Locally advanced cervical cancer with bladder invasion: clinical outcomes and predictive factors for vesicovaginal fistulae

Genitourinary Fistula: 5 Years' Experience of Five Referral Centers in Iran

INTRODUCTION AND HYPOTHESIS

Genitourinary fistula is a devastating ailment that has an impact on women's physical health, mental health, emotional health, and financial security. The management of genitourinary fistula depends on the type, size, and duration of fistula formation. The purpose of this study is to report the features of genitourinary fistula in Iranian women and our experience in the management of fistula.

METHODS

Retrospective chart reviews of 283 patients were performed to determine the cause of the fistula, prior repairs, tissue interposition, and the success rate. The operation was considered successful if the patient did not have any urine leakage during the observation time.

RESULTS

The mean (SD) age of women was 49.51 (19.39; range: 21-70) years, Of these, 137 (52.9%) had a history of previous genitourinary fistula surgery. The average fistula was 1.53 (0.041) cm in size. The median (interquartile range) operation lasted 70 (15) min. The success rate after fistula repair was 91.5%. The typical follow-up period lasted 13.26 (range: 1-88) months. Forty-three (15.2%) patients had a big fistula (>2.5 cm) and 4 patients (1.4%) had a history of pelvic radiation therapy, among other reasons for failure. After a second repair, all patients' initial failures were resolved. There were no significant complications, as classified by Clavien-Dindo class 2 or greater. Additionally, there were no bowel, ureteral, or nerve injuries.

CONCLUSIONS

Our patients with genitourinary fistula had a successful outcome following repair techniques, without any significant morbidity or mortality.

Management and long-term clinical outcomes of patients with stage IVA cervical cancer with bladder involvement

OBJECTIVE

To describe the long-term outcomes of patients with stage IVA cervical cancer, a rare and deadly disease for which long-term toxicity data are scarce, to guide clinician counseling and survivorship support.

METHODS

In a retrospective review of a prospectively maintained database, we identified 76 patients with stage IVA cervical cancer with biopsy- or MRI-proven bladder mucosal involvement who received definitive radiotherapy (external beam radiotherapy [EBRT] alone or EBRT plus brachytherapy) with or without chemotherapy at our institution between 2000 and 2020. We used Kaplan-Meier modeling to estimate recurrence-free survival (RFS) and overall survival (OS) and used proportional hazard modeling to identify clinical variables associated with recurrence or survival. We performed actuarial competing risk modeling for severe late toxicity (grades 3 to 5, occurring >6 months of follow-up) and vesicovaginal fistulae (VVF), censoring for pelvic recurrence and death, and made comparisons between potential predictors using Gray's test and binary logistic regression.

RESULTS

The median follow-up time was 76 months (interquartile range 58-91). The median OS duration was 35 months (range, 18-not reached), and the 2- and 5-year OS rates were 53.6% and 40.9%, respectively. OS and RFS did not differ significantly between patients who received EBRT alone (N = 18) or EBRT plus brachytherapy (N = 49). Current smoking was a strong predictor of severe late toxicity, whose incidence was 14% at 2 years and 17% at 10 years. The VVF incidence was 24% at 2 years and 32% at 10 years.

CONCLUSION

Patients with stage IVA cervical cancer, even those who receive EBRT alone, can have long-term survival. These patients should be followed closely for late radiation-related toxicity.

Dosimetric comparison between stereotactic body radiotherapy and carbon-ion radiation therapy for prostate cancer

Background

Prostate cancer rates have been steadily increasing in recent years. As high-precision radiation therapy methods, stereotactic body radiation therapy (SBRT) and carbon-ion radiation therapy (CIRT) have unique advantages. Analyzing the dosimetric differences between SBRT and CIRT in the treatment of localized prostate cancer can help provide patients with more accurate, individualized treatment plans.

