Risk of Late Urinary Complications Following Image Guided Adaptive Brachytherapy for Locally Advanced Cervical Cancer: Refining Bladder Dose-Volume Parameters

Prevention and management of radiotherapy-related toxicities in gynecological malignancies. Position paper on behalf of AIRO (Italian Association of Radiotherapy and Clinical Oncology)

Multi-modal therapies for gynecological cancers management may determine a wide range of side effects which depend on therapy-related factors and patient characteristics and comorbidities. Curative or adjuvant pelvic radiotherapy is linked with acute and late toxicity due to irradiation of organs at risk, as small and large bowel, rectum, bladder, pelvic bone, vagina and bone marrow. Successful toxicity management varies with its severity, Radiation Centre practice and experience and skills of radiation oncologists. This position paper was designed by the Italian Association of Radiation and Clinical Oncology Gynecology Study Group to provide radiation oncologists with evidence-based strategies to prevent and manage acute and late toxicities and follow-up recommendations for gynecological cancer patients submitted radiotherapy. Six workgroups of radiation oncologists with over 5 years of experience in gynecologic cancers were setup to investigate radiotherapy-related toxicities. For each topic, PubMed database was searched for relevant English language papers from January 2005 to December 2022. Titles and abstracts of results were checked to verify suitability for the document. Reference lists of selected studies and review papers were added if pertinent. Data on incidence, etiopathogenesis, prevention, treatment and follow-up of acute and late side effects for each organ at risk are presented and discussed.

Predictive Factors for Toxicity After Primary Chemoradiation for Locally Advanced Cervical Cancer: A Systematic Review

PURPOSE

Women with locally advanced cervical cancer (LACC) undergoing primary platinum-based chemoradiotherapy and brachytherapy often experience toxicities. Normal-tissue complication probability (NTCP) models quantify toxicity risk and aid in optimizing radiation therapy to minimize side effects. However, it is unclear which predictors to include in an NTCP model. The aim of this systematic review was to provide an overview of the identified predictors contributing to gastrointestinal (GI), genitourinary (GU), and vaginal toxicities and insufficiency fractures for LACC.

METHODS AND MATERIALS

A systematic search was performed and articles evaluating the relationship between predictors and toxicities in women with LACC treated with primary chemoradiation were included. The Quality In Prognosis Studies tool was used to assess risk of bias, with high-risk studies being excluded from further analysis. Relationships between dose-volume parameters, patient and treatment characteristics, and toxicity endpoints were analyzed.

RESULTS

Seventy-three studies were identified. Twenty-six had a low or moderate risk of bias and were therefore included. Brachytherapy-related dose-volume parameters of the GI tract, including rectum and bowel equivalent dose in 2 Gy fractions (EQD2) D2 cm3, were frequently related to toxicities, unlike GU dose-volume parameters. Furthermore, (recto)vaginal point doses predicted toxicities. Few studies evaluated external beam radiation therapy dose-volume parameters and identified rectum EQD2 V30 Gy, V40 Gy, and V55 Gy, bowel and bladder EQD2 V40 Gy as toxicity predictors. Also, total reference air kerma and vaginal reference length were associated with toxicities. Relationships between patient characteristics and GI toxicity were inconsistent. The extent of vaginal involvement at diagnosis, baseline symptoms, and obesity predicted GU or vaginal toxicities. Only 1 study evaluated insufficiency fractures and demonstrated lower pretreatment bone densities to be associated.

CONCLUSIONS

This review detected multiple candidate predictors of toxicity. Larger studies should consider insufficiency fractures, assess dose levels from external beam radiation therapy, and quantify the relationship between the predictors and treatment-related toxicities in women with LACC to further facilitate NTCP model development for clinical use.

A visualization analysis of hotspots and global trends on pelvic floor dysfunction in cervical cancer

BACKGROUND/OBJECTIVE

Cervical cancer is the major cause of cancer-related mortalities in women globally. It constitutes one of the life-threatening conditions for women in developing countries. The popularization of cervical cancer screening and the improvement of treatment levels has caused the mortality rate of cervical cancer to decrease gradually, but pelvic floor dysfunction before and after cervical cancer treatment has become prominent and attracted more and more attention. Bibliometric analysis has been carried out in this research. The main goal of this research is to provide a comprehensive insight into the knowledge structure and global research hotspots about pelvic floor dysfunction in cervical cancer.

METHODS

Literature related to cervical cancer and pelvic floor dysfunction as of May 2023 was searched on the Web of Science Core Collection (WOSCC). The visualization and bibliometric analyses of the number and contents of publications were performed to analyze the temporal trends, spatial distribution, collaborative networks, influential references, keyword co-occurrence, and clustering.

RESULTS

There were 870 publications from 74 countries or regions, with the U.S. publications in a leading position. Since 2020, the number of publications has rapidly increased with the emphasis on the quality of life of cervical cancer patients. Although pelvic floor dysfunction in cervical cancer mainly occurs in developing countries, developed countries have made great contributions to this disease. However, in developing countries such as China and India, the quality of publications needs to be improved. In this field, the studies focused on the sexual dysfunction or urinary incontinence of cervical cancer patients, and the most cited papers discussed the effect of cervical cancer treatment on the sexual activities of females. The frontier keywords were represented by pelvic radiotherapy and risk factors.

