Current controversies in high-dose-rate versus low-dose-rate brachytherapy for cervical cancer

Dosimetric comparison of stereotactic MR-guided radiation therapy (SMART) and HDR brachytherapy boost in cervical cancer

PURPOSE

The standard of care in locally advanced cervical cancer (LACC) is concomitant chemoradiotherapy followed by high-dose-rate brachytherapy (HDR-BT). Although previous studies compared HDR-BT with stereotactic body radiotherapy (SBRT), there is scarce data regarding the dosimetric outcomes of stereotactic MR-guided adaptive radiation therapy (SMART) boost in lieu of HDR-BT.

METHODS AND MATERIALS

In this single-institutional in-silico comparative study, LACC patients who were definitively treated with external beam radiotherapy followed by HDR-BT were selected. Target volumes and organs at risk (OARs) were delineated in MRI and HDR-planning CT. An HDR-BT and a SMART boost plan were generated with a prescribed dose of 28 Gy in four fractions for all patients. The HDR-BT and SMART boost plans were compared in regard to target coverage as well OARs doses.

RESULTS

Mean EQD2 D90 to HR-CTV and IR-CTV for HDR-BT plans were 89.7 and 70.5 Gy, respectively. For SMART, the mean EQD2 D90 to HR-PTV, HR-CTV, and IR-CTV were 82.9, 95.4, and 70.2 Gy, respectively. The mean D2cc EQD2 of bladder, rectum, and sigmoid colon for HDR-BT plans were 86.4, 70.7, and 65.7 Gy, respectively. The mean D2cc EQD2 of bladder, rectum, and sigmoid colon for SMART plans were 81.4, 70.8, and 73.6 Gy, respectively. All dose constraints in terms of target coverage and OARs constraints were met for both HDR-BT and SMART plans.

CONCLUSIONS

This dosimetric study demonstrates that SMART can be applied in cases where HDR-BT is not available or ineligible with acceptable target coverage and OAR sparing. However, prospective clinical studies are needed to validate these results.

Efficacy of high-dose-rate brachytherapy with different radiation source activities among cervical cancer patients and risk factors for long-term outcomes: A 6-year retrospective study

PURPOSE

This study aimed to assess the impact of dose rates due to natural decay of Iridium-192 sources and the risk factors of clinical outcomes for cervical cancer patients treated with high-dose-rate (HDR) brachytherapy.

METHODS AND MATERIALS

Four ninety-four patients were divided into relatively-high-radioactive (rHR), relatively-medium-radioactive (rMR), and relatively-low-radioactive (rLR) groups for retrospective treatment response comparison. The short-term outcomes were evaluated using the 1-month /3-month follow-up results based on RECIST 1.1. Local recurrence-free survival (LRFS) and metastatic recurrence-free survival (MRFS) were selected as long-term outcomes. A class of transformation models with adaptive lasso was applied to assess the risk factors of long-term outcomes.

RESULTS

No significant difference was identified in short- or long-term outcomes of different radioactive groups. Subgroup analyses demonstrated similar findings. In multivariate factor analysis, advanced stage was significantly associated with higher risk of local recurrence and metastatic recurrence (HR = 1.66, 95%confidence interval [CI] = 1.14-2.43, p = 0.008; HR = 1.57, 95%CI = 1.23-2.00, p < 0.001). Significant associations were observed between local recurrence and pathology, and between metastatic recurrence and pre-treatment serum indices, respectively (HR = 8.62, 95%CI = 2.28-32.60, p = 0.002; HR = 1.98, 95%CI=1.20-2.26, p = 0.008).

CONCLUSIONS

Overall, there was no significant difference in long- or short-term efficacy of the HDR brachytherapy among the groups with different levels of activity of radiation sources. Stage, pathology, and pretreatment serum indices were crucial factors that affected the long-term outcomes.

Low-energy X-ray irradiation: A novel non-thermal microbial inactivation technology

Over the last several decades, food irradiation technology has been proven neither to reduce the nutritional value of foods more than other preservation technologies, nor to make foods radioactive or dangerous to eat. Furthermore, food irradiation is a non-thermal food processing technology that helps preserve more heat sensitive nutrients than those found in thermally processed foods. Conventional food irradiation technologies, including γ-ray, electron beam and high energy X-ray, have certain limitations and drawbacks, such as involving radioactive isotopes, low penetration ability, and economical unfeasibility, respectively. Owing to the recent developments in instrumentation technology, more compact and cheaper tabletop low-energy X-ray sources have become available. The generation of low-energy X-ray, unlike γ-ray, does not involve radioactive isotopes and the cost is lower than high energy X-ray. Furthermore, low-energy X-ray possesses unique advantages, i.e., high linear energy transfer (LET) value and high relative biological effect (RBE) value. The advantages allow low-energy X-ray irradiation to provide a higher microbial inactivation efficacy than γ-ray and high energy X-ray irradiation. In the last few years, various applications reported in the literature indicate that low-energy X-ray irradiation has a great potential to become an alternative food preservation technique. This chapter discusses the technical advances of low-energy X-ray irradiation, microbial inactivation mechanism, factors influencing its efficiency, current applications, consumer acceptance, and limitations.

Elimination of cervical cancer as a public health problem-how shorter brachytherapy could make a difference during COVID-19

The World Health Organization has called for elimination of cervical cancer as a public health problem and has adopted strategies in this regard. However, the estimates for achieving the goals depend on the ability to provide timely treatment in a certain proportion of cases. The coronavirus disease 2019 pandemic has had a serious impact on healthcare delivery in many low and middle income countries (LMICs) with the highest burden of cervical cancer; funds and infrastructure are being reallocated to deal with the emergency, and cancer care has been seriously affected. In the absence of clear and reliable estimates, the exact extent of disruption remains unclear. It is, therefore, essential that pragmatic approaches are adopted to save lives. There has been considerable debate regarding the use of the 9 Gy × 2 fractions high dose rate brachytherapy schedule for the treatment of locally advanced cervical carcinoma. However, in LMICs with the highest global burden of locally advanced cervical cancer cases, radiation facilities have been using this fractionation schedule in many cases to deal with the overwhelming number of patients, who would have otherwise been denied timely treatment. In view of the current pandemic, and the difficulties in accessing and delivering timely healthcare, mortality owing to delayed treatment cannot be denied in LMICs, which already have underequipped healthcare facilities. Use of the shortest available fractionation schedule to provide timely treatment would serve to save more lives in regions with high incidence and mortality from the disease.

