MRI-guided adaptive radiotherapy in locally advanced cervical cancer from a Nordic perspective

Model assessment of individual tumor control rate and adverse effects in comparing locally advanced cervical cancer treatment using intracavitary with and without interstitial brachytherapy

Purpose

This study assessed the modeled probability of tumor control and organ at risk toxicities in locally advanced cervical cancer in patients treated by external beam radiation plus brachytherapy using intracavitary combined with interstitial brachytherapy (IC/IS) vs. intracavitary brachytherapy (IC) alone.

Material and methods

Twenty cervical cancer patients with a mean HR-CTV volume of 47.4 cm³ and a mean width of 54 mm were planned with both IC/IS and IC brachytherapy alone. A probit model was utilized to model 3-year (3-yr) local control rate (LC), 3-yr cancer specific survival rate (CSS), and the adverse effect (AE) of the organ at risk by using a modeled data set from multiple institutions. Modeling results were used to estimate the LC, CSS, and AE of the treatments in this study.

Results

Using the IC/IS technique, an EQD₂ increase of 12.3 Gy to D₉₀ (from 76.1 Gy to 88.3 Gy) of HR-CTV is expected to increase 3-yr LC and 3-yr CSS by 12.5%, and 11.0%, respectively. Comparing IC/IS to IC alone, the expected G2⁺ AE were 7.7% vs. 7.9% for the bladder, and 5.9% vs. 6.8% for the rectum.

Conclusions

The IC/IS technique improved dose coverage to the HR-CTV without significantly increasing dose to 2 cm³ of the organ at risk (OAR) surrounding it. With different regimens of EBRT combined with BT, IC/IS can be used to increase the probability of LC and CSS, or decrease the risk of AE.

Five-year results for image-guided brachytherapy (IGBT) for cervical carcinoma: a report from single institute of Thailand

Aim

To report of long-term results and toxicity profiles using image-guided brachytherapy (IGBT) combined with whole pelvic radiation therapy (WPRT) for cervical carcinoma.

Materials and Methods

In total, 52 patients with locally advanced cervical carcinoma were enrolled into the study. WPRT was used to treat the clinical target volume (CTV) with a dose of 45–50·4 Gy in 23–28 fractions. IGBT using computed tomography was performed at the dose of 6·5–7 Gy×4 fractions to the minimum dose covering 90% of target volume (D90) of high-risk clinical target volume (HR-CTV).

Results

The mean cumulative dose in equivalent doses of 2 Gy for the D90 of HR-CTV, dose at 2% at refereed volume (D2cc) of bladder, D2cc of rectum and D2cc of sigmoid colon were 92·4, 87·9, 69·6, and 72 Gy, respectively. At the median follow-up time of 61 months, the 5-year local control, disease-free survival, and overall survival rates were 96·2, 75 and 84·6% respectively. Two patients (3·8%) developed grade 3–4 gastrointestinal and two patients (3·8%) developed grade 3–4 genitourinal toxicities.

Conclusion

The combination of WPRT plus IGBT showed very promising long-term results with excellent local control and toxicity profiles.

Clinical outcome of interstitial pulsed dose rate brachytherapy in multimodality treatment of locally advanced primary or recurrent rectal and sigmoid cancer with high risk of incomplete microscopic resection

OBJECTIVE

To evaluate the role of interstitial pulsed dose rate brachytherapy (PDR-BT) in multimodality treatment of locally advanced primary or recurrent rectal and sigmoid cancer with high risk of microscopic incomplete resection (R1).

METHODS AND MATERIAL

A total of 73 consecutive patients (recurrent/primary: 40/33) were treated with PDR-BT between 2001 and 2010. Patients received preoperative external beam radiotherapy (EBRT) and concomitant chemotherapy. Following resection of the tumor and the involved pelvic organs, a median of four (3-8) catheters were sutured to the tumor bed with a distance of approximately 1 cm between the catheters. A target respecting the catheters with a margin of 5 mm was contoured on computed tomography (CT) and three-dimensional (3D) dose planning with a planning aim for BT of D90 > 30 Gy, (0.6 Gy/pulse, 1 pulse/h) was performed. Previously irradiated patients (27%) underwent surgery that was directly followed by PDR-BT. Postoperative EBRT was then applied to the tumor bed 3-5 weeks after PDR-BT.

RESULTS

A total of 23 patients (31%) received a radical resection (R0) and 45 patients (62%) received an R1 resection. Five patients (7%) received a macroscopic incomplete resection (R2). The five-year overall survival was 33%. Local control at five years was 67% for patients who received a R0 resection and 32% for patients who received an R1 resection. The five-year actuarial risk of a grade 3-4 BT-related complication was 5%.

CONCLUSIONS

Meaningful disease control and survival can be obtained at an acceptable rate of late morbidity in selected patients with locally advanced primary and recurrent rectal or sigmoid cancer using (chemo) RT, extensive surgery and PDR-BT when a high risk of an R1 resection is expected.

Improving the efficiency of image guided brachytherapy in cervical cancer

Brachytherapy is an essential component of the treatment of locally advanced cervical cancers. It enables the dose to the tumor to be boosted whilst allowing relative sparing of the normal tissues. Traditionally, cervical brachytherapy was prescribed to point A but since the GEC-ESTRO guidelines were published in 2005, there has been a move towards prescribing the dose to a 3D volume. Image guided brachytherapy has been shown to reduce local recurrence, and improve survival and is optimally predicated on magnetic resonance imaging. Radiological studies, patient workflow, operative parameters, and intensive therapy planning can represent a challenge to clinical resources. This article explores the ways, in which 3D conformal brachytherapy can be implemented and draws findings from recent literature and a well-developed hospital practice in order to suggest ways to improve the efficiency and efficacy of a brachytherapy service. Finally, we discuss relatively underexploited translational research opportunities.

Long term results from a prospective database on high dose rate (HDR) interstitial brachytherapy for primary cervical carcinoma

OBJECTIVE

Present long-term outcomes in primary cervical cancer treated with external beam and high dose rate interstitial brachytherapy.

METHODS

High dose rate (HDR) interstitial (IS) brachytherapy (BT) and external beam (EBRT) were administered from 1992 to 2009 to 315 patients who were unsuitable for intracavitary (IC) BT alone. Histology was 89% squamous cell, 8% adenocarcinoma, and 3% adenosquamous. FIGO stage was I-14%, II-47%, III-34%, and IVA-5%. Median tumor size was 6cm. Lymph node metastases were 26% pelvic and 9.5% para-aortic. Treatment planning was 49% 2D and 51% 3D-CT. The mean doses were central EBRT EQD210 37.3±4.3Gy (sidewall 49.2±3.6Gy) and HDR EQD210 42.3±5.3Gy (nominal 5.4Gy×6 fractions using a mean of 24 catheters and 1 tandem). Total EQD210 mean target dose was 79.5±5.4Gy. Standardized planned dose constraints were ICRU points or D0.1cc bladder 80%, rectum 75% and urethra 90% of the HDR dose per fraction. Morbidity assessment was CTCAEv3. Median and mean follow-up were 50 and 61months (3-234).

