thyroid nodules

Artificial intelligence may be used to identify benign thyroid nodules

Posted by

0


An ultrasound-based artificial intelligence classifier of thyroid nodules identified benign nodules with sensitivity similar to fine-needle aspiration, according to data presented at ENDO 2022.

“Artificial analysis of thyroid ultrasound images can identify nodules that are very unlikely to be malignant,” Nikita Pozdeyev, MD, PhD, assistant professor at University of Colorado Anschutz Medical Campus, told Healio. “These are mostly spongiform nodules that have a less than 3% probability of malignancy.”

Nikita Pozdeyev, MD, PhD
Pozdeyev is an assistant professor at University of Colorado Anschutz Medical Campus.

Pozdeyev and colleagues trained a supervised deep learning classifier of thyroid nodules on 32,545 images of 621 thyroid nodules acquired from University of Washington. The classifier was then tested on an independent set of 145 nodules collected from the University of Colorado. The Big Transfer BiT-M ResNet-50×1 convolutional neural net architecture was modified to contain, 3, 4, 6 and 3 PreActBottleneck units per block 1 through 4. Weights pretrained on the ImageNet-21k dataset were loaded, and weights for blocks 3 and 4 fine-tuned for the binary classification task of distinguishing between benign and malignant thyroid nodules.

“We used an approach used to train clinically relevant classifiers called transfer learning,” Pozdeyev said in a press conference. “We took a model trained on natural images like cars, dogs and humans, and then that model is trained on an image set with tens of millions of images. Then we modified that model to work on a specific task — in our case, to take ultrasound images of thyroid nodules and make a call: cancerous or benign.”

When scaled by nodule size and using six random cine clip images per nodule, the classifier achieved an area under receiver operating characteristic curve of 0.872 on five-fold cross-validation. In the training data set of thyroid nodules, the classifier achieved a sensitivity of 94%, a specificity of 52% and a negative predictive value of 96% when determining benign vs. malignant nodules.

In the independent test set of thyroid nodules, the classifier achieved a sensitivity of 97% and a specificity of 61%. The negative predictive value was 98.5% and the positive predictive value was 40%.

“Computer-assisted diagnosis systems will be increasingly used by physicians of all specialties, including endocrinology,” Pozdeyev told Healio. “Our proof-of-concept study showed that an artificial intelligence-based thyroid nodule classifier can objectively select thyroid nodules that are unlikely to be malignant, do not require fine-needle aspiration biopsy, and can be managed with active surveillance. The validation of such a computer-assisted diagnosis system in a prospective clinical trial will be necessary before introduction into clinical practice.”

Radiofrequency ablation effective for most children with benign thyroid nodules

Posted by

0


Most children who undergo image-guided radiofrequency ablation for treatment of benign nonfunctional thyroid nodules have at least a 50% reduction in nodule volume 4 years after treatment, according to study data published in Thyroid.

“Radiofrequency ablation was effective in reducing the volume of benign nonfunctional thyroid nodules in children, providing significant symptomatic relief with a good safety profile during short- and long-term follow-up,” Xinguang Qiu, MD, of the department of thyroid surgery at The First Affiliated Hospital of Zhengzhou University in China, and colleagues wrote. “Radiofrequency ablation should be considered as a beneficial, minimally invasive treatment modality for selected pediatric patients.”

Radiofrequency ablation reduces mean volume of benign thyroid nodules by more than 50% in children
Children undergoing radiofrequency ablation for the treatment of benign thyroid nodules had a mean volume reduction ratio of 65% or more at 3 months, 6 months and 1 year of follow up. Data were derived from Li L, et al. Thyroid. 2022;doi:10.1089/thy.2021.0454.

Researchers reviewed data from 62 patients aged 18 years or younger with benign thyroid nodules treated with radiofrequency ablation at The First Affiliated Hospital of Zhengzhou University from July 2014 to August 2017 (75.8% girls; mean age, 14.4 years). Participants underwent an ultrasonography prior to the procedure to evaluate thyroid nodule composition and symptoms and had follow-up 3, 6 and 12 months after treatment. After 1 year, follow-up visits were performed annually. Ultrasonography and laboratory tests were repeated at each follow-up visit. Volume reduction ratio was calculated to assess the extent of nodule volume reduction.

