NRG Oncology/RTOG 0921: A phase 2 study of postoperative intensity-modulated radiotherapy with concurrent cisplatin and bevacizumab followed by carboplatin and paclitaxel for patients with endometrial cancer

Daily Online Adaptive Radiation Therapy of Postoperative Endometrial and Cervical Cancer With PTV Margin Reduction to 5 mm: Dosimetric Outcomes, Acute Toxicity, and First Clinical Experience

Purpose

This study evaluated the first clinical implementation of daily iterative cone beam computed tomography (iCBCT)-guided online adaptive radiation therapy (oART) in the postoperative treatment of endometrial and cervical cancer.

Methods and Materials

Seventeen consecutive patients treated with daily iCBCT-guided oART were enrolled in this prospective study, with a reduced uniform 3-dimensional PTV margin of 5 mm. Treatment plans were designed to deliver 45 or 50.4 Gy in 1.8 Gy daily fractions to PTV. Pre- and posttreatment ultrasound and iCBCT scans were performed to record intrafractional bladder and rectal volume changes. The accuracy of contouring, oART procedure time, dosimetric outcomes, and acute toxicity were evaluated.

Results

The average time from first iCBCT acquisition to completion of treatment was 22 minutes and 26 seconds. During this period, bladder volume increased by 44 cm3 using iCBCT contouring, whereas rectal volume remained stable (62.9 cm3 pretreatment vs 61.9 cm3 posttreatment). A total of 91.6% of influencers and 88.1% of CTVs required no or minor edits. The adapted plan was selected in all (434) fractions and significantly improved the dosimetry coverage for CTV and PTV, especially the vaginal PTV coverage by nearly 7% (P < .05). The adapted bladder Dmean was 104.61 cGy, and the rectum Dmean was 123.67 cGy, significantly lower than the scheduled plan of 108.24 and 128.19 cGy, respectively. The bone marrow and femur head left and right dosimetry were also improved with adaptation. Grade 2 acute gastrointestinal and genitourinary toxicities were 24% and 0, respectively. There was a grade 3 acute toxicity of decreased white blood cell count in 1 patient.

Conclusions

Daily oART was associated with favorable dosimetry improvement and low acute toxicity, supporting its safety and efficacy for postoperative treatment of endometrial and cervical cancer. These results need to be validated in a larger prospective randomized controlled cohort.

Dual effects of radiotherapy on tumor microenvironment and its contribution towards the development of resistance to immunotherapy in gastrointestinal and thoracic cancers

Successful clinical methods for tumor elimination include a combination of surgical resection, radiotherapy, and chemotherapy. Radiotherapy is one of the crucial components of the cancer treatment regimens which allow to extend patient life expectancy. Current cutting-edge radiotherapy research is focused on the identification of methods that should increase cancer cell sensitivity to radiation and activate anti-cancer immunity mechanisms. Radiation treatment activates various cells of the tumor microenvironment (TME) and impacts tumor growth, angiogenesis, and anti-cancer immunity. Radiotherapy was shown to regulate signaling and anti-cancer functions of various TME immune and vasculature cell components, including tumor-associated macrophages, dendritic cells, endothelial cells, cancer-associated fibroblasts (CAFs), natural killers, and other T cell subsets. Dual effects of radiation, including metastasis-promoting effects and activation of oxidative stress, have been detected, suggesting that radiotherapy triggers heterogeneous targets. In this review, we critically discuss the activation of TME and angiogenesis during radiotherapy which is used to strengthen the effects of novel immunotherapy. Intracellular, genetic, and epigenetic mechanisms of signaling and clinical manipulations of immune responses and oxidative stress by radiotherapy are accented. Current findings indicate that radiotherapy should be considered as a supporting instrument for immunotherapy to limit the cancer-promoting effects of TME. To increase cancer-free survival rates, it is recommended to combine personalized radiation therapy methods with TME-targeting drugs, including immune checkpoint inhibitors.

Radiation therapy for vulvar cancer: consensus technical guidelines of the GINECOR working group of the Spanish Society of Radiation Oncology. Part 2: radiotherapy recommendations

PURPOSE

The present consensus statement was developed by the GINECOR working group on behalf of the Spanish Society of Radiation Oncology (SEOR). This document provides an up-to-date review of the technical aspects in radiation treatment of vulvar cancer.

METHODS

A two-round modified Delphi study was conducted to reach consensus on the appropriateness of technical aspects of external beam radiotherapy and brachytherapy. Three clinical scenarios were proposed: adjuvant treatment of vulvar cancer, radiation treatment of locally advanced vulvar carcinoma and locoregional recurrences. After the first round, an extensive analysis of current medical literature from peer-reviewed journal was performed to define evidence-based treatment options. In the second round, participants were asked to indicate their level of agreement with the preliminary recommendations according to the GRADE (Grade of Recommendation, Assessment, Development, and Evaluation) criteria, as follows: strongly agree; agree; neither agree nor disagree; disagree and strongly disagree.

RESULTS

The main recommendations on external beam radiotherapy and brachytherapy, both in adjuvant setting and local advanced disease are summarized. Recommendations include treatment technique, treatment volume, and doses in target and organs at-risk. Taking into consideration the different clinical scenarios of recurrent disease, the radiation treatment should be individualized.

CONCLUSIONS

In the absence of robust clinical data, these recommendations may help to select the optimal radiotherapy approach for this relatively rare cancer.

Head and Neck Radiation Therapy Patterns of Practice Variability Identified as a Challenge to Real-World Big Data: Results From the Learning from Analysis of Multicentre Big Data Aggregation (LAMBDA) Consortium

Purpose

Outside of randomized clinical trials, it is difficult to develop clinically relevant evidence-based recommendations for radiation therapy (RT) practice guidelines owing to lack of comprehensive real-world data. To address this knowledge gap, we formed the Learning from Analysis of Multicenter Big Data Aggregation consortium to cooperatively implement RT data standardization, develop software solutions for data analysis, and recommend clinical practice change based on real-world data analyzed. The first phase of this "Big Data" study aimed at characterizing variability in clinical practice patterns of dosimetric data for organs at risk (OARs) that would undermine subsequent use of large-scale, electronically aggregated data to characterize associations with outcomes. Evidence from this study was used as the basis for practical recommendations to improve data quality.

