Feasibility of bipolar radiofrequency ablation in patients with parathyroid adenoma: a first evaluation.

AIM: The aim of this study was to first assess the feasibility of bipolar radiofrequency ablation in patients with parathyroid adenoma. MATERIAL AND METHODS: Bipolar RFA was performed in 9 patients with primary parathyroid adenoma in one single session. Measured parameters were PTH and calcium serum levels prior to and after bRFA. Furthermore, using an NRS pain scale (1-10), the individual, subjective maximum sensation of pain was documented. RESULTS: The bRFA resulted in a highly significant (p = .003906) decrease of serum PTH levels (median 67 ng/l) in comparison to those prior to the intervention (median 199 ng/l). Regarding calcium levels, there was no statistical significance (p = .460938), with a decrease of median serum levels comparing pre- and post-bRFA values from 2.82 mmol/l to 2.66 mmol/l. The evaluation of the individual pain sensation during the procedure was assessed by the patients with a median of 5/10 on the NRS scale. In none of the 9 cases complications such as infections, persisting pain or nerve injury occurred. CONCLUSION: For the first time, it was possible to depict the successful therapy of parathyroid adenoma by means of bRFA. This work thus proves bRFA to be an effective, safe, applicable and, concerning sensation of pain, very well tolerable thermoablative technique in the treatment of parathyroid adenoma.

Combination of Ultrasound-Guided Percutaneous Microwave Ablation and Radioiodine Therapy in Benign Thyroid Disease: A 3-Month Follow-Up Study.

PURPOSE: Pilot studies of combined therapies treating benign nodular goiters reported promising results. The aim of this study was to investigate the effectiveness of combined microwave ablation (MWA) and radioiodine therapy (RIT) with a special focus on thyroid function at the 3-month follow-up. MATERIALS AND METHODS: 15 patients (median age: 55 years) with a large goiter and benign thyroid nodules or Graves' disease were treated with the combined therapy. Serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobuline (Tg) and, additionally, antibody levels against thyroglobulin (TgAb), thyrotropin receptors (TRAb) and thyroid peroxidase (TPOAb) were measured at enrollment, post MWA and at the 3-month follow-up (3MFU). Furthermore, the goiter volume, I-131 dose and hospitalization time were analyzed to evaluate effectiveness. MWA was operated under local anesthesia with a system working in a wavelength field of 902 to 928 MHz. RESULTS: TSH, T4, T3 and Tg did not change at 3MFU, except for in two patients in whom the initial TSH levels improved to normal thyroid functioning levels at follow-up. One of the patients developed a high TRAb-level that receded back into the normal range. At 3MFU, the combined therapy showed a mean thyroid volume reduction of 26.4 ml ±â€Š7.9 ml (30.5 % ±â€Š4.6 % (p < 0.05)). By utilizing the combined therapy, administered activity could be reduced by 26.6 % ±â€Š4.8 % (p < 0.05) and hospitalization time by 30.9 % ±â€Š19.9 % (p < 0.05). CONCLUSION: The data confirmed the effectiveness of the combination of MWA with RIT. The combined therapy is an innovative and conservative approach and could become a safe alternative to surgery for the treatment of very large benign nodular goiters. Due to the short follow-up and the limited number of patients, further studies will be necessary. KEY POINTS: • The combined therapy shows a significant volume reduction in benign nodular goiters. • Initial MWA improves the RIT results by reducing the required therapy activity. • Thyroid function is preserved after combined therapy.

Localized Thyroid Tissue Ablation by High Intensity Focused Ultrasound: Volume Reduction, Effects on Thyroid Function and Immune Response.

PURPOSE: The aim of this study was to assess the effectiveness of high intensity focused ultrasound (HIFU) in reducing thyroid nodule volume while preserving thyroid function as measured by immunological response. MATERIALS AND METHODS: 12 patients (9 females) whose average age was 56.9 years (37 - 81) were treated with HIFU in an ambulatory setting. All patients had a single benign thyroid nodule treated in one HIFU session. The median nodular outline volume (NOV) was 3.4  ml (range 0.6 - 5.0  ml). The therapeutic ultrasound probe (Echopulse(®) THC900 888-H) used works with a frequency of 3  MHz, reaching temperatures of 80 - 90° C and a mean output between 87.6 and 192.8  W. To assess possible effects of HIFU on thyroid function, serum levels of triiodothyronine (T3), thyroxine (T4), thyrotropin (TSH), thyroglobulin (hTg) and antibodies against thyroglobulin (TAbs), thyrotropin receptors (TRAbs) and thyroid peroxidase (TPOAbs) were measured at enrollment, 24-hours post-HIFU treatment and at 3-month follow-up.Pre- post thyroglobulin reduction was measured to evaluate the success of ablation and the nodular outline volume (NOV) was evaluated at baseline and the 3-month follow-up to assess effectiveness. RESULTS: All measured hormone levels were within normal ranges and remained stable (p > 0.05). No clinically meaningful immune reaction was induced (p > 0.05). Thyroglobulin serum levels increased significantly at 24 hours after ablation (p < 0.05) and decreased significantly at the 3-month follow-up (p < 0.05), returning to pre-ablative levels. The median reduction in nodular outline volume (NOV) was 55 % (p < 0.05). CONCLUSION: HIFU is a safe and effective alternative for treating benign thyroid nodules, while preserving thyroid function. Further investigations with multiple treatments should be conducted to evaluate whether additional treatments can achieve greater volume reduction.

