Daniel B Brown, professor of Radiology and director, Interventional Oncology, Vanderbilt-Ingram Cancer Center, Nashville, USA, puts together a 2015 checklist on the latest portal vein embolization developments for Interventional News readers. He also presented on the subject at the Symposium of Clinical Interventional Oncology (CIO, Hollywood, USA). “The rationale for portal vein embolization rests on patient survival. It is a procedure that involves collaboration with surgical and medical oncology and is a simple procedure with demonstrable benefit and minimal recovery,” noted Brown.
- Portal vein embolization increases the number of patients who can undergo surgery compared to prior decades when this technology was not available. Patients who have a liver remnant that would be too small after surgery [ie, those who need portal vein embolization before subsequent surgery] catch-up and do every bit as well as patients who do not need portal vein embolization in order to undergo curative resection. So, if the liver remnant after embolization grows enough that they are able to go on to surgery, at that point their outcomes are the same as the people who did not need portal vein embolization in the first place. The ability to rapidly expand the future liver remnant is gaining traction as the best evidence of surgical tolerance. (Shindoh J, et al, Journal of Gastrointestinal Surgery, 2014 and Leung U, et al, Journal of the American College of Surgery, 2014)
- The number of patients getting operated on for liver cancer currently are getting more chemotherapy than they were before and are, in general, older and sicker than they were before. Yet, they have the same outcomes, including for portal vein embolization, so what we are doing as interventional oncologists is working. We help the surgeons operate on heavily pretreated patients with more morbidities than in years past. Part of this is due to improved surgical and postoperative care, but this is also due to the ability to get patients to surgery by portal vein embolization.
- Some technical details regarding the procedure that are important: the patient should be on chemotherapy almost immediately after treatment as it does not prevent the future liver remnant from growing. (Fischer C, et al, Journal of the American Medical Association Surgery 2013)
- Secondly: beyond the use of particles alone for portal vein embolization, the supplemental use of coils or plugs limits the risk of recanalisation of the portal vein after embolization with particles. (Malinowski M, et al, Journal of Surgical Research; in press)
- In terms of interest, there is a preliminary paper from the Mount Sinai group in New York, USA, looking at the use of sodium tetradecyl sulfate foam as an embolic agent for portal vein embolization, rather than particles. It is early work, the first 35 patient, but there pretty good outcomes with the patients. (Fischman AM, et al, Journal of Vascular and Interventional Radiology 2014)
SIRFLOX study results
“Trying to incorporate locoregional therapies into existing paradigms remains challenging. Interventional oncology needs to position itself as complementary to other treatments, similar to how radiation and chemotherapy are combined for some diseases,” said Brown. With that in view, he is looking forward to the results of the SIRFLOX study.
SIRFLOX is a multicentre randomised controlled study that will assess the effect of adding targeted radiation, in the form of SIR-Spheres to a standard chemotherapy regimen of FOLFOX6m as first-line therapy in patients with non-resectable liver metastases from primary colorectal carcinoma. Data will be analysed to establish whether the primary endpoint of the study has been reached by around the third week of March 2015. It is expected that the final results of the SIRFLOX study will be submitted to and presented at the 2015 American Society of Clinical Oncology (ASCO) annual meeting in Chicago in June 2015.
Brown said: “This is the type of large, randomised controlled study that, if positive, could change the role of liver directed therapy for patients with metastatic colorectal cancer. While I do not know the outcome of the SIRFLOX study (At the time this issue went to press, the results of the SIRFLOX study were unknown) I am hoping that this will show that the addition of Y-90 either at the end of first-line for consolidation, at the beginning of first-line, or at the beginning of second line therapy (as they are trying in the EPOCH study) will show benefit. It is important to see interventional oncology techniques being combined with traditional therapies; that will be a lot of the future.”