Malignant tumors are major causes of morbidity and mortality in China.Despite advances in surgical,radiological,chemotherapeutic,molecular targeting,and immunotherapeutic treatments,patients with malignant tumors stil...Malignant tumors are major causes of morbidity and mortality in China.Despite advances in surgical,radiological,chemotherapeutic,molecular targeting,and immunotherapeutic treatments,patients with malignant tumors still have poor prognoses.Low-dose-rate brachytherapy,specifically 125I seed implantation,is beneficial because of its high local delivery dose and minimal damage to surrounding tissues.Consequently,it has gained increasing acceptance as a treatment modality for various malignant tumors.In this study,we explored the fundamental principles,clinical applications,and new technologies associated with 125I radioactive seed implantation.展开更多
AIM To evaluate a 3 D-printed coplanar template for iodine-125 seed implantation therapy in patients with pancreatic cancer. METHODS A retrospective analysis of our database was performed, and a total of 25 patients w...AIM To evaluate a 3 D-printed coplanar template for iodine-125 seed implantation therapy in patients with pancreatic cancer. METHODS A retrospective analysis of our database was performed, and a total of 25 patients with pancreatic cancer who underwent iodine-125 seed implantation between January 2014 and November 2017 were analyzed. Of these, 12 implantations were assisted by a 3 D-printed coplanar template(group A), and 13 implantations performed freehand were selected as a control group(group B). A 3 D coplanar template was designed and printed according to a preoperative CT scan and treatment planning system. The iodine-125 seeds were then implanted using the template as a guide. Dosimetric verification was performed after implantation. Pre-and postoperative D90, V100, and V150 were calculated. The success rate of iodine-125 seed implantation, dosimetric parameters, and complications were analyzed and compared between the two groups.RESULTS Iodine-125 seed implantation was successfully performed in both groups. In group A, the median pre-and postoperative D90 values were 155.32 ± 8.05 Gy and 154.82 ± 16.43 Gy, respectively; the difference between these values was minimal and not statistically significant(P > 0.05). Postoperative V100 and V150 were 91.05% ± 4.06% and 64.54% ± 13.40%, respectively, which met the treatment requirement. A better dosimetric parameter was observed in group A than in group B, and the difference was statistically significant(V100: 91.05% ± 4.06% vs 72.91% ± 13.78%, P < 0.05). No major procedure-related complications were observed in either group. For group A, mild hemorrhage was observed in 1 patient with a peritoneal local hematoma due to mesenteric vein damage from the iodine-125 seed implantation needle. The hematoma resolved spontaneously without treatment. Postoperative blood amylase levels remained within the normal range for all patients.CONCLUSION A 3 D-printed coplanar template appears to be a safe and effective iodine-125 seed implantation guidance tool to improve implantation accuracy and optimize dosimetric distribution.展开更多
AIM:To investigate the therapeutic effect of radical treatment and palliative treatment in stage Ⅳ pancreatic cancer patients.METHODS:81 patients were enrolled in the study.Radical treatment was performed on 51 patie...AIM:To investigate the therapeutic effect of radical treatment and palliative treatment in stage Ⅳ pancreatic cancer patients.METHODS:81 patients were enrolled in the study.Radical treatment was performed on 51 patients,while 30 patients were put under palliative treatment.The procedural safety and interval survival for stage Ⅳ pancreatic cancer(IS-Ⅳ) was assessed by almost 2.5 years of follow-ups.The IS-Ⅳ of patients under the two kinds of treatment,and the effects of treatment timing and frequency on IS-Ⅳ,were compared.RESULTS:The IS-Ⅳ of patients who received radical treatment was significantly longer than those who received palliative treatment(P < 0.001).The IS-Ⅳ of patients who received delayed radical or palliative treatment was longer than those who received accordingly timely treatment(P = 0.0034 and 0.0415,respectively).Multiple treatments can play an important role in improving the IS-Ⅳ of patients who received radical treatment(P = 0.0389),but not for those who received palliative treatment(P = 0.99).CONCLUSION:The effect of radical treatment was significantly more obvious than that of palliative treatment,and multiple radical treatments may contribute more to patients than a single radical treatment.展开更多
