Computerized tomography-guided percutaneous high-dose-rate interstitial brachytherapy for malignant lung lesions

Effect of 3-Dimensional Interstitial High-Dose-Rate Brachytherapy With Regional Metastatic Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non-Small Cell Lung Cancer: 5-Year Follow-up of a Phase 2 Clinical Trial

PURPOSE

We aimed to reveal the 5-year clinical outcomes of 3-dimensional (3D) interstitial high-dose-rate (HDR) brachytherapy with regional metastatic lymph node intensity modulated radiation therapy (IMRT) for locally advanced peripheral non-small cell lung cancer (NSCLC), which has been shown to have low toxicity and improved 2-year survival rates in patients with this disease.

METHODS AND MATERIALS

In this phase 2, single-arm, open-label clinical trial, 83 patients with locally advanced peripheral NSCLC were enrolled (median follow-up [range], 53.7 [4.3-120.4] months). All eligible patients received 3D interstitial HDR brachytherapy with regional metastatic lymph node IMRT. The primary endpoint was overall survival (OS). Secondary endpoints were local recurrence-free survival, regional recurrence-free survival, progression-free survival, distant metastasis-free survival, toxicities, and quality of life.

RESULTS

The final analysis included 75 patients (19 [25.3%] females, 56 [74.7%] males; median [range] age, 64 [44-80] years; stage IIIA, 34 [45.3%]; stage IIIB, 41 [54.7%]). At the latest follow-up, 32 (42.7%) patients had survived. The median OS was 38.0 months (5-year OS, 44.5%; 95% confidence interval [CI], 33.8%-58.6%). Local recurrence-free survival, recurrence-free survival, and distant metastasis-free survival at 5 years were 79.2% (95% CI, 68.5%-91.5%), 73.6% (95% CI, 61.5%-88.1%), and 50.3% (95% CI, 38.3%-66.1%), respectively. The dominant failure pattern was distant disease, corresponding to 40% (30 of 75) of patients and 65.2% (30 of 46) of all failures. Two (2.7%) patients developed grade 1 acute pneumonitis. Grade 2 and 3 acute esophagitis occurred in 11 (14.7%) and 4 (5.3%) patients, respectively. No late radiation-related grade ≥2 late adverse events were observed.

CONCLUSIONS

3D interstitial HDR brachytherapy with regional metastatic lymph node IMRT for locally advanced peripheral NSCLC shows significant OS and has a low toxicity rate. Additional evaluation in a phase 3 trial is recommended to substantiate these findings.

Percutaneous high-dose-rate interstitial brachytherapy for non-resectable, chemo resistant malignant lesion of lung and liver

PURPOSE

To explore the feasibility and efficacy of interstitial brachytherapy application for nonresectable and chemo-resistant malignant liver and lung lesions.

MATERIALS AND METHODS

Percutaneous high-dose-rate interstitial brachytherapy (HDR ISBT) was applied in nine lesions of seven middle-aged patients with advanced carcinoma (five patients with liver lesion and two patients with lung lesion). All patients were surgically ineligible. All patients had already received systemic chemotherapy. Under computed tomography (CT) guidance (for lung lesion) or ultrasonography (USG) guidance (for liver lesion), a single stainless steel brachytherapy needle was inserted percutaneously in patients with lesion size ≤4 centimeter (cm) and multiple needles were inserted in patients of lesion size >4cm. A single dose of 15 Gy to 20 Gy with HDR ISBT was prescribed at the periphery of the lesion. The needles were removed just after treatment. Patients were kept under observation for 24 h after treatment.

RESULTS

The median size of the lesion was 6.5 cm. In all the cases of liver lesion, more than 75% shrinkage of tumor volume in follow-up at 6 mo was observed. It was more than 50% for lung lesion. None of the patients had developed significant complications as on the median follow up period of 15 mo (ranges 3-27 mo).

CONCLUSIONS

Percutaneous CT-guided high-dose-rate interstitial brachytherapy is a minimally invasive, safe, and feasible treatment option with minimal complication for inoperable, chemo resistant, advanced cancers with encouraging treatment outcomes.

