Our consultants

Dr Cowell is a Consultant Clinical Oncologist at the Edinburgh Cancer Centre, where she has worked since January 2025. She graduated from the University of Edinburgh in 2012 and completed her early medical training at Wythenshawe Hospital and The Christie Cancer Centre in Manchester, where she developed a strong interest in Oncology. She then spent three years working in Australia, before returning to the UK to undertake core medical training in Brighton. Dr Cowell completed her specialist Clinical Oncology training at the Beatson West of Scotland Cancer Centre in Glasgow, where she developed a particular interest in the treatment of head and neck and breast cancers. She holds Membership of the Royal College of Physicians and is a Fellow of the Royal College of Radiologists.

Dr Cowell was awarded the Carol Sicher Fellowship from the Royal College of Radiologists in 2022, during which she carried out research into the impact of the COVID-19 pandemic on patients with head and neck cancer, presenting her work at a national conference. She has also been involved in research exploring advanced imaging techniques and personalised radiotherapy approaches for treatment resistant cancers.

Alongside her clinical work, Dr Cowell is actively involved in teaching and training healthcare professionals at all levels; from medical students to senior trainees, and contributes to national exam preparation courses. She is currently an Education and Morbidity and Mortality Lead for the cancer centre. She is involved in clinical research and is the principal investigator for an upcoming clinical trial exploring pre-mastectomy radiotherapy for patients with breast cancer.

Dr Cowell is known for her compassionate, patient-centred approach to care. She works closely with multidisciplinary teams and values clear communication, ensuring that patients feel supported and fully informed throughout their treatment. Outside of work, she enjoys musical theatre and Zumba.

Dr Stuart Walter qualified from Peninsula Medical School, based across Devon and Cornwall, in 2012. He stayed in Cornwall for his foundation training and a Clinical Fellowship in Oncology. Following this he spent a year working in Western Australia and conducting cancer research projects. On returning to the UK he completed his General Medical and Clinical Oncology training in Edinburgh - gaining a consultant post in early 2025; initially in Breast and Head & Neck Cancer. Dr Walter moved to the Lung and Upper GI Cancer teams in December 2025, and continues to part of the Oligometastatic SABR team. He takes an active role in clinical research and has helped South East Scotland become one of the leading recruiters worldwide for the COMET3 and COMET10 SABR Trials, as well as designing and running the SPITFIRE study investigating radiation pneumonitis - a dose-limiting toxicity in thoracic radiotherapy. Dr Walter works alongside the University of Edinburgh Medical School providing lectures and other teaching sessions.

Dr Mactier is a Consultant Clinical Oncologist working within the breast and head and neck cancers teams. She qualified from Aberdeen Medical School and then completed general medical rotations in Newcastle and Glasgow prior to starting Clinical Oncology training in Edinburgh. She has an interest in data-driven research, having completed her PhD exploring markers of radiation resistance in oropharyngeal cancers and holds an Honorary Clinical Lectureship with the University of Glasgow.

Dr Mark Zahra graduated in medicine from the University of Malta and then did his post-graduate training in Cambridge, which included 2 years in clinical research. He was appointed as a consultant clinical oncologist in Edinburgh specialising in the management of colorectal and gynaecological cancers. He has a particular interest in the technical aspects of radiotherapy and the role of imaging in planning radiation treatment. He introduced the use of high dose rate (HDR) brachytherapy in Edinburgh and also the use of image guided techniques and interstitial implants for gynaecological cancers. He is also specialised in the use of drugs including chemotherapy, biological agents and immunotherapy for the management of cancer. He strongly believes that patients should be directly involved in the decisions regarding their management, and that the patient’s best interest should be at the heart of decision making in healthcare.

Rachel Nirsimloo is a Medical Oncology Consultant specialising in the treatment of ovarian cancer. She graduated from King’s College London working in London and Newcastle before starting speciality training in Medical Oncology in Edinburgh.

As part of her undergraduate degree at King’s, she also completed a BSc in Philosophy with basic medical sciences. Subsequently during her speciality oncology training, she completed an MSc with the University of Edinburgh in Molecular Pathology, with a particular interest in the clinical utilisation of cfDNA as a biomarker. Currently she has an active interest in clinical trials, most recently as principal investigator for an early phase drug trial in patients with advanced ovarian cancer.

She is involved in education, acting as clinical supervisor for medical oncology trainees and regularly mentors nursing and pharmacy colleagues to help them achieve practitioner and prescribing qualifications.

Rachel also has an interest in Global and Acute Oncology. She set up and led the Acute Oncology Service at St John’s Hospital, Livingston with the aim of ensuring timely and equitable access to specialist oncology review and advice for all cancer patients.

Dr Morgan is a Consultant Clinical Oncologist specialising in radiotherapy and drug treatments for gynaecological, colorectal and anal cancers. She is actively recruiting to clinical trials within these subspecialties and is keen to expand the portfolio of trials open here at ECC.

Dr Morgan has a keen interest in medical education and has completed further qualifications in relation to this.

She is a clinical supervisor for undergraduate medical students and oncology trainees alike and has recently become an examiner for the RCR part 2A examinations.

