Radioactive Iodine-125 in Tumor Therapy: Advances and Future Directions

Intraoperative implantation of 125I seeds improves prognosis in refractory stage IIIB cervical cancer: a case report and literature review

BACKGROUND

Concurrent chemoradiation is the standard treatment for advanced cervical cancer. However some patients still have a poor prognosis, and currently, there is no effective treatment for recurrence. In recent years, 125I seed implantation therapy has emerged as a treatment for advanced malignant tumors including surgically unresectable tumors, residual tumors after surgical resection, and metastatic tumors. However, the use of 125I seeds implantation in primary advanced cervical cancer has not been reported. In this study, we present a case of stage IIIB cervical cancer in a patient who had poor response to radiotherapy and chemotherapy. Subsequently, a radical hysterectomy was performed, and 125I radioactive seeds were successfully implanted during the surgery. This effectively controlled the lesions that were resistant to radiotherapy and had the potential to improve the prognosis.

CASE PRESENTATION

A 56-year-old woman was diagnosed with stage IIIB (FIGO 2009) IIIC1r (FIGO 2018) squamous carcinoma of the cervix. After receiving 4 cycles of platinum-based chemotherapy and 30 rounds of radiotherapy, she underwent a radical hysterectomy. The localized cervical lesions were reduced, but there was no reduction in the size of the enlarged pelvic lymph nodes. Therefore, 125I seed implantation was performed under direct surgical vision for the right paracervical lesion and the enlarged pelvic lymph nodes on the right side. During the 18-month follow-up period, the enlarged lymph nodes subsided without any signs of recurrence or metastasis.

CONCLUSION

Intraoperative implantation of 125I seeds in lesions that are difficult to control with radiotherapy or in sites at high risk of recurrence is a feasible and effective treatment option for patients with advanced squamous cervical cancer, and it may contribute to improved survival.

Introducing Specific Iodine Ions in Perovskite-Based Nanocomplex to Cater for Versatile Biomedical Imaging and Tumor Radiotherapy

Multimodal biomedical imaging and imaging-guided therapy have garnered extensive attention owing to the aid of nanoagents with the aim of further improving the therapeutic efficacy of diseases. The ability to engineer nanocomplexes (NCs) or control how they behave within an organism remains largely elusive. Here, a multifunctional nanoplatform is developed based on stabilized I-doped perovskite, CsPbBr3 -x Ix @SiO2 @Lip-c(RGD)2 (PSL-c(RGD)2 ) NCs. In particular, by regulating the amount of regular I- ions introduced, the fluorescence emission spectrum of perovskite-based NCs can be modulated well to match the requirement for biomedical optical imaging at the scale from molecule, cell to mouse; doping 125 I enables the nanoformulation to be competent for single-photon emission computed tomography (SPECT) imaging; the introduction of 131 I- imparts the NCs with the capability for radiotherapy. Through facile manipulation of specific iodine ions, this nanoplatform exhibits a remarkable ability to match multifunctional biomedical imaging and tumor therapy. In addition, their in vivo behavior can be manipulated by adjusting the thickness of the silica shell and the surface polarity for more practical applications. These experimental explorations offer a novel approach for engineering desirable multimodal NCs to simultaneously image and combat malignant tumors.

Utility of spectral CT with orthopedic metal artifact reduction algorithms for 125I seeds implantation in mediastinal and hepatic tumors

Background

Virtual monochromatic image (VMI) combined with orthopedic metal artifact reduction algorithms (VMI + O-MAR) can effectively reduce artifacts caused by metal implants of different types. Nevertheless, so far, no study has systematically evaluated the efficacy of VMI + O-MAR in reducing various types of metal artifacts induced by 125I seeds. The aim of this study was to assess the effectiveness of combining spectral computed tomography (CT) images with O-MAR in reducing metal artifacts and improving the image quality affected by artifacts in patients after 125I radioactive seeds implantation (RSI).

