Manifestation pattern of early-late vaginal morbidity after definitive radiation (chemo)therapy and image-guided adaptive brachytherapy for locally advanced cervical cancer: an analysis from the EMBRACE study

Brachytherapy in the treatment of locally advanced cervical cancer has changed substantially because of the introduction of combined intracavitary/interstitial applicators and an adaptive target concept, which is the focus of the prospective, multi-institutional EMBRACE study (www.embracestudy.dk) on image-guided adaptive brachytherapy (IGABT). So far, little has been reported about the development of early to late vaginal morbidity in the frame of IGABT. Therefore, the aim of the present EMBRACE analysis was to evaluate the manifestation pattern of vaginal morbidity during the first 2 years of follow-up. In total, 588 patients with a median follow-up time of 15 months and information on vaginal morbidity were included. Morbidity was prospectively assessed at baseline, every 3 months during the first year, and every 6 months in the second year according to the Common Terminology Criteria for Adverse Events, version 3, regarding vaginal stenosis, dryness, mucositis, bleeding, fistula, and other symptoms. Crude incidence rates, actuarial probabilities, and prevalence rates were analyzed. At 2 years, the actuarial probability of severe vaginal morbidity (grade ≥3) was 3.6%. However, mild and moderate vaginal symptoms were still pronounced (grade ≥1, 89%; grade ≥2, 29%), of which the majority developed within 6 months. Stenosis was most frequently observed, followed by vaginal dryness. Vaginal bleeding and mucositis were mainly mild and infrequently reported. Severe vaginal morbidity within the first 2 years after definitive radiation (chemo)therapy including IGABT with intracavitary/interstitial techniques for locally advanced cervical cancer is limited and is significantly less than has been reported from earlier studies. Thus, the new adaptive target concept seems to be a safe treatment with regard to the vagina being an organ at risk. However, mild to moderate vaginal morbidity is still pronounced with currently applied IGABT, and it needs further attentio

Multicentre evaluation of a novel vaginal dose reporting method in 153 cervical cancer patients

Recently, a vaginal dose reporting method for combined EBRT and BT in cervical cancer patients was proposed. The current study was to evaluate vaginal doses with this method in a multicentre setting, wherein different applicators, dose rates and protocols were used. In a subset of patients from the EMBRACE study, vaginal doses were evaluated. Doses at the applicator surface left/right and anterior/posterior and at 5mm depth were measured. In addition, the dose at the Posterior-Inferior Border of Symphysis (PIBS) vaginal dose point and PIBS±2cm, corresponding to the mid and lower vagina, was measured. 153 patients from seven institutions were included. Large dose variations expressed in EQD2 with α/β=3Gy were seen between patients, in particular at the top left and right vaginal wall (median 195 (range 61-947)Gy/178 (61-980)Gy, respectively). At 5mm depth, doses were 98 (55-212)Gy/91 (54-227)Gy left/right, and 71 (51-145)Gy/67 (49-189)Gy anterior/posterior, respectively. The dose at PIBS and PIBS±2cm was 41 (3-81)Gy, 54 (32-109)Gy and 5 (1-51)Gy, respectively. At PIBS+2cm (mid vagina) dose variation was coming from BT. The variation at PIBS-2cm (lower vagina) was mainly dependent on EBRT field border location. This novel method for reporting vaginal doses coming from EBRT and BT through well-defined dose points gives a robust representation of the dose along the vaginal axis. In addition, it allows comparison of vaginal dose between patients from different centres. The doses at the PIBS points represent the doses at the mid and lower parts of the vagina. Large variations in dose throughout the vagina were observed between patients and centre

Tools for large-scale data analytics of an international multi-center study in radiation oncology for cervical cancer

Purpose: To develop and implement a software that enables centers, treating patients with state-of-the-art radiation oncology, to compare their patient, treatment, and outcome data to a reference cohort, and to assess the quality of their treatment approach. Materials and Methods: A comprehensive data dashboard was designed, which al- lowed holistic assessment of institutional treatment approaches. The software was tested in the ongoing EMBRACE-II study for locally advanced cervical cancer. The tool created individualized dashboards and automatic analysis scripts, verified pro- tocol compliance and checked data for inconsistencies. Identified quality assurance (QA) events were analysed. A survey among users was conducted to assess usability. Results: The survey indicated favourable feedback to the prototype and highlighted its value for internal monitoring. Overall, 2302 QA events were identified (0.4% of all collected data). 54% were due to missing or incomplete data, and 46% originated from other causes. At least one QA event was found in 519/1001 (52%) of patients. QA events related to primary study endpoints were found in 16% of patients. Sta- tistical methods demonstrated good performance in detecting anomalies, with precisions ranging from 71% to 100%. Most frequent QA event categories were Treatment Technique (27%), Patient Characteristics (22%), Dose Reporting (17%), Outcome 156 (15%), Outliers (12%), and RT Structures (8%). Conclusion: A software tool was developed and tested within a clinical trial in radia- tion oncology. It enabled the quantitative and qualitative comparison of institutional patient and treatment parameters with a large multi-center reference cohort. We demonstrated the value of using statistical methods to automatically detect implau- sible data points and highlighted common pitfalls and uncertainties in radiotherapy for cervical cancer

