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Objective To investigate the feasibility of 3D-printing coplanar coordinate template (3D-PCT) for guiding 125I radioactive seed implantation in the treatment of pelvic wall recurrence of cervical cancer on ensuring the accuracy of dose.Methods From Oct 2016 to Dec 2017 in Peking University Third Hospital,totally 10 patients with pelvic wall recurrent cervical cancer after radiotherapy were treated with 125I radioactive seed implantation assisted by 3D-PCT.The median age was 53.5 years old (37-71 years old).KPS score of the cohort were more than 70.All patients had received pelvic radiation therapy previously.The median volume of the lesion was 31.9 cm3 (3.5-58.0 cm3).The prescription dose was 120-180 Gy.The activity of seeds was 0.55-0.67 mCi(1 Ci =3.7 × 1010Bq),while the number of seeds was 12-81 (median 50) on preoperative plan.Radioactive seeds implantation was performed under 3D-PCT guidance according to the preoperative plan.The actual number of implanted seeds was 53 (10-82).Dosimetry parameters of preoperative plan and postoperative plan including D90,D100,V100,V150,V200,external index (EI),conformal index (CI),heterogeneity index (HI),and organat-risk doses of D2 cm3,D1 cm3 and D0.1 cm3 were compared using the nonparametric test.Results The seed number of postoperative plan was more than that of preoperative plan (Z =-2.255,P ＜ 0.05),but all of the dosimetric parameters showed no significant difference (P ＞ 0.05).D2 cm3 and D1 cm3 of rectum for postoperative plan were lower than that of preoperative plan (Z =-2.100,-2.240,P ＜ 0.05),while other dose parameters of normal tisssues showed no statistically significant difference (P ＞ 0.05).Conclusions Assisted by 3D-PCT for 125I radioactive seed implantation in pelvic wall recurrence of cervical cancer,the actual postoperative dose could meet the requirement of the preoperatie plan through the intraoperative optimization of dose.3D-PCT could ensure the precise of delivered dose of 125I radioactive seed implantation.
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Objective To discuss the necessity and feasibility of intraoperative use of treatment planning system (TPS) to make real-time planning for the treatment of retroperitoneal metastatic carcinoma with CT-guided 125I seed brachytherapy.Methods The clinical data of 20 patients with retroperitoneal lymph node metastases,who received CT-guided 125I seed brachytherapy during the period from January 2013 to December 2015,were retrospectively analyzed.The patients were divided into group A (n=10) and group B (n=10).The intraoperative TPS was employed to formulate the real-time planning for the patients of group A,while real-time planning was not adopted for the patients of group B.The quality verification of preoperative planning and postoperative effect was conducted for the patients of both groups.Comparing the preoperative and postoperative absorbed dose,the minimum absorbed dose (D90) error percentage of 90％ target volume,the error percentage of the covered volume by 90％ prescription dose to the target volume (V90),the error percentage of the covered volume by 100％ prescription dose to the target volume (V100),and the error percentage of the covered volume by 150％ prescription dose to the target volume (V150) were calculated in all patients of both groups,and the results were statistically analyzed.Results The mean error percentage of D90,V90,V100,V150 in group A were (-1.30±6.80) Gy,(-0.60±2.10)％,(-0.47±2.70)％ and (89.60±282.00)％ respectively,which in group B were (-9.33±46) Gy,(11.50±13.7)％,(-13.40±15.90)％ and (10.37±2.00)％ respectively.The differences in the error percentage of D90,V90 and V100 between group A and group B were statistically significant (P＜0.05 in all),while no statistically significant difference in the error percentage of V150 existed between group A and group B (P＞0.05).Conclusion The use of intraoperative TPS real-time planning can significantly improve the consistency of target region dose before and after seed implantation and make the dose distribution more reasonable,which is of great value for the standardization of CT-guided 125I seed brachytherapy of retroperitoneal lymph node metastases.
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Objective To investigate the feasibility of reducing CT scanning dose in the process of 125I radioactive seed implantation.Methods GEMS phantom and 062 M phantom were scanned using GE Lightspeed RT large hole CT with 120 kV,100 kV and 80 kV separately,and 150-10 mA (20 mA decreased progressively).The scanning dose,CT value and noise of the region of interest were recorded and the image quality was evaluated.Image signal-to-noise ratio (SNR) and contrast to noise ratio (CNR) values were calculated.Results With the decreasing of tube voltage and current,the SNR values were reduced accorgingly.The values had significant difference with those of standard images except the images acquired with 120 kV,150-70 mA and 100 kV,150-90 mA (t =-9.294-3.717,P ＜0.05).With the decreasing of the tube voltage and current,the CNR decreased significantly.The image quality was too low to evaluate while CNR lower than 2.The high contrast resolution of the CT images were not affected obviously with the tube voltage and current lowering.Conclusions In the process of 125I radioactive seed implantation,it is feasible to choose lower tube voltage and tube current(100 kV,70 mA) to scan the same area repeatedly except for the first scan with standard chest scanning parameters.The patient radiation dose has fallen dramatically.
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Objective To evaluate the efficacy and safety of radioactive 125 I seed implantation combined with paclitaxel (PTX) for treating senile non‐small cell lung cancer(NSCLC) .Methods The clinical data in 35 patients with NSCLC in our hospi‐tal from June 2013 to August 2014 were retrospectively analyzed ,including 12 cases receiving the lung tumor radioactive 125 I seed implantation therapy(group A) ,10 cases treated with PTX combined with cisplatin (TP scheme)after receiving radioactive 125I seed implantation therapy(group B) and 13 cases only conducted TP scheme(group C) .The 21 d chemotherapy was a evaluation cycle . The adverse reactions were evaluated after 1 cycle and the curative efficacy was evaluated after 2 cycles .Results Thirty‐five cases were followed up for 6 months .The adverse reactions could be evaluated in all the cases .The short‐term efficacy could be evaluated in 34 cases .The group A had no obvious adverse reactions ,the main adverse reactions in the group B and C were bone marrow sup‐pression and digestive tract reactions without statistically significant differences (P> 0 .05) .The effective rates after 4 cycles of chemotherapy in the group A and B were 66 .7% and 80 .0% ,the clinical benefit rates were 83 .3% and 90 .0% respectively ,which were higher than 23 .1% and 53 .8% in the group C respectively ,the differences were statistically significant ( P< 0 .05 ) . Conclusion Radioactive125 I seed implantation therapy and PTX combined with radioactive 125 I seed implantation for treating senile early NSCLC are superior to the simple PTX chemotherapy ,which have high effective rate and benefit rate ,safety ,mini‐invasion and mild adverse reactions ,and can increase the patient′s living quality .