Interventional oncologists tread new ground with focal control

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Afshin Gangi

As interventional oncologists embrace their growing clinical role and claim their place on multidisciplinary oncological teams, focal therapy is becoming an important part of their practice, writes Afshin Gangi, Strasbourg, France. Gangi will be made an Honorary Fellow at the 2015 British Society of Interventional Radiology (BSIR) annual meeting.

 

Working collaboratively within a multidisciplinary team and refining and extending our indications has transformed the interventional oncological management of tumours. While palliation remains a major part of interventional oncology care, focal control has created new avenues for our role in curing tumours. This is true for interventional oncologists on multidisciplinary teams treating cancer in the musculoskeletal system, liver, lungs and kidneys.

Our work within multidisciplinary teams with specialties including surgeons, radiotherapists and oncologists enables us to treat patients with multiple metastases. Within such a team, while one of the other specialties might take care of some of the metastases, we, as interventional oncologists could use focal control to take care of other metastases and treat these as if they were the primary tumour. With this multidisciplinary collaboration, we have seen several patients who have long periods of survival and remission from the disease. While they are not cured, they still have long palliative remission. Patients with neuroendocrine tumours are a good example of those who have long periods of remission with their cancer under control.

Before, each physician on the team involved in cancer care was thinking only in terms of radiotherapy, or surgery, or interventional radiology, or medical oncology. Now, we are doing a lot more multidisciplinary work. As an interventional oncologist, I am part of an overall plan of care. For instance, for many patients, I might focally remove a part of a tumour and then refer the patient for further radiotherapy or consolidation with a surgeon. We have changed our approach substantially in this regard and it is of real benefit to the patient.

Our oncological colleagues are increasingly asking for the presence of interventional oncologists on these tumour boards, and we need many more interventional oncologists to join these boards.

However, with greater power, there is greater responsibility and therefore, it is also very important that interventional oncologists are appropriately trained in a clearly drawn up curriculum and that there is quality control in interventional oncology. The Oncology Alliance Subcommittee (OAS) of CIRSE, chaired by Andy Adam, (King’s College London, UK) is in the process of creating both an interventional oncology curriculum and a quality assurance framework, both of which are essential to our practice and patient care.

Tumour management has rapidly evolved and we have extended our ablation indications, particularly in larger and benign tumours. Speaking particularly in the case of bone and spinal metastases, we used to manage pain using cement, but today, radiotherapists ask me to consolidate bone and also to kill the pain. If the tumour is too extended, I have to first treat the pain, then fix the fracture and then transfer the patient for radiotherapy in the oncology department where they take care of the borders of the tumour and treat the cancer. Or, if I do an ablation and am unsure if my margins are optimally ablated, after consolidation and pain management, I transfer the patient to radiotherapy to extend my margins. In patients who have spinal metastasis from myeloma for instance, in the majority of patients, interventional radiology techniques do not treat the myeloma itself. What I do is treat the pain and consolidate the bone and then the radiotherapist can take care of the cancer. This approach of using cementoplasty followed by radiotherapy dramatically reduces the risk of pathological fracture. The risk of collapse after radiotherapy alone in myeloma patients with spinal metastases is very high, because the response to treatment is and the vertebrae become empty, making the risk of fracture higher. The value of cementoplasty is that the analgesic effect is also very fast. In 24-48 hours we have a result and this makes the two techniques very complementary. This multidisciplinary approach also works with surgery; in a patient with long bone metastases like femoral metastases for instance, surgeons have considerable difficulty in removing a tumour that is extremely aggressive. In such a case, interventional radiologists can carry out a large ablation of the bone tumour that is a focal control of the tumour.

However, in these cases I cannot achieve perfect consolidation percutaneously. The materials on the market today are not satisfactory for long bone, so my goal is to carry out tumour management and then refer the patient to orthopaedics. Orthopaedic surgeons can then carry out a rod installation very easily and it is about twenty minutes work. So in this type of collaboration, we kill the tumours and they consolidate the bone. These innovative multidisciplinary ways of collaboration are very interesting and extremely beneficial to the patient.

Growth of embolization

We also use multiple interventional radiology techniques for musculoskeletal intervention. For instance, it is becoming increasingly common to use embolization. Patients with bone metastases now survive for much longer as the cancer in these patients is very well controlled by oncologists. However, the patients who do not respond well to chemotherapy are referred to us for focal control. In hypervascular tumours, such as neuroendocrine metastases, we increasingly use embolization because the hypervascularity of these tumours makes ablation a challenge due to the heat sink effect. In these cases, we do a previous particle embolization, reducing the vascularity of the tumour and then do an ablation for focal control afterwards which results in a larger ablation zone. Often, we use multiple techniques in the same patient and seek to achieve more, but the size of the tumour is still a limiting factor. In patients with multiple metastases, the oncologists might take care of the liver metastases, and interventional radiology will “curatively” take care of bone metastases, so while we do not cure the patient of their cancer, together with other specialties, we achieve better focal control.

Important techniques

Cryoablation is a very effective modality for bone tumours. Another promising new technology is focused ultrasound. Recent data from a retrospective study we have carried out has shown that just over 40% of cancer patients can be treated with this technique both for pain management and with a curative intent without any aggression of the skin. However, high-intensity focused ultrasound is a difficult procedure, is expensive and has to be done under MR, which is not available widely. If we can combine the lessons learned by interventional radiologists from other modalities such as radiofrequency ablation with the use of focused ultrasound, we can increase the number of patients we can treat while using the latter modality. Currently 59% of patients cannot be treated with high intensiy focused ultrasound, as their tumours are too near nerve roots (or near the bowel, or spinal cord). But if we use our clinical experience of using radiofrequency to better control the thermal diffusion in this technique, we can prevent potential complications in these patients with difficult-to-treat tumours. We can dissect, push the organ away, use the insertion of a needle to increase the gap between the colon and the tumour, and use infusions to protect vital organs and structures, thus increasing the pool of patients who can be treated using this technique. As clinicians, interventional oncologists are becoming adept at applying the right modalities, at the right moment, on the right patient.

 

When I first began medicine and my residency, every patient with bone metastases did not have a hopeful prognosis. Today, it is really not the same, now I can tell the patient that they are more akin to a patient who has a chronic disease, such as diabetes. The patient has to come and see me regularly and I sometimes have to carry out  an invasive procedure.

Afshin Gangi is the lead in Oncological Interventional Radiology, King’s College London, London, UK, Head of the department of Interventional Radiology, Université de Strasbourg, Strasbourg, France and chairman of Radiology and Nuclear Medicine, CHU Strasbbourg. He has reported no disclosures pertaining to this article