Prognostic assessment of patients who receive radiotherapy for bone metastases from breast cancer.

For prognostic assessment in women who receive radiotherapy (RT) for bone metastases (BMs) from breast cancer (BC), prognostic factors specific for BMs from BC were investigated in the present study. The prognostic assessment was performed by retrospectively reviewing 143 women who received first-time RT for BMs from BC between January 2007 and June 2018. The median follow-up time and median overall survival (OS) time from the first-time RT for BMs were 22 and 18 months, respectively. In the multivariate analysis, nuclear grade 3 (NG 3) [hazard ratio, 2.18; 95% confidence interval (CI), 1.34-3.53], brain metastases (hazard ratio, 1.96; 95% CI, 1.01-3.81), liver metastases (hazard ratio, 1.75; 95% CI, 1.17-2.63), performance status (PS) (hazard ratio, 1.63; 95% CI, 1.10-2.41) and previous systemic therapy (hazard ratio, 1.58; 95% CI, 1.03-2.42) were significant factors for OS, whereas age, hormone-receptor/human epidermal growth factor receptor 2 status, number of BMs and synchronous lung metastases were not significant factors. When points according to risk levels [unfavorable points (UFPs)] were assigned to each risk factor (1.5 points for NG 3 and brain metastases; and 1 point for PS ≥2, previous systemic therapy and liver metastases), the median OS times of patients with a total number of UFPs ≤1 (n=45), 1.5-3 (n=55) and ≥3.5 (n=43) were 36, 17 and 6 months, respectively. Overall, in patients who received first-time RT for BMs from BC, NG 3, brain/liver metastases, poor PS and previous systemic therapy were unfavorable prognostic factors. Comprehensive prognostic assessment using these factors seemed to be useful for the prediction of prognoses in patients with BMs from BC.

Prognostic value of human epidermal growth factor receptor 2 status and systemic therapy in breast cancer with brain metastases treated with radiotherapy.

PURPOSE: To evaluate the prognostic value of human epidermal growth factor receptor 2 (HER2) status and how to use HER2-targeted therapy in breast cancer (BC) with brain metastases (BM) treated with radiotherapy. METHODS: We retrospectively reviewed the data of 103 BC patients with parenchymal BM treated with radiotherapy. We collected data on the hormone receptor (HR), HER-2 amplification status, and systemic therapy after treatment for BM. The primary outcome was overall survival (OS), which was calculated from the diagnosis of BM to death. RESULTS: The median follow-up time from the diagnosis of the first BM was 9.1 months (range, .7-88 months). The 2-year OS of the HR-positive and HER2-positive (HR+HER2+) BC (31.3 mo) was significantly better than those of the HR-HER2+ (9,5 mo, p=.002), HR+HER2- (9.9mo, p=.003), and triple-negative BC (3.9 mo, p<.001) ( . Of the 36 HER2-positive patients, 31 patients treated with HER2-targeted therapy after radiotherapy for BM had a significantly better 2-year OS than those who did not receive HER2-targeted therapy (43% vs. 0%; p < .001). Among the 31 patients treated with HER2-targeted therapy, the 2-year OS for those treated with multiple anti-HER2 agents during the entire course of treatment was significantly higher than that for patients treated with a single agent (60% vs. 24%; p = .006). CONCLUSIONS: HR+HER2+ BC patients with BM treated with radiotherapy show a better prognosis than other subtypes. For HER2-positive patients with good prognosis, it may be important to continue HER2-targeted therapy appropriately after radiotherapy for BM.

[Surgical Outcomes and Clinicopathological Analysis of Laparoscopic Distal Pancreatectomy].

SUBJECTS: We first reviewed surgical outcomes and pathological findings of 32 patients(laparoscopic group: LDP n=11, open group: ODP n=21)who underwent distal pancreatectomy for pancreatic cancer from January 2018 to October 2022. Then we reviewed long-term outcomes, and recurrence type for 20 patients(LDP: n=5, ODP: n=15)from January 2018 to February 2021. RESULTS: LDP group had significantly longer operation time and less blood loss. There was no difference in length of hospital stay, postoperative complications, number of dissected lymph nodes, positive lymph node metastasis rate, and adjuvant chemotherapy rate. Because of high rate of pancreatic stump closure by hand sewing in ODP, postoperative pancreatic fistula rate was higher in ODP than in LDP. The 2-year relapse-free survival rate was 60% in LDP, 33% in ODP, and the 2-year overall survival rate was 60% in LDP, 71% in ODP, and there were no significant differences. As for the type of recurrence, in LDP group, 2 cases of distant metastases and no local recurrence was observed, and in ODP group, 6 cases each of local recurrences and distant metastases were observed. CONCLUSION: LDP was not inferior to ODP in short and long- term outcomes, safety, curability, and local control ability.

