External Beam Boost for Cancer of the Cervix Uteri When Intracavitary Therapy Cannot Be Performed

Cone-Beam Computed Tomography (CBCT)-Guided Adaptive Boost Radiotherapy for a Patient With Locally Advanced Cervical Cancer Ineligible for Brachytherapy

Brachytherapy is a critical component of locally advanced cervical cancer treatment, and patients ineligible for brachytherapy historically have poor outcomes. Delivery of boost with stereotactic body radiation therapy (SBRT) has been studied, though toxicity is a concern. Recent case reports have explored adaptive radiation boost, which can adjust plans for inter-fraction motion using magnetic resonance guidance. Herein, we report the first patient with locally advanced cervical cancer ineligible for brachytherapy who was treated with a cone-beam computed tomography (CBCT)-guided adaptive boost following completion of chemoradiation. A 71-year-old female with locally advanced cervical cancer was treated with chemoradiation and was deemed ineligible for a brachytherapy boost due to tumor size, geometry, and a fistula with a tumor in the bladder. She was prescribed a boost to the primary tumor of 25 Gy in five fractions using CBCT-guided adaptive radiation following the completion of chemoradiation. A simulation was performed using a non-contrast CT fused with a mid-chemoradiation magnetic resonance imaging (MRI) scan to create an initial plan. For each treatment fraction, kilovoltage CBCTs were acquired, contours of organs at risk (OARs) were adjusted to reflect anatomy-of-the-day, and an adapted plan was generated. The initial and adapted plans were compared using dose-volume histogram objectives, and the adapted plan was used if it resolved OAR constraint violations or improved target coverage. The use of the initial treatment plan would have resulted in constraint violations for the rectum, sigmoid, and bladder in all fractions. The adapted plans achieved hard constraints in all fractions for all four critical OARs. The mean total treatment time across all five fractions was 58 minutes. This case demonstrates the feasibility of a CBCT-guided adaptive boost approach and the dosimetric benefits of plan adaptation in this setting. Though larger-scale and longer-term data are needed, CBCT-guided adaptive radiation may present a feasible alternative modality to deliver boost doses for brachytherapy-ineligible patients.

Locally advanced squamous cervical carcinoma (M0): management and emerging therapeutic options in the precision radiotherapy era

Squamous cervical carcinoma (SCC) requires particular attention in diagnostic and clinical management. New diagnostic tools, such as (positron emission tomography-magnetic resonance imaging) PET-MRI, consent to ameliorate clinical staging accuracy. The availability of new technologies in radiation therapy permits to deliver higher dose lowering toxicities. In this clinical scenario, new surgical concepts could aid in general management. Lastly, new targeted therapies and immunotherapy will have more room in this setting. The aim of this narrative review is to focus both on clinical management and new therapies in the precision radiotherapy era.

Radiobiological and dosimetric comparison of 60Co versus 192Ir high-dose-rate intracavitary-interstitial brachytherapy for cervical cancer

BACKGROUND

High-dose-rate (HDR) intracavitary-interstitial brachytherapy (IC-ISBT) is an effective treatment for bulky, middle, and advanced cervical cancer. In this study, we compared the differences between 60Co and 192Ir HDR IC-ISBT plans in terms of radiobiological and dosimetric parameters, providing a reference for clinical workers in brachytherapy.

METHODS

A total of 30 patients with cervical cancer receiving HDR IC-ISBT were included in this study, and IC-ISBT plans for each individual were designed with both 60Co and 192Ir at a prescribed dose of CTV D90 = 6 Gy while keeping the dose to OARs as low as possible. Physical dose and dose-volume parameters of CTV and OARs were extracted from TPS. The EQD2, EUBED, EUD, TCP, and NTCP were calculated using corresponding formulas. The differences between the 60Co and 192Ir IC-ISBT plans were compared using the paired t-test.

RESULTS

In each patient's 60Co and 192Ir IC-ISBT plan, the average physical dose and EQD2 of 60Co were lower than those of 192Ir, and there were statistically significant differences in D2cc and D1cc for the OARs (p < 0.05); there were statistically significant differences in D0.1 cc for the bladder (p < 0.05) and no significant differences in D0.1 cc for the rectum or intestines (p > 0.05). The EUBED ratio (60Co/192Ir) at the CTV was mostly close to 1 when neither 60Co or 192Ir passed their half-lives or when both passed two half-lives, and the difference between them was not significant; at the OARs, the mean value of 60Co was lower than that of 192Ir. There was no statistical difference between 60Co and 192Ir in the EUD (93.93 versus 93.92 Gy, p > 0.05) and TCP (97.07% versus 97.08%, p > 0.05) of the tumors. The mean NTCP value of 60Co was lower than that of 192Ir.

CONCLUSIONS

Considering the CTV and OARs, the dosimetric parameters of 60Co and 192Ir are comparable. Compared with 192Ir, the use of 60Co for HDR IC-ISBT can ensure a similar tumor control probability while providing better protection to the OARs. In addition, 60Co has obvious economic advantages and can be promoted as a good alternative to 192Ir.

Stereotactic Body Radiotherapy Boost with the CyberKnife for Locally Advanced Cervical Cancer: Dosimetric Analysis and Potential Clinical Benefits

(1) Aim: To compare the treatment plans of stereotactic body radiotherapy (SBRT) with CyberKnife (CK) and high-dose-rate (HDR) intracavitary/interstitial brachytherapy (IC/ISBT) and examine the feasibility of CK-SBRT as a viable alternative to BT in patients with locally advanced cervical cancer (LACC). (2) Methods: A BT plan of 28 Gy in four fractions delivered previously to 20 patients with LACC was compared with a CK plan based on the same CT images with structures delineation for BT. The SBRT treatment plan was further divided according to two different approaches, with the high-risk planning target volume (HR-PTV) defined by the high-risk clinical target volume (HR-CTV) without and with a 5 mm margin, which were named CK-CTV plan and CK-PTV plan, respectively. The dose distributions and dosimetric parameters of the target volumes and organs at risk (OARs) were recorded and compared for the three boost plans. Radiobiological metrics were calculated based on the EUD for the hybrid plans. Additionally, the relationship between tumor volume and tolerance doses for the OARs in the BT plan and CK-PTV plan was investigated. (3) Results: Target coverage was better with the CK plan than with the BT plan, as the D95%, D98%, HI and CI of the CK-CTV plan and CK-PTV plan were higher than those of the BT plan; an exception was the D50%. Similarly, the TCP of the target was also significantly in favor of the CK hybrid plans (p < 0.01). For the OARs, the CK-CTV plan was superior to the BT plan as regards the rectum D2cc, bladder D2cc and bladder Dmax. The CK-PTV plan could achieve dosimetric parameters comparable to those of the BT plan for OARs concerning the small residual tumor volume. The NTCP of the rectum for the WPI+CK-CTV plans was significantly lower than that of the WPI+BT plans (p < 0.01). (4) Conclusions: CK-based SBRT can achieve better target coverage, dose sparing for the OARs and radiobiological effects compared with the BT plan for tumors that are not excessively large. CK-based SBRT could be an alternative option to administer a radiation boost for patients with LACC.

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.

Comparative Analysis of 60Co and 192Ir Sources in High Dose Rate Brachytherapy for Cervical Cancer

High-dose-rate (HDR) brachytherapy (BT) is an essential treatment for cervical cancer, one of the most prevalent gynecological malignant tumors. In HDR BT, high radiation doses can be delivered to the tumor target with the minimum radiation doses to organs at risk. Despite the wide use of the small HDR 192Ir source, as the technique has improved, the HDR 60Co source, which has the same miniaturized geometry, has also been produced and put into clinical practice. Compared with 192Ir (74 days), 60Co has a longer half-life (5.3 years), which gives it a great economic advantage for developing nations. The aim of the study was to compare 60Co and 192Ir sources for HDR BT in terms of both dosimetry and clinical treatment. The results of reports published on the use of HDR BT for cervical cancer over the past few years as well as our own research show that this treatment is safe and it is feasible to use 60Co as an alternative source.

