CT-guided iodine-125 seed permanent implantation for recurrent head and neck cancers

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.

Current radiotherapy for recurrent head and neck cancer in the modern era: a state-of-the-art review

BACKGROUND

In the management of head and neck cancer (HNC) patients, local recurrence is a common cause of treatment failure. Only a few patients with recurrent HNC (rHNC) are eligible for salvage surgery and the majority of patients receive systemic therapy and radiotherapy. In recent years, with the development of irradiation technology, radiotherapy for rHNC patients has markedly attracted clinicians' attention and its therapeutic effects on patients with end-stage cancer are worthy of investigation as well.

METHODS

Several studies have investigated the role of radiotherapy in the treatment of rHNC patients. We reviewed retrospective reports and prospective trials published in recent decades that concentrated on the management of rHNC.

RESULTS

A growing body of evidence supported the application of irradiation to rHNC patients. According to the results of this review, current radiotherapy could achieve a better efficacy with a lower incidence of toxicity.

CONCLUSION

Radiotherapy is a promising treatment for rHNC patients.

Clinical application and accuracy assessment of imaging-based surgical navigation guided 125I interstitial brachytherapy in deep head and neck regions

Brachytherapy has the advantages of being minimally invasive and highly conformal, and it achieves good results in head and neck tumors. To precisely implant the radioactive seeds according to the preplan in deep head and neck regions, the surgical navigation is applied. This study aims to explore the clinical application and accuracy of imaging-based surgical navigation-guided 125I interstitial brachytherapy in terms of seed position. We included 41 patients with tumors in deep head and neck regions. The brachytherapy treatment plan was designed, and the preplanned data were transferred to the navigation system. Needle implantation and seed delivery were performed under surgical navigation system guidance with or without the combination of individual template. The treatment accuracy was evaluated by comparing seed cluster locations between the preoperative treatment plan and the postoperative treatment outcome. A total of 2879 seeds were delivered. The range, mean and median distances between the geometric centers of the preoperative seed point clusters and the postoperative seed point clusters were 0.8-10.5 mm, 4.5 ± 2.3 mm and 4.1 mm, respectively. The differences between preoperative and postoperative volumes of the minimum bounding box of seed point clusters were nonsignificant. In conclusion, the imaging-based surgical navigation system is a promising clinical tool to provide the preplanned data for interstitial brachytherapy intraoperatively, and it is feasible and accurate for the real-time guidance of needle implantation and seed delivery in deep head and neck regions.

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.

Chinese Expert Consensus on Iodine125 Seed Implantation for Recurrent Cervical Cancer in 2021

The treatment modality for recurrent cervical cancer (rCC) is limited, and the prognosis of these patients is poor. Seed implantation could be an important component of rCC management in the context of dose boost or salvage therapy after surgery or radiotherapy, which is characterized by a minimally invasive, high local dose, and rapidly does fall, sparing normal tissue. For patients with good performance status and lateral pelvic wall recurrence with an available puncture path, seed implantation was recommended, as well as for selected central pelvic recurrence and extra-pelvic recurrence. The combination of brachytherapy treatment planning system and CT guidance was needed, and three-dimensional printing templates could greatly improve the accuracy, efficiency, and quality of seed implantation to achieve a potential ablative effect and provide an efficient treatment for rCC. However, the recommendations of seed implantation were mainly based on retrospective articles and lack high-quality evidence, and multicenter prospective randomized studies are needed. In this consensus on iodine¹²⁵ seed implantation for rCC, indication selection, technical process and requirements, dosimetry criteria, radiation protection, combined systemic therapy, and outcomes of seed implantation for rCC are discussed.

Recommendations for intraoperative mesh brachytherapy: Report of AAPM Task Group No. 222

Mesh brachytherapy is a special type of a permanent brachytherapy implant: it uses low-energy radioactive seeds in an absorbable mesh that is sutured onto the tumor bed immediately after a surgical resection. This treatment offers low additional risk to the patient as the implant procedure is carried out as part of the tumor resection surgery. Mesh brachytherapy utilizes identification of the tumor bed through direct visual evaluation during surgery or medical imaging following surgery through radiographic imaging of radio-opaque markers within the sources located on the tumor bed. Thus, mesh brachytherapy is customizable for individual patients. Mesh brachytherapy is an intraoperative procedure involving mesh implantation and potentially real-time treatment planning while the patient is under general anesthesia. The procedure is multidisciplinary and requires the complex coordination of multiple medical specialties. The preimplant dosimetry calculation can be performed days beforehand or expediently in the operating room with the use of lookup tables. In this report, the guidelines of American Association of Physicists in Medicine (AAPM) are presented on the physics aspects of mesh brachytherapy. It describes the selection of radioactive sources, design and preparation of the mesh, preimplant treatment planning using a Task Group (TG) 43-based lookup table, and postimplant dosimetric evaluation using the TG-43 formalism or advanced algorithms. It introduces quality metrics for the mesh implant and presents an example of a risk analysis based on the AAPM TG-100 report. Recommendations include that the preimplant treatment plan be based upon the TG-43 dose calculation formalism with the point source approximation, and the postimplant dosimetric evaluation be performed by using either the TG-43 approach, or preferably the newer model-based algorithms (viz., TG-186 report) if available to account for effects of material heterogeneities. To comply with the written directive and regulations governing the medical use of radionuclides, this report recommends that the prescription and written directive be based upon the implanted source strength, not target-volume dose coverage. The dose delivered by mesh implants can vary and depends upon multiple factors, such as postsurgery recovery and distortions in the implant shape over time. For the sake of consistency necessary for outcome analysis, prescriptions based on the lookup table (with selection of the intended dose, depth, and treatment area) are recommended, but the use of more advanced techniques that can account for real situations, such as material heterogeneities, implant geometric perturbations, and changes in source orientations, is encouraged in the dosimetric evaluation. The clinical workflow, logistics, and precautions are also presented.

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].