This case report describes a patient with advanced gallbladder cancer who developed septic shock associated with iodine-125(^(125)I)seed implantation.The treatment process is described to provide a clinical reference ...This case report describes a patient with advanced gallbladder cancer who developed septic shock associated with iodine-125(^(125)I)seed implantation.The treatment process is described to provide a clinical reference for similar cases.A 52-year-old woman with recurrence of advanced gallbladder cancer underwent ^(125)I seed implantation and developed postoperative sepsis with septic shock.The blood culture suggested infection with Aeromonas caviae and Enterococcus faecalis.Vancomycin and imipenem were immediately administered according to the drug sensitivity results,along with immunoglobulin therapy and vasoactive drugs.The patient’s condition gradually stabilized after comprehensive treatment.Sepsis with septic shock is a rare but potentially fatal complication of ^(125)I seed implantation.Timely administration of broad-spectrum antibiotics,immunoglobulin therapy,and vasoactive drugs is very important to stabilize the patient’s condition.Our treatment of this patient can serve as a reference for clinicians to manage this complication in similar cases.展开更多
The use of iodine-125(125I) in cancer treatment has been shown to relieve patients' pain. Considering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we...The use of iodine-125(125I) in cancer treatment has been shown to relieve patients' pain. Considering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that 125 I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. 125 I seeds with different radioactivity(0, 14.8, 29.6 MBq) were implanted separately through L4–5 and L5–6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion. von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting 125 I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radioactivity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechanical pain threshold was elevated after implanting 125 I seeds without influencing motor functions of the hind limb, although cell injury was present.展开更多
Objectives: To explore the clinical efficacy and survival of CT-guided Iodine-125 radioactive seed implantation in the treatment of stage Ⅳ primary hepatocellular carcinoma.Methods: A retrospective study of 62 patien...Objectives: To explore the clinical efficacy and survival of CT-guided Iodine-125 radioactive seed implantation in the treatment of stage Ⅳ primary hepatocellular carcinoma.Methods: A retrospective study of 62 patients with primary hepatocellular carcinoma in our hospital from January2017 to December 2018 [60 males, 2 females, age(52.76 ± 10.82) years old], All patients were implanted with Iodine-125 radioactive seeds under CT guidance, followed up regularly after operation to observe the clinical efficacy, including comparison of changes in cancer size before and after treatment, tumor marker AFP, and improvement in complications such as abdominal pain and ascites. Follow-up 3–36 months to assess patient survival.Results: Among the 62 patients, 3 months after Iodine-125 radioactive seed implantation, 5 cases(8.1%) had complete remission of cancer, 33 cases(53.2%) had partial remission, 12 cases(19.4%) had stable lesions, and 12 cases(19.4%) had disease progression. The effective rate was 61.3%. The tumor volume(31.44 ± 14.51 cm3) was significantly smaller than before(50.96 ± 30.13 cm3)(t=5.303, p < 0.05). The tumor marker AFP(69.28 ±50.99) ug/L of 3 months after implantation was significantly lower than that before treatment(90.63 ± 68.58)ug/L(t=3.702, P < 0.05). The average survival time of Iodine-125 seed implantation for stageⅣhepatocellular carcinoma is 11.47 ± 0.85 months, and the median survival time is 9 months. The survival time of the group with better pathological differentiation(grade Ⅰ+ⅡⅠ) was significantly better than that of the group with poor differentiation(grade Ⅲ+Ⅳ)(x2=6.869 p < 0.05). Among the 38 patients with different degrees of abdominal pain,22 patients improved better than before;15 of 28 patients with different degrees of ascites were better than before. All patients had no serious complications related to treatment.Conclusions: Iodine-125 radioactive seed implantation therapy can safely and effectively treat hepatocellular carcinoma, and relieve the clinical symptoms of abdominal pain and ascites.展开更多
AIM: To evaluate the feasibility, efficacy and safety of intraoperative radiofrequency ablation (RFA) combined with 125 iodine seed implantation for unresectable pancreatic cancer. METHODS: Thirty-two patients (21 mal...AIM: To evaluate the feasibility, efficacy and safety of intraoperative radiofrequency ablation (RFA) combined with 125 iodine seed implantation for unresectable pancreatic cancer. METHODS: Thirty-two patients (21 males and 11 females) at the age of 68 years (range 48-90 years) with unresectable locally advanced pancreatic cancer admitted to our hospital from January 2006 to May 2008 were enrolled in this study. The tumor, 4-12 cm in diameter, located in pancreatic head of 23 patients and in pancreatic body and tail of 9 patients, was found to be unresectable during operation. Diagnosis of