Short-Term Effects of Genicular Artery Embolization on Symptoms and Bone Marrow Abnormalities in Patients with Refractory Knee Osteoarthritis

PurposeTo evaluate the short-term outcomes of genicular artery embolization (GAE) for knee osteoarthritis (OA) with and without bone marrow lesion (BML) and/or subchondral insufficiency fracture of the knee (SIFK).Materials and MethodsThis single-institution prospective observational pilot study analyzed 24 knees in 22 patients with mild to moderate knee OA, including 8 knees without BML, 13 knees with BML, and 3 knees with both BML and SIFK. The area and volume of BMLs on magnetic resonance images were measured before and after GAE. Baseline and postoperative pain and physical function were assessed using the visual analog scale (VAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC).ResultsGAE significantly reduced the BML area and volume 3 months after embolization in the knees with BML (both P < .0005). GAE significantly decreased the VAS scores at 3 and 6 months after embolization in patients without BML (both P = .04) and those with BML (both P = .01). GAE also lowered the WOMAC scores 3 months after embolization in patients without and with BML (P = .02 and P = .0002, respectively). However, GAE did not significantly alter the BML area and volume (both P = .25), VAS scores (P = 1.00), and WOMAC scores (P = .08) in patients with BML and SIFK at 3 months after GAE.ConclusionsThis observational pilot study suggested that GAE effectively reduces the BML area and volume and improves pain and physical function in patients with knee OA accompanied by BML but is inefficacious in those with both BML and SIFK.     

Multicenter Randomized Sham Controlled Study of Genicular Artery Embolization for Knee Pain Secondary to Osteoarthritis

PurposeTo assess the safety and efficacy of genicular artery embolization (GAE) compared with a sham procedure in the treatment of knee pain secondary to mild to moderate osteoarthritis (OA).Materials and MethodsA multicenter, single-blinded, randomized controlled trial was conducted to evaluate knee OA symptom reduction after GAE versus sham procedure. Subjects (n = 21) with mild to moderate OA and intractable knee pain were randomized 2:1 to either GAE or a sham procedure. Subjects who were randomized to the sham procedure and did not report clinical improvement in both the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and visual analog scale (VAS) scores were unblinded and able to crossover to treatment at 1 month. Longitudinal data were collected for 12 months, and subjects were excluded if they required additional analgesics at follow-up. Reductions in the VAS and total WOMAC scores were compared using mixed-effects linear regression models.ResultsAll subjects in the sham group failed to show significant improvements at 1 month and crossed over to the treatment arm. There was a statistically significantly greater pain reduction in the treatment group than in the sham group at 1 month (VAS, 50.1 mm; standard error [SE], 10.6; 95% confidence interval [CI], 29.0, 72.3; P<.01). Disability improvement was also significantly greater in the treatment group (WOMAC, 24.7 points; SE, 10.4; 95% CI, 3.5, 45.9; P=.02). Only minor adverse events were reported. Five subjects were excluded after increased analgesic use. Sensitivity analysis with all excluded patients confirmed significant improvements at 1 and 12 months.ConclusionIn patients with mild to moderate knee OA, GAE results in symptomatic improvement greater than the sham procedure with clinically significant reduction in pain and disability.     

Genicular Artery Embolization for the Treatment of Knee Pain Secondary to Osteoarthritis

PurposeTo evaluate the efficacy and safety of embolization of hyperemic synovial tissue for the treatment of knee pain secondary to osteoarthritis (OA).Materials and MethodsTwenty patients with radiographic knee OA and moderate-to-severe pain refractory to conservative therapy were enrolled in a prospective, 2-site pilot study. Genicular artery embolization (GAE) was performed with 75- or 100-μm spherical particles. Patients were assessed with magnetic resonance imaging at baseline and at 1 month and with the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at baseline and at 1, 3, and 6 months. Adverse events were recorded at all timepoints.ResultsEmbolization of at least 1 genicular artery was achieved in 20/20 (100%) patients. Mean VAS improved from 76 mm ± 14 at baseline to 29 mm ± 27 at 6-month follow-up (P < .01). Mean WOMAC score improved from 61 ± 12 at baseline to 29 ± 27 at 6-month follow-up (P < .01). Self-limiting skin discoloration occurred in 13/20 (65%) patients. Two of 20 (10%) patients developed plantar sensory paresthesia that resolved within 14 days.ConclusionsGAE to treat knee pain secondary to OA can be performed safely and demonstrates potential efficacy. Further randomized comparative studies are needed to determine true treatment effect versus placebo effect.     

