In-room computed tomography-based brachytherapy for uterine cervical cancer: results of a 5-year retrospective study

Effective timing of hyaluronate gel injection in image-guided adaptive brachytherapy for uterine cervical cancer: a proposal of the 'adjusted dose score'

Hyaluronate gel injection (HGI) in the rectovaginal septum and vesicovaginal septum is effective in the setting of high-dose-rate image-guided adaptive brachytherapy (IGABT) for cervical cancer. We aimed to retrospectively investigate optimal conditions for HGI to achieve optimal dose distribution with a minimum number of HGI. We classified 50 IGABT plans of 13 patients with cervical cancer who received IGABT both with and without HGI in the rectovaginal septum and vesicovaginal septum into the following two groups: plan with (number of plans = 32) and plan without (number of plans = 18) HGI. The irradiation dose parameters of high-risk clinical target volume (CTVHR) and organs at risk per fraction were compared between these groups. We also developed the adjusted dose score (ADS), reflecting the overall irradiation dose status for four organs at risk and CTVHR in one IGABT plan and investigated its utility in determining the application of HGI. HGI reduced the maximum dose to the most exposed 2.0 cm3 (D2.0 cm3) of the bladder while increasing the minimum dose covering 90% of CTVHR and the percentage of CTVHR receiving 100% of the prescription dose in one IGABT plan without causing any associated complications. An ADS of ≥2.60 was the optimum cut-off value to decide whether to perform HGI. In conclusion, HGI is a useful procedure for improving target dose distribution while reducing D2.0 cm3 in the bladder in a single IGABT plan. The ADS can serve as a useful indicator for the implementation of HGI.

Hands-on-training tailored in response to pre-questionnaire-based survey on image-guided brachytherapy effectively reduces anxiety about its implementation

This study assessed the significance of hands-on-training (HoT) and questionnaire-based surveys on 3D image-guided brachytherapy (3D-IGBT) and a combination of intracavitary and interstitial brachytherapy, the so-called 'hybrid' BT (HBT), in uterine cervical cancer. In October 2023, 29 radiation oncologists, nurses, radiologic technologists and medical physicists from 10 Japanese facilities participated in an HoT on 3D-IGBT and HBT. Questionnaires were distributed to each participant before and after the HoT, and feedback was obtained through online channels. The questionnaire response rate was 83% (24/29), with at least one participant responding from each facility. 'Insertion of applicators and needles', 'human resource shortage' and 'pain relief and sedation' were the primary concerns of radiation oncologists. 'Applicator reconstruction', ' optimization of dwell positions', ' treatment planning' and ' human resource shortages ' were the primary concerns of radiological technologists and medical physicists. The HoT content was adjusted according to the results of preliminary surveys. The concerns expressed by the participants were addressed during the lectures and practical training. Significant reductions in anxiety were observed toward all items of the 10-point self-assessment after the HoT, regardless of the profession. The average score on satisfaction with the HoT (on a 10-point scale) was 9.52 (minimum of 8 and maximum of 10). In conclusion, HoT tailored in response to a pre-questionnaire-based survey effectively reduced participants' anxiety regarding the implementation of 3D-IGBT and HBT.

The prognostic effect of tumor volume, reduction ratio, and cumulative doses on external beam radiotherapy with central-shielding method and image-guided adaptive brachytherapy for cervical cancer

Objective

To evaluate the prognostic effect of tumor volume at diagnosis, tumor reduction ratio during external beam radiotherapy (EBRT) with central-shielding method, and cumulative minimal dose to 90% of the high-risk clinical target volume (CTVHR D90) on combined EBRT and image-guided adaptive brachytherapy (IGABT) for cervical cancer.

Methods

Consecutive patients who underwent definitive radiotherapy or concurrent chemoradiotherapy for cervical cancer at Gunma University Hospital between January 2010 and December 2019 were retrospectively reviewed. Tumor volume at diagnosis and reduction ratio were calculated using magnetic resonance imaging at diagnosis and before the first IGABT session. The cumulative dose of EBRT and IGABT was calculated as an equivalent dose in 2 Gy fractions (EQD2). Optimal cutoff values were determined according to a receiver operating characteristic curve. Treatment outcomes were evaluated using the Kaplan-Meier method and compared using the log-rank test and Cox proportional hazards regression.

Results

A total of 254 patients were included in the analysis. The median follow-up for all patients was 57 (2-134) months. The 5-year overall survival (OS) was 81.9%, progression-free survival (PFS) was 71.3%, and local control (LC) was 94.5%. The patients were divided into four groups according to tumor volume at diagnosis and reduction ratio. The group with tumor volume at diagnosis ≥ 34.1 cm3 and reduction ratio < 68.8% showed significantly worse OS, PFS, and LC than the other three groups (All p < 0.05). In this group, the patients with a cumulative CTVHR D90 < 69.6 GyEQD2 showed significantly worse PFS and LC (p = 0.042 and p = 0.027, respectively). In the multivariate analysis of OS, adenocarcinoma/adenosquamous carcinoma, International Federation of Gynecology and Obstetrics 2009 stage III/IV, and a reduction ratio of < 68.8% were independent significant poor prognostic factors (p = 0.045, p = 0.009 and p = 0.001, respectively). In the univariate analysis of LC, a reduction ratio of < 68.8% was the only poor prognostic factor (p = 0.041).

Conclusion

The patients with large and poorly responding tumors had significantly worse prognoses in terms of OS, PFS, and LC, suggesting that dose escalation should be considered for such tumors.

High-Dose-Rate Three-Dimensional Image-Guided Adaptive Brachytherapy (3D IGABT) for Locally Advanced Cervical Cancer (LACC): A Narrative Review on Imaging Modality and Clinical Evidence

Background: Brachytherapy (BT) is a critical component of radiotherapy for locally advanced cervical cancer (LACC), and it has rapidly developed in recent decades. Since the advent of three-dimensional image-guided adaptive brachytherapy (3D-IGABT), magnetic resonance imaging (MRI) has emerged as the primary modality for image guidance. Meanwhile, other imaging modalities, such as computed tomography, 18F-fluorodeoxyglucose positron emission tomography, ultrasound, and their combinations have also been widely studied. Materials and methods: We reviewed studies on different imaging modalities utilized for target delineation and planning. Emerging techniques in IGABT like real-time image guidance and 3D printing were also included. We summarized research on their feasibility and concentrated on their clinical outcomes. Results: MRI-guided BT was the gold standard, and CT-guided BT was the most widely applied. Other modalities have shown feasibility and promising efficacy in dosimetry studies and preliminary outcomes. The longer-term clinical outcomes associated with these approaches require further elucidation. Conclusions: As 3D-IGABT was validated by promising clinical outcomes, the future of BT for LACC is expected to progress toward the refinement of more effective image-guided procedures. Moreover, achieving operational consensus and driving technological advancements to mitigate the inherent limitations associated with different imaging modes remain essential.

MucoUp® as a spacer in brachytherapy for uterine cervical cancer: A first-in-human experience

We first used MucoUp®, a hyaluronic acid used in endoscopic resection, as a spacer in brachytherapy. In five cervical cancer patients, MucoUp® insertion increased a 90% dose of the high-risk CTV to over 80 Gy while decreasing the dose of organs at risk. No related adverse events were observed.

A practical guide to hybrid interstitial/intracavitary brachytherapy for locally-advanced cervical cancer

PURPOSE

In select cases of locally advanced cervical cancer, a hybrid brachytherapy (HBT) approach consisting of a combined intracavitary (IC)/insterstitial (IS) implant can yield improved target coverage and/or decreased organ at risk dose compared to IC techniques while limiting invasiveness compared to IS techniques.

METHODS AND MATERIALS

The technique involves placement of transvaginal and/or perineal needles in addition to the tandem and ring/ovoids using either a specialized applicator or free-hand placement. Following applicator and needle placement, brachytherapy may then be planned using principles similar to IC or IS techniques. During treatment planning, it can be helpful to obtain both MRI and CT imaging, as plastic MRI-compatible needles do not show up well on MRI.

RESULTS

In patients where acceptable target coverage cannot be achieved using IC alone or doses to nearby OAR are too high, HBT should be evaluated. HBT can improve both dose to target and OAR while sparing patients the morbidity of perineal template-based interstitial brachytherapy. Specific scenarios where HBT may be preferred include bulky residual primary tumor especially with poor response to EBRT, extension into the lateral parametrium, vaginal extension of tumor, and an asymmetric target. Use of HBT can typically permit extension of dose coverage by an additional 1-2 cm beyond what can be achieved with an IC alone technique.

CONCLUSION

HBT allows for improved therapeutic ratio by improving target volume coverage and/or lowering doses to OARs. Brachytherapists should be trained on the practical aspects of administering HBT to be able to offer a less invasive and impactful treatment option when appropriate.

