Radiotherapy For Thyroid Cancer Research Articles

Radiopharmaceuticals: A New Vista for Diagnosis and Treatment of Thyroid Cancer.

Radiopharmaceuticals are in the diagnosis and treatment of cancerous and noncancerous diseases, and a hope for optimistic effort in the field of nuclear medicine. They play a crucial role in clinical nuclear medicine by providing a tool to comprehend human disease and create efficient treatments. A detailed analysis is provided regarding the crux of molecular imaging including PET and SPECT overview for the detection of cancers. For a specified understanding of radiation therapy, topics include ranging from the selection of radionuclide to its development and manufacture, and dosage requirements to establishing the importance of I- 131 Radiotherapy in thyroid cancer. In this review, we also discussed the current state of the art of nuclear medicine in thyroid cancer, including the role of radioiodine (RAI) therapeutic scans in the diagnosis of differentiated thyroid cancer. In addition, we established a brief outlook into the current status of the research in thyroid cancer and discussed the future directions in this field.

Role of External Beam Radiotherapy in Thyroid Cancer

Role of External Beam Radiotherapy in Thyroid Cancer

The Role of Radiotherapy for Patients With Thyroid Cancer in the Modern Era.

Thyroid cancer (TC) is a relatively rare malignancy. The mainstay treatment is surgery followed by radioactive iodine (RAI) and medical systemic treatments. The role of external beam radiotherapy (EBRT) in TC is controversial regarding the survival benefits. The aim of this study was to analyse the effectiveness of EBRT for different forms of TC in different stages. Between January 1990 and 2016, 75 patients underwent 255 radiotherapy (RT) courses at our Institution. Local control (LC) and progression-free survival (PFS) were analyzed. The cohort consisted of 22 patients who received curative RT and 53 patients who received RT in a palliative setting. The estimated 5-year LC for the curative group was 92±8% and the palliative group 78±7%. The estimated 5-year PFS for the curative group was 27±9% and for palliative group 31±6%. The addition of RT in TC seems to be safe and effective. Our analysis showed an excellent local control (median >15 years) regardless of the treatment setting.

Patterns of relapse following radiotherapy for differentiated thyroid cancer: Implication for target volume delineation

Introduction Post-operative residual disease in differentiated thyroid cancer is an indication for external beam radiotherapy (EBRT) especially if there is poor radioiodine uptake by the residual disease. There are no standardized guidelines or consensus in target delineation for radiotherapy in thyroid cancer. Aims To determine the pattern of recurrence in patients with well differentiated thyroid cancer who received adjuvant or definitive radiotherapy as well as radioiodine ablation following surgery or biopsy with a view to better defining future target volume delineation for radiotherapy. Materials and methods Forty-nine patients with differentiated thyroid cancer received radical external beam radiotherapy and radioiodine ablation (3.5 GBq) following thyroidectomy or biopsy between 1990 and 2000. Nineteen patients had macroscopic residual (11) or inoperable disease (8), whilst 30 patients had clear (5) or microscopic positive resection margin (24), and 1 patient the resection margin status was unknown. All the patients were deemed high risk for local recurrence or progressive disease. The thyroid bed and regional nodes were irradiated using two radiotherapy techniques: (1) non co-planar lateral fields (NCLF) in coronal plane using 6 MV photons to a dose of 45–50 Gy in 16 fractions over 22 days and (2) anterior–posterior parallel pair of 6 MV photons to a dose of 40–42.5 Gy in 16 fractions over 22 days. There was no attempt to irradiate the lymph nodes in that part of the anterior and posterior mediastinum extending from the brachiocephalic veins to the carina. Results The median follow-up was 5.4 years (range 0.9–12.4 years). The actuarial 5-year cause-specific survival and local control for the whole group was 75.7% and 81.4%, respectively. Of the 4 patients with mediastinal recurrence, all had neck recurrences and two had distant metastases. All the medisastinal recurrences occurred in superior mediastinum (level VII) and all were treated with NCLF in coronal plane radiotherapy technique. Furthermore, mediastinal recurrences did not occur in isolation. The 5-years loco-regional control rate was 89.1% for those with clear or microscopic positive margins and 69.2% for those with macroscopic residual or inoperable disease. Five-year cause specific survival was 58.3% for patients with macroscopic residual or inoperable disease and 91.4% for those with clear or microscopic positive margins. Conclusion The status of postoperative margin relating to bulk of disease influences local control and cause specific survival. Surgical resection in locally advanced thyroid cancer should be performed by an experienced surgeon to achieve macroscopic clearance where possible. The majority of recurrences were loco-regional. The few superior mediastinal recurrences did not occur in isolation. All the mediastinal recurrences occurred in the superior mediastinum (level VII). We recommend the target volume should encompass the thyroid bed and regional neck nodes and the superior mediastinum level VII excluding the lymph nodes on both sides of the trachea within the anterior and posterior mediastinum extending from the brachiocephalic veins to the carina (compartment 4). Thus, this should facilitate dose escalation to improve loco-regional control and avoiding radiation induced mediastinal toxicity.

Endovascular Stenting for Pseudoaneurysms of the Cervical Carotid Artery

The authors report two cases of pseudoaneurysm of the cervical carotid artery treated with endovascular stenting. One patient presented with cerebral ischemia due to traumatic carotid dissection and underwent stent placement 3 weeks after injury when the wide-necked pseudo aneurysm was seen to enlarge at the dissecting portion. The aneurysm thrombosed while the carotid artery remained patent without ischemic complications for 2 years. The other patient developed repeated massive bleeding from an exposed pseudoaneurysm at the right carotid-subclavian junction resulting from radiotherapy for thyroid cancer with subsequent skin infection. Since skin grafting failed and two attempts at coil embolization resulted in compaction with recurrent enlargement of the aneurysm, endovascular stenting was performed with endosaccular coil packing between the stent struts. Hemostasis was achieved for 2 months. Both cases illustrate successes of the stent in highly difficult situations.

Tumors after radiotherapy for thyroid cancer. A case-control study within a cohort of thyroid cancer patients.

A case-control study of Swedish thyroid cancer patients was conducted to evaluate the possible influence of 131I treatment and external radiotherapy on the risk of developing a subsequent cancer. Both cases and controls derived from a cohort of Swedish thyroid cancer patients treated with 131I (n = 834) or by other means (n = 1,121). Thirty-six breast, 13 stomach, 12 kidney, and 5 bladder cancers were found more than 2 years after 131I treatment/thyroid cancer diagnosis. Individual, absorbed dose in the organs was calculated by using ICRP tables, administered activity of 131I, and 24-h 131I uptake. In studying the effect of 131I and external radiotherapy no statistically significant dose-response relationships were found for cancers of the breast, stomach, bladder or kidney. When the absorbed dose from 131I was analyzed separately the risks remained essentially the same. The present follow-up time and the relatively low absorbed dose that the patients received from 131I and external radiotherapy necessitate studies with a longer follow-up time or a larger patient material before more firm conclusions can be made.