[Dosimetric analysis of different optimization algorithms for three-dimensional brachytherapy for gynecologic tumors].

OBJECTIVE: To investigate the dosimetric difference between manual and inverse optimization in 3-dimensional (3D) brachytherapy for gynecologic tumors. METHODS: This retrospective study was conducted among a total of 110 patients with gynecologic tumors undergoing intracavitary combined with interstitial brachytherapy or interstitial brachytherapy. Based on the original images, the brachytherapy plans were optimized for each patient using Gro, IPSA1, IPSA2 (with increased volumetric dose limits on the basis of IPSA1) and HIPO algorithms. The dose-volume histogram (DVH) parameters of the clinical target volume (CTV) including V200, V150, V100, D90, D98 and CI, and the dosimetric parameters D2cc, D1cc, and D0.1cc for the bladder, rectum, and sigmoid colon were compared among the 4 plans. RESULTS: Among the 4 plans, Gro optimization took the longest time, followed by HIPO, IPSA2 and IPSA1 optimization. The mean D90, D98, and V100 of HIPO plans were significantly higher than those of Gro and IPSA plans, and D90 and V100 of IPSA1, IPSA2 and HIPO plans were higher than those of Gro plans (P < 0.05), but the CI of the 4 plans were similar (P > 0.05). For the organs at risk (OARs), the HIPO plan had the lowest D2cc of the bladder and rectum; the bladder absorbed dose of Gro plans were significantly greater than those of IPSA1 and HIPO (P < 0.05). The D2cc and D1cc of the rectum in IPSA1, IPSA2 and HIPO plans were better than Gro (P < 0.05). The D2cc and D1cc of the sigmoid colon did not differ significantly among the 4 plans. CONCLUSION: Among the 4 algorithms, the HIPO algorithm can better improve dose coverage of the target and lower the radiation dose of the OARs, and is thus recommended for the initial plan optimization. Clinically, the combination of manual optimization can achieve more individualized dose distribution of the plan.

[An investigation of the advantages of the adjustable angle stitch template compared with CT-guided 125I seeds free-hand implantation in the treatment of non-small cell lung carcinoma].

Objective: To investigate the advantages of adjustable angle needle path template compared with CT-guided 125I seeds free-hand implantation in the treatment of non-small cell lung carcinoma. Methods: This randomized controlled trial involved the retrospective analysis of the clinical data of 45 patients with non-small cell lung carcinoma who underwent 125I seeds implantation at the Shandong Cancer Hospital, Shaanxi Provincial Tumor Hospital and The Third Affiliated Hospital of Shandong First Medical University from May 2018 to January 2023. Patients were divided into the template (n=21) and free-hand (n=24) groups, according to the modality used. The template group comprised 16 males and 5 females, aged (66±12) years, while the free-hand group comprised 16 males and 8 females, aged (62±8) years. The dose distribution, implant quality, intraoperative computed tomography (CT) scan times, and 125I seed reseeding numbers after implantation were compared between the two groups to evaluate the potential advantages of adjustable angle needle path template-assisted implantation over free-hand 125I implantation. Results: Statistical comparison revealed no significant differences in age (t=1.16, P=0.253), tumor volume [(71±26) vs. (71±22) cm3, t=0.21, P=0.837), or any other baseline characteristics between the template and free-hand groups. Overall, 45 patients successfully completed the operation. In the template group, the mean values of the D90 (dose that was delivered to 90% of the target volume), V100 (the target volume receiving 100% of the prescription dose), coverage index (CI), relative dose homogeneity index (HI), and external volume index (EI) pre-and post-implantation were (131.0±2.1) vs. (131.1±5.5) Gy, 90.0%±0.4% vs. 91.0%±2.8%, 0.83±0.07 vs. 0.82±0.05, 41%±11% vs. 37%± 13%, and 4.3%(2.9%, 14.0%) vs.8.8%(5.2%,14.6%), respectively. None of these parameters showed any significant difference (all P>0.05). In the free-hand group, the mean value of D90 pre- and post-implantation was (131.4±2.9) vs.(128.6±8.6) Gy, showing no significant difference (P>0.05), the mean values of V100, CI, HI, and EI pre-and post-implantation were 90.0%±0.5% vs. 89.0%± 3.0%, 0.84±0.04 vs. 0.71±0.09, 41%±9% vs. 34%±10%, and 7.7% (4.9%,11.0%) vs.24.2% (14.3%, 35.3%), respectively, showing significant differences (all P<0.05). The number of reseeding seeds in the template group was lower than that in the free-hand group [2.0 (0,2.5) vs. 4.0 (2.0, 7.0), Z=-3.36, P=0.001], showing a statistically significant difference. Further, the number of CT scans in the template group was significantly less than that in the free-hand group (3.9±0.5 vs. 4.6±1.2, t=-2.54, P=0.016). The incidences of adverse reactions were 23.8% (5/21) and 33.3% (8/24) (χ2=12.86, P=0.002) in the template and free-hand groups, respectively, indicating a significant difference. Conclusion: Compared with free-hand implantation, use of the adjustable angle needle path template technique can shorten the operation time, reduce the number of scans, reduce the incidence of complications, and improve treatment efficacy to a certain extent.

