Impact of Heparin Preadministration for Detection of Prosthetic Valve Endocarditis With FDG PET/CT.

ABSTRACT: A 57-year-old woman with history of aortic and mitral valves replacement was referred to FDG PET/CT before valvular prosthesis renewal surgery. First FDG PET/CT was suboptimal for interpretation due to prominent physiological myocardial FDG uptake, despite patient preparation including 12 hours of fasting and low-carbohydrate, fat-rich diet. Therefore, scan was repeated with IV heparin preadministration at another day and revealed focal FDG uptake on the region of prosthetic heart valves, suggesting endocarditis. FDG PET/CT has been proven to be a useful technique to detect endocarditis, but appropriate patient preparation for adequate suppression of physiological myocardial uptake is important. Heparin preadministration seems to be an important component of patient preparation.

Unusual Presentation of Herpes Zoster Infection Mimicking Soft Tissue Metastases of Breast Cancer on 18F-FDG PET/CT Imaging.

ABSTRACT: Herpes zoster infection caused by reactivation of dormant varicella zoster virus results in painful vesicular rash in corresponding dermatome. We report a case of a 56-year-old woman with breast cancer who was referred to PET/CT scan for adjuvant chemotherapy response assessment. Her scan showed multiple FDG-avid skin lesions. Blinded to the patient's clinical information, these skin lesions initially looked suspicious for soft tissue metastases. However, the patient history revealed that she had been experiencing herpes zoster infection during the scan, and these lesions with FDG uptake were eventually confirmed to be caused by herpes zoster infection by physical examination.

Nuclear medicine training and practice in Turkey.

Nuclear medicine applications in Turkey started in the early 1950s, grew as an independent medical discipline and finally were recognized by the Ministry of Health in 1973. Later on, the professional organization of nuclear medicine physicians and other related professionals including radiopharmacists and technologists under the Turkish Society of Nuclear Medicine were established in 1975. Recently after completing more than a half century in Turkey, nuclear medicine has proved to be a strong and evolving medical field with more than 600 physicians serving for the changing needs of clinical practice throughout these years. This article describes past and present facts in this field and attempts to provide insights into the future which hopefully will be brighter than before.

The EANM clinical and technical guidelines for lymphoscintigraphy and sentinel node localization in gynaecological cancers.

The accurate harvesting of a sentinel node in gynaecological cancer (i.e. vaginal, vulvar, cervical, endometrial or ovarian cancer) includes a sequence of procedures with components from different medical specialities (nuclear medicine, radiology, surgical oncology and pathology). These guidelines are divided into sectione entitled: Purpose, Background information and definitions, Clinical indications and contraindications for SLN detection, Procedures (in the nuclear medicine department, in the surgical suite, and for radiation dosimetry), and Issues requiring further clarification. The guidelines were prepared for nuclear medicine physicians. The intention is to offer assistance in optimizing the diagnostic information that can currently be obtained from sentinel lymph node procedures. If specific recommendations given cannot be based on evidence from original scientific studies, referral is made to "general consensus" and similar expressions. The recommendations are designed to assist in the practice of referral to, and the performance, interpretation and reporting of all steps of the sentinel node procedure in the hope of setting state-of-the-art standards for high-quality evaluation of possible metastatic spread to the lymphatic system in gynaecological cancer. The final result has been discussed by a group of distinguished experts from the EANM Oncology Committee and the European Society of Gynaecological Oncology (ESGO). The document has been endorsed by the SNMMI Board.

Analysis of dendritic cells in sentinel lymph nodes of patients with endometrial and patients with cervical cancers.