pancreatic cancer was made through intraoperative biopsy. Patients were treated with FRA combined with 125 iodine seed implantation. In brief, a RFA needle was placed, which was confirmed by intraoperative ultrasound to decrease the potential injury of surrounding vital structures, a 125 iodine seed was implanted near the blood vessels and around the tumor border followed by bypass palliative procedure (cholangio-jejunostomy and/or gastrojejunostomy) in 29 patients.RESULTS: The serum CA 19-9 level was decreased from 512 ± 86 U/mL before operation to 176 ± 64 U/mL, 108 ± 42 U/mL and 114 ± 48 U/mL, respectively, 1, 3 and 6 mo after operation (P < 0.05). The pain score on day 7 after operation, 1 and 3 mo after combined therapy was decreased from 5.86 ± 1.92 before operation to 2.65 ± 1.04, 1.65 ± 0.88 and 2.03 ± 1.16, respectively, after operation (P < 0.05). The rate of complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD) in 32 patients was 21.8% (7/32), 56.3% (18/32), 15.6% (5/32) and 6.3% (2/32), respectively, 6 mo after operation, with a median overall survival time of 17. 5 mo. The median survival time of patients at stage Ⅲ was longer than that of those at stage Ⅳ (19 mo vs 10 mo, P = 0.0026). The median survival time of patients who received and did not receive chemotherapy after operation was 20 mo and 16 mo, respectively (P = 0.0176). Of the 32 patients, 3 (10.6%) experienced postoperative complications including transient biliary leaks in 2 patients and acute pancreatitis in 1 patient. All the patients recovered well after conservative support treatment. CONCLUSION: Intraoperative RFA combined with 125 iodine seed implantation is a feasible and safe procedure for unresectable pancreatic cancer with acceptable minor complications, and can prolong the survival time of patients, especially those at stage Ⅲ.展开更多
AIM:To determine the mechanism of the radiationinduced biological effects of 125I seeds on pancreatic carcinoma cells in vitro.METHODS:SW1990 and PANC-1 pancreatic cancer cell lines were cultured in DMEM in a suitable...AIM:To determine the mechanism of the radiationinduced biological effects of 125I seeds on pancreatic carcinoma cells in vitro.METHODS:SW1990 and PANC-1 pancreatic cancer cell lines were cultured in DMEM in a suitable environment.Gray’s model of iodine-125(125I)seed irradiation was used.In vitro,exponential phase SW1990,and PANC-1cells were exposed to 0,2,4,6,and 8 Gy using 125I radioactive seeds,with an initial dose rate of 12.13c Gy/h.A clonogenic survival experiment was performed to observe the ability of the cells to maintain their clonogenic capacity and to form colonies.Cell-cycle and apoptosis analyses were conducted to detect the apoptosis percentage in the SW1990 and PANC-1 cells.DNA synthesis was measured via a tritiated thymidine(3H-Td R)incorporation experiment.After continuous low-dose-rate irradiation with 125I radioactive seeds,the survival fractions at 2 Gy(SF2),percentage apoptosis,and cell cycle phases of the SW1990 and PANC-1 pancreatic cancer cell lines were calculated and compared.RESULTS:The survival fractions of the PANC-1 andSW1990 cells irradiated with 125I seeds decreased exponentially as the dose increased.No significant difference in SF2 was observed between SW1990 and PANC-1 cells(0.766±0.063 vs 0.729±0.045,P<0.05).The 125I seeds induced a higher percentage of apoptosis than that observed in the control in both the SW1990and PANC-1 cells.The rate of apoptosis increased with increasing radiation dosage.The percentage of apoptosis was slightly higher in the SW1990 cells than in the PANC-1 cells.Dose-dependent G2/M cellcycle arrest was observed after 125I seed irradiation,with a peak value at 6 Gy.As the dose increased,the percentage of G2/M cell cycle arrest increased in both cell lines,whereas the rate of DNA incorporation decreased.In the 3H-Td R incorporation experiment,the dosimetry results of both the SW1990 and PANC-1cells decreased as the radiation dose increased,with a minimum at 6 Gy.There were no significant differences in the dosimetry results of the two cell lines when they were exposed to the same dose of radiation.CONCLUSION:The pancreatic cancer cell-killing effects induced by 125I radioactive seeds mainly occurred via apoptosis and G2/M cell cycle arrest.展开更多
文摘Malignant tumors are major causes of morbidity and mortality in China.Despite advances in surgical,radiological,chemotherapeutic,molecular targeting,and immunotherapeutic treatments,patients with malignant tumors still have poor prognoses.Low-dose-rate brachytherapy,specifically 125I seed implantation,is beneficial because of its high local delivery dose and minimal damage to surrounding tissues.Consequently,it has gained increasing acceptance as a treatment modality for various malignant tumors.In this study,we explored the fundamental principles,clinical applications,and new technologies associated with 125I radioactive seed implantation.