The application of 3D brachytherapy in cervical stump cancer: A retrospective study

Purpose

Cervical stump cancer is a carcinoma that grows on the cervical stump after a sub-total hysterectomy. There have been no studies on the application of 3D brachytherapy in cervical stump cancer. In the present study, we aimed to compare the curative effects, toxicity, and dosimetry of 3D and 2D brachytherapy in cervical stump cancer.

Material and methods

Thirty-one patients admitted between 2012 and 2021, who were concurrently treated with intensity-modulated radiation therapy and brachytherapy for cervical stump cancer were divided into three groups according to the brachytherapy techniques: 2D brachytherapy, 3D image-guided brachytherapy (3D-IGBT), and 2D + 3D. For patients undergoing 2D brachytherapy and 3D-IGBT, data on survival, complications, and dose to target area or organs at risk (OARs) were collected and compared. Furthermore, dosimetry difference was investigated by reconstructing the 2D plan into a 3D plan.

Results

The median follow-up duration of all patients was 58 months. The overall 5-year progression-free survival, overall survival, and local control rates were 69.6%, 90.2%, and 78.2%, respectively. Late complications in the rectum, sigmoid colon, and bladder were milder in 3D brachytherapy than in 2D brachytherapy. Concerning the D90 value of clinical target volume (CTV) and D2cm3 value of OARs in EQD2, the 3D brachytherapy provided a lower dose to CTV (76.5 Gy vs. 95.9 Gy, on average) and OARs compared with 2D brachytherapy.

Conclusions

Despite lacking statistical significance, 3D brachytherapy showed better outcomes regarding late toxicity than 2D brachytherapy, owing to the lower dose coverage in the bladder, rectum, sigmoid colon, and small intestine.

Retrospective analysis of local recurrence pattern by computed tomography image-guided intracavitary and interstitial brachytherapy for locally advanced cervical cancer in a single Japanese institution

PURPOSE

The purpose of this study was to investigate the treatment results with focus on local control (LC) by computed tomography (CT)-guided intracavity brachytherapy and interstitial brachytherapy (ICBT/ISBT) for locally advanced cervical cancer (LACC).

METHODS AND MATERIALS

Patients with LACC undergoing ICBT/ISBT at least once in our institution between January 2017 and June 2019 were analyzed retrospectively. The primary endpoint was local control (LC), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and late toxicities. Differences between patient subgroups for prognostic factors in LC, PFS, and OS were analyzed using the log-rank test. The recurrence patterns of LC were also investigated.

RESULTS

Forty-four patients were included in the present study. The median high-risk clinical target volume (HR-CTV) at the initial brachytherapy was 48.2 cc. The median total dose of HR-CTV D90 (EQD2) was 70.7 Gy. The median followup period was 39.4 months. The 3-year LC, PFS and OS rates in all patients were 88.2%, 56.6%, and 65.4% (95% CI 50.3-78.0%), respectively. Corpus invasion and large HR-CTV (70 cc or more) were significant prognostic factors in LC, PFS, and OS. Marginal recurrences at the fundus of the uterus were detected in 3 of 5 patients in whom local recurrence was observed. Late toxicities of Grade 3 or higher were detected in 3 patients (6.8%).

CONCLUSIONS

Favorable LC was achieved by performing CT-guided ICBT/ISBT for LACC. The brachytherapy strategy for patients with corpus invasion or large HR-CTV may need to be reconsidered.

Pilot study of plasma creatine riboside as a potential biomarker for cervical cancer

This pilot study aimed primarily to evaluate plasma levels of a novel metabolite, creatine riboside, in patients with cervical cancer (discovery and validation cohorts, n = 11 for each) compared with non-cancer subjects (controls, n = 30). We found that the pre-treatment plasma creatine riboside level was significantly higher in the discovery cohort than in controls. The cut-off value determined from the discovery cohort distinguished 90.9% of the patients in the validation cohort from controls. Unbiased principal component analysis of plasma metabolites in high-creatine riboside samples demonstrated enrichment of pathways involved in arginine and creatine metabolism. These data indicate the potential utility of plasma creatine riboside as a biomarker of cervical cancer.

Association between Tumor Mutational Burden, Stromal CD8+ Tumor-Infiltrating Lymphocytes, and Clinical Factors in Cervical Cancers Treated with Radiotherapy

BACKGROUND

Tumor mutational burden (TMB) and stromal CD8-positive tumor-infiltrating lymphocytes (CD8⁺TILs) serve important roles in antitumor immune responses to radiotherapy. This study aimed to elucidate the association between TMB, CD8⁺TILs, and clinical factors in patients with cervical cancer treated with radiotherapy.

METHODS

Patients with squamous cell carcinoma of the uterine cervix treated with definitive radiotherapy, and with available somatic mutation data and immunohistochemical staining data from identical tumor tissues, were enrolled retrospectively. The association between TMB and/or CD8⁺TIL density and patient characteristics, mutation profiles, and treatment outcome was analyzed.

RESULTS

The study analyzed 44 patients (median follow-up period, 61 months). There was no significant correlation between TMB and CD8⁺TIL density, or between TMB or CD8⁺TIL density and patient characteristics. TMB-high or CD8⁺TIL density-low status was associated with worse overall survival and distant metastasis-free survival; the predictive value of these factors became greater when used in combination. TMB-high or CD8⁺TIL density-high status was associated with ARID1A mutations.

CONCLUSIONS

These data indicate independence of TMB and CD8⁺TIL density and the involvement of ARID1A alterations in antitumor immune responses in patients with cervical cancers treated with radiotherapy, warranting further mechanistic research and prospective validation.

Is it time to modify the Japanese Uterine Cervical Cancer Guidelines to recommend a higher dose for radio-resistant tumors?

Compared with the European or the United States' uterine cervical cancer management guidelines, which aim to deliver >85 Gy EQD2 (the equivalent effective dose in 2 Gy per fraction) to the high-risk clinical target volume (CTVHR) D90 (minimal dose of 90% of the CTVHR), the dose goal of the corresponding Japanese guidelines does not recommend delivering such a high dose to the CTVHR D90. Subsequently, while the rate of late radiation-induced toxicities is reported to be much lower in the Japanese schedule, the local control rate is relatively inferior to that of clinical results reported by the IntErnational study on MRI-guided BRAchytherapy in CErvical cancer study (EMBRACE-I) in which the dose goal for CTVHR D90 was >85 Gy and showed >90% local control regardless of tumor stage. In daily clinical practice, patients with residual disease supposedly due to insufficient total dose delivery are occasionally referred to our hospital for the possibility of re-irradiation, which is not usually recommended because the risk of late severe radiation-induced toxicity is high. In this report, the authors hope to raise a discussion in our community about modifying our treatment guidelines to recommend a higher dose at least for patients with poor response.

CT-based image-guided brachytherapy in uterine cervical cancer: Effect of tumor dose and volume on local control

BACKGROUND AND PURPOSE

To determine the optimal primary tumor dose for cervical cancer treatment using computed tomography (CT)-based image-guided brachytherapy (IGBT).

MATERIALS AND METHODS

We retrospectively reviewed 171 patients with cervical cancer who underwent both external beam radiation therapy (EBRT) and IGBT between May 2015 and December 2019. Majority of EBRT plan included central shielding technique. CT-based IGBT was performed weekly a median of three times. Magnetic resonance imaging preceded the first and third session of IGBT for target delineation.

RESULTS

The median age of the patients was 64 years (range: 30-91 years). The median follow-up time for living patients was 43 months (range: 6-76 months). The 3-year local control rates according to the International Federation of Gynecology and Obstetrics (FIGO, 2008) stages were 89%, 100%, 92%, 89%, 78%, and 100% for stages IB, IIA, IIB, IIIA, IIIB, and IVA, respectively. The median EBRT dose to the central pelvis and parametrium/pelvic wall was 41.4 Gy and 50.4 Gy, respectively. Patients who received a cumulative 2 Gy equivalent dose (EQD2) (α/β = 10 Gy) of high-risk clinical target volume (HR CTV) D90% ≥ 75 Gy achieved a long-term local control rate of 93%, compared with 80% in those who received <75 Gy (p = 0.02).

CONCLUSION

This is one of the largest CT-based IGBT series examining the treatment of cervical cancer based on the tumor dose-volume relationship. An HR CTV D90% ≥75 Gy was significantly associated with favorable local control in this study.