Efficacy and Safety of Three-dimensional Conformal Radiotherapy for Macroscopic Vascular Invasion of Hepatocellular Carcinoma.

Chemotherapy is insufficient to treat macroscopic vascular invasion (MVI) of hepatocellular carcinoma (HCC). We retrospectively investigated the treatment outcomes of patients who underwent three-dimensional conformal radiotherapy (3D-CRT) for HCC MVI and analyzed prognostic factors by multivariate analysis using a Cox proportional hazard model. Sixty-five patients were studied. MVI sites were the portal vein (n=48 patients), portal and hepatic veins (n=8), and hepatic vein (n=9). The median irradiation dose was 50 Gy. The median survival time (MST) was 7.5 months. Performance status 2 or 3, modified albumin-bilirubin grade 2b or 3, and massive/diffuse type were poor prognostic factors. Nineteen patients (29%) with a treatment effect of 3 or 4 (≥ 50% of tumor necrosis or regression) at the irradiation sites according to the Response Evaluation Criteria in Cancer of the Liver showed longer survival than those with an effect of 1 or 2 (MST 18.7 vs. 5.9 months, p<0.001). No treatment-related death occurred. The hepatic function reserve was preserved in more than 70% of patients. 3D-CRT controlled HCC MVI safely and was suggested to be a good treatment option.

Local control after palliative external beam radiotherapy for bone metastases in patients with favorable prognosis.

Advancement in systemic therapy has increased the importance of local control (LC) of bone metastatic sites treated with radiotherapy in intermediate-term survivors (surviving ≥1 year). To establish individualized radiotherapy for bone metastases, factors affecting LC of bone metastases treated with traditional fractionated moderate dose palliative radiotherapy (FMRT) in intermediate-term survivors were evaluated. Between January 2010 and December 2019, 317 lesions in 240 patients treated with FMRT for bone metastases surviving for at least 1 year and followed-up with CT for at least 6 months were reviewed retrospectively. The median survival and radiographic follow-up times were 24 months (range, 12-123 months) and 20 months (range, 1-119 months), respectively. The median FMRT dose [biologically effective dose (BED)10] was 39.0 Gy (range, 28.0-71.7 Gy). Multivariate analysis revealed that age (≥70 years), non-vertebral bone metastasis, bone metastasis from moderate and unfavorable primary tumor sites (esophageal, colorectal, hepatobiliary/pancreatic, kidney/ureter and sarcoma/melanoma cancers), and no administration of post-FMRT bone-modifying agents (BMAs) were unfavorable factors for LC of bone metastasis. The 2-year LC rates for FMRT doses (BED10) ≤39.0 Gy and >39.0 Gy were 90 and 87%, respectively. The 2-year LC rates of patients administered and not administered post-FMRT antineoplastic agents (ATs) were 91 and 78%, respectively. The sites of bone metastasis and primary tumors, and post-FMRT BMAs were factors associated with LC of bone metastasis in long-term survivors. However, a FMRT dose (BED10) ≥39.0 Gy and post-FMRT ATs were not significant factors.

Local control of bone metastases treated with external beam radiotherapy in recent years: a multicenter retrospective study.

BACKGROUND: Over the past decades, remarkable advancements in systemic drug therapy have improved the prognosis of patients with bone metastases. Individualization is required in external beam radiotherapy (EBRT) for bone metastases according to the patient's prognosis. To establish individualized EBRT for bone metastases, we investigated factors that affect the local control (LC) of bone metastases. METHODS: Between January 2010 and December 2019, 536 patients received EBRT for 751 predominantly osteolytic bone metastases. LC at EBRT sites was evaluated with a follow-up computed tomography. The median EBRT dose was biologically effective dose (BED10) (39.0) (range of BED10: 14.4-71.7 Gy). RESULTS: The median follow-up time and median time of computed tomography follow-up were 11 (range 1-123) months and 6 (range 1-119) months, respectively. The 0.5- and 1-year overall survival rates were 73% and 54%, respectively. The 0.5- and 1-year LC rates were 83% and 79%, respectively. In multivariate analysis, higher age (≥ 70 years), non-vertebral bone metastases, unfavorable primary tumor sites (esophageal cancer, colorectal cancer, hepatobiliary/pancreatic cancer, renal/ureter cancer, sarcoma, melanoma, and mesothelioma), lower EBRT dose (BED10 < 39.0 Gy), and non-administration of bone-modifying agents (BMAs)/antineoplastic agents after EBRT were significantly unfavorable factors for LC of bone metastases. There was no statistically significant difference in the LC between BED10 = 39.0 and BED10 > 39.0 Gy. CONCLUSIONS: Regarding tumor-related factors, primary tumor sites and the sites of bone metastases were significant for the LC. As for treatment-related factors, lower EBRT doses (BED10 < 39.0 Gy) and non-administration of BMAs/antineoplastic agents after EBRT were associated with poor LC. Dose escalation from BED10 = 39.0 Gy did not necessarily improve LC.

