43.6 °C, respectively, at 20 mm significantly greater than 37.7 °C and 33.7 ± 1.7 °C, respectively, at 10 mm ablation depth. The coagulative necrosis area was significantly (P < 0.0001) greater at 20 mm depth than at 10 mm depth (mean 17.0 × 20.7 mm2 vs. 14.2 × 16.6 mm2). In the in vivo experiment, the local temperature increased significantly (P < 0.05) from around 36 °C before ablation to over 41 °C at 20 min after ablation, with the temperature at the electrode tip (90.4 °C) and within the vertebral body (67.0 °C) significantly (P < 0.05) greater than at the posterior (41.9 °C) and lateral wall (41.8 °C). From 2 to 5 weeks, bone remodeling began. Clinically, all four patients had successful RFA and vertebroplasty, with no neurological deficits. The pain scores were significanlty (P < 0.05) improved before (4.5-10, mean 8.0) compared with at four weeks (0-1.8, mean 1.8). CONCLUSION: The clustered electrode can be efficiently and safely applied in the treatment of spinal tumors without damaging the spinal cord and adjacent nerves by heat distribution.

Palliative pain relief and safety of percutaneous radiofrequency ablation combined with cement injection for bone metastasis.

PURPOSE: To investigate the pain relief effect and safety of percutaneous radiofrequency ablation (RFA) with a multitined electrode combined with cement injection in patients with painful metastatic bone tumors. MATERIALS AND METHODS: Sixteen patients with 34 osteolytic metastatic lesions were treated with RFA including 4 males and 12 females (age range 54-84). Thirteen patients with spinal metastases received additional cement injection. Medical imaging, a visual analog scale (VAS) and the EORTC QLQ-C30 were performed to evaluate the metastatic lesion, pain and quality of life, respectively, before and after RFA and at follow-ups. RESULTS: The RFA and/or vertebroplasty with cement injection were successful in all patients (100%). Except for one patient who had cement leakage, no intraprocedural complications occurred. After RFA, severe refractory pain was greatly relieved in all patients, with pretreatment VAS score of 8.1 ± 1.4 significantly reduced to 5.5 ± 1.1 at 24 h, 2.8 ± 0.6 at 1 week and 1.4 ± 0.8 at 6 months (P < 0.01). The EORTC QLQ-C30 scale at 1 month demonstrated significant improvement (P < 0.05) in the physical (P = 0.03) and emotion function (P = 0.003), global health status (P = 0.002), pain (P = 0.001) and insomnia (P = 0.002). The analgesics were reduced after the procedure and stopped 2 months later in all patients, with greatly improved quality of life and no apparent pain. Followed up for 6-12 months, all patients remained alive with no recurrence of pain. Palliative pain relief and safety of percutaneous radiofrequency ablation combined with cement injection for bone metastasis. CONCLUSION: RFA with or without bone cement is safe and effective in the palliative treatment of pain caused by metastatic bone tumors.

In vivo effects of radiofrequency ablation on long bones and the repair process in swine models.

PURPOSE: To investigate in vivo effect of radiofrequency ablation (RFA) on swine long bones and the repair process. MATERIALS AND METHODS: RFA was performed in six swine at the end and middle part of the tibia or femur. After RFA, radiological examinations were performed, and the swine were killed immediately and at different time points post-RFA for histopathological examination. RESULTS: All swine had successful RFA. The RFA-induced elliptical necrotic area ranged from 3.81-5.24 cm2 (mean 4.08 ± 0.73 cm2) at the bone end but 5.60-8.98 cm2 (mean 7.58 ± 1.41) at the middle part immediately after RFA until 10 days, with the necrosis area significantly smaller (P = 0.000) at the end than at the middle. RFA only damaged the cortical bone slightly (0.01 cm thick) with no damage to the soft tissues outside the compact bone at both the end and middle. Surrounding the elliptic pale zone of coagulative necrosis was a narrow brown band of hemorrhage and inflammatory exudate. From day 10 until week 12, tissue proliferation and repair became increasingly apparent, with proliferated granulation, fibrous tissue, and fresh and mature bone trabecula. CONCLUSION: RFA can quickly and effectively destroy the cancellous bone tissue without affecting the cortical bone and activate bone remodeling.

Angiogenic study in Graves' disease treated with thyroid arterial embolization.

PURPOSE: To investigate angiogenesis in the thyroid of Graves' disease (GD) treated with thyroid arterial embolization through analysis of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and microvessel density (MVD). MATERIALS AND METHODS: Forty-two GD patients were treated with thyroid arterial embolization and followed up for 1-68 months after embolization. Before embolization and at 7 days, 3, 6, 12, 36 and 48 months following embolization, TT3, TT4, FT3, FT4, TSH and thyroid stimulating antibody (TSAb) were tested respectively. Thyroid biopsy was performed under the guidance of computed tomography for immunohistochemical staining of VEGF and bFGF, and MVD within the thyroid gland was marked by CD34. RESULTS: VEGF and bFGF were mostly expressed in the cytoplasm and on the cell membrane. The expression of VEGF was increased (P < 0.05) at < or = 6 months compared with before embolization and decreased (P < 0.05) at > or = 1 year compared with either at < or = 6 months or before embolization. The expression of bFGF was not statistically different at < or = 6 months compared with before embolization but was decreased (P < 0.05) at > or = 1 year compared with either at ?6 months or before embolization. Thyroid MVD marked by CD34 had similar changes to those of the VEGF expression after embolization. There was a positive correlation between VEGF and bFGF (P < 0.05) and between VEGF or bFGF and MVD (P < 0.05). Thyroid hormones mostly returned to normal and TSAb was decreased in longer follow-up. CONCLUSION: Thyroid arterial embolization can decrease the expression of VEGF, bFGF and MVD. Consequently, angiogenesis within the GD thyroid will be decreased in the long term after embolization and may serve as the basis for reduced thyroid size and function.

Long-term immunological study in Graves' disease treated with thyroid arterial embolization.

OBJECTIVE: The aim of this study was to investigate long-term immunological changes after the treatment of Graves' disease (GD) with thyroid arterial embolization and the effect of thyroid arterial embolization on the body's immunological functions. MATERIALS AND METHODS: Forty-one patients with clinically and laboratorily ascertained GD were treated with thyroid arterial embolization and followed up for 3-54 months following embolization. Prior to embolization and at 1, 3, 6, 12, and 36 months following embolization, thyroid autoimmune antibodies were tested respectively, including thyroid stimulating antibody (TSAb), thyrotropin antibody (TRAb), thyroglobulin antibody (TGAb), and thyroid microsomal antibody (TMAb), as well as subgroup lymphocytes of CD16+CD56+, CD19+, CD3+, CD3+CD4+ and CD3+CD8+. The autoimmune status of GD patients prior to embolization and the dynamic changes of the immunological function after embolization were analyzed. RESULTS: The therapy of thyroid arterial embolization could effectively decrease the activity/titer and positive rate of TRAb and the ratio of CD4+/ CD8+ to normal levels at 6 months following embolization, while the ratio of CD3+CD8+ increased gradually to normal level at 1 year following embolization. In patients with recurrence, TSAb and TRAb remained at a higher level, while the rate of CD3+CD8+ and the ratio of CD4+/CD8+ were not statistically significantly different from those before embolization. CONCLUSION: Immunological functional disorder exists in GD patients. The treatment method of thyroid arterial embolization can effectively resume the basic immunological function to normal range while patients with recurrence have no significant improvement, suggesting that thyroid arterial embolization has an effective role in adjusting the immunological function.