Interstitial Laser Photocoagulation Research Articles

Creation of indications for interstitial laser photocoagulation of thyroid nodules

Relevance. Minimally invasive interventions under ultrasound control are a promising method for treating thyroid nodules with proven clinical effects. Indications for the use of minimally invasive methods are constantly changing and being supplemented. It is of practical interest to expand the indications for interstitial laser photocoagulation of thyroid nodes as experience accumulates. The purpose of the study: to study the changes in indications for performing interstitial laser photocoagulation of thyroid nodes over 15 years.Materials and methods. Based on the experience of treating 876 patients with colloidal goiter using interstitial laser photocoagulation, the dynamics of indications for this technique were studied. The treatment data were analyzed in two-time groups: group 1 — the initial stage of the introduction of the technique, and group 2 — the stage of widespread use of the technique. With the accumulation of experience, the adjustment of photocoagulation and ultrasound modes was carried out. The control of the treatment was evaluated in dynamics by reducing the volume of nodes.Results and conclusions. During the study, it was found that in both groups of patients, it was possible to achieve regression and decrease in the size of the nodes, depending on the pathology and size of the nodes. This made it possible to expand the indications at the expense of patients with large nodes (more than 30 mm in diameter). With recurrent nodular goiter, good results were also obtained. It has been established that interstitial laser photocoagulation is a safe, predictable method of treatment with the possibility of selecting individual regimens, well tolerated by patients. Indications for the use of the method are wide and are set individually based on the predicted risk/effectiveness ratio. The method does not negatively affect the quality of life of patients. When selecting patients, the opinion of both the doctor and patient should be taken into account.

Management of Osteoid Osteoma Using Radiofrequency Ablation

Background: Osteoid osteomas (OO) are the third most common benign bone tumors affecting mostly children and adolescents with more tendency toward males. There are different treatment options consisting of medical therapy . Of note percutaneous thermal ablation (PTA) procedures that refer to radio frequency ablation (RFA) and interstitial laser photocoagulation (ILP) have also been recently applied with high success rates. Objectives: We aimed to assess the safety and outcomes of RFL and ILP in patients with OO as well as compare the efficacy of these two procedures. Patients and Methods: Medical records of 60 OO patients were retrospectively reviewed. Patients were divided into two groups, of which 40 underwent RFA procedures and 20 went through ILP. All patients were followed up clinically either through telephone interview or outpatient clinic visit and imaging was conducted in case signs and symptoms recurred. Results: In patients who underwent RFA, pain was relieved within 1 - 7 days in 35, and 1 - 3 months in five patients. Primary and secondary clinical effectiveness were 90.00% and 92.50%, respectively. In ILP, the technical success rate was 100% and the initial clinical success rate was 85.00%. Conclusion: Similar to previous published studies, this study showed high success rates for both RFA and ILA. Total pain relief occurred in 96.6% of the patients.

Laser photocoagulation therapy for thyroid nodules: long-term outcome and predictors of efficacy.

The aim of the present study was to retrospectively evaluate the efficacy of interstitial laser photocoagulation (ILP) ablation of thyroid nodules during a 6-year follow-up period and to identify possible predictors of the final outcome. Forty-three outpatients (38 women) were assigned to ILP therapy. The study group included euthyroid patients with benign thyroid nodules. Thyroid size, nodule volume and features, and autoimmune test were collected at baseline. Patients underwent US control after the ILP procedure and 1month, 6months, 12months later and then annually. During the follow-up, two distinct groups of patients emerged: the responders (N = 33) and the non-responder (N = 10) ones to ILP. In the responder group, the nodule volume significantly decreased during the follow-up, but a trend toward a slight increase in nodule volume was recorded up to the end of follow-up. No significant decrease in nodule volume was observed in the non-responder group. Neither baseline clinical nor demographic features were significantly different between responders and non-responders groups. In the whole group of patients, the energy delivered per mL of nodule tissue was significantly correlated with the percent volume decrease at the end of follow-up. Interstitial laser photocoagulation is a safe technique able to reduce byabout 50% the volume of benign thyroid nodules in the majority of treated patients. However, due to the great variability of results, an active follow-up is required. The only independent predictor of ILP outcome is the energy delivered per mL of nodule tissue.