Methods and Materials

Dosimetric details of patients with head and neck cancer treated with radiation therapy between 2014 and 2019 were analyzed. Institutional patterns of practice were characterized, including structure nomenclature, volumes, and frequency of contouring. Dose volume histogram (DVH) distributions were characterized and compared with institutional constraints and literature values.

Results

Plans for 4664 patients treated to a mean plan dose of 64.4 ± 13.2 Gy in 32 ± 4 fractions were aggregated. Before implementation of TG-263 guidelines in each institution, there was variability in OAR nomenclature across institutions and structures. With evidence from this study, we identified a targeted and practical set of recommendations aimed at improving the quality of real-world data.

Conclusions

Quantifying similarities and differences among institutions for OAR structures and DVH metrics is the launching point for next steps to investigate potential relationships between DVH parameters and patient outcomes.

Long-Term Follow-Up Results of Adjuvant Intensity-Modulated Radiotherapy with Concurrent Paclitaxel and Cisplatin in High-Risk Endometrial Cancer Patients

Purpose. The purpose of this study was to retrospectively review the outcomes of patients with high-risk endometrial cancer treated with adjuvant radiotherapy with concurrent paclitaxel and cisplatin (TP). Methods. Patients with endometrial cancer who underwent radical surgery were screened between Jan 2005 and Dec 2018. Patients with high-risk factors who received adjuvant chemoradiotherapy were included in the study. High risks included stage I, endometrioid-type grade 3 with deep myometrial invasion or lymphovascular space invasion (or both), endometrioid-type stage II to IVa, or stage I to III with serous or clear cell histology. The adjuvant treatment regimen included one cycle of TP chemotherapy, followed by pelvic intensity-modulated radiotherapy (IMRT) with concurrent TP, followed by an additional one cycle of TP. Failure free survival (FFS) and overall survival (OS) were estimated. Patterns of recurrence and occurrence of adverse events were described. Results. A total of 450 patients with high-risk endometrial cancer were screened, 231 of whom were included in this study. After a median follow-up of 70 months, the 5-year OS was 94.7%, and the 6-year OS was 91.8%. The 5-y and 6-y FFS were 90.8% and 87.9%, respectively, which were related to stage ( $P<0.05$ ). A total of 14 patients experienced tumor recurrence, including 7 pelvic recurrence and 7 distant metastases. Seven patients died, all due to tumor progression. A total of 164 patients (71%) completed the prescribed course of treatment. A total of 205 patients had adverse events, 46 patients (20%) had grade 1, 92 patients (40%) had grade 2, 49 patients (21%) had grade 3, and 18 patients (8%) had grade 4. There were 83 nonhematologic and 122 hematologic toxicities (26 grade 3 and 18 grade 4). Conclusion. Adjuvant pelvic radiotherapy combined with synchronous TP chemotherapy can achieve excellent long-term survival for high-risk endometrial cancer patients. Moreover, this combination therapy has good safety and feasibility, which is worthy of further study and verification.

An International Consensus on the Design of Prospective Clinical–Translational Trials in Spatially Fractionated Radiation Therapy for Advanced Gynecologic Cancer

Simple Summary

Spatially fractionated radiation therapy (SFRT) delivers intentionally heterogenous dose to tumors. This is a major departure from current radiation therapy, which strives for uniform dose. Early pilot experience suggests promising treatment outcomes with SFRT in patients with challenging bulky tumors, including gynecologic cancer. Well-conducted prospective multi-institutional clinical trials are now needed to further test SFRT as a treatment modality. However, clinical trial development is hampered by the variabilities in SFRT approach and the overall unfamiliarity with heterogeneous dosing. A broad consensus among SFRT experts, potential investigators, and the wider radiation oncology community is needed so that clinical trials in SFRT can be successfully designed and carried out. We developed an international consensus guideline for the design parameters of clinical/translational trials in SFRT for gynecologic cancer. High-to-moderate consensus was achieved, and harmonized fundamental design parameters for SFRT trials in advanced gynecologic cancer were defined.

Abstract

Despite the unexpectedly high tumor responses and limited treatment-related toxicities observed with SFRT, prospective multi-institutional clinical trials of SFRT are still lacking. High variability of SFRT technologies and methods, unfamiliar complex dose and prescription concepts for heterogeneous dose and uncertainty regarding systemic therapies present major obstacles towards clinical trial development. To address these challenges, the consensus guideline reported here aimed at facilitating trial development and feasibility through a priori harmonization of treatment approach and the full range of clinical trial design parameters for SFRT trials in gynecologic cancer. Gynecologic cancers were evaluated for the status of SFRT pilot experience. A multi-disciplinary SFRT expert panel for gynecologic cancer was established to develop the consensus through formal panel review/discussions, appropriateness rank voting and public comment solicitation/review. The trial design parameters included eligibility/exclusions, endpoints, SFRT technology/technique, dose/dosimetric parameters, systemic therapies, patient evaluations, and embedded translational science. Cervical cancer was determined as the most suitable gynecologic tumor for an SFRT trial. Consensus emphasized standardization of SFRT dosimetry/physics parameters, biologic dose modeling, and specimen collection for translational/biological endpoints, which may be uniquely feasible in cervical cancer. Incorporation of brachytherapy into the SFRT regimen requires additional pre-trial pilot investigations. Specific consensus recommendations are presented and discussed.

Construction of a predictive model for radiation proctitis after radiotherapy for female pelvic tumors based on machine learning

OBJECTIVES

Radiation therapy is a main method for female pelvic malignancies, which can cause some adverse reactions, such as radiation proctitis (RP). The incidence of RP is highly positively correlated with radiation dose. There is an urgent need for a scientific method to accurately predict the occurrence of RP to help doctors make clinical decisions. In this study, based on the clinical data of female pelvic tumor patients and dosimetric parameters of radiotherapy, the random forest method was used to screen the hub features related to the occurrence of RP, and then a machine learning algorithm was used to construct a risk prediction model for the occurrence of RP, in order to provide technical support and theoretical basis for the prediction and prevention of RP.