RESULTS

The 10-year actuarial local control was 87%, regional control 84%, and loco-regional control 77%. Distant metastasis free survival was 66%, cause specific survival 56%, disease free survival 54%, and overall survival 40%. The rates of late grade GU and GI toxicities were 4.8% G3 and 5.4% G4.

CONCLUSIONS

Template-guided interstitial can be safely performed to successfully deliver high radiation dose to locally advanced cervix cancer and avoid excessive dose and injury to adjacent vital pelvic organs. We achieved high tumor control with low morbidity in patients who were poor candidates for intracavitary brachytherapy.

Magnetic resonance image-guided brachytherapy for cervical cancer : Prognostic factors for survival

OBJECTIVE

The purpose of this work was to identify prognostic factors for survival after magnetic resonance image (MRI)-guided brachytherapy combined with external beam radiotherapy for cervical cancer.

MATERIAL AND METHODS

External beam radiotherapy of 45-50.4 Gy was delivered by either three-dimensional conformal radiotherapy or helical tomotherapy. Patients also received high-dose-rate MRI-guided brachytherapy of 5 Gy in 6 fractions.

RESULTS

We analyzed 128 patients with International Federation of Gynecology and Obstetrics stage IB-IVB cervical cancer who underwent MRI-guided brachytherapy. Most patients (96 %) received concurrent chemotherapy. Pelvic lymph node metastases and para-aortic lymphadenopathies were found in 62 % and 14 % of patients, respectively. The median follow-up time was 44 months. Complete remission was achieved in 119 of 128 patients (93 %). The 5‑year local recurrence-free, cancer-specific, and overall survival rates were 94, 89, and 85 %, respectively. Negative pelvic lymphadenopathy, gross tumor volume (GTV) dose covering 90 % of the target (GTV D90) of >110 Gy, and treatment duration ≤56 days were associated with better overall survival in univariate analyses. Multivariable analysis showed that GTV D90 of >110 Gy and treatment duration ≤56 days were possibly associated with overall survival with near-significant P-values of 0.062 and 0.073, respectively.

CONCLUSIONS

The outcome of MRI-guided brachytherapy combined with external beam radiotherapy in patients with cervical cancer was excellent. GTV D90 of >110 Gy and treatment duration ≤56 days were potentially associated with overall survival.

Simultaneous integrated boost (SIB) of the parametrium and cervix in radiotherapy for uterine cervical carcinoma: a dosimetric study using a new alternative approach

OBJECTIVE

To compare the dose distributions of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) using the simultaneous integrated boost (SIB) technique with that of the traditional midline block (MB) technique for boosting the parametrium in patients with cervical cancer.

METHODS

Treatment plans using VMAT or IMRT with the SIB technique (VMAT-SIB and IMRT-SIB) and IMRT followed by the MB technique (IMRT-MB) were generated for each of the 10 patients with cervical cancer. For the SIB plans, 45-Gy and 50-Gy dose levels in 25 equal fractions were set for the pelvis planning target volume 45 (PTV₄₅) and the parametrial boost volume (PTV₅₀), respectively. For the IMRT-MB plans, the parametrium was sequentially boosted with the MB technique (5.4 Gy in three fractions) after pelvic IMRT (PTV₄₅).

RESULTS

Volume receiving 100% of the prescribed dose or more coverage of the PTV₅₀ was significantly better for VMAT-SIB and IMRT-SIB than that for IMRT-MB (99.08 and 99.31% compared with 91.79%, respectively; p < 0.05). VMAT-SIB and IMRT-SIB both generated significantly greater doses to the organs at risk (OARs) except for the volume receiving 50 Gy or more doses, which were significantly lower for the bladder and bowel. Comparable results were achieved with VMAT-SIB and IMRT-SIB.

CONCLUSION

The VMAT-SIB and IMRT-SIB techniques are promising in terms of dose distributions and tumour coverage, although these approaches might result in slightly higher doses of radiation to the OARs. Advances in knowledge: This is the first study to examine the feasibility of the SIB technique using IMRT or VMAT to boost the parametrium. The techniques dosimetrically produced better target coverage but resulted in slightly higher doses to the OARs.

Development and clinical implementation of a new template for MRI-based intracavitary/interstitial gynecologic brachytherapy for locally advanced cervical cancer: from CT-based MUPIT to the MRI compatible Template Benidorm. Ten years of experience

PURPOSE

To study outcome and toxicity in 59 patients with locally advanced cervix carcinoma treated with computed tomography (CT)-based Martinez universal perineal interstitial template (MUPIT) and the new magnetic resonance imaging (MRI)-compatible template Benidorm (TB).

MATERIAL AND METHODS

From December 2005 to October 2015, we retrospectively analyzed 34 patients treated with MUPIT and 25 treated with the TB. Six 4 Gy fractions were prescribed to the clinical target volume (CTV) combined with external beam radiotherapy (EBRT). The organs at risk (OARs) and the CTV were delineated by CT scan in the MUPIT implants and by MRI in the TB implants. Dosimetry was CT-based for MUPIT and exclusively MRI-based for TB. Dose values were biologically normalized to equivalent doses in 2 Gy fractions (EQD2).

RESULTS

Median CTV volumes were 163.5 cm3 for CT-based MUPIT (range 81.8-329.4 cm3) and 91.9 cm3 for MRI-based TB (range 26.2-161 cm3). Median D90 CTV (EBRT + BT) was 75.8 Gy for CT-based MUPIT (range 69-82 Gy) and 78.6 Gy for MRI-based TB (range 62.5-84.2 Gy). Median D2cm3 for the rectum was 75.3 Gy for CT-based MUPIT (range 69.8-132.1 Gy) and 69.9 Gy for MRI-based TB (range 58.3-83.7 Gy). Median D2cm3 for the bladder was 79.8 Gy for CT-based MUPIT (range 71.2-121.1 Gy) and 77.1 Gy for MRI-based TB (range 60.5-90.8 Gy). Local control (LC) was 88%. Overall survival (OS), disease free survival (DFS), and LC were not statistically significant in either group. Patients treated with CT-based MUPIT had a significantly higher percentage of rectal bleeding G3 (p = 0.040) than those treated with MRI-based TB, 13% vs. 2%.

CONCLUSIONS

Template Benidorm treatment using MRI-based dosimetry provides advantages of MRI volume definition, and allows definition of smaller volumes that result in statistically significant decreased rectal toxicity compared to that seen with CT-based MUPIT treatment.

Implementation of image-guided brachytherapy (IGBT) for patients with uterine cervix cancer: a tumor volume kinetics approach

Purpose

To evaluate tumor shrinking kinetics in order to implement image-guided brachytherapy (IGBT) for the treatment of patients with cervix cancer.

