Clinical outcomes of radioactive seed brachytherapy and microwave ablation in inoperable stage I non-small cell lung cancer.

This study assessed the efficacy and safety of radioactive iodine-125 seed ablation brachytherapy (RSABT) in comparison to microwave ablation therapy (MWAT) for treating inoperable stage I non-small cell lung cancer (NSCLC). We conducted a retrospective analysis of data from stage I NSCLC patients who underwent CT-guided RSABT or MWAT. The primary outcomes measured were progression-free survival (PFS), overall survival (OS), and the occurrence of adverse events. Of the patients included in the study, 71 underwent RSABT and 105 received MWAT. The median follow-up time for these groups was 47.4 months and 60 months, respectively. The PFS rates at 1-year, 3-year, and 5-year for the RSABT group were 87.3%, 72.6%, and 65.8%, while for the MWAT group, they were 89.5%, 69.3%, and 43.7%, respectively (P = 0.011). The OS rates at 1-year, 3-year, and 5-year for the RSABT group were 97.2%, 78.1%, and 66.1%, and for the MWAT group, they were 99%, 75.8%, and 55%, respectively (P = 0.112). Upon multivariate analysis, the treatment modality was identified as an independent predictor of PFS (P = 0.008). Additionally, both sex and T stage were found to be independent predictors of both PFS and OS (P < 0.05). Adverse events, such as pneumothorax, occurred in 50% of the MWAT group and 39% of the RSABT group (P = 0.313). The incidence of pleural effusion was 44% in the MWAT group compared to 14% in the RSABT group (P < 0.001). Needle bleeding was observed in 32% of the RSABT group and 5% of the MWAT group (P < 0.001). We conclude RSABT demonstrates promising efficacy and safety in the treatment of stage I NSCLC. However, further studies are essential to validate these preliminary findings.

Safety and efficacy of stereotactic ablative brachytherapy as a salvage therapy for recurrent chest wall cancer: A retrospective, multicenter study.

Purpose: To evaluate the safety and efficacy of stereotactic ablative brachytherapy (SABT) as a salvage therapy for patients with recurrent chest wall cancer (rCWC) who have previously received external beam radiotherapy (EBRT) or surgery. Materials and methods: Between November 2013 and October 2020, a total of 130 patients (including 75 men with a median age of 63 years) with rCWC treated with SABT were enrolled in this multicenter retrospective study. There were 97 cases of non-small-cell lung carcinoma, 24 cases of breast cancer, and 9 cases of thymic cancer. Of the patients included, 102 patients previously received surgery and 58 patients received EBRT, with systemic treatment progressing after recurrence. None of them were suitable or refused to undergo salvage EBRT or surgery again. Results: During the 22 (4-70)-month median patient follow-up, 59 patients died. The local control (LC) rates at 6, 12, 24, and 36 months were 88.3%, 74.3%, 50.4%, and 36.7%, respectively. The 1-, 2- and 3-year survival rates were 85%, 56%, and 42%, respectively. The median overall survival was 26 months (95% CI, 18.9-33.1 months). The pain relief rate was 81%, and the median to remission time was 10 days. Univariate and multivariate analyses showed that independent prognostic factors for LC included tumor size and postoperative D90. On the other hand, independent prognostic factors for survival include the Karnofsky performance status (KPS) score, tumor size, and D90 19 patients (14.6%) developed grade I/II skin reaction complications. No grade III or severer complications occurred. Conclusion: SABT is safe and effective as a salvage therapy for rCWC following EBRT/surgery. For patients with a KPS score greater than 80, prescribed dose greater than 130 Gy, and tumor size less than 4 cm may bring better results.

Clinical Outcome of CT-Guided Stereotactic Ablative Brachytherapy for Unresectable Early Non-Small Cell Lung Cancer: A Retrospective, Multicenter Study.