Repeat Prostatic Artery Embolization

This is a single-center retrospective analysis of 3 patients (mean age, 61 y ± 8.6) who underwent repeat prostatic artery (PA) embolization (PAE; rPAE) because of clinical failure after PAE. Revascularization of the central gland through a recanalized PA was the most frequent pattern observed (5 of 7; 71.4%), followed by revascularization through penile collateral vessels (2 of 7; 28.6%). Technical success during rPAE was achieved in 5 hemiprostates (83.3%). Clinical success at 6 months after rPAE was achieved in 2 of 3 patients (66.6%). Implications of these findings could be valuable to those performing PAE.     

Outcomes of Hemorrhoidal Artery Embolization from a Multidisciplinary Outpatient Interventional Center

PurposeTo evaluate the safety and efficacy of outpatient transarterial embolization for symptomatic refractory internal hemorrhoids.Materials and MethodsRetrospective analysis of 134 patients who underwent hemorrhoidal artery embolization (HAE) for symptomatic internal hemorrhoids between August 2021 and June 2022 (76 men and 58 women) was performed. The mean age was 54.9 years, with a mean Goligher hemorrhoid grade (HG) of 2.1. Branches of the superior rectal artery (SRA) or middle rectal artery supplying the corpus cavernosum recti were embolized with both spherical particles and microcoils. Standard-of-care evaluations were performed at baseline and the 1 month follow-up, which included hemorrhoid-related pain (HRP) (0–10), hemorrhoid symptoms score (HSS) (5–20), quality of life (QoL) (0–4), French bleeding score (FBS) (0–9), and HG (0–4). Clinical success was defined as improvement of symptoms without additional treatment.ResultsEmbolization of at least 1 hemorrhoidal artery was achieved in 133 (99%) of the 134 patients. The mean number of SRA branches embolized per patient was 2.9 ± 1.0. Clinical success was seen in 93% (124 of 134) of patients at the 1-month follow-up, with 10 patients requiring repeat embolization. There were significant improvements in all mean outcomes at 1 month: HSS (11–7.8; P < .01), HRP (4.1–1.3; P < .01), QoL (2.2–0.8; P < .01), FBS (4.4–2.2; P < .01), and HG (2.3–1.2; P < .05). There were no severe adverse events.ConclusionsHAE is a safe and effective outpatient treatment for refractory symptomatic internal hemorrhoids in the short term.     

Association between Baseline Osteoarthritic Features on MR Imaging and Clinical Outcome after Genicular Artery Embolization for Knee Osteoarthritis

PurposeTo explore the association between baseline osteoarthritis (OA)-related magnetic resonance (MR) imaging features and pain reduction after genicular artery embolization (GAE) in patients with mild-to-moderate symptomatic knee OA resistant to conservative therapy.Materials and MethodsThis was a retrospective analysis of patients with mild-to-moderate symptomatic knee OA treated with GAE using imipenem-cilastatin sodium. The clinical outcome was scored at baseline and 6 months after treatment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MR images were scored using the MR imaging osteoarthritis knee score. Linear regression was used to evaluate associations of before-treatment MR imaging scores with WOMAC_pain and WOMAC_total reduction after 6 months.ResultsFifty-four patients (22.2% male; median age, 69.4 years; median WOMAC_pain at baseline, 12) were evaluated. Of all OA features scored, a higher cartilage full-thickness defect score showed the strongest association with less reduction of both WOMAC_pain (B,?0.63 [95% confidence interval (CI), ?0.91 to ?0.34]; P < .001) and WOMAC_total scores (B, ?1.77 [95% CI, ?2.87 to ?0.67]; P < .001) following treatment. The presence of grade 2–3 effusion synovitis (B, ?2.99 [95% CI, ?5.39 to ?0.60]) bone marrow lesions (B, ?0.52 [95% CI, ?0.86 to ?0.19]), osteophytes (B, ?0.21 [95% CI, ?0.36 to ?0.06]), and cartilage defect surface area score (B, ?0.25 [95% CI ?0.42 to ?0.08]) all showed a significant association with less WOMAC_pain reduction (all P < .05).ConclusionsIn patients with mild-to-moderate symptomatic knee OA treated with GAE, the presence and severity of full-thickness cartilage defects, effusion synovitis, bone marrow lesions, osteophytes, and cartilage surface area scores at baseline are associated with less favorable clinical outcomes at 6 months.     

