Radioiodine treatment of differentiated thyroid cancer related to guidelines and scientific literature

Regulación de los servicios de medicina nuclear: percepción de la problemática y desafíos para el manejo del cáncer en Colombia

Introducción. La modificación de las normas sobre medicina nuclear en Colombia ha afectado la administración de la terapia de yodo radioactivo en el tratamiento del cáncer de tiroides.Objetivos. Determinar las áreas de acuerdo en torno al problema, los requisitos actuales y los nuevos exigidos en la normativa para el funcionamiento de los servicios de medicina nuclear.Materiales y métodos. Se hizo un estudio Delphi de dos rondas con cada grupo de expertos, ‘clínicos’ y ‘de entidades reguladoras’. En la primera ronda se exploraron los puntos de vista sobre las implicaciones de la normativa en medicina nuclear y, en la segunda, se calificaron las declaraciones de la primera según su relevancia.Resultados. La problemática de los servicios de medicina nuclear está relacionada con la claridad normativa, y la falta de sinergia y coherencia entre los organismos de inspección, vigilancia y control. Las exigencias del sistema de gestión de desechos requieren una alta inversión económica que puede influir en la oferta del servicio y repercutir en el control integral del cáncer de tiroides. Entre las necesidades presentes y futuras, se encuentran la unificación de criterios entre los auditores, la delimitación de funciones de los actuantes, la asistencia técnica para cumplir con la normativa, y la veeduría a los organismos de inspección, vigilancia y control por parte de los entes reguladores.Conclusión. Los hallazgos del estudio sugieren que los servicios de medicina nuclear atraviesan un momento de múltiples desafíos institucionales, normativos y económicos, que ponen en riesgo el desarrollo y mantenimiento de la medicina nuclear en la atención oncológica.

Assessing potential impact of 2015 American Thyroid Association guidelines on community standard practice for I-131 treatment of low-risk differentiated thyroid cancer: case study of Jordan

OBJECTIVES

The 2015 American Thyroid Association (ATA) guidelines called for significantly more selective ¹³¹I therapy in patients with low-risk differentiated thyroid cancer (DTC). We hypothesized that application of these guidelines would significantly reduce the ¹³¹I activity utilized by an academic tertiary hospital in Jordan.

METHODS

All DTC patients managed at Jordan University Hospital (JUH) between 1/2009 and 6/2019 were classified according to the 2015 ATA risk category and ¹³¹I activity was assigned accordingly. The actual ¹³¹I activity administered was compared with that recommended by the 2015 ATA guidelines.

RESULTS

In total, 135/182 DTC patients (74.2%) managed at JUH underwent ¹³¹I therapy. Of those, 58 (43%) had ATA low-, 58 (43%) intermediate-, and 19 (14%) high-risk disease. The low-, intermediate-, and high-risk DTC patients received an average (±SD) initial ¹³¹I activity of 3.53 ± 0.95, 4.40 ± 1.49, and 5.06 ± 2.52 GBq, respectively. Withholding ¹³¹I therapy altogether in the 2015 ATA low-risk patients would result in decreasing the ¹³¹I activity in the overall patient population by 37%. Withholding ¹³¹I therapy only in low-risk papillary thyroid microcarcinomas while administering 1.11 GBq of ¹³¹I to other low-risk patients would result in 28% reduction of ¹³¹I.

CONCLUSION

This study demonstrates a significant reduction in ¹³¹I therapeutic activity that would be given to DTC patients in an academic tertiary setting in Jordan, following acceptance of the 2015 ATA recommendations. Institutions that adopted the 2015 ATA guidance should measure outcomes in comparison to their historical controls and report those findings, while long-term results of randomized controlled trials are forthcoming.

Contemporary considerations in adjuvant radioiodine treatment of adults with differentiated thyroid cancer

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy with a growing incidence worldwide. The initial conventional management is surgery, followed by consideration of ¹³¹ I treatment that includes three options. These are termed remnant ablation (targeting benign thyroid remnant), adjuvant (targeting presumed microscopic DTC) and known disease (targeting macroscopic DTC) treatments. Some experts mostly rely on clinicopathologic assessment for recurrence risk to select patients for the ¹³¹ I treatment. Others, in addition, apply radioiodine imaging to guide their treatment planning, termed theranostics (aka theragnostics or radiotheragnostics). In patients with low-risk DTC, remnant ablation rather than adjuvant treatment is generally recommended and, in this setting, the ATA recommends a low ¹³¹ I activity. ¹³¹ I adjuvant treatment is universally recommended in patients with high-risk DTC (a primary tumor of any size with gross extrathyroidal extension) and is generally recommended in intermediate-risk DTC (primary tumor >4 cm in diameter, locoregional metastases, microscopic extrathyroidal extension, aggressive histology or vascular invasion). The optimal amount of ¹³¹ I activity for adjuvant treatment is controversial, but experts reached a consensus that the ¹³¹ I activity should be greater than that for remnant ablation. The main obstacles to establishing timely evidence through randomized clinical trials for ¹³¹ I therapy include years-to-decades delay in recurrence and low disease-specific mortality. This mini-review is intended to update oncologists on the most recent clinical, pathologic, laboratory and imaging variables, as well as on the current ¹³¹ I therapy-related definitions and management paradigms, which should optimally equip them for individualized patient guidance and treatment.

Role of Emerging Environmental Risk Factors in Thyroid Cancer: A Brief Review

Environmental factors are recognized as risk factors of thyroid cancer in humans. Exposure to radiation, both from nuclear weapon or fallout or medical radiation, and to some organic and inorganic chemical toxicants represent a worldwide public health issue for their proven carcinogenicity. Halogenated compounds, such as organochlorines and pesticides, are able to disrupt thyroid function. Polychlorinated biphenyls and their metabolites and polybrominated diethyl ethers bind to thyroid, transport proteins, replace thyroxin, and disrupt thyroid function as phthalates and bisphenolates do, highly mimicking thyroid hormones. A better knowledge of environmental risks represents a very important tool for cancer prevention through true risks prevention and management. This approach is very important because of the epigenetic origin’s theory of cancer. Therefore, the aim of this review was study the association between environmental agents and thyroid cancer promotion.