Studies On Safety And Clinical Effect Of Gastric Tissue With Interstitial Implantation Of ～(125)Ⅰ Seeds

The gastric carcinoma is common digestive system tumors which does great harm to the peoples'health. At present, surgical operation combining with other methods to improve curative effect usually is a main method. The disease is characterized with higher postoperative recurrence rate. When found, most patients are at advanced stage and miss the best chance of operation. So the medical workers are looking for new therapeutic methods all the time. Recently, radiotherapy is a considerable treatment of gastric carcinoma, but its application domain is limited. Radiotherapy hasn't become a routine curative method because external irradiation dosage is beyond normal tissue tolerance. Interstitial implantation of radioactive seeds, one kind of brachytherapy, is a good method which can greatly damage carcinoma by implanting radioactive microsources which can irradiate low radioactivityγrays with low capacity continuously whereas normal tissue is not or slightly injured. ¹²⁵I is the most common radioactive seed. Compared with external irradiation, it has many advantages: low strength of radioactive source, short distance of function, strong damage on tumor, little injury to normal tissue, continuous irradiation, highly biological effect and thorough treatment. Recently,Prof. Wang studied the lethal effect on the human gastric carcinoma xenografts in nude mice after interstitial brachytherapy with ¹²⁵I seeds. The research indicated lethal effect on the human gastric carcinoma xenografts in nude mice after interstitial brachytherapy with ¹²⁵I seeds. This provided a new way in the domain of treating gastric carcinoma and provided reliable theoretical basis for clinical application of ¹²⁵I brachytherapy. To solve some more critical problems on safety, earlier radioactive damage and clinical effect of gastric tissue with interstitial implantation of ¹²⁵I seeds, further animal experiments and clinical study were carried out.Partâ… The radioactive injury of normal gastric wall induced by 125-Iodine brachytherapy in rabbitsObjective: To investigate the pathological changes of rabbits'normal gastric wall induced by ¹²⁵I brachytherapy.Methods: 60 rabbits were randomly divided into control group and treated group. Three ¹²⁵I seeds were implanted into the muscle layer of rabbits'gastric wall according TPS in all groups. And the arrangement of these three seeds was like a triangle. The control group was planted into cold seeds, and ¹²⁵I seeds with their radiative activity 2.96×107Bq into treated group. Then the two groups randomized into 12 subgroups separately, which would be sacrificed on 7th day, 14thd day, 30th day, 60th day, 120th day and 180th day. Compare the weight and the hair of the treated group and the control group. The white blood cell counts and pathological changes were detected respectively in all rabbits. The seeds'losing-rate was calculated. Based on acute radiation injury standard of Radiation Therapy Oncology Group (RTOG), the radioactive damage of earlier period was evaluated.Results:â‘ There were no ulcer, perforation, bleeding and related death in all rabbits. The seeds'losing-rate was 5.6% (5/90) in control group, and 8.89%(8/90)in treated group.â‘¡The weight of rabbits all lessen after operation and increased gradually with drink and food recovering. There was no significant difference between control and treated groups at the same time (P<0.05). WBC count had no obvious statistical significance (P>0.05).â‘¢The hair in the control group didn't fall off and the skin had no change. The hair in the treated group fell off slightly after 7d⁶0d, became raritas but hadn't noalopecia areata. The radioactive damage was one degree. The alopecie grew during 120d¹80d.â‘£Little inflammation occurred in control group around the seeds while severe inflammation occurred in treated group including degeneration and necrosis around seeds. The diameter of severe inflammation area was less than 2mm and located in the serous membrane and muscle layer. The severity of these pathological changes was not depent on the prescription dose.Conclusion: Pathologic changes would occur after interstitial radiotherapy at the dose of 120Gy, but there was no early unreversible radioactive injury, such as bleeding and perforation. The results showed that 120Gy might be the tolerated and feasible dose for normal gastric wall of rabbits. Partâ…¡Clinical discussion on Unresectable Advanced Gastric Carcinoma with ¹²⁵I Radioactive Seeds Implantation Therapy SimplyObjective: To discuss the primary method and the effect of advanced gastric carcinoma with ¹²⁵I implantation therapy.Methods: 10 cases of unresectable advanced gastric carcinoma were selected. The pattern of CT was chosen as target reference. Applying brachytherapy planning system established ¹²⁵I seeds distribution, activity and quantity. The matched peripheral dose(MPD)was 110¹30Gy. Intra-operative or percutnaeous ¹²⁵I seeds implantation were established with uniplane or biplane according to the plan. After operation, hemogram, CT image, KPS, period of pain relief and survival period were observed.Results: 1 case was complete response (CR), 4 cases were partial response (PR) , 3 cases were No change (NC) and 2 cases were progressive disease(PD). The total effective rate was 50% (5/10). The rate of pain relief was 89%(8/9). Patients' appetite and KPS were improved. The longest survival time was 10 months and median survival time was 4.5 months. Seeds fell off in 6 cases and the expulsion rate was 3.8%(26/692). There were 0¹ degree radiotherapeutic side-effect, no abdominal pain, vomitus cruentus and intestinal obstruction.Conclusions: Applying iodine-125 implantation to treat advanced gastric carcinoma with reasonable seeds distribution can improve clinical symptoms and their quality of life significantly. The radioactive damage is mild. That method can be used as an important supplementary treatment for unresectable advanced gastric carcinoma.