Koramadai Karuppusamy Kamaleshwaran

Predictive value of serum prostate specific antigen in detecting bone metastasis in prostate cancer patients using bone scintigraphy

Introduction: Radionuclide bone scan (BS) used to be the investigation of choice for detecting osseous metastases in prostate cancer. Now, with the availability serum prostate specific antigen (PSA) testing, clinicians do have a timely, cost-effective method to determine those patients who are highly unlikely to have osseous metastases. We determine the utility of PSA for predicting the presence of skeletal metastasis on BSs in prostate cancer patients. Materials and Methods: Retrospective analysis of medical records of 322 consecutive prostate cancers patients subjected to BS during the last 3 years was done. 52 cases were excluded due to following reasons: Serum PSA not available, hormonal or other therapy given prior to serum PSA measurement, and/or BS, and symptomatic for bone metastasis. In remaining 270 cases, PSA value and BS were evaluated. BS was performed with Tc99m methylene diphosphonate (MDP) as per the standard protocol. Results: BS was found to be positive in 153/270 (56%) and negative in 117 (46%) patients. Of the 153 positive cases, 108 (70%) had serum PSA > 100 ng/ml, 42 (28%) had PSA of 20-100 ng/ml and only 3 (2%) had PSA < 20 ng/ml. All the patients with PSA > 100 ng/ml had multiple skeletal metastasis. Of the 117 negative cases, 110 (94%) had a PSA < 20 ng/ml, 5 had between 20 and 100 ng/ml and only 2 (1.8%) had PSA > 100 ng/ml. Of the 113 patients with serum PSA < 20 ng/ml, 110 (97.4%) did not show any bony metastasis. 150/157 (95.5%) patients with PSA > 20 ng/ml had bone metastasis. Using this criterion, 110 (40.7%) scans would have been omitted. Conclusions: Serum PSA < 20 ng/ml have high predictive value in ruling out skeletal metastasis. Our data are in corroboration with results from previous studies that BS should be performed only if PSA > 20 ng/ml. Using this cut-off, unnecessary investigation can be avoided. Avoiding BS in this group of patients would translate into a significant cost-saving and reduction in their psychological and physical burden.

Single photon emission computed tomography/computed tomography of the skull in malignant otitis externa

Malignant otitis externa is a severe, rare infective condition of the external auditory canal and skull base. The diagnosis is generally made from a range of clinical, laboratory, and imaging findings. Technetium 99m methylene diphosphonate bone scintigraphy is known to detect osteomyelitis earlier than computed tomography. The authors present a patient with bilateral malignant otitis externa where the extent of skull base involvement was determined on 3-phase bone scintigraphy with single photon emission computed tomography/computed tomography.

A Freeze-Dried Kit for the Preparation of 188Re-HEDP for Bone Pain Palliation: Preparation and Preliminary Clinical Evaluation

(188)Re-HEDP is an established radiopharmaceutical used for pain palliation in patients with osseous metastasis. Considering commercial availability of (188)W/(188)Re generator, the accessibility to a lyophilized kit would make preparation of this radiopharmaceutical feasible at the hospital radiopharmacy having access to a generator. A protocol for the preparation of a single-vial lyophilized hydroxyethane 1,1-diphosphonic acid (HEDP) kit was developed and its consistency was checked by preparing six batches. Each sterile lyophilized kit prepared as per the protocol contained 9 mg of HEDP, 3 mg of gentisic acid, and 4 mg of SnCl2.2H2O. Randomly selected kits from all six batches were subjected to thorough quality control tests that were passed by all batches. (188)Re-HEDP could be prepared by addition of 1 mL of freshly eluted Na(188)ReO4 (up to 3700 MBq) containing 1 μmol of carrier ReO4(-) (perrhenate) and heating at 100°C for 15 minutes. (188)Re-HEDP with >95% radiochemical purity could be consistently prepared using the lyophilized kits. Sterile (188)Re-HEDP prepared using the lyophilized kit was evaluated in patients with osseous metastasis. Post-therapy images of the patient were compared with (99m)Tc-MDP bone scan and found to be satisfactory. The bone-to-background as well as tumor-to-normal bone uptake ratio was found to be significant. All patients who received therapy reported significant pain relief within a week to 10 days post-administration of (188)Re-HEDP.

