Effectiveness and safety of CT-guided 125I seed brachytherapy for postoperative locoregional recurrence in patients with non–small cell lung cancer

Prognostic value of pretreatment FDG PET-CT for short-term efficacy of radioactive iodine-125 seed implantation in patients with NSCLC

PURPOSE

To analyze the short-term clinical response of radioactive iodine-125 seed implantation (I125-SI) in patients of non-small-cell lung cancer (NSCLC) and explore possible correlations of various metabolic parameters of pretreatment FDG PET-CT with the short-term efficacy of this treatment modality.

METHODS AND MATERIALS

The present study is a retrospective analysis of treatment records of 46 NSCLC patients who were treated with I125-SI for lung tumors in Tianjin First Central Hospital from January 2016 to December 2018. The correlation among parameters D90, gender, pathological pattern, age, maximum tumor diameter, Metabolic Tumor Volume (MTV), SUVmax, SUVpeak, SUVmean, Total Lesion Glycolysis (TLG), High metabolic tumor cell ratio (HMR) and Carcinoembryonic antigen(CEA)with short-term efficacy of I125-SI was analyzed by two independent-sample t-test, Mann-Whitney U test or Chi-squared test and binary logistic regression.

RESULTS

After uneventful completion of treatment, patients were followed up at regular intervals. At the first month followup, none of cases showed complete response (CR), while 4 cases showed partial response (PR). After 3 months, there were 2 cases of CR, and 25 cases of PR; after 6 months, there were 5 cases of CR, and 27 cases of PR. D90 (p= 0.028, OR:1.075, 95% CI:1.008-1.147), MTV (p= 0.026, OR: 0.918, 95% CI: 0.851-0.990), HMR (p= 0.020, OR: 0.003, 95% CI: 0-0.407) were independent predictors for the short-term efficacy. The predictive accuracy of MTV was medium (AUC = 0.781; cutoff value = 44.58). However, the predictive accuracies of D90 and HMR were low, with the values of AUC being 0.650 for both the parameters, and their cutoff values being 127.8 Gy and 0.27 respectively.

CONCLUSIONS

I125-SI is an effective therapy with few complications in NSCLC patients. Small MTV, high D90 and low HRM were found to be linked with better local control at 6 months postimplantation.

Effect of I-125 Seed Implantation on Lung Cancer and Its Environmental Impact

ABSTRACT

This paper compares the efficacy and adverse effects of iodine-125 ( 125 I) seed implantation and external beam radiotherapy (EBRT) in the treatment of lung cancer as well as impact of the 125 I radiation on the environment around the patients. A total of 40 patients who were admitted with lung cancer to our hospital from October 2017 to October 2018 were enrolled into this study. The patients were randomly assigned into study groups treated with 125 I seed implantation (20 patients) and a control group treated with EBRT (20 patients). The patients were followed up for 6 mo by CT scanning of the tumor size as well as measuring serum carcinoembryonic antigen (CEA), cytokeratin fragment (CYRA21-1), and neurospecific enolase (NSE) levels. The dose rate of 125 I at various distances and times after implantation was also measured. The local tumor control rate was higher in the study group than in the control group. CEA, NSE and CYFRA21-1 significantly decreased from the pre-treatment baseline in both groups (p < 0.05). Side effects of pneumothorax, hemoptysis, chest pain, and leukopenia occurred in the patients treated with 125 I seed implantation. Radiation of the 125 I isotope, which was correlated with the number of implanted 125 I seeds, decreased rapidly in a time- and distance-dependent manner. A lead apron could significantly block radiation of 125 I. Compared to EBRT, brachytherapy with 125 I seed implantation in the lung cancer had a better therapeutic outcome with fewer complications. A lead apron could protect members of patient's family as well as public from 125 I radiation.

Biliary self-expandable metallic stent combined with iodine-125 seeds in the treatment of malignant biliary obstruction (Bismuth type I or II)

BACKGROUND

The purpose of this research was to evaluate the safety and efficacy of a self-expandable metallic stent (SEMS) combined with iodine-125 (125I) seeds in the treatment of Bismuth type I or II malignant biliary obstruction (MBO).

