Percutaneous ablation of renal cell carcinoma Where do we stand now? Sanja Stojanović, Spasić Aleksandar Clinical Center of Vojvodina / Center for Radiology Novi Sad Serbia
Renal cell carcinoma approximately less than 4 % of all new cancers in the western world The detection rate has been increasing in recent years Incidental finding
Which RCCs are we speaking about T1 T2: T3: T4: T1a: tumour confined to kidney, <4 cm T1b:tumourconfined to kidney,>4 cm but <7 cm
4 cm Treated area deployment of thermal energy
ELECTRODES
How to enlarge area of ablation
Hyperthermic ablation in depth understanding of the mechanism Thermal conduction from small heating zone Mechanism of celullar injury Central zone necrosis Periphery - sublethal Immune activation antigen presentation Chu CF, Dupuy D. Thermal ablation of tumours: biological mechanisms and advances in therapy. Cancer; 2014.
Cryoablation Liquefied gases (Argon) -20 to -40 C 1cm beyond the lesion Mechanism of cellular injury Even better immune activation - sometime inactivation Chu CF, Dupuy D. Thermal ablation of tumours: biological mechanisms and advances in therapy. Cancer; 2014.
Immunomodulation Often too weak to completely overcome disease Synergy with ablation - imunnoadjuvants Chu CF, Dupuy D. Thermal ablation of tumours: biological mechanisms and advances in therapy. Cancer; 2014.
Partial Nephrectomy Thermal Ablation
PATIENT SELECTION BIAS
- Patients that are not fit or are not willing to undergo surgical treatment - Active surveilance onlyfor those patients with ct1a RCC that cannot undergo percutaneous treatment
Partial Nephrectomy Thermal Ablation Armamentorium Lethal mechanism Immunomodulation Pathology Image guidance Effect of procedure
RF CRYO Cornelis FH et al. A Comparative Study of Ablation Boundary Sharpness AfterPercutaneousRadiofrequency, Cryo-, Microwave, and Irreversible Electroporation Ablation in Normal Swine Liver and Kidneys. CIRSE; 2017.
Biopsy-mandatory Percentage Survival Fuhrman grading 18G needle Multiple subtypes of RCC Byopsy Pathology Abla on Comparisson with other modalities (PN) Disease Specific Survival (months) Metastases T1a 7% RCC 3-4cm 11% Further therapy by oncologists
Patient selection Small renal mass: T1a; T1b? Comorbid conditions Advanced age Single kidney Multiple masses(vhl)
Ideal lesionfor RF Small ( 3cm/4cm?) Posterior Exophytic Far away from critical structures
Multiple tumours Proximity of colon Proximity of spleen Proximity of hilus - pyeloureter -vascular
Image guidance CT US inferior control ablation induced artifacts MRI robust equipement availibility
colon Hydrodissection RCC to push away structures in close proximity infusion of liquid One needle Two needles
Complications Hemorrhage(thinner or thicker needles) Subcapsular Retroperitoneal Hematuria Central locations Cryoablation better tolerated by pyelocaliceal wall Pyeloperfusion (cold or warmed liquids)
Atwell TD et al. PercutaneousAblation ofrenal Masses Measuring3.0 cm and Smaller: ComparativeLocal Control and Complications After Radiofrequency Ablation and Cryoablation. AJR; 2013.
Prediction of complications Radius Exophytic/endophytic % Major Complication Nearness to collecting system Anterior/posterior 4-6 7-9 10-12 R.E.N.A.L. Score Location relative to polar lines Schmit GD et al. Usefulness of R.E.N.A.L. NephrometryScoring System forpredicting Outcomes and Complications of PercutaneousAblation of 751 Renal Tumors. J.Urology; 2013.
10-12 % Local Failure 7-9 4-6 Radius Months Post Treatment Exophytic/endophytic Nearness to collecting system Anterior/posterior Location relative to polar lines Prediction of local success
Approach Electrodeposition Skin landmark 90 angle
RF or PN
Single kidney / multiple RCC - Renal reserve -Partial nephrectomy or thermal ablation? - Control of complications
T1a lesion 26mm lesion Position 1 Position 2 After ablation
Control sectional imaging -4 weeks after ablation rest of the ablated tumour -after 3, 6, 9 or 12 months institution protocol -US: liquid complica ons (Hydronephrosis, Collec ons...) CT/MRI 3 months 1 year 2 years
Follow up Early follow up imaging not recommended unless complication (bleeding..) suspected Late follow up -no consensus on chosen modality Comparation to preoperative imaging Lack of enhancement Decrease in size of the ablative zone Peripheral enhancement (usualy disappears after 6 months) Recurrent tumor versus inflammatory changes --New baseline after 6 months
Conclusion - Guidelines - T1a(b) tumours - Biopsy - Pursuing excellence in technique and understanding of lethal mechanisms - Learning curve
Thank you for your attention!