From the 2019 HVPAA National Conference
Dr. Tharakeswara Bathala (The University of Texas MD Anderson Cancer Center), Dr. Corey Jensen (The University of Texas MD Anderson Cancer Center), Dr. Tara Sagebiel (The University of Texas MD Anderson Cancer Center), Dr. Albert Russell Klekers (The University of Texas MD Anderson Cancer Center), Dr. Nicolaus Wagner-Bartak (The University of Texas MD Anderson Cancer Center)
Background
It is a common practice at some institutions and in some practices to acquire delayed (excretory) phase CT images through the abdomen in addition to portal venous phase images during routine abdominopelvic CT examinations. Delayed phase CT may not be required for all cases.
Objective
The aim of the project is to decrease utilization of delayed phase CT abdomen and pelvis for routine follow-up and surveillance of hematological malignancy by 25% by March of FY 2017.
Methods
Survey tools to assess the utility of delayed phase images of the kidneys and bladder for three months using PS360 dictation system. Pareto chart and analysis for frequent findings seen on delayed phase images. Consensus review of cases following survey. Survey tools to analyze best practices at other NCCN recognized cancer centers. Process maps to analyze the steps at the time of CT image acquisitions. success of the projected is assessed by the following measures: 1. At least 25% reduction in utilization of delayed phase CT abdomen and pelvis for routine follow-up and surveillance of hematological malignancy. 2) Trends in obtaining additional imaging for assessment of disease burden or incidental findings due to lack of delayed phase imaging of kidneys and bladder.
Results
Delayed phase imaging constitutes 20% of total scan time, i.e 4 min out of 20 min (ranges from 3.2 min to 5.4 min). A total of 1708 patients with hematological malignancies were included in the analysis (FY16). In 95% of the cases, delayed phase imaging did not show any additional findings at the time of dictation. In 4.8% cases, findings seen on portovenous phase imaging were more conspicuous on delayed phase imaging. Majority of which are renal cysts. Impaired renal function (0.2%) was the only finding that would have been undiagnosed without delayed phase imaging. Delayed phase images constitutes 30% of total radiation exposure of CT AP. We achieved the set goal of decreasing delayed phase imaging by >25% in Jan 2017. Every patient that avoided delayed phase imaging saved 3.2 min of scanner time which means approximately 4 additional patients could gain access to CT schedule everyday in FY18 (pink bar in graph). Change implemented in two other cancers: Melanoma and Testicular cancers.
Conclusion
Delayed phase imaging is of low-value in the follow-up evaluation of hematological, testicular and skin malignancies. Incidence of incidental findings in these subset of population is <7% as reported in the literature. Elimination of delayed phase imaging in routine follow-up CT examination decrease radiation exposure by 30%, improve operational efficiency and sometimes may call for additional work-up for the evaluation of a small number of incidental findings. Potential to expand the reduction in delayed CT imaging to include other malignancies such as breast, CNS, lung, GI tract, MSK.
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