Clinical PET Cast

In this third episode on PET/MRI, we’ll focus on the overall goals for using MRI instead of CT with PET, namely less radiation and more accuracy. These properties have particular benefits in pediatrics and neurology that I’ll discuss. We’ll review the active area of protocol development with PET/MRI, including the issues in attenuation correction. Finally, we’ll look at emerging tracers that could add to some of the excitement over PET/MRI.

While PET/MRI continues to be a very hot topic in the literature, we’re still not quite sure how to use it. So, to continue the discussion about PET/MRI, we’ll use the transition from PET to PET/CT as a model. We’ll look at the potential benefits PET/MRI may bring to TNM staging and discuss what may be possible for therapy assessment. I’ll also get into some design strategies for combining PET and MRI hardware so that they can be used in one session.

In this episode, we’ll dive into the exciting new technology of PET/MRIs. We can learn a lot from our history, and I’ll discuss what image fusion and PET/CT hardware have provided us over the years. But while PET/CT has certainly helped our accuracy in staging, I’ll use a pediatric example to point out how PET/CT can also lead to more dose. Because of the possibility of lower dose and other potential gains, I’ll discuss the reasons PET/MRI scanners hold such promise.

In this episode, I’ll continue to discuss the evaluation of response to therapy using PET. A number of factors affect when to assess therapy response and how to interpret the results, and there are differences between radiation therapy and chemotherapy. Within radiation therapy, it is very important to consider the particular disease, so I’ll discuss specifics for ovarian, cervical, lung, colorectal, and liver cancer. Most of this discussion uses data on the popular FDG tracer, but I will also mention some of what we have to look forward to with newer isotopes.

In this episode we will be looking at PET/CT and the evaluation of different therapeutic interventions. More and more, the interest in PET/CT is not only in the initial evaluation of disease, but also in the subsequent evaluation of therapy response. We will look at the literature to discuss the different recommended standards for defining the disease’s response as complete, partial, stable, or progressive.

A journal article I read recently had several amusing examples of  “unremarkable” words. This illustrates how easy it is for reports to  contain phrases that only the writer can clearly understand. While some  issues are caused by dictation technology and the tendency of us humans  to occasionally “zone out,” we can still improve the quality of our  reports by following templates and a list of required elements. In this episode, I’ll illustrate this process using a typical report from our site.

In this episode, I’ll discuss the issues of unclear language in written reports. With the growing use of EMR and demands for quick turnaround time, we’re spending less face time with our colleagues. This episode I’ll particularly focus on some studies concerning terminology, and how synonyms can make it difficult to determine to what degree an abnormality is present.

In this episode I’ll discuss prostate cancer and PET. Prostate imaging with PET remains unapproved for reimbursement by CMS, and we’ll examine several reasons why this is the case. One of the major limitations has to do with the tracers available, and along those lines I’ll talk about radiopharmaceuticals currently under investigation.

I’ll continue the discussion of head and neck malignancies and reporting. Every PET/CT report needs to discuss the Tumor (T), the presence of regional lymph nodes, and the presence of metastases. A well-written and organized report will make your clinical and surgery colleagues quite happy with the results.

Today I’ll continue our discussion of head and neck cancer and PET/CT by going through a number of studies important to both. Several of these studies provide illuminating data by comparing PET/CT to either PET or CT data alone, including data from high-contrast CT. We’ll see how PET/CT can increase the confidence of the radiologist and even find disease in head and neck patients otherwise considered cured.  

In this episode, I’m going to discuss head and neck cancer, including normal variations, clinical indications, and my favorite topic, radiation therapy planning with PET. Head and neck cancer is not as common as other cancers, but the high morbidity and mortality rates make it an important topic. I’ll also discuss the patient preparation and overall procedure used at our site with head and neck cases.

As we continue our discussion of lung cancer, I want to cover how radiation therapy and PET are becoming linked. I’ll discuss the three key volumes used for any plan, the most important of which is the Gross Tumor Volume (GTV) that the therapist delineates using imaging. In lung cancer, PET can have a particular influence on the size of the GTV, either by increasing or decreasing this volume. For example, PET can detect regional lymph nodes in non-small cell lung cancer patients.

Today I’m going to continue my discussion of PET and lung cancer by going through a number of interesting studies. I’ve spoken before about the pitfalls of SUV, but there is research that shows that the SUV combined with Hounsfield units can be very helpful when studying adrenal lesions. Due to a lack of standardized criteria, it is difficult to completely quantify PET’s ability to help categorize patient response, yet the data shows that PET is very useful in therapy response and predicting patient survival.  

Today I’ll continue my discussion of PET and lung cancer. The SUV can be a valuable tool to use as a baseline and for follow-up, but essentially an SUV measurement on its own isn’t really better than visual analysis. I’ll discuss the various pitfalls of SUV, as well as tips for examining both solitary pulmonary nodules and the mediastinum.

In this episode, I will discuss the history of approved reimbursements from CMS, from the 1998 approval for solitary pulmonary nodules to more recent changes in terminology that affect our billing.  Lung cancer has a high mortality rate in both men and women, and the current statistics on the subject are striking.  I will also go into detail about how our site uses PET with lung cancer cases.

In this follow-up to Pediatric PET, I’ll move to discussing specific applications and disease states. In pediatrics, it is particularly important to minimize dose, since the patient will hopefully have many more years to live. I’ll talk about how standalone PET, and the new developments in PET/MR, can potentially help reduce the frequency of using diagnostic CT.

Today I want to talk about pediatric PET, and the issues we encounter before any images even get to the radiologist.  It may sound simplistic, but children are not little adults, and often patient sedation is required.  Because of this, it’s best to coordinate exams close to each other in time, and in the same room if possible.  Overall, we want to minimize sedation time, dose, delays between scans, and patient discomfort.  And of course, don’t forget about the parents!

In this third look at fusing anatomic and physiological data, I want to examine why SPECT/CT has not enjoyed the popularity of PET/CT.  SPECT/CT can offer many of the same benefits as PET/CT, such as improved image quality, and it has some interesting brachytherapy applications,  Later in this podcast, I will also examine the future of PET/MR.

In this episode, I continue my discussion of the advancements made by hardware fusion. The adoption of the combined PET/CT instrument gave us dramatic decreases in imaging time, reduced dose, and most importantly, gains in image quality. Even with these advancements, software fusion remains important for the future, since it allows comparison of images from different time points.

We’ve already benefited a great deal from fusion thanks to the clinical context it provides for surgery and radiation therapy.  In this episode, I’m going to discuss both software and hardware fusion and the advancements made by these techniques.  Software techniques have improved with deformable registration, and the combined instrument in hardware is really very useful for improving image quality.