基金Supported by the National Natural Science Foundation of China,No.81771949 and No.81471808the Project of Medical Key Specialty of Shanghai Municipality,No.ZK2015A22the Science and Technology Commission of Shanghai Municipality,No.18411968600
文摘AIM To evaluate a 3 D-printed coplanar template for iodine-125 seed implantation therapy in patients with pancreatic cancer. METHODS A retrospective analysis of our database was performed, and a total of 25 patients with pancreatic cancer who underwent iodine-125 seed implantation between January 2014 and November 2017 were analyzed. Of these, 12 implantations were assisted by a 3 D-printed coplanar template(group A), and 13 implantations performed freehand were selected as a control group(group B). A 3 D coplanar template was designed and printed according to a preoperative CT scan and treatment planning system. The iodine-125 seeds were then implanted using the template as a guide. Dosimetric verification was performed after implantation. Pre-and postoperative D90, V100, and V150 were calculated. The success rate of iodine-125 seed implantation, dosimetric parameters, and complications were analyzed and compared between the two groups.RESULTS Iodine-125 seed implantation was successfully performed in both groups. In group A, the median pre-and postoperative D90 values were 155.32 ± 8.05 Gy and 154.82 ± 16.43 Gy, respectively; the difference between these values was minimal and not statistically significant(P > 0.05). Postoperative V100 and V150 were 91.05% ± 4.06% and 64.54% ± 13.40%, respectively, which met the treatment requirement. A better dosimetric parameter was observed in group A than in group B, and the difference was statistically significant(V100: 91.05% ± 4.06% vs 72.91% ± 13.78%, P < 0.05). No major procedure-related complications were observed in either group. For group A, mild hemorrhage was observed in 1 patient with a peritoneal local hematoma due to mesenteric vein damage from the iodine-125 seed implantation needle. The hematoma resolved spontaneously without treatment. Postoperative blood amylase levels remained within the normal range for all patients.CONCLUSION A 3 D-printed coplanar template appears to be a safe and effective iodine-125 seed implantation guidance tool to improve implantation accuracy and optimize dosimetric distribution.
基金Supported by The Hai Zhu District Scientific and Technologica Plan,No.2010-Y-27"Comprehensive Research of Pancreati Cancer Cryotherapy",Guangzhou,China
文摘AIM:To investigate the therapeutic effect of radical treatment and palliative treatment in stage Ⅳ pancreatic cancer patients.METHODS:81 patients were enrolled in the study.Radical treatment was performed on 51 patients,while 30 patients were put under palliative treatment.The procedural safety and interval survival for stage Ⅳ pancreatic cancer(IS-Ⅳ) was assessed by almost 2.5 years of follow-ups.The IS-Ⅳ of patients under the two kinds of treatment,and the effects of treatment timing and frequency on IS-Ⅳ,were compared.RESULTS:The IS-Ⅳ of patients who received radical treatment was significantly longer than those who received palliative treatment(P < 0.001).The IS-Ⅳ of patients who received delayed radical or palliative treatment was longer than those who received accordingly timely treatment(P = 0.0034 and 0.0415,respectively).Multiple treatments can play an important role in improving the IS-Ⅳ of patients who received radical treatment(P = 0.0389),but not for those who received palliative treatment(P = 0.99).CONCLUSION:The effect of radical treatment was significantly more obvious than that of palliative treatment,and multiple radical treatments may contribute more to patients than a single radical treatment.
基金Supported by the Guangzhou Huadu District Science and Technology Project(No.20-HDWS-054).
文摘This case report describes a patient with advanced gallbladder cancer who developed septic shock associated with iodine-125(^(125)I)seed implantation.The treatment process is described to provide a clinical reference for similar cases.A 52-year-old woman with recurrence of advanced gallbladder cancer underwent ^(125)I seed implantation and developed postoperative sepsis with septic shock.The blood culture suggested infection with Aeromonas caviae and Enterococcus faecalis.Vancomycin and imipenem were immediately administered according to the drug sensitivity results,along with immunoglobulin therapy and vasoactive drugs.The patient’s condition gradually stabilized after comprehensive treatment.Sepsis with septic shock is a rare but potentially fatal complication of ^(125)I seed implantation.Timely administration of broad-spectrum antibiotics,immunoglobulin therapy,and vasoactive drugs is very important to stabilize the patient’s condition.Our treatment of this patient can serve as a reference for clinicians to manage this complication in similar cases.