Tumor size before image-guided brachytherapy is an important factor of local control after radiotherapy for cervical squamous cell carcinoma: analysis in cases using central shielding

We analyzed the local control (LC) of cervical squamous cell carcinoma treated by computed tomography (CT)-based image-guided brachytherapy (IGBT) using central shielding (CS). We also examined the value of tumor diameter before brachytherapy (BT) as a factor of LC. In total, 97 patients were analyzed between April 2016 and March 2020. Whole-pelvic (WP) radiotherapy (RT) with CS was performed, and the total pelvic sidewall dose was 50 or 50.4 Gy; IGBT was delivered in 3-4 fractions. The total dose was calculated as the biologically equivalent dose in 2 Gy fractions, and distribution was modified manually by graphical optimization. The median follow-up period was 31.8 months (6.3-63.2 months). The 1- and 2-year LC rates were 89% and 87%, respectively. The hazard ratio was 10.11 (95% confidence interval: 1.48-68.99) for local recurrence in those with a horizontal tumor diameter ≥ 4 cm compared to those with < 4 cm before BT. In CT-based IGBT for squamous cell carcinoma, favorable LC can be obtained in patients with a tumor diameter < 4 cm before BT. However, if the tumor diameter is ≥ 4 cm, different treatment strategies such as employing interstitial-BT for dose escalation may be necessary.

Treatment Outcomes of Computer Tomography-Guided Brachytherapy in Cervical Cancer in Hong Kong: A Retrospective Review

Simple Summary

This retrospective study reviews 135 patients with locally advanced cervical cancer treated with chemo-radiotherapy with image-guided adaptive brachytherapy with CT guidance. The study has a long follow-up period of 53.6 months. The outcome was excellent with a five-year local control, pelvic control, distant metastasis-free survival and overall survival rates being 90.7%, 84.2%, 80.0% and 87.2%, respectively. Adenocarcinoma was significantly associated with worse local control, pelvic control, distant metastasis-free survival and overall survival rates.

Abstract

(1) Background: To report the long-term clinical outcomes of computer-tomography (CT)-guided brachytherapy (BT) for locally advanced cervical cancer. (2) Methods: A total of 135 patients with FIGO stage IB-IVA cervical cancer treated with definitive radiotherapy +/− chemotherapy with an IGABT boost at Queen Mary Hospital, Hong Kong, between November 2013 and December 2019 were included. Treatment included pelvic radiotherapy 40 Gy/20 Fr/4 weeks +/− chemotherapy then CT-guided BT (7 Gy × 4 Fr) and a sequential parametrial boost. The primary outcome was local control. Secondary outcomes were pelvic control, distant metastasis-free survival, overall survival (OS) and late toxicities. (3) Results: The median follow-up was 53.6 months (3.0–99.6 months). The five-year local control, pelvic control, distant metastasis-free survival and OS rates were 90.7%, 84.3%, 80.0% and 87.2%, respectively. The incidence of G3/4 long-term toxicities was 6.7%, including proctitis (2.2%), radiation cystitis (1.5%), bowel perforation (0.7%), ureteric stricture (0.7%) and vaginal stenosis and fistula (0.7%). Patients with adenocarcinomas had worse local control (HR 5.82, 95% CI 1.84–18.34, p = 0.003), pelvic control (HR 4.41, 95% CI 1.83–10.60, p = 0.001), distant metastasis-free survival (HR 2.83, 95% CI 1.17–6.84, p = 0.021) and OS (HR 4.38, 95% CI: 1.52–12.67, p = 0.003) rates. Distant metastasis-free survival was associated with HR-CTV volume ≥ 30 cm³ (HR 3.44, 95% CI 1.18–9.42, p = 0.025) and the presence of pelvic lymph node (HR 3.44, 95% CI 1.18–9.42, p = 0.025). OS was better in patients with concurrent chemotherapy (HR 4.33, 95% CI: 1.40–13.33, p = 0.011). (4) Conclusions: CT-guided BT for cervical cancer achieved excellent long-term local control and OS. Adenocarcinoma was associated with worse clinical outcomes. (4) Conclusion: CT-guided BT for cervical cancer achieved excellent long-term local control and OS. Adenocarcinoma was associated with worse clinical outcomes.

Galalae R. Ultrasound-Guided Brachytherapy for Cervical Cancer - A Tool for Quality Improvement in Brachytherapy?

Nowadays, brachytherapy is one of the major components to treat inoperable cervical cancer. Brachytherapy yields a higher dose to the target (cervix) while sparing normal tissues. Developments of brachytherapy stepped forward in the previous decade by image-guided brachytherapy (IGBT) turning brachytherapy from point-based planning to volume-based planning and IGBT improves the treatment quality for cervical cancer. Magnetic resonance imaging (MRI) or computed tomography (CT) is utilized in brachytherapy and showed promising results internationally. However, in a limited-resource area, the implementation of IGABT is difficult due to many causes (manpower, equipment, or budgets). To improve the quality in limited resources, ultrasound is introduced. The utilization of ultrasound in brachytherapy practice is to prevent uterine perforation during application. With present data, measurement by ultrasound showed the correlation to MRI measurement in uterine dimensions. With these aspects, there are many researches using ultrasound to improve the quality of treatment in brachytherapy, for example, to guide contouring on CT or to support brachytherapy planning. The use of ultrasound improves the quality of brachytherapy in comparison to conventional planning and supports the improvement in brachytherapy for cervical cancer.

Survival outcome of cervical cancer patients treated by image-guided brachytherapy: a 'real world' single center experience in Thailand from 2008 to 2018

The objective of our study was to evaluate the survival outcome of cervical cancer patients treated using image-guided brachytherapy (IGBT). From 2008 to 2018, 341 patients with cervical cancer were treated by radical radiotherapy. IGBT (by computed tomography [CT] or transabdominal ultrasound [TAUS]) was used to treat all of these patients. The characteristic data and patient status after treatment were recorded. All data were evaluated for survival outcome analysis. From a total of 341 patients, 295 patients were analyzed and 46 patients were excluded due to data missing in the survival outcomes. At the median follow-up time of 48 months (IQR 30-80 months), The 4-year local control, progression-free survival and overall survival rates were 89.5%, 74.9% and 69.1%, respectively. For overall survival, the size (> 5 cm), pathology (non-SCCA), stage (stage III-IV by FIGO 2009), lymph node (LN) (presented) and overall treatment time (OTT) (> 56 days) showed statistical significance in univariate analysis while non-SCCA pathology, advanced stage, presented LN and longer OTT showed statistical significance in multivariate analysis. In conclusion, our analysis reports a 4-year overall survival rate of 69.1%. Non-SCCA pathology, advanced stage disease, LN presence and longer OTT showed worse prognostic factors in multivariate analysis.

Patient-Derived Training Simulator for Image-Guided Adaptive Brachytherapy of Locally Advanced Cervical Cancers: Development and Initial Use

Image-guided adaptive brachytherapy (IGABT) using intracavitary and interstitial (IC/IS) techniques plays a pivotal role in definitive radiotherapy for locally advanced cervical cancers. However, the training opportunities for interstitial needle application are limited, preventing this technique from becoming widespread. This study aimed to develop a training simulator for IC/IS brachytherapy. The simulator consists of a soft silicone tumor phantom and acrylic tube mimicking the vagina; it has high visibility because of translucent materials and is compatible with computed tomography (CT) and magnetic resonance imaging (MRI). A patient harboring a typical bulky and irregular-shaped cervical tumor was selected from 495 in-house IGABT-treated candidates, and a tumor phantom (68 × 49 × 45 mm) modeled on this patient was produced from three-dimensional real-scale measurements of the MRI-based high-risk clinical target volume at first brachytherapy. In trial use by two physicians with different levels of IGABT skills, a Fletcher-Suit Asian Pacific applicator, and a Venezia applicator with interstitial needles were nicely applied to the simulator, facilitating successful creation of CT-based treatment plans consistent with clinical practice. Thus, the training simulator can be useful for the training of IC/IS brachytherapy, and warrants further research employing a greater number of phantoms and practitioners to verify its educational value.

Japanese Society for Radiation Oncology Consensus Guidelines of combined intracavitary and interstitial brachytherapy for gynecological cancers

It has been postulated that the combination of intracavitary and interstitial brachytherapy (IC/IS) is effective and safe for large and irregularly shaped uterine cervical cancer patients. However, due to its invasiveness compared to conventional intracavitary brachytherapy (ICBT), it has to be said that the implementation speed of IC/IS is slow. Until now, there have been no guidelines for required equipment, human resources, and procedural guide focusing solely on IC/IS. The purpose of this guideline is to provide radiation oncologists and medical physicists who wish to start IC/IS with practical and comprehensive guidance for a safe IC/IS introduction and to help accelerate the spread of the utilization of IC/IS nationwide. This is the English translation of the Japanese IC/IS Guidelines, and it was created in an effort to share the Japanese approach to the management of locally advanced uterine cervical cancer worldwide.

High tumor mutational burden predicts worse prognosis for cervical cancer treated with radiotherapy

PURPOSE

Tumor mutational burden (TMB) is a surrogate biomarker of neo-antigens and high TMB status is associated with favorable response to immune-checkpoint inhibitors (ICIs). This study aimed to elucidate the association between TMB and the outcome of definitive radiotherapy in patients with cervical cancer.