Diagnostic accuracy of elastography and scintigraphic imaging after thermal microwave ablation of thyroid nodules.

PURPOSE: The aim of this study is to evaluate structural alterations of thyroid tissue after microwave ablation using elastography and scintigraphic imaging to investigate the applicability of these diagnostic methods for follow-up.  MATERIALS AND METHODS: 35 patients with 39 thyroid nodules were evaluated using elastography and scintigraphic imaging before and after ultrasound-guided microwave ablation. Elastography was analyzed according to color-coded output and results were classified using a fourfold elasticity score (ES). Nodules color-coded blue were classified ES1 for high elasticity through ES2 and ES3 for lower elasticity, and nodules with very low elasticity were color-coded red and classified as ES4. (99m)Tc-pertechnetate served as a tracer for scintigraphic imaging of hot and indifferent nodules and (99m)Tc-MIBI for cold nodules. RESULTS: Before microwave ablation, elastography detected a median elasticity score of ES 2 ±â€Š0.7, and after ablation the median score was ES 3 ±â€Š0.6. Overall, the median score increased by 1ES ±â€Š0.6 (p < 0.01). Scintigraphic imaging detected a median reduction of tracer uptake in ablated tissue of 38.7 %±â€Š27.5(p < 0.01). (99m)Tc-pertechnetate scans showed a median decrease of tracer uptake of 26.3 %±â€Š16.3 and (99m)Tc-MIBI scans detected uptake reduction of 54.7 %±â€Š29.2. CONCLUSION: Scintigraphic imaging using (99m)Tc-pertechnetate and (99m)Tc-MIBI provides quantifiable results and is promising as a diagnostic follow-up after microwave ablation. Strain elastography detects decreasing tissue elasticity, but accuracy is limited by the necessary reduction of color-coded output to elasticity scores.

Percutaneous microwave ablation of benign thyroid nodules. Functional imaging in comparison to nodular volume reduction at a 3-month follow-up.

AIM: Thyroid nodules represent a common clinical issue. Amongst other minimally invasive procedures, percutaneous microwave ablation (MWA) poses a promising new approach. The goal of this retrospective study is to find out if there is a correlation between volume reduction after 3 months and 99mTc-uptake reduction of treated thyroid nodules. PATIENTS, METHODS: 14 patients with 18 nodules were treated with MWA. Pre-ablative assessment included sonographical and functional imaging of the thyroid with 99mTc-pertechnetate and 99mTc-MIBI. Additionally, patients underwent thyroid scintigraphy 24 hours after ablation in order to evaluate the impact of the treatment on a functional level and to ensure sufficient ablation of the targeted area. At a 3-month follow-up, ultrasound examination was performed to assess nodular volume reduction. RESULTS: Mean relative nodular volume reduction after three months was 55.4 ± 17.9% (p < 0.05). 99mTc-uptake 24 hours after treatment was 45.2 ± 31.9% (99mTc-MIBI) and 35.7 ± 20.3% (99mTc-pertechnetate) lower than prior to ablation (p < 0.05). Correlating reduction of volume and 99mTc-uptake, Pearson's r was 0.41 (p < 0.05) for nodules imaged with 99mTc-MIBI and -0.98 (p < 0.05) for 99mTc-pertechnetate. According to scintigraphy 99.6 ± 22.6% of the determined target area could be successfully ablated. CONCLUSIONS: MWA can be considered as an efficient, low-risk and convenient new approach to the treatment of benign thyroid nodules. Furthermore, scintigraphy seems to serve as a potential prognostic tool for the later morphological outcome, allowing rapid evaluation of the targeted area in post-ablative examination.

Combination of ultrasound guided percutaneous microwave ablation and radioiodine therapy in benign thyroid diseases. A suitable method to reduce the 131I activity and hospitalization time?

