Permanent Iodine-125 Interstitial Planar Seed Brachytherapy for Close or Positive Margins for Thoracic Malignancies

American Brachytherapy Society (ABS) consensus statement for soft-tissue sarcoma brachytherapy

PURPOSE

Growing data supports the role of radiation therapy in the treatment of soft tissue sarcoma (STS). Brachytherapy has been used for decades in the management of STS and can be utilized as monotherapy or as a boost to external beam radiation. We present updated guidelines from the American Brachytherapy Society regarding the utilization of brachytherapy in the management of STS.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in STS and STS brachytherapy created an updated clinical practice guideline including step-by-step details for performing STS brachytherapy based on a literature review and clinical experience.

RESULTS

Brachytherapy monotherapy should be considered for lower-recurrence risk patients or after a local recurrence following previous external beam radiation; a brachytherapy boost can be considered in higher-risk patents meeting implant criteria. Multiple dose/fractionation regimens are available, with determination based on tumor location and treatment intent. Techniques to limit wound complications are based on the type of wound closure; wound complication can be mitigated with a delay in the start of brachytherapy with immediate wound closure or by utilizing a staged reconstruction technique, which allows an earlier treatment start with a delayed wound closure.

CONCLUSIONS

These updated guidelines provide clinicians with data on indications for STS brachytherapy as well as guidelines on how to perform and deliver high quality STS brachytherapy safely with minimal toxicity.

Brachytherapy for lung cancer

Brachytherapy (BT) is a minimally invasive anticancer radiotherapeutic modality where the tumor is directly irradiated via a radioactive source that is precisely implanted in or adjacent to the tumor. BT for lung cancer may be conducted in the form of endobronchial BT and radioactive seed implantation (RSI-BT), mainly for nonsmall cell lung cancer (NSCLC). For patients with early-stage lung cancer who are not suitable for surgery or external beam radiotherapy (EBRT), BT may be used as an alternative treatment, and curative results could be achieved in certain patients with cancer confined to the trachea lumen. For patients with locally advanced/metastatic lung cancer, BT could be selectively applied alone or as a boost to EBRT, which could improve the local tumor control and patient's survival. In addition, BT is also useful as a salvage treatment in select patients with locally recurrent/residual lung cancer that failed other treatments (e.g., surgery, chemotherapy, and EBRT). However, clinical outcomes are mainly obtained from retrospective studies. Prospective studies are limited and needed. In recent years, the introduction of modern image guidance, novel radioactive seeds, BT treatment planning systems (BT-TPS), after-loading technique, and three-dimensional printing template (3D-PT) assistance, among others, have potentially improved the clinical outcomes of BT. However, a comprehensive review of BT with newly published literature was lacking. This review is to discuss BT for NSCLC based on recent literature published in PubMed.

A Comparative Study on the Effects of Postoperative 125I Brachytherapy and Irradiation After Surgical Decompression and Stabilization for Metastatic Spinal Cancers

Purpose

The study aims to investigate and compare the efficacy and safety of intraoperative ¹²⁵I implantation and postoperative irradiation after surgical decompression and stabilization in the treatment of patients with metastatic epidural spinal cord compression (MESCC).

Methods

The study retrospectively enrolled 122 MESCC patients treated with surgical decompression and pedicle stabilization combined with ¹²⁵I brachytherapy (the brachytherapy group) or postoperative radiotherapy (the irradiation group). Operation time, intraoperative blood loss, pain relief, postoperative ambulatory status, postoperative survival outcome, complications, and length of hospitalization were collected and compared between the two groups. Ten potential risk factors were analyzed for postoperative survival outcome.

Results

No significant difference was found in baseline characteristics between the two groups (P>0.05). Postoperative VAS score was significantly decreased, as compared with preoperative scores in both groups (P˂0.001). The VAS in the brachytherapy group was significantly lower than that in the irradiation group at postoperative 1 month, 3 months, and 6 months (P˂0.05). The postoperative ambulatory rates were 90.0% (54/60) in the brachytherapy group and 83.9% (52/62) in the irradiation group (P=0.32). The median overall survival time was similar between the two groups (7.43 months vs 7.27 months, P=0.37). Of all patients in the brachytherapy group, 25.0% (15/60) of patients suffered from complications, while 46.8% (29/62) of patients had complications in the irradiation group (P=0.0086). According to the multiple Cox regression, primary sites (P=0.038), ECOG performance status (P=0.014), and visceral metastases (P=0.0016) showed significance for postoperative survival outcome.

Conclusion

Surgical decompression and spine stabilization combined with ¹²⁵I brachytherapy is a relatively safe and useful method in MESCC patients.