Methods

We selected computed tomography positioning images and the contours of target volumes of 16 patients with localized prostate cancer who received radiotherapy. We delineated the organs at risk (OARs) on the CyberKnife (CK) treatment planning system (TPS) MultiPlan4.0, which were imported into the CIRT uniform scanning TPS HIMM-1 ci-Plan. Two treatment plans, SBRT and CIRT, were designed for the same patient, and we used SPSS 22.0 for the statistical analysis of data.

Results

Both SBRT and CIRT plans met the prescribed dose requirements. In terms of target volume exposure dose, D2 (P<0.001), D5 (P<0.001), D50 (P<0.001), D90 (P=0.029), D95 (P<0.001), D98 (P<0.001), and Dmean (P<0.001) under SBRT were significantly higher than those under CIRT; the conformity index (CI) under SBRT was significantly better than that under CIRT (P<0.001); the target volume coverage rate (V95%) and dose homogeneity index (HI) under CIRT were significantly better than those under SBRT (P<0.001). In terms of OAR exposure dosage, the Dmax of the bladder and rectum under SBRT was significantly lower than that under CIRT (P<0.001), but Dmean was in the other direction; the exposure dose of the intestinal tract under CIRT was significantly lower than that under SBRT (P<0.05); Dmax of the femoral head under CIRT was significantly lower than that under SBRT (P<0.05), and there was no statistical difference between them at other doses.

Conclusions

In this study, we found that when CIRT was used for treating localized prostate cancer, the dose distribution in target volume was more homogeneous and the coverage rate was higher; the average dose of OARs was lower. SBRT had a better CI and higher dose in target volume; the dose hotspot was lower in OARs. It is important to comprehensively consider the dose relationship between local tumor and surrounding tissues when selecting treatment plans.

Image-guided adaptive brachytherapy for advanced cervical cancer spreading to the bladder and/or rectum: Clinical outcome and prognostic factors

INTRODUCTION

Refinements of brachytherapy techniques have led to better local control of locally advanced cervical cancer (LACC), especially with the development of image-guided adaptive brachytherapy (IGABT). Data on the efficacy of brachytherapy in cervical cancer spreading to adjacent organs are scarce. We report the experience of our institution in the treatment of these advanced tumors with IGABT.

MATERIALS AND METHODS

Medical records of patients treated for a LACC spreading to the bladder and/or rectum between 2006 and 2020 at Gustave Roussy Institute were analyzed. Dosimetric parameters were collected and converted into 2 Gy per fraction equivalent doses, including the minimal dose received by 90% of the high-risk target volume (D₉₀ CTV_HR) and intermediate-risk target volume (D₉₀ CTV_IR), as well as the dose received by the most exposed 2 cm³ of the organs at risk. A Cox regression model was used to study the potential associations between clinical and dosimetric factors with survival endpoints and fistula formation.

RESULTS AND STATISTICAL ANALYSIS

A total of 81 patients were identified. All patients received pelvic+/- para-aortic radiotherapy, 45 Gy in 25 fractions +/- boost to gross lymph nodes. Concomitant platinum-based chemotherapy was administered in 93.8% of cases. The median D₉₀ CTV_HR dose was 75.5 Gy_EQD2 (SD: 10.39 Gy_EQD2) and median CTV_HR volume was 47.6 cm³ (SD: 27.9 cm³). Median bladder and rectal D2_cm3 dose were 75.04 Gy_EQD2 (SD: 8.72 Gy_EQD2) and 64.07 Gy_EQD2 (SD: 6.68 Gy_EQD2). After a median follow-up of 27.62 ± 25.10 months, recurrence was found in 34/81 patients (42%). Metastatic failure was the most common pattern of relapse (n = 25). Use of a combined interstitial/intracavitary technique and D₉₀ CTV_HR ≥ 75.1 Gy_EQD2 were prognostic factors for OS in univariate analysis (HR = 0.24, 95%IC: 0.057-1, p = 0.023; HR = 0.2, 95%IC: 0.059-0.68, p = 0.0025, respectively). In multivariate analysis, a D₉₀ CTV_HR ≥ 75.1 Gy_EQD2 was significant for OS (HR = 0.23; 95%IC: 0.07, 0.78, p = 0.018). The occurrence of vesicovaginal fistula (VVF) was the most frequent pattern of local recurrence (HR = 4.6, 95%CI: 1.5-14, p = 0.01).