Stereotactic Ablative Brachytherapy: Recent Advances in Optimization of Radiobiological Cancer Therapy

Brachytherapy (BT), a type of focal anti-cancer radiotherapy, delivers a highly focused radiation dose to localized tumors, sparing surrounding normal tissues. Recent technological advances have helped to increase the accuracy of BT and, thus, improve BT-based cancer treatment. Stereotactic ablative brachytherapy (SABT) was designed to improve the ablative effect of radiation, which was achieved via improved image guidance, and calculation of ablative dose, shorter treatment duration, and better organ preservation. Recently collected data characterized SABT as having the potential to cure various early-stage cancers. The method provides higher tumor control rate levels that were previously achievable only by surgical resection. Notably, SABT is suitable for application with unresectable malignancies. However, the pathological assessment of SABT irradiated tumors is limited due to difficulties in specimen acquisition. Prostate, lung, liver, and gynecological cancers are the most commonly reported SABT-treated malignancies. This study will give an overview of SABT, focusing on the advances in SABT optimization, and provide insights on the future benefits of the combined application of SABT with cancer immunotherapies.

Outcomes with multi-disciplinary management of central lung tumors with CT-guided percutaneous high dose rate brachyablation

BACKGROUND

Centrally located lung tumors present treatment challenges given their proximity to mediastinal structures including the central airway, esophagus, major vessels, and heart. Therapeutic options can be limited for medically inoperable patients, particularly if they have received previous thoracic radiotherapy. High dose rate (HDR) brachyablation was developed to improve the therapeutic ratio for patients with central lung tumors. The purpose of this study is to report initial safety and efficacy outcomes with this treatment for central lung malignancies.

METHODS

From September 2015 to August 2019, a total of 25 patients with 37 pulmonary tumors were treated with percutaneous HDR brachyablation. Treatment was delivered by a multi-disciplinary team of interventional radiologists, pulmonologists, and radiation oncologists. Twenty-three patients received a median dose of 21.5 Gy (range 15-27.5) in a single fraction, whereas two patients received median dose of 24.75 Gy (range 24-25.5) over 2-3 fractions. Tumor local control (LC) was evaluated by Response Evaluation Criteria in Solid Tumors v1.1. Treatment-related toxicities were graded by Common Terminology Criteria for Adverse Events v5.0, with adverse events less than 90 days defined as acute, and those occurring later were defined as late. LC, progression-free survival (PFS), and overall survival (OS) rates were estimated by the Kaplan-Meier method.

RESULTS

Of 37 treated tumors, 88% were metastatic. Tumor location was central and ultra-central in 24.3% and 54.1%, respectively. Average tumor volume was 11.6 cm³ (SD 12.4, range 0.57-62.8). Median follow-up was 19 months (range 3-48). Two-year LC, PFS, and OS were 96.2%, 29.7%, and 65.5%, respectively. Thirteen of 39 (33.3%) catheter implantation procedures were associated with trace minor pneumothorax requiring no intervention, 1 (2.5%) procedure with minor radiographic pulmonary hemorrhage, and 4 (10.3%) with major pneumothorax requiring chest tube insertions. All procedural complications resolved within 24 h from treatment. Acute grade 1-2 toxicity was identified in 4 patients, whereas none developed late toxicity beyond 90 days of follow-up.

CONCLUSION

Percutaneous HDR brachyablation is a safe and promising treatment option for centrally located primary and metastatic lung tumors. Future comparisons with stereotactic body radiotherapy and other ablative techniques are warranted to expand multi-disciplinary management options.

Computed tomography guided interstitial percutaneous high-dose-rate brachytherapy in the management of lung malignancies. A review of the literature

A growing number of patients with lung cancer are not amenable to surgery due to their age or comorbidities. For this reason, local ablative techniques have gained increasing interest recently in the management of inoperable lung tumors. High-dose-rate percutaneous interstitial brachytherapy, performed under CT-guidance, is a newer form of brachytherapy and is a highly conformal radiotherapy technique. The aim of this study was to describe this method and review the existing literature. Eight articles comprising 234 patients reported toxicity and clinical outcome. The follow-up ranged from 6 to 28 months. Diverse fractionation schemes were reported, with 20 Gy in a single fraction being the most frequently utilized. Toxicity was limited; major pneumothoraces occurred after only 8% of the interventions. Local control rates at one year ranged between 37% and 91%. In conclusion, high-dose-rate percutaneous interstitial brachytherapy is a safe, fast, and efficient treatment option for inoperable lung tumors.

