Akitomo Sugawara

Incidence of seed migration to the chest, abdomen, and pelvis after transperineal interstitial prostate brachytherapy with loose 125 I seeds

BackgroundThe aim was to determine the incidence of seed migration not only to the chest, but also to the abdomen and pelvis after transperineal interstitial prostate brachytherapy with loose 125I seeds.MethodsWe reviewed the records of 267 patients who underwent prostate brachytherapy with loose 125I seeds. After seed implantation, orthogonal chest radiographs, an abdominal radiograph, and a pelvic radiograph were undertaken routinely to document the occurrence and sites of seed migration. The incidence of seed migration to the chest, abdomen, and pelvis was calculated. All patients who had seed migration to the abdomen and pelvis subsequently underwent a computed tomography scan to identify the exact location of the migrated seeds. Postimplant dosimetric analysis was undertaken, and dosimetric results were compared between patients with and without seed migration.ResultsA total of 19,236 seeds were implanted in 267 patients. Overall, 91 of 19,236 (0.47%) seeds migrated in 66 of 267 (24.7%) patients. Sixty-nine (0.36%) seeds migrated to the chest in 54 (20.2%) patients. Seven (0.036%) seeds migrated to the abdomen in six (2.2%) patients. Fifteen (0.078%) seeds migrated to the pelvis in 15 (5.6%) patients. Seed migration occurred predominantly within two weeks after seed implantation. None of the 66 patients had symptoms related to the migrated seeds. Postimplant prostate D90 was not significantly different between patients with and without seed migration.ConclusionWe showed the incidence of seed migration to the chest, abdomen and pelvis. Seed migration did not have a significant effect on postimplant prostate D90.

Prediction of seed migration after transperineal interstitial prostate brachytherapy with I-125 free seeds

PURPOSE The present study was undertaken to determine the incidence and predictors of seed migration after transperineal interstitial prostate brachytherapy using I-125 free seeds. METHODS AND MATERIALS Between September 2004 and November 2007, 158 patients who underwent transperineal interstitial prostate brachytherapy as monotherapy for clinical T1/T2 carcinoma of the prostate gland were reviewed. Implants had been performed with standard techniques. All 158 patients underwent followup radiographs (orthogonal chest radiographs, a kidney-ureter-bladder radiograph, and a posteroanterior pelvic radiograph) to assess the presence of seed migration at 3 months after transperineal interstitial prostate brachytherapy. Patient characteristics and treatment status were recorded. Univariate and multivariate analyses were performed to identify predictors of seed migration. RESULTS Seed migration occurred in 35 of 158 patients (22.2%). Univariate analyses revealed that preoperative prostate volume estimated by transrectal ultrasound, the number of needles, the number of seeds implanted, and the presence or absence of pubic arch interference (PAI) were significantly associated with seed migration. These results indicated that larger prostate glands were more likely to have seed migration. However, the absolute difference in prostate size was not overly impressive (22.4 vs. 26.3cm(3)). Multivariate analysis revealed that the number of seeds implanted and the presence or absence of PAI were significant predictors of seed migration. CONCLUSION The number of seeds implanted and the presence or absence of PAI provide the most predictive information on seed migration.

A prospective longitudinal survey of erectile dysfunction in patients with localized prostate cancer treated with permanent prostate brachytherapy.

PURPOSE Few studies have evaluated changes in erectile function with time before and after prostate brachytherapy using the International Index of Erectile Function-15, a sensitive, validated tool for assessing male sexual dysfunction. In this prospective study we evaluated the natural history of erectile function after prostate brachytherapy without supplemental therapy (external beam radiotherapy, phosphodiesterase-5 inhibitors or androgen deprivation therapy) using the International Index of Erectile Function-15. MATERIALS AND METHODS We identified 119 patients who were followed at least 12 months after prostate brachytherapy between 2004 and 2010. Sexual and erectile function status were assessed before brachytherapy (baseline), and 3, 6, 12, 18, 24 and 36 months postoperatively using the International Index of Erectile Function-15. RESULTS Mean total International Index of Erectile Function-15 score, and scores on the erectile function, orgasmic function, sexual desire and intercourse satisfaction domains 3 months after brachytherapy were significantly lower than at baseline (p <0.05). They remained lower until 36 months after prostate brachytherapy. Erectile function was maintained 12 months after brachytherapy in 16 of the 48 men (33.3%) with a baseline erectile function domain score of 11 or greater. There was no significant difference in clinical features except the age of patients who maintained the erectile function domain score and their counterparts 12 months after brachytherapy. Multivariate analysis revealed that age 70 years or greater was the only predictive factor for deteriorating erectile function after brachytherapy (p = 0.035). CONCLUSIONS Findings indicate a global decrease in all domains of the International Index of Erectile Function-15 score 12 months after prostate brachytherapy. Also, patient age may influence the preservation of brachytherapy related potency.

