Optimized EPI for fMRI studies of the orbitofrontal cortex

A common problem in gradient-echo echo planar imaging (EPI) is the occurrence of image distortions and signal losses caused by susceptibility gradients near air/tissue interfaces. Since EPI is frequently used for functional magnetic resonance imaging experiments based on the blood oxygenation level-dependent effect, functional studies of certain brain regions affected by susceptibility gradients, such as the temporal lobes and the orbitofrontal cortex, may be compromised. In this work a method for signal recovery in certain regions of the orbitofrontal cortex is presented. The influence of in-plane susceptibility gradients is reduced by optimization of the imaging slice orientation. Through-plane susceptibility gradients are partly compensated by means of a moderate preparation gradient pulse similar to z-shimming. In contrast to several other techniques proposed in the literature for reducing susceptibility effects, this method does not compromise the temporal resolution and is therefore applicable to event-related studies.

Flavopiridol in untreated or relapsed mantle-cell lymphoma: results of a phase II study of the National Cancer Institute of Canada Clinical Trials Group

PURPOSE

To determine the response rate and toxicity of flavopiridol in patients with previously untreated or relapsed mantle-cell lymphoma.

PATIENTS AND METHODS

Adult patients with previously untreated or in first or second relapse of previously responsive mantle-cell lymphoma were given flavopiridol 50 mg/m2/d by intravenous bolus for 3 consecutive days every 21 days with antidiarrheal prophylaxis. Flavopiridol was continued until disease progression, unacceptable toxicity, or stable disease for four cycles. Disease was reassessed every two cycles.

RESULTS

From 33 registered patients, 30 were eligible after pathology review, 30 were assessable for toxicity, and 28 were assessable for response. A median of four cycles of treatment was administered; 90% of patients received at least 90% of planned dose-intensity. No complete responses were seen; three patients had a partial response (11%), 20 patients had stable disease (71%), and five patients had progressive disease (18%). The median duration of response was 3.3 months (range, 2.8 to 13.2 months). The most common toxicities were diarrhea (97%), fatigue (73%), nausea (47%), and vomiting (27%). At least one nonhematologic grade 3 or 4 toxicity was seen in 14 patients (47%). Hematologic toxicity was modest.

CONCLUSIONS

Flavopiridol given as a daily bolus for 3 consecutive days every 3 weeks has modest activity as a single agent for mantle-cell lymphoma. The number of stable and partial responses that was seen indicates that it is biologically active and may delay progression. Future studies in mantle-cell lymphoma should test this agent with other active agents and using different schedules.

Use of simulated clients in training veterinary undergraduates in communication skills

A course in communication skills has been developed specifically for veterinary students, based on those delivered at many medical schools, and making extensive use of professional actors as simulated clients. Its aim is to raise awareness of the importance of communication among veterinary undergraduates at all stages of the curriculum, and it allows them to role-play in acted-out scenarios. Facilitated small groups provide an environment in which students can receive feedback on their own performance and also give feedback to their colleagues. An independent evaluation suggests that the opportunity to role-play increased the students' confidence in communicating with others. They were able to identify their personal strengths as communicators and gain insights into the aspects of communication they could improve. Feedback and subsequent discussions were highly valued, with the actors playing a crucial role in providing feedback from the client's perspective. Students were able to use the knowledge they acquired when consulting with real clients. Most of the students suggested that the course should continue in its current format, but with more time provided for it in the curriculum.

Impingement syndrome associated with whiplash injury

We examined 524 patients with whiplash injuries for delayed onset of shoulder pain in order to establish whether this was due to impingement syndrome. A total of 476 patients (91%) responded to a questionnaire of which 102 (22%) were entered into the study; 43 had both a positive impingement sign and Neer test. The incidence of impingement-type pain was 9%. After treatment 23 patients (5%) had a significant improvement in their symptoms, ten (2%) had a moderate improvement and nine had no improvement. Impingement-type pain can occur after whiplash injuries and can be successfully treated.

