SPECT/CT scans allow precise anatomical location of sentinel lymph nodes in breast cancer and redefine lymphatic drainage from the breast to the axilla.

BACKGROUND: Historical studies of lymphatic drainage of the breast have suggested that the lymphatic drainage of the breast was to lymph nodes lying in the antero-pectoral group of nodes in the axilla just lateral to the pectoral muscles. The purpose of this study was to confirm this is not correct. METHODS: The hybrid imaging method of SPECT/CT allows the exact anatomical position of the sentinel lymph node (SLN) in the axilla to be documented during pre-operative lymphoscintigraphy (LS) in patients with breast cancer. We have done this in a series of 741 patients. The Level I axillary nodes were defined as anterior, mid or posterior. This was related to the anatomical location of the primary cancer in the breast. RESULTS: A SLN was found in the axilla in 97.8% of our patients. Just under 50% of SLNs located in the axilla were not in the anterior group and lay in the mid or posterior group of Level I axillary nodes. There was a SLN in a single node field in 460 patients (63%), two node fields in 261(36%), three node fields in 6 and four node fields in 1 patient. CONCLUSION: Axillary lymphatic drainage from the breast is not exclusively to the anterior (or antero-pectoral) group of Level I nodes. SYNOPSIS: SPECT/CT lymphoscintigraphy shows that the breast does not always drain to the anterior group of Level I lymph nodes in the axilla but may drain to the mid axilla and/or posterior group in about 50% of patients with breast cancer regardless of the location of the cancer in the breast. These data redefine lymph drainage from the breast to axillary lymph nodes.

Therapeutic nuclear medicine in pediatric malignancy.

The following review aims to provide contemporary information on therapeutic nuclear medicine procedures in paediatric malignancies. Neuroblastoma is the most common paediatric extra cranial solid cancer characterized by meta-iodobenzylguanidine (mIBG) avidity in >/=90% of patients. There exists approximately a 30-year experience with I-131-mIBG treatment. Ongoing efforts include a more standardized approach including dosimetric data for patient selection and treatment guidance of I-131-mIBG therapy. Neuroendocrine tumours (NETs) are very rare neoplasms in the paediatric population accounting for <1% of all paediatric malignancies. These neoplasms are characterized by the presence of neuroamine uptake mechanisms and/or peptide receptors at the cell membrane. These features constitute the basis of the clinical use of peptide receptor radionuclide therapy (PRRNT) using radiolabeled somatostatin analogues. Osteosarcoma is the most common primary bone tumour in children usually treated with chemotherapy and surgery. In palliative situations bone seeking radionuclide therapies (strontium-89 [Sr-89], rhenium-186 hydroxyethylene diphosphonate [Rh-186 HEDP] and Samarium-153-ethylene diamine tetramethylene phosphonic acid [Sm-153-EDTMP]) may be offered to patients with painful metastatic osteosarcoma or in case of recurrent bone sites inaccessible to local therapies (surgery, external irradiation). Thyroid cancer is a rare childhood malignancy with an approximate incidence of 0.54 per 100000 per year but is the most frequent tumour of endocrine glands in children and adolescents. Management includes radioiodine therapy but there are some distinct differences in comparison to adult thyroid cancer management.

Zolpidem for persistent vegetative state--a placebo-controlled trial in pediatrics.

OBJECTIVE: The aim of this study was to determine if zolpidem is associated with improved responsiveness or regional cerebral perfusion in patients with persistent vegetative states. METHODS: Following ethics approval, children with persistent vegetative state were enrolled in a prospective, double-blind, placebo-controlled randomised trial. Patients underwent 2 treatments of 4 days, separated by 10 days. Each child received either a daily dose of zolpidem or placebo with a dosage of 0.14-0.2 mg/kg. Responsiveness and regional cerebral perfusion were the outcomes of interest. These were assessed using the Rancho levels of cognitive functioning scale, the coma/near-coma scale and F (18)-FDG positron emission tomography. These were conducted at baseline and after completion of the treatments. RESULTS: 3 children were enrolled. The Rancho assessment scales showed no change with treatment. The coma/near-coma scale showed a tendency to increase with zolpidem, suggesting reduced responsiveness - when compared to baseline or placebo. The positron emission tomography scans showed no significant changes between treatments. CONCLUSION: Zolpidem was associated with a tendency towards reduced responsiveness in patients with persistent vegetative states. There were no objective changes on positron emission tomography suggestive of an associated increase in cerebral blood flow with zolpidem. It would appear that zolpidem does not offer a beneficial effect in this setting.

