Scintigraphic Localization Research Articles

Clinical, Biochemical, and Sonographic Factors Influencing Performance of Parathormone Washout Measurement vs. 99mTc-MIBI Scintigraphy in the Preoperative Diagnostics of Parathyroid Adenomas.

The purpose of the study was to assess the clinical, biochemical, and sonographic factors influencing the performance of parathormone washout measurement (PTHw) vs. MIBI in the preoperative localization of parathyroid adenoma (PA). The studied group consisted of 39 patients with primary or tertiary hyperparathyroidism. The measurement of PTH concentrations was performed using an electro-chemiluminescence immunoassay. Scintigraphic localization of PA was carried out using dual-tracer planar neck scintigraphy, using 74 MBq 99mTc-pertechnetate and 740 MBq of 99mTc-MIBI. MIBI was unambiguously positive in 74% of patients. Among patients with negative or inconclusive MIBI, 90% had a positive PTHw result. Among patients with negative PTHw, two out of three had a positive MIBI result. The PTHw of lesions <10 mm in their largest diameter yielded positive results in 95%, compared to 75% for MIBI. For lesions ≥10 mm in largest diameter, 88% were visualised using MIBI. In conclusion, PTHw is a highly effective, easy, quick, safe, and relatively cheap procedure which might be considered for PA localisation, especially in patients with lesions presenting typical ultrasound features and a size below 10 mm. MIBI remains a useful procedure in specialized centres, particularly for patients in whom PTHw failed, larger lesions, and in cases of the ectopic location of PA.

Update of the role of Nuclear Medicine techniques in the pre-surgical localization of primary hyperparathyroidism

Primary hyperparathyroidism is one of the most frequent endocrine disorders. Its diagnosis is biochemical. Imaging techniques are not useful for the diagnosis of this pathology; they are just tools for pre-surgical localization. In this continuing education, we will analyze the different imaging modalities used in this indication, focusing on Nuclear Medicine. The most commonly used imaging technique in this context is the parathyroid scintigraphy, nowadays double phase protocol with 99mTc-MIBI and the double tracer with 99mTc-MIBI/99mTc-pertechnetate, associated in the first case to SPECT or SPECT/CT, in an early or late phase. The PET/CT with different tracers is showing good results, especially applied to cases of failure in the pre-surgical scintigraphic localization. We expose the results of the morphological imaging techniques as well, and the usefulness of combining techniques.

Evaluation of the diagnostic accuracy of skeletal scintigraphy for the causes of front foot pain determined by magnetic resonance imaging.

There is good correlation between increased radiopharmaceutical uptake anywhere in the feet of sports or leisure horses and the presence of foot pain. However, low sensitivity of scintigraphy for identifying lesions contributing to foot pain as determined by magnetic resonance imaging (MRI) has been reported. The aim of this retrospective, cross-sectional, analytical study was to assess the accuracy of scintigraphy for identifying the cause(s) of foot pain, using MRI as the reference standard. Sports and leisure horses that underwent both skeletal scintigraphy and MRI of the front feet between March 2008 and December 2014 and for which a definitive diagnosis of the cause(s) of front foot pain was reached were included (121 feet of 70 horses). Imaging studies were evaluated retrospectively, blindly. Agreements between scintigraphic localization of increased radiopharmaceutical uptake and subjective categorization of lesions with MRI diagnosis were assessed using Kappa statistics (κ). Measures of diagnostic accuracy were calculated. Sensitivity of increased radiopharmaceutical uptake varied among regions (31.8-76.2%) but specificity was at least high for all (84.6-100%). Agreements between both scintigraphy measures and MRI diagnosis were substantial for the distal phalanx (palmar processes and body) (κ=0.77 and κ=0.74, respectively), and ungular cartilages and chondral ligaments (κ=0.62, for both). When all regions were combined, agreements of increased radiopharmaceutical uptake (κ=0.49) and relevance categorization (κ=0.45) with MRI diagnosis were moderate. In conclusion, skeletal scintigraphy does not meet the minimum reliability level for a diagnostic test, but is reliable for identification of osseous trauma to the distal phalanx and ungular cartilages.