Material and methods

This study has prospectively evaluated tumor shrinking kinetics of thirteen patients with uterine cervix cancer treated with combined chemoradiation. Four high dose rate brachytherapy fractions were delivered during the course of pelvic external beam radiation therapy (EBRT). Magnetic resonance imaging (MRI) exams were acquired at diagnosis (D), first (B1), and third (B3) brachytherapy fractions. Target volumes (GTV and HR-CTV) were calculated by both the ellipsoid formula (VE) and MRI contouring (VC), which were defined by a consensus between at least two radiation oncologists and a pelvic expert radiologist.

Results

Most enrolled patients had squamous cell carcinoma and FIGO stage IIB disease, and initiated brachytherapy after the third week of pelvic external beam radiation. Gross tumor volume volume reduction from diagnostic MRI to B1 represented 61.9% and 75.2% of the initial volume, when measured by VE and VC, respectively. Only a modest volume reduction (15-20%) was observed from B1 to B3.

Conclusions

The most expressive tumor shrinking occurred in the first three weeks of oncological treatment and was in accordance with gynecological examination. These findings may help in IGBT implementation.

Clinical outcomes from an innovative protocol using serial ultrasound imaging and a single MR image to guide brachytherapy for locally advanced cervix cancer

PURPOSE

The aim of this study was to report clinical outcomes in a series of patients who underwent serial ultrasound and a single MRI to plan and verify intracavitary brachytherapy.

METHODS AND MATERIALS

Data for patients who were referred for curative intent radiotherapy for International Federation of Gynecology and Obstetrics (FIGO) Stage 1-1V cervix cancer between January 2007 and March 2012 were analyzed. All patients received external beam radiotherapy with concurrent chemotherapy and sequential high-dose rate brachytherapy. Brachytherapy was planned and verified using serial ultrasound imaging and a single MRI.

RESULTS

Data from 191 patients were available for analyses. The median (range) followup time was 5.08 (0.25-8.25) years. Five-year local control, failure-free survival, cancer-specific survival, and overall survival were 86%, 57.3%, 70% and 63%, respectively. Mean (standard deviation) combined external beam radiotherapy and brachytherapy target doses, equivalent to doses in 2 Gy fractions were 80.4 Gy10 (3.89), median (range) 80 (49-96) Gy10. Grade 3 or greater gastrointestinal, genitourinary, or vaginal late toxicity occurred in 3%, 1.6%, and 2% of patients, respectively. Survival, patterns of failure, and late complication rates were similar to published series of MRI/CT-based brachytherapy practices.

CONCLUSIONS

This large study demonstrates that favorable treatment outcomes can be obtained using a pragmatic and innovative combination of ultrasound and MR imaging.

Analytical modeling and feasibility study of a multi-GPU cloud-based server (MGCS) framework for non-voxel-based dose calculations

PURPOSE

In this paper, a multi-GPU cloud-based server (MGCS) framework is presented for dose calculations, exploring the feasibility of remote computing power for parallelization and acceleration of computationally and time intensive radiotherapy tasks in moving toward online adaptive therapies.

METHODS

An analytical model was developed to estimate theoretical MGCS performance acceleration and intelligently determine workload distribution. Numerical studies were performed with a computing setup of 14 GPUs distributed over 4 servers interconnected by a 1 Gigabits per second (Gbps) network. Inter-process communication methods were optimized to facilitate resource distribution and minimize data transfers over the server interconnect.

RESULTS

The analytically predicted computation time predicted matched experimentally observations within 1-5 %. MGCS performance approached a theoretical limit of acceleration proportional to the number of GPUs utilized when computational tasks far outweighed memory operations. The MGCS implementation reproduced ground-truth dose computations with negligible differences, by distributing the work among several processes and implemented optimization strategies.

CONCLUSIONS

The results showed that a cloud-based computation engine was a feasible solution for enabling clinics to make use of fast dose calculations for advanced treatment planning and adaptive radiotherapy. The cloud-based system was able to exceed the performance of a local machine even for optimized calculations, and provided significant acceleration for computationally intensive tasks. Such a framework can provide access to advanced technology and computational methods to many clinics, providing an avenue for standardization across institutions without the requirements of purchasing, maintaining, and continually updating hardware.

A prospective study of DWI, DCE-MRI and FDG PET imaging for target delineation in brachytherapy for cervical cancer

BACKGROUND AND PURPOSE

We examined the utility of dynamic contrast-enhanced MRI (DCE-MRI), diffusion-weighted MRI (DWI), and FDG-PET imaging for brachytherapy target delineation in patients with locally advanced cervical cancer.

MATERIALS AND METHODS

Twenty-two patients had DWI, DCE-MRI, and FDG-PET/CT scans after brachytherapy applicator insertion, in addition to standard T2-weighted (T2w) 3T MRI. Gross tumor volume (GTV_B) and high-risk clinical target volume (HRCTV) were contoured first on T2w images, and then modified if indicated upon review of DWI/DCE-MRI/FDG-PET images by two observers. The primary endpoint was utility, determined by the number of patients whose volumes were modified, and interobserver variability.

RESULTS

Eleven patients' T2w-GTV_B were modified based on DWI/DCE-MRI/FDG-PET by observer 1, due to clearer demarcation (7) and residual disease not well visualized on T2w MRI (4). GTV_B was modified in 17 patients by observer 2 (11 and 6, respectively). Incorporation of functional imaging improved the conformity index (CI) for GTV_B from 0.54 (T2w alone) to 0.65 (P=0.003). HRCTV was modified in 3 and 8 patients by observers 1 and 2, respectively, with a trend toward higher CI using functional imaging (0.71 to 0.76, P=0.06).

CONCLUSIONS

DWI/DCE-MRI/FDG-PET imaging as a supplement to T2w MRI decreased interobserver variability in GTV_B delineation.

Adaptive radiotherapy strategies for pelvic tumors - a systematic review of clinical implementations

Introdution: Variation in shape, position and treatment response of both tumor and organs at risk are major challenges for accurate dose delivery in radiotherapy. Adaptive radiotherapy (ART) has been proposed to customize the treatment to these motion/response patterns of the individual patients, but increases workload and thereby challenges clinical implementation. This paper reviews strategies and workflows for clinical and in silico implemented ART for prostate, bladder, gynecological (gyne) and ano-rectal cancers.

MATERIAL AND METHODS

Initial identification of papers was based on searches in PubMed. For each tumor site, the identified papers were screened independently by two researches for selection of studies describing all processes of an ART workflow: treatment monitoring and evaluation, decision and execution of adaptations. Both brachytherapy and external beam studies were eligible for review.

RESULTS

The review consisted of 43 clinical studies and 51 in silico studies. For prostate, 1219 patients were treated with offline re-planning, mainly to adapt prostate motion relative to bony anatomy. For gyne 1155 patients were treated with online brachytherapy re-planning while 25 ano-rectal cancer patients were treated with offline re-planning, all to account for tumor regression detected by magnetic resonance imaging (MRI)/computed tomography (CT). For bladder and gyne, 161 and 64 patients, respectively, were treated with library-based online plan selection to account for target volume and shape variations. The studies reported sparing of rectum (prostate and bladder cancer), bladder (ano-rectal cancer) and bowel cavity (gyne and bladder cancer) as compared to non-ART.

