Differential diagnosis of adnexal masses: risk of malignancy index, ultrasonography, magnetic resonance imaging, and radioimmunoscintigraphy.

A risk of malignancy index (RMI), based on menopausal status, ultrasound (US) findings, and serum CA125, has previously been described and validated in the primary evaluation of women with adnexal masses and is widely used in selective referral of women from local cancer units to specialized cancer centers. Additional imaging modalities could be useful for further characterization of adnexal masses in this group of women. A prospective cohort study was conducted of 196 women with an adnexal mass referred to a teaching hospital for diagnosis and management. Follow-up data was obtained for 180 women; 119 women had benign and 61 women malignant adnexal masses. The sensitivity and specificity of specialist US, magnetic resonance imaging (MRI), radioimmunoscintigraphy (RS), and the RMI were determined. We identified a subgroup of women with RMI values of 25-1000 where the value of further specialist imaging was evaluated. Sensitivity and specificity for specialist US were 100% and 57%, for MRI 92% and 86%, and for RS 76% and 87%, respectively. Analysis of 123 patients managed sequentially, using RMI cutoff values of > or =25 and <1000 and then US and MRI provided a sensitivity of 94% and a specificity of 90%. Using this RMI cutoff followed by specialist US and MRI, as opposed to the traditional RMI cutoff value of 250, can increase the proportion of patients with cancer appropriately referred in to a cancer center, with no change in the proportion of patients with benign disease being managed in a local unit.

Radioimmunoscintigraphy with Tc-99m-labelled SM3 in differentiating malignant from benign adnexal masses.

OBJECTIVE: Ultrasound scanning, serum CA125 and menopausal status have previously been combined in a risk of malignancy index for the differential diagnosis of adnexal masses. Although this approach has greater accuracy than either individual tests or clinical assessment, it has a significant false positive and false negative rate. Efforts have been directed at refining differential diagnosis and this study assessed the role of radioimmunoscintigraphy using the stripped mucin 3 (SM3) antibody that has a 17-fold greater uptake in malignant than benign ovarian tumours in vitro. DESIGN: Prospective study of patients with a pelvic mass using radioimmunoscintigraphy. SETTING: Department of Nuclear Medicine of St Bartholomew's Hospital in collaboration with Cancer Network. POPULATION: A total of 93 patients with pelvic masses were recruited for this study of which 32 had ovarian cancer and 61 had benign lesions. METHODS: Radioimmunoscintigraphy was performed with Tc-99m-labelled SM3 (600 MBq), anterior and posterior pelvis imaged at 10 minutes and at 4 and 24 hours and evaluated with change detection analysis and probability mapping. MAIN OUTCOME MEASURES: Sensitivity and specificity of radioimmunoscintigraphy for ovarian cancer. RESULTS: Radioimmunoscintigraphy had a sensitivity for ovarian cancer of 84% (27 true positive and 5 false negatives) and a specificity of 87% (53 true negatives and 8 false positives) giving a negative predictive value of 91%. CONCLUSION: These results suggest that radioimmunoscintigraphy could be used to reduce the number of false positive findings in a strategy to refine differential diagnosis of the pelvic mass.

Turfgrass thatch effects on pesticide leaching: a laboratory and modeling study.

Process-based models are frequently used to assess the water quality impacts of turfgrass management emanating from proposed or existing golf courses. Thatch complicates the prediction of pesticide transport because surface-applied pesticides must pass through an organic-rich layer before entering the soil. This study was conducted to (i) compare the use of a linear equilibrium model (LEM) and two-site nonequilibrium (2SNE) model to predict pesticide transport through soil and thatch + soil columns, and (ii) evaluate thatch effects on pesticide transport through soil columns with a volume-averaging approach. Pesticide breakthrough curves were obtained for soil and thatch + soil columns from a 1 cm h(-1) flux applied one day after applying triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) and carbaryl (1-napthyl-methyl carbamate). Pesticide and bromide transport parameters indicated that nonequilibrium processes were affecting pesticide transport. Columns containing zoysiagrass (Zoysia japonica Steud.) thatch had lower triclopyr and carbaryl leaching losses than did soil-only columns, although total reductions attributable to thatch did not exceed 15% of the applied pesticide. When laboratory-based retardation factors were used, the 2SNE model explained 88 to 93% of the variability for triclopyr and 70 to 94% of the variability for carbaryl. Laboratory-based retardation factors performed well in a 2SNE model to predict the peak concentration and tailing behavior of triclopyr and carbaryl with a volume-averaging approach. These results suggest that separate representation of the thatch layer in process-based models is not a prerequisite to obtain reasonable estimates of pesticide transport under steady state flow conditions.