Pulmonary inflammatory myofibroblastic tumor after Hodgkin's lymphoma and application of PET imaging.

Inflammatory myofibroblastic tumor (IMT) is a rare tumor with a particular histological pattern of myofibroblasts and mixed inflammatory infiltrate. IMT has been rarely described in association with malignancy. This case report is of a 16-year-old male who had Hodgkin's disease (stage IVA) and who after chemotherapy and radiotherapy developed IMT, 16 months post completion of therapy. The IMT was in the lung in an area which was previously involved with HD and had undergone radiotherapy. PET imaging with F(18)FDG was used in the initial diagnosis and has been used in follow-up after full surgical resection of the lesion.

Somatic malignant transformation in a sacrococcygeal teratoma in a child and the use of F18FDG PET imaging.

A 6-year-old female presented with a subcutaneous sacral mass. Biopsy revealed an adenocarcinoma most likely arising from a sacrococcygeal teratoma (SCT). CT imaging revealed a massive tumour consistent with SCT. F(18)FDG Positron Emission Tomography (PET) scan confirmed marked metabolic activity in the tumour mass and regional lymph node involvement. After chemotherapy repeat CT and PET studies revealed a poor response but no evidence of peritoneal or distant metastases. Radical abdomino-pelvic and gluteal surgery was performed with removal of the entire tumour confirmed as a moderately differentiated adenocarcinoma arising in an immature teratoma. Follow up imaging including PET scanning 5 months after her surgery revealed widespread peritoneal, hepatic and pulmonary metastases. Somatic malignant transformation of an SCT in a child of this age has not been previously reported.

Application of the Meckel's scan in a case of gastric corrosive injury.

This report describes a useful application of (99m)Tc-pertechnetate abdominal scintigraphy (Meckel's scan) in the assessment of gastric viability after corrosive injury. The Meckel's scan provided information about residual gastric mucosal function and prognosis in a less invasive manner than more usual methods.

Lymphatic mapping of the breast: locating the sentinel lymph nodes.

When the concept of sentinel lymph node biopsy was described in patients with melanoma, researchers quickly started to use lymphatic mapping techniques in breast cancer patients in an attempt to locate the sentinel node in the axilla. We have been performing mammary lymphoscintigraphy in this role for 6 years and have now studied 159 patients. Like others, we have found that most breast cancers (93%) have lymphatic drainage that includes the axilla, and we have found an average of 1.4 axillary sentinel nodes in these patients. Surgical biopsy of the axillary sentinel nodes accurately staged the node field in 96% of patients. We have also found, however, that the pattern of lymphatic drainage from the cancer site is unpredictable; and in 49% of patients lymphatic drainage occurred across the center line of the breast to axillary or internal mammary sentinel nodes. In more than half of our patients (56%) lymphatic drainage occurred to lymph nodes outside the axilla including the internal mammary (45%), supraclavicular (13%), and interpectoral and intramammary interval nodes (12%). These nodes are also sentinel nodes, and their presence indicates that a sentinel node biopsy procedure that stages only the status of the axillary lymph nodes has the potential to understage about half the patients with breast cancer. High quality lymphoscintigraphy allows accurate mapping of peritumoral lymphatic drainage in most patients with breast cancer. It is possible that in the future accurate nodal staging in each individual will involve biopsy of all sentinel lymph nodes, regardless of their location.

Infantile-onset paroxysmal dystonia: a diagnostic dilemma.

A 4-year-old boy presented with a history of paroxysmal dystonic posturing since birth. Episodes were triggered by stress, fatigue, and cold. Sleep, for as short as 1 minute, resulted in complete resolution of dystonia. He was developmentally normal, with no focal neurologic deficits. Cerebrospinal fluid, homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA) were borderline low. On ictal spectroscopy, there was reduced blood flow to the right temporal region, caudate nuclei, and thalami. The typical infantile form of dystonia is benign, resolving by 2 years of age in an otherwise normal child. Our patient remains symptomatic at 4 years of age.

Measurement of midfemoral shaft geometry: repeatability and accuracy using magnetic resonance imaging and dual-energy X-ray absorptiometry.