ADAPTIVE MAGNETIC RESONANCE-GUIDED EXTERNAL BEAM RADIATION THERAPY FOR CONSOLIDATION IN RECURRENT CERVICAL CANCER

Purpose

Adaptive magnetic resonance (MR)-guided brachytherapy takes an important place as consolidation within the care of cervical malignancies, but may be impracticable in some unusual cases. This work aimed to present the case of adaptive MR-guided external beam radiation therapy (aMRgRT) used as a boost in a recurrence of cervical cancer.

Methods and Materials

We report on a case of a parametrial recurrence in a 31-year-old patient who already underwent a trachelectomy as treatment for her primary growth. After concomitant radio-chemotherapy, a brachytherapy boost was performed. Because of its position in relation to the left uterine artery after trachelectomy, impeding interstitial catheters set up, the relapse was insufficiently covered. With the aim to refine the coverage of target volumes, aMRgRT treatment was undertaken to allow for achievement of the dosimetric goals.

Results

In clinical circumstances where the brachytherapy step was hindered, aMRgRT presents many advantages. First, daily native MR-imaging outperforms usual x-ray imaging in the pelvis, refining repositioning. Second, its specific workflow allows for the performance of adaptive treatment, with consideration of both the inter- and intrafraction motions of organs at risk and target volumes.

Conclusion

In nonfeasible brachytherapy situations, aMRgRT could be a satisfying substitute. Nevertheless, brachytherapy remains the standard of care as a boost in locally advanced cervical cancer.

MR-guided SBRT boost for patients with locally advanced or recurrent gynecological cancers ineligible for brachytherapy: feasibility and early clinical experience

Background and purpose

Chemoradiotherapy (CRT) followed by a brachytherapy (BT) boost is the standard of care for patients with locally advanced or recurrent gynecological cancer (LARGC). However, not every patient is suitable for BT. Therefore, we investigated the feasibility of an MR-guided SBRT boost (MRg-SBRT boost) following CRT of the pelvis.

Material and methods

Ten patients with LARGC were analyzed retrospectively. The patients were not suitable for BT due to extensive infiltration of the pelvic wall (10%), other adjacent organs (30%), or both (50%), or ineligibility for anesthesia (10%). Online-adaptive treatment planning was performed to control for interfractional anatomical changes. Treatment parameters and toxicity were evaluated to assess the feasibility of MRg-SBRT boost.

Results

MRg-SBRT boost was delivered to a median total dose of 21.0 Gy in 4 fractions. The median optimized PTV (PTV_opt) size was 43.5ccm. The median cumulative dose of 73.6Gy₁₀ was delivered to PTV_opt. The cumulative median D2ccm of the rectum was 63.7 Gy; bladder 72.2 Gy; sigmoid 65.8 Gy; bowel 59.9 Gy (EQD2₃). The median overall treatment time/fraction was 77 min, including the adaptive workflow in 100% of fractions. The median duration of the entire treatment was 50 days. After a median follow-up of 9 months, we observed no CTCAE ≥ °II toxicities.

Conclusion

These early results report the feasibility of an MRg-SBRT boost approach in patients with LARGC, who were not candidates for BT. When classical BT-OAR constraints are followed, the therapy was well tolerated. Long-term follow-up is needed to validate the results.

Evaluation of sociodemographic and baseline patient characteristic differences in cervical cancer patients treated with either external beam or brachytherapy boost

PURPOSE

Chemoradiation is considered the standard of care for locally advanced cervical cancer. While brachytherapy (BT) boost is associated with improved survival and less toxicity compared to external beam radiation therapy (EBRT) boost, it is unclear why many patients do not receive a BT boost. In this study, we compared sociodemographic and baseline patient characteristics between patients receiving EBRT boost versus BT boost.

METHODS

We analyzed patients in the National Cancer Database diagnosed between 2004 and 2016 with FIGO stage IIB-IVA cervical cancer treated with nonpalliative doses of chemoradiation. Logistic regression analysis was utilized to evaluate BT utilization over time and by other clinicopathological and sociodemographic factors.

RESULTS

Overall, 5764 patients were evaluated, of which 4937 (86%) underwent BT boost. Using multivariable logistic regression, higher FIGO stage was a significant predictor for utilization of EBRT versus BT boost, with odds ratio 2.92 (95% confidence interval [CI] 2.04-4.16; p < 0.001), 2.68 (95%CI 2.22-3.24; p < 0.001), and 4.51 (95%CI 3.05-6.67; p < 0.001) for IIIA, IIIB, and IVA, respectively, compared to IIB. Increased utilization of EBRT boost was also associated with community cancer facility types, lower income (based on zip code), earlier year of diagnosis, and higher comorbidity score.

CONCLUSIONS

In FIGO stage IIB-IVA cervical cancer patients treated with nonpalliative doses of chemoradiation, overall utilization of BT is 86%. Higher FIGO stage, community cancer facilities, lower income, earlier year of diagnosis, and higher comorbidity score were significant predictors of EBRT boost utilization. Future studies are needed to better understand reasons for this as higher FIGO stage patients are the mostly likely to benefit from a BT boost.

Stereotactic ablative body radiotherapy boost for cervical cancer when brachytherapy boost is not feasible

BACKGROUND

The purpose of this study was to analyze the treatment efficacy and safety of stereotactic ablative body radiotherapy (SABR) boost for cervical cancer patients not amenable to brachytherapy.

METHODS

A retrospective review of the medical records from single institution of 25 eligible patients was performed. The patients underwent pelvic radiotherapy (RT) in 25 or 28 fractions with a median dose of 45 Gy (range 44-50.4 Gy). SABR boost was delivered after pelvic RT, with a median dose of 25 Gy (range 20-33 Gy), and a median fraction number of 5 (range 4-6). 21 patients with a follow-up period of more than one year were included in the toxicity analysis, and hematuria and hematochezia that occurred later than 3 months after the RT were graded.

RESULTS

The median follow-up period after radiotherapy was 2.85 years (range 0.33-6.60). The 3-year local control, locoregional control, disease-free survival, and overall survival rates were 80.9%, 75.8%, 40.9%, and 77.1%, respectively. 5 patients experienced grade 3 toxicity (3 genitourinary, 3 gastrointestinal), and no grade 4-5 toxicity was reported. Univariate analysis showed that cumulative D_2cc in equivalent dose in 2 Gy fractions (EQD2) of rectum was marginally predictive for any grade of hematochezia (P = 0.051). Cumulative D_2cc EQD2 of bladder was not predictive for hematuria. In the receiver operating characteristic (ROC) curve analysis, the optimal threshold of cumulative rectal D_2cc EQD2 was 81.2 Gy for any grade of hematochezia.

CONCLUSION

SABR boost for cervical cancer was effective and tolerable. Although it cannot substitute brachytherapy, it can be a treatment option when brachytherapy is not possible.

Concurrent Taxol-Based Doublet Chemotherapy as an Alternative for Intracavitary Brachytherapy Boost in Locally Advanced Carcinoma Cervix- Retrospective Analysis From a Tertiary Care Center

Objective

In light of the dogma that brachytherapy is irreplaceable for the successful treatment of cervical cancer, and the limited availability of brachytherapy facilities in developing countries, we sought to evaluate the toxicity and efficacy of taxol- and platinum-based doublet chemotherapy delivered concurrently with external beam radiotherapy (EBRT) in locally advanced cervical cancer as an alternative to brachytherapy, which is mandated as the standard of care according to current guidelines.

