Side effects of CT-guided implantation of 125I seeds for recurrent malignant tumors of the head and neck assisted by 3D printing non co-planar template

Multimodal image-guided surgical robot versus 3D-printed template for brachytherapy of malignant tumours in the skull base and deep facial region: a clinical comparative study

This study compared a multimodal image-guided robot and three-dimensionally (3D) printed templates for implanting iodine-125 (I125) radioactive seeds in patients with malignant tumours in the skull base and deep facial region. Seventeen patients who underwent I125 radioactive seed implantation between December 2018 and December 2019 were included. The operation time, intraoperative blood loss, and accuracy of seed implantation were compared between the multimodal image-guided robot-assisted implantation (experimental) group (n = 7) and 3D-printed template-assisted implantation (control) group (n = 10). In total, 291 seeds were implanted in the experimental group and 436 in the control group; the mean error of seed implantation accuracy was 1.95 ± 0.13 mm and 1.90 ± 0.08 mm, respectively (P = 0.309). The preparation time was 26.13 ± 5.28 min in the experimental group and 0 min in the control group, while the average operation time was 34.44 ± 6.39 min versus 43.70 ± 6.06 min, respectively. The intraoperative blood loss was 4.96 ± 1.76 ml (experimental) versus 8.97 ± 2.99 ml (control) (P = 0.123). Multimodal image-guided robot-assisted I125 radioactive seed implantation met the clinical requirements for treating malignant tumours in the skull base and deep facial regions.

Efficacy of radioactive 125I seed implantation in treating inoperable or refused operation head and neck cancers

PURPOSE

This study aims to observe the curative effect of radioactive 125I seed implantation in treating inoperable or refused operation head and neck cancer.

METHODS

Data from 132 patients with head and neck malignant tumors underwent computed tomography-guided radioactive 125I seed implantation from April 2004 to August 2020 were analyzed retrospectively. The Kaplan-Meier method was used to calculate the local control and survival rates. The logarithmic rank test and the Cox proportional risk model were used for univariate and multivariate analysis, respectively.

RESULTS

A total of 132 patients were enrolled. All tumors were confirmed to be malignant through pathological analysis. Herein, we revealed that the seeds were implanted at the primary tumor site (23 cases, representing 17.4%), recurrent (9 cases, representing 6.8%), or metastatic lymph nodes (100 cases, representing 75.8%). Three months after the operation, 96 patients were evaluated as effective, whereas 36 patients were considered ineffective. The median local control time was 16 months; the local rates at 6, 12, 18, and 24 months were observed to be 75%, 47%, 35%, and 22%, respectively. The study reports a median survival period (OS) of 15 months. Additionally, the survival rates at 6, 12, 18, and 24 months were 61%, 42%, 31%, and 27%, respectively. Regarding side effects, skin or mucosal toxicity occurred in 14 patients. Grade I skin toxicity occurred in seven cases (5.3%), grade IV skin toxicity in one case (0.8%), grade I mucosal ulcer in four cases (3.0%), and grade I dry mouth in four cases (3.0%). The multivariate analysis showed that short-term efficacy and tumor site were independent prognostic factors (P < 0.001, 0.006, respectively). Additionally, the multivariate analysis showed that the independent OS influencing factors included D90, the longest tumor diameter, and short-term efficacy (P = 0.017, 0.001, <0.001).

CONCLUSION

Radioactive 125I seed implantation is a safe and effective salvage therapy for patients with inoperable or refused operation head and neck cancer.

Automatic planning for head and neck seed implant brachytherapy based on deep convolutional neural network dose engine

BACKGROUND

Seed implant brachytherapy (SIBT) is an effective treatment modality for head and neck (H&N) cancers; however, current clinical planning requires manual setting of needle paths and utilizes inaccurate dose calculation algorithms.

PURPOSE

This study aims to develop an accurate and efficient deep convolutional neural network dose engine (DCNN-DE) and an automatic SIBT planning method for H&N SIBT.

METHODS

A cohort of 25 H&N patients who received SIBT was utilized to develop and validate the methods. The DCNN-DE was developed based on 3D-unet model. It takes single seed dose distribution from a modified TG-43 method, the CT image and a novel inter-seed shadow map (ISSM) as inputs, and predicts the dose map of accuracy close to the one from Monte Carlo simulations (MCS). The ISSM was proposed to better handle inter-seed attenuation. The accuracy and efficacy of the DCNN-DE were validated by comparing with other methods taking MCS dose as reference. For SIBT planning, a novel strategy inspired by clinical practice was proposed to automatically generate parallel or non-parallel potential needle paths that avoid puncturing bone and critical organs. A heuristic-based optimization method was developed to optimize the seed positions to meet clinical prescription requirements. The proposed planning method was validated by re-planning the 25 cases and comparing with clinical plans.

RESULTS

The absolute percentage error in the TG-43 calculation for CTV V100 and D90 was reduced from 5.4% and 13.2% to 0.4% and 1.1% with DCNN-DE, an accuracy improvement of 93% and 92%, respectively. The proposed planning method could automatically obtain a plan in 2.5 ± 1.5 min. The generated plans were judged clinically acceptable with dose distribution comparable with those of the clinical plans.

CONCLUSIONS

The proposed method can generate clinically acceptable plans quickly with high accuracy in dose evaluation, and thus has a high potential for clinical use in SIBT.

Prognostic value of pretreatment FDG PET-CT for short-term efficacy of radioactive iodine-125 seed implantation in patients with NSCLC

PURPOSE

To analyze the short-term clinical response of radioactive iodine-125 seed implantation (I125-SI) in patients of non-small-cell lung cancer (NSCLC) and explore possible correlations of various metabolic parameters of pretreatment FDG PET-CT with the short-term efficacy of this treatment modality.

METHODS AND MATERIALS

The present study is a retrospective analysis of treatment records of 46 NSCLC patients who were treated with I125-SI for lung tumors in Tianjin First Central Hospital from January 2016 to December 2018. The correlation among parameters D90, gender, pathological pattern, age, maximum tumor diameter, Metabolic Tumor Volume (MTV), SUVmax, SUVpeak, SUVmean, Total Lesion Glycolysis (TLG), High metabolic tumor cell ratio (HMR) and Carcinoembryonic antigen(CEA)with short-term efficacy of I125-SI was analyzed by two independent-sample t-test, Mann-Whitney U test or Chi-squared test and binary logistic regression.

