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Biomedical subjects

M J Michell

Publications and source records attributed to M J Michell.

At least 19 recordsLinked to original sources
PubMed2006

The impact of image guided needle biopsy on the outcome of mammographically detected indeterminate microcalcification.

A study was carried out to examine the impact of development in image guided needle biopsy on the outcome of mammographically detected indeterminate microcalcification. Between 01.04.1991 and 31.03.2001, the South East London Breast Screening Programme detected 392 cases of indeterminate microcalcificaton. Histological diagnosis was obtained using open biopsy, fine needle aspiration cytology (FNAC), 18/14 G wide bore needle core biopsy (WBNCB) and 11 G vacuum assisted core biopsy (VACB). The study period group was divided into two. Group A (between 01.04.1991 and 31.03.1996) and group B (between 01.04.1996 and 31.03.2001). There was a significant reduction in the benign open biopsy rate in group B compared to group A (25% vs. 51%) (P=0.0001). Of the malignant cases, there is a higher percentage of ductal carcinoma in situ (DCIS) in group B compared to group A (77% vs. 62%). In conclusion, the implementation of more effective methods of image guided biopsy has led to a 50% reduction in benign open biopsies for indeterminate microcalcification and to an increase in the detection of DCIS.

Biopsy, Needle↗
PubMed2002

15. Image-guided breast biopsy.

The introduction of mammographic screening has led to an increased number of impalpable in situ and invasive breast cancers. Image-guided percutaneous biopsy in these patients has advantages over surgical biopsy, primarily cost savings and reducing the number of operations required for definitive treatment. Image-guided breast biopsy is also useful in palpable lesions. Image-guided biopsy should be used in conjunction with full clinical and imaging work-up as part of the triple assessment protocol. Techniques available include fine needle aspiration, automated needle-gun core and vacuum assisted large core biopsy. Lesions visible on ultrasound are preferentially biopsied using ultrasound guidance, while those seen only mammographically are biopsied using stereotactic guidance. Major complications are rare following image-guided biopsy. In most cases further management can be decided based on the biopsy result. If there is discordance between clinical and imaging features and the biopsy result, image-guided percutaneous biopsy should be repeated or surgical biopsy may be required.

Biopsy, Needle↗
PubMed2001

Breast cancer screening.

Mammographic screening reduces breast cancer mortality by 24% in women aged > or = 50 years. Women aged 50-53 are invited for their first screen in the National Health Service Breast Screening Programme (NHSBSP), thereafter at three-year intervals until the age of 64. Two-view mammography is offered at the first (prevalent) screening examination and one-view for subsequent (incident) screens. The screening films are sorted into either 'normal' or 'abnormal requiring further assessment'. Assessment is carried out by a specialist multidisciplinary team using the triple approach: clinical examination, imaging and, where appropriate, needle biopsy. Imaging is planned according to the mammographic abnormality--paddle compression view to assess parenchymal distortion, magnification view to assess microcalcification. After confirmation of a suspicious abnormality, needle biopsy is performed. Results of triple assessment are considered together by the multidisciplinary team and further management is planned. There are four likely outcomes: benign/normal, confirmed breast cancer, suspicious but needing diagnostic surgical excision, and diagnostic uncertainty needing early recall for screening.

Adult↗
PubMed2000

An investigation into why two-view mammography is better than one-view in breast cancer screening.

AIM: To determine why two-view mammography in screening for breast cancer is more effective than using a single medio-lateral oblique view. MATERIALS AND METHODS: In the United Kingdom Coordinating Committee on Cancer Research randomized trial of one- vs two-view mammography in breast cancer screening the oblique view was assessed by one radiologist and two views (oblique and cranio-caudal) assessed by another. For the present study the mammographic films were retrieved from the screening centres and assessed by three consultant radiologists. Mammographic films were available from 110 women; 87 had their breast cancer detected by both one and two views and in 23 it was missed by one view but detected using two views. Outcome measures were breast size, location and size of the cancer, mammographic features, presence of microcalcification and overall radiological assessment. RESULTS: Although 23 cancers were missed in the original trial when one view was used, only two were not visible on the oblique view. Cancers missed using a single oblique view (and only detected if the cranio-caudal view was available with the oblique) tended to be smaller by about 4 mm (P = 0.05), centrally located in the breast (P = 0.16), not spiculated or round, (P </= 0. 001) and lacked microcalcification (P = 0.15). Breast size and breast radiographic density were not significantly associated with breast cancer detection. CONCLUSIONS: The results provide the basis for the observation that two-view mammographic screening is more effective than one-view mammographic screening.Hackshaw, A. (2000). Clinical Radiology55, 454-458.

Breast Neoplasms↗
PubMed2000

Multiple 14G stereotactic core biopsies in the diagnosis of mammographically detected stellate lesions of the breast.

