32P-磷酸铬-聚L-乳酸缓释粒子近距离放射治疗前列腺癌合并淋巴结转移

目的 观察32P-磷酸铬-聚L-乳酸(32P-CP-PLLA)缓释粒子植入对裸鼠前列腺癌实体瘤和区域淋巴结转移灶的治疗作用.方法 建立裸鼠原位前列腺癌及淋巴结转移模型,4周后分别进行高、中、低剂量(剂量分别为3.7、7.4、14.8 MBq)32P-CP-PLLA缓释粒子瘤体局部植入,观察(1)不同剂量32P-CP-PLLA缓释粒子的体内生物学分布;(2)上述缓释粒子对瘤体和淋巴结病理形态学影响以及抑瘤率;(3)观察血WBC和PLT变化,研究其血液不良反应.结果 SPECT显示32P-CP-PLLA缓释粒子植入后主要聚集在瘤体局部和区域淋巴结,形态学检查显示实体瘤和区域淋巴结转移灶瘤组织呈出血、坏死性改变;抑瘤率与给药剂量正相关,给药剂量为3.7、7.4、14.8 MBq,抑瘤率分别为:(70.16±5.48)%、(80.18±5.84)%、(84.97±4.79)%,无明显骨髓抑制反应.结论 32P-CP-PLLA缓释粒子瘤体局部植入对前列腺癌肿瘤组织和区域性淋巴结转移灶具有杀伤作用.     

32P-磷酸铬-聚L乳酸粒子植入肝癌H22移植瘤模型治疗淋巴道转移的潜能

目的 观察32P-磷酸铬-聚L乳酸(32P-CP-PILA)粒子瘤体植入后对KM小鼠肝癌H22淋巴转移模型区域淋巴结(LN)治疗的潜能.方法 KM小鼠55只,建立右爪垫移植瘤淋巴道转移模型,随机分11组(n=5).移植瘤体分别植入32P-CP-PLLA粒子或注射胶体32P-磷酸铬(32P-CP),剂量依序为18.5、37.0、74.0 MBq;另剂量为37 MBq/只,植瘤后于3、7、10、13 d不同时间植入32P-CP-PLLA 粒子.给药后动态γ显像,14 d处死,解剖KM小鼠,剥离引流区右腘窝淋巴结(PLA)和腹股沟淋巴结(ILN),电子天平称取质量,对瘤体和LN进行光镜、电镜检测,观察量效关系和时效关系.结果 γ显像证实移植瘤体32P-CP-PLLA粒子组较胶体32P-CP组局限浓聚且持久,放射性粒子无移位或脱落.区域LN聚集的放射性随给药剂量增加而增大,质量则反之;同剂量LN活度胶体组明显高于粒子组.同等剂量下,PLN的质量胶体组与粒子组差异无统计学意义(P＞0.05);ILN的质量胶体组小于粒子组(P＜0.05).不同时间植入粒子,各组PLN质量差异有统计学意义(F=31.268,P＜0.01).结论 32P-CP-PLLA粒子植入瘤内靶向定位性好,在治疗移植瘤的同时对淋巴道转移有一定的治疗作用.     

32P-磷酸铬瘤体内注射治疗裸鼠人胰腺癌Pc-3移植瘤

目的　研究32 P 磷酸铬 ( 32 P胶体 )间质注射人胰腺癌Pc 3移植瘤后在荷瘤裸鼠体内的生物学分布及抗癌效应。方法　 5 4只荷瘤裸鼠分为 9组 :1～ 3组瘤体内注射32 P胶体 14 .8MBq ,给药后 12、2 4、72h处死 ;4～ 9组瘤体注射剂量分别为 3 .7、7.4、14 .8、18.5、2 9.6和 0MBq ,给药后 14d处死 ,每组 6只鼠。通过光镜、透射电镜及免疫组织化学检测等方法 ,观察体内放射性动态分布 ( %ID/g)及形态学改变 ,计算抑瘤率、PCNA指数 (PI)。 结果　32 P胶体注射后主要浓聚并较长时间滞留在瘤体内。各剂量组的抑瘤率依序为 2 0 .8%、3 8.3 %、5 0 .7%、70 .2 %和 82 .3 % (F=2 61.3 4,P <0 .0 1)。PI依序为 70 .2、65 .2、45 .2、2 0 .2、10 .3和 92 .0 (F =3 75 .3 2 ,P <0 .0 1)。结论　32 P胶体瘤体内注射是一种安全、有效治疗胰腺癌的核素介入疗法。     

