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Objective:To design a knowledge-based cervical cancer planning model and apply it to cases of endometrial cancer and rectal cancer in order to explore the generalization of the model.Methods:A total of 179 cases of pelvic regions with different prescribed doses of dual-arc volumetric modulated arc therapy clinical plans were collected, of which 99 cases of cervical cancer clinical plans with a prescribed dose of 50.4 Gy were used as the training set to establish the RapidPlan model, and the remaining clinical plans were divided into 4 validation groups with 20 cases in each group. The clinical plans for cervical cancer and endometrial cancer with a prescription dose of 50.4 Gy were named groups A and B, while the clinical plan for endometrial cancer and rectal cancer with a prescription dose of 45 Gy were named groups C and D. The model was used to redesign the clinical plans in the 4 groups and the automatic plans were obtained. The planning target volume (PTV) and organ at risk (OAR) dosimetry parameters were compared between automatic plans and clinical plans.Results:The conformity index (CI) of the automatic plans in the A, B, C, and D groups were equivalent to that of the clinical plans ( P>0.05). The homogeneity index (HI) and D2% of the automatic plans in groups A, B, and C were all lower than those in clinical plans(HI, Z=-3.248, -3.360, -2.329, P<0.05; D2%, Z=-2.987, -3.397, -2.442, P<0.05). The HI and D2% of the automatic plans in group D were similar those in the clinical plans ( P>0.05). While ensuring the PTV coverage, the average value of OAR dosimetry parameters in all automatic plans groups were lower than that of the clinical plans. Conclusions:The RapidPlan model established by the cervical cancer clinical plans can complete the automatic plan design for endometrial cancer and rectal cancer under different prescription doses, which preliminarily proves the possibility of the generalization of the RapidPlan model.
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Objective:To investigate the accuracy and feasibility of 3D-printing individualized template-guided and CT-guided 192Ir interstitial brachytherapy in the central recurrent gynecologic tumors by comparing pre-plan and intraoperative physical dosimetric parameters. Methods:This study involved 38 patients with central recurrent gynecologic tumors who underwent 3D printing individual template (3D-PIT)-assisted and CT-guided 192Ir interstitial brachytherapy in the Department of Radiation Oncology of the Peking University Third Hospital from Jan 2018 to Dec 2019.The prescription doses for the target tumor areas were 10-36 Gy to be delivered at 5-6 Gy/fraction for 2-6 fractions.The pre-plan and intraoperative dosimetric parameters were compared, including the minimum prescription doses delivered to 90% and 100% of target volume( D90, D100)and the mean percentage of volume receiving 100% of the prescription doses ( V100). Meanwhile, the doses delivered to 2 cm 3 ( D2 cm 3) of organs at risk (bladders, rectums, and colons) were analyzed.The quality parameters of the brachytherapy were studied, including conformity index (CI), homogeneity index (HI), and external index (EI) of the target volume.Perioperative complications were also observed. Results:A total of 194 treatments were included.During the treatment, 5-13 (median 6) needles were inserted, with a prescription dose of 5-6 Gy per fraction.There were no statistical differences between pre-plan and intraoperative D90, D100, V100, CI, HI, and EI as well as the D2 cm 3 of bladders and colons at risk ( P>0.05). In contrast, for the D2 cm 3 of rectums, the intraoperative dose was slightly higher than the pre-plan dose, showing a statistical difference ( t=-0.335, P=0.027). Conclusions:The 3D-PIT-assisted and CT-guided 192Ir interstitial brachytherapy at a high dose rate is accurate and feasible in the treatment of recurrent gynecologic tumors, meeting the pre-plan dose requirement.
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The main treatment options for cervical cancer include surgery and/or radiotherapy combined with chemotherapy. Radiotherapy consists of external beam radiotherapy and brachytherapy (BT). BT contains high-dose-rate (HDR-BT) and low-dose-rate brachytherapy (LDR-BT). The prognosis of cervical cancer is relatively good. However, some patients experience substantial treatment failures, such as intra-pelvic and/or extra-pelvic recurrences. Recurrent cervical cancer (RCC) has poor prognosis due to lack of effective and safe approach. In 2002, Professor Wang Junjie introduced CT-guidance into the field of LDR-BT, and fully applied 3D printing technology in BT in 2015, which met the requirement of preoperative LDR-BT planning, and significantly improving the precision, quality and efficiency of BT. In 2018, Professor Wang Junjie proposed the concept of stereotactic ablation brachytherapy (SABT). Chinese experts have attempted to treat RCC with BT for nearly two decades and accumulated certain clinical experience. Based on the 3D-printing template (3D-PT) assisted CT-guidance, the standard and consensus of BT for RCC were established, including the indications, dosimetric requirements, technological procedures and radiation protection, etc. At present, there is still a lack of phage Ⅲ clinical and evidence-based medicine for the treatment of RCC with 3D-PT guidance, which requires prospective multi-center, randomized studies to improve the evidence-based level of BT.