Randomized comparison trial of the RIK and the Nimbus 3 mattresses

A randomized comparison trial was carried out at Queen's Hospital, Burton-on-Trent, to compare patient outcomes on the RIK mattress (KCI) and the Nimbus 3 mattress (Huntleigh Healthcare). One hundred and fifty-eight patients, who were assessed to be at particular risk of development of pressure ulcers using the Waterlow score (85 on RIK mattress, 83 on Nimbus), completed the trial. There were no statistically significant differences in baseline parameters at recruitment or pressure ulcer progress. Lack of difference can be as useful as evidence of superiority. Other factors such as nursing interventions required accessible equipment, and costs are important when making equipment choices. For a significant proportion of patients, a static (RIK) mattress can be as effective as an active (Nimbus 3) mattress for management of pressure ulcers.

Techniques for imaging neuroscience

In the last 20 years, a number of non-invasive spatial mapping techniques have been demonstrated to provide powerful insights into the operation of the brain during task performance. These are, in order of their emergence as robust technologies: positron emission tomography, source localization with EEG and MEG, and functional magnetic resonance imaging. The imaging neuroscience study areas represented in this volume use the first or last of these - PET and fMRI. The physical principles underlying both of these techniques are outlined, and the important assumptions and limitations are made explicit. The range of applications for each is briefly indicated.

No smoke without fire--simple recommendations to avoid arthroscopic burns

Despite anecdotal stories, the potential of the arthroscope tip or the light cable end to cause thermal burns to the surgical drapes and to patients has not been investigated in orthopaedic surgery. This study shows that the arthroscopic tip registering a temperature of 41.9 degrees C, is unlikely to cause skin burns but causes singeing of drapes without combustion. The light cable end registers a temperature of 101 degrees C with the potential for causing skin burns. It has been demonstrated to cause combustion of disposable arthroscopic drapes within seconds at a distance of 0.5 cm. It is recommended that the light source should be switched on only after the light cable has been connected to the arthroscope. The light cable end must not rest on the drapes once the light source has been switched on, as thermal burns will occur within seconds. A retractable shield of 2.5 cm fitted to the light cable end may virtually avoid the potential for combustion.

Laparoscopic ultrasonography is a complement to cholangiography for the detection of choledocholithiasis at laparoscopic cholecystectomy

Background

Intraoperative cholangiography and laparoscopic ultrasonography are both used in the detection of common bile duct stones at laparoscopic cholecystectomy. The aim of this prospective study was to determine whether laparoscopic ultrasonography has an alternative or a complementary role with respect to cholangiography in achieving this end.

Methods

The biliary trees of 900 patients undergoing laparoscopic cholecystectomy were examined routinely by the two methods. The diagnostic power of each investigation and of the two techniques in combination was evaluated. The statistical non-random concordance between the two methods was also determined.

Results

Laparoscopic ultrasonography was performed in all 900 patients. Cholangiography was performed in 762 (85 per cent). The mean (range) duration was 9·8 (4–21) min for laparoscopic ultrasonography and 17·6 (7–42) min for cholangiography. For the detection of common bile duct stones, with a kappa coefficient of 0·57 (95 per cent confidence interval (c.i.) 0·43 to 0·71), the non-random concordance between the two methods was considered to be fair to good. The sensitivity of laparoscopic ultrasonography was 0·80 (95 per cent c.i. 0·65 to 0·91) and its specificity was 0·99 (95 per cent c.i. 0·98 to 1·00). The respective values for cholangiography were 0·75 (95 per cent c.i. 0·59 to 0·87) and 0·99 (95 per cent c.i. 0·98 to 1·00). The examinations combined had a sensitivity of 0·95 (95 per cent c.i. 0·86 to 0·99) and a specificity of 0·98 (95 per cent c.i. 0·96 to 1·00).

Conclusion

Laparoscopic ultrasonography and intraoperative cholangiography are complementary, as the combination of both methods maximizes the intraoperative detection of choledocholithiasis.

Bilateral decompression of lumbar spinal stenosis involving a unilateral approach with microscope and tubular retractor system

Object. The authors studied a consecutive series of patients with spinal stenosis in whom surgery was performed by a single surgeon who used a microscopic tubular retractor system (METRx-MD); patients underwent prospective evaluation involving radiography and magnetic resonance (MR) imaging.

The objective was to assess the feasibility and surgery-related efficacy of performing unilateral-approach bilateral decompression and utilization of METRx-MD instrumentation in patients with spinal stenosis.

Methods. Seventeen consecutive patients with spinal stenosis underwent bilateral decompression; surgery was performed via a unilateral approach using METRx-MD instrumentation. The procedures were performed on an outpatient basis after induction of general anesthesia. Preoperative and 3-month follow-up plain radiographs with flexion—extension views were obtained. Preoperative and postoperative MR imaging was also performed. All studies were assessed by a single radiologist blinded to the clinical results.

