Comparison of hyperparathyroidism types and utility of dual radiopharmaceutical acquisition with Tc99m sestamibi and 123I for localization of rapid washout parathyroid adenomas.

Tc99m-sestamibi dual-time imaging is a standard tool for localization of adenomas/hyperplasia in hyperparathyroidism. We investigated the degree and causes of localization failure among different types of hyperparathyroidism. Pre-operative parathyroid hormone levels and size of the gland were major determinants of Tc99m-sestamibi positivity; 123I scan may be helpful in localization failures. INTRODUCTION: Tc99m-sestamibi dual-time imaging is a standard tool for localization of adenomas/hyperplasia in hyperparathyroidism. However, parathyroid adenomas/hyperplasia has been reported to washout as fast as normal thyroid tissue ("rapid washout") which may lead to diagnostic failure. We aimed to evaluate the determinants of rapid washout and to determine the role of subtraction imaging for detection of parathyroid adenomas/hyperplasia with rapid washout. METHODS: Retrospective analysis of patients with hyperparathyroidism who have undergone Tc99m-sestamibi dual-time imaging and parathyroid surgery. Rapid washout was correlated to the type of hyperparathyroidism in surgically confirmed cases. Biochemical and pathological data were reviewed. RESULTS: A total of 135 hyperparathyroidism patients met the inclusion criteria. Ninety-six (72%), 29 (21%), and 10 (7%) had primary, secondary, and tertiary hyperparathyroidisms, respectively. Rapid washout was identified in 28/87 glands (32%), 14/53 glands (26%), and 1/16 glands (6%) with primary, secondary, and tertiary hyperparathyroidisms, respectively. Glands that were positive on late-phase Tc99m-sestamibi scans were significantly large being 1.7 (IQR 1.4-2.3) vs. 1.45 (IQR 1-2) cm (p = 0.003). High parathyroid hormone levels (PTH) were associated with early-phase Tc99m-sestamibi positivity in both primary (p = 0.01) and secondary hyperparathyroidism (p = 0.03) but not with last phase (p = 0.11, p = 0.37, respectively). Correlative imaging with subtraction scintigraphy was positive in 14/16 (87.5%) parathyroid adenomas. CONCLUSION: Pre-operative PTH levels and size of the gland were major determinants of Tc99m-sestamibi positivity on early-phase Tc99m-sestamibi scans, whereas size is an independent predictor of late-phase Tc99m-sestamibi positivity. Subtraction scintigraphy might be a useful tool in suspected cases of rapid washout adenomas/hyperplasia.

Sialoadenitis secondary to ¹³¹I therapy for well-differentiated thyroid cancer.

Radioiodine (¹³¹I) is an important therapy for patients who have well-differentiated thyroid cancer. However, ¹³¹I may also result in side effects in multiple organs and glands. The glands that are frequently affected are the salivary glands with the major untoward effects including sialoadenitis and increased risk of second primary malignancy. This report will review sialoadenitis secondary to ¹³¹I therapy including (1) proposed mechanisms, (2) incidence and clinical presentations, (3) possible approaches to improve prevention, (4) management, and (5) sequelae of sialoadenitis (e.g. xerostomia and salivary duct obstruction). A discussion of second primary malignancies is beyond the scope of this review. With a better understanding of the above, dentists, oral surgeons, otolaryngologists, endocrinologists, nuclear medicine physicians, and nuclear radiologists will be more likely to implement more effective preventive measures to reduce the incidence and severity of ¹³¹I-induced sialoadenitis, and if it does occur, to identify and treat sialoadenitis sooner, thereby potentially reducing not only the severity of the initial symptoms, but also the severity of subsequent sequelae.

The relative frequency in which empiric dosages of radioiodine would potentially overtreat or undertreat patients who have metastatic well-differentiated thyroid cancer.

