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Dive into the research topics where Mohammed Keshtgar is active.

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Featured researches published by Mohammed Keshtgar.


The Lancet | 2010

Targeted intraoperative radiotherapy versus whole breast radiotherapy for breast cancer (TARGIT-A trial): an international, prospective, randomised, non-inferiority phase 3 trial

Js Vaidya; David Joseph; Jeffrey Tobias; Max Bulsara; Frederik Wenz; Christobel Saunders; Michael Alvarado; Henrik Flyger; Samuele Massarut; Wolfgang Eiermann; Mohammed Keshtgar; John Dewar; Uta Kraus-Tiefenbacher; Marc Sütterlin; Laura Esserman; Helle M R Holtveg; Mario Roncadin; Steffi Pigorsch; M Metaxas; Mary Falzon; April Matthews; Tammy Corica; Norman R. Williams; Michael Baum

BACKGROUND After breast-conserving surgery, 90% of local recurrences occur within the index quadrant despite the presence of multicentric cancers elsewhere in the breast. Thus, restriction of radiation therapy to the tumour bed during surgery might be adequate for selected patients. We compared targeted intraoperative radiotherapy with the conventional policy of whole breast external beam radiotherapy. METHODS Having safely piloted the new technique of single-dose targeted intraoperative radiotherapy with Intrabeam, we launched the TARGIT-A trial on March 24, 2000. In this prospective, randomised, non-inferiority trial, women aged 45 years or older with invasive ductal breast carcinoma undergoing breast-conserving surgery were enrolled from 28 centres in nine countries. Patients were randomly assigned in a 1:1 ratio to receive targeted intraoperative radiotherapy or whole breast external beam radiotherapy, with blocks stratified by centre and by timing of delivery of targeted intraoperative radiotherapy. Neither patients nor investigators or their teams were masked to treatment assignment. Postoperative discovery of predefined factors (eg, lobular carcinoma) could trigger addition of external beam radiotherapy to targeted intraoperative radiotherapy (in an expected 15% of patients). The primary outcome was local recurrence in the conserved breast. The predefined non-inferiority margin was an absolute difference of 2.5% in the primary endpoint. All randomised patients were included in the intention-to-treat analysis. This trial is registered with ClinicalTrials.gov, number NCT00983684. FINDINGS 1113 patients were randomly allocated to targeted intraoperative radiotherapy and 1119 were allocated to external beam radiotherapy. Of 996 patients who received the allocated treatment in the targeted intraoperative radiotherapy group, 854 (86%) received targeted intraoperative radiotherapy only and 142 (14%) received targeted intraoperative radiotherapy plus external beam radiotherapy. 1025 (92%) patients in the external beam radiotherapy group received the allocated treatment. At 4 years, there were six local recurrences in the intraoperative radiotherapy group and five in the external beam radiotherapy group. The Kaplan-Meier estimate of local recurrence in the conserved breast at 4 years was 1.20% (95% CI 0.53-2.71) in the targeted intraoperative radiotherapy and 0.95% (0.39-2.31) in the external beam radiotherapy group (difference between groups 0.25%, -1.04 to 1.54; p=0.41). The frequency of any complications and major toxicity was similar in the two groups (for major toxicity, targeted intraoperative radiotherapy, 37 [3.3%] of 1113 vs external beam radiotherapy, 44 [3.9%] of 1119; p=0.44). Radiotherapy toxicity (Radiation Therapy Oncology Group grade 3) was lower in the targeted intraoperative radiotherapy group (six patients [0.5%]) than in the external beam radiotherapy group (23 patients [2.1%]; p=0.002). INTERPRETATION For selected patients with early breast cancer, a single dose of radiotherapy delivered at the time of surgery by use of targeted intraoperative radiotherapy should be considered as an alternative to external beam radiotherapy delivered over several weeks. FUNDING University College London Hospitals (UCLH)/UCL Comprehensive Biomedical Research Centre, UCLH Charities, National Institute for Health Research Health Technology Assessment programme, Ninewells Cancer Campaign, National Health and Medical Research Council, and German Federal Ministry of Education and Research (BMBF).