High Dose Rate Brachytherapy for Inoperable Endometrial Cancer: a Case Series and Systematic Review of the Literature

Endometrial cancer is a common gynaecological cancer, is typically early stage and treated with surgery. For patients where surgery is difficult or dangerous, definitive radiation therapy is the next best option. This study included a single institution case series (step 1) and a systematic review of the literature (step 2). In step 1, all endometrial cancer cases that were treated with definitive image-guided brachytherapy at a single institution from 2008 to 2020 were retrospectively analysed. In step 2, a systematic review of Medline (PubMed) from 1975 to 2020 was carried out using the key words around endometrial cancer and brachytherapy, followed by a narrative synthesis. In total, in step 1, 31 cases were included in this study, stages I-IV, with 96.7% receiving external beam radiation. All patients received three fractions of 7.5 Gy or five fractions of 6 Gy high dose rate brachytherapy, with a median EQD2 of 75.55 (40-84.3). The 2-year Kaplan-Meier (KM) local control was 83.1% and the 2-year KM overall survival was 77.4%. There was no late toxicity ≥grade 3. In step 2, 19 articles were included in the final analysis, with between six and 280 patients. The local control ranged from 70 to 100%, with low toxicity. Definitive radiation therapy with image-guided brachytherapy seems to have good local control with low toxicity for patients who are poor surgical candidates.

Stereotactic Ablative Brachytherapy: Recent Advances in Optimization of Radiobiological Cancer Therapy

Brachytherapy (BT), a type of focal anti-cancer radiotherapy, delivers a highly focused radiation dose to localized tumors, sparing surrounding normal tissues. Recent technological advances have helped to increase the accuracy of BT and, thus, improve BT-based cancer treatment. Stereotactic ablative brachytherapy (SABT) was designed to improve the ablative effect of radiation, which was achieved via improved image guidance, and calculation of ablative dose, shorter treatment duration, and better organ preservation. Recently collected data characterized SABT as having the potential to cure various early-stage cancers. The method provides higher tumor control rate levels that were previously achievable only by surgical resection. Notably, SABT is suitable for application with unresectable malignancies. However, the pathological assessment of SABT irradiated tumors is limited due to difficulties in specimen acquisition. Prostate, lung, liver, and gynecological cancers are the most commonly reported SABT-treated malignancies. This study will give an overview of SABT, focusing on the advances in SABT optimization, and provide insights on the future benefits of the combined application of SABT with cancer immunotherapies.

Toxicities and Recurrences after Co-60 High-Dose-Rate Brachytherapy for Cervical Cancer in a Tertiary Government Hospital in the Philippines

Introduction Despite the rising popularity of high-dose-rate (HDR) brachytherapy and use of Co-60 in the country, local data on brachytherapy outcomes are lacking. The study reviewed the incidence of toxicities and recurrences in patients with cervical cancer treated with Co-60 intracavitary HDR brachytherapy in a tertiary government hospital in the Philippines.

Methods Records of patients with cervical cancer who completed external beam radiotherapy (EBRT) and brachytherapy from 2016 to 2018 were reviewed. Patient-related (age, smoking history, body mass index, histology, stage, mass size) and treatment-related (overall treatment time [OTT], EBRT machine used, brachytherapy fractionation, dose prior to midline shielding/central tumor dose [CTD]) parameters were analyzed for possible associations with the incidence of toxicities and recurrences.

Results One hundred and sixty-three patients were identified and reviewed for baseline characteristics. Patients who had inadequate follow-up (<90 days) were excluded in the analysis of outcomes. Among the remaining 132 patients, median follow-up duration was 389 days. Gastrointestinal (GI) and genitourinary (GU) toxicities were present in 19.7% (n = 26) and 1.5% (n = 2), respectively. Recurrence was noted in 31.8% (n = 42). The most commonly involved sites of locoregional and distant recurrence was the uterocervix (n = 16, 59.3%) and para-aortics (n = 42, 31.8%), respectively. CTD was significantly associated with toxicities (p = 0.03), while OTT was borderline significantly associated with recurrence (p = 0.06).

Conclusion We present outcomes of GI and GU toxicities, and locoregional and distant recurrences after chemoradiation and Co-60 HDR brachytherapy in a tertiary government hospital in the Philippines. Our study suggests that CTD was significantly associated with incidence of toxicities, while OTT was weakly associated with recurrence. Interventions should be made to control these factors, especially in high-volume, low-resource cancer centers.

Tumor response and the quality of life after isolated hypoxic pelvic perfusion for advanced G3 cervical cancer: A case series

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Standard treatment of cervical cancer is associated with considerable toxicity and permanent adverse events.

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Isolated hypoxic pelvic perfusion overcomes chemoresistance and generates effective and onlasting tumor response.

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Complete and durable clinical and radiological remissions are achieved with no identifiable signs of systemic toxicity.

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Quality of life is maintained.

Introduction

We present a case series of three patients with advanced cervical cancer who either refused the standard of care systemic or chemoradiation treatment or did not benefit from it.

Methods

We treated patients with isolated hypoxic pelvic perfusion (HPP).

Results

Two patients achieved complete clinicopathologic response and one patient required surgical excision of the necrotic residual mass containing no viable cancer cells. There were no long-term systemic or local side effects. All patients are cancer free for up to 15 years after conclusion of treatment.

Conclusion

HPP is an effective option for treatment of advanced cervical cancer that generates rapid and onlasting remissions at low side effects. Gynecologic oncologists shall be aware of HPP to facilitate wider adaption of our technique.

Treatment Outcomes and Dose Rate Effects Following Gamma Knife Stereotactic Radiosurgery for Vestibular Schwannomas

BACKGROUND

Gamma Knife radiosurgery (GKRS; Elekta AB) remains a well-established treatment modality for vestibular schwannomas. Despite highly effective tumor control, further research is needed toward optimizing long-term functional outcomes. Whereas dose-rate effects may impact post-treatment toxicities given tissue dose-response relationships, potential effects remain largely unexplored.

OBJECTIVE

To evaluate treatment outcomes and potential dose-rate effects following definitive GKRS for vestibular schwannomas.

METHODS

We retrospectively reviewed 419 patients treated at our institution between 1998 and 2015, characterizing baseline demographics, pretreatment symptoms, and GKRS parameters. The cohort was divided into 2 dose-rate groups based on the median value (2.675 Gy/min). Outcomes included clinical tumor control, radiographic progression-free survival, serviceable hearing preservation, hearing loss, and facial nerve dysfunction (FND). Prognostic factors were assessed using Cox regression.

