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Background and purpose 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. Material and methods 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 5 mm depth were measured. In addition, the dose at the Posterior–Inferior Border of Symphysis (PIBS) vaginal dose point and PIBS±2 cm, corresponding to the mid and lower vagina, was measured. Results 153 patients from seven institutions were included. Large dose variations expressed in EQD2 with α/β = 3 Gy 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 5 mm 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±2 cm was 41 (3–81) Gy, 54 (32–109) Gy and 5 (1–51) Gy, respectively. At PIBS+2 cm (mid vagina) dose variation was coming from BT. The variation at PIBS−2 cm (lower vagina) was mainly dependent on EBRT field border location. Conclusions 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 centres. [ABSTRACT FROM AUTHOR]

IntroductionThe reliability of hyperthermia treatment planning (HTP) is strongly dependent on the accuracy of the electric properties of each tissue. The values currently used are mostly based onex vivomeasurements. In this study,in vivoconductivity of human muscle, bladder content and cervical tumours, acquired with magnetic resonance-based electric properties tomography (MR-EPT), are exploited to investigate the effect on HTP for cervical cancer patients.MethodsTemperature-based optimisation of five different patients was performed using literature-based conductivity values yielding certain antenna settings, which are then used to compute the temperature distribution of the patient models with EPT-based conductivity values. Furthermore, the effects of altered bladder and muscle conductivity were studied separately. Finally, the temperature-based optimisation was performed with patient models based on EPT conductivity values.ResultsThe tumour temperatures for all EPT-based dielectric patient models were lower compared to the optimal tumour temperatures based on literature values. The largest deviation was observed for patient 1 with ΔT90 = −1.37 °C. A negative impact was also observed when the treatment was optimised based on the EPT values. For four patients ΔT90 was less than 0.6 °C; for one patient it was 1.5 °C.ConclusionsElectric conductivity values acquired by EPT are higher than commonly used from literature. This difference has a substantial impact on cervical tumour temperatures achieved during hyperthermia. A higher conductivity in the bladder and in the muscle tissue surrounding the tumour leads to higher power dissipation in the bladder and muscle, and therefore to lower tumour temperatures. [ABSTRACT FROM PUBLISHER]

Abstract: Background and purpose: Traditionally, vaginal dose points have been defined at the vaginal source level, thus not providing dose information for the entire vagina. Since reliable vaginal dose volume/surface histograms are unavailable, a strategy for comprehensive vaginal dose reporting for combined EBRT and BT was established and investigated. Material and methods: An anatomical vaginal reference point was defined at the level of the Posterior–Inferior Border of Symphysis (PIBS), plus two points ±2cm (mid/introitus vagina). For BT extra points were selected for the upper vagina at 12/3/6/9o’clock, at the vaginal surface and 5mm depth. A vaginal reference length (VRL) was defined from ring centre to PIBS. Fifty-nine patients treated for cervical cancer were included in this retrospective feasibility study. Results: The method was applicable to all patients. Total EQD2 doses at PIBS and ±2cm were 36.7Gy (3.1–68.2), 49.6Gy (32.1–89.6) and 4.3Gy (1.0–46.6). At the vaginal surface at ring level doses were respectively 266.1Gy (67.6–814.5)/225.9Gy (61.5–610.5) at 3/9o’clock, and 85.1Gy (55.4–140.3)/72.0Gy (49.1–108.9) at 12/6o’clock. Mean VRL on MRI was 5.6cm (2.0–9.4). Conclusions: With this novel system, a comprehensive reporting of vaginal doses is feasible. The present study has demonstrated large dose variations between patients observed in all parts of the vagina, resulting from different contributions from EBRT and BT. [Copyright &y& Elsevier]

Background and purpose Regarding latest developments, the need of a radiotherapy ‘Patterns of Care’ survey was expressed by the Dutch National Platform Radiotherapy for Gynaecological Cancer (LPRGT). Therefore, this study investigated current practice for cervical cancer in all 16 radiation oncology centres in the Netherlands specialised in gynaecological oncology. Material and methods A structured ‘patterns of care’ questionnaire was completed and followed by an in-depth interview with radiation oncologists from all radiotherapy centres specialised in gynaecological oncology. Specific topics addressed were: definition of target volumes, treatment preparation, imaging for treatment planning, treatment planning, and image-guided adaptive radiotherapy for external beam radiotherapy and brachytherapy. Results Current radiotherapy practice in the Netherlands for cervical cancer appears to be in accordance with international standards. However, at the time of the survey some differences were revealed that might have relevant clinical impact. For instance: 1) Half of the centres acquired positron emission tomography combined with CT (PET-CT) for staging and target delineation for every patient, 2) The definition of upper border of the para-aortal lymph node area and dose prescription for external beam radiotherapy varied between the centres, and 3) 12 centres used a single treatment plan for delivering EBRT, and four used a plan-of-the-day strategy with a library of 3–4 treatment plans. Conclusions Most differences were found at the cutting edge of clinical evidence. However, the majority of these uncertainties are topics being addressed in current and planned (inter)national studies. [ABSTRACT FROM AUTHOR]

Dosimetric intra-fraction uncertainties in MRI-guided brachytherapy were analysed for HR-CTV and OARs. While dose differences were generally small, individual outliers occurred. In contrast to HDR, patients treated with PDR show increased mean rectal dose over time. Re-imaging prior to dose delivery helps to detect unfavorable anatomical changes, and allows for intervention. [ABSTRACT FROM AUTHOR]

Background and Purpose: 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. Methods and Materials: 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. Results: 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. Conclusion: 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 attention. [ABSTRACT FROM AUTHOR]