Seed migration after transperineal interstitial prostate brachytherapy with I-125 free seeds: analysis of its incidence and risk factors

Seed Density as a New Predictive Index of Seed Migration in Brachytherapy for Prostate Cancer Using Iodine-125 Loose Seed

AIM

This study aimed to examine the usefulness of seed density as a predictor of seed migration in patients with prostate cancer who received brachytherapy using Iodine-125 loose seed.

METHODS

From May 2006 to April 2016, 320 patients with localized prostate cancer underwent transperineal brachytherapy using iodine-125 loose seeds. Among them, 202 (63.1%) patients received brachytherapy monotherapy and 118 (36.9%) received combined brachytherapy and external beam radiotherapy. Seed density was calculated using the following formula: seed density = implanted seed number/prostate volume. All patients underwent radiography of the chest, abdomen and pelvis, and computed tomography at 1 day, 1 month, and 1 year after brachytherapy to evaluate the presence of seed migration.

RESULTS

In total, the number of implanted seeds was 21,876. Seed migration was detected in 92 (28.8%) patients. Of a total of 21,876 seeds, 144 (0.66%) showed migration. The number of needles, number of seeds, and seed density were significantly higher in the group with migration than in the group without migration (p = 0.05). The ROC cutoff values for prostate volume, number of needles, number of seeds, and seed density were 20.9 cc, 21, 65, and 3.0, respectively. In the univariate analysis, prostate volume, number of needles, number of seeds, seed density, and treatment modality were all significant factors in predicting migration (p = 0.05). In the multivariate analysis, seed density and treatment modality were significant factors in predicting migration (p = 0.05).

CONCLUSION

Seed density is useful for predicting seed migration. In cases with seed density > 3.0, it is necessary to take measures such as considering the use of stranded seeds.

Peritricuspid annular prostate pellet

A 75-year-old was treated for prostate adenocarcinoma with brachytherapy in September 2018. A routine follow-up chest radiograph 3 months later revealed a metallic object of the same dimensions as a brachytherapy pellet located in the right ventricle. Further imaging showed the brachtherapy pellet was located in the anterobasal right ventricular endocardium close to the tricuspid valve. Frequent asymptomatic premature ventricular contractions were observed with likely origin from the left ventricular outflow tract, an area remote from the site of the pellet. The patient remains asymptomatic and subsequent imaging shows that the position of the pellet has not changed.

Reducing seed migration to near zero with stranded-seed implants: Comparison of seed migration rates to the chest in 1000 permanent prostate brachytherapy patients undergoing implants with loose or stranded seeds

PURPOSE

Pulmonary seed emboli to the chest may occur after permanent prostate brachytherapy (PPB). The purpose of this study is to analyze factors associated with seed migration to the chest in a large series of PPB patients from a single institution undergoing implant with either loose seeds (LS), mixed loose and stranded seeds (MS), or exclusively stranded seeds in an absorbable vicryl suture (VS).

METHODS AND MATERIALS

Between May 1998 and July 2015, a total of 1000 consecutive PPB patients with postoperative diagnostic chest x-rays at 4 months after implant were analyzed for seed migration. Patients were grouped based on seed implant technique: LS = 391 (39.1%), MS = 43 (4.3%), or VS = 566 (56.6%). Univariate and multivariate analysis were performed using Cox proportional hazards regression models to determine predictors of seed migration.

RESULTS

Overall, 18.8% of patients experienced seed migration to the chest. The incidence of seed migration per patient was 45.5%, 11.6%, and 0.9% (p < 0.0001), for patients receiving LS, MS, or VS PPB, respectively. The right and left lower lobes were the most frequent sites of pulmonary seed migration. On multivariable analysis, planimetry volume (p = 0.0002; HR = 0.7 per 10 cc [0.6-0.8]), number of seeds implanted (p < 0.0001, HR = 2.4 per 25 seeds [1.7-3.4]), LS implant (p < 0.0001, HR = 15.9 [5.9-42.1]), and MS implant (p = 0.001, HR = 7.9 [2.3-28.1]) were associated with seed migration to the chest.

CONCLUSIONS

In this large series, significantly higher rates of seed migration to the chest are observed in implants using any LS with observed hazard ratios of 15.9 and 7.9 for LS and MS respectively, as compared with implants using solely stranded seeds.