The accuracy and safety of CT-guided iodine-125 seed implantation assisted by 3D non-coplanar template for retroperitoneal recurrent carcinoma

PURPOSE

To investigate the accuracy, dosimetric parameters, and safety of 3D-printing non-coplanar template (3D-PNCT)-assisted CT guidance for radioactive iodine-125 (125I) seed implantation brachytherapy (RSI-BT) for retroperitoneal recurrent carcinomas METHODS AND MATERIALS: We enrolled 15 patients with 17 retroperitoneal recurrent carcinomas after external beam radiotherapy (EBRT). All patients received CT-guided 125I RSI-BT assisted by 3D-PNCT successfully. We compared the original needle insertion position, angular, and the needle tip distance deviations of preoperative plan with that of intraoperative in brachytherapy treatment planning system (B-TPS). The dosimetric parameters of RSI-BT were evaluated on preoperative plan, intraoperative real-time plan, and postoperative plan, including D90, D100 (the dose to 90% and 100% of the target volume), V100, V150, and V200 (the volume receives 100%, 150%, and 200% of the prescribed doses). The quality assurance of RSI-BT evaluated on conformal index (CI), external index (EI), and homogeneity index (HI) of the targets were compared among preoperative plan, intraoperative real-time plan, and postoperative plan. The perioperation complications and RSI-BT-related toxicity were assessed.

RESULTS

The median follow-up was 8.2 months (range 1-18.5 months). One patient was lost to follow-up after RSI-BT. Fourteen patients were assessed for response rate and toxicity. The mean entrance point distance deviation for all 165 needles was 4.50 ± 4.10 mm (range, 0-30). The mean angular deviation was 2.70 ± 3.00° (range, 0-20). The needle tip distance deviation was 6.90 ± 6.00 mm (range, - 30-28). D90 for preoperative plan, intraoperative plan, and postoperative plan were 140.55 ± 23.93, 124.25 ± 28.04, and 128.98 ± 22.75, respectively. There was significant difference between D90 of preoperative plan with that of intraoperative plan (p = 0.036). Four lesions reached CR, six lesions reached PR, three lesions were SD, and three lesions were PD. Four patients with moderate pain became mild, and two with mild pain relieved completely after RSI-BT. The other parameters showed no differences among preoperative plan, intraoperative plan, and postoperative plan. The perioperative complications were observed in four patients, including three patients of grade 1 and one patient of grade 2. No ≥ grade 3 side effects were observed.

CONCLUSION

CT-guided 125I RSI-BT assisted by 3D-PNCT was a safe, accurate, and feasible strategy for recurrent carcinomas located in the retroperitoneal regions.

A new multimodal, image-guided, robot-assisted, interstitial brachytherapy for the treatment of head and neck tumors-A preliminary study

BACKGROUND

Interstitial brachytherapy (BT) is becoming an accepted treatment option for head and neck cancer patients for whom surgery poses high risks. Multimodal, image-guided, robotic surgery has the potential to allow precise seed implantation into tumors. Our aim was to introduce a new multimodal, image-guided surgical robot during the performance of interstitial BT for the treatment of tumors in the head and neck regions.

METHODS

Clinical data for three patients were analyzed, retrospectively; patients had received ¹²⁵ I seed implantations from July 2019 to October 2019. Multimodal, image-guided, robotic surgery was performed in all patients. Postoperative computed tomography data were imported to software to evaluate the accuracy of the seed position and the operation times.

RESULTS

The mean placement error of the ¹²⁵ I seed was 1.9 ± 0.74 mm. The mean operation time is 47 minutes.

CONCLUSION

The experimental results showed that the Remebot has promise for use during BT for the head and neck.

Expert consensus on computed tomography-assisted three-dimensional-printed coplanar template guidance for interstitial permanent radioactive 125I seed implantation therapy

Interstitial permanent radioactive seed implantation delivers a high local dose to tumors and sharply drops off at surrounding normal tissues. Radioactive seeds implanted via ultrasound or computed tomography (CT) guidance are minimally invasive and facilitate quick recovery. Transrectal ultrasound-guided ¹²⁵I seed implantation assisted by a transperineal plane template is standard for early-stage prostate carcinoma, with a highly consistent target volume dose distribution. The postplan dose evaluation is consistent with the preplan evaluation. Until now, there was no workflow for seed implantation elsewhere in the body, and it was difficult to effectively preplan for seed implantation because of patients' position changes, organ movement, and bone structure interference. Along with three-dimensional (3D) printing techniques and seed implantation planning systems for brachytherapy, coplanar and X Y axis coordinate templates were created, referred to as 3D-printed coplanar templates (3D-PCT). ¹²⁵I seed implantation under CT guidance with 3D-PCT assistance has been very successful in some carcinomas. Preplanning was very consistent with postplanning of the gross tumor volume. All needles are kept parallel for 3D-PCT, with no coplanar needle rearrangement. No standard workflow for 3D-PCT-assisted seed implantation exists at present. The consensus topics for CT-assisted guidance compared to 3D-PCT-assisted guidance for seed implantation are as follows: Indications for seed implantation, preplanning, definition of radiation doses and dosimetry evaluation, 3D-PCT workflow, radiation protection, and quality of staff. Despite current data supporting ¹²⁵I seed implantation for some solid carcinomas, there is a need for prospectively-randomized multicenter clinical trials to gather strong evidence for using ¹²⁵I seed implantation in other solid carcinomas.

Prospect of robotic assistance for fully automated brachytherapy seed placement into skull base: Experimental validation in phantom and cadaver

BACKGROUND AND PURPOSE

To investigate the feasibility and accuracy of robot-assisted brachytherapy for skull base tumours.

MATERIAL AND METHODS

A custom robot system was tested on both phantom and cadaveric specimen. Cone beam CT (CBCT) images were transferred to the graphical user interface (GUI) for planning trajectories and the data were sent to the robot control unit. Following registration, the puncture needle was inserted into the target by the robot under navigation guidance, and seeds were implanted. Placement error was instantly displayed on the GUI; the result was verified after postoperative image scanning.

RESULTS

A total of 150 seeds (100 for phantom experiments, 50 for cadaveric studies) were deposited by the robot system. In phantom experiments the mean placement error was 0.57 ± 0.21 mm (measured by the navigation system) vs. 1.41 ± 0.38 mm (measured by image fusion) (p < 0.001); in cadaveric studies the corresponding figures were 0.60 ± 0.30 mm vs. 2.48 ± 0.32 mm (p < 0.001). There was no significant difference for comparison of accuracy test in phantom experiments (p = 0.173) as well as in cadaveric studies (p = 0.354). Accuracy was better in the phantom experiment than in cadaveric studies (p < 0.001).

CONCLUSIONS

The performance of robot-assisted skull base brachytherapy is feasible and accurate. Dosimetric coverage will need to be demonstrated in further studies.