OBJECTIVE: The aim of this study was to identify the immune response in sentinel lymph nodes (SLNs) of patients with endometrial and patients with cervical cancers by analyzing the number of S-100-, CD1a-, CD83-positive (+) dendritic cells that are the major antigen-presenting cells. METHODS: A total of 56 patients with early-stage cancer (n = 32, with cervical; n = 24, with endometrial cancer) underwent SLN biopsy. Sentinel lymph nodes and non-SLNs were stained with antibodies against S-100, CD1a, and CD83 as markers for dendritic cells to find out whether SLNs were immunomodulated compared with non-SLNs. RESULTS: The mean values of S-100(+) and CD1a(+) dendritic cells in both the tumor-free and the metastatic SLNs were significantly higher than those of both the tumor-free and the metastatic non-SLNs. When metastatic SLNs were compared with nonmetastatic SLNs, CD83(+) dendritic cells were found significantly more abundant in nonmetastatic SLNs. CONCLUSIONS: Significantly higher numbers of S-100(+) and CD1a(+) dendritic cells in the SLNs compared with those in the non-SLNs may indicate that SLNs are the first sites of immunostimulation. Immunosupression may be the underlying factor for the metastatic involvement of SLNs, which might be secondary to the significantly decreased number of mature dendritic cells in metastatic SLNs compared with tumor-free SLNs.

Osteoid osteoma in a 16-year-old boy presenting with atrophy of the left thigh: diagnostic difficulties.

Osteoid osteoma is an osteoblastic benign lesion of the bone. The pathognomonic symptom is significant pain, which responds well to nonsteroidal antiinflammatory drugs. When typical clinical and radiological features are present, the diagnosis is not difficult. However, if the lesion is in an area not clearly seen on plain radiographs, or clinical features are atypical, then diagnosis becomes difficult. We present a case of osteoid osteoma with delayed diagnosis that presented itself with neurological signs. Prominent features present in the patient included pain that responded well to medication and muscle atrophy, which led to a wider differential diagnosis. Diagnosis was made approximately two years after the onset of his initial symptoms, after having been investigated and treated both in our own hospital and elsewhere. This case illustrates clinical and radiological diagnostic problems of osteoid osteoma, demonstrating that it can present itself with neurological signs. Correct diagnosis then requires detailed history and clinical awareness.

Sentinel lymph node detection in early stage cervical cancer: a prospective study comparing preoperative lymphoscintigraphy, intraoperative gamma probe, and blue dye.

OBJECTIVE: The objective of this prospective study was to determine the feasibility of sentinel lymph node (SLN) detection in patients with cervical cancer using lymphoscintigraphy (LS), gamma probe, and blue dye. METHODS: A total of 32 patients with early stage cervical cancer (FIGO IA2-IIA) who were treated with total abdominal hysterectomy and bilateral pelvic and paraortic lymphadenectomy underwent SLN biopsy. LS was performed on all the patients following the injection of 74 MBq technetium-99m-nanocolloid pericervically. The first appearing persistent focal accumulation on either dynamic or static images of LS was considered to be an SLN. Blue dye was injected just prior to surgical incision in 16 patients (50%) at the same locations as the radioactive isotope injection. During the operation, blue-stained node(s) were excised as SLNs. For gamma probe, a lymph node was accepted as an SLN, if its ex vivo radioactive counts were at least 10-fold above background radioactivity. SLNs, which were negative by routine hematoxylin and eosin (H&E) examination, were histopathologically reevaluated for the presence of micrometastases by step sectioning and immunohistochemical staining with pancytokeratin. RESULTS: At least one SLN was identified for each patient by gamma probe. Intraoperative gamma probe was the most sensitive method with a technical success rate of SLN detection of 100% (32/32), followed by LS 87.5% (28/32) and blue dye 68.8% (11/16), respectively. The average number of SLNs per patient detected by gamma probe was 2.09 (range 1-5). The localizations of the SLNs were external iliac 47.8%, obturatory 32.8%, common iliac 9%, paraaortic 4.4%, and paracervical 6%. Micrometastases, not detected by routine H&E were found by immunohistochemistry in one patient. On the basis of the histopathological analysis, the negative predictive value for predicting metastases was 100%, and there were no false-negative results. CONCLUSIONS: Preoperative LS with radiocolloids, intraoperative lymphatic mapping with blue dye and gamma probe are all feasible methods comparable with each other for SLN detection in early stage cervical cancer patients, but gamma probe is the most useful method in terms of technical success.

