Results of External-beam Radiotherapy Alone in Invasive Cancer of the Uterine Cervix: A Retrospective Analysis

Phase I/II study of stereotactic body radiotherapy boost in patients with cervical cancer ineligible for intracavitary brachytherapy

PURPOSE

Stereotactic body radiotherapy (SBRT) boost is a promising treatment for cervical cancer patients who are ineligible for intracavitary brachytherapy (ICBT). The aim of this multicenter, single-arm, phase I/II study was to prospectively evaluate the efficacy and toxicity of SBRT boost.

MATERIALS AND METHODS

ICBT-ineligible patients with untreated cervical cancer were enrolled. Patients underwent whole-pelvic radiotherapy (45 Gy in 25 fractions) with SBRT boost to the primary lesion. In the phase I dose-escalation cohort (3 + 3 design), patients were treated with SBRT boost of 21 or 22.5 Gy in three fractions. Although dose-limiting toxicity was not confirmed, a dose of 21 Gy was selected for the phase II cohort because it was difficult to reproduce the pelvic organs position in two patients during the phase I trial. The primary endpoint was 2-year progression-free survival.

RESULTS

Twenty-one patients (phase I, n = 3; phase II, n = 18) were enrolled between April 2016 and October 2020; 17 (81%) had clinical stage III-IV (with para-aortic lymph node metastases) disease. The median (range) follow-up was 40 (10-84) months. The initial response was complete response in 20 patients and partial response in one patient. The 2-year locoregional control, progression-free survival, and overall survival rates were 84%, 67%, and 81%, respectively. Grade ≥ 3 toxicity was confirmed in one patient each in the acute (diarrhea) and late (urinary tract obstruction) phases.

CONCLUSION

These findings suggested that a SBRT boost is more effective than the conventional EBRT boost and can be an important treatment option for ICBT-ineligible patients with cervical cancer.

STUDY REGISTRATION

This study was registered at the University Hospital Medical Information Network Clinical Trials Registry (UMIN000036845).

Stereotactic body radiotherapy boost in patients with cervical cancer

Our aim was to evaluate the oncological outcomes of stereotactic body radiotherapy (SBRT) boost in patients with cervical cancer. The data of 21 patients who received SBRT boost after definitive radiotherapy (RT) or chemoradiotherapy (CRT) between March 2012 and April 2019 were retrospectively evaluated. External beam radiotherapy (EBRT) was applied to patients with a total dose of 50.4 Gy in 28 fractions. Kaplan-Meier method was used for survival analysis (IBM SPSS 23 software) and p < .05 value was considered significant. After definitive RT or CRT, there was a complete response in 9 (43%) patients, partial response in 11 (52%) patients and stable disease in 1 (5%) patient. The median follow-up period was 28 months (range, 7.5-88 months). Two-years cancer-specific survival rate was 80%. While 2-year LC rate was 75% in patients with residual tumour size <4 cm, it was 50% when there was ≥4 cm residual tumour after definitive CRT (p = .1). The treatment was well-tolerated and no acute or late toxicity was observed. Although brachytherapy (BRT) is an essential part of the treatment in locally advanced cervical cancer, SBRT may be used in patients with small residual disease who are not candidate for BRT. IMPACT STATEMENTCervical cancer is one of the most common cancers in the world, and external beam radiotherapy (EBRT) and brachytherapy (BRT) are the main treatment options. However, in rare cases where BRT is not feasible, it has been questioned whether stereotactic body radiotherapy (SBRT) as an alternative to BRT.What is already known on this subject? Nowadays, BRT still appears to be the gold standard treatment. However, studies with a small number of patients and short follow-up periods in the literature show that SBRT can be a good alternative in cases where BRT cannot be performed.What do the results of this study add? Our study is one of the series with the largest number of patients in the literature and with the longest follow-up period. In this area where there is no prospective study, we think that retrospective data with high patient numbers are enlightening.What are the implications of these findings for clinical practice and/or further research? Our study shows that SBRT is an alternative option in cases with small residual disease where BRT cannot be applied, and it provides a basis for a prospective randomised study.