CONCLUSION

Implementations of ART were dominated by offline re-planning and online brachytherapy re-planning strategies, although recently online plan selection workflows have increased with the availability of cone-beam CT. Advantageous dosimetric and outcome patterns using ART was documented by the studies of this review. Despite this, clinical implementations were scarce due to challenges in target/organ re-contouring and suboptimal patient selection in the ART workflows.

Metal artefacts in MRI-guided brachytherapy of cervical cancer

The importance of assessing the metal-induced artefacts in magnetic resonance imaging (MRI)-guided brachytherapy is growing along with the increasing interest of integrating MRI into the treatment procedure of cervical cancer. Examples of metal objects in use include intracavitary cervical applicators and interstitial needles. The induced artefacts increase the uncertainties in the clinical workflow and can be a potential obstacle for the accurate delivery of the treatment. Overcoming this problem necessitates a good understanding of its originating sources. Several efforts are recorded in the literature to quantify the extent of such artefacts, in phantoms and in clinical practice. Here, we elaborate on the origin of metal-induced artefacts in the light of brachytherapy applications, while summarizing recent efforts that have been made to assess and overcome the induced distortions.

Comparison of Computed Tomography- and Magnetic Resonance Imaging-based Clinical Target Volume Contours at Brachytherapy for Cervical Cancer

PURPOSE

We prospectively compared computed tomography (CT)- and magnetic resonance imaging (MRI)-based high-risk clinical target volume (HR-CTV) contours at the time of brachytherapy for cervical cancer in an effort to identify patients who might benefit most from MRI-based planning.

METHODS AND MATERIALS

Thirty-seven patients who had undergone a pretreatment diagnostic MRI scan were included in the analysis. We delineated the HR-CTV on the brachytherapy CT and brachytherapy MRI scans independently for each patient. We then calculated the absolute volumes for each HR-CTV and the Dice coefficient of similarity (DC, a measure of spatial agreement) for the HR-CTV contours. We identified the clinical and tumor factors associated with (1) a discrepancy in volume between the CT HR-CTV and MRI HR-CTV contours; and (2) DC. The mean values were compared using 1-way analysis of variance or paired or unpaired t tests, as appropriate. Simple and multivariable linear regression analyses were used to model the effects of covariates on the outcomes.

RESULTS

Patients with International Federation of Gynecology and Obstetrics stage IB to IVA cervical cancer were treated with intracavitary brachytherapy using tandem and ovoid (n=33) or tandem and cylinder (n=4) applicators. The mean CT HR-CTV volume (44.1 cm³) was larger than the mean MRI HR-CTV volume (35.1 cm³; P<.0001, paired t test). On multivariable analysis, a higher body mass index (BMI) and tumor size ≥5 cm with parametrial invasion on the MRI scan at diagnosis were associated with an increased discrepancy in volume between the HR-CTV contours (P<.02 for both). In addition, the spatial agreement (as measured by DC) between the HR-CTV contours decreased with an increasing BMI (P=.013).

CONCLUSIONS

We recommend MRI-based brachytherapy planning for patients with tumors >5 cm and parametrial invasion on MRI at diagnosis and for those with a high BMI.

Dose-volume effect relationships for late rectal morbidity in patients treated with chemoradiation and MRI-guided adaptive brachytherapy for locally advanced cervical cancer: Results from the prospective multicenter EMBRACE study

PURPOSE

To establish dose volume-effect relationships predicting late rectal morbidity in cervix cancer patients treated with concomitant chemoradiation and MRI-guided adaptive brachytherapy (IBABT) within the prospective EMBRACE study.

MATERIAL AND METHOD

All patients were treated with curative intent according to institutional protocols with chemoradiation and IGABT. Reporting followed the GEC-ESTRO recommendations ( [Formula: see text] , [Formula: see text] ), applying bioeffect modeling (linear quadratic model) with equieffective doses (EQD2₃). Morbidity was scored according to the CTC-AE 3.0. Dose-effect relationships were assessed using comparisons of mean doses, the probit model and log rank tests on event-free periods.

RESULTS

960 patients were included. The median follow-up was 25.4months. Twenty point one percent of the patients had grade 1 events, 6.0% grade 2, 1.6% grade 3 and 0.1%, grade 4. The mean D_ICRU, [Formula: see text] , and [Formula: see text] were respectively: 66.2±9.1Gy, 72.9±11.9Gy, and 62.8±7.6Gy. Increase of dose was associated with increase in severity of single endpoints and overall rectal morbidity (grade 1-4) (p<0.001-0.026), except for stenosis (p=0.24-0.31). The probit model showed significant relationships between the [Formula: see text] , [Formula: see text] , and D_ICRU and the probability of grade 1-4, 2-4, and 3-4 rectal events. The equieffective [Formula: see text] for a 10% probability for overall rectal grade⩾2 morbidity was 69.5Gy (p<0.0001). After sorting patients according to 6 [Formula: see text] levels, less favorable outcome was observed in the high dose subgroups, for bleeding, proctitis, fistula, and overall rectal morbidity. A [Formula: see text] ⩾75Gy was associated with a 12.5% risk of fistula at 3years versus 0-2.7% for lower doses (p>0.001). A [Formula: see text] <65Gy was associated with a two times lower risk of proctitis than [Formula: see text] ⩾65Gy.

CONCLUSIONS

Significant correlations were established between late rectal morbidity, overall and single endpoints, and dose-volume ( [Formula: see text] , [Formula: see text] ) and dose-point (D_ICRU) parameters. A [Formula: see text] ⩽65Gy is associated with more minor and less frequent rectal morbidity, whereas a [Formula: see text] ⩾75Gy is associated with more major and more frequent rectal morbidity.

Tumor dose-volume response in image-guided adaptive brachytherapy for cervical cancer: A meta-regression analysis

PURPOSE

Image-guided adaptive brachytherapy is a high precision technique that allows dose escalation and adaptation to tumor response. Two monocentric studies reported continuous dose-volume response relationships, however, burdened by large confidence intervals. The aim was to refine these estimations by performing a meta-regression analysis based on published series.

METHODS AND MATERIALS

Eligibility was limited to series reporting dosimetric parameters according to the Groupe Européen de Curiethérapie-European SocieTy for Radiation Oncology recommendations. The local control rates reported at 2-3 years were confronted to the mean D90 clinical target volume (CTV) in 2-Gy equivalent using the probit model. The impact of each series on the relationships was pondered according to the number of patients reported.