GEC-ESTRO ACROP recommendations on calibration and traceability of LE-LDR photon-emitting brachytherapy sources at the hospital level

Prostate brachytherapy treatment using permanent implantation of low-energy (LE) low-dose rate (LDR) sources is successfully and widely applied in Europe. In addition, seeds are used in other tumour sites, such as ophthalmic tumours, implanted temporarily. The calibration issues for LE-LDR photon emitting sources are specific and different from other sources used in brachytherapy. In this report, the BRAPHYQS (BRAchytherapy PHYsics Quality assurance System) working group of GEC-ESTRO, has developed the present recommendations to assure harmonized and high-quality seed calibration in European clinics. There are practical aspects for which a clarification/procedure is needed, including aspects not specifically accounted for in currently existing AAPM and ESTRO societal recommendations. The aim of this report has been to provide a European wide standard in LE-LDR source calibration at end-user level, in order to keep brachytherapy treatments with high safety and quality levels. The recommendations herein reflect the guidance to the ESTRO brachytherapy users and describe the procedures in a clinic or hospital to ensure the correct calibration of LE-LDR seeds.

Ultrasound-Guided 125I Seed Implantation in Treatment of Abdominal Wall Metastases

Background: The treatment of abdominal wall metastasis presents a challenge, because resection can be followed by poor healing and external radiotherapy is associated with serious adverse events. This study aimed to evaluate the efficacy and safety of interstitial ¹²⁵I seed implantation under ultrasound (US) guidance for treating abdominal wall metastasis. Materials and Methods: The cases of 21 patients with 28 abdominal wall metastases who received brachytherapy with ¹²⁵I seeds at the department from August 2010 to March 2015 were retrospectively reviewed. ¹²⁵I seeds were implanted in the abdominal wall lesions under US guidance and with the help of a treatment planning system. Follow-up was performed using computed tomography at 1 d and at 3, 6, and 12 months after implantation. The lymphocyte count before the surgery was compared with the 3-month postoperative count. The main indicators observed were changes in tumor size, side effects, and complications. Results: All 21 patients were successfully treated with ¹²⁵I seed implantation under US guidance. The median follow-up since ¹²⁵I seed implantation was 15 months (range 6-23 months). The response rates and local tumor control after 3, 6, and 12 months were 78.6% and 89.3%, 64.3% and 85.7%, and 52.4% and 71.4%, respectively. The mean preoperative lymphocyte count was 0.262 ± 0.117 × 10⁹/L, which did not differ significantly from the postoperative count, which was 0.259 ± 0.094 × 10⁹/L (p = 0.122). Procedure-related complications included fever, bleeding, and pain, but all these were Grade 1-2. No severe side effects or complications were noted. Conclusions: Percutaneous interstitial implantation of ¹²⁵I seeds under US guidance is safe and feasible for abdominal wall metastases. However, its long-term efficacy requires further investigation.

DTI and pathological changes in a rabbit model of radiation injury to the spinal cord after 125I radioactive seed implantation

Excessive radiation exposure may lead to edema of the spinal cord and deterioration of the nervous system. Magnetic resonance imaging can be used to judge and assess the extent of edema and to evaluate pathological changes and thus may be used for the evaluation of spinal cord injuries caused by radiation therapy. Radioactive ¹²⁵I seeds to irradiate 90% of the spinal cord tissue at doses of 40–100 Gy (D90) were implanted in rabbits at T₁₀ to induce radiation injury, and we evaluated their safety for use in the spinal cord. Diffusion tensor imaging showed that with increased D90, the apparent diffusion coefficient and fractional anisotropy values were increased. Moreover, pathological damage of neurons and microvessels in the gray matter and white matter was aggravated. At 2 months after implantation, obvious pathological injury was visible in the spinal cords of each group. Magnetic resonance diffusion tensor imaging revealed the radiation injury to the spinal cord, and we quantified the degree of spinal cord injury through apparent diffusion coefficient and fractional anisotropy.

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

BACKGROUND

For the recurrence of head and neck cancer after operation and radiotherapy, the local control of radioactive seed implantation is good, and it has a certain palliative effect. This study aims to investigate the acute and late side effects of a three-dimentional printing non co-planar template (3D-PNCT) for computed tomography (CT)-guided radioactive 125I seed (RIS) implantation in recurrent cancer of the head and neck.

METHODS

Between January 2016 and December 2016, forty-two patients with local recurrent malignant tumors of the head and neck received 3D-PNCT-assisted RIS implantation. The prescribed dose was 110-160 Gy. Preoperative planning design, production of individual guide plates, RIS implantation, postoperative dose evaluation, and follow-up were completed for all patients. Side effects in the skin, mucous membranes, blood and spinal cord were evaluated.

RESULTS

All patients underwent surgery successfully. Duration of follow-up was 4-14 (median, of 8.5) months. The activity of a single RIS was 0.34-0.7 (median, 0.6) mCi. The number of RIS was 10-126 (median, 34). The number of implantation needles was 4-31 (median, 11). The mean D2cc (dose to the most exposed 2-cc volume) and D0.1cc (dose to the most exposed 0.1-cc volume) of the skin were 24.9 (7.1-85.5) and 47.5 (9.4-167.2), respectively, whereas those of the spinal cord were 8.4 (4.5-33.3) and 14.2 (13.6-63.0), mucosa were 35.1 (4.2-82.8) and 87.0 (6.6-214.1), parotid glands were 16.2 (12.8-19.7) and 29.8 (26.1-33.4) and those of the trachea were 17.9 (2.5-45.9) and 32.7 (3.9-83.9), respectively. No case had an acute reaction of grade ≥ 3. Three cases had a grade-1 skin reaction. Blood toxicity did not occur, nor spinal-cord injury. Xerostomia was not aggravated than that of before brachytherapy. One case had a grade-3 nerve response.

CONCLUSIONS

3D-PNCT-assisted RIS implantation can provide good accuracy for positioning. For local recurrent malignant tumor of head and neck, there were no obvious adverse reactions.

Dosimetric characterization of GMS BT-125-1 125 I radioactive seed with Monte Carlo simulations and experimental measurement

Purpose

To investigate the dosimetric characteristics of the new GMS BT‐125‐1 ¹²⁵I radioactive seed, including dose rate constant, radial dose functions, and anisotropy functions.

Methods

Dosimetric parameters of GMS BT‐125‐1 ¹²⁵I seed including dose rate constant, radial dose functions, and anisotropy functions were calculated using the Monte Carlo code of MCNP5, and measured with thermoluminescent dosimeters (TLDs). The results were compared with those of PharmaSeed BT‐125‐1, PharmaSeed BT‐125‐2 ¹²⁵I, and model 6711 ¹²⁵I seeds.