Methods

The records from our institution were reviewed to identify patients who underwent chemoradiation with two doses of tri-weekly docetaxel (80mg/m2) and carboplatin (AUC 5) concurrent with EBRT between January 2017 and 2019 for locally advanced cervical carcinoma. Here, 48 cases were analysed, with a median follow-up period of two years.

Results

The two groups were homogenously matched, and the patients who received EBRT boost and brachytherapy boost achieved complete pathological response rates of 68% and 83%, respectively (p=0.243). The odds ratio was 0.45 (95% confidence interval, 0.09-2.08), indicative of non-significance and non-inferiority based on the analysis using the chi-squared test (with Pearson’s correlation) and Student's t-test. The disease-free survival durations calculated using Kaplan-Meier estimates were 22 and 24 months, two-year disease-free survival rates were 83% and 91.3%, and two-year overall survival (OS) were 85.6% and 94% for the EBRT boost and brachytherapy boost groups, respectively (p=0.657).

Conclusion

In this retrospective analysis, we concluded that EBRT boost was non-inferior to brachytherapy boost and could be considered as a reasonable alternative in locally advanced cervical cancer when used concurrently with more dose-intense chemotherapy.

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.

Stereotactic Body Radiation Therapy Boost in Patients With Cervical Cancer Ineligible for Brachytherapy

BACKGROUND

Standard treatment for locally advanced cervical cancer is external beam radiotherapy followed by brachytherapy (BT). Stereotactic body radiation therapy (SBRT) is a possible option for treating patients ineligible for BT.

PATIENTS AND METHODS

From October 2012 to July 2020, nine women with cervical cancer received SBRT to high-risk volumes. The Kaplan-Meier method was used to estimate the rates of overall and disease-free survival.

RESULTS

The median age was 52 years; 88% of patients had squamous carcinoma. Reasons for forgoing BT were cervical canal stenosis, treatment refusal and hematological disease. The median boost dose was 18 Gy and the median dose per fraction was 6 Gy. Median follow-up was 16 months. The median survival was 24 months, the actuarial 2-year OS rate was 70%, and median disease-free survival was 11 months. One grade 3 late vaginal toxicity was reported. No acute nor late grade 4 toxicities were observed.

CONCLUSION

SBRT boost in patients with cervical cancer ineligible for BT led to acceptable survival outcomes and a safe toxicity profile.

Brachytherapy or external beam radiotherapy as a boost in locally advanced cervical cancer: a Gynaecology Study Group in the Italian Association of Radiation and Clinical Oncology (AIRO) review

This review analyzes the experience and trends in external beam radiotherapy for delivering a boost in locally advanced cervical cancer, identifying whether radiation therapy modalities impact clinical outcomes with the ultimate aim of evaluating alternatives to brachytherapy. Three independent Italian radiation oncologists conducted a literature search on different external beam radiotherapy boost modalities in locally advanced cervical cancer. The search yielded 30 studies. Eight dosimetric studies, evaluating target coverage and dose to organs at risk, and nine clinical investigations, reporting clinical outcomes, were analyzed. Dosimetric studies comparing external beam radiotherapy boost with brachytherapy produced divergent results, while clinical studies were limited by their retrospective nature, heterogeneous doses, radiation schedules, volumes and techniques, diverse follow-up times, and small cohorts of patients. Evidence emerged that high-tech external beam radiotherapy seemed no better than image-guided brachytherapy for delivering a boost in locally advanced cervical cancer. Prospective clinical studies comparing high-tech external beam radiotherapy and image-guided brachytherapy should be encouraged.

Long-term results of robotic radiosurgery for non brachytherapy patients with cervical cancer

BACKGROUND

Consolidation brachytherapy is a critical treatment component for cervical cancer patients undergoing primary chemoradiation. Some patients are unsuitable for brachytherapy for a variety of reasons. The use of alternatives (LINAC-based stereotactic radiosurgery or external beam boosts) compromise oncologic results in cervical cancer patients. Thus, we evaluated the value of brachytherapy-like doses prescriptions using robotic radiosurgery (CyberKnife®, CR, Acuuray, Sunnyvale, CA, USA).

METHODS

From 06/2011 to 06/2015, 31 patients (median age 53 years; range 30-77 years) with histologically proven FIGO stages IB-IVB cervical cancer underwent primary chemoradiation. All patients were either not suitable for intracervical brachytherapy for a variety of reasons or refused the brachytherapy. To achieve an adequate dose within the tumor, a CK boost was applied after fiducial implantation. In 29 patients, a dose of either five times 6 Gy or five times 5 Gy was prescribed to the target volume. Two patients received three times 5 Gy. The target dose was prescribed to the 70% isodose. Treatment toxicity was documented once weekly regarding vaginal mucositis, bladder, and bowel irritation according to CTCAE v. 4.03. If possible 3 months after completion of treatment intracervical curettage was performed to exclude residual tumor and the patients were followed up clinically. Sparing of organs at risk (OAR) and outcome in terms of local control (LC), overall survival (OS), and progression-free survival (PFS) were assessed.

RESULTS

Of the 31 patients, 30 have completed CK boost therapy. The median follow-up time was 40 months (range 5-84 months). General treatment tolerability was good. Except for 1 patient, who had diarrhea grade 3, no treatment related side effects above grade 2 were reported. Sparing of OAR was excellent. The 1‑, 3‑, and 5‑year OS rates were 89, 60, and 57% respectively across all stages. Seven patients showed progression (28%), only two of them with local relapse (8%), resulting in an LC rate of 92% after 3 and 5 years. Mean PFS was 41 months (range 2-84 months). Patients with local recurrence had PFS of 5 and 8 months. Five patients developed distant metastases. Fifteen patients (48%) underwent intracervical curettage 3 months after completion of treatment of which 14 (93%) had complete pathologic response.

CONCLUSION

Brachytherapy remains the standard of care for patients diagnosed with cervical cancer and indication for primary chemoradiation. In terms of local control, CyberKnife®-based boost concepts provide excellent local control. It can be an alternative for patients who cannot receive adequate brachytherapy. Distant relapse still remains a challenge in this context.

Intensity modulated radiation therapy boost in locally-advanced cervical cancer in the absence of brachytherapy

OBJECTIVE

Standard treatment in locally-advanced cervical cancer is external beam radiotherapy concomitant with platinum-based chemotherapy, followed by brachytherapy. The goal of our study was to determine whether an intensity modulated radiation therapy (IMRT) boost is feasible in patients unfit for brachytherapy.

METHODS

We retrospectively analyzed data of 25 patients unfit for brachytherapy with median age 55 years (range, 30-82) with locally-advanced/metastatic cervical cancer who underwent external beam radiotherapy to pelvis ±para-aortic lymph nodes and sequential IMRT boost between July 2014 and December 2017. Total dose of 45-50.4 Gy in 25-28 fractions (1.8 Gy/fraction) was administered to the cervix, uterus, parametria, ovaries, vaginal tissues (based on vaginal extension), involved lymph nodes, or relevant draining lymph-nodal groups. Para-aortic nodes were included if involved at radiological staging or if common iliac nodes were positive. The IMRT boost included all residual tumor after external beam radiotherapy identified on MRI. The Kaplan-Meier method was used to calculate 2 years' overall survival, 2 years' progression-free survival, and 2 years' local control. Overall survival- and progression-free survival were calculated considering the starting of radiotherapy or neo-adjuvant chemotherapy if prescribed, while local control was calculated from the end of radiotherapy.

