Objective To measure the setup errors and organ movements of patients with esophagus carcinoma during radiotherapy and find a reasonable margin from the clinic target volume (CTV) to the planning target volume (PTV). Methods (1) Set-up veri cation: Forty-two cases of untreated esophageal cancer were enrolled into this study. The physicist firstly made the planning according to the doctor requests and ensured the best distribution at the target. Thereafter, the 0° and 90° digitally reconstructed radiograph (DRR) was transmitted to the iView GT workshop. Meanwhile, two copies of cross-cut electronic portal image (EPI) were required before radiotherapy. Two doctors confirmed the variance of the osteal mark from the EPI and DRR,and output a 3D direction (left to right, superior to inferior, anterior to posterior) of the setup errors through the iView GT software. (2)Breathing motion:Ten cases of untreated esophageal cancer were enrolled into this study.Three distinct breathing levels were deflned: FB (free breathing), EBH (expiration with breath-held) and IBH (inspiration with breath-held). We gave the treatment planning in FB, then by moving the isocenter to EBH and IBH, we recalculated the dose distribution without changing the field angle, shape and weighing (Mus). Displacements were analyzed at four points (anterior, posterior, right lateral and left lateral) and five levels of target (upper, quarter, isocenter, three-quarter and lower). Results (1) The systematic setup errors were -0.23 cm, -0.02 cm and -0.06 cm, and the random errors were 0.44 cm, 0.45 cm and 0.44 cm at the direction of left to right(LR), superior to inferior (SI), anterior to posterior(AP), respectively. (2) The organ movements were 0.3 cm, 0.6cm and 0.3cm at the LR, SI, AP, respectively. Conclusions As an alternative, the root-sum-of-squares of set-up error and organ motion are suggested by σtot=√ (σITV2+σSM2). The CTV to PTV margins are 0.8cm left to right, 0.78cm superior to inferior, 0.5cm anterior to posterior.

Objective To evaluate the respiration-induced target volume motion in 3D-CRT for mid-thoracic esophageal carcinoma in order to guide the radiation oncologist to choose the expansion marginfor ITV.Methods Ten patients with mid-thoracic esophageal carcinoma were scanned by multi-spiral CTsimulator respectively in free breathing(FB),breath.hold after normal inspiration and expiration(IBH and EBH)with the same scanning range.Then the CT images of three series were transfefred to the treatmentplanning system.The target volume was outlined following the same standard.The motion of the centerpoint of GTV,the center point of each slice of GTV and the edge of the GTV in selected slice weremeasured respectively to obtain the comprehensive value of GTV motion。in order to find the appropriate IMvalue according to the 95％confidence interval of the GTV motion.Results①The GTV motion betweenIBH and EBH was(0.19±0.16)cm in the left.right direction,(0.54±0.19)cm in the cranial andcaudal irection.and(0.16±0.14)cm in anterior.posterior directions for the center of GTV,.For thecenter point of each slice of GTV.they ere(0.19±0.15)cm,(0.54±0.16)cm,(0.16±0.13)cm in three directions above.respectively.For the edge of the GTV in selected slice.they were(0.26±0.19)cm,(0.54±0.18)cm,(0.24±0.19)cm,respectively.The comprehensive value of GTV motion between IBH and EBH was(0.23±0.17)cm,(0.54±0.17)cm,(0.21±0.17)cm.respectively.The 95％confidence interval was 0.21-0.25 cm.0.53-0.56 cm and 0.19-0.22 cm in three directions.②The direction of GTV motion：No motion was noticed in 8.2％.while 73.3％to the right side and 18.5％to the left side in the left-right direction when IBH were compared with EBH.100％were moved to caudal in the the cranial and caudal direction[(0.54±0.17)cm].In the anterior-posterior direction,no motion was noticed in 8.2％,while 16.6％to the posterior and 75.2％to the anterior when IBH were compared with EBH.③The GTV motion was correlated with the vafiance of 1ung volumes in IBH-EBH(r=0.683,P=0.032)and not with GTV volume and length.Conclusions Respiration can induce target volume motion in 3 DCRT for mid-thoracic esophageal carcinoma.Compared to EBH.the GTV tends to move to the caudal,the anterior and the ight side in IBH.