METHODS

A total of 100 female patients with pelvic tumors, who received static three-dimensional conformal intensity-modulated radiation therapy in the Department of Radiation Oncology of the Affiliated Hospital of Xiangnan University from January 2019 to December 2020, were retrospectively collected, and their clinically relevant data and radiotherapy planning system data were collected. During radiotherapy and 18 months after radiotherapy, 35 cases developed RP (RP group), and the remaining 65 cases had no RP (non-RP group). The clinical and dosimetric characteristics of patients were ranked by the importance of random forest algorithm, and the independent prognostic characteristics associated with the occurrence of RP were selected for machine learning modeling. A total of 6 machine learning algorithms including support vector machines, random forests, logistic regression, lightweight gradient boosting machines, Gaussian naïve Bayes, and adaptive enhancement were used to build models. The performance of the model was evaluated by the area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F1 score. Finally, the random forest model was determined as the prediction model, and the calibration curve and decision curve of the prediction model were drawn to evaluate the accuracy and clinical benefit of the model.

RESULTS

The parameters for random forest prediction model in the training set were as follow: AUC, 1.000, accuracy, 0.988, sensitivity, 1.000, specificity, 1.000, positive predictive value, 1.000, negative predictive value, 0.981, and F1 score, 1.000. In validation set, AUC was 0.713, accuracy was 0.640, sensitivity was 0.618, specificity was 0.822, positive predictive value was 0.500, negative predictive value was 0.656, and F1 score was 0.440. Random forest showed high predictive performance. Moreover, the Brief of the calibration curve for the prediction model was 0.178, the prediction accuracy was high, and the decision curve showed that the prediction model could benefit clinically.

CONCLUSIONS

Based on the clinical and dosimetric parameters for the female pelvic tumor patients, the prediction model of radiation proctitis constructed by random forest algorithm has high predictive ability and strong clinical usability.

Management of stage III and IVa uterine cancer

The prognosis of patients with advanced endometrial cancer is poor with limited therapeutic options. Nevertheless, the integration of molecular features in the clinico-pathological classification of endometrial cancer has significantly refined prognostic risk groups, representing a major breakthrough not only in the management of the disease but also in treatment perspectives. New therapeutic compounds such as target therapies, immunotherapy, and hormonal therapies have emerged for this clinical setting. Furthermore, molecular-driven clinical trials may improve significantly the efficacy of new treatments selecting those patients who are highly likely to respond. This review aims at describing the state of the art of advanced stage III-IVa endometrial cancer management, providing also the most interesting clinical perspectives.

The role for vaginal cuff brachytherapy boost after external beam radiation therapy in endometrial cancer

PURPOSE

To evaluate the role and technique of a vaginal cuff brachytherapy (VB) boost to adjuvant external beam (EB) radiation for endometrial cancer through a systematic review.

METHODS AND MATERIALS

Relevant trials were identified through a systematic search of the literature.

RESULTS

A total of 21 prospective and retrospective studies which had a patient cohort undergoing EB + VB was identified to evaluate for rates of vaginal and pelvic recurrences, overall survival, and toxicity. Additional database studies were utilized to demonstrate differences in local control and overall survival between EB and EB + VB.

CONCLUSIONS

While there is limited prospective evidence to guide the use of a VB boost after EB, the evidence suggests that patients with a higher risk of a vaginal recurrence such as those with cervical stromal involvement in select Stage III patients may derive local control and survival benefits from a VB boost. Additional individual risk factors such as grade, histology, extent of invasion, margin status, age, and the use of lower doses of EB should be considered when deciding when to add a VB boost.

Diagnostic and Therapeutic Values of Angiogenic Factors in Endometrial Cancer

Endometrial cancer (EC) is the most frequent gynecological malignancy in developed countries and requires a relatively invasive diagnostic evaluation and operative therapy as the primary therapeutic approach. Angiogenesis is one of the main processes needed for cancer growth and spread. The production of angiogenic factors (AFs) appears early in the process of carcinogenesis. The detection of AFs in plasma and tissue and a better understanding of the angiogenic properties of EC may contribute not only to earlier but also more specific diagnosis and consequently tailored and individual therapeutic approaches. AFs and their receptors also have high potential as binding sites for targeted cancer therapy. In this review, we discuss angiogenesis in EC and the characteristics of the AFs that most contribute to angiogenesis in EC. We also highlight therapeutic strategies that target angiogenesis as potential EC therapy.

Sequencing chemotherapy before radiotherapy for women with stage IIIC endometrial cancer

OBJECTIVE

It is unclear how to best sequence adjuvant chemotherapy and radiotherapy for advanced endometrial cancer. We studied the outcomes for women treated with chemotherapy before radiotherapy in a chemotherapy-first (chemotherapy for 6 cycles followed radiotherapy) or 'sandwich' approach (chemotherapy for 3 cycles followed by radiotherapy and subsequently chemotherapy for 3 cycles).

METHODS

Women with stage IIIC endometrial cancer and no gross residual disease treated with chemotherapy before radiotherapy between April 2003 and April 2016 were included. The Kaplan-Meier method was used to estimate recurrence and survival. We performed a meta-analysis of endometrial cancer trials comparing chemotherapy and radiotherapy versus radiotherapy alone.

