Value of radiologic correlation and follow-up scintigraphy in detecting osseous metastasis in patients with non-specific bone scintigraphy lesions

Bone scintigraphy is highly sensitive in detecting bone metastasis but specificity is only about 50-60%. The aim of this study is to evaluate the value of radiologic correlation and followwup scintigraphy in detecting osseous metastasis in patients with equivocal bone scans. Bone scan results with non-specific interpretation of bone lesions from January to December 2007 were included. Results with no evidence of bone metastasis or metastatic bone disease were excluded from the study. Correlation with radiographs [X-ray, CT-scan, MRI] and follow-up bone scan within 6 months from the initial bone scan were reviewed. Of the 2322 bone scans, 435 have non-specific findings of bone lesions. From 435, only 228 patients have records of radiograph correlation and scintigraphic follow-up. Twenty two percent of the total population showed positive findings of bone metastasis in radiographs. The percentages of the non-specific findings determined to be negative from bone metastasis on correlation with X-ray, CT-scan, MRI and follow-up bone scan were 84%, 70%,73%, and 85%, respectively, whereas osseous metastasis revealed on radiologic correlation and follow-up scan were 76%, 30%,27%, and 75%, respectively. In conclusion, the finding of osseous metastasis in bone scan is increased when correlated with radiographs and scintigraphic follow-up.

Metastatic thyroid carcinoma in the kidney

Thyroid carcinoma, particularly papillary thyroid carcinoma, may present with a wide range of clinical course--from an indolent to an aggressive form of poorly differentiated thyroid carcinoma. About 10% of patients with papillary thyroid cancer develop distant metastasis to the lymph nodes, lungs, mediastinum, or bone. Several cases of unusual metastasis to the kidney have been reported previously. A rare case of renal metastasis from papillary thyroid carcinoma and the roles of PET and SPECT-CT in its detection are presented here.

Primary tumor size and the mapped sentinel node: Nuclear medicine in the management of early stage breast carcinoma

A treatment option for early stage breast cancer is nodal evaluation by axillary lymph node dissection (ALND). An alternative to ALND is sentinel lymph node (SLN) biopsy employing radionuclide SLN mapping. This study was designed to investigate the relationship between malignancy spread to the SLN and primary tumor size by reviewing the clinical profile of 20 female breast cancer patients who underwent radionuclide SLN mapping procedure, sentinel lymph node and primary tumor biopsy, as well as axillary lymph node dissection. The accuracy of radionuclide mapping in the identifying the sentinel node and determining the status of the axillary lymph nodes was reviewed. Among the mapped sentinel nodes, 15% were positive for metastatic lymphadenopathy and 85% without malignant spread. The malignant sentinel nodes had a mean size of 5.5 ± 0.87 cm and the negative sentinel nodes had a mean size of 2.95 ±2.2 cm. The SLN identified by radionuclide mapping truly represented the status of the rest of the axillary nodes for the presence or absence of metastatic lymphadenopathy. Primary tumor size is a prognostic factor for cancer spread to the sentinel node. However, the combination of primary tumor histology and tumor size may prove to be a stronger prognostic indicator malignancy spread to the sentinel lymph node.

Parathyroid scintigraphy and gamma probe-guided surgery in the management of parathyroid carcinoma

This paper aims to present one of the rarest types of malignancies, parathyroid carcinoma. Parathyroid carcinoma is an important cause of primary hyper par athyroidism. Diagnostic evaluation of patients presenting with signs and symptoms of hyperparathyroidism consists of serum calcium and parathyroid hormone determination, parathyroid imaging using ultrasound, computed tomography, magnetic resonance imaging, or Tc-99m sestamibi scintigraphy, and histopathologic evaluation of tissues after surgical intervention. Therapeutic management of an identified parathyroid tumor is by parathyroidectomy during neck exploration or radioisotope-guided with the use of a gamma probe. The histology of a resected tumor determines if the initial surgery completes the management, or, in cases of parathyroid carcinoma, if another completion surgical intervention is to be made. This paper will present a patient who has been initially diagnosed with primary hyperparathyroidism and was referred to our nuclear medicine department for parathyroid scintigraphy. The patient underwent MIRP and rapid intraoperative PTH determination. Histopathologic report on the tissues revealed parathyroid carcinoma. The patient underwent a second surgery for definitive treatment. This paper will discuss the clinical role of nuclear medicine in the diagnosis and surgical management of parathyroid carcinoma.