RESULTS

Median radiation dose to pelvis ±para-aortic lymph nodes was 50.4 Gy (45-50.4), boost treatment was homogeneously performed to a total dose of 25 Gy in five fractions every other day.After a median follow-up of 26 months (range, 4-77), tumor persistence at cervix at 6 months from the end of radiotherapy or local recurrence occurred in five women (20%), eight (32%) experienced a further distant progression (two of them had also tumor persistence). Two-year local control and overall survival rates for all stages were 78% and 67%, respectively. According to Common Terminology Criteria for Adverse Events v.4 scoring criteria, 10 patients experienced gastrointestinal and/or genitourinary grade G1-2 acute toxicity. G2 rectal late toxicity requiring laser-coagulation was registered in two patients, there were no gastrointestinal and/or genitourinary acute or late toxicities≥G3.

CONCLUSION

The combination of external beam radiotherapy and brachytherapy remains the standard of care, however our preliminary data show the feasibility of IMRT boost in terms of toxicity with promising results in terms of local control and overall survival.

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.

What is the evidence for the clinical value of SBRT in cancer of the cervix?

AIM

The aim of this review is to describe and analyze indications and results of the use of SBRT in uterine cervix cancer, reviewing articles published from January 2010 up to August 2017, for any one of the four indications listed:1Patient refusal or anatomic impediments to interstitial or intracavitary brachytherapy (BCT), i.e. SBRT as an "alternative" for BCT;2Patients with voluminous tumors, or asymmetric tumors where BCT alone would not achieve curative doses, i.e. SBRT as a primary adjunct to BCT;3Pelvic and para aortic adenopathy where SBRT could be used as a boost, i.e. SBRT as a primary adjunct to external beam pelvic radiotherapy;4Small volume recurrences (postoperative or post radiotherapy), i.e. SBRT for salvage.

BACKGROUND

Cervix cancer standard treatment involves pelvic irradiation and chemotherapy, recent advances in irradiation techniques might offer new possible approaches.

MATERIAL AND METHODS

Systematic review of the English language literature about Cervix cancer, SBRT, published from January 2010 to January 2018 identified through a database search of PubMed, and Ovid MEDLINE, using pre-defined search phrases.

RESULTS

The results in the literature, in general, demonstrate rather weak efficacy of SBRT. In this review, we did not find strong evidence to recommend routine SBRT as a primary treatment for cervico-uterine cancers, i.e. as a replacement for BCT; in highly selected cases it might be considered useful as salvage therapy for relapsed cervix cancer.

CONCLUSION

The existing data to not warrant recommending SBRT for the definitive treatment of cervix cancer, but may have some value in the recurrent/relapsed setting.

The Potential Value of MRI in External-Beam Radiotherapy for Cervical Cancer

The reference standard treatment for cervical cancer is concurrent chemoradiotherapy followed by magnetic resonance imaging (MRI)-guided brachytherapy. Improvements in brachytherapy have increased local control rates, but late toxicity remains high with rates of 11% grade ≥3. The primary clinical target volume (CTV) for external-beam radiotherapy includes the cervix and uterus, which can show significant inter-fraction motion. This means that generous margins are required to cover the primary CTV, increasing the radiation dose to organs at risk and, therefore, toxicity. A number of image-guided radiotherapy techniques (IGRT) have been developed, but motion can be random and difficult to predict prior to treatment. In light of the development of integrated MRI linear accelerators, this review discusses the potential value of MRI in external-beam radiotherapy. Current solutions for managing pelvic organ motion are reviewed, including the potential for online adaptive radiotherapy. The impacts of the use of MRI in tumour delineation and in the delivery of stereotactic ablative body radiotherapy (SABR) are highlighted. The potential role and challenges of using multi parametric MRI to guide radiotherapy are also discussed.

Radiobiological considerations in combining doses from external beam radiotherapy and brachytherapy for cervical cancer

The recommended radio-therapeutic treatment for cervix cancer consists of a first phase of external beam radiotherapy (EBRT) plus a second phase of brachytherapy (BT), the combined treatment being delivered within 8 weeks. In order to assess a comprehensive dosimetry of the whole treatment, it is necessary to take into account that these two phases are characterized by different spatial and temporal dosimetric distributions, which complicates the task of the summation of the two contributions, EBRT and BT. Radiobiology allows to tackle this issue pragmatically by means of the LQ model and, in fact, this is the usual tool currently in use for this matter. In this work, we describe the rationale behind the summation of the dosimetric contributions of the two phases of the treatment, EBRT and BT, for cervix cancer, as carried out with the LQ model. Besides, we address, from a radiobiological point of view, several important considerations regarding the use of the LQ model for this task. One of them is the analysis of the effect of the overall treatment time in the result of the global treatment. Another important question considered is related to the fact that the capacity of LQ to predict the treatment outcomes is deteriorated when the dose per fraction of the radiotherapic scheme exceeds 6-10 Gy, which is a typical brachytherapy fractionation. Finally, we analyze the influence of the uncertainty and the variability of the main parameters utilized in the LQ model formulation in the assessment of the global dosimetry.

Chemoradiotherapy completion and neutropenia risk in HIV patients with cervical cancer

Cervical cancer (CC) is one of the acquired immunodeficiency syndrome (AIDS) defining diseases and the human immunodeficiency virus (HIV) infection is thought to relate with increased acute toxicity of chemoradiotherapy (CRT).We investigated the effect of HIV status in the incidence of neutropenia associated with cisplatin-based CRT for CC and its impact in treatment completion.This is a single-center retrospective cohort study. Data collection was performed for all the consecutive stage Ib-IV CC women treated with cisplatin-based CRT from 2012 to 2016, and with known HIV status.Sixty-one patients were included, 6 were HIV+. HIV+ patients had a higher risk of neutropenia at any cycle during cisplatin CRT [adjusted odds ratio (OR) 7.3, 95% confidence interval (95% CI) 1.02-52.3; P = .05]. Despite the absolute differences, mean neutrophil count was nonsignificantly lower in HIV+ women, both at baseline [4455/μL (interquartile range, IQR: 1830-6689) vs 6340 (IQR: 1720-18,970) for HIV-, P = .98] and at the end of treatment [1752/μL (IQR: 1100-2930) vs 3147/μL (IQR: 920-18,390) in HIV-; P = .06]. Moreover, when considering the effect of time, CRT seems to induce a consistent drop of neutrophils in both groups (P = .229). No febrile neutropenia events occurred.In HIV+ women, there were more CT cycle delays (P = .013), patients were more prone to use granulocyte colony-stimulating factor (G-CSF; HIV+ 40.0% vs HIV- 4.0%; P = .04) and less likely to complete at least 5 cycles of cisplatin (P = .02). All patients received adequate dose of pelvic RT, regardless of HIV status.HIV+ patients have a significantly increased risk of neutropenia during CRT treatment for CC and are less likely to complete chemotherapy with cisplatin.

Dosimetric Comparison of Pencil-Beam Scanning and Photon-Based Radiation Therapy as a Boost in Carcinoma of Cervix

Purpose

Brachytherapy is essential for local treatment in cervical carcinoma, but some patients are not suitable for it. Presently, for these patients, the authors prefer a boost by using intensity-modulated radiation therapy (IMRT). The authors evaluated the dosimetric comparison of proton-modulated radiation therapy versus IMRT and volumetric-modulated arc therapy (VMAT) as a boost to know whether protons can replace photons.