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OBJECTIVE: To investigate the efficacy of image-guided radioactive 125I seed (IGRIS) implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy (EBRT), and analyze the influence of clinical and dosimetric factors on efficacy. METHODS: From July 2005 to October 2015, 36 patients with PRCC received IGRIS. We evaluated local progression-free survival (LPFS) and overall survival (OS). RESULTS: The median follow up was 11.5 months. The 1- and 2-year LPFS rate was 34.9% and 20%, respectively. The multivariate analysis indicated recurrence site (central or pelvic wall) (hazard ratio [HR]=0.294; 95% confidence interval [CI]=0.121–0.718), lesion volume (HR=2.898; 95% CI=1.139–7.372), D 90 (HR=0.332; 95% CI=0.130–0.850) were the independent factors affecting LPFS. The 1- and 2-year OS rate was 52.0% and 19.6%, respectively. The multivariate analysis suggested pathological type (HR=9.713; 95% CI=2.136–44.176) and recurrence site (HR=0.358; 95% CI=0.136–0.940) were the independent factors affecting OS. The dosimetric parameters of 33 patients mainly included D 90 (128.5±47.4 Gy), D 100 (50.4±23.7 Gy) and V 100 (86.7%±12.9%). When D 90 ≥105 Gy or D 100 ≥55 Gy or V 100 ≥91%, LPFS was extended significantly, but no significant difference for OS. The 79.2% of 24 patients with local pain were suffering from pain downgraded after radioactive 125I seed implantation. CONCLUSION: IGRIS implantation could be a safe and effective salvage treatment for PRCC after EBRT, which could markedly release the pain. Recurrence site, tumor volume and dose were the main factors affected efficacy. Compared with central recurrence, it was more suitable for patients with pelvic wall recurrent cervical cancer after EBRT.
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Humans , Brachytherapy , Disease-Free Survival , Follow-Up Studies , Multivariate Analysis , Radiometry , Radiotherapy , Radiotherapy, Image-Guided , Recurrence , Salvage Therapy , Tumor Burden , Uterine Cervical NeoplasmsABSTRACT
Objective To evaluate the efficacy and adverse effects of 125I seeds implantation for pelvic recurrence of cervical cancer (PRCC) after radiotherapy.Methods From July 2005 to October 2015,36 PRCC patients (median 44 years) after radiotherapy in Peking University Third Hospital were enrolled in this retrospective study.All patients underwent 125I seeds implantation under ultrasound or CT guidance.Treatment planning was performed before implantation to estimate the number and activity of 125I seeds.The seed numbers ranged from 10-140 (median:62.5),and the activity ranged from 18.5-29.6 (median:25.9) MBq.Postoperatively,the median dose delivered to 90％ gross tumor volume (D90) was 127.3 Gy.Kaplan-Meier method was used to calculate local progress free survival (LPFS) rate and overall survival (OS) rate,and log rank test and Cox regression were used for univariate and multivariate analyses.Results The median follow-up time was 11.5 months.The local control rate was 88.89％(32/36).The 1-year LPFS rate was 34.9％ and the 1-year OS rate was 52.0％.Thirty-one patients died,of which 22 (70.97％,22/31) died from cancer.Univariate analysis showed that the location of recurrence (x2=5.195),volume of lesion (hazard ratio (HR)=1.012) and D90(HR=0.988) were significantly correlated with LPFS (all P＜0.05).Multivariate analysis showed that the location of the recurrence was significantly related with LPFS (HR =0.215,P＜0.05).The 1-year LPFS rates of pelvic wall recurrence and central recurrence were 41.6％ and 26.7％ (x2 =5.195,P＜0.05),and 1-year OS rates were 54.7％ and 49.5％ (x2 =2.535,P＞0.05),respectively.Vaginal fistula,which may be caused by the treatment,occurred in 1 case.No other sever adverse effects were observed.Conclusions 125I seeds implantation is a safe and effective treatment for PRCC after radiotherapy.With the treatment of 125I seeds implantation,patients with pelvic wall recurrence may achieve better therapeutic effects than those with central recurrence.
