Automated breast volume scanner (ABVS) in assessing breast cancer size: A comparison with conventional ultrasound and magnetic resonance imaging

Objectives

To compare automated breast volume scanner (ABVS), ultrasound (US) and MRI in measuring breast cancer size, and evaluate the agreement between ABVS and US in assessing lesion location and sonographic features.

Methods

We retrospectively included 98 women with 100 index cancers who had undergone US and ABVS followed by 1.5T MRI. Images were interpreted by a pool of readers reporting lesion size, location and breast imaging reporting and data system (BI-RADS) features. Bland-Altman analysis (with logarithmic data transformation), intraclass correlation coefficient (ICC) and Cohen’s kappa statistic were used for statistical analysis.

Results

MRI showed the best absolute agreement with histology in measuring cancer size (ICC 0.93), with LOA comparable to those of ABVS (0.63–1.99 vs. 0.52–1.73, respectively). Though ABVS and US had highly concordant measurements (ICC 0.95), ABVS showed better agreement with histology (LOA 0.52–1.73 vs. 0.45–1.86, respectively), corresponding to a higher ICC (0.85 vs. 0.75, respectively). Except for posterior features (k=0.39), the agreement between US and ABVS in attributing site and BI-RADS features ranged from substantial to almost perfect (k=0.68–0.85).

Conclusions

ABVS performs better than US and approaches MRI in predicting breast cancer size. ABVS performs comparably to US in sonographic assessment of lesions.

Key Points

? ABVS approaches MRI in predicting breast cancer size. ? ABVS is equivalent to US in localising and characterising breast cancer. ? ABVS is more accurate than US in assessing breast cancer size. ? ABVS has the potential to replace US in breast cancer staging.

     

Magnetic resonance imaging in patients with nipple discharge: should we recommend it?

Objectives  

Comparing the sensitivity of Contrast-Enhanced Magnetic Resonance Imaging (CEMRI), mammography and ultrasonography in patients with nipple discharge (ND).     

Role of magnetic resonance imaging in probably benign (BI-RADS category 3) microcalcifications of the breast

Purpose

This study was undertaken to evaluate whether magnetic resonance (MR) imaging is able to rule out malignancy in the case of BI-RADS 3 microcalcifications, providing a sufficient negative predictive value (NPV) for early work-up, and to reduce unnecessary stereotactically guided vacuum-assisted biopsy (SVAB) procedures.

Materials and methods

We prospectively enrolled consecutive women with BI-RADS 3 microcalcifications, who subsequently underwent MR imaging and SVAB. The MR studies were reviewed according to the MR-BI-RADS classification system; lesions assessed as MR-BI-RADS 1 and 2 were considered negative for malignancy, categories MR-BI-RADS 3, 4 and 5 indicated malignant lesions. The presence of additional findings was recorded. Histologic analysis and follow-up were the reference standard. MR sensitivity, specificity, positive predictive value (PPV) and NPV were calculated.

Results

The final population consisted of 71 lesions. Histologic analysis showed malignancy in six cases (malignancy rate 8 %). At MR analysis, 60 (85 %) lesions were considered negative for malignancy and 11 (15 %) malignant. Additional MR imaging findings were identified in 19 (27 %) patients, all corresponding to nonmalignant lesions. MR sensitivity was 33 %, specificity 86 %, PPV 18 % and NPV 93 %.

Conclusions

Because of its relatively low NPV, MR imaging is not able to safely exclude malignancy in the case of BI-RADS 3 microcalcifications. The relatively high malignancy rate found in this study might support SVAB in the case of BI-RADS 3 microcalcifications.     

Gap junction synthesis and degradation as therapeutic targets

The synthesis and the degradation of gap junctions involve multiple steps that may provide targets for the modulation of intercellular communication. Many studies using cultured cells have examined the effects of inhibitors of protein synthesis, trafficking, or degradation upon connexins. Similarly, activators or inhibitors of various protein kinases have been shown to affect connexin assembly or proteolysis. These studies have helped to elucidate the connexin life-cycle. But, because of their lack of specificity for gap junction proteins, these agents would be expected to have limited therapeutic utility and to produce several deleterious side effects. However, more selective agents are being developed based on specific features of the connexin sequences. Molecular genetic approaches have been used to introduce wild-type connexins to increase intercellular communication in otherwise poorly coupled cells. Decreased intercellular communication may be obtained by application of peptides that mimic the extracellular loops and may prevent docking of hemi-channels. Alternatively, introducing mutant connexins that interfere with the oligomerization/export of endogenous connexins or with channel function by formation of non-functional heteromeric hemi-channels can also reduce intercellular communication.     

Effect of iomeprol on rat hippocampal slice synaptic transmission: comparison with other X-ray contrast agents

