Exceptionally Rare Isolated Thyroidal Metastasis of Pulmonary Carcinosarcoma: A Tale of 18F-FDG-positive Thyroid Nodule

Pulmonary carcinosarcomas (PCS) are uncommon and aggressive malignant tumors with epithelial and mesenchymal components and have a worse prognosis than other non-small-cell lung cancers. Metastases of non-thyroidal malignancies to the thyroid are rare. We reported a unique case of isolated thyroidal metastasis of PCS and discussed 18F-fluorodeoxyglucose (18F-FDG) positivity in incidentally found thyroid nodules on 18F-FDG positron emission tomography scan.

Sonographic Features of Atypical and Initially Missed Parathyroid Adenomas: Lessons Learned From a Single-Center Cohort

CONTEXT

Awareness of typical and atypical ultrasonographic (US) features of parathyroid adenomas (PAs) is crucial since US is the most widely used first-line imaging modality.

OBJECTIVE

The purpose of this study was to describe the atypical features of PAs on US and other possible factors leading to a false negative examination in a large single-center cohort.

MATERIALS AND METHODS

The US records of 457 PAs in 445 patients with biochemically proven primary hyperparathyroidism (PHPT) were evaluated in a prospectively maintained database. Atypical size, composition, shape, echogenicity, location, and vascular pattern on US were noted. For patients who previously had at least one negative US examination in referring centers, the main possible reason was defined accordingly.

RESULTS

The study group included 359 female and 86 male patients with PHPT. Typical sonographic features were observed in 231 PAs (51%), whereas 226 (49%) had at least one atypical US feature. The most common atypical features were atypical size (29%), followed by atypical echogenicity (19%), shape (8%), location (7%), and composition (7%), respectively. There were 122 initially missed PAs in all groups. The most frequent main atypical US features leading to false negative examinations were atypical size (22.1%) and atypical location (18.8%). Inexperience was third most common reason (16.3%) for false negative US examinations.

CONCLUSIONS

Almost half of PAs have at least one atypical feature on US. Awareness of the high prevalence of atypical US features could increase the accuracy of US examination and potentially decrease demand for more expensive second-line imaging modalities.

Early Dynamic Risk Stratification Decreases Rate of Ablative and Adjuvant Radioiodine Use in ATA Low and Intermediate Risk Papillary Thyroid Cancer Patients

Objectives

In differentiated thyroid cancer (DTC), radioiodine (RAI) therapy is most frequently employed for remnant ablation or as adjuvant therapy for the remaining disease. The application of RAI to patients classified as intermediate risk (InR) is still a matter of debate. The aim of this study is to analyze the effect of early postoperative risk assessment on RAI use on papillary thyroid cancer patients who are classified as low risk (LoR) or InR.

Methods

This is a single-center, prospective registry study. One-hundred-eighty-six patients operated between January 2012 and August 2021 and categorized as LoR or InR were included in this study. All patients had total thyroidectomy and central lymph node dissection by the same endocrine surgeon. An early dynamic risk assessment (EDRA) consisting of neck ultrasonography, serum thyroglobulin (Tg) and anti-Tg levels was performed 6 weeks after surgery. Most of the patients were either followed up without RAI or received ablative low activity (30-50 mCi) RAI based on predetermined criteria.

Results

Median follow-up was 63 months. Sixty-six (61%) patients in the LoR group and 43 (56%) patients in the InR group did not receive RAI treatment. Thirty-eight (35%) and 22 (29%) patients in LoR and InR groups received ablative (30-50 mCi) RAI therapy, respectively. In LoR group 5 (4.6%) patients and in InR group 12 (16%) patients received 100 mCi or more RAI activity. Only one patient in the InR group recurred during follow-up. No statistically significant difference regarding local recurrence was found between patients who didn't receive RAI or were treated with RAI within both LoR (p=0.152) and InR (p=0.272) groups.

Conclusion

There is consensus for LoR patients about omitting RAI therapy after surgery. Indications for RAI treatment in InR DTC are still under debate. RAI use based on EDRA seems to be a better option than decisions solely made on histopathological risk factors and decreases adjuvant high-activity RAI use without increasing recurrence risk.

The sonographer's and pathologist's perspective of echogenic microfoci in papillary thyroid carcinoma

Objective

Punctate echogenic foci (PEF)/microcalcifications are thought to represent psammoma bodies (PB) in histopathology. However, there are few and contradictory data on this. Different types of sonographic echogenic microfoci (EMF) are seen in papillary thyroid carcinoma (PTC), and their histopathological equivalents are not clearly known. There is also conflicting data on the interobserver agreement between the sonographers on EMF.

Methods

We prospectively collected US video records of PTC nodules with and without EMF in two large thyroid centers. All video recordings were independently interpreted by three blinded, experienced sonographers. EMF were classified as true microcalcifications (punctate echogenic foci (PEF) ≤1 mm long), linear microechogenities (>1 mm long, posterior acoustic enhancement of the back wall of a microcystic area), comet-tail artifacts/reverberations or linear microechogenities with comet-tail artifacts/reverberations, non-shadowing coarse echogenic foci (>1 mm nonlinear areas) and unclassifiable. Histopathological evaluation was performed by two blinded, qualified pathologists.

Results

A total of 114 malignant nodules were included. The average Cohen's kappa (κ) of three sonographers for the EMF presence was 0.775, indicating substantial agreement. A substantial agreement for PEF with 0.658 κ, only fair agreement for other types of EMF with 0.052 to 0.296 κ were detected. EMF were significantly associated with PB and papillae. PEF had an evident relationship with PB in multivariate analysis. There was a strong positive correlation between the amount of PEF and PB (r = 0.634, P < 0.001).

Conclusions

PEF in PTC mainly correspond to PB on histopathology. Although observation of EMF varies among sonographers, this inconsistency can be reduced by classifying EMF into subgroups and keeping the term 'PEF' only for true microcalcifications.

Differentiation of Benign and Malignant Thyroid Nodules with ANFIS by Using Genetic Algorithm and Proposing a Novel CAD-Based Risk Stratification System of Thyroid Nodules

The thyroid nodule risk stratification guidelines used in the literature are based on certain well-known sonographic features of nodules and are still subjective since the application of these characteristics strictly depends on the reading physician. These guidelines classify nodules according to the sub-features of limited sonographic signs. This study aims to overcome these limitations by examining the relationships of a wide range of ultrasound (US) signs in the differential diagnosis of nodules by using artificial intelligence methods. An innovative method based on training Adaptive-Network Based Fuzzy Inference Systems (ANFIS) by using Genetic Algorithm (GA) is used to differentiate malignant from benign thyroid nodules. The comparison of the results from the proposed method to the results from the commonly used derivative-based algorithms and Deep Neural Network (DNN) methods yielded that the proposed method is more successful in differentiating malignant from benign thyroid nodules. Furthermore, a novel computer aided diagnosis (CAD) based risk stratification system for the thyroid nodule's US classification that is not present in the literature is proposed.

