New opportunities for hyperthermia in oncology
An interview with Professor Stephan Bodis, Congress President of the "European Society for Hyperthermic Oncology" and director of the Radiation Oncology Centre of the Cantonal Hospitals of Aarau and Baden, Switzerland.
Although hyperthermia, the heat treatment of tumour tissue, has been practiced for many decades, it is still on the periphery in the range of cancer treatments. Now technical advancements and promising clinical trials could enhance knowledge of hyperthermia treatment in the future among physicians and patients. The new developments are also the focus of the 30th Annual Meeting of the "European Society for Hyperthermic Oncology" (ESHO) taking place on 24-26th June 2015 in Switzerland (Zurich and Aarau). The Congress Presidents are Professor Niels Kuster (ETH Zurich and IT'IS Foundation) and Professor Stephan Bodis.
PRIMO MEDICO: Professor Dr. Bodis, what new possibilities have arisen, for example, through the development of medical devices?
Prof. Bodis: Using a new digital generation of devices with the new control options, you can, for example, control the intensity of heat better and also use a more targeted approach. As an example, there is a so-called "feedback loop" that says what the temperature is in the tumour itself and then, if necessary, initiates an automatic correction. This concerns the delicate issue that the heat must be dissipated quickly through the perfusion of the tissue. Therefore, everything hinges on the exact measurement of the spot or at least in the vicinity of the tumour. These thermo probes can be placed directly into the tumour. The semi-invasive form, however, is pleasant for patients in whom the probes are placed in body cavities: with pancreatic cancer, they are placed in the bile duct, the duodenum and the stomach for example. Very promising, but not yet fully developed, is magnetic-based temperature measurement, with which it is possible to create a sort of heat map. There is already a device on the market, but it still has some "teething problems". But I assume that we will achieve a significant advance that will be seen by patients within two years with a second generation of devices.
PM: What progress has been made for hyperthermia in the software field?
Prof. Bodis: We urgently need to get to where we already are in radiation oncology. That is to say, we want a precise anatomical and metabolic image of the tumour situation, we want to have a software-planning simulation, with which we can consider different plan versions in advance and then create a customised treatment plan. This would have to be discussed and selected in an interdisciplinary fashion. It would also provide the opportunity for these therapeutic plans to be constantly checked and updated during treatment. Some of these components are already in use in Europe in new systems.
PM: What findings have the latest studies revealed?
Prof. Bodis: There has been good data from different clinical studies in recent years, but these data were ignored for much too long. There are some leading oncology journals that have considered the field of oncological hyperthermia. And there are meta-analyses that summarise and analyse all clinical trial data available. I want to refer to a recent publication in "Cancer Treatment Reviews", written here in Aarau by Professor Dr. Med. Niloy Datta with an international team. He has searched across all tumour organs for already published study data available that demonstrates that hyperthermia can make a difference, primarily for the local control of the tumour, but also for the survival of the patient. We are finally aware that we must use what has already been published to communicate better.
PM: Where do new studies begin in your opinion?
Prof. Bodis: There are three ways to use hyperthermia in combination with radiotherapy for improved local control of the tumour: There are also developments that are rarely used at present or have not yet gone beyond the stage of clinical or even pre-clinical studies and require further investigations, such as the use of thermosensitive liposomes or nanoparticles in which the heat is transported directly to the "place of need" and released there first. There are still very few studies in this area. A separate clinical study that we are planning for the early autumn concerns pancreatic cancer, pancreatic carcinoma, one of the most lethal tumours in adults. It is often discovered at a stage where a surgical procedure is very difficult or no longer possible. Here we will compare the best chemoradiotherapy with and without hyperthermia treatment. Another separate study involves confirmation of the data that is already available: the treatment of patients with advanced locally invasive bladder cancer whose only option is often the removal of the bladder while installing a replacement bladder. So far we have seen seven patients treated with hyperthermia combined with chemoradiotherapy and all patients are free of tumours to date. However, the course of observations is still very short. The scientific fact is that we need more information and a longer observation period so that we can make more use of these results.
PM: Why does hyperthermia lack the support of a lobby?
Prof. Bodis: Hyperthermia is a niche therapy. Heat treatments are instinctively more commonly associated with the wellness and wellbeing therapies. And it is a form of therapy that for a long time did not develop its technical possibilities fully. This has to do with the fact that there are too few research groups for hyperthermia to be taken up full-time. Therefore, we have no national lobby wanting to work with hyperthermia and that is strong enough to promote this issue internationally.
PM: How do the new findings affect the patient?
Prof. Bodis: A hyperthermia session takes a long time and the patient sweats due to the elevated body temperatures of 39-43 degrees Celsius. In the future, it is conceivable that one could work with smaller volumes and lower temperatures. Use of the biological profile of the tumour and the patient as well as modern software and hardware would also help. Key words concerning these therapy applications are "personalised hyperthermia" and "adaptive hyperthermia", which are constantly trying to achieve the dose that is optimal for these patients.
PM: Is it conceivable that hyperthermia could be routinely integrated into future treatment plans for cancer patients?
Prof. Bodis: In certain indications, hyperthermia, always combined with radio and/or chemotherapy, is already part of the routine treatment, for example in the Netherlands and Germany and with some reservations in Switzerland. What could soon become widespread is re-treatment with hyperthermia and radiation at the chest wall in the recurrence of breast cancer and for rectal cancer. The primary use of radiation and chemotherapy is routine in advanced anal cancer, advanced cervical cancer, advanced bladder cancer or certain head and neck cancers. Basically whenever radiochemotherapy alone is not enough for a cure. In my opinion, improvements in thermometry and planning software are key for the future. Without accurate representation of what we do, its credibility still has some difficulties. The surgeon can naturally explain how they will operate. Similarly, we need to create treatment plans and demonstrate how we use hyperthermia to treat our patients in an understandable manner. We believe in the "tumour boards", i.e. interdisciplinary case conferences. Here we increasingly demonstrate and discuss hyperthermia plans. This is the key to acceptance.