RATIONALE AND OBJECTIVES: All contrast agents should be neurologically safe because although some are not indicated for procedures, such as myelography, just the same they may come in contact with nervous tissue during contrast-enhanced imaging. This is because even when they are intravascularly injected, the presence of undiagnosed blood-brain barrier damage may allow them to penetrate the brain barrier. In the present study, we investigated the neurologic safety of iomeprol by studying in vitro its potential effects on the central nervous system (CNS) synaptic transmission. Other widely used x-ray contrast agents were also assessed for comparative purposes. METHODS: CNS synaptic transmission was evaluated in terms of evoked field potentials recorded from the pyramidal region of rat hippocampal slices. The field potentials were evoked by electrical stimulation of the Schaffer collateral pathway. The effects of the contrast agents were evaluated in terms of number and amplitude of population spikes (PS) and as the maximal slope of the excitatory postsynaptic potentials (EPSP). The contrast agents were tested at final concentrations of 3, 10, and 30 mg(iodine)/mL in iso-osmolal condition with respect to artificial cerebrospinal fluid (CSF). RESULTS: Iomeprol, like ioversol, principally exerted a mild inhibitory effect on CNS synaptic transmission, an effect that was preceded by a weak, transient excitation. Iopentol exerted a rapid and complete inhibition of synaptic transmission without showing any excitatory effects. Iobitridol, though belonging to the nonionic monomeric class, exerted, surprisingly, an epileptogenic action at the highest concentration, whereas its inhibitory action was slow and mild. Diatrizoate, as expected, exerted an epileptogenic activity even at the lowest concentration, followed by a marked inhibitory action. Ioxaglate, as expected because it is an ionic though dimeric contrast agent, exerted an epileptogenic action at the intermediate concentration, whereas it barely demonstrated an inhibitory effect at all. All the contrast agent effects observed in the study reversed or tended to reverse during washout. CONCLUSIONS: Even taking in account the limitation because of the use of an in vitro approach and high contrast agent concentrations, we can conclude that the positive neuro-tolerability of iomeprol is further confirmed by this model as it proved to be devoid of epileptogenic activity and, among the contrast agents exhibiting inhibitory action, it was the contrast agent with the least amount of activity. In addition, contrary to that generally reported in the literature, nonionic, low osmolal contrast agents are not all identical in their neuro-tolerability when assessed in the rat hippocampal slice model.     

Axillary radiotherapy instead of axillary dissection: A randomized trial

Background Surgical dissection of the axilla is a standard part of the treatment of breast cancer but, by itself, does not improve prognosis; furthermore, most patients with small-sized breast cancer and a clinically uninvolved axilla never develop axillary metastases. We evaluated disease-free and overall survival in patients with early breast cancer treated by breast-conservation surgery without dissection of acillary lymph nodes, receiving or not receiving axillary radiotherapy (RT). Methods From 1995 to 1998, 435 patients older than 45 years with breast cancer up to 1.2 cm were randomized, 214 to breast conservation without axillary treatment and 221 to breast conservation plus axillary RT. Results After a follow-up of 28 to 68 months (median, 42 months), two women (1%) in the no axillary treatment group and one (.5%) in the axillary RT group developed axillary metastases. Rates of distant metastases and local treatment failure were also very low, and 5-year overall survival was 99%. Conclusions After a mean of 46 months of follow-up, our results indicate that axillary dissection can be safely avoided in patients with very small invasive carcinomas and a clinically negative axilla. Whether axillary RT should be added can be assessed only by longer follow-up. Presented at the 54th Annual Meeting of the Society of Surgical Oncology, Washington, DC, March 15–18, 2001.     

Real-time in vivo dosimetry using micro-MOSFET detectors during intraoperative electron beam radiation therapy in early-stage breast cancer.

PURPOSE: In a previous paper we reported the results of off-line in vivo measurements using radiochromic films in IOERT. In the present study, a further step was made, aiming at the improvement of the effectiveness of in vivo dosimetry, based on a real-time check of the dose. MATERIALS AND METHODS: Entrance dose was determined using micro-MOSFET detectors placed inside a thin, sterile, transparent catheter. The epoxy side of the detector was faced towards the beam to minimize the anisotropy. Each detector was plugged into a bias supply (standard sensitivity) and calibrated at 5 Gy using 6 MeV electrons produced by a conventional linac. Detectors were characterized in terms of linearity, precision and dose per pulse dependence. No energy and temperature dependence was found. The sensitivity change of detectors was about 1% per 20 Gy accumulated dose. Correction factors to convert surface to entrance dose were determined for each combination of energy and applicator. From November 2004 to May 2005, in vivo dosimetry was performed on 45 patients affected by early-stage breast cancer, who underwent IOERT to the tumour bed. IOERT was delivered using electrons (4-10 MeV) at high dose per pulse, produced by either a Novac7 or a Liac mobile linac. RESULTS: The mean ratio between measured and expected dose was 1.006+/-0.035 (1 SD), in the range 0.92-1.1. The procedure uncertainty was 3.6%. Micro-MOSFETs appeared suitable for in vivo dosimetry in IOERT, although some unfavourable aspects, like the limited lifetime and the anisotropy with no build-up, were found. Prospectively, a real-time action level (+/-6%) on dose discrepancy was defined. CONCLUSIONS: Excellent agreement between measured and expected doses was found. Real-time in vivo dosimetry appeared feasible, reliable and more effective than the method previously published.     

Large concentrations of nitrous oxide decrease the isoflurane minimum alveolar concentration sparing effect of morphine in the rat

Many adjuvant drugs have demonstrated anesthetic-sparing properties when combined with volatile anesthetics. Nitrous oxide is combined with volatile anesthetics to reduce the concentrations of volatile anesthetics required to produce anesthesia. Analgesic doses of opioids clearly reduce the requirement for inhaled anesthetics in both human patients and experimental animals. We performed this study to determine whether the combination of nitrous oxide and morphine decreased isoflurane minimum alveolar anesthetic concentration (MAC) even further in the rat. Fifty-eight female rats were used. The rats were divided into 8 groups: isoflurane in 4 possible nitrous oxide concentrations (0%, 30%, 50%, or 70%) with saline or morphine (1 mg/kg). Then the MAC of isoflurane (MAC(ISO))was determined from alveolar gas samples at the time of tail clamp. The MAC of isoflurane was significantly different at each nitrous oxide concentration, and increasing nitrous oxide concentrations reduced anesthetic requirements for isoflurane. The administration of morphine reduced the MAC(ISO) when used with 0% or 30% nitrous oxide. This MAC(ISO) by morphine reduction was less with 50% nitrous oxide and nonexistent at 70% nitrous oxide. However, with morphine present the MAC(ISO) was independent of the nitrous oxide concentration in the 30%-70% range.