Clinical outcomes of 125I brachytherapy with and without external-beam radiation therapy for localized prostate cancer: results from 300 patients at a single institution in Japan

Comparison of chronic gastrointestinal and genitourinary toxicities between brachytherapy and external beam radiotherapy for patients with prostate cancer: A systematic review and meta-analysis

BACKGROUND

125I BT is an effective radiotherapy for prostate cancer. However, comparison data of GI and GU toxicities between BT, BT + EBRT, and EBRT-alone patient groups is limited.

OBJECTIVE

To define the GI and GU toxicities in prostate cancer to prevent adverse events after treatment.

METHODS

We searched published studies in PubMed, Cochrane, and Embase databases up to December 31, 2022. The endpoints were the RRs of GI and GU toxicities. Pooled data were assessed using a random-effects model.

RESULTS

Fifteen eligible studies were included into this analysis. LDR-BT had significantly lower RRs than LDR-BT + EBRT for acute GI (2.13; 95% CI, 1.22-3.69; P= 0.007) and late GI toxicities (3.96; 95% CI, 1.23-12.70; P= 0.02). Moreover, EBRT had significantly higher RRs than LDR-BT for acute GU (2.32; 95% CI, 1.29-4.15; P= 0.005) and late GU toxicities (2.38; 95% CI, 1.27-4.44; P= 0.007). HDR-BT had significantly higher RRs for acute GU toxicities than LDR-BT alone (0.30; 95% CI, 0.23-0.40; P< 0.00001).

CONCLUSION

The results implied that BT with and without EBRT can result in both GI and GU toxicities in patients with prostate cancer, with LDR-BT leading to a poorer urinary function than EBRT.

CT-guided Radioactive 125I Seed Implantation for Abdominal Incision Metastases of Colorectal Cancer: Safety and Efficacy in 17 Patients

INTRODUCTION

To retrospectively evaluate the safety and efficacy of computed tomography (CT)-guided iodine-125 (¹²⁵I) seed implantation for patients with abdominal incision metastases from colorectal cancer.

MATERIALS AND METHODS

Data of patients with abdominal incision metastases of colorectal cancer from November 2010 to October 2020 were retrospectively reviewed. Each incisional metastasis was percutaneously treated with ¹²⁵I seed implantation under CT guidance. Follow-up contrast-enhanced CT was reviewed, and the outcomes were evaluated in terms of objective response rate, complications, and overall survival.

RESULTS

A total of 17 patients were enrolled in this study. The median follow-up was 18 months (range, 2.7-22.1 months). At 3, 6, 12, and 18 months after the treatment, objective response rate was 52.9%, 63.6%, 33.3%, and 0%, respectively. A small amount of local hematoma occurred in two patients and resolved spontaneously without any treatment. Two patients experienced a minor displacement of radioactive seeds with no related symptoms. Severe complications, such as massive bleeding and radiation injury, were not observed. No ≥ grade 3 adverse events were identified. By the end of follow-up, 14 patients died of multiple hematogenous metastases. The one-year overall survival rate was 41.6%, and the median overall survival was 8.6 months.

CONCLUSION

CT-guided ¹²⁵I seed implantation brachytherapy is safe and feasible for patients with abdominal incision metastases from colorectal cancer.

Optimized Therapeutic 177Lu-Labeled PSMA-Targeted Ligands with Improved Pharmacokinetic Characteristics for Prostate Cancer

Clinical trials have shown the significant efficacy of [¹⁷⁷Lu]Lu-PSMA-617 for treating prostate cancer. However, the pharmacokinetic characteristics and therapeutic performance of [¹⁷⁷Lu]Lu-PSMA-617 still need further improvement to meet clinical expectations. The aim of this study was to evaluate the feasibility and therapeutic potential of three novel ¹⁷⁷Lu-labeled ligands for the treatment of prostate cancer. The novel ligands were efficiently synthesized and radiolabeled with non-carrier added ¹⁷⁷Lu; the radiochemical purity of the final products was determined by Radio-HPLC. The specific cell-binding affinity to PSMA was evaluated in vitro using prostate cancer cell lines 22Rv1and PC-3. Blood pharmacokinetic analysis, biodistribution experiments, small animal SPCET imaging and treatment experiments were performed on normal and tumor-bearing mice. Among all the novel ligands developed in this study, [¹⁷⁷Lu]Lu-PSMA-Q showed the highest uptake in 22Rv1 cells, while there was almost no uptake in PC-3 cells. As the SPECT imaging tracer, [¹⁷⁷Lu]Lu-PSMA-Q is highly specific in delineating PSMA-positive tumors, with a shorter clearance half-life and higher tumor-to-background ratio than [¹⁷⁷Lu]Lu-PSMA-617. Biodistribution studies verified the SPECT imaging results. Furthermore, [¹⁷⁷Lu]Lu-PSMA-Q serves well as an effective therapeutic ligand to suppress tumor growth and improve the survival rate of tumor-bearing mice. All the results strongly demonstrate that [¹⁷⁷Lu]Lu-PSMA-Q is a PSMA-specific ligand with significant anti-tumor effect in preclinical models, and further clinical evaluation is worth conducting.

Acute and late side-effects after low dose-rate brachytherapy for prostate cancer; incidence, management and technical considerations

PURPOSE

To review common reported side effects and complications after primary LDR-BT (monotherapy) and discuss some of the technical aspects that could impact the treatment outcomes.

METHODS AND MATERIALS

A literature search was undertaken using medical subject headings (MeSH) complemented by the authors' personal and institutional expertise.