RESULTS

An exhaustive literature search retrieved 13 series reporting on 1299 patients. D90 high-risk CTV ranged from 70.9 to 93.1 Gy. The probit model showed a significant correlation between the D90 and the probability of achieving local control (p < 0.0001). The D90 associated to a 90% probability of achieving local control was 81.4 Gy (78.3-83.8 Gy). The planning aim of 90 Gy corresponded to a 95.0% probability (92.8-96.3%). For the intermediate-risk CTV, less data were available, with 873 patients from eight institutions. Reported mean D90 intermediate-risk CTV ranged from 61.7 to 69.1 Gy. A significant dose-volume effect was observed (p = 0.009). The D90 of 60 Gy was associated to a 79.4% (60.2-86.0%) local control probability.

CONCLUSION

Based on published data from a high number of patients, significant dose-volume effect relationships were confirmed and refined between the D90 of both CTV and the probability of achieving local control. Further studies based on individual data are required to develop nomograms including nondosimetric prognostic criteria.

Effect of tumor dose, volume and overall treatment time on local control after radiochemotherapy including MRI guided brachytherapy of locally advanced cervical cancer

BACKGROUND AND PURPOSE

Currently, there is no consensus on dose prescription in image guided adaptive brachytherapy (IGABT) in locally advanced cervical cancer. The purpose of this study was to provide evidence based recommendations for tumor dose prescription based on results from a multi-center patient series (retroEMBRACE).

MATERIALS AND METHODS

This study analyzed 488 locally advanced cervical cancer patients treated with external beam radiotherapy±chemotherapy combined with IGABT. Brachytherapy contouring and reporting was according to ICRU/GEC-ESTRO recommendations. The Cox Proportional Hazards model was applied to analyze the effect on local control of dose-volume metrics as well as overall treatment time (OTT), dose rate, chemotherapy, and tumor histology.

RESULTS

With a median follow up of 46months, 43 local failures were observed. Dose (D90) to the High Risk Clinical Target Volume (CTV_HR) (p=0.022, HR=0.967 per Gy) was significant for local control, whereas increasing CTV_HR volume (p=0.004, HR=1.017 per cm³), and longer OTT (p=0.004, HR=1.023 per day) were associated with worse local control. Histology (p=0.084), chemotherapy (p=0.49) and dose rate (p=1.00) did not have significant impact on local control. Separate analyses according to stage of disease showed that dose to CTV_HR, residual gross tumor volume (GTV_res), and Intermediate Risk CTV (CTV_IR) has significant impact on local control.

CONCLUSION

CTV_HR dose of ⩾85Gy (D90) delivered in 7weeks provides 3-year local control rates of >94% in limited size CTV_HR (20cm³), >93% in intermediate size (30cm³) and >86% in large size (70cm³) CTV_HR. CTV_IR and GTV_res dose of ⩾60Gy and ⩾95Gy (D98) leads to similar local control. A dose of 5Gy (CTV_HR) is required to compensate an increase of OTT by one week. Increased CTV_HR volume by 10cm³ requires additional 5Gy for equivalent local control.

Dosimetric study for cervix carcinoma treatment using intensity modulated radiation therapy (IMRT) compensation based on 3D intracavitary brachytherapy technique

Purpose

Intensity modulated radiation therapy (IMRT) compensation based on 3D high-dose-rate (HDR) intracavitary brachytherapy (ICBT) boost technique (ICBT + IMRT) has been used in our hospital for advanced cervix carcinoma patients. The purpose of this study was to compare the dosimetric results of the four different boost techniques (the conventional 2D HDR intracavitary brachytherapy [CICBT], 3D optimized HDR intracavitary brachytherapy [OICBT], and IMRT-alone with the applicator in situ).

Material and methods

For 30 patients with locally advanced cervical carcinoma, after the completion of external beam radiotherapy (EBRT) for whole pelvic irradiation 45 Gy/25 fractions, five fractions of ICBT + IMRT boost with 6 Gy/fractions for high risk clinical target volume (HRCTV), and 5 Gy/fractions for intermediate risk clinical target volume (IRCTV) were applied. Computed tomography (CT) and magnetic resonance imaging (MRI) scans were acquired using an in situ CT/MRI-compatible applicator. The gross tumor volume (GTV), the high/intermediate-risk clinical target volume (HRCTV/IRCTV), bladder, rectum, and sigmoid were contoured by CT scans.

Results

For ICBT + IMRT plan, values of D₉₀, D₁₀₀ of HRCTV, D₉₀, D₁₀₀, and V₁₀₀ of IRCTV significantly increased (p < 0.05) in comparison to OICBT and CICBT. The D_2cc values for bladder, rectum, and sigmoid were significantly lower than that of CICBT and IMRT alone. In all patients, the mean rectum V₆₀ Gy values generated from ICBT + IMRT and OICBT techniques were very similar but for bladder and sigmoid, the V₆₀ Gy values generated from ICBT + IMRT were higher than that of OICBT. For the ICBT + IMRT plan, the standard deviations (SD) of D₉₀ and D_2cc were found to be lower than other three treatment plans.

Conclusions

The ICBT + IMRT technique not only provides good target coverage but also maintains low doses (D_2cc) to the OAR. ICBT + IMRT is an optional technique to boost parametrial region or tumor of large size and irregular shape when intracavitary/interstitial brachytherapy cannot be used.

Vaginal dose de-escalation in image guided adaptive brachytherapy for locally advanced cervical cancer

PURPOSE

Vaginal stenosis is a major problem following radiotherapy in cervical cancer. We investigated a new dose planning strategy for vaginal dose de-escalation (VDD).

MATERIALS AND METHODS

Fifty consecutive locally advanced cervical cancer patients without lower or middle vaginal involvement at diagnosis from 3 institutions were analysed. External beam radiotherapy was combined with MRI-guided brachytherapy. VDD was obtained by decreasing dwell times in ovoid/ring and increasing dwell times in tandem/needles. The aim was to maintain the target dose (D90 of HR-CTV⩾85Gy EQD2) while reducing the dose to the surface of the vagina to <140% of the physical fractional brachytherapy dose corresponding to a total EQD2 of 85Gy.

RESULTS

The mean vaginal loading (ovoid/ring) was reduced from 51% to 33% of the total loading with VDD, which significantly reduced the dose to the vaginal dose points (p<0.001) without compromising the target dose. The dose to the ICRU recto-vaginal point was reduced by a mean of 4±4Gy EQD2 (p<0.001), while doses to bladder and rectum (D_2cm³) were reduced by 2±2Gy and 3±2Gy, respectively (p<0.001).

CONCLUSIONS

VDD significantly reduces dose to the upper vagina which is expected to result in reduction of vaginal stenosis.

