RESUMO
Purpose: Microwave ablation (MWA) represents a novel thermal ablative treatment of benign thyroid nodules. The aim was to determine the energy required per ml volume reduction in order to match the required energy to the volume-of-interest (VOI). Materials and Methods: 25 patients with 25 nodules (6 solid, 13 complex and 6 cystic) were treated by microwave ablation (MWA). The transmitted energy (E) was correlated with the volume change (∆ V) after 3 months. The energy required per ml volume reduction after 3 months was calculated by E/∆ V. Results: MWA resulted in a significant (pâ<â0.0001) volume reduction (∆ V) with a mean of 12.4â±â13.0âml (range: 1.5â-â63.2âml) and relative reduction of 52â±â16â% (range: 22â-â77â%). There was a positive correlation between E and ∆ V (râ=â0.82; pâ<â0.05). The mean E/∆ V was 1.52â±â1.08 (range: 0.4â-â4.6) kJ/ml for all nodules and 2.30â±â1.5 (0.9â-â4.6), 1.5â±â0.9 (0.4â-â3.6), 0.75â±â0.25 (0.4â-â1.2) kJ/ml, respectively, for solid, complex and cystic nodules with a significant difference in E/∆ V for solid and cystic (pâ<â0.03). Conclusion: The energy required per volume depends on the nodule consistency. Solid nodules require more energy than cystic ones. The estimation of the energy needed per volume-of-interest as an additional parameter should help to avoid under- or overtreatment. Key Points: â¢âThe estimated required energy for a volume-of-interest depends on the nodule consistencyâ¢âIn solid nodules a higher energy transmission than in cystic nodules is recommendedâ¢âThe energy transmission as an additional marker to ultrasound is helpful for improving periprocedural monitoring Citation Format: â¢âKorkusuz Y, Kohlhase K, Gröner D etâal. Microwave Ablation of Symptomatic Benign Thyroid Nodules: Energy Requirement per ml Volume Reduction. Fortschr Röntgenstr 2016; 188: 1054â-â1060.
Assuntos
Ablação por Cateter/métodos , Micro-Ondas/uso terapêutico , Nódulo da Glândula Tireoide/patologia , Nódulo da Glândula Tireoide/terapia , Relação Dose-Resposta à Radiação , Transferência de Energia , Humanos , Pessoa de Meia-Idade , Doses de Radiação , Resultado do Tratamento , Carga Tumoral/efeitos da radiaçãoRESUMO
PURPOSE: To determine the safety and efficacy of bipolar radiofrequency ablation (RFA) in benign thyroid nodules. METHODS: 23 patients with 24 symptomatic benign thyroid nodules (21 regressive, 3 adenomas) ranging in volume from 0.5 to 112âml (mean ± sd: 18â±â24.4âml) underwent bipolar RFA. Pain during the procedure was measured on a 10-point scale. Side-effects revealed by ultrasound or patients' complaints were documented. Periablative efficacy was measured 24 hours after RFA as change (Δ) in serum thyreoglobulin (Tg) and sonographic criteria (echogenity, Doppler blood flow and elasticity) categorized on a 3-point scale (echogenity, Doppler blood flow) or 4-point scale (elasticity). Efficacy in the 3 autonomous adenomas was measured as normalization of (99âm)Tc-pertechnate scintigraphy. RESULTS: Bipolar RFA was well tolerated by all patients with a median pain score of 3â±â1.5 (range: 1â-â7). Side-effects were hematomas in 4 of 23 patients (17â%). Bipolar RFA resulted in a significant (pâ<â0.01) decrease in echogenity, blood flow, elasticity (Δâ=â1â±â0.28, 1â±â0.46 and 1â±â0.85 points, respectively), a median increase in Tg of 403â±â2568âng/ml as well as in a normalization of scintigraphy. CONCLUSION: Bipolar RFA is a safe and effective treatment option for symptomatic benign thyroid nodules. KEY POINTS: â¢âBipolar RFA is a safe and effective treatment for benign thyroid nodules.â¢âUltrasound imaging allows guidance during bipolar radiofrequency ablation.â¢â(99âm)Tc-pertechnetate is able to detect the ablation area of autonomous adenomas. Citation Format: â¢âKorkusuz Y, Erbelding C, Kohlhase K etâal. Bipolar Radiofrequency Ablation of Benign Symptomatic Thyroid Nodules: Initial experience with Bipolar Radiofrequency. Fortschr Röntgenstr 2016; 188: 671â-â675.