Interventional radiotherapy (brachytherapy) for re-irradiation of recurrent head and neck malignancies: oncologic outcomes and morbidity.

Objective: Management of recurrent head and neck cancer (HNC) is challenging. One option in previously irradiated patients is re-irradiation using interventional radiotherapy (IRT), the modern form of brachytherapy. Re-irradiation using IRT can be delivered as an exclusive strategy for salvage or through a postoperative or perioperative approach after salvage surgery. The aim of the present study is to analyse a bicentric Italian series focusing on the use of IRT as a re-irradiation modality and assess the resulting evidence concerning oncologic outcomes and morbidity. Methods: This is a retrospective study performed in two referral centres in Italy: Policlinico Universitario Agostino Gemelli in Rome and Azienda Ospedaliera Universitaria in Sassari. All patients who had previously received a full course of external beam RT and have been re-irradiated using high-dose-rate IRT between December 2010 and June 2023 were included. Patients were retreated either by a combination of surgery and perioperative (either endocavitary or interstitial) IRT or by exclusive interstitial IRT. Results: Thirty-four patients were included in the present series, 2 of whom underwent more than one IRT re-irradiation. Notably, no patient reported specific IRT-related toxicities. Median follow-up, excluding patients who died of HNC, was 24.5 months. Two-year local relapse-free survival was 26%, disease-specific survival 39.1%, and overall survival 36.6%. Conclusions: The present series is the largest reported experience of re-irradiation by IRT for HNC in Italy. The very low rate of toxicity confirms IRT as the safest re-irradiation modality. It is noteworthy to underline that IRT is a multidisciplinary strategy based on the close cooperation between surgeons and radiation oncologists during every phase, from the recommendation of treatment and implantation in the operating theatre, to its prescription and dose painting.

The relationship between quality of life and sex role of women with gynecological cancers undergoing brachytherapy.

