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Headed up by Dr Carrie Minnaar, we are the only practice in sub-Saharan Africa offering Hyperthermia to oncology patients in a hospital setting. We offer specialised treatments in the form of modulated electro-hyperthermia. Modulated Electro-Hyperthermia, also known as Oncothermia, is a form of local Hyperthermia that is able to selectively heat up tumours using low frequency radio waves. The technique is suitable for tumours regardless of their depth or location in the body.

Dr Carrie Minnaar first studied hyperthermia in Germany in 2009 and completed her PhD on hyperthermia in oncology at Wits in 2019. Currently, Dr Minnaar practices oncologic hyperthermia at the Wits Donald Gordon Medical Centre.

As part of the Wits Donald Gordon Medical Centre in Johannesburg, we are actively involved in research and clinical trials on the use of Hyperthermia.

ONC Hyperthermia



Dr. Carrie Minnaar specialises in hyperthermic oncology and is well-recognised for her ongoing clinical trials in this field. She holds a PhD in Radiation Sciences from Wits University.

Dr. Minnaar has specialised in hyperthermic oncology since 2009, when she attended training on local and whole body hyperthermia techniques in Frankfurt, Germany. Dr Minnaar’s PhD was dedicated to the improvement of treatment outcomes for locally advanced HIV-positive and negative cervical cancer patients in resource constrained settings in Africa.

Her work includes a positive phase III trial using modulated electro hyperthermia combined with chemoradiotherapy; several published papers on the results and in related fields of hyperthermia; and co-author of a book on hyperthermia. She has lectured and facilitated training on the technique in oncology facilities around the world. Dr Minnaar is also a member of the European Society for Therapeutic and Radiation Oncology (ESTRO); The International Clinical Hyperthermia Society (ICHS); South African Radiobiology Society; African Society for Hyperthermic Oncology (ASHO). In 2019, she was awarded both the ICHS Clinical Excellence and ESHO Young Investigators Award, followed again in 2021, when she received the ctRO Young Investigator Award from ESTRO.

Dr. Minnaar is currently researching the use of modulated electro-hyperthermia for the management of brain tumours in adults and children and campaigning for the acceptance and inclusion of hyperthermia in oncology practices in South Africa.




In 2019 I was diagnosed with Vaginal Cancer. In January 2020 I met with my Oncologist to discuss my treatment plan. I would have Chemo every Tuesday and Radiation every day. Dr Kotzen, my Radiation Oncologist, gave my name to Dr Carrie to discuss the treatment she had to offer.

I met Carrie and it was truly the best thing that happened to me. We discussed when and how I would do the treatment. I was a bit skeptical in the beginning as I did not know what to expect.

At my first appointment Carrie explained and showed me the equipment. I did my first treatment, and my thought was WOW. One hour of lying on a waterbed with a heat pad on the area where the tumour was. Lights turned down low and a very peaceful atmosphere. It was the hour I started looking forward to after my radiation. I am convinced that the Chemo, Radiation and Hyperthermia treatment is the reason why I beat Cancer.

I did think (at the time) that I could not understand why every medical aid would not want to pay for this treatment. It really is the SPA treatment in the Cancer journey. It was the only treatment that did not make me feel sick afterwards. Hyperthermia treatment is truly a wonderful experience.


I have been with Carrie since the beginning of my cancer journey when she began her venture at the Donald Gordon Medical Centre. I have been an on and off ovarian cancer patient since the year 2008. Throughout the period of 15 years, my husband and I have completed a great deal of research and as a result, we are strong believers in the use of hyperthermia treatment aiding in the shrinking and curing of tumours. I began hyperthermia treatment with Carrie as she is the only one in the country with a hyperthermia machine she also has incredible experience. Over the years, I have travelled abroad to many different countries and locations seeking the appropriate treatment and it has remained refreshing to know that Carrie is right here in South Africa on my doorstep.

The hyperthermia machine works absolutely incredibly and comfortably, as a patient all you need to do is lie down on the bed for one hour while the hyperthermia machine heats the affected area or areas that are in need. As a patient, there is no pain or discomfort experienced at any level and it can be described as lying on an oversized hot water bottle. For comfort and support, Carrie remains in the room with you throughout the duration of the treatment, so that she is able to regulate the temperature and monitor you. Whilst you are having hyperthermia treatment you have the opportunity to rest, watch your favourite program, movie, listen to music and before you know it you are completely finished your treatment.