Results

The dose rate constant of GMS BT‐125‐1 ¹²⁵I seed was 0.959 cGy·h−1·U−1, with the difference of 0.94%, 0.83%, and 0.73% compared with the PharmaSeed BT‐125‐1 ¹²⁵I seed, PharmaSeed BT‐125‐2 ¹²⁵I seed, and Model 6711 ¹²⁵I seed, respectively. For radial dose function, the differences between the Monte Carlo and the experimental g(r) results were mostly within 10%. Monte Carlo results of g(r) for GMS BT‐125‐1 ¹²⁵I seed were found in agreement (within 3.3%) with corresponding results for the PharmaSeed BT‐125‐2 ¹²⁵I seed. The largest differences were 8.1% and 6.2% compared with PharmaSeed BT‐125‐1 ¹²⁵I seed and model 6711 ¹²⁵I seed, respectively. For anisotropy function, the difference between GMS BT‐125‐1 ¹²⁵I seed and PharmaSeed BT‐125‐2 ¹²⁵I seed was typically <10%.

Conclusions

The measured dose rate constant, radial dose functions, and two‐dimensional anisotropy functions for the GMS BT‐125‐1 ¹²⁵I seed showed good agreement with the Monte Carlo results. The dose rate constant of the GMS BT‐125‐1 ¹²⁵I seed is similar to that of the PharmaSeed BT‐125‐1 ¹²⁵I seed, the PharmaSeed BT‐125‐2 ¹²⁵I seed, and the model 6711 ¹²⁵I seed. For radial dose functions and two‐dimensional anisotropy functions, the GMS BT‐125‐1 ¹²⁵I seed is similar to the PharmaSeed BT‐125‐2 ¹²⁵I seed but different from the PharmaSeed BT‐125‐1 ¹²⁵I seed and the model 6711 ¹²⁵I seed.

CT-guided 125I brachytherapy for locally recurrent nasopharyngeal carcinoma

Purpose: The study evaluated the feasibility, clinical effectiveness, and quality of life of computed tomography (CT)-guided 125I brachytherapy for locally recurrent nasopharyngeal carcinoma (NPC). Methods: We recruited 81 patients diagnosed with locally recurrent NPC after previous radiotherapy with or without chemotherapy. Thirty-nine patients received 125I brachytherapy (group A) and 42 received re-irradiation (IMRT, group B). The evaluated outcomes were local control, complications, and quality of life. Cox proportional hazards regression analysis was used to compare local tumor progression-free survival (LTPFS) and overall survival (OS) in the two treatment groups. Results: The median follow-up was 30 months (range, 5-68 months), median LTPFS was 21 in group A and 17 months in group B. The 1-, 2-, and 3-year OS in group A were 84.6%, 51.3%, 30.7%, and 85.7%, 50.0%, and 32.6% in group B. In group A, 10/39 patients (25.6%) experienced at least one ≥grade III complication; no grade V complications occurred. In group B, 28/42 (66.7%) experienced at least one ≥grade III complication and 6/42 (14.3%) died of severe grade V complications. No significant between-group difference existed in the Quality of Life score on the EORTC QLQ-H&N35 questionnaire before treatment. In group A, quality of life was significantly improved after treatment; but did not improve, or even deteriorated in group B. Conclusions: 125I brachytherapy was a feasible, safe, and effective treatment for locally recurrent NPC. 125I brachytherapy significantly reduced complications caused by re-irradiation and improved patients' quality of life.

125I brachytherapy of locally advanced non-small-cell lung cancer after one cycle of first-line chemotherapy: a comparison with best supportive care

OBJECTIVES

The objective of this study was to assess the efficacy of computed tomography (CT)-guided ¹²⁵I brachytherapy alone in improving the survival and quality of life of patients with unresectable locally advanced non-small-cell lung cancer (NSCLC) after one cycle of first-line chemotherapy.

PATIENTS AND METHODS

Sixteen patients with locally advanced NSCLC were treated with CT-guided ¹²⁵I brachytherapy after one cycle of first-line chemotherapy (group A). Sixteen patients who received only best supportive care (group B) were matched up with the patients in group A. Primary end point included survival, and secondary end point included assessment of safety, effectiveness of CT-guided ¹²⁵I brachytherapy, and improvement in the quality of life.

RESULTS

The two groups were well balanced in terms of age, disease histology, tumor stage, tumor location, and performance status (P>0.05). The median follow-up time was 16 months (range, 3-30). The total tumor response rate was 75.0% in group A, which was significantly higher than that in group B (0.0%) (P<0.01). The median progression-free survival time was 4.80 months for patients in group A and 1.35 months for patients in group B (P<0.001). Kaplan-Meier survival analysis showed that the median survival time of group A was 9.4±0.3 months versus 8.4±0.1 months in group B (P=0.013). Tumor-related symptoms of patients were significantly relieved, and the quality of life was markedly improved in group A than in group B.

CONCLUSION

CT-guided ¹²⁵I brachytherapy improved the survival of patients with locally advanced NSCLC and quality of life after one cycle of first-line chemotherapy compared with best supportive care.

Surgery combined with postoperative 125 I seed brachytherapy for the treatment of mucoepidermoid carcinoma of the parotid gland in pediatric patients

BACKGROUND

This retrospective study was undertaken to analyze the effectiveness and safety of surgery combined with postoperative ¹²⁵ I seed brachytherapy in the treatment of mucoepidermoid carcinoma (MEC) of the parotid gland with risk factors in pediatric patients.

PROCEDURE

From September 2002 to January 2012, 24 patients, ages 5-16 years (mean, 13.2 years; median, 12.3 years), with MEC of the parotid gland were included. Patients with high risk factors received ¹²⁵ I seed brachytherapy (median actuarial D90, 97 Gy) within 4 weeks following surgery. Radioactivity was 18.5-33.3 MBq per seed and the prescription dose was 60-120 Gy. Overall and disease-free survival rates, local control rate, and distant metastasis were recorded. Radiation-associated late side effects, including dermatitis, hearing loss, thyroid nodules, and secondary malignancy, were also evaluated.

RESULTS

During the follow-up period of 5-13.4 years (median, 7.2 years), the overall and disease-free survival rates were all 100%. No patients developed local recurrence, regional/distant metastasis, and no severe radiation-associated complications including the second malignancy were noted.

CONCLUSION

Surgery combined with postoperative ¹²⁵ I seed brachytherapy is effective and safe in the treatment of MEC of the parotid gland in pediatric patients, with no evidence of severe late radiation-related complications. More patients and longer follow-up data are still needed to prove the efficacy of ¹²⁵ I brachytherapy.