PURPOSE: This study aims to analyze the relationship between the quality of life and sex roles of women diagnosed with cancer and undergoing brachytherapy. METHODS: The research is a cross-sectional descriptive study. The sample of the study included 116 women over 35 years old who were diagnosed with a gynecologic cancer and underwent intracavitary brachytherapy at the Radiation Oncology Department of a university hospital. Personal information form, SF-36 the Quality of Life Scale, and BEM Sex Role Inventory were used in the study. The researcher collected the data through face-to-face interview. The data were collected in the nurses' room after 3 different brachytherapy treatments that patients received weekly. RESULTS: It was found that the average score of the physical functioning subscale was 32.80 ± 24.33, the average score of role physical was 15.43 ± 28.78, the average score of role emotional was 17.81 ± 28.96, the average score of vitality was 39.13 ± 16.12, the average score of social functioning was 43.53 ± 20.55, the score average of pain was 50.0 ± 20.09, the average score of general health was 42.67 ± 14.61, and the general health of mental health was 55.86 ± 16.12. In the BEM sex roles scale, the average score of BEM femininity was 105.56 ± 13.95, and the average score of BEM masculinity was 80.61 ± 12.77. In our study, a very low, negative, and significant relationship was determined between the role of femininity and emotional role limitation, physical functionality, social functionality, and general health perception in the women undergoing brachytherapy (p < 0.05). CONCLUSIONS: Based on the findings of the present study, we can state that an increase in the "role of femininity" in women undergoing brachytherapy was effective in the decrease in the quality of lives of women. It can be claimed that the results will be a guidance for the nurses who will play an important role in increasing the quality of lives of the women undergoing brachytherapy.

Clinical Outcomes and Dosimetric Evaluationof Interstitial Brachytherapyin Gynecological Malignancies.

BACKGROUND: In management of Carcinoma Cervix, Brachytherapy plays a crucial role. Most commonly used technique is Intracavitary Brachytherapy (ICBT). In cases where ICBT is not technically feasible or it may result in suboptimal dose distribution, Interstitial Brachytherapy (ISBT) is recommended. With this study we wanted to study the clinical outcome and dosimetric details of interstitial brachytherapy in gynecological cancers. MATERIALS & METHODS: We analysed clinicaloutcome and dosimetric details of interstitial brachytherapy (ISBT) done for gynecological malignancies in our institute during the period 1st January 2013 to 31st December 2020. RESULTS: Total of 42 interstitial brachytherapy (ISBT) details were analysed.37 patients had Carcinoma Cervix and 5 patients had Carcinoma Vagina. In the majority of the patients, ISBT dosage schedule was three fractions 7Gy each. D2cc to rectum, bladder, sigmoid and bowel were 4.88 Gy, 5.62 Gy, 3.57 Gy and 2.47 Gy respectively. Mean CTV volume was 129.89 cc. EQD2 dose to CTV combining EBRT and ISBT dose was 85.88 Gy. D90 and D100 to CTV from ISBT were 111.96% and 68.21 % of prescribed dose respectively. Grade III/IV toxicities were seen in 5 (12%) patients. Local control rates at 1year &2 years were 88% & 85.7% respectively. DFS at 1 year, 2 years and 3 years were 80.7%, 72.3% and 65.7% respectively. OS at 1year, 2 years, 4 years and 5 years were 92.5%, 65.5%, 59.5% and 42.3% respectively. CONCLUSION: 3D imagebased dosimetry with CT based planning using MUPIT implant is a feasible option for gynecological malignancies warranting interstitial brachytherapy. In view of good clinical outcomes in terms of toxicity profile, Local control, DFS and OS with acceptable GEC-ESTRO dosimetric data, we recommend routine use interstitial brachytherapy if facilities are available and in clinical situations were ISBT is indicated.

A survey on brachytherapy training of gynecological cancer focusing on the competence of residents in China.

BACKGROUND: The brachytherapy is an indispensable treatment for gynecological tumors, but the quality and efficiency of brachytherapy training for residents is still unclear. METHODS: An anonymous questionnaire was designed to collect information on gynecological brachytherapy (GBT) training for radiation oncology residents from 28 training bases in China. The questionnaire content was designed based on the principle of competency based medical education (CBME). The Likert scale was employed to evaluate self-reported competence and comprehension regarding GBT. A total of 132 senior residents were included in the final analysis. RESULTS: 53.79% (71/132) of senior residents had experience in performing image-guided GBT, whereas 76.52% (101/132) had observed the procedure during their standardized residency training. The proportion of senior residents who reported having the self-reported competence to independently complete the GBT was 78.03% for intracavity GBT, 75.00% for vaginal stump GBT, and 50.03% for interstitial GBT, respectively. The number of successful completion of Interstitial, intracavity and vaginal GBT was correlated with the self- confidence of trainees after standardized training. In particular, the independent completion of interstitial GBT for more than 20 cases was an independent factor for the self-reported competence of senior residents. During the training period, 50.76% and 56.82% of the residents had not participated in the specialized examinations and professional GBT courses. CONCLUSIONS: The study revealed that the self-confidence of residents to independently complete brachytherapy was relatively high, and the specialized curriculum setting and training process assessment for brachytherapy training still need to be strengthened in the future.