Prostatic Artery Embolization for Benign Prostatic Hyperplasia: Bleomycin-Eluting versus Bland Microspheres in a Canine Model

PurposeTo prospectively assess safety and efficacy of prostatic artery embolization (PAE) with bleomycin-eluting microspheres for benign prostatic hyperplasia (BPH) in a canine model.Materials and MethodsTwelve adult male beagles (mean age, 1.6 y ± 0.2; range, 1.2–2.0 y) were randomly assigned to group A (n = 6; PAE with bleomycin-eluting 30–60-μm HepaSphere microspheres) and group B (n = 6; PAE with bland 30–60-μm HepaSphere microspheres) between April 2017 and November 2018. Plasma bleomycin concentration in group A was measured within 7 days. Prostate volume (PV) and ischemic volume after PAE were measured by magnetic resonance imaging. Prostates and adjacent organs were harvested after the last magnetic resonance study and histopathologically examined.ResultsPlasma bleomycin concentration peaked at 10 minutes at 2,055.0 ng/mL ± 606.1 and lasted for 1,440 min at low levels after PAE. PV reduction percentage was greater in group A than in group B at 1 month (74.1% ± 4.3 vs 63.7% ± 3.5; P = .006) and 3 months (61.5% ± 6.7 vs 46.1% ± 3.8; P = .001) after PAE. Proportion of prostate ischemic volume was greater in group A than in group B (75.3% ± 3.0 vs 62.0% ± 7.1; P = .006) at 1 month after PAE. Proportion of prostate ischemic volume at 1 month positively correlated with PV percentage reduction at 3 months in group A (r = 0.840, P = .036) and group B (r = 0.844, P = .035). There were no complications or nontarget embolization to surrounding organs after the procedures.ConclusionsIn a canine model, PAE with bleomycin-eluting microspheres was feasible and well tolerated and caused ischemic necrosis and reduction in PV.     

Angiographic Revascularization after Bariatric Embolization in a Swine Model

This study evaluated fundal arteriole angiographic revascularization after embolization with embolic microspheres of 3 different diameters in a swine model (16 swine, 31 arterioles). In the 50-μm group, 7 of 11 (64%) arterioles recanalized completely, 3 of 11 (27%) arterioles recanalized partially, and 1 of 11 (9%) arterioles had collateralization (no recanalization). In the 100- to 300-μm group, 7 of 10 (70%) arterioles recanalized completely and 3 of 10 (30%) arterioles) recanalized partially. In the 300- to 500-μm group, 7 of 10 (70%) arterioles recanalized completely, 1 of 10 (10%) arterioles recanalized partially, and 2 of 10 (20%) arterioles had collateralization. No difference was found between the groups in the degree of recanalization (P = .64). All embolized arterioles exhibited some degree of angiographic revascularization, irrespective of the microsphere size.     

Angiographic Findings during Repeat Prostatic Artery Embolization

PurposeTo describe mechanisms of prostate revascularization based on imaging findings during repeat prostatic artery embolization (PAE; rPAE).Materials and MethodsThis is a retrospective analysis of 10 rPAEs performed between October 2012 and September 2018 in patients with recurrent lower urinary tract symptoms (LUTS) after PAE (mean age, 68.2 y ± 4.5). Two interventional radiologists reviewed PAE and rPAE images and defined 6 patterns of revascularization. Correlation between embolization of the posterolateral (PL) prostatic branch during previous PAE and prostate revascularization on rPAE was assessed by Fisher exact test. One hemiprostate was excluded because no detectable revascularization was observed.ResultsAll patients showed LUTS improvement after previous PAEs (P < .01 for 5 outcome measures) and had recurrence during follow-up. rPAEs were performed a mean of 40.9 months after previous PAEs (18–96 mo). Of 19 hemiprostates analyzed, 11 presented revascularization by 2 or more branches (57.9%). The PL branch (29.0%) and the recanalized main prostatic artery (25.8%) were the most frequent revascularizing branches observed, followed by distal branches of obturator (12.9%), internal pudendal (12.9%), superior vesical (12.9%), and contralateral arteries (6.5%). Embolization of the PL branch during previous PAE significantly reduced the incidence of revascularization by this branch (P = .002).ConclusionsMechanisms of revascularization in rPAE are diverse and complex. Revascularization by the PL branch and recanalization of the previously embolized prostatic artery were the most frequent patterns observed. Embolization of the PL branch may reduce the incidence of prostate revascularization and LUTS recurrence after PAE.     