基金supported by Technology Foundation for Selected Overseas Chinese Scholar,Ministry of Personnel of China,2011,Ren 1144
文摘The use of iodine-125(125I) in cancer treatment has been shown to relieve patients' pain. Considering dorsal root ganglia are critical for neural transmission between the peripheral and central nervous systems, we assumed that 125 I could be implanted into rat dorsal root ganglia to provide relief for neuropathic pain. 125 I seeds with different radioactivity(0, 14.8, 29.6 MBq) were implanted separately through L4–5 and L5–6 intervertebral foramen into the vicinity of the L5 dorsal root ganglion. von Frey hair results demonstrated the mechanical pain threshold was elevated after implanting 125 I seeds from the high radioactivity group. Transmission electron microscopy revealed that nuclear membrane shrinkage, nucleolar margination, widespread mitochondrial swelling, partial vacuolization, lysosome increase, and partial endoplasmic reticulum dilation were visible at 1,440 hours in the low radioactivity group and at 336 hours in the high radioactivity group. Abundant nuclear membrane shrinkage, partial fuzzy nuclear membrane and endoplasmic reticulum necrosis were observed at 1,440 hours in the high radioactivity group. No significant difference in combined behavioral scores was detected between preoperation and postoperation in the low and high radioactivity groups. These results suggested that the mechanical pain threshold was elevated after implanting 125 I seeds without influencing motor functions of the hind limb, although cell injury was present.
文摘Objectives: To explore the clinical efficacy and survival of CT-guided Iodine-125 radioactive seed implantation in the treatment of stage Ⅳ primary hepatocellular carcinoma.Methods: A retrospective study of 62 patients with primary hepatocellular carcinoma in our hospital from January2017 to December 2018 [60 males, 2 females, age(52.76 ± 10.82) years old], All patients were implanted with Iodine-125 radioactive seeds under CT guidance, followed up regularly after operation to observe the clinical efficacy, including comparison of changes in cancer size before and after treatment, tumor marker AFP, and improvement in complications such as abdominal pain and ascites. Follow-up 3–36 months to assess patient survival.Results: Among the 62 patients, 3 months after Iodine-125 radioactive seed implantation, 5 cases(8.1%) had complete remission of cancer, 33 cases(53.2%) had partial remission, 12 cases(19.4%) had stable lesions, and 12 cases(19.4%) had disease progression. The effective rate was 61.3%. The tumor volume(31.44 ± 14.51 cm3) was significantly smaller than before(50.96 ± 30.13 cm3)(t=5.303, p < 0.05). The tumor marker AFP(69.28 ±50.99) ug/L of 3 months after implantation was significantly lower than that before treatment(90.63 ± 68.58)ug/L(t=3.702, P < 0.05). The average survival time of Iodine-125 seed implantation for stageⅣhepatocellular carcinoma is 11.47 ± 0.85 months, and the median survival time is 9 months. The survival time of the group with better pathological differentiation(grade Ⅰ+ⅡⅠ) was significantly better than that of the group with poor differentiation(grade Ⅲ+Ⅳ)(x2=6.869 p < 0.05). Among the 38 patients with different degrees of abdominal pain,22 patients improved better than before;15 of 28 patients with different degrees of ascites were better than before. All patients had no serious complications related to treatment.Conclusions: Iodine-125 radioactive seed implantation therapy can safely and effectively treat hepatocellular carcinoma, and relieve the clinical symptoms of abdominal pain and ascites.