[Tolerability of Definitive Chemoradiotherapy in Elderly Patients with Esophageal Cancer].

Definitive chemoradiotherapy(CRT)for esophageal cancer is the standard treatment and alternative to surgery. However, the tolerability of CRT in elderly patients is not well known. In this study, we retrospectively analyzed 60 patients with esophageal cancer who were treated with CRT(5-FU 700 mg/m2, cisplatin 70 mg/m2, radiation 60 Gy)at our hospital between January 2015 and September 2017. The patients were divided into 2 groups: an elderly group comprising 16 patients aged >75 years and a non-elderly group comprising 44 patients aged <74 years. The relative dose intensity of cisplatin in the elderly group was significantly lower than that in the non-elderly group. Radiotherapy was successfully executed in both groups. More patients in the elderly(25%)than the non-elderly group(7%)developed pneumonitis, and all patients who developed severe pneumonitis in the elderly group died. Application of definitive CRT and irradiation methods in elderly patients with a subpleural reticular shadow should be carefully considered before initiating therapy.

[A Case of Liver Metastasis 28 Years after Resection for Gastrointestinal Stromal Tumor of Duodenum].

A 69-year-old woman underwent a pancreaticoduodenectomy at the age of 41 years for a submucosal tumor of duodenum, which was diagnosed as leiomyoma at that time. Twenty eight years later, a liver tumor, which is 10 cm in a diameter, was identified on an abdominal ultrasonography. The left hepatectomy was undertaken. Immunohistochemical examination indicated that the tumor was positive for c-kit and diagnosed as a gastrointestinal stromal tumor(GIST). The pathological reexamination revealed the primary tumor was also positive for c-kit and diagnosed as GIST. Therefore, the liver tumor was considered as a metastasis of the duodenal GIST, which was resected 28 years earlier.

[Laparoscopic Local Gastrectomy for Gastric Schwannoma and Extramurally Developed Gastric GIST].

Among gastric submucosal tumors, neurogenic tumors are considered to be rare diseases. We experienced a case of laparoscopic local gastrectomy of gastric schwannoma coexisting with extramurally developed gastric GIST found accidentally during surgery. A 61-year-old man was pointed out a gastric submucosal tumor with a diameter of 15 mm in a medical checkup. Endoscopic ultrasound-guided fine needle aspiration(EUS-FNA)was performed, and immunostaining showed that c-kit(-), CD34(-), S-100(+), SMA(-), MIB-1<2%. Diagnosis was gastric schwannoma. We performed laparoscopic local gastrectomy. During the surgery another extramural nodule was accidentally found with a diameter of 8 mm at the anterior wall of the gastric body near lesser curvature. Immunostaining showed c-kit(+), CD34(+)and was diagnosed GIST. Because a gastric schwannoma coexisting with GIST is a rare case, we decided to report it by adding discussion with some literatures.

[A Case of Pancreatic Metastasis from Colon Cancer Successfully Treated with Capecitabine/Oxaliplatin plus Bevacizumab].

A 50-year-old man underwent low anterior resection for rectal cancer. The final diagnosis was rectal cancer of pT3N0M0, fStage Ⅱ. CT performed for examination of obstructive jaundice at 17 months after surgery revealed metastatic lesions of the pancreatic head and right lung. By core needle biopsies, the lesions were pathologically diagnosed as metachronous metastases of rectal cancer. Chemotherapy was carried out but was discontinued at 5 courses due to severe side effects. The pancreatic metastasis disappeared after 11 months. As the lung metastasis remained, a right upper lobectomy was performed 1 month later. The patient remains alive without recurrence 6 months after the partial lung resection.