[Brachytherapy : a crucial part of locally advanced cervical cancer treatment]. / La curiethérapie : un atout majeur dans le traitement du cancer du col de l'utérus localement avancé.

Cervical cancer is the 4th most diagnosed cancer in women. At a locally advanced stage, standard treatment combines chemotherapy, radiotherapy and a brachytherapy boost. Brachytherapy is a radiotherapy modality, often unknown, which allows the delivery of a very targeted high dose because it's given directly in contact with the tumor. This technique has proven its effectiveness in the treatment of locally advanced cervical cancer. It represents a major advantage because, despite technical advances, there is currently no alternative yielding equivalent results.

Le cancer du col utérin est le 4ème cancer féminin le plus diagnostiqué. à un stade localement avancé, la prise en charge standard relève d'un traitement associant de la chimiothérapie, de la radiothérapie et une curiethérapie de clôture. La curiethérapie est une modalité de radiothérapie, souvent méconnue du grand public, qui permet de délivrer une dose élevée de façon très ciblée, car celle-ci est donnée directement au contact de la tumeur. Cette technique a prouvé son efficacité et son caractère indispensable dans le traitement du cancer du col utérin localement avancé. Elle représente un atout majeur car, malgré l'évolution des techniques de radiothérapie externe plus modernes, il n'y a, à ce jour, aucune alternative équivalente.

Effective timing of hyaluronate gel injection in image-guided adaptive brachytherapy for uterine cervical cancer: a proposal of the 'adjusted dose score'.

Hyaluronate gel injection (HGI) in the rectovaginal septum and vesicovaginal septum is effective in the setting of high-dose-rate image-guided adaptive brachytherapy (IGABT) for cervical cancer. We aimed to retrospectively investigate optimal conditions for HGI to achieve optimal dose distribution with a minimum number of HGI. We classified 50 IGABT plans of 13 patients with cervical cancer who received IGABT both with and without HGI in the rectovaginal septum and vesicovaginal septum into the following two groups: plan with (number of plans = 32) and plan without (number of plans = 18) HGI. The irradiation dose parameters of high-risk clinical target volume (CTVHR) and organs at risk per fraction were compared between these groups. We also developed the adjusted dose score (ADS), reflecting the overall irradiation dose status for four organs at risk and CTVHR in one IGABT plan and investigated its utility in determining the application of HGI. HGI reduced the maximum dose to the most exposed 2.0 cm3 (D2.0 cm3) of the bladder while increasing the minimum dose covering 90% of CTVHR and the percentage of CTVHR receiving 100% of the prescription dose in one IGABT plan without causing any associated complications. An ADS of ≥2.60 was the optimum cut-off value to decide whether to perform HGI. In conclusion, HGI is a useful procedure for improving target dose distribution while reducing D2.0 cm3 in the bladder in a single IGABT plan. The ADS can serve as a useful indicator for the implementation of HGI.

Carbon ion radiotherapy for mesonephric adenocarcinoma of the uterine cervix: a case report.