Monte Carlo simulation of the effect of magnetic fields on brachytherapy dose distributions in lung tissue material

The aim of this work was to use TOPAS Monte Carlo simulations to model the effect of magnetic fields on dose distributions in brachytherapy lung treatments, under ideal and clinical conditions. Idealistic studies were modeled consisting of either a monoenergetic electron source of 432 keV, or a polyenergetic electron source using the spectrum of secondary electrons produced by ¹⁹²Ir gamma-ray irradiation. The electron source was positioned in the center of a homogeneous, lung tissue phantom (ρ = 0.26 g/cm³). Conversely, the clinical study was simulated using the VariSource VS2000 ¹⁹²Ir source in a patient with a lung tumor. Three contoured volumes were considered: the tumor, the planning tumor volume (PTV), and the lung. In all studies, dose distributions were calculated in the presence or absence of a constant magnetic field of 3T. Also, TG-43 parameters were calculated for the VariSource and compared with published data from EGS-brachy (EGSnrc) and PENELOPE. The magnetic field affected the dose distributions in the idealistic studies. For the monoenergetic and poly-energetic studies, the radial distance of the 10% iso-dose line was reduced in the presence of the magnetic field by 64.9% and 24.6%, respectively. For the clinical study, the magnetic field caused differences of 10% on average in the patient dose distributions. Nevertheless, differences in dose-volume histograms were below 2%. Finally, for TG-43 parameters, the dose-rate constant from TOPAS differed by 0.09% ± 0.33% and 0.18% ± 0.33% with respect to EGS-brachy and PENELOPE, respectively. The geometry and anisotropy functions differed within 1.2% ± 1.1%, and within 0.0% ± 0.3%, respectively. The Lorentz forces inside a 3T magnetic resonance machine during ¹⁹²Ir brachytherapy treatment of the lung are not large enough to affect the tumor dose distributions significantly, as expected. Nevertheless, large local differences were found in the lung tissue. Applications of this effect are therefore limited by the fact that meaningful differences appeared only in regions containing air, which is not abundant inside the human.

Combination of Brachytherapy with Iodine-125 Seeds and Systemic Chemotherapy versus Systemic Chemotherapy Alone for Synchronous Extracranial Oligometastatic Non-Small Cell Lung Cancer

Background

A proportion of patients with synchronous oligometastatic non-small cell lung cancer (NSCLC) have poor survival, and currently no standard treatment is available, which poses a great challenge to physicians. This study aimed to assess and compare the efficacy and safety of the combination of brachytherapy with iodine-125 seeds and systemic chemotherapy versus systemic chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Materials and Methods

After a systematic retrospective review of the case database between 1st Mar 2014 and 30th Mar 2018, data were obtained on 69 NSCLC patients with extracranial oligometastatic NSCLC. Among them, 32 patients received brachytherapy with iodine-125 seeds combined with systemic chemotherapy (group A), and the remaining 37 patients received chemotherapy alone (group B). The primary endpoint was overall survival (OS), and the secondary endpoints included progression-free survival (PFS), objective response rate (ORR), and complications.

Results

The demographic and clinical characteristics were not significantly different between the groups (all p>0.05). The overall 3-month ORR was significantly higher in group A (65.6% vs 37.8%, p=0.030) than in group B. With a median follow-up time of 23 months, the PFS and OS were 11.6 (95% CI: 7.0–16.2) months vs 6.3 (95% CI: 3.4–9.2) months (p=0.036) and 17.6 (95% CI: 13.9–21.3) months vs 11.2 (95% CI: 7.7–14.7) months (p=0.042) in groups A and B, respectively. Furthermore, in Cox regression analysis, local brachytherapy was an independent prognostic factor for both PFS (HR=0.416, 95% CI: 0.246–0.702, p=0.001) and OS (HR=0.375, 95% CI: 0.216–0.653, p=0.001). Severe complications were not observed in either of the groups.