Patients and Methods

Five patients who received external beam radiation therapy to the pelvis by IMRT were reviewed. Three different plans were made, including pencil beam scanning (PBS), IMRT, and VMAT. The prescribed planning target volume (PTV) was 20 Gy in 4 fractions. The dose to 95% PTV (D_95%), the conformity index, and the homogeneity index were evaluated for PTV. The D_max, D_2cc, and D_mean were evaluated for organs at risk along with the integral dose of normal tissue and organs at risk.

Results

The PTV coverage was optimal and homogeneous with modulated protons and photons. For PBS, coverage D_95% was 20.01 ± 0.02 Gy (IMRT, 20.08 ± 0.06 Gy; VMAT, 20.1 ± 0.04 Gy). For the organs at risk, D_max of the bladder for PBS was 21.05 ± 0.05 Gy (IMRT, 20.8 ± 0.21 Gy; VMAT, 21.65 ± 0.41 Gy) while the D_max for the rectum for PBS was 21.04 ± 0.03 Gy (IMRT, 20.81 ± 0.12 Gy; VMAT, 21.66 ± 0.38 Gy). Integral dose to normal tissues in PBS was 14.17 ± 2.65 Gy (IMRT, 25.29 ± 6.35 Gy; VMAT, 25.24 ± 6.24 Gy).

Conclusions

Compared with photons, modulated protons provide comparable conformal plans. However, PBS reduces the integral dose to critical structures significantly compared with IMRT and VMAT. Although PBS may be a better alternative for such cases, further research is required to substantiate such findings.

External beam techniques to boost cervical cancer when brachytherapy is not an option-theories and applications

The management of locally advanced cervical cancer relies on brachytherapy (BT) as an integral part of the radiotherapy delivery armamentarium. Occasionally, intracavitary BT is neither possible nor available. In these circumstances, post-external beam radiotherapy (EBRT) interstitial brachytherapy and/or hysterectomy may represent viable options that must be adequately executed in a timely manner. However, if these options are not applicable due to patient related or facility related reasons, a formal contingency plan should be in place. Innovative EBRT techniques such as intensity modulated and stereotactic radiotherapy may be considered for patients unable to undergo brachytherapy. Relying on provocative arguments and recent data, this review explores the rationale for and limitations of non-brachytherapy substitutes in that setting aiming to establish a formal process for the optimal execution of this alternative plan.

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

Purpose

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

Material and methods

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

Results

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

Conclusions

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

Weekly Cisplatin and Volumetric-Modulated Arc Therapy With Simultaneous Integrated Boost for Radical Treatment of Advanced Cervical Cancer in Elderly Patients: Feasibility and Clinical Preliminary Results

BACKGROUND

To evaluate the feasibility and clinical preliminary results of weekly cisplatin and volumetric-modulated arc therapy to the pelvis with simultaneous integrated boost to macroscopic disease in a cohort of elderly patients.

MATERIALS AND METHODS

Inclusion criteria of this prospective study were age ≥70 years, Karnofsky performance status 70 to 100, locally advanced histologically proven squamous cervical carcinoma, and patients unable to undergo brachytherapy. Radiation doses prescribed were 66 Gy to the macroscopic disease and 54 Gy to the pelvic nodes in 30 fractions. Weekly cisplatin dose was 40 mg/mq.

RESULTS

A total of 30 patients were recruited. Median follow-up was 32 months (range: 8-48 months). Median age was 72 years (range: 70-84 years). The 3-year overall survival and local control were 93% and 80%, respectively. The median time to progression was 24 months (range: 6-30 months). Analyzing clinical outcome grouping based on the stage of disease, II versus III, the 3-year overall survival was 100% and 85%, respectively. The 3-year local control was 91% for stage II and 67% for stage III. Acute and late toxicities were acceptable without severe events.

CONCLUSION

Weekly cisplatin and volumetric-modulated arc therapy-simultaneous integrated boost for radical treatment of advanced cervical cancer in the current cohort of elderly patients were feasible. Long-term results and prospective randomized trials are advocated.

Long-term follow-up results of simultaneous integrated or late course accelerated boost with external beam radiotherapy to vaginal cuff for high risk cervical cancer patients after radical hysterectomy

BACKGROUND

To assess the safety and efficacy of simultaneous integrated boost (SIB) or late course accelerated boost (LCAB) with external beam radiotherapy (EBRT) to the vaginal cuff for high risk cervical cancer patients after radical hysterectomy.

METHODS

Between October 2009 and January 2012, patients with high risk cervical cancer who had undergone radical surgery followed by EBRT to the vaginal cuff were enrolled. Patients were treated with either intensity modulated radiotherapy (IMRT)/volumetric modulated arc therapy (VMAT) with SIB (arm A) or IMRT/VMAT to the pelvis followed by LCAB (arm B) to vaginal cuff. In arm A, the pelvic and boost doses were 50.4 Gy and 60.2 Gy in 28 fractions, respectively. In arm B, pelvic irradiation to 50 Gy in 25 fractions followed by a boost of 9 Gy in 3 fractions were delivered. Chemotherapy was given concurrently.

RESULTS

Overall, 80 patients were analyzed in this study (42 in arm A, 38 in arm B). In arm A and B, median follow-up was 37 and 32 months, respectively. The 3-year disease-free survival and overall survival in arms A vs B were 88.7% vs. 93.4% (p = 0.89), and 91.8% vs.100% (p = 0.21), respectively. The 3-year local-regional control and distant failure were 97.6% vs. 100% (p = 0.34), and 4.8% vs. 5.3% (p = 0.92), respectively. Grade 3-4 acute leukopenia and dermatitis were seen in 11 (26.2%) and 8 (19.0%) patients in Arm A, vs. 7 (17.8%) and 6 (15.8%) patients in Arm B, respectively (p > 0.05). Only Grade 1-2 chronic gastrointestinal (GI) and genitourinary (GU) toxicities were observed.

CONCLUSIONS

Our results indicate that both SIB and LCAB to vaginal cuff for high risk cervical cancer patients after radical hysterectomy are associated with excellent survival, local control and low toxicity.

VMAT for the treatment of gynecologic malignancies for patients unable to receive HDR brachytherapy

This investigation studies the use of volumetric-modulated arc therapy (VMAT) to deliver the following conceptual gynecological brachytherapy (BT) dose distributions: Type 1, traditional pear-shaped dose distribution with substantial dose gradients; Type 2, homogeneous dose distribution throughout PTV (BT prescription volume); and Type 3, increased dose to PTV without organ-at-risk (OAR) overdose. A tandem and ovoid BT treatment plan, with the prescription dose of 6 Gy to point A, was exported into the VMAT treatment planning system (TPS) and became the baseline for comparative analysis. The 200%, 150%, 130%, 100%, 75%, and 50% dose volumes were converted into structures for optimization and evaluation purposes. The 100% dose volume was chosen to be the PTV. Five VMAT plans (Type 1) were created to duplicate the Ir-192 tandem and ovoid inhomogeneous dose distribution. Another five VMAT plans (Type 2) were generated to deliver a homogeneous dose of 6 Gy to the PTV. An additional five VMAT plans (Type 3) were created to increase the dose to the PTV with a homogeneous dose distribution. In the first set of plans, the dose given to 99% of the 200%-100% dose volumes agreed within 2% of the BT plan on average. Additionally, it was found that the 75% dose volumes agreed within 5% of the BT plan and the 50% dose volumes agreed within 6.4% of the BT plan. In the second set of comparative analyses, the 100% dose volume was found to be within 1% of the original plan. Furthermore, the maximum increase of dose to the PTV in the last set of comparative analyses was 8 Gy with similar doses to OARs as the other VMAT plans. The maximum increase of dose was 2.50 Gy to the rectum and the maximum decrease of dose was 0.70 Gy to the bladder. Henceforth, VMAT was successful at reproducing brachytherapy dose distributions demonstrating that alternative dose distributions have the potential to be used in lieu of brachytherapy. It should also be noted that differences in radiobiology need to be further investigated.