Clinical outcomes in cervical cancer patients treated by FDG-PET/CT-based 3-dimensional planning for the first brachytherapy session

The aim of the study was to evaluate the treatment outcomes in cervical cancer patients treated with 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT)-guided 3-dimensional brachytherapy (3D-BT) planning for the first brachytherapy session.We retrospectively analyzed 87 patients with cervical cancer who received definitive radiotherapy (RT). Primary tumor size was ≤4 cm in 22 patients (25.3%), >4 cm and ≤6 cm in 45 patients (51.7%), and >6 cm in 20 patients (23.0%). The median total dose of external beam RT was 50.4 (50.4-60.4) Gy. FDG-PET/CT-guided 3D-BT with an iridium-192 source was performed. The clinical target volume (CTV) for 3D-BT included the entire cervix and the abnormal FDG-uptake with a 1-cm expansion. A planned total dose was 24 Gy at 4 Gy per insertion 3 times per week using a tandem and 2 ovoids.The mean D95 and D90 for the CTV were 73.4 (±5.9) Gy and 77.9 (±6.9) Gy, respectively (EQD2, α/β=10). The D2cc for the rectum and bladder was 374 (±97.4) cGy and 394 (±107.6) cGy per fraction, respectively. The EQD2 (α/β=3) for the D2cc was 74.5 (±12.4) Gy for the rectum and 77.3 (±14.6) Gy for the bladder. The median follow-up period was 40 (8-61) months. The 3-year overall survival (OS), progression-free survival (PFS), and local control (LC) rates were 84.7%, 72.1%, and 89.2%, respectively. The 3-year LC rate was 100% for tumors ≤ 4 cm, 91.1% for tumors > 4 cm and ≤ 6 cm, and 70.5% for tumors > 6 cm (P = 0.014). Local failure developed in 9 patients. Three patients had local failures outside of the CTV. Grade 1, 2, and 3 rectal bleeding developed in 5, 4, and 2 patients, respectively. One patient experienced rectovaginal fistula.FDG-PET/CT-guided 3D-BT planning is a feasible approach, which showed favorable clinical outcomes.

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

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 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.

RESULTS

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.

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.

Image-guided adaptive brachytherapy in cervical cancer: Patterns of relapse by brachytherapy planning parameters

PURPOSE

Cervical cancer patients with a bulky high-risk clinical target volume (HR-CTV) get the largest benefit of dose escalation in terms of local control. However, the expected survival benefit could be lessened by a higher metastatic risk. We examined the patterns of relapse according to major prognostic factors: the HR-CTV volume and to the D90 HR-CTV.

METHODS AND MATERIALS

The clinical records of patients treated with pulsed-dose-rate image-guided adaptive brachytherapy after concurrent pelvic chemoradiation were reviewed. All patients had an optimal workup before treatment comprising a 18-fluorodeoxyglucose positron emission tomography/computed tomography and a para-aortic lymph node dissection. Patients with initial extrapelvic disease were excluded.

RESULTS

A total of 109 patients fulfilled inclusion criteria. Median followup was 39 months. An HR-CTV volume ≥40 cm(3) was associated with a poorer local failure-free survival. There was a strong inverse correlation between the HR-CTV volume and the D90 of the HR-CTV (correlation coefficient r = -0.696; p < 0.001) with increasing HR-CTV volume being associated with a decreasing D90 HR-CTV. A D90 HR-CTV <85 Gy and an HR-CTV volume ≥40 cm(3) were significant univariate factors for experiencing nonlocal failure (p = 0.002 and 0.035, respectively), even after exclusion of local relapses.

CONCLUSION

A lower ability to reach the target D90 HR-CTV planning and an HR-CTV volume ≥ 40 cm(3) correlated with a high propensity of relapsing at distance, these factors being interrelated. Next step of treatment personalization should design strategies integrating this risk, which is now the main cause of failure.

Long term experience with 3D image guided brachytherapy and clinical outcome in cervical cancer patients

BACKGROUND AND PURPOSE

To report our 10years' experience and learning curve of the treatment of cervical cancer patients with chemo radiotherapy and MRI (or CT in 9 selected patients) guided brachytherapy using pulsed dose rate (PDR) brachytherapy (BT).

METHODS AND MATERIALS

Hundred and seventy consecutive patients with cervical cancer FIGO stage IB-IVB (without metastases beyond the para-aortic nodal region) were treated in our institute between 2002 and 2012. Patients received external beam radiotherapy (nodal boost to the lymph nodes positive at diagnosis)±chemotherapy followed by a pulsed or low dose rate brachytherapy boost. MRI (or CT) images were taken with the applicator in situ. The first 16 patients were treated according to X-ray-based plans, optimized on MRI. High-risk CTV, intermediate-risk CTV, bladder, rectum and sigmoid were retrospectively contoured according to the GEC-ESTRO recommendations. In all other patients, treatment plans were optimized after delineation of the target volumes and organs at risk at MRI (or CT). Doses were converted to the equivalent dose in 2Gy (EQD2) by applying the linear quadratic model. The median age of the patients was 55years (range 16-88). 41% had stage III or IV disease. Of the 170 patients, 91 patients had on imaging metastatic lymph nodes at diagnosis (62 patients pelvic lymph node involvement and 29 para-aortic). In 27 (16%) patients the intracavitary technique was combined with interstitial brachytherapy.

RESULTS

The mean D90 and D100 for the high-risk CTV were 84.8±8.36Gy and 67.5±6.29Gy for the entire patient group. Mean D90 and D100 values for the IR CTV were 68.7±5.5Gy and 56.5±6.25Gy. There was an important learning curve between both patient groups, with an increase in mean D90 of 75.8Gy for the first 16 patients compared to 85.8Gy for the second group. At the same time, the mean dose to 2cm³ of bladder and sigmoid decreased from 86.1Gy to 82.7Gy and from 70Gy to 61.7Gy, respectively. At a median follow-up of 37months (range 2-136months), local control rate for all patients was 96%, the regional control (pelvic and para-aortic) rate 81% and crude disease free survival rate 55%. The overall survival at 5years is 65%. The higher dose to the target volume resulted in an increase in local control from 88% in the first 16 patients compared to 97% in the second patient group. Regarding late toxicity, 21 patients (12%) presented grade 3-4 late morbidity. Rectal, urinary, sigmoid and vaginal morbidity was 5%, 6%, 2% and 5%, respectively. A correlation between rectal D2cm³ >65Gy and grade >3 late morbidity was found (p=0.006).

CONCLUSION

Although the majority of the patients presented with locally advanced carcinoma, excellent local and regional control rates were achieved. Rectal, urinary, sigmoid and vaginal grade 3-4 morbidity was 5%, 6%, 2% and 5%, respectively. A correlation between rectal D2cm³ >65Gy and grade >3 late morbidity was found (p=0.006).

Image guided radiation therapy boost in combination with high-dose-rate intracavitary brachytherapy for the treatment of cervical cancer

Purpose

The purpose of this study was to demonstrate the dosimetric and clinical feasibility of image guided radiation therapy (IGRT) combined with high-dose-rate (HDR) intracavitary brachytherapy (ICBT) to improve dose distribution in cervical cancer treatment.

