MyMedR

The quantification of PET-CT radiotracers to determine minimal scan time using quadratic formulation

Said MA, Musarudin M, Zulkaffli NF

Ann Nucl Med, 2020 Dec;34(12):884-891.

PMID: 33141408 DOI: 10.1007/s12149-020-01543-x

OBJECTIVE: 18F is the most extensively used radioisotope in current clinical practices of PET imaging. This selection is based on the several criteria of pure PET radioisotopes with an optimum half-life, and low positron energy that contributes to a smaller positron range. In addition to 18F, other radioisotopes such as 68Ga and 124I are currently gained much attention with the increase in interest in new PET tracers entering the clinical trials. This study aims to determine the minimal scan time per bed position (Tmin) for the 124I and 68Ga based on the quantitative differences in PET imaging of 68Ga and 124I relative to 18F.

METHODS: The European Association of Nuclear Medicine (EANM) procedure guidelines version 2.0 for FDG-PET tumor imaging has adhered for this purpose. A NEMA2012/IEC2008 phantom was filled with tumor to background ratio of 10:1 with the activity concentration of 30 kBq/ml ± 10 and 3 kBq/ml ± 10% for each radioisotope. The phantom was scanned using different acquisition times per bed position (1, 5, 7, 10 and 15 min) to determine the Tmin. The definition of Tmin was performed using an image coefficient of variations (COV) of 15%.

RESULTS: Tmin obtained for 18F, 68Ga and 124I were 3.08, 3.24 and 32.93 min, respectively. Quantitative analyses among 18F, 68Ga and 124I images were performed. Signal-to-noise ratio (SNR), contrast recovery coefficients (CRC), and visibility (VH) are the image quality parameters analysed in this study. Generally, 68Ga and 18F gave better image quality as compared to 124I for all the parameters studied.

CONCLUSION: We have defined Tmin for 18F, 68Ga and 124I SPECT CT imaging based on NEMA2012/IEC2008 phantom imaging. Despite the long scanning time suggested by Tmin, improvement in the image quality is acquired especially for 124I. In clinical practice, the long acquisition time, nevertheless, may cause patient discomfort and motion artifact.

Matched MeSH terms: Iodine Radioisotopes/chemistry

Clinical determinants of fluorodeoxyglucose positron emission tomography/computed tomography in differentiated thyroid cancer patients with elevated thyroglobulin and negative (131)iodine whole body scans after (131)iodine therapy

Shamim SE, Nang LB, Shuaib IL, Muhamad NA

Malays J Med Sci, 2014 May;21(3):38-46.

PMID: 25246834

A cross-sectional prospective study has been conducted on differentiated thyroid cancer (DTC) patients using negative (131)Iodine ((131)I) whole body scans and elevated thyroglobulin (Tg) levels. The main objective of this research was to determine the prevalence of the conversion of differentiated to dedifferentiated thyroid cancer patients during follow up at the Hospital Kuala Lumpur. It has been demonstrated that fluorodeoxyglucose (FDG) uptake is inversely proportional to the iodine concentration and to differentiation of the cells.

Matched MeSH terms: Iodine Radioisotopes

Fulltext Radiation doses to patient's relatives following radioiodine therapy

Sulaiman BT, Clarke SE

Med J Malaysia, 1996 Mar;51(1):131-3.

PMID: 10967992

A total of 10 volunteers were monitored for radiation doses, whose spouses were given radio-iodine (131I) orally. Nine of the spouses were given radio-iodine for Graves' disease and one for thyroid carcinoma. It was found that the highest radiation dose received by the volunteer was only 13.5% of the annual dose limit for individual members of the public. Hence, patients treated with radio-iodine do not pose a significant radiation hazard to the public.

Matched MeSH terms: Iodine Radioisotopes/therapeutic use*

Fulltext Radionuclide therapy of hepatocellular carcinoma

Sundram F

Biomed Imaging Interv J, 2006 Jul;2(3):e40.