Radiosensitization using hydrogen peroxide in patients with cervical cancer

The purpose of the present study was to analyze the feasibility and safety of radiosensitization using hydrogen peroxide for cervical cancer. In superficial tumors, breast cancer and hepatocellular carcinoma, the safety and effectiveness of radiosensitization has been reported; to the best of our knowledge, however, there are no reports on cervical cancer. A total of 20 patients with cervical cancer were recruited. Inclusion criteria were as follows: Patients who required radical external beam radiotherapy (RT); ineligible for or refused brachytherapy; age, ≥20 years; no hematogenous metastasis; Eastern Cooperative Oncology Group Performance Status up to 2; and had not undergone prior treatment. Hydrogen peroxide was used twice a week in combination with RT. A 3% hydrogen peroxide solution-soaked gauze was inserted into the vagina during RT. A total of 45 Gy was delivered in 25 fractions to the whole pelvis with a boost of 10 Gy in 5 fractions if pelvic or para-aortic metastatic lymph nodes were observed. Ultimately, 18 patients were evaluated. Among the 17 patients (excluding one patient with tumor in situ), the one- and two-year overall survival rates were both 90% in patients with stage I/II and 86% in stage III/IV cervical cancer. The adverse events were well tolerated with no severe acute or late adverse events. Although limited by small sample size, short observation time and low radiation dose, the present study demonstrated that radiosensitization treatment may be an option for patients who cannot undergo brachytherapy. The study was retrospectively registered at the university hospital medical information network center (no. UMIN000039045) on January 6, 2020.

Determining the recommended dose of stereotactic body radiotherapy boost in patients with cervical cancer who are unsuitable for intracavitary brachytherapy: a phase I dose-escalation study

OBJECTIVE

Some patients are ineligible for intracavitary brachytherapy (ICBT) for locally advanced cervical cancer. Stereotactic body radiotherapy (SBRT) could be a good treatment option for such patients. This phase I clinical trial aimed to determine the recommended SBRT boost dose for ICBT-ineligible cervical cancer patients.

METHODS

Patients with untreated uterine cervical cancer (clinical stages IB1-IIIB) who were ineligible for ICBT were enrolled. Radiotherapy consisted of whole-pelvis radiotherapy (45 Gy in 25 fractions) followed by SBRT. Three dose levels of SBRT (19.5/21/22.5 Gy in three fractions) were set; the treatment protocol began at 21 Gy (level 2). The 'rolling-six' design study was used to establish the recommended dose of SBRT. Each dose level covered three or six patients. The primary endpoint included dose-limiting toxicity (DLT), defined as the occurrence of grade 3 (or worse) non-hematologic adverse effects within 6 months after SBRT.

RESULTS

The median follow-up after registration was 17 (range, 8-32) months. Three patients were enrolled in study level 2 (SBRT of 21 Gy); none of the patients exhibited DLT within 6 months after treatment completion. In study level 3 (SBRT of 22.5 Gy), three patients did not exhibit DLT. Although all six patients achieved locoregional control during follow-up, one patient treated with level 2 SBRT experienced distant metastases 14 months after registration.

CONCLUSIONS

The recommended dose of SBRT boost was 22.5 Gy in three fractions. We plan to conduct a phase II multi-center clinical trial using the methodology obtained from the current study.

Clinical outcomes following conventional external beam radiotherapy boost in Japanese patients with cervical cancer who are ineligible for intracavitary brachytherapy

OBJECTIVE

While external beam radiotherapy boost has been one of the standard management options for locally advanced cervical cancer that is not treatable with intracavitary brachytherapy, its efficacy remains unclear. We assessed clinical outcomes in Japanese patients with cervical cancer who underwent external beam radiotherapy alone and identified related prognostic factors.

METHODS

Patients treated with definitive external beam radiotherapy for cervical cancer unsuitable for intracavitary brachytherapy, including whole pelvic irradiation and external beam radiotherapy boost, were retrospectively examined. The endpoints were progression-free survival, overall survival and adverse events. Additionally, various patient-, tumor- and treatment-specific factors were evaluated to identify significant predictors of progression-free survival.

RESULTS

The study included 37 patients; 3 (8%), 5 (14%), 17 (46%) and 12 (32%) had clinical International Federation of Gynecology and Obstetrics (FIGO) stages I, II, III and IVA, respectively. A total radiation dose of 56-70.2 Gy was administered (84% of patients received 59.4-60.4 Gy). The median follow-up period after radiotherapy was 17 (range, 2-84) months. The progression-free survival rates at 1 and 2 years were 45 and 29%, respectively; the corresponding overall survival rates were 74 and 43%, respectively. On univariate and multivariate analyses of progression-free survival at 2 years, International Federation of Gynecology and Obstetrics stage IVA and a maximum primary tumor diameter >5 cm were associated with significantly worse outcomes (P = 0.026 and P = 0.027, respectively).