Material and methods

For 42 cervical cancer patients, magnetic resonance imaging (MRI) scans were acquired after completion of whole pelvic irradiation 45-46 Gy and 5 fractions of B + I (ICBT + IGRT) treatment were subsequently received. The high risk clinical target volume (HRCTV), intermediate risk clinical target volume (IRCTV), bladder, rectum, and sigmoid were contoured on the computed tomography (CT) scans. The total planning aim doses for HRCTV was D_90% > 85 Gy, whilst constraints for rectum and sigmoid were D_2cc < 75 Gy and D_2cc < 90 Gy for bladder in terms of an equivalent dose in 2 Gy (EQD2) for external beam radiotherapy (EBRT) and brachytherapy boost. The IGRT plan was optimized on top of the ICBT dose distribution. A dosimetric comparison was made between B + I and optimized ICBT (O-ICBT) only.

Results

The mean D_90% of HRCTV was comparable for B + I and O-ICBT (p = 0.82). For B + I plan, HRCTV D_100%, IRCTV D_100%, and IRCTV D_90% were significantly increased by a mean of 10.52 Gy, 5.61 Gy, and 2.70 Gy, respectively (p < 0.01). The D_2cc for bladder, rectum, and sigmoid were lower by a mean of 21.36, 6.78, and 10.65 Gy, respectively (p < 0.01). The mean rectum V60 Gy value over 42 patients was almost the same for both techniques but for bladder and sigmoid B + I had higher V60 Gy mean values as compared with the O-ICBT.

Conclusions

B + I can improve dose distribution in cervical cancer treatment; it could be useful for tumors extended beyond the reach of intracavitary/interstitial brachytherapy (IC/ISBT) or for centers that are inexperienced or ill-equipped with IC/ISBT techniques. Additional confirmatory prospective studies with larger numbers of patients and longer follow-up are required to validate the durability.

Adaptive planning strategy for high dose rate prostate brachytherapy—a simulation study on needle positioning errors

The development of magnetic resonance (MR) guided high dose rate (HDR) brachytherapy for prostate cancer has gained increasing interest for delivering a high tumor dose safely in a single fraction. To support needle placement in the limited workspace inside the closed-bore MRI, a single-needle MR-compatible robot is currently under development at the University Medical Center Utrecht (UMCU). This robotic device taps the needle in a divergent way from a single rotation point into the prostate. With this setup, it is warranted to deliver the irradiation dose by successive insertions of the needle. Although robot-assisted needle placement is expected to be more accurate than manual template-guided insertion, needle positioning errors may occur and are likely to modify the pre-planned dose distribution.In this paper, we propose a dose plan adaptation strategy for HDR prostate brachytherapy with feedback on the needle position: a dose plan is made at the beginning of the interventional procedure and updated after each needle insertion in order to compensate for possible needle positioning errors. The introduced procedure can be used with the single needle MR-compatible robot developed at the UMCU. The proposed feedback strategy was tested by simulating complete HDR procedures with and without feedback on eight patients with different numbers of needle insertions (varying from 4 to 12). In of the cases tested, the number of clinically acceptable plans obtained at the end of the procedure was larger with feedback compared to the situation without feedback. Furthermore, the computation time of the feedback between each insertion was below 100 s which makes it eligible for intra-operative use.

A practical review of magnetic resonance imaging for the evaluation and management of cervical cancer

Cervical cancer is a leading cause of mortality in women worldwide. Staging and management of cervical cancer has for many years been based on clinical exam and basic imaging such as intravenous pyelogram and x-ray. Unfortunately, despite advances in radiotherapy and the inclusion of chemotherapy in the standard plan for locally advanced disease, local control has been unsatisfactory. This situation has changed only recently with the increasing implementation of magnetic resonance image (MRI)-guided brachytherapy. The purpose of this article is therefore to provide an overview of the benefits of MRI in the evaluation and management of cervical cancer for both external beam radiotherapy and brachytherapy and to provide a practical approach if access to MRI is limited.

Pelvic radiotherapy and sexual function in women

BACKGROUND

During the past decade there has been considerable progress in developing new radiation methods for cancer treatment. Pelvic radiotherapy constitutes the primary or (neo) adjuvant treatment of many pelvic cancers e.g., locally advanced cervical and rectal cancer. There is an increasing focus on late effects and an increasing awareness that patient reported outcomes (PROs) i.e., patient assessment of physical, social, psychological, and sexual functioning provides the most valid information on the effects of cancer treatment. Following cure of cancer allow survivors focus on quality of life (QOL) issues; sexual functioning has proved to be one of the most important aspects of concern in long-term survivors.

METHODS

An updated literature search in PubMed was performed on pelvic radiotherapy and female sexual functioning/dysfunction. Studies on gynaecological, urological and gastrointestinal cancers were included. The focus was on the period from 2010 to 2014, on studies using PROs, on potential randomized controlled trials (RCTs) where female sexual dysfunction (FSD) at least constituted a secondary outcome, and on studies reporting from modern radiotherapy modalities.

RESULTS

The literature search revealed a few RCTs with FSD evaluated as a PRO and being a secondary outcome measure in endometrial and in rectal cancer patients. Very limited information could be extracted regarding FSD in bladder, vulva, and anal cancer patients. The literature before and after 2010 confirms that pelvic radiotherapy, independent on modality, increases the risk significantly for FSD both compared to data from age-matched healthy control women and compared to data on patients treated by surgery only. There was only very limited data available on modern radiotherapy modalities. These are awaited during the next five years. Several newer studies confirm that health care professionals are still reluctant to discuss treatment induced sexual dysfunction with patients.

CONCLUSIONS

Pelvic radiotherapy has a persistent deteriorating effect on the vaginal mucosa impacting negatively on the sexual functioning in female cancer patients. Hopefully, modern radiotherapy modalities will cause less vaginal morbidity but results are awaited to confirm this assumption. Health care professionals are encouraged to address potential sexual dysfunction both before and after radiotherapy and to focus more on quality than on quantity.

Dose-effect relationship and risk factors for vaginal stenosis after definitive radio(chemo)therapy with image-guided brachytherapy for locally advanced cervical cancer in the EMBRACE study

BACKGROUND/PURPOSE

To identify risk factors for vaginal stenosis and to establish a dose-effect relationship for image-guided brachytherapy in locally advanced cervical cancer.

MATERIALS/METHODS

Patients from the ongoing EMBRACE study with prospectively assessed morbidity (CTCAEv3.0) at baseline and at least one follow-up were selected. Patient-, disease- and treatment characteristics were tested as risk factors for vaginal stenosis G ⩾ 2 in univariate and multivariable analyses (Cox proportional hazards model) and a dose-effect curve was deduced from the estimates. The ICRU rectum point was used to derive the recto-vaginal reference point dose.

RESULTS

In 630 patients included (median follow-up 24months), 2-year actuarial estimate for vaginal stenosis G ⩾ 2 was 21%. Recto-vaginal reference point dose (HR=1.025, p=0.029), external beam radiotherapy (EBRT) dose >45 Gy/25 fractions (HR=1.770, p=0.056) and tumor extension in the vagina (HR=2.259, p ⩽ 0.001) were risk factors for vaginal stenosis, adjusted for center reporting effects. Based on the model curve, the risk was 20% at 65 Gy, 27% at 75 Gy and 34% at 85 Gy (recto-vaginal reference point dose).