RESULTS

After uneventful completion of treatment, patients were followed up at regular intervals. At the first month followup, none of cases showed complete response (CR), while 4 cases showed partial response (PR). After 3 months, there were 2 cases of CR, and 25 cases of PR; after 6 months, there were 5 cases of CR, and 27 cases of PR. D90 (p= 0.028, OR:1.075, 95% CI:1.008-1.147), MTV (p= 0.026, OR: 0.918, 95% CI: 0.851-0.990), HMR (p= 0.020, OR: 0.003, 95% CI: 0-0.407) were independent predictors for the short-term efficacy. The predictive accuracy of MTV was medium (AUC = 0.781; cutoff value = 44.58). However, the predictive accuracies of D90 and HMR were low, with the values of AUC being 0.650 for both the parameters, and their cutoff values being 127.8 Gy and 0.27 respectively.

CONCLUSIONS

I125-SI is an effective therapy with few complications in NSCLC patients. Small MTV, high D90 and low HRM were found to be linked with better local control at 6 months postimplantation.

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.

3D printing in brachytherapy: A systematic review of gynecological applications

PURPOSE

To provide a systematic review of the applications of 3D printing in gynecological brachytherapy.

METHODS

Peer-reviewed articles relating to additive manufacturing (3D printing) from the 34 million plus biomedical citations in National Center for Biotechnology Information (NCBI/PubMed), and 53 million records in Web of Science (Clarivate) were queried for 3D printing applications. The results were narrowed sequentially to, (1) all literature in 3D printing with final publications prior to July 2022 (in English, and excluding books, proceedings, and reviews), and then to applications in, (2) radiotherapy, (3) brachytherapy, (4) gynecological brachytherapy. Brachytherapy applications were reviewed and grouped by disease site, with gynecological applications additionally grouped by study type, methodology, delivery modality, and device type.

RESULTS

From 47,541 3D printing citations, 96 publications met the inclusion criteria for brachytherapy, with gynecological clinical applications compromising the highest percentage (32%), followed by skin and surface (19%), and head and neck (9%). The distribution of delivery modalities was 58% for HDR (Ir-192), 35% for LDR (I-125), and 7% for other modalities. In gynecological brachytherapy, studies included design of patient specific applicators and templates, novel applicator designs, applicator additions, quality assurance and dosimetry devices, anthropomorphic gynecological applicators, and in-human clinical trials. Plots of year-to-year growth demonstrate a rapid nonlinear trend since 2014 due to the improving accessibility of low-cost 3D printers. Based on these publications, considerations for clinical use are provided.

CONCLUSIONS

3D printing has emerged as an important clinical technology enabling customized applicator and template designs, representing a major advancement in the methodology for implantation and delivery in gynecological brachytherapy.

Safety and efficacy of CT-guided radioactive iodine-125 seed implantation as a salvage treatment for recurrent head and neck cancer after two or more courses of radiotherapy

BACKGROUND

In the past, patients with recurrent head and neck cancer (rHNC) who had previously received a high dose of radiation and were unable to undergo surgery were mainly treated with palliative chemotherapy due to the high incidence of side effects from re-irradiation. With the development of radiotherapy technology, re-irradiation of recurrent lesions by radioactive iodine-125 seed implantation (RISI) has been proposed as a feasible therapeutic approach. This study aimed to investigate the safety and efficacy of computed tomography (CT)-guided RISI in the treatment of rHNC after two or more courses of radiotherapy, and to analyze the prognostic factors.

METHODS

Data of 33 patients with rHNC who received CT-guided RISI after two or more courses of radiotherapy were collected and statistically analyzed. The median cumulative dose of the previous radiotherapy was 110 Gy. Short-term efficacy was assessed by Response Evaluation Criteria in Solid Tumors (version 1.1) criteria, while adverse events were evaluated by Common Terminology Criteria for Adverse Events (version 5.0) criteria.

RESULTS

The median gross tumor volume (GTV) was 29.5 cc, and the postoperative median dose to 90% of target volume (D90) was 136.8 Gy. For adverse reactions, enhanced pain was found in 3 (9.1%) patients, followed by grade 1 to 2 acute skin reactions in 3 (9.1%) patients, grade 2 to 3 late skin reactions in 2 (6.1%) patients, grade 1 to 2 early mucosal reactions in 4 (12.1%) patients, and mandibular osteonecrosis in 1 (3.0%) patient. Regarding the treatment efficacy, the 1- and 2-year local control (LC) rates were 47.8% and 36.4% (median LC time, 10 months), and the 1- and 2-year overall survival (OS) rates were 41.3% and 32.2% (median OS time, 8 months). The absence of adverse events was associated with better LC.

CONCLUSIONS

CT-guided RISI, as a salvage therapy, demonstrated acceptable safety and efficacy in the treatment of rHNC after two or more courses of radiotherapy.

TRIAL REGISTRATION

This study was registered at Chinese Clinical Trial Register database (Registration No. ChiCTR2200063261 ) in September 2, 2022.

Dose prediction of organs at risk in patients with cervical cancer receiving brachytherapy using needle insertion based on a neural network method

OBJECTIVE

A neural network method was employed to establish a dose prediction model for organs at risk (OAR) in patients with cervical cancer receiving brachytherapy using needle insertion.

METHODS

A total of 218 CT-based needle-insertion brachytherapy fraction plans for loco-regionally advanced cervical cancer treatment were analyzed in 59 patients. The sub-organ of OAR was automatically generated by self-written MATLAB, and the volume of the sub-organ was read. Correlations between D2cm³ of each OAR and volume of each sub-organ-as well as high-risk clinical target volume for bladder, rectum, and sigmoid colon-were analyzed. We then established a neural network predictive model of D2cm³ of OAR using the matrix laboratory neural net. Of these plans, 70% were selected as the training set, 15% as the validation set, and 15% as the test set. The regression R value and mean squared error were subsequently used to evaluate the predictive model.

RESULTS

The D2cm³/D90 of each OAR was related to volume of each respective sub-organ. The R values for bladder, rectum, and sigmoid colon in the training set for the predictive model were 0.80513, 0.93421, and 0.95978, respectively. The ∆D2cm³/D90 for bladder, rectum, and sigmoid colon in all sets was 0.052 ± 0.044, 0.040 ± 0.032, and 0.041 ± 0.037, respectively. The MSE for bladder, rectum, and sigmoid colon in the training set for the predictive model was 4.779 × 10^-3, 1.967 × 10^-3 and 1.574 × 10^-3, respectively.

