430 likes | 1.16k Views
Management of Small renal tumors. Dr. NGAI Ho Yin Division of Urology Department of Surgery United Christian Hospital. Most common: Renal cell carcinoma Less common: Oncocytoma Renal cortical adenoma AML. Rare: Neoplasm: Transitional cell carcinoma Metastatic tumors Infection:
E N D
Management of Small renal tumors Dr. NGAI Ho Yin Division of Urology Department of Surgery United Christian Hospital
Most common: Renal cell carcinoma Less common: Oncocytoma Renal cortical adenoma AML Rare: Neoplasm: Transitional cell carcinoma Metastatic tumors Infection: Renal abscess Vascular Infarct Vascular malformation Differential Dx of solid renal mass
Natural history of small renal tumor • Meta-analysis from Uzzo et al. (2006) • 234 enhancing renal masses • From 9 series • Mean follow-up: 34 months • Mean initial size: 2.60cm • Mean growth rate 0.28cm/yr Uzzo et al. The natural history of observed enhancing renal masses: Meta-analysis and review of the world literature. J Urol 175:425-431. Feb 2006
Analysis of Histology related to Tumor size ( Mayo clinic, from 1970-2000, n=2935 ) Frank I et al. Solid Renal Tumors: an analysis of pathological features related to tumor size.J Urol 170:2217-2220. Feb 2003
Natural history of small renal tumor • For single, small solid renal tumor • Almost 50% are benign if <1cm • Most will grow slowly, ~0.28cm/yr • size = chance of RCC & high grade disease • Aggressive potential of RCC increase after 3cm
Management strategy What are the available options in dealing with small renal tumors ?
Options • Observation • Radical Nephrectomy • Nephron-Sparing Surgery • Tumor Excision • Open partial nephrectomy • Laparoscopic partial nephrectomy • Tumor Ablation • Laparoscopic cryoablation • Radiofrequency ablation (RFA)
Radical nephrectomy • Gold Standard curative operation • Described by Robson 1963 • Surgical Principles • Early ligation of the renal artery & vein • Removal of the kidney outside Gerota’s fascia • +/- Removal of ipslateral adrenal gland • +/- Complete lymphadenectomy from the crus of diaphragm to aortic bifurcation
Radical nephrectomy • 5 yr survival ( organ-confined ) ~ 95%
Nephron Sparing Surgery • Goal of NSS: • Complete oncological excision of tumor with minimal technical complications • Optimal functional preservation for renal remnant Indication
Nephron Sparing Surgery 1. Open partial nephrectomy Principles
Nephron Sparing SurgeryOpen partial nephrectomy • Data from 3 major centers including: • Cleveland clinic Hafez KS, Novick AC, Butler BP. Management of small solitary unilateral renal cell carcinomas: impact of central versus peripheral tumor location. J Urol 1998;159:1156–60 • Mayo clinic Lerner SE, Hawkins CA, Blue ML, et al. Disease outcome in patients with low stage renal cell carcinoma treated with nephron sparing or radical surgery. J Urol 2002;167:884–9. • Memorial Sloan-Kettering Cancer Center Lee CT, Katz J, Shi W, Thaler HT, Reuter VE, Russo P. Surgical management of renal tumors 4 cm or less in a contemporary cohort. J Urol 2000;163:730–6. • NSS and radical nephrectomy provide equally effective curative treatment for single, small (<=4cm) localized RCC
Nephron Sparing SurgeryOpen partial nephrectomy • Novick AC. Laparoscopic and partial nephrectomy. Clin Cancer Res 2004; 10:6322S-7S • Review of 1262 patients with open NSS for RCC since 1990 • Mean Cancer-specific survival for all patients undergoing open NSS for localized RCC • 88% to 97.5% at Mean Follow-up 4-6 years
Nephron Sparing SurgeryOpen partial nephrectomy • Benefit in decreasing risk of progression to chronic renal insufficiency and ESRF • Memorial Sloan-Kettering Cancer CenterMcKiernan J, Simmons R, Katz J, Russo P. Natural history of chronic renal insufficiency after partial and radical nephrectomy. Urology 2002;59:816–20. • Mayo clinicLau WK, Blute ML, Weaver AL, Torres VE, Zincke H. Matchedcomparison of radical nephrectomy vs nephron-sparing surgery in patientswith unilateral renal cell carcinoma and a normal contralateralkidney. Mayo Clin Proc 2000;75:1236–42. • Renal insufficiency (Increase in Serum Cr >2mg/dl) • At 10 years time : • 12.4% in radical nephrectomy group • 2.3% in NSS group