In 2022 I sought treatment abroad and found myself having treatment at an oncology centre in Istanbul, Turkey. The treatment protocol that I followed stressed the importance and necessity of hyperthermia treatment. Consequently, I found that the use of chemo and hyperthermia simultaneously possessed the capacity to shrink my tumours incredibly so much so that after my Turkey journey, I decided to again carry on the hyperthermia treatment with Carrie here in South Africa.

Thank you Carrie for helping and supporting me through my treatment and cancer journey. If anyone feels as though they would like to reach out to me for any reason, I am available for them to do so, I am a call away.


Chanel Christodoulou


When we got the call from the oncologist to say that I would benefit doing the immunotherapy along with the radiation we felt we needed to give this fight every chance! We went to meet Carrie and got the low down of the treatment .. my initial reaction was wow so much heat in one go!

Carrie was so reassuring .. the length she went to -to explain the treatment and how it works and then the length she went to make sure I was comfortable during the process. It was such an incredible experience.. I can literally say that we have become friends. My cancer is stable and we have my next check-up shortly. I am feeling incredibly confident and grateful that we took the option to do this additional treatment.


I have been a patient of Dr. Carrie Minnaar’s for the past three years and from the very start have found her to be insightful, empathetic, and caring. She communicates the benefits of hyperthermia in an effective manner and is in fact a world recognized authority in the field.

Sessions with Dr, Carrie pass by pleasantly and comfortably, and patient are spoilt for choice during treatment- be it from being offered a wide selection of movies, cartoons, or documentaries to watch, or music to listen to, or just being let to sleep, or better still talking to her on wide variety of topics.

I firmly believe in the efficacy of the treatment she administers and that is why I have continued to remain in the care.

Carrie Anne Minnaar: Honorary lecturer Department of Radiation Sciences, University of the Witwatersrand, South Africa; Hyperthermia Specialist: Wits Donald Gordon Medical Centre, Oncology Department, Johannesburg, South Africa

Qualifications: MSc (2008) University of Johannesburg; PhD: Radiation Sciences (2019) University of Witwatersrand

Work Experience: 2014-2019: Hyperthermia department at the Charlotte Maxeke Johannesburg Academic Hospital, 2014-2019: Principle investigator for a phase III randomised controlled trial on Modulated Electro-Hyperthermia as a radiosensitiser for locally advanced cervical cancer for HIV-positive and negative women; 2020-current: Hyperthermia Specialist in a private academic hospital, managing trials and treating patients in private practice; 2020-current: honorary lecturer at the University of the Witwatersrand; 2015-current: International consulting and training in hyperthermia – trained hospital staff in UK, Australia, Japan, South Korea, Spain, India, and Mexico.

Research Interests: Radiobiology; Modulated electro-hyperthermia as a- radiosensitiser, -as an immune-modulator in oncology, – as a chemosensitiser, cervical cancer, brain tumours.

Memberships: European Society for Therapeutic and Radiation Oncology (ESTRO); International Clinical Hyperthermia Society (ICHS); South African Radiobiology Society; African Society for Hyperthermic Oncology (ASHO).

Awards: ESTRO: ctRO Yong Investigator Award (2021); ICHS: Clinical Excellence Award (2019); ESHO Young Investigators Award (2019)


How I got involved in hyperthermia (By Dr Carrie Minnaar)

I was first introduced to hyperthermia in 2009 when a patient of mine was treated in Germany with hyperthermia. Following the good response seen in the patient, I went to Germany to learn more about the use of hyperthermia in oncology. Internationally hyperthermia is widely used as an adjunct to chemotherapy or radiotherapy protocols with excellent results.

Hyperthermia was even done in South Africa 20 or so years ago, however the techniques used were crude and often invasive, very expensive, very demanding on resources, and carried high risks. This resulted in hyperthermia falling out of favour in South Africa. The newer technologies available internationally are however a lot safer, more affordable, and even more effective. One study by van der Zee and colleagues in the Netherlands even showed that hyperthermia added to radiotherapy for the management of locally advanced cervical cancer resulted in a cost saving of more than 3000 Euros a year. I felt very strongly that this treatment that resulted in a cost saving AND improved clinical outcomes was critically important in South Africa, especially in the resource constrained settings of our country. Therefore, when I returned home, I began working on plans to reintroduce hyperthermia to South Africa, using one of the newer devices.