244 RADIO-GUIDED SURGERY: OUR EXPERIENCE IN SENTINEL LYMPH NODE BIOPSY IN PROSTATE CANCER

You have accessJournal of UrologyProstate Cancer: Staging (I)1 Apr 2013244 RADIO-GUIDED SURGERY: OUR EXPERIENCE IN SENTINEL LYMPH NODE BIOPSY IN PROSTATE CANCER Marco Grasso, Salvatore Blanco, Angelica Grasso, Giorgio Bovo, Andrea Crespi, and Maurizio Arosio Marco GrassoMarco Grasso Monza, Italy More articles by this author , Salvatore BlancoSalvatore Blanco Monza, Italy More articles by this author , Angelica GrassoAngelica Grasso Milan, Italy More articles by this author , Giorgio BovoGiorgio Bovo Monza, Italy More articles by this author , Andrea CrespiAndrea Crespi Monza, Italy More articles by this author , and Maurizio ArosioMaurizio Arosio Monza, Italy More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.1624AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The standard surgical treatment of PCa consists of radical prostatectomy (RP). The gold standard for N-staging is operative extended lymphadenectomy (eLND) that includes removal of the nodes overlying the external iliac artery and vein, the nodes within the obturator fossa located cranially and caudally to the obturator nerve, and the nodes medial and lateral to the internal ileac artery. Lymphadenectomy with removal of the sentinel lymph node is now evolving towards the concept of radioguided surgery as an instrument for the removal of the lymph nodes of primary drainage. METHODS From October 2011 to September 2012 laparotomic SLN dissection was performed in 43 pts during radical prostatectomy. Twenty hours before surgery, 240 MBq of 99mTc Nanocoll® in 0.8 ml of physiological solution (divided into 4 injections of 60 MBq) were injected into the prostate gland under transrectal ultrasound guidance. Intraoperatively, all LNs detected by gamma-probe with an activity significantly higher than background (4 cps) were removed and classified as SLNs. We have evaluated radioactive exposure rates as well. RESULTS The intraoperative detection of SLNs occurred in all 43 pts, while the scintigraphic localization was observed in 42/43 pts. In 1/43 pt the abnormal bladder activity probably masked the SLN, that was however detected intraoperatively by gamma-probe. In 16 pts SLNs were exclusively outside the obturator fossa while in 14 pts SLNs were both inside and outside obturator fossa. A total of 77 SLNs were found, at histopathological analysis 8/77 SLNs resulted positive for metastases (5/43 pts): 3/4 were in the obturator fossa while the remaining SLN was in the internal iliac chain, that is not a routinely sampled region. CONCLUSIONS Our preliminary data confirm the feasibility and the safety of SLN biopsy in nodal staging of PCa. The intraoperatively SLN detection rate resulted 100%. In 4 cases (10%) a micrometastases was found outside of obturator fossa in a not routinely sampled site. The technique has proved safe, the risk of exposure for all operators is contained and does not warrant classification as “staff exposed” involved in any of the categories that are not already exposed to other sources of risk, particular attention should be given to personal contamination, special attention should be paid to the management of contaminated waste. Radioguided surgery can enable us find positive lymph nodes even in usual sites and in patients with low PSA. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e100-e101 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information Marco Grasso Monza, Italy More articles by this author Salvatore Blanco Monza, Italy More articles by this author Angelica Grasso Milan, Italy More articles by this author Giorgio Bovo Monza, Italy More articles by this author Andrea Crespi Monza, Italy More articles by this author Maurizio Arosio Monza, Italy More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Sentinel node biopsy in patients with breast cancer and previous breast surgery

Aim The aim of this study was to establish the efficacy and safety of sentinel lymph node biopsy for lymph node staging in patients with breast cancer and prior breast surgery, considering its extension, localization and time since the previous surgical procedure. Materials and methods A sentinel lymph node biopsy was performed in 38 patients with early breast cancer and previous breast surgery: recent excisional biopsy in 22 patients (Group I), previous lumpectomy or mammoplasty in 16, including one case of cancer treated with breast-conserving surgery (tumor recurrence). Lymphoscintigraphy was performed after periareolar injection, also sometimes adding an injection near to the surgical scar. After removing the sentinel node, axillary lymph node dissection was performed when the lymph node was positive (and not localized). Results The efficacy of the scintigraphic localization of the sentinel node was 92.1% of the patients, with 15.8% of extra-axillary drainages. Axillary intraoperative detection was 81.6%. The identification rate after recent excisional biopsy or previous surgery was similar (81.8 vs 81.2%). However, extra-axillary sentinel nodes were more frequent in Group II (9.1 vs 25%). Having a localization of previous surgical procedures in upper outer quadrant caused drainages outside of the axilla more frequently (27.2 vs 11.1%). Axillary detection rate was similar to other quadrants (81.8 vs 81.5%). The rate of breast cancer-related events was 5.2% (2/38), without axillary recurrences (mean follow-up: 3 years). Conclusion Sentinel lymph node biopsy in patients with previous but not extensive breast surgery is safe. Extra-axillary drainages are more common when the previous surgical area was wide, especially in the upper-outer quadrant.