32P-磷酸铬胶体放射性滑膜切除的远期随访

目的了解^32P-磷酸铬胶体放射性滑膜切除治疗类风湿性关节炎的远期疗效和放射性损害。方法对1986～1988年间用^32P-磷酸铬胶体作放射性滑膜切除的类风湿性关节炎患者的远期疗效、复发、放射性损害进行随访、总结。结果患者远期疗效好、复发少、无明显放射性损害。结论^32P-胶体放射性滑膜切除是治疗早期类风湿性关节炎的可行方法。     

放射性~(103)Pd粒子植入治疗前列腺癌

前列腺癌组织间近距离放射治疗(prostate brachytherapy,PB)亦称放射性粒子植入治疗,已成为一种有效且便于接受的治疗方法。103Pd是继125I之后进入临床使用的新型放射性核素。1103Pd粒子永久植入治疗原理经超声或CT引导将103Pd粒子植入肿瘤体内,通过核素连续释放低能量γ射线对肿瘤细胞进行杀伤,达到较好治疗肿瘤的目的。由于103Pd粒子剂量衰减迅速,对正常组织损伤较小,具有肿瘤局部剂量高而周围正常组织剂量低的特点。目前用于永久粒子植入近距离放射治疗前列腺癌的粒子主要是125I和103Pd。Peschel[1]认为103Pd半衰期更短(17天),更适于治疗生长快、分化差和恶性程度高(Gleason评分>6)的前列腺癌。2103Pd粒子植入的操作方法前列腺癌粒子植入的标准术式是在模板和经直肠超声的引导下经会阴进行粒子植入。经会阴穿刺放射粒子永久植入近距离治疗(transperineal interstitial permanentbrachytherapy,TIPB)所需设备包括三维立体治疗计划系统、固定器、超声仪和粒子植入设备。2.1前列腺超声图像的采集患者首先固定体位,留置导尿管并...     

晶须碳酸钙/聚L-乳酸复合材料的合成与实验研究

目的 合成晶须碳酸钙/聚L-乳酸复合材料,并评价其生物相容性、力学性能及降解性。方法 采用溶液共混法聚合晶须碳酸钙/聚L-乳酸复合材料,对其进行初始强度及降解后的力学测定、体外细胞共培养及降解速率的测定。结果 复合材料对细胞无毒性,聚L-乳酸加入晶须碳酸钙后,力学性能均有不同程度提高且降解失重率减小。结论 晶须碳酸钙与聚L-乳酸复合后,提高了材料的力学性能,延缓了降解,并具有一定的生物活性。     

