High dose rate brachytherapy in nasopharyngeal carcinoma: a neglected practice

Nasopharyngeal carcinomas (NPCs) are one of the most chemo- and radio- sensitive cancers of the head and neck region. It differs from other head and neck cancers in terms of signs and symptoms, treatment response and overall survival. Surgery is not the preferred treatment option, with chemoradiation being the treatment of choice, with an excellent local control rate, prognosis and overall survival. But the management of recurrent NPC is quite challenging and the treatment options available includes re-irradiation, chemotherapy, brachytherapy or surgery in rare cases. Re-irradiation in case of recurrent NPC is very difficult due to the already irradiated tissue in the radiation path, but re-irradiation with brachytherapy is an excellent treatment option for giving further doses of radiation to the nasopharynx in cases of recurrence or residual disease, by taking in consideration the already irradiated area and the radiation dose given before, and achieving a good local control rate and overall survival.

Vaginal stenosis and dilator use after pelvic brachytherapy

Introduction: To prevent vaginal stenosis, the use of a vaginal dilator is recommended. Objective: To analyze sociodemographic data, gynecological conditions and the use of vaginal dilator after pelvic brachytherapy. Materials and Methods: Cross-sectional, retrospective study, period 2016-2020, collected between October/2020 and February /2021, from records of women with gynecological cancer treated with brachytherapy at the Centro de Pesquisa Oncológicas (Brazil). The variables included sociodemographic data and gynecological conditions in following the treatment. In the analysis, descriptive statistics, chi-squaretest, Fisher's exact test and Mann-Whitney test were applied. Results: 519 patients records were included in the investigation; the analyzes showed significant associations between the topography and staging (p<0.001), education (p=0.004) and age (p<0.001); the comparison between the distribution of the ionizing radiation dose showed a difference with the continued sexual relationship category (p=0.006); the comparison between the proportions of continued sexual relationship and using a vaginal dilator was significant (p<0.001); 49.10% (131) adhered to the use of vaginal dilator; 24.50% (127) are not sexually active and do not adhere to the use of the dilator. Discussion: It is evident that social and gynecological conditions interfere with the presence of vaginal stenosis and the use of a vaginal dilator after pelvic brachytherapy. Conclusions: The adherence found in the use of dilator affirms the contributions and the need for health education by nurses and physicaltherapists during and following the treatment.

Study on the dosimetry effect of rotational errors of a multi-channel cylinder applicator of vagina / 中国医学装备

Objective:To investigate the dosimetry effect of rotational errors of multi-channel cylinder vaginal applicator of intravaginal irradiation after surgery of endometrial cancer.Methods:A total of 18 patients who underwent surgery of endometrial cancer at Peking Union Medical College Hospital from June to December 2022 were selected.The plans of patients who adopted the treatment of multi-channel cylinder applicator of vagina were retrospectively analyzed,which maintained the same retained mode with clinical plan.The applicator was rotated clockwise by 22.5? and 45.0?,respectively,simulating the rotational errors that occurred in placing the applicator among clinical inter-fractions.And then,the changes of dosimetry of target area and organs at risk(OAR)under two kinds of rotation amplitudes were further analyzed.Results:When the applicator was rotated as 22.5?,the minimum doses to 90%volumes of CTV by 2.03%than that of clinical plan,which was significantly different(t=5.86,P<0.05),and the maximal doses to 2cc of OARs of bladder and rectum respectively increased 2.35%and 2.71%,and the differences of them were statistically significant(t=-3.49,-2.40,P<0.05),respectively.When the applicator was rotated as 45?,the D90 of the target area decreased by 5.75%than that of clinical plan,which was statistically significant(t=14.07,P<0.05).The D2cc values of the bladder and rectum increased respectively by 6.50%and 9.49%than that of clinical plan,which were statistically significant(t=-7.72,-6.9,P<0.05).The differences of the exposed doses of sigmoid colon and small intestine after the applicator was rotated by 22.5? and 45.0? between the plan and original plan were respectively less,which were not statistical significance.Conclusion:The multi-channel cylinder applicator can provide individualized dose distribution in intravaginal irradiation.However,attention should be paid to the placement of the applicator when patients undergo inter-fractional treatment,in order to avoid deviations in the angular alignment from the original plan.This can impact the dosages of the target area and OARs.