PMID: 21614248 MyJurnal DOI: 10.2349/biij.2.3.e40

Hepatocellular carcinoma (HCC) is a malignant tumour of the hepatocyte. It is a common malignancy worldwide and causes almost half a million deaths annually. Asia is a high risk area. Although surgery (hepatectomy or liver transplantation) is the main form of curative treatment, the majority of patients are not eligible for surgery due to extent of tumour and dysfunction of liver. Radiopharmaceuticals used for transarterial treatment of HCC were Yttrium-90 microspheres, Iodine-131 lipiodol, Rhenium-188 lipiodol, and Holmium-166 Chitosan complex. Yittrium-90 microspheres are glass or resin microspheres of mean sphere diameter of 20 to 30 micrometre. The activity administered was about 4 GBq. Reported response rate was about 20%, and median survival was 54 weeks. On inoperable tumours, reported objective response of I-131 lipiodol was 40 to 70%, and median survival was six to nine months. It showed efficacy similar to TACE. In adjuvant treatment following curative resection of HCC, reported three year survival was 86% compared with 46% for the control group. The administered activity in both adjuvant and inoperable HCC was about 2 GBq (55 mCi). Rhenium-188 lipiodol is a new radioconjugate, and using it we treated 70 patients with inoperable HCC. This treatment was a part of a multi-centre trial sponsored by the International Atomic Energy Agency. Partial response was obtained in 17% of cases, while 49% had stable disease at three months, and 34% showed disease progression. In terms of survival, 19% survived one year, 60% for six months, and 90% for three months. The mean activity was about 4.6 GBq (124 mCi). This method was safe and free from adverse effects.

Matched MeSH terms: Iodine Radioisotopes

Fulltext Clinical use of PET/CT in thyroid cancer diagnosis and management

Sundram F

Biomed Imaging Interv J, 2006 Oct;2(4):e56.

PMID: 21614336 MyJurnal DOI: 10.2349/biij.2.4.e56

The incidence of thyroid cancer is low, but when it occurs, it is mainly of the papillary histopathological type. Although PET/CT has a limited role in the diagnosis, it plays a significant role in the overall post-surgery management of a patient with thyroid cancer. This follow-up role is important, especially in patients with elevated serum thyroglobulin, but negative radioiodine whole body scans. There is increasing evidence that PET/CT should be a part of routine care in the Tg positive Radioiodine scan negative patient.

Matched MeSH terms: Iodine Radioisotopes

Fulltext Cardiac Iodine-123-Meta-Iodo-Benzylguanidine Uptake in Carotid Sinus Hypersensitivity

Tan MP, Murray A, Hawkins T, Chadwick TJ, Kerr SR, Parry SW

PLoS One, 2015;10(6):e0126241.

PMID: 26057525 DOI: 10.1371/journal.pone.0126241

Carotid sinus syndrome is the association of carotid sinus hypersensitivity with syncope, unexplained falls and drop attacks in generally older people. We evaluated cardiac sympathetic innervation in this disorder in individuals with carotid sinus syndrome, asymptomatic carotid sinus hypersensitivity and controls without carotid sinus hypersensitivity.

Matched MeSH terms: Iodine Radioisotopes/metabolism*

Pre-ablative diagnostic whole-body scan following total thyroidectomy for well-differentiated thyroid cancer: is it necessary?

Teoh CM, Rohaizak M, Chan KY, Jasmi AY, Fuad I

Asian J Surg, 2005 Apr;28(2):90-6.

PMID: 15851360

This study reviewed the incidence of positive pre-ablative diagnostic scan after total thyroidectomy and the efficacy of the current ablative dose. The predictive factors for outcome using a standard ablative dose and postoperative complications of total thyroidectomy were also examined.

Matched MeSH terms: Iodine Radioisotopes/therapeutic use

Fulltext Deliberate self-harm in a patient with hyperthyroidism with acute psychosis

Wong HH, Pang NTP

BMJ Case Rep, 2021 Oct 14;14(10).

PMID: 34649855 DOI: 10.1136/bcr-2021-242333

A woman in her 30s with underlying Graves' disease, who recently completed radioactive iodine treatment, presented with 2 weeks of acutely altered behaviour associated with auditory hallucinations and religious preoccupations. Laboratory investigation demonstrated elevated free thyroxine levels and suppressed thyroid-stimulating hormone levels. Additionally, there was a presence of antithyroid peroxidase antibodies consistent with autoimmune thyroid disease. She responded to antipsychotics and achieved biochemical euthyroidism. Subsequently, antipsychotic was tapered off during outpatient follow-up at the patient's own request, with supplement thyroxine continuing. After 1 week, acute hallucinations and religious preoccupations re-emerged, driving her to inflict self-injuries by swallowing coins and nails and banging her head against the wall, sustaining laceration wounds. Furthermore, she hammered a roofing nail into the external genitalia, embedded in the symphysis pubis. After supplemental thyroxine was stopped and olanzapine was started, she achieved biochemical euthyroid followed by remission of psychosis within 1 week. This case illustrates the importance of elucidating organic causes of psychosis as they are easily and swiftly reversible.

Matched MeSH terms: Iodine Radioisotopes

Fulltext The use of SPECT-CT improves accuracy of post-radioiodine therapy imaging and changes the management strategy in a case of advanced follicular thyroid carcinoma

Wong TH, Amir Hassan SZ

Med J Malaysia, 2015 Dec;70(6):356-7.