Dose volume histogram analysis of focal liver reaction in follow-up multiphasic CT following stereotactic body radiotherapy for small hepatocellular carcinoma

PURPOSE To investigate threshold dose (TD) of focal liver reaction (FLR) following stereotactic body radiotherapy (SBRT) for patients with hepatocellular carcinoma (HCC) and liver cirrhosis. MATERIALS AND METHODS In consecutive 50 patients receiving SBRT for small HCC, 38 patients receiving SBRT and follow up >6 months, FLR on follow-up CT had been previously studied. Patients with good concordance between FLR and highly irradiated area were eligible. Dose volume histogram (DVH) was used to identify TDs for FLR. Clinical factors were analyzed for correlation with TDs. RESULTS Of 24 eligible patients, 23 had Child-Pugh score A and 1 scored B. Presence of FLR peaked at a median of 6 (range; 3-12) months. The median and 95% confidential intervals of TDs of pre-contrast and portal-venous phase CT were 32.4 Gy (30.3-35.4) and 34.4 Gy (31.9-36.0), respectively. Each median coefficient representing the concordance was 74.9% (range; 55.8-98.0%) and 80.5% (range; 70.8-92.4%), respectively. No clinical factors significantly correlated with the TDs. CONCLUSION We proposed 30 Gy/5 fractions as TD of FLRs following SBRT for patients with HCC and liver cirrhosis. This TD will enable us to predict injured liver volume and to avoid complication beforehand from toxicity. Further pathological and clinical studies, in addition to more practical and precise data of DVH, are needed to clarify the significance of FLRs.

Prediction of PSA bounce after permanent prostate brachytherapy for localized prostate cancer.

BackgroundWe aimed to calculate the frequency and features of the development of a prostate-specific antigen (PSA) bounce after prostate brachytherapy alone, to correlate the bounce with clinical and dosimetric factors and to identify factors that predict PSA bounce.MethodsPSA bounce was evaluated in 86 patients with T1-T2 prostate cancer who underwent radioactive seed implantation using iodine-125 (I-125) without hormonal therapy or external-beam radiation therapy (EBRT) from September 2004 to December 2007. A PSA bounce was defined as a rise of at least 0.4 ng/ml greater than a previous PSA level with a subsequent decline equal to, or less than, the initial nadir.ResultsCalculated by the Kaplan-Meier method, the incidence of PSA bounce at a 2-year follow-up was 26%. Median time to the PSA bounce was 15 months. Univariate analysis demonstrated that age, dose received by 90% of the prostate gland (D90), volume of gland receiving 100% of the prescribed dose (V100), and V150 were significantly associated with the PSA bounce, while pretreatment PSA level, Gleason score, pretreatment prostate volume, clinical T stage, and V200 were not. In multivariate analysis, age 67 years or less and D90 more than 180 Gy were identified as independent factors for predicting the PSA bounce (P < 0.05).ConclusionPSA bounce is not a rare phenomenon after prostate brachytherapy. It is more common in younger patients and patients receiving higher doses of radiation.

Prostate brachytherapy seed migration to a left varicocele.

PURPOSE To report a rare case of seed migration to a left varicocele after transperineal interstitial prostate brachytherapy with loose iodine-125 ((125)I) seeds. METHODS AND MATERIALS A 73-year-old man presented with a serum prostate-specific antigen level of 5.21 ng/mL, Gleason score of 7 (3+4), and clinical T1c adenocarcinoma of the prostate. The patient underwent transperineal interstitial prostate brachytherapy with loose (125)I seeds followed by external beam radiation therapy. Two weeks after seed implantation, a followup pelvic radiograph was obtained. One month after seed implantation, a pelvic computed tomography scan for postimplant dosimetric analysis was carried out. Subsequent ultrasound examination of the scrotum was undertaken. RESULTS Two weeks after seed implantation, an anteroposterior pelvic radiograph showed that a migrated seed was overlapped by the scrotum. Postimplant pelvic computed tomography revealed that a seed had migrated to the left side of the scrotum. Subsequent ultrasound examination of the scrotum revealed that the patient had a left varicocele to which the seed had migrated. The patient had no symptoms related to the migrated seed. CONCLUSIONS This is the first report of seed migration to a left varicocele after transperineal interstitial prostate brachytherapy with loose (125)I seeds. For the present case, we suggest that the seed moved from the prostate to the left varicocele through the pelvic veins, bypassing the systemic circulation.