Plan reproducibility of intraoperatively custom-built linked seeds compared to loose seeds for prostate brachytherapy

Purpose

Few studies have compared the implant quality of linked and loose seeds for prostate brachytherapy. This study aimed to evaluate and compare plan reproducibility of intraoperatively built custom linked seeds and loose seeds for prostate brachytherapy.

Material and methods

Between December 2010 and March 2014, 76 localized prostate cancer patients received Iodine-125 brachytherapy with external beam radiotherapy. Linked and loose seeds were implanted in 39 and 37 patients, respectively. The primary endpoint was the mean (± standard deviation) of the absolute change in the minimum dose received by 90% of the prostate volume between intraoperative and post-operative planning (ΔD₉₀) to confirm plan reproducibility. Comparisons between the groups were evaluated using 2-sample t tests.

Results

The ΔD₉₀ values were 6.95 ± 11.6% and –0.41 ± 8.5% for the loose and linked seed groups, respectively (p < 0.01). The linked seed group showed decreased post-operative D₉₀ (118.8% vs. 127.2%), V₁₅₀ (51.7% vs. 66.7%), and RV₁₀₀ (0.44 ml vs. 0.61 ml) compared to the loose seed group (p < 0.01), whereas lung migration tended to be reduced (0% vs. 8%).

Conclusions

The plan reproducibility of the linked seed group was better than that of the loose seed group. Moreover, the linked seed group showed less migration and lower rectal dose.

Late seed migration after prostate brachytherapy with Iod-125 permanent implants

BACKGROUND

Seed migration is a common finding after low dose rate brachytherapy of the prostate. It has often been assessed soon after implantation, but little is known about late seed migration. We evaluated the incidence, site, symptoms, and therapeutic consequences of late seed migration more than 3 years postoperatively.

MATERIALS AND METHODS

We retrospectively examined the data of 63 unselected patients with transrectal ultrasound-guided, transperineal low dose rate brachytherapy of the prostate with stranded seeds between 2001 and 2010. A pelvic X-ray was taken the day after implantation and after 6 weeks in combination with a pelvic computed tomography/magnetic resonance imaging scan (image fusion) for dosimetry. Late radiological follow-up with a further pelvic and chest X-ray was conducted 3 or more years postoperatively. We differed between seed loss without anatomical detection and seed migration into another anatomical region.

RESULTS

We found seed loss up to 3 years and more after brachytherapy in 36 of 63 patients (57%). Between one and nine seeds had been lost. Late seed migration after 3 or more years occurred in two of 36 patients (6%), with pelvic migration of one seed and extrapelvic migration of one seed to the lung and two seeds to the liver, respectively. All late seed migrations were asymptomatic and had no therapeutic consequences.

CONCLUSION

Beside a frequent number of seed losses, seed migration 3 or more years after implantation was as well a frequent finding but seems to be asymptomatic. Long-term follow-up with complementary radiological controls could be helpful in detecting any rare complications.

Does Seed Migration Increase the Risk of Second Malignancies in Prostate Cancer Patients Treated With Iodine-125 Loose Seeds Brachytherapy?

PURPOSE

To evaluate the risk of second malignancies after migration of seeds (MS) in prostate cancer patients treated with ¹²⁵I loose seeds brachytherapy.

METHODS AND MATERIALS

Data from 2802 prostate cancer patients treated with ¹²⁵I loose seeds brachytherapy in 3 Canadian centers were reviewed. After seeds implant, all patients underwent postimplant pelvic radiography and computed tomography scan for postimplant dosimetry. These images were used to assess whether seed migration occurred. The incidence of second malignancies was determined through the review of patient charts. The 7- and 10-year cumulative incidences of second malignancies and their 95% confidence intervals (CIs) were calculated. Fine and Gray competing risk regression analysis was used to assess the factors associated with the development of second malignancies.

