In this poster, current Society recommendations on the treatment of renal cell carcinoma (RCC) specifically those impacting the Interventional Radiologist will be discussed. - Imaging evaluation o Pre-procedure imaging:  In addition to diagnosing, characterising and staging disease; these provide the basis for anatomical classification systems such as Preoperative Aspects and Dimensions Used for an Anatomical (PADUA) classification system and the R.E.N.A.L. nephrometry score.  Looking at tumour size, location, relation to the collecting system and exophytic/endophytic nature, the systems can provide objective prognostication of possible morbidity following percutaneous ablation/nephron sparing surgical procedures.  Whilst there is no recommended maximum time frame from last imaging to invasive treatment, growth rate of SRMs may be considered.
Clear-cell RCC typically grow faster (0.25cm/year), although up to 82% of malignant SRMs can undergo rapid growth (volume doubling) [366]. o Post treatment surveillance:  Individual risk based assessment will determine the level of scrutiny required in the post-procedure imaging.  For localised RCC, considering a potential higher local recurrence rate after percutaneous thermal ablation therapy, a more rigorous imaging follow-up regime is suggested.
Whilst there is no evidence-based standard, a suggested regime for high-risk local recurrence is CT evaluation at 3 and 6 months, followed by 6 monthly to 2 years, yearly to 5 years and biennial beyond 5 years.
Conversely, expert consensus from Asia suggests 6 monthly imaging to 2 years with subsequent yearly imaging evaluation up to 5 years. - Role and timing of renal biopsy. o Percutaneous tumour biopsies are beneficial for:  Histological diagnosis of indeterminate radiological renal lesions.  Identifying patients suitable for active surveillance by evidence of tumour grade and histotype.  Histology prior to time of percutaneous ablation therapy is preferred as this reduces the rates of unnecessary treatment.
In a series of 182 patients, 27.5% of patients avoided further invasive treatment (surgery or ablation) due to a benign diagnosis from the biopsy specimen.  Identifying the treatment algorithm in metastatic disease. o Recommended biopsy techniques include:  Using a coaxial technique for core biopsy – 18 gauge needles are sufficient for tissue diagnosis.
Ideally, a minimum of two good quality cores should be acquired from the solid enhancing components avoiding central necrotic areas.
Fine needle aspiration is not recommended.  Performing biopsy of cystic renal tumour masses only if there is an appreciable soft tissue target. - Choice of Thermal Ablation: o Size, location and vascularity are the main denominators in deciding the thermal ablation technique. o Typically, lesions under 3cm can be managed with similar local recurrence risk by RFA, MWA or cryotherapy. o Larger lesions are better treated via MWA or cryotherapy given the ability to create larger ablation zones.
Pre-ablation embolisation may be considered in those with hypervascularity rendering risk of either heat sink effect and subsequent reduced ablation or bleeding post ablation, the latter more associated with cryotherapy. o For centrally located tumours, cryoblation is preferred given the reduced risk of urothelial injury. - Common thermal ablation complications and how to avoid them. o Avoiding thermal injury to the collecting system is especially important in relation to the pelvi-ureteric junction and adjacent proximal ureter.
Options include retrograde pyeloperfusion [Fig. 1] and choosing cryotherapy as the ablative therapy mode. o Thermal injury to adjacent organs, typically bowel, may be manipulated by a combination of patient positioning, hydro-/pneumodissection [Fig. 2] and, balloon interposition insufflation.