Interstitial Laser Photocoagulation Using 980 nm Diode Laser in Benign Thyroid Nodule: A Feasibility Study

The aim of this study was to investigate the feasibility of using 980 nm diode laser for interstitial laser photocoagulation (ILP) before clinical application in benign thyroid nodule treatment. The bovine livers were cut into blocks to irradiate with 980 nm laser through the lumen of a 20-gauge spinal needle using a fiber optic guide. Laser irradiation was performed with the output power of 2 W and 3 W for 60, 120 and 180 seconds respectively. The liver blocks containing lesions were dissected along the axis of the fiber optic tracts and then cut transversely into slices. The thermal effect was evaluated by measuring the dimensions of the zone of coagulation necrosis. We present a case treated with 980 nm diode laser for the benign large thyroid nodule. All the irradiated areas zone measured in the gross specimens were 5.5 mm ± 1.4 mm (2 W, 60 s), 6.9 mm ± 1.4 mm (2 W, 120 s), 7.3 mm ± 0.5 mm (2 W, 180 s), 8.8 mm ± 2.2 mm (3 W, 60 s), 9.2 mm ± 0.8 mm (3 W, 120 s), 12.5 mm ± 4.1 mm (3 W, 180 s) respectively. The transverse diameter was as 5.1 mm ± 0.5 mm (2 W, 60 s), 6.1 mm ± 0.2 mm (2 W, 120 s), 9.9 mm ± 2.5 mm (2 W, 180 s), 6.2 mm ± 1.8 mm (3 W, 60 s), 7.7 mm ± 1.2 mm (3 W, 120 s), 8.8 mm ± 0.7 mm (3 W, 180 s) respectively. ILP was well tolerated and there was no complication. Interstitial laser photocoagulation with 980 nm diode laser induces well-defined tissue ablation correlated with energy parameters in bovine liver tissue and therefore, could be an efficient therapeutic tool in benign thyroid nodular disease.

Diagnosis modified parathyroid the treatment of primary hyperparathyroidism interstitial laser photocoagulation

Interstitial laser photocoagulation is an advanced minimally invasive treatment for primary hyperparathyroidism. The basis of its use is accurate topical diagnosis changed parathyroid glands (OSCHZH). Proposed fine-needle aspiration biopsy OSCHZH modified with a certain level of parathyroid hormone (PTH) in the wash of the needle (FNAB / PTH). The method is reliable, informative and safe. It is shown that TAPB / PTH allows an accurate verification of modified OSCHZH thereby ensure that minimally invasive treatment of primary hyperparathyroidism without traditional surgery.

Interstitial Laser Photocoagulation (ILP) of Benign Cystic Thyroid Nodules—A Prospective Randomized Trial

Recurrence rate, after aspiration, in cystic thyroid nodules is very high. Interstitial laser photocoagulation (ILP) is a minimally invasive procedure that reduces the need for surgery in patients with a benign solid thyroid nodule. The aim of the study was to evaluate the efficacy of ILP on remission rates in recurrent, predominantly cystic thyroid nodules. Forty-four consecutive outpatients with a symptomatic, recurrent, and cytologically benign cystic (cyst volume ≥ 2 mL) thyroid nodule were randomized to a single aspiration with (n = 22) or without (n = 22) subsequent ILP and followed up after 1, 3, and 6 months. Successful outcome (cyst volume ≤ 1 mL) was obtained in 15 of 22 (68%) patients in the ILP group, compared to 4 of 22 (18%) in the aspiration group (P = .002). In the ILP group, the solid part of the nodule was reduced from a median of 1.8 to 1.0 mL (P = .02). In the aspiration-alone group, neither the cyst volume nor the solid nodule volume was significantly reduced. The reduction in median visual analog score (0-10 cm) for pressure symptoms was significantly higher in the ILP group (from 3.0 to 0.0 cm) than in the aspiration-alone group (from 4.0 to 3.5 cm) (P = .006, between groups). No major side effects occurred, and thyroid function was unaffected throughout. US-guided aspiration and subsequent ILP of benign recurrent predominantly cystic thyroid nodules is safe. It significantly reduces recurrence rate, the volume of the solid nodule component, and pressure symptoms. ILP constitutes an important alternative to surgery in such patients.