Optimization of the gamma probe-guided parathyroidectomy.

The objective of this study was to determine the patient-specific optimal time to surgery preoperatively to improve operative success in gamma probe-guided parathyroid localization. Fifteen patients with hyperparathyroidism underwent a double-phase Tc99m-MIBI (15-20 mCi) parathyroid scintigraphy to study the Tc99m-MIBI clearance kinetics from parathyroid and thyroid glands and to determine the time point at which the optimal target-to-background ratio was achieved. Optimal time to surgery was determined on the basis of the time at which the target-to-background ratio was maximal. On the day of surgery the patients received the same dose of Tc99m-MIBI and were taken to the operating room at the time of optimal target-to-background ratio. A four-gland exploration was performed with identification and excision of hot lesions using a gamma probe. Ex vivo lesion-to-background ratios were determined. Histopathologic confirmation of a successful parathyroidectomy was obtained intraoperatively by frozen section. The total operative time and the time to localize and excise the parathyroid glands were recorded. The mean surgery time was compared with that of previous parathyroidectomies performed by the same surgical team without use of preoperative scintigraphy and intraoperative gamma probe. Scintigraphy correctly localized parathyroid pathology in 12 of 15 (80%) patients. Intraoperative gamma probe was successful in 15 of 15 (100%). The optimal time to surgery was found to be different for each patient, and the mean time was calculated as 136 +/- 43 minutes. Mean surgery time for the excision of parathyroid gland was 91 +/- 46 minutes, which was significantly shorter than previous four-gland exploration without use of scintigraphy and gamma probe (160 +/- 61 minutes; t = 3.021, P = 0.007). The mean ex vivo lesion-to-background gamma probe count ratio of abnormal parathyroid glands (77.35) was found to be significantly higher than that of all other lesions with abnormal Tc99m-MIBI uptake (5.05) (U = 10.5, P < 0.0001). Optimal target-to-background ratio is essential for the success of gamma probe-guided parathyroidectomy. This ratio was highly variable among the patients in this study. Individualization of the best surgical exploration time after Tc99m-MIBI injection will improve the surgical success of this operation.

Preserving osseous viability in osteocutaneous flap prefabrication: experimental study in rabbits.

This study presents a technique that preserves osseous viability in prefabricated osteocutaneous flaps with a soft-tissue vascular carrier, with a pedicled skin flap acting as the vascular carrier to neovascularize a partially devascularized bone segment before its transfer. Using a total of 50 New Zealand White rabbits, two groups were randomized as experimental and control animals. In the experimental group (n = 30), a bipedicled dorsal scapular skin flap was anchored with sutures to the scapular bone, by bringing it into contact with the exposed dorsal surface of the bone after stripping the dorsal muscular attachments. Following 4 weeks of neovascularization, the prefabricated composite flaps were harvested, based on the caudally-based dorsal skin flap, after stripping the ventral muscular attachments of the bone. In the control group (n = 20), non-vascularized scapular bone grafts were implanted under bipedicled dorsal scapular skin flaps with sutures. After 4 weeks, prefabricated composite flaps were harvested, based on the caudally-based dorsal skin flap. In both groups, on day 7 after the second stage, the viability of the bony component of the flaps was evaluated by direct observation, scintigraphy, measurement of bone metabolic activity, microangiography, dye injection study, and histology. Results indicated that the bone segments in the experimental group demonstrated a greater survival than in the control group. The authors conclude that this technique of osteocutaneous flap prefabrication preserves the viability of the bony component with a soft-tissue vascular carrier, in contrast to the conventional method of pre-transfer grafting. The technique may be useful clinically in selected cases.