CONCLUSION

Advances in brachytherapy modalities improved local control and survival while reducing toxicities. Enhancing local control through dose escalation and combined intracavitary/interstitial brachytherapy techniques is a major factor in patients cure probability, together with systemic intensification to better control distant events.

Diagnostic Framework of Pelvic Massive Necrosis with Peritonitis following Chemoradiation for Locally Advanced Cervical Cancer: When Is the Surgery Not Demandable? A Case Report and Literature Review

Concurrent platinum-based chemoradiation (CCRT) is the established treatment for locally advanced cervical cancer and has an acceptable toxicity. Radiation-induced necrosis of the uterus and pelvic tissue is a rare and usually late potential complication. Limited data are available about its management. Here, we describe a case of a patient affected by a locally advanced cervical cancer (stage IVA) who received CCRT, obtaining a partial response with persistence of bladder and rectal infiltration. Unfortunately, after the first brachytherapy dose, the patient developed a worsening clinical picture with fever and altered laboratory data indicative of sepsis; the computed tomography revealed a massive necrosis of the uterus with pelvic abscess and peritonitis. We performed a laparoscopic emergency surgery with removal of the necrotic tissue, supracervical hysterectomy, bilateral-oophorectomy, and abscess drainage. Thereafter, once the severe inflammatory condition was resolved, the patient underwent pelvic exenteration with palliative/curative intent. The postoperative PET/CT was negative for residual disease. However, the patient needed further hospitalization for re-occurrence of peritonitis with multiple abscesses. A careful diagnosis is crucial in locally advanced cervical cancer patients who, after CCRT, present persistent pain and problematic findings at imaging and laboratory parameters. In these cases, radiation-induced necrosis of the pelvis should be suspected. This case helps to clarify the central role of surgery, especially when actinic necrosis leads to complications such as abscess, fistulae, and extensive tissue destruction that cannot be conservatively medically handled. Laparoscopy represents an ideal approach to realizing the correct diagnosis, as well as enabling the performance of important therapeutic surgical procedures.

The feasibility of reduced field-of-view diffusion-weighted imaging in evaluating bladder invasion of uterine cervical cancer

OBJECTIVES

Uterine cervical cancer with bladder mucosal invasion is classified as FIGO stage IVA with poor prognosis. MRI can rule out the bladder invasion and skipping cystoscopy may be possible; however, high false-positive rate may be problematic. The purpose of this study is to evaluate the diagnostic performance of reduced field-of-view (FOV) diffusion-weighted imaging (DWI) in evaluating bladder mucosal invasion of cervical cancer.

METHODS

3T MRI including T2WI and reduced FOV DWI in 15 women with histologically proven cervical cancer (two stage IIIB, six stage IVA, seven stage IVB) were retrospectively evaluated compared with cystoscopic findings.

RESULTS

Cystoscopy revealed mucosal invasion in 13 of 15 cases. The border between the tumor and the bladder wall was unclear on T2WI and clear on reduced FOV DWI in all 15 cases. The diagnosis of mucosal invasion on reduced FOV DWI had a sensitivity of 100%, specificity of 50%, accuracy of 93%, PPV of 93%, and NPV of 100%.

CONCLUSIONS

Addition of reduced FOV DWI may improve the staging accuracy of MRI for cervical cancer in assessing the bladder mucosal invasion.

ADVANCES IN KNOWLEDGE

Reduced FOV DWI may improve the staging accuracy of cervical cancer in assessing bladder mucosal invasion with high NPV and PPV, which may be helpful for avoiding unnecessary cystoscopy.