CONCLUSION

The neural network method based on a dose-prediction model of OAR in brachytherapy using needle insertion was simple and reliable. In addition, it only addressed volumes of sub-organs to predict the dose of OAR, which we believe is worthy of further promotion and application.

Dosimetric evaluation of iodine-125 brachytherapy for brain tumors using MR guidance combined with a three-dimensional non co-planar template

PURPOSE

To investigate the consistency between preoperative and postoperative dosimetry when ¹²⁵I brachytherapy for brain tumors is performed with magnetic resonance (MR) guidance and a three-dimensional non co-planar template (3DNPT).

METHODS AND MATERIALS

Thirty patients with brain tumors (metastatic or gliomas) underwent radioactive ¹²⁵I seed implantation. A preoperative treatment plan was determined with MR imaging, and the operation was done under 3DNPT assistance and MR guidance. The dosimetry was verified postoperatively based on postoperative CT-MR fusion images. Postoperative dosimetric parameters and implant quality indices were defined and compared with those in the preoperative treatment plan. Furthermore, a comparison of preoperative and postoperative doses to normal brain tissues and organs at risk was also performed.

RESULTS

All mean postoperative dosimetries were calculated. Target coverage parameters D90, D100, %CTV100, %CTV150, and %CTV200 were 143.6 cGy, 76.6 cGy, 88.2%, 63.1%, and 41.4%, respectively. The values of implant quality indices CI, EI, and HI were 0.75, 0.14, and 0.28, respectively. No significant differences between most preoperative and postoperative dosimetric parameters were found (p > 0.05). The differences were also insignificant for organs at risk. Postoperative %CTV150 and %CTV200 were higher than the preoperative, whereas postoperative HI was significantly lower than in the treatment plan.

CONCLUSIONS

Magnetic resonance guidance combined with 3DNPT allows accurate positioning and direction in ¹²⁵I brachytherapy for brain tumors. However, seed distribution and dose homogeneity require further improvement.

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.

A comparative study of dosimetric parameters of 3D-printed non-coplanar template-assisted CT-guided iodine-125 seed implantation brachytherapy in patients with inguinal lymph node metastatic carcinomas

PURPOSE

To compare the pre-plan and post-plan dosimetric parameter differences of 3D-printed non-coplanar templates (3D-PNCT)-assisted computed tomography (CT)-guided iodine-125 (125I) radioactive seed implantation brachytherapy (RISI) in patients with inguinal lymph node metastasis (ILNM).

MATERIAL AND METHODS

This was a retrospective study of 15 patients with ILNM carcinomas treated with 3D-PNCT-assisted CT-guided RISI between May, 2015 and April, 2018. All patients underwent prior external beam radiotherapy (EBRT) or surgery. Dosimetric parameters included D90, D100 (dose delivered to 90% and 100% of the volume, respectively), V100, V150, V200 (percentage of target volume receiving 100%, 150%, and 200% of the prescribed dose, respectively). Quality parameters included conformal index (CI), external index (EI), and homogeneity index (HI). Paired t-test and Bland-Altman analysis were applied to compared pre-plan and post-plan parameters.

RESULTS

The median gross tumor volume (GTV) in the pre-plan was 8.7 ml (range, 0.8-185.1 ml). There were statistically significant differences in V100, V150, CI, and EI (p < 0.05). Bland-Altman analysis indicated that accidental error of RISI was small. In 1 of the 15 cases, D90 and D100 exceeded the prescribed therapeutic accuracy. In 1 of the 15 cases, V150, EI, and GTV were outside the specified accuracy range (95% confidence interval).

CONCLUSIONS

3D-PNCT-assisted CT-guided RISI is a safe, accurate, and feasible choice in ILNM treatment. The procedure of RISI has significantly improved. The pre-plan can be accurately executed by 3D-PNCT-assisted CT-guided RISI.

The efficacy and safety of 125I brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer

Objective

To evaluate the safety and effectiveness of Iodine-125 (¹²⁵I) brachytherapy combined with pre-operative transarterial chemoembolization in patients with locally advanced head and neck cancer.

Methods

In this study, a total of thirty-seven individuals suffering from locally advanced head and neck cancer were involved. The patients were subjected to transarterial chemoembolization as well as implantation of ¹²⁵I seeds under the guidance of CT and ultrasonography. Follow-up was conducted for 36 months to study the following parameters: the local control rate, survival rate, and clinical complications.

Results

In total, thirty-six patients at the end of three months showed an objective response rate of 69.8% and disease control rate of 93.0%, respectively. The 1, 2, and 3-year cumulative overall survival rate was 89.2%, 73.0%, and 45.9%, respectively. The adverse events of the treatment included infection (n=1, Grade III), radiation brachial plexus injury (n=1, Grade III), leukopenia (n=1, Grade III), cerebrovascular embolism (n=1, Grade IV).

Conclusion

The combination of ¹²⁵I brachytherapy and pre-operative transarterial chemoembolization was safe and effective in patients with locally advanced head and neck cancer.

3D printing in palliative medicine: systematic review

Background

Three-dimensional printing (3DP) enables the production of highly customised, cost-efficient devices in a relatively short time, which can be particularly valuable to clinicians treating patients with palliative care intent who are in need of timely and effective solutions in the management of their patients’ specific needs, including the relief of distressing symptoms.

Method

Four online databases were searched for articles published by December 2020 that described studies using 3DP in palliative care. The fields of application, and the relevant clinical and technological data were extracted and analysed.

Results

Thirty studies were reviewed, describing 36 medical devices, including anatomical models, endoluminal stents, navigation guides, obturators, epitheses, endoprostheses and others. Two-thirds of the studies were published after the year 2017. The main reason for using 3DP was the difficulty of producing customised devices with traditional methods. Eleven papers described proof-of-concept studies that did not involve human testing. For those devices that were tested on patients, favourable clinical outcomes were reported in general, and treatment with the use of 3DP was deemed superior to conventional clinical approaches. The most commonly employed 3DP technologies were fused filament fabrication with acrylonitrile butadiene styrene and stereolithography or material jetting with various types of photopolymer resin.

Conclusion

Recently, there has been a considerable increase in the application of 3DP to produce medical devices and bespoke solutions in the delivery of treatments with palliative care intent. 3DP was found successful in overcoming difficulties with conventional approaches and in treating medical conditions requiring highly customised solutions.