Radioguided occult lesion localization for minimally-invasive parathyroidectomy without quick PTH monitoring and frozen section: impact of the learning curve

Objectives

Minimally-invasive parathyroidectomy (MIP) is a surgical procedure that reduces the duration of operation, hospital costs, and hypocalcemia, and shortens the length of hospital stay. This study addressed the important procedural details of the radioguided occult lesion localization (ROLL)-MIP technique and evaluated the consequences of the learning curve from a series of patients.

Patients and Methods

A total of 80 patients who underwent ROLL-MIP for a single parathyroid adenoma were included into this retrospective study. In order to analyze the effect of the learning curve, these subjects were then divided into 2 groups per time period and the operative times were compared. Group A consisted of 22 previously reported patients who served as the control group. Group B consisted of 58 consecutive patients.

Results

Serum calcium and parathyroid hormone (PTH) levels were normalized in all of the patients within 2 days and remained normal during the follow-up period (31 ± 18.5 months). None of the patients who underwent ROLL-guided parathyroidectomy suffered temporary or permanent recurrent laryngeal nerve injuries. Mean operation time (time from incision to excision of the adenoma) was 23 ± 6 min in Group A and 18 ± 7 min in Group B. Mean operative times were significantly shorter in group B.

Conclusion

The success of MIP administered with the ROLL technique in a single adenomatous patient was quite high. This method seems especially valuable in patients with atypically located or small adenomas.

The impact of the multifocality and subtypes of papillary thyroid carcinoma on central compartment lymph node metastasis

OBJECTIVE

Papillary thyroid carcinoma (PTC) may often appear as multifocal disease. Few studies demonstrated a higher rate of central compartment lymph node metastasis (CCLNM) in multifocal PTC patients. Therefore, the effect of different histological subtypes of multifocal PTC on CCLNM is another subject for further examination. The aim of the present study is to evaluate the rate of central lymph node positivity in multifocal PTC as compared to unifocal disease, and to identify the role of different histologic subtypes of PTC on central neck lymph node positivity.

PATIENTS AND METHODS

Patients with PTC who underwent total thyroidectomy (TT) + central cervical lymph node dissection (CCLND) at authors' institution between January 2012 and June 2016 were included (n=274). Independent Samples t-test, Mann-Whitney U test and Chi-square tests were used to determine univariate associations, and multivariate analysis was conducted by logistic regression.

RESULTS

The rate of CCLND positivity in multifocal PTC is higher than unifocal tumors and the difference is significant (p < 0.05). The univariate analysis demonstrated significant relation with male sex, lymphovascular invasion and size of dominant nodule > 10 mm regarding of CCLND positivity in multifocal PTC patients. The comparison between solitary and mixed histologic subtype of multifocal PTC is also significant (p < 0.05).

CONCLUSIONS

Multifocality is an important risk factor for CCLNM. Male sex, dominant tumor size >10 mm and mixed histological subtype in multifocal PTC may play an important role in CCLND positivity.

The risk of hypoparathyroidism after central compartment lymph node dissection in the surgical treatment of pT1, N0 thyroid papillary carcinoma

OBJECTIVE

The role of central compartment lymph node dissection (CCLND) in the treatment of papillary thyroid carcinoma (PTC) is still controversial. The benefits of CCLND should be weighed against its potential risks. We aim to evaluate the positivity of central lymph nodes in pT1, N0 PTC and to establish the complication rates of total thyroidectomy (TT)+CCLND.

PATIENTS AND METHODS

This is a retrospective study on prospectively collected data over a 45-month period. A total of 329 patients were included. Total thyroidectomy was performed in 130 (39.5%) of these patients due to benign thyroid pathologies, and 199 (60.5%) pT1, N0 PTC patients had TT+CCLND. Our TT technique was applied in the same way in both groups. Central lymph node positivity, the number of lymph nodes removed during CCLND and the operative complications were evaluated. T-test and chi-square analysis were conducted in independent groups for statistical evaluation.

RESULTS

The rate of central lymph node positivity in TT+CCLND group was 38%. The average number of lymph nodes removed by CCLND is 10.2 (1-36). Complication rates between TT and TT+CCLND groups were statistically significant (3.8% vs. 11.1%, respectively) (p<0.05). The difference was found to be particularly more pronounced for transient hypocalcemia. Although there was no significant relation between the number of lymph nodes removed during CCLND and the number of parathyroid glands detected in the pathology specimens (p>0.05), the relation between the development of symptomatic hypocalcemia and the number of the parathyroid glands removed during surgery was significant (p <0.05).

CONCLUSIONS

Central compartment lymph node metastasis in PTC is common. CCLND may increase the rate of transient hypocalcemia.

Schwannomatozis of the Chest Wall: FDG PET Findings

Authors present a rare case of bifocal schwannoma of thoracic wall showing metabolic activity on FDG PET images. A 43-year-old male with palpable mass on lateral chest wall was referred for F-18 FDG PET/CT imaging for differential diagnosis. His medical history and basic laboratory results were unremarkable. PET/CT images revealed a mild FDG uptake in the solid soft tissue mass in the left lateral chest wall that was growing outside of the thorax. It was located in 7th intercostal space and adjacent ribs were intact. Incidentally, second mass lesion was detected in the right posterior seventh intercostal space protruding to the pleural space and showing higher FDG uptake on PET/CT images. The lesions were surgically removed at the same session for definite diagnosis and treatment. Histopathologic evaluation of both lesions revealed benign schwannoma.

Sonographic measurement of diuretic-induced renal length changes: are they correlated with renal function?

OBJECTIVES

The purposes of this study were to prospectively identify diuretic-induced renal length changes and to determine whether the percentages of the renal length changes allow estimation of the differential renal function.

METHODS

Twenty-three children (14 boys and 9 girls; mean age, 7.83 years) who were undergoing technetium Tc 99m diethylenetriamine pentaacetic acid or technetium Tc 99m mercaptoacetyltriglycine diuretic renography were included in this study. Renal lengths were measured by sonography just before and 15 to 20 minutes after diuretic injection. The Spearman test was used to assess the correlation between renal length increases due to diuretic injection and the differential renal function.

RESULTS

The mean renal lengths ± SD measured before and after diuretic administration were 91.52 ± 20.87 and 95.38 ± 21.46 mm, respectively. The increase in renal length after diuretic administration was statistically significant (P < .001). There was a positive correlation between the renal length change and functional status (P = .006).

CONCLUSIONS

Renal length may change after diuretic injection according to the functional status, and the sonographic measurements of these changes may be used as an alternative to other imaging methods in estimation of renal function.