RESULTS

The study cohort included 227 patients with available follow-up. Following GKRS 2-yr and 4-yr clinical tumor control rates were 98% (95% CI: 95.6%-100%) and 96% (95% CI: 91.4%-99.6%), respectively. Among 177 patients with available radiographic follow-up, 2-yr and 4-yr radiographic progression-free survival rates were 97% (95% CI: 94.0%-100.0%) and 88% (95% CI: 81.2%-95.0%). The serviceable hearing preservation rate was 72.2% among patients with baseline Gardner-Robertson class I/II hearing and post-treatment audiological evaluations. Most patients experienced effective relief from prior headaches (94.7%), tinnitus (83.7%), balance issues (62.7%), FND (90.0%), and trigeminal nerve dysfunction (79.2%), but not hearing loss (1.0%). Whereas GKRS provided effective tumor control independently of dose rate, GKRS patients exposed to lower dose rates experienced significantly better freedom from post-treatment hearing loss and FND (P = .044).

CONCLUSION

Whereas GKRS provides excellent tumor control and effective symptomatic relief for vestibular schwannomas, dose-rate effects may impact post-treatment functional outcomes. Further research remains warranted.

Modern Brachytherapy

Brachytherapy involves the placement of radioactive sources within or very close to the tumor. This placement allows a high dose of radiotherapy to be delivered to the tumor while sparing the surrounding normal tissue. The delivery of brachytherapy has changed markedly over the years, with newer radioactive sources making delivery safer, image guidance techniques allowing more accurate placement of sources, and advanced planning systems allowing brachytherapy to be truly adaptive. This article explores the most modern techniques and current uses of brachytherapy in the treatment of gynecological, prostate, breast, rectal, and skin cancers.

Can Chemotherapy be Integrated with Brachytherapy in Locally Advanced Carcinoma Cervix- A Proof of Principle Study

Introduction: Cancer of the cervix is the second most common cancer in women in India. Chemoradiotherapy is the standard treatment for locally advanced carcinoma cervix. Chemotherapy is not given on days of brachytherapy due to the fear of increased toxicity though studies supporting or refuting it are limited. We intended to study feasibility of adding chemotherapy to brachytherapy with assessment of acute toxicity and response rates. Methods: 29 patients of locally advanced carcinoma cervix (FIGO IIB to IIIB) were assigned to receive either three sessions of high dose rate (HDR) brachytherapy alone or HDR brachytherapy with concurrent chemotherapy of Paclitaxel and Carboplatin after completion of external beam radiation with concurrent Cisplatin. Patients were assessed for compliance of treatment, toxicity and response rates at three and six months. The p-value less than 0.05 was considered statistically significant. Fischer’s exact test was used for statistical analysis. Results: 15 patients were assigned to the standard of care arm and 14 patients to the experimental chemo-brachytherapy arm. The median number of cycles of chemotherapy possible with brachytherapy was two (Range: 1 -3). At three months after treatment all patients except one patient in each arm had a complete response. There was two acute grade 3 hematological toxicity and two acute grade 3 or higher gastrointestinal toxicity in the experimental arm but none in the standard arm. The experimental arm had a statistically higher incidence of acute grade 3 and 4 toxicity than the standard arm (p=0.042). Conclusions: Chemo-brachytherapy is associated with higher acute toxicity with comparable response rates. Small patient numbers and short follow up impedes us from providing conclusive evidence.

Concurrent chemoradiation for cervical cancer: Comparison of LDR and HDR brachytherapy

PURPOSE

To compare clinical outcomes between low-dose-rate (LDR) brachytherapy and high-dose-rate (HDR) brachytherapy for cervical cancer patients.

METHODS AND MATERIALS

All consecutive newly diagnosed cervical cancer patients undergoing pretreatment 18-fluorodeoxyglucose positron emission tomography imaging and treated with curative-intent definitive chemoradiation from 1997 to 2016 at a U.S. academic center were included. Brachytherapy boost was LDR or HDR 2D treatment planning from 1997 to 2005 and HDR with MR-based 3D planning from 2005 to 2016. Local control (LC), cancer-specific survival (CSS), and late bowel/bladder complications were evaluated.

RESULTS

Tumor stages were International Federation of Gynecology and Obstetrics IB1-IIB (n = 457; 75%) and III-IVA (n = 152; 25%). Brachytherapy was LDR for 104 patients and HDR for 505 patients. Concurrent weekly cisplatin was administered to 536 patients (88%). With median followup of 9.4 years, there was no difference in LC (p = 0.24) or CSS (p = 0.50) between LDR and HDR brachytherapy. Cox multivariable regression showed that only International Federation of Gynecology and Obstetrics stage III-IVA (HR=2.4, p = 0.004) was associated with worse LC. A propensity-matched cohort (90 LDR vs. 90 HDR) was created, and the 5-year LC rates were 88% LDR and 82% HDR, p = 0.26; 5-year CSS rates were 66% LDR and 58% HDR, p = 0.19; 5-year grade ≥3 bowel/bladder toxicities were 23% LDR and 16% HDR, p = 0.44. For all patients, the 5-year late toxicity in stage III-IVA patients was higher with LDR 47% vs. HDR 15%, p = 0.03, with no difference in LC, 86% and 75%, respectively (p = 0.09).

CONCLUSIONS

There was no difference in LC with either LDR or HDR brachytherapy. The late complication rate was reduced with HDR and 3D-planned brachytherapy compared to LDR and 2D-planned brachytherapy.

Treatment of locally advanced carcinoma cervix with special emphasis on brachytherapy: A practice pattern survey among young radiation oncologist of India

BACKGROUND

Carcinoma cervix is one of the two most common cancers of Indian women with very high morbidity and mortality burden. Although India probably is the leading country in numbers patients of cervix treated radically with combination of teletherapy and brachytherapy (BT), there is presumed diversity of practice across the country due to the inequality of available infrastructure, absence of uniform the training of the radiation oncologists, and absence of any national guidelines. The present survey was conducted to determine current practice patterns in management of locally advanced carcinoma cervix with regard to gynecologic high-dose-rate among the radiation oncologist across the country.

METHODOLOGY

A 25-item survey was undertaken to study the standard management pattern of Stage IIB-IIIB cervical cancer with special emphasis on the BT practice patterns among various young radiation oncologist working across the country. The survey was undertaken in person in the form of interview questionnaire among the younger members of association of radiation oncologist of India during two national conferences, along with telephonic interview of other members as obtained from the national directory.

RESULTS

About 57 young radiation oncologists from 57 centers across the country were surveyed. 25 of them represented private nonacademic centers, 24 represented government academic centers, the rest were from private academic, nongovernmental organization (NGO) run and other centers. The most common teletherapy dose prescribed was 46 Gy/23# for Stage II, and50 Gy/25 # for Stage III disease. HDR after loader with 192Ir is the most common machine (82.6%) in use and computed tomography scan is the most commonly (30/57) used imaging for planning. The most common intracavitary dose pattern for all stages was 7 Gy × 3 fractions (30/57s) and 9 Gy × 2 (12/57) fractions. Although in most centers, computed tomography-based delineation of organs at risk is done routinely; however, target volume delineation and dose prescription/optimization for the same is routinely done in handful of centers (5/57). The mean planned dose to Point A for combined external-beam radiation and BT (EQD210) was about 77.5 Gy for Stage IIIB and 72.6 Gy for Stage II disease.

