International Journal of Hyperthermia最新文献

Objective: Osteoarthritis of the knee is a common cause of pain, functional disability, and reduced quality of life in the elderly. Despite its prevalence, there are limited currently available noninvasive treatment options. MRI-guided focused ultrasound (MRgFUS) is a noninvasive thermal ablation method which is used in a spectrum of musculoskeletal conditions. It is FDA approved for the treatment of painful bone metastases and osteoid osteoma and has been considered for the treatment of other painful conditions such as osteoarthritis. The purpose of this case report is to describe the use of MRgFUS for the treatment of osteoarthritic knee pain in an active 72-year-old male.

Method: The patient suffered significant limitations due to lateral knee pain with jogging and walking down the stairs. MRgFUS ablation treatment was performed to the lateral knee, targeting the periosteum in the patients' area of pain.

Results: Following treatment, the patient experienced considerable reduction in his activity limiting symptoms with a duration of at least 6 months.

Conclusions: It is important for radiologists to be aware of MRgFUS as an innovative ablation modality. Similar pain reduction was observed in two small series of MRgFUS treatment of knee pain from Japan. MRgFUS appears promising as a safe, noninvasive treatment option for temporary relief of knee pain. This may be particularly valuable for patients who are unwilling or unable to undergo total knee arthroplasty. Future study is needed to assess the efficacy and safety of this treatment in a larger population.

Purpose: In magnetic resonance-guided focused ultrasound (MRgFUS) breast therapies, the focal location must be characterized to guide successful treatment. Focal characterization is difficult because heterogeneous breast tissues introduce phase aberrations that blur and shift the focus and traditional guidance methods do not work in adipose tissues. The purpose of this work is to evaluate numerical simulations of MRgFUS that predict the focal location. Those simulations are compared to clinical magnetic resonance acoustic radiation force imaging (MR-ARFI) data collected during in vivo treatment of breast tumors.

Methods: The focal location was evaluated before MRgFUS treatment with MR-ARFI in five patients. The hybrid angular spectrum method (HAS) was applied to simulate pressure fields which were converted to forces, then convolved with a 3D Green's function (with time-of-arrival weighting) to produce a simulation of the MR-ARFI tissue displacement.

Results: The focal locations found by the simulations and the MR-ARFI measurements were on average separated by 3.7 mm (SD: 0.9 mm). Characterization of the focal zone spatial distributions had a normalized root mean squared difference of 8.1% (SD: 2.5%). The displacement magnitudes of the simulations underestimated the MR-ARFI measurements by 82% (SD: 5.6%).

Conclusions: The agreement between MR-ARFI measurements and simulations demonstrates that HAS can predict the in vivo focal location in heterogeneous tissues, though accurate patient-specific properties are needed to improve predictions of tissue displacement magnitude. Tools developed in this study could be used to streamline MRgFUS treatment planning and optimization, for biomechanical property estimation, and in developing phase aberration correction techniques.

Background: Thyroid nodule rupture (TNR) is a rare and severe complication after thermal ablation (TA), mostly from benign thyroid nodules (BTN).

Objective: To summarize the incidence of TNR after TA and analyze the causes and prevention strategies.

Materials and methods: This retrospective study enrolled 3971 patients who underwent TA for BTN from January 2014 to March 2024. The incidence, causes, and risk factors of TNR were analyzed. Propensity score matching (PSM) controlled for confounding factors. Multivariate regression identified risk factors for TNR. ROC curves determined the optimal cutoff value for the maximum diameter (MD) for TNR.

Results: TNR occurred in 8 cases [0.2% (8/3971)]. The mean time from TA to TNR was 29.6 ± 13.0 days (range, 20-60 days). After PSM, MD was larger in the TNR group than in the non-TNR group [mean 4.1 ± 1.6 cm vs. mean 1.8 ± 1.2 cm; p < 0.001]. The optimal cutoff value of MD for TNR was 2.75 cm. After PSM, the incidence of pressure on the ablation zone was significantly higher in the TNR group than in the non-TNR group [100% (8/8) vs. 0 (0/32); p < 0.001], which has been suspected as a case of TNR. Antibiotic drugs, aspiration, or incision drainage could successfully manage all TNR cases.