Saving the zone of stasis in burns with activated protein C: an experimental study in rats

Salvage of the zone of stasis is a major subject of focus in burn research. Use of various antithrombotic, anti-inflammatory and antioxidant drugs have been studied experimentally, with reports of favourable results; however, none became popular in clinical practice. Activated protein C (APC) is a well-known physiologic anticoagulant. Recent studies revealed that APC contributes not only to systemic anticoagulant activities but also to anti-inflammatory activities by inhibiting leucocyte activation associated with TNF production. The likely favourable effects of APC on salvage of the zone of stasis were investigated on a well-described experimental rat burn model representing the zone of stasis according to the 'burn comb model'. Twenty Sprague-Dawley rats were used and randomly separated into experimental and control groups. Two hours after inducing injury, 100 microg kg(-1) APC (Sigma, Boehringer Ingelheim, Germany) was administered to the experimental group through the caudal vein while 0.9% saline was injected through the same route in the control group. Laser Doppler flowmetry measurements and autoradiography were used for evaluation of perfusion and viability in the zone of stasis. At day 3, the differences between the results obtained from the treatment and the control groups were found to be statistically significant (p<0.05). Our experimental study revealed that APC improved tissue perfusion and decreased the area of skin necrosis in the zone of stasis in rats. The dual effect of APC, each of which has been shown to be favourable in saving the zone of stasis, may make this agent effective with a single effect in treatment of burn injury.

Performance of acidified 14C-urea capsule breath test during pantoprazole and ranitidine treatment

BACKGROUND AND AIM

Urea breath test (UBT) results could be false negative in patients taking antisecretory drugs. This effect would be prevented by citric acid administration during UBT. We prospectively investigated whether acidified 14C-urea capsule prevents false negative UBT results in patients taking antisecretory drugs and show interference with the duration of medications.

METHODS

Sixty Helicobacter pylori positive patients were included. Pantoprazole (40 mg/day) was given to 27 patients for 28 days and ranitidine (300 mg. o.d.) to 33 patients for 60 days. Urea breath tests were repeated on days 14 and 28 in both groups and on day 60 in the ranitidine group.

RESULTS

The baseline mean breath counts of two groups did not show any significant difference. Pantoprazole led to a significant decrease in mean breath counts on day 14 (P < 0.005). Six of 27 and 3 of 25 patients taking pantoprazole developed negative or equivocal UBT results on days 14 and 28, respectively. Two of 32, 2 of 32 and 3 of 21 patients taking ranitidine developed negative or equivocal UBT results on days 14, 28 and 60, respectively.

CONCLUSIONS

The use of acidified 14C-urea capsule did not prevent false negative UBT results in patients taking pantoprazole and ranitidine, and the duration of medication does not affect the test results.

Poor efficacy of ranitidine bismuth citrate-based triple therapies for Helicobacter pylori eradication

BACKGROUND

Helicobacter pylori eradication rates have tended to decrease recently possibly related with increasing antibiotic resistance. The present study investigated the efficacy of three different ranitidine bismuth citrate (RBC) based triple regimens in a population with high prevalence of H. pylori.

METHODS

300 consecutive H. pylori positive patients with non-ulcer dyspepsia were randomized into three regimens: (1) RBC 400 mg, amoxicillin 1000 mg and tetracycline 500 mg [RBC-AT], (2) RBC 400 mg, amoxicillin 1000 mg and clarithromycin 500 mg [RBC-AC], (3) RBC 400 mg, metronidazole 500 mg and tetracycline 500 mg [RBC-MT]. Tetracycline was given q.i.d, all other drugs were given b.i.d. for 14 days. Gastroscopy and (14)C-Urea breath test (UBT) were performed before enrollment and UBT only was repeated 6 weeks after the end of treatment.

RESULTS

274 patients completed the protocols. The overall 'intention to treat' and 'per protocol' H. pylori eradication rates in all subjects were 57.6% (95% CI: 52-63) and 63.1% (95% CI: 57-68), respectively. The eradication rates achieved in the groups (RBC-AT, RBC-AC and RBC-MT) were 64.4% (95% CI: 54-74), 66.2% (95% CI: 56-76), and 58.9% (95% CI: 49-68) on 'per protocol' analyses, respectively. There was no difference in eradication rates, compliance and major side effects between the groups.

CONCLUSION

The current RBC-based H. pylori eradication therapy is not adequately effective.

Rosai Dorfman disease of the parotid and submandibular glands: salivary gland scintigraphy and oral findings in two siblings

Rosai-Dorfman disease (RDD) is an unusual clinical entity characterized by benign pseudolymphomatous proliferation with significant histiocytic infiltration. In the present paper, extranodal RDD of the major salivary glands causing salivary hypofunction and the results of salivary gland scintigraphy and ultrasound are presented in two siblings. Case 1: a 10-year-old boy with bilateral painless masses around the parotid and submandibular glands was referred. Ultrasound examination showed bilateral, well-defined, hypoechoic solid mass lesions within both parotid glands with minimal normal parenchyma in the upper poles. Both submandibular glands were markedly hypoechoic and heterogeneous. Mass lesions within the parotid glands appeared as cold lesions with regular contours on scintigraphy. Dynamic images showed normal uptake and normal response to secretion in the upper poles of the parotid glands, corresponding with ultrasonographically normal parenchyma. Both submandibular glands showed markedly diminished uptake and secretion. Case 2: a 9-year-old boy presented with mass lesions around the submandibular glands. Ultrasound examination showed normal parotid glands and markedly hypoechoic and heterogeneous submandibular glands. Salivary gland scintigraphy showed normal uptake and secretion of parotid glands with markedly diminished uptake and secretion in both submandibular glands. There were severe carious lesions in both patients due to salivary hypofunction. Treatments of the two patients' teeth were performed. Major salivary gland involvement of RDD is important for dentists as it may cause xerostomia and can mimic dental abscess. Functional evaluation of salivary glands with scintigraphy, besides radiological and pathological techniques, will help to explain whether salivary glands are affected or not and improve the diagnostic effectiveness.

The efficacy of bismuth containing quadruple therapy as a first-line treatment option for Helicobacter pylori

BACKGROUND

Helicobacter pylori eradication rates have tended to decrease recently, mostly due to increasing antibiotic-resistance. The present study aimed to compare the efficacy of bismuth-based quadruple regimen with proton pump inhibitor-based triple regimen for eradication of H. pylori.

METHODS

Consecutive H. pylori-positive patients with non-ulcer dyspepsia were randomized into one of two regimens: (i) bismuth subsalicylate 300 mg q.i.d., lansoprazole 30 mg b.i.d., tetracycline 500 mg q.i.d. and metronidazole 500 mg t.i.d. (BLTM group) for 14 days; (ii) lansoprazole 30 mg b.i.d., amoxicillin 1 g b.i.d and clarithromycin 500 mg b.i.d. (LAC) for 14 days. Gastroscopy and (14)C-Urea breath test (UBT) were performed before enrollment, and UBT only was repeated for 6 weeks after treatment.

RESULTS

A total of 240 patients were randomized into groups and 212 of them completed the protocols. The 'intention-to-treat' (ITT) and 'per protocol' (PP) H. pylori eradication rates were 70% (95%CI 61-78) and 82.3% (95%CI 74-89) in the BLTM group, and 57.5% (95%CI 48-66) and 62.7% (95%CI 53-71) in the LAC group. The BLTM treatment achieved a significantly better eradication rate compared with LAC treatment in PP analysis (82.3% vs. 62.7%, P = 0.002). Mild to severe side-effects, which were more frequent in the BLTM group, were reported in 18.2% of the patients.