CONCLUSION

This study provides an objective and comprehensive analysis of the literature available on pelvic floor dysfunction in cervical cancer and identifies future trends and current hotspots. It can provide a valuable reference for researchers in this field.

Contouring of emerging organs-at-risk (OARS) of the female pelvis and interobserver variability: A study by the Italian association of radiotherapy and clinical oncology (AIRO)

Purpose

To provide straightforward instructions for daily practice in delineating emerging organs-at-risk (OARs) of the female pelvis and to discuss the interobserver variability in a two-step multicenter study.

Methods and materials

A contouring atlas with anatomical boundaries for each emerging OAR was realized by radiation oncologists and radiologists who are experts in pelvic imaging, as per their knowledge and clinical practice. These contours were identified as quality benchmarks for the analysis subsequently carried out. Radiation oncologists not involved in setting the custom-built contouring atlas and interested in the treatment of gynecological cancer were invited to participate in this 2-step trial. In the first step all participants were supplied with a selected clinical case of locally advanced cervical cancer and had to identify emerging OARs (Levator ani muscle; Puborectalis muscle; Internal anal sphincter; External anal sphincter; Bladder base and trigone; Bladder neck; Iliac Bone Marrow; Lower Pelvis Bone Marrow; Lumbosacral Bone Marrow) based on their own personal knowledge of pelvic anatomy and experience. The suggested OARs and the contouring process were then presented at a subsequent webinar meeting with a contouring laboratory. Finally, in the second step, after the webinar meeting, each participant who had joined the study but was not involved in setting the benchmark received the custom-built contouring atlas with anatomical boundaries and was requested to delineate again the OARs using the tool provided. The Dice Similarity Coefficient (DSC) and the Jaccard Similarity Coefficient (JSC) were used to evaluate the spatial overlap accuracy of the different volume delineations and compared with the benchmark; the Hausdorff distance (HD) and the mean distance to agreement (MDA) to explore the distance between contours. All the results were reported as sample mean and standard deviation (SD).

Results

Fifteen radiation oncologists from different Institutions joined the study. The participants had a high agreement degree for pelvic bones sub-structures delineation according to DICE (IBM: 0.9 ± 0.02; LPBM: 0.91 ± 0.01). A moderate degree according to DICE was showed for ovaries (Right: 0.61 ± 0.16, Left: 0.72 ± 0.05), vagina (0.575 ± 0.13), bladder sub-structures (0.515 ± 0.08) and EAS (0.605 ± 0.05), whereas a low degree for the other sub-structures of the anal-rectal sphincter complex (LAM: 0.345 ± 0.07, PRM: 0.41 ± 0.10, and IAS: 0.4 ± 0.07).

Conclusion

This study found a moderate to low level of agreement in the delineation of the female pelvis emerging OARs, with a high degree of variability among observers. The development of delineation tools should be encouraged to improve the routine contouring of these OARs and increase the quality and consistency of radiotherapy planning.

The effect of lower urinary tract substructure doses on side effects of cervical cancer image-guided adaptive brachytherapy

OBJECTIVE

Image-Guided Adaptive Brachytherapy (IGABT) provides a survival advantage in locally advanced cervical cancer (LACC). Although side effects are seen less with this technique, dose parameters that cause urinary side effects are still questionable. We aim to investigate whether the radiotherapy doses of the lower urinary tract substructures (LUSS) affect the urinary system side effects (USSE) of cervical cancer external beam radiotherapy (EBRT) and the IGABT.

METHODS

LUSS (bladder, trigone, bladder neck, and urethra) doses were calculated in 40 patients diagnosed with LACC and receiving primary EBRT, IGABT, and concomitant chemotherapy. D0.1cc, D2cc, and D50% values were examined by contouring the bladder, trigone, bladder neck, and urethra from the intracavitary BT planning computed tomography (CT) images taken every 4 BT fractions, retrospectively. Besides, late USSE (urgency, dysuria (recurrent), frequency, obstruction, incontinence, hematuria, fistula, cystitis) were queried and categorized according to Common Toxicity Criteria for Adverse Events version 5.0.

STATISTICAL ANALYSIS USED

The Chi-square and Fisher's exact tests, Mann-Whitney U-test.

RESULTS

For the whole study population, for both incontinence and dysuria, trigone (D50%), urethra (D50%, D0.1cc,), and bladder neck (D50%, D0.1cc, D2cc) volume and hot spot doses remained significant. For cystitis, urethra (D50%, D0.1cc,) and bladder neck doses (D0.1cc, D50%, D2cc) are worth investigating.

CONCLUSIONS

Although USSE is less common in the intensity-modulated radiation therapy and IGABT era, it may be meaningful to take the doses of LUSS into account when planning IGABT. In addition, delineation of LUSS using only CT seems feasible. More proof is needed to determine delineation technique and dose constraints for LUSS for IGABT.