Radiotherapy of cervical cancer

External beam radiotherapy and brachytherapy are major treatments in the management of cervical cancer. For early-stage tumours with local risk factors, brachytherapy is a preoperative option. Postoperative radiotherapy is indicated according to histopathological criteria. For advanced local tumours, chemoradiation is the standard treatment, followed by brachytherapy boost, which is not optional. We present the update of the recommendations of the French Society of Oncological Radiotherapy on the indications and techniques for external beam radiotherapy and brachytherapy for cervical cancer.

Patterns of care and clinical outcomes in stage IVA cervical cancer: 14-year experience from a tertiary care centre in South India

Aim:

To analyse the patterns of care and clinical outcomes of patients diagnosed with cervical cancer International Federation of Gynecology and Obstetrics (FIGO) stage IVA treated at a tertiary care centre in South India.

Materials and methods:

The electronic medical records of 2,476 patients diagnosed with cervical cancer at a tertiary care institution between January 2005 and December 2018 were reviewed. Among them, 96 patients diagnosed with histologically proven carcinoma cervix stage IVA established by either cystoscopy or proctoscopy were included. Four patients who did not receive treatment at the study centre were excluded and 92 patients were available for final analysis.

Results:

The median follow-up period was 12 months (2–131 months). Of the 92 patients, 59 patients (64·13%) received radiation therapy (RT) alone, 22 patients (23·9%) received chemoradiation (CRT), three patients (3·26%) received neoadjuvant chemotherapy (NACT) followed by RT, one (1·08%) received NACT followed by CRT, four patients (4·35%) received chemotherapy alone, while three (3·26%) were offered best supportive care. The median progression-free survival (PFS) was 12 months (95% CI: 9·6–14·4 months) and median overall survival (OS) was 25 months (95% CI: 16·6–33·4 months). The 2-year and 3-year PFS was 30 and 20%, respectively, and the OS was 50 and 32%, respectively.

Conclusion:

The management of stage IVA cervical cancer needs to be individualised to achieve a fine balance between local control, toxicity, and quality of life. RT is the mainstay of treatment with concurrent chemotherapy in carefully selected patients. Involvement of palliative care team early in the course of treatment adds a holistic approach to the continuum of oncological care.

Practical aspects of palliative care & palliative radiotherapy in incurable cervical cancer

Cervical cancer is the most common cause of cancer-related deaths among economically disadvantaged women. The symptoms of pain, discharge, constipation, foul smell, insomnia and depression can be controlled with inexpensive medicines such as oral morphine, maintenance oral metronidazole, antidepressants and laxatives. These medications should be prescribed according to the palliative care guidelines and titrated to the individual patient's clinical response, pathophysiology, and metabolic parameters. A hypothetical clinical scenario illustrates some aspects of pain and symptom management, inter-disciplinary palliative care, medical ethics and communication needs in low-resource settings. Palliative radiotherapy is a cost-effective intervention to reduce vaginal discharge, bleeding, pressure effects and nociceptive or neuropathic pain caused by pelvic and para-aortic disease. The role of palliative radiotherapy in patients with malignant fistulae is discussed and the literature on hypo-fractionated pelvic radiotherapy is briefly reviewed.

Neoadjuvant chemotherapy combined with radical surgery for stage IB2/IIA2 cervical squamous cell carcinoma: a prospective, randomized controlled study of 35 patients

Objective

This study aimed to evaluate the clinical outcomes for patients with stage IB2/IIA2 cervical squamous cell carcinoma treated with neoadjuvant chemotherapy combined with radical surgery.

Methods

A total of 68 patients with cervical squamous cell carcinoma were randomly divided into the experimental group (n = 35) and the control group (n = 33). The patients in the experimental group received paclitaxel plus cisplatin neoadjuvant chemotherapy for two cycles, then underwent radical hysterectomy and bilateral adnexectomy at 2 weeks post-chemotherapy. The control group only underwent radical hysterectomy and bilateral adnexectomy after the diagnosis of cervical squamous cell carcinoma. The toxic and side effects of chemotherapy in the experimental group were observed. Also, the operation method, operation time, blood loss, grade of wound healing, complications, and postoperative pathology were noted in the two groups. Primary foci and pelvic lymph node recurrence and distant metastasis were observed, and 3-year and 5-year survival rates were calculated.