Role of stereotactic radiosurgery in gynecologic cancer

PURPOSE OF REVIEW

This current work offers an opinion on the evidence accumulated in humans regarding stereotactic ablative radiation (SABR) therapy, a favorable option for the treatment of persistent or recurrent metastatic gynecologic cancers.

RECENT FINDINGS

SABR precisely and accurately kills cancer cells, making durable disease control possible. This article evaluates SABR's clinical performance and the variations in the main components of SABR technology, such as target localization and radiation beam collimation coupled with respiratory motion tracking, in the context of their contribution to the banked clinical successes in gynecologic radiation oncology.

SUMMARY

In an era of patient requests for short radiotherapy courses, SABR now provides well tolerated and efficacious treatment for women with gynecologic cancers.

Robotic radiosurgery as an alternative to brachytherapy for cervical cancer patients

BACKGROUND AND PURPOSE

To compare MRI-guided brachytherapy (BT) and two different dose prescriptions for robotic radiosurgery (RRS) in locally advanced cervical cancer.

METHODS AND MATERIALS

Eleven patients with FIGO stage IIB-IIIB cervical cancer underwent RRS instead of BT for various reasons. A total dose of 30 Gy was administered in five fractions. The maximum dose was chosen such that the prescribed dose was 70 % of the maximum dose (RRS70). To simulate BT more closely, additional plan calculations were carried out for a higher maximum dose with the same enclosing dose of 30 Gy being now 25 % of the maximum dose (RRS25). BT plans were calculated for the same patients (BTRRS). Finally, the resulting three sets of treatment plans were compared with 38 other patients treated with MRI-guided BT and the same dose prescription (BTref). Plan comparisons were performed based on DVH parameters with regard to target coverage (V100), conformation number (CN), and sparing of the organs at risk (OARs).

RESULTS

The best coverage of V100 = 100 ± 0 % was obtained with RRS25, followed by RRS70 with 97.1 ± 2.7 %, BTref with 90.9 ± 8.9 %, and the intraindividual BTRRS with 80.6 ± 6.4 %. The sparing of OARs was associated with D0.1 cc, D2 cc, and D5 cc to the rectum, sigmoid, and bladder walls. OAR doses were compliant with the GEC-ESTRO guidelines and comparable among RRS70, RRS25, BTRRS, and BTref. By contrast, RRS25 could not fulfill these guidelines, exceeding considerably the tolerable dose constraints for the walls of the critical OARs.

CONCLUSION

Despite of the excellent coverage and higher maximum dose, the unacceptably high exposure to the OARs disqualified RRS25 as an alternative for BT in cervical cancer patients. By contrast, RRS70 offered the best protection for the OARs, comparable to BT, and even better target coverage and conformity than BT.

Intensity modulated proton beam radiation for brachytherapy in patients with cervical carcinoma

PURPOSE

To evaluate intensity modulated proton therapy (IMPT) in patients with cervical cancer in terms of coverage, conformity, and dose-volume histogram (DVH) parameters correlated with recommendations from magnetic resonance imaging (MRI)-guided brachytherapy.

METHODS AND MATERIALS

Eleven patients with histologically proven cervical cancer underwent primary chemoradiation for the pelvic lymph nodes, the uterus, the cervix, and the parametric region, with a symmetric margin of 1 cm. The prescription was for 50.4 Gy, with 1.8 Gy per fraction. The prescribed dose to the parametria was 2.12 Gy up to 59.36 Gy in 28 fractions as a simultaneous boost. For several reasons, the patients were unable to undergo brachytherapy. As an alternative, IMPT was planned with 5 fractions of 6 Gy to the cervix, including the macroscopic tumor with an MRI-guided target definition, with an isotropic margin of 5 mm for planning target volume (PTV) definition. Groupe-Europeen de Curietherapie and European society for Radiotherapy and Oncology (GEC-ESTRO) criteria were used for DVH evaluation. Reference comparison plans were optimized for volumetric modulated rapid arc (VMAT) therapy with the RapidArc (RA).

RESULTS

The dose to the high-risk volume was calculated with α/β = 10 with 89.6 Gy. For IMPT, the clinical target volume showed a mean dose of 38.2 ± 5.0 Gy (35.0 ±1.8 Gy for RA). The D98% was 31.9 ± 2.6 Gy (RA: 30.8 ± 1.0 Gy). With regard to the organs at risk, the 2Gy Equivalent Dose (EQD2) (α/β = 3) to 2 cm(3) of the rectal wall, sigmoid wall, and bladder wall was 62.2 ± 6.4 Gy, 57.8 ± 6.1 Gy, and 80.6 ± 8.7 Gy (for RA: 75.3 ± 6.1 Gy, 66.9 ± 6.9 Gy, and 89.0 ± 7.2 Gy, respectively). For the IMPT boost plans in combination with external beam radiation therapy, all DVH parameters correlated with <5% risk for grades 2 to 4 late gastrointestinal and genitourinary toxicity.

CONCLUSION

In patients who are not eligible for brachytherapy, IMPT as a boost technique additionally to external beam radiation therapy provides good target coverage and conformity and superior DVH parameters, compared with recommendations to MRI-guided brachytherapy. For selected patients, IMPT might be a valid alternative to brachytherapy and also superior to reference VMAT plans.

Stereotactic body radiotherapy as an alternative to brachytherapy in gynecologic cancer

Introduction. Brachytherapy plays a key role in the treatment of many gynecologic cancers. However, some patients are unable to tolerate brachytherapy for medical or other reasons. For these patients, stereotactic body radiotherapy (SBRT) offers an alternative form of treatment. Methods. Retrospective review of patients prospectively collected on SBRT database is conducted. A total of 11 gynecologic patients who could not have brachytherapy received SBRT for treatment of their malignancies. Five patients have been candidates for interstitial brachytherapy, and six have required tandem and ovoid brachytherapy. Median SBRT dose was 25 Gy in five fractions. Results. At last followup, eight patients were alive, and three patients had died of progressive disease. One patient had a local recurrence. Median followup for surviving patients was 420 days (median followup for all patients was 120 days). Two patients had acute toxicity (G2 dysuria and G2 GI), and one patient had late toxicity (G3 GI, rectal bleeding requiring cauterization). Conclusions. Our data show acceptable toxicity and outcome for gynecologic patients treated with SBRT who were unable to receive a brachytherapy boost. This treatment modality should be further evaluated in a phase II study.

Brachytherapy-emulating robotic radiosurgery in patients with cervical carcinoma

PURPOSE

To evaluate the technique, dosimetry, dose-volume-histograms (DVHs) and acute toxicity for CyberKnife® boost irradiation instead of intra-cervical brachytherapy in patients with cervical cancer.

METHODS AND MATERIALS

Eleven who were not suitable for brachytherapy with FIGO stage IIB-IIIB cervical cancer underwent primary chemoradiation. After fiducial implantation, T2 contrast-enhanced planning MRI and CT scans at 2-mm slice thickness were collected in the treatment position. The clinical target volume was defined as cervix + macroscopic residual tumour on MRI. Five fractions of 6 Gy each were prescribed to the target volume with a covering single dose 6 Gy. DVH parameters were evaluated for the target and organs at risk. Acute toxicity was documented once a week.