CONCLUSION

Approximately 70% of patients with cervical cancer treated with external beam radiotherapy boost instead of intracavitary brachytherapy experienced disease progression within 2 years. These results stress the necessity of devising alternative non-intracavitary brachytherapy treatment approaches, particularly for patients with International Federation of Gynecology and Obstetrics stage IVA and bulky primary tumors.

Brachytherapy: A critical component of primary radiation therapy for cervical cancer: From the Society of Gynecologic Oncology (SGO) and the American Brachytherapy Society (ABS)

Brachytherapy is well-established as an integral component in the standard of care for treatment of patients receiving primary radiotherapy for cervical cancer. A decline in brachytherapy has been associated with negative impacts on survival in the era of modern EBRT techniques. Conformal external beam therapies such intensity modulated radiation therapy (IMRT) or stereotactic body radiation therapy (SBRT) should not be used as alternatives to brachytherapy in patients undergoing primary curative-intent radiation therapy for cervical cancer. Computed tomography or magnetic resonance image-guided adaptive brachytherapy is evolving as the preferred brachytherapy method. With careful care coordination EBRT and brachytherapy can be successfully delivered at different treatment centers without compromising treatment time and outcome in areas where access to brachytherapy maybe limited.

Tumor Boost Using External Beam Radiation in Cervical Cancer Patients Unable to Receive Intracavitary Brachytherapy: Outcome From a Multicenter Retrospective Study (Korean Radiation Oncology Group 1419)

PURPOSE

We conducted this study to evaluate the outcomes of external-beam radiotherapy tumor boost (EBRT-B) in cervical cancer patients who could not receive intracavitary brachytherapy.

METHODS

A total of 11 hospitals provided the data of patients who received EBRT-B during the period from January 2005 through October 2012.

RESULTS

A total of 75 patients were included. The median radiotherapy dose was 46 Gy (range, 40-54 Gy) for whole pelvis and 24 Gy (range, 9-35 Gy) for EBRT-B. Initial tumor responses assessed at 2 to 6 months after radiotherapy were as follows: 46 with complete response, 22 with partial response, 2 with stable disease, and 3 with progressive disease. After a median follow-up time of 33 months, 30 patients (40.0%) showed disease progression including 21 (28.0%) with local progression. The 5-year local failure-free survival rate was 70.0%. Achieving complete response at the first follow-up visit and an overall treatment time of 53 days or less were significantly related to favorable local failure-free survival. The rate of grade 3 or higher toxicity was 2.6%.

CONCLUSIONS

Approximately 70% of patients had local tumor control after curative radiotherapy using EBRT-B. Early tumor response and overall treatment time of 53 days or less were closely associated with favorable local control.

Concurrent cisplatin-based chemoradiotherapy versus exclusive radiotherapy in high-risk cervical cancer: a meta-analysis

Objective

To evaluate the efficacy and safety of cisplatin-based concurrent chemoradiotherapy (DDP-CCRT) in patients with high-risk cervical carcinoma (CC) compared with exclusive radiotherapy (RT).

Materials and methods

Databases were searched for randomized controlled trials (RCTs) and cohort studies comparing DDP-CCRT with RT alone. Risk of bias assessment for RCTs was performed using the Cochrane Collaboration’s tool, and the Newcastle–Ottawa quality scale was used to perform quality assessment for cohort studies. Meta-analysis was conducted using Review Manager 5 and Stata 12.0 software.

Results

Finally, eight RCTs and three cohort studies containing 2,130 subjects were included. Analysis on total failures revealed a statistically significant difference in favor of DDP-CCRT (risk ratio =0.77, 95% confidence intervals [CIs]: 0.67–0.89). No significant heterogeneity was detected for pooled analysis concerning overall survival; the result of which demonstrated the superiority of DDP-CCRT over RT alone (hazard ratio =0.68, 95% CI: 0.57–0.80), and stable and established accumulative effects were observed in cumulative meta-analysis. Similar results were observed for progression-free survival (hazard ratio =0.63, 95% CI: 0.50–0.76). In terms of treatment-related Grade 3 and 4 adverse events, our pooled analysis with a fixed-effects model showed significantly enhanced toxicity in the DDP-CCRT group compared with that in the RT group (odds ratio =3.13, 95% CI: 2.37–4.13).

Conclusion

Solid and stable beneficial effects are associated with DDP-CCRT, and its superiority over comparative RT in patients with high-risk CC is confirmed. DDP-CCRT should be considered one of the frontline treatment options for high-risk CC patients without contraindications. However, enhanced toxicity associated with DDP-CCRT should never be ignored.