Biopsia de ganglio centinela en pacientes con cáncer de mama y cirugía mamaria previa

Aim The aim of this study was to establish the efficacy and safety of sentinel lymph node biopsy for lymph node staging in patients with breast cancer and prior breast surgery, considering its extension, localization and time since the previous surgical procedure. Material and methods A sentinel lymph node biopsy was performed in 38 patients with early breast cancer and previous breast surgery: recent excisional biopsy in 22 patients (Group I), previous lumpectomy or mammoplasty in 16, including one case of cancer treated with breast-conserving surgery (tumor recurrence). Lymphoscintigraphy was performed after periareolar injection, also sometimes adding an injection near to the surgical scar. After removing the sentinel node, axillary lymph node dissection was performed when the lymph node was positive (and not localized). Results The efficacy of the scintigraphic localization of the sentinel node was 92.1% of the patients, with 15.8% of extra-axillary drainages. Axillary intraoperative detection was 81.6%. The identification rate after recent excisional biopsy or previous surgery was similar (81.8 vs 81.2%). However, extra-axillary sentinel nodes were more frequent in Group II (9.1 vs 25%). Having a localization of previous surgical procedures in upper outer quadrant caused drainages outside of the axilla more frequently (27.2 vs 11.1%). Axillary detection rate was similar to other quadrants (81.8 vs 81.5%). The rate of breast cancer-related events was 5.2% (2/38), without axillary recurrences (mean follow-up: 3 years). Conclusion Sentinel lymph node biopsy in patients with previous but not extensive breast surgery is safe. Extra-axillary drainages are more common when the previous surgical area was wide, especially in the upper-outer quadrant.

99mTc-prulifloxacin in artificially infected animals

SummaryAim: The radiosynthesis of 99mTc-Prulifloxacin (99mTc-PRN) was assessed in terms of stability, binding with Staphylococcus aureus (S. aureus), biodistribution in rats (RT) and scintigraphic profile in rabbits (RB). Animals, material, methods: 99mTc-PRN was synthesized by mixing 25 μg of stannous fluoride (SnF2) with 18.5 MB of sodium pertechnetate. Thereafter, 0.5 mg of the prufloxacin (PRN) was added to the reaction mixture and the pH was set at 5.1 with 0.01 mol/l HCl. The reaction mixture was incubated at room temperature. The same process was repeated by increasing the concentration of the stannous fluoride from 25 to 250 μg, sodium pertechnetate from 18,5 to 185 MBq and the PRN from 0.5 to 5 mg. The radiochemical stability of the 99mTc-PRN was investigated in higher concentration of the cystein. In-vitro binding investigation was performed using living and heat killed S. aureus to verify specificity of the 99mTc-PRN. Biodistribution was evaluated in artificially infected rats and scintigraphic precision in rabbits at different interval. Results: The 99mTc-RPN prepared by mixing 2 mg of PRN, 74 MBq sodium pertechnetate, 100 μg stannous fluoride at pH 5.4, appeared to be more than 90% stable with a maximum radiochemical yield of 98.15 ± 0.25% at 30 min. The 99mTc-PRN showed higher stability in serum and satisfactory in-vitro binding to living as compared to heat killed S. aureus. 14.25 ± 0.15% of the injected dose was accumulated in the infected muscle of the model RT. Infected to normal muscle ratio was 5.12 and inflamed to normal muscle was 1.2. The biodistribution was validated by the scintigraphic localization of infection in rabbits. Conclusion: This investigation of 99mTc-PRN confirmed its momentous radiochemical immovability in saline, serum, preferential in-vitro binding to living bacteria, higher uptake in the infected muscle of model RT and precise localization in the infected muscle of model RB.