AIM: Goiters and thyroid nodules are an ongoing problem in healthcare. There has not been any treatment of goiters and thyroid nodules based on the combined therapy of microwave ablation (MWA) and radioiodine therapy (RIT) until now. In this study the potential benefit of a combined therapy versus single RIT is evaluated in order to achieve improvements concerning ¹³¹I-dose and hospitalization time. PATIENTS, MATERIAL, METHODS: Ten patients with goiter and benign thyroid nodules or Graves' disease were included. Pre-ablation assessments included sonographical imaging, functional imaging with 99mTc and FNAB to collect data of nodules and total thyroid volume and to exclude malignancy. Prior to treatment, radioiodine uptake test was performed. MWA was operated under local anesthesia with a system working in a wavelength field 902-928 MHz. Post-MWA, thyroid volume was recalculated ultrasonically. Due to reduced vital volume, changes of ¹³¹I-dose and hospitalization time could be monitored. RESULTS: Mean absolute thyroid volume reduction by MWA before applying RIT was 22 ± 11 ml, meaning a relative reduction of 24 ± 6% (p < 0.05). Thereby, administered activity could be reduced by 393 ± 188 MBq using the combined therapy, reflecting a relative reduction of 24 ± 6% (p < 0.05). Additionally, mean hospitalization time was decreased by 2.1 ± 0.8 days using MWA prior to RIT, implying a relative reduction of 28 ± 6% (p < 0.05). CONCLUSION: Depending on ablated volume by MWA, RIT-monotherapy requires on average 31.2% more ¹³¹I-activity than the combined therapy. The combined therapy remarkably decreases ¹³¹I-dose and hospitalization time. The combined MWA and RIT therapy is a considerable, effective and safer alternative to surgery for the treatment of very large benign nodular goiters.

Percutaneous thermal microwave ablation of thyroid nodules. Preparation, feasibility, efficiency.

UNLABELLED: Microwave ablation (MWA) is a new minimal invasive method for thermal ablation of benign thyroid nodules. In contrast to well-established radiofrequency ablation (RFA), MWA offers several advantages with similarly successful results. There has not been any use of functional imaging with 99mTc-pertechnetate and 99mTc-MIBI-scans as a mere qualitative analysis of this imaging in the field of MWA in Europe until now. The aim of this study has been to demonstrate the feasibility of MWA as well as the applicability of functional imaging to verify effectiveness with a centerspecific score. PATIENTS, METHODS: 11 patients (5 women, 6 men, average age 62.3 years) with 18 benign thyroid nodules were treated. MWA was operated under local anesthesia with a system working in a wavelength field of 902 to 928 MHz (Avecure MWG881, MedWaves, Inc. San Diego, CA). Pre- and postablative scans were controlled by two specialists in nuclear medicine with longtime work experience. RESULTS: A center specific functional imaging score (CSFIS) was defined, a decrease of 1.4 points at an average was noticeable (range 1-3 points). In 66.7% (n = 12) of all nodules the score decreased by 1 point, 27.8% (n = 5) by 2 points and 5.6% (n = 1) by 3 points. The treatment was well tolerated and no severe complications were observed. CONCLUSION: The preliminary data suggests that MWA is an effective method to treat benign thyroid nodules. Functional imaging is a promising technique for early verification of effectiveness of thermal ablation.

[Colour-coded duplex-sonography versus scintigraphy. Can scintigraphy be replaced by sonography for diagnosis of functional thyroid autonomy?]. / 99mTc-Szintigraphie versus Farbduplex-Sonographie. Kann zur Diagnose der funktionellen Schilddrüsenautonomie auf die Szintigraphie verzichtet werden?

UNLABELLED: Since the development of colour coded duplex-sonography (ccds), several attempts have been made to implement this technique for diagnosis of focal lesions in the thyroid. There are controversial discussions on whether ccds might replace thyroid scintigraphy in diagnosis of hyperfunctional thyroid nodules. Aim of this study was the comparison of ccds and thyroid scintigraphy in diagnosis of functional thyroid autonomy. PATIENTS, MATERIAL AND METHODS: 192 patients with thyroid nodules > 10mm detected by conventional sonography underwent thyroid scintigraphy. Additionally, these patients were subjected to ccds of the thyroid. In total, 286 thyroid nodules were examined by scintigraphy, ccds and blood tests. RESULTS: Thyroid scintigraphy showed 67% of thyroid nodules as hyperfunctional, 19% indifferent and 14% as hypofunctional. Mean 99mTc uptake of hyperfunctional nodules was 2.19%, of indifferent nodules 1.12% and of hypofunctional nodules 1.06% respectively. The ccds allowed perinodular measurement of flow speed (hyperfunctional: 0.23 ± 0.1 m/s; hypofunctional: 0.22 ± 0.1; indifferent: 0.21 ± 0.09), resistance index (hyperfunctional: 1.21 ± 1.16; hypofunctional: 0.62 ± 0.48; indifferent: 0.93 ± 1.02) and pulsatility index (hyperfunctional: 0.97 ± 0.45; hypofunctional: 0.84 ± 0.4; indifferent: 1.04 ± 0.6) in all nodules as well as intranodular measurement in some of the nodules (24% in hyperfunctional, 2% in indifferent and 15% in hypofunctional nodules). Statistic analysis of the obtained ccds data did not show any practically relevant correlations (p>0.05) with 99mTc uptake, basal TSH, fT3 or fT4. CONCLUSION: Thyroid scintigraphy cannot be replaced by ccds for diagnosis of functional thyroid autonomy. Reliable diagnostics still require a combination of thyroid scintigraphy, sonography and blood tests.