Feature Importance Analysis of a Deep Learning Model for Predicting Late Bladder Toxicity Occurrence in Uterine Cervical Cancer Patients

(1) In this study, we developed a deep learning (DL) model that can be used to predict late bladder toxicity. (2) We collected data obtained from 281 uterine cervical cancer patients who underwent definitive radiation therapy. The DL model was trained using 16 features, including patient, tumor, treatment, and dose parameters, and its performance was compared with that of a multivariable logistic regression model using the following metrics: accuracy, prediction, recall, F1-score, and area under the receiver operating characteristic curve (AUROC). In addition, permutation feature importance was calculated to interpret the DL model for each feature, and the lightweight DL model was designed to focus on the top five important features. (3) The DL model outperformed the multivariable logistic regression model on our dataset. It achieved an F1-score of 0.76 and an AUROC of 0.81, while the corresponding values for the multivariable logistic regression were 0.14 and 0.43, respectively. The DL model identified the doses for the most exposed 2 cc volume of the bladder (BD_2cc) as the most important feature, followed by BD_5cc and the ICRU bladder point. In the case of the lightweight DL model, the F-score and AUROC were 0.90 and 0.91, respectively. (4) The DL models exhibited superior performance in predicting late bladder toxicity compared with the statistical method. Through the interpretation of the model, it further emphasized its potential for improving patient outcomes and minimizing treatment-related complications with a high level of reliability.

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BACKGROUND

The European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort to improve overall quality of care for cervical cancer patients across all aspects, ESGO and the European SocieTy for Radiotherapy and Oncology (ESTRO) initiated the development of quality indicators for radiation therapy of cervical cancer.

OBJECTIVE

To develop a list of quality indicators for radiation therapy of cervical cancer that can be used to audit and improve clinical practice by giving to practitioners and administrators a quantitative basis to improve care and organizational processes, notably for recognition of the increased complexity of modern external radiotherapy and brachytherapy techniques.

METHODS

Quality indicators were based on scientific evidence and/or expert consensus. The development process included a systematic literature search for identification of potential quality indicators and documentation of scientific evidence, consensus meetings of a group of international experts, an internal validation process, and external review by a large international panel of clinicians (n=99).

RESULTS

Using a structured format, each quality indicator has a description specifying what the indicator is measuring. Measurability specifications are detailed to define how the quality indicators will be measured in practice. Targets were also defined for specifying the level which each unit or center should be aiming to achieve. Nineteen structural, process, and outcome indicators were defined. Quality indicators 1-6 are general requirements related to pretreatment workup, time to treatment, upfront radiation therapy, and overall management, including active participation in clinical research and the decision making process within a structured multidisciplinary team. Quality indicators 7-17 are related to treatment indicators. Quality indicators 18 and 19 are related to patient outcomes.

DISCUSSION

This set of quality indicators is a major instrument to standardize the quality of radiation therapy in cervical cancer. A scoring system combining surgical and radiotherapeutic quality indicators will be developed within an envisaged future ESGO accreditation process for the overall management of cervical cancer, in an effort to support institutional and governmental quality assurance programs.

ESGO/ESTRO quality indicators for radiation therapy of cervical cancer

BACKGROUND

The European Society of Gynaecological Oncology (ESGO) has previously defined and established a list of quality indicators for the surgical treatment of cervical cancer. As a continuation of this effort to improve overall quality of care for cervical cancer patients across all aspects, ESGO and the European SocieTy for Radiotherapy and Oncology (ESTRO) initiated the development of quality indicators for radiation therapy of cervical cancer.

OBJECTIVE

To develop a list of quality indicators for radiation therapy of cervical cancer that can be used to audit and improve clinical practice by giving to practitioners and administrators a quantitative basis to improve care and organizational processes, notably for recognition of the increased complexity of modern external radiotherapy and brachytherapy techniques.

METHODS

Quality indicators were based on scientific evidence and/or expert consensus. The development process included a systematic literature search for identification of potential quality indicators and documentation of scientific evidence, consensus meetings of a group of international experts, an internal validation process, and external review by a large international panel of clinicians (n = 99).

RESULTS

Using a structured format, each quality indicator has a description specifying what the indicator is measuring. Measurability specifications are detailed to define how the quality indicators will be measured in practice. Targets were also defined for specifying the level which each unit or center should be aiming to achieve. Nineteen structural, process, and outcome indicators were defined. Quality indicators 1-6 are general requirements related to pretreatment workup, time to treatment, upfront radiation therapy, and overall management, including active participation in clinical research and the decision making process within a structured multidisciplinary team. Quality indicators 7-17 are related to treatment indicators. Quality indicators 18 and 19 are related to patient outcomes.

DISCUSSION

This set of quality indicators is a major instrument to standardize the quality of radiation therapy in cervical cancer. A scoring system combining surgical and radiotherapeutic quality indicators will be developed within an envisaged future ESGO accreditation process for the overall management of cervical cancer, in an effort to support institutional and governmental quality assurance programs.

What is appropriate target delineation for MRI-based brachytherapy for medically inoperable endometrial cancer?

PURPOSE

For medically inoperable endometrial cancer (MIEC), the volumetric target of image-guided brachytherapy (IGBT) techniques is not well established. We propose a high-risk CTV (HRCTV) concept and report associated rates of local control and toxicity.

METHODS AND MATERIALS

For all MIEC patients receiving definitive external beam radiotherapy (EBRT) followed by MRI-based IGBT at a single institution, BT dose was prescribed to HRCTV defined as GTV plus endometrial cavity with a planning goal of a summed EQD2 D90 of ≥85 Gy. Freedom from local progression (FFLP) and overall survival (OS) were estimated via Kaplan Meier method.

