A Systematic Review and Meta-Analysis of the Relationship Between the Radiation Absorbed Dose to the Thyroid and Response in Patients Treated with Radioiodine for Graves' Disease.

Background: Patients with Graves' disease are commonly treated with radioiodine. There remains controversy over whether the aim of treatment should be to achieve euthyroidism or hypothyroidism, and whether treatments should be administered with standard levels of radioactivity or personalized according to the radiation absorbed doses delivered to the thyroid. The aim of this review was to investigate whether a relationship exists between radiation absorbed dose and treatment outcome. Methods: A systematic review and meta-analysis of all reports published before February 13, 2020, were performed using PubMed, Web of Science, OVID MEDLINE, and Embase. Proportion of patients achieving nonhyperthyroid status was the primary outcome. Secondary outcomes were proportion of patients who were specifically euthyroid or hypothyroid. A random-effects meta-analysis of proportions was performed for primary and secondary outcomes, and the impact of the radiation absorbed dose on treatment outcome was assessed through meta-regression. The study is registered with PROSPERO (CRD42020175010). Results: A total of 1122 studies were identified of which 15, comprising 2303 Graves' disease patients, were eligible for the meta-analysis. A strong association was found between radiation absorbed dose and nonhyperthyroid and hypothyroid outcomes (odds ratio [OR] = 1.11 [95% confidence interval {CI} 1.08-1.14] and OR = 1.09 [CI 1.06-1.12] per 10 Gy increase). Higher rates of euthyroid outcome were found for radiation absorbed doses within the range 120-180 Gy when compared with outside this range (n = 1172, OR = 2.50 [CI 1.17-5.35], p = 0.018). A maximum euthyroid response of 38% was identified at a radiation absorbed dose of 128 Gy. Conclusions: The presented radiation absorbed dose-response relationships can facilitate personalized treatment planning for radioiodine treatment of patients with Graves' disease. Further studies are required to determine how patient-specific covariates can inform personalized treatments.

Dosimetry-based treatment for Graves' disease.

OBJECTIVE: The aim of this retrospective study was to assess the long-term outcome of a personalized dosimetry approach in Graves' disease aiming to render patients euthyroid from a planned thyroid absorbed dose of 60 Gy. PATIENTS AND METHODS: A total of 284 patients with Graves' disease were followed prospectively following administration of radioiodine calculated to deliver an absorbed dose of 60 Gy. Patients with cardiac disease were excluded. Outcomes were analysed at yearly intervals for up to 10 years with a median follow-up of 37.5 months. RESULTS: A single radioiodine administration was sufficient to render a patient either euthyroid or hypothyroid in 175 (62%) patients, the remainder requiring further radioiodine. The median radioactivity required to deliver 60 Gy was 77 MBq. Less than 2% patients required 400-600 MBq, the standard activity administered in many centres. In the cohort receiving a single administration, 38, 32 and 26% were euthyroid on no specific thyroid medication at 3, 5 and 10 years, respectively. Larger thyroid volumes were associated with the need for further therapy. The presence of nodules on ultrasonography did not adversely affect treatment outcome. CONCLUSION: A personalized dosimetric approach delayed the long-term onset of hypothyroidism in 26% of patients. This was achieved using much lower administered activities than currently recommended. Future studies will aim to identify those patients who would benefit most from this approach.

Diffuse large B-cell non Hodgkin's lymphoma in a 65-year-old woman presenting with hypopituitarism and recovering after chemotherapy: a case report.

INTRODUCTION: Diffuse large B-cell non Hodgkin's lymphoma may involve the pituitary either as a primary central nervous system lymphoma or, more frequently, as metastasis from systemic lymphoma leading to hypopituitarism. A partial recovery of pituitary function after treatment with chemotherapy has previously been described but complete recovery with cessation of all hormone supplements is excessively rare. We report a patient presenting with anterior hypopituitarism with subsequent complete and sustained recovery of pituitary function after successful treatment of the lymphoma. CASE PRESENTATION: A 65-year-old Caucasian woman with lethargy, loss of appetite and peripheral edema was found to have anterior hypopituitarism. Magnetic resonance imaging showed no mass lesions in the pituitary although a positron emission tomography scan showed abnormal pituitary activity. An abdominal computed tomography scan revealed multiple intra-abdominal lymph nodes, which on histology proved diagnostic of diffuse large B-cell non Hodgkin's lymphoma. She received six cycles of R-CHOP chemotherapy, after which she achieved a complete metabolic response at all known previous sites of the disease, confirmed by positron emission tomography scanning. Concomitant with the tumor response, there was full recovery of adrenal, thyroid and gonadal axes which has persisted at 10 months follow-up. CONCLUSION: Although rare, it is important to recognize lymphomatous infiltration of the pituitary as a potentially reversible cause of hypopituitarism.