[Incorporation monitoring of employees of a radioiodine therapy ward. Is incorporation monitoring required for routine?]. / Überwachung der Mitarbeiter einer Radioiodtherapiestation mittels Ausscheidungsmessungen. Ist im Routinebetrieb eine Inkorporationsüberwachung erforderlich?

UNLABELLED: Aim of the study was to determine the annual incorporation of staff on a radioiodine therapy ward and the resulting annual effective dose (aed). Following the German incorporation guideline (gig), incorporation monitoring is not necessary for potential aed below 0.5 mSv/a. For aed > 0.5 mSv/a adherence to the 1 mSv dose limit must be verified. For doses > 1 mSv/a incorporation has to be monitored by the authority. Furthermore, the (131)I incorporation factor from the gig should be verified. METHODS: To determine the actual work related incorporation, the (131)I activity concentration in urine samples (collection over 24 h) of 14 employees of different professions were examined over a period of 27 months. RESULTS: Measured activity concentrations were related to the individual time of exposure. A constant activity supply for at least three days was assumed. The mean annual effective doses were 2.4 · 10⁻¹ mSv/a (nursing staff; n = 3), 5.6 · 10⁻² mSv/a (cleaning staff; n = 2), 2.8 · 10⁻³ mSv/a (technical staff; n = 2) and 5.2 · 10⁻³ mSv/a (physicians; n = 7). All aed were below the dose limits of the gig. The calculated mean incorporation factors ranged from 3.0 · 10⁻8 for the nursing staff to 3.6 · 10⁻¹° for the technical staff (cleaning staff: 7 · 10⁻9; physicians: 6.5 · 10⁻¹°) and were therefore well below the (131)I incorporation factor defined by the gig. CONCLUSIONS: To estimate the aed caused by incorporation of (131)I it has to be subdivided for the different requirements in the diverse fields of activity of the employees. Regarding those who spend most of their time nearby the patient an incorporation monitoring by the authority might be required. The (131)I incorporation factor from the guideline (10⁻6) can be reduced by a factor of 10. For (99m)Tc and (18)F an incorporation factor of 10⁻7 is accepted.

Diagnosing and quantification of acute alcohol intoxication--comparison of dual-energy CT with biochemical analysis: initial experience.

PURPOSE: To quantify the correlation between fat content of an acute alcohol intoxication and the difference of computer tomography attenuation value in dual-energy CT in comparison to biochemical triglyceride analysis and to evaluate qualitatively the value of DECT in the diagnosis of fatty liver caused by ethanol-dosage in rats. MATERIALS AND METHODS: DECT at 140 kV and 80 kV was performed on 20 rats before and two days after the administration of 3 ml of 50% ethanol. The CT attenuation value in the livers at 140 kV, 80 kV and the differences between them in Hounsfield units (ΔH) were collected. Parts of the liver (100 mg) were measured in biochemical triglyceride analysis as the reference standard. A blood sample was also taken to measure specific liver enzymes. RESULTS: Linear correlation between biochemical triglyceride analysis and CT density of ΔH was found (r=0.949). 140 kV attenuation data were between 44 HU and 61.3 HU, 80 kV attenuation data were between 58.4 HU and 64.7 HU, and ΔH data were between 3.4 HU and 14.4 HU (p≤0.037). The biochemical triglyceride analysis data were between 7.1 mg/g and 41.1 mg/g. The hepatic enzymes serum aspartate (ASAT) aminotransferase and alanine aminotransferase (ALAT) were elevated in all rats. ASAT correlated directly with ΔHU (r=-0.86). CONCLUSION: DECT provides a non-invasive method to determine and evaluate hepatic fat content after acute alcohol intoxication. It provides the possibility to detect and quantify the hepatic fat content of liver graft.