BACKGROUND: Mesonephric adenocarcinoma is an extremely rare subtype of uterine cervical cancer that is associated with a poor prognosis and for which a standardized treatment protocol has not been established. Carbon ion radiotherapy (CIRT) is an emerging radiotherapy modality that has been shown to have a favorable anti-tumor effect, even for tumors resistant to conventional photon radiotherapy or chemotherapy. However, there is no report on CIRT outcomes for mesonephric adenocarcinoma of the uterine cervix. CASE PRESENTATION: We treated a 47-year-old Japanese woman with mesonephric adenocarcinoma of the uterine cervix (T2bN0M0 and stage IIB according to the 7th edition of the Union for International Cancer Control and International Federation of Gynecology and Obstetrics, respectively) with CIRT combined with brachytherapy and concurrent chemotherapy. CIRT consisted of whole pelvic irradiation and boost irradiation to the gross tumor; 36.0 Gy (relative biological effectiveness [RBE]) in 12 fractions and 19.2 Gy (RBE) in 4 fractions, respectively, performed once a day, four times per week. Computed tomography-based image-guided adaptive brachytherapy was performed after completion of CIRT, for which the D90 (i.e., the dose prescribed to 90% of the target volume) for the high-risk clinical target volume was 20.4 Gy in a total of 3 sessions in 2 weeks. A weekly cisplatin (40 mg/m2) dose was administered concomitantly with the radiotherapy for a total of five courses. From 4 months post-CIRT, the patient developed metastasis of the lung, with a total of 10 lung metastases over 70 months; these lesions were treated on each occasion by photon stereotactic body radiotherapy and/or systemic therapy. At 8 years from initial treatment (i.e., 2 years after the last treatment), the patient is alive without any evidence of recurrence and maintains a high quality of life. CONCLUSIONS: This is the first report of CIRT for treatment of mesonephric adenocarcinoma of the uterine cervix. The present case indicates the potential efficacy of CIRT in combination with brachytherapy for treatment of this disease.

Brachytherapy in craniopharyngiomas: a systematic review and meta-analysis of long-term follow-up.

OBJECTIVE: Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas (CPs). The potential benefits of brachytherapy for CPs have not yet been clarified. The purpose of this work was to conduct a meta-analysis to analyze the long-term efficacy and adverse reactions profile of brachytherapy for CPs. MATERIALS AND METHODS: The relevant databases were searched to collect the clinical trials on brachytherapy in patients with CPs. Included studies were limited to publications in full manuscript form with at least 5-year median follow-up, and adequate reporting of treatment outcomes and adverse reactions data. Stata 12.0 was used for data analysis. RESULTS: According to the inclusion and exclusion criteria, a total of 6 clinical trials involving 266 patients with CPs were included in this meta-analysis. The minimum average follow-up was 5 years. The results of the meta-analysis showed that 1-year, 2-3 years and 5 years progression free survival rates (PFS) are 75% (95%CI: 66-84%), 62% (95%CI: 52-72%) and 57% (95%CI: 22-92%), respectively. At the last follow-up, less than 16% of patients with visual outcomes worser than baseline in all included studies. While, for endocrine outcomes, less than 32% of patients worser than baseline level. CONCLUSION: In general, based on the above results, brachytherapy should be considered as a good choice for the treatment of CP.

AAPM Task Group Report 267: A joint AAPM GEC-ESTRO report on biophysical models and tools for the planning and evaluation of brachytherapy.

Brachytherapy utilizes a multitude of radioactive sources and treatment techniques that often exhibit widely different spatial and temporal dose delivery patterns. Biophysical models, capable of modeling the key interacting effects of dose delivery patterns with the underlying cellular processes of the irradiated tissues, can be a potentially useful tool for elucidating the radiobiological effects of complex brachytherapy dose delivery patterns and for comparing their relative clinical effectiveness. While the biophysical models have been used largely in research settings by experts, it has also been used increasingly by clinical medical physicists over the last two decades. A good understanding of the potentials and limitations of the biophysical models and their intended use is critically important in the widespread use of these models. To facilitate meaningful and consistent use of biophysical models in brachytherapy, Task Group 267 (TG-267) was formed jointly with the American Association of Physics in Medicine (AAPM) and The Groupe Européen de Curiethérapie and the European Society for Radiotherapy & Oncology (GEC-ESTRO) to review the existing biophysical models, model parameters, and their use in selected brachytherapy modalities and to develop practice guidelines for clinical medical physicists regarding the selection, use, and interpretation of biophysical models. The report provides an overview of the clinical background and the rationale for the development of biophysical models in radiation oncology and, particularly, in brachytherapy; a summary of the results of literature review of the existing biophysical models that have been used in brachytherapy; a focused discussion of the applications of relevant biophysical models for five selected brachytherapy modalities; and the task group recommendations on the use, reporting, and implementation of biophysical models for brachytherapy treatment planning and evaluation. The report concludes with discussions on the challenges and opportunities in using biophysical models for brachytherapy and with an outlook for future developments.