RESULTS

A total of 102 patients were included. The mean (SD) age was 63.8 (10.6) years; 84 patients received the chemotherapy-first approach and 18 patients received the 'sandwich' approach. Pelvic and para-aortic nodes were removed in 99% and 88.2%, respectively. Among all the patients, we observed 1 pelvic (1%), 1 para-aortic (1%), and 5 vaginal (4.9%) recurrences. At 3 years, for the 'sandwich' and chemotherapy-first approaches, the vaginal recurrence was 11.8% and 4.2%, pelvic recurrence was 0% and 1.5%, para-aortic recurrence was 0% and 1.2%, distant recurrence was 42.9% and 24.4%, and overall survival was 70.3% and 81.7%, respectively. With 'chemotherapy before radiotherapy' 94.9% completed 4+ chemotherapy cycles (vs 71-90% reported in the literature for 'radiotherapy before chemotherapy'). In a meta-analysis of endometrial cancer trials, distant recurrence rates were reduced with 4+ chemotherapy cycles but not with 3 cycles (p=0.01).

CONCLUSION

Chemotherapy before radiation sequencing for stage IIIC endometrial cancer was associated with a high proportion of patients completing 4+ chemotherapy cycles and low locoregional lymphatic recurrence rate, despite delaying radiotherapy until after 3-6 cycles of chemotherapy and not administering concurrent cisplatin.

Evaluation of a highly refined prediction model in knowledge-based volumetric modulated arc therapy planning for cervical cancer

Background and purpose

To explore whether a highly refined dose volume histograms (DVH) prediction model can improve the accuracy and reliability of knowledge-based volumetric modulated arc therapy (VMAT) planning for cervical cancer.

Methods and materials

The proposed model underwent repeated refining through progressive training until the training samples increased from initial 25 prior plans up to 100 cases. The estimated DVHs derived from the prediction models of different runs of training were compared in 35 new cervical cancer patients to analyze the effect of such an interactive plan and model evolution method. The reliability and efficiency of knowledge-based planning (KBP) using this highly refined model in improving the consistency and quality of the VMAT plans were also evaluated.

Results

The prediction ability was reinforced with the increased number of refinements in terms of normal tissue sparing. With enhanced prediction accuracy, more than 60% of automatic plan-6 (AP-6) plans (22/35) can be directly approved for clinical treatment without any manual revision. The plan quality scores for clinically approved plans (CPs) and manual plans (MPs) were on average 89.02 ± 4.83 and 86.48 ± 3.92 (p < 0.001). Knowledge-based planning significantly reduced the D_mean and V_{18 Gy} for kidney (L/R), the D_mean, V_{30 Gy}, and V_{40 Gy} for bladder, rectum, and femoral head (L/R).

Conclusion

The proposed model evolution method provides a practical way for the KBP to enhance its prediction ability with minimal human intervene. This highly refined prediction model can better guide KBP in improving the consistency and quality of the VMAT plans.

Spatially Fractionated Radiation Therapy Using Lattice Radiation in Far-advanced Bulky Cervical Cancer: A Clinical and Molecular Imaging and Outcome Study

Spatially fractionated radiation therapy (SFRT) has shown promise in generating high tumor response and local control in the treatment of various palliative and locally advanced bulky tumors. SFRT has not yet been studied systematically in cancer of the cervix. Here we report the first series of patients receiving SFRT for advanced/bulky cervical cancer. Ten patients with far-advanced bulky cervical cancer, stage IIIB-IVA (seven squamous cell and three adeno/adenosquamous carcinomas) received lattice radiation therapy (LRT), a variant of SFRT. The LRT regimen consisted of a dose of 24 Gy in three fractions, given to an average of five high-dose spheres within the gross tumor volume (GTV). The dose in the peripheral GTV was limited to 9 Gy in three fractions, using the volumetric modulated arc therapy (VMAT) technique. LRT was followed subsequently by conventionally fractionated external beam irradiation to 44.28 Gy (range: 39.60-45.00 Gy in 1.8 Gy fractions). All patients received concurrent cisplatin chemotherapy. Tumor response was assessed clinically, by morphological imaging (CT, MRI) and 18FDG PET/CT. Tumor control and survival rates were estimated using Kaplan-Meier analysis. All patients had local control at a median follow-up of 16 months (1-77). The two-year disease-specific survival rate was 53.3%. All cancer deaths were due to metastatic failure with local control maintained. Among the three patients who died of disease, all had adeno- or adenosquamous carcinoma histology, and no deaths from disease occurred among the patients with squamous cell carcinoma (P = 0.010). There were no grade ≥3 short-term or long-term treatment-related complications. Intra-treatment morphological tumor regression was highly variable (mean: 54%, range: 6-91%). After therapy, the complete metabolic response was 88.9% (8/9), and one patient out of the nine patients with post-treatment PET-CT had partial response (11.1%). Our preliminary data suggest that LRT-based SFRT is well tolerated in patients with far-advanced bulky cervical cancer and results in favorable tumor responses and high local control. These observations confirm prior reports of favorable tumor control and toxicity outcomes with SFRT in other advanced/bulky malignancies. Our findings are corroborated by high molecular-imaging-based tumor response. These encouraging hypothesis-generating results require cautious interpretation and confirmation with larger patient cohorts, preferably through a multi-institutional controlled randomized clinical trial.

Impact of CT-based planning and bladder volume changes on the dosimetry of vaginal vault brachytherapy

Aim:

To compare dose to target and organs at risk (OARs) in conventional plan (2D) versus computed tomography (CT)-based three-dimensional (3D) plan in vaginal cuff brachytherapy (VBT) and to compare the effect of bladder distension on target and OARs dosimetry.

Materials and methods:

Post-hysterectomy patients with an indication for VBT were included in the study. All patients underwent planning CT scans with a full bladder and an empty bladder protocol. For each CT, two plans were generated—one library-based 2D plan and another CT-based 3D plan. Dosimetric parameters were recorded for clinical target volume (CTV) and OARs.

Results:

A total of 92 observations were made from data collected from 46 patients. Difference between CTV dose in terms of 2D and 3D plans were not statistically significant for CTV (p = 0·11). Significant reduction in D0·1cc, D1cc and D2cc dose parameters were observed in bladder, rectum, sigmoid and bowel doses with the 3D plan (p < 0·001). Bladder distension showed a 20% reduction in dose for bowel (p < 0·001). Bladder distension also showed a 6·12% (p = 0·047) increase in D2cc, but there was a significant reduction in the mean dose to the bladder.