The dosage of (131)I for the treatment of metastatic well-differentiated thyroid cancer is typically selected empirically. Benua and Leeper implemented a method to estimate the maximum dosages of (131)I that could be administered to a patient so as not to exceed a maximum tolerated radiation absorbed dose (MTD), which was defined as 200 rads (cGy) to the blood. The objective of this study was to determine the frequency of (131)I treatments in which the patient (1) would have exceeded the MTD (i.e., overtreatment) or (2) would have been able to receive higher dosages of (131)I thereby delivering a potentially higher radiation absorbed dose to their metastases (i.e., undertreatment) had the patient been administered various assumed empiric dosages of (131)I. The dosimetrically-determined maximum tolerated radioactivities (MTA) to deliver 200 rads to the blood (MTD) were tabulated at our facility. Data were then grouped to determine the percentage of patients who would have received less than or more than the MTD for various assumed empiric dosages of (131)I. A total of 127 dosimetries were performed. For assumed empiric dosages of (131)I (100 mCi, 150 mCi, 200 mCi, 250 mCi, and 300 mCi), the percentage of treatments for which patients would have exceeded the MTD were less than 1%, 5%, 11%, 17%, and 22%, respectively, and could have received a higher dosage of (131)I were more than 99%, 95%, 89%, 83%, and 78%, respectively. A significant number of patients receiving various empiric dosages of (131)I may exceed 200 rads (cGy) to the blood (potential overtreating). Likewise, the majority of patients may be able to receive much higher dosages of (131)I relative to empiric dosages thereby delivering potentially higher radiation absorbed doses to the metastases without exceeding 200 rads (cGy) to the blood (potential undertreating).

Prospective serial technetium diphosphonate and indium-111 white blood cell labeled imaging in primary uncemented total hip arthroplasty.

Although technetium diphosphonate (TcMP) and Indium-111 white blood cell labeled (Ind-WBC) imaging are reported useful in identifying aseptic and septic loosening in cemented hip arthroplasty, their usefulness has not been identified in uncemented porous coated hip arthroplasty. We attempted to define the natural history of TcMP and Ind-WBC imaging in primary P.C.A. uncemented total hip arthroplasty. Twenty-five hips in 21 patients were scanned immediately postoperatively, at 3 months, 6 months, 12 months, 18 months, and 24 months after surgery with both TcMP and Ind-WBC tracers. Clinical and radiographic follow-up were also obtained at each interval. Intensity and distribution of tracer activity were recorded as well as the time when stabilization occurred around the acetabulum, femoral porous surface areas, and femoral stem tip. Acetabular cup and femoral porous surface areas stabilized in the first year on both TcMP and Ind-WBC imaging. Focal femoral hip activity continued at 24 months in 72% of TcMP and 24% of Ind-WBC images. TcMP and Ind-WBC images used to assess uncemented total hip arthroplasty should not be over interpreted. Although persistent intense activity after one year around the acetabulum and porous surface femoral areas should be considered abnormal for both TcMP and Ind-WBC scans, femoral tip activity is present in the majority of patients, with or without thigh pain, at 24 months on TcMP scans. Tip activity can also persist at 24 months on Ind-WBC images and should be interpreted in conjunction with TcMP images.

The use of scintigraphy in the management of patients with pulmonary aspiration.

Pulmonary aspiration was assessed using a scintigraphic swallowing procedure in 14 dysphagics in whom penetration of the larynx had been previously diagnosed. No patient had recent evidence of aspiration pneumonia. Imaging was performed during and following ingestion of a cupful of thin liquid admixed with between 1-2 mCi of Tc-99m sulfur colloid. Follow-up scans were obtained several hours later as needed to assess airway clearance. Five of the fourteen (36%) showed penetration distal to the trachea. Seven (50%) were indeterminate for aspiration, as isotope localized to the neck could not be clearly designated as being in either airway or foodway. Two subjects had negative studies. Of patients with subtracheal penetration, (1) fractions of the ingested material which were aspirated ranged from < 1%-25%, and (2) elimination from airways was complete or near-complete by 3 hours. The presence of an immediate or delayed cough was noted but did not correlate with subtracheal aspiration. Based on the results of scintigraphy, 8 of 9 patients on some form of liquid restriction at the time of testing were allowed to ease restrictions. Five patients without prior liquid restriction were allowed to continue to drink. We propose that scintigraphy provides important data on airway penetration and clearance that is useful in the dietary management of dysphagic patients.

Scintigraphic detection of salivary aspiration: description of a new diagnostic technique and case reports.