The Lancet | 2014

Risk-adapted targeted intraoperative radiotherapy versus whole-breast radiotherapy for breast cancer: 5-year results for local control and overall survival from the TARGIT-A randomised trial

Js Vaidya; Frederik Wenz; Max Bulsara; Jeffrey Tobias; David Joseph; Mohammed Keshtgar; Henrik Flyger; Samuele Massarut; Michael Alvarado; Christobel Saunders; Wolfgang Eiermann; M Metaxas; Elena Sperk; Marc Sütterlin; Douglas Brown; Laura Esserman; Mario Roncadin; Alastair Thompson; John Dewar; Helle M R Holtveg; Steffi Pigorsch; Mary Falzon; Eleanor E.R. Harris; April Matthews; Chris Brew-Graves; Ingrid Potyka; Tammy Corica; Norman R. Williams; Michael Baum

BACKGROUND The TARGIT-A trial compared risk-adapted radiotherapy using single-dose targeted intraoperative radiotherapy (TARGIT) versus fractionated external beam radiotherapy (EBRT) for breast cancer. We report 5-year results for local recurrence and the first analysis of overall survival. METHODS TARGIT-A was a randomised, non-inferiority trial. Women aged 45 years and older with invasive ductal carcinoma were enrolled and randomly assigned in a 1:1 ratio to receive TARGIT or whole-breast EBRT, with blocks stratified by centre and by timing of delivery of targeted intraoperative radiotherapy: randomisation occurred either before lumpectomy (prepathology stratum, TARGIT concurrent with lumpectomy) or after lumpectomy (postpathology stratum, TARGIT given subsequently by reopening the wound). Patients in the TARGIT group received supplemental EBRT (excluding a boost) if unforeseen adverse features were detected on final pathology, thus radiotherapy was risk-adapted. The primary outcome was absolute difference in local recurrence in the conserved breast, with a prespecified non-inferiority margin of 2·5% at 5 years; prespecified analyses included outcomes as per timing of randomisation in relation to lumpectomy. Secondary outcomes included complications and mortality. This study is registered with ClinicalTrials.gov, number NCT00983684. FINDINGS Patients were enrolled at 33 centres in 11 countries, between March 24, 2000, and June 25, 2012. 1721 patients were randomised to TARGIT and 1730 to EBRT. Supplemental EBRT after TARGIT was necessary in 15·2% [239 of 1571] of patients who received TARGIT (21·6% prepathology, 3·6% postpathology). 3451 patients had a median follow-up of 2 years and 5 months (IQR 12-52 months), 2020 of 4 years, and 1222 of 5 years. The 5-year risk for local recurrence in the conserved breast was 3·3% (95% CI 2·1-5·1) for TARGIT versus 1·3% (0·7-2·5) for EBRT (p=0·042). TARGIT concurrently with lumpectomy (prepathology, n=2298) had much the same results as EBRT: 2·1% (1·1-4·2) versus 1·1% (0·5-2·5; p=0·31). With delayed TARGIT (postpathology, n=1153) the between-group difference was larger than 2·5% (TARGIT 5·4% [3·0-9·7] vs EBRT 1·7% [0·6-4·9]; p=0·069). Overall, breast cancer mortality was much the same between groups (2·6% [1·5-4·3] for TARGIT vs 1·9% [1·1-3·2] for EBRT; p=0·56) but there were significantly fewer non-breast-cancer deaths with TARGIT (1·4% [0·8-2·5] vs 3·5% [2·3-5·2]; p=0·0086), attributable to fewer deaths from cardiovascular causes and other cancers. Overall mortality was 3·9% (2·7-5·8) for TARGIT versus 5·3% (3·9-7·3) for EBRT (p=0·099). Wound-related complications were much the same between groups but grade 3 or 4 skin complications were significantly reduced with TARGIT (four of 1720 vs 13 of 1731, p=0·029). INTERPRETATION TARGIT concurrent with lumpectomy within a risk-adapted approach should be considered as an option for eligible patients with breast cancer carefully selected as per the TARGIT-A trial protocol, as an alternative to postoperative EBRT. FUNDING University College London Hospitals (UCLH)/UCL Comprehensive Biomedical Research Centre, UCLH Charities, National Institute for Health Research Health Technology Assessment programme, Ninewells Cancer Campaign, National Health and Medical Research Council, and German Federal Ministry of Education and Research.