Although macroscopic geometric architecture is an important determinant of bone strength, there is limited published information relating to the validation of the techniques used in its measurement. This study describes new techniques for assessing geometry at the midfemur using magnetic resonance imaging (MRI) and dual-energy X-ray absorptiometry (DXA) and examines both the repeatability and the accuracy of these and previously described DXA methods. Contiguous transverse MRI (Philips 1.5T) scans of the middle one-third femur were made in 13 subjects, 3 subjects with osteoporosis. Midpoint values for total width (TW), cortical width (CW), total cross-sectional area (TCSA), cortical cross-sectional area (CCSA), and volumes from reconstructed three-dimensional (3D) images (total volume [TV] and cortical volume [CVol]) were derived. Midpoint TW and CW also were determined using DXA (Lunar V3.6, lumbar software) by visual and automated edge detection analysis. Repeatability was assessed on scans made on two occasions and then analyzed twice by two independent observers (blinded), with intra- and interobserver repeatability expressed as the CV (CV +/- SD). Accuracy was examined by comparing MRI and DXA measurements of venison bone (and Perspex phantom for MRI), against "gold standard" measures made by vernier caliper (width), photographic image digitization (area) and water displacement (volume). Agreement between methods was analyzed using mean differences (MD +/- SD%). MRI CVs ranged from 0.5 +/- 0.5% (TV) to 3.1 +/- 3.1% (CW) for intraobserver and 0.55 +/- 0.5% (TV) to 3.6 +/- 3.6% (CW) for interobserver repeatability. DXA results ranged from 1.6 +/- 1.5% (TW) to 4.4 +/- 4.5% (CW) for intraobserver and 3.8 +/- 3.8% (TW) to 8.3 +/- 8.1% (CW) for interobserver variation. MRI accuracy was excellent for TV (3.3 +/- 6.4%), CVol (3.5 +/- 4.0%), TCSA (1.8 +/- 2.6%), and CCSA (1.6 +/- 4.2%) but not TW (4.1 +/- 1.4%) or CW (16.4 +/14.9%). DXA results were TW (6.8 +/- 2.7%) and CW (16.4 +/- 17.0%). MRI measures of geometric parameters of the midfemur are highly accurate and repeatable, even in osteoporosis. Both MRI and DXA techniques have limited value in determining cortical width. MRI may prove valuable in the assessment of surface-specific bone accrual and resorption responses to disease, therapy, and variations in mechanical loading.

Sentinel lymph node biopsy in patients with melanoma and breast cancer.

Sentinel lymph node biopsy (SNLB) is a new method for staging regional node fields in patients with cancers that have a propensity to metastasise to lymph nodes. The majority of early experience has been obtained in patients with melanoma and breast cancer. The technique requires the close cooperation of nuclear medicine physicians, surgical oncologists and histopathologists to achieve the desired accuracy. It involves: (i) identification of all lymph nodes that directly drain a primary tumour site (the sentinel nodes) by the use of pre-operative lymphoscintigraphy, (ii) selective excision of these nodes by the surgeon, guided by pre-operative blue dye injection and a gamma detecting probe intra-operatively and (iii) careful histological examination of the sentinel nodes by the histopathologist using serial sections and immunohistochemical stains. If the nodes are normal it can be inferred with a high degree of accuracy that all nodes in the node field are normal. This means that radical dissections of draining node fields can be avoided in patients with normal lymph nodes. A further advantage of lyamphatic mapping is that drainage to sentinel nodes in unusual locations is identified, leading to more accurate nodal staging than could be achieved with routine dissection of the closest node field.

Reliability of DMSA for the diagnosis of renal parenchymal abnormality in children.