RESULTS

DmeanPTV ranged from 33.6-40 Gy, median 36.7 Gy with a coverage of the PTV calculated to 100% of the prescribed dose ranging from 93.0-99.3% (median 97.7%). For the PTV the median CN was 0.78 (range, 0.66 to 0.87) and the median CI was 1.28 (range 1.15 to 1.52). Gastrointestinal (GI) and genitourinary (GU) toxicity was mild. There was no grade 3 or higher GI and GU toxicity. After 6 months of follow up, there were no local recurrences. For the complete treatment, a median EQD2 to 1 cc and 2 cc of the bladder wall was 98.8 Gy and 87.1 Gy, respectively. Median EQD2 to 1 cc and 2 cc of the rectal wall was 72.3 Gy and 64 Gy, respectively, correlating with a risk < 10% for Grade 2-4 late toxicity.

CONCLUSIONS

CyberKnife robotic radiosurgery in patients with cervical cancer provides excellent target coverage with steep dose gradients toward normal tissues and safe DVH parameters for bladder, rectum and sigmoid. Acute toxicity was mild. Longer follow-up is needed to evaluate the oncological equality.

Intraoperative Ultrasound Guidance During Intracavitary Brachytherapy Applicator Placement in Cervical Cancer: The University of Alabama at Birmingham Experience

Objective

The objective of this study was to evaluate the University of Alabama at Birmingham experience with routine intraoperative ultrasound (IUS)–guided tandem placement for cervical cancer.

Methods

Between 1999 and 2008, 243 cervical cancer patients underwent IUS-guided tandem placement. One hundred thirty-nine patients received low-dose-rate brachytherapy, and 104 received high-dose-rate brachytherapy. Three hundred fifty-six IUS-guided procedures were performed. Clinical and imaging data were retrospectively analyzed to evaluate complications requiring reinsertion of tandem placement in the context of IUS.

Results

All 243 cervical cancer patients completed intracavitary brachytherapy. Five (1.4%) of 356 IUS-guided applicator placements resulted in uterine perforation. All of these patients underwent successful tandem insertion on the second attempt, and no significant clinical sequelae occurred. Intraoperative ultrasound enabled direct uterine visualization and facilitated real-time feedback for selection of a suitable tandem length and curvature; no suboptimal placements requiring return to the operating room occurred (excluding perforation).

Conclusions

In this large series, IUS guidance substantially increased the rate of successful applicator placement and diminished the rate of uterine perforation relative to historical controls. We strongly recommend the use of IUS guidance during operative intrauterine tandem placement for cervical cancer.

Stereotactic body radiation therapy via helical tomotherapy to replace brachytherapy for brachytherapy-unsuitable cervical cancer patients - a preliminary result

Aim

To review the experience and to evaluate the results of stereotactic body radiation therapy (SBRT) via helical tomotherapy (HT), for the treatment of brachytherapy-unsuitable cervical cancer.

Methods

Between September 1, 2008 to January 31, 2012, nine cervical cancer patients unsuitable for brachytherapy were enrolled. All of the patients received definitive whole pelvic radiotherapy with or without chemotherapy, followed by SBRT via HT.

Results

The actuarial locoregional control rate at 3 years was 78%. The mean biological equivalent dose in 2-Gy fractions of the tumor, rectum, bladder, and intestines was 76.0 ± 7.3, 73.8 ± 13.2, 70.5 ± 10.0, and 43.1 ± 7.1, respectively. Only two had residual tumors after treatment, and the others were tumor-free. Two patients experienced grade 3 acute toxicity: one had diarrhea; and another experienced thrombocytopenia. There were no grade 3 or 4 subacute toxicities. Three patients suffered from manageable rectal bleeding in months 11, 14, and 25, respectively. One stage I VA patient experienced fistula formation in month 3.

Conclusion

SBRT via HT provides the possibility for treatment of locally advanced cervical cancer in patients who are unsuitable for brachytherapy. Long-term follow up and enrollment of more such patients to receive SBRT via the HT technique are warranted.

Retrospective feasibility study of simultaneous integrated boost in cervical cancer using Tomotherapy: the impact of organ motion and tumor regression

Background

Whole pelvis intensity modulated radiotherapy (IMRT) is increasingly being used to treat cervical cancer aiming to reduce side effects. Encouraged by this, some groups have proposed the use of simultaneous integrated boost (SIB) to target the tumor, either to get a higher tumoricidal effect or to replace brachytherapy. Nevertheless, physiological organ movement and rapid tumor regression throughout treatment might substantially reduce any benefit of this approach.

Purpose

To evaluate the clinical target volume - simultaneous integrated boost (CTV-SIB) regression and motion during chemo-radiotherapy (CRT) for cervical cancer, and to monitor treatment progress dosimetrically and volumetrically to ensure treatment goals are met.

Methods and materials

Ten patients treated with standard doses of CRT and brachytherapy were retrospectively re-planned using a helical Tomotherapy - SIB technique for the hypothetical scenario of this feasibility study. Target and organs at risk (OAR) were contoured on deformable fused planning-computed tomography and megavoltage computed tomography images. The CTV-SIB volume regression was determined. The center of mass (CM) was used to evaluate the degree of motion. The Dice’s similarity coefficient (DSC) was used to assess the spatial overlap of CTV-SIBs between scans. A cumulative dose-volume histogram modeled estimated delivered doses.

Results

The CTV-SIB relative reduction was between 31 and 70%. The mean maximum CM change was 12.5, 9, and 3 mm in the superior-inferior, antero-posterior, and right-left dimensions, respectively. The CTV-SIB-DSC approached 1 in the first week of treatment, indicating almost perfect overlap. CTV-SIB-DSC regressed linearly during therapy, and by the end of treatment was 0.5, indicating 50% discordance. Two patients received less than 95% of the prescribed dose. Much higher doses to the OAR were observed. A multiple regression analysis showed a significant interaction between CTV-SIB reduction and OAR dose increase.

Conclusions

The CTV-SIB had important regression and motion during CRT, receiving lower therapeutic doses than expected. The OAR had unpredictable shifts and received higher doses. The use of SIB without frequent adaptation of the treatment plan exposes cervical cancer patients to an unpredictable risk of under-dosing the target and/or overdosing adjacent critical structures. In that scenario, brachytherapy continues to be the gold standard approach.

The departmental impact of magnetic resonance imaging in the management of cervical cancer brachytherapy: a discussion paper

This discussion paper will explore the impact of using Magnetic Resonance Imaging (MRI) in the treatment of cervical cancer with brachytherapy. It is written from the perspective of current departmental practice in the UK and aims to highlight the issues associated with using MRI as a tool for image guided brachytherapy planning. To support the discussion, a literature review was undertaken focussing specifically on the use of MRI in brachytherapy treatment planning for cervical cancer. Results from planning case studies and clinical series were analysed, and the literature showed that image guided brachytherapy treatment planning is a promising development. MRI assisted planning could theoretically be implemented in centres that have access to a MRI scanner. Alternative brachytherapy technologies (e.g. Computed Tomography (CT) assisted planning), and alternative radiotherapy modalities (e.g. an external beam radiotherapy boost), were not found to be superior in effect or of implementation. Although MRI shows great promise, the evidence base for MRI in brachytherapy planning for cervical cancer is currently limited and therefore careful implementation and evaluation is required. It is suggested by the authors that new methods of working are devised to ensure consistency and quality in implementation and delivery, and that outcomes are measured and audited to evaluate efficacy.