[Predicting the effectiveness of organ-preserving treatment of choroidal melanoma using optical coherence tomography data]. / Prognozirovanie effektivnosti organosokhrannogo lecheniya melanomy khorioidei po dannym opticheskoi kogerentnoi tomografii.

Optical coherence tomography (OCT) is currently widely used for the diagnosis of choroidal melanoma (CM), but the problem of predicting the outcomes of planned CM treatment remains unsolved. PURPOSE: This study was conducted to identify OCT signs that adversely affect the outcome of organ-preserving CM treatment. MATERIAL AND METHODS: OCT scan images of 30 patients who underwent organ-preserving treatment and were under observation were selected for this study. Brachytherapy (BT) as monotherapy was performed in 27 patients (in 2 cases - twice, and in 1 case - three times), in one patient - in combination with the previous transpupillary thermotherapy (TTT). Multiple TTT (4 sessions within 4 months) as monotherapy were performed in 2 patients. In 9 cases, a single organ-preserving treatment (BT - 6 patients, TTT - 3 patients) was ineffective. In these cases, the effectiveness of the first stage of organ-preserving treatment was taken into account. RESULTS: Seven signs of an unfavorable prognosis of the performed treatment were identified by analyzis of tomograms and statistical processing of the obtained data. These signs include: the presence of intraretinal edema, detachment of the neuroepithelium (NED) over the tumor, including with a break in the photoreceptors, accumulation of transudate over the tumor, the presence of large cysts, intraretinal cavities and NED near the tumor (secondary retinal detachment). A combination of three or more signs were observed in all cases of inefficiency of the first stage of treatment. Most often, intraretinal edema and NED over the tumor were combined with the accumulation of subretinal transudate and NED near the tumor. The presence of 6 or all 7 signs took place in cases of a negative therapeutic effect after local destruction. CONCLUSION: When planning organ-preserving CM treatment, in addition to biometric parameters, it is necessary to pay special attention to the identification of such morphological signs as NED over and near the tumor, accumulation of transudate under the NED, the presence of intraretinal edema, large intraretinal cysts and cavities.

Dose and DNA damage modelling of diffusing alpha-emitters radiation therapy using Geant4.

PURPOSE: Diffusing alpha-emitters radiation therapy (DaRT) is a brachytherapy technique using α-particles to treat solid tumours. The high linear energy transfer (LET) and short range of α-particles make them good candidates for the targeted treatment of cancer. Treatment planning of DaRT requires a good understanding of the dose from α-particles and the other particles released in the 224Ra decay chain. METHODS: The Geant4 Monte Carlo toolkit has been used to simulate a DaRT seed to better understand the dose contribution from all particles and simulate the DNA damage due to this treatment. RESULTS: Close to the seed α-particles deliver the majority of dose, however at radial distances greater than 4 mm, the contribution of ß-particles is greater. The RBE has been estimated as a function of number of double strand breaks (DSBs) and complex DSBs. A maximum seed spacing of 5.5 mm and 6.5 mm was found to deliver at least 20 Gy RBE weighted dose between the seeds for RBEDSB and RBEcDSB respectively. CONCLUSIONS: The DNA damage changes with radial distance from the seed and has been found to become less complex with distance, which is potentially easier for the cell to repair. Close to the seed α-particles contribute the majority of dose, however the contribution from other particles cannot be neglected and may influence the choice of seed spacing.