After extensively researching the different devices, I decided the best device for our market is the modulated electro-hyperthermia device manufactured by Oncotherm. It is the safest device, and it is non-invasive and does not require temperature monitoring as a safety parameter. It is therefore exceptionally easy to administer and is perfect for our local healthcare system. To gain acceptance locally, we would have to show the clinical and financial impact in our unique setting. Fortunately, the staff at the Radiation Oncology Department at the University of the Witwatersrand were progressive and open to starting a clinical trial, and the manufacturer of the device supported the idea.

We therefore began planning our first trial at the Charlotte Maxeke Johannesburg Academic Hospital and the positive results over the years have helped us to campaign for the inclusion of hyperthermia in private practice. While at the University conducting the clinical trial, I was also able to complete my PhD in Radiation Sciences, focusing on the effects of hyperthermia on the response of healthy tissues and tumour tissue to radiation.

I have now been using hyperthermia for ten years and am fortunate enough to have international and local research collaborations and projects and have traveled all over the world to talk about hyperthermia and to train doctors on the device that I use – the Oncotherm device. I am still actively involved in research and clinical trials on the device, and we are even starting an in vitro research project at the radio-biology lab at the university. [SIC]

Summary of Dr Carrie Minnaar’s Research

When Dr Carrie started campaigning for hyperthermia in South Africa, there had not yet been any research on hyperthermia in South Africa, or in a low-to-middle-income country. Dr Carrie and her colleagues began the first phase three clinical trial on hyperthermia in South Africa. It was also the first trial to investigate the impact of hyperthermia in our unique demographic and in HIV positive patients.

The trial looked at modulated electro-hyperthermia combined with radiation and chemotherapy for the treatment of locally advanced cervical cancer at the Charlotte Maxeke Johannesburg Academic Hospital. The trial enrolled 210 women and followed them for five years after treatment. Several papers were published on the results of trial and some very important discoveries were made.

The team published the local disease control results at six months post treatment which showed that the tumour was completely resolved in 46% of the participants who had the hyperthermia treatment versus only 24% of the participants in the control arm. This means that the rate of local disease control was almost doubled.[1]

A further evaluation of the toxicity showed that modulated electro-hyperthermia did not change or cause more side effects from the chemotherapy or radiation. The side effects from the modulated electro-hyperthermia were very mild and included some localised pain during treatment, which was managed by changing the treatment settings, and in 10% of the participants painful nodules in the fatty tissue developed which were also easily managed and which did not stop the treatment. In comparison to the side effects from the radiation and the chemotherapy, the hyperthermia treatment was very well tolerated and caused minimal discomfort.[1]

The quality of life of the participants who were treated with hyperthermia was also improved: they had less pain and returned to normal functioning faster than the control participants. This was the case at three-, and six-months post treatment [2] and at two years post treatment the hyperthermia group still reported a higher quality of life than the control group [3].

A third paper analysed the response of tumours that were not in the pelvis: 54% of the participants in both groups had disease in lymph nodes outside of the pelvis, as well as in the cervix and pelvis. At six months post treatment, of the participants in the hyperthermia group had complete resolution of all the tumours, compared to 5.8% of the participants in the control group. This showed that the hyperthermia treatment is also able to assist the immune system to recognise the tumours cells and attack them, no matter where they are in the body. This is very important especially because more and more drugs are targeting the immune system and aim to promote immune recognition of malignant cells. [4] At three years post treatment, the participants who had complete resolution of all tumours in the hyperthermia group remained alive and well and disease free, except for one participant who passed away not from cancer or any cancer-related cause.[3] This led to further research on how modulated electro-hyperthermia affects the immune system. [5]

The three year follow up results showed that the rate of disease free survival was doubled in the group treated with hyperthermia plus chemotherapy and radiation, versus chemotherapy and radiation alone [4]. Finally , a cost effectiveness analysis at three years showed that there is potential for medical schemes and the government to save money with the inclusion of modulated electro-hyperthermia as the improved outcomes means less costs for the treatment of recurrences.[4]