~(125)I粒子植入对人纤维肉瘤裸鼠皮下移植瘤微血管生成的影响

目的观察不同活度的125I粒子植入对人纤维肉瘤裸鼠移植瘤微血管生成的影响。方法建立人纤维肉瘤细胞HT-1080裸鼠皮下移植瘤模型24只,随机分4组,实验组A、B、C组分别植入单颗活度为14.8、22.2、29.6MBq的125I粒子,对照组D组植入单颗空源。15d后比较各实验组及对照组之间移植瘤大小,计算抑瘤率,观察移植瘤微血管结构的变化及血管内皮生长因子(vascular endothelial growth factor,VEGF)的表达,比较各组微血管密度(microvascular density,MVD)。结果粒子植入后15d,A、B、C、D组的肿瘤体积分别为:(879.32±54.90)mm3、(186.91±32.70)mm3、(122.01±34.72)mm3和(1302.71±62.39)mm3,各组差异均有统计学意义(F=844.21,P=0.000)。125I粒子对A、B、C组肿瘤体积抑制率分别为32.50%、85.65%和90.63%。与D组比较,实验组可见移植瘤细胞坏死,微血管不同程度减少,内皮细胞杀伤明显。4组VEGF表达阳性率分别为54.2%(13/24)、29.2%(7/24)、20.8%(5/24)、66.7%(16/24),A、D组间VEGF表达差异无统计学意义(χ2=0.784,P=0.376),B、C组的VEGF表达均显著低于D组,差异有统计学意义(χ2=6.762,P=0.009;χ2=10.243,P=0.001),A、C组与B组VEGF表达比较,差异均无统计学意义(χ2=3.086,P=0.079;χ2=0.444,P=0.505),A、C组比较,VEGF表达差异具有统计学意义(χ2=5.689,P=0.017)。4组MVD表达分别为(27.49±3.10)个、(10.27±3.57)个、(9.14±2.49)个、(30.15±4.26)个,差异具有统计学意义(F=253.22,P=0.000),A、D组间MVD表达差异无统计学意义(q=3.814,P0.05),但B、C组的MVD表达均显著低于D组,差异有统计学意义(q=28.502,P0.05;q=30.123,P0.05)。B、C组与A组表达MVD比较,差异有统计学意义(q=24.689,P0.05;q=26.309,P0.05),B、C组间比较差异无统计学意义(q=1.628,P0.05)。结论 125I粒子组织间植入对人纤维肉瘤微血管生成有显著抑制作用,粒子初始活度影响治疗效果。     

~(125)I粒子置入治疗前列腺癌患者的护理

对22例前列腺癌患者B超引导下行前列腺125I粒子置入术,术前做好患者心理、生理及仪器1、25I粒子准备,术后防止感染、保持尿道通畅;做好饮食护理及并发症观察。结果22例患者均一次顺利完成125I粒子置入;随访10~30个月,尿道刺激症状改善,无严重并发症发生。提示正确、合理的护理是保证B超导向下125I粒子组织间置入术疗效的重要环节。     

放射性~(125)I粒子对家兔正常门静脉早期放射性损伤的实验研究

目的研究不同剂量放射性125I粒子植入不同时间对家兔正常门静脉的早期放射性损伤。方法将48只家兔随机分为对照组和实验组,实验组正常门静脉表面分别植入80、120、160Gy125I粒子,对照组正常门静脉表面植入空源粒子。于粒子植入30、60d观察家兔的一般情况、白细胞计数、大体、光镜及电镜的变化。结果实验组无溃疡、穿孔、出血、死亡等严重并发症。光镜下实验各组粒子植入后血管壁损伤主要为内皮改变及肌层水肿,损伤程度根据schmidt标准改进评分,实验组各组间粒子植入后30d和60d损伤程度评分差异有统计学意义(F=192.67,P=0.000;F=294.19,P=0.000);粒子植入后30d和60d实验组各组内Schmidt评分差异有统计学意义(P0.05)。电镜结果 :损伤主要表现为内膜层线粒体、粗面内质网及吞饮小泡改变,且随剂量的增加和时间的延长加重。粒子植入前后不同时间对照组和实验组白细胞计数差异均无统计学意义(P0.05)。结论 125I粒子植入门静脉,在剂量为80～160Gy门静脉损伤轻微,主要在内皮层和肌层,且随时间的延长和剂量的增加损伤程度加重,但损伤深度未见增加。     