METHODS

The clinical data of 74 cases of MBO treated with percutaneous SEMS combined with 125I seeds (combination group) and 81 cases of MBO treated with SEMS implantation alone (control group) in our hospital from January 2015 to December 2019 were retrospectively analyzed. The short-term and long-term efficacy of the two groups were compared. Multivariate Cox regression analysis was used to analyze the factors affecting the surgical efficacy and survival rate.

RESULTS

The liver blood test results of both groups improved at one week and one month post-stent insertion. No significant difference was established in the short-term efficacy or complications between the two groups (P = NS). Improved stent patency was observed in the combined group, 9.01 ± 4.38 months versus 6.79 ± 3.13 months, respectively (P < 0.001). Improved survival was also noted in the combined group 12.08 ± 5.38 months and 9.10 ± 4.16 months, respectively (P < 0.001). Univariate and multivariate analyses showed that the type of biliary stent and liver metastasis were independent factors affecting survival.

CONCLUSION

The implementation of SEMS combined with 125I seeds resulted in significantly longer stent patency and survival times than that of SEMS implantation alone, which is thus worthy of clinical promotion and application.

Dosimetry study of three-dimensional print template for 125I implantation therapy

Background

¹²⁵I seed implantation has been found to show good therapeutic effects on tumors. Recent studies showed that three-dimensional (3D) print template-assisted ¹²⁵I seed implantation can optimize radiation dose distribution. This study aimed to compare the dose distribution differences in ¹²⁵I seed implantation among 3D print noncoplanar template- (3DPNCT), 3D print coplanar template- (3DPCT) assisted implantation and traditional free-hand implantation.

Methods

We systematically searched the PubMed, EMbase, Cochrane Library, Wan Fang Med Online, China National Knowledge Infrastructure (CNKI) from the earliest to November 2020 without time or language restrictions. And the references of primary literature were also searched. The outcome measures were dosimetry and operation time. This meta-analysis was carried out using Stata 12.0.

Results

A total of 16 original articles were selected for inclusion. The differences of D90, D100, V90, and V100 values pre- and post-implantation with traditional free-hand implantation showed statistically significant (p < 0.05). The differences of D90, D100, V100, V150, V200, and D2cc of organs at risk (OAR) values pre- and post-implantation with 3D print template showed no statistically significant (p > 0.05). Compared with traditional free-hand implantation without any templates, 3D print template could improve postoperative D90 (Standard mean difference, SMD = 0.67, 95% confidence interval (CI) = 0.35 to 0.98, p < 0.001), D100 (SMD = 0.82, 95%CI = 0.40 to 1.23, p < 0.001), V90 (SMD = 1.48, 95%CI = 0.95 to 2.00, p < 0.001), V100 (SMD = 1.41, 95%CI = 0.96 to 1.86, p < 0.001), and reduce operation time (SMD = − 0.93, 95%CI = − 1.34 to − 0.51, p < 0.001). In three studies, both 3DPNCT and 3DPCT plans were designed for all patients. The prescribed dose and seed activity were same. Pooled analysis of D90, D100, V100, D2cc of OAR, number of seeds and number of needles showed no significant differences between 3DPNCT and 3DPCT groups (p > 0.05). However, in 3DPNCT group, V150 and V200 were increased (SMD = 0.35, 0.49; 95%CI = 0.04 to 0.67, 0.02 to 0.96; p = 0.028, 0.043); the number of through bone needles was reduced (SMD = − 1.03, 95%CI = − 1.43 to − 0.64, p < 0.001).

Conclusions

Compared with traditional free-hand implantation, 3D print template-assisted ¹²⁵I seeds implantation can optimize dose distribution and reduce the implantation time at the same time. Compared with 3D print coplanar template, 3D print noncoplanar template can increase the volume of high dose within tumor target and is more safer in the respect of puncture route.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01845-y.

