Managing the Incidentaloma : the Curse of Modern Imaging

Transcription

1 Managing the Incidentaloma : the Curse of Modern Imaging Michael P. Federle, MD Associate Chair for Education Department of Radiology Stanford University Learning Objectives Consistently characterize incidental masses of the KIDNEY, and implement evidence-based work-up and follow-up protocols. Specify age factors that impact diagnostic interpretation. Incidentaloma An unsuspected and unsought finding on an imaging study performed for an unrelated purpose Extremely common (> 40% of all adults on body CT scans) While some may be beneficial (e.g., small RCC or AAA), most effects are negative Patients + referring MDs experience anxiety, get additional testing or Rx, with enormous expense Anecdotal (but Instructive) Tales Chairman of Radiology Dept gets CT colonography which shows incidental renal, hepatic, and lung masses Has additional CTs, PET scan, liver Bx, thoracoscopy (all benign) Total costs >$50,000 (would have been >> $ 100K now in California) Painful 5 week recuperation Casarella: Radiology 2002; 224: 927 (June, 2008; CT for unrelated Sx) 53 y/o woman (my sister-in-law) Hypodense mass in panc head likely panc Ca or IPMN (Same patient + CT) Subtle renal mass (not called) LMD: You have a panc tumor and need a Whipple procedure 1

2 (March 2009, 10 months later) Surgeon: You have an IPMN with a 50% chance of being malignant; need a Whipple (May 2011) You have a branch duct IPMN that has been stable for >3years and needs no Rx (May, 2011) but you also have a small but growing RCC that should be resected (June, 2011) Resected RCC via Laparoscopic enucleation (Jan, 2014) Alive + well, pancreas intact Incidentaloma Individual radiologists (even within same group) make disparate recommendations for further evaluation Erodes the credibility of radiologists Some (other MDs, govt officials) regard this as a form of self-referral to do more studies Prevalence of incidentalomas has impeded Medicare approval for CT colonography CMS does not want to pay for all the additional Dx + Rx for extracolonic lesions picked up on CTC Negative Effect on Referring MDs Primary care physicians resent the amount of time they have to spend chasing down incidental findings, instead of more productive work (UPMC surgeon: another VOMIT lesion [victim of modern imaging technology]) 1 st SAM Question: How common are incidentalomas seen on abdominal CT studies? % % % % 5. >40% 2

3 2 nd SAM Question: How often do patients benefit from detection of incidentalomas? 1. 1% % % % 5. >20% Scope of Problem ~1500 consecutive imaging studies for research study (primarily abdominal CT) 40% had at least 1 incidental finding Only 1% had a beneficial effect from this finding (Arch Internal Med 2010; 170: 1525) Scope of Problem 7 studies on incidental findings on CT colongraphy ( ) Incidentalomas found in 41 to 98% of studies Added cost of working these up could be 100s to 1000s of dollars per patient This was one of the main reasons that CMS declined reimbursement for CTC in 2009 Why do Radiologists Issue Vague + Inconsistent Interpretations + Recommendations? Uncertainty over the most reliable techniques + criteria to make a specific Dx Fear of malpractice suit Observations We need to improve the performance + interpretation of CT (+ other) scans to minimize the prevalence of indeterminate lesions We need more consistency among radiologists in reporting findings + making recommendations for further w/u Know and use ACR guidelines and recommendations (e.g., Fleischner Society) Keep your eyes open for other evidencebased guidelines Precedents for Improving Consistency + Value of Reporting BI-RADS (sponsored by ACR) Breast Imaging Reporting + Data System Standardized numerical codes assigned by radiologist to provide concise + less ambiguous classification of breast lesions (from benign to highly suggestive of malignancy) Has added tremendous consistency + value to mammography reports 3