Interstitial laser photocoagulation for the treatment of osteoid osteoma: Retrospective study on 35 cases

The aim of our retrospective study was to evaluate the efficacy of interstitial laser photocoagulation for the treatment of osteoid osteomas and to identify the factors leading to failure of the procedure. Thirty-five patients received interstitial laser photocoagulation treatment. A minimum of 3 months follow-up was required. The laser fibre was positioned within the nidus under CT guidance, and energy between 500 and 1800 J was delivered at a power of 2 Watts/s. Follow-up was by outpatient appointment and through a questionnaire sent to the patients. Thirty patients replied to the questionnaire. Mean follow-up was 40 months. The technical success rate was 100%. The primary success rate (no pain at 1 month) was 94.3%. The rate of recurrence was 6%. The rate of complications was 11.4% (a skin burn, patellar enthesopathy, a broken item of material, sacro-iliac fibrous alterations). Factors likely to favour failure of the procedure are the size of the nidus (P=0.04) and poor positioning of the laser fibre (P=0.03). Interstitial laser photocoagulation is an effective and safe treatment for osteoid osteomas.

OP06.07: Preliminary experience with microwave ablation for selective feticide in monochorionic twin pregnancies

Microwave ablation (MWA) is an alternative technique to radiofrequency ablation (RFA) and interstitial laser photocoagulation (ILP) in the treatment of some solid tumours. MWA offers the same benefits as RFA and ILP, but is less dependent on tissue properties (areas of high perfusion, tissues with poor electrical and thermal conductivity) and has the ability to heat faster in a larger volume. As opposed to RFA and ILP, we are not aware of previous experiences with MWA in fetal procedures, and we report here our preliminary experience. Review of two cases of monochorionic twins discordant for fetal abnormalities undergoing selective feticide by MWA below 18 weeks of gestation between November 2011 and March 2012. MW was performed using a 2.45-MHz generator (AMICA-GEN, HS Hospital Service, Aprilia, Italy) delivering energy through a 16-gauge internally cooled coaxial antenna. All the procedures were performed percutaneously under ultrasonographic guidance. The antenna was centred in the abdomen of the abnormal fetus close to the insertion of the umbilical cord. A single microwave energy application was delivered at 50 W net power at the applicator end, for 3 min. In case 1, one of the twins had a complex cardiac abnormality with hydrops; cervical length was 22 mm; MWA was performed at 17 + 3 weeks. There was PROM of the terminated twin 4 days later, and the entire pregnancy was lost after 7 days. In case 2, one of the twins had anencephaly; cervical length was 40 mm; MWA was performed at 16 + 2 weeks. The pregnancy carried on uneventfully, and a healthy infant was delivered at term. In both cases MWA was technically easy, and ultrasound evidence of tissue coagulation was seen immediately after the beginning of energy delivery. Our preliminary experience shows that MWA is easily applicable to intrafetal procedures. MWA has potential advantages over RFA and ILP: there is immediate evidence of tissue coagulation on ultrasound, the technique is less dependent on tissue properties. Evaluation in larger series is required.

Non-surgical approach to the benign nodular goiter: new opportunities by recombinant human TSH-stimulated 131I-therapy

The optimal treatment strategy in a goiter patient depends--among other factors--on goiter size, the degree of cosmetic or compressive symptoms, the age of the patient, the impact on the upper airways, the wish to maintain normal thyroid function, the ability of the thyroid gland to take up (131)I, and the possibility of thyroid malignancy. When treatment is warranted in a patient with benign goiter, the choice usually stands between surgery and (131)I-therapy. Focal destructive treatment, by ethanol sclerotherapy or interstitial laser photocoagulation, may be considered in patients with a solitary benign nodule. If thyroid hyperfunction due to nodular autonomy is the dominant problem, life-long anti-thyroid drug treatment may be relevant in elderly individuals. With the advent of recombinant human TSH (rhTSH) stimulation the goiter reduction following (131)I-therapy is significantly enhanced and this treatment is of particular benefit, as compared with conventional (131)I-therapy, in patients with a low baseline thyroid (131)I uptake and a large goiter. If the rhTSH dose does not exceed 0.1 mg the risk of temporary hyperthyroidism and acute thyroid swelling is low. Since patient satisfaction seemingly is not improved by the greater goiter reduction obtained by rhTSH-stimulated (131)I-therapy, and permanent hypothyroidism is more frequent, it may be more relevant to reduce the administered radioactivity equivalent to the rhTSH-induced increase in the thyroid (131)I uptake. Future large-scale well-controlled studies should explore this strategy, with focus on cost-benefit and quality of life. A major hindrance of widespread and routine use of rhTSH-stimulated (131)I-therapy is its present status as an off-label treatment.