AIM: The aim of this retrospective study was to measure the accuracy of stereotactic guided 14 gauge core biopsy in distinguishing between benign and malignant causes of a mammographically detected stellate breast lesion and to assess the impact of the number of core samples taken on the sensitivity for detection of malignancy. MATERIALS AND METHODS: Seventy-two patients with mammographically detected stellate lesions of the breast formed the study group. All patients in the study group underwent multiple 14 gauge core biopsies using prone stereotactic breast biopsy equipment. The diagnostic accuracy of the technique was measured by retrospectively comparing the outcome with the core biopsy results. The result of each core sample was separately recorded to allow analysis of the effect of increasing the number of samples on accuracy. RESULTS: Nine of 72 (12%) did not have surgery. Forty of 72 (56%) had a benign surgical outcome and 23/72 (32%) a malignant surgical outcome [7/72 (10%) non-invasive, 16/72 (22%) invasive carcinoma]. The absolute sensitivity for multiple stereotactic guided core biopsies of stellate lesions for the detection of malignancy was 78% with a complete sensitivity of 100%. The sensitivity for the detection of invasive carcinoma was 94% (15 out of 16 patients). No statistically significant improvement in sensitivity was shown for multiple samples vs one sample, but in two patients, malignant tissue was only found in core samples 6-9, the first five cores showing atypia only. CONCLUSION: Multiple stereotactic guided 14 gauge core biopsies accurately distinguish malignant from benign causes of stellate breast lesions. When core biopsy histology is malignant, therapeutic surgery can be planned. When the core biopsy shows typical features of a benign radial scar, diagnostic surgical excision may not be required to confirm the diagnosis.Kirwan, S. E., (2000). Clinical Radiology55, 763-766.

Biopsy, Needle↗
PubMed1999

Stereotactic 14G core biopsy of non-palpable breast cancer: what is the relationship between the number of core samples taken and the sensitivity for detection of malignancy?

AIM: Percutaneous 14-gauge core biopsy (CB) guided by digital stereotactic mammography is now an established technique in the investigation of women with non-palpable suspicious mammographic lesions. Diagnostic sensitivity of CB is affected both by the nature of the mammographic abnormality and by the number of core samples taken. METHODS AND RESULTS: A retrospective review of 500 women who have undergone CB in our institution showed that in 235 cases, invasive or non-invasive carcinoma was found on final surgical histology. Correlation between CB result and surgical histology revealed a significant increase in sensitivity for the diagnosis of malignancy if a larger number of cores were taken (84.3% for two cores and 90.2% for five cores vs. 97.9% for six or more cores). This trend was maintained when patients were subdivided according to mammographic abnormality, either soft tissue mass or microcalcifications. The effect on diagnostic sensitivity of increasing the number of tissue cores obtained was most pronounced in patients with microcalcifications graded as low or moderately suspicious for malignancy (70.1% for two cores and 79.1% for five cores vs 94.0% for six or more cores). The presence of an invasive component in a malignant lesion was correctly diagnosed using CB in 79.2% overall if at least six cores were taken. If the mammographic lesion was a soft tissue mass, this figure rose to 95.7%, but was only 35.7% if the visible lesion was composed of microcalcifications alone. CONCLUSION: Our series confirms the reliability of stereotactic CB in the diagnosis of breast carcinoma. Diagnostic sensitivity is improved by increasing the number of cores taken (to six or more), particularly in women with mammographic microcalcifications of an equivocal nature.

Biopsy↗
PubMed1999

Image-guided breast biopsy: analysis of pain and discomfort related to technique.

A prospective study to evaluate the pain experienced during image-guided core biopsy and fine-needle aspiration (FNA) in a series of 200 woman. There was no significant difference between the pain experienced between core biopsy and FNA. Pain experienced was operator dependent with one of the three radiologists causing significantly more pain than the other two.

Journal Article↗
PubMed1998

Variations in referral pattern for postoperative radiotherapy of patients with screen-detected breast cancer in the south Thames (east) region.

This paper describes the findings of a region-wide audit undertaken in 1995-1996 of post-operative radiotherapy treatment for patients with screen-detected breast cancer. The study covers the first 3 years from the start of the South Thames (East) Breast Screening Programme in June 1988 up to March 1992. The audit shows that only 60% of the patients with invasive carcinoma who were treated by conservation surgery are known to have received radiotherapy. A considerable variation in referral patterns was observed across the region. Analysis suggests that whilst geographical, patient choice and tumour factors may play an important role in the selection of patients for radiotherapy treatment after conservative surgery for early breast cancer, management protocols of surgical units were the most critical factor, and that these appear to vary, depending on the level of involvement of the clinician with the screening programme (as measured by case-load).