Dosimetric analysis of radiation pneumonitis induced by 125I seed implantation for the treatment of malignant lung tumors / 中华放射医学与防护杂志

Objective:To investigate the incidence of radiation pneumonitis (RP) induced by 125I seed implantation for the treatment of malignant lung tumors and analyze related dosimetric parameters. Methods:A retrospective analysis was conducted on 31 cases of malignant lung tumors treated with 125I seed implantation from January 2017 to December 2022 at Hebei Provincial Tumor Radioactive Seeds Implantation Diagnosis and Treatment Center. These cases consisted of eight patients with squamous cell carcinoma, 10 patients with adenocarcinoma, and 13 patients with metastatic cancer in other sites. At 1-6 months after treatment, these patients received postoperative chest CT scans, with the efficacy evaluated based on the Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST 1.1), including the objective response rate (ORR) and the disease control rate (DCR). The efficacy of RP was evaluated using the Radiation Therapy Oncology Group (RTOG) criteria. Postoperative dosimetric parameters, including D90 (minimum peripheral dose received by 90% of the target volume), V8 (percentage of lung volume receiving 8 Gy), V32 (percentage of lung volume receiving 32 Gy), and Dmean (mean radiation dose) of the affected lung, were statistically analyzed. The relationships of the RP occurrence with postoperative D90, V8, V32, and Dmean were analyzed by comparison with relevant external radiotherapy data, to identify the parameters that are correlated closely with RP occurrence. Results:All the patients underwent successful surgeries. The postoperative efficacy evaluation after six months showed complete response (CR) in 11 cases, partial response (PR) in 11 cases, stable disease (SD) in eight cases, and progressive disease (PD) in one case, with an overall response rate (ORR) of 71.0%, and a disease control rate (DCR) of 96.8%. Three patients suffered RP, with an incidence rate of 9.7%. Postoperative V8, V32, and Dmean could not serve as predictive indicators for RP. Follow-up observation revealed that three RP cases (3/5) exhibited postoperative D90 exceeding 170 Gy and no RP cases (0/26) showed postoperative D90 below 170 Gy. Conclusions:In the treatment of malignant lung tumors with 125I seed implantation, there is a certain correlation between RP and postoperative D90, while there is no correlation between it and V8, V32, and Dmean.

Tumor volume affects the short-term efficacy of cervical cancer and brachytherapy / 中华放射肿瘤学杂志

Objective:To evaluate the effect of tumor volume on the radiation dose and efficacy of locally advanced cervical cancer patients undergoing radical radiotherapy and chemotherapy.Methods:Clinical data of 126 patients who were diagnosed with cervical cancer (stage ⅡB-ⅣA) and underwent radical concurrent chemoradiotherapy in Guangxi Medical University Cancer Hospital from November 2019 to November 2022 were retrospectively analyzed. The cut-off values of tumor volume before (pre-TV) and after (post-TV) external radiotherapy and tumor volume reduction rate (TVRR) were calculated by Jamovi software. The effects of pre-TV, post-TV and TVRR on short-term efficacy, progression-free survival (PFS), brachytherapy (BT) mode , high-risk clinical target volume (HR-CTV) and organs at risk (OAR) dose were investigated by univariate and multivariate analyses.Results:Pre-TV≥67.03 cm 3 and post-TV≥14.88 cm 3 were poor prognostic factors for 6-month PFS and objective response rate (ORR) (both P<0.05), and post-TV was an independent prognostic factor. In the TVRR≥73.0% and <73.0% groups, no statistical differences were observed in the 6-month PFS and ORR. In the pre-TV≥67.03 cm 3 group, the cases number of intracavitary brachytherapy (ICBT) and intracavitary / interstitial brachytherapy (IC/IS-BT) was 36 (50.0%), while in the pre-TV<67.03 cm 3 group, the cases number of ICBT and IC/IS-BT was 41 (76%) and 13 (24%), respectively ( P=0.003). In the post-TV≥14.88 cm3 group, the cases number of ICBT and IC/IS-BT was 28 (47%) and 32 (53%), while 49 (72%) and 17 (26%) in the post-TV<14.88 cm3 group, respectively ( P=0.002). The dose of HR-CTV D 90% in the TVRR≥73.0% group was significantly higher than that in the TVRR<73.0% group ( P=0.014), but there was no significant difference in the dose of bladder D 2 cm3, rectal D 2 cm3 and small intestine D 2 cm3 (all P>0.05). The dose of HR-CTV D 90% in the post-TV<14.88 cm 3 group was significantly higher than that in post-TV≥14.88 cm 3 group ( P<0.001), and the dose of bladder D 2 cm3 in the post-TV≥14.88 cm 3 group was higher than that in the post-TV<14.88 cm 3 group ( P<0.05). There was no significant difference in the dose of rectal D 2 cm3 and small intestinal D 2 cm3 between two groups (both P>0.05). The number of concurrent chemotherapy (≥4 times vs.<4 times) had no statistical difference for 6-month PFS and TVRR. Conclusions:Pre-TV and post-TV are the influencing factors of short-term efficacy and BT mode selection for locally advanced cervical cancer. Post-TV is an independent prognostic factor and also indirectly affects the dose of HR-CTV D 90% and bladder D 2 cm3 Increasing the number of concurrent chemotherapy (≥4 times) does not improve TVRR and short-term efficacy.