Axillary node status in breast cancer patients prior to surgery by imaging with Tc-99m humanised anti-PEM monoclonal antibody, hHMFG1.

In early breast cancer axillary nodes are usually impalpable and over 50% of such patients may have an axillary clearance when no nodes are involved. This work identifies axillary node status by imaging with a Tc-99m radiolabelled anti-Polymorphic Epithelial Mucin, humanised monoclonal antibody (human milk fat globule 1), prior to surgery in 30 patients. Change detection analysis of image data with probability mapping is undertaken. A specificity of 93% and positive predictive value of 92% (both 100% if a second cancer in the axilla with negative nodes is considered) were found. A strategy for combining negative imaging with the sentinel node procedure is presented.

Guided bone regeneration using bone grafts and collagen membranes.

When nonabsorbable membranes are used for guided bone regeneration (GBR), second surgeries are required for membrane retrieval. In addition, these types of membranes show a high incidence of flap sloughing and membrane exposure that often lead to infection and unfavorable results. Absorbable barriers such as collagen membranes were developed to overcome these drawbacks. This article presents the principles and the clinical procedure of using barrier membranes composed of absorbable collagen in GBR aimed at the repair and regeneration of ridge dehiscence defects around implants. The unique properties of collagen membranes that make them ideally suited to GBR procedures are reviewed. In addition, the indications and contraindications for using collagen membranes for GBR procedures are examined. Finally, cases are presented to demonstrate details of surgical principles and techniques.

Absence of toxicity of Bacillus thuringiensis pollen to black swallowtails under field conditions.

A single laboratory study on monarch butterflies has prompted widespread concern that corn pollen, engineered to express Bacillus thuringiensis (Bt) endotoxin, might travel beyond corn fields and cause mortality in nontarget lepidopterans. Among the lepidopterans at high potential risk from this technology is the black swallowtail butterfly, Papilio polyxenes, whose host plants in the midwestern U. S. are located principally in narrow strips between roads and crop fields. A field study was performed to assess whether mortality of early instar black swallowtails was associated either with proximity to a field of Bt corn or by levels of Bt pollen deposition on host plants. Potted host plants were infested with first instar black swallowtails and placed at intervals from the edge of a field of Bt corn (Pioneer 34R07 containing Monsanto event 810) at the beginning of anthesis. We confirmed by ELISA that pollen from these plants contained Cry1Ab endotoxin (2.125 +/- 0.289 ng/g). Although many of the larvae died during the 7 days that the experiments were run, there was no relationship between mortality and proximity to the field or pollen deposition on host plants. Moreover, pollen from these same plants failed to cause mortality in the laboratory at the highest pollen dose tested (10,000 grains/cm(2)), a level that far exceeded the highest pollen density observed in the field (200 grains/cm(2)). We conclude that Bt pollen of the variety tested is unlikely to affect wild populations of black swallowtails. Thus, our results suggest that at least some potential nontarget effects of the use of transgenic plants may be manageable.

Efficacy of immunoscintigraphy for detection of lymph node metastases.

The size of a lymph node is not in principle a limitation for the detection of cancer by Nuclear Medicine techniques. A radioactive pinhead is detectable if it has enough radioactivity on it. The approach of Nuclear Medicine to the demonstration of impalpable lymph nodes or to those lymph nodes detected by radiological techniques that are under 1 cm as to whether or not they contain cancer, is to increase the activity attached to cancer cells in such a lymph node as much as possible and to use sophisticated image analysis techniques to distinguish such uptake from its environment. This may be undertaken using a non specific technique such as F-18 Deoxyglucose and Positron Emission Tomography which is highly sensitive and which has been successful. The alternative approach is to use a highly specific and sensitive agent, such as a radio-labelled peptide or a radio-labelled monoclonal antibody together with image analysis. This paper describes these approaches and in particular the use of Tc-99m SM3 monoclonal antibody in the detection of impalpable axillary nodes in patients with breast cancer before surgery, using a change detection analysis providing a probability map of the significance of uptake of this radiopharmaceutical. It is a robust approach, providing the patient and the surgeon with information as to the likely need for extensive axillary surgery well prior to operation. A negative study should be followed by a sentinel node evaluation at surgery.