Conclusion

The combination of brachytherapy with iodine-125 seeds and systemic chemotherapy is superior to chemotherapy alone for synchronous extracranial oligometastatic NSCLC.

Hypofractionated 192Ir source stereotactic ablative brachytherapy with coplanar template assistance in the primary treatment of peripheral lung cancer

Purpose

In this study, we reported the safety and efficacy of hypofractionated ¹⁹²Ir source stereotactic ablative brachytherapy (SABT) with coplanar template assistance for peripheral lung cancer, and compared the dosimetric parameters between SABT and stereotactic body radiotherapy (SBRT).

Material and methods

Thirty-three peripheral lung cancer patients, with the gross lung tumor volume (GTVL) < 5 cm in diameter were enrolled in this study. We assessed the safety and efficacy of SABT, and compared the dosimetric parameters between SABT and SBRT.

Results

Chest computed tomography (CT) of post-SABT revealed mild pneumothorax in 2 of 33 patients. Complete response (CR) plus partial response (PR) rate for GTVL at 6-month was 100%. Local control (LC) rate for GTVL at 1-year was 96.9%. For organs at risk (OARs), D1000 cm³, and D1500 cm³ for lung in 1, 3, and 5 fractions were not statistically different between SABT and SBRT (all p > 0.05); the remaining dosimetric parameters were significantly lower in SABT than in SBRT (all p < 0.01).

Conclusions

SABT can provide safe and effective treatment, and warrant generalization for peripheral lung cancer.

Single fraction computed tomography-guided high-dose-rate brachytherapy or stereotactic body radiotherapy for primary and metastatic lung tumors?

PURPOSE

To provide a pilot dosimetric study of computed tomography (CT)-guided high-dose-rate (HDR) brachytherapy (BRT) and stereotactic body radiotherapy (SBRT) for primary and metastatic lung lesions.

MATERIAL AND METHODS

For nine lung primary and metastasis patients, 3D image-based BRT plan using a single virtual catheter was planned for 34 Gy in single fraction to the gross tumor volume (GTV) + 3 mm margin to account for tumor deformation. These plans were compared to margin-based (MB-) and robustness optimized (RO-) SBRT, assuming the same tumor deformation under real-time tumor tracking. Consistent dose calculation was ensured for both BRT and SBRT plans using the same class of collapsed cone convolution superposition algorithm. Plan quality metrics were compared by Friedman tests and Wilcoxon t-tests.

RESULTS AND CONCLUSIONS

Brachytherapy plans showed significant higher GTV mean dose compared to MB- and RO-SBRT (122.2 Gy vs. 50.4 and 44.7 Gy, p < 0.05), and better dose gradient index (R50) = 2.9 vs. 4.3 and 8.4 for MB- and RO-SBRT, respectively. Dose constraints per the RTOG 0915 protocol were achieved for all critical organs except chest wall in BRT. All other dose-volume histograms (DVH) metrics are comparable between BRT and SBRT. Treatment delivery time of BRT and SBRT plans significantly increased and decreased with increasing GTV size, respectively. SBRT using advanced MLC tracking technique and non-coplanar VMAT can achieve comparable dosimetric quality to HDR BRT. Whether or not, the significantly higher GTV dose can increase killing of radioresistant tumor cells and offset the effect of tumor reoxygenation in single fraction BRT, requires further clinical investigation.

131I-chTNT injection to relieve tracheal obstruction in advanced NSCLC patient

OBJECTIVE

To relieve large airway obstruction in a patient with advanced non-small cell lung cancer (NSCLC) by injecting the mouse-human chimeric monoclonal antibody radiolabeled with iodine 131 chimeric tumor necrotic treatment (131I-chTNT) and to study the irradiation absorption in the tumor and critical organs.

METHODS

A 50-year-old patient with NSCLC was treated with radioimmunotherapy. His airway was still obstructed in spite of intensive chemotherapy and radiotherapy.131I-chTNT was injected into the tumor at the right bronchus through a fiberscope. A131I scan was performed during treatment, and a computed tomography (CT) scan of the chest and fiberscope were performed pre- and post-treatment.131I-chTNT distribution in tissues was followed for up to 4 weeks using gamma camera imaging.