Radioactive seeds insertion with chemotherapy for advanced non-small-cell lung cancer: A meta-analysis

BACKGROUND

Non-small-cell lung cancers (NSCLCs) are only eligible to undergo curative surgical resection in <20% of patients. In patients with inoperable NSCLC, computed tomography (CT)-guided radioactive seed insertion (RSI) is a common treatment practice.

OBJECTIVES

To assess the relative efficacy of chemotherapy alone versus chemotherapy in combination with CT-guided RSI in patients with advanced NSCLC.

METHODS

We searched the Pubmed, Embase, and Cochrane Library databases for relevant articles published as of July 2020. Complete and total response rates (CR and TR, respectively) served as the primary endpoints for this meta-analysis, with disease control (DC) rate, myelosuppression rate, progression-free survival (PFS), overall survival (OS), and CT-guided RSI-related pneumothorax serving as secondary endpoints.

RESULTS

In total, eight studies incorporating 281 patients that underwent combination treatment and 297 patients that underwent chemotherapy along were included in this meta-analysis. The CR (21.5% vs. 4.0%, P < 0.00001), TR (73.8% vs. 42.6%, P < 0.00001), and DC (94.1% vs. 78.2%, P < 0.00001) rates were significantly higher for patients in the combined treatment group relative to patients in the chemotherapy only group. Furthermore, pooled PFS (P < 0.00001) and OS (P = 0.0006) were significantly longer for patients in the combined treatment group, whereas no differences in pooled myelosuppression rates were observed between groups (34.3% vs. 30.7%, P = 0.47). The pooled rate of CT-guided RSI-related pneumothorax was 15%.

CONCLUSIONS

Combination chemotherapy and CT-guided RSI can significantly improve clinical response and prolong survival in advanced-stage NSCLC patients without inducing other significant toxic side effects.

Safety and efficacy of CT-guided radioactive iodine-125 seed implantation assisted by a 3D printing template for the treatment of thoracic malignancies

OBJECTIVE

To ascertain the safety and efficacy of radioactive iodine-125 seed implantation (RISI) for the treatment of thoracic tumors.

METHODS

Clinical patients with primary or metastatic tumors in the chest treated with RISI were analyzed. The RISI process included the following stages: preoperative planning, template design and 3D printing, CT-guided RISI assisted by a template, and postoperative dosimetric verification. The prescribed dose was ≥ 80 Gy. The main analytic measures were the local control (LC) rate and toxicity.

RESULTS

From April 2015 to July 2018, a total of 92 patients, including 41 with lung cancer and 51 with lung metastases, were analyzed. The median lesion diameter was 5 cm. The median postoperative D90 was 142.6 Gy. The median follow-up was 10.7 months. The overall survival rates at 1 year and 3 years were 59.7% and 22.2%, respectively. The LC rates at 1 year and 3 years were 64.9% and 32.8%, respectively. The LC rates at 3 years for patients with D90 < 140 Gy and D90 > 140 Gy were 23.1% and 54.3%, respectively (P = 0.014). The LC rate of metastatic lung cancer was more favorable than that of primary lung cancer. The multivariate analyses showed that the dose and lesion type were independent factors for LC (P < 0.05). No factors were related to OS. The incidence of pneumothorax and hemoptysis was 35.8% and 3.2%, respectively. Few cases of radiotherapy-related toxicity effects were observed.

CONCLUSIONS

RISI may be safe and efficacious and is associated with few complications during the treatment of thoracic tumors. If patients need local treatment and surgery or radiotherapy is not available, RISI could be considered.

Experimental study of pelvic perioperative brachytherapy with iodine 125 seeds (I-125) in an animal model

Purpose

The aim of this study is to investigate the feasibility of perioperative I-125 low-dose-rate brachytherapy mesh implantation in pelvic locations in an animal model, before applying it clinically.

Material and methods

The animal model was the Romanov adult ewe. Non-radioactive dummy I-125 seeds were implanted by laparotomy in the pelvic area. Forty-five dummy seeds were placed on a 10 cm² polyglactin mesh to obtain a dose of 160 Gy at 5 mm from the center of each seed. Three CT scans were performed at day 15, day 70, and day 180 after surgery to check the positioning of the mesh for eventual seed migration according to bony landmarks and to perform a 3D theoretical dosimetric study. The experimental study design was based on Simon’s minimax plan with a preliminary analysis of 10 ewes to validate the protocol and a second series of 7 ewes.

