Issues & Status of PET imaging in Ontario

Summary of findings relating to the status of PET imaging in cancer care across Ontario

There are a number of issues that are common to every province and impact the success of PET imaging across Canada. The following findings relate to the status of PET imaging and highlight the political underpinnings of clinical decision making in the province of Ontario.

Although the province has nine clinical scanners, Ontario funds just 806 scans per scanner – a number that places it far below the national average of 1,643 scans per scanner. When provincial scan numbers are calculated per million people, Ontario funds just 553 scans per million. This ratio places Ontario last among all provinces with PET scanners.

Interviews with physicians suggested the poor utilization may be the result of confusion among referring doctors about the current status of PET in Ontario (with regard to regulations, how to access PET scans and the current indications for PET) and a restricted list of PET scan indications. In contrast, the former Chairman of the PET Steering Committee, Dr. Bill Evans, believed the low utilization was the result of the appropriate use of PET imaging.

Moreover, there have been documented problems with the proper utilization of some PET scanners in the province, such as a low number of scans performed in the early stages of operation, delays in use after intallation, or dedication to research over clinical activities.

The ICES report (2001) has served as the foundation for all PET policies in Ontario, yet questions about the validity of the assessment tools used in the report persist a full decade after its findings were submitted. At the core of the issue are questions about the appropriateness of the health technology assessment (HTA) system used by the government in evaluating a diagnostic imaging tool such as PET.

This question was raised in the Journal of Nuclear Medicine by prominent Canadian nuclear medicine physician Dr. Sandy McEwan (McEwan, 2005). Using the Ontario situation as an example, McEwan stated “… HTA is a policy tool, often used to justify negative funding decisions, rather than a rigorous scientific methodology ... HTA algorithms have been assigned to assess the evaluation and efficacy of new drugs and medical interventions ... they are totally unsuited to the evaluation of the clinical importance of imaging tests.”

McEwan points out that one key outcome assessed by HTA is the survival benefit conferred by an imaging test, even though imaging tests are not designed to improve survival but to direct treatment planning and ensure that the best strategy is followed for the patient’s condition. Conversely, the HTA ignores the important role of imaging in “treatment planning and assessment of response, the reductions in downstream costs such as saved operations due to upstaging, and the contribution of imaging to diagnostic confidence.” Until these endpoints are incorporated in the HTA, McEwan – and, indeed, much of the nuclear medicine community in Ontario – believes that the results of the HTA of imaging modalities “will remain arbitrary and capricious."

Many nuclear medicine physicians that were interviewed claim that the procedures being evaluated by the clinical trials had already been widely accepted in other jurisdictions. As a consequence, they suggest it is unlikely that additional evidence from the Ontario trials would have any impact on the use of PET in other countries or provinces. In fact, one physician stated that, “the volume of literature showing evidence for PET is decreasing because the evidence is now accepted everywhere but in Ontario.”

  • The Ontario PET trials didn’t commence until 2004, whereas health care reimbursement for PET imaging had already been approved in the United States and United Kingdom for multiple forms of cancer.
  • Length of the trials have undermined the legitimacy of the PET clinical trials since new technology is constantly being developed and it is difficult to ensure that the technology used at the start of the trials is the same at the end.
  • Lack of available funding for the trials made it logistically impossible to recruit the required number of patients to complete the trial in a timely manner.
  • Clinical trials, such as PET PREDICT in 2005, have been accused of "violating fundamental research ethics" by designing "an experiment for which the instrument is incapable of performing". In this case using a resolution of PET that was not capable of detecting the vast majority of potential metastatic disease in the trial. In addition, patients were not informed this technicality nor that the data analysis tool itself (the HTA) had not been validated for the purposes of this trial. Consequently, patients went through the PET scan and were subjected to radiation to search for something that the PET scanner was not designed to detect. Many believe that this was a deliberate course of action taken by the MOH to delay the implementation of clinical PET scanning for Ontario cancer patients.

The Ontario Ombudsman was involved with two formal investigations into the government’s handling of funding for PET technology. The first was initiated at the request of Dr. David Webster, a Sudbury nuclear medicine physician and former head of the OANM. Dr. Webster asked the Ombudsman’s office to investigate claims of fundamental government process issues that were affecting Ontario cancer patients. Following a six-month investigation, the Ombudsman concluded that the government had addressed the concerns of Dr. Webster. But Dr. Webster did not receive a copy of the letter wherein the government supposedly addressed the concerns. In answering Dr. Webster’s questions about what exactly the government had done to resolve his concerns, the Ombudsman told Dr. Webster that all responses were protected by the Privacy of Information Act.

The rational introduction of PET into the Ontario system can only be accomplished by looking at all tests performed on a cancer patient and effectively establishing an algorithm describing the most appropriate pathway to obtain information. However, Ontario’s guidelines for funding PET do not always allow for such logic.

In lung cancer patients, for example, Ontario PET funding guidelines currently dictate that a lung needle biopsy be done first to determine if the patient is a candidate for a PET scan. The lung needle biopsy is a high risk procedure that involves sticking a needle into the chest. It is not uncommon to result in collapsed lungs or bleeding that can lead to hospitalization or even immediate surgery to control bleeding.

  • Oncologists – Interviews and the apparent low number of referrals for PET scans suggest that oncologists are unlikely to join nuclear medicine physicians to advocate for more PET technology and better use of existing technology. The oncology community seems to be more interested in obtaining new therapeutic agents than new diagnostic tools. Any money spent on PET comes from the same budget that funds treatments and drugs for cancer patients. In addition, many oncologists are familiar with the use of evidence-based medicine to prove the efficacy of cancer therapies and believe that PET imaging technology should be judged according to that standard. However, evidence-based medicine cannot properly validate PET because it is a diagnostic imaging test, not a treatment that directly impacts patient survival. Without proof that PET improves patient survival, oncologists remained unconvinced of its benefits.
  • Radiologists – There is discord among radiologists relating to the dual nature of the hybrid PET/CT technology. Nuclear medicine physicians are not all trained in reading CT scans and therefore require a radiologist to read the CT portion of the scan. Conversely, most radiologists are only minimally trained to read PET images and, in theory, require a nuclear medicine physician to read that portion.
    Billing practices also appear to be a point of contention between nuclear medicine specialists and radiologists. Some worry that radiologists are attempting to enhance their incomes by restricting the emergence of newer PET technology so they can focus on reading more lucrative CT and MRI scans. One physician estimated that radiologists can read (and be paid for) about 30 to 40 CT scans per day. In contrast, they can probably only read 10 to 15 PET exams per day. Therefore, an increased emphasis on PET imaging would substantially reduce the income of radiologists. According to one physician, "It’s all about billing," while another commented, "If the public knew about the turf wars, they would march all the doctors off the end of the gangplank."

Nuclear medicine physicians in Ontario are very frustrated by that province's restrictive policies toward PET scanning. This frustration has grown over the years as the PET clinical trials have continued while increasingly positive data on PET has been presented – and accepted – in jurisdictions around the world. As a result, nuclear medicine specialists have now become more vocal in discussions with the media and politicians in an effort to increase the penetration of PET scanning in Ontario.

This summary contains excerpts from "Positron Emission Tomography (PET) for Cancer Care Across Canada: Time for a National Strategy", Susan D. Martinuk (2011).

© 2011 AAPS, Inc. and TRIUMF

Reproduced with permission.