Low Level Laser Therapy for Autoimmune Thyroiditis
Low Level Laser Therapy for Autoimmune Thyroiditis
INTRODUCTION: Chronic autoimmune thyroiditis (TCA) is the main cause of acquired
 hypothyroidism, which requires continuous treatment with levothyroxine (LT4). A randomized,
 placebo-controlled trial including 43 patients with hypothyroidism caused by TCA without
 nodules on ultrasonography study (US) was conducted from March 2006 to March 2009
 (NCT01129492). Among them, 23 were submitted to low-level laser therapy (LLLT) and 20 to
 placebo. The LLLT was effective in improving the echogenicity, the volume and of the thyroid
 vascularization pattern by US. There was also improvement in the thyroid function and
 reduction of serum thyroid peroxidase antibodies (TPOAb). Although the results have shown
 promising and LLLT has shown to be safe in many study models, the long-term LLLT actions on
 the thyroid parenchyma are unknown. Thus, the objective of this study is to perform
 biochemical tests and thyroid US six years after the clinical trial interventions to evaluate
 levothyroxine dose, serum levels of autoantibodies and, especially, the frequency and nature
 of nodules in the gland and then compare these variables between LLLT and placebo groups.
 METHODS: This study will include the trial participants performed six years before. The
 levothyroxine dose and serum levels of thyrotropin (TSH), T3, T4, free T4, TPOAb and
 anti-thyroglobulin antibodies (TgAb) will be evaluated in these patients. The thyroid US will
 assess the texture (with particular attention to identifying nodules), echogenicity, volume,
 as well as vascularization of the gland. The US nodules features, such as dimensions, shape,
 margins, extracapsular invasion, echogenicity, texture, hypoechoic halo, calcification,
 internal content, vascularization pattern and resistivity index will be searched. Regional
 lymph nodes and other characteristics will be also investigated. The USs will be carried out
 by only one examiner who will be blinded for the previously performed intervention (LILT or
 placebo). The same investigator will execute a fine needle aspiration (FNA) of patients with
 thyroid nodules. The cytological analysis of the material collected from the nodules will be
 undertaken by a pathologist who will be also blinded for the treatment assignments. RESULTS:
 The following variables will be compared between the two groups: levothyroxine doses,
 antithyroid antibodies, US parameters, thyroid nodules (if detected) and in this case, the
 result of their respective FNA.
Inclusion Criteria:

 All patients who have hypothyroidism caused by autoimmune thyroiditis included in the
 randomized, placebo controlled clinical trial (NCT01129492)

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 Exclusion Criteria:

 All patients who have hypothyroidism caused by autoimmune thyroiditis included in the
 aforementioned trial (NCT01129492) who underwent surgery and/or therapeutic administration
 of radioiodine for thyroid diseases during the period between the initial assessment of
 patients up to the present study.