Design and clinical application of intracavitary-interstitial brachytherapy applicator template in locally advanced cervical cancer / 中华放射肿瘤学杂志

Objective:To design and evaluate the application value of intracavitary-interstitial brachytherapy (IC-ISBT) applicator template for locally advanced cervical cancer.Methods:MRI data of 100 patients with ⅡB-ⅣA stage cervical cancer (International Federation of Gynecology and Obstetrics 2018 staging system) before and after external beam radiation therapy (EBRT) admitted to Sun Yat-sen University Cancer Center from March 2019 to September 2020 were collected. The range of primary cervical lesions was retrospectively analyzed and compared. Based on the residual mass of patients, the corresponding high-risk clinical target volume (HR-CTV) was delineated, and the IC-ISBT applicator template was designed and initially applied to cervical cancer patients. Dosimetry analysis and efficacy evaluation were compared between the applicator template-guided ( n=37) and free-hand implantation groups ( n=63). Chi-square test or Fisher exact test was performed for categorical variables, and t-test or U-test for continuous variables. Results:The median distance between the residual tumor margin (clockwise 3, 6, 9, 12 o'clock) and the center of 100 patients with ⅡB-ⅣA stage cervical cancer after EBRT was 16.5, 14.0, 17.0 and 13.0 mm, respectively. The corresponding HR-CTV was superimposed to reconstruct the three-dimensional diagram, and the cylindrical IC-ISBT applicator template with mushroom-like head was designed and manufactured: the longest and shortest diameter of the head was 35 and 20 mm, respectively; the central channel was adapted to the uterine tube, the C1-C12 channels was arranged in inner circle, and the peripheral B1-B5 and A1-A4 pin channels were expanded bilaterally. In terms of dose coverage, there was no significant difference between the HR-CTV D 90% [(635.12±22.65) vs. (635.80±25.84) cGy], bladder D 2 cm3 [(473.79±44.78) vs. (463.55±66.43) cGy)], rectum D 2 cm3 [(396.99±73.54) vs. (408.00±73.94) cGy] and sigmoid colon D 2 cm3 [(293.07±152.72) vs. (311.31±135.77) cGy] between the template-guided and free-hand implantation groups (all P>0.05), but the HR-CTV D 98% was significantly higher [(544.78±32.07) vs. (536.78±32.04) cGy, P=0.007] and the rectum D 1 cm3 and D 0.1 cm3 were significantly lower [(438.62±69.65) vs. (453.97±67.89) cGy, P=0.016; (519.46±70.67) vs. (543.82±81.24) cGy, P=0.001] in the template-guided implantation group. In addition, there was no significant difference in the complete response rate between two groups (86% vs. 83%, P>0.05). Conclusions:This IC-ISBT applicator template is reasonably designed, and the therapeutic efficacy of the template-guided implantation is equivalent to that of free-hand implantation. The dose coverage of the target area meets the clinical demand with a better protection of the organs at risk. The applicator template has the potential to be widely used as a conventional template in clinical practice as the applicator-guided implantation is convenient to operate and repeat.

Efficacy analysis of 125I seeds implantation combined with transcatheter arterial chemoembolization therapy for primary liver cancer / 中华核医学与分子影像杂志