Brachytherapy for lung cancer

Brachytherapy (BT) is a minimally invasive anticancer radiotherapeutic modality where the tumor is directly irradiated via a radioactive source that is precisely implanted in or adjacent to the tumor. BT for lung cancer may be conducted in the form of endobronchial BT and radioactive seed implantation (RSI-BT), mainly for nonsmall cell lung cancer (NSCLC). For patients with early-stage lung cancer who are not suitable for surgery or external beam radiotherapy (EBRT), BT may be used as an alternative treatment, and curative results could be achieved in certain patients with cancer confined to the trachea lumen. For patients with locally advanced/metastatic lung cancer, BT could be selectively applied alone or as a boost to EBRT, which could improve the local tumor control and patient's survival. In addition, BT is also useful as a salvage treatment in select patients with locally recurrent/residual lung cancer that failed other treatments (e.g., surgery, chemotherapy, and EBRT). However, clinical outcomes are mainly obtained from retrospective studies. Prospective studies are limited and needed. In recent years, the introduction of modern image guidance, novel radioactive seeds, BT treatment planning systems (BT-TPS), after-loading technique, and three-dimensional printing template (3D-PT) assistance, among others, have potentially improved the clinical outcomes of BT. However, a comprehensive review of BT with newly published literature was lacking. This review is to discuss BT for NSCLC based on recent literature published in PubMed.

125I Seed Brachytherapy Combined with Single-Agent Chemotherapy in the Treatment of Non-Small-Cell Lung Cancer in the Elderly: A Valuable Solution

Purpose

The aim of this study was to compare the effectiveness and safety of CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy versus combined chemotherapy in the treatment of elderly NSCLC.

Materials and Methods

We retrospectively analyzed 110 patients (64 men and 46 women; mean age=71.25±7.14 years) who were diagnosed with NSCLC without distant metastases between January 2015 and May 2020. A total of 50 patients received ¹²⁵I brachytherapy combined with single-agent chemotherapy (group A), whereas 60 patients received combined chemotherapy (group B). The response to therapy and adverse effect were compared between groups. The local response rate was evaluated by CT. Progression-free survival (PFS) and overall survival (OS) data were obtained through clinical follow-up.

Results

All patients had been treated and were followed-up for 3-60 months. The median OS and PFS were 23.71±1.41 months (95% CI=20.95-26.47) vs 16.12±0.93 months (95% CI=14.31-17.93) (P<0.05) and 15.08±0.85 months (95% CI=13.42-16.74) vs 10.03±0.53 months (95% CI=9.01-11.06) (P<0.05) in group A and group B, respectively. The local response rate and clinical symptoms of patients in group A were significantly relieved when compared with group B. Severe complications were not observed in either group.

Conclusion

CT-guided ¹²⁵I seed brachytherapy combined with single-agent chemotherapy is an effective and safe therapy and shows promising results compared to combined chemotherapy alone for NSCLC in the elderly. A randomized study will be needed to assess the superiority of this combined modality treatment.

Combination of Brachytherapy with Iodine-125 Seeds and Systemic Chemotherapy versus Systemic Chemotherapy Alone for Synchronous Extracranial Oligometastatic Non-Small Cell Lung Cancer

Background

A proportion of patients with synchronous oligometastatic non-small cell lung cancer (NSCLC) have poor survival, and currently no standard treatment is available, which poses a great challenge to physicians. This study aimed to assess and compare the efficacy and safety of the combination of brachytherapy with iodine-125 seeds and systemic chemotherapy versus systemic chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Materials and Methods

After a systematic retrospective review of the case database between 1st Mar 2014 and 30th Mar 2018, data were obtained on 69 NSCLC patients with extracranial oligometastatic NSCLC. Among them, 32 patients received brachytherapy with iodine-125 seeds combined with systemic chemotherapy (group A), and the remaining 37 patients received chemotherapy alone (group B). The primary endpoint was overall survival (OS), and the secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and complications.

Results

The demographic and clinical characteristics were not significantly different between the groups (all p>0.05). The overall 3-month ORR was significantly higher in group A (65.6% vs 37.8%, p=0.030) than in group B. With a median follow-up time of 23 months, the PFS and OS were 11.6 (95% CI: 7.0–16.2) months vs 6.3 (95% CI: 3.4–9.2) months (p=0.036) and 17.6 (95% CI: 13.9–21.3) months vs 11.2 (95% CI: 7.7–14.7) months (p=0.042) in groups A and B, respectively. Furthermore, in Cox regression analysis, local brachytherapy was an independent prognostic factor for both PFS (HR=0.416, 95% CI: 0.246–0.702, p=0.001) and OS (HR=0.375, 95% CI: 0.216–0.653, p=0.001). Severe complications were not observed in either of the groups.