Emerging technologies in brachytherapy

Brachytherapy is a mature treatment modality. The literature is abundant in terms of review articles and comprehensive books on the latest established as well as evolving clinical practices. The intent of this article is to part ways and look beyond the current state-of-the-art and review emerging technologies that are noteworthy and perhaps may drive the future innovations in the field. There are plenty of candidate topics that deserve a deeper look, of course, but with practical limits in this communicative platform, we explore four topics that perhaps is worthwhile to review in detail at this time. First, intensity modulated brachytherapy (IMBT) is reviewed. The IMBT takes advantage ofanisotropicradiation profile generated through intelligent high-density shielding designs incorporated onto sources and applicators such to achieve high quality plans. Second, emerging applications of 3D printing (i.e. additive manufacturing) in brachytherapy are reviewed. With the advent of 3D printing, interest in this technology in brachytherapy has been immense and translation swift due to their potential to tailor applicators and treatments customizable to each individual patient. This is followed by, in third, innovations in treatment planning concerning catheter placement and dwell times where new modelling approaches, solution algorithms, and technological advances are reviewed. And, fourth and lastly, applications of a new machine learning technique, called deep learning, which has the potential to improve and automate all aspects of brachytherapy workflow, are reviewed. We do not expect that all ideas and innovations reviewed in this article will ultimately reach clinic but, nonetheless, this review provides a decent glimpse of what is to come. It would be exciting to monitor as IMBT, 3D printing, novel optimization algorithms, and deep learning technologies evolve over time and translate into pilot testing and sensibly phased clinical trials, and ultimately make a difference for cancer patients. Today's fancy is tomorrow's reality. The future is bright for brachytherapy.

PD-1 Inhibitor Maintenance Therapy Combined Iodine-125 Seed Implantation Successfully Salvage Recurrent Cervical Cancer after CCRT: A Case Report

Cervical cancer is the fourth most common cancer in females worldwide. Patients with stage III and IV cervical cancer based on the Federation of Gynecology and Obstetrics (FIGO) classification have higher recurrence rates. Because of organs at risk (OAR) protection and the low indication rate of salvage surgery, the choice of treatment is always challenging. Systemic chemotherapy is palliative and can be performed in conjunction with surgery or radiotherapy; however, it has no significant benefit to survival. Brachytherapy and stereotactic body radiotherapy (SBRT) are characterized by extremely high radiation doses applied to tumor cells while sparing the normal tissues. Several studies have investigated the efficacy of these technologies in recurrent cervical cancer and showed promising results. The immune checkpoint inhibitors approach was also investigated and showed promising results too. Herein, we report a case of a patient with cervical cancer that recurred five months after adjuvant chemotherapy and concurrent chemoradiotherapy. The disease prognosis after interstitial implantation brachytherapy (IIB) was determined. Then, the patient underwent radioactive 125I-seed implantation combined with PD-1 inhibitor treatment. The patient exhibited a partial response after seed implantation, and up to now, the duration of this partial response was 24 months.

Clinical Outcome of CT-Guided Stereotactic Ablative Brachytherapy for Unresectable Early Non-Small Cell Lung Cancer: A Retrospective, Multicenter Study

Objective

To analyze the efficacy and safety of low dose rate stereotactic ablative brachytherapy (L-SABT) for treatment of unresectable early-stage non-small cell lung cancer (NSCLC).

Methods

Data of patients with early-stage NSCLC who received CT-guided L-SABT (radioactive I-125 seeds implantation) at eight different centers from December 2010 to August 2020 were retrospectively analyzed. Treatment efficacy and complications were evaluated.

Results

A total of 99 patients were included in this study. Median follow-up duration was 46.3 months (6.1-119.3 months). The 1-year, 3-year, and 5-year local control rates were 89.1%, 77.5%, and 75.7%, respectively. The 1-year, 3-year, and 5-year overall survival rates were 96.7%, 70.1%, and 54.4%, respectively. Treatment failure occurred in 38.4% of patients. Local/regional recurrence, distant metastasis, and recurrence combined with metastasis accounted for 15.1%, 12.1%, and 11.1%, respectively. Pneumothorax occurred in 47 patients (47.5%) with 19 cases (19.2%) needing closed drainage. The only radiation-related adverse reaction was two cases of grade 2 radiation pneumonia. KPS 80-100, T1, the lesion was located in the left lobe, GTV D90 ≥150 Gy and the distance between the lesion and chest wall was < 1 cm, were associated with better local control (all P < 0.05); on multivariate analysis KPS, GTV D90, and the distance between the lesion and chest wall were independent prognostic factors for local control (all P < 0.05). KPS 80-100, T1, GTV D90 ≥150 Gy, and the distance between the lesion and chest wall was < 1 cm were also associated with better survival (all P < 0.05); on multivariate analysis KPS, T stage, and GTV D90 were independent prognostic factors for survival (all P < 0.05). The incidence of pneumothorax in patients with lesions <1 cm and ≥1cm from the chest wall was 33.3% and 56.7%, respectively, and the differences were statistically significant (P = 0.026).

Conclusion

L-SABT showed acceptable efficacy in the treatment of unresectable early-stage NSCLC. But the incidence of pneumothorax is high. For patients with T1 stage and lesions <1 cm from the chest wall, it may have better efficacy. Prescription dose greater than 150 Gy may bring better results.

Long-Term Outcomes of Personalized Stereotactic Ablative Brachytherapy for Recurrent Head and Neck Adenoid Cystic Carcinoma after Surgery or External Beam Radiotherapy: A 9-Year Study

The management of recurrent head and neck adenoid cystic carcinoma (HNACC) remains a problematic challenge. This study aims to evaluate the long-term outcomes of personalized stereotactic ablative brachytherapy (SABT) as a salvage treatment for recurrent HNACC after surgery or external beam radiotherapy (EBRT). 21 patients with recurrent HNACC after surgery or EBRT successfully underwent iodine-125 (I-125) seed SABT from May 2011 to November 2019. The objective response rate (ORR), disease control rate (DCR), local control time (LCT), overall survival (OS), symptomatic relief and adverse events (AEs) were analyzed. Following SABT, the ORR and DCR were 85.7% and 100%, respectively. The 3-, and 5-year LCT rates were 68.8% and 55.1%, respectively, and the 3- and 5-year OS rates were 85.9% and 66.2%, respectively. Furthermore, univariate analyses showed that higher D90 (>137.1 Gy) was a strong positive prognostic factor of LCT (p < 0.05). The pain disappeared in one patient 3 months after SABT and partial pain improvement was observed in nine patients 1 to 6 months after SABT. Additionally, dyspnea was relieved in one patient with the tumor involving the trachea. The major AEs were mild intraoperative hemorrhage and skin/mucosal toxicities which were generally graded ≤2 and well-tolerated. Personalized SABT was an effective and safe alternative option for recurrent HNACC after the previous failure of surgery or EBRT. The parameter of D90 may influence the local control.