Objective To evaluate the respiration-induced dosimetric variance in 3DCRT for midthoracic esophageal carcinoma, in order to guide the radiation oncologist to choose the expansion margin. Methods Ten patients with mid-thoracic esophageal carcinoma were scanned by multi-spiral CT simulator respectively in free breathing ( FB), breath-hold after normal inspiration and expiration ( IBH and EBH )with the same scanning range. Then the CT images of three series were transferred to the treatment planning system. The target volume was outlined following the same standard. Plan1 was designed in the images of FB and transported completely to the images of IBH and EBH as Plan2 and Plan3 respectively to observe the dosimetric variance in target volume. Results For GTV, there was a statistical difference only in V100 of the three plans ( H = 6.423, P = 0.040 ) and no significant difference was found in other indexes. For CTV, the V100 and V95 were better in Plan1 (F=3.992, P=0.030; H=9.920, P=0.007) and no significant difference was found in other indexes. While ()TV, the Dmin, V100 and V95 was better in Plan1 ( F = 3.677, P = 0.039; F = 4.539, P = 0.020; H = 6.846, P = 0.033 ) and no significant difference was found in other indexes. There were no significant differences in all the indexes for the spinal cord and lung in the three plans. Conclusions The change in dose distribution was not so much with the standard expansion. It can meet the needs of clinical treatment.

Objective:To explore the effect and molecular mechanism of circ_0000263 on HeLa cell activity, apoptosis, telomerase activity, and radiosensitivity.Methods:The Hela cells were divided into si-NC, si-circ, vector, circ_0000263, anti-NC, anti-miR-338-3p, miR-NC, miR-338-3p, si-circ+anti-NC, si-circ+ anti-miR-338-3p, si-circ+vector, si-circ+TERT, sh-NC, sh-circ groups. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expressions of circ_0000263 and miR-338-3p. Cell clone formation array was used to detect cell survival; cell counting kit-8 (CCK-8) to detect cell proliferation; flow cytometry to detect apoptosis; western blot method to detect the expressions of proliferating cell nuclear antigen (PCNA), Cleaved-casp3, telomerase reverse transcriptase (TERT) proteins; double luciferase assay to detect the targeting relationships of circ_0000263 and miR-338-3p, miR-338-3p and TERT; telomere repeat amplification enzyme linked immunosorbent assay (TRAR-ELISA) to detect telomerase activity.Results:Circ_0000263 was highly expressed in Hela cells, miR-338-3p was low expressed, and TERT was highly expressed; circ_0000263 was also highly expressed in Hela cells treated with radiation ( P＜0.05). Knockdown of circ_0000263 inhibited the clone formation and cell proliferation ability of HeLa cells, and enhanced the radiosensitivity and apoptosis of HeLa cells. In contrast, knockdown of circ_0000263 decreased PCNA protein expression level and enhanced Cleaved-casp3 protein expression level in HeLa cells ( P＜0.05). The apoptosis rate in the si-circ group was (13.19±1.12)%, which was higher than (6.80±0.62)% of si-NC group ( P＜0.05). The apoptosis rate in the si-circ+4 Gy group was (24.82±1.57)%, which was higher than (17.00±0.96)% of si-NC+4 Gy group ( P＜0.05). Circ_0000263 targeted regulated miR-338-3p, and miR-338-3p targeted regulated TERT. MiR-338-3p was lowly expressed in HeLa cells, and knockdown of circ_0000263 elevated miR-338-3p expression level in HeLa cells. Circ_0000263 regulated TERT expression and inhibited telomerase activity through miR-338-3p. MiR-338-3p/TERT can restore the effect of circ_0000263 on the radiosensitivity of Hela cells. The apoptosis rate in the si-circ+anti-NC group was (27.37±0.89)%, which was higher than (18.22±1.18)% of the si-circ+anti-miR-338-3p group ( P＜0.05). The apoptosis rate in the si-circ+vector group was (27.55±0.48)%, which was higher than (20.10±0.68)% of si-circ+TERT group ( P＜0.05). After 72 hours of radiation by 4 Gy, the cell survival fraction of si-circ+anti-NC group was 0.41±0.02, which was lower than 0.66±0.03 of the si-circ+anti-miR-338-3p group ( P＜0.05); the cell survival fraction of si-circ+vector group was 0.42±0.05, which was lower than 0.70±0.03 of si-circ+TERT group ( P＜0.05). Conclusion:Inhibiting the expression of circ_0000263 supresses the proliferation of Hela cells by regulating miR-338-3p/TERT, promotes apoptosis, inhibits telomerase activity, increases the radiosensitivity of cancer cells, and provides a theoretical basis for improving the radiosensitivity of Hela cells.

