Combined Interstitial and Intracavitary High-Dose Rate Brachytherapy of Cervical Cancer

Survey to assess present practice and address challenges in gynaecological brachytherapy in Australia and New Zealand

INTRODUCTION

This survey assessed gynaecological brachytherapy caseloads, local training requirements and quality assurance processes across Australia and New Zealand.

METHODS

The survey was developed by the Gynaecological Oncology Radiation Oncology Collaboration (GOROC) and emailed to all centres offering gynaecological brachytherapy across Australia and New Zealand. It covered 9 areas including caseloads per centre and per radiation oncologist, techniques practised, local training requirements and quality assurance processes over a 2-year period - 2019 and 2020.

RESULTS

The response rate was 18 out of 25 centres. All centres offered vaginal vault brachytherapy and 89% treated an average of at least 10 patients per annum. Intracavitary and/or interstitial brachytherapy was offered at 89% of centres of which 31% treated less than an average of 10 patients per annum and 23% of radiation oncologists did less than an average of 5 or more insertions per annum as recommended in the GOROC guidelines. Most centres required only Fellowship from the Royal Australian and New Zealand College of Radiologist to practice gynaecological brachytherapy. Peer review of volumes and dosimetry was routinely performed in 28% and 17% of centres, respectively.

CONCLUSION

This survey adds to the limited literature available regarding practice patterns of brachytherapy worldwide. Ensuring adequate training and robust quality assurance processes with volume and dosimetry review may support all centres and clinicians to continue to safely offer this complex technique.

Current status of the working environment of brachytherapy in Japan: a nationwide survey-based analysis focusing on radiotherapy technologists and medical physicists

Brachytherapy (BT), especially in high dose rate (HDR), has become increasingly complex owing to the use of image-guided techniques and the introduction of advanced applicators. Consequently, radiotherapy technologists and medical physicists (RTMPs) require substantial training to enhance their knowledge and technical skills in image-guided brachytherapy. However, the current status of the RTMP workload, individual abilities and quality control (QC) of BT units in Japan remains unclear. To address this issue, we conducted a questionnaire survey from June to August 2022 in all 837 radiation treatment facilities in Japan involving RTMPs. This survey focused on gynecological cancers treated with HDR-BT (GY-HDR) and permanent prostate implantation using low-dose-rate BT (PR-LDR). The responses revealed that the average working time in the overall process for HDR varied: 120 min for intracavitary BT and 180 min for intracavitary BT combined with interstitial BT. The QC implementation rate, in accordance with domestic guidelines, was 65% for GY-HDR and 44% for PR-LDR, which was lower than the 69% observed for external beam radiation therapy (EBRT). Additionally, the implementation rate during regular working hours was low. Even among RTMP working in facilities performing BT, the proportion of those able to perform QC for BT units was ~30% for GY-HDR and <20% for PR-LDR, significantly lower than the 80% achieved for EBRT. This study highlights the vulnerabilities of Japan's BT unit QC implementation structure. Addressing these issues requires appropriate training of the RTMP staff to safely perform BT tasks and improvements in practical education and training systems.

External beam radiotherapy followed by image-guided adaptive brachytherapy in locally advanced cervical cancer: a multicenter retrospective analysis

PURPOSE

To evaluate oncological outcomes and toxicities in patients with locally advanced cervical cancer (LACC) treated with concurrent chemoradiotherapy followed by image-guided adaptive brachytherapy at two Italian centres.

MATERIAL AND METHODS

A retrospective analysis was conducted on 122 patients with LACC treated between 2010 and 2022. Primary endpoints were local control (LC), pelvic control (PC), and nodal control (NC). Secondary endpoints included disease-free survival (DFS), metastasis-free survival (MFS), overall survival (OS), and late toxicity. Correlations between patient characteristics and oncological outcomes were conducted.

RESULTS

Brachytherapy planning was CT and MRI-based in 88 (72.1%) and 34 patients (27.9%), respectively. The mean total dose (EQD2) delivered to high-risk clinical target volume was 82 Gy. Overall treatment time was ≤ 50 days and > 50 days in 48 (39.3%) and 74 patients (60.7%), respectively. At a mean follow up of 101 months, 3 and 5-year LC rates were 87% and 85%, respectively. Five-year PC and NC rates were 77% and 85.1%. Five-year DFS and OS were 61% and 65.4%, respectively, with significant correlations between these outcomes and FIGO stage and nodal status at diagnosis. Gastrointestinal, genitourinary and vaginal adverse effects were the most reported late toxicities and 8 (6.5%) grade 3-5 events were observed. 32 patients (26.2%) had vaginal stenosis and it was significantly related to 3D imaging used for brachytherapy planning.

CONCLUSIONS

The study confirmed the efficacy and safety of chemoradiotherapy and IGABT for LACC. Full implementation of MRI treatment planning and interstitial techniques could further enhance personalized treatment and outcomes.

Brachytherapy for cervical cancer: from intracavitary to interstitial technique

Cervical cancer is a common malignant tumor of female reproductive system. Radiation therapy is one of the main methods of cervical cancer treatment, of which brachytherapy is an essential and important part of radiation therapy for locally advanced cervical cancer. With the rapid development of imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI), brachytherapy for cervical cancer has gradually developed from traditional two-dimensional image-guided technology to three-dimensional image-guided technology. And there are more and more treatment methods, including intracavitary brachytherapy, interstitial brachytherapy, and intracavitary combined interstitial implantation brachytherapy. We performed a PubMed search for introduce the application progress of intracavity, implantation, intracavity combined implantation brachytherapy and radioactive seed implantation, and discuss the dosimetric feasibility of internal and external fusion irradiation.