Conclusion

The combination of brachytherapy with iodine-125 seeds and systemic chemotherapy is superior to chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Analysis of Cells Proliferation and MicroRNAs Expression Profile in Human Chondrosarcoma SW1353 Cells Exposed to Iodine-125 Seeds Irradiation

Chondrosarcoma is the second most common bone malignancy in adults, and it is often resistant to traditional chemotherapy and radiation therapy. Permanent implantation of iodine-125 (¹²⁵I) seeds has been explored for the treatment of many types of cancer. In this study, the aim was to investigate the proliferative and microRNA (miRNA) effects of ¹²⁵I seeds irradiation on human chondrosarcoma SW1353 cells. First, a new in vitro ¹²⁵I seed irradiation model was established, and cell viability and miRNA microarray assays were performed before and after exposure to the ¹²⁵I seeds. Cell proliferation was inhibited, and miRNA expression was substantially altered by irradiation exposure. The inhibition of cell proliferation was positively correlated with increased radiation doses, with cells showing the highest total radiation dose 7 days after irradiation. A total of 2549 miRNAs were detected in the SW1353 cells after exposure to 6 Gy of radiation, which included 189 differentially expressed miRNAs (98 upregulated and 91 downregulated). Four miRNAs were found to play important roles in the inhibition of cell proliferation after irradiation exposure, including miR-1224-5p, miR-492, miR-135b-5p, and miR-6839-5p. The target genes of the associated miRNAs mentioned were vascular endothelial growth factor A (VEGFA), C-X-C motif chemokine 12 (CXCL12), mitogen-activated protein kinase kinase kinase kinase 3 (MAP4K3), and apoptosis facilitator Bcl-2-like protein 14 (BCL2L14). Hence, the mitogen-activated protein kinase signaling pathway may be involved in how chondrosarcoma cells respond to ¹²⁵I seed irradiation.

Biliary self-expandable metallic stent combined with Iodine-125 seeds strand in the treatment of hilar malignant biliary obstruction

Objective

To assess the safety and effectiveness of a self-expandable metallic stent (SEMS) combined with Iodine-125 seeds strand to treat hilar malignant biliary obstruction (MBO).

Methods

This retrospective study included patients who had received SEMS with ¹²⁵I seeds strand (seeds group) or SEMS alone (controls) to treat hilar MBO. Demographic, biochemical, stent patency, overall survival and complications data were extracted and analysed.

Results

A total of 76 patients were included (seeds group, n = 40; controls, n = 36), with a total of 608 seeds deployed in the seeds group (mean, 15.2 ± 4.1 [range, 8–25] seeds per patient). Statistically significant between-group differences were shown in median stent patency time (seeds group, 387.0 ± 27.9 days [95% confidence interval {CI} 332.4, 441.6] versus controls, 121.0 ± 9.1 days [95% CI 103.2, 138.8]) and in median overall survival (seeds group, 177.0 ± 17.9 days [95% CI 141.8, 212.2] versus controls, 123.0 ± 20.4 [95% CI 83.0, 163.0]). There were no statistically significant between-group differences in complication rates.

Conclusion

SEMS combined with ¹²⁵I seeds strand is safe, feasible, and tolerable in treating patients with hilar MBO, and may be effective in prolonging stent patency time and overall survival.