Results

After the first step, 9 of 10 ewes were investigated. For 8 of 9 animals, the 160 Gy isodose line volume was within 10%, showing feasibility of the procedure and allowing 7 more to be added. At the end of the study, 16 of 17 animals were examined. No seeds loss was observed. The volume difference of the 160 Gy isodose line was within 10% in 13 of 16 ewes between the three CT scans. Twelve out of 16 had a coordinate deviation less than or equal to 10 mm on the three axes between the first and the third scans.

Conclusions

These results show the technical feasibility of the pelvic mesh implantation in ewes. A phase I study for patients with locally advanced or recurrent pelvic tumors amenable to surgery, in combination with surgical resection should be possible.

High- and low-dose-rate intraoperative radiotherapy for thoracic malignancies resected with close or positive margins

PURPOSE

Local recurrence is a significant problem after surgical resection of thoracic tumors. As intraoperative radiotherapy (IORT) can deliver radiation directly to the threatened margin, we have used this therapy in an attempt to reduce local recurrence, using high-dose-rate (HDR) as well as low-dose-rate (LDR) techniques.

METHODS AND MATERIALS

We performed a retrospective review of patients undergoing LDR ((125)I) mesh placement or HDR ((192)Ir) afterloading therapy during lung tumor resection between 2001 and 2013 at our institution. Competing risks methods were used to estimate the cumulative incidence of local failure. We also assessed possible predictive factors of local failure.

RESULTS

Fifty-nine procedures (41 LDR and 18 HDR) were performed on 58 patients. Median follow-up was 55.1 months. Cumulative incidence of local failure at 1, 2, and 3 years was 28.5%, 34.2%, and 34.2%, respectively. Median overall survival was 39.9 months. There was no significant difference in local failure according to margin status, HDR vs. LDR, use of adjuvant external beam radiotherapy, or metastatic vs. primary tumor. Two patients (3.4%) experienced Grade 3+ toxicities likely related to brachytherapy. Additionally, 7 patients experienced Grade 3+ postsurgical complications unlikely related to brachytherapy.

CONCLUSIONS

IORT is associated with good local control after resection of thoracic tumors otherwise at very high risk for local recurrence. There is a low incidence of severe toxicity attributable to brachytherapy. HDR-IORT appears to have equivalent outcomes to LDR-IORT. HDR or LDR-IORT can, therefore, be considered in situations where the oncologic completeness of thoracic tumor resection is in doubt.

American Brachytherapy Society consensus guidelines for thoracic brachytherapy for lung cancer

PURPOSE

To update brachytherapy recommendations for pretreatment evaluation, treatment, and dosimetric issues for thoracic brachytherapy for lung cancer.

METHODS AND MATERIALS

Members of the American Brachytherapy Society with expertise in thoracic brachytherapy updated recommendations for thoracic brachytherapy based on literature review and clinical experience.

RESULTS

The American Brachytherapy Society consensus guidelines recommend the use of endobronchial brachytherapy for disease palliation in patients with central obstructing lesions, particularly in patients who have previously received external beam radiotherapy. The use of interstitial implants after incomplete resection may improve outcomes and provide enhanced palliation. Early reports support the use of CT-guided intratumoral volume implants within clinical studies. The use of brachytherapy routinely after sublobar resection is not generally recommended, unless within the confines of a clinical trial or a registry.

CONCLUSIONS

American Brachytherapy Society recommendations for thoracic brachytherapy are provided. Practitioners are encouraged to follow these guidelines and to develop further clinical trials to examine this treatment modality to increase the evidence base for its use.

Brachytherapy in the treatment of lung cancer - a valuable solution

The majority of patients with lung cancer are diagnosed with clinically advanced disease. Many of these patients have a short life expectancy and are treated with palliative aim. Because of uncontrolled local or recurrent disease, patients may have significant symptoms such as: cough, dyspnea, hemoptysis, obstructive pneumonia, or atelectasis. Brachytherapy is one of the most efficient methods in overcoming difficulties in breathing that is caused by endobronchial obstruction in palliative treatment of bronchus cancer. Efforts to relieve this obstructive process are worthwhile, because patients may experience improved quality of their life (QoL). Brachytherapy plays a limited but specific role in definitive treatment with curative intent in selected cases of early endobronchial disease as well as in the postoperative treatment of small residual peribronchial disease. Depending on the location of the lesion, in some cases brachytherapy is a treatment of choice. This option is fast, inexpensive, and easy to perform on an outpatient basis. Clinical indications, different techniques, results, and complications are presented in this work.