RESULTS

The radiation material accumulated notably in the tumor, relieving the patient's symptoms by suppressing the tumor. Recanalization of the airway was achieved so that the patient was able to breathe easily and cough.

CONCLUSION

As a new type of radioimmunotherapy,131I-chTNT may be helpful in treatment of advanced lung cancer.

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.

Computed Tomography-Guided Interstitial High-Dose-Rate Brachytherapy in Combination With Regional Positive Lymph Node Intensity-Modulated Radiation Therapy in Locally Advanced Peripheral Non-Small Cell Lung Cancer: A Phase 1 Clinical Trial

PURPOSE

To assess the technical safety, adverse events, and efficacy of computed tomography (CT)-guided interstitial high-dose-rate (HDR) brachytherapy in combination with regional positive lymph node intensity modulated radiation therapy in patients with locally advanced peripheral non-small cell lung cancer (NSCLC).

METHODS AND MATERIALS

Twenty-six patients with histologically confirmed NSCLC were enrolled in a prospective, officially approved phase 1 trial. Primary tumors were treated with HDR brachytherapy. A single 30-Gy dose was delivered to the 90% isodose line of the gross lung tumor volume. A total dose of at least 70 Gy was administered to the 95% isodose line of the planning target volume of malignant lymph nodes using 6-MV X-rays. The patients received concurrent or sequential chemotherapy. We assessed treatment efficacy, adverse events, and radiation toxicity.

RESULTS

The median follow-up time was 28 months (range, 7-44 months). There were 3 cases of mild pneumothorax but no cases of hemothorax, dyspnea, or pyothorax after the procedure. Grade 3 or 4 acute hematologic toxicity was observed in 5 patients. During follow-up, mild fibrosis around the puncture point was observed on the CT scans of 2 patients, but both patients were asymptomatic. The overall response rates (complete and partial) for the primary mass and positive lymph nodes were 100% and 92.3%, respectively. The 1-year and 2-year overall survival (OS) rates were 90.9% and 67%, respectively, with a median OS of 22.5 months.

CONCLUSION

Our findings suggest that HDR brachytherapy is safe and feasible for peripheral locally advanced NSCLC, justifying a phase 2 clinical trial.

CT-guided conformal cryoablation for peripheral NSCLC: initial experience

PURPOSE

To study the feasibility of CT-guided and monitored percutaneous conformal cryoablation of Non-Small Cell Lung Cancer for patients who are not suitable for surgical resection.

MATERIALS AND METHOD

CT-guided percutaneous conformal cryoablation was performed on 46 patients with peripheral Non-Small Cell Lung Cancer. Patients with tumor sizes less than 3 cm in diameter were treated with double-needle clamping cryoablation, while the patients with 3-5 cm tumor sizes were treated with multiple-needle conformal cryoablation. CT was used to monitor the extent of cryoablation during the procedures. At month 1, 3, 6, 12, and 24 post-procedure, enhanced CT scans and/or PET-CT scans were performed to evaluate the impact of the therapy.

RESULTS

The average tumor CT values were 32±10 HU and -21±8 HU before and after cryoablation, respectively. The largest diameters of the lesions at month 1, 3, 6, 12, and 24 post-procedure were 2.63±0.56 cm, 1.93±0.51 cm, 1.55±0.39 cm, 1.43±0.40 cm, and 1.38±0.38 cm, respectively, in patients with tumor diameter less than 3 cm, and 3.63±0.39 cm, 2.98±0.31 cm, 2.62±0.32 cm, 2.54±0.34 cm, and 2.56±0.37 cm respectively in patients with the tumor diameters between 3 and 5 cm. At the 24th month, there were 36 cases of complete response (83.7%), 7 cases of partial response (16.3%), and no cases of stable disease or progressive disease. 3 patients died due to multiple metastases.

CONCLUSION

CT-guided percutaneous conformal cryoablation is a safe, effective, and minimally invasive therapeutic method for peripheral lung cancer.