Objective To evaluate the efficacy and adverse reactions of CT-guided 125I radioactive seed implantation in treatment of locally recurrent rectal cancer (LRRC).Methods Thirty patients with LRRC who refused operation or were unable to endure pelvic radiotherapy received 125I seed implantation under CT guidance.Three-dimensional treatment planning system was used to calculate the number,activity,and dose of the seeds needed.The activity of seeds ranged from 14.8 to 29.6 MBq with a median of 25.9 MBq,the seed numbers ranged from 33 to 137 with a median of 74.5,the prescription doses ranged from120-160 Gy,and the actual verification dose D90 ranged from 75.91 to 159.32 Gy with a median of 119.77 Gy.Dosimetric verification by CT scanning was conducted immediately after the treatment.Follow-up was conducted for 15.2 months(4.2-35.0 months).Results The follow-up rate was 93.3％.The pain relief rate was 95.2％.The overall response rate was 50.0％,including a complete response rate of 13.3％ and a partial response rate of 36.7％.The 1-and 2-year local control rates were 30.0％ and 8.0％ respectively.The median local control survival time was 7.8 month.The 1-and 2-year survival rates were 66.5％ and 32.9％ respectively.The median overall survival time was 21.5 months.Complications,mainly adverse effects of skin and urinary system (frequent urination,urgent urination,and dysuria) occurred in 6 patients with a rate of 20.0％.Conclusions Minimally invasive and with satisfying efficacy and tolerable complications,CT-guided 125I radioactive seed implantation is a favorable option for treatment of LRRC,especially for the patients who have undergone previous pelvic radiation.

Objective To explore the clinical features and genetic etiology of children with cystinuria with onset of kidney stone. Methods The clinical data of 3 children with cystinuria with onset of kidney stone and the gene analysis results of SLC3A1 and SLC7A9 by PCR sequencing were retrospectively analyzed.Results Three male children were from three unrelated families, kidney stone were presented in 2 cases at 1 year old and 1 case at 14 years old. The blood amino acid spectrum was normal in all 3 cases, while the free carnitine were decreased. The urinary amino acid spectrum indicated that cystine, ornithine, arginine,and threonine increased.Gene analysis confirmed that 1 case had homozygous mutations of SLC7A9 gene c.325G>A, and his parents were carriers of c.325G>A heterozygous mutation;other 2 cases had heterozygous mutations of SLC3A1 gene, c.1365delG and c.1113C>A heterozygous mutation in one case, and c.1897_1898insTA and c.1093C>T heterozygous mutation in one case, and their parents were heterozygous mutation carriers. After treatment with potassium citrate and L-carnitine, the conditions were improved in all cases. Conclusions Inherited metabolic disease should be considered for children with kidney stone. Urine amino acid analysis and gene detection are important methods for the diagnosis of cystinuria.