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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 determine the maximum tolerated dose ( MTD) and dose?limiting toxicity ( DLT) of weekly PTX and DDP concurrent postoperative radiotherapy in Chinese women with high?and intermediate?risk early cervical cancer. Methods Women with high risks postoperative cervical carcinoma, ECOG≤2 were eligible. Pelvis RT (6/10 MV X?ray,3DCRT 40 Gy/20f,para?metrial boost 10?20 Gy/5?10f) was followed by 2?4f brachytherapy applications ( 192 Ir,5 Gy/f) . Concurrent weekly chemotherapy was started at DDP 20 mg/m2 and PTX 10 mg/m2 weekly,and escalated in three?patient cohorts according to 3+3 methods. Results 25 patients were enrolled and treated over seven doses levels until dose?limiting toxicity (DLT) was reached. Median age was 48 years (range,34?66).All of patients finished RT in 7 weeks. Grade 3,4 non?hematologic toxicities were diarrhea and observed in two patients (4 cycles,DLT) at level 7.Grade 3,4 hematologic,principally leukopenia and neutropenia,and occurs late cycles. One grade 4 leukopenia and neutropenia was observed at dose level 6 but not seen in three additional patients. No one was delayed treatment time by concurrent chemotherapy.22 patients finished 6 cycles. Median follow?up is 59. 5 months. Three patients have died of cancer metastasis and recurrence. One patient has died of respiratory failure. Conclusions Combination PTX and DDP administered concurrently with pelvic EBRT can be safely administered at the MTD of DDP 35 mg/m2 and PTX 30 mg/m2 weekly for six cycles in Chinese women with postoperative cervical cancer.
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Objective To investigate the effect of cetuximab (C225) on the radiosensitivity of colorectal cancer cells CL187 and underlying mechanism.Methods Cell survival was detected by colony forming assay.The levels of apoptosis and cell cycle distribution were determined by flow cytometer.The mitotic ratio was measured by Wright' s-Giemsa mixed coloring method.The protein levels of Bax and Bcl2 were detected by Western blot.Results The sensitizing enhancement ratio of C225 was approximately 1.4.C225 treatment and 125I seed radiation induced G1 cell cycle arrest individually.C225 increased the radiation-induced apoptosis (t =6.6,P ＜ 0.05) and cellular Bax/Bcl-2 ratio (t =9.4,P ＜ 0.05),but did not increase radiation-induced G1 arrest.In addition,there was no difference in mitotic index among different groups.Conclusions C225 sensitizes CL187 to 125I seed irradiation,which might be related with increase of radiation-induced apoptosis.
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Objective To investigate the inhibition effect of continuous low dose rate radiation by 125Ⅰ radioactive seeds on Hep-2 cells and the corresponding mechanisms.Methods Hep-2 cells were divided into three groups,control group,single dose radiation group with high dose rate form X-rays (SDR) and continuous low dose rate radiation by 125Ⅰ seeds group (125Ⅰ-CLDR).After exposure to SDR and 125Ⅰ-CLDR,colony formation assay was used to determine the radiosensitivity and RBE,trypan blue exclusion assay was used to determine cell proliferation,and flow cytometry was used to detect cell apoptosis and cell cycle arrest.Results The radiosensitivity of Hep-2 cells to 125Ⅰ-CLDR was higher than that to SDR.The RBE of 125Ⅰ-CLDR versus SDR was approximately 1.61.The α/β ratio of 125Ⅰ-CLDR group was higher than that of SDR group.Both SDR and 125Ⅰ-CLDR inhibited cell proliferation (t =30.9,40.7,P＜0.05),in which 125Ⅰ-CLDR was stronger than SDR (t =9.8,P＜0.05).In addition,the incidences of apoptosis and G2/M arrest induced by125Ⅰ-CLDR were also stronger than those induced by SDR (t =5.8,19.8,P ＜ 0.05).Conclusions 125Ⅰ-CLDR generates more serious inhibition effects than SDR on reducing cellular DNA repair capacity,inducing cell apoptosis and G2/M arrest and inhibiting proliferation of Hep-2 cells.
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Objective To investigate the effect of C225 on DNA repair and molecular pathways in CL187 colorectal cancer cells after irradiated by 125Ⅰ radioactive seeds.Methods In the experiment involved were four groups:control group,100 nmol/L C225 treatment group,125Ⅰ radioactive seeds continuous low-dose rate irradiation group and C225 combined with 125Ⅰ radioactive seeds continuous lowdose rate irradiation group.Cells were collected at 48 h after 4 Gy irradiation,and γH2AX foci/cell and γH2AX foci positive cells were counted with immunofluorescence.At the same time,DNA repair proteins were detected by Western blot.Cells were lyzed immediately after 4 Gy irradiation,and changs in EGFR downstream signaling molecules were detected by Western blot.Results Compared with 125Ⅰ seeds irradiated cells,cells treated with C225 and 125Ⅰ seeds irradiation showed more γH2AX foci per cell (t =8.0,P =0.05),and more γH2AX foci positive cells (t =6.8,P ＜ 0.05) and less expression of Ku70 (t =6.6,P ＜ 0.05) and DNA-PKcs (t =5.6,P ＜ 0.05).Combined with 125Ⅰ-CLDR irradiation,C225 reduced cellular EGFR level(t =4.9,P ＜0.05) and inhibited the activation of Akt(t =5.5,P ＜0.05).Conclusions In the condition of 125Ⅰ seeds irradiation,C225 reduced the expression of Ku70 and DNA-PKcs,inhibited the activation of Akt and attenuated the DNA damage repair capacity in CL187 colorectal cancer cells.