OBJECTIVE: To analyze the efficacy and safety of low dose rate stereotactic ablative brachytherapy (L-SABT) for treatment of unresectable early-stage non-small cell lung cancer (NSCLC). METHODS: Data of patients with early-stage NSCLC who received CT-guided L-SABT (radioactive I-125 seeds implantation) at eight different centers from December 2010 to August 2020 were retrospectively analyzed. Treatment efficacy and complications were evaluated. RESULTS: A total of 99 patients were included in this study. Median follow-up duration was 46.3 months (6.1-119.3 months). The 1-year, 3-year, and 5-year local control rates were 89.1%, 77.5%, and 75.7%, respectively. The 1-year, 3-year, and 5-year overall survival rates were 96.7%, 70.1%, and 54.4%, respectively. Treatment failure occurred in 38.4% of patients. Local/regional recurrence, distant metastasis, and recurrence combined with metastasis accounted for 15.1%, 12.1%, and 11.1%, respectively. Pneumothorax occurred in 47 patients (47.5%) with 19 cases (19.2%) needing closed drainage. The only radiation-related adverse reaction was two cases of grade 2 radiation pneumonia. KPS 80-100, T1, the lesion was located in the left lobe, GTV D90 ≥150 Gy and the distance between the lesion and chest wall was < 1 cm, were associated with better local control (all P < 0.05); on multivariate analysis KPS, GTV D90, and the distance between the lesion and chest wall were independent prognostic factors for local control (all P < 0.05). KPS 80-100, T1, GTV D90 ≥150 Gy, and the distance between the lesion and chest wall was < 1 cm were also associated with better survival (all P < 0.05); on multivariate analysis KPS, T stage, and GTV D90 were independent prognostic factors for survival (all P < 0.05). The incidence of pneumothorax in patients with lesions <1 cm and ≥1cm from the chest wall was 33.3% and 56.7%, respectively, and the differences were statistically significant (P = 0.026). CONCLUSION: L-SABT showed acceptable efficacy in the treatment of unresectable early-stage NSCLC. But the incidence of pneumothorax is high. For patients with T1 stage and lesions <1 cm from the chest wall, it may have better efficacy. Prescription dose greater than 150 Gy may bring better results.

Automatic segmentation of organs at risk and tumors in CT images of lung cancer from partially labelled datasets with a semi-supervised conditional nnU-Net.

BACKGROUND AND OBJECTIVE: Accurately and reliably defining organs at risk (OARs) and tumors are the cornerstone of radiation therapy (RT) treatment planning for lung cancer. Almost all segmentation networks based on deep learning techniques rely on fully annotated data with strong supervision. However, existing public imaging datasets encountered in the RT domain frequently include singly labelled tumors or partially labelled organs because annotating full OARs and tumors in CT images is both rigorous and tedious. To utilize labelled data from different sources, we proposed a dual-path semi-supervised conditional nnU-Net for OARs and tumor segmentation that is trained on a union of partially labelled datasets. METHODS: The framework employs the nnU-Net as the base model and introduces a conditioning strategy by incorporating auxiliary information as an additional input layer into the decoder. The conditional nnU-Net efficiently leverages prior conditional information to classify the target class at the pixelwise level. Specifically, we employ the uncertainty-aware mean teacher (UA-MT) framework to assist in OARs segmentation, which can effectively leverage unlabelled data (images from a tumor labelled dataset) by encouraging consistent predictions of the same input under different perturbations. Furthermore, we individually design different combinations of loss functions to optimize the segmentation of OARs (Dice loss and cross-entropy loss) and tumors (Dice loss and focal loss) in a dual path. RESULTS: The proposed method is evaluated on two publicly available datasets of the spinal cord, left and right lung, heart, esophagus, and lung tumor, in which satisfactory segmentation performance has been achieved in term of both the region-based Dice similarity coefficient (DSC) and the boundary-based Hausdorff distance (HD). CONCLUSIONS: The proposed semi-supervised conditional nnU-Net breaks down the barriers between nonoverlapping labelled datasets and further alleviates the problem of "data hunger" and "data waste" in multi-class segmentation. The method has the potential to help radiologists with RT treatment planning in clinical practice.

Multiorgan segmentation from partially labeled datasets with conditional nnU-Net.