Effects of radioactive 125I on apoptosis of HGC-27 gastric cancer cells

Effects of radioactive ¹²⁵I particles at different doses on apoptosis of HGC-27 gastric cancer cells were investigated. HGC-27 gastric cancer cell suspension was used to establish a tumor-bearing mouse model. The model was reared for approximately 3 weeks and then divided into the control group (implanted with blank particles), the low dose group (implanted with 1.48×10^-7 Bq ¹²⁵I particles), the medium dose group (implanted with 2.22×10^-7 Bq ¹²⁵I particles) and the high dose group (implanted with 2.96×10^-7 Bq ¹²⁵I particles) (n=15 per group). Six nude mice were randomly sacrificed to collect the tumor tissue and measure tumor volume and mass. TUNEL (TdT-mediated dUTP nick-end labeling) was used for detecting apoptosis of tumor cells, and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) for detecting the relative expression of Bax, caspase-3 and caspase-8. On the 28th day after implantation, the apoptotic rate in the low, medium and high dose groups was significantly higher than that in the control group, which in the medium and high dose groups was significantly lower than that in the low dose group (P<0.05). On the 28th day after implantation, the relative expression of Bax, caspase-3 and caspase-8 mRNA in the control group was significantly lower than that in the low, medium and high dose groups (P<0.05), which in the low dose group was significantly higher than that in the medium and high dose groups (P<0.05). ¹²⁵I particles can inhibit the growth of HGC-27 gastric cancer cell transplants and promote the expression of Bax, caspase-3 and caspase-8 mRNA in the tumor tissue. Low-dose ¹²⁵I particles are significantly more effective than medium- or high-dose ¹²⁵I particles.

Design and validation of a surgical navigation system for brachytherapy based on mixed reality

PURPOSE

An accurate position of the needle is vitally important in low-dose-rate seed implantation brachytherapy. Our paper aims to implement a mixed reality navigation system to assist with the placement of the I¹²⁵ seed implantation thoracoabdominal tumor brachytherapy needle and to validate the accuracy and quality of this type of method.

METHODS

With the surgical navigation system, based on mixed reality through a novel modified multi-information fusion method, the fusion of virtual organs and a preoperative plan for a real patient and the tracking of surgical tools in real time were achieved. Personalized image recognition and pose estimation were used to track needle punctures in real time and to perform registration processes. After a one-time registration with a hexagonal prism tracker that used an iterative closest point algorithm, all information, including medical images and volume renderings of organs, needles, and seeds, was precisely merged with the patient. Doctors were able to observe the tumor target and to visualize the preoperative plan. This system was validated in both phantom and animal experiments. The accuracy of this system was validated by calculating the positional and rotational error of each needle insertion. The accuracy of implantation of each seed was determined in an animal experiment to test the accuracy in low-dose-rate brachytherapy. The efficiency of this system was also validated through time consumption assessments.

RESULTS

In the phantom experiment, the average error of the needle locations was 0.664 mm and the angle error was 4.74°, average time consumption was 16.1 min with six needles inserted. Based on the results of the animal experiment, the accuracy of the needle insertion was 1.617 mm, while the angle error was 5.574° and the average error of the seed positions was 1.925 mm.

CONCLUSIONS

This paper describes the design and experimental validation of a novel surgical navigation system based on mixed reality for I¹²⁵ seed brachytherapy for thoracoabdominal tumors. This system was validated through a series of experiments, including phantom experiments and animal experiments. Compared with the traditional image-guided system, the procedure presented here is convenient, displays clinically acceptable accuracy and reduces the number of CT scans, allowing doctors to perform surgery based on a visualized plan. All the experimental results indicated that the procedure is ready to be applied in further clinical studies.

How many times 125I seed implantation brachytherapy can be repeated for pulmonary metastases: clinical efficacy and complications

Purpose

The aim of the study was to determine how many times iodine-125 (¹²⁵I) seed brachytherapy (ISB) for recurrent pulmonary metastases (RPM) can be done, and the clinical efficacy and complications of repeated ISB in RPM treatment.

Material and methods

Between September 2013 and August 2018, 18 patients with RPM, after conventional chemotherapy, radiotherapy, and trans-arterial chemoembolization, received CT-guided repeated ISB. Patients were followed up, and local control, survival, and post-operative complications were analyzed retrospectively. The Kaplan-Meier method was used for survival analyses.