Breast Neoplasms↗
PubMed1997

Variation in management of small invasive breast cancers detected on screening in the former south east Thames region: observational study.

OBJECTIVE: To examine the variation in surgical and adjuvant treatment of breast cancer of known histology and detected on screening in a large cohort of patients treated by the surgeons of a health region. DESIGN: Part prospective, part retrospective observational study using the databases of a region's breast screening programme and of the cancer registry. SETTING: The former South East Thames region. SUBJECTS: 600 women aged 49-79 who presented during 1991-2 with invasive breast cancer up to 20 mm in diameter that had been detected on screening. These patients were treated by 35 surgeons. MAIN OUTCOME MEASURES: Mastectomy rate by surgeon and the use of adjuvant treatment (radiotherapy, tamoxifen, and chemotherapy) were compared with risk factors, tumour grade, resection margins, and axillary node status. RESULTS: The mastectomy rate varied between nil and 80%, although the numbers at these extremes were small (0/13 v 8/10). Surgeons operating on more than 20 such cases had a lower mastectomy rate (15%) than surgeons treating fewer cases (23%), but this difference was confounded by variation in casemix. There were also wide variations in mastectomy rates and in axillary sampling rates that were independent of casemix or caseload. There was broad agreement on the use of adjuvant tamoxifen (94%), but few patients received chemotherapy (2.5%). 78 patients (19%) did not receive radiotherapy, including 51 out of 317 patients with unfavourable tumours, and 26 patients did not receive tamoxifen. Whether the patient received adjuvant treatment was more dependent on referral by the surgeon than the risk factors for local recurrence and was independent of caseload. CONCLUSION: Mastectomy rates for similar tumours vary widely by surgeon independently of casemix or caseload, but surgeons with a higher caseload tend to have a lower mastectomy rate. Omission of postoperative radiotherapy or tamoxifen after conservative treatment is not related to risk factors for local recurrence or caseload. Confidential feedback of treatment profiles to individual surgeons has been used, but when benefit has been established treatment should be guided by evidence based protocol.

Aged↗
PubMed1995

Classification of ductal carcinoma in situ by image analysis of calcifications from digital mammograms.

There is evidence to suggest that non-comedo cases of ductal carcinoma in situ (DCIS) may have a lower risk of progressing to invasive disease than comedo DCIS and may be managed with less radical treatment. Most cases of DCIS present as calcifications on the mammogram and, due to differences in the tumour architecture, comedo calcifications often have a characteristic linear or branching appearance. In this study, computer methods were developed to identify the comedo cases using the imaging features of individual calcifications and of calcification clusters. Classifier performance was measured using the area under the receiver operating characteristic (ROC) curve and was optimized by systematic testing of many different combinations of these features. On a test-set of 42 cases the computer achieved a ROC curve area of 0.91 using six combined cluster features. These results are encouraging given the observed overlap in appearance between the comedo and non-comedo cases.

Breast Diseases↗
PubMed1994

Case report: computed tomography appearances in a right paraduodenal hernia.

The computed tomography (CT) appearances of a right paraduodenal hernia are described. The working diagnosis at the time of the scan was of acute pancreatitis and we discuss the differentiation of the two conditions on CT. The CT findings are compared with those previously reported in other types of internal hernia.

Acute Disease↗
PubMed1993

Side-effects of screening.

There has been a 42% increase in the number of mammograms performed outside the national screening programme (operating in Camberwell, southeast London) which was not anticipated in the Forrest Report, a document to the Health Ministers of the U.K. by a working group chaired by Sir Patrick Forrest. The report compiles recommendations on breast screening, using mammography and breast self-examination, to reduce the mortality in women aged 50-64 years. This 42% increase is attributable mainly to referrals from menopause clinics and general practitioners of patients mainly in the screening age group. When we looked at referrals from general practitioners, suspicious mammographic findings were reported in 20% of patients referred with a breast lump, in contrast to only 4% of patients referred with breast pain or nodularity. Better education of both the public and general practitioners, concerning the signs and symptoms of breast cancer, may reduce demands to perform mammographies outside the current national screening programme.

Ambulatory Care Facilities↗
PubMed1991

Fibrous mastopathy in insulin dependent diabetics.

The cases of two poorly controlled insulin dependent diabetic women, presenting with hard discrete breast lumps clinically suspicious of carcinoma are presented. Mammography revealed dense dysplastic parenchymal changes with no specific features of carcinoma and ultrasound showed acoustic shadowing but no discrete mass. Excision biopsy of these lumps was performed. Histologically they were benign, and were composed of fibrous tissue with a chronic inflammatory cell infiltrate. With better awareness of fibrous mastopathy which can occur in this group of diabetic patients, and with the absence of specific radiological features of malignancy, some of these women may be observed and spared excision biopsy.

Adult↗