Methods

A total of 45 patients who underwent dual-layer detector spectral CT (DLCT; IQon, Philips Healthcare) scanning of mediastinal and hepatic tumors after 125I RSI were retrospectively included. Spectral data were reconstructed into conventional image (CI), VMI, CI combined with O-MAR (CI + O-MAR), and VMI + O-MAR to evaluate the de-artifact effect and image quality improvement. Objective indicators included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and artifact index (AI) of lesions affected by artifacts. Subjective indicators included assessment of overcorrected artifacts and new artifacts, different morphology of artifacts, and overall image quality.

Results

In artifact-affected lesion areas, SNR and CNR in the CI/VMI + O-MAR groups were better than those in CI groups (all P values <0.05). The AI showed a downward trend as VMI keV increased (all P values <0.001). The AI values of the CI/VMI (50-150 keV) group were all higher than the groups of CI/VMI + O-MAR (50-150 keV) (P<0.001). Overcorrection artifacts and new artifacts were concentrated in the VMI50/70 keV groups. In the evaluation of artifact morphology, as the VMI keV increased, the number of near-field banding artifacts in hyperdense artifacts gradually decreased, whereas the number of minimal or no artifacts increased, and the total number of hyperdense artifacts were decreased. The diagnostic and image quality scores of hyperdense artifacts were higher than those of hypodense artifacts as VMI keV increased.

Conclusions

High VMI level combined with O-MAR substantially improve objective and subjective image quality, lesion display ability, and diagnostic confidence of CT follow-up after 125I RSI, especially at the VMI + O-MAR 150 keV level.

Heterogeneous physical phantom for I-125 dose measurements and dose-to-medium determination

PURPOSE

In this paper we present a further step in the implementation of a physical phantom designed to generate sets of "true" independent reference data as requested by TG-186, intending to address and mitigate the scarcity of experimental studies on brachytherapy (BT) validation in heterogeneous media. To achieve this, we incorporated well-known heterogeneous materials into the phantom in order to perform measurements of 125I dose distribution. The work aims to experimentally validate Monte Carlo (MC) calculations based on MBDCA and determine the conversion factors from LiF response to absorbed dose in different media, using cavity theory.

METHODS AND MATERIALS

The physical phantom was adjusted to incorporate tissue equivalent materials, such as: adipose tissue, bone, breast and lung with varying thickness. MC calculations were performed using MCNP6.2 code to calculate the absorbed dose in the LiF and the dose conversion factors (DCF).

RESULTS

The proposed heterogeneous phantom associated with the experimental procedure carried out in this work yielded accurate dose data that enabled the conversion of the LiF responses into absorbed dose to medium. The results showed a maximum uncertainty of 6.92 % (k = 1), which may be considered excellent for dosimetry with low-energy BT sources.

CONCLUSIONS

The presented heterogeneous phantom achieves the required precision in dose evaluations due to its easy reproducibility in the experimental setup. The obtained results support the dose conversion methodology for all evaluated media. The experimental validation of the DCF in different media holds great significance for clinical procedures, as it can be applied to other tissues, including water, which remains a widely utilized reference medium in clinical practice.

Primary Pulmonary Artery Leiomyosarcoma with Pulmonary Metastasis Depicted on Enhanced Computer Tomography: A Case Description and an Analysis of the Literature

Pulmonary artery leiomyosarcoma is an extremely rare disease, with only a few dozen cases reported worldwide to date. This disease is easily misdiagnosed as pulmonary thromboembolism, leading to improper treatment and accurate diagnosis in the later stages of the disease. Furthermore, this delayed diagnosis may also be the reason for the extremely high mortality rate of patients suffering from it. Early invasive surgery with the goal of complete surgical resection is the standard treatment method. Chemotherapy and radiation therapy have been tried with variable outcomes.