Genicular Artery Embolization to Improve Pain and Function in Early-Stage Knee Osteoarthritis—24-Month Pilot Study Results

Ten patients with painful early-stage knee osteoarthritis underwent transcatheter arterial embolization of neoangiogenic branches from genicular arteries. At 12 months, 6 patients had responded to treatment according to study criteria. Median pain, function, and quality-of-life scores had improved by 15.4%, 21.3%, and 100%, respectively, for the 10 patients. Median 30-second chair stand test and 6-minute walk test scores had improved by 43% and 26%, respectively. No major adverse events occurred. Improvements following transcatheter arterial embolization provide evidence that embolization might be an effective treatment technique for people with early-stage knee osteoarthritis, although more rigorous evaluation is required.     

Nontarget Radiopaque Embolic Deposition during Prostatic Artery Embolization

This study evaluated detectable nontarget embolization (NTE) during prostatic artery embolization (PAE) and the safety and efficacy of using radiopaque particles in PAE. Ten patients aged >40 years with prostate glands of >50 mL and refractory lower urinary tract symptoms were analyzed. Unenhanced computed tomography scans at baseline and at 3 months after PAE, using 40–90-μm radiopaque spherical embolic beads, were compared to assess the NTE. Growth models evaluated changes from baseline to 3, 6, and 12 months in International Prostate Symptom Score (IPSS), peak urine flow rate (Qmax), quality of life (QoL), International Index of Erectile Function (IIEF), and postvoid residual (PVR). The IPSS, QoL, and Qmax improved at all time points (P < .05), with no trend in PVR or IIEF. Adverse events that occurred were minor. Radiographic NTE was seen in all patients, correlating at times with postprocedural symptoms (eg, rectal pain). Symptoms were not correlated with the NTE in some patients, whereas other patients remained asymptomatic despite NTE.     

Feasibility of Transtibial Access for Uterine Artery Embolization

Ten women with a mean body mass index of 31.5 kg/m² and symptomatic uterine pathology underwent uterine artery embolization (UAE) via transtibial access (TTA). Nine out of 10 UAEs were successfully performed via TTA, with 2 minor adverse events. Outpatients with leiomyomas had stable to improved symptoms at follow-up; hospitalized patients with abnormal uterine bleeding from malignant tumors or arteriovenous malformations were discharged shortly after UAE with the cessation of hemorrhage. TTA is a feasible alternative for UAE for patients with obesity, diminutive radial arteries, or atherosclerosis that may confer an added risk of rare neurologic adverse events from transradial access.     

Bronchial Artery Aneurysm: Prevalence,Clinical Characteristics,and Long-Term Prognosis Following Bronchial Artery Embolization

PurposeTo investigate the prevalence, clinical characteristics, and long-term prognosis of bronchial artery aneurysm (BAA) following bronchial artery embolization (BAE).Materials and MethodsThe medical records of consecutive patients who underwent bronchial artery angiography between August 2013 and December 2019 were retrospectively reviewed. Patients who were diagnosed with BAA during this period were included in this study. The prevalence, patients’ characteristics, symptoms, comorbidities, angiographic findings, and long-term prognosis following BAE were investigated.ResultsBAA was observed in 20 of 508 patients who underwent bronchial artery angiography (3.9%). The patients’ median age was 69 (interquartile range [IQR], 63.5–76.7) years. The main causes of BAA were cryptogenic, bronchiectasis or cystic fibrosis, and pulmonary aspergillosis. The median diameter of ruptured BAAs was significantly smaller than that of unruptured BAAs (5.4 mm [IQR, 4.8–7.3 mm] vs 9.0 mm [IQR, 7.2–13.9 mm], P = .009). All the patients were successfully treated with BAE, without major adverse events. The median follow-up period after BAE was 970 (IQR, 561–1,796) days. The BAA-related survival rate was 100% at 2 and 3 years after BAE, and the overall survival rate after BAE was 89.2% (95% confidence interval [CI] 89.0–89.3) at 2 years and 74.3% (95% CI 74.0–74.5) at 3 years. BAA-related adverse events and mortality did not occur during the follow-up period.ConclusionsBAA was observed in 3.9 % (20/508) of the patients who underwent bronchial artery angiography. All the patients with BAA were successfully treated with BAE. BAA rupture and consequent mortality did not occur during the follow-up period.     