MATERIALS AND METHODS

TMB and treatment outcome were retrospectively analyzed in patients with newly diagnosed cervical cancer treated with definitive radiotherapy available with somatic mutation data of pre-treatment tumors obtained using a commercially available gene panel.

RESULTS

The study enrolled 98 patients (median follow-up period, 61 months). The median TMB was 9.5 mutations per megabase (range, 3.0-35.5 mutations per megabase). After dichotomization based on this median value, the 5-year overall survival (OS) for TMB-high patients was significantly worse than that of TMB-low patients (61.1% vs. 82.2%). Multivariate analysis identified high TMB status as a significant prognostic factor for worse OS, along with advanced stage, para-aortic lymph node involvement, and absence of concurrent chemotherapy.

CONCLUSION

These data indicate that TMB is a potential prognostic factor for worse survival in patients with cervical cancer treated with definitive radiotherapy, thereby providing a rationale for treatment of TMB-high cervical cancers with a combination of ICIs plus radiotherapy. This retrospective study of 98 patients demonstrates for the first time that tumor mutational burden (TMB) is an independent prognostic factor for worse overall survival of patients treated with definitive radiotherapy, providing a rationale for treatment of TMB-high cervical cancers with a combination of immune-checkpoint inhibitors plus radiotherapy.

Secondary cancers after carbon-ion radiotherapy and photon beam radiotherapy for uterine cervical cancer: A comparative study

BACKGROUND

There are limited studies on the risk of secondary cancers after carbon-ion radiotherapy (CIRT). We assessed the incidence of secondary cancers in patients treated with CIRT for cervical cancer. We also evaluated the incidence of secondary cancers in patients who received standard photon radiotherapy (RT) throughout the same period.

METHODS

This retrospective study included patients with cervical cancer who underwent curative RT at our hospital. All cancers discovered for the first time after RT were classified as secondary cancers. To compare the risk of secondary cancers among cervical cancer survivors to the general population, standardized incidence ratios (SIRs) were calculated.

RESULTS

The analysis included a total of 197 and 417 patients in the CIRT and photon RT groups, respectively. The total person-years during the observation period were 1052.4 in the CIRT group and 2481.5 in the photon RT group. The SIR for all secondary cancers was 1.1 (95% confidence interval [CI], 0.6-2.1) in the CIRT group and 1.4 (95% CI, 1.0-2.1) in the photon RT group. The 10-year cumulative incidence of all secondary cancers was 9.5% (95% CI, 4.0-21.5) in the CIRT group and 9.4% (95% CI, 6.2-14.1) in the photon RT group. The CIRT and photon RT groups were not significantly different in incidence (p = 0.268).

CONCLUSIONS

The incidence of secondary cancers after CIRT for cervical cancer was similar to that after photon RT. Validation of our findings after long-term observation is warranted.

A retrospective study of small-pelvis radiotherapy plus image-guided brachytherapy in stage I-II non-bulky cervical squamous cell carcinoma

We herein report a retrospective analysis of the efficacy of a combination therapy of pelvic irradiation that excluded the common iliac lymph nodes region and image-guided brachytherapy (IGBT) for non-bulky (≤4 cm) cervical cancer. Thirty-three patients with stage I-II cervical squamous cell carcinoma (≤4 cm) and without pelvic/para-aortic lymphadenopathy who were treated with definitive radiotherapy alone between February 2009 and September 2016 were included. The radiotherapy consisted of CT-based small-pelvis irradiation (whole pelvis minus common iliac lymph node area) of 20 Gy/10 fractions followed by pelvic irradiation with a midline block of 30 Gy/15 fractions and IGBT of 24 Gy/4 fractions (6 Gy/fraction for high-risk [HR] clinical target volume [CTV] D90%). In-room computed tomography (CT) imaging with applicator insertion was used for brachytherapy planning, with physical examinations and diagnostic magnetic resonance imaging (MRI) also being referred to for determination of HR CTV. Over a median follow-up of 60.5 months (range, 7-89), two patients developed distant recurrence and one developed local and distant recurrence. Two patients died from cervical cancer, one from hepatocellular carcinoma and one from non-cancerous disease. The 2/5-year local control (LC), progression-free survival (PFS) and overall survival (OS) rates were 100%/96.7%, 93.8%/90.6% and 93.9%/93.9%, respectively. No pelvic/para-aortic lymph node recurrence was observed. There were no late complications of grade 3 or higher in the small bowel, large bowel/rectum, or bladder. Our results suggest that a combination therapy of IGBT plus small-pelvis irradiation excluding common iliac lymph nodes provides reasonable clinical outcomes and can be a treatment option in non-bulky (≤4 cm) cervical squamous cell carcinoma.

How should we appropriately classify low-risk uterine cervical cancer patients suitable for de-intensified treatment?

We suggested de-escalation would be possible for cervical cancer like human papillomavirus (HPV)-related oropharyngeal cancer. However, the classification was based on tumor shrinkage that can be obtained after half of the treatment was finished. Our other article found adverse factors which can be obtained prior to treatment, and they might classify patients earlier.

Phase Ib study of durvalumab (MEDI4736) in combination with carbon-ion radiotherapy and weekly cisplatin for patients with locally advanced cervical cancer (DECISION study): study protocol for a prospective open-label single-arm study

INTRODUCTION

Concurrent chemoradiotherapy is considered the standard treatment strategy for locally advanced cervical cancer. Most recent reports indicate that patients with bulky tumours or adenocarcinoma subtypes have poorer local control. Carbon-ion radiotherapy (CIRT) with the concurrent use of chemotherapy has shown promising results in such cases of difficult-to-treat uterine cervical cancer. Programmed death-ligand 1 (PD-L1) upregulation was observed in tumour tissue samples from patients who had undergone CIRT. Thus, a combination of CIRT and anti-PD-L1 antibody may suppress metastasis by activating antitumour immune response, in addition to exhibiting strong local effects.

OBJECTIVE

We will assess the safety and tolerability (primary endpoint) of the concomitant use of durvalumab, an anti-PD-L1 antibody, with CIRT and weekly cisplatin for locally advanced cervical cancer.

METHODS AND ANALYSIS

This study is a non-randomised, open-label, prospective phase 1b study. Up to 10 patients with histologically proven uterine cervical cancer at stage IIB, IIIA, IIIB, IIIC1 or IVA as per International Federation of Gynecology and Obstetrics (2018) staging will be enrolled. All patients will receive CIRT of 74.4 Gy relative biological effectiveness in 20 fractions over 5 weeks (four fractions per week). Weekly cisplatin at a dose of 40 mg/m2 will be administrated up to five times. Durvalumab at a dose of 1500 mg/body will be administrated at weeks 2 and 6. Safety and tolerability will be evaluated based on the frequency of dose-limiting toxicities until 92 days after CIRT starts. Patients will be followed-up strictly as per the scheduled protocol for 1 year after CIRT initiation.

ETHICS AND DISSEMINATION

The Human Research Ethics Committees of QST Hospital (#C21-002) and Chiba University (#2021006) have approved this study protocol. The findings will be published in peer-reviewed journals and presented at scientific conferences.

TRIAL REGISTRATION NUMBER

Japan Registry of Clinical Trials (jRCT2031210083), registered on 12 May 2021.

Clinical advantage and outcomes of computed tomography-based transvaginal hybrid brachytherapy performed only by sedation without general or saddle block anesthesia

BACKGROUND

Three-dimensional image-guided brachytherapy is the standard of care in cervical cancer radiotherapy. In addition, the usefulness of the so-called "hybrid brachytherapy (HBT)" has been reported, which involves the addition of needle applicators to conventional intracavitary brachytherapy for interstitial irradiation.

AIM

To evaluate the clinical outcomes of CT-based HBT consisting of transvaginal insertion of needle applicators (CT-based transvaginal HBT) and only intravenous sedation without general or saddle block anesthesia.

METHODS AND RESULTS

This is a retrospective chart review of patients who received definitive radiotherapy, including CT-based transvaginal HBT, between February 2012 and July 2019. The inclusion criteria were as follows: (i) histologically diagnosed disease, (ii) untreated cervical cancer, (iii) International Federation of Gynecology and Obstetrics (FIGO) stage IB1-IVA disease in the 2008 FIGO staging system, and (iv) patients who underwent CT-based transvaginal HBT at least once in a series of intracavitary brachytherapy. Overall, 54 patients fulfilled the eligibility criteria in the present study. The median follow-up period was 32 (IQR, 19-44) months. No patient complained of symptoms such as persistent bleeding or abdominal pain after the treatment. The 3-year local control (LC), disease-free survival, and overall survival rates for all 54 patients were 86.6%, 60.3%, and 90.7% (95% CI [81.3%-100.0%]), respectively. The 3-year LC rate was 87.7% in patients with FIGO III-IVA and 90.4% in tumor size >6.0 cm. The incidence rate of late adverse events, grade ≥3, in the rectum and bladder was 0% and 1.8%, respectively. In the dose-volume histogram analyses, transvaginal HBT increased the dose of HR-CTV_D90 by ~7.5% without significantly increasing the dose of organs at risk.