The objective of this study was to evaluate the variability of technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy interpretation by four nuclear medicine physicians for the diagnosis of renal parenchymal abnormality in children, and to compare variability among three different DMSA methods in clinical use: planar alone, single-photon emission tomography (SPET) alone, and planar with SPET. One hundred consecutive DMSA studies were independently interpreted 3 times by four participating nuclear medicine specialists from different departments and in random order. All scans were classified by the presence or absence of renal parenchymal abnormality using the modified four-level grading system of Goldraich. Indices of agreement were the percentage of agreement and the kappa statistic. Disagreement was analysed using children, kidneys and kidney zones (three zones per kidney). Using patients as the unit of analysis, agreement for planar and planar with SPET methods was 87%-88% (kappa 0.74) for the normal-abnormal scan classification. The corresponding agreement value for the SPET alone method was 78% (kappa 0.56). Similarly, substantial disagreement (disagreement > or = 2 categories) occurred in 2.5% and 1.3% of comparisons between observers for planar alone and planar with SPET, respectively, but in 5.2% of comparisons for SPET alone. These results did not vary appreciably whether interpretation of patients, kidneys or kidney zones was compared. It is concluded that the four experienced nuclear medicine physicians showed substantial agreement in the interpretation of planar alone and planar with SPET DMSA scintigraphic images. Interpretation of SPET DMSA images, without planar images, was significantly more variable than interpretation using the two other methods, disagreement occurring in more than 20% of comparisons. SPET DMSA scintigraphy, when used without planar images, does not provide a firm basis for clinical decision making in the care of children who may have renal damage. There is no apparent benefit of reduced variability from the extra provision of SPET data to nuclear medicine physicians who already have planar images.

An unusual white blood cell scan in a child with inflammatory bowel disease: a case report.

Technetium-99m-labeled leukocyte (WBC) imaging is a valuable screening method for inflammatory bowel disease, especially in children, because of its high rate of sensitivity, low cost, and ease of preparation. A 14-year-old girl is described who had juvenile arthritis and iritis complicated by inflammatory bowel disease. She was examined for recurrent abdominal pain. A Tc-99m stannous colloid WBC scan was performed, and tracer accumulation was seen in the small bowel in the region of the distal ileum on the initial 1-hour image. Delayed imaging at 3 hours also revealed tracer accumulation in the cecum and ascending colon, which was not seen on the early image. A biopsy of the colon during endoscopy showed no evidence of active inflammation in the colon. The small bowel was not seen. Computed tomography revealed changes suggestive of inflammatory bowel disease in the distal ileum. The appearance on the WBC study was most likely a result of inflammatory bowel disease involving the distal ileum, with transit of luminal activity into the large bowel.

Interval nodes: the forgotten sentinel nodes in patients with melanoma.

BACKGROUND: Any sentinel lymph node that receives lymph drainage directly from a primary melanoma site, regardless of its location, may contain metastatic disease. This is true even if the sentinel node does not lie in a recognized node field. Interval (in-transit) nodes that lie along the course of a lymphatic vessel between a primary melanoma site and a recognized node field are sometimes seen during lymphatic mapping for sentinel node biopsy. If drainage to such interval nodes is ignored by the surgeon during sentinel node biopsy, metastatic melanoma will be missed in some patients. HYPOTHESIS: When lymph drains directly from a cutaneous melanoma site to an interval node, that sentinel node has the same chance of harboring micrometastatic disease as a sentinel node in a recognized node field. DESIGN: Preoperative lymphoscintigraphy with technetiumTc 99m antimony trisulfide colloid was performed to define lymphatic drainage patterns and, since 1992, to locate the sentinel lymph nodes for surgical biopsy or for permanent skin marking of their location with point tattoos. SETTING: Melanoma unit of a university teaching hospital. PATIENTS: A total of 2045 patients with cutaneous melanoma were studied in 13 years. RESULTS: Interval nodes were found in 148 patients (7.2%). The incidence of interval nodes varied with the site of the primary melanoma. Interval nodes were more common with melanomas on the trunk than with those on the lower limbs. Micrometastatic disease was found in 14% of interval nodes that underwent biopsy as sentinel nodes. This incidence is similar to that found in sentinel nodes located in recognized node fields, confirming the potential clinical importance of interval nodes. CONCLUSIONS: Interval nodes should be removed surgically along with any additional sentinel nodes in standard node fields if the sentinel node biopsy procedure is to be complete. In some patients, an interval node will be the only lymph node that contains metastatic disease.

How accurate is dimercaptosuccinic acid scintigraphy for the diagnosis of acute pyelonephritis? A meta-analysis of experimental studies.