Radiocharacterization of the 99mTc–rufloxacin complex and biological evaluation in Staphylococcus aureus infected rat model

99mTc–rufloxacin (99mTc–RUN) complex was prepared by reaction of different amounts of reduced sodium pertechnetate with different amount of Rufloxacin (RUN) antibiotic for the in vivo scintigraphic localization of the Staphylococcus aureus (S. aureus) infectious foci in Male Wister Rats (MWR) model. The 99mTc–RUN complex was radiochemically and biologically characterized in terms of radiochemical stability in saline, serum, in vitro binding with S. aureus and biodistribution in artificially infected with S. aureus MWR. The 99mTc–RUN complex showed stability more than 90% up to 240 min in normal saline with a maximum stability value of 98.10 ± 0.18% at 30 min after reconstitution. At 37 °C the complex showed in vitro permanence in serum up to 16 h with 13.90% side products during incubation. The 99mTc–RUN complex showed saturated in vitro binding with S. aureus at different intervals with a maximum uptake value of 71.50%. Infected to normal muscle, infected to inflamed and inflamed to normal muscles ratios were approximately 6.04, 4.31 and 1.40. Based on the stability of the complex in saline, serum, in vitro binding with S. aureus and biodistribution results, the 99mTc–RUN complex is recommended for in vivo scintigraphic localization of the S. aureus in vivo infectious foci in human.

Evaluation of 99mTcN–moxifloxacin dithiocarbamate, as a potential radiopharmaceutical for scintigraphic localization of infectious foci

In the current study radio complexation of the moxifloxacin dithiocarbamate (MXND) with technetium-99m (99mTc) using the [99mTc–N]2+ core through legend exchange reaction was explored. The 99mTcN–MXND complex was biologically evaluated as a potential radiopharmaceutical for in vivo scintigraphy using artificially infected male sprague–dawley rats (MSDR) with Staphylococcus aureus (S. aureus). The radiochemistry of the complex was explored in terms of radiochemical purity (RCP), in vitro stability in serum at 37 °C for 16 h, in vitro binding with S. aureus and biodistribution in artificially infected with S. aureus MSDR. It was observed that the complex showed stability of more than 90% up to 4 h after reconstitution with a maximum RCP value of 97.55 ± 0.42% at 30 min. The complex showed significantly in vitro stability in serum at 37 °C with an insignificant free species up to 16.50% within 16 h. In vitro saturated binding with S. aureus was noted up to 120 min with maximum value of 73.25% at 90 min of incubation. Almost sixfold uptake was noted in the infected muscle of the MSDR as compared to inflamed and normal muscle. The 97.55 ± 0.42% RCP values, stability in serum with insignificant untagged 16.50% species, 73.25% in vitro binding with S. aureus and sixfold uptake in the target organ posed the 99mTcN–MXND complex as a promising radiopharmaceutical for S. aureus infectious foci.

¡En guardia, centinela!

Injection technique and radiocolloid size are two critical parameters that must be carefully selected according to patient presentation and lesion appearance for accurate sentinel node detection in breast cancer. Scintigraphic detection and intraoperative localization are dependent on these parameters. The present clinical case illustrates how much deep intralesional tracer injection bears on our capacity to detect extra-axillary sentinel nodes and how the use of smaller-size radiocolloids may sometimes facilitate sentinel node detection.

111Indium-transferrin for localization and quantification of gastrointestinal protein loss

Objective. To evaluate the indium-111 (111In)-transferrin method as a means of localization and quantification of gastrointestinal protein loss. Methods. Fourteen patients and 15 healthy subjects underwent an 111In-transferrin study consisting of abdominal scintigraphy, whole-body counting measurement and determination of plasma activity of 111In during the course of 5 days. Two of the patients went through a subsequent chromium-51–trichloride test with analysis of radioactivity in faeces in order to compare the results of the two methods. Results. The patients had a mean±SEM whole-body loss of 111In of 10.9±2.9% for 96 h, while the healthy controls lost 1.8±1.3% (p=0.0045). The decay in plasma activity followed biexponential kinetics. The characteristic plasma transit time was 5.0±1.0 h in patients and 12.1±1.5 h in controls (p=0.0007). Scintigraphically, patients had obvious abdominal foci of activity, while the control subjects showed diffuse activity. Anatomic localization of the leaking spot seemed more uncertain. By comparison with the 51Cr trichloride test, the loss of radio-labelled protein appeared to be in the same order of magnitude. Conclusions. Quantification of gastrointestinal protein loss can be done without collecting faeces. Normal subjects have a loss of a few per cent, making the 111In-transferrin method comparable with the former standard using 51CrCl3–trichloride. Plasma measurements of 111In are not predictive of the magnitude of the loss. Scintigraphic localization of the site of the loss needs to be optimized, for instance by serial imaging or image fusion with an anatomical modality.

