The Importance of Stuart G. Silverman, MD, FACR Professor of Radiology Harvard ard Medical School Director, Abdominal Imaging and Intervention Brigham and Women s Hospital Boston, MA The Importance of Stuart G. Silverman, MD, FACR Disclosure of financial relationship with relevant commercial interest Lippincott, Williams, and Wilkins Philadelphia, PA Book Royalties Renal Mass Bx: Why not? Most renal masses do not need to be biopsied. Importance of Imaging Most renal masses can be diagnosed with imaging alone Renal Mass Bx: New? Improved US, CT, MRI technology is resulting in the detection of more, small, solid renal masses Benign solid renal masses are prevalent - 25% of small solid renal tumors are benign (Frank et al J Urol 03) Renal Mass Bx: Why? Test characteristics excellent (Malignant and benign tumors) Safety established (Significant bleeding rare) Needle tract seeding rare (not more than other tumors) Page 1
Renal Masses in Patients with Known Extrarenal Primary Cancer Primary n Mets RCC Benign Lymphoma 20 9 10 1 Lung 16 8 8 0 Breast 5 1 3 1 Others 13 2 10 1 Total 54 20 31 3 Rybicki et al AJR 2003 Poor Surgical Candidate Medical co morbidities (e.g., heart or lung disease Solitary kidney Renal insufficiency Biopsy allows urologist to assess risk benefit and plan surgery confidently. Solid Masses may be benign Of 815 nephrectomies /NSS for solid and cystic renal masses, 2000-20052005 16.4% benign Masses 1-2 cm 25% benign Masses 2-3 cm 15% benign Masses 3-4 cm 18% benign Masses 6-7 cm 17% benign Snyder et al J Urol 2006 Hyperdense + Enhancing RCC typically papillary, or clear cell sub-type that has bled Angiomyolipoma with minimal fat Oncocytoma Lymphoma Metanephric adenoma (rare) Leiomyoma (rare) Metastases (rare) Silverman et al RadioGraphics 2007 AML with Minimal Fat Biopsy can be used to diagnose AML, particularly with the aid of immunocytochemistry AML RCC MART1 + - SMA + - HMB-45 + - RCC - + Granter et al, Cancer 1999 Page 2
Oncocytoma vs Oncocytic RCC: Immunocytochemistry Onc OncRCC AE1/AE3 + + EMA - + RCC - + Colloidal Fe - +* S100A1 + -* *refers to Chromophobe RCC only Liu and Fanning Cancer Cytopath 2001 Li et al Histopathology 2007 Oncocytic Renal Neoplasms Oncocytoma Chromophobe RCC Granular RCC Hale s Colloidal Iron stain is negative Eosinophilic variant of papillary RCC Angiomyolipoma These are rare Renal Oncocytoma Oncocytoma cannot always be diagnosed with certainty with bx. Oncocytoma can be diagnosed with a high degree of probability using immunocytochemistry. The diagnosis of an oncocytic neoplasm allows for less invasive treatment options to be considered Liu Cancer 2001 Fundamental Facts Unlike surgery where the mass may be examined, ablation is an in situ treatment and there is no opportunity for full pathology examination. Tissue diagnosis prior to ablation is entirely dependent on biopsy. Tuncali et al AJR 2004 Yesteryear The image-based detection of a non-fat containing solid mass in an adult led to the radiologist s confident diagnosis of RCC often leading to surgical removal of the mass. A pathology diagnosis was rendered in all cases Today As many as 25% of small (< 3 cm) solid renal tumors are benign. Imaging cannot be used alone to diagnose small renal cancers with sufficient confidence. Enhancement may be found in benign neoplasms, inflammation, and vascular abnormalities. Page 3
Renal Mass Referred for Ablation CT or MRI Benign Biopsy in advance or during ablation When to biopsy? Biopsy in advance of ablation Sporadic small (< 3cm) masses Biopsy during ablation Malignant Ablation Non-diagnostic Observe vs. Ablation with repeat Bx Benign No treatment Prior RCC (ipsilateral, contralateral) and enhancing mass Established familial RCC syndrome?large, heterogeneously enhancing Biopsy of Cat III Masses Biopsy and imaging follow-up may save patients with Category III cystic masses from having surgery. Harisinghani et al AJR 2003 Biopsy of Cat III Masses Benign results may lack specificity (eg, renal epithelium, fibrous tissue, atypical cells) No known time interval that proves benign results Biopsy of Cat III Masses Benign results may be helpful as additional data. Unless a specific benign entity is rendered, benign results cannot be used alone. Multiple Renal Masses This patient has renal oncocytosis a syndrome in which multiple oncocytomas develop, often bilaterally, and typically with one dominant one. 2-12% of oncocytomas are multifocal; 4-14% are bilateral Tikoo S, et al. AJSP 1999;23:1094 Page 4
Multiple Renal Masses DDx of multiple solid renal masses includes papillary RCC, oncocytosis, lymphoma, and metastases Biopsy can be used to make a confident diagnosis of oncocytoma. Biopsy determines management Established Indications Distinguish RCC from metastasis in patient with extrarenal malignancy Confirm unresectable suspected RCC Dx suspicious mass in poor surgical candidate Dx suspected pyelonephritis Emerging Indications Small, hyperdense, homogeneously enhancing renal masses Renal masses referred for ablation Indeterminate cystic renal mass (Bosniak Category III) Multiple solid renal masses Silverman et al Radiology 2006 Importance of Biopsy Biopsy prevents benign masses from being treated unnecessarily. Is Biopsy Cost-Effective? A Markov state transition model was developed to observe a hypothetical cohort of healthy 60-year year-old men with an incidentally detected, 2 or less cm solid renal mass. Immediate treatment was the highest cost, most effective diagnostic strategy, providing the longest overall survival of 18.53 life-years. Active surveillance was the lowest cost, least effective diagnostic strategy. On cost-effectiveness analysis using a societal willingness to pay threshold of $50,000 active surveillance was the preferred choice at a $75,000 willingness to pay threshold while biopsy and treatment were acceptable ($56,644 and $70,149 per life- year, respectively). When analysis was adjusted for quality of life, biopsy dominated immediate treatment as the most cost-effective diagnostic strategy at $33,840 per quality adjusted life-year gained. Heilbrun et al. J Urol 2012 Page 5
Management flowchart Berland LL et al, JACR 2010 Management flowchart Management flowchart Berland LL et al, JACR 2010 JACR 2010 Page 6