Role of gambogic acid and NaI131 in A549/DDP cells

Resistance to platinum in tumor tissue is a considerable barrier against effective lung cancer treatment. Radionuclide therapy is the primary adjuvant treatment, however, the toxic side effects limit its dosage in the clinical setting. Therefore, the present study aimed to determine whether an NaI¹³¹ radiosensitizer could help reduce the toxic side effects of radionuclide therapy. In vitro experiments were conducted to determine whether NaI¹³¹ can inhibit platinum resistance in A549/DDP cells, which are cisplatin-resistant non-small cell lung cancer cells, and whether gambogic acid (GA) is an effective NaI¹³¹ radiosensitizer. Cell proliferation following drug intervention was analyzed using MTT and isobolographic analysis. Apoptosis was assessed by flow cytometry. In addition, the mechanisms of drug intervention were analyzed by measuring the expression of P-glycoprotein (P-gP), B cell lymphoma 2 (Bcl-2), Bcl2-associated X protein (Bax) and P53 using western blot analysis and immunocytochemistry. According to isobolographic analysis, a low concentration of NaI¹³¹ combined with GA had a synergistic effect on the inhibition of A549/DDP cell proliferation, which was consistent with an increased rate of apoptosis. Furthermore, the overexpression of Bax, and the downregulation of P-gP, P53 and Bcl-2 observed demonstrated the potential mechanism(s) of NaI¹³¹ and GA intervention. NaI¹³¹ may induce apoptosis in A549/DDP cells by regulating apoptosis-related proteins. A low concentration combination of NaI¹³¹ and GA was able to significantly inhibit A549/DDP cell proliferation and induce cell apoptosis. Thus, the two drugs appear to have a synergistic effect on apoptosis of A549/DDP cells.

(125)I Seed Permanent Implantation as a Palliative Treatment for Stage III and IV Hypopharyngeal Carcinoma

OBJECTIVES

The aim of this study was to investigate the feasibility and safety of percutaneous (125)I seed permanent implantation for advanced hypopharyngeal carcinoma from toxicity, tumor response, and short-term outcome.

METHODS

(125)I seeds implant procedures were performed under computed tomography for 34 patients with advanced hypopharyngeal carcinoma. We observed the local control rate, overall survival, and acute or late toxicity rate.

RESULTS

In the 34 patients (stage III, n=6; stage IV, n=28), the sites of origin were pyriform sinus (n=29) and postcricoid area (n=5). All patients also received one to four cycles of chemotherapy after seed implantation. The post-plan showed that the actuarial D90 of (125)I seeds ranged from 90 to 158 Gy (median, 127 Gy). The mean follow-up was 12.3 months (range, 3.4 to 43.2 months). The local control was 2.1-31.0 months with a median of 17.7 months (95% confidence interval [CI], 13.4 to 22.0 months). The 1-, 2-, and 3-year local controls were 65.3%, 28.6%, and 9.5% respectively. Twelve patients (35%) died of local recurrence, fourteen patients (41%) died of distant metastases, and three patients (9%) died of recurrence and metastases at the same time. Five patients (15%) still survived to follow-up. At the time of analysis, the median survival time was 12.5 months (95% CI, 9.5 to 15.4 months). The 1-, 2-, and 3-year overall survival rates were 55.2%, 20.3%, and 10.9%, respectively. Five patients (15%) experienced grade 3 toxic events and nine patients (26%) have experienced grade 2 toxic events.

CONCLUSION

This review shows relatively low toxicity for interstitial (125)I seed implantation in the patients with advanced stage hypopharyngeal cancer. The high local control results suggest that (125)I seed brachytherapy implant as a salvage or palliative treatment for advanced hypopharyngeal carcinoma merit further investigation.

Effect of pedicle fixation combined with (125)I seed implantation for metastatic thoracolumbar tumors

Purpose

The aim of this study was to investigate the clinical efficacy of pedicle fixation combined with ¹²⁵I brachytherapy in treating metastatic thoracolumbar tumors.

Patients and methods

A retrospective analysis of the clinical data of seven metastatic thoracolumbar tumor patients who received pedicle fixation combined with radioactive ¹²⁵I seed implantation brachytherapy in our department between January 2009 and December 2013 was performed. The visual analog scale (VAS) for pain and the Karnofsky performance status (KPS) score before the operation and 1, 6, and 12 months after the operation were observed and recorded. The changes in the scores at each time point were compared.

Results

All the patients underwent a successful operation, without any complications during their hospitalization. All the patients received postoperative follow-up, and the duration of follow-up was 15–50 months, with an average of 32.2 months. One pancreatic cancer patient died of liver failure and hypoproteinemia 28 months post surgery. The VAS scores of patients before the operation and 1, 6, and 12 months after the operation were 7.43±0.98, 2.71±0.49, 3.00±0.82, and 4.29±0.98, respectively; the KPS scores were 52.9±9.5, 84.3±5.3, 75.7±5.3, and 72.9±4.9, respectively. These results suggest that the VAS score at each time point was significantly decreased compared with that before the operation, while the KPS score was significantly increased compared with that before the operation. Both differences had statistical significance (P<0.05).

Conclusion

As a therapy for advanced malignant tumors with thoracolumbar metastasis, pedicle fixation combined with ¹²⁵I brachytherapy can effectively relieve short-term pain and improve patient’s quality of life.

Clinical application of computed tomography-guided (125)I seed interstitial implantation for head and neck cancer patients with unmanageable cervical lymph node metastases

Background

To assess clinical application of computed tomography (CT)-guided ¹²⁵I seed implantation for patients who cannot endure or unwillingly receive repeated surgery, chemotherapy, or radiotherapy for unmanageable cervical lymph node metastases in head and neck cancer (HNC).

Methods

Thirty-one consecutive patients received CT-guided ¹²⁵I seed implantation between February 2010 and December 2013. To evaluate the clinical efficiency, karnofsky performance score (KPS), numeric rating scale (NRS), and tumor volume at 3-, and 6-month post-implantation were compared with pre-implantation, along with local control rate (LCR), overall survival rate (OSR), and complications at 3, 6 months, 1, and 2 years.