CONCLUSION

The bismuth-based quadruple regimen achieved a better eradication rate compared with proton pump inhibitor-based triple regimens as a first-line eradication option for H. pylori in our population.

Bilateral femoral insuffiency fractures treated with inflatable intramedullary nails: a case report

Stress fractures could be classified as fatigue fractures and insufficiency fractures (IF). Fatigue fractures occur when abnormal mechanical stress is applied to a normal bone, on the other hand insufficiency fractures occur when normal to moderate pressure is applied to a bone that has decreased resistance (Daffner and Pavlov in Am J Radiol 159:242-245, 1992). IF have been observed mainly in patients with postmenopausal osteoporosis, and are becoming more common with the increase of elderly population (Daffner and Pavlov in Am J Radiol 159:242-245, 1992). Other systemic and metabolic conditions that can result in osteopenia and IF include osteomalacia, hyperparathyroidism, hyperthyroidism, rheumatoid arthritis, fluoride treatment, diabetes mellitus, fibrous dysplasia, Paget's disease, irradiation and mechanical factors (Daffner and Pavlov in Am J Radiol 159:242-245, 1992; Soubrier et al. in Joint Bone Spine 70:209-218, 2003; Epps et al. in Am J Orthop 33:457-460, 2004; Austin and Chrissos in Orthopedics 28:795-797, 2005). In this case report, the authors present an osteoporotic woman who developed bilateral insufficiency fracture of the femoral shaft after longstanding steroid, thyroxine replacement and alendronate therapy due to partial empty sella syndrome and osteoporosis, resulting in the treatment of the fracture by inflatable intramedullary nailing.

Massive inguinoscrotal herniation of the bladder with ureter: incidental demonstration on bone scan

Inguinoscrotal herniation of the bladder is a rare clinical entity. The condition is often diagnosed incidentally or during the course of surgical repair of inguinal hernias. In a smaller number of cases, bladder hernia can be seen during nuclear medicine studies. We report a rare case of massive inguinoscrotal bladder herniation with ureter, causing urinary stasis on bone scintigraphy.

Assessment of distraction regenerate using quantitative bone scintigraphy

In this study, we examined whether quantitative bone scintigraphy can be used to assess new bone formation following distraction osteogenesis (DO). A vertical osteotomy was performed on the right hemimandible of male Sprague-Dawley rats, and a custom-made distraction device was applied. Following the gradual distraction, rats were divided into 2 subgroups, the second and fourth week. Cephalograms were taken and scintigraphic and histomorphometric analysis was performed at the second and fourth week. Scintigraphic findings showed good correlation with histomorphometric results. Results were compared with sham-operated (skin and muscle incision and placement of pin but no osteotomy) and acute distraction (5-mm acute distraction) groups. Scintigraphic mean uptake ratios were significantly higher in the gradual distraction group compared with the sham-operated and acute distraction groups. Quantitative bone scintigraphy is a promising method for the assessment of DO and consolidation. It could offer objective qualitative and quantitative data for the noninvasive evaluation of bony regenerate.

A physiologic approach to decreasing upward creep of the heart during myocardial perfusion imaging

When body position changes from erect to supine, the effect of gravity on the organs also changes and is a possible underlying mechanism for upward creep of the heart during SPECT acquisitions. We hypothesized that if we provide enough time for the organs to settle after a positional change, the range of this vertical motion causing reconstruction artifacts can be decreased. Our aim was to evaluate the effect that a 5-min bed rest on the imaging table before both rest and stress SPECT acquisitions would have on upward creep of the heart.

METHODS

Before both stress and rest SPECT acquisitions, the first 101 consecutive patients (group A) had a 5-min bed rest and the remaining 99 patients (group B) did not have any bed rest after they were positioned on the imaging table. Upward creep was detected by comparing the distance between the lower edge of the image and the lowest part of the heart silhouette on the last projection image of detector 2 and the first projection image of detector 1.

RESULTS

Upward creep was found in 53% (54/101) and 55% (56/101) of patients in group A and in 89% (88/99) and 86% (85/99) of patients in group B in stress and rest SPECT studies, respectively. Upward creep of the heart was decreased prominently in group A, and this decrease was statistically significant (p < 0.001).

CONCLUSION

We conclude that before SPECT acquisition, at least a 5-min bed rest on the imaging table significantly decreases vertical motion of the heart.

Disseminated metastatic disease of osteosarcoma of the femur in the abdomen: unusual metastatic pattern on Tc-99m MDP bone scan

A 25-year-old patient with osteosarcoma of the right distal femur underwent a bone scintigraphy with Tc-99m methylene diphosphonate (MDP). Whole-body bone scan revealed extensive metastatic disease in the abdominal region. Abdominal computerized tomography confirmed the presence of ascites and calcified masses on the greater omentum and peritoneal surfaces. Here we describe a case of unusual metastatic pattern of an osteosarcoma showing extensive intraabdominal metastases without prominent lung involvement after intensive chemotherapy.

Scintigraphic Imaging of Endothelium-Dependent Vasodilation in the Forearm A Preliminary Report

BACKGROUND

The diagnosis of endothelial dysfunction has been gaining clinical importance, but although endothelial function testing is available in the research setting, no technique yet exists that is simple, safe, reproducible and easily performed as a clinical screening method. The aim of this study was to design a new, scintigraphic method of imaging the flow-mediated dilation in the forearm, which represents the functional characteristic of endothelial dysfunction.

METHODS AND RESULTS

The study group comprised 118 subjects in whom left forearm ischemia was induced by inflating a sphygmomanometer cuff to supra systolic pressure for 4.5 min. Later, dynamic acquisition (2 s frame/min) was initiated after the injection of technetium-99m methoxy-isobutyl isonitril into the dorsal pedal veins. Equivalent regions of interest were drawn on both arms to detect total activity counts during 1 min and the perfusion ratios (left arm/right arm) were calculated. The left arm counts (22,203.3+/-12,372.7) were significantly higher than the right arm counts (9,980.9+/-5,931.9) (p<0.001). A significant decrease in perfusion ratios was noted in the hypertension and hypercholesterolemia groups. An increase in the number of risk factors caused an insignificant decrease in perfusion ratio (p=0.346).

CONCLUSION

Non-invasive evaluation of endothelium-dependent vasodilation by semiquantitative scintigraphic method using radioactive perfusion tracer provided promising results.

The effects of tangential radiotherapy on lung clearance in breast cancer patients

PURPOSE

The aim of this study was to investigate the effects of tangential radiotherapy (RT) on lung clearance in the patients with breast cancer by using (99m)Tc-DTPA aerosol scintigraphy.