A Functional Stent Encapsulating Radionuclide in Temperature-Memory Spiral Tubes for Malignant Stenosis of Esophageal Cancer

Stent implantation is a commonly used palliative treatment for alleviating stenosis in advanced esophageal cancer. However, tissue proliferation induced by stent implantation and continuous tumor growth can easily lead to restenosis. Therefore, functional stents are required to relieve stenosis while inhibiting tissue proliferation and tumor growth, thereby extending the patency. Currently, no ideal functional stents are available. Here, iodine-125 (125 I) nuclides are encapsulated into a nickel-titanium alloy (NiTi) tube to develop a novel temperature-memory spiral radionuclide stent (TSRS). It has the characteristics of temperature-memory, no cold regions at the end of the stent, and a uniform spatial dose distribution. Cell-viability experiments reveal that the TSRS can reduce the proliferation of fibroblasts and tumor cells. TSRS implantation is feasible and safe, has no significant systemic radiotoxicity, and can inhibit in-stent and edge stenosis caused by stent-induced tissue proliferation in healthy rabbits. Moreover, TSRS can improve malignant stenosis and luminal patency resulting from continuous tumor growth in a VX2 esophageal cancer model. As a functional stent, the TSRS combines the excellent properties of NiTi with brachytherapy of the 125 I nuclide and will make significant contributions to the treatment of malignant esophageal stenosis.

Effect of I-125 Seed Implantation on Lung Cancer and Its Environmental Impact

ABSTRACT

This paper compares the efficacy and adverse effects of iodine-125 ( 125 I) seed implantation and external beam radiotherapy (EBRT) in the treatment of lung cancer as well as impact of the 125 I radiation on the environment around the patients. A total of 40 patients who were admitted with lung cancer to our hospital from October 2017 to October 2018 were enrolled into this study. The patients were randomly assigned into study groups treated with 125 I seed implantation (20 patients) and a control group treated with EBRT (20 patients). The patients were followed up for 6 mo by CT scanning of the tumor size as well as measuring serum carcinoembryonic antigen (CEA), cytokeratin fragment (CYRA21-1), and neurospecific enolase (NSE) levels. The dose rate of 125 I at various distances and times after implantation was also measured. The local tumor control rate was higher in the study group than in the control group. CEA, NSE and CYFRA21-1 significantly decreased from the pre-treatment baseline in both groups (p < 0.05). Side effects of pneumothorax, hemoptysis, chest pain, and leukopenia occurred in the patients treated with 125 I seed implantation. Radiation of the 125 I isotope, which was correlated with the number of implanted 125 I seeds, decreased rapidly in a time- and distance-dependent manner. A lead apron could significantly block radiation of 125 I. Compared to EBRT, brachytherapy with 125 I seed implantation in the lung cancer had a better therapeutic outcome with fewer complications. A lead apron could protect members of patient's family as well as public from 125 I radiation.

CT-guided iodine-125 brachytherapy as salvage therapy for local-regional recurrent breast cancer

Background

The treatment of local-regional recurrent breast cancer (BC) after external beam radiotherapy is challenging. We aim to evaluate the effectiveness and safety of computed tomography (CT)-guided percutaneous iodine-125 brachytherapy for local recurrent BC.

Methods

We retrospectively analyzed 15 patients with local recurrent BC treated with CT-guided interstitial implantation of iodine-125 seeds. Regular contrast-enhanced CT was conducted to evaluate the tumor response. Follow-up survival, quality of life, and adverse events were analyzed.