4 CT Colongraphy Reporting + Data System C-RADS E classification of extracolonic findings C-RADS For documenting polyps +extracolonic findings seen on CT colonography Provides some guidance for structured reporting + managing these findings C 1-4 ( normal to likely malignant polyps or masses) Zalis et al: Radiology 2005; 236: 3 Fleischner Society Guidelines (Small lung nodules on CT) >99% of all nodules <4mm in size are benign (and extremely common) Only in selected cases (larger nodules; unusual morphology; high-risk patients) is follow-up indicated Know + follow these guidelines! Post them at your workstations Radiology 2005; 237: 395 Fleischner Recommendations for Followup and Management of Nodules Smaller than 8 mm Detected Incidentally at Nonscreening CT Note. Newly detected indeterminate nodule in persons 35 years of age or older. Average of length and width. Minimal or absent history of smoking and of other known risk factors. History of smoking or of other known risk factors. The risk of malignancy in this category (<1%) is substantially less than that in a baseline CT scan of an asymptomatic smoker. Nonsolid (ground-glass) or partly solid nodules may require longer follow-up to exclude indolent adenocarcinoma. Incidental Findings on Abdominal-Pelvic CT Huge problem Incidental renal, adrenal, hepatic, pancreatic lesions (cystic +/or solid) ACR appointed an Incidental Findings Committee to address the problem (large group of very experienced + expert radiologists) Led by Lincoln Berland, MD ACR White Paper on Incidentalomas Managing Incidental Findings on Abdominal CT: White Paper of the ACR Incidental Findings Committee Lincoln L. Berland, MD, Stuart G. Silverman, MD, Richard M. Gore, MD, William W. Mayo-Smith, MD, Alec J. Megibow, MD, MPH, Judy Yee, MD, James A. Brink, MD, Mark E. Baker, MD, Michael P. Federle, MD, W. Dennis Foley, MD, Isaac R. Francis, MD, Brian R. Herts, MD, Gary M. Israel, MD, Glenn Krinsky, MD, Joel F. Platt, MD, William P. Shuman, MD and Andrew J. Taylor, MD Journal of the American College of Radiology Volume 7, Issue 10, Pages (October 2010) DOI: /j.jacr Copyright 2010 American College of Radiology Terms and Conditions 4

5 Objectives of ACR Committee Incidental Solid Renal Mass 1 Detected on CT <1 cm cm 5 > 3 cm 9 Develop an evidence-based consensus on sets of organ-specific lesions that are encountered commonly on CT Develop medically appropriate approaches to managing these incidental + often indeterminate lesions General population CT or MRI at 6 and 12 mo. then yearly for 5 yrs. 3,4 Limited life expectancy or co-morbidities 7 If follow-up appropriate, CT or MRI at 6 and 12 mo. Then yearly for 5 yrs. 3,8 General population General population Surgery 7 Surgery 7,10 Limited life expectancy and Co-morbidities 3 Limited life expectancy or co-morbidities 3 Follow-up 8 Hyperattenuating, homogeneously enhancing: consider MRI, biopsy 6 Surgery 6 Follow-up 8 Solid Renal Mass Potential Benefits of this (+ Similar) Project Reduce risks to patients from additional unnecessary tests + procedures Limit the expense to patients + insurers Achieve greater consistency + quality in reporting + managing incidental findings Provide guidance + support for radiologists who are concerned about medicolegal issues Help focus research efforts to lead to more evidence-based approaches to incidental (+ other) findings Reporting Considerations (Difficult to Achieve Total Consensus) Low attenuation mass likely to be simple cyst (or other benign lesion; e.g., adenoma or hemangioma ) [I use this a lot, often with specific recommendations, depending on setting] Is a renal cyst (or other specific benign lesion) [I use this as often as possible] Don t report it at all (or bury it in the body of the report ) [I use this a lot in elderly + very ill] Indeterminate, but with no malignant features [I would only use this coupled with a specific recommendation] Goals of this Course (2 day course for radiologists, ) Bosniak I or II Incidental Cystic Renal Mass 1 Detected on CT Bosniak IIF Bosniak III or IV Provide the tools for registrants to make more confident, accurate, and clinically useful interpretations and recommendations when confronted with the dreaded incidentaloma Benign General population Limited life expectancy No further follow-up 2 or co-morbidities 7 If follow-up appropriate, CT or MRI at 6 and 12 mo. CT or MRI at 6 and 12 then yearly for 5 yrs. 3,4 mo. Then yearly for 5 yrs. 3,8 No morphologic change Morphologic change 5 Benign Surgery, follow-up or no No further follow-up Further follow-up based on Life expectancy and Co-morbidities General population Surgery 6 Limited life expectancy or co-morbidities If follow-up appropriate, CT or MRI at 6 and 12 mo, then yearly for 5 yrs. 3,9 Further action based on change, life expectancy and co-morbidities Cystic Renal Lesion 5