CONCLUSION

Although fractionation patterns may vary, the overall mean dose administered for cervical cancer is similar across the country, which is slightly lower than the recommended doses as per stage by various international guidelines.

Which Patients With Cervical Squamous Cell Carcinoma Might Benefit From Neoadjuvant Chemotherapy?

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 55-year-old postmenopausal woman, gravida 5 para 5, with past medical history significant for hypertension, presented to the emergency department with profuse vaginal bleeding and a hemoglobin level of 9 g/dL. The biopsy from an irregular 6-cm cervical mass was consistent with moderately differentiated cervical squamous cell carcinoma. The physical examination did not reveal vaginal or parametrial extension of the tumor. Pelvic magnetic resonance imaging disclosed the known carcinoma, as well as a 9.2 × 7.7 × 6.7 cm anterior uterine fibroid (Fig 1). A staging positron emission tomography scan was negative for metastatic disease. After blood transfusion and vaginal packing, the patient was referred to discuss the immediate management of her newly diagnosed bleeding bulky cervical cancer. In the absence of parametrial or vaginal extension and in the absence of lymph node metastasis (both on clinical examination and imaging), she was classified as having International Federation of Gynecology and Obstetrics stage IB2 disease.

Differences in urethral dosimetry between CT and MR imaging in multichannel vaginal cylinder brachytherapy

PURPOSE

In image-based brachytherapy (IBBT), the dosimetry of small structures may be particularly sensitive to changes in contouring between imaging modalities. We therefore sought to characterize differences in urethral dosimetry in vaginal brachytherapy based on contouring on MRI vs. CT.

METHODS AND MATERIALS

We retrospectively identified our most recent 15 patients treated with intracavitary brachytherapy for distal vaginal malignancies. On T2-weighted MRI, both the lumen and urethral wall were contoured. On CT, the urethral lumen alone was contoured, as the wall is indistinguishable from surrounding tissue. High-dose-rate (HDR) IBBT plans were generated for all patients.

RESULTS

Mean urethral volume was higher on MRI than CT at 3.7 cc vs. 1.1 cc (p < 0.0005). As a result, there were statistically significant increases on MRI in D_0.1cc and D_0.5cc, as well as EQD2 D_0.1cc and EQD2 D_0.5cc when applied to a full course of treatment (45 Gy EBRT + 25 Gy IBBT).

CONCLUSIONS

We have quantified the expected differences in urethral volume and dosimetry when contoured on MRI vs. CT. Inclusion of the urethral wall on MRI, with its average thickness of 2.2 mm, likely more accurately reflects the true organ at risk and results in an increase in reported dose compared to CT.

Dedicated high dose rate 192Ir brachytherapy radiation fields for in vitro cell exposures at variable source-target cell distances: killing of mammalian cells depends on temporal dose rate fluctuation

Afterloading brachytherapy is conducted by the stepwise movement of a radioactive source through surgically implanted applicator tubes where at predefined dwell positions calculated dwell times optimize spatial dose delivery with respect to a planned dose level. The temporal exposure pattern exhibits drastic fluctuations in dose rate at a given coordinate and within a single treatment session because of the discontinuous and repeated source movement into the target volume. This could potentially affect biological response. Therefore, mammalian cells were exposed as monolayers to a high dose rate 192Ir source by utilizing a dedicated irradiation device where the distance between a planar array of radioactive source positions and the plane of the cell monolayer could be varied from 2.5 mm to 40 mm, thus varying dose rate pattern for any chosen total dose. The Gammamed IIi afterloading system equipped with a nominal 370 GBq (10 Ci) 192-Ir source was used to irradiate V79 Chinese hamster lung fibroblasts from both confluent and from exponential growth phase with dose up to 12 Gy (at room temperature, total exposure not exceeding 1 h). For comparison, V79 cells were also exposed to 6 MV x-rays from a clinical linear accelerator (dose rate of 2.5 Gy min-1). As biological endpoint, cell survival was determined by standard colony forming assay. Dose measurements were conducted with a diamond detector (sensitive area 7.3 mm2), calibrated by means of 60Co radiation. Additionally, dose delivery was simulated by Monte Carlo calculations using the EGSnrc code system. The calculated secondary electron fluence spectra at the cell location did not indicate a significant change of radiation quality (i.e. higher linear energy transfer) at the lower distances. Clonogenic cell survival curves obtained after brachytherapy exhibited an altered biological response compared to x-rays which was characterized by a significant reduction of the survival curve shoulder when dose rate fluctuations were high. Therefore, also for the time scale of the present investigation, cellular effects of radiation are not invariant to the temporal pattern in dose rate. We propose that with high dose rate variation the cells activate less efficiently their DNA damage response than after continuous irradiation.

Outcomes with image-based interstitial brachytherapy for vaginal cancer

PURPOSE

To compare clinical outcomes of image-based versus non-image-based interstitial brachytherapy (IBBT) for vaginal cancer.

METHODS AND MATERIALS

Of 72 patients with vaginal cancer treated with brachytherapy (BT), 47 had image guidance (CT=31, MRI=16) and 25 did not. Kaplan-Meier (KM) estimates were generated for any recurrence, local control (LC), disease-free interval (DFI), and overall survival (OS) and Cox models were used to assess prognostic factors.

RESULTS

Median age was 66 and median follow-up time was 24months. Median cumulative EQD2 dose was 80.8Gy in the non-IBBT group and 77Gy in the IBBT group. For non-IBBT versus IBBT, the 2-year KM LC was 71% vs. 93% (p=0.03); DFI was 54% vs. 86% (p=0.04); and OS 52% vs. 82% (p=0.35). On multivariate analysis, IBBT was associated with better DFI (HR 0.24, 95% CI 0.07-0.73). Having any 2 or more of chemotherapy, high-dose-rate (HDR) BT or IBBT (temporally correlated variables) significantly reduced risk of relapse (HR=0.33, 95% CI=0.13-0.83), compared to having none of these factors.

CONCLUSION

Over time, the use of chemotherapy, HDR, and IBBT has increased in vaginal cancer. The combination of these factors resulted in the highest rates of disease control. Image-guided brachytherapy for vaginal cancer patients maximizes disease control.

Dosimetric evaluation of tandem-based cervical high-dose-rate brachytherapy treatment planning using American Brachytherapy Society 2011 recommendations

Purpose

This study evaluated dosimetric parameters for cervical high-dose-rate (HDR) brachytherapy treatment using varying dose prescription methods.