Efficacy and Safety Aiming at the Combined-Modality Therapy of External Beam Radiotherapy (40Gy) and Iodine-125 Seed Implantation for Locally Advanced NSCLC in the Elderly

Purpose

To evaluate the efficacy and safety of combined-modality therapy for elderly patients with locally advanced non-small-cell lung cancer (NSCLC) invading the chest wall.

Patients and Methods

We retrospectively enrolled 21 elderly patients (aged ≥60 years) with locally advanced NSCLC invading the chest wall. For external beam radiotherapy (EBRT) of the primary tumor, 40Gy was applied and supplemented with iodine-125 seed implantation while 60Gy was applied to the lymph nodes of the mediastinum. Follow-up was conducted every 3 months postoperatively. The related analytic parameters were change in tumor size, the objective response rate (ORR), the disease control rate (DCR), the degree of pain relief, the improvement of physical status, and toxicity.

Results

The combined-modality therapy significantly inhibited local growth of the tumor (from 7.84±1.20 to 4.69±1.90 cm) (P <0.0001), with 71.4% ORR and 90.5% DCR at 1 year. The cancer-related pain was significantly relieved (P <0.05) and physical status was significantly improved (P <0.05). No procedure-associated death or grade > 2 irradiation-related adverse effects were reported in this study.

Conclusion

The combined-modality therapy of EBRT with 40Gy and permanent iodine-125 seed implantation is an efficacious and safe treatment option for elderly patients with locally advanced NSCLC invading the chest wall.

Long-Term Safety and Efficacy of CT-Guided I125 Radioactive Seed Implantation as a Salvage Therapy for Recurrent Head and Neck Squamous Carcinoma: A Multicenter Retrospective Study

Purpose

To investigate the safety and efficacy of CT-guided I¹²⁵ radioactive seed implantation (RSI) as a salvage therapy for recurrent head and neck squamous carcinoma (rHNSC) after external beam radiotherapy (EBRT) or surgery.

Materials and Methods

This is a multicenter retrospective study of 113 patients (83 males; median age 57 years) with rHNSC who underwent CT-guided I¹²⁵ RSI between February 2003 and December 2017. Of the included patients, 107 patients previously received EBRT and 65 patients received surgery and all were ineligible or rejected for salvage surgery and/or repeat EBRT.

Results

During a median follow-up duration of 20 months (range, 3-152 months), 87 patients died. The 1-, 2-, 3-, and 5-year local control rate were 57.4%, 41.8%, 29.3%, and 15.2%, respectively. The median time to progression was 15 months [95% confidence interval (CI), 6.1-23.9 months]. The median overall survival (OS) was 20 months (95% CI, 12.4-27.6 months). The 1-, 2-, 3-, and 5-year OS rate were 63.6%, 44.6%, 29.9%, and 21.7%, respectively. Univariate and multivariate analyses revealed that KPS score and postoperative D90 were significantly associated with patients’ OS. The complications were mainly grade I/II skin and mucosal reactions: 18 cases (15.9%) of grade I/II and eight cases (7.0%) of grade III radiation dermatitis, and 14 cases (12.4%) of grade I/II and three cases (2.7%) grade III mucosal reactions. No grade IV or severer complications were found.

Conclusion

CT-guided I¹²⁵ RSI may be safe as a salvage therapy for rHNSC after EBRT/surgery, yielding promising efficacy compared with historical data. KPS score and postoperative D90 may be significantly associated with OS.

Development of A 3D-Printed Navigational Template for Establishing Rabbit VX2 Lung Cancer Model

BACKGROUND

The CT-guided percutaneous puncture-inoculation for establishing the rabbit VX2 lung cancer model (LCM) is time-consuming, requires repeated CT scans, and has a high complication rate. Therefore, this study aimed to develop a navigational template using 3D technology to provide an alternative method for establishing the model with improved success and complication rates.

MATERIALS AND METHODS

Ideal pressure was determined using chest CT data from 15 anesthetized rabbits fitted with sphygmomanometer cuff around their chests. Subsequently, a preliminary 3D template with a square window and cross-sign to facilitate precise installation was designed. Using another 20 rabbits fixed with the preliminary template, an ideal common puncture point and parameter were determined, a navigational tunnel was set up on the template surface, and the final puncture navigational template was printed out. Eight-four rabbits (42/group) were assigned to the experimental (template-guided puncture) and control (traditional puncutre) groups and underwent VX2 tumor-fragment inoculation to validate the template. Differences in various parameters between two groups were analyzed.

RESULTS

The ideal pressure was 30 mmHg. All rabbits were inoculated successfully and the template adequately fit the rabbit chest. The experimental group displayed significantly better operation time (198.93±36.64 vs 735.14±91.19 seconds); number of CT scans (0 vs 7.19±1.64); pneumothorax (11.9% vs 35.7%), chest seeding (16.7% vs 35.7%), and mid-lung field tumor-bearing (88.1% vs 59.5%) rates than the control group (all, P <0.05). The groups did not differ in rib injury, tumor volume or survival time (all, P > 0.05).

CONCLUSIONS

We successfully developed a puncture navigational template, providing an alternative method for establishing the rabbit VX2 LCM.

The Accuracy of Individualized 3D-Printing Template-Assisted I125 Radioactive Seed Implantation for Recurrent/Metastatic Head and Neck Cancer

Purpose

To evaluate the accuracy of individualized 3D-printing template-assisted I¹²⁵ radioactive seed implantation (3D-PT assisted I¹²⁵ RSI) for recurrent/metastatic head and neck cancer.

Materials and Methods

From February 2017 to January 2020, clinical data of 41 patients (mean age, 58.5 ± 16.1 years; 28 males) with recurrent (48.8%)/metastatic (51.2%) head and neck cancer underwent individualized 3D-PT assisted I¹²⁵ RSI under CT guidance in a single institute were retrospectively reviewed. Total 430 seed needles [mean, 10.5 (range 3–17) per patient] were inserted.

