## 4 Discussion  
The aim of our study was to elucidate the MR semeiotics of radiotherapy-induced changes on both neoplastic tissues and healthy ocular structures in patients with uveal melanoma undergoing secondary enucleation after proton beam radiotherapy. When performing this MR imaging-pathologic correlation we took into account certain histopathologic features and compared them with individually matched MR images. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**MR Finding** & **T2** & **T1** & **Gd-T1** & **DWI** \\ \hline \multirow{3}{*}{Uveitis} & \multirow{3}{*}{High signal} & \multirow{3}{*}{Low signal} & \multirow{3}{*}{Enhancement} & \multirow{3}{*}{High signal} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \multirow{3}{*}{Endophthalmitis} & \multirow{3}{*}{High signal of the anterior chamber} & \multirow{3}{*}{High signal of the anterior chamber and vitreous body} & \multirow{3}{*}{-} & \multirow{3}{*}{High signal} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \multirow{3}{*}{Vitreous hemorrhage} & \multirow{3}{*}{Variable signal intensity with possible fluid-fluid level} & \multirow{3}{*}{High signal of the anterior chamber and vitreous body} & \multirow{3}{*}{Moderately hyperintense} & \multirow{3}{*}{High signal} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \multirow{3}{*}{Optic nerve degeneration} & \multirow{3}{*}{Moderately hyperintense} & \multirow{3}{*}{-} & \multirow{3}{*}{-} & \multirow{3}{*}{-} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \multirow{3}{*}{Iris neovascularizationization} & \multirow{3}{*}{Low signal} & \multirow{3}{*}{Intermediate signal} & \multirow{3}{*}{Conspicuous enhancement of the ciliary body} & \multirow{3}{*}{-} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \multirow{3}{*}{Radiation-induced cataract} & \multirow{3}{*}{-} & \multirow{3}{*}{Peripheral high signal} & \multirow{3}{*}{Peripheral high signal} & \multirow{3}{*}{-} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & high signal \\ \hline \multirow{3}{*}{Periocular fibrotic adhesion} & \multirow{3}{*}{Low signal} & \multirow{3}{*}{Low signal} & \multirow{3}{*}{-} & \multirow{3}{*}{-} \\  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \cline{1-1} \cline{5-5}  & & & & \\ \hline \end{tabular}
\end{table} 
Table 6: MR imaging appearance of irradiated extratumoral ocular tissues. The histopathologic appearance of eyes with uveal melanoma undergoing secondary enucleation after radiotherapy is different from that of eyes undergoing primary enucleation. [PERSON] et al. [27] and [PERSON] et al. [19] described the histopathologic changes in eyes with uveal melanoma that had undergone secondary enucleation after proton beam radiotherapy and plaque brachytherapy, respectively, comparing them with those of primary enucleation. Irradiated lesions demonstrated more inflammation, necrosis, fibrosis, blood vessel damage, and hemorrhage, as well as fewer mitoses than nonirradiated tumors [19; 27]. As for extratumoral findings, eyes undergoing secondary enucleation had more vitreous hemorrhage and iris neovascularization [19].