Results

Eighty-two metastases in 18 patients were treated with ISB, with 71 implantations (mean number of implantations per patient, 4; range, 3-8). The total number of implanted ¹²⁵I seeds was 1,220 (mean number per patient, 68; minimum, 40; maximum, 110). The mean value of D₉₀ for ISB was 138 Gy. Local control was 91.46%, 90.24%, and 89.02% at 1, 3, and 6 months after ISB, respectively. After repeated ISB, good local control was achieved, and all patients were discharged from hospital within 3 days. One month after, six metastases of large diameter were treated with ISB; computed tomography revealed level 1 radioactive injury to the lungs, but special treatment was not administered. Post-operative renal, hepatic, and vascular functions were normal.

Conclusions

ISB for RPM is safe and efficacious. RPM treatment seems not to be limited by number of times ISB could be repeated; at least up to 8 times for different sites of lung.

Evaluation of Iodine-125 Interstitial Brachytherapy Using Micro-Positron Emission Tomography/Computed Tomography with 18F-Fluorodeoxyglucose in Hepatocellular Carcinoma HepG2 Xenografts

BACKGROUND Iodine-125 interstitial brachytherapy (125I-IBT) is a promising treatment option for unresectable hepatocellular carcinoma (HCC). This study evaluated the usefulness of micro-positron emission tomography/computed tomography (micro-PET/CT) with 18F-fluorodeoxyglucose (18F-FDG) in assessing response to 125I-IBT in HCC HepG2 xenograft. MATERIAL AND METHODS Twelve mice with bilateral HepG2 xenografts were divided into 3 equal groups implanted with iodine-125 seeds into the left xenografts with a dose of 30, 50, and 80 Gy, respectively, and the right xenografts were used as internal controls. Before and 28 days after treatment, the 18F-FDG micro-PET/CT was performed. The ratios of left to right xenografts of tumor volume (RTV), maximum standardized uptake value (RSUVmax), mean optical density of caspase-3 expression (RMODcaspase-3), and apoptosis index (RAI) were compared. RESULTS The RTV means of the 50 and 80 Gy groups were significantly lower than in the 30 Gy group after treatment (P<0.01) and the RTV means after treatment were lower than baseline in the 50 and 80 Gy groups (P<0.05). The RSUVmax mean after treatment was lower than baseline in the 80 Gy group (P<0.05). The RMODCaspase-3 and RAI means of the 80 Gy group were higher than in the 30 Gy group (P<0.05). The RSUVmax was correlated negatively to RMODcaspase-3 (r=-0.624, P<0.05) and RAI (r=-0.651, P<0.05). CONCLUSIONS This study suggest that 125I-IBT inhibits tumor growth via upregulating caspase-3 expression and prompting apoptosis in HCC HepG2 xenografts. The 18F-FDG micro-PET/CT may be a useful functional imaging modality to assess early response to 125I-IBT in HCC HepG2 xenograft.

Efficacy of Iodine-125 Seed Implantation in Locoregionally Recurrent and Unresectable Breast Cancer: a Retrospective Study

The management of locoregionally recurrent and unresectable breast cancer is a therapeutic challenge. This retrospective study aimed to assess the efficacy of 125I seed implantation brachytherapy as a palliative management in locoregionally recurrent breast cancer. We analyzed 36 locoregionally recurrent and unresectable breast cancers in our hospital between 2012 and 2016. All patients were treated with CT-guided 125I seed permanent implantation. The dose distribution of 125I seeds was calculated using a computerized treatment planning system. Complete response, partial response, stable disease, and local tumor control rates were calculated. Long-term efficacy was assessed based on survival rates ranging from 1 to 4 years. The follow-up period ranged from 6 to 53 months. The median local control was 28 months (95% CI: 16.2-39.8 months). The percentage of patients who showed 6-month, 1-year, 2-year, and 3-year local control was 97.2%, 77.8%, 52.8%, and 33.3%, respectively. Median survival time for all patients was 48 months (95% CI: 40.9-55.1 months); 1-year, 2-year, 3-year, and 4-year survival rates were 97.2%, 80.6%, 63.9%, and 46.5%, respectively. Pain relief response rate was 88.9%. No serious complications were detected during the follow-up period. The results of this study demonstrate that 125I seed implantation could be considered a feasible and promising minimally invasive therapy for locoregionally recurrent and unresectable breast carcinoma.