Accurate and robust multiorgan abdominal CT segmentation plays a significant role in numerous clinical applications, such as therapy treatment planning and treatment delivery. Almost all existing segmentation networks rely on fully annotated data with strong supervision. However, annotating fully annotated multiorgan data in CT images is both laborious and time-consuming. In comparison, massive partially labeled datasets are usually easily accessible. In this paper, we propose conditional nnU-Net trained on the union of partially labeled datasets for multiorgan segmentation. The deep model employs the state-of-the-art nnU-Net as the backbone and introduces a conditioning strategy by feeding auxiliary information into the decoder architecture as an additional input layer. This model leverages the prior conditional information to identify the organ class at the pixel-wise level and encourages organs' spatial information recovery. Furthermore, we adopt a deep supervision mechanism to refine the outputs at different scales and apply the combination of Dice loss and Focal loss to optimize the training model. Our proposed method is evaluated on seven publicly available datasets of the liver, pancreas, spleen and kidney, in which promising segmentation performance has been achieved. The proposed conditional nnU-Net breaks down the barriers between nonoverlapping labeled datasets and further alleviates the problem of data hunger in multiorgan segmentation.

Hybrid optimization based on non-coplanar needles for brachytherapy dose planning.

PURPOSE: An ideal dose distribution in a target is the ultimate goal of preoperative dose planning. Furthermore, avoiding vital organs or tissues such as blood vessels or bones during the puncture procedure is significant in low-dose-rate brachytherapy. The aim of this work is to develop a hybrid inverse optimization method based on non-coplanar needles to assist the physician during conformal dose planning, which cannot be properly achieved with a traditional coplanar template. MATERIAL AND METHODS: The hybrid inverse optimization technique include two novel technologies: an inverse optimization algorithm and a dose volume histogram evaluation method. Brachytherapy treatment planning system was designed as an experimental platform. Left lung adenocarcinoma case was used to test the performance of the method in non-coplanar and coplanar needles, and malignant tumor of spine case was involved to test the practical application of this technique. In addition, the optimization time of every test was also recorded. RESULTS: The proposed method can achieve an ideal dose distribution, avoiding vital organs (bones). In the first experiment, 13 non-coplanar needles and 24 seeds were used to get an ideal dose distribution to cover the target, whereas 11 coplanar needles and 23 seeds were used to cover the same target. In the second experiment, the new method used 22 non-coplanar needles and 65 seeds to cover the target, while 63 seeds and 22 needles were used in the actual operation. In addition, the computation time of the hybrid inverse optimization method was 20.5 seconds in the tumor of 94.67 cm3 by using 22 needles, which was fast enough for clinical application. CONCLUSIONS: The hybrid inverse optimization method achieved high conformity in the clinical practice. The non-coplanar needle can help to achieve a better dose distribution than the coplanar needle.

A novel auto-positioning method in Iodine-125 seed brachytherapy driven by preoperative planning.

Iodine-125 seed brachytherapy has great potential in the treatment of malignant tumors. However, the success of this treatment is highly dependent on the ability to accurately position the coplanar template. The aim of this study was to develop an auto-positioning system for the template with a design focus on efficiency and accuracy. In this study, an auto-positioning system was presented, which was composed of a treatment planning system (TPS) and a robot-assisted system. The TPS was developed as a control system for the robot-assisted system. Then, the robot-assisted system was driven by the output of the TPS to position the template. Contrast experiments for error validation were carried out in a computed tomography environment to compare with the traditional positioning method (TPM). Animal experiments on Sprague-Dawley rats were also carried out to evaluate the auto-positioning system. The error validation experiments and animal experiments with this auto-positioning system were successfully carried out with improved efficiency and accuracy. The error validation experiments achieved a positioning error of 1.04 ± 0.19 mm and a positioning time of 23.15 ± 2.52 min, demonstrating a great improvement compared with the TPM (2.55 ± 0.21 mm and 40.35 ± 2.99 min, respectively). The animal experiments demonstrated that the mean deviation of the seed position was 0.75 mm. The dose-volume histogram of the preoperative planning showed the same as the postoperative dosimetry validation. A novel auto-positioning system driven by preoperative planning was established, which exhibited higher efficiency and accuracy compared with the TPM.

Expert consensus on computed tomography-assisted three-dimensional-printed coplanar template guidance for interstitial permanent radioactive 125I seed implantation therapy.