Experimental stereotactic irradiation of normal rabbit lung: computed tomographic analysis of radiation injury and the histopathological features

PurposeThe aim of this study was to establish an animal experimental model of pulmonary stereotactic irradiation and clarify the morphological patterns of pulmonary radiation injury with computed tomography and the histopathological features.Materials and methodsTiny spherical regions in the lungs of seven anesthetized rabbits were irradiated stereotactically with a single fractional dose of 21–60 Gy. Subsequently, the irradiated lungs were observed biweekly with computed tomography (CT) for 24 weeks. Radiation injury of the lung was examined histopathologically in one specimen.ResultsLocalized hypodense changes were observed 7–15 weeks after irradiation in three rabbits irradiated with 60 Gy, and the findings persisted beyond that time. The electron density ratios in the lung fields obtained from the CT images were shown to be decreasing, corresponding to the hypodensity changes. No clear increased density opacity was observed in any rabbit in the 60-Gy irradiated group. Severe localized fibrotic change was observed in the histopathological specimens.ConclusionSpecific localized hypodensity changes were found in only three rabbits irradiated with 60 Gy, the highest dose we employed.

Preimplant factors affecting postimplant CT-determined prostate volume and the CT/TRUS volume ratio after transperineal interstitial prostate brachytherapy with 125I free seeds

BackgroundThe aim was to identify preimplant factors affecting postimplant prostate volume and the increase in prostate volume after transperineal interstitial prostate brachytherapy with 125I free seeds.MethodsWe reviewed the records of 180 patients who underwent prostate brachytherapy with 125I free seeds for clinical T1/T2 prostate cancer. Eighty-one (45%) of the 180 patients underwent neoadjuvant hormonal therapy. No patient received supplemental external beam radiotherapy. Postimplant computed tomography was undertaken, and postimplant dosimetric analysis was performed. Univariate and multivariate analyses were performed to identify preimplant factors affecting postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.ResultsPreimplant prostate volume by transrectal ultrasound, serum prostate-specific antigen, number of needles, and number of seeds implanted were significantly correlated with postimplant prostate volume by computed tomography. The increase in prostate volume after implantation was significantly higher in patients with neoadjuvant hormonal therapy than in those without. Preimplant prostate volume by transrectal ultrasound, number of needles, and number of seeds implanted were significantly correlated with the increase in prostate volume after implantation. Stepwise multiple linear regression analysis showed that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy were significant independent factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.ConclusionsThe results of the present study show that preimplant prostate volume by transrectal ultrasound and neoadjuvant hormonal therapy are significant preimplant factors affecting both postimplant prostate volume by computed tomography and the increase in prostate volume after implantation.

Rectal Injury during Permanent Seed Implantation for Prostate Brachytherapy

Serious complications have not been previously reported during seed implantation for prostate brachytherapy. We present an unreported case of rectal injury caused by an ultrasound probe. A 67-year-old male presented with a serum prostate-specific antigen level of 5.50 ng/ml, a Gleason score of 7 (3 + 4) and clinical T2a adenocarcinoma of the prostate. A transperineal permanent prostate brachytherapy implantation was performed. The patient subsequently complained of abdominal pain postoperatively. A gastrointestinal perforation was suspected based on an abdominal X-ray obtained on the day after the brachytherapy. Rectal injury was recognized during an exploratory laparotomy, and a primary closure and temporary diversion ileostomy were performed. The healing of the injury was confirmed by colonoscopy and an ileostomy closure was performed 2 months after the temporary diversion. The investigating committee for this accident concluded that the ultrasound probe had perforated the rectum. This is the first case of a rectal injury during seed implantation for prostate brachytherapy.