Applications of SPECT/CT in Nuclear Radiology

The purpose of this pictorial essay is to illustrate several clinical situations in which SPECT/CT can be effectively applied in nuclear radiology practice. SPECT/CT has recently emerged as a valuable adjunct to standard techniques in clinical nuclear radiology. This technique provides significantly improved scintigraphic localization and characterization of disease, increasingly important in this era of minimally invasive surgery and targeted radiotherapy.

Papillary thyroid carcinoma with lymph node metastases

Papillary thyroid cancer (PTC) is the most frequently occurring human thyroid cancer with good prognosis following appropriate treatment. Lymph node (LN) metastases are the main way through which PTC spread cancer cells. The mechanisms underlying PTC with local invasion, LN metastases and distant metastases are not well investigated. Tumor secrete cytokines, such as vascular endothelial growth factor (VEGF)-C and -D bind to VEGF receptors on lymphatic endothelial cells and induce proliferation (budding) from nearby lymphatic capillaries and growth of new lymphatic capillaries. About one-third of patients can be diagnosed at the time of surgical findings. Different image studies, such as ultrasonography with fine needle aspiration cytology, scintigraphic localization and positron emission tomography were reported to detect LN metastases. Important factors in predicting LN metastases are vascular invasion, male gender, absence of tumor capsule, and perithyroid involvement. Tumor recurrence in LN after primary treatment of PTC had an independent and highly significant negative effect on survival in patients over 45 year-old. Recombinant adeno-associated virus-mediated gene transfer of sVEGFR3-Fc is a feasible therapeutic scheme for blocking lymphogenous metastasis. In conclusion, aggressive surgical procedures performed by experienced surgeons or postoperative radioactive iodine therapy to minimize local recurrence of LN for PTC patients with high risk.

Does imaging in sentinel node scintigraphic localization add value to the procedure in patients with breast cancer?

Imaging sentinel nodes with pre-operative lymphoscintigraphy effectively assures successful sentinel node identification. However, sentinel nodes are still identified in the majority of image negative patients. Given the logistics and cost required to perform pre-operative lymphoscintigraphy its routine use may not be justified. It may be valuable for surgeons in the learning phase and in obese patients who have increased risk of intra-operative failed localization. A negative pre-operative lymphoscintiscan predicts inability to localize with the hand-held gamma probe. Patients with no 'hot node' on the lymphoscintiscan are more likely to have failed localization using the gamma probe only. Therefore, blue dye should be used along with the gamma probe to optimize the localization rate in these patients.

Somatostatin receptor subtypes in human pheochromocytoma: subcellular expression pattern and functional relevance for octreotide scintigraphy.

The stable somatostatin analog octreotide has been successfully used for imaging and treatment of a variety of human tumors. In pheochromocytoma, data on somatostatin receptor subtyping have thus far been sparse. Pheochromocytomas often express more than one somatostatin receptor, and it is uncertain by which receptor subtype the functional responses of octreotide are mediated. Here, we have examined somatostatin receptor protein expression in a panel of 52 pheochromocytomas from 35 randomly selected patients by immunostaining with specific polyclonal anti-sst(1-5) and monoclonal mouse anti-SS-14 antibodies. Staining pattern, distribution and subcellular localization of somatostatin receptor subtypes were investigated. Seventeen patients received (111)In-octreotide scintigraphy. Although the vast majority of tumors (90%) showed positive immunohistochemical staining for sst(3), immunoreactive sst(2A) receptors were only seen in 13 tumors (25%). All other somatostatin receptor subtypes were less frequently detected. Interestingly, among sst(3)-positive tumors strikingly different subcellular distributions of immunoreactive sst(3) receptors were observed. In most cases, immunoreactive sst(3) receptors were distributed throughout the cytosol. Scintigraphic localization of tumors larger than 1 cm in diameter was always successful in the presence of immunoreactive sst(2A) receptors. In the absence of sst(2A), true-positive octreotide scintigraphy was only seen in the presence of membrane-associated sst(3) immunoreactivity. Our findings suggest that selective expression of functional membrane-associated sst(3) receptors is sufficient for high tracer uptake during octreotide scintigraphy in a subgroup of human pheochromocytomas. These tumors may represent a potential target treatment with somatostatin receptor agonists with improved sst(3) activity.