CONCLUSION

Considering the favorable clinical outcomes, CT-based transvaginal HBT may be a good option for treating cervical cancer.

Small dose of oral gastrografin for computed tomography-based image-guided brachytherapy in patients with uterine cervical cancer

Oral administration of a water-soluble iodine contrast agent (gastrografin) was reported to assist in the appropriate contouring of the small intestine on computed tomography (CT)-based radiotherapy (RT) planning. The efficacy and optimal dose of gastrografin in CT-based image-guided brachytherapy (IGBT) for cervical cancer remain unknown. This study aimed to investigate the efficacy of pretreatment oral administration of gastrografin at a small dose of 50 ml in CT-based IGBT for cervical cancer. A total of 422 sessions in 137 patients who underwent CT-based IGBT with 50 ml of oral gastrografin (concentration, 3% or 4%) were analyzed. Preparation of gastrografin was judged as effective when the small intestine was contrast-enhanced at the area where the small intestine was in contact with the uterus/adnexa. About 287 out of 422 sessions (68%) were judged as effective with gastrografin preparation. The 135 ineffective sessions were considered as follows: (i) the contrast enhancement of the small intestine was not confirmed (n = 36), (ii) the small intestine was not in contact with the uterus/adnexa despite the confirmation of the contrast enhancement of the small intestine (n = 34), and (iii) gastrografin was absent in the small intestine at the area in contact with the uterus/adnexa, even when gastrografin was observed in the small intestine at the area not in contact with the uterus/adnexa (n = 65). In conclusion, pretreatment oral administration of a small dose gastrografin achieved moderate efficacy for accurate contouring of the small intestine close to the uterus/adnexa in CT-based IGBT for cervical cancer.

Mutation Analysis of Radioresistant Early-Stage Cervical Cancer

Radiotherapy is a definitive treatment for early-stage cervical cancer; however, a subset of this disease recurs locally, necessitating establishment of predictive biomarkers and treatment strategies. To address this issue, we performed gene panel-based sequencing of 18 stage IB cervical cancers treated with definitive radiotherapy, including two cases of local recurrence, followed by in vitro and in silico analyses. Simultaneous mutations in KRAS and SMAD4 (KRASmt/SMAD4mt) were detected only in a local recurrence case, indicating potential association of this mutation signature with radioresistance. In isogenic cell-based experiments, a combination of activating KRAS mutation and SMAD4 deficiency led to X-ray resistance, whereas either of these factors alone did not. Analysis of genomic data from 55,308 cancers showed a significant trend toward co-occurrence of mutations in KRAS and SMAD4. Gene Set Enrichment Analysis of the Cancer Cell Line Encyclopedia dataset suggested upregulation of the pathways involved in epithelial mesenchymal transition and inflammatory responses in KRASmt/SMAD4mt cancer cells. Notably, irradiation with therapeutic carbon ions led to robust killing of X-ray-resistant KRASmt/SMAD4mt cancer cells. These data indicate that the KRASmt/SMAD4mt signature is a potential predictor of radioresistance, and that carbon ion radiotherapy is a potential option to treat early-stage cervical cancers with the KRASmt/SMAD4mt signature.

Comparative dosimetry of brachytherapy treatment planning between a volume-based plan by CT and a point-based plan by TAUS in CT datasets for brachytherapy

Aim:

To evaluate comparative dosimetry of brachytherapy treatment planning between a volume-based plan by computed tomography (CT) and a point-based plan by transabdominal ultrasound (TAUS) in CT datasets for brachytherapy.

Materials and methods:

From 2019 to 2021, 59 different datasets of CT images were collected from 38 patients treated by intracavitary brachytherapy with tandem ovoid or tandem ring applicators. At that time, TAUS was performed to prevent uterine perforation and to evaluate topography of the cervix during application. In volume-based planning by CT, the target dose was used to keep the dose at 90% of high-risk clinical target volume (HR-CTV), to give a dose of at least 7Gy, while in the point-based plan by TAUS, the target dose was used to keep the minimum dose to eight cervix reference points (measured by TAUS), to give a dose of at least 7Gy. The doses to targets and organs at risk were evaluated and compared between volume-based planning by CT and the point-based plan by TAUS.

Results:

Of 59 fractions, a tandem ovoid applicator was used in 48 fractions (81·3%). In the volume-based plan by CT, the mean doses to HR-CTV(D90), intermediate-risk clinical target volume (IR-CTV)(D90), bladder(D2cc), rectum(D2cc) and sigmoid colon(D2cc) were 7·0, 3·9, 4·9, 2·9 and 3·3 Gy, respectively, while in the point-based plan by TAUS, the mean doses to HR-CTV(D90), IR-CTV(D90), bladder(D2cc), rectum(D2cc) and sigmoid colon(D2cc) were 8·2, 4·6, 5·9, 3·4 and 3·9 Gy, respectively. The percentages of mean dose differences between TAUS and CT of HR-CTV(D90), IR-CTV(D90), bladder(D2cc), rectum(D2cc) and sigmoid colon(D2cc) were 17·7, 19·5, 20·5, 19·5, 21·3 and 19·8%, respectively. With the target dose to the point-based plan by TAUS (7 Gy to the cervix reference points), this was close to D98 of HR-CTV with a mean percentage of difference of 0·6%.

Findings:

The point-based plan by TAUS showed higher values to targets and organs at risk than the volume-based plan by CT. With the point-based plan by TAUS, it was close to D98 of HR-CTV.

The Non-Cancer Specific Elevation of the Serum Squamous Cell Carcinoma Antigen during the Post-Radiotherapy Follow-Up of Cervical Cancer Patients

The elevation of the serum squamous cell carcinoma (SCC) antigen unrelated to disease progression occurs during the follow-up of patients with cervical cancer treated with radiotherapy. Although known empirically, the incidence and characteristics of this non-cancer specific elevation in SCC remain unclear. Here, we examined the post-treatment kinetics of SCC in 143 consecutive patients with squamous cell carcinoma of the cervix treated with definitive radiotherapy; in all patients, progression-free disease status was confirmed by periodic monitoring for at least 36 months (median, 61 months). We found that the 5-year cumulative incidence of post-treatment SCC elevation was unexpectedly high at 37.3% (59/143 patients), and that 59.3% (35/59) of event-positive patients experienced multiple events. The median peak SCC level for a given event was 2.0 ng/mL (interquartile range, 1.7–2.9 ng/mL). The multivariate analysis showed that renal dysfunction was associated significantly with a greater incidence of SCC elevation (p = 0.046). In addition, the 5-year cumulative incidence of SCC elevation was significantly greater in patients with renal dysfunction than in those without (54.8% vs. 32.9%, respectively; hazard ratio, 2.1 [95% confidence interval, 1.1–4.2]; p = 0.028). These data will be useful for monitoring cervical cancer patients treated with radiotherapy.

Dosimetric feasibility of computed tomography-based image-guided brachytherapy in locally advanced cervical cancer: a Japanese prospective multi-institutional study

The aim of this study was to assess the feasibility of planning dose-volume histogram (DVH) parameters in computed tomography-based 3D image-guided brachytherapy for locally advanced cervical cancer. In a prospective multi-institutional study, 60 patients with stage IIA2-IVA cervical cancer from eight institutions were treated with external beam radiotherapy using central shielding and intracavitary or hybrid (combined intracavitary/interstitial) brachytherapy (HBT). The dose constraints were set as a cumulative linear quadratic equivalent dose (EQD2) of at least 60 Gy for high-risk clinical target volume (HR-CTV) D90, D2cc ≤ 75 Gy for rectum, D2cc ≤ 90 Gy for bladder and D2cc ≤ 75 Gy for sigmoid. The median HR-CTV D90 was 70.0 Gy (range, 62.8-83.7 Gy) in EQD2. The median D2cc of rectum, bladder and sigmoid was 57.1 Gy (range, 39.8-72.1 Gy), 68.9 Gy (range, 46.5-84.9 Gy) and 57.2 Gy (range, 39.2-71.2 Gy) in EQD2, respectively. In 76 of 233 sessions (33%), 23 patients underwent HBT, and the median number of interstitial needles was 2 (range, 1-5). HBT for a bulky HR-CTV (≥40 cm3) significantly improved the HR-CTV D90 compared with intracavitary brachytherapy alone (P = 0.010). All patients fulfilled the dose constrains for target and at risk organs by undergoing HBT in one-third of sessions. We conclude that the planning DVH parameters used in our protocol are clinically feasible.