Iodine-125 interstitial brachytherapy reduces tumor growth via Warburg effect inhibition in non-small cell lung cancer A549 ×enografts

Iodine-125 interstitial brachytherapy (125I-IBT) is an alternative and effective treatment option for unresectable non-small cell lung cancer (NSCLC), and the Warburg effect is a determinant of tumor growth. The present study aimed to explore the influence of 125I-IBT on tumor growth and the Warburg effect, and the potential mechanisms underlying NSCLC progression. Mice with A549 cell xenografts were evenly divided into a control group without 125I-IBT, and three treatment groups receiving 125I-IBT with 20, 40 and 60 Gy. Tumor volume (TV), maximum standardized uptake value (SUVmax) determined by 18F-fluorodeoxyglucose (18F-FDG) micro-positron emission tomography/computed tomography and mean optical density (MOD) of mammalian target of rapamycin (mTOR), c-Myc, hypoxia inducible factor-1α (HIF-1α) and glucose transporter 1 (GLUT1) staining were compared among groups. Tumor inhibition rate (TIR), 18F-FDG uptake attenuation rate (FUAR) and expression suppression rate (ESR) were also calculated on day 14 and 28. The results demonstrated that the mean TV in the 60 and 40 Gy groups was smaller compared with the control TVs since days 14 and 16, respectively. The mean SUVmax value of the 60 Gy group at day 14, and all treatment group SUVmax values at day 28 were lower compared with the controls. In addition, the MOD of mTOR and GLUT1 was lower in the 60 Gy group, compared with the other groups, and c-Myc and HIF-1α values were lower in the 40 and 60 Gy groups, compared with the control and 20 Gy group (P<0.05). SUVmax positively correlated to TV (day 14, r=0.711; day 28, r=0.586) and the MOD of c-Myc and GLUT1 (r=0.621 and 0.546, respectively; P<0.01). Furthermore, dose dependent increases were observed for TIR, FUAR and ESR. In conclusion, 125I-IBT reduced tumor growth by inhibiting the Warburg effect, which may have resulted from downregulation of mTOR, c-Myc, HIF-1α and GLUT1 expression, particularly c-Myc and GLUT1, in NSCLC A549 ×enografts.

Effectiveness and safety of a robot-assisted 3D personalized template in 125I seed brachytherapy of thoracoabdominal tumors

PURPOSE

This research aims to evaluate the effectiveness and safety of a robot-assisted 3D personalized template in 125I seed brachytherapy of thoracoabdominal tumors.

MATERIAL AND METHODS

Forty-three patients with different tumors were involved in this research between 2013 and 2015. They were all eligible to 125I seed implantation based on robot-assisted 3D personalized template. Meanwhile, 51 patients with similar tumors, which were treated with a conventional coplanar template, were involved for comparison. Follow-up was carried out after the surgery to evaluate the therapeutic efficacy, including overall survival (OS) of the patient and local control (LC) of the tumor. Complications were also summarized to evaluate the safety. Besides, statistical analysis was achieved to investigate possible factors associated with the result.

RESULTS

In the robot-assisted 3D personalized template-guided brachytherapy, the median target volume treated by the prescription dose (V100) was 95.3% (range, 92.4-109.8), and the median dose administered to 90% of the target volume (D90) was 126.1 Gy (range, 114.2-132.0), improved 5% and 8% compared with the conventional template-guided brachytherapy, respectively. The median OS was 30 months (95% CI: 19.4-40.6) and the rates of 2-year OS and LC were 58.1% and 86.0%, respectively. The median OS was prolonged 10 months and the 2-year OS and LC were improved 18.9% and 23.3% compared with the conventional template-guided brachytherapy, respectively.

CONCLUSIONS

Through analysis of the selected patients with thoracoabdominal tumors, the robot-assisted 3D personalized template in 125I seed brachytherapy was a more effective and safer method. It can achieve a more favorable OS and LC.

Implantation of computed tomography-guided Iodine-125 seeds in combination with chemotherapy for the treatment of stage III non-small cell lung cancer

Purpose

We investigated the role of computed tomography (CT)-guided Iodine-125 (¹²⁵I) seed implantation in combination with chemotherapy for the treatment of stage III non-small cell lung carcinoma (NSCLC).