RESULTS

Thirty two MIEC patients received EBRT followed by MRI-based IGBT between December 2015 and August 2020. Median follow up was 19.8 months. A total of 75% of patients had FIGO stage I/II disease, 56% endometrioid histology, and 50% grade 3 disease. OS was 73.6% (95% CI 57.8%-89.3%) at 12 months and 65.8% (95% CI 48.4%-83.2%) at 24 months. FFLP was 93.8% (95% CI 85.3%-100%) at 12 months and 88.8% (95% CI 86.6%-91.0%) at 24 months. 23 (72%) patients experienced no RT-related toxicity, while 2 of 32 patients (6%) experienced late grade 3+ toxicities (grade 3 refractory vomiting; grade 5 GI bleed secondary to RT-induced proctitis).

CONCLUSIONS

Patients with MIEC receiving definitive EBRT followed by MRI-based IGBT prescribed to the MRI-defined HRCTV demonstrated favorable long-term local control with an acceptable toxicity profile.

Image-guided adaptive brachytherapy for advanced cervical cancer spreading to the bladder and/or rectum: Clinical outcome and prognostic factors

INTRODUCTION

Refinements of brachytherapy techniques have led to better local control of locally advanced cervical cancer (LACC), especially with the development of image-guided adaptive brachytherapy (IGABT). Data on the efficacy of brachytherapy in cervical cancer spreading to adjacent organs are scarce. We report the experience of our institution in the treatment of these advanced tumors with IGABT.

MATERIALS AND METHODS

Medical records of patients treated for a LACC spreading to the bladder and/or rectum between 2006 and 2020 at Gustave Roussy Institute were analyzed. Dosimetric parameters were collected and converted into 2 Gy per fraction equivalent doses, including the minimal dose received by 90% of the high-risk target volume (D₉₀ CTV_HR) and intermediate-risk target volume (D₉₀ CTV_IR), as well as the dose received by the most exposed 2 cm³ of the organs at risk. A Cox regression model was used to study the potential associations between clinical and dosimetric factors with survival endpoints and fistula formation.

RESULTS AND STATISTICAL ANALYSIS

A total of 81 patients were identified. All patients received pelvic+/- para-aortic radiotherapy, 45 Gy in 25 fractions +/- boost to gross lymph nodes. Concomitant platinum-based chemotherapy was administered in 93.8% of cases. The median D₉₀ CTV_HR dose was 75.5 Gy_EQD2 (SD: 10.39 Gy_EQD2) and median CTV_HR volume was 47.6 cm³ (SD: 27.9 cm³). Median bladder and rectal D2_cm3 dose were 75.04 Gy_EQD2 (SD: 8.72 Gy_EQD2) and 64.07 Gy_EQD2 (SD: 6.68 Gy_EQD2). After a median follow-up of 27.62 ± 25.10 months, recurrence was found in 34/81 patients (42%). Metastatic failure was the most common pattern of relapse (n = 25). Use of a combined interstitial/intracavitary technique and D₉₀ CTV_HR ≥ 75.1 Gy_EQD2 were prognostic factors for OS in univariate analysis (HR = 0.24, 95%IC: 0.057-1, p = 0.023; HR = 0.2, 95%IC: 0.059-0.68, p = 0.0025, respectively). In multivariate analysis, a D₉₀ CTV_HR ≥ 75.1 Gy_EQD2 was significant for OS (HR = 0.23; 95%IC: 0.07, 0.78, p = 0.018). The occurrence of vesicovaginal fistula (VVF) was the most frequent pattern of local recurrence (HR = 4.6, 95%CI: 1.5-14, p = 0.01).

CONCLUSION

Advances in brachytherapy modalities improved local control and survival while reducing toxicities. Enhancing local control through dose escalation and combined intracavitary/interstitial brachytherapy techniques is a major factor in patients cure probability, together with systemic intensification to better control distant events.

Long-term urological complications after conservative local treatment (surgery and brachytherapy) in children with bladder-prostate rhabdomyosarcoma: A single-team experience

BACKGROUND

Outcome of children with bladder-prostate rhabdomyosarcoma (RMS) has improved with multimodal therapies, including surgery and/or radiotherapy for local treatment. Our aim was to report long-term urological complications after a conservative approach combining conservative surgery and brachytherapy.

PATIENTS AND METHODS

Eighty-six patients, free of disease, were retrospectively reviewed. Symptoms related to urinary tract obstruction, incontinence, infection, and lithiasis were reported and graded according to the Common Terminology Criteria for Adverse Events (CTCAE) classification. Only symptomatic patients underwent urodynamic studies. Risk factors for complications were analyzed.