Heritability estimates for octyl acetate and octyl butyrate in the mature fruit of the wild parsnip.

The aliphatic esters octyl acetate and octyl butyrate occur as major components of essential oils in the vittae, or oil tubes, of the wild parsnip (Pastinaca sativa). We determined phenotypic variation and narrow-sense heritabilities of these octyl esters in wild parsnip fruits from 30 maternal families. The mean octyl acetate content was 1.56 microg/mg dry fruit (0.08-5.51 microg/mg dry fruit) and the mean octyl butyrate content was 4.28 microg/mg dry fruit (1.28-14.22 microg/ mg dry fruit). Narrow-sense heritabilities for each ester's content were calculated by analysis of half-sib families (HS) and parent-offspring regression (OP). Heritabilities were 0.389 (HS) and 0.654 (OP) for octyl acetate and 0.670 (HS) and 0.626 (OP) for octyl butyrate. The amounts of the esters were phenotypically correlated with each other and with the linear furanocoumarins bergapten and xanthotoxin, phototoxic compounds that co-occur in the vittae with the esters. Ester amounts were not genetically correlated, indicating that these compounds could respond independently to selection pressures. These octyl esters may serve as carrier solvents that enhance penetration of these furanocoumarins into herbivore integuments and gut walls.

99mTc-labelled SM3 in the preoperative evaluation of axillary lymph nodes and primary breast cancer with change detection statistical processing as an aid to tumour detection.

The extent of primary surgery for breast cancer could be tailored to the patient if previous information on the presence or absence of lymph node involvement could be reliably determined. Prospective radioimmunoscintigraphy in 29 patients with primary breast cancer that was found on screening has been undertaken with 555 MBq (15 mCi) 99mTc SM3, an Imperial Cancer Research Fund (ICRF) murine monoclonal antibody, 0.5 mg with images at 10 min and 22 h, and analysis using a change detection algorithm. Sites of significant change between the early and later images were displayed as a map of probabilities. Image-positive and -negative axillary lymph nodes were compared by histology in the 28 evaluable patients. The correct identification of the presence or absence of node involvement, even if impalpable, has been shown in 24 out of 28 patients (29 lymph node groups). Sensitivity was 90% (nine out of ten), specificity 84% (16 out of 19) and accuracy 86%. These results encourage further assessment of this technique.

Breast cancer 99mTc SM3 radioimmunoscintigraphy.

99mTc SM3 radioimmunoscintigraphy is combined with kinetic analysis and probability mapping using a change detection algorithm to investigate axillary node involvement before primary surgery in patients with breast cancer. Whereas planar imaging was unsuccessful, axillary node involvement was correctly determined in 11 out of 13 patients 6 out of 7 true negatives and 5 out of 6 true positives down to 0.35 grams. A prospective study is underway.

The accuracy of parathyroid gland localization in primary hyperparathyroidism using sestamibi radionuclide imaging.

Primary hyperparathyroidism is a common condition due to either a parathyroid adenoma or, less commonly, parathyroid hyperplasia, whose treatment is essentially surgical. We have, therefore, assessed the accuracy of Tc-99m pertechnetate/Tc-99m sestamibi (methoxy-isobutyl isonitrile) imaging in the localization of adenomas and hyperplastic parathyroids. The clinical records of all patients who had Tc-99m pertechnetate/Tc-99m sestamibi imaging and parathyroid surgery at this hospital were reviewed. The technique used involves standard subtraction methodology with the addition of a novel change detection algorithm to optimize localization. Of 46 patients scanned in 48 patient episodes, 36 patients had adenomas; 28 (78%) were accurately localized to the correct quadrant, and 4 were correctly lateralized. Two patients with parathyroid carcinomas had their metastases correctly localized. Thus, in 34 of 38 (89.5%) of the scans, adenomas or carcinomas were able to be anatomically localized. Six patients presented with hyperplasia; 5 were diagnosed by sestamibi scans, and 3 of these accurately localized all hyperplastic glands. Four additional patients had known hyperplasia, of which 2 were rendered normocalcemic after removal of their sestamibi-positive glands; the other 2 had small second glands detected only at surgery. In patients with unknown pathology, imaging suggested that 6 patients had hyperplasia; this was correct in 5 cases (83%). Nine of the 12 scans in patients who had had previous parathyroid surgery accurately localized the tumors, 7 in the neck and 2 outside. We suggest that sestamibi imaging can help to distinguish hyperplasia from adenomatous disease; when imaging is required, we recommend it as the imaging modality of choice in all patients with primary hyperparathyroidism, especially in reoperated patients.

