Evaluation of planning aims and dose prescription in image-guided adaptive brachytherapy and radiochemotherapy for cervical cancer: Vienna clinical experience in 225 patients from 1998 to 2008

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.

The Effect of Contemporary Brachytherapy Practices on Prognosis in Women with Locally Advanced Cervical Cancer

(1) Background: Over the past two decades use of new imaging modalities and the adaptation of applicators have allowed for advances in volumetric (3D) imaging-based brachytherapy practices for patients with locally advanced cervical cancer. The aim of this study was to compare the oncological outcome and toxicity for three consecutively introduced brachytherapy practices in a large single-center cohort; (2) Methods: Patients treated for cervical cancer with primary radiotherapy and curative intent were consecutively included in this retrospective, single-center cohort study from 2006 to 2019. This cohort was divided into three groups (CT, MRI, and MRI+needles) based on the timing of the introduction of a novel brachytherapy practice; 3D brachytherapy planning using CT- and MRI-guided adaptive brachytherapy and the use of parametrial interstitial needles, respectively. Actuarial estimates were compared between groups. Multivariable Cox regression analyses were performed to correct for other risk factors. Crude rates of severe (≥grade 3) late toxicity were reported; (3) Results: A total of 397 patients were included in this cohort. At a median follow-up of 40 months (interquartile range (IQR) 22-62), actuarial 3-year local control, pelvic control, disease-free survival, and overall survival for the entire cohort were 91% (95% (Confidence Interval (CI)) 88-94), 88% (95% CI 84-91), 69% (95% CI 64-74), and 75% (95% CI 70-79), respectively). Local control, disease-free survival, and overall survival were significantly improved in the MRI+needles group compared to the CT group (p = 0.040, p = 0.004, and p < 0.001, respectively). Independent risk factors for overall survival were treatment in either the CT or MRI group (vs. MRI+needles), older age at diagnosis, adeno (squamous) carcinoma, FIGO stage III/IV, and lymph node metastases. The crude rate of severe late toxicity was 27% in the CT, 26% in the MRI, and 20% in the MRI+needles group; (4) Conclusions: Prognosis in women with locally advanced cervical cancer treated with state-of-the-art MRI-guided adaptive brachytherapy combined with parametrial interstitial needles compares favorably to patients treated with more traditional CT only based brachytherapy.

Providing Patients with Locally Advanced Cervical Cancer Access to Brachytherapy: Experience from a Referral Network for Women Treated in Overseas France

Image-guided adaptive brachytherapy (IGABT) is part of the standard of care for locally advanced cervical cancer (LACC). Access to IGABT is limited in many regions, thus leading to treatment care disparities. We report the experience of a referral network for women with LACC between radiotherapy facilities in Overseas France and Gustave Roussy. This is a retrospective review of patients with LACC referred to Gustave Roussy, for pulsed-dose-rate (PDR) image-guided adaptive BT after initial radiation therapy in the French overseas between 2014 and 2021. Sixty-four patients were eligible to receive IGABT. Overall treatment time (OTT) was 60.5 days (IQR: 51−68.5). The median follow-up time was 17 months. At two years, estimated probabilities of LC, progression-free survival, and overall survival (OS) were 94.6% (95% CI: 88.9−100.0%), 72.7% (95% CI: 61.1−86.5%), and 82.5% (95% CI: 72.0−94.5%). In multivariable analysis, a D90CTVHR < 85GyEQD2 and a CTVHR volume > 40 cm3 were significant for poorer PFS (p = 0.001 and p = 0.009, respectively) and poorer OS (p = 0.004 and p = 0.004). The centralization of this advanced technique to expert centers requires a well-defined workflow and appropriate dimensioning of resources to minimize OTT.

Increasing global accessibility to high-level treatments for cervical cancers

Human papillomaviruses (HPV)-related gynecological cancers are a major health care issue, and a leading cause of cancer death in low- and middle-income countries (LMIC). In 2020, the World Health Organization launched a program aimed at cervical cancer elimination, by screening and vaccination strategies. Offering the best possible care to women diagnosed with invasive cancer is a complementary objective. Treatment of cervical cancer as per modern standards is complex and multimodal, mainly relying on surgery, external-beam radiotherapy (+/-chemotherapy) and brachytherapy. In parallel with the pivotal role of multidisciplinary discussion, international societies provide guidance to define the most effective and least toxic anti-cancer strategy, homogenize treatment protocols and provide benchmark quality indicators as a basis for accreditation processes. The challenge is to offer the appropriate diagnostic workup and treatment upfront and to avoid non- evidence-based treatment that consumes resources, impairs quality of life (QoL), and compromises oncological outcome. Various strategies may be applied for improving treatment quality: development of surgical mentorship, companion-training programs and international cooperation. The lack of radiotherapy/brachytherapy facilities is a major concern in LMIC. Reinforcing international support in terms of education, training, research and development and technical cooperation with national projects is required to increase access to minimum requirements but also introduce modern techniques, upgrade radiotherapy/brachytherapy services, and expand access to modern systemic treatments. In countries with robust economies, compliance to standards should also be increased. Integrative cancer care and multidisciplinary approaches are needed to tackle the dual challenge of increasing cure rates while minimizing QoL impairment. Appropriate dimensioning of the resources to avoid harmful treatment delays and access to expert referral centers is also a priority.

[Dose optimization in 3D pulsed dose rate brachytherapy for patients with locally advanced cervical cancer: A French multicenter phase II trial]

PURPOSE

We present the results of the PHRC Tridicol, a prospective French phase II study whose objective was to increase the dose delivered to the target volume during brachytherapy for locally advanced cervical cancers.

MATERIAL AND METHODS

Eight centers included 48 patients, treated with concomitant radiochemotherapy, then uterovaginal brachytherapy.