Pneumonia is the feared consequence of persistent aspiration of saliva. Although some persons with impaired protection of the laryngeal airway are thought to be at risk, it is not known with certainty which factors are important. Some patients receive tracheostomies to enhance airway safety, often without clear evidence of aspiration of oropharyngeal secretions. A simple, readily available technique is described by which oral secretions are scintigraphically labeled with technetium-99m sulfur colloid via slow intraoral infusion. Subsequent sequential chest imaging with a gamma camera allows detection and tracking of the aspirated material. Three persons are described in whom this technique was used. In one, the scintigraphic analysis was instrumental in implicating infected saliva as the likely source of recurrent pulmonary infections. Although the method is useful in detecting aspiration of saliva in high risk persons, more study is needed to equate the degree of aspiration visualized with the risk of pulmonary disease.

Scintigraphy for the detection and quantification of subglottic aspiration: preliminary observations.

Eleven patients with previously documented aspiration underwent a radioisotopic swallowing study to detect and quantify airway penetration. In those subjects able to complete a rapid-acquisition phase during swallowing, no laryngotracheal penetration was seen despite previous evidence of aspiration. However, sequential static pulmonary imaging showed significant aspiration in three individuals. Attempts were made to measure the percentage of ingested material aspirated and the clearance rate from the airways. Eight patients (73%) failed to show definite evidence of aspiration on scintigrams. It is hypothesized that the lack of scintigraphic detection in previously proven aspirators was due either to interval improvement of the dysphagia or to difficult-to-detect laryngotracheal aspiration. Isotopic imaging during swallowing appears to have little utility; however, after ingestion, the technique can demonstrate more distal penetration not detected on videofluoroscopy. More studies are suggested to better define the sensitivity and specificity of scintigraphy in aspiration detection and to determine whether these techniques have prognostic value that could alter patient management.

EEG and neuroimaging localization in partial epilepsy.

We have studied cortical localization provided by surface and sphenoidal electroencephalograms (EEGs) and that of computed tomography (CT), magnetic resonance imaging (MR) and single photon emission tomography (SPECT) in 58 patients with partial epilepsy. Each patient had EEG, MR and SPECT during a hospitalization period of 1-2 weeks. CT scans were obtained either during the same period or had been performed in the preceding year. EEG evaluation consisted of 3-5 days of continuous monitoring including video-telemetry and ambulatory recording as well as conventional EEGs with special electrode placements. Additionally 33 of 58 patients (55%) who were potential surgical candidates had sphenoidal recordings. All patients had an abnormal EEG which showed evidence of epileptic hyperexcitability. EEG abnormality was localized in 43 patients (74%). Neuroimaging studies were focally abnormal in 38 patients (66%); 12 CT (21%), 29 MR (50%) and 24 SPECT (41%). Thirty four of 43 patients with localized EEG had at least 1 focally abnormal neuroimaging study (79%), whereas 4 of 15 (27%) patients with non-localized EEG did so. Twenty-eight of 29 patients with focal MR (97%), 11 of 12 patients with focal CT (92%) and 20 of 24 patients with focal SPECT (83%) had a concordant focal EEG. EEG and neuroimaging localization agreed in all 15 patients in whom both MR and SPECT disclosed a concordant focal abnormality. This study demonstrates a significant (P less than 0.005) correlation between surface/sphenoid EEG and neuroimaging localization in partial epilepsy.

Lymphocele: the spectrum of scintigraphic findings in lymphoceles associated with renal transplant.

Lymphocele is a well recognized complication of renal transplant surgery. We performed a retrospective review of 305 renal transplant patients with over 2,500 scintigraphic exams to describe the pattern of activity on technetium-99m-DTPA blood flow and dynamic imaging, and iodine-131-OIH studies. Diagnostic criteria for a lymphocele were ultrasonic evidence of a perirenal fluid collection and analysis of that fluid that demonstrated BUN, creatinine, and electrolytes similar to the patient's plasma. Scintigraphic findings were attributed to a lymphocele if abnormalities were in the same area as the ultrasound fluid collection. Scintigraphic findings attributable to lymphocele resolved in all patients following surgical drainage or peritoneal window placement. Six of the 11 documented lymphoceles demonstrated a cold defect on initial dynamic images that "filled in" to equal background activity and another exceeded background. Three cases showed a rim of increased activity surrounding the lymphocele ("rim sign").