CONCLUSION

Keeping the EBRT dose at 45 Gy/25 fractions and decreasing the dose contribution of brachytherapy to the vagina decrease the risk of stenosis. A planning aim of ⩽65 Gy EQD2 (EBRT+brachytherapy dose) to the recto-vaginal reference point is therefore proposed.

Health-Related Quality of Life in Locally Advanced Cervical Cancer Patients After Definitive Chemoradiation Therapy Including Image Guided Adaptive Brachytherapy: An Analysis From the EMBRACE Study

PURPOSE

This study analyzed functioning and symptom scores for longitudinal quality of life (QoL) from patients with locally advanced cervical cancer who underwent definitive chemoradiation therapy with image guided adaptive brachytherapy in the EMBRACE study.

METHODS AND MATERIALS

In total, 744 patients at a median follow-up of 21 months were included. QoL was prospectively assessed using European Organization for Research and Treatment of Cancer Quality of Life core module 30 (EORTC QLQ-C30) and EORTC cervical cancer module 24 (CX24) questionnaires at baseline, then every 3 months during the first year, every 6 months in the second and third years, and finally yearly thereafter in patients with no evidence of disease. Outcomes were evaluated over time and compared to those from an age-matched female reference population.

RESULTS

General QoL and emotional and social functioning were impaired at baseline but improved during the first 6 months after treatment, to reach a level comparable to that of the reference population, whereas cognitive functioning remained impaired. Both social and role functioning showed the lowest scores at baseline but which increased after treatment to reach a plateau at 6 months and then declined slightly at 3 and 4 years. The overall symptom experience was elevated at baseline and decreased to a level within the range of that of the reference population. Similarly, tumor-related symptoms (eg, pain, appetite loss, and constipation), which were present before treatment, decreased substantially at the first follow-up after treatment. Several treatment-related symptoms developed either immediately after and persisted over time (diarrhea, menopausal symptoms, peripheral neuropathy, and sexual functioning problems) or developed gradually after treatment (lymphedema and dyspnea).

CONCLUSIONS

This longitudinal prospective QoL analysis showed that patients' general QoL and functioning were impaired before treatment compared to those of reference data. Several tumor-related symptoms resolved after treatment, and functioning and general QoL returned to that of the level of the reference population, indicating a transient impact of diagnosis and treatment. However, several treatment-related symptoms and problems did develop and persist, either immediately or gradually after treatment.

Individualised 3D printed vaginal template for MRI guided brachytherapy in locally advanced cervical cancer

Intracavitary-interstitial applicators for MRI guided brachytherapy are becoming increasingly important in locally advanced cervical cancer. The 3D printing technology enables a versatile method for obtaining a high degree of individualisation of the implant. Our clinical workflow is presented and exemplified by a stage IVA cervical cancer with superior dose distribution.

Image Guided Cervical Brachytherapy: 2014 Survey of the American Brachytherapy Society

PURPOSE

To provide an update of the 2007 American brachytherapy survey on image-based brachytherapy, which showed that in the setting of treatment planning for gynecologic brachytherapy, although computed tomography (CT) was often used for treatment planning, most brachytherapists used point A for dose specification.

METHODS AND MATERIALS

A 45-question electronic survey on cervical cancer brachytherapy practice patterns was sent to all American Brachytherapy Society members and additional radiation oncologists and physicists based in the United States between January and September 2014. Responses from the 2007 survey and the present survey were compared using the χ(2) test.

RESULTS

There were 370 respondents. Of those, only respondents, not in training, who treat more than 1 cervical cancer patient per year and practice in the United States, were included in the analysis (219). For dose specification to the target (cervix and tumor), 95% always use CT, and 34% always use MRI. However, 46% use point A only for dose specification to the target. There was a lot of variation in parameters used for dose evaluation of target volume and normal tissues. Compared with the 2007 survey, use of MRI has increased from 2% to 34% (P<.0001) for dose specification to the target. Use of volume-based dose delineation to the target has increased from 14% to 52% (P<.0001).

CONCLUSION

Although use of image-based brachytherapy has increased in the United States since the 2007 survey, there is room for further growth, particularly with the use of MRI. This increase may be in part due to educational initiatives. However, there is still significant heterogeneity in brachytherapy practice in the United States, and future efforts should be geared toward standardizing treatment.

Simulation analysis of optimized brachytherapy for uterine cervical cancer: Can we select the best brachytherapy modality depending on tumor size?

PURPOSE

To choose the optimal brachytherapeutic modality for uterine cervical cancer, we performed simulation analysis.

METHODS AND MATERIALS

For each high-risk clinical target volume (HR CTV), we compared four modalities [classical conventional intracavitary brachytherapy (ConvICBT), Image-guided ICBT (IGICBT), intracavitary/interstitial brachytherapy (ICISBT), and interstitial brachytherapy (ISBT) with perineal approach] using dose-volume histograms using eight sizes of HR CTV (2 × 2 × 2 cm to 7 × 4 × 4 cm) and organs at risk model.

RESULTS

In ConvICBT, the doses covered 90% of the HR CTV [D90(HR CTV)] decreased from 197% prescribed dose (PD) for the HR CTV size (2 × 2 × 2 cm) to 73% PD for 5 × 4 × 4 cm, whereas the other three modalities could achieve 100% PD for all HR CTV sizes. The minimum doses received by the maximally irradiated 2-cm(3) volumes for organs at risks of IGICBT demonstrated lower values than those of ConvICBT for the HR CTV size of 4 × 3 × 3 cm or smaller. ICISBT demonstrated lower values than those of IGICBT for 4 × 3 × 3 cm or larger. ISBT demonstrated lowest values for 5 × 4 × 4 cm or larger.

CONCLUSIONS

HR CTV size of 4 × 3 × 3 cm seems to be a threshold volume in this simulation analysis, and IGICBT is a better choice for smaller HR CTV than the threshold volume. On larger HR CTV, ICISBT or ISBT is the better choice.

Magnetic resonance imaging-guided brachytherapy for cervical cancer: initiating a program

Over the past decade, the application of magnetic resonance imaging (MRI) has increased, and there is growing evidence to suggest that improvements in accuracy of target delineation in MRI-guided brachytherapy may improve clinical outcomes in cervical cancer. To implement a high quality image guided brachytherapy program, a multidisciplinary team is required with appropriate expertise as well as an adequate patient load to ensure a sustainable program. It is imperative to know that the most important source of uncertainty in the treatment process is related to target delineation and therefore, the necessity of training and expertise as well as quality assurance should be emphasized. A short review of concepts and techniques that have been developed for implementation and/or improvement of workflow of a MRI-guided brachytherapy program are provided in this document, so that institutions can use and optimize some of them based on their resources to minimize their procedure times.