Pinhole imaging of 131I-metaiodobenzylguanidine (131I-MIBG) in an animal model of neuroblastoma.

To evaluate (131)I-MIBG scintigraphic localization of xenotransplanted and spontaneously arising neuroblastomas in murine models of high-risk neuroblastoma. Neuroblastoma xenografts were created by inoculation of human neuroblastoma cell suspensions into the subcutaneous flanks of athymic nude mice. In addition, spontaneous paraspinal neuroblastomas were detected by direct palpation in MYCN transgenic mice. After measured tumor volumes exceeded 200 mm(3), each mouse received an intraperitoneal injection of 18 muCi/g (131)I-metaiodobenzylguanidine ((131)I-MIBG). Pinhole scintigraphy was performed to evaluate the MIBG biodistribution and to attempt to visualize the tumors. Each mouse was imaged on a gamma camera equipped with a 3-mm pinhole on one head and an HEGP collimator on the other. Images demonstrated absorption of radiolabeled MIBG and visualization of tumors. Analysis of the images allowed for quantification of relative MIBG uptake and for determination of linear and area measurements of the tumors. High-energy pinhole imaging effectively demonstrates uptake of radiolabeled MIBG by human neuroblastoma tumors in murine laboratory models. This technique allows for in vivo assessment of tumor burden. In the future, we plan to use this method to evaluate sensitivity for detecting metastatic spread as well as investigating the therapeutic efficacy of high-dose (131)I-MIBG in combination with radiosensitizing agents.

Experienced Scintigraphers Contribute to Success of Minimally Invasive Parathyroidectomy by Skilled Endocrine Surgeons

Minimally invasive parathyroidectomy (MIP) has become the preferred surgical treatment for selected patients diagnosed with primary hyperparathyroidism (PHPT) at our tertiary-care center. Preoperative scintigraphy establishes the position of a parathyroid adenoma, dictates the incision site, and can minimize incision size and consequent tissue dissection. We reviewed our database and sought to identify factors that led to discordant preoperative imaging and operative findings and to assess the effect of experience on these findings. A retrospective review was performed on all patients with biochemically proven PHPT who underwent Tc-99m sestamibi scintigraphy and surgical intervention. Patient demographics, date of surgical intervention, scintigraphic localization, surgical findings, pre- and postoperative biochemical markers, histopathology, coexisting thyroid pathology, and 6-month follow up were recorded. Preoperative images that were discordant with operative findings were independently reviewed. Parathyroid scintigraphy was performed on 125 consecutive patients for PHPT between November 1999 and January 2002. Seventy-six patients had MIPs, 35 had standard cervical explorations, 11 had MIPs that were converted to standard cervical explorations, and three had surgery directed to an ectopic location. At 6-month follow-up 98.4 per cent were cured. Preoperative imaging and surgical findings were ipsilateral and concordant in 105 of 118 (89%) patients with parathyroid adenoma. The anatomic origin of an adenoma was predicted in only 83 of 118 (68%) patients. Most of the inaccurate scintigraphy readings occurred during the first 13 of the 26 months that MIPs were performed at our institution. Only two discordant cases occurred during the last 9 months of this period. Biochemical markers, prior neck operation, and concomitant thyroid pathology had no correlation with imaging sensitivity. Scintigraphic interpretation of smaller adenomas was less reliable; discordant cases were more common in small adenomas. Communication between endocrine surgeons and nuclear medicine physicians about the MIP technique and anatomic orientation of adenomas led to better scintigraphic localization as experience increased. Now that MIP by skilled endocrine surgeons is becoming the favored treatment for PHPT experienced nuclear medicine physicians may be the most important factor to achieve maximum success.