聚L-乳酸修饰的聚丙烯疝补片的研制及动物实验研究

目的将聚L-乳酸修饰的聚丙烯补片应用于动物实验,进一步验证补片的防粘连效果。方法聚L-乳酸修饰的聚丙烯补片置入腹腔并覆盖腹腔缺损,同时与聚丙烯补片为对照组,通过腹腔内粘连面积、粘连程度、组织病理学改变等检查了解补片粘连情况。结果单纯聚丙烯组术后死亡率高,剖腹探查发现补片表面与腹腔脏器发生直接粘连,粘连面积广泛,粘连程度重。聚L-乳酸修饰的聚丙烯组补片表面亦有粘连,主要集中在补片边缘粘连面积、程度较轻。结论聚L-乳酸修饰的聚丙烯平片是可行的,动物实验表明聚L-乳酸修饰的聚丙烯补片可以减少动物的腹腔内粘连。     

前列腺癌近距离治疗的效果和不良反应分析

目的探讨局限性前列腺癌患者接受近距离治疗的疗效及不良反应。方法2001～2010年接受近距离治疗的局限性前列腺癌患者67例。随访术后PSA变化及不良反应发生情况，并分析影响治疗效果的相关因素。结果64例（95．5％）获得平均33．9（4～112）个月的随访。术前PSA平均为20．04ng／mL，术后最低PSA值平均为1．15ng／mL，40例（62．5％）患者最低PSA值〈1ng／mL，26例（40．6％）患者最低PSA值〈0．5ng／mL，达最低PSA值时间平均为术后11（1～26）个月。术后常见短期不良反应有：发热4例，血尿8例，便血3例。长期不良反应有：尿路刺激症状19例，便血7例，血尿2例，尿失禁2例，尿潴留1例。结论近距离治疗是局限性前列腺癌的有效治疗方法，疗效肯定，并发症发生率低，严重不良反应少见。     

125I放射粒子植入治疗前列腺癌12例临床分析

目的探讨前列腺125I放射粒子植入内放疗在前列腺癌治疗中的意义。方法依据治疗计划,在直肠B超引导下,经会阴穿刺植入前列腺125I放射粒子对12例前列腺癌行三维适形内放疗。结果全组手术顺利,平均植入125I放射粒子58粒,平均手术时间80min,术后平均住院时间7．2d。随访12例术后3个月结果：平均PSA由19．8ng／mL降至0．74ng／mL;随访6例术后6个月结果：5例PSA进一步降低,平均降至0．11ng／mL;1例升高,由0．51ng／mL升高至1．65ng／mL;无1例出现严重的并发症。结论采用永久性放射粒子植入前列腺、三维适形内放疗是一种有效、微创的治疗前列腺癌的方法。     

Transperineal interstitial permanent prostate brachytherapy for Japanese prostate cancer patients in Hawaii

BACKGROUND: Our aim was to report clinical and biochemical outcomes of transperineal interstitial permanent prostate brachytherapy in the treatment of Japanese patients with clinically organ-confined prostate cancer in Hawaii. METHODS: Ninety-five Japanese patients underwent transperineal interstitial permanent prostate brachytherapy using either iodine-125 or palladium-103 for clinical T1c-T2b N0 M0 prostate cancer. These procedures were carried out between December 1998 and December 2002 at The Queen's Medical Center in Honolulu, Hawaii. Prostate-specific antigen measurements were collected from all patients at follow up. Biochemical failure was defined by three consecutive rises in prostate-specific antigen levels, based on the criteria of the American Society for Therapeutic Radiology and Oncology Consensus panel. RESULTS: The median patient age was 71 years (range, 46-87 years). Thirty-six patients were implanted with either iodine-125 or palladium-103 as monotherapy; 59 patients received moderate-dose external beam irradiation first, followed by a prostate brachytherapy boost. The median follow-up length, calculated from the day of implantation, was 801 days (range, 237-1421 days). During this follow-up period, The Kaplan-Meier estimate of freedom from biochemical failure in this series was 94%. No major complications were observed. CONCLUSIONS: Clinical and biochemical outcomes in the treatment of Japanese patients in Hawaii suffering from localized prostate cancer, using transperineal interstitial permanent prostate brachytherapy, with or without external beam irradiation, compared favorably to results in similarly treated patients in the general US population.     