European Journal of Nuclear Medicine and Molecular Imaging | 2000

Radiation safety of the sentinel lymph node technique in breast cancer

Wendy Waddington; Mohammed Keshtgar; I. Taylor; Sunil R. Lakhani; M.D. Short; P.J. Eli

Abstract.Many publications attest to the potential of the sentinel lymph node technique in advancing the clinical management of melanoma and, more recently, breast cancer. Whilst not yet universally regarded as the standard of care, the technique is gaining wide acceptance. Use of a radiolabelled colloidal tracer is central to optimising sensitivity, and this brings with it the need to address radiation safety issues relating to the use of radioactive materials in the operating theatre and pathology laboratory, and the generation of radioactive waste. The radiation dose to the patient should also be determined if the professional is to reassure the patient by placing this in its proper context. For the purpose of this investigation, biodistribution data were obtained from patient studies to quantify the migration of tracer beyond the injection site, thereby permitting a detailed assessment of the internal dosimetry of the tracer and the resulting radiation dose to the patient. Uptake of tracer in the sentinel nodes, reticulo-endothelial system and circulating blood was investigated. The radiation dose to surgical staff was recorded using whole-body monitors and extremity dosimeters worn at the fingers. Clinical waste in the operating theatre was monitored and the radioactive content of significantly contaminated items determined. The radiation dose to pathology staff was estimated from knowledge of the radioactive content of the specimens obtained and a study of work practices. Migration of tracer was found to be minimal, with greater than 95% retention at the injection site. The effective dose resulting to the patient was 2.1×10–2 mSv/MBq, with a mean breast dose of 7.2×10–1 mGy/MBq. A mean whole-body dose of 0.34 µSv was received by surgical staff per procedure, with a mean finger dose of 0.09 mSv (90 µSv). Radiation doses received by pathology staff will be predominantly below measurable levels and are likely to be negligible unless primary specimens from a large number of studies are analysed promptly upon their excision. At operation, surgical swabs can become significantly contaminated and have been found to contain up to 22% of the administered activity, dependent upon the surgical procedure performed. It is concluded that moderate activities of technetium-99m labelled tracer are administered to the patient, and the radiation risk to the patient is consequently low relative to that from many other medical exposures. The radiation doses to staff groups involved in all aspects of the technique are low, and under normal circumstances and levels of workload, routine radiation monitoring will not be required. Standard biohazard precautions prevent direct intake of radioactive contamination. Radioactive waste is created in the operating theatre, and may be generated in the pathology laboratory if specimens are not routinely stored until fully decayed. This will require special handling if the disposal of radioactive material is not permitted.


International Journal of Radiation Oncology Biology Physics | 2011

Long-Term Results of Targeted Intraoperative Radiotherapy (Targit) Boost During Breast-Conserving Surgery

Js Vaidya; Michael Baum; Jeffrey Tobias; Frederik Wenz; Samuele Massarut; Mohammed Keshtgar; Basil S. Hilaris; Christobel Saunders; Norman R. Williams; Chris Brew-Graves; Tammy Corica; Mario Roncadin; Uta Kraus-Tiefenbacher; Marc Sütterlin; Max Bulsara; David Joseph

PURPOSE We have previously shown that delivering targeted radiotherapy to the tumour bed intraoperatively is feasible and desirable. In this study, we report on the feasibility, safety, and long-term efficacy of TARGeted Intraoperative radioTherapy (Targit), using the Intrabeam system. METHODS AND MATERIALS A total of 300 cancers in 299 unselected patients underwent breast-conserving surgery and Targit as a boost to the tumor bed. After lumpectomy, a single dose of 20 Gy was delivered intraoperatively. Postoperative external beam whole-breast radiotherapy excluded the usual boost. We also performed a novel individualized case control (ICC) analysis that computed the expected recurrences for the cohort by estimating the risk of recurrence for each patient using their characteristics and follow-up period. RESULTS The treatment was well tolerated. The median follow up was 60.5 months (range, 10-122 months). Eight patients have had ipsilateral recurrence: 5-year Kaplan Meier estimate for ipsilateral recurrence is 1.73% (SE 0.77), which compares well with that seen in the boosted patients in the European Organization for Research and Treatment of Cancer study (4.3%) and the UK STAndardisation of breast RadioTherapy study (2.8%). In a novel ICC analysis of 242 of the patients, we estimated that there should be 11.4 recurrences; in this group, only 6 recurrences were observed. CONCLUSIONS Lumpectomy and Targit boost combined with external beam radiotherapy results in a low local recurrence rate in a standard risk patient population. Accurate localization and the immediacy of the treatment that has a favorable effect on tumour microenvironment may contribute to this effect. These long-term data establish the long-term safety and efficacy of the Targit technique and generate the hypothesis that Targit boost might be superior to an external beam boost in its efficacy and justifies a randomized trial.