The current state and future perspectives of radiotherapy for cervical cancer

Radiotherapy is an effective treatment method for cervical cancer and is typically administered as external beam radiotherapy followed by intracavitary brachytherapy. In Japan, center shielding is used in external beam radiotherapy to shorten treatment time and reduce the doses delivered to the rectum or bladder. However, it has several challenges, such as uncertainties in calculating the cumulative dose. Recently, external beam radiotherapy has been increasingly performed with intensity-modulated radiotherapy, which reduces doses to the rectum or bladder without center shielding. In highly conformal radiotherapy, uncertainties in treatment delivery, such as inter-fractional anatomical structure movements, affect treatment outcomes; therefore, image-guided radiotherapy is essential for appropriate and safe performance. Regarding intracavitary brachytherapy, the use of magnetic resonance imaging-based image-guided adaptive brachytherapy is becoming increasingly widespread because it allows dose escalation to the tumor and accurately evaluates the dose delivered to the surrounding normal organs. According to current evidence, a minimal dose of D90% of the high-risk clinical target volume is significantly relevant to local control. Further improvements in target coverage have been achieved with combined interstitial and intracavity brachytherapy for massive tumors with extensive parametrical involvement. Introducing artificial intelligence will enable faster and more accurate generation of brachytherapy plans. Charged-particle therapies have biological and dosimetric advantages, and current evidence has proven their effectiveness and safety in cervical cancer treatment. Recently, radiotherapy-related technologies have advanced dramatically. This review provides an overview of technological innovations and future perspectives in radiotherapy for cervical cancer.

Salvage radiotherapy for locally recurrent cervical and endometrial carcinoma: clinical outcomes and toxicities

BACKGROUND

The management of locally recurrent gynecological carcinoma remains a challenge due to the limited availability of data. This study aims to share our institutional experience in using definitive radiotherapy (RT) for the treatment of locally recurrent cervical and endometrial carcinoma.

METHODS

The study retrospectively reviewed 20 patients in our hospital completing salvage 3D image-based HDR brachytherapy, with or without EBRT, for locally recurrent cervical and endometrial carcinoma after surgery. The Kaplan-Meier method was applied to estimate the disease-free survival (DFS) and overall survival (OS). The toxicities were assessed by CTCAEv5.

RESULTS

During a median observation period of 21 months, the study reported a tumor objective response rate of 95%. The 3-year DFS and OS rates were 89.4% and 90.9%, respectively. The EBRT combined with brachytherapy achieved a median cumulative dose of 88 Gy to CTV D90. 14 patients received concurrent and/or systemic chemotherapy. Two patients suffered locoregional recurrence after salvage treatment, one of whom only received salvage brachytherapy for prior RT history. The analysis identified significant predictors for DFS, including tumor histology and FIGO stage. 5 patients observed acute grade 1-2 rectal (15%) or genitourinary (10%) toxicities. Late toxicities including grade 1-2 rectal bleeding (10%) and grade 2 pelvic fracture (5%) were seen in 3 patients.

CONCLUSIONS

3D image-guided brachytherapy combined with EBRT shows effective tumor control and acceptable toxicity profile for women with locally recurrent gynecologic cancer. The success in managing vaginal recurrence is notably influenced by histologic subtype and FIGO staging.

A Retrospective Study of Chemotherapy and 3D-Image-Guided Afterloading Intracavitary Radiotherapy in Locally Advanced Cervical Cancer

Aim

To investigate the value of neoadjuvant chemotherapy combined with 3D-image-guided afterloading intracavitary radiotherapy in locally advanced cervical cancer (LACC).

Methods

Patients with cervical cancer admitted to our hospital from January 1, 2020 to January 1, 2021 were retrieved and analyzed. Cases treated with neoadjuvant chemotherapy and 3D-image-guided afterloading intracavitary radiotherapy were assigned into the observation group (OG), while cases with neoadjuvant chemotherapy alone were assigned into the control group (CG). The short-term effects were determined by RECIST 1.1. Total effective rate (TR) = complete remission (CR) + partial remission (PR). The serum levels of squamous epithelial cell carcinoma antigen (SCC-Ag), glycoantigen 125 (CA125), carcinoembryonic antigen (CEA), and vascular endothelial growth factor (VEGF) were assessed. In view of the difference between tumor markers and diameters before and after treatment, the correlation between them was analyzed by Pearson test. The adverse events were compared, and the amount of operative bleeding and operation time were evaluated. Cox regression analysis was conducted to assess the influencing factors of 1-year disease-free survival time.

Results

Sixty-seven patients were retrieved, including 30 cases in the OG and 37 cases in the CG. There were no significant differences in age, pathological type, tumor size, FIGO stage, past medical history, or smoking history between the two groups (P > 0.05). The TR of patients in the OG was higher than that in the CG (P < 0.05). The SCC-Ag, CA125, CEA, and VEGF levels in the OG decreased markedly after treatment (P < 0.001). The difference in SCC-Ag, CA125, CEA, and VEGF was positively correlated with the difference in tumor diameter before and after treatment (P < 0.05). The incidence of adverse events revealed no obvious difference between the OG and CG (P > 0.05). Cox regression analysis showed that FIGO stage and treatment regimens were independent prognostic factors for 1-year disease-free survival (P < 0.05).

Conclusion

Neoadjuvant chemotherapy combined with 3D-image-guided afterloading intracavitary radiotherapy can improve the TR rate and 1-year disease-free survival of LACC patients without increasing the incidence of adverse events.