Results

The tumor volume was obviously decreased at 3-, and 6-month post-implantation (21.23 ± 8.83 versus 9.19 ± 7.52 cm²; 21.23 ± 8.83 versus 6.42 ± 9.79 cm²; P < 0.05) compared with pre-implantation. The NRS was statistically reduced (3.06 ± 1.06 versus 7.77 ± 0.92; 2.39 ± 1.15 versus 7.77 ± 0.92; P < 0.05), while KPS was significantly improved (83.18 ± 5.97 versus 73.60 ± 7.90; 82.86 ± 5.43 versus 73.60 ± 7.90; P < 0.05) postoperatively at 3 and 6 months, respectively. The LCR at 3, 6 months, 1, and 2 years was 96.30, 83.87, 64.51, and 45.16 %, respectively. The OSR was 100, 100, 67.74, and 45.16 %, respectively. Three cases experienced grade I and two had grade II acute radiation toxicity.

Conclusions

CT-guided seed implantation may be feasible and safe for HNC patients whose neck nodes are not manageable by routine strategies with fewer complications, higher LCR, and significant pain relief.

Cesium-131 brachytherapy in high risk and recurrent head and neck cancers: first report of long-term outcomes

Purpose

The feasibility and efficacy of re-irradiation using contemporary radiation techniques to treat recurrent head and neck cancer has been demonstrated but the role of brachytherapy is unclear. Here we describe the use of ¹³¹Cs brachytherapy with concurrent salvage surgery in 18 patients.

Material and methods

Eligible patients underwent maximal gross resection of the tumor with implantation of brachytherapy seeds delivering a minimum dose of 80 Gy to the tumor bed. Rates of overall survival, locoregional progression free survival, disease-free survival, and radiation-induced toxicity were analyzed.

Results

Retrospective Kaplan-Meier analysis shows median overall survival was 15 months and disease free survival was 12 months. Two patients developed grade 3 toxicity; all other complications were grade 1-2 with no grade 4 or 5 complications.

Conclusions

Compared to prior literature, our study shows comparable rates of survival with a decreased rate of radiation-induced toxicity.

Three-dimensional verification of ¹²⁵I seed stability after permanent implantation in the parotid gland and periparotid region

Objective

To evaluate seed stability after permanent implantation in the parotid gland and periparotid region via a three-dimensional reconstruction of CT data.

Material and methods

Fifteen patients treated from June 2008 to June 2012 at Peking University School and Hospital of Stomatology for parotid gland tumors with postoperative adjunctive ¹²⁵I interstitial brachytherapy were retrospectively reviewed in this study. Serial CT data were obtained during follow-up. Mimics and Geomagic Studio software were used for seed reconstruction and stability analysis, respectively.

Results

Seed loss and/or migration outside of the treated area were absent in all patients during follow-up (23–71 months). Total seed cluster volume was maximized on day 1 post-implantation due to edema and decreased significantly by an average of 13.5 % (SD = 9.80 %; 95 % CI, 6.82–17.68 %) during the first two months and an average of 4.5 % (SD = 3.60 %; 95 % CI, 2.29–6.29 %) during the next four months. Volume stabilized over the subsequent six months.

Conclusions

¹²⁵I seed number and location were stable with a general volumetric shrinkage tendency in the parotid gland and periparotid region. Three-dimensional seed reconstruction of CT images is feasible for visualization and verification of implanted seeds in parotid brachytherapy.

Gelfoam embolization or 125I seed implantation may be a more effective treatment than surgical treatment for giant benign sacral neurogenic tumors

Background

The goal of the present study was to assess the effects of computed tomography (CT)-guided iodine-125 (¹²⁵I) seed implantation or gelatin sponge particle (GSP) embolization on patients with giant benign sacral neurogenic tumors.

Methods

A total of 24 cases with giant sacral neurogenic tumor were performed in a retrospective study between 2000 and 2012. Nineteen cases received surgical resection, and five cases received non-surgical treatment. In surgical group, patients with type III sacral tumor had received a combined anterior-posterior approach and patients with type IV were treated with simple anterior approach. In non-surgical group, CT-guided ¹²⁵I seed implantation or GSP embolization was applied to occlude vessels. Besides, CT scanning or magnetic resonance imaging was used to assess the size and development of tumors.

Results

Two of the five patients were treated three times with GSP embolization, one had received GSP embolization combined with CT-guided ¹²⁵I seed implantation, one case did not receive any treatment, and one patient was lost to follow-up. Patients in non-surgical group were followed up for 2–8 years.

Conclusions

Our study suggested that CT-guided ¹²⁵I seed implantation or GSP embolization treatment is very useful to slow down the development of giant benign sacral neurogenic tumors.

Modern head and neck brachytherapy: from radium towards intensity modulated interventional brachytherapy

Intensity modulated brachytherapy (IMBT) is a modern development of classical interventional radiation therapy (brachytherapy), which allows the application of a high radiation dose sparing severe adverse events, thereby further improving the treatment outcome. Classical indications in head and neck (H&N) cancers are the face, the oral cavity, the naso- and oropharynx, the paranasal sinuses including base of skull, incomplete resections on important structures, and palliation. The application type can be curative, adjuvant or perioperative, as a boost to external beam radiation as well as without external beam radiation and with palliative intention. Due to the frequently used perioperative application method (intraoperative implantation of inactive applicators and postoperative performance of radiation), close interdisciplinary cooperation between surgical specialists (ENT-, dento-maxillary-facial-, neuro- and orbital surgeons), as well interventional radiotherapy (brachytherapy) experts are obligatory. Published results encourage the integration of IMBT into H&N therapy, thereby improving the prognosis and quality of life of patients.

CT-guidance interstitial (125)Iodine seed brachytherapy as a salvage therapy for recurrent spinal primary tumors

Background

Management of spinal neoplasms has relied on open surgery and external beam radiotherapy (EBRT). Although primary spinal tumors are rare, their treatment remains a pervasive problem. This analysis sought to evaluate the safety and efficacy of CT-guided ¹²⁵I seed brachytherapy for recurrent paraspinous and vertebral primary tumors.

Methods

From November 2002 to June 2014, 17 patients who met the inclusion criteria were retrospectively reviewed. 14 (82.4%) had previously undergone surgery, 15 (88.2%) had received conventional EBRT and 3 (17.6%) had chosen chemotherapy. The number of ¹²⁵I seeds implanted ranged from 7 to 122 (median 79) with specific activity of 0.5-0.8 mCi (median 0.7 mCi). The post-plan showed that the actuarial D₉₀ of ¹²⁵I seeds were 90–183 Gy (median 137 Gy). The follow-up period ranged from 2 to 69 months (median 19 months). The local control rate was calculated by the Kaplan-Meier method.