Twenty-two levels were surgically decompressed. The mean operative time was 90 minutes and the mean blood loss was 28 ml per level. Preoperatively stenosis was severe at 13 levels, moderate/severe at eight, and moderate at one. Postoperatively stenosis was absent at 13 levels, mild at seven, mild/moderate at one, and moderate at one. Preoperatively degenerative spondylolisthesis was documented in eight patients, with flexion—extension radiography revealing motion in three cases. On early (3-month) postoperative x-ray films there was no evidence of progression in any case. Grade I spondylolisthesis developed postoperatively in one patient, who remained asymptomatic.

Conclusions. Minimally invasive bilateral decompression and instrumentation-assisted fusion can be successfully performed via a unilateral approach in patients with acquired spinal stenosis; the procedure can be undertaken on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity rates.

How much cortex can a vein drain? Downstream dilution of activation-related cerebral blood oxygenation changes

The draining vein problem is recognized as one of the most severe constraints on the spatial resolution of BOLD contrast fMRI, used widely in imaging neuroscience. Changes in blood oxygenation arising from local brain activity-related changes in blood flow propagate downstream in veins and can give rise to spurious activation at sites remote from neuronal activity. The geometry of the venous vasculature is quite regular in structure and is well depicted in photomicrographs. Quantitative analysis of this geometry, together with hydrodynamic considerations, permit upper bounds dependent on the area of cortical neuronal activity to be derived for the spatial extent of draining vein contamination. It is estimated that an activated cortical area of 100 mm(2) will generate an oxygenation change in venous blood that extends without dilution along the vein no more than 4.2 mm beyond the edge of the activated area. At greater distances along the draining vein this oxygenation change will be diluted. The model leads to a quantitative prediction of the functional form of this dilution.

Bilateral decompressive surgery in lumbar spinal stenosis associated with spondylolisthesis: unilateral approach and use of a microscope and tubular retractor system

Object

The objective of this study was to assess the feasibility and efficacy of treating spondylolisthesis-related spinal stenosis via unilateral approach bilateral decompression in which METRx-MD instrumentation is placed.

Methods

Eight consecutive patients with spinal stenosis underwent bilateral decompressions via a unilateral approach in which METRx-MD instrumentation was placed. The procedures were performed on an outpatient basis after induction of general anesthesia. The patients underwent preoperative and 3-month postoperative plain radiography in which flexion–extension x-ray films were obtained. Preoperative and postoperative magnetic resonance imaging was also performed. All radiographs and neuroimages were read by a single radiologist blinded to the clinical results.

Eight vertebral levels in the eight patients were sugically decompressed (in one patient an additional level of non-spondylolisthesis-related stenosis was decompressed). The mean operative time was 92 minutes and the mean blood loss was 33 ml/level. Preoperatively stenosis was severe in five patients, moderate/severe in two, and moderate in one; postoperatively stenosis was absent in five, mild in two, and mild/moderate in one. Motion was detected on flexion–extension radiographs in three patients, but on early (3-month) postoperative radiographs there was no evidence of progression.

Conclusions

By following the authors' procedure, minimally invasive bilateral decompression of acquired spinal stenosis associated with spondylolisthesis can be successfully performed on an outpatient basis, with reasonable operative times, minimal blood loss, and acceptable morbidity.

Ultrastaging of early colon cancer using lymphatic mapping and molecular analysis

Approximately one-third of node-negative colon cancers will recur, possibly due to understaging and inadequate pathological examination of lymph nodes (LNs). We evaluated the sensitivity, accuracy and feasibility of staging based on lymphatic mapping, focused examination, and molecular analysis of the sentinel node (SN) in patients with primary colorectal carcinoma. Between 1996 and 2000, 100 patients with colon carcinoma (CRC) underwent lymphatic mapping immediately after peritumoral injection of 1.0 cc of isosulphan blue dye. All LNs in the CRC specimen were examined by routine haematoxylin and eosin (H&E) staining. Sentinel nodes were examined by step serial sectioning, cytokeratin immunohistochemistry (CK-IHC) and/or reverse transcriptase-polymerase chain reaction (RT-PCR) analysis in an attempt to identify occult micrometastatic disease. Lymphatic mapping was successful in 97% of the cases. There were 5 false-negative cases, predominately associated with T3/T4 tumours. Aberrant lymphatic drainage was identified in 8 patients (8%) altering the operative approach. 26 patients had H&E-positive LNs. In 74 patients who were node-negative by routine H&E, 18 (24%) had occult nodal micrometastases missed on routine H&E examination, but detected by focused analysis of the SN. RT-PCR analysis of the SN was performed in 40 patients, 26 of which were negative by H&E and CK-IHC. In 12/26 (46%) of these patients, there was additional evidence of micrometastatic disease. In this study, focused examination of the SN in conjunction with RT-PCR analysis identified micrometastatic disease in a significant number of node-negative patients. This may have important implications when selecting patients for adjuvant treatment protocols.

