Objective To study the feasibility of helical tomoterapy (HT) at prescription dose escalation for nasopharyngeal carcinoma (NPC).Methods Static-IMRT (sIMRT) and HT plans were designed for 10 nasopharyngeal carcinoma patients which were treated by sIMRT and HT treatment plan.Prescription dose was escalated for each plan until any organs at risk (OARs) reached the quantitative analysis of normal tissue effects within the clinical threshold.Dosimetric factors of target and OARs were analyzed for both sIMRT and HT plans.Results Compared with sIMRT plan, prescribed dose of HT plans increased 42.6％ (t =6.373, P ＜ 0.01), and the homogeneity index was also improved (t =-2.288, P＜0.05);the conformity index decreased (P ＞ 0.05).The limits of HT prescribed dose escalation were spinal cord (2 cases), optic nerve (5 cases) and brainstem (3 cases).The limits of sIMRT prescribed dose escalation were lens (1 case), spinal cord (1 case) and parotid (8 cases).Conclusions HT could improve prescription dose of nasopharyngeal carcinoma while keeping the OARs safe.Compared with sIMRT, HT technology might be used at high dose NPC radiotherapy.

Objective To investigate the distribution rules of setup errors in different locations for tomotherapy.Methods 151 patients induding 53 head and neck tumors,45 thoracic tumors,20 abdominal tumors,and 33 pelvic tumors,who accepted tomotherapy were retrospectively analyzed in this study.The planning CT images of patients were obtained in simulation,and all patients underwent megavoltage CT (MVCT) scan before radiotherapy.And the setup errors were calculated by rigid registering MVCT images to planning CT images,and setup errors on + x(left),-x(right),+ y(in),-y(out),+z(ventral),-z (dorsal)axes were analyzed respectively.Results A total of 3 281 MVCT scans were performed on 151 patients,The setup errors on +x (left),-x(right),+y(in),-y(out),+z (ventral),-z (dorsal)axes were (1.61 ± 1.21),(1.76 ±2.11),(2.26 ± 1.74),(1.83 ± 1.47),(3.24±1.76) and (1.75 ± 1.61)mm for head and neck tumors;(2.43 ±1.88),(2.55 ± 1.92),(3.06 ±2.64),(3.90 ±2.91),(6.71 ±3.46) and (2.64 ±2.77)mm for thoracic tumors;(3.67±3.06),(2.37±1.77),(3.18±1.96),(3.98±3.01),(6.74±3.25) and (1.92±2.00) mm for abdominal tumors;(2.92 ±2.13),(2.17±1.68),(3.50±2.61),(3.72±2.66),(7.18± 3.43) and (1.92 ± 1.61)mm for pelvic tumors,respectively.The setup errors were different between +z and-z with statistically significant in all tumors (t =-4.119、-5.033、-3.763、-5.057,P ＜ 0.05).The setup errors on + z direction of patients immobilized with thermoplastic mask were smaller than those immobilized with vacuum cushions for thoracic tumors (t =-2.357,P ＜ 0.05).Conclusions The setup errors of head and neck tumors are less than other parts tumor in tomotherapy.The patients immobilized with thermoplastic mask can reduce the setup errors for thoracic tumors.The heterogeneity of setup errors on ventral-dorsal directions for the all parts of tumors should not be ignored.

OBJECTIVE To study active components and antitussive effect of aboveground part of Pinellia ternata （non- medicinal stems and leaves）， and compare them with the underground part of P. ternata （medicinal underground tubers）， providing scientific basis for the comprehensive utilization and product development of P. ternata. METHODS TLC， GC， HPLC and UPLC- MS/MS were used for qualitative and quantitative analysis of amino acids， volatile oil， total flavonoids and succinic acid from the aboveground and underground parts of P. ternata. The antitussive effects of the aboveground and underground parts of P. ternata were compared and studied through cough inducing experiment with concentrated ammonia water. RESULTS Results of TLC showed that at the corresponding positions on the chromatograms of the reference substances of P. ternata， and arginine， alanine， valine， leucine and rutin control， the aboveground and underground parts of P. ternata showed spots of the same color. Results of GC showed that the similarity among characteristic chromatograms of volatile oil from aboveground and underground parts of P. ternata was 0.767； results of HPLC and UPLC-MS/MS showed that compared with underground parts of P. ternata， the contents of succinic acid， quercetin， kaempferol and isorhamnetin increased by 0.15%， 0.15%， 0.09% and 0.03%， and aspartate content decreased by 2.5 mg/g. Pharmacodynamics results showed that compared with model control group， the cough incubation period of rats was prolonged significantly in administration groups （P＜0.05）， and the cough frequency within 3 min was significantly decreased （P＜0.05）； there was no statistical significance in the cough frequency within 3 min among administration groups （P＞0.05）. CONCLUSIONS The composition of amino acids， volatile oils and total flavonoids in aboveground part of P. ternata are similar to underground part of P. ternata， while the content of aspartic acid is lower than that in underground part. The aboveground part of P. ternata can prolong the cough incubation period of rats and reduce the number of coughs， which has a certain antitussive effect， but the effect is slightly weaker than that of the underground part.