Effects of direct injection of dehydrated ethanol on PC3 human prostate cancer cells in nude mice: Preliminary study

OBJECTIVES: The effect of direct local injection of dehydrated ethanol on hormone-independent prostatic carcinoma cells (PC3 cells) implanted in nude mice was investigated. METHODS: PC3 tumors were implanted subcutaneously into 30 nude mice. Three weeks later, dehydrated ethanol was injected directly into the tumors. Twenty-three animals received an injection of ethanol at a volume of 40 microL, 80 microL, or 160 microL, and were divided into a low-dose group (n = 11) and a high-dose group (n = 12) on the basis of the ethanol/tumor volume ratio (<30% versus> or =30%). The control group (n = 7) was injected with 40 microL of physiological saline. The tumor volume before treatment was 324.9 +/- 110.9 mm(3) and was assessed as well as 1 day, 4 days, 1 week, 2 weeks, and 3 weeks after injection. Then the changes of tumor volume were compared between the two ethanol groups (low-dose group and high-dose group) and the control group. Histological examination was performed for up to 3 weeks after injection. RESULTS: Assessment of tumor volume showed that the ethanol/tumor volume ratio was 16.1 +/- 5.3% in the low-dose group (n = 5) and 51.8 +/- 20.3% in the high-dose group (n = 6). Tumor growth was significantly inhibited after 1 and 2 weeks in the ethanol groups compared with the control group (n = 3). After 3 weeks, there was a tendency for tumor regrowth in the low-dose group, but growth inhibition was maintained in the high-dose group. Histological examination showed tumor degeneration and necrosis with feeding vessel obstruction in the acute phase. CONCLUSIONS: Local injection of dehydrated ethanol regressed tumors of prostatic carcinoma cells in nude mice, with the degeneration of tumor cells and occlusion of feeding vessels.     

Validation and comparison of the two Kattan nomograms in patients with prostate cancer treated with (125) iodine brachytherapy

Study Type – Clinical (prospective trial) Level of Evidence 2b What's known on the subject? and What does the study add? In clinical practice, we know that it is necessary to identify new biomarkers that can better detect prostate cancer (PC), at the same time as reducing the number of unnecessary biopsies. Recently, studies have suggested that the most relevant clinical scenario in which the prostate cancer antigen 3 (PCA3) score could be used comprises patients with a previous negative prostate biopsy and persistently elevated PSA levels. At the same time, although multiparametric MRI is not currently used as a first approach for diagnosing PC, it can be useful for directing targeted biopsies, especially in those patients with elevated PSA levels and a previous negative TRUS‐guided biopsy. Considering all of these aspects, the present study aimed to evaluate the role of multiparametric MRI as an additional diagnostic tool for improving the accuracy of the urinary PCA3 test in patients with increased PSA levels and a previous negative prostate biopsy. Our hypothesis is that the potential value of the PCA3 test as a biomarker for PC diagnosis could be improved by the use of multiparametric MRI in directing prostate biopsy. In the present study, we show that, in cases with a previous negative biopsy and persistently elevated PSA levels submitted to multiparametric MRI to direct biopsies, the sensitivity of the PCA3 test significantly improved (79% vs 68%). However, further larger randomized studies on this combination using a new biomarker and a new imaging modality for PC diagnosis are expected.

OBJECTIVE

• ? To evaluate the role of multiparametric magnetic resonance imaging (MRI) as an additional diagnostic tool for improving the accuracy of the urinary prostate cancer antigen 3 (PCA3) test in patients with an increase in prostate‐specific antigen (PSA) levels and a previous negative prostate biopsy.