Image distortion correction in fMRI: A quantitative evaluation

A well-recognized problem with the echo-planar imaging (EPI) technique most commonly used for functional magnetic resonance imaging (fMRI) studies is geometric distortion caused by magnetic field inhomogeneity. This makes it difficult to achieve an accurate registration between a functional activation map calculated from an EPI time series and an undistorted, high resolution anatomical image. A correction method based on mapping the spatial distribution of field inhomogeneities can be used to reduce these distortions. This approach is attractive in its simplicity but requires postprocessing to improve the robustness of the acquired field map and reduce any secondary artifacts. Furthermore, the distribution of the internal magnetic field throughout the head is position dependent resulting in an interaction between distortion and head motion. Therefore, a single field map may not be sufficient to correct for the distortions throughout a whole fMRI time series. In this paper we present a quantitative evaluation of image distortion correction for fMRI at 2T. We assess (i) methods for the acquisition and calculation of field maps, (ii) the effect of image distortion correction on the coregistration between anatomical and functional images, and (iii) the interaction between distortion and head motion, assessing the feasibility of using field maps to reduce this effect. We propose that field maps with acceptable noise levels can be generated easily using a dual echo-time EPI sequence and demonstrate the importance of distortion correction for anatomical coregistration, even for small distortions. Using a dual echo-time series to generate a unique field map at each time point, we characterize the interaction between head motion and geometric distortion. However, we suggest that the variance between successively measured field maps introduces additional unwanted variance in the voxel time-series and is therefore not adequate to correct for time-varying distortions.

Initial demonstration of in vivo tracing of axonal projections in the macaque brain and comparison with the human brain using diffusion tensor imaging and fast marching tractography

Diffusion tensor imaging (DTI), a magnetic resonance imaging technique, is used to infer major axonal projections in the macaque and human brain. This study investigates the feasibility of using known macaque anatomical connectivity as a "gold-standard" for the evaluation of DTI tractography methods. Connectivity information is determined from the DTI data using fast marching tractography (FMT), a novel tract-tracing (tractography) method. We show for the first time that it is possible to determine, in an entirely noninvasive manner, anatomical connection pathways and maps of an anatomical connectivity metric in the macaque brain using a standard clinical scanner and that these pathways are consistent with known anatomy. Analogous human anatomical connectivity is also presented for the first time using the FMT method, and the results are compared. The current limitations of the methodology and possibilities available for further studies are discussed.

Support needs of veterinary surgeons during the first few years of practice: perceptions of recent graduates and senior partners