Conclusion:

Our study demonstrates the dosimetric benefits with 3D CT-based planning for VBT over 2D-based conventional planning and benefit of bladder distension in the reduction of bowel dose without compromising dose to the target volume.

Use of bevacizumab before or after radiotherapy increases the risk of fistula formation in patients with cervical cancer

OBJECTIVE

Several reports have documented the risk of fistula formation after bevacizumab in patients previously treated with radiation therapy. The aim of this study was to investigate the risk of fistula formation with bevacizumab and radiotherapy compared with radiotherapy alone.

METHODS

We retrospectively analyzed patients with stage I-IV cervical cancer between January 2013 and December 2018. Patients who had a history of pelvic radiotherapy, who were treated with intracavitary brachytherapy alone, received radiotherapy at another hospital, received concurrent bevacizumab and radiotherapy, or had missing follow-up data or a short follow-up period (<6 months) were excluded. The fistula rates were compared between the groups using the Cox proportional hazards model and propensity score analyses.

RESULTS

A total of 302 patients were included in the study: 249 patients were treated with definitive or adjuvant radiotherapy, and 53 patients were treated with radiotherapy before or after bevacizumab. With a median follow-up of 35.9 (IQR 22.8-53.5) months, the 3 year cumulative fistula incidence rate was significantly higher in the radiotherapy + bevacizumab group than in the radiotherapy group (27.0% vs 3.0%, p<0.001). Bevacizumab administration was significantly associated with fistula formation in the multivariable adjusted model (HR 4.76, 95% CI 1.71 to 13.23) and three propensity score adjusted model (all p<0.05). Biologically equivalent dose in 2 Gy fractions for 2 cc of the rectum more than 76 Gy was also associated with fistula formation (HR 4.30, 95% CI 1.52 to 12.18). Additionally, a 10 month interval between radiotherapy and bevacizumab reduced the incidence of fistula formation in the radiotherapy + bevacizumab group (p=0.032).

CONCLUSIONS

In patients with cervical cancer treated with pelvic radiotherapy, the addition of bevacizumab substantially increased the risk of fistula formation. Physicians should perform pelvic radiotherapy in combination with bevacizumab with caution; moreover, close monitoring for fistula formation is warranted in these patients.

Targeted Alpha Therapy in mCRPC (Metastatic Castration-Resistant Prostate Cancer) Patients: Predictive Dosimetry and Toxicity Modeling of 225Ac-PSMA (Prostate-Specific Membrane Antigen)

Radioligand therapy is a type of internal radiotherapy combining a short-range radioisotope labeled to a carrier with a high affinity for a specific receptor expressed on tumor cells. Targeted alpha therapy (TAT) combines a high-linear energy transfer (LET) emitter (²²⁵Ac) with a prostate-specific membrane antigen (PSMA) carrier, specifically binding tumor cells in patients with metastatic castration-resistant prostate cancer. Although the antitumor activity of ²²⁵Ac-PSMA is well-documented, this treatment is nowadays only used as salvage therapy because the high incidence of xerostomia limits the therapeutic window. Thus, methods to reduce salivary toxicity and models able to describe xerostomia incidence are needed. We recently studied the efficacy of salivary gland protectors administered in combination with ¹⁷⁷Lu-PSMA therapy. Starting from these data, we performed a predictive dosimetric evaluation of ²²⁵Ac-PSMA to assess the impact of salivary gland protectors in TAT. ²²⁵Ac-PSMA predictive dosimetry was performed in 13 patients treated with ¹⁷⁷Lu-PSMA. Sequential whole-body planar images were acquired 0.5–1, 16–24, 36–48, and 120 h post-injection. ¹⁷⁷Lu time-activity curves were corrected for ²²⁵Ac physical decay and assumed in equilibrium for all daughters. The OLINDA/EXM spherical model was used for dose estimation of the parotid and submandibular glands. The dose for each daughter was calculated and summed for the total dose estimation. The biologically effective dose formalism was extended to high-LET emitters. For the total biologically effective dose formalism extended to high-LET emitters, including the contribution of all daughter isotopes, the brachytherapy formalism for a mixture of radionuclides was implemented. Equivalent doses in 2 Gy/fraction (EQD2) were then calculated and compared with the normal tissue complication probability model derived from external beam radiotherapy for grade ≥2 xerostomia induction. Median predictive doses were 0.86 Bd_RBE5/MBq for parotid glands and 1.05 Bd_RBE5/MBq for submandibular glands, with a 53% reduction compared with previously published data. The results show that the radiobiological model implemented is conservative, as it overestimates the complication rate with respect to the clinical data. Our data shows the possibility of reducing salivary gland uptake in TAT with the coadministration of organ protectors, but these results should be confirmed for TAT with ²²⁵Ac-PSMA by carrying out prospective trials with defined toxicity endpoints and dosimetry procedures.

NRG Oncology/RTOG Consensus Guidelines for Delineation of Clinical Target Volume for Intensity Modulated Pelvic Radiation Therapy in Postoperative Treatment of Endometrial and Cervical Cancer: An Update

PURPOSE

Accurate target definition is critical for the appropriate application of radiation therapy. In 2008, the Radiation Therapy Oncology Group (RTOG) published an international collaborative atlas to define the clinical target volume (CTV) for intensity modulated pelvic radiation therapy in the postoperative treatment of endometrial and cervical cancer. The current project is an updated consensus of CTV definitions, with removal of all references to bony landmarks and inclusion of the para-aortic and inferior obturator nodal regions.

METHODS AND MATERIALS

An international consensus guideline working group discussed modifications of the current atlas and areas of controversy. A document was prepared to assist in contouring definitions. A sample case abdominopelvic computed tomographic image was made available, on which experts contoured targets. Targets were analyzed for consistency of delineation using an expectation-maximization algorithm for simultaneous truth and performance level estimation with kappa statistics as a measure of agreement between observers.