Objective:To explore the clinical efficacy of 125I seeds implantation combined with transcatheter arterial chemoembolization (TACE) in the treatment of primary liver cancer. Methods:A retrospective analysis of data from 40 patients with primary liver cancer at the Northern Theater General Hospital from January 2018 to December 2020 (26 males, 14 females, age 41 to 82 years) was performed. Among them, 21 patients were in treatment group and underwent 125I seeds implantation combined with TACE treatment, while 19 patients were in control group and received TACE treatment. Alpha-fetoprotein (AFP) levels between the two groups were compared, effective rate and disease control rate (DCR) of the two groups were analyzed, and overall survival (OS) and progression-free survival (PFS) were observed. Data were analyzed by using Mann-Whitney U test, χ2 test, Kaplan-Meier method and log-rank test. Results:Two months after 125I seeds implantation, the effective rates of treatment group and control group were 76.19%(16/21) and 8/19, respectively ( χ2=4.83, P=0.028); the DCRs were 90.48%(19/21) and 11/19, respectively ( χ2=4.21, P=0.040). AFP levels in both groups decreased significantly, with treatment group showing a greater decrease rate (0.87(0.84, 0.90) and 0.66(0.65, 0.67); z=5.42, P<0.001). No serious adverse reaction was observed in either group. The median OS of treatment group and control group were 18.2 and 10.6 months, respectively ( χ2=10.98, P=0.037); the median PFS of the two groups were 8.4 and 6.1 months, respectively ( χ2=7.54, P=0.041). Conclusion:125I seeds implantation combined with TACE treatment can exert a synergistic and enhancing effect in the treatment of primary liver cancer.

Comparison of 90Y PET/CT and 90Y bremsstrahlung SPECT/CT imaging in evaluation of radiation dose after 90Y-selective internal radiation therapy in liver malignancies / 中华核医学与分子影像杂志

Objective:To compare the differences of actual absorbed doses of liver malignant tumors after 90Y-selective internal radiation therapy (SIRT) evaluated by 90Y PET/CT and 90Y bremsstrahlung (BRS) SPECT/CT imaging, and to compare the image quality of the 2 imaging methods. Methods:Twenty-one patients (15 males and 6 females; age: (52.4±15.4) years) with liver malignant tumors (15 cases of primary liver cancer, 6 cases of liver metastases; 39 lesions) between September 2021 and August 2022 were retrospectively analyzed. All patients underwent both 90Y PET/CT imaging and 90Y BRS SPECT/CT imaging in the Department of Nuclear Medicine, Hainan Cancer Hospital. The ratios of the actual absorbed doses based on 90Y PET/CT imaging and 90Y BRS SPECT/CT imaging to the lowest standard absorbed dose(100 Gy) for tumor response were calculated. The image contrast and distinguishability of the two imaging methods were scored. Wilcoxon signed rank test and Wilcoxon rank sum test were used for data analysis. Results:The tumor absorbed doses evaluated by 90Y PET/CT and 90Y BRS SPECT/CT were 143.94(55.91, 233.48) Gy and 107.82(53.59, 157.53) Gy respectively. The doses evaluated by 90Y PET/CT were higher than the standard threshold in 24 lesions, while 19 lesions showed higher evaluated doses by 90Y BRS SPECT/CT than the standard threshold. Compared with 90Y PET/CT, 90Y BRS SPECT/CT underestimated the tumor absorbed dose of -24.25%(-32.32%, -12.14%). The ratio of dose evaluated by 90Y PET/CT to the lowest standard threshold was 1.33(0.56, 1.91), which was higher than that of dose evaluated by 90Y BRS SPECT/CT to the lowest standard threshold (0.97(0.47, 1.25); z=0.04, P<0.001). PET/CT image contrast was scored 0, 1, 2, 3 in 2, 2, 12, 23 lesions respectively, and SPECT/CT image contrast was scored 0, 1, 2, 3 in 2, 3, 16, 18 lesions respectively ( z=-1.29, P=0.199). The distinguishability scores of 0, 1, 2 based on PET/CT images were found in 3, 15, 21 lesions, while those based on SPECT/CT images were found in 4, 32, 3 lesions respectively ( z=-2.79, P=0.005). Conclusion:90Y PET/CT imaging is superior to 90Y BRS SPECT/CT imaging in radiation dose evaluation and tumor focus differentiation in patients with liver malignant tumors after 90Y-SIRT.

Progress in clinical application of 125I seeds brachytherapy in the treatment of oral and maxillofacial malignant tumors / 中华核医学与分子影像杂志

Oral and maxillofacial malignant tumors threaten the life and health of patients, and seriously affect their swallowing, language function and face. 125I seeds brachytherapy for oral and maxillofacial malignant tumors has been widely concerned and studied because of its advantages such as less surgical trauma, large and uniform dose distribution in the target tissue, little damage to the surrounding normal tissue, and reducing radiation exposure of medical staff. Low-dose brachytherapy with 125I seeds can effectively reduce the tumor volume and prolong the survival time of patients. This article reviews the clinical application of 125I seeds brachytherapy in oral and maxillofacial malignant tumors.