Multiple pulmonary sclerosing hemangiomas (pneumocytoma) mimicking lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Pulmonary sclerosing hemangioma (PSH), or the alternative name of “sclerosing pneumocytoma,” is a rare benign neoplasm. PSH is often asymptomatic and presents as a solitary or multiple pulmonary nodules on radiologic imaging studies. Few articles have been reported to describe the fluorodeoxyglucose positron emission tomography (FDG PET) findings about PSH. The authors describe an interesting but uncommonly encountered cause of false positive FDG PET scan in the thorax in a 25-year-old woman, a known case of arteriovenous malformation of oral cavity who underwent embolization and presented with incidental detection of bilateral lung nodules. She is asymptomatic and is on follow-up.

Concurrent sublingual thyroid and thyroglossal cyst with functioning thyroid tissue in the absence of an orthotopic thyroid gland

The prevalence of ectopic thyroid tissue is approximately 1/100 000–300 000 persons and is reported to occur in one in 4000–8000 patients with thyroid disease. It is the only thyroid in 70% of all cases, and identifi cation of functioning thyroid tissue in the orthotopic gland is crucial, as it would infl uence surgical management. Technetium-99m pertechnetate scintigraphy is routinely used to acquire functional information on both normal and ectopic thyroid glands. The authors report a rare case of a thyroglossal cyst with functioning thyroid tissue in it coexisting with a functioning sublingual thyroid, without any orthotopic thyroid gland in the neck. The detection of functioning thyroid tissue in a thyroglossal cyst is important when surgical management is contemplated. The technetium-99m pertechnetate (Tco4 ) thyroid scan is routinely used for identifying ectopic thyroid glands. We describe here an unusual case of a thyroglossal cyst with functioning thyroid tissue coexisting with a functioning sublingual thyroid, without an orthotopic thyroid gland in the neck, documented during a routine Tco4 − scan. A 16-year-old boy with no clinical signs or symptoms of physical or mental retardation presented with progressive swelling in the anterior neck, fi rst noticed when he was 5 years old. Physical examination revealed a 3to 4-cm mobile, nontender, midline swelling with a smooth surface and fi rm consistency that moved with deglutition and protrusion of the tongue. The thyroid profi le was as follows: total triiodothyronine (T3) 110 ng/ dl (normal 86–186), total thyroxine (T4) 5.5 g/dl (normal 4.5–12.5), and thyroid-stimulating hormone (TSH) 111 μIU/ml (normal 0.25–4.5 μIU/ml). He was not taking any supplementary thyroid hormone treatment. Thyroid scintigraphy was performed 20 min after intravenous injection of 4 mCi (148 MBq) of Tco4 . A static anterior planar image was acquired for 250 000 counts (Fig. 1), followed by a lateral view with markers (not shown here). A well-defi ned focus of tracer concentration was seen in the fl oor of the mouth with diffuse, globular tracer uptake immediately below, corresponding to the clinically palpable mass. Hybrid single photon emission computed tomography/computed tomography (SPECT/CT) of the head and neck region (Fig. 2) on a dual-head gamma camera localized the upper focus to the sublingual region, confi rming a functioning ectopic Received: March 22, 2010 / Accepted: May 24, 2010

Paget's disease of pelvis mimicking metastasis in a patient with lung cancer evaluated using staging and follow-up imaging with fluorine-18 fluorodeoxyglucose-positron emission tomography/computed tomography.