RESULTS

The reported incidence of acute and late grade 2 or above urinary, bowel and sexual side effects is very variable across the literature. The learning curve and the implant quality have a clear impact on the toxicity outcomes. Being aware of some of the technical challenges encountered during the procedure and ways to mitigate them could decrease the incidence of side effects. Careful planning of seed placement and seed deposition allow sparing of the organs at risk and a lower incidence of urinary and gastro-intestinal toxicity.

CONCLUSIONS

Low dose-rate brachytherapy remains a standard monotherapy treatment in the setting of favorable-risk prostate cancer. High disease control and low long-term toxicities are achievable in expert hands with a good technique.

Efficacy and safety of CT-guided 125I brachytherapy in elderly patients with non-small cell lung cancer

Non-small cell lung cancer (NSCLC) has become the most common cancer type and the leading cause of cancer-associated mortality worldwide. The aim of the present retrospective study was to evaluate the efficacy and safety of computed tomography (CT)-guided ¹²⁵I brachytherapy alone in elderly patients with NSCLC. A total of 26 elderly patients with NSCLC stage I–III who had an inoperable lesion or progressive disease following radio-chemotherapy were treated with CT-guided ¹²⁵I seed implantation for lung lesions and included in the present study. The prescribed dose of ¹²⁵I brachytherapy was 80–140 Gy, and dosimetric verification was performed immediately after the procedure. The response rate (RR) and local control rate (LCR) were analyzed according to the Response Evaluation Criteria in Solid Tumors (version 1.1). Survival was estimated using the Kaplan-Meier method. Safety and complications were also documented. All patients were aged 65–85 years (median age, 77 years) and successfully completed the procedure, and the median follow-up time was 9.4 months (range, 3–31 months). After a 6-month follow-up, for pulmonary lesions, complete response (CR) was achieved in 11 (42.3%) cases, partial response in 9 (34.6%) cases, stable disease in 4 (15.4%) cases and progressive disease in 2 (7.7%) cases. The 6-month RR and LCR were 76.9 (20/26) and 92.3% (24/26), respectively. The mean overall survival (OS) time was 11.7±7.6 months and the 0.5- and 1-year OS rates were 90.1 and 73.3%, respectively. Tumor-related symptoms in patients were significantly alleviated following the procedure. No severe complications occurred during and after the procedure of ¹²⁵I seed implantation. In conclusion, CT-guided ¹²⁵I brachytherapy is a feasible, effective and safe therapy and may be considered as an alternative option to surgery and radiotherapy for elderly patients with NSCLC.

B7-H3-targeted Radioimmunotherapy of Human Cancer

BACKGROUND

Targeted Radioimmunotherapy (RIT) is an attractive approach to selectively localize therapeutic radionuclides to malignant cells within primary and metastatic tumors while sparing normal tissues from the effects of radiation. Many human malignancies express B7-H3 on the tumor cell surface, while expression on the majority of normal tissues is limited, presenting B7-H3 as a candidate target for RIT. This review provides an overview of the general principles of targeted RIT and discusses publications that have used radiolabeled B7-H3-targeted antibodies for RIT of cancer in preclinical or clinical studies.

METHODS

Databases including PubMed, Scopus, and Google Scholar were searched for publications through June 2018 using a combination of terms including "B7-H3", "radioimmunotherapy", "targeted", "radiotherapy", and "cancer". After screening search results for relevancy, ten publications were included for discussion.

RESULTS

B7-H3-targeted RIT studies to date range from antibody development and assessment of novel Radioimmunoconjugates (RICs) in animal models of human cancer to phase II/III trials in humans. The majority of clinical studies have used B7-H3-targeted RICs for intra- compartment RIT of central nervous system malignancies. The results of these studies have indicated high tolerability and favorable efficacy outcomes, supporting further assessment of B7-H3-targeted RIT in larger trials. Preclinical B7-H3-targeted RIT studies have also shown encouraging therapeutic outcomes in a variety of solid malignancies.

CONCLUSION

B7-H3-targeted RIT studies over the last 15 years have demonstrated feasibility for clinical development and support future assessment in a broader array of human malignancies. Future directions worthy of exploration include strategies that combine B7-H3- targeted RIT with chemotherapy or immunotherapy.

Predictive factors of benefit from iodine-125 brachytherapy for hepatocellular carcinoma with portal vein tumor thrombosis

PURPOSE

The aims of this study were to evaluate treatment responses and predictive factors for overall survival (OS) in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombosis (PVTT) treated with iodine-125 (¹²⁵I) brachytherapy.

METHODS AND MATERIALS

Seventy-seven HCC patients with PVTT underwent ¹²⁵I brachytherapy after transcatheter arterial chemoembolization. Clinical, laboratory, and radiological evaluation were performed before and after treatment, as well as at 4-6 weeks intervals for 7 years to assess the efficacy and toxicity of therapy. Treatment response was assessed using modified response evaluation criteria in solid tumors. OS and predictive factors for each subgroup were evaluated after treatment.

RESULTS

In total, 11 patients (14.29%) achieved complete response, and 41 patients (53.25%) achieved partial response. The response rate (complete response + partial response) was 67.53% (52/77). The median OS was 9 months. The multivariable Cox regression model indicated that post-treatment tumor size with PVTT (p = 0.016, hazard ratio [HR] = 1.889, 95% confidence interval [CI]: 1.127 to 3.166) and baseline hemoglobin (p = 0.013, HR=0.518, 95% CI: 0.308 to 0.872) and alkaline phosphatase (p = 0.002, HR=2.275, 95% CI: 1.338 to 3.868) levels were significant independent predictors of OS.

CONCLUSIONS

¹²⁵I brachytherapy results in favorable treatment responses in HCC patients with PVTT. Notably, post-treatment tumor size and baseline hemoglobin and alkaline phosphatase levels are significant independent predictive factors for OS and provide the most predictive information regarding OS.