Early and late toxicity of radioiodine therapy: detection and management.

OBJECTIVE: To review the early and late toxicity associated with radioiodine (131I) therapy, highlighting the need for early detection and, where possible, preventive measures. METHODS: We performed a literature search on MEDLINE using the terms radioiodine, 131I toxicity, complications, Graves disease, and thyroid cancer and chose the most relevant studies for this review. Where appropriate, we refer to our own published series of patients as well. RESULTS: Uptake of 131I into the salivary glands, lacrimal glands, fetal thyroid, and adult thyroid accounts for the early toxic effects of radioiodine therapy. Delayed radiation effects to the gonads, bone marrow, and cell nuclei give rise to late complications. Toxicity may also arise from uptake into metastatic tumors located at vulnerable sites, including the spinal cord, brain, and lungs. CONCLUSION: Although radioiodine therapy for benign and malignant thyroid disorders is usually well tolerated, clinicians involved in the management of thyroid disorders need to be aware of the potential toxicity of radioiodine and take all measures to reduce these effects to a minimum.

Thyroid cancer causing obstruction of the great veins in the neck.

BACKGROUND AND AIMS: To report our experience and review the literature of thyroid cancer obstructing the great veins in the neck, highlighting clinical aspects and response to treatment. METHODS: Clinical data were collected from the thyroid cancer register and from follow-up clinic visits of patients referred to the Thyroid Unit at the Royal Marsden Hospital. A Medline literature search was conducted between 1980 and 2007. RESULTS: Of 1448 patients with thyroid cancer on our cancer register and treated in our unit over the last 60 years, we identified five patients, four women and one man, aged 43 - 81 years with a median follow up of 28 (24-78) months in whom tumour had occluded the great veins in the neck. All patients underwent total thyroidectomy and all subsequently received ablative 131I with the exception of patient 3 whose post-operative isotope scan shown no significant 131I uptake. External beam radiotherapy to the neck and upper mediastinum was used for residual disease control in the 5 patients. The median survival was 28 months and the disease-free survival was 24 months. One patient remains asymptomatic but with disease 53 months after initial presentation. Survival in this small series is significantly better than that previously reported for this condition. CONCLUSION: A multimodality therapeutic approach comprising surgery, radioiodine and external beam radiotherapy may give the best results for patients in whom thyroid cancer is occluding the great veins.

Neuroendocrine carcinoma arising in soft tissue: three case reports and literature review.

BACKGROUND: Neuroendocrine tumours (NET) are tumours arising from neuroendocrine cells of neural crest origin. They are characterised by the presence of neurosecretory granules which react positively to silver stains and to specific markers including neuron specific enolase, synaptophysin and chromogranin. Metastasis to the skin occurs infrequently but primary soft tissue NET is excessively rare. CASE PRESENTATION: We report our experience with 3 such cases. In the first case, the NET originated in muscle and was treated with wide surgical excision and adjuvant radiotherapy. The second case presented as a subcutaneous mass in the foot and the tumour was positive on 123I mIBG scan. She has had prolonged recurrence-free survival following primary hypo-fractionated radiotherapy. In the third case, a cutaneous nodule proved to be a NET and at surgery, lymph node disease was present. He has remained disease-free after surgical excision without the need for external beam radiotherapy. CONCLUSION: These tumours appear to have a good prognosis. Complete excision offers potentially curative treatment. Adjuvant radiotherapy may be helpful when the tumour margin is narrow. For patients with unresectable disease or where surgery would not be appropriate, radiotherapy appears to be an effective therapeutic option.