Results

Only one patient in the experiment had grade III bone marrow suppression; no other grade III and IV chemotherapy toxic reactions were observed. The operation was successfully completed in all patients. The operation time, intraoperative blood loss, placement of the ureteral catheter, bladder injury, ureteric injury, postoperative urinary tub, pelvic drainage tube indwelling time, anal exhaust time, postoperative complications, and metastatic ratio of lymph nodes were not significantly different between the two groups (P > 0.05). The number of dissected lymph nodes, deep myometrial invasion, and vascular tumor emboli showed a significant difference in the experimental group compared with the control group (P < 0.05). The 3-year disease-free survival (82.9% vs 81.9%), 5-year disease-free survival (71.4% vs 60.6%), 3-year overall survival (91.4% vs 87.8%), and 5-year overall survival (82.9% vs 75.6%) were not statistically significantly different between the experimental group and the control group (P > 0.05).

Conclusions

Neoadjuvant chemotherapy in IB2/IIA2 stage cervical squamous cell carcinoma showed low toxic side effects. Radical surgery after chemotherapy is safe and feasible. It plays a coordinating role in reducing the tumor infiltration depth of the deep muscle layer and the incidence of vascular tumor emboli, reducing the use of postoperative adjuvant therapy, and improving the quality of life of patients, but does not improve the 3-year/5-year survival rate.

Chronic Inflammation and Radiation-Induced Cystitis: Molecular Background and Therapeutic Perspectives

Radiation cystitis is a potential complication following the therapeutic irradiation of pelvic cancers. Its clinical management remains unclear, and few preclinical data are available on its underlying pathophysiology. The therapeutic strategy is difficult to establish because few prospective and randomized trials are available. In this review, we report on the clinical presentation and pathophysiology of radiation cystitis. Then we discuss potential therapeutic approaches, with a focus on the immunopathological processes underlying the onset of radiation cystitis, including the fibrotic process. Potential therapeutic avenues for therapeutic modulation will be highlighted, with a focus on the interaction between mesenchymal stromal cells and macrophages for the prevention and treatment of radiation cystitis.

[Can stereotactic body radiotherapy replace brachytherapy for locally advanced cervical cancer? French society for radiation oncology statement]

Brachytherapy is part of the treatment of locally advanced cervical cancers, accounting for about half of the total delivered dose. The benefit of dose escalation is the most important in advanced cases or if the tumor has responded poorly. The use of interstitial implantations makes it possible to reach doses of the order of 85 to 90Gy (including external beam radiotherapy contribution) in most patients, through image-guided approaches. Brachytherapy delivery is one of the quality criteria for patient care. To date, no data allow us to consider as an alternative the use of external boost through intensity-modulated or stereotactic body radiotherapy. Indeed, the doses delivered to the tumor and the capacity to spare normal tissues remains lower, as compared to what is permitted by brachytherapy. It is therefore appropriate for centers that do not have access to the technique to establish networks with centers where brachytherapy is performed, to allow each patient to have access to the technique. It is also necessary to promote brachytherapy teaching. The issue of reimbursement will be crucial in the coming years to maintain expertise that is today insufficiently valued in its financial aspects, but has a very high added value for patients.

