External Radiotherapy for Locoregional Control in Thyroid Carcinoma

Area of Science:

• Oncology
• Radiation Oncology
• Endocrinology

Background:

• Well-differentiated thyroid cancers (WDTC) are typically managed with surgery, radioactive iodine, and thyroxine therapy.
• External radiotherapy (ERT) is reserved for specific indications in WDTC management.
• Indications for ERT include adjuvant therapy for residual disease, palliation of unresectable tumors, and salvage for recurrent disease.

Purpose of the Study:

• To review the role and techniques of external radiotherapy (ERT) in managing well-differentiated thyroid cancers (WDTC).
• To highlight the importance of high radiation doses for locoregional control.
• To emphasize the benefits of modern ERT techniques in minimizing treatment-related morbidity.

Main Methods:

• Review of indications for ERT in WDTC.
• Discussion of required radiation doses for locoregional control.
• Evaluation of modern ERT techniques, specifically intensity-modulated radiotherapy (IMRT).

Main Results:

• High radiation doses (≥60Gy) are necessary for effective locoregional control of gross or microscopic residual WDTC.
• Intensity-modulated radiotherapy (IMRT) enables precise dose delivery to target volumes.
• IMRT effectively protects adjacent critical structures such as the trachea, larynx, esophagus, and spinal cord.

Conclusions:

• ERT plays a vital role in selected WDTC cases, particularly for residual, unresectable, or recurrent disease.
• Achieving high radiation doses is critical for successful locoregional control.
• Advanced ERT techniques like IMRT are essential for balancing efficacy and minimizing late toxicities in WDTC treatment.