Angiographic Findings Relevant to Prostatic Artery Embolization in Patients with Prostate Cancer

The 2014–2018 angiograms of 58 patients with prostate cancer were retrospectively analyzed to illustrate angiographic findings during prostatic artery embolization. Arteriovenous fistulae were observed in 6 patients (6/58, 10.3%), with no difference between patients with or without prior iodine-125 seeds implantation (5/48, 10.4% vs 1/10, 10.0%; P > .05); tumor staining was not detected. The origins of the prostatic arteries included the internal pudendal artery (n = 45, 32.4%), the superior vesical artery (n = 38, 27.3%), the obturator artery (n = 28, 20.1%), the gluteal-pudendal trunk (n = 21, 15.1%), the inferior gluteal artery (n = 3, 2.2%), the accessory pudendal artery (n = 3, 2.2%), and the superior gluteal artery (n = 1, 0.7%).     

Timing of Uterine Artery Embolization for Leiomyoma during the Menstrual Cycle

PurposeTo investigate differences in outcomes of uterine artery embolization (UAE) for leiomyoma when performed during different phases of the menstrual cycle.Materials and MethodsIn this single-institution retrospective analysis, 111 premenopausal patients (median [range] age, 44 [33–52] years) undergoing UAE for symptomatic leiomyoma between June 2014 and February 2020 were included. Twenty-one patients underwent UAE in the menstrual phase (the early follicular phase), 27 in the late follicular phase, and 63 in the luteal phase. Baseline characteristics and technical and peri-procedural outcomes were compared among groups. Leiomyoma infarction on contrast-enhanced magnetic resonance imaging 1 week after UAE and 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire scores, the volume reduction rates of the uterus and largest leiomyoma, follicle stimulating hormone values, adverse events, and amenorrhea, were compared among groups.ResultsA 4-month follow-up was completed for all patients. No significant differences were observed among groups in baseline characteristics or technical and peri-procedural outcomes. There were no significant differences in the multivariate-adjusted 1-week infarction rates of all leiomyoma volumes (P = .161) or multivariate-adjusted 4-month outcomes, including changes in the Uterine Fibroid Symptom and Quality of Life questionnaire symptoms and total scores (P = .864 and P = .798, respectively), the volume reduction rates of the uterus and the largest leiomyoma (P = .865 and P = .965, respectively), and follicle stimulating hormone values (P = .186) among the groups. No significant differences were noted in the 4-month adverse events (P = .260) or amenorrhea (P = .793) among the groups.ConclusionsThe present study demonstrated no significant differences in the outcomes of UAE for leiomyoma when performed during different phases of the menstrual cycle.     

Role of Ultrasound Elastography in Patient Selection for Prostatic Artery Embolization