Material and methods

The data from 182 patients with stage III NSCLC who were treated with radioactive ¹²⁵I seed implantation between June 2002 and June 2009, and who received sequential platinum-based combination chemotherapy using the most common combination of platinum and gemcitabine, were retrospectively reviewed. The 182 patients received a prescribed dose of 110.0 Gy, with a median radioactivity of 0.70 mCi (range, 0.64-0.78 mCi, 2.37-3.26 × 107 Bq). The median number of ¹²⁵I seeds was 38 pellets (range, 6-105 pellets). The median post-operation dose covering 100% of the target volume (D₁₀₀) was 94.5 Gy (range, 54.6-125.5 Gy). The median D₉₀ was 143.0 Gy (range, 121.6-184.0).

Results

The 1-, 3-, and 5-year overall survival rates were 83.35%, 25.57%, and 11.34%, respectively; the median survival time was 24.76 months. At 1, 3, and 5 years, the local control rates were 92.01%, 86.51%, and 76.45%, respectively; the median local control time was 25.28 months. For patients with stage IIIA and IIIB NSCLC, the median survival times were 26.67 and 24.59 months, respectively (p = 0.2). Pre-treatment hemoglobin level, tumor volume, and postoperative D₁₀₀ were significantly associated with survival. A total of 24 patients experienced pneumothorax (incidence rate, 13.20%), and 17 patients experienced hemothorax (incidence rate, 5.0%).

Conclusions

CT-guided ¹²⁵I seed implantation combined with chemotherapy is an effective, minimally invasive method for the treatment of stage III NSCLC. Furthermore, hemoglobin levels before treatment, D₁₀₀, and the maximum diameter of the tumor may be prognostic factors in patients with NSCLC treated sequentially with radiotherapy and chemotherapy.

Design and validation of a CT-guided robotic system for lung cancer brachytherapy

PURPOSE

Currently, lung brachytherapy in clinical setting is a complex procedure. Operation accuracy depends on accurate positioning of the template; however, it is difficult to guarantee the positioning accuracy manually. Application of robotic-assisted systems can simplify the procedure and improve the manual positioning accuracy. Therefore, a novel CT-guided robotic system was developed to assist the lung cancer brachytherapy.

METHODS

A four degree-of-freedom (DOF) robot, controlled by a lung brachytherapy treatment planning system (TPS) software, was designed and manufactured to assist the template positioning. Target position of the template can be obtained from the treatment plan, thus the robot is driven to the target position automatically. The robotic system was validated in both the laboratory and the CT environment. In laboratory environment, a 3D laser tracker and an inertial measurement unit (IMU) were used to measure the mechanical accuracy in air, which includes positioning accuracy and position repeatability. Working reliability was also validated in this procedure by observing the response reliability and calculating the position repeatability. Imaging artifacts and accuracy of the robot registration were validated in the CT environment by using an artificial phantom with fiducial markers. CT images were obtained and used to test the image artifact and calculate the registration accuracy. Phantom experiments were conducted to test the accuracy of needle insertion by using a transparent hydrogel phantom with a high imitation artificial phantom. Also, the efficiency was validated in this procedure by comparing time costs in manual positioning with robotic positioning under the same experimental conditions.

RESULTS

The robotic system achieved the positioning accuracy of 0.28 ± 0.25 mm and the position repeatability of 0.09 ± 0.11 mm. Experimental results showed that the robot was CT-compatible and responded reliably to the control commands. The mean registration accuracy of the robotic system was 0.49 ± 0.29 mm. Phantom experiments indicated that the accuracy of needle insertion was 1.5 ± 1.7 mm at a depth ranging from 30 to 80 mm. The time used to adjust the template to the target position was 12 min on average by robotic system automatically. An average of 30 min was saved compared with the manual positioning procedure in phantom experiments.

CONCLUSIONS

This paper describes the design and experimental validation of a novel CT-guided robotic system for lung cancer brachytherapy. The robotic system was validated in a number of aspects which prove that it was capable of locating the template with clinically acceptable accuracy in the CT environment. All experimental results indicated that the system is reliable and ready to be applied to further studies on animals.