6 Simple Benign Cyst Cyst Renal Mass Complex Benign Cyst Cystic RCCa Multiocular Cystic Nephroma Hematoma Abscess Aneurysm Solid 3 rd SAM Question: How commonly are cystic renal lesions seen on routine abdominal CT scans in adult patients? % % % % 5. >50% 4 th SAM Question: How often can these be confidently diagnosed as benign by imaging alone? % % % % 5. >50% Bosniak Category 1: Simple Renal Cyst Features: Imperceptible or hairline walls No septa, calcifications or solid components Water attenuation No enhancement < 20 HU change is probably pseudoenhancement Management: Ignore Simple Renal & Hepatic Cysts Bosniak Cat. 1: Simple Cyst 6

7 Bosniak Category 2 (minimally complex; benign) Features Few hairline-thin septa without measureable enhancement May have thin calcification in septa or wall (Subtype): Hyperdense cyst Homogeneously high attenuation (usually > 70 HU) 3 cm diameter Nonenhancing Management: Ignore Bosniak 2 3 years Bosniak 2 hyperdense cyst (90 HU on NECT + CECT) surprisingly sonolucent Hyperdense Cyst minimal (pseudo) enhancement Can We Dx Hyperdense cyst on Nonenhanced CT (NECT)? Often we can: CT # > 70 HU 99.9 % predictive of benign hyperdense cyst HU is danger zone Need additional w/u Could be CECT, MR or US CT # < 20 HU ~ always simple cyst AJR 2011; 197:139 AJR 2012; 198:1115 Bosniak 2 Hyperdense cyst Can t characterize on only CECT US shows sonolucent mass 7

8 Problems with Bosniak Classification Difficulty deciding between cat. 2 and cat. 3 Important Rx implications Relatively frequent problem Wall or septum too thick? > 3 cm in diameter Equivocal enhancement Or, if there are Sx (e.g., hematuria) Call these 2F (need follow-up) Repeat scans in 3, 6, and 12 months, then annually Follow for 5 years (cystic RCCs are slow growing) Bosniak Category 3: Complex Cyst or Neoplasm Features: Thickened, irregular walls or septa with measurable enhancement Management: Surgery for most patients Observe (or even ignore) for those with serious comorbidities or limited life expectancy Cystic Renal Masses- Bosniak Category 3 Complicated Cyst Multiocular Cystic Nephroma septate, encapsulated mass Require surgery in most cases Hemorrhagic cyst Multilocular cystic nephroma Cystic or necrotic RCC Multilocular Cystic Nephroma (Multilocular Renal Cyst) Multilocular Cystic Nephroma note enhancing septa; capsule herniation into renal pelvis Multiple non-communicating cysts within a tumor capsule Septa enhance, may calcify Herniation into renal pelvis Usually boys and middle age women Caution! RCC can have identical appearance Federle: DI: Abdomen 8

9 Multilocular Cystic Nephroma indistinguishable from RCC Bosniak Category 4: Cystic Neoplasm Features: Same as for Category 3, but also with enhancing soft tissue components Almost all are RCCs or MCNs Management: Surgery for most Nephron-sparing if small + accessible Observe (or even ignore) for those with serious comorbidities or limited life expectancy Bosniak 4 calcified cystic RCC Complex Cystic RCC Cystic RCC mimics multilocular cystic nephroma Cystic RCC (41 y/o woman) Mimics multilocular cystic nephroma 9

10 5 th SAM Question: What is this lesion? 1. Simple cyst (Bosniak 1) 2. Hyperdense cyst (Bos. 2) 3. Renal cell carcinoma 4. Can t tell Bosniak 4 inappropriate Rx: recommend clinical correlation + f/u (no time frame) enhancing mural nodule Patient returned 3 years later metastatic RCC Summary Incidentalomas are a major problem Radiologists + clinicians need to work out rational approaches to managing these Individual cases are best resolved by discussion among these physicians Summary Most cystic renal masses can be diagnosed with confidence by imaging criteria Some overlap between Bosniak category lesions is problematic Some patients will require long term followup 10