Methods

This study includes 125 tandem-based cervical HDR brachytherapy treatment plans of 25 patients who received HDR brachytherapy. Delineation of high-risk clinical target volumes (HR-CTVs) and organ at risk were done on original computed tomographic images. The dose prescription point was defined as per International Commission in Radiation Units and Measurements Report Number 38 (ICRU-38), also redefined using American Brachytherapy Society (ABS) 2011 criteria. The coverage index (V100) for each HR-CTV was calculated using dose volume histogram parameters. A plot between HR-CTV and V100was plotted using the best-fit linear regression line (least-square fit analysis).

Results

Mean prescribed dose to ICRU-38 Point A was 590·47±28·65 cGy, and to ABS Point A was 593·35±30·42 cGy. There was no statistically significant difference between planned ICRU-38 and calculated ABS Point A doses (p=0·23). The plot between HR-CTV and V100is well defined by the best-fit linear regression line with a correlation coefficient of 0·9519.

Conclusion

For cervical HDR brachytherapy, dose prescription to an arbitrarily defined point (e.g., Point A) does not provide consistent coverage of HR-CTV. The difference in coverage between two dose prescription approaches increases with increasing CTV. Our ongoing work evaluates the dosimetric consequences of volumetric dose prescription approaches for these patients.

Major causes of impractical brachytherapy in elderly patients with uterine cervical cancer

AIM

Incomplete brachytherapy is a major risk factor for recurrence. However, high-dose-rate intracavitary brachytherapy has not been assessed adequately in elderly patients with invasive cervical cancer. The present study investigated the clinical importance of intracavitary brachytherapy and risk factors of incomplete intracavitary brachytherapy in elderly patients with cervical cancer.

MATERIAL AND METHODS

Subjects were 76 patients aged 70-89 years old with invasive cervical cancer. All subjects were recruited between January 1997 and September 2010, and were planning to receive external beam radiation therapy followed by high-dose-rate intracavitary brachytherapy. Survival rates and the incidence of complications were compared between the 70s and 80s age groups. Risk factors for recurrence in elderly patients were evaluated using multivariate analysis, and risk factors for impractical intracavitary brachytherapy were also estimated.

RESULTS

No significant differences were observed in 3-year progression-free survival rates or the incidence of complications in the two age groups. Cox multivariate analysis showed that histology (non-squamous cell carcinoma), incomplete intracavitary brachytherapy, and lymph node swelling were significant prognostic factors for recurrence. Impractical application was the major reason for incomplete treatment. Multiple logistic regression analysis revealed that a previous history without vaginal births (P = 0.016) was an independent risk factor for the impractical application, independent of tumor diameter ≥ 4 cm (P = 0.007).

CONCLUSIONS

Incomplete intracavitary brachytherapy decreased the survival rates of elderly patients. Larger tumors and patients without a history of vaginal births were the two major causes of impractical intracavitary brachytherapy, which may be fatal, especially in elderly patients with bulky tumors.

University Cooperation Platform (UCP) between Christian-Albrechts-University Kiel (Germany) and Chiang Mai University (Thailand): implementation of image-guided gynecological brachytherapy

Starting in 1999, the University Cooperation Platform (UCP) implemented an exchange program of researchers and clinicians/physicists between the Christian-Albrechts-University Kiel in Germany and Chiang Mai University in Thailand, to initiate a sustainable base for long-term development of image-guided brachytherapy and in general for high-technology radiotherapy in Chiang Mai. A series of UCP protocols, based constructively on each other, were performed and evaluated at intermediate term follow-up. The first protocol, addressing computed tomography (CT)-optimized brachytherapy for advanced cervical cancer (n = 17), showed a significant reduction of D_2cc for the bladder and sigmoid (p < 0.001) while maintaining a very high dose in D₉₀ high-risk clinical target volume (HR-CTV) in comparison with standard point-based planning. In addition, after a follow-up of 19 months no tumor relapse was observed. The second UCP protocol, testing the impact of magnetic resonance imaging (MRI) guidance (n = 15) in patients with cervical cancer, proved significantly smaller D_2cc doses for the bladder, rectum, and sigmoid (p = 0.003, p = 0.015, and p = 0.012), and secured highly curative mean doses in D₉₀ HR-CTV of 99.2 Gy. The acute and late toxicity was excellent without any observed grade 3 or higher morbidity. In the third protocol, the combination of image-guided brachytherapy (IGBT) and whole pelvis intensity-modulated external beam radiotherapy (WP-IMRT) (n = 15) reaffirmed the significant reduction of D_2cc doses for the bladder, rectum, and sigmoid (p = 0.001 or p < 0.001) along with high equivalent dose at 2 Gy (EQD2) in the HR-CTV, and demonstrated very low acute therapy-related toxicity in absence of grade 3 morbidity. The implementation of transabdominal ultrasound (TAUS) was the focus of the fourth UCP project aiming a more generous potential use of image-guidance on long-term, and enhancing the quality of soft tissue assessment complementary to conventionally planned gynecological brachytherapy. Analyses in 29 patients revealed significantly reduced OARs doses in bladder with a total EQD2 > 80 Gy for bladder in only 17.2% versus 62.1% in conventional planning, and in rectum EQD2 > 75 Gy in 44.8% versus 79.3%, respectively.

In conclusion, analyses revealed excellent results for the high-dose-rate IGBT in patients with advanced gynecological cancer both by using CT and MRI, and/or the combination with WP-IMRT. They also define MRI as gold standard for soft tissue assessment and to determine more accurately HR-CTV. The use of TAUS-guidance adds quality aspects to the “classical” conventional X-ray based planning, especially in terms of real-time measures and adequate soft tissue information, and may lower significantly the dose in OARs. The review of all UCP-results reconfirms the importance of the established program that will continue to operate with subsequent projects.

High versus low-dose rate brachytherapy for cervical cancer

OBJECTIVES

Brachytherapy plays an important role in the treatment of cervical cancer. While small trials have shown comparable survival outcomes between high (HDR) and low-dose rate (LDR) brachytherapy, little data is available in the US. We examined the utilization of HDR brachytherapy and analyzed the impact of type of brachytherapy on survival for cervical cancer.

METHODS

Women with stages IB2-IVA cervical cancer treated with primary (external beam and brachytherapy) radiotherapy between 2003-2011 and recorded in the National Cancer Database (NCDB) were analyzed. Generalized linear mixed models and Cox proportional hazards regression were used to examine predictors of HDR brachytherapy use and the association between HDR use and survival.