MATERIAL AND METHODS

Thirty-three female patients [non-smoker: 20, ex-smoker: 13] performed surgery and systemic chemotherapy for breast carcinoma [47+/-13 years] were included in the study. All patients underwent (99m)Tc-DTPA aerosol scintigraphy prior to RT (pre RT), midway through RT (mid RT) and after RT (post RT). Total dose was 50 Gy in modified radical mastectomy and 60 Gy in lumpectomy (2 Gy/fraction). Posterior dynamic images of lungs were obtained immediately after the inhalation of (99m)Tc-DTPA aerosol.

RESULTS

Pulmonary function tests were normal in three measurements for all cases. In the ex-smokers, there was no significant difference among pre RT, mid RT and post RT clearance values in both lungs. Pre RT lung clearance in non-smoker group did not differ from that in ex-smokers. However, the lung clearance for non-smoker group showed significantly increase following RT.

CONCLUSION

In this study, we observed that tangential radiotherapy caused an increase in the lung clearance in the cases of non-smokers even in non-irradiated lung, and that the effect of RT on lung clearance was closely depended on smoking habit before RT.

Unilateral temporary functional stasis in the upper urinary tract caused by “a filled bladder” on Tc-99m DTPA diuresis renography: A teaching case

A 2-year-old girl with recurrent urinary tract infection having slight left pelvicaliceal dilatation on her renal ultrasound underwent a Tc-99m DTPA diuresis renography. During the excretion phase, a prominent and persisting left pelvicaliceal stasis was noticed even after the diuretic injection. However, it disappeared simultaneously with an uncontrolled micturition. This patient is presented to show the effect of filled bladder on the physiological drainage of urine. Since urine flow in the urinary system is more complicated than simple drainage, a thorough understanding of the physiological basis for diuresis renography and the pitfalls of the technique is required for its appropriate use in the management of patients suspected of urinary tract obstruction.

Fused pelvic kidneys: “hourglass sign” on Tc-99m DTPA diuresis renography

A 13-year-old girl with fused pelvic kidneys detected on ultrasonographic examination was referred to our department for a diuresis renography to assess urine drainage dynamics and exclude the possibility of urinary tract obstruction. Renal scan demonstrated fused pelvic kidneys functioning normally without obstruction. The authors present this case to demonstrate the diuresis renography findings of the combined position, fusion and rotation anomalies of the kidneys that is a rare congenital anomaly of the urinary tract.

Varices of inferior epigastric veins caused by chronic inferior vena cava obstruction: Mimicking normal venous flow pattern on radionuclide venography

A 21-year-old patient with long-standing inferior vena cava obstruction secondary to idiopathic thrombosis extending from the external iliac veins underwent a radionuclide venography with Tc-99m pertechnetate labeled erythrocytes. The blood pool phase of the study revealed bilaterally distorted inferior epigastric veins mimicking normal venous flow pattern. The authors present this case to discuss the possible alternative routes and the underlying physiopathologic mechanism of this unusual flow pattern in chronic inferior vena cava obstruction.

Unusual patterns of I-131 contamination

Whole body imaging with radioiodine can detect functioning metastases, which can often be effectively treated with appropriate amounts of radioiodine. Non-physiologic I-131 uptake detected on images is usually interpreted as suggesting functioning thyroid metastases. However, extra-thyroidal I-131 accumulation does not always imply thyroid cancer metastases and has been reported on many occasions, including various non-thyroidal neoplasms, and contamination by body secretions. In order to avoid unnecessary therapeutic interventions it is extremely important to properly distinguish false-positive sites of I-131 localization. Three patients with unusual radioiodine contamination patterns, either presented for the first time or rarely presented in the existing literature, were reported. Reported cases consist of contamination in hair (due to styling hair with sputum), contamination in neck (due to drooling during sleep) and, contaminated chewing gum. False positive contamination sources were clarified by careful examination of patients and further images when necessary.

Iodine-131 treatment and high-resolution CT: results in patients with lung metastases from differentiated thyroid carcinoma

Between 1984 and 2002, pulmonary metastases were detected in 42 (4%) out of 1,023 patients with differentiated thyroid carcinoma (DTC) in our department. The age at diagnosis ranged from 6 to 77 years. Lung metastases were diagnosed by both increased thyroglobulin (Tg) levels and positive uptake of iodine-131 on scans, and/or positive radiological findings. The primary tumours were histologically classified as papillary (30 patients), follicular (nine patients) and poorly differentiated (two tall cell, one insular carcinoma). The duration of follow-up ranged from 24 to 228 months. The end-results of the (131)I therapy were evaluated. The treatment of choice was (131)I therapy of metastases after total thyroidectomy plus lymph node dissection (if lymph node metastases were present). Applied single and total (131)I activities were 1.8-10.4 GBq and 5.5-43.7 GBq, respectively. Lung metastases were present at the time of diagnosis in 30 patients and developed during the follow-up period in the remaining 12. Twelve patients with extensive metastases died of thyroid carcinoma and another died due to secondary malignancy (malignant mesothelioma). Ten patients with lung metastases remain completely free of disease and are probably cured, while another seven were stable at the time of study. Three- and five-year survival rates were 86% (36/42) and 76% (32/42), respectively. To define the diagnostic value of high-resolution computed tomography (HRCT) and identify the distinctive features of lung metastases from DTC, 22 patients were further examined with HRCT within 2 weeks of the initial diagnosis of lung metastases and the results were compared with chest X-ray findings. HRCT detected metastases in 10 out of 14 patients with a normal chest X-ray and confirmed metastases in all patients with positive (n=5) and suspicious (n=3) chest X-ray. HRCT did not show any abnormalities in four patients with positive lung uptake on (131)I whole-body images. Stage of disease, existence of distance metastases other than to the lung, and HRCT characteristics were significant prognostic variables. Lung metastases from DTC can be cured with (131)I therapy in a considerable number of patients, especially when they are not associated with other distant metastases; they should therefore be treated at an early stage. HRCT clearly improved diagnostic ability in the evaluation of lung metastases compared with chest X-ray and should be the primary method when radiological correlation is needed. The main, and new, finding of the study is that HRCT not only improves diagnostic ability but is also of prognostic value.

Uterine doughnut in early proliferating phase: potential pitfall in gastrointestinal bleeding studies

A 41-year-old woman with rectal bleeding was referred to our department for gastrointestinal (GI) bleeding study. She was in early post-menstrual period and had stable vital signs. A GI bleeding study with Tc-99m SC revealed uterine blush in the pelvis. The shape of activity and quick fading excluded a GI bleeding. To rule out an intermittent bleeding, patient underwent a second bleeding study with Tc-99m RBC. Serial images showed uterine "doughnut" in the pelvis. The activity neither changed in shape nor showed distal movement with time excluding a GI hemorrhage. Uterus in early proliferating phase could be a potential pitfall in GI bleeding studies.