RESULTS

There were 76 males and 10 females. The median follow-up was 6.3 years (18 months to 24 years). Complications occurred after a median follow-up of 5 years (0-21). Twenty-two patients (26%) had long-term urological complications. Urinary tract obstruction was found in 15 patients (17%) and urinary incontinence in 14 patients (16%). Recurrent urinary tract infection occurred in four patients and urinary lithiasis in four (5%). The underlying physiopathology included bladder dysfunction in 15 patients (17%), urethral stenosis in six (7%), and ureterovesical junction stenosis in five (6%). On univariate analysis, posterior bladder wall dissection (p = .001), bladder neck trigone dissection (p = .010), and partial prostatectomy (p = .023) were significantly associated with an increased risk of bladder dysfunction; on multivariate analysis, only age ≤2 years (p = .028) at operation and posterior bladder wall dissection (p = .006) were found to be significant.

CONCLUSION

The conservative surgical approach combined with brachytherapy for bladder-prostate RMS leads to long-term urological complications in 26% of survivors. Optimizing brachytherapy doses for young children and establishing a clear and long-term follow-up protocol could help to reduce these complications.

Two New Potential Therapeutic Approaches in Radiation Cystitis Derived from Mesenchymal Stem Cells: Extracellular Vesicles and Conditioned Medium

Background: Radiation cystitis (RC) results from chronic inflammation, fibrosis, and vascular damage. The urinary symptoms it causes have a serious impact on patients’ quality of life. Despite the improvement in irradiation techniques, the incidence of radiation cystitis remains stable over time, and the therapeutic possibilities remain limited. Mesenchymal stem/stromal cells (MSC) appear to offer2 a promising therapeutic approach by promoting tissue repair through their paracrine action via extracellular vesicles (MSC-EVs) or conditioned medium from human mesenchymal stromal cells (MSC-CM). We assess the therapeutic potential of MSC-EVs or MSC-CM in an in vitro model of RC. Methods:in vitro RC was induced by irradiation of human bladder fibroblasts (HUBF) with the small-animal radiation research platform (SARRP). HUBF were induced towards an RC phenotype after 3 × 3.5 Gy irradiation in the presence of either MSC-EVs or MSC-CM, to assess their effect on fibrosis, angiogenesis, and inflammatory markers. Results: Our data revealed in vitro a higher therapeutic potential of MSC-EVs and MSC-CM in prevention of RC. This was confirmed by down-regulation of α-SMA and CTGF transcription, and the induction of the secretion of anti-fibrotic cytokines, such as IFNγ, IL10 and IL27 and the decrease in the secretion of pro-fibrotic cytokines, IGFBP2, IL1β, IL6, IL18, PDGF, TNFα, and HGF, by irradiated HUBFs, conditioned with MSC-EVs or MSC-CM. The secretome of MSC (MSC-CM) or its subsecretome (MSC-EVs) are proangiogenic, with the ability to induce vessels from HUVEC cells, ensuring the management of bladder vascular lesions induced by irradiation. Conclusion: MSC-EVs and MSC-CM appear to have promising therapeutic potential in the prevention of RC in vitro, by targeting the three main stages of RC: fibrosis, inflammation and vascular damage.

Effect of bladder volume on radiation doses to organs at risk and tumor in cervical cancer during image-guided adaptive brachytherapy and treatment outcome analysis

There is no consensus in clinical practice on the optimal bladder volume during brachytherapy. The present study aimed to assess the effect of bladder volume on radiation dose to organs at risk and tumor in cervical cancer during image-guided adaptive brachytherapy and clinical outcome. The retrospective study included patients treated at University of Hong Kong-Shenzhen Hospital between January 2015 and July 2019. Patients with International Federation of Gynecology and Obstetrics (2009) stage IB1-IVB (retroperitoneal lymph nodes metastasis only) cervical cancer treated by external beam radiotherapy with concurrent cisplatin followed by brachytherapy were assessed. A total of 421 brachytherapy insertions were analyzed. Every 83 and 90 cm³ (cc) increase in bladder volume led to an incremental raise of 1 Gy in bladder wall minimum dose received by the most irradiated 1 and 2 cc volumes (D1 and D2cc) of the bladder wall, respectively. An increase in bladder volume was associated with increased D1 and D2cc of bladder (both P<0.001, respectively) and rectal wall (P=0.150 and P=0.084, respectively), and decreased D1cc (P=0.003) and D2cc (P=0.001) of sigmoid wall, the maximum doses to the most minimally exposed 90 (D90) and 95% (D95) of the high risk-clinical target volume (HR-CTV; D90, P=0.010; D95, P=0.006). Patients with cumulative HR-CTV D90≤89.6 Gy had shorter median overall survival (OS) than those with cumulative HR-CTV D90>89.6 Gy (42.1 months vs. not reached, P=0.001). Patients with grade 2 acute urinary toxicity had significantly higher cumulative bladder wall D2cc than those with acute urinary toxicity<grade 2 (86.7±3.7 vs. 78.5±7.9 Gy; P=0.001). As the bladder volume increased, the dose to the bladder and rectal wall increase and dose to the sigmoid colon wall and HR-CTV decrease based on intracavitary brachytherapy. The higher dose of HR-CTV predicted better OS and the higher dose received by the bladder wall was associated with more grade 2 acute urinary toxicity.

Five-fraction HDR brachytherapy in locally advanced cervical cancer: A monocentric experience

PURPOSE

The 5-fraction scheme (5×5-5.5Gy) is a common High-Dose Rate (HDR) intracavitary brachytherapy regimen for locally advanced cervical cancer (LACC). Yet, its equivalence with Pulse-Dose rate (PDR) schemes remains unproved. The present study aimed at reporting on the outcome of LACC patients treated with 5-fraction HDR brachytherapy.