Dr Noble is a Consultant Clinical Oncologist at the Edinburgh Cancer Centre (ECC), Honorary Senior lecturer with Edinburgh University, NHS Scotland NRS Research Fellow, and Assistant Editor for Cinical Oncology. He completed undergraduate medical studies at the University of Cambridge, and trained as a Clinical Oncologist in the East of England, based at the Cambridge Cancer Centre. During training, Dr Noble won a 3-year Cancer Research UK Clinical Research Fellowship and completed a PhD investigating technical aspects of Adaptive Radiotherapy for Head & Neck Cancer, and moved to Edinburgh to take up a Consultant post in August 2020.

Dr Noble specialises in treating Head & Neck Cancer, and has an academic interest in advanced imaging, image analysis, and radiotherapy treatment techniques, biomarkers of disease and normal tissue response to radiation, and data science across all tumour types. He has an active portfolio of basic and translational research projects, works closely within the Edinburgh Radiotherapy Research Group led by Professors Duncan McLaren and Bill Nailon, with ENT colleagues from the ECC Head & Neck Unit including Mr Iain Nixon, and with Radiologist Dr Rishi Ramaesh. Projects funded by the Scottish Chief Scientists Office (CSO) include IMAGINE (grant no: TCS/17/26) – in which advanced radiomics and machine learning techniques are applied to on-treatment image guidance (IG) scans to look for predictors of more severe toxicity, PRISTINE (grant no: TCS/21/39), in which Scotlands only PET-MRI machine will be used to improve staging and treatment personalisation for men with high-risk early prostate cancer, and SR-1171 in which circulating tumour DNA is used to assess and monitor treatment response in patients who have undergone curative treatment for HPV-driven Head & Neck Cancer. In the PROSECCA project, funded by Prostate Cancer UK (grant no: MA-CT20-010), the research team aim to collate longitudinal health records, disease data, and radiotherapy planning and imaging data for all Scottish men who have been treated with IMRT to improve our ability to predict treatment response and side effects.

Dr Noble has a number of external collaborators including Dr. Claire Patterson and Professor Gareth Inman from the Beatson Cancer Centre in Glasgow - looking at using a combination of MRI imaging features, and genomic analysis to improve our ability to predict poor treatment response in high-risk oropharyngeal cancer, and with Dr Raj Jena from the Cambridge Cancer Centre in the CRUK-funded HAMLET study – the first propsective analysis of machine learning predictive models in radiation therapy. In addition, he works closely within the ECC Head & Neck trials team, led by Dr Devraj Srinivasan, which recruits extensively to national and international trials including COMPARE, PATHOS, POPPY, BURAN, and VERSATILE. Dr Noble would be please to discuss proposals for projects, trials, supervision, and further collaboration.

Dr Stillie is a Clinical Oncology Consultant and Honorary Senior Lecturer at the University of Edinburgh specialising in the management of gynaecological malignancies with radiotherapy, brachytherapy and systemic anti cancer treatment and involved in clinical trials . In addition to her clinical practice she has local and national roles in education and training in the undergraduate and postgraduate setting. She is a Clinical and Educational Supervisor for Clinical Fellows and Speciality Trainees in Oncology at the Edinburgh Cancer Centre, oversees the oncology component of the MBChB Curriculum, and is a Lead for Undergraduate Medical Education in NHS Lothian. At a national level she is a Senior Examiner and Deputy Chair for the Royal College of Radiologists FRCR examination board and a founding member of the RCR undergraduate committee. In addition, she is the deputy chair of the Gynaecology South East Scotland Cancer Network.

Dr Macnair graduated from Newcastle University in 2009 with merit. Following University, he trained down in London completing his MRCP in 2012 prior to starting his specialist training. His specialist clinical oncology training was based in South London at the Royal Marsden, Sussex Cancer Centre and also Imperial College London. He passed his FRCR in 2017. He has completed an MD with UCL in clinical trial methodology while he worked as a clinical research fellow at the MRC clinical trials unit. He also took a year out of training to do a year with the Faculty of Medical Leadership and Management. During this year he worked jointly at Macmillan Cancer Support and the Royal College of Radiologists. He completed his final year of training in the Edinburgh Cancer Centre before starting as a consultant.

Dr Mackenzie studied medicine at the University of Dundee, graduating in 2003 with and MB ChB and BMedSci. She was a junior doctor in Edinburgh, Fife and Dundee before starting specialty training in Clinical Oncology in Edinburgh in 2008. During her training she developed a special interest in head and neck cancers and after completing specialty training undertook a fellowship in Calgary, Canada. During her fellowship she focused on head and neck and skin cancers and developed a special interest in peer review of radiotherapy planning. She returned from Canada to start her consultant post in 2015. Her consultant role involves treatment of head and neck and skin cancers with both radiotherapy and drug therapies. She is involved in clinical trials for both patient groups. Dr Mackenzie is lead oncologist for SCAN for head and neck cancer and was part of the RCR working group publishing guidelines on peer review in radiotherapy planning.

Dr Law has been a Consultant in Clinical Oncology at Edinburgh Cancer Centre since 2011 having completed a fellowship at Peter Maccallum Cancer Centre in Melbourne before that. He has an interest in urological cancers particularly testes cancer and also brachytherapy for prostate cancer. He is  involved in education and acts as college tutor, educational and clinical supervisor for the clinical oncology trainees. Dr Law is also involved in clinical trials and also one of the organisers of the Edinburgh Oncology course and the pan-Scotland teaching for oncology trainees.