RESULTS

Mean age and median follow-up were 63.5 years and 74 (range, 12-246) months, respectively. Migration of seeds occurred in 263 of 2802 patients (9.4%). Second malignancy occurred in 87 patients (3.1%) for the entire cohort and was not different between patients who experienced MS (9, 3.4%) and those who did not (78, 3.1%) (P = .755). The 7-year cumulative incidence rates of second malignancies were 2.95% (95% CI 1.20%-6.00%) (with MS) versus 2.82% (2.10%-3.70%) (without MS) (P = .756). The corresponding values at 10 years were 6.16% (2.20%-12.3%) versus 4.51% (3.20%-5.50%) (P = .570). Migration of seeds did not seem to be a significant predictive factor for second malignancies development (adjusted hazard ratio 1.27 [95% CI 0.63-2.55]; P = .510). In both models, only advanced age was significantly associated with second malignancies development.

CONCLUSIONS

These results did not show an increased risk of second malignancies associated with MS after ¹²⁵I loose seeds brachytherapy for prostate cancer patients. Longer follow-up and more events are required to better correlate MS and second malignancies.

Long term outcome and side effects in patients receiving low-dose I125 brachytherapy: a retrospective analysis

Objectives:

To retrospectively evaluate the disease free survival (DFS), disease specific survival (DSS),overall survival (OS) and side effects in patients who received low-dose rate (LDR) brachytherapy with I125 stranded seeds.

Materials and methods:

Between july 2003 and august 2012, 274 patients with organ confined prostate cancer were treated with permanent I125 brachytherapy. The median follow-up, age and pretreatment prostate specific antigen (iPSA) was 84 months (12-120), 67 years (50-83) and 7.8 ng/mL (1.14-38), respectively. Median Gleason score was 6 (3-9). 219 patients (80%) had stage cT1c, 42 patients (15.3%) had stage cT2a, 3 (1.1%) had stage cT2b and 3 (1.1%) had stage cT2c. The median D90 was 154.3 Gy (102.7-190.2).

Results:

DSS was 98.5%.OS was 93.5%. 13 patients (4.7%) developed systemic disease, 7 patients (2.55%) had local progression. In 139 low risk patients, the 5 year biochemical freedom from failure rate (BFFF) was 85% and 9 patients (6.4%) developed clinical progression. In the intermediate risk group, the 5 year BFFF rate was 70% and 5 patients (7.1%) developed clinical progression. Median nPSA in patients with biochemical relapse was 1.58 ng/mL (0.21 – 10.46), median nPSA in patients in remission was 0.51 ng/mL (0.01 – 8.5). Patients attaining a low PSA nadir had a significant higher BFFF (p<0.05). Median D90 in patients with biochemical relapse was 87.2 Gy (51 – 143,1). Patients receiving a high D90 had a significant higher BFFF (p<0.05).

Conclusion:

In a well selected patient population, LDR brachytherapy offers excellent outcomes. Reaching a low PSA nadir and attaining high D90 values are significant predictors for a higher DFS.

Lessons Learned from Autopsying an Unidentified Body with Iodine-125 Seeds Implanted for Prostate Brachytherapy

We report here lessons learned from an autopsy case involving radioactive materials. We performed an autopsy of an unidentified mummified man with no available medical history whom from imaging findings we suspected had received radioactive seed implants for prostate brachytherapy. We returned the excised prostate and seeds to the body. A few days later, the body was identified by DNA matching and cremated. According to the man's medical record, he had undergone iodine-125 seeds implantation for prostate cancer 11 months earlier. We should have removed the radioactive seeds from the body to prevent radiation exposure to the bereaved family and/or environmental pollution due to cremation. Surprisingly, one seed was found in the stored prostate specimen. Forensic experts should be cognizant of the risk of both radiation exposure in the autopsy room and environmental pollution. We must remain abreast of the latest advances in medicine.

Iodine-125 seed migration within brain parenchyma after brachytherapy for brain metastasis: case report

This case report documents the migration of 3 iodine-125 (125I) seeds from the tumor resection cavity into brain parenchyma over a 7-year period. A 66-year-old woman had a history of metastatic ovarian carcinoma, nickel allergy, and reaction to a titanium hip implant that required reoperation for hardware removal. In this unique case of parenchymal migration, the seed paths seemed to follow white matter tracts, traveling between 18.5 and 35.5 mm from the initial implant site. The patient's initial neurological decline, which was thought to be related to radiation necrosis, appeared to stabilize with medical therapy. She subsequently developed progressive right hemispheric edema that resulted in neurological deterioration and death. Considering her previous reactions to nickel and titanium, the authors now speculate that her later clinical course reflected an allergic reaction to the titanium casing of the 125I seeds. Containing a trace amount of nickel, 125I seeds can elicit a delayed hypersensitivity reaction in patients with a history of nickel dermatitis. Preoperative patch testing is recommended in these patients, and 125I seed implantation should be avoided in those who test positive.