A new, practical, low-dose 14C-urea breath test for the diagnosis of Helicobacter pylori infection: clinical validation and comparison with the standard method

The carbon-14 urea breath test (UBT) is a reliable and non-invasive technique for the diagnosis of Helicobacter pylori (HP) infection. In this study we evaluated the diagnostic performance of a new, practical and low-dose (14)C-UBT system for the diagnosis of HP and compared the results with those obtained using the standard method. Seventy-five patients (56 female, 19 male) with dyspepsia underwent (14)C-UBT and endoscopy with antral biopsies for histological analysis. The rapid urease test (CLO test) was applied to 50 of these patients. After a 6-h fasting period, a 37-kBq (14)C-urea capsule was swallowed for UBT. Breath samples were collected and counted using two different methods, the Heliprobe method and the standard method. In the Heliprobe method, patients exhaled into a special dry cartridge system (Heliprobe BreathCard) at 10 min. The activities of the cartridges were counted using a designated small GM counter system (Heliprobe analyser). Results were expressed both as counts per minute (HCPM) and as grade (0, not infected; 1, equivocal; 2, infected) according to the counts. In the standard method, breath samples were collected by trapping in a liquid CO(2) absorber. Radioactivity was counted as disintegrations per minute (SDPM) using a liquid scintillation counter after addition of a liquid scintillation cocktail. Histological examination was used as a gold standard. Two patients were excluded from the study because of inadequate biopsy sampling. Forty-eight patients (65%) were found to be HP positive on histology. The Heliprobe method correctly classified 48 of 48 HP-positive patients and 19 of 25 HP-negative patients (sensitivity 100%, specificity 76%, PPV 88%, NPV 100%, accuracy 91%). The standard method correctly classified 48 of 48 HP-positive patients and 20 of 25 HP-negative patients (sensitivity 100%, specificity 80%, PPV 90%, NPV 100%, accuracy 93%). On the other hand, the CLO test identified 26 of 32 HP-positive and 12 of 16 HP-negative patients (sensitivity 81%, specificity 75%, PPV 86%, NPV 66%, accuracy 79%). With the Heliprobe method, all of the positive results were grade 2, and all of the negative results were grade 0. No patients were defined as having grade 1 results. Counts allowed clear discrimination of HP-positive and -negative patients with both methods, the difference being statistically significant in each case ( P<0.001). A significant correlation was found between HCPM and SDPM ( r 0.863, P<0.001). According to the ROC analysis, the area under the curve was nearly the same with HCPM (AUC, 0.888; 95% CI, 0.785-0.992) and SDPM (AUC, 0.898; 95% CI, 0.802-0.994). In conclusion, the new (14)C-UBT system is a highly accurate method for the diagnosis of HP infection. It is rapid and practical, and therefore suitable for clinical and office practice.

Diagnostic approach to prostate cancer using total prostate specific antigen-based parameters together

This prospective study investigated the value of serum total prostate specific antigen (tPSA)-based parameters in the diagnosis of prostate cancer (PCa). Serum tPSA, free to tPSA ratio (f/tPSA), PSA density (PSAD), and PSA transition zone (PSAT) were evaluated in 110 patients with histologically confirmed benign prostate hyperplasia (BPH) and 98 patients with PCa. Once the serum tPSA was elevated (greater than 4 ng/ml) or digital rectal examination (DRE) was suspicious, transrectal ultrasound-guided biopsies were recommended. The tPSA, f/tPSA, PSAD, and PSAT levels were significantly different between the BPH and PCa groups. In patients with a tPSA level of 4.1-9.9 ng/ml or an abnormal DRE finding, only PSAT was found to have discriminating power. The cut-off values were 0.15 for f/tPSA, 0.30 for PSAT, and 0.15 for PSAD. The diagnostic sensitivity of a positive result for one of these parameters in the whole group was 84%, but 75% in patients with a tPSA of 4.1-9.9 ng/ml or an abnormal DRE finding. The diagnostic specificity of positive results for 3 parameters was 92% in the whole group and 93% in patients with a tPSA of 4.1-9.9 ng/ml or an abnormal DRE finding. All parameters were influenced by the histological grades. Histological grades showed a negative correlation (r = -0.56) with f/t PSA and a positive correlation (r = 0.44) with PSAT. No diagnostic marker investigated heretofore was able to rule out or detect early PCa in patients with a PSA level of 4.1-9.9 ng/ml. Using the PSA-based parameters together can be helpful in management of these patients. If all of the PSA-based parameters are negative, biopsy might be postponed; patients who have three positive PSA-based parameters should be biopsied. In case of one or two of the parameters, the patient's age and race should be considered in clinical decision-making.

Post-surgical ablation of thyroid remnants with high-dose (131)I in patients with differentiated thyroid carcinoma

The aims of this study were to evaluate the efficacy of an empirically determined "fixed" high ablative dose of radioiodine ((131)I) therapy and to determine the utility of ultrasonography (US) in dose determination. A retrospective analysis was performed of 242 thyroid cancer cases treated with "fixed" high-dose (131)I for ablation of thyroid remnants without a pre-ablative (131)I diagnostic scintigraphy or radioiodine uptake study. Treatment doses ranged from 1850 MBq (50 mCi) to 7.4 GBq (200 mCi). The selection of the treatment dose was based on the surgical and pathological findings as well as the remnant thyroid volume calculated by US. A successful ablation was defined as the absence of activity in the thyroid bed on subsequent imaging studies. Successful ablation was obtained in 218 of the 242 patients (90%). In 162 of the 218 patients (74.3%), successful ablation was achieved after a single (131)I treatment. The remnant thyroid volume calculated by US was significantly different (P=0.04) between those who were successfully ablated and those who were not. The total (131)I dose needed for successful ablation was significantly higher in males (P=0.003). Patients with higher post-operative thyroglobulin (Tgb) levels and patients with a higher stage of disease required higher doses (P=0.036 and P=0.021 respectively). Serum Tgb levels were under 10 ng.ml(-1) in 220 of the 242 patients (90%) following radioiodine ablation while not receiving L-thyroxine suppression. Nineteen patients (7.8%) showed metastases on post-therapy scan and successful treatment was achieved in 11 of 19 (57.8%). Four of the 19 patients with distant metastases (revealed on post-treatment scan) were found to have been given a treatment dose of less than 200 mCi based on the proposed empirical approach. These results indicate that "fixed" high-dose (131)I treatment is clinically feasible with an acceptable dose underestimation rate, and the utilization of US in the determination of the thyroid remnant volume provides more accurate and reproducible results.

Comparison of In-111 octreotide and Tc-99m (V) DMSA scintigraphy in the detection of medullary thyroid tumor foci in patients with elevated levels of tumor markers after surgery

PURPOSE

In this retrospective study, the authors evaluated the utility of In-111 octreotide (OctreoScan) and Tc-99m (V) DMSA scintigraphy for the localization of recurrent metastatic tumor foci in patients with medullary thyroid cancer (MTC) and compared the findings with those of conventional radiologic imaging methods.

METHODS

The scintigraphic images were compared with computed tomography (CT) and magnetic resonance imaging (MRI) and ultrasonography (US) in 14 patients (8 men, 6 women; age range, 22 to 74 years) with elevated calcitonin and carcinoembryonic antigen levels after total thyroidectomy. All scintigraphic image findings were evaluated qualitatively as mild uptake (+) and moderate to marked uptake (++).