Interstitial laser photocoagulation for benign thyroid nodules: Time to treat large nodules

Interstitial laser photocoagulation (ILP) is a new therapeutic option for the ablation of non-functioning and hyper-functioning benign thyroid nodules. Amelioration of the ablation procedure currently allows treating large nodules. Aim of this study was to evaluate the therapeutic efficacy of ILP, performed according to a modified protocol of ablation, in patients with large functioning and non-functioning thyroid nodules and to identify the best parameters for predicting successful outcome in hyperthyroid patients. Fifty-one patients with non-functioning thyroid nodules (group 1) and 26 patients with hyperfunctioning thyroid nodules (group 2) were enrolled. All patients had a nodular volume ≥40 ml. Patients were addressed to 1-3 cycles of ILP. A cycle consisted of three ILP sessions, each lasting 5-10 minutes repeated at an interval of 1 month. After each cycle of ILP patients underwent thyroid evaluation. A nodule volume reduction, expressed as percentage of the basal volume, significantly occurred in both groups (F = 190.4; P < 0.0001 for group 1 and F = 100.2; P < 0.0001 for group 2). Receiver-operator-characteristic (ROC) curves were constructed for: (i) percentage of volume reduction; (ii) difference in nodule volume; (iii) total amount of energy delivered expressed in Joule. ROC curves identified the percentage of volume reduction as the best parameter predicting a normalized serum TSH (area under the curve 0.962; P < 0.0001). Intraoperative complications consisted in: (i) mild pain occurring in five (6.5%) patients, (ii) vasovagal reaction in two (2.6%) patients, (iii) fever within 24 hours from ILP in five (6.5%) patients. No major complications including persistent pain, laringeal nerve dysfunction, hypoparathyroidism, pseudocystic transformation, and/or neck fascitis were observed. ILP represents a valid alternative to surgery also for large benign thyroid nodules, both in terms of nodule size reduction and cure of hyperthyroidism (87% of cured patients after the last ILP cycle). ILP should not be limited to patients refusing or being ineligible for surgery and/or radioiodine.

Long-term outcome following interstitial laser photocoagulation of benign cold thyroid nodules

To evaluate the long-term efficacy of interstitial laser photocoagulation (ILP) in solitary benign thyroid nodules. A total of 78 euthyroid outpatients (45 participating in randomized trials) with a benign solitary solid and scintigraphically cold thyroid nodule causing local discomfort were assigned to ILP. ILP (using one laser fiber) was performed under continuous ultrasound (US) guidance and with an output power of 1.5-3.5 W. Thyroid nodule volume was assessed by US and thyroid function determined by routine assays, before and during follow-up. Pressure symptoms and cosmetic complaints were evaluated on a visual analogue scale (0-10 cm). Of the total patients, six had thyroid surgery 6 months after ILP and three were lost to follow-up. The median follow-up for the remaining 69 patients was 67 months (range 12-114). The overall median nodule volume decreased from 8.2 ml (range 2.0-25.9) to 4.1 ml (range 0.6-33.0; P<0.001) at the final evaluation, corresponding to a median reduction of 51% (range: -194 to 95%). This correlated with a significant decrease in pressure as well as cosmetic complaints. After 12--96 months (median 38 months) of ILP, 21 patients (29%) had thyroid surgery because of an unsatisfactory result. All had benign histology. Thyroid function was unaltered throughout and side effects were restricted to mild local pain. US-guided ILP results in a satisfactory long-term clinical response in the majority of patients with a benign solitary solid cold thyroid nodule. Further large-scale studies should aim at optimizing selection criteria for ILP, preferably in randomized studies.