Effects of radical resection or brachytherapy as initial treatment on the prognosis of patients with high-risk prostate cancer / 现代泌尿外科杂志

【Objective】 To investigate the effects of radical prostatectomy (RP) or brachytherapy (BT) on the prognosis of patients with high-risk prostate cancer as initial treatment, in order to provide a reference for the selection of clinical treatment options. 【Methods】 The clinical data of 133 191 patients diagnosed with high-risk prostate cancer and treated with RP or BT during 2005 and 2014 were extracted from the SEER database.The 5-year and 10- year cancer-specific survival (CSS) and overall survival (OS) were compared with K-M analysis and univariate and multivariate Cox regression.The clinical data of another 253 patients diagnosed with high-risk prostate cancer in Subei People’s Hospital during 2015 and 2020 were collected, including 153 patients who received RP and 100 patients who received BT.The 5-year biochemical progress-free survival (bPFS) and CSS were compared with K-M analysis. 【Results】 Univariate analysis of SEER data showed that BT was associated with a higher risk of death (HR=1.319, 95%CI: 1.256-1.386, P<0.001); age, marital status and TNM stage were associated with higher risk of death (P<0.001).Multivariate analysis, adjusted for relevant variables, showed that BT did not result in a higher risk of death compared with RP (HR=0.964, 95%CI:0.924-0.996, P=0.808). The OS curve showed that the longer the observed survival time, the better OS of RP as compared to BT (P<0.001); however, the CSS survival curve showed that the longer the observed survival time, the better CSS of BT compared to RP (P<0.001).The single-center data analysis showed no significant difference between BT and RP in the 5-year bPFS (P=0.263) and CSS (P=0.946). 【Conclusion】 For patients with high-risk prostate cancer, there is a significant difference in the prognosis of the two treatments if there is no adjustment of age, marital status, TNM stage and other factors, and the efficacy of RP is better than that of BT, especially in patients with survival more than 10 years.However, there is no statistically significant difference in the prognosis after the possible confounding factors are adjusted.Therefore, the initial treatment choice for these patients should be weighed from multiple perspectives, and patients’ choices must be respected after they are fully informed.

Anesthetic challenges during endobronchial brachytherapy: A case report

@#Lung cancer is the leading cause of cancer death worldwide. It may present as airway obstruction in a patient with endobronchial masses. Endobronchial brachytherapy (EBBT) has been shown to provide palliative therapy. It is the insertion of a radioactive material near the mass to reduce tumor size, thereby improving airway obstruction. This is the first case of EBBT done in our institution during the COVID-19 pandemic. A 53-year-old male, 60 kg, ASA Physical Status 2 for hypertension, smoker, malignancy, and previous pulmonary tuberculosis patient, presented with a cough and dyspnea. An endobronchial mass almost obstructing the right mainstem bronchus was seen on a computed tomography (CT) scan. He was diagnosed with squamous cell carcinoma of the lung and underwent radiotherapy and erlotinib chemotherapy. On repeat CT scan, there was no noted decrease in the size of the mass. EBBT was suggested, and a multi-disciplinary team was formed for the planned procedure. Pulmonology, radiation oncology, and anesthesiology teams were identified, and thorough planning was done prior to the actual procedure. Three fractions of EBBT were done under sedation using midazolam, fentanyl, and dexmedetomidine infusion. Lidocaine spray and transtracheal block were also performed as adjuncts prior to sedation. The procedure went as planned, and points for improvement were discussed for subsequent fractions. Due to persistent cough and discomfort from the catheter, additional ipratropium nebulization for minimization of secretions, and oral dextromethorphan for cough suppression were incorporated. After each fraction, the patient was monitored post-procedure for any side effects both from the radiotherapy and anesthetic technique. Qualitative reduction in mass size was noted in subsequent fractions. The patient was able to complete 3 fractions and was advised to follow-up after a month. EBBT is an emerging palliative and treatment modality for lung cancer, especially for intraluminal masses. Anesthetic considerations will depend on each case’s characteristics such as airway anatomy, patient comfort and capacity, and procedural requirements. Conscious sedation with topical anesthesia is an adequate and appropriate anesthetic option, especially in cases where severe airway obstruction may compromise ventilation if airway reflexes are blunted. A multidisciplinary approach with different services and stakeholders is important for the proper planning, execution, and management of such patients.