Rectovaginal fistula in a cervical cancer patient treated with sequential radiotherapy and bevacizumab: A dose-volume analysis

Bevacizumab is a monoclonal antibody against vascular endothelial growth factor that exerts antitumor effect by preventing tumor angiogenesis. Gastrointestinal fistula is a common side effect of bevacizumab in combination with radiotherapy. This case of rectovaginal fistula indicates that the side effect may be unpredictable by the conventional dose-volume parameters for the rectum.

Cervical Stump Cancer Treated With Radiotherapy Using Computed Tomography-Guided Brachytherapy

Cervical stump cancer, which arises in the remaining uterine cervix of a woman with a history of supravaginal hysterectomy, accounts for 1.6-4.4% of all cervical cancers. The close proximity of the rectosigmoid colon to the primary tumor, which is due to the absence of the uterine corpus, should be considered carefully in the treatment planning of brachytherapy. Although three-dimensional image-guided brachytherapy (3D-IGBT) is used widely to treat cervical cancer in those with an intact uterine corpus, the safety and efficacy of 3D-IGBT for cervical stump cancer remains unclear. Here, we report a case of cervical stump cancer (T3bN1M0) treated successfully with definitive radiotherapy, which combined external beam radiotherapy and computed tomography (CT)-based IGBT. By applying the dose prescription concept used for definitive brachytherapy of cervical cancer with an intact uterine corpus, IGBT achieved satisfactory dose conformity to the tumor while sparing the adjacent rectosigmoid colon. This led to local tumor control for three years and eight months, with no late adverse effects. This case suggests that radiotherapy using CT-based IGBT is a safe and effective treatment for cervical stump cancer.

Impact of pre-brachytherapy magnetic resonance imaging on dose-volume histogram of locally advanced cervical cancer patients treated with radiotherapy including high-dose-rate brachytherapy

Purpose

This study investigated the suitability of brachytherapy technique selection based on pre-brachytherapy magnetic resonance imaging (MRI) findings in cervical cancer by evaluating dose-volume histogram parameters.

Material and methods

We retrospectively evaluated data from 61 patients with cervical cancer who underwent pre-brachytherapy MRI within 7 days before their first high-dose-rate brachytherapy treatment, selected according to pre-brachytherapy MRI findings. Combined intracavitary brachytherapy with interstitial techniques (IC/ISBT) or interstitial brachytherapy (ISBT) were favored treatments for poor-responding tumors after concurrent chemoradiotherapy, asymmetrical tumors, bulky parametrial extensions, bulky primary disease, and extensive paravaginal or distal vaginal involvement. Intracavitary brachytherapy (ICBT) was the preferred treatment for small tumors without extensive involvement of the vagina and parametrium.

Results

The median tumor size was 58 mm on pre-treatment MRI and 38 mm on pre-brachytherapy MRI. On pre-brachytherapy MRI, 13 patients had a tumor with severe vaginal invasion, 15 patients presented with an asymmetrical bulky tumor, and 4 patients had bulky residual tumors. IC/ISBT or ISBT were administered to 26 patients (43%). Median equivalent dose in 2 Gy fractions of clinical target volume D₉₀ was 70.8 Gy for all patients. Median clinical target volume D₉₀ in each brachytherapy session exceeded the prescribed dose in both patients treated with ICBT and IC/ISBT or ISBT. Median equivalent dose in 2 Gy fractions of D_2cc to the bladder, sigmoid colon, and rectum was 69.5, 52.0, and 58.4 Gy, respectively. All cases remained within the doses recommended for organs at risk.

Conclusions

Pre-brachytherapy MRI may be helpful in selecting suitable candidates for each type of brachytherapy and deliver the recommended doses to the tumor and organs at risk, particularly in cases with large tumors, poor response to concurrent chemoradiotherapy, asymmetrical tumors, severe vaginal invasion, extensive parametrial invasion, and/or corpus invasion.

Comparison of clinical outcomes achieved with image-guided adaptive brachytherapy for cervix cancer using CT or transabdominal ultrasound

PURPOSE

This study aimed to evaluate retrospectively the treatment results when using various image-guided adaptive brachytherapy treatments for cervical cancer treated by radical radiotherapy.

METHODS AND MATERIALS

From 2014 to 2017, 188 patients with cervical carcinoma were treated by whole pelvic radiotherapy plus four fractions of image-guided brachytherapy. Eight patients were excluded because of missing data. Consequently, 180 patients were analyzed. Of 180 patients, 92 were treated by CT-based brachytherapy (CT-BT), and transabdominal ultrasound-based brachytherapy (TAUS-BT) was used to treat another group. The treatment results and toxicity outcomes were evaluated by comparing the image-guidance techniques.

RESULTS

The mean follow-up time was 32 months (interquartile range 29.5-42 months). The mean age was 57 years (interquartile range from 50 to 65 years). In the CT-BT group, the mean cumulative doses to high-risk clinical target volume, bladder, rectum, and sigmoid were 87.2 Gy, 84.0 Gy, 68.8 Gy, and 69.8 Gy, respectively. In the TAUS-BT group, the mean cumulative doses to the cervix reference, bladder, and rectum points were 84.0 Gy, 65.5 Gy, and 74.0 Gy, respectively. There were no differences in the 2-year local control rate (p = 0.88) and disease-free survival rate (p = 0.34) in both groups. No difference in gastrointestinal and genitourinary toxicity was observed in both groups, but there was higher vaginal toxicity in the TAUS-BT group compared with the CT-BT group (p = 0.03).

CONCLUSIONS

No difference in treatment results was observed between CT-based and TAUS-based approaches. However, TAUS-BT had higher vaginal toxicity in our retrospective analysis.

The pan-cancer analysis of the two types of uterine cancer uncovered clinical and prognostic associations with m6A RNA methylation regulators

The role of m6A RNA methylation modification in uterine cancer has not been studied until now. We explored the relationship between m6A regulators and clinical characteristics and prognosis in uterine corpus endometrial carcinoma (UCEC) and uterine carcinosarcoma (UCS) with the data from the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). We found that several regulators were up-regulated or down-regulated in the two types of cancer, and identified two cluster subgroups with statistically significant differences in pathological grade, age and survival rate. Multivariate Cox regression analysis showed that methyltransferase-like 16 (METTL16) had a low hazard ratio in UCEC. We used several regulators to construct a risk signature and divided tumor patients into high-risk and low-risk groups, and found that the high-risk group had significantly lower survival rates. Independent prognostic analysis showed that the insulin-like growth factor 2 mRNA binding protein 1 (IGF2BP1) was a pan-prognostic regulator of uterine cancer. This result was further verified in the Gene Expression Omnibus (GEO) database. Based on above results, we conducted gene-ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses to further reveal a potential mechanism for m6A RNA methylation regulators. We found that IGF2BP1 was enriched in gene expression (GO:0010467), poly(A) RNA binding (GO:0044822) and RNA binding (GO:0003723) pathways. KEGG analysis showed that IGF2BP1 was enriched in microRNAs in the cancer (hsa05206) pathway. Our study systematically elucidated the relationship between m6A RNA methylation regulators and uterine cancer and constructed the risk signature that can predict the prognosis and clinicopathological characteristics of uterine cancer.

Mutation profiling of uterine cervical cancer patients treated with definitive radiotherapy

OBJECTIVE

To elucidate tumor mutation profiles associated with outcomes of uterine cervical cancer (UCC) patients treated with definitive radiotherapy.

METHODS

Ninety-eight patients with newly diagnosed and pathologically confirmed UCC (82 squamous cell carcinomas, 12 adenocarcinomas, and four adenosquamous carcinomas) who were treated with definitive radiotherapy were analyzed. DNA was extracted from pre-treatment tumor biopsy specimens. The exons of 409 cancer-related genes were sequenced using a next-generation sequencer. Genetic mutations were identified and analyzed for correlations with clinical outcome.

RESULTS

Recurrent mutations were observed in PIK3CA (35.7%), ARID1A (25.5%), NOTCH1 (19.4%), FGFR3 (16.3%), FBXW7 (19.4%), TP53 (13.3%), EP300 (12.2%), and FGFR4 (10.2%). The prevalence of mutations in FGFR family genes (i.e., FGFR1-4) was almost as high (24.5%) as that in PIK3CA and ARID1A, both of which are well-studied drivers of UCC. Fifty-five percent (21 of 38) of the identified FGFR mutations were located in the FGFR protein tyrosine kinase domain. Five-year progression-free survival (PFS) rates for FGFR mutation-positive patients (n = 24) were significantly worse than those for FGFR mutation-negative patients (n = 74) (43.9% vs. 68.5%, respectively; P = 0.010). Multivariate analysis identified FGFR mutations as significant predictors of worse 5 year PFS (P = 0.005), independent of clinicopathological variables.

