Appropriate Follow-up Imaging for Incidental Abdominal Lesions

Measure Specification

Incidental renal and adrenal lesions are commonly found during imaging studies where the abdomen can be viewed, with most of the findings being benign. Given the low rate of malignancy, unnecessary follow-up procedures are costly and present a significant burden to patients. To avoid excessive testing and costs, follow-up is not recommended for these small lesions.

The ACR Incidental Findings Committee recommends the following considerations for incidental renal masses: Overview: Incidental renal masses are a common problem in imaging; an algorithm is provided to guide management of the incidental renal mass based on imaging features. - Key properties of the algorithm include (1) guidance based on the CT examination on which the mass was detected; (2) guidance for solid, cystic, and fat-containing masses; (3) acknowledgment that many renal masses that are too small to characterize (TSTC) are either benign or otherwise insignificant; (4) incorporation of renal mass biopsy as a diagnostic tool; and (5) surveillance of subcentimeter solid renal masses.

- The importance of shared decision making between patients and physicians is emphasized, particularly in patients with limited life expectancy and comorbidities. 1) Although most renal masses on unenhanced CT are incompletely characterized, a homogenous lesion between -10 and 20 HU is highly likely to be a benign cyst. (American College of Radiology (ACR), 2017) 2) Although the majority of lesions are characterized on initial imaging, one definition for the indeterminate renal mass is a lesion containing areas that measure 20-70 Hounsfield units (HU) on noncontrast imaging.

Homogenous lesions measuring <20 HU or >70 HU can be considered benign, whereas lesions either entirely or partially within the 20-70 HU range should be considered indeterminate and warrant further evaluation. (ACR, 2015) 3) A homogenous lesion 70 HU or greater on unenhanced CT can confidently be diagnosed as a hyperdense Bosniak II cyst requiring no further characterization or treatment.

Further characterization of these masses would add anxiety and cost and is unlikely to alter the diagnosis. (American College of Radiology (ACR), 2017) 4) The hyperdense cyst can present a diagnostic problem in that its initial attenuation coefficients are high, which can theoretically obscure tiny papillary projections along its wall. However, a homogenous renal mass measuring >70 HU at unenhanced CT has been shown to have a >99.

9% chance of representing a high-attenuation renal cyst rather than RCC. (ACR, 2015) 5) Any homogenous renal mass on contrast-enhanced CT between -10 and 20 HU is a benign simple cyst, not requiring further evaluation. (American College of Radiology (ACR), 2017) 6) For a lesion characterized as a cystic renal mass, that is, one predominantly consisting of homogenous round or oval regions without measurable enhancement, we advocate using the Bosniak classification system.

Bosniak I and II cystic masses are reliably considered benign and need no follow up. (American College of Radiology (ACR), 2017) 7) Although there are no data to suggest how to manage very small (<1 cm) renal masses, some feel that if the lesion in question appears to be a simple cyst—i.e., a low-attenuation (0-20 HU) mass containing no septations, nodularity, calcifications, or enhancement—it can be presumed to be benign and need not be further pursued.

(ACR, 2015) 8) Refer to the Management of Incidental Renal Masses: A White Paper of the ACR Incidental Findings Committee (2017) https://www.jacr.org/article/S1546-1440(17)30497-0/pdf for further detailed guidance The ACR Incidental Findings Committee Adrenal Subcommittee for management of incidental adrenal recommends the following for unenhanced CT, or washout protocol CT, or MRI with in- and opposed-phase sequences or equivalent protocols examinations for adrenal masses : 1) If an adrenal mass has diagnostic features of a benign lesion such as a myelolipoma (presence of macroscopic fat) or cyst (simple cyst-appearing without enhancement), no additional workup or follow-up imaging is needed.

2) If the lesion is 1 to 4 cm and has a density of ≤10 HU on CT or signal loss compared with the spleen on out-of- phase images of a chemical-shift MRI (CS-MRI) examination, it is almost always diagnostic of a lipid-rich adenoma. If there are no diagnostic benign imaging features but the adrenal mass has been stable for ≥1 year or longer, it is very likely benign requiring no additional imaging.

(American College of Radiology (ACR), 2017) 3) Refer to the Management of Incidental Adrenal Masses: A White Paper of the ACR Incidental Findings Committee (2017) https://www.jacr.org/article/S1546-1440(17)30551-3/pdf for further detailed guidance.

This measure contains one strata defined by a single submission criteria. This measure produces a single performance rate. Implementation Considerations For the purposes of MIPS implementation, this procedure measure is submitted each time a procedure is performed during the performance period. Telehealth: NOT TELEHEALTH ELIGIBLE: This measure is not appropriate for nor applicable to the telehealth setting.

This measure is procedure based and therefore doesn’t allow for the denominator criteria to be conducted via telehealth. It would be appropriate to remove these patients from the denominator eligible patient population. Telehealth eligibility is at the measure level for inclusion within the denominator eligible patient population and based on the measure specification definitions which are independent of changes to coding and/or billing practices.

Measure Submission: The quality data codes listed do not need to be submitted by MIPS eligible clinicians, groups, or third party intermediaries that utilize this collection type for submissions; however, these codes may be submitted for those third party intermediaries that utilize Medicare Part B claims data. The coding provided to identify the measure criteria: Denominator or Numerator, may be an example of coding that could be used to identify patients that meet the intent of this clinical topic.

When implementing this measure, please refer to the ‘Reference Coding’ section to determine if other codes or code languages that meet the intent of the criteria may also be used within the medical record to identify and/or assess patients. For more information regarding Application Programming Interface (API), please refer to the Quality Payment Program (QPP) website.