Image-guided Tumor Ablation: Standardization of Terminology and Reporting Criteria

The field of interventional oncology with use of image-guided tumor ablation requires standardization of terminology and reporting criteria to facilitate effective communication of ideas and appropriate comparison between treatments that use different technologies, such as chemical (ethanol or acetic acid) ablation, and thermal therapies, such as radiofrequency (RF), laser, microwave, ultrasound, and cryoablation. This document provides a framework that will hopefully facilitate the clearest communication between investigators and will provide the greatest flexibility in comparison between the many new, exciting, and emerging technologies. An appropriate vehicle for reporting the various aspects of image-guided ablation therapy, including classification of therapies and procedure terms, appropriate descriptors of imaging guidance, and terminology to define imaging and pathologic findings, are outlined. Methods for standardizing the reporting of follow-up findings and complications and other important aspects that require attention when reporting clinical results are addressed. It is the group's intention that adherence to the recommendations will facilitate achievement of the group's main objective: improved precision and communication in this field that lead to more accurate comparison of technologies and results and, ultimately, to improved patient outcomes. The intent of this standardization of terminology is to provide an appropriate vehicle for reporting the various aspects of image-guided ablation therapy.

Development of novel tunable light scattering coating materials for fiber optic diffusers in photodynamic cancer therapy

AbstractTo homogenize light emitted from fiber optic diffusers for photodynamic therapy (PDT), novel coating materials with tunable properties were designed. A class VI medical grade UV‐curable acrylic resin for biomedical applications was used for the polymer matrix, and titanium dioxide (TiO2) was added to the resin as a scattering agent. UV‐curability of coatings containing TiO2 was significantly influenced by the grade and surface treatment of the TiO2 studied. Despite using a free‐radical system without inert gas protection, all samples demonstrated considerable thermal postcuring. A novel TiO2 surface treatment methodology was developed based on unsaturated alkoxyorganosilanes combined with unsaturated carboxylic acids for compatibilizing TiO2 for use in the resin material studied. By adjusting the concentration of the surface‐modifying agent, the scattering efficiency and UV curability can be controlled by decreasing the effective particle size and enhancing the dispersibility of the powder filler within the resin. This modification will enable fine‐tuning of the effective size of TiO2 particles to the wavelength of laser light to be scattered to maximize scattering efficiency in photodynamic cancer therapy and possibly also in other forms of cancer treatment (interstitial laser hyperthermia or interstitial laser photocoagulation). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Non-excision treatment of multiple cutaneous neurofibromas by laser photocoagulation

Neurofibromatosis type 1 (NF-1) is an autosomal dominant disorder characterized by skin tumours derived from peripheral nerves. It is a clinically diagnosed disorder of a mainly cosmetic concern. There are different excision modalities for treatment of cutaneous neurofibromas; however, none is considered to be universally accepted treatment. This study was conducted to evaluate a non-excision treatment of multiple cutaneous neurofibromas, using surface and interstitial approaches of neodymium:yttrium aluminum garnet (Nd:YAG) laser (1,064 nm) photocoagulation, depending upon the size and location of the lesions. Twelve patients with multiple cutaneous neurofibromas were included. Surface laser photocoagulation by long-pulsed Nd:YAG laser has been used for treatment of flat lesions, while interstitial laser photocoagulation by continuous wave (CW) Nd:YAG laser has been used for treatment of bulkier lesions. After 14 months of follow up, both approaches of laser photocoagulation have shown different success rates, as denoted by the regression of the lesions, an overall acceptable cosmetic outcome, and, generally, patients' satisfaction. Within the limitations of the present study, laser photocoagulation has proven to be a promising technique that may be an alternative or additive modality for treatment of multiple cutaneous neurofibromas. It is a minimally invasive, office-based technique that could be used safely and effectively, with a limited rate of complications. Surface laser photocoagulation has proven to be an effective tool for treatment of flat lesions, especially those located in exposed areas, with a favourable cosmetic result, while interstitial laser photocoagulation could be reserved for bulkier lesions, especially those located in non-exposed areas. However, further studies are necessary to refine the procedure, and to confirm the present encouraging findings, especially over a longer period of follow up, as well as to evaluate laser parameters for optimization of the technique.