Nephron Sparing SurgeryOpen partial nephrectomy • Gold standard in nephron-sparing surgery • Comparable efficacy, morbidity & mortality as radical nephrectomy • Additional benefit in renal preservation
Nephron Sparing Surgery 2. Laparoscopic partial nephrectomy Principle
Nephron Sparing SurgeryLaparoscopic partial nephrectomy • Largest single institutional report of LPN by Gill et al. Comparative analysis of laparoscopic versus open partial nephrectomy for renal tumors in 200 patients. Journal of Urology. 170(1):64-8, 2003 Jul. • Patients with solitary renal tumor (<=7cm) in size ( clinical T1 RCC ) • LPN (n=100) : Sept 1999 to Jan 2002 • OPN (n=100) : Apr 1998 to May 2001
Nephron Sparing SurgeryLaparoscopic partial nephrectomy p=0.01
Nephron Sparing SurgeryLaparoscopic partial nephrectomy • Oncological efficacy of LPN by Allaf et al. ( John Hopkins Medical institution – 3-year follow-up) • 48 patients with RCC(Mean tumors size 2.4cm)treated by LPN • Intra-op FS margin : all negative • Mean FU 37.7 months • Final pathology: • 42 patients : pT1 • 6 patients : pT3a Laparoscopic partial nephrectomy: evaluation of long-term oncological outcome. Journal of Urology. 172(3):871-3, 2004 Sep.
Nephron Sparing SurgeryLaparoscopic partial nephrectomy • Results : • No recurrence in 46 patients • 1 patient with VHL locally recurred at 18th months • 1 patient recurred at new location of same kidney at 4 yrs time
Nephron Sparing SurgeryLaparoscopic partial nephrectomy • Benefits from LPN: • Less blood loss • Less analgesic requirement • Shorter hospital stay • Shorter convalescence • Short term data suggesting promising survival outcomes • Problems of LPN: • Longer warm ischaemic time • More major intra-op & post-op urological Cx • No long term data concerning the oncological efficacy • Laparoscopic NSS is an effective treatment for clinically small localized RCC despite long term result needed.
Nephron Sparing Surgery 3. Laparoscopic Cryoablation
Nephron Sparing SurgeryLaparoscopic Cryoablation • Method: • Usage of a liquid nitrogen-cooled cryoprobe • At temperature of –40 ‘C • By dual freeze-thaw cycle • Direct cellular injury & Indirect damage to microvasculature • To ablate normal and cancerous tissues • Problems : • No histopathology to assume clearance • May Need extra biopsy for margin clearance
Nephron Sparing SurgeryLaparoscopic Cryoablation • Gill et al. Renal cryoablation: outcome at 3 years. Journal of Urology. 173(6):1903-7, 2005 Jun. • 3 yrs results • 56 patients with small renal tumors • 75% reduction in mean cryolesion size at 3 years • 38% (17 lesions) completely disappeared • Post-op needle biopsy: residual tumor in 2 patients • 3 years Cancer-specific survival ( unilateral sporadic renal tumor ) = 98%
Nephron Sparing SurgeryLaparoscopic Cryoablation • Laparoscopic Cryoablation: • Technically safe and intermediate results are encouraging • Longer term follow-up needed for oncological efficacy of cryoablation
Nephron Sparing Surgery 4. Radio Frequency Ablation
Nephron Sparing SurgeryRadio Frequency Ablation • Using a RFA needle (Percutaneous> open / laparoscopic) • Deliver high-frequency alternating current to cancerous tissue • Induce ionic agitation frictional heat • intracellular temperature (60-100 ํC) • Desiccation, Cellular protein denaturation and membrane disintegration
Nephron Sparing SurgeryRadio Frequency Ablation • Rendon et al. • 11 renal tumors • RFA Immediate / Delayed nephrectomy • Found viable cancer cells in specimen : • 4/5 (80%) [immediate group] • 3/6 (50%) [delayed group]
Nephron Sparing SurgeryRadio Frequency Ablation • Michaels et al. • 20 renal tumors (mean 2.4cm) in 15 pts • RFA Open Partial Nephrectomy • Results: • All 20 specimens had evidence of morphologically unchanged tumors
Nephron Sparing SurgeryRadio Frequency Ablation • Current RFA regimens: • Ineffective for total destruction of renal tumor tissue in a significant number of patients. • Still experimental in treatment of RCC
Conclusion • For small solid renal tumor <= 4cm • Most are RCC • Evidence suggested NSS is equally effective as radical nephrectomy • NSS with better preservation of renal functions in long term • OPN is the gold standard among choices of NSS • LPN is promising technique with its potential advantages