Tumor growth patterns on magnetic resonance imaging and treatment outcomes in patients with locally advanced cervical cancer treated with definitive radiotherapy.

BACKGROUND: To evaluate the prognostic value of tumor growth patterns on magnetic resonance (MR) images in patients with locally advanced cervical cancer (LACC) treated with definitive radiotherapy or concurrent chemoradiotherapy (RT/CCRT). METHODS: We retrospectively reviewed 102 patients with LACC who received definitive RT/CCRT and who underwent MR imaging before RT/CCRT. Growth patterns on pretreatment T2-weighted MR images were classified into expansive or infiltrative type according to tumor morphologic patterns in the myometrium and/or parametrial space. RESULTS: The median age was 60 years (range 26-90 years). The median follow-up time was 47.7 months (range 5.7-123 months). The numbers of patients with stages IB, II, III, and IVA were 17, 39, 43, and 3, respectively. The 3-year overall survival (OS) rates for stages IB, II, III, and IV were 87%, 76%, 74%, and 67%, respectively. Regarding growth patterns on MR images, 31 were of expansive type and 71 were of infiltrative type. The infiltrative type was significantly associated with lower OS and locoregional recurrence-free survival (LRRFS) than the expansive type (3-year OS, 70% vs. 93%, p = 0.003; 3-year LRRFS, 64% vs. 94%, p = 0.001). On multivariate analysis, infiltrative tumor growth patterns were a significant independent factor for low OS (hazard ratio [HR], 3.81; 95% confidence interval [CI] 1.26-16.7; p = 0.015) and low LRRFS (HR, 4.27; 95% CI 1.43-18.5; p = 0.007). CONCLUSION: Tumor growth patterns on MR images could be an indicator of survival and locoregional control in patients with LACC treated with definitive RT/CCRT.

[Primary Small-Cell Carcinoma of the Digestive Tract-An Analysis of Six Cases].

INTRODUCTION: Primary small-cell carcinomas occur commonly in the lungs but rarely in the other organs. We studied the treatment outcomes in 6 cases of primary small-cell carcinoma of the digestive tract at our hospital. PATIENTS: Six patients were diagnosed with small-cell carcinoma of the digestive tract histopathologically and treated at our hospital from September 2000 to December 2018. RESULTS: The average age of the patients was 61.5 years(range: 40-80 years). Patients were 3 men and 3 women. The occurrence sites were the esophagus, stomach, and colon in 1, 2, and 3 patients, respectively. The patient with esophageal cancer underwent chemoradiotherapy without surgery. Other patients, except for 1 patient with colon cancer, underwent adjuvant chemotherapy after the surgery. Two of the 6 patients survived for over 5 years. DISCUSSION: For small-cell carcinomas of the digestive tract with poor prognosis, long-term survival can be expected using multidisciplinary treatments depending on the case.

Early response assessment of re-ossification after palliative conventional radiotherapy for vertebral bone metastases.

BACKGROUND: To evaluate the therapeutic outcomes in patients with bone metastases receiving radiotherapy (RT), it is important to use objective radiological response criteria. The aim of this study was to investigate the changes in pain and re-ossification after RT for painful vertebral bone metastases without paralysis by malignant spinal cord compression. METHODS: The participants included 55 patients who received RT for painful vertebral bone metastases without paralysis in our institution between 2012 and 2016. Bone modifying agents (BMAs) were administered in all patients. Follow-up assessments were done just before the start of RT and at 1, 2, 3, 4, and 6 months after RT. Radiological responses of irradiated vertebrae by RT were assessed by computed tomography (CT) using MD Anderson response classification criteria (MDA criteria) and the pain response was assessed by Numeric Rating Scale (NRS). Response was classified as complete response (CR), partial response (PR), progressive disease (PD), and stable disease (SD). RESULTS: The rates of CR were 2%, 7%, 20%, 30%, and 56% at 1, 2, 3, 4, and 6 months, respectively. The rates of CR or PR were 15%, 49%, 77%, 91%, and 91% at 1, 2, 3, 4, and 6 months, respectively. The rates of CR or PR were significantly higher in patients with breast cancer than in patients with lung cancer (p = 0.043). At one month, there was an association between the NRS and radiological response assessed by MDA criteria. There was a significant trend that, with a better response, there were more patients without pain (p = 0.021). CONCLUSIONS: Under BMAs administration, successful RT for vertebral bone metastases decreased pain and caused re-ossification. The MD Anderson criteria could be useful for assessment of radiological responses of irradiated vertebrae.

