Ask the Doctor: How often while on watch and wait should patients get CT or other scans?

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are slow-growing types of blood cancer. Treatment is based on the severity of associated symptoms as well as the rate of cancer growth. If patients show no or few symptoms, doctors may decide not to treat the disease right away, an approach referred to as “watch and wait” or “active surveillance.” Some patients on “watch and wait” are concerned about undergoing CT scans frequently and Ryan Jacobs, MD, (Levine Cancer Institute/Atrium Health) discusses how often patients will typically receive CT and others scans while on watch and watch.

How often while on watch and wait should patients get CT or other scans?

Most CLL patients, particularly those on watch and wait (or active surveillance as I like to refer to it as), do not need any routine CT imaging.  I tell my CLL patients that there are 3 main components of evaluation that I follow over time while they are on active surveillance with each visit: Blood work, physical exam, and their symptoms as elucidated on clinic interview.

The majority of CLL patients have a significant leukemic burden and the progress of their disease can be followed simply by peripheral blood draws and checking on the CBC with differential.  This allows us to see the interval changes in the lymphocyte count over time as well as check on any significant changes in their hemoglobin and platelet count.  This is done in conjunction with regular clinic visits and physical exams where the treating oncologist will note any significant changes in palpable lymphadenopathy as well as ask patients how they are feeling.  When we are talking to the patient as an oncologist, we are looking for symptoms that might clue us into issues that might be occurring secondary to enlarging lymph nodes that we might not be able to pick up on the exam.

This could be unexplained pain that is progressing or other symptoms like abdominal swelling/discomfort or feeling full after eating only small amounts of food.  Oncologists should use these clinical indicators to prompt them to pursue imaging if there is a concern.  Any patient that is progressing to need treatment certainly needs imaging to assess the disease burden in the lymph nodes prior to starting therapy, but there is really no need to do routine imaging on an asymptomatic patient that is on active surveillance.  We should limit the cost to the patient and the radiation exposure by doing CT imaging only as clinically indicated.

One exception to this discussion would be an SLL patient or small lymphocytic lymphoma patient with no significant leukemic disease burden showing up on their blood work.  Here, the oncologist is not able to easily follow disease burden with blood work and is restricted to a physical exam and patient interview.  Although there still is no standard interval to check imaging, it may make sense to periodically check imaging depending on where the patient’s disease burden is most significant on initial diagnosis. If a patient’s SLL involves nodal areas that could be easily followed by an exam, routine imaging may still not be necessary.  But an SLL patient where the disease is more dominant in the abdomen/pelvis area where perhaps significant progression could occur that would not show up on physical exam may make sense to assess disease progression at intervals with CT imaging.  For a patient without symptoms, I would say imaging should not be checked any more frequently than once every 6 months, and most patients could be monitored at intervals longer than that.

So, in summary, most patients with CLL/SLL do not need routine imaging at all.  In fact, if a patient is diagnosed with CLL/SLL and is asymptomatic, you do not even need imaging at the initial diagnosis.  Imaging should be reserved in most circumstances for patients going on treatment, or to work up a specific clinical problem that is discovered through interactions with their oncologist.  When done, imaging should be with basic CAT scans with contrast if possible.  PET/CT imaging is not routinely done in CLL/SLL patients and should be restricted to situations where there is a concern for progression to more aggressive lymphoma.