RESULTS

In-111 octreotide may be superior to Tc-99m (V) DMSA for the detection of tumor foci of patients with MTC on a patient basis (78.5% versus 57.1%) and on a lesion basis (44.1% versus 30.2%). The sensitivity rate for In-111 octreotide (78.5%) was also similar to that of CT and MRI on a patient basis. Conversely, the combined use of Tc-99m (V) DMSA and In-111 octreotide revealed the best sensitivity rate (85.7%) on a patient basis, whereas the combined use of CT and MRI showed the best sensitivity rate (81.3%) on a lesion basis.

CONCLUSIONS

These findings suggest that In-111 octreotide is superior to Tc-99m (V) DMSA and has a similar sensitivity rate to CT and MRI for the diagnosis of recurrent or metastatic MTC. Although the combined use of In-111 octreotide and Tc-99m (V) DMSA was most sensitive, the combined use of CT and MRI with radionuclide imaging methods may better detect more metastatic tumor foci.

A practical approach to glomerular filtration rate measurements: creatinine clearance estimation using cimetidine

Determination of creatinine clearance (Ccr) is not a reliable indicator of glomerular filtration rate (GFR), owing to tubular secretion of creatinine. It has been reported that Ccr measurements can approximate true GFR after cimetidine (Ci) administration. In this study, GFR was estimated by Cockcroft and Gault's equation (C(C-G)) based on measurement of plasma creatinine, and Ccr was determined by the standard clearance equation using 4- and 24-hr urine samples (Ccr4 and Ccr24, respectively) in 17 patients and 10 healthy controls. After cimetidine administration (800 mg, 3 times daily), GFR values were recalculated at the same time periods (C(CiC-G), CcrCi4 and CcrCi24, respectively). The results were all compared to those obtained by the 99mTc-DTPA protein-free double-sample method (C(DTPA)), which is a reference method for GFR determination. The coefficient of variation (CV%) for Ccr24/C(DTPA) was high before cimetidine administration; Ccr24 and CcrCi24 values were significantly different from C(DTPA) (CV 23.1%, Ccr24/C(DTPA) = 1.17, p 0.005; and CV 14.1%, CcrCi24/C(DTPA) = 0.92, p 0.006, respectively). Ccr4 values obtained before cimetidine ingestion showed large variation and were significantly different from C(DTPA) (CV 15.5%, Ccr4/C(DTPA) = 1.11, p 0.001). CcrCi4 values after cimetidine were similar to CDTPA (CV 6.9%, CcrCi4/C(DTPA) = 1.01, p 0.28). C(C-G) estimates were higher before cimetidine intake (CV 12.4%, C(C-G)/C(DTPA) = 1.21, p <0.001), whereas C(CiC-G) values were not significantly different from C(DTPA) values (CV 7.0%, C(CiC-G)/C(DTPA) = 1.01, p 0.67). This study shows that GFR estimations by C(C-G), Ccr4, Ccr24, or CcrCi24 are insufficiently reliable. On the other hand, C(CiC-G) and CcrCi4 results are acceptable for true GFR estimations.

Utility of ventilation and perfusion scan in the diagnosis of young military recruits with an incidental finding of hyperlucent lung

Swyer-James-MacLeod syndrome (SJMS) is considered to be a relatively uncommon disease presenting with unilateral hyperlucent lung due to hypoplasia of a pulmonary artery and bronchiectasis of the affected lung. In this report, we describe the ventilation-perfusion (V/Q) scan findings of nine male recruits (aged 20-29 years, mean 24.4+/-2.96 years) with SJMS in whom the diagnosis was first established in adulthood. V/Q scan findings of all patients were compared with those on planar radiographs, pulmonary function studies, high resolution computed tomography (HRCT) and digital subtraction angiography (DSA). The ventilation (133Xe) and perfusion (99Tcm-macro-aggregated albumin) scans showed the characteristic pattern of a matched V/Q defect and marked air trapping on the washout phase on 133Xe scintigraphy. HRCT displayed hypodense lung with integrity of main airways, and markedly diminished vasculature on the affected side in all patients. A smaller pulmonary artery on the affected side with poor peripheral vasculature was observed with DSA in all patients. All patients had features of obstructive airway disease in varying degrees on pulmonary function studies. In contrast to other imaging methods, bronchiectasis as an etiological factor was displayed on HRCT. Some pulmonary areas, which were normal on HRCT and planar radiographs, showed air trapping on V/Q scan. Although a V/Q scan was more helpful in determining the extent of the disease and correlates well with conventional imaging methods, HRCT was the most valuable imaging method for the evaluation of aetiology in unilateral hyperlucent lung.

Use of CA15-3, CEA and prolactin for the primary diagnosis of breast cancer and correlation with the prognostic factors at the time of initial diagnosis

The main goals of the clinical use of tumor markers are to evaluate the adequacy of the treatment, monitor recurrence and follow up response to the treatment applied. For this purpose a baseline level for the commonly used tumor marker must be known at the time of initial diagnosis, before any therapy, in order to compare with the tumor marker levels which will be obtained after the treatment and during the clinical follow-up. The aim of this study was to investigate the correlation, if there is any, of the baseline levels of CA15-3, CEA and prolactin (PRL) in patients with breast cancer with the most commonly used prognostic factors, i) the presence of distant metastasis, ii) the presence of axillary lymphatic invasion, iii) the number of invaded axillary lymph nodes, iv) tumor size and v) stage of the disease, for breast cancer. Baseline serum CA15-3, CEA and PRL levels of 172 patients with breast masses were determined prior to biopsy. The sensitivity and specificity of baseline CA15-3, CEA and PRL were; 23.2% and 95.3%, 17.41% and 83.7%, 5.8% and 97.6%, respectively. At least one of the three tumor markers was high in 36% (31/86) of the breast cancer patients. Baseline CA15-3 levels were frequently higher than CEA in patients with bone metastasis (60% vs. 20%) and axillary lymphatic invasion (31.8% vs. 25%), and showed a better correlation with the stage of disease. Baseline tumor marker levels showed no statistically significant correlation with either the number of invaded axillary lymph nodes or tumor size. In conclusion, sensitivities and negative predictive values for baseline CA15-3, CEA and PRL were not satisfactory for primary diagnosis of breast cancer. Correlation of baseline CA15-3 was found superior to CEA and PRL in terms of stage of disease, presence of axillary invasion and distant metastasis.

The role of Tc-99m (V) DMSA scintigraphy in the evaluation of superscan on bone scintigraphy

PURPOSE

This study evaluated the biodistribution of Tc-99m (V) DMSA in patients with superscans on bone imaging and defined its role in differentiating the underlying cause.

METHODS

Nine patients (five with metastatic and four with metabolic bone disease) with classical superscans were entered into the study. All patients had the necessary radiologic and biochemical studies and a final diagnosis was reached accordingly. Tc-99m (V) DMSA scintigraphy was performed 1 week after Tc-99m MDP whole-body bone imaging.