RESULTS

The median follow-up was 63 months. The dose of brachytherapy delivered in biological equivalent dose (EQD2) to 90% of the High Risk CTV (D90 CTV HR) was 80Gy in median dose. The 5-year local control rate (LC) was 84%, close to the hypothesis of 86.7%. The rate of severe complications (grade 3-4) was 23% at 5 years. The rectal dose was correlated with the risk of severe complications.

CONCLUSION

HR CTV dose was below the target (85Gy) due to low use of parametrial interstitial needles, as the centers did not always have an adequate applicator, or were at the time at the beginning of their learning curve. The 5-year LC rate was improved compared to that of the comparable STIC PDR group (78%) but lower than the retroEMBRACE cohort of GEC ESTRO (89%). The complication rate was higher than in the comparable group of STIC PDR but close to that of retroEMBRACE. Training brachytherapy teams in interstitial implantation or referring patients to referral centers should help improve the therapeutic index of cervical cancer.

MRI-guided brachytherapy for locally advanced cervical cancer: Program initiation, learning curve and dose delivery results in Kuopio University Hospital

BACKGROUND AND PURPOSE

Image guided adaptive brachytherapy, the standard treatment for locally advanced cervical cancer (LACC), is a complex medical procedure that requires an experienced multidisciplinary team. The aims of this analysis were to assess (1) the learning curve of brachytherapy team, (2) dose-volume parameters, (3) the use of an interstitial component, and (4) the overall treatment time (OTT).

MATERIALS AND METHODS

Our study cohort comprised 117 LACC patients treated in Kuopio University Hospital with magnetic resonance imaging guided intracavitary (IC) or combined intracavitary/interstitial (IC/IS) high dose rate brachytherapy during 2009-2018. Target volumes and organs at risk (OAR) were contoured according to ICRU/GEC-ESTRO recommendations. Treatment plans were optimized individually without using standard loading patterns.

RESULTS

Mean dose to 90% of the high-risk clinical target volume (HR-CTV D90) improved after the first 15 patients, however the team's learning curve to reliably fulfill the main planning aim (PA) of 85 Gy required a total 43 patients and more than 10 patients annually. Significant difference was detected between IC and IC/IS brachytherapy in achieving the PA of HR-CTV D90. Especially, HR-CTV volumes >30 cm³ benefitted from IS needles. Needle insertion did not cause serious complications. With the brachytherapy program, the OTT of patients from outside institutions was reduced to the same level as our own patients.

CONCLUSION

Brachytherapy requires good experience of multidisciplinary team and the continuous development of the program to fulfill PA and to avoid OTT prolongation. The use of IS needles is safe and improves the fulfillment of PA to target volume.

Predictive value of Excel forms based on an automatic calculation of dose equivalent in 2 Gy per fraction in adaptive brachytherapy for cervical cancer

Purpose

External beam radiotherapy (EBRT) combined with brachytherapy (BT) is the standard mode of radical radiotherapy for locally advanced cervical cancer. The cumulative equivalent doses in 2 Gy per fraction (EQD₂) is an important basis for estimating the probability of local control of tumors and monitoring the occurrence of side effects in normal tissues. The purpose of this study was to explore the predictive value of Excel forms based on an automatic calculation in radical adaptive BT for cervical cancer.

Material and methods

A retrospective analysis of 119 patients suffering from cervical cancer, treated with radical radiotherapy. All patients were treated with EBRT and adaptive BT. EBRT prescribed dose was 42.0-50.4 Gy in 21-28 fractions. BT nominal prescribed dose was 28 Gy in 4 fractions, separated by one week. Total EQD₂ prediction at nth (n = 1-3) BT (TEPB_n) or actual cumulative EQD₂ (ACEQD₂) can be calculated automatically by inputting the physical dose based on an in-house designed application. The relationship between TEPB_n and ACEQD₂ was evaluated, and the predictive value of Excel forms based on the automatic calculation was analyzed.

Results

For the volume of high-risk clinical target, there was a significant decrease between BT1 and BT2. Similarly, for the volume of intermediate-risk clinical target, there was a significant decrease between BT2 and BT3. The sensitivity ranges of TEPB₁, TEPB₂, and TEPB₃ prediction were 74.5-91.3%, 83.7-95.7%, and 92.9-99.1%, respectively, and the specificity ranges were 46.7-80.0%, 53.3-90.5%, and 66.7-90.5%, respectively.

Conclusions

The in-house designed application has the function of quickly reading dose-volume histogram (DVH) parameters from the treatment planning system, which allows for balance between the total dose to target volumes and organs at risk (OARs). Excel forms based on EQD₂ automatic calculation presents high predictive accuracy.

[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.

Brachytherapy: An overview for clinicians

Brachytherapy is a specific form of radiotherapy consisting of the precise placement of radioactive sources directly into or next to the tumor. This technique is indicated for patients affected by various types of cancers. It is an optimal tool for delivering very high doses to the tumor focally while minimizing the probability of normal tissue complications. Physicians from a wide range of specialties may be involved in either the referral to or the placement of brachytherapy. Many patients require brachytherapy as either primary treatment or as part of their oncologic care. On the basis of high-level evidence from randomized controlled trials, brachytherapy is mainly indicated: 1) as standard in combination with chemoradiation in patients with locally advanced cervical cancer; 2) in surgically treated patients with uterine endometrial cancer for decreasing the risk of vaginal vault recurrence; 3) in patients with high-risk prostate cancer to perform dose escalation and improve progression-free survival; and 4) in patients with breast cancer as adjuvant, accelerated partial breast irradiation or to boost the tumor bed. In this review, the authors discuss the clinical relevance of brachytherapy with a focus on indications, levels of evidence, and results in the overall context of radiation use for patients with cancer.