Results

Among the 15 patients, five were elderly patients (older than 80 years) and six were complicated with chronic underlying diseases. The median number of 125I seeds implantation was 33 (range: 20-130) with median dose 90 (D90, the minimum dose covering 90% of the target volume) of 108 Gy (range: 60-120 Gy). There was no significant difference in D90, V100 (the volume of the target receiving 100% of the prescription dose), and V150 (the volume of the target receiving 150% of the prescription dose) before and after operation (p > 0.05). The median follow-up was 14 months (range: 6-18 months). Six months after operation, the ORR was 66.7% (10/15) and the LCR was 93.3% (14/15). The 6- and 12-month survival rates were 100 and 41.6%, respectively, and the median survival time was 12.5 months. PS score decreased from 1.53 ± 0.81 to 0.53 ± 0.49. The pain score decreased from 2.87 ± 1.67 before operation to 1.07 ± 1.18 after operation, and the differences were statistically significant (p< 0.05). No severe complications occurred.

Conclusions

CT-guided iodine-125 brachytherapy provided a safe and effective choice for recurrent BC with significant local therapeutic effects and minor complications, especially for elderly patients with chronic underlying disease and those who were not eligible for surgical resection and had failed to benefit from systemic therapy.

Computed tomography-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by non-small cell lung cancer

BACKGROUND

Airway stenosis secondary to non-small cell lung cancer (NSCLC) is one of the severe complications that can lead to life-threatening outcomes.

OBJECTIVE

To investigate the clinical utility of computed tomography (CT)-guided interstitial implantation of radioactive I-125 seeds in the treatment of hilar airway stenosis caused by NSCLC.

METHODS

The cases of hilar airway stenosis caused by NSCLC in our hospital from 2017 to 2022 were collected and divided into observation and control groups. Both groups underwent conventional lung cancer treatment, and the observation group was treated with CT-guided interstitial implantation of radioactive I-125 seeds. The mean tumor diameter, hilar airway stenosis, and obstructive pneumonia scores at 3 months after treatment were compared between the two groups.

RESULTS

After 3 months of treatment, the mean tumor diameter (28.8 ± 9.3 mm vs 49.33 ± 16.75 mm, P < 0.001), hilar airway stenosis (20.55 ± 30.36% vs 84.85 ± 26.19%, P < 0.001), and obstructive pneumonia score (2.19 ± 1.41 vs 3.48 ± 1.12, P < 0.001) of the observation group were significantly lower than those of the control group.

CONCLUSION

CT-guided interstitial implantation of I (125) radioactive seeds in the treatment of hilar airway stenosis caused by NSCLC can effectively reduce the tumor volume, relieve airway stenosis, and alleviate the associated obstructive pneumonia and has a certain value of application in the clinic.

Safety and efficacy of stereotactic ablative brachytherapy as a salvage therapy for recurrent chest wall cancer: A retrospective, multicenter study

Purpose

To evaluate the safety and efficacy of stereotactic ablative brachytherapy (SABT) as a salvage therapy for patients with recurrent chest wall cancer (rCWC) who have previously received external beam radiotherapy (EBRT) or surgery.

Materials and methods

Between November 2013 and October 2020, a total of 130 patients (including 75 men with a median age of 63 years) with rCWC treated with SABT were enrolled in this multicenter retrospective study. There were 97 cases of non-small-cell lung carcinoma, 24 cases of breast cancer, and 9 cases of thymic cancer. Of the patients included, 102 patients previously received surgery and 58 patients received EBRT, with systemic treatment progressing after recurrence. None of them were suitable or refused to undergo salvage EBRT or surgery again.

Results

During the 22 (4-70)-month median patient follow-up, 59 patients died. The local control (LC) rates at 6, 12, 24, and 36 months were 88.3%, 74.3%, 50.4%, and 36.7%, respectively. The 1-, 2- and 3-year survival rates were 85%, 56%, and 42%, respectively. The median overall survival was 26 months (95% CI, 18.9-33.1 months). The pain relief rate was 81%, and the median to remission time was 10 days. Univariate and multivariate analyses showed that independent prognostic factors for LC included tumor size and postoperative D90. On the other hand, independent prognostic factors for survival include the Karnofsky performance status (KPS) score, tumor size, and D90 19 patients (14.6%) developed grade I/II skin reaction complications. No grade III or severer complications occurred.

