Analysis of memory function and MRI changes in nasopharyngeal carcinoma patients after radiotherapy / 中华放射医学与防护杂志

ABSTRACT

Objective To analyse the memory function and MRI changes in local-advanced nasopharyngeal carcinoma patients before-and after-radiation.Methods Clinical data,dosimetric data,digital span score and MRI of 14 cases with nasopharyngeal carcinom treated in Zhejiang Cancer Hospital from November 2015 to August 2016 were retrospectively analysed.There were 1 case at T2 stage,7 cases at T3 and 6 at T4.They received IMRT or TOMO therapy concurrent with 2 cycles Nedaplatin after 2-3 cycles PF/TP induction chemotherapy.Results The IMRT dosimetric data of 9 cases were available.For hippocampus and temporal lobe,the mean volume was (15.17 ± 2.17) and (95.07 ± 12.26) cm3,respectively,while the mean dose was (1 154.06 ±771.63) and (1 306.61 ±603.69) Gy,and the max dose (3 797.61 ± 1 450.98) and (5 394.17 ± 982.28) Gy,respectively.The equivalent uniform dose (EUD) was (2 233.28 ±872.73) Gy for hippocampus and (3 113.11 ±603.69) Gy for temporal lobe.10 patients received digit span score before-and 3 months after-radiotherapy.The mean score of forward digit span was 8.8 ± 1.8 before radiation and 8.1 ± 1.59 at 3 months after radiation(P ＞ 0.05),while thatof backward digit span decreased from 6.2 ± 1.04 before radiation to 5.3 ± 2.36 at 3 months after radiation (t =3.25,P ＜ 0.05).9 patients' MRI were available.Volume reduction of temporal lobe was observed (t =4.57,P ＜ 0.01) by voxel-based morphometry (VBM).Conclusions Radiation-induced injury to hippocampus and temporal lobe is inevitable in local-advanced nasopharyngeal carcinoma patients.There might be some connection between memory loss and temporal lobe volume atrophy after radiotherapy.Enrollment of larger sample analysis is expected.