PMID: 26988209

This is a case of follicular thyroid carcinoma with extensive lung, bone and brain metastases. Multi-modality treatments including total thyroidectomy, modified radical neck dissection, cranial radiotherapy and Iodine-131 (RAI) therapy were instituted. Post RAI therapy planar whole body scan showed RAI avid metastases in the skull, cervical spine, bilateral lungs and abdomen. With the use of SPECTCT imaging, rare adrenal metastasis and additional rib metastasis were identified. Besides, management strategy was altered due to detection of non-RAI avid brain and lung metastatic lesions.

Matched MeSH terms: Iodine Radioisotopes

Features of post-radioiodine whole body scan in non-invasive Follicular Thyroid Neoplasm with papillary-like nuclear features (NIFTP)

Wong TH, Tan TH, Chin SC, Lee BN

Med J Malaysia, 2018 06;73(3):181-182.

PMID: 29962506

Recently, encapsulated follicular variant of papillary thyroid carcinoma has been reclassified as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) to emphasize the benign nature of this entity. In our institution, we have assessed 455 patients treated with radioiodine ablation for differentiated thyroid carcinoma and 20 of them were retrospectively found to fulfill the new NIFTP criteria. There was no evidence of metastasis on post radioiodine whole body scans for NIFTP cases and these patients were in remission subsequently. The benign features of these patients' whole body scans and good clinical outcome following treatment further support NIFTP as a low risk thyroid neoplasm.

Matched MeSH terms: Iodine Radioisotopes

Fulltext Results of long-term follow-up after compensated fixed-dose therapy for thyrotoxicosis

Zaini A, Khir A, Doi SA, Chan SP, Paramsothy M, Khoo BH

J Int Med Res, 1992 Jun;20(3):279-88.

PMID: 1397673

To evaluate the effects of simple compensated fixed-dose iodine-131 therapy for thyrotoxicosis, the long-term results for 74 patients treated with a fixed dose of iodine-131 ranging from 5 to 12 mCi (185 to 444 MBq) were evaluated in the first 2 years of a trial. The dose selected was loosely based on the gross size of the thyroid gland. Routine antithyroid drug therapy was given for a minimum of 3 months after iodine-131 therapy. The mean (+/- SD) duration of follow-up was 74.5 +/- 42 months. The results indicated that roughly 25% of patients treated in this way will become hypothyroid after 5 years and that 85% are cured (need no further therapy during the follow-up period) using a single dose of iodine-131. Of those cured using a single iodine-131 dose, 81% were no longer receiving drugs after 6 months and 85% after 1 year. Such a regimen seems currently to be among the best available where prolonged periods of medication-free euthyroidism after therapy are sought.

Matched MeSH terms: Iodine Radioisotopes/therapeutic use*

Fulltext Transient hypothyroidism following I131 treatment for thyrotoxicosis

Zaini A, Ngan A, Paramsothy M, Khoo BH, Ch'ng SL

Med J Malaysia, 1983 Dec;38(4):331-3.

PMID: 6599994

Matched MeSH terms: Iodine Radioisotopes/adverse effects*; Iodine Radioisotopes/therapeutic use

Hyperthyroidism in pregnancy

Zainuddin Z, Shaker AAH

Family Physician, 2005;13(3):2-4.

MyJurnal

Thyroid diseases are common in women, including at the time of pregnancies. Many typical features of hyperthyroidism are common in normal pregnancies and this may delay or mask the diagnosis. Uncontrolled thyrotoxicosis increases the rate of miscarriage, intrauterine growth restriction (IUGR), premature labour and perinatal mortality. Multi-disciplinary efforts are required to achieve optimal control of thyrotoxicosis. Anti-thyroid drugs are safe and should be used with the lowest possible doses. Radioiodine treatment is contraindicated during pregnancy and lactation. Indications of surgery include: compression symptoms, thyroid malignancy, non-compliance to medications or when the patient develop drugs side effects

Matched MeSH terms: Iodine Radioisotopes

Fulltext Understanding issues in preparing patients for radioactive iodine treatment of thyroid disorders

Zanial AZ, Hamzah F

The Malaysian Journal of Nursing, 2015;7(1):3-6.

MyJurnal

Thyroid disorders could be broadly categorised into benign and malignant diseases. Approaches for the
management of benign and malignant thyroid disorders have been well documented including the treatment
using radioactive iodine (RAI). RAI has long been used to treat hyperthyroidism and well differentiated
thyroid cancer. Nevertheless, there are various factors that may influence the outcome of RAI treatment
including matters related to patient preparations. Thus, healthcare personnel play an important role in
assisting patients to make the necessary preparations. This article aims to give nurses and clinicians of
various specialities an insight into the overview of RAI treatment for thyroid disorders particularly in
Malaysia and further discusses the issues related to preparations of patients.

Matched MeSH terms: Iodine Radioisotopes

Displaying publications 21 - 34 of 34 in total