Nodule size as predictive factor of efficacy of radiofrequency ablation in treating autonomously functioning thyroid nodules

CONTEXT

No defined pre-treatment factors are able to predict the response to radiofrequency ablation (RFA) of an autonomously functioning thyroid nodule (AFTN).

OBJECTIVE

Primary endpoint was to evaluate the success rate of RFA to restore euthyroidism in a cohort of adult patients with small solitary AFTN compared with medium-sized nodules. Secondary endpoints included nodule volume reduction and rate of conversion from hot nodules to cold using scintiscan.

METHODS

This was a 24-month prospective monocentric open parallel-group trial. Twenty-nine patients with AFTN were divided into two groups based on thyroid volume: 15 patients with small nodules (<12 mL) in group A and 14 patients with medium nodules (>12 mL) in group B. All patients underwent a single session of RFA and were clinically, biochemically, and morphologically evaluated at baseline and at 1, 6, 12 and 24 months after treatment.

RESULTS

After RFA, there was greater nodule volume reduction in group A compared with group B (p < 0.001 for each follow-up point). In group A, there was a greater increase in TSH levels than in group B at 6 (p = 0.01), 12 (p = 0.005), and 24 months (p < 0.001). At 24 months, the rate of responders was greater in group A than in group B (86 vs. 45%; p < 0.001). In group A, 86% of nodules converted from hot to cold compared with 18% in group B (p < 0.001).

CONCLUSIONS

A single session of RFA was effective in restoring euthyroidism in patients with small AFTNs. Nodule volume seems to be a significant predictive factor of the efficacy of RFA in treating AFTN.

Efficacy and safety of a single radiofrequency ablation of solid benign non-functioning thyroid nodules

Objective

The objective of our study is to evaluate the clinical outcomes and safety of radiofrequency thermal ablation (RFA) for benign thyroid nodules (BTNs) over a 1-year follow-up.

Subjects and methods

This is a monocentric retrospective study. Forty-eight patients with solid, non-functioning BTNs were treated by RFA using a 17G internally cooled electrode. We categorized thyroid nodules as small (≤ 12 mL), medium (12 to 30 mL), or large (over 30 mL). BTNs volume reduction, thyroid function, cosmetic and compressive score changes and side effect evaluation at 6 and 12 months were evaluated.

Results

BTN volume decreased significantly from baseline to 6 (mean percentage decrease of BTN volume was 66.8 ± 13.6%, p < 0.001). At 12 months, the mean percentage reduction of BTN volume compared to six months was 13.7 ± 17.1% (p < 0.001). At 6-month, symptom score had improved significantly (p < 0.001) while it does not change significantly between 6 and 12 months. In particular, symptom score improved significantly in the medium (p < 0.001) and large (p < 0.01) subgroups. Cosmetic score improved significantly between baseline and 6 months (p < 0.001) and between 6 and 12 months (p < 0.01). In all the subgroups, cosmetic score improved significantly between baseline and 6 months, while between 6 and 12 months it improved significantly only in the large group (p < 0.05). RFA was well tolerated. Only one patient experienced permanent right paramedian vocal cord palsy.

Conclusions

A single RFA treatment was effective in reducing BTNs volume, in particular small and medium nodules. Cosmetic score improved in all treated BTNs while symptom score only got better in the medium and large BTNs.

Prospective study of effectiveness of ultrasound-guided radiofrequency ablation versus control group in patients affected by benign thyroid nodules

CONTEXT

Ultrasound-guided radiofrequency ablation (RFA) of solid thyroid nodules (TNs) is a minimally invasive procedure that may induce a volume reduction of symptomatic solid benign TNs.

OBJECTIVE

The aim of the study was to evaluate the effectiveness and safety of RFA in debulking benign TNs.

DESIGN AND PATIENTS

Eighty-four consecutive patients with symptomatic and cytologically benign solid nodules were randomly assigned to either a single RFA session (group A; n = 42) or follow-up (group B; n = 42) at our center. Entry criteria were a solid thyroid nodule or predominantly solid (with a fluid component ≤ 30% of the volume), normal thyroid function, no autoimmunity, and no previous thyroid gland treatment. Three subgroups were formed according to the baseline volume of nodules: small (≤ 12 mL), medium (from 12 to 30 mL), or large (>30 mL).