Interstitial permanent radioactive seed implantation delivers a high local dose to tumors and sharply drops off at surrounding normal tissues. Radioactive seeds implanted via ultrasound or computed tomography (CT) guidance are minimally invasive and facilitate quick recovery. Transrectal ultrasound-guided 125I seed implantation assisted by a transperineal plane template is standard for early-stage prostate carcinoma, with a highly consistent target volume dose distribution. The postplan dose evaluation is consistent with the preplan evaluation. Until now, there was no workflow for seed implantation elsewhere in the body, and it was difficult to effectively preplan for seed implantation because of patients' position changes, organ movement, and bone structure interference. Along with three-dimensional (3D) printing techniques and seed implantation planning systems for brachytherapy, coplanar and X Y axis coordinate templates were created, referred to as 3D-printed coplanar templates (3D-PCT). 125I seed implantation under CT guidance with 3D-PCT assistance has been very successful in some carcinomas. Preplanning was very consistent with postplanning of the gross tumor volume. All needles are kept parallel for 3D-PCT, with no coplanar needle rearrangement. No standard workflow for 3D-PCT-assisted seed implantation exists at present. The consensus topics for CT-assisted guidance compared to 3D-PCT-assisted guidance for seed implantation are as follows: Indications for seed implantation, preplanning, definition of radiation doses and dosimetry evaluation, 3D-PCT workflow, radiation protection, and quality of staff. Despite current data supporting 125I seed implantation for some solid carcinomas, there is a need for prospectively-randomized multicenter clinical trials to gather strong evidence for using 125I seed implantation in other solid carcinomas.

Clinical application of planar puncture template-assisted computed tomography-guided percutaneous biopsy for small pulmonary nodules.

AIMS: The aims of this study were to evaluate the clinical application of planar puncture template (PPT) in computed tomography (CT)-guided percutaneous needle lung biopsy. SUBJECTS AND METHODS: A total of 56 patients with small pulmonary nodules who received CT-guided percutaneous lung biopsy assisted by PPT were included in the study. Five steps were included in the study: fixing position, CT scanning and designing needle pathway, installing navigation system and template, puncturing fixation needle, and performing biopsy needle insertion and biopsy. The success rate of puncture, pathological results, and complications were analyzed. In addition, the factors that influenced the success rate and complications were analyzed. RESULTS: Biopsy was successfully completed in all 56 patients. The nodule diameter was 0.45-3 cm. The fixation needle technique was applied in 47 cases. Biopsy was performed 1 time in 50% of patients and 2 times in 38% of patients. For pathology, only one case showed no positive result, with a puncture success rate of 98%. The diagnostic rate of malignant tumor was 73%. For complications, the incidence of needle tract bleeding was 68%, the incidence of pneumothorax was 30%, and the thoracic drainage was required in two patients. Hemoptysis was observed in two cases. Univariate analysis: The nodule size was related to both the rate of 1-time biopsy and incidence of complications. Smaller nodule was relevant to lower rate of 1-time biopsy (P = 0.01) and higher incidence of complications (P < 0.05). The fixation needle was related to 1-time biopsy rate. The 1-time biopsy rate was significantly higher in patients with fixation needle than those without fixation needle (P = 0.001). Meanwhile, no significant difference was observed in the incidence of complications in different number of fixation needles (P > 0.05). CONCLUSIONS: PPT-assisted lung biopsy technology can provide high success rate and low complication incidence. It would be helpful to make the puncture procedures more standard for better clinical applications.

Percutaneous computed tomography-guided permanent 125I implantation as therapy for pulmonary metastasis.

