Adam, London, UK, who has been president of every major radiology and interventional radiology association in Europe, including CIRSE, the European Society of Radiology and the Royal College of Radiologists, proposed that an alliance with radiation oncology would benefit both interventional radiologists and radiation oncologists: “the radiation oncologists would gain a ‘surgical arm’ to their armamentarium and the interventional radiologists would gain access to the infrastructure and resident medical staff that they need to look after their own patients.” he said.
“I believe that radiation oncology and interventional oncology are natural partners. They both undertake local treatment, albeit by different means, use imaging quite heavily, have research themes in common (such as the enhancement of outcomes by combining with chemotherapy), and there are procedures such as radioembolization and brachytherapy for cholangiocarcinoma that need the skills of both the radiation oncologist and the interventional oncologist.
“We must not forget that radiology and radiation oncology have a common origin and that, in some countries, these specialties are represented by the same Royal Colleges. These colleges have a great opportunity to facilitate collaboration between these disciplines to the benefit of both. Each may have lessons for the other. The sophisticated imaging techniques that are currently used in image-guided radiotherapy may find useful applications in the planning of ablation. There is potential for cross-training in carefully selected areas and opportunities for clinical collaboration. This would have substantial advantages for interventional radiologists in particular as they would gain access to infrastructure and the staff and that they need to look after their own patients,” he said.
Adam began his lecture, titled “Treating cancer in the transparent patient” by pointing to a slide depicting minimally invasive surgery in the 11th century. He explained that at that time, most organs were “out of sight and out of reach”. “[But] our patients have been made virtually transparent by modern imaging techniques and almost every organ in the body is within the reach of the interventional radiologist,” he said.
Role of surgery in 21st century cancer care
Adam told delegates that interventional oncology faces quite a challenge if it wants to join surgery, radiotherapy and chemotherapy as the fourth pillar in the treatment of cancer. “Surgery, quite deservedly, has a permanent role in oncology it is the only method that can remove an organ and the draining lymphatics. It is the most appropriate treatment when dealing with large tumours when local resection with adequate margins is possible. But science does advance and the boundaries between disciplines do shift. Therefore it is certainly appropriate and necessary to ask questions such as ‘is surgery still the most appropriate first-line treatment for dealing with small tumours in solid organs, which can be treated by ablation? What is the role of pre-operative volume reduction with chemotherapy in solitary tumours? What about in multiple tumours? Is surgery appropriate if there are synchronous pulmonary and hepatic metastases? Is a large margin always necessary?’ These questions arise out of data that raise them.”
He noted that percutaneous ablation has some advantages over surgery: it is more precise, so there is minimal destruction of normal parenchyma, which makes it possible to destroy multiple tumours. Also, because the energy is applied “inside/out”, and does not have to traverse adjacent structures, the risk of collateral damage is reduced.
Challenges facing interventional oncology
Adam illustrated some of the key, scientific challenges facing interventional oncology. “We have to understand tumour biology better than we do today if we really want to work out precisely which aspects of surgery can be safely replaced with interventional techniques. We need to understand the limitations of local treatment, and the role of adjuvant and neoadjuvant chemotherapy. And a lot of research has to be carried out into synergy with radiotherapy.”
Interventional oncology started with palliative procedures, but today in some instances it can replace surgery, he said. He drew attention to the “potentially curative” procedures such as tumour ablation, selective internal radiation therapy and chemoembolization. “These are potential game changers that require the creation of new patient pathways, encourage direct referrals of new patients and invite comparison of outcomes and costs with alternative methods of treatment.”
As an example, he spoke about surgery looking increasingly inappropriate for the management of small renal tumours which are <2cm. “Solitary kidney lesions suspected to be renal cell carcinoma are malignant by final pathology in only 60% of cases. Small-sized renal cell carcinoma lesions are mostly low (1–2) grade. There is a possible overtreatment of small suspicious lesions that may be adequately treated with less-invasive modalities. However, active surveillance does not appear to work very well either, as lack of growth does not indicate benignity. Seventy five per cent of tumours grow under surveillance and 40% of patients crossover to resection. So ablation is coming into its own [in this type of cancer],” he said.
Adam shared Breen et al’s as-yet unpublished data, which was an outcome analysis of 139 consecutive renal tumours in 118 patients treated by percutaneous cryoablation. Breen et al achieved successful ablation in 91.3% in a single session, successful repeat ablation in 6.5% of cases, and subtotal ablation in 2.2% of cases. A single late local recurrence at 12 months has been retreated. “These are really excellent results and make a strong case for a prospective comparison between cryotherapy and nephron-sparing surgery,” he said.
Adam said that there are four factors that determine who does what in practical disciplines such as surgery and interventional radiology: quality and quantity of research, quality of training, the number of practitioners in the field and clinical control of patients.” He further explained: “There is no doubt that interventional radiologists need to do more research and better research”. He said that training is improving, with subspecialty recognition of interventional radiology in some countries, such as the UK. He believes that accredited training in interventional oncology should be considered, within interventional radiology. “We need a special model of the interventional oncology curriculum that should focus on interventional radiology procedures and equipment and also a detailed understanding of the relevant imaging. Most importantly, it should incorporate the basics of chemotherapy and radiotherapy. This is necessary if interventional oncologists are going to look after their own patients, because they must be in a position to explain the advantages and disadvantages of other methods of treatment.”
Adam also dwelt on the importance of interventional radiology undertaking primary clinical responsibility for their own patients on the same basis as any other clinician, and noted that in the UK obstacles to this pattern of practice were disappearing.
He noted that interventional oncology was a fast-developing field that was seeing advances in equipment, improvements in imaging guidance, the emergence of novel therapies and several combination treatment methods with radiotherapy and chemotherapy that were appearing along the horizon.
“Imaging is the heart of what we do. Developments such as instant 3D CT and appropriate software for planning are enabling us to deal with tumours much more effectively than in the past. The combination of structural and functional imaging is making it possible for us to deal with recurrent tumours at an earlier stage. Novel therapies such as microwave and irreversible electroporation are overcoming current limitations. There are also new concepts, enhanced by interventional radiological techniques, such as nanotechnology for ablation and oncolytic viral therapy. Combination treatments are very exciting and combination with chemotherapy or radiotherapy may enable larger areas to be ablated, result in a decreased rate of recurrence and a reduction of complications, for example, less damage to adjacent structures,” he said.
“We have already replaced some brutal and primitive techniques with elegant interventional radiology methods. This trend will accelerate, and in a few short years interventional oncology will be firmly established as the fourth pillar in the treatment of cancer,” he concluded.