MATERIALS AND METHODS

The medical records of all consecutive patients treated with curative-intent HDR brachytherapy for a LACC in a French Cancer Center were retrospectively reviewed.

RESULTS

Thirty-eight LACC patients underwent a 5-fraction intracavitary HDR brachytherapy between 2015 and 2019 (median dose=25Gy/5 fractions, following external-beam radiotherapy). Median age at diagnosis was 60 (range: 29-87). Thirty-one patients (81.5%) underwent concurrent chemotherapy. Tumor stages ranged from 3 IB2 (7.8%), 4 IB3 (10.5%), 4 IIA2 (10.5%), 12 IIB (31.7%), 1 IIIA (2.6%), 2 IIIB (5.3%), 7 IIIC1 (18.5%), 4 IIIC2 (10.5%), 1 IVA (2.6%) (2018 FIGO). Median D90% to CTV_HR reached 79.5Gy (EQD2). Median D90% to CTV_IR reached 59.5Gy (EQD2). Median Bladder D2cc was 69.8Gy (EQD2). Median Rectum D2cc was 58.3Gy (EQD2). Acute/late grade 3 toxicity was reported in one patient (2.6%). No grade 4-5 toxicity occurred. At a median 38 months follow-up, 10 patients (26.3%) had local (n=7, 18.4%), nodal (n=6, 15.7%) and/or distant (n=7, 18.4%) relapse. Three-year overall survival rate was of 81.6%.

CONCLUSION

The 5-fraction HDR scheme was well tolerated even in frail patients. Three-year local control was lower than expected. Treatment (absence of parametrial interstitial implants and use of cervical EBRT boost) and patients' characteristics (age, comorbidities) may explain such results.

Interstitial brachytherapy for gynecologic malignancies: Complications, toxicities, and management

From both a disease and management perspective, locally advanced gynecologic cancers present a significant challenge. Dose escalation with brachytherapy serves as a key treatment, providing conformal radiation while sparing at-risk organs. Intracavitary brachytherapy techniques have been shown to be effective, with improving tumor control and toxicity profiles with the advent of three-dimensional image planning. Despite this, the variations in tumor size, location, and pelvic anatomy may lead to suboptimal dosimetry with standard intracavitary applicators in some clinical scenarios. The addition of interstitial needles (interstitial brachytherapy (ISBT)) can improve the conformality of brachytherapy treatments by adding needles to peripheral (and central) regions of the target volume, improving the ability to escalate doses in these undercovered regions while sparing organs at risk. Interstitial brachytherapy can be delivered by intracavitary and interstitial hybrid applicators (ICBT/ISBT), perineal template (P-ISBT), or by free-hand technique. ISBT has however yet to be widely available because of concerns of complications and toxicities from this specialized treatment. However, with the increasing use of three-dimensional image-guided brachytherapy, there is an opportunity to increase the level of expertise in the gynecologic radiation oncology community with an improved understanding of the potential complications and morbidity. In this article, we review the acute and long-term toxicity in both ICBT/ISBT and P-ISBT using image-guided brachytherapy.

Risk factors and dose-effects for bladder fistula, bleeding and cystitis after radiotherapy with imaged-guided adaptive brachytherapy for cervical cancer: An EMBRACE analysis

PURPOSE

To identify patient- and treatment-related risk factors for fistula, bleeding, cystitis, pain and difficulty in voiding in locally advanced cervical cancer patients treated with radio(chemo)therapy and image-guided adaptive brachytherapy (IGABT).

MATERIAL AND METHODS

Morbidity within the EMBRACE-I study was prospectively reported for physician-assessed (CTCAE) fistula, bleeding and cystitis and patient-reported (EORTC) pain and difficulty in voiding. Analysis of risk factors was performed in patients without bladder infiltration. Risk factors were tested with Cox regression for grade (G) ≥ 3 cystitis, for G ≥ 2 fistula, bleeding and cystitis, and for EORTC "very much" and "quite a bit" or worse.

RESULTS

Of 1416 patients enrolled, 1153 and 884 patients without bladder infiltration were evaluable for the analysis of CTCAE and EORTC items, respectively. Median follow-up was 48[3-120] months. Crude incidence rates for G ≥ 2 fistula, bleeding and cystitis were 0.7%, 2.7% and 8.8%, respectively, and 16% and 14% for "quite a bit" or worse pain and difficulty in voiding, respectively. Baseline urinary morbidity and overweight/obesity were significant risk factors for most endpoints. Bladder D_2cm3 correlated with G ≥ 2 fistula, bleeding and cystitis, while ICRU bladder point dose correlated with EORTC pain "quite a bit" or worse. An increase from 75 Gy to 80 Gy in bladder D_2cm3 resulted in an increase from 8% to 13% for 4-year actuarial estimate of G ≥ 2 cystitis.

CONCLUSION

Clinical and treatment-related risk factors for bladder fistula, bleeding and cystitis were identified within a prospective and multi-institutional setting. A dose-effect was established with bladder D_2cm3, reinforcing the importance of continued optimization during individualized IGABT planning.