RESULTS

In four of five patients with widespread skeletal metastases, Tc-99m (V) DMSA scan showed diffusely increased bone uptake. In the remaining patient, the Tc-99m (V) DMSA scan showed a normal distribution pattern. All patients with metabolic bone disease had increased bone uptake on Tc-99m (V) DMSA scans.

CONCLUSION

Tc-99m (V) DMSA shows increased bone uptake in patients having a superscan appearance in metastatic or metabolic bone disease. Tc-99m (V) DMSA imaging may play a role in the evaluation of patients with equivocal bone scan findings for a superscan.

The comparison of dual phase Tc-99m MIBI and tc-99m MDP scintimammography in the evaluation of breast masses: preliminary report

The aim of this prospective study was to determine the diagnostic value of Tc-99m MDP scintimammography (SMG) for the detection of breast cancer in patients with breast masses and to compare the results with Tc-99m MIBI scintimammography. Twenty patients, categorized as suspicious, positive or benign for breast cancer according to the mammographic findings were included in the study. Dual phase Tc-99m MIBI and Tc-99m MDP SMG were performed in the prone lateral position within 5 days of each other. Although early and late Tc-99m MIBI SMG showed equal (90.4%) sensitivity, the specificity of late Tc-99m MIBI (87.5%) was found superior to early (62.5%) imaging. The overall sensitivity and specificity of early Tc-99m MDP SMG were 71.4% and 62.5%, respectively. Although late Tc-99m MDP imaging showed 100% specificity, its sensitivity was only 23.8%. In the patients with palpable masses, both early Tc-99m MDP and Tc-99m MIBI showed equal sensitivity (100%), but the sensitivity of early Tc-99m MIBI (37.5%) was found slightly higher than Tc-99m MDP (25.0%) for nonpalpable breast lesions. The sensitivity of Tc-99m MIBI and Tc-99m MDP SMG in detecting metastatic axillary involvement was 66.6% and 50%, respectively. High sensitivity and specificity together with its low cost, easy availability and the possibility of detecting bone metastases seems to make Tc-99m MDP a contributive agent in the evaluation of breast lesions as an alternative to Tc-99m MIBI.

Synthesis of [99mTc]ethylenedicysteine-colchicine for evaluation of antiangiogenic effect

Angiogenesis is in part responsible for tumor growth and the development of metastasis. Radiolabeled angiongenesis inhibitors would be useful to assess tumor microvasculature density. Colchicine (COL), a potent antiangiogenic agent, is known to inhibit microtubule polymerization and cell arrest at metaphase. This study aimed to develop 99mTc-labeled COL (EC-COL) using ethylenedicysteine (EC) as a chelator to assess tumor microvascular density. EC was conjugated to trimethylcolchicinic acid using N-hydroxysuccinimide and 1-ethyl-3-dimethylaminopropyl carbodiimide as coupling agents with a yield of 50-60%. In vivo stability was analyzed in rabbit serum at 0.5-4 h. Tissue distribution and planar imaging studies of [99mTc]EC-COL were evaluated in breast tumor-bearing rats at 0.5, 2 and 4 h. The data was compared to that using [99mTc]EC (control). The radiochemical yield of [99mTc]EC-COL was greater than 95%. [99mTc]EC-COL was stable in rabbit serum. In vivo biodistribution of [99mTc]EC-COL in breast tumor-bearing rats showed increased tumor-to-blood (0.52+/-0.12 to 0.72+/-0.07) and tumor-to-muscle (3.47+/-0.40 to 7.97+/-0.93) ratios as a function of time. Conversely, tumor-to-blood values showed a time-dependent decrease with [99mTc]EC over the same time period. Planar images confirmed that the tumors could be visualized clearly with [99mTc]EC-COL from 0.5 to 4 h. [99mTc]EC-COL may be useful to assess antiangiogenic and therapeutic effects during chemotherapy.

Noninvasive assessment of tumor hypoxia with 99mTc labeled metronidazole

PURPOSE

The assessment of tumor hypoxia by imaging modality prior to radiation therapy would provide a rational means of selecting patients for treatment with radiosensitizers or bioreductive drugs. This study aimed to develop a 99mTc-labeled metronidazole (MN) using ethylene-dicysteine (EC) as a chelator and evaluate its potential use to image tumor hypoxia.

METHODS

EC was conjugated to amino analogue of MN using Sulfo-N-hydroxysuccinimide and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide-HCl as coupling agents, the yield was 55%. Tissue distribution of 99mTc-EC-MN was determined in breast tumor-bearing rats at 0.5, 2, and 4 hrs. Planar imaging and whole-body autoradiograms were performed. The data was compared to that using 99mTc-EC (control), [18F]fluoromisonidazole (FMISO) and [(131)I] iodomisonidazole (IMISO).

RESULTS

In vivo biodistribution of 9mTc-EC-MN in breast tumor-bearing rats showed increased tumor-to-blood and tumor-to-muscle ratios as a function of time. Conversely, tumor-to-blood values showed time-dependent decrease with 9mTc-EC in the same time period. Planar images and autoradiograms confirmed that the tumors could be visualized clearly with 99mTc-EC-MN from 0.5 to 4 hrs. There was no significant difference of tumor-to-blood count ratios between 99mTc-EC-MN and [(131)I]IMISO at 2 and 4 hrs postinjection. From 0.5 to 4 hrs, both 9mTc-EC-MN and [(131)I]MISO have higher tumor-to-muscle ratios compared to [18]FMISO.

CONCLUSIONS

It is feasible to use 9mTc-EC-MN to image tumor hypoxia.

99Tcm-MIBI scintimammography in the evaluation of breast lesions and axillary involvement: a comparison with mammography and histopathological diagnosis

The aim of this prospective study was to determine the diagnostic value of prone lateral 99Tcm-MIBI scintimammography in the detection of primary breast cancer and axillary lymph node involvement in patients with breast lesions. We evaluated 83 palpable and 22 non-palpable lesions in 77 consecutive patients with a clinically palpable mass and/or suspicious mammographic finding. Early and late scintimammograms were performed after the intravenous injection of 740 MBq 99Tcm-MIBI. The overall sensitivity of both scintimammography and mammography in the detection of primary breast cancer was 94%. The overall specificity was 84% and 56% for scintimammography and mammography respectively. In the patients with palpable masses, the sensitivity of scintimammography was 97% and the specificity was 84%; in those with non-palpable masses, the sensitivity was 35% and the specificity 100%. For the detection of axillary lymph node involvement, the sensitivity and specificity of scintimammography were 68% and 93% respectively. However, conventional mammography showed 37% sensitivity and 86% specificity. In conclusion, scintimammography is an accurate and clinically valuable tool for evaluating palpable and non-palpable breast abnormalities. In addition to its high sensitivity, it improves the specificity of mammography both in the evaluation of breast masses and in the detection of axillary involvement.