PATIENTS AND METHODS

• ? The present study comprised a prospective randomized study on patients with a previous negative transrectal ultrasonography (TRUS)‐guided prostate biopsy and elevated PSA levels.
• ? In total, 180 cases were analyzed, and all were submitted to PCA3 assay.
• ? Patients in group A were submitted to a second random TRUS‐guided prostate biopsy, whereas patients in group B were submitted to a multiparametric MRI examination and then to a second TRUS‐guided prostate biopsy.

RESULTS

• ? At the second biopsy, a histological diagnosis of prostate cancer was found in 26 of 84 cases (30.9%) in group A and in 29 of 84 cases (34.5%) in group B.
• ? In group A, the sensitivity and specificity of the PCA3 score were 68.0% and 74.5% respectively (positive predictive value of 53.1%, negative predictive value of 84.6% and accuracy of 72.6%).
• ? In group B, the sensitivity and specificity of the PCA3 score were 79.3% and 72.7%, respectively (positive predictive value of 60.5%, negative predictive value of 86.9% and accuracy of 75.0%).
• ? For the PCA3 score, the area under the receiver‐operator characteristic curve was 0.825 (95% confidence interval, 0.726–0.899) in group A and 0.857 (95% confidence interval, 0.763–0.924) in group B (P < 0.001).

CONCLUSION

• ? In patients with a previous negative biopsy and persistently elevated PSA levels, the use of multiparametric MRI for indicating sites suitable for rebiopsy can significantly improve the sensitivity of the PCA3 test in the diagnosis of prostate cancer.

     

Three-year results of treatment for prostate cancer with low-dose rate temporary iridium-192 brachytherapy

AIM: To report the 3-year treatment results of definitive irradiation by using a temporary interstitial implant with low-dose rate iridium-192 with or without external beam radiotherapy in the treatment of localized prostate cancer. METHODS: One-hundred and forty-three patients with pathologically defined prostate carcinoma were treated from December 1997 to April 2003. The patients were classified into a low-risk group (T2, PSA20 ng/mL or Gleason score>or=7). Low-risk patients were treated with low-dose-rate iridium brachytherapy as monotherapy delivering 70 Gy. High-risk patients were treated with the combination of brachytherapy and external beam radiotherapy delivering 40 Gy and 36 Gy, respectively. Kaplan-Meier estimates of prostate-specific antigen (PSA) progression-free survival rate were analysed. To assess the treatment quality in different periods, PSA progression-free survival rates in late era (year of 2000 and after) and in early era (before 2000) were compared. Morbidity was graded according to the Radiation Therapy Oncology Group grading scale. RESULTS: One hundred and nineteen patients were analysed, of which 86 patients underwent monotherapy with an iridium implant, and 33 were treated with the combination of external beam radiotherapy. Twenty-four patients were excluded from the analysis because the classification of risk group did not suit the criteria. The total (n=119) PSA progression-free survival rate at 3 years was 80.3%. The PSA progression-free survival rate at 3 years for the monotherapy group (n=86) and the combination therapy group (n=33) were 78.2% and 86.9%, respectively. There were 23 patients who were followed for more than 36 to 63 months, and, during this period, only 1 patient who received the monotherapy was diagnosed as PSA failure at 50 months. The 3-year PSA progression-free survival rate of monotherapy in late era was significantly higher than that in early era; however, no significant difference was seen in the combination treatment. Morbidity for the combination treatment was low; however, for the monotherapy, three patients developed severe rectal ulcers, and colostomies were made. CONCLUSIONS: The PSA progression-free survival rate after low-dose rate iridium-192 brachytherapy with or without external beam radiotherapy can be satisfactory and longer follow up is necessary to compare the efficacy of other treatments.     