Pagets disease of bone is a benign disease, of uncertain etiology, characterized by an accelerated turnover, that is, bone resorption and formation. Pagets disease may be present in up to 5% of the population, and the majority of cases are asymptomatic. We report the imaging findings of Pagets disease of pelvis discovered incidentally in patient with lung cancer evaluated by fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) for staging. FDG PET-CT scan showed intense uptake in the right lung lower lobe primary and mediastinal lymph nodes. Furthermore, increased uptake noted in left hemipelvis suggestive of Pagets disease. He underwent follow-up FDG PET-CT after chemotherapy showed decrease in lung mass and mediastinal nodes. However, the uptake in left hemipelvis remains same confirming Pagets disease.

Spindle cell sarcoma of pulmonary artery mimicking thromboembolism with lung metastasis detected in fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography

Pulmonary artery sarcoma (PAS), although rare, must be considered in the differential diagnosis of pulmonary thromboembolism (PTE). This tumor is highly malignant and the prognosis is very poor. As much as the standardized uptake values (SUVs) at fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) have helped in differentiating between benign and malignant tumors, visualization of a low-attenuation filling defect within a pulmonary artery on contrast-enhanced chest computed tomography (CT) can be suggestive of a malignancy, such as PAS, if the lesion shows high FDG uptake at PET. We present a case of PAS that showed high FDG uptake on integrated FDG PET/CT and with lung metastasis. Patient underwent endoscopic bronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA), which confirmed spindle cell sarcoma.

Rare case of trilateral retinoblastoma with spinal canal drop metastasis detected with fluorine-18 fluorodeoxyglucose positronemission tomography/computed tomography imaging

Trilateral retinoblastoma (TRb) is a rare syndrome associating hereditary bilateral or unilateral retinoblastoma (Rb) with an intracranial neuroblastic tumor. The latter arises in the midline, most often in the pineal gland, less frequently in the suprasellar or parasellar region. The outcome is usually fatal because of secondary spinal dissemination. We report 10-year-old boy presented with a right eye proptosis and leukocoria, and the magnetic resonance imaging (MRI) showed right orbital mass lesion infiltrating optic nerve and diagnosis of retinoblastoma was made. He was referred for fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) to find out the extent of the disease. PET/CT showed abnormal FDG-uptake within right orbital mass lesion, suprasellar enhancing lesion and drop metastasis in the cervical spinal canal level. He was diagnosed as a case of TRb with spinal canal drop metastasis. He underwent chemotherapy and craniospinal irradiation.

Hybrid Single-Photon Emission Computed Tomography/Computed Tomography Imaging Features of Tumoral Calcinosis in Technetium-99m Methylene Diphosphonate Bone Scintigraphy

Tumoral calcinosis (TC) is an uncommon ectopic calcification syndrome. TC is a benign condition characterized by the presence of large calcific soft tissue deposits occurring predominantly in a periarticular location. It generally occurs as a complication of renal dialysis or trauma, and is rarely seen in familial and sporadic cases. Bone scintigraphy is a sensitive method for diagnosing TC. We report a case of year old female with. She underwent bone scintigraphy to see the sites of involvement, which showed intense foci of tracer activity in soft tissue in bilateral thigh and gluteal region. Hybrid single-photon emission computed tomography/computed tomography of the pelvis and thigh localized tracer uptake to the calcification in the gluteal and thigh region.

Mediastinal ectopic benign colloid goitre detected using iodine-131 whole body scintigraphy and single-photon emission computed tomography-computed tomography.

Ectopic thyroid tissue primarily occurs along the course of the embryologic migration of the thyroid gland. Mediastinal thyroid may be differentiated into primary and secondary form. Primary mediastinal goiters are quite rare, occurring in <1% of all goiters. We present findings of 29-year-old female, case of papillary carcinoma of the thyroid who underwent iodine-131 whole body scintigraphy after total thyroidectomy showed a primary mediastinal mass lesion along with residual thyroid. She underwent mediastinal mass excision through sternotomy and biopsy confirmed as ectopic nodular colloid goiter with no malignancy.