The acetabulum: a prospective study of three-phase bone and indium white blood cell scintigraphy following porous-coated hip arthroplasty.

Although few studies address the use of three-phase bone scanning (TPBS) and indium-111-labeled white blood cell scintigraphy (111In-WBC) in hip arthroplasty utilizing a porous-coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ form that seen with the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous-coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and 111In-WBC at approximately 7 days, and 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the acetabulum. All 25 prostheses (144 of 144 scans) demonstrated increased uptake on the bone-phase images. Although this activity decreased with time, 76% had persistent uptake at 24 mo. Twenty-three of 25 prostheses (126 of 140 scans) showed increased uptake on 111In-WBC scintigraphy, invariably decreasing with time, but with 37% having significant uptake at 24 mo. Scintigraphic patterns in the uncomplicated porous-coated hip arthroplasty patient appear to differ from patterns described in cemented prostheses.

Nasal radioiodine activity: a prospective study of frequency, intensity, and pattern.

The nose has been reported as a site of radioiodine accumulation on 131I whole-body scintigraphy. To determine the frequency, intensity, and pattern of nasal radioiodine accumulation, a prospective study was performed on 21 patients referred for 131I whole-body scintigraphy during a 26-mo interval. All patients were dosed with 5 mCi (18.5 MBq) of 131I p.o., and imaged 72 hr later. Ninety-five percent (20/21) of patients had nasal radioactivity greater than background, and in 75% (15/20) of positive patients the pattern of activity was round. Clinical follow-up of these patients has shown no evidence of tumor involvement in the nasal area. We conclude that nasal radioiodine activity is a normal finding. Radioiodine uptake in the nasal area, without clinical suspicion of metastatic disease, should not be considered a criterion for surgical intervention or radioiodine therapy.

Three-phase bone scan and indium white blood cell scintigraphy following porous coated hip arthroplasty: a prospective study of the prosthetic tip.

Although few reports address the use of three-phase bone scanning (TPBS) and 111In-labeled white blood cell (In-WBC) scintigraphy in hip arthroplasty utilizing a porous coated prosthesis, the literature suggests that scintigraphic patterns in the uncomplicated patient may differ from that seen in the cemented prosthesis. In an attempt to determine the scintigraphic natural history, 25 uncomplicated porous coated hip arthroplasties in 21 patients were prospectively studied with serial TPBS and In-WBC at approximately 7 days, and at 3, 6, 12, 18, and 24 mo postoperatively. This report deals with findings related to the prosthetic tip. Only one of 136 flow studies were abnormal and only two of 136 blood-pool images demonstrated focally increased activity. All 25 prostheses (120 of 143 scans) demonstrated increased uptake on the bone phase images. The area about the tip was divided into three segments; increased uptake at 24 mo was noted in the medial, distal, and lateral segments in 16%, 72%, and 56% of prostheses, respectively. Twenty of 25 prostheses (82 of 142 scans) showed uptake on In-WBC scintigraphy, being noted in 48% of prostheses at 24 mo. We conclude that scintigraphic patterns in the uncomplicated patient with a porous coated prosthesis appear to differ from patterns described in cemented prostheses.

In-111-labeled white blood cell uptake in noninfected closed fracture in humans: prospective study.

Since indium-111 white blood cell (In-111 WBC) scintigraphy is often used to evaluate for osteomyelitis in bone fractures, it is important to know if noninfected fractures have In-111 WBC uptake. Twenty-seven noninfected closed fracture sites in 19 patients were prospectively evaluated with technetium-99m methylene diphosphonate bone scintigraphy and In-111 WBC scintigraphy. In-111 WBC uptake was present in 41% of the 27 sites. In the 11 positive sites, the In-111 WBC uptake was 1+ (definite but minimal) in 55%, 2+ (moderate) in 36%, and 3+ (marked) in 9%. The visual intensity of the radioactive uptake on In-111 WBC scintigrams relative to that on bone scintigrams was less in 82%, equal in 9%, and greater in 9%. The visual size of the area of uptake on In-111 WBC scintigrams and bone scintigrams was smaller in 36%, equal in 55%, and greater in 9%. Factors that may help distinction of In-111 WBC uptake due to fracture alone from infection associated with fracture are discussed.