Identification of auto-transplanted parathyroid tissue by Tc-99m methoxy isobutyl isonitrile scintigraphy.

Parathyroid tissue is sometimes auto-transplanted into the forearm after 'total' parathyroidectomy in patients with renal failure. Recurrent hyperparathyroidism demands identification of the source of PTH secretion which cannot be assumed to be the forearm. To this end, Tc-99m methoxy isobutyl isonitrile (MIBI) scintigraphy was used to identify functioning auto-transplanted parathyroid tissue in seven patients undergoing renal replacement therapy (five with functioning renal transplants and two on haemodialysis). Serum PTH was estimated in venous blood taken proximal and distal to the forearm graft and from the contralateral arm, and subsequent Tc-99m MIBI scanning was carried out without knowledge of the PTH results. Five patients had a significant gradient in PTH levels between sites proximal and distal to the graft, and between the proximal site and the contralateral arm, suggesting functioning parathyroid tissue in the graft. Subsequent Tc-99m MIBI scintigraphy confirmed the activity of the auto-transplanted parathyroid tissue in these five patients. In the remaining two patients without a significant PTH gradient between the sampling sites, Tc-99m MIBI scintigraphy did not identify any functioning forearm parathyroid tissue. The scan results therefore correlated well with the gradients in PTH levels, suggesting that MIBI scintigraphy can be used to identify functioning auto-transplanted parathyroid tissue. The results also indicate that any patient who has undergone auto-transplantation of parathyroid tissue must have blood samples taken from veins proximal to the graft and either distal to it, or from the contralateral arm when parathyroid status is re-assessed, particularly when surgery is being considered for recurrent hyperparathyroidism.

A study comparing SPECT with CT and MRI after closed head injury.

After closed head injury nineteen patients had single photon emission tomography (SPECT) using the lipophilic tracer 99m-Technetium hexamethyl-propylene-amineoxime (HMPAO) to compare the defects shown by CT and MRI. SPECT showed more focal cerebral lesions than either CT or MRI alone or in combination. Most lesions shown by SPECT were not shown by CT or MRI in the corresponding anatomical regions. The most severely disabled patients showed the highest number of SPECT lesions (average four per patient) and the lowest (mean, SE) cerebral blood flow (718, 69 ml/min) compared with the less disabled patients (two per patient and 1058, 51 ml/min, p less than 0.05). There was a correlation between the Glasgow Outcome Scale grade and the global cerebral blood flow (r 0.74, p less than 0.05). The perfusion defects may correlate with clinical signs that were not explained by CT or MRI findings. SPECT may complement the clinical evaluation in the assessment of outcome after head injury.

Pitfalls after total parathyroidectomy and parathyroid autotransplantation in chronic renal failure.

We have described 4 patients with chronic renal failure receiving regular haemodialysis treatment who underwent total parathyroidectomy with autotransplantation of parathyroid fragments into the forearm musculature for hypercalcaemic hyperparathyroidism. In all, there was an immediate and profound fall in plasma calcium levels. Hypercalcaemia recurred 1-5 years post-operatively and was resistant to resection of the autograft. In 3 cases, thallium-technetium subtraction scanning and multiple venous sampling for estimation of parathyroid hormone levels suggested multiple sites of hypersecretion of parathyroid hormone in the neck. In 1 case, these investigations revealed a mediastinal adenoma which was successfully removed. These cases reinforce previous suggestions that total parathyroidectomy is frequently incomplete and undermine the procedure of total parathyroidectomy with autotransplantation in patients with persisting uraemia.