UNLABELLED: The purpose of this study was to evaluate the performance of dimercaptosuccinic acid (DMSA) scintigraphy in the diagnosis of acute pyelonephritis and to compare the test performance of the standard technique, planar DMSA, with the newly introduced technique, SPECT DMSA. METHODS: All published animal studies in which DMSA scintigraphy was compared with histopathology, the reference standard for acute pyelonephritis, were identified using a comprehensive search strategy with the MEDLINE and EMBASE databases. Test performances of all DMSA methods and SPECT versus planar DMSA were analyzed using summary receiver operating characteristic (sROC) curves. RESULTS: Seven studies were identified, including 2 of SPECT DMSA. Problems in study design or reporting were common, with numerical errors in 4 studies. Overall, at a sensitivity of 86%, specificity was estimated to be 91%. Detection of acute pyelonephritis was at a lower threshold for SPECT than for planar DMSA (sensitivity/specificity values of 97%0/66% compared with 82%/ 97%), and the overall test performance of SPECT was not demonstrably better than that of planar DMSA. When applied to a group of children with a prevalence of renal damage of 40%, this means that 98% of children with abnormal planar DMSA scans will have renal damage, whereas only 65% of those with abnormal SPECT scans will have renal damage. Planar and SPECT DMSA will miss 11% and 3% of children with renal damage, respectively. Out of 100 children in the hypothetical group with 40% experiencing renal damage, SPECT will identify 6 extra true cases of renal damage at the expense of 19 extra false positives, when compared with planar DMSA. CONCLUSION: Published studies of DMSA test performance are few in number and have significant methodologic problems that should be avoided in future studies. DMSA, particularly the planar technique, performs well for the diagnosis of acute pyelonephritis. Using test performance criteria, SPECT DMSA alone has not been shown to be preferable to the established planar method and will result in a small number of true-positives at the expense of a larger number of false-positives.

Role of ischemia and infarction in late right ventricular dysfunction after atrial repair of transposition of the great arteries.

OBJECTIVES: This study was conducted to assess whether myocardial ischemia and/or infarction are involved in the pathogenesis of late right ventricular dysfunction in adult survivors of atrial baffle repair for transposition of the great arteries in infancy. BACKGROUND: The medium-term success of intraatrial baffle repair for transposition of the great arteries is good, with many patients surviving into adult life, but prognosis can be limited by progressive right ventricular dysfunction. We hypothesized that ongoing myocardial ischemia and/or infarction are important factors in the pathogenesis of this complication. Radionuclide techniques offer an opportunity to study both myocardial perfusion and concomitant ventricular wall motion. METHODS: Dipyridamole sestamibi single-photon emission computed tomography followed by rest sestamibi single-photon emission computed tomography was used to assess right ventricular myocardial perfusion, wall motion, wall thickening and ejection fraction in 22 adolescents/young adults who had undergone atrial baffle repair for simple transposition of the great arteries at median 6.7 (range 0.5 to 54) months of age. The patients were aged 10 to 25 (median 15.5) years; 19 in New York Heart Association class I, 2 in class II and 1 in class III. All were in a regular cardiac rhythm during the studies. The right ventricular tomographic images were examined in three parallel and two orthogonal planes, analyzed in 12 segments. RESULTS: Perfusion defects were evident in all patients in at least one segment, in either the rest or stress images. Twelve patients (55%) demonstrated fixed defects only, nine (41%) had fixed and reversible defects and one (4.5%) had reversible defects only. Concomitant wall-thickening abnormalities occurred in 83% of segments with fixed perfusion defects, mirrored by a reduction in wall motion in 91% of segments analyzed. Right ventricular ejection fraction was correlated with age (R = 0.62; p = 0.002), and with wall-thickening abnormalities (R = 0.60; p < 0.005). CONCLUSIONS: Reversible and fixed perfusion defects with concordant regional wall motion abnormalities occur in the right (systemic) ventricle 10 to 20 years after Mustard repair for transposition of the great arteries; this may be important in the pathogenesis of late right ventricular dysfunction in this group.

Popliteal lymph node metastasis from primary cutaneous melanoma.

AIMS: To document the incidence of popliteal lymph node involvement by metastatic melanoma and to consider the implications of this information for clinical management. METHODS: From the computerized database of the Sydney Melanoma Unit, all patients with primary melanomas located at or distal to the knee were identified and their records were examined. Experience with those patients who developed popliteal node metastases was then reviewed. RESULTS: Thirteen of 4262 patients (0.31%) with primary melanomas of the distal lower limb developed popliteal node metastases. Six of the 13 patients had previous, synchronous or subsequent groin node metastases. CONCLUSIONS: Popliteal lymph node involvement by metastatic melanoma is a rare event. The study results suggest only two indications for full popliteal node clearance-either a histologically positive sentinel node in the popliteal fossa or clinical evidence of metastatic disease in a popliteal node.