RESULTS

Sixteen participants provided 13 sets of contours. Participants were asked to provide separate contours of the following areas: vaginal cuff, obturator, internal iliac, external iliac, presacral, common iliac, and para-aortic regions. There was substantial agreement for the common iliac region (sensitivity 0.71, specificity 0.981, kappa 0.64), moderate agreement in the external iliac, para-aortic, internal iliac and vaginal cuff regions (sensitivity 0.66, 0.74, 0.62, 0.59; specificity 0.989, 0.966, 0.986, 0.976; kappa 0.60, 0.58, 0.52, 0.47, respectively), and fair agreement in the presacral and obturator regions (sensitivity 0.55, 0.35; specificity 0.986, 0.988; kappa 0.36, 0.21, respectively). A 95% agreement contour was smoothed and a final contour atlas was produced according to consensus.

CONCLUSIONS

Agreement among the participants was most consistent in the common iliac region and least in the presacral and obturator nodal regions. The consensus volumes formed the basis of the updated NRG/RTOG Oncology postoperative atlas. Continued patterns of recurrence research are encouraged to refine these volumes.

Targeted therapies in gynecological cancers: a comprehensive review of clinical evidence

Advanced and recurrent gynecological cancers are associated with poor prognosis and lack of effective treatment. The developments of the molecular mechanisms on cancer progression provide insight into novel targeted therapies, which are emerging as groundbreaking and promising cancer treatment strategies. In gynecologic malignancies, potential therapeutic targeted agents include antiangiogenic agents, poly (ADP-ribose) polymerase (PARP) inhibitors, tumor-intrinsic signaling pathway inhibitors, selective estrogen receptor downregulators, and immune checkpoint inhibitors. In this article, we provide a comprehensive review of the clinical evidence of targeted agents in gynecological cancers and discuss the future implication.

Cisplatin plus capecitabine concomitant with intensity-modulated radiation therapy in non-metastatic anal squamous cell carcinoma: the experience of a single research cancer center

Background and Aims:

The standard treatment of non-metastatic anal squamous cell carcinoma (ASCC) consists of chemotherapy with mitomycin (MMC) plus 5-fluorouracil (5FU) for 1–2 cycles concomitant with pelvic radiotherapy. Subsequent studies introduced cisplatin (CDDP) combined with 5FU, with unclear results. We evaluated the doublet capecitabine (C) and CDDP as a possible alternative to MMC-5FU regimen concomitant with intensity-modulated radiation therapy (IMRT).

Patients and Methods:

We carried out a retrospective study on 67 patients affected by stage I–III ASCC, treated with CDDP (60–70 mg/m² every 21 days for two courses) plus C (825 mg/m² twice daily for 5 days/week) chemotherapy concomitant with IMRT for curative intent.

Results:

At a median follow up of 41 months, the clinical complete response calculated at the 6-month time-point (6-moCR), the 6-month objective response rate and the 6-month disease control rate were 93%, 94%, and 99%, respectively.

Disease-free survival rates at 1, 2, and 3 years were 89%, 87%, and 85%, while the overall survival rates at 1 and 2 years were 100% and 95%. The colostomy-free survival rates were 90% at 1 year and 88% at 2 years. Grade 3–4 acute adverse events were reported in 61% of patients; predominantly skin toxicity (46%) and limited hematological toxicity (12%).

Conclusion:

In this retrospective study, chemotherapy with C plus CDDP concomitant with IMRT proved safe and effective, and may represent a possible alternative option to standard MMC-containing regimen for curative intent.

COVID-19 impact on timing of brachytherapy treatment and strategies for risk mitigation

PURPOSE

The purpose of this study was to highlight the importance of timely brachytherapy treatment for patients with gynecologic, breast, and prostate malignancies, and provide a framework for brachytherapy clinical practice and management in response to the COVID-19 pandemic.

METHODS AND MATERIALS

We review amassing evidence to help guide the management and timing of brachytherapy for gynecologic, breast, and prostate cancers. Where concrete data could not be found, peer-reviewed expert opinion is provided.

RESULTS

There may be a significant negative impact on oncologic outcomes for patients with gynecologic malignancies who have a delay in the timely completion of therapy. Delay of prostate or breast cancer treatment may also impact oncologic outcomes. If a treatment delay is expected, endocrine therapy may be an appropriate temporizing measure before delivery of radiation therapy. The use of shorter brachytherapy fractionation schedules will help minimize patient exposure and conserve resources.

CONCLUSIONS

Brachytherapy remains a critical treatment for patients and may shorten treatment time and exposure for some. Reduced patient exposure and resource utilization is important during COVID-19. Every effort should be made to ensure timely brachytherapy delivery for patients with gynecologic malignancies, and endocrine therapy may help temporize treatment delays for breast and prostate cancer patients. Physicians should continue to follow developing institutional, state, and federal guidelines/recommendations as challenges in delivering care during COVID-19 will continue to evolve.

Intensity-modulated radiotherapy (IMRT) in the treatment of squamous cell anal canal cancer: acute and early-late toxicity, outcome, and efficacy

PURPOSE

To retrospectively review our experience on 84 patients with squamous cell anal canal cancer (SCAC) within 12 months after combined treatment with intensity-modulated RT (IMRT), in terms of acute and early-late toxicity, overall treatment time and interruptions, colostomy-free survival (CFS), and tumor response.

METHODS

Acute gastrointestinal (GI), genitourinary (GU), and cutaneous (CU) toxicities were assessed according to Common Toxicity Criteria for Adverse Events (CTCAE) version 4.03. Early-late toxicity was scored using the Radiation Therapy Oncology Group (RTOG) late radiation morbidity scoring system. Tumor response was evaluated with response evaluation criteria in solid tumors (RECIST) v1.1.

