Source: www.medscape.com
Authors: Zosia Chustecka, Désirée Lie, MD

Scanning with positron emission tomography (PET) scanning has an impact on the intended management of patients with cancer in approximately one third of cases, and new data suggest that this impact is consistent across all cancer types.

The results come from the National Oncologic PET Registry (NOPR), and the latest data are reported in the December issue of the Journal of Nuclear Medicine.

“Although the effectiveness of PET may differ somewhat between individual cancers, it’s in the same ballpark,” says coauthor Barry Siegel, MD, professor of radiology at Mallinckrodt Institute of Radiology in St. Louis, Missouri. “This result was a little unexpected, but it leads us to believe that a continual parsing of PET’s usefulness, cancer by cancer and indication by indication, for purposes of reimbursement does not make clinical sense.”

At present in the United States, the Centers for Medicare & Medicaid Services (CMS) restricts the reimbursement of PET scans for only 9 cancer types. The cancers that are covered include non–small-cell lung cancer, esophageal cancer, colorectal cancer, head and neck cancer, lymphoma and melanoma (all for diagnosis, staging, and restaging), breast cancer (for restaging and treatment monitoring), thyroid cancer (for restaging under very specific circumstances), and cervical cancer (for initial staging if conventional imaging result is negative for extrapelvic metastasis).

NOPR was launched in 2006 in response to a proposal from the CMS to expand coverage for PET to other cancers. In this registry, patients are covered under the CMS evidence development program to undergo PET scans for many other cancers and indications, including cancers of the ovary, uterus, prostate, pancreas, stomach, kidney, and bladder. The latest results show that PET has a similar impact across all of these cancer types. Although there was some variation, particularly a high impact on multiple myeloma, the differences across the cancer types were not statistically significant, and overall there was an impact in 38% of cases.

“We found that it did not vary significantly, and that the changes in treatment plans for rare cancers — such as stomach cancer — clustered around the same one-third mark as the more common cancers,” said lead author Bruce Hillner, MD, professor of medicine at Virginia Commonwealth University in Richmond. “As a result, we believe that the coverage for PET in the staging, restaging and detection of recurrent cancer should be handled the same across the board,” he said in a statement.

“The data from NOPR as well as from other studies, the totality of the PET literature in cancer, show that it is a very effective tool for imaging in cancer, and that it should be approved broadly,” Dr. Siegel said in an interview with Medscape Oncology. There is no restriction on the use of computed tomography or magnetic resonance imaging by cancer type, he pointed out, and the use of PET scanning across all cancer types “is just as logical,” he added.

“Basically, what we were trying to do is to inform CMS policy,” he explained. “We wanted to collect data to show that, if you were thinking of picking and choosing, then you should cover this cancer and maybe not this one, but the truth of the matter is that when you look at the data it’s hard to say what to include or exclude,” he said. “Our recommendation is to include all cancers. PET is as mature a cancer imaging tool as CT and MRI, and I just don’t understand why we don’t have a level playing field.”

The CMS is expected to decide on the reimbursement of PET scans in other cancers soon. A draft is expected on January 10, 2009, and after another public comment period, the final National Coverage Determination will be made on April 9, 2009.

Dr. Siegel told Medscape Oncology that he was cautiously optimistic. “Our sense is that the CMS has a good understanding of our data, and I think there will be some additional coverage, and I have my fingers crossed for global coverage.”

Changes in Intended Management After PET Scans

The latest report assessed the impact of PET for 18 cancer types, none of which are currently on the list for CMS reimbursement. This study looked at 3 distinct indications: initial staging, restaging, and detection of suspected recurrence. Only patients who had pathologically confirmed cancer were included; hence, this study excluded the use of PET for diagnosis. It also excluded patients in whom PET was being used to monitor response to chemotherapy or radiotherapy (this indication has also been studied in NOPR, and results have recently been published online in Cancer).

Table. Impact of PET Scanning on Intended Management of Cancer

Type of Cancer No. of PET Scans % Cases With Change in Intended Management
Prostate 5309 35.1
Ovary 4509 41.4
Bladder 3578 37.8
Pancreas 3314 39
Stomach 2025 36.9
Small-cell lung cancer 2983 41.2
Kidney 2877 35.8
Uterus 2869 36.5
Myeloma 1784 48.7
Connective tissue 1350 36.4
Nonmelanoma skin 1057 31.4
Liver and intrahepatic bile ducts 1038 42.9
Cervix 984 32.7
Gallbladder 806 39.7
Other female genitalia 709 37.1
Thyroid 629 35.6
All other 4042 36.6
TOTAL 40,863 38.0

As a result of seeing the PET scans, clinicians changed their intended management of the cancer as follows:

* From nontreatment to treatment in 30% of cases
* From treatment to nontreatment in 8% of cases
* Change in goal from curative to palliative (or vice versa) in 14% of cases
* Change to supportive care or observation in 15.1% of cases
* Major change (eg, from surgery to chemotherapy) in 8.6% of cases
* Minor change (eg, addition or deletion of a mode of therapy) in 23.3% of cases

“We believe that the NOPR results show the impact of PET to be strikingly consistent for a wide range of cancers,” the researchers conclude. “Accordingly, the use of PET in management for patients with known cancer should not be restricted by cancer type or testing indication.”