Selective internal radiation therapy segmentectomy: A new minimally invasive curative option for primary liver malignancies?

Transarterial radioembolization or selective internal radiation therapy (SIRT) has emerged as a minimally invasive approach for the treatment of tumors. This percutaneous technique involves the local, intra-arterial delivery of radioactive microspheres directly into the tumor. Historically employed as a palliative measure for liver malignancies, SIRT has gained traction over the past decade as a potential curative option, mirroring the increasing role of radiation segmentectomy. The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods, particularly well-suited for patients where surgical resection or ablation is not feasible. Radiation segmentectomy is a more selective approach, aiming to deliver high-dose radiation to one to three specific hepatic segments, while minimizing damage to surrounding healthy tissue. Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments.

Experimental validation of the accuracy of robotic-assisted radioactive seed implantation for tumor treatment.

An experimental validation of a robotic system for radioactive iodine-125 seed implantation (RISI) in tumor treatment was conducted using customized phantom models and animal models simulating liver and lung lesions. The robotic system, consisting of planning, navigation, and implantation modules, was employed to implant dummy radioactive seeds into the models. Fiducial markers were used for target localization. In phantom experiments across 40 cases, the mean errors between planned and actual seed positions were 0.98 ± 1.05 mm, 1.14 ± 0.62 mm, and 0.90 ± 1.05 mm in the x, y, and z directions, respectively. The x, y, and z directions correspond to the left-right, anterior-posterior, and superior-inferior anatomical planes. Silicone phantoms exhibiting significantly smaller x-axis errors compared to liver and lung phantoms (p < 0.05). Template assistance significantly reduced errors in all axes (p < 0.05). No significant dosimetric deviations were observed in parameters such as D90, V100, and V150 between plans and post-implant doses (p > 0.05). In animal experiments across 23 liver and lung cases, the mean implantation errors were 1.28 ± 0.77 mm, 1.66 ± 0.69 mm, and 1.86 ± 0.93 mm in the x, y, and z directions, slightly higher than in phantoms (p < 0.05), with no significant differences between liver and lung models. The dosimetric results closely matched planned values, confirming the accuracy of the robotic system for RISI, offering new possibilities in clinical tumor treatment.

Treatment of malignant airway obstruction with Y-shape sigma stent loaded with I125 seeds installed via rigid bronchoscopy.

PURPOSE: To summarize and analyze the safety and efficacy of a Y-shape Sigma stent loaded with I125 in patients with inoperable malignant main airway obstruction. METHODS: This study was approved by the Institutional Ethics Committee, and a written informed consent was obtained from each participant. A Y-shape Sigma stent loaded with I125 was placed under vision from rigid bronchoscopy. The primary endpoint was alleviation of symptoms and improvement of Karnofsky Performance Status (KPS) score, and the secondary endpoint was complications and technical success. RESULTS: From November 2018 through June 2023, total 33 patients with malignant airway obstruction were palliatively treated by installing Y-shape Sigma stents loaded with I125. The airway lumen was immediately restored and the average airway opening significantly increased to 70 ± 9.4% after the procedure from baseline 30.2 ± 10.5% (p < 0.05). Average KPS score was improved from baseline 30.0 ± 10.0 to 70.0 ± 10.0 (p < 0.05) as well as PaO2 from baseline 50.1 ± 15.4 mmHg to 89.3 ± 8.6 mmHg (p < 0.05). The technical success rate of placing the stent in this study was 73%, and adverse events or complications including bleeding, I125 loss, and airway infection occurred during or after the procedure. CONCLUSION: Placement of Y-shape Sigma stents under vision from rigid bronchoscopy in the patients with malignant airway obstruction is feasible and it immediately alleviates dyspnea and significantly improves quality of life.

Brachytherapy on-a-chip: a clinically-relevant approach for radiotherapy testing in 3d biology.