RESULTS

A total of 10,564 women including 2681 (25.4%) who received LDR and 7883 (74.6%) that received HDR were identified. Use of HDR increased from 50.2% in 2003 to 83.9% in 2011 (P<0.0001). In a multivariable model, year of diagnosis was the strongest predictor of use of HDR. While patients in the Northeast were more likely to receive HDR therapy, there were no other clinical or socioeconomic characteristics associated with receipt of HDR. In a multivariable Cox model, survival was similar between the HDR and LDR groups (HR=0.93; 95% CI 0.83-1.03). Similar findings were noted in analyses stratified by stage and histology. Kaplan-Meier analyses demonstrated no difference in survival based on type of brachytherapy for stage IIB (P=0.68), IIIB (P=0.17), or IVA (P=0.16) tumors.

CONCLUSIONS

The use of HDR therapy has increased rapidly. Overall survival is similar for LDR and HDR brachytherapy.

Severe gastrointestinal complications in the era of image-guided high-dose-rate intracavitary brachytherapy for cervical cancer

PURPOSE

The purposes of this analysis are to report a modern series of severe gastrointestinal toxic effects after definitive chemoradiotherapy in the treatment of locally advanced cervical cancer at our institution and to review the existing literature on factors that contribute to toxic effects and preventive strategies and management.

METHODS

Our institution's cervical cancer cohort was evaluated for patients with late grade 3 to 4 gastrointestinal toxic effects who were retrospectively reviewed for clinical or dosimetric parameters that could have contributed to late toxic effects. A review of the published literature was performed to identify factors associated with late toxic effects, prophylactic agents, and corrective therapy.

FINDINGS

Five of 85 patients were identified as having late grade 3 to 4 gastrointestinal toxic effects with a median follow-up of 13.3 months. Two of 5 patients developed late grade 3 toxic effects, and 3 of 5 developed late grade 4 toxic effects. Three of the 5 patients reviewed ultimately required permanent colostomies. Cumulative median dose (in equivalent dose in 2-Gy fractions) of clinical target volume to the hottest 90% was 107.2 Gy, rectal dose to the hottest 2 cc (D2cc) was 81.7 Gy, sigmoid D2cc was 61.7 Gy, and bladder D2cc was 79.5 Gy. No patient had evidence of disease recurrence in the pelvis. One patient developed oligometastatic disease in the suprarenal gland and was successfully salvaged with adrenalectomy.

IMPLICATIONS

Despite its risk of toxic effects, intracavitary brachytherapy remains a critical component of the treatment of locally advanced cervical cancer. Even with modern radiotherapy planning and delivery techniques, extra attention is warranted to continue to strive for optimal outcomes.

Cost-effectiveness analysis of 3D image-guided brachytherapy compared with 2D brachytherapy in the treatment of locally advanced cervical cancer

PURPOSE

Three-dimensional image-guided brachytherapy (IGBT) is a significant advance in locally advanced cervical cancer treatment. However, its cost-effectiveness (C/E) is unknown. We performed a C/E analysis of IGBT compared with conventional (two-dimensional [2D]) brachytherapy in the treatment of locally advanced cervical cancer.

METHODS AND MATERIALS

A Markov model was constructed to model locally advanced cervical cancer treated with five fractions of high-dose-rate brachytherapy. The model captured clinical parameters, quality of life utility, and treatment costs through the literature review. Costs were 2013 Medicare reimbursement. Strategies were compared using the incremental cost-effectiveness ratio (ICER), and effectiveness was measured in quality-adjusted life-years (QALYs). To account for uncertainty, one-way, two-way, and probabilistic sensitivity analyses were performed. Strategies were evaluated from a payer's perspective with a willingness-to-pay threshold of $50,000/QALY gained.

RESULTS

Treatment costs for five fractions of IGBT and 2D brachytherapy were $21,374 and $17,931, respectively. In the base-case analysis, the IGBT strategy costs $3003 more than 2D brachytherapy while gaining 0.16 QALYs, resulting in an ICER of $18,634 per QALY gained. In one-way sensitivity analyses, results were most sensitive to variation of treatment costs, but the ICER remained <$50,000/QALY gained for all cost ranges. Variation of survival, local control, and complication rates was less influential. A probabilistic sensitivity analysis demonstrated that IGBT was favored in 63% of model iterations at a $50,000/QALY gained threshold.

CONCLUSION

IGBT for locally advanced cervical cancer is a C/E option compared with 2D brachytherapy. These findings were robust to variation of parameter values supporting the routine use of IGBT in locally advanced cervical cancer.

High dose rate versus low dose rate intracavity brachytherapy for locally advanced uterine cervix cancer

BACKGROUND

This is an updated version of the original Cochrane review published in 2010 (Issue 7).Carcinoma of the uterine cervix is the second most common cancer and the third leading cause of cancer death among women. Radiotherapy has been used successfully to treat cervical cancer for nearly a century. The combination of external beam radiotherapy (EBRT) and intracavity brachytherapy (ICBT) has become a standard treatment for cervical cancer. Whether high dose rate (HDR) or low dose rate (LDR) brachytherapy improves outcomes in terms of local control rates, survival and complications for women with cervical cancer remains controversial.

OBJECTIVES

To assess the efficacy and safety of HDR versus LDR ICBT in combination with EBRT for women with uterine cervical cancer.

SEARCH METHODS

We searched the Cochrane Gynaecological Cancer Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (1966 to March 2014), EMBASE (1974 to March 2014), and the Chinese Biomedical Literature Database (CBM) (1978 to March 2014) for relevant original, published trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared HDR with LDR ICBT, combined with EBRT, for women with locally advanced uterine cervical cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data using standardised forms. Primary outcome measures included overall survival (OS), relapse-free survival (RFS) and pelvic control rate, while secondary outcomes included rates of recurrence and complications.

MAIN RESULTS

Four studies involving 1265 women met the inclusion criteria. In our meta-analysis to compare HDR and LDR ICBT, the pooled risk ratios (RRs) were 0.95 (95% confidence interval (CI) 0.79 to 1.15), 0.93 (95% CI 0.84 to 1.04) and 0.79 (95% CI 0.52 to 1.20) for 3-, 5- and 10-year overall survival rates respectively; and 0.95 (95% CI 0.84 to 1.07) and 1.02 (0.88 to 1.19) for 5- and 10-year disease-specific survival (DSS) rates respectively. The RR for RFS was 1.04 (95% CI 0.71 to 1.52) and 0.96 (95% CI 0.81 to 1.14) at 3- and 5- years. For local control rates the RR was 0.95 (95% CI 0.86 to 1.05) and 0.95 (95% CI 0.87 to 1.05) at 3- and 5- years; with a RR of 1.09 (95% CI 0.83 to 1.43) for locoregional recurrence, 0.79 (95% CI 0.40 to 1.53) for local and distant recurrence, 2.23 (95% CI 0.78 to 6.34) for para-aortic lymph node metastasis, and 0.99 (95% CI 0.72 to 1.35) for distance metastasis. For bladder, rectosigmoid and small bowel complications, the RR was 1.33 (95% CI 0.53 to 3.34), 1.00 (95% CI 0.52 to 1.91) and 3.37 (95% CI 1.06 to 10.72) respectively. These results indicated that there were no significant differences except for increased small bowel complications with HDRs (P = 0.04).