Chronic Inflammation and Radiation-Induced Cystitis: Molecular Background and Therapeutic Perspectives

Radiation cystitis is a potential complication following the therapeutic irradiation of pelvic cancers. Its clinical management remains unclear, and few preclinical data are available on its underlying pathophysiology. The therapeutic strategy is difficult to establish because few prospective and randomized trials are available. In this review, we report on the clinical presentation and pathophysiology of radiation cystitis. Then we discuss potential therapeutic approaches, with a focus on the immunopathological processes underlying the onset of radiation cystitis, including the fibrotic process. Potential therapeutic avenues for therapeutic modulation will be highlighted, with a focus on the interaction between mesenchymal stromal cells and macrophages for the prevention and treatment of radiation cystitis.

Importance of the ICRU bladder point dose on incidence and persistence of urinary frequency and incontinence in locally advanced cervical cancer: An EMBRACE analysis

PURPOSE

To identify patient- and treatment-related risk factors and dose-effects for urinary frequency and incontinence in locally advanced cervical cancer (LACC) treated with radio(chemo)therapy and image-guided adaptive brachytherapy (IGABT).

MATERIAL AND METHODS

Physician-assessed (CTCAE) and patient-reported (EORTC) frequency and incontinence recorded in the EMBRACE-I study were analysed. Risk factors analysis was performed in patients without bladder infiltration and with baseline morbidity available. Cox regression was used for CTCAE grade (G) ≥ 3 and G ≥ 2 and for EORTC "very much" and "quite a bit" or worse. Logistic regression was used for late persistent morbidity defined when CTCAE G ≥ 1 or EORTC ≥ "quite a bit" were scored in at least half of follow-ups.

RESULTS

Longitudinal data on 1153 and 884 patients were available for CTCAE and EORTC analysis, respectively. Median follow-up was 48[3-120] months. Crude incidence rates of G≥2 were 13% and 11% for frequency and incontinence, respectively. Baseline morbidity and overweight-obesity were risk factors for both symptoms. Elderly patients were at higher risk for incontinence. Patients receiving conformal-radiotherapy were at higher risk for frequency. ICRU bladder point (ICRU-BP) dose was a stronger predictor for incontinence than bladder D_2cm3. The 5-year actuarial estimate of G ≥ 2 incontinence increased from 11% to 20% with ICRU-BP doses > 75 Gy compared to ≤ 65 Gy. Frequency showed weaker associations with dose.

CONCLUSION

ICRU-BP dose, in addition to clinical parameters, is a risk factor for urinary incontinence and shows a dose-effect after radio(chemo)therapy and IGABT. ICRU-BP dose should be monitored during treatment planning alongside volumetric parameters. Frequency seems associated with larger irradiated volumes.

[Can stereotactic body radiotherapy replace brachytherapy for locally advanced cervical cancer? French society for radiation oncology statement]

Brachytherapy is part of the treatment of locally advanced cervical cancers, accounting for about half of the total delivered dose. The benefit of dose escalation is the most important in advanced cases or if the tumor has responded poorly. The use of interstitial implantations makes it possible to reach doses of the order of 85 to 90Gy (including external beam radiotherapy contribution) in most patients, through image-guided approaches. Brachytherapy delivery is one of the quality criteria for patient care. To date, no data allow us to consider as an alternative the use of external boost through intensity-modulated or stereotactic body radiotherapy. Indeed, the doses delivered to the tumor and the capacity to spare normal tissues remains lower, as compared to what is permitted by brachytherapy. It is therefore appropriate for centers that do not have access to the technique to establish networks with centers where brachytherapy is performed, to allow each patient to have access to the technique. It is also necessary to promote brachytherapy teaching. The issue of reimbursement will be crucial in the coming years to maintain expertise that is today insufficiently valued in its financial aspects, but has a very high added value for patients.

Ring Versus Ovoids and Intracavitary Versus Intracavitary-Interstitial Applicators in Cervical Cancer Brachytherapy: Results From the EMBRACE I Study

PURPOSE

The aim of this study was to investigate the influence of brachytherapy technique and applicator type on target dose, isodose surface volumes, and organ-at-risk (OAR) dose.

METHODS AND MATERIALS

Nine hundred two patients treated with tandem/ovoids (T&O) (n = 299) and tandem/ring (T&R) (n = 603) applicators from 16 EMBRACE centers were analyzed. Patients received external beam radiation therapy and magnetic resonance imaging guided brachytherapy with dose prescription according to departmental practice. Centers were divided into 4 groups, according to applicator/technique: Ovoids and ring centers treating mainly with the intracavitary (IC) technique and ovoids and ring centers treating routinely with the intracavitary/interstitial (IC/IS) technique. V85Gy EQD210, CTVHR D90% (EQD210), and bladder, rectum, sigmoid, and vaginal 5-mm lateral-point doses (EQD23) were evaluated among center groups. Differences between T&O and T&R were tested with multivariable analysis.