CONCLUSIONS

FGFR mutations are associated with worse PFS in UCC patients treated with definitive radiotherapy. These results warrant further validation in prospective studies.

Induction of Micronuclei in Cervical Cancer Treated with Radiotherapy

Micronuclei (MN) trigger antitumor immune responses via the cyclic GMP-AMP synthase-signaling effector stimulator of interferon genes (cGAS-STING) pathway. Radiotherapy induces MN in peripheral blood lymphocytes. However, data for solid tumors are lacking. Here, we analyzed MN post-radiotherapy in solid tumor samples. Tumor biopsy specimens were obtained from seven prospectively recruited patients with cervical cancer, before treatment and after receiving radiotherapy at a dose of 10 Gy (in five fractions). The samples were stained with 4',6-diamidino-2-phenylindole dihydrochloride, and 200 nuclei per sample were randomly identified and assessed for the presence of MN or apoptosis, based on nuclear morphology. The median number of MN-harboring nuclei was significantly greater in samples from patients treated with radiotherapy than in pre-treatment samples (151 (range, 16-327) versus 28 (range, 0-61); p = 0.015). No significant differences in the number of apoptotic nuclei were observed between pre-treatment and 10 Gy samples (5 (range, 0-30) versus 12 (range, 2-30); p = 0.30). This is the first report to demonstrate MN induction by radiotherapy in solid tumors. The results provide clinical evidence of the activation of antitumor immune responses by radiotherapy.

Preliminary survey of 3D image-guided brachytherapy for cervical cancer at representative hospitals in Asian countries

3D image-guided brachytherapy (3D-IGBT) has become a standard therapy for cervical cancer. However, the use of 3D-IGBT is limited in East and Southeast Asia. This study aimed to clarify the current usage patterns of 3D-IGBT for cervical cancer in East and Southeast Asia. A questionnaire-based survey was performed in 11 countries within the framework of the Forum for Nuclear Cooperation in Asia. The questionnaire collected the treatment information of patients with cervical cancer who underwent 3D-IGBT. The cumulative external beam radiotherapy and 3D-IGBT doses were summarized and normalized to a biological equivalent dose of 2 Gy per fraction (EQD2) using a linear-quadratic model. Of the 11 institutions representing the participating countries, six (55%) responded to the questionnaire. Overall, data of 36 patients were collected from the six institutions. Twenty-one patients underwent whole-pelvic irradiation and 15 underwent whole-pelvic irradiation with central shielding. Patients received a median of four treatment sessions of 3D-IGBT (range, 2-6). All 3D-IGBT sessions were computed tomography (CT)-based and not magnetic resonance image-based. The median doses to the high-risk clinical target volume D90, bladder D2cc, rectum D2cc and sigmoid colon D2cc were 80.9 Gy EQD2 (range, 58.9-105.9), 77.7 Gy EQD2 (range, 56.9-99.1), 68.0 Gy EQD2 (range, 48.6-90.7) and 62.0 Gy EQD2 (range, 39.6-83.7), respectively. This study elucidated the current patterns of 3D-IGBT for the treatment of cervical cancer in East and Southeast Asia. The results indicate the feasibility of observational studies of CT-based 3D-IGBT for cervical cancer in these countries.

FIGO 2018 Staging for Cervical Cancer: Influence on Stage Distribution and Outcomes in the 3D-Image-Guided Brachytherapy Era

Recent widespread use of three-dimensional image-guided brachytherapy (3D-IGBT) has improved radiotherapy outcomes of cervical cancer dramatically. In 2018, the International Federation of Gynecology and Obstetrics (FIGO) staging system for cervical cancer was revised. However, the influence of the revisions on the stage distribution and outcomes of cervical cancers treated with 3D-IGBT remains unclear. Here, we retrospectively analyzed 221 patients with cervical squamous cell carcinoma treated with definitive radiotherapy using 3D-IGBT (median follow-up, 60 months). The stage distribution and outcomes were compared between the 2009 and 2018 schemas. Stage migration occurred in 52.9% of the patients. Patients classified with the 2018 criteria as stage IIIC_r had the highest proportion (43.8%) of migration, and were mainly from the 2009 stages IIB and IIIB. The 2009 and 2018 schemas showed comparable performance at stratifying 5-year overall survival (OS) and 5-year progression-free survival (PFS) for patients in stages IB–IVA. The 2018 criteria effectively stratified 5-year OS and PFS in the stage III substages. The 5-year OS and PFS for stage IIIC1_r patients varied according to tumor T stage. These data provide evidence for the utility of the revised 2018 FIGO staging system in the clinical management of cervical cancers in the 3D-IGBT era.

Retrospective DVH analysis of point A based intracavitary brachytherapy for uterine cervical cancer

Combining external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT) is important for definitive treatment of cervical cancer. In cervical cancer patients receiving radiotherapy, we evaluated treatment outcomes in relation to dose-volume histogram parameters, including the computed tomography (CT)-based high-risk clinical target volume (HR-CTV) for ICBT. Between 2010 and 2015, 89 consecutive cervical cancer patients were mostly treated with 40 Gy of EBRT in 20 fractions and 18 Gy of ICBT prescribed to point A in 3 fractions. CT scans were obtained during ICBT. The HR-CTV D90 was calculated and the total doses of ICBT and EBRT were converted to the equivalent dose in 2 Gy fractions (EQD2). When the patients were divided into four groups according to EQD2 of the HR-CTV D90, the 3-year local recurrence-free survival rates were 95.2, 78.4, 52.7 and 42.9% for patients receiving >80 , 70-80 , 60-70 and <60 Gy, respectively. There was a significant negative correlation between EQD2 of the HR-CTV D90 and the HR-CTV volume at first ICBT (r = -0.713). Local recurrence was more frequent when the HR-CTV volume was ≥22 cc and EQD2 of the HR-CTV D90 was <70 Gy. Multivariate analysis showed that EQD2 of the HR-CTV D90 and concurrent chemotherapy (≥4 cycles) were significant determinants of overall survival. HR-CTV D90 was an important prognostic indicator for local recurrence. HR-CTV D90 >70 Gy is required for the better local control, especially in patients with a larger HR-CTV (≥22 cc at initial ICBT).

Outcomes analysis of pre-brachytherapy MRI in patients with locally advanced cervical cancer

INTRODUCTION

Various brachytherapy options are available for treating cervical cancer. This study investigated whether pre-brachytherapy magnetic resonance imaging (MRI) findings could help identify the appropriate brachytherapy technique for cervical cancer.

METHODS

We retrospectively evaluated patients with cervical cancer who underwent pre-brachytherapy MRI within 7 days before their first high-dose rate brachytherapy treatment between December 2009 and September 2015. Patients who could not undergo MRI at pre-treatment and/or pre-brachytherapy and complete radical radiotherapy were excluded. Conventional intracavitary brachytherapy was the preferred treatment for ≤4 cm and symmetrical tumors. Non-conventional intracavitary brachytherapy, including interstitial brachytherapy, was the preferred treatment for bulky tumors, asymmetrical tumors, tumors with severe vaginal invasion, or bulky barrel-shaped tumors. The 3-year rates of overall survival, disease-free survival, and local control were compared using the Kaplan-Meier method and the log-rank test. Overall survival and local control rates were assessed using Cox regression analysis to identify risk factors for poor overall survival and local control outcomes.

RESULTS

A total of 146 patients were included in the study. The median tumor sizes were 52 mm (range 17-85) at the pre-treatment MRI and 30 mm (range 0-78) at the pre-brachytherapy MRI. Six patients had International Federation of Gynecology and Obstetrics (FIGO) stage IB2, 67 patients had stage II, 64 patients had stage III, and nine patients had stage IVA disease. A total of 124 (85%) patients had squamous cell carcinoma and 22 (15%) patients had adenosquamous cell carcinoma or adenocarcinoma. The MRI findings showed severe vaginal invasion (pre-treatment: 19 patients, pre-brachytherapy: 10 patients), asymmetrical bulky tumors (pre-treatment: 28 patients, pre-brachytherapy: 16 patients), and severe corpus invasion (pre-treatment: 39 patients, pre-brachytherapy: 18 patients). Based on the pre-brachytherapy MRI findings, non-conventional intracavitary brachytherapy was administered to 34 (23.3%) patients. Brachytherapy seemed to be appropriate for 133 (91.1%) patients and inappropriate for 13 (8.9%) patients. The 3-year rates were 84.2% for overall survival and 90.1% for local control. Grade 3 late rectal complications occurred in two (1%) patients. Multivariate analysis showed that tumor characteristics (size, shape, and extent of invasion) were not risk factors, although inappropriate brachytherapy was significantly related to poor local control (p<0.001).