Postal surveys or personal interviews of 76 recent veterinary graduates and their 49 employers were undertaken to establish their perceptions of good practice when integrating a new graduate into a business and their preferred methods of assessment and development. Practice type and location were the main influences on graduates looking for their first job. Interviews were mostly informal. Employers expected basic veterinary competence and candidates expected good quality support. Most graduates (93 per cent) had their own consultations on the first day. During early consultations 2 per cent of senior vets accompanied the new graduate, 95 per cent of practices provided senior back-up either in person or by telephone but in 3 per cent no back-up was available. Most new graduates (90 per cent) were satisfied with their workload. Three-fifths were on-call within the first week, and 95 per cent within a month. Graduates received calls directly in 45 per cent of practices, in 9 per cent seniors screened the calls, and the remainder used a third party. Assistance from experienced lay staff varied greatly. Discussion of problems was mainly informal. There was little spontaneous feedback and problems resulted from inadequate communication. One in three new graduates left their first job within two years, and one in six identified lack of support, heavy workload, stress or clashes with staff as a primary reason. This high turnover was a problem for employers. From the new graduates' perspectives, initial problems included: being on call (59 per cent), financial aspects (47 per cent) and surgery (43 per cent). Communicating with clients and learning to prioritise jobs were also difficult. New graduates took longer over procedures (79 per cent of employers commented) and required extra back-up (91 per cent) both of which reduced income (59 per cent). Nearly all the seniors felt that their current new graduates had coped 'quite well', although it was claimed that new graduates lacked the ability to talk to clients at the appropriate level, wanted to bring all their scientific knowledge to bear on every case, and often failed to consider the obvious or to appreciate clients' needs. Only 18 per cent of practices had formal and regular review procedures but all monitored the response of clients and watched the new graduate perform. Feedback to their new colleague was considered 'adequate' by 85 per cent of seniors, although 45 per cent of graduates felt they had not received enough. Eighty-three per cent of new graduates felt 'moderately prepared' by their undergraduate course, and 76 per cent of senior vets were 'generally satisfied' Both wanted improvements in extramural studies and increased exposure to routine cases. Senior partners sought greater commitment in the undergraduate curriculum to financial/legal issues and communication skills. Over a third of employers (38 per cent) had a 'great influence' on the choice of continuing professional development courses for their recent graduates. New graduates chose courses to deal with a perceived weakness, or to specialise, and welcomed opportunities to meet other new graduates and share early experiences. It was concluded that turnover and staff problems would be reduced if practices became more effective in coping with new arrivals, especially by supporting their development.

RF inhomogeneity compensation in structural brain imaging

Three-dimensional T(1)-weighted magnetization-prepared rapid gradient-echo (MP-RAGE) sequences with centric phase encoding (PE) in the inner loop provide structural brain images with a high spatial resolution and high tissue contrast. A disadvantage of this sequence type is the susceptibility to inhomogeneities of the radiofrequency (RF) coil, which may result in poor image contrast in some peripheral regions. A special excitation pulse is presented which compensates for these effects in both the head/foot and anterior/posterior directions. This pulse has a duration of only 1.3 ms and is thus compatible with the short repetition times (TRs) required for MP-RAGE imaging. It is shown experimentally that images acquired with the compensation pulse may be segmented without using intensity correction algorithms during data postprocessing.

Echo time dependence of BOLD contrast and susceptibility artifacts

Echo-planar imaging with gradient echo allows whole-brain images to be rapidly acquired. However, its main limitation is that magnetic field inhomogeneities in regions of the brain close to bone and air-filled sinuses result in reduced signal-to-noise ratio and signal loss. In particular this is a problem for imaging the temporal lobes, and can therefore affect the results of some language-related studies. Decreasing the echo time (TE) increases the signal-to-noise ratio and reduces the amount of signal loss in susceptible regions. In this study we investigate the TE dependence of BOLD (blood oxygenation level-dependent) contrast and, in particular, how it is influenced in regions with susceptibility artifacts. We use a dual echo-time sequence to compare brain activations measured with two different TEs, TE = 40 ms and TE = 27 ms. The paradigm involves comparing famous faces to scrambled faces, a low-level control condition. It was chosen because famous faces have been repeatedly shown to activate the fusiform gyri and anterior temporal lobes in both PET and fMRI. Our results show that it is possible to detect robust activations at a lower TE in brain regions not affected by susceptibility artifacts (i.e., fusiform gyri), allowing for faster scanning times. However, although the amount of signal loss is reduced at the lower TE, this does not appear to be sufficient to recover the BOLD signal in regions affected by susceptibility artifacts (i.e., anterior temporal lobes).

Detecting latency differences in event-related BOLD responses: application to words versus nonwords and initial versus repeated face presentations

We introduce a new method for detecting differences in the latency of blood oxygenation level-dependent (BOLD) responses to brief events within the context of the General Linear Model. Using a first-order Taylor approximation in terms of the temporal derivative of a canonical hemodynamic response function, statistical parametric maps of differential latencies were estimated via the ratio of derivative to canonical parameter estimates. This method was applied to two example datasets: comparison of words versus nonwords in a lexical decision task and initial versus repeated presentations of faces in a fame-judgment task. Tests across subjects revealed both magnitude and latency differences within several brain regions. This approach offers a computationally efficient means of detecting BOLD latency differences over the whole brain. Precise characterization of the hemodynamic latency and its interpretation in terms of underlying neural differences remain problematic, however.