Progress of seed 125I implantation combined with other regimens in the treatment of unresectable pancreatic cancer / 中国医师杂志

pancreatic cancer is a common malignant tumor of digestive system, with poor prognosis. About 80% of patients have lost the opportunity of surgical resection when diagnosed. In different treatment schemes, radioactive seed 125I implantation can improve the quality of life of patients with unresectable pancreatic cancer and is expected to improve their survival rate. This article reviews the clinical applications of 125I particle implantation therapy combined with chemotherapy, cryotherapy, intracavitary irradiation, stent placement, radiofrequency ablation, nanoknife, and bypass surgery, in order to better promote its clinical application. However, it is necessary to establish unified dosage standards and regulatory guidelines to make them safer and more widely serve clinical practice.

Assessment of Specification for testing of quality control in γ-ray sources afterloading brachytherapy (WS 262-2017) in Jiangsu Province, China / 中国辐射卫生

Objective To evaluate the implementation, application, problems, and suggestions associated with the WS 262-2017 Specification for Testing of Quality Control in γ-Ray Sources Afterloading Brachytherapy among radiation workers in Jiangsu Province, China, and to provide a scientific basis for further revision and implementation of this standard. Methods A questionnaire survey was conducted among employees of public and private institutions involved in radiation health technology services, radiation health supervision, and medical services in Jiangsu Province who carried out afterloading testing, supervision, and treatment. The survey primarily focused on the implementation status, technical content, and implementation effect of WS 262-2017, and the results were summarized and analyzed. Results A total of 185 valid questionnaires were collected, and 73.5% of the respondents were aware of the standard. Among the respondents who were aware of the standard, 29.4% did not participate in relevant training, and 41.2% did not use or infrequently used the standard. Moreover, 94.1% of survey respondents considered the standard to be scientifically robust and free of issues, 88.6% responded that the main technical content of the standard was highly operable, and 97.8% agreed that the main content of the standard was coordinated and consistent with relevant regulatory standards. In addition, 88.6%, 90.8%, and 87.0% of survey respondents reported that this standard provided significant assistance and played an important role in optimizing radiation protection, quality control and testing of radiation therapy equipment, and improving professional skills for technical personnel. Conclusion Radiation workers in Jiangsu Province have a high awareness rate of WS 262-2017 and believe that this standard is scientifically rigorous and plays an important role. There is no need for revision, but relevant departments should strengthen the promotion and training concerning the standard.

Comparison of outcome of interdigitated versus sequential brachytherapy along with concurrent chemoradiation in locally advanced carcinoma cervix

Background: Carcinoma cervix is a significant health concern, particularly in lower socioeconomic groups. The effectiveness of interdigitated versus sequential brachytherapy, both with concurrent chemoradiation, in treating this condition remains underexplored.Methods: This quasi-experimental study at Rajshahi Medical College Hospital enrolled 63 patients with biopsy-proven squamous cell cervical cancer. They were randomly divided into two arms: arm a received pelvic EBRT 50 Gy in 25 fractions, followed by HDR brachytherapy (7 Gy weekly × 3 weeks) starting after 30 Gy of EBRT; arm B received the same pelvic EBRT, followed by HDR brachytherapy (7 Gy weekly × 3 weeks) starting a week after the completion of EBRT.Results: Mean age was 47.82±8.45 years (range: 29-64 years). The mean OTT was significantly reduced in arm-A (36.58 days) compared to arm-B (59.5 days). In terms of treatment response, 90.32% of patients in arm-A and 78.12% in arm-B experienced a complete response.Conclusions: Interdigitated brachytherapy with concurrent chemoradiation significantly reduces treatment time without compromising treatment effectiveness. Despite a shorter treatment duration, the complete response rate was slightly higher in the interdigitated arm.

Comparison of outcome of interdigitated versus sequential brachytherapy along with concurrent chemoradiation in locally advanced carcinoma cervix

Background: Carcinoma cervix is a significant health concern, particularly in lower socioeconomic groups. The effectiveness of interdigitated versus sequential brachytherapy, both with concurrent chemoradiation, in treating this condition remains underexplored.Methods: This quasi-experimental study at Rajshahi Medical College Hospital enrolled 63 patients with biopsy-proven squamous cell cervical cancer. They were randomly divided into two arms: arm a received pelvic EBRT 50 Gy in 25 fractions, followed by HDR brachytherapy (7 Gy weekly × 3 weeks) starting after 30 Gy of EBRT; arm B received the same pelvic EBRT, followed by HDR brachytherapy (7 Gy weekly × 3 weeks) starting a week after the completion of EBRT.Results: Mean age was 47.82±8.45 years (range: 29-64 years). The mean OTT was significantly reduced in arm-A (36.58 days) compared to arm-B (59.5 days). In terms of treatment response, 90.32% of patients in arm-A and 78.12% in arm-B experienced a complete response.Conclusions: Interdigitated brachytherapy with concurrent chemoradiation significantly reduces treatment time without compromising treatment effectiveness. Despite a shorter treatment duration, the complete response rate was slightly higher in the interdigitated arm.