RESULTS

Acute toxicity for 84 subjects (100%): severe (≥ G3) GI and skin toxicity was observed in 4 (5%) and 19 patients (23%), respectively. Early-late toxicity for 73 subjects (87%): severe (≥ G3) GI and vulvo-vaginal toxicity was observed in 2 (3%) and 2 (3%) patients, respectively. No acute or early-late severe GU toxicity was reported. A treatment interruption occurred in 65 patients (77%). CFS was 96% (95% CI 89-99) at 6 months and 92% (95% CI 83-96) at 12 months. At 6 months complete response (CR), partial response (PR) and progressive disease (PD) was observed in 70 (83%), 3 (4%), and 7 patients (8%), respectively. At 12 months, CR was observed in 60 patients (81%); eleven patients (15%) experienced PD.

CONCLUSION

Our study showed an excellent clinical result and very low acute toxicity rates, confirming the IMRT as standard of care for curative treatment of anal cancer patients. The current trial was registered with the number IEO N87/11.

Is one brachytherapy fraction of 7 Gy similar to more fractions after external beam irradiation in postoperative endometrial carcinoma?

PURPOSE

To determine whether brachytherapy with a single hypofractionated dose of 7 Gy provides the similar vaginal-cuff relapses and safety profile in terms of complications compared to schedules of 2 or 3 fractions of lower doses in patients treated previously with external beam irradiation in postoperative endometrial carcinoma.

METHODS/MATERIAL

From June 2003 to December 2016, 325 patients were treated with 3 different schedules of high-dose-rate brachytherapy after external beam irradiation for postoperative endometrial carcinoma. The patients were divided into 3 groups: Group-1: 125 patients were treated with 3 fractions of 4-6 Gy per fraction (3 fractions/week) between 2003 and 2008; Group-2: 93 patients were treated with 2 consecutive daily fractions of 5-6 Gy between 2008 and 2011; Group-3: 107 patients received a single fraction of 7 Gy between 2011 and 2016. Bladder and rectum complications were assessed using RTOG scores and with the objective scores of LENT-SOMA for the vagina.

STATISTICS

the chi-square test.

RESULTS

The mean follow-up of Groups 1, 2 and 3 was 95, 67 and 51 months, respectively. Three patients in Group-1, 2 in Group-2, 1 in Group-3 developed vaginal-cuff relapse (p = 0.68). No differences were found in late toxicity among the three groups.

CONCLUSIONS

One single dose of 7 Gy is safe and effective and may be the best treatment schedule with a similar incidence of vaginal-cuff relapses, complications and patient comfort with less hospital attendance.

LncRNA HEIH Enhances Paclitaxel-Tolerance of Endometrial Cancer Cells via Activation of MAPK Signaling Pathway

This study aimed to investigate the function of lncRNA HEIH on promoting endometrial cancer cells' tolerance of paclitaxel (PTX). LncRNA HEIH expression was measured by QRT-PCR in endometrial cancer tissues, human healthy tissues and cell lines. The PTX-resistant endometrial cancer cells (Ishikawa-RE and HHUA-RE) were intermittently exposed to increase concentrations of PTX and were constructed as evidenced by MTT assay. Besides, the specific siRNA of HEIH (siHEIH) and pcDNA3.1-HEIH plasmid transfection were utilized to alter the expression of HEIH in the cells and investigate the effects of HEIH on resistance to PTX in endometrial cancer cells. Moreover, MTT, colony formation and apoptosis analysis were taken advantage to evaluate cell viability and proliferation when treated with PTX. Then, differential genes in PTX-resistant and HEIH-knock-down PTX-resistant endometrial cancer cells were screened out by microarray analysis. Finally, gene-set enrichment analysis was used to predict the promising signaling pathway of HEIH and western blotting analysis were performed to verify the relevant genes expression of MAPK signaling pathway. LncRNA HEIH, the dysregulation of which involved in production of drug-resistance, was overexpressed in PTX-resistant endometrial cancer cells. Up-regulating HEIH would activate MAPK pathway, promote chemo-resistance of endometrial cancer cells and enhance cell proliferation and viability, whereas silencing HEIH depressed the MAPK signaling pathway, contributed to restoring chemo-sensitivity to PTX and repressed cell physiological process. Down-regulating lncRNA HEIH expression reversed the PTX-resistance of endometrial cancer cells through MAPK signaling pathway.

Genital marginal failures after intensity-modulated radiation therapy (IMRT) in squamous cell anal cancer: no higher risk with IMRT when compared to 3DCRT

Intensity-modulated radiotherapy (IMRT) is considered the preferred option in squamous cell canal cancer (SCAC), delivering high doses to tumor volumes while minimizing dose to surrounding normal tissues. IMRT has steep dose gradients, but the technique is more demanding as deep understanding of target structures is required. To evaluate genital marginal failure in a cohort of patients with non-metastatic SCAC treated either with IMRT or 3DCRT and concurrent chemotherapy, 117 patients with SCAC were evaluated: 64 and 53 patients were treated with IMRT and 3DCRT techniques, respectively. All patients underwent clinical and radiological examination during their follow-up. Tumor response was evaluated with response evaluation criteria in solid tumors v1.1 guideline on regular basis. All patients' data were analyzed, and patients with marginal failure were identified. Concomitant chemotherapy was administered in 97 and 77.4% of patients in the IMRT and 3DCRT groups, respectively. In the IMRT group, the median follow-up was 25 months (range 6-78). Progressive disease was registered in 15.6% of patients; infield recurrence, distant recurrence and both infield recurrence and distant recurrence were identified in 5, 4 and 1 patient, respectively. Two out of 64 patients (3.1%) had marginal failures, localized at vagina/recto-vaginal septum and left perineal region. In the 3DCRT group, the median follow-up was 71.3 months (range 6-194 months). Two out of 53 patients (3.8%) had marginal failures, localized at recto-vaginal septum and perigenital structures. The rate of marginal failures was comparable in IMRT and 3DCRT groups (χ² test p = 0.85). In this series, the use of IMRT for the treatment of SCAC did not increase the rate of marginal failures offering improved dose conformity to the target. Dose constraints should be applied with caution-particularly in females with involvement of the vagina or the vaginal septum.