A randomised phase II trial of S-1 plus cisplatin versus vinorelbine plus cisplatin with concurrent thoracic radiotherapy for unresectable, locally advanced non-small cell lung cancer: WJOG5008L.

BACKGROUND: Cisplatin-based chemoradiotherapy is the standard treatment for unresectable, locally advanced non-small-cell lung cancer (NSCLC). This trial evaluated two experimental regimens that combine chemotherapy with concurrent radiotherapy. METHODS: Eligible patients with unresectable stage III NSCLC were randomised to either the SP arm (S-1 and cisplatin) or VP arm (vinorelbine and cisplatin), with early concurrent thoracic radiotherapy of 60 Gy, comprising 2 Gy per daily fraction. The primary endpoint was the overall survival rate at 2 years (2-year overall survival (OS)) (Study ID: UMIN000002420). RESULTS: From September 2009 to September 2012, 112 patients were enroled. Of the 108 eligible patients, the 2-year OS was 75.6% (80% confidence interval (CI), 67-82%) in the SP arm and 68.5% (80% CI: 60-76%) in the VP arm. The hazard ratio (HR) for death between the two arms was 0.85 (0.48-1.49). The median progression-free survival was 14.8 months for the SP arm and 12.3 months for the VP arm with an HR of 0.92 (0.58-1.44). There were four treatment-related deaths in the SP arm and five in the VP arm. CONCLUSIONS: The null hypotheses for 2-year OS were rejected in both arms. The West Japan Oncology Group will employ the SP arm as the investigational arm in a future phase III study.

Early response assessment of palliative conventional radiotherapy for painful uncomplicated vertebral bone metastases.

BACKGROUND: Radiation therapy (RT) is the common treatment for painful vertebral bone metastases without paralysis by malignant spinal cord compression. However, no studies have focused on the time course of pain after RT. Then, we investigated the change of pain after RT for painful vertebral bone metastases without paralysis. METHODS: Participants included 101 patients who received RT for painful vertebral bone metastases without paralysis in our institution between 2012 and 2016. All patients received RT and pain response was evaluated by Numeric Rating Scale (NRS). Follow-up assessments were performed just before the start of RT and every month for six months after RT. Pain response was classified as complete response (CR), partial response (PR), pain progression (PP), and indeterminate response (IR) based on the response criteria of International Bone Metastases Consensus Working Party. Responders were classified as either CR or PR, and non-responders as either PP or IR. RESULTS: Median NRS scores for pain were 5 before RT, decreasing to 0 by one month after RT and remaining zero until last follow-up, representing a significant decrease over time (P < 0.001). The rate of responders at each month from one to six months was 93, 96, 95, 100, 98, and 96%, respectively. Multivariate analysis revealed that Spinal Instability Neoplastic Score (SINS) was the only risk factor for response to RT at one month. At one month pain disappeared in 88% of the patients with spinal stability (SINS < 7), although pain disappeared 58% of the patients with spinal instability (SINS ≥ 7), which was significant (P = 0.002). CONCLUSIONS: Pain decreased significantly over time and 93% of patients were classified as responders as early as one month after RT in patients with painful vertebral bone metastases without paralysis. Pretreatment SINS could be a predictor of pain response to RT.

Risk factors for pericardial effusion after chemoradiotherapy for thoracic esophageal cancer-comparison of four-field technique and traditional two opposed fields technique.

Pericardial effusion is an important late toxicity after concurrent chemoradiotherapy (CCRT) for locally advanced esophageal cancer. We investigated the clinical and dosimetric factors that were related to pericardial effusion among patients with thoracic esophageal cancer who were treated with definitive CCRT using the two opposed fields technique (TFT) or the four-field technique (FFT), as well as the effectiveness of FFT. During 2007-2015, 169 patients with middle and/or lower thoracic esophageal cancer received definitive CCRT, and 94 patients were evaluable (51 FFT cases and 43 TFT cases). Pericardial effusion was observed in 74 patients (79%) and appeared at 1-18.5 months (median: 5.25 months) after CCRT. The 1-year incidences of pericardial effusions were 73.2% and 76.7% in the FFT and TFT groups, respectively (P = 0.6395). The mean doses to the pericardium were 28.6 Gy and 31.8 Gy in the FFT and TFT groups, respectively (P = 0.0259), and the V40 Gy proportions were 33.5% and 48.2% in the FFT and TFT groups, respectively (P < 0.0001). Grade 3 pericardial effusion was not observed in patients with a pericardial V40 Gy of <40%, or in patients who were treated using the FFT. Although the mean pericardial dose and V40 Gy in the FFT group were smaller than those in the TFT group, the incidences of pericardial effusion after CCRT were similar in both groups. As symptomatic pericardial effusion was not observed in patients with a pericardial V40 Gy of <40% or in the FFT group, it appears that FFT with a V40 Gy of <40% could help minimize symptomatic pericardial effusion.