European Journal of Cancer | 2008

Do phytoestrogens reduce the risk of breast cancer and breast cancer recurrence? What clinicians need to know

Louiza S. Velentzis; Jayne V. Woodside; Marie Cantwell; Anthony J. Leathem; Mohammed Keshtgar

Oestrogen is an important determinant of breast cancer risk. Oestrogen-mimicking plant compounds called phytoestrogens can bind to oestrogen receptors and exert weak oestrogenic effects. Despite this activity, epidemiological studies suggest that the incidence of breast cancer is lower in countries where the intake of phytoestrogens is high, implying that these compounds may reduce breast cancer risk, and possibly have an impact on survival. Isoflavones and lignans are the most common phytoestrogens in the diet. In this article, we present findings from human observational and intervention studies related to both isoflavone and lignan exposure and breast cancer risk and survival. In addition, the clinical implications of these findings are examined in the light of a growing dietary supplement market. An increasing number of breast cancer patients seek to take supplements together with their standard treatment in the hope that these will either prevent recurrence or treat their menopausal symptoms. Observational studies suggest a protective effect of isoflavones on breast cancer risk and the case may be similar for increasing lignan consumption although evidence so far is inconsistent. In contrast, short-term intervention studies suggest a possible stimulatory effect on breast tissue raising concerns of possible adverse effects in breast cancer patients. However, owing to the dearth of human studies investigating effects on breast cancer recurrence and survival the role of phytoestrogens remains unclear. So far, not enough clear evidence exists on which to base guidelines for clinical use, although raising patient awareness of the uncertain effect of phytoestrogens is recommended.


International journal of breast cancer | 2011

Cancer Multidisciplinary Team Meetings: Evidence, Challenges, and the Role of Clinical Decision Support Technology

Patkar; D Acosta; T Davidson; A Jones; J Fox; Mohammed Keshtgar

Multidisciplinary team (MDT) model in cancer care was introduced and endorsed to ensure that care delivery is consistent with the best available evidence. Over the last few years, regular MDT meetings have become a standard practice in oncology and gained the status of the key decision-making forum for patient management. Despite the fact that cancer MDT meetings are well accepted by clinicians, concerns are raised over the paucity of good-quality evidence on their overall impact. There are also concerns over lack of the appropriate support for this important but overburdened decision-making platform. The growing acceptance by clinical community of the health information technology in recent years has created new opportunities and possibilities of using advanced clinical decision support (CDS) systems to realise full potential of cancer MDT meetings. In this paper, we present targeted summary of the available evidence on the impact of cancer MDT meetings, discuss the reported challenges, and explore the role that a CDS technology could play in addressing some of these challenges.


British Journal of Surgery | 2008

Impact of rapid molecular screening for meticillin‐resistant Staphylococcus aureus in surgical wards

Mohammed Keshtgar; A. Khalili; P. G. Coen; C. Carder; B. Macrae; A. Jeanes; P. Folan; D. Baker; M. Wren; A.P.R. Wilson

This study aimed to establish the feasibility and cost‐effectiveness of rapid molecular screening for hospital‐acquired meticillin‐resistant Staphylococcus aureus (MRSA) in surgical patients within a teaching hospital.