Results

All seed needles were inserted manually in a single attempt with the technical success rate of 100% without major perioperative complications. The mean needle’s entrance deviation was 0.090 cm (95% Confidence Interval, 0.081–0.098). The mean intraoperative depth and angle of the needle were consistent with that of planned (6.23 ± 0.24 vs. 6.21 ± 0.24 cm, p = 0.903; 83.14 ± 3.64 vs. 83.09 ± 3.66 degrees, p = 0.985, respectively). The mean deviation between the needle’s planned and intraoperative depth and angle was 0.168 ± 0.024 cm and 1.56 ± 0.14 degrees, respectively. The postoperative dosimetry parameters, including D90, D100, V100, V150, V200, conformity index, external index, and homogeneity index, were all well-coordinated with planned dosimetry without significant difference (p = 0.515, 0.662, 0.958, 0.865, 0.872, 0.278, 0.456, and 0.989, respectively).

Conclusions

Within the limitation of this study, individualized 3D-PT assisted I¹²⁵ RSI may be accurate in obtaining favorable postoperative dosimetry for patients with recurrent/metastatic head and neck cancer.

Clinical Trial Registration

[website], identifier [registration number].

Accuracy and dosimetric parameters comparison of 3D-printed non-coplanar template-assisted computed tomography-guided iodine-125 seed ablative brachytherapy in pelvic lateral recurrence of gynecological carcinomas

PURPOSE

To investigate the accuracy of needle distribution and dosimetric parameter differences of 3D-printing non-coplanar template (3D-PNCT)-assisted computed tomography (CT)-guided iodine-125 seed ablative brachytherapy (125I-SAB) in gynecological cancer patients with non-central pelvic recurrence between pre-operative plan and post-operative plan.

MATERIAL AND METHODS

Thirty-eight patients with forty-one non-central pelvic recurrent gynecological carcinomas after radiotherapy were enrolled in this study. All patients received 3D-PNCT-assisted CT-guided 125I-SAB from January 2016 to January 2019. The position, angle, and depth of seed needles were measured in both pre-operative plan and intra-operative real-time plan in brachytherapy treatment planning system (B-TPS). Dosimetric parameters of D90, D100, V100, V150, and V200 as well as quality parameters of conformal index (CI), external index (EI), and homogeneity index (HI) were compared between pre-operative plan and post-operative plan. Peri-operation complications and radiation-related toxicity were assessed.

RESULTS

Median follow-up time was 12 months (range, 5-34 months). Prescribed dose was 100-170 Gy (median, 120 Gy). Radioactivity of 125I seed was 0.4-0.7 mCi (median, 0.55 mCi). Mean depth deviation for 499 needles was 0.8 ±1.0 cm. Mean angular deviation was 2.2 ±2.1 degrees. Mean tip distance deviation of needles was 0.4 ±0.3 cm. There were significant differences between pre-operative and post-operative plans in CI (p = 0.001) and EI (p = 0.005). No significant differences were shown in D90, D100, V100, V150, V200, and HI between pre-operative and post-operative plans. Only few patients suffered from ≤ grade 2 toxicities.

CONCLUSIONS

3D-PNCT-assisted CT-guided 125I-SAB is safe and feasible for non-central pelvic recurrence of gynecological cancer. All complications are tolerable and mild.

Safety and efficacy of 3D-printed templates assisted CT-guided radioactive iodine-125 seed implantation for the treatment of recurrent cervical carcinoma after external beam radiotherapy

Objective

To investigate the safety and efficacy of 3-dimensional (3D) printing non-coplanar templates (PNCT) assisted computer tomography (CT) guided radioactive ¹²⁵I seed implantation (RISI) for the treatment of recurrent cervical carcinoma (RCC) after external beam radiotherapy (EBRT).

Methods

A total of 103 patients with inoperable post-EBRT RCC were included in this retrospective study. A total of 111 lesions received RISI. Eight lesions were at the pelvic center, 75 lesions were at the pelvic lateral, and 28 lesions were extra-pelvic metastasis. The median prescription dose was 120 Gy. The primary end points were adverse events and local control (LC), and the secondary end points were overall survival (OS) and progression-free survival.

Results

Grade 2 adverse events of acute nausea, diarrhea, and pollakiuria occurred in 1, 2, and 1 patient, respectively. One patient suffered from grade 3 acute proctitis. Late toxicity was observed in 2 patients with rectovaginal fistula. No grade 5 toxicity occurred. The 3-year LC and OS rates were 75.1% and 20.8%, respectively. The median OS was 17 months. The multivariate analysis showed that the minimum dose received by the “hottest” 90% of the gross tumor volume (D₉₀) ≥130 Gy, squamous cell carcinoma, hemoglobin ≥80 g/L and good short-term efficacy (complete response or partial response) were independent predictors of LC and OS (all p<0.05).

Conclusions

3D-PNCT assisted CT-guided RISI is a safe, effective, and minimally invasive modality for RCC. The hemoglobin level, pathological type, dose distribution and short-term efficacy are considered as independent factors for clinical outcomes.

Artificial intelligence (AI) and interventional radiotherapy (brachytherapy): state of art and future perspectives

Purpose

Artificial intelligence (AI) plays a central role in building decision supporting systems (DSS), and its application in healthcare is rapidly increasing. The aim of this study was to define the role of AI in healthcare, with main focus on radiation oncology (RO) and interventional radiotherapy (IRT, brachytherapy).

Artificial intelligence in interventional radiation therapy

AI in RO has a large impact in providing clinical decision support, data mining and advanced imaging analysis, automating repetitive tasks, optimizing time, and modelling patients and physicians' behaviors in heterogeneous contexts. Implementing AI and automation in RO and IRT can successfully facilitate all the steps of treatment workflow, such as patient consultation, target volume delineation, treatment planning, and treatment delivery.

Conclusions

AI may contribute to improve clinical outcomes through the application of predictive models and DSS optimization. This approach could lead to reducing time-consuming repetitive tasks, healthcare costs, and improving treatment quality assurance and patient's assistance in IRT.

Efficacy and Safety of Iodine-125 Brachytherapy in the Treatment of Recurrent or Metastatic Head and Neck Squamous Cell Carcinoma

Background

Recurrent or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) is a difficult challenge for physicians, especially when patients have been treated with external beam radiotherapy. The purpose of this study was to assess the clinical efficacy and safety of computed tomography (CT)-guided iodine-125 brachytherapy as a palliative treatment for R/M HNSCC.

Methods

From May 2011 to July 2018, we enrolled 87 patients with R/M HNSCC who had previously received external beam radiotherapy. Among these patients, 43 successfully underwent CT-guided iodine-125 brachytherapy and chemotherapy (group A); 44 patients who only received chemotherapy (group B) were matched with patients in group A. Patients' pain score, Eastern Cooperative Oncology Group (ECOG) score, tumor compression symptoms, and side effects of iodine-125 implantation were recorded. Clinical follow-up was performed to assess progression-free survival (PFS) and overall survival (OS).