[A Case of Jejunal Ectopic Pancreatic Cancer with Small Bowel Obstruction].

Were port a caseof an 82-year-old man who presented with vomiting. Computed tomography(CT)revealed a jejunum tumor and small bowel obstruction. Enteroscopy revealed a protruded lesion and biopsy indicated adenocarcinoma. PET-CT revealed nothing without jejunal tumor. Therefore, with a preoperative diagnosis of primary small bowel cancer, we performed operation. Surgery indicated peritoneal disseminations and a jejunal tumor 40 cm distal from the ligament of Treitz, and we performed small bowel partial resection. Pathological examination revealed adenocarcinoma originating from a Heinrich type I ectopic pancreas in the jejunum. Ectopic pancreatic cancer in the jejunum is rare, and we review case reports in the literature.

Impact of early tumor reduction on outcome differs by histological subtype in stage III non-small-cell lung cancer treated with definitive radiotherapy.

BACKGROUND: We retrospectively investigated the impact on survival of early tumor reduction during definitive radiotherapy for inoperable stage III non-small cell lung cancer (NSCLC) patients, according to their histological subtypes. METHODS: Between November 2006 and December 2012, 152 consecutive patients with inoperable stage III NSCLC who underwent definitive radiotherapy were reviewed retrospectively. Forty-one patients were excluded for not satisfying the inclusion criteria. Forty-five (40.5 %) and 48 (43.2 %) patients were diagnosed with squamous cell carcinoma (SQC) and adenocarcinoma (ADC), respectively. The tumor reduction rate (TRR) was defined as follows: TRR = 1-[gross tumor volume (GTV) on computed tomography at shrinking irradiation field planning]/(GTV on computed tomography at the initial treatment planning). The Cox proportional hazard model was used to identify significant prognostic factors for overall survival (OS) and progression-free survival (PFS). RESULTS: We evaluated 111 patients, with a median follow-up time of 52.2 months in surviving patients. The median TRR was 45.9 %. In all patients, there were significant associations between TRR and PFS (P = 0.036) on multivariate analysis, although TRR had no correlation with OS (P = 0.141). With respect to histological subtype, multivariate analyses revealed that a higher TRR showed significant associations with better OS and PFS in the SQC group (P = 0.013 and 0.040, respectively). In contrast, a higher TRR was associated with poorer OS in the ADC group (P = 0.030); there was no association between TRR and PFS. CONCLUSION: We found that a higher TRR is a promising prognostic factor for better survival and disease control in SQC patients.

Multi-institutional retrospective analysis of learning curves on dosimetry and operation time before and after introduction of intraoperatively built custom-linked seeds in prostate brachytherapy.

This multi-institutional retrospective analysis examined learning curves for dosimetric parameters and operation time after introduction of intraoperatively built custom-linked (IBCL) seeds. Data from consecutive patients treated with seed implantation before and after introduction of IBCL seeds (loose seed, n = 428; IBCL seed, n = 426) were collected from 13 centers. Dose-volume histogram parameters, operation times, and seed migration rates were compared before and after introduction of IBCL seeds. At the 1-month CT analysis, no significant differences were seen in dose to 90% of prostate volume between before and after IBCL seed introduction. No learning curve for dosimetry was seen. Prostate and rectal volume receiving at least 150% of prescription dose (V150 and RV150) were higher in the loose-seed group than in the IBCL-seed group. Operation time was extended by up to 10 min when IBCL seeds were used, although there was a short learning curve of about five patients. The percentage of patients with seed migration in the IBCL-seed group was one-tenth that in the loose-seed group. Our study revealed no dosimetric demerits, no learning curve for dosimetry, and a slightly extended operation time for IBCL seeds. A significant reduction in the rate of seed migration was identified in the IBCL-seed group.