Dose-effect relationship between vaginal dose points and vaginal stenosis in cervical cancer: An EMBRACE-I sub-study

Background and purpose: To evaluate dose–effect relationships between vaginal dose points and vaginal stenosis in patients treated for locally advanced cervical cancer with radio(chemo)therapy and image-guided adaptive brachytherapy. Material and methods: Patients from six centres participating in the EMBRACE-I study were included. Information on doses to different vaginal dose points, including the Posterior-Inferior Border of Symphysis (PIBS) points and recto-vaginal reference (RV-RP) point, were retrieved from the treatment planning system. In addition, the vaginal reference length (VRL) was evaluated. Vaginal stenosis was prospectively assessed according to the CTCAEv3.0 system at baseline and follow-up. Primary endpoint was grade 2 or higher (G ≥ 2) vaginal stenosis. Impact of dose to the vaginal dose points, and impact of VRL, age, vaginal involvement and applicator on vaginal stenosis G ≥ 2 was evaluated with a Cox proportional-hazard regression model. Results: 301 patients were included. Median follow-up was 49 months. During follow-up, the incidence of G0, G1, G2, and G3 vaginal stenosis was 25% (76), 52% (158), 20% (59) and 3% (8), respectively. Median total doses to PIBS+2 cm, PIBS, PIBS-2 cm and the RV-RP were 52.9 (IQR 49.3–64.7), 41.0 (IQR 15.4–49.0), 4.1 (IQR 2.9–7.0) and 64.6 (IQR 60.0–70.6) Gy EQD23, respectively. Higher doses to the PIBS, PIBS + 2 cm and RV-RP points were significantly associated with increased risk for vaginal stenosis G ≥ 2. Other risk factors for vaginal stenosis were: vaginal involvement at diagnosis, higher age, shorter VRL and use of a tandem-ovoid applicator. Conclusion: Higher doses to the PIBS+2 cm, PIBS and RV-RP dose points are associated with vaginal stenosis G ≥ 2

Results of image guided brachytherapy for stage IB cervical cancer in the RetroEMBRACE study

Objective: Multiple treatment options are used in early local-stage cervical cancer, including combinations of surgery with neoadjuvant/adjuvant radiotherapy and chemotherapy. Our aim was to determine the outcome for definitive chemoradiation with image guided brachytherapy (IGBT). Methods: FIGO1994 staging system was used in our study. We included 123 patients with stage IB cervical cancer, treated at 12 centers with external beam radiotherapy (EBRT) ± Chemotherapy and IGBT. Three- and 5-year actuarial local control (LC), pelvic control (PC), overall survival (OS), cancer-specific survival (CSS) and late morbidity (CTCAE v 3.0) were computed. Results: Median age was 48 (23-82) years. FIGO1994 stage distribution was: IB1 68% and IB2 32%; 41% of the entire cohort had nodal metastases and 73% squamous-cell carcinoma. MRI-based tumor size was >40 mm in 63%. Median EBRT dose was 45 (40-50) Gy; 84% received chemotherapy. At IGBT, mean CTV-HR D90 was 93 ± 17 Gy (EQD210). D2cc for bladder was 76 ± 14 Gy, rectum 66 ± 11 Gy, sigmoid 66 ± 10 Gy, bowel 67 ± 7 Gy (EQD23). At 43-months median follow-up, 9% of patients had systemic, 6% paraaortic, 3% pelvic-nodal and 2% local failure. Five-year LC was 98%, PC 96%, CSS 90%, OS 83%. Intestinal G3--4 morbidity was 8%, urinary 7% and vaginal 0%. Conclusions: Chemoradiation with IGBT for FIGO1994 stage IB cervical cancer leads to excellent loco-regional control with limited morbidity. In IB node-negative disease, it can be regarded equivalent to surgery in terms of oncologic outcome. In tumors with unfavorable pre-treatment characteristics, chemoradiation is the first choice to avoid combining surgery with adjuvant therapy. Keywords: Brachytherapy; Cervix cancer; Image guided brachytherapy