Several recent publications have confirmed and validated these findings, Dr. Siegel commented to Medscape Oncology. In particular, several multicenter prospective trials have been conducted in Australia (J Nucl Med. 2008;49:1451-1457, 1593-1600) that provide “very strong process validation” of our data from the registry, he said.

Funding for development of NOPR was provided by the Academy for Molecular Imaging, but the registry is otherwise self-supported by fees paid by participating PET facilities. Dr. Siegel has disclosed equity ownership and serving on the medical advisory board of the Radiology Corporation of America and has received lecture honoraria from PETNET Pharmaceuticals Inc and Philips Medical Systems Puerto Rico.

Source:  J Nucl Med. 2008;49:1928-1935.

Clinical Context

PET assesses regional glucose metabolism and has been used widely for imaging in patients with cancer. Currently, the CMS in the United States provides coverage for its use for 9 malignant tumors.

The NOPR was developed to collect data on the clinical usefulness of PET to meet requirements for evidence-based coverage of PET. This is a report of data collected during 2 years from the NOPR to examine the frequency of change in cancer management associated with PET use.
Study Highlights

* The NOPR collected data from the PET facility, treating clinicians, and interpreting clinicians during 2 years, including indication for testing, patient’s cancer type, patient’s performance status, and the clinician’s management.
* Clinician’s intended management was dichotomized as either treatment (such as surgery, radiation, or chemotherapy) or no treatment (such as observation, biopsy, or supportive care).
* A change in management was defined as change from treatment to nontreatment or vice versa.
* These approaches also assessed how often the intent of planned therapies changed from curative to palliative or vice versa, or in the type or number of therapies planned.
* Only patients with histologically confirmed cancers were included, who were undergoing PET for initial staging, restaging, or detection of suspected recurrences.
* Excluded were cases for which PET was used for cancer diagnosis or monitoring therapy.
* Primary outcome was the impact of PET on clinician management overall and by cancer type.
* The final cohort consisted of 40,863 scans performed on 34,536 patients.
* 14,365 were for initial staging of newly diagnosed cancer, 14,584 for restaging of cancer after treatment completion, and 11,914 for the evaluation of suspected recurrence of a previously treated cancer.
* Mean patient age was 72.4 years, 50% were men, and 88.2% had a performance status of 0 or 1.
* The summary cancer stage before PET was judged as no evidence of disease in 12.0%, locoregional disease in 33.5%, metastatic disease in 29.4%, and unknown in 25.1%.
* Overall, PET led to a change in intended management from treatment to nontreatment or vice versa in 38.0%.
* Among the 13.6% with 2 PET scans, the frequency of change in intended treatment was slightly higher vs the second scan (39.2% vs 36.2%).
* Among those with 3 or more scans, the value for the third and other scans was 34%.
* There were 16 cancer types.
* The frequency of a change in intended management by cancer type ranged from a low of 31.4% for nonmelanoma skin cancer to a high of 48.7% for myeloma.
* The change in management differed significantly for 7 of 16 cancer types.
* The cancer-specific values varied little, from a low of 9.6% for nonmelanoma skin cancers to 16.2% for ovarian cancer.
* Only for myeloma did PET have a significantly greater impact on intended management vs other cancers.
* Myeloma was the only cancer type among those 7 with an OR notably different from 1.0.
* Change from nontreatment to treatment was substantially more likely than the converse (30.0% vs 8.0% overall).
* A change in goal of treatment, from curative to palliative or vice versa, occurred in 14.1% overall with limited variation by cancer type.
* In 15.1% of cases, when treatment was planned before PET, change to supportive care or observation occurred most frequently after cancer of the kidney and least often after female genital cancers.
* A major change in planned treatment occurred in 8.6% of cases overall, most often in tumors of the liver and intrahepatic bile ducts and least often in myeloma and nonmelanoma skin cancers.
* The impact of PET was greater for detection of suspected recurrences (OR, 1.56) vs initial staging or restaging.
* Patients with myeloma and ovarian cancer were more likely and those with kidney cancer and stomach cancer were less likely to have a change in management after PET.
* The authors concluded that the impact of PET on intended management was consistent for a wide range of cancers and recommended that use of PET not be restricted to some cancer types.

Pearls for Practice

* Use of PET for patients with confirmed cancer is associated with change in intended management in 38% of cases.
* Frequency of change in management after PET does not vary by cancer type and is highest for myeloma and for cancer recurrences.