Plaque brachytherapy – Radiating positivity

Background: Plaque brachytherapy is an evolving, yet effective globe and vision-sparing modality for the treatment of intraocular tumors by transscleral irradiation of the tumor base with a radioactive implant. The American Brachytherapy Society (ABS) along with the collaboration of the international multicenter Ophthalmic Oncology Task Force (OOTF) was assembled to reach a consensus regarding establishing practice guidelines and setting standards of care for intraocular tumors. The advent of plaque brachytherapy has revolutionized the outcomes of intraocular tumors, thus ensuring globe salvage, reducing morbidity and mortality, and avoiding cosmetic disfigurement. A well-planned dosimetry for plaque brachytherapy results in achieving local tumor control and excellent prognosis. Purpose: This technique provides the advantage of focal radiation, thus eliminating the damage to the adjacent structures, minimal periorbital tissue damage, absence of cosmetic disfigurement owing to lack of retarded bone growth as seen in external beam radiotherapy. Thus, it reduces the risk of metastasis, and with the recent advances, it provides a shorter duration of treatment. Synopsis: In this video, we shall display the concept of plaque brachytherapy, the various types of plaques available, different radiations sources, planning dosimetry and calculations, target disease spectrum, surgical placement, and post-radiation outcomes in terms of local tumor control and prognosis. Highlights: This video highlights the history, basic principles and techniques of plaque brachytherapy and provides an understanding of its applications in the world of ocular oncology.

A preliminary study on stereotactic ablative brachytherapy for lung metastases from cervical cancer / 中国辐射卫生

Objective To preliminarily study the effectiveness and safety of stereotactic ablative brachytherapy (SABT) for lung metastases from cervical cancer. Methods We analyzed the clinical data of 18 patients with cervical cancer with lung metastasis treated with SABT to compare gross tumor volume (VGTV) and squamous cell carcinoma (SCC) antigen before and after SABT. The clinical benefit rate (CBR) and adverse reactions were recorded. Results After SABT treatment, there were significant decreases in VGTV (t=1.708, P<0.05) and the SCC antigen level (t=1.704, P<0.05). CBR reached 94.4%. Adverse reactions of grades 3-4 did not occur in any patient. Fourteen patients had mild complications, including 1 case of bloody sputum and 1 case of a small pneumothorax. Ten cases developed mild radiation-induced lung injury, with grade 2 radiation pneumonitis in 4 cases. The Karnofsky performance status score and needle depth were not associated with the occurrence of adverse reactions, while the radius of GTV and interstitial lung disease were associated with the occurrence of adverse reactions. Conclusion SABT is a safe and effective alternative to the treatment of lung metastases from cervical cancer.

Workflow and time efficiency analysis of different image guided brachytherapy for cervical cancer / 中华放射医学与防护杂志

Objective:To explore the radiation dose of brachytherapy plan for cervical cancer patients under different image-guided method and the time efficiency characteristics of each part of the clinical workflow, so as to provide reference for the overall arrangement of clinical brachytherapy.Methods:The workflow of 223 patients with brachytherapy was retrospectively analyzed. The whole workflow was divided into 5 parts: applicator placement, image acquisition, delineation of target and organs at risk, plan design and review, and treatment implementation. The image-guided brachytherapy was divided into X-ray guided 2D treatment groups, and computed tomography(CT)and magnetic resonance imaging (MRI) guided 3D treatment groups. The radiation dose and the time spent in each part of the three image-guided brachytherapy workflow were calculated. The radiation dose was evaluated using total reference air kerma (TRAK). The results were analyzed using the nonparametric test of SPSS 20 software.Results:TRAK 4.2(4.4, 3.9) cGy was significantly higher in X-ray guided 2D treatment group than in the CT guided 3D treatment group [3.5(3.9, 2.7) cGy, H =90.73, P < 0.01] and the MRI guided 3D treatment group[2.7(2.9, 2.4) cGy, H =90.73, P < 0.01]. The total workflow time of the X-Ray film guidance group was the shortest [55.0(67.0, 50.0) min], followed by the CT guidance group [80.0(91.0, 72.0) min], and the total workflow time of the MRI image guidance group was the longest [119.0(143.0, 105.5) min, H =106.39, P <0.01]. The image acquisition time of the MRI-guided group was significantly higher than that of the X-ray film guidance group and the CT-guided group ( H =44.80, P<0.01). The time of target delineation in the MRI-guided group was significantly longer than that in the CT-guided group ( Z=-5.10, P<0.01). The MRI-guided group took the longest time for planning, followed by the CT-guided group, and the X-ray guided group took the shortest time ( H =57.93, P<0.01). Conclusions:The 2D brachytherapy mode guided by X-ray film had the shortest process time but higher TRAK, while the 3D brachytherapy mode guided by MR had the longest process time, and the planned TRAK result were comparable to those guided by CT. When multiple patients are treated with brachytherapy at the same time, the work efficiency can be improved by interspersing different phases and the waiting time can be avoided.