Scintigraphic Localization of Parathyroid Adenomas Prior to Minimally Invasive Parathyroidectomy for Primary Hyperparathyroidism

Dr. Clark is a Resident and Dr. Morton is Professor of Radiology and Nuclear Medicine Section Head, Department of Radiology, Wake Forest University School of Medicine, Medical Center Blvd., Winston-Salem, NC 27157; E-mail: [email protected]. The authors have disclosed that they have no significant relationships with or financial interests in any commercial organizations pertaining to this educational activity.

Limitations of Technetium 99m Sestamibi Scintigraphic Localization for Primary Hyperparathyroidism Associated with Multiglandular Disease

Successful surgical treatment of primary hyperparathyroidism requires the localization and excision of the parathyroid tissue responsible for excessive parathyroid hormone secretion while ensuring that the patient will have sufficient endogenous parathyroid hormone production to maintain eucalcemia. In selecting patients with primary hyperparathyroidism for unilateral parathyroidectomy the surgeon should be able to diagnose multiglandular disease either preoperatively or intraoperatively. We performed a retrospective review of 123 patients who underwent surgical treatment for primary hyperparathyroidism to determine the potential feasibility of selecting patients for minimally invasive surgery based on preoperative imaging studies. All patients were studied preoperatively with 99m technetium-sestamibi scintigraphy. High-resolution ultrasonography was performed in 119 of these patients. All patients except one underwent bilateral cervical exploration. A patient with an intrathoracic adenoma was successfully diagnosed by scintigraphy thereby allowing treatment by a limited thoracotomy. One hundred eight patients had solitary adenomas and 15 had multiglandular disease. In none of the patients with bilateral multiglandular disease were all abnormal glands localized preoperatively. Patients in our study with primary hyperparathyroidism and multiglandular disease were underdiagnosed by preoperative imaging. A minimally invasive approach based solely on preoperative imaging studies may result in treatment failure in patients with multiglandular involvement.

Gammagrafía de receptores de somatostatina. ¿Cuándo hacer una SPECT?

Somatostatin receptor scintigraphy has become an essential tool in the treatment planning of patients with carcinoid tumor (CaT) and pancreatic neuroendocrine tumors (PNET). However, the contribution of SPECT images in the diagnosis and staging of these tumors has not been well established. 1) To find out if SPECT improves the sensitivity of planar imaging and adds any value to tumor diagnosis, and 2) To determine under which circumstances SPECT images must be obtained. We have evaluated 49 patients, 26 females and 23 males, using both planar and SPECT 111In-DTPAOC images. The patients were classified into three groups according to their clinical indication: Group A: Indolent symptoms of CaT or PNET (n = 9); Group B: Known or functioning CaT or PNET tumors (n = 22); Group C: Post-surgical follow-up (n = 18). The total number of SPECT studies were 51 (37 abdomen, 13 thorax and 1 brain). In all cases SPECT was performed 24 hours after 111In-DTPAOC injection. Scintigraphic images were compared with surgical findings in 17 patients and with a synthesis of biochemical, clinical and CT findings in the other patients. 16 primary lesions were detected with planar images whereas SPECT detected 18. The two tumors detected only by SPECT were a bronchial CaT and an insulinoma located in the pancreatic tail. Planar and SPECT image sensitivities were 66.6% and 75% respectively. Twenty one patients developed metastatic disease. Sensitivities of planar and SPECT images for metastases were 76.1% and 90.4% respectively. Furthermore, SPECT helps planar images in the evaluation of six patients with uncertain images (lesions with low receptor density or with an uncertain scintigraphic localization). Therefore, in 15.6% of patients with primary or metastatic tumors, planar images were normal whereas SPECT was abnormal and SPECT provided an added value in 21.8% of the studies with abnormal planar images. We recommend the use of SPECT images in: 1) Patients with specific functional clinical syndrome or with a known CaT or PNET and normal planar images. 2) When planar images are abnormal only in primary tumor. 3) In order to confirm the absence of other metastases in patients with known liver metastases. 4) In order to enhance the detection of lesions with low receptor density and uncertain planar images and 5) In order to determine exactly the anatomic location of some lesions