Conclusion: TNR could be encountered in case of pressure on the BTN after TA. Protecting the ablation site from pressure might be crucial in preventing TNR, especially within two months. TNR is more likely to occur if the MD of BTN exceeds 2.75 cm under pressure. Observation, antibiotics, and aspiration could successfully manage all TNR cases.

Objective: The objective of this study was to assess the efficacy of focused ultrasound ablation surgery (FUAS) in treating patients with adenomyosis and coexisting pelvic adhesions.

Materials and methods: A total of 396 patients diagnosed with adenomyosis and who underwent FUAS between January 2014 and December 2022 were enrolled. Pelvic adhesions were evaluated using magnetic resonance imaging (MRI), and the patients were categorized into either adhesive group or non-adhesive group. The aim was to investigate the comparative efficacy between the two groups.

Results: Among the 396 patients, pelvic adhesions were detected in 123 (31.06%) women. Compared to the non-adhesive group, patients in the adhesive group exhibited a higher preoperative dysmenorrhea score (7 vs. 6, p  < 0.001), a lower short-term clinical success rate (74.80% vs. 84.62%, p = 0.025), and a higher long-term cumulative recurrence rate (log-rank p = 0.009). The adhesive group exhibited a high incidence of anal discomfort during the procedure compared to the non-adhesive group (18.70% vs. 7.69%, p = 0.002). Additionally, patients with severe adhesion demonstrated a lower ratio of non-perfused volume ratio (NPVR) (38.81% vs. 46.58%, p = 0.009). Multivariate binary logistic regression analysis revealed that pelvic adhesion independently increased the risk of dysmenorrhea (OR = 4.730, 95%CI: 2.026-11.044, p < 0.001), while severe pelvic adhesion was identified as an independent risk factor for NPVR (OR = 2.226, 95%CI: 1.181-4.196, p = 0.013).

Conclusion: The preoperative assessment of pelvic adhesions plays a crucial role in predicting intraoperative adverse events of FUAS in patients with adenomyosis, as well as determining both short-term and long-term efficacy, thereby providing valuable guidance for the development of comprehensive treatment.

Objective: The present study aimed to analyze the relationship between the incidence of complications and tumor size following thermal ablation of benign thyroid nodules (BTNs).

Methods: In this retrospective study, 1198 patients who underwent thermal ablation for unifocal BTN were enrolled. Receiver Operating Characteristic analysis was performed to select the cutoff values of the maximum diameter (MD) for dividing patients into different groups or subgroups. Multivariable logistic regression was performed to identify the risk factors. Propensity score matching (PSM) was employed to control for confounding variables.

Results: The overall complication rate was 3.8% (45/1198). Major complications included hoarseness (2.4%), nodule rupture (0.3%) and delayed hemorrhage (0.1%), whereas minor complications were limited to intraoperative hemorrhage (0.9%). The difference in the overall complication rate between the smaller group (< 3.15 cm) and the larger group (> 3.15 cm) was significant (1.0% vs. 6.5%, p < 0.001). In the subgroup analysis, a significant difference was observed between the 3.15-4.15 cm and > 4.15 cm subgroups (4.2% vs. 8.7%, p = 0.023); however, no significant difference was identified between the < 2.35 and 2.35-3.15 cm subgroups (0.6% vs. 1.6%, p = 0.390). Multivariable logistic regression indicated that MD and the nodule component were associated with complications. After PSM, no significant difference in complication rates was observed between MWA and RFA in either the smaller group (p = 1.000) or the larger group (p = 0.186).

Conclusions: The incidence of complications in thermal ablation is greater for larger thyroid nodules, particularly for predominantly solid nodules with MDs greater than 3.15 cm.