CyberKnife Boost for Patients with Cervical Cancer Unable to Undergo Brachytherapy

Standard radiation therapy for patients undergoing primary chemosensitized radiation for carcinomas of the cervix usually consists of external beam radiation followed by an intracavitary brachytherapy boost. On occasion, the brachytherapy boost cannot be performed due to unfavorable anatomy or because of coexisting medical conditions. We examined the safety and efficacy of using CyberKnife stereotactic body radiotherapy (SBRT) as a boost to the cervix after external beam radiation in those patients unable to have brachytherapy to give a more effective dose to the cervix than with conventional external beam radiation alone. Six consecutive patients with anatomic or medical conditions precluding a tandem and ovoid boost were treated with combined external beam radiation and CyberKnife boost to the cervix. Five patients received 45 Gy to the pelvis with serial intensity-modulated radiation therapy boost to the uterus and cervix to a dose of 61.2 Gy. These five patients received an SBRT boost to the cervix to a dose of 20 Gy in five fractions of 4 Gy each. One patient was treated to the pelvis to a dose of 45 Gy with an external beam boost to the uterus and cervix to a dose of 50.4 Gy. This patient received an SBRT boost to the cervix to a dose of 19.5 Gy in three fractions of 6.5 Gy. Five percent volumes of the bladder and rectum were kept to ≤75 Gy in all patients (i.e., V75 Gy ≤ 5%). All of the patients remain locally controlled with no evidence of disease following treatment. Grade 1 diarrhea occurred in 4/6 patients during the conventional external beam radiation. There has been no grade 3 or 4 rectal or bladder toxicity. There were no toxicities observed following SBRT boost. At a median follow-up of 14 months, CyberKnife radiosurgical boost is well tolerated and efficacious in providing a boost to patients with cervix cancer who are unable to undergo brachytherapy boost. Further follow-up is required to see if these results remain durable.

Should helical tomotherapy replace brachytherapy for cervical cancer? Case report

BACKGROUND

Stereotactic body radiation therapy (SBRT) administered via a helical tomotherapy (HT) system is an effective modality for treating lung cancer and metastatic liver tumors. Whether SBRT delivered via HT is a feasible alternative to brachytherapy in treatment of locally advanced cervical cancer in patients with unusual anatomic configurations of the uterus has never been studied.

CASE PRESENTATION

A 46-year-old woman presented with an 8-month history of abnormal vaginal bleeding. Biopsy revealed squamous cell carcinoma of the cervix. Magnetic resonance imaging (MRI) showed a cervical tumor with direct invasion of the right parametrium, bilateral hydronephrosis, and multiple uterine myomas. International Federation of Gynecology and Obstetrics (FIGO) stage IIIB cervical cancer was diagnosed. Concurrent chemoradiation therapy (CCRT) followed by SBRT delivered via HT was administered instead of brachytherapy because of the presence of multiple uterine myomas with bleeding tendency. Total abdominal hysterectomy was performed after 6 weeks of treatment because of the presence of multiple uterine myomas. Neither pelvic MRI nor results of histopathologic examination at X-month follow-up showed evidence of tumor recurrence. Only grade 1 nausea and vomiting during treatment were noted. Lower gastrointestinal bleeding was noted at 14-month follow-up. No fistula formation and no evidence of haematological, gastrointestinal or genitourinary toxicities were noted on the most recent follow-up.

CONCLUSIONS

CCRT followed by SBRT appears to be an effective and safe modality for treatment of cervical cancer. Larger-scale studies are warranted.

Should helical tomotherapy replace brachytherapy for cervical cancer? Case report

BACKGROUND

Stereotactic body radiation therapy (SBRT) administered via a helical tomotherapy (HT) system is an effective modality for treating lung cancer and metastatic liver tumors. Whether SBRT delivered via HT is a feasible alternative to brachytherapy in treatment of locally advanced cervical cancer in patients with unusual anatomic configurations of the uterus has never been studied.

CASE PRESENTATION

A 46-year-old woman presented with an 8-month history of abnormal vaginal bleeding. Biopsy revealed squamous cell carcinoma of the cervix. Magnetic resonance imaging (MRI) showed a cervical tumor with direct invasion of the right parametrium, bilateral hydronephrosis, and multiple uterine myomas. International Federation of Gynecology and Obstetrics (FIGO) stage IIIB cervical cancer was diagnosed. Concurrent chemoradiation therapy (CCRT) followed by SBRT delivered via HT was administered instead of brachytherapy because of the presence of multiple uterine myomas with bleeding tendency. Total abdominal hysterectomy was performed after 6 weeks of treatment because of the presence of multiple uterine myomas. Neither pelvic MRI nor results of histopathologic examination at X-month follow-up showed evidence of tumor recurrence. Only grade 1 nausea and vomiting during treatment were noted. Lower gastrointestinal bleeding was noted at 14-month follow-up. No fistula formation and no evidence of haematological, gastrointestinal or genitourinary toxicities were noted on the most recent follow-up.

CONCLUSIONS

CCRT followed by SBRT appears to be an effective and safe modality for treatment of cervical cancer. Larger-scale studies are warranted.

Adaptive management of cervical cancer radiotherapy

Since the breakthrough 10 years ago with concomitant radio-chemotherapy, substantial progress in the treatment of locally advanced cervical cancer has been lacking. Radiotherapy continues to be the cornerstone in the treatment of this disease and now shows much potential for progress, as image guidance of both external beam radiation therapy and brachytherapy, linked with strong tools for treatment planning and dose delivery, is becoming available. With these new techniques, it again seems possible to improve the therapeutic ratio as we begin to understand how the treatment for each patient can be individualized, not only in terms of volume (3-dimensional), but also during treatment (4-dimensional), as the tumor regresses and the topography of the target and organs at risk change significantly. New promising data with increased loco-regional control and decreased morbidity compared with the past are appearing. At the dawn of this new era, it is the aim of the present article to give an overview of the use of image-guided adaptive radiotherapy in the multimodal management of locally advanced cervical cancer.

Brachytherapy versus radical hysterectomy after external beam chemoradiation: a non-randomized matched comparison in IB2-IIB cervical cancer patients

Background

A current paradigm in the treatment of cervical cancer with radiation therapy is that intracavitary brachytherapy is an essential component of radical treatment. This is a matched retrospective comparison of the results of treatment in patients treated with external beam chemoradiation (EBRT-CT) and radical hysterectomy versus those treated with identical chemoradiation followed by brachytherapy.

Methods

In this non-randomized comparison EBRT-CT protocol was the same in both groups of 40 patients. In the standard treated patients, EBRT-CT was followed by one or two intracavitary Cesium (low-dose rate) applications within 2 weeks of finishing external radiation to reach a point A dose of at least 85 Gy. In the surgically treated patients, radical hysterectomy with bilateral pelvic lymph node dissection and para-aortic lymph node sampling were performed within 7 weeks after EBRT-CT. Response, toxicity and survival were evaluated.

Results

A total of 80 patients were analyzed. The patients receiving EBRT-CT and surgery were matched with the standard treated cases. There were no differences in the clinicopathological characteristics between groups or in the delivery of EBRT-CT. The pattern of acute and late toxicity differed. Standard treated patients had more chronic proctitis while the surgically treated had acute complications of surgery and hydronephrosis. At a maximum follow-up of 60 months, median follow-up 26 (2–31) and 22 (3–27) months for the surgery and standard therapy respectively, eight patients per group have recurred and died. The progression free and overall survival are the same in both groups.

Conclusion

The results of this study suggest that radical hysterectomy can be used after EBRT-CT without compromising survival in FIGO stage IB2-IIB cervical cancer patients in settings were brachytherapy is not available. A randomized study is needed to uncover the value of surgery after EBRT-CT.