Seed migration after transperineal interstitial prostate brachytherapy by using loose seeds: Japanese prostate cancer outcome study of permanent iodine-125 seed implantation (J-POPS) multi-institutional cohort study

Background

The incidence and associated factors of loose seed migration were investigated in cohort 1 of the Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 Seed Implantation (J-POPS).

Methods

The study subjects were 2160 patients, consisting of 1641 patients who underwent permanent iodine-125 seed implantation (PI) and 519 patients who underwent PI combined with external beam radiation therapy (PI + EBRT). The presence or absence of seed migration to the chest and abdominal/pelvic region was determined.

Results

Seed migration was observed in 22.7 % of PI group patients and 18.1 % of PI + EBRT group patients (p = 0.0276). Migration to the lungs and abdominal/pelvic region was observed in 14.6 % and 11.1 % of the patients in the PI group, and 11.2 % and 8.5 % of the patients in the PI + EBRT group, respectively. In the PI group, the number of implanted seeds was associated with the seed migration incidence. Neither the PI nor the PI + EBRT group showed any difference in the volume of the prostate receiving 100 % of the prescribed dose (V100 [%]) or the minimal dose received by 90 % of the prostate volume (D90 [Gy]) between the patients with and without seed migration.

Conclusions

This prospective cohort study investigating the largest number of past cases showed no difference in D90 (Gy) or V100 (%) between seed migration or the absence thereof in both the PI group and PI + EBRT group.

Trial registration

ClinicalTrials.gov: NCT00534196

Foreign bodies in the heart

BACKGROUND

Foreign bodies in the heart are rare, may reach the heart by different ways, and cause serious complications. X-ray, computerized tomography, and echocardiography are main diagnostic modalities. Foreign body can be removed surgically, percutaneously or can be managed conservatively. In this work, we analyzed 100 published cases of a foreign body in the heart and 4 cases that were identified in our hospital.

METHODS

We searched the literature for foreign body in the heart and found 100 published previously cases. Additional 4 cases were identified in our echo laboratory. A total series of 104 patients with a foreign body in the heart were analyzed for the etiology, clinical presentation, symptoms, complications and management.

RESULTS

Mean patients' age was 46, there were more men than woman 73 versus 31 [P < 0.00005]. The most common foreign bodies were parts of inferior vena cava filters and devices implanted for relieving hydrocephalus. Foreign bodies in the heart were symptomatic in 56% of patients. Right heart chambers were occupied more often. A total of 20% presented within the first 24 hours and 30% of patients presented years after the penetration of the foreign body. A majority of foreign bodies reached the heart by migration [88%]. Mortality was reported in 4 patients [3.8%]. Here 54% of the patients underwent surgical and 29% percutaneous removal of the foreign body, while 14% were followed conservatively.

CONCLUSION

Foreign bodies in the heart may present with a wide variety of symptoms. Physicians should be aware of this rare and peculiar complications which may be fatal. Larger devices may result in more severe complications.

Multi-modality organ-based approach to expected imaging findings, complications and recurrent tumour in the genitourinary tract after radiotherapy

PURPOSE

Radiotherapy (RT) is an integral component in the management of many abdominal and pelvic malignancies. Imaging follow-up in patients who have received RT is performed to assess for treatment response, evaluate for tumour recurrence and to diagnose complications related to treatment. The purpose of this pictorial review is to depict the expected imaging findings and potential complications following RT in the genitourinary (GU) tract using an organ-based approach and to review the diagnosis of locally recurrent tumour in the GU tract following RT.

CONCLUSIONS

Some GU malignancies, namely cervical and prostatic carcinoma, can be treated with radical RT with intent to cure. More frequently, the GU tract is indirectly treated as a result of RT to adjacent cancers. Expected imaging findings, RT-related complications and the diagnosis of recurrent tumour following RT in the GU tract often necessitate a multi-modality imaging approach, the incorporation of functional imaging techniques and an organ-based approach for diagnosis.