Anti-tumor activities of probiotics in cervical cancer

Cervical cancer is considered as an important malignancy among women worldwide. Currently-used treatments of cervical cancer are reported to be cytotoxic for patients. Moreover, these therapies have shown some side effects which can negatively affect the lives of women suffering from this cancer. Therefore, there is need for anti-tumor agents that are less toxic than common therapeutic drugs. Besides, applying agents for preventing or reducing the side effects of cervical cancer therapies can be effective in improving the life quality of cervical cancer patients. Studies have shown that probiotics have several effects on biological processes. One of the most prominent aspects in which probiotics play a role is in the field of cancer. There are multiple studies which have focused on the functions of probiotics in diagnosis, prevention, or treatment of cancer. Besides their direct anti-tumor activities, probiotics can be used as an additional agent for enhancing or modulating other diagnostic and therapeutic methods. Herein, the effects of probiotics on cervical cancer cells are discussed, which may be useful in the prevention and treatment of this cancer. We review the studies concerned with the roles of probiotics in modulating and reducing the gastrointestinal adverse effects caused by cervical cancer therapies. Furthermore, we cover the investigations focusing on the combination of probiotics with other drugs for diagnosis or treatment of cervical cancer.

SMYD2 promotes cervical cancer growth by stimulating cell proliferation

Background

Cervical cancer is the most common gynecological malignancy with low terminal cure rate, and therefore new therapeutic targets are urgently needed to combat this disease. SMYD2, as an oncogene, is abnormal highly expressed in multiple types of tumors and further affects the occurrence and development, but the potential correlations between SMYD2 expression and cervical cancer progression is still unclear.

Methods

We first used the bioinformatics website to screen the data of cervical cancer in (The Cancer Genome Atlas) TCGA and survival analysis was used to find the different survival rates in the SMYD2 high expression group and low expression group. Through immunohistochemistry, the association between SMYD2 expression and clinical-pathological features of cervical cancer patients was further evaluated. Quantitative PCR and Immunoblot were applied to investigate the relative mRNA and protein expression levels, respectively. In vivo and in vitro experiments were performed to explore the function of SMYD2 in cancer progression.

Results

We first found a high expression of SMYD2 in cervical cancer, and survival analysis found that the poorer survival rate in the SMYD2 high expression group than that in the low expression group. Herein, our study demonstrated that the expression of SMYD2 in patients with cervical cancer was associated with FIGO stage, tumor size and further correlated with poor prognosis. Our data further showed that the inhibition of SMYD2 expression in cervical cancer cell line Caski and Siha could dramatically block the proliferation of cervical cancer cells. Additionally, SMYD2-shRNA lentivirus infected remarkably inhibited tumorigenesis in mice compared with the scramble group.

Conclusions

Taken together, this study provides strong evidence of the involvement of SMYD2 in cervical cancer growth and indicates that it could have high potential as a therapeutic target of cervical cancer.

Regular Low-Dose Oral Metronidazole Is Associated With Fewer Vesicovaginal and Rectovaginal Fistulae in Recurrent Cervical Cancer: Results From a 10-Year Retrospective Cohort

PURPOSE

Anaerobic necrosis in cervical cancer can lead to malodor, fistulae, and treatment abandonment. In this retrospective cohort study, we examined the association between maintenance metronidazole and the incidence of malignant fistulae in recurrent cervical cancer.

METHODS

We screened all cervical cancer records registered between 2007 and 2016 in the local palliative care database at Christian Medical College, Vellore, India. There were 208 eligible patients with post-treatment residual/recurrent pelvic disease. Among them, 76 had received oral maintenance metronidazole 200 mg once per day for 2 to 86 weeks (interquartile range, 4-16 weeks).

RESULTS

Seventy-two patients developed at least one fistula. Forty-nine had vesicovaginal fistulae, 10 had rectovaginal fistuale, and 13 developed both types of fistulae. Patients on maintenance metronidazole had fewer fistulae (22.4% v 41.7%; P = .005), a longer median fistula-free survival (42.9 months v 14.1 months; P < .001), and a postrecurrence survival of 11.5 months versus 8.7 months (P = .112). We performed Cox multivariable proportional hazards regression analysis on the data from the subset of 146 patients observed until death. Bladder/rectal infiltration had a higher risk of fistula (HR, 5.24; P = .011), whereas distant metastases (HR, 2.46; P = .012) and Eastern Cooperative Oncology Group performance status greater than 1 (HR, 1.64; P = .008) were associated with a higher risk of death. Maintenance metronidazole was associated with a lower risk of fistula (hazard ratio [HR], 0.33; 95% CI, 0.16 to 0.67; P = .002) and a lower risk of death (HR, 0.56; 95% CI, 0.39 to 0.81; P = .002).

