Objective To Study The Clinical Application Of Radioactive I¹²⁵ Seeds Implantation In The Treatment Of Mediastinal Lymph Node Metastasis Of Lung Cancer Group 4L And The Relative Safe And Effective Prescr Iption Dose

ObjectIve: 1.ObjectIve to InvestIgate the effIcacy,safety and clInIcal value of radIoact Ive I¹²⁵ seeds ImplantatIon In the treatment of lung cancer wIth med IastInal lymph node metastasIs In group 4L.2.Based on the qualIty control of D90,the relatIve safe and effectIve prescrIptIon dose of radIoactIve I¹²⁵ seeds Implantat Ion In the treatment of lung cancer was explored.Methods: Ten patIents wIth 4L medIastInal lymph node metastasIs of lung cancer were treated by CT-guIded I¹²⁵ brachytherapy.Before the ImplantatIon,TPS was employed to confIrm the seed number and needle placement.I¹²⁵ radIoactIve seeds wereImplanted by settIng CT Gantry at an oblIque angle and posItIonIng the template.All the pat Ients were prescrIbed dose 120 Gy wIth radIoactIv Ity of 2.59×107Bq per seed and TPS qualIty verIfIed after surgery.Observe the Improvement In clInIcal symptoms and lymph node sIzes.RetrospectIve study of 28 Late NSCLC（non-small cell lung cancer）patIents wIth recurrence after radIotherapy and chemotherapy In our hospItal from 2012 Oct to 2015 May.CT guIded percutaneous ImplantatIon of I¹²⁵ part Icles,the actIv Ity of 0.7mCI,the number of10-80.PatIents were d IvIded Into two groups accordIng to the prescrIptIon dose,D90 was 10000-12000 cGy In group A.D90 was12000-14000 cGy In group B.The dose verIfIcatIon of CT after operat Ion,chest CT after the operatIon by 2and 6months.Compared wIth the tumor s Ize before treatment,the effIcacy was determIned.ComparIson of the 2and 6 months objectIve response rate of the two groups（PR+CR）,the 2and 6 months local control rate and the IncIdence of compl Icat Ions.Results: SatIsfactIon rate of qualIty verIfIcatIon ImmedIately after operatIon were 93.3%.AccordIng to the chest CT-scan two months after ImplantatIon,4 patIents had complete ablatIon,8 partIal ablatIon,and 3stable d Iseases.The symptoms of all patIents IncludIng shortness of breath,cough,and hoarseness showed varyIng degree of Improvement.There was 4 pneumothorax In all operatIons and we treated by closed draInage of cavIty（2 cases）or thoracocentesIs（1 case）.There was nomajor vascular,tracheal and esophageal Injury.The patIents were dIvIded Into two groups: AB group.PatIents wIth D90 10000-12000 cGY were group A.PatIents wIth D90 12000-14000 cGY were group B.The 2months objectIve response rate of group A and group B were 50% and78.5%.The 2 months local control rate of group A and group B were71.4% and 85.7%.The 6 months objectIve response rate of group A and group B were 57.1% and 85.7%.The 6 months local control rate of group A and group B were 78.5% and 92.8%.χ2test p values were less than0.05,there was statIstIcal sIgnIfIcance.No serIous compl IcatIon.ConclusIons: The results of thIs study confIrmed that CT guIded percutaneous InterstItIal Implantat Ion of radIoactIve I¹²⁵ partIcles In the treatment of lung cancer wIth lymph node metastasIs of 4L group Is a safe and effectIve method.At the same tIme,It has been confIrmed that radIoactIve I¹²⁵ seeds ImplantatIon In the treatment of advanced non-small cell lung cancer,the prescrIptIon dose of 12000-14000 cGy may have a better effect,whIch provIdes a new proposal for the choIce of prescrIptIon dose In clInIc.