Journal of Biomedical Optics | 2004

Elastic scattering spectroscopy for intraoperative determination of sentinel lymph node status in the breast

Kristie Johnson; Dennis W. Chicken; David Christopher O. Pickard; Andrew Lee; Gavin M. Briggs; Mary Falzon; Irving J. Bigio; Mohammed Keshtgar; Stephen G. Bown

The ability to provide the best treatment for breast cancer depends on establishing whether or not the cancer has spread to the lymph nodes under the arm. Conventional assessment requires tissue removal, preparation, and expert microscopic interpretation. In this study, elastic scattering spectroscopy (ESS) is used to interrogate excised nodes with pulsed broadband illumination and collection of the backscattered light. Multiple spectra are taken from 139 excised nodes (53 containing cancer) in 68 patients, and spectral analysis is performed using a combination of principal component analysis and linear discriminant analysis to correlate the spectra with conventional histology. The data are divided into training and test sets. In test sets containing spectra from only normal nodes and nodes with complete replacement by cancer, ESS detects the spectra from cancerous nodes with 84% sensitivity and 91% specificity (per-spectrum analysis). In test sets that included normal nodes and nodes with partial as well as complete replacement by cancer, ESS detects the nodes with cancer with an average sensitivity of 75% and specificity of 89% (per-node analysis). These results are comparable to those from conventional touch imprint cytology and frozen section histology, but do not require an expert pathologist for interpretation. With automation of the technique, results could be made available almost instantaneously. ESS is a promising technique for the rapid, accurate, and straightforward detection of metastases in excised sentinel lymph nodes.


British Journal of Cancer | 2009

Lignans and breast cancer risk in pre- and post-menopausal women: meta-analyses of observational studies

Louiza S. Velentzis; Marie Cantwell; Christopher Cardwell; Mohammed Keshtgar; Anthony J. Leathem; Jayne V. Woodside

Phyto-oestrogens are plant compounds structurally similar to oestradiol, which have been proposed to have protective effects against breast cancer. The main class of phyto-oestrogens in the Western diet is lignans. Literature reports on the effect of lignans in breast cancer risk have been conflicting. We performed three separate meta-analyses to examine the relationships between (i) plant lignan intake, (ii) enterolignan exposure and (iii) blood enterolactone levels and breast cancer risk. Medline, BIOSIS and EMBASE databases were searched for publications up to 30 September 2008, and 23 studies were included in the random effects meta-analyses. Overall, there was little association between high plant lignan intake and breast cancer risk (11 studies, combined odds ratio (OR): 0.93, 95% confidence interval (95% CI): 0.83–1.03, P=0.15), but this association was subjected to marked heterogeneity (I2=44%). Restricting the analysis to post-menopausal women, high levels of plant lignan intake were associated with reduced breast cancer risk (7 studies, combined OR: 0.85, 95% CI: 0.78, 0.93, P<0.001) and heterogeneity was markedly reduced (I2=0%). High enterolignan exposure was also associated with breast cancer (5 studies, combined OR: 0.73, 95% CI: 0.57, 0.92, P=0.009) but, again, there was marked heterogeneity (I2=63%). No association was found with blood enterolactone levels (combined OR: 0.82, 95% CI: 0.59–1.14, P=0.24). In conclusion, plant lignans may be associated with a small reduction in post-menopausal breast cancer risk, but further studies are required to confirm these results.


Lancet Oncology | 2002

Clinical role of sentinel-lymph-node biopsy in breast cancer

Mohammed Keshtgar; Peter J. Ell

The introduction of sentinel-lymph-node biopsy has brought new impetus to the early staging of cancer in general, and breast cancer in particular. This technique has rekindled the discussion on the present role and routine practice of axillary-lymph-node dissection in early breast cancer, the methods available for the histopathological assessment of lymph nodes, and the current thoughts about best surgical practice in the management of breast cancer. Sentinel-lymph-node biopsy has spread so rapidly that surgeons, pathologists, and patients are no longer willing or able to ignore the possible consequences of its implementation. A vast amount of data (over 1150 publications in the peer-reviewed literature on this subject to date) attests to the explosive interest in the past 5 years. In this article we review our own experience and discuss recommendations for clinical practice.

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Dive into the Mohammed Keshtgar's collaboration.

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Michael Baum

University College London

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Christobel Saunders

Sir Charles Gairdner Hospital

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Tammy Corica

Sir Charles Gairdner Hospital

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Js Vaidya

University College London

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Shramana Banerjee

Royal Free London NHS Foundation Trust

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David Joseph

Sir Charles Gairdner Hospital

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Max Bulsara

University of Notre Dame

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Jeffrey Tobias

University College London

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