Results

For 5 Chondrosarcomas, the 1-, 2-, 3-year local control rates were 75%, 37.5%, and 37.5%, respectively, with a median of 34 months (range, 4–39 months). For 4 chordomas, the local control rate was 50% with a median follow-up of 13 months (range, 3–17 months). For 3 fibromatosis, all of them were survival without local recurrence at the end of follow-up. During the follow-up period, 35.3% (6/17) died from metastases, 17.6% (3/17) developed local recurrence by 8, 14 and 34 months while 64.7% (11/17) remained alive. 100% experienced pain relief and normal or improved ambulation, without more than Frankel grade 3 radiation myelopathy.

Conclusions

Percutaneous ¹²⁵I seed implantation can be an alternative or retreatment for recurrent spinal primary tumors.

Migration of radioactive iodine-125 seeds: case report

Iodine-125 kills cancer cells mainly through the release of X and γ ray and was used in the treatment of prostate cancer earliest in the USA and other developed countries,Now it is widely used to handle all kinds of entity malignant tumor. After being implanted in a tumor it rarely wander to other parts of the body through the blood vessels. Hence,we implanted 50 Iodine-125 particles in the tumor. Three days after surgery, lateral X-ray film of head and neck suggest that 4 Iodine-125 particles left the tumor, two of which migrated to the sphenoid bone,while the other two migrated to the midline below the vortex of the skull.

The different biological effects of single, fractionated and continuous low dose rate irradiation on CL187 colorectal cancer cells

PURPOSE

To determine the biological effectiveness of single, fractionated and continuous low dose rate irradiation on the human colorectal cancer cell line CL187 in vitro and explore the cellular mechanisms.

MATERIALS AND METHODS

The CL187 cells were exposed to radiation of 6 MV X-ray at a high dose rate of 4Gy/min and 125I seed at a low dose rate of 2.77 cGy/h. Three groups were employed: single dose radiation group (SDR), fractionated dose radiation group (FDR) by 2Gy/f and continuous low dose rate radiation group (CLDR). Four radiation doses 2, 4, 6 and 8Gy were chosen and cells without irradiation as the control. The responses of CL187 cells to distinct modes of radiation were evaluated by the colony-forming assay, cell cycle progression as well as apoptosis analysis. In addition, we detected the expression patterns of DNA-PKcs, Ku70 and Ku80 by Western blotting.

RESULTS

The relative biological effect for 125I seeds compared with 6 MV X-ray was 1.42. 48 hrs after 4Gy irradiation, the difference between proportions of cells at G2/M phase of SDR and CLDR groups were statistically significant (p = 0.026), so as the FDR and CLDR groups (p = 0.005). 48 hrs after 4Gy irradiation, the early apoptotic rate of CLDR group was remarkably higher than SDR and FDR groups (CLDR vs. SDR, p = 0.001; CLDR vs. FDR, p = 0.02), whereas the late apoptotic rate of CLDR group increased significantly compared with SDR and FDR group (CLDR vs. SDR, p = 0.004; CLDR vs. FDR, p = 0.007). Moreover, DNA-PKcs and Ku70 expression levels in CLDR-treated cells decreased compared with SDR and FDR groups.

CONCLUSIONS

Compared with the X-ray high dose rate irradiation, 125I seeds CLDR showed more effective induction of cell apoptosis and G2/M cell cycle arrest. Furthermore, 125I seeds CLDR could impair the DNA repair capability by down-regulating DNA-PKcs and Ku70 expression.

Refractory Nasopharyngeal Carcinoma

Objective

To evaluate the feasibility of positron emission tomography combined with computed tomography (PET-CT)–guided 125I seed implantation in the treatment of patients with refractory nasopharyngeal carcinoma after repeated traditional radiochemotherapy.

Study Design

Case series with chart review.

Setting

University medical center.

Subjects and Methods

A total of 26 patients (18 men, 8 women; mean age, 51.3 ± 10.8 years; totaling 53 lesions with an average diameter of 2.86 ± 1.61 cm) were treated by PET-CT–guided 125I seed implantation. All of the patients received a PET-CT scan 2 months after the treatment. Follow-up was conducted for ~2 to 43 months (median, 28.2 months) to observe the local control rate, overall survival rate, and clinical complications.

Results

The local control rates of refractory nasopharyngeal carcinoma after repeated traditional radiochemotherapy after 3, 6, 12, 24, and 36 months were 90.6% (48/53), 79.3% (42/53), 71.7% (38/53), 62.3% (33/53), and 56.6% (30/53), respectively. The overall 1-, 2-, and 3-year survival rates were 87.2%, 71.3%, and 56.5%, respectively, with a median survival time of 28.2 months. Of all patients, 19.2% (5/26) died of local recurrence and 15.4% (4/26) died of metastases. One patient died of hypertensive cerebral hemorrhage, and another patient died from cachexia and infection. The long-term complications included hyperpigmentation at operative sites (n = 5), insensible feeling on the lateral cheek (n = 2), dryness of the oral cavity (n = 1), and headache (n = 1).

Conclusion

PET-CT–guided 125I seed implantation is an acceptable and feasible method for treating refractory nasopharyngeal carcinoma with minimal damage and few complications.

125I brachytherapy alone for recurrent or locally advanced adenoid cystic carcinoma of the oral and maxillofacial region

BACKGROUND AND PURPOSE

This retrospective study was to evaluate the local control and survival of (125)I brachytherapy for recurrent and/or locally advanced adenoid cystic carcinoma (ACC) of the oral and maxillofacial region.

PATIENTS AND METHODS

A total of 38 patients with recurrent and/or locally advanced ACC of the oral and maxillofacial region received (125)I brachytherapy alone from 2001-2010. Twenty-nine were recurrent cases following previous surgery and radiation therapy. The other 9 cases involved primary tumors. Overall, 12 tumors were located in the major salivary glands, 12 in the minor salivary glands, and 14 in the paranasal region, the nasal cavity or the skull base. The prescribed dose was 100-160 Gy.

RESULTS

Patients were followed for 12-122 months (median 51 months). The 2-, 5-, and 10-year local tumor control rates were 86.3, 59, and 31.5 %, respectively. The 2-, 5-, and 10-year overall survival rates were 92.1, 65 and 34.1 %, respectively. Tumors > 6 cm had significantly lower local control and survival rates. No severe complications were observed during follow-up.

CONCLUSION

(125)I brachytherapy is a feasible and effective modality for the treatment of locally advanced unresectable or recurrent ACC.