Compensation of susceptibility-induced BOLD sensitivity losses in echo-planar fMRI imaging

Gradient-echo echo-planar imaging is a standard technique in functional magnetic resonance imaging (fMRI) experiments based on the blood oxygenation level-dependent (BOLD) effect. A major problem is the occurrence of susceptibility gradients near air/tissue interfaces. As a consequence, the detection of neuronal activation may be greatly compromised in certain brain areas, especially in the temporal lobes and in the orbitofrontal cortex. Common approaches to overcome this problem, such as z-shimming or the use of tailored radio frequency pulses, usually compensate only for susceptibility gradients in the slice selection direction. In the present study, the influence of susceptibility gradients in the phase encoding direction is investigated both theoretically and experimentally. It is shown that these gradients influence the effective echo time TE and may reduce considerably the local BOLD sensitivity, even in the case of acceptable image intensities. A compensation method is proposed and tested in an fMRI experiment based on a hypercapnic challenge. The results suggest that the compensation method allows for the detection of activation in brain areas which are usually unavailable for BOLD studies.

Epoetin alfa in cancer patients: evidence-based guidelines

Anemia is a common cause of cancer-related fatigue. A systematic review of the literature was performed to establish guidelines on the use of epoetin alfa for the treatment of anemia. The evidence in support of these guidelines was selected, reviewed, and summarized by the members of the Canadian Cancer and Anemia Guidelines Development Group. The effects of epoetin alfa on quality of life (QOL) in patients with cancer were examined in 5 randomized, placebo-controlled trials and 2 large, open-label, nonrandomized, community-based studies. The effects of epoetin alfa on red blood cell transfusion requirements were examined in 19 randomized controlled trials (RCTs) with 21 comparisons. All trials compared epoetin alfa to a suitable control group, examined specified outcome measures that could be analyzed, and studied patients with cancer who were receiving chemotherapy. Trials involving patients with hematologic malignancies originating in the bone marrow were excluded. Outcome measures included 1) quality of life (QOL) (as measured by scales including the Linear Analogue Self-Assessment [LASA] and the Functional Assessment of Cancer Therapy [FACT] subscales), and 2) transfusion requirements (as measured by the proportion of patients requiring transfusion and amount of transfusion). The analysis confirmed that epoetin alfa produced statistically significant and clinically relevant improvements in QOL in patients with cancer. The overall relative risk ratio for transfusion among patients receiving epoetin alfa was calculated to be 0.60 (95% Cl, 0.53-0.69; P < 0.00001), representing a 40% reduction in the proportion of patients requiring transfusion. These results support recommendations for the use of epoetin alfa in patients with cancer-related anemia.

Detection of MAGE-A3 in breast cancer patients' sentinel lymph nodes

The detection of occult metastatic breast cancer cells by RT-PCR is limited by the poor specificity of most tumour mRNA markers. MAGE-A3 is a highly specific tumour mRNA marker that is not expressed in non-cancer cells. This study assesses MAGE-A3 mRNA as a molecular marker for the detection of tumour cells in the sentinel lymph nodes (SLN) of breast cancer patients. Serial frozen sections of SLN (n = 121) were obtained from 77 AJCC (American Joint Committee on Cancer) Stage I-IIIA breast cancer patients. MAGE-A3 mRNA analysis of SLN was performed by RT-PCR and Southern blot analysis. Tumour cells were detected in 48 of 121 (40%) SLN from 77 patients by H&E or IHC staining, and 35 of 77 (45%) patients, overall, had histopathologically (H&E and/or IHC) positive SLN. Among histopathologically negative SLN, 28 of 73 (38%) SLN were MAGE-A3 mRNA positive by RT-PCR. Overall, 41 of 77 (53%) patients and 50 of 121 (41%) SLN were positive for MAGE-A3. MAGE-A3 mRNA expression in the SLN occurred more frequently with infiltrating lobular carcinoma (P < 0.001) than with infiltrating ductal carcinoma, adding further evidence of possible phenotypic differences between these 2 subtypes of breast cancer. Due to its high specificity, MAGE-A3 mRNA is a potentially useful marker for detecting breast cancer cells in the SLN. One half of breast tumours expressed MAGE-A3 mRNA, which has important potential implications for antigen-specific targeted immunotherapy.