Metastatic malignant melanoma: computed tomography-guided 125I seed implantation treatment

The aim of this study is to evaluate the therapeutic efficacy of computed tomography (CT)-guided interstitial iodine-125 (I) seed implantation for metastatic malignant melanoma treatment. From November 2008 to May 2011, 24 patients with metastatic malignant melanoma who had undergone surgery for excision of primary lesions and repeated chemotherapy underwent CT-guided I seed implantation. Their clinical situations, biochemical indicators, MRIs, and CTs were observed. The follow-up time ranged from 5 to 24 months (mean 19.6 months). The local control rates of metastatic malignant melanoma after surgery excision for primary lesion after 2, 6, 12, and 24 months were 86.8, 78.6, 62.1, and 55.0%, respectively. One patient died of liver failure 5 months after brachytherapy and another died of a metastatic brain tumor 8 months after brachytherapy. Two patients died of lung dysfunction from pulmonary metastases 15 months after brachytherapy. All other patients survived throughout the follow-up period. The 2-year survival rate was 83.3%. During the procedure, one patient presented with minimal bleeding from the applicator route and another presented with pneumothorax with 20% pulmonary compression, which improved after intraprocedure suctioning. Four patients had low-grade fever on day 3. Three showed mild decreases in their white blood cell counts. CT-guided I seed implantation is a safe, feasible, and promising approach to the treatment of patients with metastatic malignant melanoma after surgery excision for primary lesions and repeated chemotherapy, but large-scale randomized clinical trials should be conducted before the technique can be used routinely.

Safety and efficacy of radiation dose delivered via iodine-125 brachytherapy mesh implantation for deep cavity sarcomas

BACKGROUND

Radiation delivered as brachytherapy (BRT) via catheters placed during extremity soft tissue sarcoma (STS) resection results in acceptable local control rates; however, there are limitations in deep cavities. (125)I seeds embedded in mesh provide a flexible BRT platform that may be contoured to irregular deep cavities surfaces, but the risks and benefits are unknown.

METHODS

Patients with thoracic, abdominal, pelvic, retroperitoneal, and deep truncal STS undergoing resection and implantation of permanent (125)I mesh BRT at our institution were reviewed. Local recurrence rates within the tumor bed covered by mesh (in field) and postoperative complications were analyzed.

RESULTS

Between 2000 and 2010, a total of 46 patients were treated for primary (n = 8, 17 %) or recurrent (n = 38, 83 %) deep cavity STS (median follow-up 34.8 months); 74 % received external-beam radiotherapy for this or a prior presentation. In-field recurrences were observed in 9 patients (19.5 %). Crude cumulative incidences of in-field, regional, and distant recurrences at 5 years were 26.3, 54.2, and 54.1 %, respectively. 5-year overall survival rate was 47.2 %; median survival was 44.0 months. Twenty-two patients (48 %) experienced complications, half of whom (24 %) developed grade III/IV complications requiring percutaneous intervention (n = 6) or reoperation (n = 5) at a median of 35.5 days. There were no postoperative deaths.

CONCLUSIONS

To our knowledge, this is the first study to report safety and efficacy for permanent (125)I mesh BRT implantation after resection of deep cavity STS. Local in-field recurrence rates were relatively low in this high-risk population. However, 24 % developed complications requiring intervention. (125)I mesh BRT appears effective, but it should be used with caution.

Comparison of Iodine-125 seeds implantation and afterloading radiotherapy in murine models of human cervical cancer

OBJECTIVE

To compare the efficacies and side effects of Iodine-125 (125I) seeds implantation with afterloading radiotherapy on tumor xenografts derived from Hela cells.

METHODS

Mice bearing Hela cells were randomly divided into three groups: two therapeutic groups receiving four 125I seeds implantation and afterloading therapy, respectively, and the one control group without any intervention. Comparisons were evaluated in aspects of curative efficacies (tumor volume, tumor inhibition rate and metastasis) and side effects (body weight, ovarian endocrine functions, skin lesion surrounding the tumor).

RESULTS

The xenografts tumor volume of therapeutic groups were significantly smaller than that of controls(p < 0.05),both of the 125I seeds implantation and afterloading therapy showed excellent tumor inhibition rate. Furthermore, 125I seeds implantation had milder side effects on skin, weight loss, ovarian endocrine functions.

CONCLUSIONS

(125)I seed implantation may be an alternative minimally invasive therapy for cervical cancer.

