NACT+IMRT versus NACT+IMRT+CCRT in locoregionally advanced NPC patients: a retrospective study

Effect of intensity-modulated radiation therapy on sciatic nerve injury caused by echinococcosis

Conventional radiotherapy has a good killing effect on femoral echinococcosis. However, the sciatic nerve around the lesion is irreversibly damaged owing to bystander effects. Although intensity-modulated radiation therapy shows great advantages for precise dose distribution into lesions, it is unknown whether intensity-modulated radiation therapy can perfectly protect the surrounding sciatic nerve on the basis of good killing of femoral echinococcosis foci. Therefore, this study comparatively analyzed differences between intensity-modulated radiation therapy and conventional radiotherapy on the basis of safety to peripheral nerves. Pure-breed Meriones meridiani with bilateral femoral echinococcosis were selected as the research object. Intensity-modulated radiation therapy was used to treat left femoral echinococcosis of Meriones meridianus, while conventional radiotherapy was used to treat right femoral echinococcosis of the same Meriones meridianus. The total radiation dose was 40 Gy. To understand whether intensity-modulated radiation therapy and conventional radiotherapy can kill femoral echinococcosis, trypan blue staining was used to detect pathological changes of bone Echinococcus granulosus and protoscolex death after radiotherapy. Additionally, enzyme histochemical staining was utilized to measure acid phosphatase activity in the protoscolex after radiotherapy. One week after radiotherapy, the overall structure of echinococcosis in bilateral femurs of Meriones meridiani treated by intensity-modulated radiation therapy disappeared. There was no significant difference in the mortality rate of protoscoleces of Echinococcus granulosus between the bilateral femurs of Meriones meridiani. Moreover, there was no significant difference in acid phosphatase activity in the protoscolex of Echinococcus granulosus between bilateral femurs. To understand the injury of sciatic nerve surrounding the foci of femoral echinococcosis caused by intensity-modulated radiation therapy and conventional radiotherapy, the ultrastructure of sciatic nerves after radiotherapy was observed by transmission electron microscopy. Additionally, apoptosis of neurons was examined using a terminal-deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, and expression of Bcl-2 and Bax in sciatic nerve tissue was detected by immunohistochemical staining and western blot assay. Our results showed that most neurons in the left sciatic nerve of Meriones meridiani with echinococcosis treated by intensity-modulated radiation therapy had reversible injury, and there was no obvious apoptosis. Compared with conventional radiotherapy, the number of apoptotic cells and Bax expression in sciatic nerve treated by intensity-modulated radiation therapy were significantly decreased, while Bcl-2 expression was significantly increased. Our findings suggest that intensity-modulated radiation therapy has the same therapeutic effect on echinococcosis as conventional radiotherapy, and can reduce apoptosis of the sciatic nerve around foci caused by radiotherapy. Experiments were approved by the Animal Ethics Committee of People’s Hospital of Xinjiang Uygur Autonomous Region, China (Approval No. 20130301A41) on March 1, 2013.

Effect of COVID-19 Epidemic on Delay of Diagnosis and Treatment Path for Patients with Nasopharyngeal Carcinoma

Introduction

2019 novel coronavirus disease (COVID-19) outbreaks have been occurring in China and other countries in the world. To prevent further spread of the disease, restrictions of population flow from the government and measures to reduce virus transmission from hospitals may lead to the delay of diagnosis and treatment in patients with nasopharyngeal carcinoma (NPC).

Methods

All NPC patients with radiotherapy indications were included from 20 weekdays before (group A) and after (group B) January 31, 2020, when the institute began to take measures against COVID-19. The waiting intervals of each step and variation from the diagnosis and treatment path of NPC between two groups were compared.

Results

Significant differences were found between the group A and group B in the median waiting days for pathological biopsy (5 vs 15, P=0.012), radiotherapy immobilization and simulation (3.5 vs 16.5, P<0.001), validation of position and plan (20 vs 61, P<0.001) and initiation of radiotherapy (28 vs 36, P=0.005). During the waiting period of radiotherapy, 32.4% of the NPC patients received an additional one cycle of chemotherapy to the original treatment strategy.

Conclusion

The prevalence of COVID-19 caused delay in the diagnosis and treatment of NPC patients to a certain extent. Additional chemotherapy could be considered to counteract the effect of treatment delay. More specific measures should be taken to balance the risk of delayed diagnosis and treatment of NPC and infection of COVID-19.