We describe the first microfluidic device for in vitro testing of brachytherapy (BT), with applications in translational cancer research. Our PDMS-made BT-on-chip system allows highly precise manual insertion of clinical BT seeds, reliable dose calculation using standard clinically-used TG-43 formalism and easy culture of naturally hypoxic spheroids in less than 3 days, thereby increasing the translational potential of the device. As the BT-on-chip platform is designed to be versatile, we showcase three different gold-standard post-irradiation bioassays and recapitulate, for the first time on-chip, key clinical observations such as dose rate effect and hypoxia-induced radioresistance. Our results suggest that BT-on-chip can be used to safely and efficiently integrate BT and radiotherapy to translational research and drug development pipelines, without expensive equipment or complex workflows.

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.

A systematic review of combined surgery and brachytherapy approaches for children and young people with relapsed and refractory rhabdomyosarcoma (Local-REFoRMS).

Approximately one third of children with rhabdomyosarcoma relapse or have refractory disease. Treatment approaches include a combination of systemic therapies and local therapies, directed at tumour site(s). This review was conducted to evaluate the effectiveness and safety of the combination of surgery and brachytherapy as local therapy for treating children and young people with relapsed/refractory rhabdomyosarcoma. This review identified studies based on a previous systematic review looking at the treatments for children and young people under 18 years old with relapsed/refractory rhabdomyosarcoma. Studies conducted after 2000 were included. Survival outcomes, relapse rates, adverse events and functional outcomes were extracted. From 16,965 records identified in the baseline systematic review, 205 included the words 'AMORE' or 'brachytherapy', and were screened for eligibility in this substudy. Thirteen studies met the inclusion criteria for Local-REFoRMS, including over 55 relapsed and refractory rhabdomyosarcoma patients. Most studies were retrospective cohort studies conducted within Europe. Most patients had embryonal disease within the head and neck or bladder/prostate regions, and received local therapy for first relapse. Approximately one quarter of patients relapsed following surgery and brachytherapy, with local relapses occurring more than metastatic relapse. Adverse events and functional outcomes were infrequently reported, but related to the site of surgery and brachytherapy. Study quality was limited by inconsistent reporting and potential selection bias. Outcomes following surgery and brachytherapy for a selected group of relapsed and refractory rhabdomyosarcoma show reasonable benefits, but reporting was often unclear and based on small sample sizes.

High-dose-rate Brachytherapy Monotherapy in Patients With Localised Prostate Cancer: Dose Modelling and Optimisation Using Computer Algorithms.

AIMS: Interstitial high-dose-rate brachytherapy (HDR-BT) is an effective therapy modality for patients with localized prostate carcinoma. The objectives of the study were to optimise the therapy regime variables using two models: response surface methodology (RSM) and artificial neural network (ANN). MATERIALS AND METHODS: Thirty-one studies with 5651 patients were included (2078 patients presented as low-risk, 3077 patients with intermediate-risk, and 496 patients with high-risk). A comparison of these therapy schedules was carried out using an effective biologically effective dose (BEDef) that was calculated assuming the number of treatment days and dose (D) per day. The modelling and optimization of therapy parameters (BEDef and risk level) in order to obtain the maximum biochemical free survival (BFS) were carried out by the RSM and ANN models. RESULTS: An optimal treatment schedule (BFS = 97%) for patients presented with low-risk biochemical recurrence would be D = 26 Gy applied in one application, 2 fractions at least 6 h apart, within an overall treatment time of 1 day (BEDef = 251 Gy) by the RSM and ANN model. For patients presented with intermediate- or high-risk an optimal treatment regime (BFS = 94% and 90%, respectively) would be D = 38 Gy applied in one application, 4 fractions at least 6 h apart, with an overall treatment time of 2 days (BEDef = 279 Gy) by the RSM and ANN models. CONCLUSIONS: The RSM and ANN models determine almost the same optimal values for the set of predicted therapy parameters that make a feasible selection of an optimal treatment regime.