PURPOSE: To evaluate intermediate-term outcomes after computed tomography (CT)-guided radioactive 125I seed implantation (CTRISI), and to determine prognostic variables associated with outcomes in patients with pulmonary metastases. MATERIAL AND METHODS: Thoracic surgeons evaluated and performed implantation of 125I radioactive seeds under CT guidance or combined with surgical resection. Patients were monitored in the thoracic surgery clinic for recurrence and survival. RESULTS: Fifty patients (31 men, 19 women; median age, 59 years; range, 16-85) underwent CTRISI. The primary cancer was colorectal in 10 (20%), malignant fibrous histiocytoma in 8 (16%), sarcoma in 5 (10%), renal in 4 (8%), and other in 22 (44%) patients. CTRISI was the sole treatment in 45 patients (90%) and was combined with surgical resection in 5 patients (10%). The actuarial D90 of implanted 125I seeds ranged from 90 to 160 Gy (median, 120 Gy). No procedurally related deaths occurred. At a median follow-up of 41.5 months (range, 7-74 months), 6 patients were alive. The median survival time was 42.1 months (95% confidence interval: 26.5-53.4), and the estimated 1-, 3-, and 5-year overall survival rates were 88.0%, 58.0%, and 26.7%, respectively. Lesion size was an important prognostic variable associated with overall and progression-free survival (p < 0.05). CONCLUSIONS: CTRISI is safe in this group of patients with pulmonary metastases and provides reasonable results. Surgical resection remains the standard for resectable cases, but CTRISI offers an alternative for selected patients or may be used as a feasible approach in combination with surgical resection for selected patients.

Expert consensus statement on computed tomography-guided 125I radioactive seeds permanent interstitial brachytherapy.

The aim of this study is to develop expert consensus statement for recommendations of patient selection criteria, prescription dose, and procedure of computed tomography (CT)-guided 125I radioactive seeds permanent interstitial brachytherapy. Members of Chinese medical association radiation oncology branch, Chinese medical association radiation therapy professional committee, Chinese cancer society minimally invasive surgery branch seed therapy group, Chinese geriatric cancer society minimally invasive surgery branch, Beijing medical association radiation oncology professional committee, China northern radioactive seeds brachytherapy group formed a committee, which consists of physician members who come from the department of radiation oncology, surgery, intervention, internal medicine, ultrasound, and nuclear medicine. The leader of the group organized experts to write the first draft based on clinical experience and literature review and then sent the draft to the commissioner for consultation, finally reached a consensus. Guidelines for patient selection criteria, prescription dose of 125I seed for different kinds of carcinomas, activity of per seed, and workflow of CT-guided permanent interstitial radioactive seed implantation (RSI) are presented in this study. The procedure of CT-guided RSI comprised eight steps: indication selection, preoperative preparation, preoperative CT simulation and position setup, preplan, intraoperative needle insertion, RSI, postoperative dosimetric evaluation, and follow-up. Patient selection criteria are developed. Guidelines for prescription dose of 125I seed for different kinds of carcinomas, activity of per seed, and workflow of CT-guided permanent interstitial RSI are provided.

125I inhibited the NSCLC both in vivo and in vitro.

Lung cancer is the main reason of cancer-linked death all over the world. Non-small cell lung cancer (NSCLC) patients always have an extremely poor prognosis. It is urgent to find novel treating methods. It was previously showed that 125I brachytherapy had been applied to the lung cancer treatment. However, fundamental researches are limited. In the present study, we first explored the mechanism by which 125I radiation induced arrest or apoptosis of the cell cycle and relevant protein expression. Furthermore, we explored its effect on the invasion. We found that 125I significantly induced cell apoptosis through mitochondrial pathway, triggered S phase arrest via regulating cyclinA2, p21 and CDK6 expressions. Meanwhile, 125I could inhibit invasion of NSCLC cells by altering the expression level of vimentin, N-cadherin and MMP-9. Furthermore, we confirmed the effects of 125I on NSCLC cell growth in vivo. The results indicated that 125I obviously inhibited the tumor growth. Thus, we determined that 125I brachytherapy remarkably restrained NSCLC cellular growth and intrusion by inducing apoptosis, S phase arrest and corresponding protein expression.

Expert consensus workshop report: Guideline for three-dimensional printing template-assisted computed tomography-guided 125I seeds interstitial implantation brachytherapy.