Results

Both groups of patients completed the treatment and were followed up for 9-66 months, with a median follow-up time of 44 months. The OS was 51 months (95% CI: 42.93-59.06 months) versus 28 months (95% CI: 23.79-32.21 months) (p < 0.05), the PFS was 10 months (95% CI: 6.15-13.84 months) versus 6 months (95% CI: 4.40-7.59 months) (p < 0.05) in groups A and B, respectively. The RR in group A was 25/43 (58.14%) versus 15/44 (34.10%) in group B (p < 0.05). Compared with group B, patients in group A had lower pain scores, better physical performance, and better improvement of compression symptoms. No serious treatment-related complications were observed in either group of patients.

Conclusion

Compared with chemotherapy alone, iodine-125 seed implantation combined with chemotherapy was a more effective and safer strategy for R/M HNSCC.

Three-dimensional printing in radiation oncology: A systematic review of the literature

Purpose/objectives

Three‐dimensional (3D) printing is recognized as an effective clinical and educational tool in procedurally intensive specialties. However, it has a nascent role in radiation oncology. The goal of this investigation is to clarify the extent to which 3D printing applications are currently being used in radiation oncology through a systematic review of the literature.

Materials/methods

A search protocol was defined according to preferred reporting items for systematic reviews and meta‐analyses (PRISMA) guidelines. Included articles were evaluated using parameters of interest including: year and country of publication, experimental design, sample size for clinical studies, radiation oncology topic, reported outcomes, and implementation barriers or safety concerns.

Results

One hundred and three publications from 2012 to 2019 met inclusion criteria. The most commonly described 3D printing applications included quality assurance phantoms (26%), brachytherapy applicators (20%), bolus (17%), preclinical animal irradiation (10%), compensators (7%), and immobilization devices (5%). Most studies were preclinical feasibility studies (63%), with few clinical investigations such as case reports or series (13%) or cohort studies (11%). The most common applications evaluated within clinical settings included brachytherapy applicators (44%) and bolus (28%). Sample sizes for clinical investigations were small (median 10, range 1–42). A minority of articles described basic or translational research (11%) and workflow or cost evaluation studies (3%). The number of articles increased over time (P < 0.0001). While outcomes were heterogeneous, most studies reported successful implementation of accurate and cost‐effective 3D printing methods.

Conclusions

Three‐dimensional printing is rapidly growing in radiation oncology and has been implemented effectively in a diverse array of applications. Although the number of 3D printing publications has steadily risen, the majority of current reports are preclinical in nature and the few clinical studies that do exist report on small sample sizes. Further dissemination of ongoing investigations describing the clinical application of developed 3D printing technologies in larger cohorts is warranted.

Dosimetry, efficacy, and safety of three-dimensional printing noncoplanar template-assisted and CT-guided 125I seed implantation for recurrent retroperitoneal lymphatic metastasis after external beam radiotherapy

OBJECTIVES

To evaluate the dosimetry, efficacy, and safety of radioactive ¹²⁵I seed implantation (RISI) assisted by three-dimensional printing noncoplanar template (3D-PNCT) and CT for recurrent retroperitoneal lymphatic metastasis (RRLM) after previous external beam radiotherapy.

METHODS AND MATERIALS

From June 2016 to August 2018, 32 patients with RRLM successfully underwent 3D-PNCT-assisted and CT-guided RISI. The dosimetry, pain relief rate, performance improvement rate, overall response rate, disease control rate, local control time (LCT), overall survival (OS), and safety profiles were evaluated.

RESULTS

Dosimetric results showed that the D90, D100, V100, V150, V200, and homogeneity index were consistent in preoperation and postoperation (p > 0.05), except for the external index and conformal index (p = 0.048, p = 0.034). After RISI, 81.3% of the patients achieved pain relief, and 71.9% achieved an improvement of performance. The overall response rate and disease control rate were 85.3% and 94.1%, respectively. The LCT rates reached 66.2% and 43.2% in 1 year and two years, respectively, with a median LCT of 15.8 months. The OS rates were 74.1% and 28.1% in 1 year and two year, respectively, with a median OS reaching 17.6 months. Univariate analysis showed that when D90 > 130 Gy or D100 > 63 Gy or tumor size ≤49.8 cm³, LCT was extended significantly, but not for OS. Except for two patients developing Grade 1 retroperitoneal hematomas, no other severe adverse events were observed.

CONCLUSIONS

3D-PNCT and CT guidance provide excellent accuracy for RISI, which can be an effective and safe alternative for RRLM after external beam radiotherapy. Radiation dose and tumor size seem to significantly influence the local control.

Significance of 125I radioactive seed implantation on growth differentiation factor and programmed death receptor-1 during treatment of oral cancer

BACKGROUND

Oral cancer (OC) is the most common malignant tumor in the oral cavity, and is mainly seen in middle-aged and elderly men. At present, OC is mainly treated clinically by surgery or combined with radiotherapy and chemotherapy; but recently, more and more studies have shown that the stress trauma caused by surgery and the side effects of radiotherapy and chemotherapy seriously affect the prognosis of patients.

AIM

To determine the significance of ¹²⁵I radioactive seed implantation on growth differentiation factor 11 (GDF11) and programmed death receptor-1 (PD-1) during treatment of OC.

METHODS

A total of 184 OC patients admitted to The Second Affiliated Hospital of Jiamusi University from May 2015 to May 2017 were selected as the research subjects for prospective analysis. Of these patients, 89 who received ¹²⁵I radioactive seed implantation therapy were regarded as the research group (RG) and 95 patients who received surgical treatment were regarded as the control group (CG). The clinical efficacy, incidence of adverse reactions and changes in GDF11 and PD-1 before treatment (T0), 2 wk after treatment (T1), 4 wk after treatment (T2) and 6 wk after treatment (T3) were compared between the two groups.

RESULTS

The efficacy and recurrence rate in the RG were better than those in the CG (P < 0.05), while the incidence of adverse reactions and survival rate were not different. There was no difference in GDF11 and PD-1 between the two groups at T0 and T1, but these factors were lower in the RG than in the CG at T2 and T3 (P < 0.05). Using receiver operating characteristic (ROC) curve analysis, GDF11 and PD-1 had good predictive value for efficacy and recurrence (P < 0.001).