文摘AIM: To evaluate the feasibility, efficacy and safety of intraoperative radiofrequency ablation (RFA) combined with 125 iodine seed implantation for unresectable pancreatic cancer. METHODS: Thirty-two patients (21 males and 11 females) at the age of 68 years (range 48-90 years) with unresectable locally advanced pancreatic cancer admitted to our hospital from January 2006 to May 2008 were enrolled in this study. The tumor, 4-12 cm in diameter, located in pancreatic head of 23 patients and in pancreatic body and tail of 9 patients, was found to be unresectable during operation. Diagnosis of pancreatic cancer was made through intraoperative biopsy. Patients were treated with FRA combined with 125 iodine seed implantation. In brief, a RFA needle was placed, which was confirmed by intraoperative ultrasound to decrease the potential injury of surrounding vital structures, a 125 iodine seed was implanted near the blood vessels and around the tumor border followed by bypass palliative procedure (cholangio-jejunostomy and/or gastrojejunostomy) in 29 patients.RESULTS: The serum CA 19-9 level was decreased from 512 ± 86 U/mL before operation to 176 ± 64 U/mL, 108 ± 42 U/mL and 114 ± 48 U/mL, respectively, 1, 3 and 6 mo after operation (P < 0.05). The pain score on day 7 after operation, 1 and 3 mo after combined therapy was decreased from 5.86 ± 1.92 before operation to 2.65 ± 1.04, 1.65 ± 0.88 and 2.03 ± 1.16, respectively, after operation (P < 0.05). The rate of complete response (CR), partial response (PR), stable disease (SD), progressive disease (PD) in 32 patients was 21.8% (7/32), 56.3% (18/32), 15.6% (5/32) and 6.3% (2/32), respectively, 6 mo after operation, with a median overall survival time of 17. 5 mo. The median survival time of patients at stage Ⅲ was longer than that of those at stage Ⅳ (19 mo vs 10 mo, P = 0.0026). The median survival time of patients who received and did not receive chemotherapy after operation was 20 mo and 16 mo, respectively (P = 0.0176). Of the 32 patients, 3 (10.6%) experienced postoperative complications including transient biliary leaks in 2 patients and acute pancreatitis in 1 patient. All the patients recovered well after conservative support treatment. CONCLUSION: Intraoperative RFA combined with 125 iodine seed implantation is a feasible and safe procedure for unresectable pancreatic cancer with acceptable minor complications, and can prolong the survival time of patients, especially those at stage Ⅲ.
基金Supported by Natural Science Foundation of China,No.81271682(partly)grants from Science and Technology Commission of Shanghai Municipality,No.11JC1407400(partly)+1 种基金the project of Luwan District Science and Technology Commission of Shanghai,No.LKW1104(partly)the project of Medical Key Specialty of Shanghai Municipality,No.ZK2012A20(partly)
文摘AIM:To determine the mechanism of the radiationinduced biological effects of 125I seeds on pancreatic carcinoma cells in vitro.METHODS:SW1990 and PANC-1 pancreatic cancer cell lines were cultured in DMEM in a suitable environment.Gray’s model of iodine-125(125I)seed irradiation was used.In vitro,exponential phase SW1990,and PANC-1cells were exposed to 0,2,4,6,and 8 Gy using 125I radioactive seeds,with an initial dose rate of 12.13c Gy/h.A clonogenic survival experiment was performed to observe the ability of the cells to maintain their clonogenic capacity and to form colonies.Cell-cycle and apoptosis analyses were conducted to detect the apoptosis percentage in the SW1990 and PANC-1 cells.DNA synthesis was measured via a tritiated thymidine(3H-Td R)incorporation experiment.After continuous low-dose-rate irradiation with 125I radioactive seeds,the survival fractions at 2 Gy(SF2),percentage apoptosis,and cell cycle phases of the SW1990 and PANC-1 pancreatic cancer cell lines were calculated and compared.RESULTS:The survival fractions of the PANC-1 andSW1990 cells irradiated with 125I seeds decreased exponentially as the dose increased.No significant difference in SF2 was observed between SW1990 and PANC-1 cells(0.766±0.063 vs 0.729±0.045,P<0.05).The 125I seeds induced a higher percentage of apoptosis than that observed in the control in both the SW1990and PANC-1 cells.The rate of apoptosis increased with increasing radiation dosage.The percentage of apoptosis was slightly higher in the SW1990 cells than in the PANC-1 cells.Dose-dependent G2/M cellcycle arrest was observed after 125I seed irradiation,with a peak value at 6 Gy.As the dose increased,the percentage of G2/M cell cycle arrest increased in both cell lines,whereas the rate of DNA incorporation decreased.In the 3H-Td R incorporation experiment,the dosimetry results of both the SW1990 and PANC-1cells decreased as the radiation dose increased,with a minimum at 6 Gy.There were no significant differences in the dosimetry results of the two cell lines when they were exposed to the same dose of radiation.CONCLUSION:The pancreatic cancer cell-killing effects induced by 125I radioactive seeds mainly occurred via apoptosis and G2/M cell cycle arrest.
