Page 5 - Microsoft Word - 6942_BPR_Epub

CUAJ – CUA Best Practice Report Guo et al
BPL: AML management

in Table 1, AMLs >4cm did appear to be at a higher risk of hemorrhage compared to those <4cm (1% vs
16%), or undergoing intervention (1% vs 34%). The absolute risk, however, is much lower than
originally described by Oesterling et al. We were also unable to find any high-level evidence
demonstrating any statistically significant correlation between size and hemorrhage.

Followup

Recommendation #2: Once the diagnosis of AML is made, imaging and clinical evaluation should
be carried out periodically. Traditionally, surveillance has been done on a biannual or annual
basis, but consideration should be given to decreasing frequency once stability has been
established. A decision for the cessation of monitoring should involve a discussion between
provider and patient, weighing risks and benefits.

Oesterling’s original paper recommended annual imaging for AMLs smaller than 4cm and biannually
for AMLs larger than 4cm. Unfortunately, there have been no prospective studies to help guide our
follow up protocols since then. Our systematic review found that these lesions generally grow quite
slowly, with average growth rates ranging from 0.1 to 1 mm/year, meaning it could take up ten years to
36
grow 1 cm. However, there were outliers described in the case series, growing up to 1.5 cm per year.
Based on this, annual monitoring (or less frequently) would seem reasonable for the majority of lesions,
and it may be reasonable to initially image more regularly and reduce frequency once stability is
demonstrated. The majority of follow up protocols we identified in our literature review used this
strategy, with initially biannual imaging and then annual imaging after one year.
There is also limited evidence for identifying optimum imaging modality. While US alone is not
sufficient for the diagnosis of AMLs, there is no evidence that CT or MRI improves follow up care. An
ideal follow up protocol would minimize the risks of ionizing radiation and the costs of axial imaging.
Another consideration is what duration of time routine imaging should continue for. The most prolonged
follow-up protocol we found in our review was for approximately five years. However, given the lack of
evidence, cessation of follow-up should be a shared decision between patient and provider, taking into
account the patient’s general health status and competing risks of mortality, as well as their goals and
concerns.
For indeterminate lesions, malignant lesions such as RCC or epithelioid AMLs cannot be ruled
out. If proceeding with active surveillance, these require more careful monitoring for progression.

Indications for intervention

Recommendation #3: The vast majority of AMLs are asymptomatic, have a low risk of
hemorrhage and can be monitored. There does appear to be an increased risk of symptoms and
hemorrhage in lesions larger than 4cm, but this is not based on high-level evidence. Symptomatic
AML should be treated to ameliorate symptoms. Treatment for asymptomatic AML >4cm should
be discussed, with the understanding that the absolute risks of hemorrhage are lower than