Clinical commissioning of the Flexitron afterloader / 中华放射医学与防护杂志

Objective:To formulate clinical commissioning procedures, items, and testing method for Flexitron afterloader hardware and software and establish relevant quality control procedures in order to meet national standards and clinical requirements.Methods:Clinical commissioning included hardware, treatment planning system (TPS), and end-to-end (ETE) full-process testing. The radioactive source positioning accuracy was measured using a source position check ruler. The accuracy and linearity of dwell time were evaluated using three method: stopwatch timing, ion chamber measurement, and video analysis. The accuracy of source position simulator, connecting tubes, source position check ruler, and other measuring tools was tested using a high-precision ruler. Films were used for calibration of marker lines and applicators. The electrometer and well chamber were used to calibrate the radioactive source activity. The display and reconstruction accuracies of the TPS were evaluated using physical image data. ETE testing was conducted using a custom-made phantom for scanning, planning, and dose measurement.Results:The accuracy testing result of the commissioning items were within acceptable limits. The deviation in source activity measurements was 0.21%, and the ETE point dose measurement deviation was 2.32%, both of which met the clinical requirements. However, there was a 2 mm difference between the nominal and measured values of the magnetic resonance marker line in the accuracy testing items. Therefore, adjustments were required when using marker line for catheter reconstruction based on magnetic resonance images.Conclusions:By summarizing the clinical commissioning experience of the Flexitron afterloader, this study has developed quality control method and baseline levels of result of afterloader and TPS items, which provides a reference for the commissioning before clinical use.

Application of canal-shaped implant template in brachytherapy for cervical cancer / 中华放射肿瘤学杂志

Objective:To explore the method of developing a canal-shaped implant template using a combined automatic pre-planning and 3D printing technology, and assess its impact on dose and efficacy improvement.Methods:Retrospective analysis of 15 patients with advanced cervical cancer admitted to the Affiliated Cancer Hospital of Guangxi Medical University from September 2020 to September 2022 was performed. Patients had characteristics such as vaginal stump recurrence, tumor eccentric growth, and previous hysterotomy, etc. Three-dimensional images were obtained by CT scan after automatic pre-planning. The PMT 3D software was used to analyze digital imaging and communications in medicine (DICOM) radiotherapy data, capture the coordinates of the pre-planned stay points to establish the implant channel, and generate the size and shape of the canal-shaped implant template based on patients' physiological structure. Dosimetric parameters, such as conformity index (CI), were evaluated. The changes of tumor size before and after treatment were analyzed by paired t-test. Results:Fifteen patients were treated with the canal-shaped implant template. The CI was 0.74±0.26, the total radiation dose (HR-CTV) D 90% (EQD 2, α/β=10) was (85.5±6.8) Gy, and the D 2 cm3 (EQD 2, α/β=3)for bladder, rectum, small intestine, and colon were (72.2±4.2), (65.8±6.1), (65.2±4.4), and (69.8±3.7) Gy, respectively, meeting clinical needs. After the treatment, the tumor volume was significantly decreased. The template had a good fit with the vaginal cavity, and a small amount of air gap on the sidewall did not affect the dose. Non-parallel needle insertion increased the utilization of the cavity space and implant needles. Conclusion:The method of developing the canal-shaped implant template using automatic pre-planning and 3D printing technology is efficient and effective, meets the requirements of modern precise radiotherapy, and has practical clinical value.