Radioactive 125I seeds (RIS) interstitial implantation brachytherapy has been a first-line treatment for early-stage cancer of the prostate gland. However, its poor accuracy and homogeneity has limited its indication and hampered its popularization for a long time. Intriguingly, scholars based in China introduced computed tomography (CT)-guided technology to improve the accuracy and homogeneity of RIS implantation and broadened the indications. Then, they creatively designed and introduced three-dimensional printing coplanar template (3D-PCT) and 3D printing noncoplanar template (3D-PNCT) into the practice of RIS implantation. Use of such templates makes RIS implantation more precise and efficacious and aids preoperative planning, real-time dose optimization, and postoperative planning. However, studies on the standard workflow for 3D-PT-assisted CT-guided RIS implantation have not been published. Therefore, the China Northern Radioactive Seeds Brachytherapy Group organized multidisciplinary experts to formulate the guideline for this emerging treatment modality. This guideline aims at standardizing 3D-PT-assisted CT-guided RIS implantation procedures and criteria for selecting treatment candidates and assessing outcomes and for preventing and managing postoperative complications.

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.

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

PURPOSE: To retrospectively evaluate the effectiveness and safety of CT-guided (125)I seed brachytherapy (CTISB) in 38 non-small cell lung cancer (NSCLC) patients with locoregional recurrence (LRR). METHODS AND MATERIALS: In total, we analyzed 38 NSCLC patients with LRR treated with percutaneous CTISB in our hospital between 2001 and 2008; among them, 15 also received combined chemotherapy: 1-6 cycles (median, 2) of platinum-based regimens. The change in tumor volume was evaluated based on followup contrast material-enhanced CT or positron emission tomography scans. RESULTS: The median Day 0 dosimetry was as follows: The volume treated with the prescription dose (V100) was 96.3% (90.1-123.5%), and the minimum dose received by at least 90% of the tumor volume (D90) was 124.8 Gy (116.0-130.7 Gy). The median duration of the followup period calculated from the first CTISB treatment was 22.5 months (range, 8-98 months). Two months after CTISB, complete response, partial response, and progressive disease were observed in 50%, 37%, and 8% of patients, respectively. Median overall survival (OS) after CTISB was 21 months (95% confidence interval, 7.4-34.6), and the rates of 2-year OS, progression-free survival, and local control were 47.4%, 39.5%, and 83.5%, respectively. Both univariate and multivariate analysis indicated that D90 was significant prognostic factors for OS and progression-free survival. CONCLUSION: For selected NSCLC patients with limited LRR, CTISB is effective and can provide a high rate of local cancer control with minimal trauma.

[The short term therapeutic effects of radioactive (125)I seeds implantation for treatment of non-small-cell lung cancer].

OBJECTIVE: To explore influential factors of local therapeutic effect in CT guided brachytherapy of (125)I seeds for non-small-cell lung carcinoma (NSCLC). METHODS: Totally 141 primary NSCLC patients diagnosed by bronchoscope or puncture biopsy were treated with CT guided (125)I seeds implantation treatment from 2003 January to 2005 January. Among them, 26 patients were treated with seeds implantation only and remaining 115 combined with chemical therapy. Preplans were performed by using treatment planning system before the implantation. We took the implantation with the prescription dose of 80 - 110 Gy, 1 seed per 1 cm(3), under the guide of computed tomography. Six months after implantation treatment, CT graphs were taken to evaluate the therapeutic effect. RESULTS: All the patients were survival until 6 months after implantation, and 37 were complete remission, 93 were partial remissions. The effective rate was 92.2%. Among all the observed factors, pathologic type(F = 5.162, P = 0.023), dose of cover 100% tumor (D(100)) (F = 100.713, P = 0.000) and treatment methods (F = 16.205, P = 0.000) were the independent influent factors (P < 0.05). Among these, D(100) was the most important factor (P = 0.000). Single factor analysis indicated that pathologic type (χ(2) = 7.313, P = 0.007), D(100) (χ(2) = 71.6, P = 0.000) and treatment methods (χ(2) = 20.5, P = 0.000) were significant influent factors. Of all 141 cases, 24 had complications during or after implantation treatment, while no severe complications were reported. There was no significant correlation between complication and local therapeutic effect (P > 0.05). CONCLUSION: CT guided implantation of (125)I seeds for lung cancer has good clinical effects and few complications. D(100) is the most important factor to influence the local therapeutic effect. Implantation treatment combined with chemotherapy is an ideal measure for NSCLC treatment.