RESULTS

For similar point A doses, mean CTVHR D90% was 3.3 Gy higher and V85Gy was 23% lower for ring-IC compared with ovoids-IC centers (at median target volumes). Mean bladder/rectum doses (D2cm3 and ICRU-point) were 3.2 to 7.7 Gy smaller and vaginal 5-mm lateral-point was 19.6 Gy higher for ring-IC centers. Routine use of IC/IS technique resulted in increased target dose, whereas V85Gy was stable (T&R) or decreased (T&O); reduced bladder and rectum D2cm3 and bladder ICRU-point by 3.5 to 5.0 Gy for ovoids centers; and similar OAR doses for ring centers. CTVHR D90% was 2.8 Gy higher, bladder D2cm3 4.3 Gy lower, rectovaginal ICRU-point 4.8 Gy lower, and vagina 5-mm lateral-point 22.4 Gy higher for ring-IC/IS versus ovoids-IC/IS centers. The P values were <.002 for all comparisons. Equivalently, significant differences were derived from the multivariable analysis.

CONCLUSIONS

T&R-IC applicators have better target dose and dose conformity than T&O-IC in this representative patient cohort. IC applicators fail to cover large target volumes, whereas routine application of IC/IS improves target and OAR dose considerably. Patients treated with T&R show a more favorable therapeutic ratio when evaluating target, bladder/rectum doses, and V85Gy. A comprehensive view on technique/applicators should furthermore include practical considerations and clinical outcome.

American Brachytherapy Society working group report on the patterns of care and a literature review of reirradiation for gynecologic cancers

PURPOSE

Recurrences of previously irradiated gynecological malignancies are uncommon. Standardized management of these cases is not well established. We aim to provide an in-depth literature review and present current practice patterns among an international group of experienced practitioners in the reirradiation setting of gynecologic cancers.

METHODS AND MATERIALS

An extensive literature search was performed and 35 articles were selected based on preset criteria. A 20-question online survey of 10 experts regarding their retreatment practices was also conducted.

RESULTS

The reviewed publications include a diverse group of patients, multiple treatment techniques, a range of total doses, local control, overall survival, and toxicity outcomes. Overall, local control ranged from 44% to 88% over 1-5 years with OS in the range of 39.5-82% at 2-5 years. Late G3-4 toxicity varied very broadly from 0% to 42.9%, with most papers reporting serious toxicities greater than 15%. The most common reirradiation technique utilized was brachytherapy. Some low-dose-rate data suggest improved outcomes with doses >50 Gy. The high-dose-rate data are more varied with some studies suggesting improved local control with doses >40 Gy. In general, a longer time interval between the first and second course of radiation as well as recurrences <2-4 cm tend to have improved outcomes.

CONCLUSIONS

Reirradiation with brachytherapy results in relatively reasonable local control and toxicities for women with recurrent gynecologic cancers. The appropriate dose for each case needs to be individualized given the heterogeneity of cases. Multidisciplinary management is critical to develop individualized plans and to clearly communicate potential side effects and expected treatment outcomes.

TAKE HOME MESSAGE

Reirradiation with brachytherapy is an acceptable effective organ preserving approach for recurrent gynecologic cancers with a reasonable local control and toxicity profile. Each case requires multidisciplinary management to develop an individualized approach. Monitoring for potential long-term toxicities is essential.

Image-Guided Gynecologic Brachytherapy for Cervical Cancer

The incorporation of magnetic resonance imaging in brachytherapy has resulted in an increased use of interstitial catheters in order to create a comprehensive treatment plan that covers the visualized tumor. However, the insertion with passive, image-guidance requires estimating the location of the tumor during the insertion process, rather than visualizing and inserting the catheters directly to the desired location under active tracking. In order to treat residual disease, multiparametric MR sequences can enhance the information available to the clinician. The precision availed by MR-guided brachytherapy results in substantial improvements in needle positioning, and resulting treatment plans.

Recommendations from gynaecological (GYN) GEC-ESTRO working group - ACROP: Target concept for image guided adaptive brachytherapy in primary vaginal cancer

BACKGROUND AND AIM

External beam radiotherapy (EBRT) combined with brachytherapy has an essential role in the curative treatment of primary vaginal cancer. EBRT is associated with significant tumour shrinkage, making primary vaginal cancer suitable for image guided adaptive brachytherapy (IGABT). The aim of these recommendations is to introduce an adaptive target volume concept for IGABT of primary vaginal cancer.

METHODS

In December 2013, a task group was initiated within GYN GEC-ESTRO with the purpose to introduce an IGABT target concept for primary vaginal cancer. All participants have broad experience in IGABT and vaginal cancer brachytherapy. The target concept was elaborated as consensus agreement based on an iterative process including target delineation and dose planning comparison, retrospective analysis of clinical data and expert opinions.

RESULTS

Gynaecological examination and MR imaging are the modalities of choice for local tumour assessment. A specific template for standardised documentation with clinical drawings for vaginal cancer was developed. The adaptive target volume concept comprises different response-related target volumes. For EBRT these are related to the primary tumour and the lymph nodes, while for IGABT these are related to the primary tumour and are consisting of the residual gross tumour volume (GTV-T_res) and the high-, and intermediate risk clinical target volumes (CTV-T_HR, CTV-T_IR).

CONCLUSION

This target concept for IGABT of primary vaginal cancer defines adaptive target volumes for volumetric dose prescription and should improve comparability of different radiotherapy schedules of this rare disease. A prospective evaluation of the target volume concept within a multicentre study is planned.