Randomized prospective study comparing a single radioiodine dose and a single laser therapy session in autonomously functioning thyroid nodules

To compare the efficacy of interstitial laser photocoagulation (ILP) with radioiodine in hot thyroid nodules. Thirty consecutive outpatients with subclinical or mild hyperthyroidism and a scintigraphically solitary hot nodule with extraglandular suppression were randomized to either one ILP session or one radioiodine ((131)I) dose. ILP was performed under continuous ultrasound-guidance and with an output power of 2.5-3.5 W. (131)I was given as a single dose based on thyroid volume and a 24-h thyroid (131)I uptake. Thyroid function and nodule volume were evaluated at inclusion and at 1, 3 and 6 months after treatment. Normalization of serum TSH was achieved in 7 out of 14 patients in the ILP group and in all 15 patients in the (131)I group (P=0.0025). In the ILP group, mean thyroid nodule volume reduction was 44+/-5% (s.e.m.; P<0.001), and in the (131)I group 47+/-8% (P<0.001), within 6 months, without between-group difference (P=0.73). The mean reduction of total thyroid volume was 7+/-5% in the ILP group (P=0.20) and 26+/-8% (P=0.006) in the (131)I group (P=0.06 between-group). Two patients in the (131)I group developed hypothyroidism but no major side effects were seen. This first randomized study, comparing ILP with standard therapy, demonstrates that ILP and (131)I therapy approximately halves thyroid nodule volume within 6 months; but in contrast to (131)I, extranodular thyroid volume is unaffected by ILP and no patient developed hypothyroidism. Using the present design, ILP seems inferior to (131)I therapy in normalization of serum TSH. The potential value of ILP as a non-surgical alternative to (131)I needs further investigation.

Low-Energy Interstitial Laser Photocoagulation for Treatment of Nonfunctioning Thyroid Nodules: Therapeutic Outcome in Relation to Pretreatment and Treatment Parameters

Interstitial laser photocoagulation (ILP) is a recently proposed therapeutic procedure for the ablation of benign thyroid nodules, which has already proven to be safe and effective. However, results supporting the routine use of ILP are still limited. The aim of the study was to evaluate the efficacy and safety of ILP treatment in benign nonfunctioning thyroid nodules and to establish whether the therapeutic outcome may be predicted by any clinical parameter at baseline. Twenty-three patients with either a solitary nodule or a dominant nodule within a multinodular goiter underwent ILP and were evaluated 1 and 3 months later. In order to assess the efficacy of low-energy ILP, the procedure was performed with an output power of 3 W, delivering a mean energy of 33.4 +/- 12.7 Joule/mL of nodule volume, which is much lower than previously reported. Nodule volume significantly decreased after ILP as assessed after 1 and 3 months (analysis of variance; F = 5.37; p = 0.007). Patients with multinodular goiter showed a greater reduction at 3 months compared with patients bearing a solitary thyroid nodule (38.6 +/- 5.3 vs. 30.9 +/- 6.5%; p < 0.01). Age, sex, ultrasound pattern (isoechogenous/hypoechogenous), pretreatment volume, number of ILP treatments, and total energy delivered did not show any significant correlation with treatment outcome. Our results demonstrate that ILP can produce a significant reduction of thyroid nodule volume even when a much lower energy than previously reported is delivered. ILP constitutes a minimally invasive technique, which can be carried out on an outpatient basis and could represent a valid nonsurgical alternative for thyroid nodule management. Dominant nodules within a multinodular goiter appear to be more responsive to ILP compared with solitary thyroid nodules.

