Treatment outcomes of MRI-guided adaptive brachytherapy in patients with locally advanced cervical cancer: institutional experiences.

PURPOSE: Image-guided adaptive brachytherapy (IGABT) is currently state of the art in the comprehensive treatment of patients with cervical cancer. Here, we report mature clinical data regarding IGABT of cervical cancer in a large patient sample, examining clinical outcomes, manifestations of late toxicities, and dosimetric findings. METHODS: Between May 2012 and October 2020, we performed a total of 544 uterovaginal IGABT applications in 131 consecutive patients with biopsy-proven cervical carcinoma not suitable for surgery. The median duration of follow-up was 43 months. RESULTS: The estimated 3­, 4­, and 5­year LC rates were 88.3% (95% confidence interval [CI] 81.1-95.5), 86.9% (95% CI 78.5-95.3), and 85.5% (95% CI 76-95%), respectively. The 3­, 4­, and 5­year OS estimates were 72.66% (95% CI 63.64-81.69%), 68.9% (95% CI 59.15-78.66%), and 63.96% (95% CI 52.94-74.97%), respectively. Patients who received ≥ 5 cycles of chemotherapy had statistically significantly better 3­year recurrence-free survival (RFS) compared to patients who completed <5 cycles (79.07% [95% CI 60.81-97.34] vs. 58.10% [95% CI 47.22-68.98]; p = 0.0185). We recorded manifestations of genitourinary and gastrointestinal toxicity grade ≥3 in 6.9% and 5.3%, respectively. CONCLUSION: Our mature long-term data on the treatment patients with locally advanced cervical cancer show that excellent treatment outcomes can be achieved with MRI-based IGABT, as well as acceptable late morbidity.

Prediction of treatment response in patients with locally advanced cervical cancer using midtreatment PET/MRI during concurrent chemoradiotherapy.

PURPOSE: We aimed to find metabolic, functional or morphological characteristics of the tumor predicting failure to achieve complete metabolic remission (CMR) by the midtreatment PET/MRI (positron emission tomography/magnetic resonance imaging) in cervical cancer patients. METHODS: We evaluated 66 patients treated between August 2015 and November 2019 who underwent pretreatment staging, subsequent midtreatment evaluation, and definitive restaging 3 months after completing the whole treatment, all using PET/MRI. The pretreatment parameters (pre-SUVmax, pre-SUVmean, pre-MTV, pre-MTV­S, pre-TLG, pre-TLG­S [SUV: standard uptake value, MTV: metabolic tumor volume, TLG: total lesion glycolysis]), and the midtreatment parameters at week 5 during chemoradiotherapy (mid-SUVmax, mid-SUVmean, mid-MTV, mid-MTV­S, mid-TLG and mid-TLG-S) were recorded. The value of ADC (apparent diffusion coefficient) was also measured. Furthermore, we recorded absolute and relative changes in all parameters-∆ and ∆%. We divided the whole group of patients into "responders" (CMR) and "non-responders" (non-CMR), and compared them on the basis of the parameters from pre-PET/MRI and mid-PET/MRI. RESULTS: A statistically significant difference in the evaluated parameters between responders and non-responders was found for the following parameters: mid-MTV, mid-TLG, mid-TLG­S, mid-MTV­S, mid-tumor size, and ∆%SUVmax. According to the ROC (receiver operating characteristic) analysis, mid-MTV­S showed the best albeit moderate discrimination ability for the prediction of non-CMR. Significant mutual correlations of all variables, in particular between mid-MTV­S and mid-TLG­S and between mid-MTV and mid-TLG, were found (all p < 0.05). CONCLUSION: Our study confirmed that when using the midtreatment PET/MRI we are able to identify metabolic parameters having the discrimination ability for the prediction of non-CMR. In particular mid-MTV­S, mid-MTV, mid-tumor size, mid-TLG­S, mid-TLG and ∆%SUVmax.

Late side effects of 3T MRI-guided 3D high-dose rate brachytherapy of cervical cancer : Institutional experiences.

PURPOSE: This article reports experiences with 3T magnetic resonance imaging(MRI)-guided brachytherapy (BT) for cervical cancer focusing on late side effects. METHODS: Between June 2012 and March 2017 a total of 257 uterovaginal BT administrations were performed in 61 consecutive patients with inoperable cervical cancer. All patients were treated with BT combined with external beam radiotherapy. RESULTS: The mean HR-CTV (high risk-clinical target volume) D90 was 87 ± 5.1 Gy equivalent dose corresponding to the conventional fractionation using 2 Gy per fraction (EQD2, range 70.7-97.9 Gy). The mean doses in OAR (organs at risk), namely rectum, sigmoid and bladder were D2 cm3rectum = 62.6 ± 6.9 Gy EQD2 (range 38.2-77.2 Gy), D2 cm3sigmoid = 66.2 ± 6.8 Gy EQD2 (43.2-78.6 Gy) and D2 cm3bladder = 75.1 ± 8.3 Gy EQD2 (58.2-92.6 Gy). There were no signs of late gastrointestinal (GI) toxicity in 49 patients, grade 3 toxicity was seen in 2 patients and grade 4 toxicity in 3 patients. There were no signs of late genitourinary (GU) toxicity in 41 patients, grade 3 toxicity was seen in 4 patients and no signs of grade 4 toxicity were seen. After the treatment, 60 patients (98.4%) achieved locoregional remission. In 54 patients (88.5%) the remission was complete, whereas in 6 patients (9.8%) remission was partial. CONCLUSION: The use of 3T MRI-guided BT leads to achievement of high rates of local control with limited late morbidity as demonstrated in this series of patients.

Image guided adaptive brachytherapy of cervical cancer - practical recommendations.

Brachytherapy (BT) is an integral part of radical radiotherapy (RT) or radiochemotherapy (RCT) in patients who are not suitable candidates for surgery. These are usually patients with locally advanced cervical cancer. The goal of all BT planning eff orts has been, still is, and certainly will continue to be, to defi ne the anatomical boundaries of the tumor and the relationship of the tumor to organs at risk (OARs) as best as possible, using available modern imaging techniques. Image guided adaptive brachytherapy (IGABT) is currently the most advanced method of uterovaginal BT. Adaptive planning allows dose escalation from BT to newly defi ned target volumes, according to the risk of recurrence, which is mainly determined by the level of tumor burden. This dose adaptation based on the response to external RCT is a major change in practice compared to conventional BT planning based on dose prescription to point A. The main advantage of the IGABT concept is that it allows the assessment of individual dose distributions in target volumes and OARs, which in turn leads to improved dose coverage of target volumes while decreasing the volume irradiated by the prescribed dose compared to conventional 2D planning. Purpose: In this review article, I provide a comprehensive up-to-date perspective on this issue, particularly in terms of practical recommendations regarding the defi nition of target volumes, the use of diff erent types of uterovaginal applicators, intraoperative complications, and potential manifestations of late gastrointestinal, genitourinary, and vaginal toxicity.

[Dose optimization in 3D pulsed dose rate brachytherapy for patients with locally advanced cervical cancer: A French multicenter phase II trial]. / Optimisation de la curiethérapie utérovaginale de débit pulsé des cancers du col utérin localement évolués : résultats finaux du PHRC Tridicol.

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.