AUTHORS' CONCLUSIONS

Since the last version of this review, no new studies were identified for inclusion in this review to provide additional information. This review showed no significant differences between HDR and LDR ICBT when considering OS, DSS, RFS, local control rate, recurrence, metastasis and treatment related complications for women with cervical carcinoma. Due to some potential advantages of HDR ICBT (rigid immobilization, outpatient treatment, patient convenience, accuracy of source and applicator positioning, individualized treatment) we recommend the use of HDR ICBT for all clinical stages of cervix cancer. The overall risk of bias was high for the included studies as many of the items were either of high or unclear risk. The GRADE assessment of the quality of the evidence was low to moderate.

Cervix cancer brachytherapy: high dose rate

Cervical cancer, although less common in industrialized countries, is the fourth most common cancer affecting women worldwide and the fourth leading cause of cancer death. In developing countries, these cancers are often discovered at a later stage in the form of locally advanced tumour with a poor prognosis. Depending on the stage of the disease, treatment is mainly based on a chemoradiotherapy followed by uterovaginal brachytherapy ending by a potential remaining tumour surgery or in principle for some teams. The role of irradiation is crucial to ensure a better local control. It has been shown that the more the delivered dose is important, the better the local results are. In order to preserve the maximum of organs at risk and to allow this dose escalation, brachytherapy (intracavitary and/or interstitial) has been progressively introduced. Its evolution and its progressive improvement have led to the development of high dose rate brachytherapy, the advantages of which are especially based on the possibility of outpatient treatment while maintaining the effectiveness of other brachytherapy forms (i.e., low dose rate or pulsed dose rate). Numerous innovations have also been completed in the field of imaging, leading to a progress in treatment planning systems by switching from two-dimensional form to a three-dimensional one. Image-guided brachytherapy allows more precise target volume delineation as well as an optimized dosimetry permitting a better coverage of target volumes.

Variable impact of intracavitary brachytherapy fractionation schedule on biologically effective dose to organs at risk in patients with cervical cancer

PURPOSE

To determine the effect of intracavitary brachytherapy (ICBT) fractionation schedule on biologically effective dose to organs at risk.

METHODS AND MATERIALS

We reviewed records from 26 patients who had CT imaging during ICBT for International Federation of Gynecology and Obstetrics stage IB2-IVA cervical cancer. Using α/β=10, we calculated hypothetical nominal doses to achieve a biologically effective dose at 2 Gy per fraction (EQD2α/β=10) of 40 Gy to Point A for high-dose-rate ICBT with 1-15 fractions. Corresponding minimum EQD2α/β=3s to the maximally irradiated 2 cc of rectum, bladder, and sigmoid were calculated for each fractionation scheme and added to EQD2α/β=3 from external beam radiotherapy. Total EQD2α/β=3s were compared with American Brachytherapy Society suggested dose constraints (rectum/sigmoid, ≤75 Gy; bladder, ≤90 Gy).

RESULTS

Except for rectal EQD2α/β=3 in three patients, the rectal, bladder, and sigmoid EQD2α/β=3s decreased with increasing fractionation in all patients. Although the total rectal EQD2α/β=3s were less than the American Brachytherapy Society rectal dose constraint in all patients at all fractionation schedules, the total bladder EQD2α/β=3s routinely exceeded the bladder dose constraint, even at maximum fractionation. By contrast, increasing fractionation decreased the number of patients with doses exceeding the sigmoid dose constraint by 48%.

CONCLUSIONS

The relationship between ICBT fractionation schedule and relative EQD2α/β=3s to rectum, bladder, and sigmoid depends on individual anatomy. Fractionation optimization can improve therapeutic ratios by minimizing the risk or severity of toxic effects. For patients in whom many fractions optimize the therapeutic ratio, low-dose-rate or pulsed-dose-rate brachytherapy may be preferred.

Concurrent chemoradiation for vaginal cancer

Background

It is not known whether the addition of chemotherapy to radiation therapy improves outcomes in primary vaginal cancer. Here, we review clinical outcomes in patients with primary vaginal cancer treated with radiation therapy (RT) or concurrent chemoradiation therapy (CRT).

Methods

Seventy-one patients with primary vaginal cancer treated with definitive RT with or without concurrent chemotherapy at a single institution were identified and their records reviewed. A total of 51 patients were treated with RT alone; 20 patients were treated with CRT. Recurrences were analyzed. Overall survival (OS) and disease-free survival (DFS) rates were estimated using the Kaplan-Meier method. Cox regression analysis was performed.

Results

The median age at diagnosis was 61 years (range, 18–92 years) and the median follow-up time among survivors was 3.0 years. Kaplan-Meier estimates for OS and DFS differed significantly between the RT and CRT groups (3-yr OS = 56% vs. 79%, log-rank p = 0.037; 3-yr DFS = 43% vs. 73%, log-rank p = 0.011). Twenty-three patients (45%) in the RT group had a relapse at any site compared to 3 (15%) in the CRT group (p = 0.027). With regard to the sites of first relapse, 10 patients (14%) had local only, 4 (6%) had local and regional, 9 (13%) had regional only, 1 (1%) had regional and distant, and 2 (3%) had distant only relapse. On univariate analysis, the use of concurrent chemotherapy, FIGO stage, tumor size, and date of diagnosis were significant predictors of DFS. On multivariate analysis, the use of concurrent chemotherapy remained a significant predictor of DFS (hazard ratio 0.31 (95% CI, 0.10–0.97; p = 0.04)).

Conclusions

Vaginal cancer results in poor outcomes. Adequate radiation dose is essential to ensure curative management. Concurrent chemotherapy should be considered for vaginal cancer patients.

[Radiobiology in brachytherapy]

Low-dose rate brachytherapy has some radiobiological advantages compared to external beam radiotherapy: subletal damages repair during irradiation leading to a relative protection of healthy tissues; no tumor cell repopulation, cell cycle redistribution and a low oxygen enhancement ratio. High dose rate and pulsed dose rate modalities allow an optimization of dose distribution by varying the dwell times over the different dwell positions. Because of the use of afterloaders, they also offer a better radioprotection of the staff. High dose rate and pulsed dose rate treatments seem to offer the same results as low-dose rate brachytherapy, particularly in cervix carcinoma. For high dose rate brachytherapy, schedules must be designed according to the linear-quadratic model. In pulsed dose rate brachytherapy, pulse dose and time intervals must also be derived from the linear-quadratic model, but half-time repair must be taken into account.