Erectile dysfunction is predictive of all-cause mortality in patients with prostate cancer treated with permanent interstitial brachytherapy

Study Type – Prognosis (individual cohort) Level of Evidence 2b What’s known on the subject? and What does the study add? Cardiovascular disease is a leading cause of death in prostate cancer patients. Pretreatment ED is a surrogate for vascular pathology. Aggressive treatment of medical co‐morbidity in prostate cancer patients may positively impact overall survival.

OBJECTIVE

• ? To evaluate the relationship between pre‐treatment erectile function and all‐cause mortality in patients with prostate cancer treated with brachytherapy.

PATIENTS AND METHODS

• ? In all, 1279 consecutive patients with clinically localized prostate cancer and pre‐implant erectile function assessed by the International Index of Erectile Function‐6 (IIEF‐6) underwent brachytherapy.
• ? Potency was defined as an IIEF‐6 score of ≥13 without pharmacological or mechanical support.
• ? Patients were stratified into IIEF‐6‐score cohorts (≤12, 13–23 and 24–30).
• ? The median follow‐up was 5.0 years.

RESULTS

• ? The 8‐year overall survival (OS) of the study population was 85.1%.
• ? The 8‐year OS for IIEF‐6scores ≤12, 13–23 and 24–30 were 78.0%, 92.8% and 91.4%, respectively (P < 0.001).
• ? Cardiovascular events accounted for a significant portion of deaths in each IIEF‐6 group.
• ? When combined with other risk factors for cardiovascular disease, an IIEF‐6 score of ≤12 had an additive effect on all‐cause mortality (IIEF‐6 score of ≤12 and less than two comorbidities vs two or more comorbidities were 18.2% and 32.1%).

CONCLUSIONS

• ? A pre‐implant IIEF‐6score of ≤12 was associated with a higher incidence of all‐cause mortality.
• ? Pre‐treatment erectile dysfunction is a surrogate for underlying vascular pathology, probably explaining the lower OS in this subset of patients.
• ? Aggressive treatment of medical co‐morbidity is warranted to impactOS.

     

Permanent prostate brachytherapy for Japanese men: Results from initial 100 patients with prostate cancer

OBJECTIVE: To evaluate the initial results of brachytherapy for prostate cancer with permanent iodine-125 implant in Japan. METHODS: The results obtained with brachytherapy in the initial 100 Japanese patients treated at Nagano Municipal Hospital were reviewed. Patients with a prostate-specific antigen (PSA) level of less than 10 ng/mL and a Gleason's scores of 5, 6, 3 + 4 were classified as having a low risk of recurrence. Patients with a PSA level of 10-20 ng/mL and/or a Gleason's score of 4 + 3 were classified as having an intermediate risk for recurrence. Seventy-eight of the low-risk patients and 19 of the intermediate-risk patients were treated by seed implants alone, or seed implants combined with preceding external radiation, respectively. A total of 53 patients received neoadjuvant hormone therapy. The efficacy and morbidity of brachytherapy were investigated using the serum PSA, International Prostate Symptom Score, quality of life score and uroflowmetry data. RESULTS: The average V100 and D90 obtained by post-implant dosimetry was 94.3 and 113.7%, respectively. Serum PSA decreased gradually after treatment, although it had still not reached a nadir after 1 year. There was little difference of the PSA level between the patients with and without neoadjuvant hormone therapy even at 1 year after seed implantation. There were no PSA biochemical failure or clinical recurrence during the follow-up period. Voiding symptoms worsened until 3 months after treatment, and then gradually improved. Acute urinary retention occurred transiently in one patient (1%). Rectal bleeding and severe diarrhea did not occur. CONCLUSION: Brachytherapy is a feasible and effective option for the treatment of prostate cancer in Japanese men. Brachytherapy may have a different effect in Japanese patients with respect to voiding symptoms. Urinary retention was rare, but voiding symptoms were persistent in Japanese patients. Neoadjuvant hormone therapy deserves investigation to determine whether it can achieve better results, especially in patients with an intermediate risk.