In another prospective study of 10 patients with metastatic RCC, 18F-sodium fluoride (NaF) PET/CT was found to be significantly more sensitive for the detection of RCC skeletal metastases than Tc-99m bone scintigraphy or CT, with sensitivities of 100%, 29%, and 46%, respectively. CT and Tc-99m bone scintigraphy in this study identified only 65% of the metastases detected by NaF-PET/CT [55]. A small series has also shown that 68Ga-labeled prostate-specific membrane antigen PET/CT can help to detect metastatic lesions in patients with the clear cell subtype of RCC [56]. Variant 2: Follow-up for clinically localized renal cell carcinoma; post ablation. Among several techniques available for the ablation of localized RCC, thermal ablation techniques using radiofrequency ablation, microwave ablation, or cryoablation are the most commonly used; these procedures can be performed percutaneously or laparoscopically [57-59]. Ablation therapy is currently considered a less invasive alternative to RN or PN for renal masses measuring <4 cm (ie, T1a tumors) [2,9,11]. There is growing evidence suggesting that ablation of small renal masses produces oncologic outcomes that approach those of surgical excision but with a significantly lower overall complication rate and a significantly lower decline in renal function [5- 7,57,60-67]. Because of the higher rate of local recurrence seen with ablation than with surgical excision, ablation requires more frequent use of imaging to monitor tumor involution over time [3,29,65]. Early detection of treatment failure or recurrence is important to maximize retreatment potential [65,68]. Because the risk of local recurrence is greater than the risk of distant metastases in this patient population, surveillance strategies should prioritize evaluation of the treatment bed. Guidelines recommend performing CT or MRI of the abdomen at 3 and 6 months after ablation and yearly thereafter for 5 years [2,9,11].
Post Treatment Follow up and Active Surveillance of Renal Cell Carcinoma. In another prospective study of 10 patients with metastatic RCC, 18F-sodium fluoride (NaF) PET/CT was found to be significantly more sensitive for the detection of RCC skeletal metastases than Tc-99m bone scintigraphy or CT, with sensitivities of 100%, 29%, and 46%, respectively. CT and Tc-99m bone scintigraphy in this study identified only 65% of the metastases detected by NaF-PET/CT [55]. A small series has also shown that 68Ga-labeled prostate-specific membrane antigen PET/CT can help to detect metastatic lesions in patients with the clear cell subtype of RCC [56]. Variant 2: Follow-up for clinically localized renal cell carcinoma; post ablation. Among several techniques available for the ablation of localized RCC, thermal ablation techniques using radiofrequency ablation, microwave ablation, or cryoablation are the most commonly used; these procedures can be performed percutaneously or laparoscopically [57-59]. Ablation therapy is currently considered a less invasive alternative to RN or PN for renal masses measuring <4 cm (ie, T1a tumors) [2,9,11]. There is growing evidence suggesting that ablation of small renal masses produces oncologic outcomes that approach those of surgical excision but with a significantly lower overall complication rate and a significantly lower decline in renal function [5- 7,57,60-67]. Because of the higher rate of local recurrence seen with ablation than with surgical excision, ablation requires more frequent use of imaging to monitor tumor involution over time [3,29,65]. Early detection of treatment failure or recurrence is important to maximize retreatment potential [65,68]. Because the risk of local recurrence is greater than the risk of distant metastases in this patient population, surveillance strategies should prioritize evaluation of the treatment bed. Guidelines recommend performing CT or MRI of the abdomen at 3 and 6 months after ablation and yearly thereafter for 5 years [2,9,11].