PET Imaging in Breast, Non-Small Cell Lung, and Prostate Cancer

Evidence supporting the use of PET scanning for a wide variety of tumor types is accumulating.¹ As such, the utilization of this imaging modality is growing. According to a study examining the use of imaging procedures from 1999 to 2006 among Medicare beneficiaries with cancer, the utilization of PET scans increased markedly more than other imaging techniques (e.g., CT scan, MRI, etc.) during this time period. Specifically for breast, lung, and prostate cancers, the annual percentage increase was 54%, 36%, and 41%, respectively.² Since this study assesses PET utilization patterns up to the year 2006, it would be interesting to observe more recent practice trends with the use of PET imaging in these tumor types.

To obtain some preliminary insights regarding the utilization of PET imaging for monitoring therapy in various tumor types, the National Comprehensive Cancer Network® (NCCN®) surveyed attendees at the 2011 NCCN 16th Annual Conference. This NCCN Trends Survey™ was conducted from March 10-11, 2011, and a convenience sample of 225 conference attendees responded to the survey. Figure 1 depicts the distribution of the types of providers who responded to the survey. Respondents mainly consisted of physicians (n = 100), followed by nurses (n = 67), pharmacists (n = 28), and other types of clinicians or non-practicing clinicians (n = 30). Survey participants were asked to rate how often they utilize PET scanning to monitor therapy in patients with breast, non-small cell lung, and prostate cancers.

For breast and non-small cell lung cancers (NSCLC), survey participants were asked to rate how often PET imaging is utilized to monitor therapy for patients in four different settings: neoadjuvant, adjuvant, first-line metastatic, and second-line metastatic. For prostate cancer, three settings were assessed: neoadjuvant, first-line metastatic, and second-line metastatic.

It appears that the use of PET imaging was mostly consistent among settings for patients with breast cancer (Figure 2). About 80% of respondents indicated that the method was utilized to monitor therapy "sometimes" or "often" for the neoadjuvant, adjuvant, and first-line metastatic settings. This dropped to about 70% for the second-line metastatic setting. In the NSCLC setting, 63% and 56% of respondents "sometimes" or "often" used PET to monitor therapy in the neoadjuvant and adjuvant settings, respectively (Figure 3). Use was slightly higher among those with metastatic disease; 77% and 67% responded this way for the first-line and second-line metastatic settings, respectively. Lastly, it appears that PET imaging was least likely to be used in the prostate cancer setting (Figure 4), with close to half of respondents indicating the test is never performed in each of the three settings (neoadjuvant , first-line metastatic, and second-line metastatic).

Overall, the survey indicates that the utilization of PET imaging for monitoring therapy varies according to tumor type. This is not surprising given the evidence supporting the use of PET varies between tumor types. The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines™) discuss the clinical utility of PET scanning in the diagnosis, staging, and monitoring of therapy in patients with cancer, and recommendations vary based on the available evidence. Surveys such as these are useful for making some preliminary postulations of current practice trends, and the data presented in this survey offers an informative preliminary look at the utilization trends of PET imaging to monitor therapy in patients with cancer.

Figure 1. Provider type distribution of survey respondents (n = 225)

Figure 2. For the following settings, how often do you use PET imaging in NSCLC for monitoring therapy?

Figure 3. For the following settings, how often do you use PET imaging in Breast Cancer for monitoring therapy?

Figure 4. For the following settings, how often do you use PET imaging in Prostate Cancer for monitoring therapy?

¹ Podoloff DA, Ball DW, Ben-Josef E, et al. NCCN Task Force: Clinical Utility of PET in a Variety of Tumor Types. JNCCN. 2009;7(Suppl 2):1-23.

² Dinan MA, Curtis LH, Hammill BG, et al. Changes in the Use and Costs of Diagnostic Imaging Among Medicare Beneficiaries With Cancer, 1999-2006. JAMA. 2010;303(16):1625-1631.