Objective To explore the efficacy of implantation of 125I seeds combined with radiotherapy and/or chemotherapy for local recurrent lung cancer at a late stage.Methods A total of thirty-two patients were received implantation of 125I seeds therapy with a MPD of 110 to 140 Gy in our hospital.CT scan was used for guidance.Before the operation,a therapeutic plan was made by TPS.The therapeutic target volume(PTV)included the clinical target volume(CTV)plus the surrounding tissues 1 cm adjacent to the edge of CTV.The activity of each seeds was set at 0.7 mCi.The distribution of the seeds was checked by CT scan immediately after the implantation.Then,chemotherapy or radiotherapy was carried out in 3 to 7 days.EP,NP,or TP was used for the patients receiving chemotherapy.Results In 2 to 4 months after the treatments,the CR,PR,and NC were 46.9%(15/32),37.5%(12/32),and 15.6%(5/32),respectively.The rate of complete local control was 84.4%(CR+PR).The 1-and 2-year survival rate in this series were 78.6%(22/28)and 66.7%(10/15).Four of these patients survived over 3 years.Eleven of the patients(34.4%)developed pneumothorax after the implantation,3 of them were cured by chest drainage;9 patients(28.1%)had hemorrhage including 5 cases of intrapulmonary bleeding and 4 cases of emptysis.In 3 cases(9.4%),the seeds missed the target,and dropped into the diaphragmatic muscle at the thoracic cavity(2 cases)or out of the target area(1 case).No seeds migration or radiation-induced lung injury was found.Conclusion Implantation of 125I seeds combined with radiotherapy and/or chemotherapy is effective for patients with local recurrent lung cancer at a late stage.

BACKGROUNDBrachytherapy offers an innovative method of delivering conformal high-dose radiation to a defining target tumor. The aim of this study is to investigate the value and effect of using radioactivity ¹²⁵I seed permanent implants combined with chemotherapy in the management of stage III or IV lung cancer.

METHODSForty-two lung cancer patients in stage III and IV (15 center lung cancer) who couldn't be relieved by routine methods were treated with ¹²⁵I seed permanent micropuncture implant brachytherapy and chemotherapy. The dose and distribution of seeds was decided by treatment planning system, and CT was used during ¹²⁵I seed permanent implant treatment. Distribution of seeds and complication was reviewed by CT scan after treatment. Chemotherapy was performed in 3 to 7 days after implanting. The effect was observed by X-ray, CT and MRI every 3 or 4 weeks.

RESULTSThe satisfaction rate of seed distribution was 83.3% (35/42). The response rate of treatment was 85.7% (36/42), including complete response rate 26.2% (11/42), partial response rate 59.5% (25/42), no change rate 14.3% (6/42). Effective rate of pain relief was 83.3% (15/18). Thirteen patients (31.0%) had complication of mild hemothorax, 8 (19.0%) with bleeding in lung and 5 (11.9%) with hemoptysis. Three patients (7.1%) had mild pneumothorax and 1 patient (2.4%) had a malposition seed. Leucopenia and radiation pneumonia didn't occurred.

CONCLUSIONS¹²⁵I seed micropuncture implant has less trauma and complication, and is a safe and effective method. This method might be helpful in the treatment of lung cancer and can be selectively used in clinic.

Objective:To investigate the safety and dose of 4D template (real-time adjustable angle template) in the treatment of advanced malignant tumors with 125I seeds. Methods:98 patients with advanced malignant tumors admitted to Department of Thoracic Surgery of Shaanxi Provincial Tumor Hospital were treated with 4D template-navigated radioactive 125I seed implantation from June 2018 to December 2019. Preoperative TPS plan, intraoperative optimization, postoperative verification of immediate dose and postoperative evaluation of implantation dose were performed. The treatment results were observed. Results:All 98 patients completed the seed implantation. The implantation dose of GTV of implantation site receiving external irradiation was (12 489±414) cGy and the dose of no external irradiation was (15 036±514) cGy. V 100% was 84.7%-94.1%, and 88.2%-93.7%. The implantation dose of CTV was (7 450±621) cGy, and (9 080±761) cGy. The quality of dose implantation was evaluated as: excellent in 89 cases (91%, 89/98), good in 7 cases (7%, 7/98), fair in 2 cases (2%, 2/98), and poor in 0 case, respectively. The symptom relief rate of patients with pain was 92%(36/39). The 1-and 2-year local control rates were 61%, 36% and 82%, 54% in patients treated with and without external irradiation, respectively. The difference was statistically significant ( P=0.02). The incidence rates of pneumothorax and hemoptysis were 19%(9/48) and 10%(5/48). No corresponding complications were observed in other parts of the patients. Conclusion:4D template-assisted 125I seed therapy is safe and effective for malignant tumors, and intraoperative adjustment of needle angle and dose optimization can realize the precise control of implantation dose.

Objective: To investigate the safety and efficacy of 125I radioactive seed implantation in the treatment of mediastinal lymph node metastasis. Methods: Records of 53 patients enrolled in Shaanxi Provincial Tumor Hospital from June 2014 to June 2018 with me-diastinal lymph node metastasis treated by computed tomography (CT)-guided 125I seed implantation were analyzed retrospectively. The preoperative treatment planning system was validated after the surgery. Intraoperative and post-operative complications were re-corded. The improvement in quality of life was observed. Chest CT follow-up was conducted 1 month, 3 months, 6 months, 1 year, and 2 years after treatment. The local focus control was evaluated. The median survival and total survival were recorded, and the survival prognosis and causes of death were analyzed. Results: The median survival time was 254 days (8.5 months), one-year survival rate was 48.67%, and complete and partial response rate was 83.02% (44/53). Multivariate Cox model analysis showed that the survival progno-sis was related to the Eastern Cooperative Oncology Group (ECOG) score, distant metastasis at the time of implantation, concurrent chemotherapy after implantation, and secondary seed implantation (P<0.05). The rates of developing pneumothorax and hemoptysis during and after the surgery were 20.75% (11/55) and 13.20% (7/55), respectively. No patients died. After implantation, the remission rate of cough, shortness of breath, pain, hoarseness, and superior vena cava syndrome was 60.00%-82.61%. Conclusions: CT-guid-ed 125I seed implantation in the treatment of mediastinal lymph node metastasis has the advantages of minimal trauma, remarkable cu-rative effect, safety, and feasibility. It has important application value and is worthy of further clinical application.