Objective:To explore the effect and molecular mechanism of circ_0000263 on HeLa cell activity, apoptosis, telomerase activity, and radiosensitivity.Methods:The Hela cells were divided into si-NC, si-circ, vector, circ_0000263, anti-NC, anti-miR-338-3p, miR-NC, miR-338-3p, si-circ+anti-NC, si-circ+ anti-miR-338-3p, si-circ+vector, si-circ+TERT, sh-NC, sh-circ groups. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expressions of circ_0000263 and miR-338-3p. Cell clone formation array was used to detect cell survival; cell counting kit-8 (CCK-8) to detect cell proliferation; flow cytometry to detect apoptosis; western blot method to detect the expressions of proliferating cell nuclear antigen (PCNA), Cleaved-casp3, telomerase reverse transcriptase (TERT) proteins; double luciferase assay to detect the targeting relationships of circ_0000263 and miR-338-3p, miR-338-3p and TERT; telomere repeat amplification enzyme linked immunosorbent assay (TRAR-ELISA) to detect telomerase activity.Results:Circ_0000263 was highly expressed in Hela cells, miR-338-3p was low expressed, and TERT was highly expressed; circ_0000263 was also highly expressed in Hela cells treated with radiation ( P＜0.05). Knockdown of circ_0000263 inhibited the clone formation and cell proliferation ability of HeLa cells, and enhanced the radiosensitivity and apoptosis of HeLa cells. In contrast, knockdown of circ_0000263 decreased PCNA protein expression level and enhanced Cleaved-casp3 protein expression level in HeLa cells ( P＜0.05). The apoptosis rate in the si-circ group was (13.19±1.12)%, which was higher than (6.80±0.62)% of si-NC group ( P＜0.05). The apoptosis rate in the si-circ+4 Gy group was (24.82±1.57)%, which was higher than (17.00±0.96)% of si-NC+4 Gy group ( P＜0.05). Circ_0000263 targeted regulated miR-338-3p, and miR-338-3p targeted regulated TERT. MiR-338-3p was lowly expressed in HeLa cells, and knockdown of circ_0000263 elevated miR-338-3p expression level in HeLa cells. Circ_0000263 regulated TERT expression and inhibited telomerase activity through miR-338-3p. MiR-338-3p/TERT can restore the effect of circ_0000263 on the radiosensitivity of Hela cells. The apoptosis rate in the si-circ+anti-NC group was (27.37±0.89)%, which was higher than (18.22±1.18)% of the si-circ+anti-miR-338-3p group ( P＜0.05). The apoptosis rate in the si-circ+vector group was (27.55±0.48)%, which was higher than (20.10±0.68)% of si-circ+TERT group ( P＜0.05). After 72 hours of radiation by 4 Gy, the cell survival fraction of si-circ+anti-NC group was 0.41±0.02, which was lower than 0.66±0.03 of the si-circ+anti-miR-338-3p group ( P＜0.05); the cell survival fraction of si-circ+vector group was 0.42±0.05, which was lower than 0.70±0.03 of si-circ+TERT group ( P＜0.05). Conclusion:Inhibiting the expression of circ_0000263 supresses the proliferation of Hela cells by regulating miR-338-3p/TERT, promotes apoptosis, inhibits telomerase activity, increases the radiosensitivity of cancer cells, and provides a theoretical basis for improving the radiosensitivity of Hela cells.