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Objective To investigate the effect and underlying mechanism of single,fractioned and continuous low dose rate radiation on CL187 colorectal cancer cell line.Methods CL187 cells were exposed to 6 MV X-rays at a high dose rate of 4 Gy/min and 125Ⅰ seed at a low dose rate of 2.77 cGy/h with three groups:single dose radiation group (SDR),fractioned dose radiation group (FDR) by 2 Gy/f,and continuous low dose rate radiation group (CLDR).The radiation doses were 0,2,4 and 8 Gy.Total cell number and cell viability were determined by trypan blue.Clone forming assay was used to evaluate the cell proliferation ability.The percentage of apoptosis cells was analyzed by flow cytometry.Western blot was used to detect the protein expression levels of PHLPP2,PTEN and Bax.Results Compared with SDR and FDR groups,the total cell number and survival fraction of CLDR group decreased.The relative biological effect (RBE) for 125Ⅰ seeds compared with 6 MV X-rays was 1.41.The percentage of apoptosis cells of CLDR group was significantly increased (t =-15.08,-11.99,P ＜ 0.05).The expression level of Bax increased in CLDR group,while no obvious changes were observed on PHLPP2 and PTEN among three groups.Conclusions The expression level of PHLPP2 increaseS in SDR,FDR and CLDR group,while it seems that it was not influenced by dose rate.The expression level of Bax increased in three groups,while more colorectal CL187 cells in CLDR group may be killed due to the increase of Bax expression.
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Objective To investigate the combination effect of cetuximab and irradiation on colorectal carcinoma CL187 cell line and underlying molecular mechanism.Methods CL187 cells with or without cetuximab treatment were irradiated by 0,4 and 8 Gy X-rays,then cell death percentage was determined by MTT 24 and 48 h post-irradiation.Clone forming assay was used to evaluate the cell reproliferation ability.Cell cycle distribution,apoptosis,and necrosis were analyzed by flow cytometry.Western blot was used to detect the protein expressions of DNA-PKcs,Ku70 and Ku80.Results The cetuximab enhanced the percentage of radiation-induced cell death,while descreased the cloning formation capacity and increased radiosenvtivity (t =-6.14、-6.53,P ＜0.05).The SER of cetuximab on CL187 cell line approached to 1.38.In addition,cetuximab also increased radiation-induced G0/G1 phase arrest (t=-4.64,P＜0.05) and the percentage of apoptosis and necrosis (t=-9.16,P ＜0.05),but it descreased the expression levels of DNA-PKcs,Ku70 and Ku80 proteins.Conclusions The cetuximab treatment might enhance the inhibitory effect of irradiation on colorectal carcinoma CL187 cell line by influencing cell cycle distribution,cell apoptosis,and the expression of DNA repair proteins.
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Objective To summarize the efficacy and the feasibility of 125I seed implantation for recurrence cervical lymph node of head and neck tumor after radiotherapy or radiotherapy plus neck dissection. Methods Thirty-six patients with the recurrence cervical lymphnode of head and neck tumor after radiotherapy (17 patients) or radiotherapy plus neck dissection (19 patients) were treated with 125I seed implantation guided by ultrasound or CT under local anesthesia. The median number of seeds was 27( range from 3 to 78 ). Postoperative quality evaluation were routinely obtained for all patients. The actuarial D90 ranged from 90-160 Gy (median, 130 Gy). Results The follow-up rate was 100%. The number of the patients who were followed up over 1-and 2-year were 11 and 3. The overall response rate was 81%. The 1-and 2-year over local control rates, over survival rates were 69% and 35%, 50% and 22%, respectively.The 1-and 2-year local control rates in patients with recurrence node after radiotherapy plus neck dissection were 72% and 54%, while those were 67% and 50% in patients with recurrence node after radiotherapy,respectively (χ2=00,P=0.965). The 1-and 2-year survival rates in two groups were 48%, 13% , and 51%, 39%, respectively (χ2=0.17, P=0.676). Conclusions 125I seed implantation is a safe,minimal invasive with low morbidity and high efficacy salvage treatment method for cervical lymph node recurrence of head and neck tumor after radiotherapy with or without neck dissection.