## 3 Discussion
### RecIST Criteria
Thirty mccRCC patients were included in the study, 25 of whom were treated with nivolumab and 5 with pembrolizumab. Ninety-three percent of patients underwent prior nephrectomy. Furthermore, 93% of patients underwent 1-2 prior systemic therapies, and 3 patients underwent 3 prior systemic treatments. The objective response rates during therapy were 30% for RECIST 1.1 (95% confidence interval (CI): 13.6-46.4) and 50% for iRECIST (95% confidence interval (CI): 13.6-46.4). The median time to progression for iRECIST was not reached, whereas for RECIST 1.1 it was 170 days (\(p\) = 0.04). Eight patients had discordance across criteria, six of whom showed pseudoppression, while two were evaluated as iUPD with no subsequent confirmation of iPD. Furthermore, the iRECIST criteria showed five more patients with iPR and one more with iCR. Therefore, significant differences between iRECIST and RECIST 1.1 were shown (\(p\) < 0.001) [28]. These studies have demonstrated that treatment with IOVE therapy is correlated with a better objective imaging response compared to IOIO therapy, as well as that the presence of lung metastases, nephrectomy, and favorable IMDC risk are correlated with experiencing an objective imaging response. Furthermore, it has been demonstrated that treatment with ICIs has a different response rate at the level of the soft tissues, and that the iRECIST criteria have a greater ability to evaluate immune-related atypical responses than the RECIST 1.1 criteria. All of these studies had a level of evidence of 2. [PERSON] et al. [29] evaluated overall survival, time to treatment discontinuation, and progression-free survival in a retrospective analysis of mRCC patients treated with tyrosine kinase inhibitors, mTOR inhibitors, or ICIs, divided by age: 159 patients (19%) were aged \(\geq\) 75 years, 324 patients (39%) were aged 65-74 years, and 355 patients (42%) were aged \(<\) 65 years. The number of patients treated with tyrosine kinase inhibitors was 729 (87%), while 43 (5%) were treated with mTOR inhibitors and 67 (8%) were treated with ICIs. Multivariate analysis, adjusted for IMDC risk score and histology, showed that age had no impact on overall survival (aHR 1.0; 95% CI 0.99-1.02, \(p\) = 0.2), time to treatment discontinuation (aHR 1.0; 95% CI 0.99-1.01, \(p\) = 0.4), or progression-free survival (aHR 1.0, 95% CI 0.99-1.01; \(p\) = 0.9). This study demonstrated that elderly patients with mRCC were more prone to toxicity, but age did not affect the results [29]. Regardless of the age of the patients, all of these results, taken together, can be helpful in selecting the best treatment option in the management and the CT-based follow-up of mRCC patients. Data and results of clinical studies related to the RECIST criteria are summarized in Table 1.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Authors** & **[PERSON] et al. (2022) [22]** & **[PERSON] et al. (2022) [26]** & **[PERSON] et al. (2020) [28]** \\ \hline \multirow{4}{*}{Objective} & \multirow{4}{*}{ \begin{tabular}{c} To compare the likelihood of objective \\ imaging response to IOIO vs. IOVE \\ therapies \\ \end{tabular}  } & Evaluate the different organ responses to nivolumab in surgically treated & To compare the iRECIST and RECIST \\  & & & mRCC by describing response \\  & & & patterns and discrepancies between \\  & & the RECIST 1.1 and iRECIST criteria & & inhibitory therapy \\ \hline Number of patients & 899 patients & 21 patients & 30 patients \\ \hline \multirow{4}{*}{Histotypes} & \multirow{4}{*}{ \begin{tabular}{c} 702 c\textbackslash{} \\ 197 non-ccRCC \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} 18 c\textbackslash{} \\ 2 pRCC \\ carcinoma \\ \end{tabular}  } & \multirow{4}{*}{ \begin{tabular}{c} 30 c\textbackslash{} \\ 30 ccRCC \\ \end{tabular}