Objective To evaluate the dose distribution and clinical efficacy of hippocampal-sparing prophylactic cranial irradiation ( HS-PCI ) in patients with small cell lung cancer by using helical tomotherapy. Methods Clinical data of 49 patients with small cell lung cancer receiving HS-PCI using helical tomotherapy in Cancer Hospital between 2014 and 2017 were retrospectively analyzed. All patients received brain MRI to exclude the possibility of brain metastasis within 1 month after standard surgery or radio-and chemo-therapy. The prescription dose was 95% PTV,25 Gy in 10 fractions. The adverse reactions and cognitive functions of patients were observed before,6 months and 1 year after treatment,and the dose distribution in the hippocampal gyrus,survival rate and brain metastasis rate were analyzed. Results The median follow-up time was 16 months. The average dose in the hippocampal gyrus was 7. 23 Gy and 8. 46 Gy in the reduction region,which was reduced by 71. 88% and 66. 16% compared with the prescription dose. The maximum dose in the hippocampal gyrus was 10. 66 Gy and 15. 43 Gy in the reduction region. Among 49 patients,8 died,the 1-year survival rate was 85. 1% and the 2-year survival rate was 70. 3%.Nine patients (18. 3%) had brain metastases,and one of them with extensive multiple brain metastases (n＝13) presented with metastasis adjacent to the hippocampal gyrus. The main adverse reactions included mild headache, dizziness and brain edema,whereas no ≥ grade 2 adverse reactions occurred. At 6 months after treatment, the HVLT-R score was significantly decreased,and declined by 6. 78% at 12 months after treatment. The HVLT-R scores did not significantly differ in patients without brain metastasis before and 12 months after treatment ( P＞0. 05 ). Conclusion Application of HS-PCI using helical tomotherapy meets the dose requirement,effectively protects the cognitive function and yields slight adverse reactions.

BACKGROUND: The X-ray 9-point grading system is established based on cervical disc degeneration and its suitability for evaluation of lumbar disc degeneration has not been validated. OBJECTIVE: To investigate the feasibility of the evaluation of lumbar intervertebral disc degeneration using the 9-point grading system with X-ray, and to explore its clinical application value. METHODS: The correlation between 9-point grading system and Pfirrmann system was statistically analyzed. Magnetic resonance imaging (MRI) and X-ray images of 172 cases with lumbar disc degeneration or simple lumbago, who were treated in the Shanghai Changzheng Hospital from June 2013 to June 2016, were retrospectively analyzed. The MRI scores of lumbar disc degeneration were evaluated according to Pfirrmann standard, and the X-ray scores were evaluated according to 9-point grading system. The two groups of scores were respectively analyzed by the correlation and regression tests via Spearman rank sum test with SPSS software. RESULTS AND CONCLUSION: (1) MRI scores (the independent variable X): 2 cases scored 1; 8 cases scored 2; 55 cases scored 3; 84 cases scored 4; 23 cases scored 5. X-ray scores (the dependent variable Y): 2 cases scored 0; 6 cases scored 1; 21 cases scored 2; 43 cases scored 3; 40 cases scored 4; 26 cases scored 5; 16 cases scored 6; 8 cases scored 7; 7 cases scored 8; 3 cases scored 9. (2) The Spearman correlation test showed that significant positive correlation was found between Pfirrmann system and 9-point grading system (P <0.01). Significance test of correlation coefficient proved that there was significant linear correlation between Pfirrmann system and 9-point grading system. Further regression analysis showed the linear regression between Pfirrmann system and 9-point grading system. (3) These findings suggested that Pfirrmann system and X-ray 9-point grading system had a good consistency in evaluating lumbar disc degeneration. As a scientific, fast and effective evaluation method, the X-ray 9-point grading system has a certain reference value in the diagnoses of lumbar degenerative diseases.