Effect of Ultrasound-Guided Interstitial Laser Photocoagulation on Benign Solitary Solid Cold Thyroid Nodules: One versus Three Treatments

Interstitial laser photocoagulation (ILP) is a safe and effective procedure when inducing thyroid nodule necrosis. In this prospective randomized study, we evaluated a possible dose-response relationship as well as patient satisfaction. Thirty euthyroid outpatients with a cytologically benign solitary solid and scintigraphically cold thyroid nodule causing local discomfort were assigned to one session of ILP (ILP-1) (n = 15) or three monthly ILP sessions (ILP-3) (n = 15) and followed for 6 months. ILP was performed under continuous ultrasound (US)--guidance and with an output power of 2.5-3.5 W. Thyroid nodule volume was assessed by US. Pressure and cosmetic complaints were evaluated on a visual analogue scale. In the ILP- 1 group, thyroid nodule volume decreased from 10.1 +/- 4.3 mL (mean +/- standard deviation [SD]) to 5.7 +/- 3.2 mL (p = 0.0004), and in the ILP-3 group from 10.8 +/- 5.5 mL to 4.6 +/- 3.0 mL (p = 0.0005) during follow-up. The overall mean difference between the two groups was 13%, corresponding to an improved mean thyroid nodule volume reduction of 30% (p = 0.03). In both groups subjective symptoms were significantly reduced, and without difference between the two groups (p = 0.7). No major side effects were seen in either group. As a nonsurgical therapeutic option, ILP-1 approximately halves thyroid nodule volume with concomitant symptom relief. There is little incremental effect of additional ILP treatment, which should be limited to patients with large nodules or limited nodule reduction after the first treatment.

Beneficial effect of combined aspiration and interstitial laser therapy in patients with benign cystic thyroid nodules: a pilot study

The aim of this study was to evaluate the effect of combined cyst aspiration and ultrasound-guided interstitial laser photocoagulation (ILP) on recurrence rate and the volume of benign cystic thyroid nodules. 10 euthyroid outpatients with a solitary and cytologically benign partially cystic thyroid nodule causing local discomfort were assigned to cyst aspiration followed by ultrasound-guided ILP and followed for 12 months. The ILP was performed under continuous ultrasound-guidance and with an output power of 2.5-3.5 W. The volume of the nodules was assessed by means of ultrasound and determination of the amount of aspirated cyst fluid, thereby calculating the volume of the solid part. Follow-up included ultrasound and determination of thyroid function. Pressure and cosmetic complaints were evaluated on a visual analogue scale. The median initial volume of the cystic nodule decreased from 9.6 ml [6.8;15.5 (quartiles)] to 3.5 ml [2.7;9.0 (quartiles)] (p = 0.0001), and the median cyst volume from 3.0 ml [2.0;6.0 (quartiles)] to 0 ml [0;0.5 (quartiles)] (p = 0.0001) during follow-up. Recurrence of the cystic part was defined as a cyst volume > 1 ml. In eight of 10 patients there was no recurrence of the cystic part. Both pressure symptoms and cosmetic complaints were significantly reduced. The only side effect was mild pain or tenderness for a few days. Our study suggests that complete cyst aspiration and subsequent ultrasound-guided ILP of benign cystic thyroid nodules is a feasible and safe technique, resulting in a significant reduction in the volume of both the solid and the cystic component. A large-scale prospective randomized study is warranted.

2455: Sonographic visualization at interstitial laser photocoagulation of benign thyroid nodules

Objectives: To define sonographic and color Doppler peculiarities of thyroid nodules influencing the efficacy and follow-up principles of interstitial laser photocoagulation (ILP). Methods: Three hundred sixty-eight thyroid nodules were treated with 1–6 ILP sessions and subsequently sonographically examined every month within one year. Results: The best results after ILP were achieved in solitary solid nodules 2.0 cm or smaller with low vascularity of peripheral or combined pattern. Hypervascular nodules needed more ILP sessions with increased laser power supply. The nodules with calcification, avascular regions of extremely high or low US-density and big fluid collections showed poor volume regression. Homogenous surrounding tissue US-pattern allows faster nodule volume decrease comparatively to autoimmune thyroiditis. In 72% nodules reduced their volume more than two times and 24% disappeared. Avascular and hypoechoic nodules in four wk period after ILP show further volume regression; persisting vascularization suggests a second ILP session. Conclusions: US-guided ILP is effective in benign thyroid nodules and may be an alternative to conservative methods. Gray-scale and color Doppler sonography is the leading follow-up modality for patients after ILP.

2456: Ultrasound effects at interstitial laser photocoagulation in nodular goiter

2456: Ultrasound effects at interstitial laser photocoagulation in nodular goiter