Difficulties in deciding whether to ablate patients with putatively "low-intermediate-risk" differentiated thyroid carcinoma: do guidelines mainly apply in the centres that produce them? Results of a retrospective, two-centre quality assurance study

PURPOSE

We determined the reasons for radioiodine thyroid remnant ablation, and the procedure's necessity based on postsurgical remnant size, in patients with putatively "low-intermediate-risk" differentiated thyroid carcinoma (DTC). We identified key clinicopathological, treatment and remnant characteristics, and factors associated with remnant size in 336 patients with pT1/2, M0 DTC ablated during the period September 2010 to October 2013 at one Cypriot or one Greek referral centre.

METHODS

Clinicopathological/treatment characteristics were compiled from charts. Experienced nuclear medicine physicians rated the numbers/intensities of uptake foci in the thyroid bed on postablation planar scintigrams using scales of 0-4 points and 0-3 points, respectively. The product of these scores was taken as the "remnant score" that ranged from 0 (no remnant) to 12 (multiple remnants, intense uptake).

RESULTS

DTC was predominantly papillary. The median [25th-75th percentile] longest primary tumour diameter was 1.0 cm [0.7-1.5 cm]. Despite favourable histotypes and primary tumour classifications, patients often had preablation characteristics suggesting elevated or uncertain risk: 31.0% of patients (104 of 336) had primary tumour multifocality, 22.0% (74) had confirmed cervical lymph node metastases, 37.2% (125) had unknown nodal status, and 38.1% (128) had antithyroglobulin antibody seropositivity. The median [25th-75th percentile] remnant score was 4 [2-6]; 39.9% of patients (134 of 336) had scores ≥6. For the entire cohort, T or N stages (r ≤ 0.174, P ≤ 0.05) correlated positively with the remnant score in a univariate Spearman analysis. The numbers of patients referred by the surgeon, cervical lymph nodes excised and metastatic nodes excised correlated negatively (r ≤ 0.243, P ≤ 0.038) with the remnant score, and the first two factors independently predicted the remnant score (P ≤ 0.037) in a multivariate analysis.

CONCLUSION

Patients with putatively "low-intermediate-risk" DTC frequently had disease characteristics denoting high or uncertain risk, suggesting that "selective" radioiodine ablation in such patients may seldom be applicable outside international centres of excellence. Proxies for surgeon experience and surgical completeness correlated with remnant number/uptake intensity and may aid ablation-related decision-making.

[Nuclear Medicine in diagnosis of breast cancer]

Breast cancer is the most common malignancy among women worldwide, creating a significant need for improved imaging modalities. The advantage of molecular imaging over other imaging methods, as confirmed by clinical experience, is the ability of providing functional information. This process is achieved by labeling a biomarker with an isotope of choice. Therefore imaging methods such as scintimammography (SM), (18)F-fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography ((18)F-FDG PET/CT), positron emission mammography (PEM), lymphoscintigraphy, have proved to be extremely efficient compared to morphological imaging of anatomical lesions, as they allow the diagnosis, staging, assessment of therapeutic efficacy and patient monitoring to contribute as much as possible to improve the prognosis. The development of new radiopharmaceuticals in PET imaging, allowing the visualization and quantification of biomarkers, such as (18)F-fluoro-17-estradiol, which is bound by the estrogen receptors (ER), (18)F-fluoro-l-thymidine (FLT) which is a marker of cell proliferation, (18)F-fluoromisonidazole (FISO) a marker of tumor hypoxia and angiogenesis markers such as (18)F-fluoroazomycinarabinoside, may give us additional information on the characteristics and progress of the disease and allow the conduct of targeted therapy. Radioimmunoassay (RIA) using monoclonal antibodies in order to recognize serum markers such as CA 15.3, CEA, cytokeratins TPA, TPS and Cyfra 21.1, are necessary in the diagnosis of a possible recurrence of the disease as well as the degree of response to treatment. Modern research focusing on the development of new specific functional breast imaging methods improves diagnostic and therapeutic management of patients with breast cancer.

Primary hyperparathyroidism and incidental multifocal metastatic papillary thyroid carcinoma in a man

Co-existence of primary hyperparathyroidism (PHPT) and non-medullary thyroid carcinoma has been previously reported in sporadic case reports and some surgical series, but the majority of cases concerned women with occult papillary carcinomas without cervical lymph node involvement. We present a 71-year man with PHPT and multinodular goiter who was subjected to surgery for single parathyroid adenoma and was found to have synchronous multifocal papillary thyroid carcinoma (PTC) with cervical lymph node involvement. Review of the literature retrieved only a few similar cases. Ultrasonography of both thyroid and parathyroid glands might be considered in patients with hyperparathyroidism. Given that there are no specific guidelines for the management of patients with synchronous PHPT and PTC, they should be managed like the cases of single PTC.

Synchronous parathyroid adenoma and thyroid papillary carcinoma: a case report

A 51-year-old female patient presented with atypical chest pain, laryngo-oesophageal reflux, increased levels of serum calcium and parathyroid hormone. Ultrasonography showed a multinodular goiter with a prominent solid nodule in the lower left thyroid lobe and a solid hypoechoic nodule outside this area.

Tc99m-sestamibi parathyroid scintigraphy was performed to investigate a primary hyperparathyroidism, revealing an area with increased uptake in the lower left thyroid lobe and another area with marked uptake lower than this level. Thyroid scintigraphy with 99mTc showed a cold nodule of the left lower pole. FNA of the thyroid nodule was positive for papillary carcinoma later verified by postoperative histopathology.

This case underlines the need for a clinical high index of suspicion for synchronous hyperparathyroidism and thyroid cancer.