Recent Advances in Endometrial Cancer

Endometrial cancer is the most common gynecologic malignancy in the United States, with yearly rates continuing to increase. Most women present with early stage disease; however, advanced disease carries a grave prognosis. As a result, novel therapies are currently under investigation for the treatment of endometrial cancer. These advances include a better understanding of the genetic basis surrounding the development of endometrial cancer, novel surgical therapies, and new molecular targets for the treatment of this disease. This review explores the literature regarding these advancements in endometrial cancer.

American Brachytherapy Task Group Report: Adjuvant vaginal brachytherapy for early-stage endometrial cancer: A comprehensive review

This article aims to review the risk stratification of endometrial cancer, treatment rationale, outcomes, treatment planning, and treatment recommendations of vaginal brachytherapy (VBT) in the postoperative management of endometrial cancer patients. The authors performed a thorough review of the literature and reference pertinent articles pertaining to the aims of this review. Adjuvant VBT for early-stage endometrial cancer patients results in very low rates of vaginal recurrence (0-3.1%) with low rates of late toxicity which are primarily vaginal in nature. Post-Operative Radiation Therapy in Endometrial Cancer 2 (PORTEC-2) supports that VBT results in noninferior rates of vaginal recurrence compared to external beam radiotherapy for the treatment of high-intermediate risk patients. VBT as a boost after external beam radiotherapy, in combination with chemotherapy, and for high-risk histologies have shown excellent results as well though randomized data do not exist supporting VBT boost. There are many different applicators, dose-fractionation schedules, and treatment planning techniques which all result in favorable clinical outcomes and low rates of toxicity. Recommendations have been published by the American Brachytherapy Society and the American Society of Radiation Oncology to help guide practitioners in the use of VBT. Data support that patients and physicians prefer joint decision making regarding the use of VBT, and patients often desire additional treatment for a marginal benefit in risk of recurrence. Discussions regarding adjuvant therapy for endometrial cancer are best performed in a multidisciplinary setting, and patients should be counseled properly regarding the risks and benefits of adjuvant therapy.

Rationally combining anti-VEGF therapy with radiation in NF2 schwannoma

Neurofibromatosis type 2 is characterized by bilateral vestibular schwannomas, which are benign tumors that originate from the nerve sheath and damage the nerve as they grow, causing neurological dysfunction such as hearing loss. Current standard radiation therapy can further augment hearing loss by inducing local damage to mature nerve tissue. Treatment with bevacizumab, a Vascular Endothelial Growth Factor (VEGF)-specific antibody, is associated with tumor control and hearing improvement in NF2 patients; however, its effect is not durable and its mechanism of action on improving nerve function is unknown. Anti-VEGF treatment can normalize the tumor vasculature, improving vessel perfusion and delivery of oxygen. It is known that oxygen is a potent radiosensitizer; therefore, combining anti-VEGF treatment with radiation therapy can achieve better tumor control and allow for the use of lower radiation doses, thus minimizing treatment-related neurological toxicity.

Targeting angiogenesis in endometrial cancer - new agents for tailored treatments

INTRODUCTION

Endometrial carcinoma represents the most frequent gynecologic tumor in developed countries. The majority of women presents with low-grade tumors but a significant subset of women experience recurrence and do not survive their disease. Patients with stage III/ IV or recurrent endometrial cancer have a poor prognosis. Identification of active and tolerable new targeted agents versus specific molecular targets is a priority objective. Angiogenesis is a complex process that plays a crucial role in the development of many types of cancer and in particular endometrial cancer.

AREAS COVERED

In this review, the authors highlight the main angiogenetic molecular pathways and the anti-angiogenic agents in Phase II clinical trials for endometrial cancer treatment. The authors focus on reports from recent years on angiogenesis inhibitors used in endometrial cancer, including anti- vascular endothelial growth factor (VEGF) monoclonal antibodies (bevacizumab and aflibercept), mammalian target of rapamycin inhibitors (mTORi) (everolimus, temsirolimus and ridaforolimus), PI3 K inhibitors (BKM120), tyrosine kinase inhibitors (brivanib, sunitinib, dovitinib and nintedanib) and thalidomide.

EXPERT OPINION

These anti-angiogenic drugs, while used either alone or in combination with chemotherapy, have presented mixed results in treating endometrial cancer patients. Challenges for the future include the identification of new pathways, early identification and overcoming resistance and the use of these molecules in combination with old and new chemotherapeutic and targeted agents.

Vaginal brachytherapy for postoperative endometrial cancer: 2014 Survey of the American Brachytherapy Society

PURPOSE

Report current practice patterns for postoperative endometrial cancer emphasizing vaginal brachytherapy (VBT).

METHODS AND MATERIALS

A 38-item survey was e-mailed to 1,598 American Brachytherapy Society (ABS) members and 4,329 US radiation oncologists in 2014 totaling 5,710 recipients. Responses of practitioners who had delivered VBT in the previous 12 months were included in the analysis. Responses were tabulated to determine relative frequency distributions. χ(2) analysis was used to compare current results with those from the 2003 ABS survey.

RESULTS

A total of 331 respondents initiated the VBT survey, of whom 289 (87.3%) administered VBT in the prior 12 months. Lymph node dissection and number of nodes removed influenced treatment decisions for 90.5% and 69.8%, respectively. High-dose-rate was used by 96.2%. The most common vaginal length treated was 4 cm (31.0%). Three-dimensional planning was used by 83.2% with 73.4% of those for the first fraction only. Doses to normal tissues were reported by 79.8%. About half optimized to the location of dose specification and/or normal tissues. As monotherapy, the most common prescriptions were 7 Gy for three fractions to 0.5-cm depth and 6 Gy for five fractions to the surface. As a boost, the most common prescriptions were 5 Gy for three fractions to 0.5-cm depth and 6 Gy for three fractions to the vaginal surface. Optimization points were placed at the apex and lateral vagina by 73.1%. Secondary quality assurance checks were performed by 98.9%.

CONCLUSIONS

VBT is a common adjuvant therapy for endometrial cancer patients, most commonly with HDR. Fractionation and planning processes are variable but generally align with ABS recommendations.