CONCLUSION

¹²⁵I radioactive seed implantation has clinical efficacy and can reduce the recurrence rate in patients with OC. This therapy has marked potential in clinical application. The detection of GDF11 and PD-1 in patients during treatment showed good predictive value for treatment efficacy and recurrence in OC patients, and may be potential targets for future OC treatment.

Efficacy and safety of CT-guided 125I seed implantation as a salvage treatment for locally recurrent head and neck soft tissue sarcoma after surgery and external beam radiotherapy: A 12-year study at a single institution

OBJECTIVES

The objective of this study was to evaluate the efficacy and safety of CT-guided radioactive ¹²⁵I seed implantation as a salvage treatment for locally recurrent head and neck soft tissue sarcoma (HNSTS) after surgery and external beam radiotherapy.

METHODS AND MATERIALS

From December 2006 to February 2018, 25 patients with locally recurrent HNSTS after surgery and external beam radiotherapy were enrolled. All the patients successfully underwent CT-guided ¹²⁵I seed implantation. The primary end points included the objective response rate (ORR) and local progression-free survival (LPFS). The secondary end points were survival (OS) and safety profiles.

RESULTS

After ¹²⁵I seed implantation, the ORR was 76.0%. The 1-, 3-, and 5-year LPFS rates were 65.6%, 34.4%, and 22.9%, respectively, with the median LPFS of 16.0 months. The 1-, 3-, and 5-year OS rates were 70.8%, 46.6%, and 34.0%, respectively, with the median OS of 28.0 months. Furthermore, univariate analyses showed that the recurrent T stage and histological grade were prognostic factors of LPFS, whereas only the histological grade was a predictor of OS. The major adverse events were skin/mucosal toxicities, which were generally of lower grade (≤Grade 2) and were well tolerated.

CONCLUSIONS

Radioactive ¹²⁵I seed implantation could be an effective and safe alternative treatment for locally recurrent HNSTS after failure of surgery and radiotherapy. Recurrent T stage and histological grade were the main factors influencing the efficacy.

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.

Radiation-related Adverse Effects of CT-guided Implantation of 125I Seeds for Thoracic Recurrent and/or Metastatic Malignancy

During radioactive Iodine-125 seed implantation (RISI), Iodine-125 radionuclide is implanted directly into a lesion and kills tumor cells by steadily emitting radiation. In our study, we analyzed the adverse effects of RISI for thoracic malignancy, and investigated the safety, dosage, and adverse effects of RISI for these cases. Between June 2007 and January 2018, 77 patients with thoracic recurrent and/or metastatic tumors who underwent CT-guided RISI were enrolled. Radiation-related adverse effects were analyzed, including pneumonia, esophagitis, hemorrhage, fistula, skin injury, heart injury, and spinal cord injury. We used the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 to evaluate adverse effects and analyzed the relationship between adverse effects and dosimetric parameters of organs at risk (OAR), including D0.1cc, D2cc, Dmean, and V20. The results of the study were as follows: The median follow-up period was 11 months. The median postoperative dose (D90) was 122 Gy (45.7–241.8 Gy). Three patients (3.9%) showed radiation pneumonitis of grade ≥2. Two patients (2.6%) showed radiation-induced esophagitis of grade ≥2. One patient (1.3%) showed an esophageal fistula. Two patients (2.6%) had a tracheal fistula. Five patients (6.5%) had radiation-related skin reactions. One patient (1.3%) reported chest wall pain, while three (3.9%) showed hemoptysis. No patients showed radiation myelitis or cardiotoxicity. The mean D2cc of organs at risk were 165.7 Gy (lung), 10.61 Gy (esophagus), 10.25 Gy (trachea), 18.07 Gy (blood vessel), 12.64 Gy (heart), 14.77 Gy (spinal cord), 17.47 Gy (skin). Dosimetric parameters, such as D0.1cc, D2cc and Dmean, were higher in patients with toxic reactions (above the upper limit of 95% confidence interval among the overall data). Chi-square test showed that skin D0.1cc > 600 Gy, D2cc > 500 Gy, and Dmean >90 Gy were associated with grade ≥2 radiation dermatitis (p < 0.05), but no clear dose-toxicity correlation was found in other OARs. So, we concluded that the overall incidence of toxicity and adverse effects from RISI for the treatment of thoracic tumors is low. The dose-toxicity characteristics have not been fully defined. Doses within the upper limit of the 95% confidence interval may be considered safe. This was a retrospective analysis, and follow-up period was minimal, indicating possible limitations of this study.

Efficacy and dosimetry analysis of image-guided radioactive ¹²⁵I seed implantation as salvage treatment for pelvic recurrent cervical cancer after external beam radiotherapy

Objective

To investigate the efficacy of image-guided radioactive ¹²⁵I seed (IGRIS) implantation for pelvic recurrent cervical cancer (PRCC) after external beam radiotherapy (EBRT), and analyze the influence of clinical and dosimetric factors on efficacy.

Methods

From July 2005 to October 2015, 36 patients with PRCC received IGRIS. We evaluated local progression-free survival (LPFS) and overall survival (OS).

Results

The median follow up was 11.5 months. The 1- and 2-year LPFS rate was 34.9% and 20%, respectively. The multivariate analysis indicated recurrence site (central or pelvic wall) (hazard ratio [HR]=0.294; 95% confidence interval [CI]=0.121–0.718), lesion volume (HR=2.898; 95% CI=1.139–7.372), D₉₀ (HR=0.332; 95% CI=0.130–0.850) were the independent factors affecting LPFS. The 1- and 2-year OS rate was 52.0% and 19.6%, respectively. The multivariate analysis suggested pathological type (HR=9.713; 95% CI=2.136–44.176) and recurrence site (HR=0.358; 95% CI=0.136–0.940) were the independent factors affecting OS. The dosimetric parameters of 33 patients mainly included D₉₀ (128.5±47.4 Gy), D₁₀₀ (50.4±23.7 Gy) and V₁₀₀ (86.7%±12.9%). When D₉₀ ≥105 Gy or D₁₀₀ ≥55 Gy or V₁₀₀ ≥91%, LPFS was extended significantly, but no significant difference for OS. The 79.2% of 24 patients with local pain were suffering from pain downgraded after radioactive ¹²⁵I seed implantation.

Conclusion

IGRIS implantation could be a safe and effective salvage treatment for PRCC after EBRT, which could markedly release the pain. Recurrence site, tumor volume and dose were the main factors affected efficacy. Compared with central recurrence, it was more suitable for patients with pelvic wall recurrent cervical cancer after EBRT.