A digital model individual template and CT-guided 125I seed implants for malignant tumors of the head and neck

To enhance the accuracy of radioactive seed implants in the head and neck, a digital model individual template, containing information simultaneously on needle pathway and facial features, was designed to guide implantation with CT imaging. Thirty-one patients with recurrent and local advanced malignant tumors of head and neck after prior surgery and radiotherapy were involved in this study. Before (125)I implants, patients received CT scans based on 0.75mm thickness. And the brachytherapy treatment planning system (BTPS) software was used to make the implantation plan based on the CT images. Mimics software and Geomagic software were used to read the data containing CT images and implantation plan, and to design the individual template. Then the individual template containing the information of needle pathway and face features simultaneously was made through rapid prototyping (RP) technique. All patients received (125)I seeds interstitial implantation under the guide of the individual template and CT. The individual templates were positioned easily and accurately, and were stable. After implants, treatment quality evaluation was made by CT and TPS. The seeds and dosages distribution (D(90),V(100),V(150)) were well meet the treatment requirement. Clinical practice confirms that this approach can facilitate easier and more accurate implantation.

Clinical investigations on the spinal osteoblastic metastasis treated by combination of percutaneous vertebroplasty and (125)I seeds implantation versus radiotherapy

To investigate the clinical efficacy of combining digital subtraction angiography-guided percutaneous vertebroplasty (PVP) and (125)I seeds implantation for the treatment of spinal osteoplastic metastasis. A combination of PVP and (125)I implantation was conducted for 50 patients with spinal osteoplastic metastasis, while the other 50 patients who received regular radiation therapy were used as a comparison. Visual analogue pain scale (VAS) and score of life quality (EORTCQLQ-30) were determined for all the patients. Surgery was successful in 89 spinal segments of vertebral body in 50 patients. Each segment of vertebral body was injected with 1-5 mL (2.8 mL for thoracic and 3.1 mL for lumbar vertebral body on average) of bone cement. Postoperative X-ray and CT examination showed that all the patients in the PVP group achieved spinal stability. During the follow-up examination from 6 months to 5 years, 49 patients (98.0%) had significantly relieved back pain, and only 1 case (2.0%) had no obvious improvement. Postoperative VAS score and Karnofsky performance score (KPS) were significantly different from the preoperative scores (p<0.05); and compared to the regular treatment group, PVP combined (125)I seeds showed much better clinical efficacy (p<0.05). PVP is a minimally invasive treatment with easy operation and less complications. PVP can effectively relieve the pain, stabilize the spine, improve the life quality, and reduce the occurrence of paraplegia in patients with spinal osteoplastic metastasis. Utilization of (125)I seeds with PVP can enhance the clinical efficacy.

Postoperative 125I brachytherapy delivered by digital model obturators for recurrent or locally advanced maxillary cancers

OBJECTIVES/HYPOTHESIS

We aimed to evaluate the feasibility and effectiveness of postoperative (125) I brachytherapy delivered by use of digital model obturators for recurrent or locally advanced maxillary cancers.

STUDY DESIGN

Retrospective study.

METHODS

From 2006 to 2008, 12 patients (seven females; median age, 65 years; range, 22-86 years) with recurrent or locally advanced maxillary cancers showing positive margins after surgery underwent (125) I brachytherapy by use of digital model obturators and interstitial implants. The radioactivity was 18.5 to 33.3 MBq per seed, and the prescription dose was 80 to 160 Gy. Functional outcome of patients was evaluated by the Performance Status Scale (PSS) for head and neck cancer before and after brachytherapy.

RESULTS

The (125) I seeds and dosages were well distributed in the radiation fields, and all patients had higher PSS scores after than before treatment with obturators. During a median follow-up of 53 months (range, 28-62 months), local control at 3 and 5 years was 83.3% and 66.7%, respectively, with a mean local control time of 53.5 ± 3.79 months. Overall survival at 3 and 5 years was 91.7% and 71.4%, respectively, with a mean survival time of 56.6 ± 2.99 months. Two patients died due to local recurrence, and one patient died due to lung metastasis. No patient had severe complications during follow-up.

CONCLUSIONS

(125) I brachytherapy delivered by digital model obturator is effective in treating maxillary cancers with positive margins after maxillectomy for advanced or recurrent cancer. The method may improve the quality of life of patients with maxillary defects. Laryngoscope, 2012.

Radiological response of ceramic and polymeric devices for breast brachytherapy

In the present study, the radiological visibility of ceramic and polymeric devices implanted in breast phantom was investigated for future applications in brachytherapy. The main goal was to determine the radiological viability of ceramic and polymeric devices in vitro by performing simple radiological diagnostic methods such as conventional X-ray analysis and mammography due to its easy access to the population. The radiological response of ceramic and polymeric devices implanted in breast phantom was determined using conventional X-ray, mammography and CT analysis.

Clinical application of CT-guided (125)I seed interstitial implantation for local recurrent rectal carcinoma

PURPOSE

The present study aimed to explore the safety profile and clinical efficacy of CT-guided radioactive seed implantation in treating local recurrent rectal carcinoma.

MATERIALS AND METHODS

CT-guided ¹²⁵I seed implantation was carried out in 20 patients with locally recurrent rectal carcinoma. 14 of the 20 patient had prior adjuvant external-beam radiation therapy (EBRT). The treatment planning system (TPS) was used preoperatively to reconstruct three dimensional images of the tumor and to calculate the estimated seed number and distribution. The median matched peripheral dose (MPD) was 120 Gy (range, 100-160 Gy).

RESULTS

Of the 20 patients, 12 were male, 8 were female, and ages ranged from 38 to 78, with a median age of 62. Duration of follow-up was 3-34 months. The response rate of pain relief was 85% (17/20). Repeat CT scan 2 months following the procedure revealed complete response (CR) of the tumor in 2 patients, partial response (PR) in 13 patients, stable disease (SD) in 3 patients, and progressive disease (PD) in 2 patients. 75% of patients had either CR or PR. Median survival time was 18.8 months (95% CI: 3.5-22.4 months). 1 and 2 year survival rates were 75% and 25%, respectively. 4 patients died of recurrent tumor; 4 patients died of distant metastases; 9 patients died of recurrent tumor and distant metastases. 3 patients survived after 2 year follow up. Two patients were found to have mild hematochezia, which was reversible with symptomatic management.

CONCLUSION

CT-guided ¹²⁵I seed implantation appeared to be a safe, useful and less complicated interventional treatment option for local recurrent rectal carcinoma.