CONCLUSION

Our data indicate that there is a significant inverse association between oral maintenance metronidazole and malignant fistulae in locally recurrent cervical cancer. The impact of this simple intervention on pelvic symptoms, fistulae, and survival should be evaluated in prospective studies.

A machine-learning-based prediction model of fistula formation after interstitial brachytherapy for locally advanced gynecological malignancies

PURPOSE

External beam radiotherapy combined with interstitial brachytherapy is commonly used to treat patients with bulky, advanced gynecologic cancer. However, the high radiation dose needed to control the tumor may result in fistula development. There is a clinical need to identify patients at high risk for fistula formation such that treatment may be managed to prevent this toxic side effect. This work aims to develop a fistula prediction model framework using machine learning based on patient, tumor, and treatment features.

METHODS AND MATERIALS

This retrospective study included 35 patients treated at our institution using interstitial brachytherapy for various gynecological malignancies. Five patients developed rectovaginal fistula and two developed both rectovaginal and vesicovaginal fistula. For each patient, 31 clinical features of multiple data types were collected to develop a fistula prediction framework. A nonlinear support vector machine was used to build the prediction model. Sequential backward feature selection and sequential floating backward feature selection methods were used to determine optimal feature sets. To overcome data imbalance issues, the synthetic minority oversampling technique was used to generate synthetic fistula cases for model training.

RESULTS

Seven mixed data features were selected by both sequential backward selection and sequential floating backward selection methods. Our prediction model using these features achieved a high prediction accuracy, that is, 0.904 area under the curve, 97.1% sensitivity, and 88.5% specificity.

CONCLUSIONS

A machine-learning-based prediction model of fistula formation has been developed for patients with advanced gynecological malignancies treated using interstitial brachytherapy. This model may be clinically impactful pending refinement and validation in a larger series.

Risk factors for fistula formation after interstitial brachytherapy for locally advanced gynecological cancers involving vagina

Purpose

To determine risk factors for fistula formation after interstitial brachytherapy (ISBT) in patients with advanced gynecologic cancers.

Material and methods

We performed an Institutional Review Board (IRB) approved retrospective review of 44 patients treated with transperineal template-based ISBT from 2011 to 2017 at a major metropolitan county and university health system. All patients were treated with image-guided high-dose-rate ISBT. Statistical analysis was performed using the χ² test to identify factors correlated with fistula formation. Survival and tumor control outcomes were calculated using Kaplan Meier analyses.

Results

Patients had a mean age of 53 years (range, 28-81 years), a mean external beam dose of 43.1 Gy (range, 42.5-51.3 Gy), and a mean brachytherapy dose of 22.8 Gy (range, 21.3-30 Gy). Two of 44 patients had fistulas that could be definitively attributed to therapy for a fistula rate of 4.5%. Six additional patients (13.6%) developed fistula after treatment with associated recurrent disease but were included in the causality analysis. We analyzed patient tumor and treatment factors, and on univariate analyses we found that age ≥ 60 years, Hispanic ethnicity, bladder involvement, rectal D2 cc ≥ 70 Gy, and whether patients had post-radiation biopsies were predictors for fistula formation. The 1-year overall survival (OS), progression-free survival (PFS), and local control (LC) were 85%, 58.5%, and 76.9%, respectively, with a mean follow-up time 23 months (range, 4.0-68.8 months).

Conclusions

We identified factors that predict fistula formation in patients with advanced gynecologic tumors treated with ISBT. These factors can be used to stratify patients into a high-risk group, with potential for modification of brachytherapy planning to reduce their risk of fistula formation.