Diagnosis of infection by preoperative scintigraphy with indium-labeled white blood cells.

Scintigraphy with indium-labeled white blood cells has been reported to be sensitive and specific in the diagnosis of low-grade sepsis of the musculoskeletal system. We reviewed the records of fifty patients who had suspected osteomyelitis or suspected infection about a total joint prosthesis and who underwent scintigraphy with technetium-99m methylene diphosphonate and scintigraphy with indium-111 oxine-labeled white blood cells before an open surgical procedure. Any patient who received preoperative antibiotics was not included in the study. For all of the patients, gram-stain examination of smears, evaluation of a culture of material from the operative site, and histological examination were done. The patients were divided into two groups. Group I was composed of twenty-four patients, each of whom had a prosthesis in place and complained of pain. Group II was composed of twenty-six patients for whom a diagnosis of chronic osteomyelitis had to be considered. With the indium scans alone, there was only one false-negative result (in Group II), but there were eighteen false-positive results (eight patients in Group II and ten patients in Group I). Although scintigraphy with indium-labeled white blood cells is quite sensitive, it is not specific in detecting chronic osteomyelitis; a negative scan should be considered highly suggestive that osteomyelitis is not present. Specificity can be increased by interpreting the indium scan in conjunction with the technetium scan.

Hypertrophic pulmonary osteoarthropathy and breast cancer.

Hypertrophic pulmonary osteoarthropathy is an uncommon, poorly understood syndrome usually seen with bronchogenic carcinomas, and rarely with tumors metastatic to the lungs or mediastinum. In a review of the literature, we have found only 140 cases associated with nonbronchogenic intrathoracic tumors. We have reported a case associated with metastatic breast carcinoma in which surgical resection led to rapid disappearance of the syndrome and prolonged palliation for the patient.

Side effects of "rational dose" iodine-131 therapy for metastatic well-differentiated thyroid carcinoma.

Benua, Leeper, and others (BEL) have advocated the estimation of radiation exposure to the blood to select a more rational maximum safe dose of radioiodine (dosimetry) to treat metastatic functioning well-differentiated thyroid carcinoma. After adopting the BEL dosimetry approach, we reviewed the immediate (during hospitalization) and intermediate (from discharge up to 3 mo) side effects after our initial 15 therapies in ten patients. The doses ranged from 51 mCi (1,887 MBq) to 450 mCi (16.65 GBq). Immediate side effects were observed in 12/15 (80%), are described in detail, and were as follows: gastrointestinal 10/15, salivary 9/15, nonsalivary neck pain, swelling, etc. 2/15, pulmonary 0/15. Intermediate side effects were observed in 10/15 (67%), are described in detail, and were as follows: gastrointestinal 0/15, salivary 3/15, nonsalivary neck pain, swelling, etc. 3/15, nasal complaints 2/15, transient bone marrow suppression 9/10, pulmonary 0/15. No patient required blood transfusions or had complications secondary to reduced blood counts. All patient complaints resolved; however, several patients may have reduced baseline blood counts one year after therapy. No other long-term side effect has been noted but the mean follow-up has been only 15 mo. In our opinion, we have not observed any side effect to date which would contraindicate the continued use and evaluation of the BEL dosimetry approach.

Radionuclide bone scanning in giant cell tumor.

Radionuclide bone scan findings are described and correlated with pathology in 23 patients with giant cell tumor (GCT) of the bone. The degree of radionuclide activity was markedly increased in 20 (87%), minimally increased in three (13%), and decreased in none of the patients. Of the 23 patients with increased radioactivity, the pattern was diffuse in 11 (48%) and doughnut in 12 (52%). Extended patterns of radioactivity were present in 19 of 22 patients; however, none were associated with true tumor extension. Bone scanning did not aid in the detection of GCT, was nonspecific, and did not differentiate benign from malignant GCT. Although radioactivity extended beyond the radiographic abnormality in the majority of patients, this was most likely secondary to other bony abnormalities or local and/or regional hyperemia, and caution should be taken in ascribing this extension to either tumor or metastasis.