Conclusion

SABT is safe and effective as a salvage therapy for rCWC following EBRT/surgery. For patients with a KPS score greater than 80, prescribed dose greater than 130 Gy, and tumor size less than 4 cm may bring better results.

Comparison of the Therapeutic Effects of Iodine-125 Seed Implantation and Conventional Radiochemotherapy for Advanced Esophageal Cancer

BACKGROUND

The purpose of this study was to explore the feasibility, safety and efficacy of iodine-125 seed implantation in the treatment of dysphagia of advanced esophageal cancer.

METHODS

We retrospectively analyzed patients with advanced esophageal cancer who underwent EUS-guided iodine-125 seed implantation or conventional chemoradiotherapy in our hospital. The propensity score match was used to reduce the baseline differences.

RESULTS

A total of 127 patients were enrolled, 17 patients received EUS-guided iodine 125 seed implantation (Group A), 31 patients received radiotherapy (Group B), 38 patients received chemotherapy (Group C) and 41 patients received chemotherapy combined with radiotherapy (Group D). At half month postoperatively, the dysphagia remission rate in Group A (100%) was better than that in Groups B (39.3%), C (20%), D (15.8%), respectively, in the original cohort (P < 0.01); At 1 month postoperatively, the dysphagia remission rate in Group A (86.7%) was better than that in Group B (57.1%) (P > 0.05), Group C (25.7%) (P < 0.05) and Group D (34.2%) (P < 0.05), respectively, in the original cohort. There was no statistically significant difference in median overall survival (OS) between Group A (16 months) and Group B (37 months) (P = 0.149), and between Group A (16months) and Group C (16 months) (P = 0.918) in the original cohort. The mean OS of Group D (54 months) was better than that of Group A (20 months) in the original cohort (P = 0.031). The incidences of grade ≥2 myelosuppression in Groups B, C, and D were 12.9%, 28.9%, and 43.9%, respectively; the incidence of grade ≥2 gastrointestinal adverse events in Groups B, C, and D were 12.9%, 15.8%, 12.2%, respectively. No serious adverse events were found in Group A. The radiation dose around the patient was reduced to a safe range after the distance from the implantation site was more than 1 m (4.2 ± 2.6 μSv/h) or with lead clothing (0.1 ± 0.07 μSv/h).

CONCLUSIONS

Compared with conventional radiotherapy or chemotherapy alone, iodine-125 seed implantation might improve dysphagia more quickly and safely, further clinical data is needed to verify whether it could effectively prolong the OS of patients.

Transarterial chemoembolisation plus I125 seeds implantation for people with unresectable hepatocellular carcinoma

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

To assess the benefits and harms of transarterial chemoembolisation (TACE) plus I125 seeds implantation compared with TACE alone, regardless of chemotherapeutic drugs and vascular occlusive agents, for people with unresectable hepatocellular carcinoma. 

A retrospective study on unresectable or inoperable head and neck cancers treated with stereotactic ablative brachytherapy

Purpose

The aim of the present study was to assess the clinical efficacy and safety of stereotactic ablative brachytherapy (SABT) for unresectable or inoperable head and neck cancers.

Material and methods

This study retrospectively assessed clinical data of 37 patients with unresectable or inoperable head and neck cancers treated with SABT from October 2016 to October 2021. Variables evaluated included local efficacy, local control rate (LCR), overall survival (OS) rate, and radiological adverse effects.