METHODS

In group A RFA was performed in a single session with the moving-shot technique. Volume and local symptom changes were evaluated 1 and 6 months after RFA.

RESULTS

In group A, the volume decreased from 24.5.5 ± 19.6 to 8.6 ± 9.5 6 months after RFA (P = .001). The greatest volume reduction was in small nodules. The pressure symptom score improved only in medium and large nodules (P < .001), whereas the cosmetic score improved in all treated patients (P < .001). The rate of thyroid volumetric reduction was not statistically different between solid and predominantly solid nodules. Only one patient experienced permanent right paramedian vocal cord palsy with inspiratory stridor without dysphonia. In group B, nodule volume remained unchanged, whereas the symptom score was worse at the 6-month evaluation (P = .01).

CONCLUSIONS

RFA is effective in reducing thyroid nodule volume. The best reduction rate was observed in small TNs. The thyroid volumetric reduction does not change according to the sonographic features. The mean treatment duration was longer in larger TNs.

Indoor radon levels in schools of South-East Italy

A survey was conducted to evaluate average levels of indoor radon and gamma doses in all educational buildings (506 schools) located in South-East Italy (the Salento peninsula, province of Lecce). In this paper the final findings relating to measurements performed with SSNTD dosemeters in 438 schools (86% of the sample) are reported. The average annual activity concentration of radon in schools located in the province of Lecce is 209 ± 9 Bq/m(3). Radon values actually ranged from 21 Bq/m(3) to 1608 Bq/m(3). About 7% of schools showed radon concentration values above 500 Bq/m(3), the Italian action level for workplaces.

Low occupational exposure to benzene in a petrochemical plant: modulating effect of genetic polymorphisms and smoking habit on the urinary t,t-MA/SPMA ratio

The identification of reliable biomarkers is critical for the assessment of occupational exposure of benzene: S-phenylmercapturic acid (SPMA) and trans,trans-muconic acid (t,t-MA) are the most currently used. t,t-MA is an open-ring metabolite, but it is also a metabolite of the food preservative sorbic acid, while SPMA is formed by conjugation with glutathione, and several studies suggested that the genetic polymorphism of glutathione S-transferases modulates its production. This study compared the ability of these metabolites to assess the benzene exposure in a big group of petrochemical workers. Furthermore, investigated how genetic polymorphism of glutathione S-transferase theta 1 (GSTT1), glutathione S-transferase mu 1 (GSTM1), glutathione S-transferase pi 1 (GSTP1) and smoking habits, may influence their excretion. Results showed that occupational exposure to benzene was negligible compared to that from smoking and confirmed the modulating effect of the genetic polymorphism of GSTT1 on the urinary excretion of SPMA, but not of t, t-MA, even at very low levels of benzene exposure. The same effect was found for GSTM1, but only for smokers. The t,t-MA/SPMA ratio was not a constant value and resulted to be higher than the corresponding Biological Exposure Index (BEI) ratio, which is currently equal to 20. Higher values of metabolite have been associated with the GSTT1 or GSTM1 null genotype and these are responsible for increase health risk. We suggest that this ratio could be used as a marker of individual susceptibility for subjects with benzene exposure.

[Health education in the prevention of ischemic heart disease in school children: feasibility study]

A feasibility study of health education was undertaken among the pupils of a primary school in order to: 1) investigate the level of participation of children and teachers to the program; 2) test the efficacy of the program itself; 3) determine whether the children can modify family's behavioral patterns of the family components. Seventy-two children, belonging to different socio-economic classes, were studied. Children were given a questionnaire at the beginning and the end of the programme course, which was held by previously trained teachers. The participation of children and teachers to the program was very satisfactory. On the contrary very low involvement of the parents was achieved. This experience emphasizes the difficulties that arise when interventions to modify adult people's life style are attempted. On the contrary, a standardized education program, to last a whole school year, could be a feasible useful and costless type of intervention not only for the primary prevention of coronary artery disease, but for any program of extensive health care.