PurposeTo determine the effects of prostatic artery embolization (PAE) on prostate elasticity as assessed using ultrasound elastography (US-E) and to describe baseline US-E's potential role in patient selection.Materials and MethodsThis was a prospective investigation that included 20 patients undergoing PAE to treat lower urinary tract symptoms attributed to benign prostatic hyperplasia (BPH). US-E with measurement of the prostatic elastic modulus (EM) and shear wave velocity (SWV) was performed before PAE and at 1-month follow-up. Baseline, 3-month, and 1-year follow-up evaluations included prostate-specific antigen, uroflowmetry, pelvic magnetic resonance imaging, and clinical assessment using the International Prostate Symptom Score (IPSS) and quality of life (QoL) metrics.ResultsSeventeen patients entered statistical analysis. US-E showed a significant reduction in mean prostatic EM (34.4 kPa vs 46.3 kPa, −24.7%, P < .0001) and SWV (3.55 m/s vs 4.46 m/s, −20.0%, P < .0001) after PAE. There were moderate positive correlations between baseline EM and 1-year IPSS (R = 0.62, P = .007) and between baseline SWV and 1-year IPSS (R = 0.68, P = .002). Baseline SWV ≥ 5.59 m/s and baseline EM ≥ 50.14 kPa were associated with suboptimal IPSS and QoL outcomes after PAE with high degrees of sensitivity (100%) and specificity (69-100%).ConclusionsPAE led to a positive effect on the BPH dynamic component related to prostatic elasticity. There was a moderate positive correlation between baseline prostatic elastographic parameters and 12-month IPSS. Measurement of baseline elastographic characteristics may become useful for the evaluation and selection of patients for PAE.     

Effect of Median Lobe Enlargement on Early Prostatic Artery Embolization Outcomes

PurposeTo evaluate outcomes after prostatic artery embolization (PAE) in patients with severe intravesical prostatic protrusion (IPP).Materials and MethodsThis was a retrospective, single health system, 2-hospital study from April 2015 to December 2018 of 54 patients who underwent elective PAE procedures (age mean 67.5 years; standard deviation [SD] 8.5). The cohort had a mean ellipsoid prostate volume of 100.1 cm³ (SD 56.7), a mean baseline International Prostate Symptom Score (IPSS) of 18.7 (SD 8.2), a mean baseline quality of life (QOL) score of 4.1 (SD 1.4), and a median follow-up of 38 days (range 10–656 days). Outcomes including IPSS and QOL score reduction (where a lower QOL score indicates an improvement in QOL), and clinical success were compared between severe (≥10 mm) and nonsevere (<10 mm) IPP patients. A linear regression model was used to examine the impact of IPP on these outcomes.ResultsNo significant differences in patient characteristics were found between nonsevere (n = 17) and severe (n = 37) IPP patients. Both cohorts showed IPSS reduction (nonsevere 6.0, P = .0397; severe 8.2, P < .0001) and QOL score reduction (nonsevere 1.0, P = .102; severe 2.0, P < .0001). No significant differences in IPSS or QOL score reduction were found between the cohorts (P = .431 and P = .127). Linear regression found that baseline IPP was not a significant contributor to the outcomes (IPSS: R² = .5, P < .0001; IPP: P = .702; QOL: R² = .5, P = .0003; IPP: P = .108).ConclusionsThere were no significant differences in early outcomes in PAE between patients with severe and nonsevere IPP.     

Thyroid Embolization for Nonsurgical Treatment of Nodular Goiter: A Single-Center Experience in 56 Consecutive Patients

PurposeTo investigate the safety and efficacy of thyroid artery embolization (TAE) in the treatment of nodular goiter (NG).MethodsDuring a 5.5-year period, 56 consecutive patients with a NG underwent TAE. In Group A, there were 20 patients with a solitary/dominant 5–11-cm nodule, and in Group B, there were 36 patients with numerous nodules. Of the 56 patients, 47 (84%) had a retrosternal goiter and 25 had hyperthyroidism. In all patients, clinical and radiological evaluations were made at baseline and 6 months after TAE, and these parameters were statistically compared.ResultsIn 56 patients, 145 of the 146 thyroid arteries were successfully embolized. The 30-day mortality rate was 1.8%. Minor and major complications occurred in 25 and 2 patients, respectively. Six months after the TAE, the mean nodule volume was reduced from 80.2 mL to 25.0 mL, the mean thyroid volume was reduced from 147.0 mL to 62.6 mL, and the mean intrathoracic extension was reduced from 31.7 mm to 15.9 mm (P < .001). Of the 22 patients with non–Graves hyperthyroidism, 19 (86%) became euthyroid. The mean thyroid-related patient-reported outcome scores improved from 155.4 to 70.4 (P < .001). Of the 51 patients, 50 (98%) declared that they would recommend TAE to other patients with NG.ConclusionsTAE is safe and effective for the treatment of NG, with a significant volume reduction of the nodule(s) and thyroid gland.