Results

The median follow-up was of 34 months (range, 5-59 months), and LCR at 6, 12, and 24 months was 89.2%, 78.2%, and 69.4%, respectively. The median survival time was 16 months [95% confidence interval (CI): 10.5-21.5 months], and the OS rate at 6, 12, and 24 months was 97.3%, 70.3%, and 34.5%, respectively. The results of univariate analysis revealed that the type of pathology and gross tumor volume (GTV) D₉₀ were related to LCR (p < 0.05). However, the type of pathology, GTV D₉₀, age, and implantation site were related to OS rate (p < 0.05). The results of multivariate analysis showed that the type of pathology and GTV D₉₀ were substantially related to LCR and OS rate (p < 0.05). The evaluation of post-operative radiological adverse reactions revealed that seven cases (18.9%) developed grade 1-2 skin reactions, four cases (10.8%) developed grade 1-2 oral mucosal outcomes, and no cases developed grade 3 or higher adverse reactions. Post-operative seed dislocation occurred in three patients with tongue cancer.

Conclusions

SABT has produced good local control and mild adverse reactions in the treatment of unresectable or inoperable head and neck cancers. Additionally, it is safe, feasible, minimally invasive, and has fewer adverse effects than other treatment modalities.

Re-Irradiation for Recurrent Cervical Cancer: A State-of-the-Art Review

The recurrence rate of cervical cancer after primary treatment can reach 60%, and a poor prognosis is reported in most cases. Treatment options for the recurrence of cervical cancer mainly depend on the prior treatment regimen and the location of recurrent lesions. Re-irradiation is still considered as a clinical challenge, owing to a high incidence of toxicity, especially in in-field recurrence within a short period of time. Recent advances in radiotherapy have preliminarily revealed encouraging outcomes of re-irradiation. Several centers have concentrasted on stereotactic body radiation therapy (SBRT) for the treatment of well-selected cases. Meanwhile, as the image-guiding techniques become more precise, a better dose profile can also be achieved in brachytherapy, including high-dose-rate interstitial brachytherapy (HDR-ISBT) and permanent radioactive seed implantation (PRSI). These treatment modalities have shown promising efficacy with a tolerable toxicity, providing further treatment options for recurrent cervical cancer. However, it is highly unlikely to draw a definite conclusion from all of those studies due to the large heterogeneity among them and the lack of large-scale prospective studies. This study mainly reviews and summarizes the progress of re-irradiation for recurrent cervical cancer in recent years, in order to provide potential treatment regimens for the management of re-irradiation.

Salvage 125I brachytherapy for liver metastases of colorectal cancer in anatomically challenging locations after failure of systemic chemotherapy-A retrospective study

PURPSOE

Colorectal cancer liver metastasis (CCLM) in anatomically challenging locations is difficult to treat. This retrospective study aimed to evaluate the effectiveness and safety of permanent ¹²⁵I seeds implantation (ISI) for treatment of CCLM in anatomically challenging locations after failure of systemic chemotherapy.

METHODS AND MATERIALS

A total of 31 liver metastases (in 25 patients) were treated by ISI under computerized tomography guidance from January 2011 to December 2017. Post-treatment follow-up was for 40 months. Adverse events were classified using the National Cancer Institute's Common Terminology Criteria for Adverse Events. Tumor response was evaluated by the mRECIST criteria. Objective response rate, overall survival rate, and complications were retrospectively analyzed.

RESULTS

All ISI procedures were performed successfully. Most patients only complained of fatigue and mild pain after ISI. Only one patient had liver rupture during the procedure. Serum alanine aminotransferase and aspartate aminotransferase levels at 1 month after ISI were not significantly different from pre-procedure levels (p > 0.05). Computed tomography at 6 months after ISI treatment showed completed response in 11 (11/31, 35.5%) lesions, partial response in 14 (14/31, 45.2%) lesions, stable disease in 4 (4/31, 12.9%) lesions, and disease progression in 2 (2/31, 6.5%) lesions; thus, the objective response rate was 80.6%. Median survival was for 12 months. The 1 and 2 year overall survival rates were 52.0% and 20.0%, respectively.

CONCLUSIONS

¹²⁵I seeds implantation for CCLM in anatomically challenging locations is safe and effective. Survival benefit is limited in the salvage setting where patients have high intrahepatic tumor load after failed systemic chemotherapy.