CONCLUSION

Pre-brachytherapy MRI may help to select appropriate brachytherapy for cervical cancer and reduce the likelihood of inappropriate brachytherapy leading to poor local control.

Definitive radiotherapy consisting of whole pelvic radiotherapy with no central shielding and CT-based intracavitary brachytherapy for cervical cancer: feasibility, toxicity, and oncologic outcomes in Japanese patients

BACKGROUND

This prospective study investigated the feasibility, toxicity, and oncologic outcomes of definitive radiotherapy (RT) consisting of whole pelvic radiotherapy with no central shielding (noCS-WPRT) and CT-based intracavitary brachytherapy (ICBT) in Japanese patients with cervical cancer.

METHODS

Patients with cervical cancer of FIGO stages IB1-IVA were eligible. The treatment protocol consisted of noCS-WPRT of 45 Gy in 25 fractions and CT-based high dose-rate ICBT of 15 or 20 Gy in 3 or 4 fractions prescribed at point A. The prescribed ICBT dose was decreased if the manual dwell time/position optimization failed to meet organs-at-risk constraints. Graphical optimization and additional interstitial needles were not applied.

RESULTS

We enrolled 40 patients. FIGO stages were IB1: 11, IB2: 13, IIA2: 1, IIB: 11, IIIB: 3, and IVA: 1. Median (range) pretreatment tumor diameter was 47 (14-81) mm. Point A doses were decreased in 19 of 153 ICBT sessions (12%). The median follow-up duration was 33 months. The 2-year rates of pelvic control, local control (LC), and progression-free survival were 83%, 85%, and 75%, respectively. Pre-ICBT tumor diameter, high-risk clinical target volume (HR-CTV), total HR-CTV D90, and overall treatment time (OTT) significantly affected LC. Late adverse events (grade ≥ 3) were observed in 3 patients (2 in the bladder, 1 in the rectum).

CONCLUSIONS

Definitive RT consisting of noCS-WPRT and CT-based ICBT was feasible for Japanese patients with cervical cancer. To further improve LC, additional interstitial needles for patients with a large HR-CTV and shorter OTT should be considered.

Impact of CT-based brachytherapy in elderly patients with cervical cancer

PURPOSE

Three-dimensional image-guided brachytherapy (3D-IGBT) has become the standard therapy for patients with cervical cancer. However, in this population, the impact of 3D-IGBT in elderly individuals remains unknown. This study assessed the efficacy of 3D-IGBT for elderly patients with cervical cancer.

METHODS AND MATERIALS

We performed a retrospective chart review of 105 consecutive patients with cervical squamous cell carcinoma aged ≥70 years who received radiotherapy alone between January 2001 and September 2014. All patients were treated with external beam radiotherapy and high-dose-rate intracavitary brachytherapy. We assessed the treatment outcomes in all patients. We then compared outcomes between two groups: patients treated by changing the Point A dose at brachytherapy (Group A, n = 71) and those treated with 3D-IGBT at least twice (Group B, n = 34).

RESULTS

The median followup period was 59 (range, 6-203) months; the median age was 77 years. The 5-year local control and cause-specific survival rates were 89% and 78%, respectively. The 5-year cumulative rates of late toxicities of the rectum and bladder of Grade ≥3 were 2.0% and 4.2%, respectively. No statistically significant differences were observed in the local control and cause-specific survival rates, or in the incidence of rectal toxicities between groups. The 3-year cumulative rates of urinary toxicity of Grade ≥1 were 20.4% and 6.9% in Group A and Group B, respectively (p = 0.035).

CONCLUSION

In elderly patients with cervical cancer, 3D-IGBT could be performed safely and effectively and contributed to decreasing urinary toxicity incidence rates.

Dose-volume parameters and local tumor control in cervical cancer treated with central-shielding external-beam radiotherapy and CT-based image-guided brachytherapy

Definitive radiotherapy for cervical cancer consists of external-beam radiotherapy (EBRT) and brachytherapy. In EBRT, a central shield (CS) reduces the dose to the rectum and bladder. The combination of whole-pelvic (WP)- and CS-EBRT and brachytherapy is the standard radiotherapy protocol in Japan. Despite clinical studies, including multi-institutional clinical trials, showing that the Japanese treatment protocol yields favorable treatment outcomes with low rates of late radiation toxicities, dose-volume parameters for the Japanese treatment protocol remain to be established. We conducted a retrospective dose-volume analysis of 103 patients with uterine cervical cancer treated with the Japanese protocol using computed tomography-based adaptive brachytherapy. The 2-year overall survival and 2-year local control rates according to FIGO stage were 100% and 100% for Stage I, 92% and 94% for Stage II, and 85% and 87% for Stage III-IV, respectively. Late adverse effects in the rectum and bladder were acceptable. Receiver operating characteristic analysis discriminated recurrence within the high-risk clinical target volume (HR-CTV) (n = 5) from no local recurrence (n = 96), with the optimal response obtained at a dose of 36.0 GyEQD2 for HR-CTV D90 and 28.0 GyEQD2 for HR-CTV D98. These values were used as cut-offs in Fisher exact tests to show that high HR-CTV D90 and HR-CTV D98 doses for brachytherapy sessions were significantly associated with tumor control within the HR-CTV. These data suggest a contribution of brachytherapy to local tumor control in WP- and CS-EBRT and brachytherapy combination treatment, warranting validation in multi-institutional prospective studies.

Global Collaborations for Cervical Cancer: Can the East-West Alliance Facilitate Treatment for all?

Despite the advances in the primary prevention of cervical cancer, there is an absolute increase in the incidence of cervical cancer as a result of an increase in world population. A vast majority of patients in low and low-middle income countries continue to present at a locally advanced stage, necessitating treatment with chemoradiation and brachytherapy. There is a dearth of equipment and trained professionals for the treatment of cervical cancer, especially in low and low-middle income countries. There is an urgent need to improve treatment availability and develop better treatments. Worldwide trends, however, reveal a low number of therapeutic and innovative research trials in cervical cancer. The present article elucidates the existing challenges and provides solutions to improve outcomes. The proposed strategies hinge on strengthening collaborations for global advocacy.

Radiation therapy for vaginal cancer in complete uterine prolapse with intrauterine adhesion: a case report

Background

We encountered a woman with vaginal cancer that was associated with complete uterine prolapse and complicated by severe intrauterine adhesions. In this case report, we describe the clinical course and successful treatment of this rare condition.

Case presentation

A 78-year-old woman (gravida 10, para 2, abortion 8) with a 10-year history of uterine prolapse presented for evaluation of bleeding from an ulceration on the surface of the irreducibly prolapsed uterus. Biopsy of a mass on her vaginal wall led to a diagnosis of keratinizing squamous cell carcinoma. Her history of eight abortion procedures had resulted in severe intrauterine adhesions, preventing tandem insertion and intracavitary brachytherapy. She was also ineligible for surgery under general anesthesia + chemotherapy because of her advanced age and presence of arrhythmia. Therefore, we devised an extensive treatment plan involving high-dose-rate interstitial brachytherapy. This treatment successfully eliminated the squamous cell carcinoma as confirmed by biopsy with no recurrence or severe late complications.

Conclusions

We found that high-dose-rate interstitial brachytherapy may be a very effective therapeutic strategy for this condition with few adverse effects.

A 3-year follow-up study of radiotherapy using computed tomography-based image-guided brachytherapy for cervical cancer

Outcomes for patients with Stage IB1-IVA cervical cancer treated with computed tomography (CT)-based image-guided brachytherapy (IGBT) were examined in this study. A total of 84 patients were analyzed between March 2012 and June 2015. Whole-pelvic radiotherapy with a central shield was performed for each patient, and the total pelvic sidewall dose was 50 Gy. IGBT was delivered in 2-4 fractions. The initial prescription dose (6.8 Gy) was delivered at Point A, and the dose distribution was modified manually by graphical optimization. The total dose was calculated as the biologically equivalent dose in 2 Gy fractions (EQD2). Concurrent chemotherapy was administered to 64 patients (76%). The median follow-up period was 36 months (range 2-62 months). The 3-year overall survival, local control, and progression-free survival rates were 94%, 89% and 81%, respectively. The mean EQD2 for HR-CTV D90 was 73.4 Gy, and the EQD2 for HR-CTV D90 was not significantly associated with the local control rate. In multivariate analysis, adenocarcinoma (P = 0.03) and tumor size ≥45 mm (P = 0.06) were risk factors for local control. The patients were divided into four groups based on histology (squamous cell carcinoma vs adenocarcinoma) and tumor size (<45 vs ≥45 mm). Those with large adenocarcinomas had significantly worse outcomes. In conclusion, CT-based IGBT achieved favorable local control, but different treatment strategies may be necessary for large adenocarcinomas.