Computed tomography fluoroscopy-guided percutaneous 125I seed implantation for safe, effective and real-time monitoring radiotherapy of inoperable stage T1-3N0M0 non-small-cell lung cancer

The management of inoperable lung cancer remains a challenge. It has been proven that computed tomography (CT)-guided iodine-125 (¹²⁵I) seed implantation is a safe and efficient method for treating lung cancer. Computed tomographic fluoroscopy (CTF) is superior to traditional CT for percutaneous management of lung lesions, due to the real-time guidance and accurate localization of the lesions. The aim of the present prospective study was to evaluate the feasibility, safety and efficacy of CTF-guided percutaneous permanent implantation of ¹²⁵I seeds for the treatment of selected patients with inoperable stage T1-3N0M0 non-small-cell lung cancer (NSCLC). A total of 24 patients with resectable but inoperable stage T1-3N0 NSCLC, with a total of 28 lesions, underwent CTF-guided percutaneous implantation of radioactive ¹²⁵I seeds. A prescription dose of 100-120 Gy was delivered to each lesion. The complications and local tumor control rates were documented. Survival was estimated using the Kaplan-Meier method. All the patients successfully completed the procedure, with a mean procedure duration of 45.7 min (range, 30-75 min). No severe complications occurred. Small asymptomatic pneumothorax with lung volume compression of <10% and minor hemorrhage along the needle track without hemoptysis occurred immediately after the procedure in 3 (12.5%) and 4 (16.7%) of the 24 patients, respectively. At a median follow-up of 31.5 months (range, 8-46 months), the local control rate (LCR) of the lesions was 78.6% (22/28). The 1-, 2- and 3-year overall survival rate was 95.8, 78 and 55%, respectively. In conclusion, CTF is the favourable imaging guidance method for the percutaneous implantation of ¹²⁵I seeds. CTF-guided brachytherapy with implantation of ¹²⁵I seeds is a safe, feasible and effective modality for the treatment of inoperable early-stage NSCLC and may be considered an alternative option in selected patients with medically inoperable NSCLC.

Computed tomographic-guided iodine-125 interstitial implants for malignant thoracic tumors

PURPOSE

To evaluate the feasibility and efficacy of percutaneous interstitial brachytherapy using iodine-125 ((125)I) radioactive seeds under computed tomographic (CT) guidance for malignant thoracic tumors.

MATERIALS AND METHODS

Forty-one patients (34 males, 7 females; 18-90 years; mean, 63.7 years) with 77 lesions (3 in the mediastinum, 7 in the chest wall, 67 in the lung) underwent percutaneous interstitial implantation of (125)I radioactive seeds under CT guidance. A treatment planning system (TPS) was employed to calculate the number and distribution of seeds preoperatively. An 18-G needle was inserted into the lesions under CT guidance and send the seeds according to TPS. Two patients with mediastinal lesions undergoing seed implantation received an artificial pneumothorax. One patient with lung carcinoma adjacent to the anterior mediastinum underwent seed implantation through the sternum. Follow-up CT was done every 2 months postoperatively.

RESULTS

The procedure was successful in all patients. No major procedure-associated death occurred. The mean duration of follow-up was 19.4 ± 1.3 months (3-49 months). A complete response (CR) was seen in 49 lesions (63.6%), partial response (PR) in 9 lesions (11.7%), stable disease (SD) in 12 lesions (12.8%), and progressive disease (PD) in 7 lesions (7.4%). The overall response rate (CR+PR) was 75.3%; the local control rate (CR+PR+SD) was 90.9%. The 1-, 2- and 3-year progression-free rates for local tumors were 91%, 88% and 88%, respectively. The 1-, 2- and 3-year survival rates were 87%, 74% and 68%, respectively.

CONCLUSION

Implantation of CT-guided (125)I seeds is feasible and effective for patients with malignant thoracic tumors.

American Brachytherapy Society (ABS) consensus statement for sarcoma brachytherapy

PURPOSE

To present recommendations for the use of brachytherapy (BT) in patients with soft tissue sarcoma (STS).

METHODS

A group of practitioners with expertise and experience in sarcoma BT formulated recommendations for BT in STS based on clinical experience and literature review.

RESULTS

The indications for adjuvant BT are discussed. There is no consensus on the use of BT alone or in combination with external beam radiation therapy (EBRT), but factors that influence the selection of this modality include tumor grade and size, prior surgeries, and tumor recurrence. Low-dose-rate, high-dose-rate, and pulsed-dose-rate radiation are all acceptable BT modalities to use for STS. Recommendations are made for patient selection, techniques, dose rates, and dosages. Outcome data and toxicity data are reviewed.

CONCLUSIONS

BT is a useful component of the treatment of STS. The advantages of BT are the targeted dose distribution, low integral dose, and short treatment times. Ultimately the clinician should select the modality or combination of modalities that are most familiar to the treatment team and suitable to the patient.