Of the study cohort, 54 children had one thyroid nodule requiring treatment, and eight had two thyroid nodules. At 3 months, the mean volume reduction ratio was 65.1%, and increased to 74.7% at 6 months and to 77.5% at 1 year. The mean volume reduction ratio was 60.3% at 2 years, 68.5% at 3 years and 55.1% at 4 years. Thirty-six nodules had strong echogenicity or hyperechogenicity at 3 months, and six retained these characteristics at 6 months.

Sixteen of the 70 nodules began to regrow after initial treatment. Of the regrowing nodules, 56.3% had a volume reduction ratio below 50%, indicating a loss in treatment efficacy. Of those that lost treatment efficacy, 66.7% became larger than before treatment. Three nodules underwent a second radiofrequency ablation and surgery was performed on two other nodules.

Children requiring treatment of bilateral nodules had a lower volume reduction rate (13.6% vs. 74.1%; P < .001), lower technical efficacy (56.3% vs. 90.7%; P = .001) and higher regrowth rate (68.8% vs. 9.3%; P < .001) compared with unilateral nodules.

“We found that bilateral nodules requiring treatment had lower volume reduction rates, lower therapeutic efficacy and higher rates of regrowth, and the presence of bilateral nodules was an independent factor related to efficacy and regrowth,” the researchers wrote. “The specific reason for these associations is unclear. In addition, such results have not been reported in adult studies. Thus, radiofrequency ablation may not be appropriate for the treatment of bilateral thyroid nodules in children.”

Nodules with a higher cystic component had a higher volume reduction ratio than those with a lower cystic component (72.4% vs. 46.7%; P = .001). Nodules with higher vascularity had a lower regrowth rate than those with low vascularity (12.1% vs. 32.4%; P = .043). In all, 4.8% of patients had complications from the procedure.

The researchers wrote that radiofrequency ablation provides benefits for many patients, but those who undergo the procedure require long-term follow-up and the lack of a pathological exam means providers can not rule out malignancy.

“This treatment requires specialized treatment centers, specialized equipment, and highly skilled and experienced physicians, so access to radiofrequency ablation may also be a barrier to its use,” the researchers wrote. “Therefore, we believe that radiofrequency ablation is more likely to be a complementary treatment modality to surgical treatment.”

Incidental Thyroid Nodules and Thyroid Cancer Considerations Before Determining Management

Posted by

4


The worldwide incidence of thyroid cancer is increasing substantially, almost exclusively attributable to small papillary thyroid cancers. Increased use of diagnostic imaging is considered the most likely explanation for this reported rise, but other factors may also be contributing. The increase in health care expenditures related to managing these presumably low-risk cancers, without a clear patient benefit, has resulted in a backlash against the early detection of thyroid cancer. Currently, there is no way to confidently predict which incidentally detected thyroid nodule may be the precursor to a more aggressive process. Predictions such as these would require more accurate characterization of the biology of individual thyroid cancers than is currently possible. With time, we might prove our ability to confidently differentiate low-risk from high-risk thyroid cancers, but until that happens, routine screening for thyroid cancer by imaging billed as a “health checkup” should not be performed. However, incidentally detected thyroid nodules should be reported, and a clear medical team management plan should be developed. Our ethical responsibility is to provide patients with objective, evidence-based information about their disease status, not to assume that we know what is best for them by selectively withholding information. In addition, providing patients with psychosocial assistance will help them process the information necessary to make informed decisions that will provide them with the most value when a small thyroid nodule or cancer is incidentally identified. Herein, we summarize the epidemiological data for disease incidence, discuss some controversies in disease management, and outline the key elements and ethical considerations of informed decision making as they apply to managing incidentally detected thyroid nodules and thyroid cancer.