The use of 1H-magnetic resonance spectroscopy in studying radiation-induced injury of the brain in elderly and young patients with nasopharyngeal carcinoma

Background: This study aims to&nbsp;investigate&nbsp;the metabolic characteristics of radiotherapy-induced temporal lobe injury&nbsp;in elderly patients with nasopharyngeal carcinoma using 1H-magnetic resonance spectroscopy (MRS). Materials and Methods: Data were collected from 21 elderly patients&nbsp;and 33 young patients before and during therapy with different&nbsp;radiation dosages&nbsp;(20,&nbsp;40, and 60 Gy). The Student&rsquo;s t-test was used to compare the 1H-MRS-based N-acetyl aspartate /Creatine (NAA/Cr), Choline/Creatine (Cho/Cr), and NAA/Cho ratios in the temporal lobes. Results: Statistically significant&nbsp;differences in the NAA/Cr&nbsp;and&nbsp;NAA/Cho&nbsp;ratios was found between the two groups&nbsp;(P < 0.05) at 20, 40, and 60 Gy.&nbsp;The Cho/Cr ratios (20/40/60 Gy) were 1.82 &plusmn; 0.16/1.61 &plusmn; 0.29/1.37 &plusmn; 0.13&nbsp;and 1.77 &plusmn; 0.19/1.48 &plusmn; 0.17/1.06 &plusmn; 0.14 in the elderly and young patients, respectively. We found significant differences between the two groups at the dosages of 40 and 60 Gy (P<0.05). The decrease in the NAA/Cr&nbsp;and&nbsp;NAA/Cho ratios in the elderly group&nbsp;was&nbsp;significantly higher than that in the young patients with dosages of 20, 40, and 60 Gy. The decrease in the Cho/Cr ratio in the elderly group (2.15%/11.29%/12.90%) was&nbsp;significantly&nbsp;lower than that in the young patients (3.30%/15.93%/17.58%). Conclusion: Under the same radiotherapy pattern and radiation dosage, the injury to the neurons in the temporal lobes was significantly greater in elderly patients than&nbsp;that in young patients.&nbsp;The intervention conducted in elderly patients at a dosage of 20 Gy might help minimize the injury to the neurons. &nbsp;