American Brachytherapy Society consensus guidelines for locally advanced carcinoma of the cervix. Part II: high-dose-rate brachytherapy

PURPOSE

This report presents an update to the American Brachytherapy Society (ABS) high-dose-rate (HDR) brachytherapy guidelines for locally advanced cervical cancer.

METHODS

Members of the ABS with expertise in cervical cancer formulated updated guidelines for HDR brachytherapy using tandem and ring, ovoids, cylinder, or interstitial applicators for locally advanced cervical cancer. These guidelines were written based on medical evidence in the literature and input of clinical experts in gynecologic brachytherapy.

RESULTS

The ABS affirms the essential curative role of tandem-based brachytherapy in the management of locally advanced cervical cancer. Proper applicator selection, insertion, and imaging are fundamental aspects of the procedure. Three-dimensional imaging with magnetic resonance or computed tomography or radiographic imaging may be used for treatment planning. Dosimetry must be performed after each insertion before treatment delivery. Applicator placement, dose specification, and dose fractionation must be documented, quality assurance measures must be performed, and followup information must be obtained. A variety of dose/fractionation schedules and methods for integrating brachytherapy with external-beam radiation exist. The recommended tumor dose in 2-Gray (Gy) per fraction radiobiologic equivalence (normalized therapy dose) is 80-90Gy, depending on tumor size at the time of brachytherapy. Dose limits for normal tissues are discussed.

CONCLUSION

These guidelines update those of 2000 and provide a comprehensive description of HDR cervical cancer brachytherapy in 2011.

American Brachytherapy Society consensus guidelines for locally advanced carcinoma of the cervix. Part II: high-dose-rate brachytherapy

PURPOSE

This report presents an update to the American Brachytherapy Society (ABS) high-dose-rate (HDR) brachytherapy guidelines for locally advanced cervical cancer.

METHODS

Members of the ABS with expertise in cervical cancer formulated updated guidelines for HDR brachytherapy using tandem and ring, ovoids, cylinder, or interstitial applicators for locally advanced cervical cancer. These guidelines were written based on medical evidence in the literature and input of clinical experts in gynecologic brachytherapy.

RESULTS

The ABS affirms the essential curative role of tandem-based brachytherapy in the management of locally advanced cervical cancer. Proper applicator selection, insertion, and imaging are fundamental aspects of the procedure. Three-dimensional imaging with magnetic resonance or computed tomography or radiographic imaging may be used for treatment planning. Dosimetry must be performed after each insertion before treatment delivery. Applicator placement, dose specification, and dose fractionation must be documented, quality assurance measures must be performed, and followup information must be obtained. A variety of dose/fractionation schedules and methods for integrating brachytherapy with external-beam radiation exist. The recommended tumor dose in 2-Gray (Gy) per fraction radiobiologic equivalence (normalized therapy dose) is 80-90Gy, depending on tumor size at the time of brachytherapy. Dose limits for normal tissues are discussed.

CONCLUSION

These guidelines update those of 2000 and provide a comprehensive description of HDR cervical cancer brachytherapy in 2011.

Imaging technologies for high dose rate brachytherapy for cervical cancer: a systematic review

The aim of this overview was to assess the utility of various imaging technologies (fluoroscopy, ultrasound, computed tomography, magnetic resonance imaging and positron emission tomography) for the treatment planning of high dose rate brachytherapy for cervical cancer. Reviews and primary studies comparing different imaging technologies used during high dose rate brachytherapy for cervical cancer and published from 1988 to 2008 were sought by searching MEDLINE and EMBASE databases, the Cochrane Library, personal files and reference lists of identified studies, and by contacting experts. Study selection, study quality assessment and data extraction were carried out in duplicate. Twelve studies met the inclusion criteria. No systematic reviews or randomised controlled studies (RCTs) were located. The validity assessment revealed that the quality of the existing studies is very variable. This is the first systematic review in the area of imaging technologies for cervix brachytherapy. No RCTs have been located and it is possible that an RCT is not the optimal methodology to assess imaging technologies. However, in this area there is a need for more prospective studies and for studies that consider the expertise of the operators in their design. The studies found supported the use of three-dimensional imaging as opposed to the traditional two-dimensional imaging. However, apart from the effectiveness of visualising tumours and surrounding tissues, the utility of imaging technologies in clinical practice is determined by other contextual factors, such as their availability, accessibility and ease of use.

International brachytherapy practice patterns: a survey of the Gynecologic Cancer Intergroup (GCIG)

PURPOSE

To determine current practice patterns with regard to gynecologic high-dose-rate (HDR) brachytherapy among international members of the Gynecologic Cancer Intergroup (GCIG) in Japan/Korea (Asia), Australia/New Zealand (ANZ), Europe (E), and North America (NAm).

METHODS AND MATERIALS

A 32-item survey was developed requesting information on brachytherapy practice patterns and standard management for Stage IB-IVA cervical cancer. The chair of each GCIG member cooperative group selected radiation oncology members to receive the survey.

RESULTS

A total of 72 responses were analyzed; 61 respondents (85%) used HDR. The three most common HDR brachytherapy fractionation regimens for Stage IB-IIA patients were 6 Gy for five fractions (18%), 6 Gy for four fractions (15%), and 7 Gy for three fractions (11%); for Stage IIB-IVA patients they were 6 Gy for five fractions (19%), 7 Gy for four fractions (8%), and 7 Gy for three fractions (8%). Overall, the mean combined external-beam and brachytherapy equivalent dose (EQD2) was 81.1 (standard deviation [SD] 10.16). The mean EQD2 recommended for Stage IB-IIA patients was 78.9 Gy (SD 10.7) and for Stage IIB-IVA was 83.3 Gy (SD 11.2) (p = 0.02). By region, the mean combined EQD2 was as follows: Asia, 71.2 Gy (SD 12.65); ANZ, 81.18 (SD 4.96); E, 83.24 (SD 10.75); and NAm, 81.66 (SD, 6.05; p = 0.02 for Asia vs. other regions).The ratio of brachytherapy to total prescribed dose was significantly higher for Japan (p = 0.0002).

CONCLUSION

Although fractionation patterns may vary, the overall mean doses administered for cervical cancer are similar in Australia/New Zealand, Europe, and North America, with practitioners in Japan administering a significantly lower external-beam dose but higher brachytherapy dose to the cervix. Given common goals, standardization should be possible in future clinical trials.

High dose rate versus low dose rate intracavity brachytherapy for locally advanced uterine cervix cancer

BACKGROUND

Carcinoma of the uterine cervix is the second most common cancer and the third leading cause of cancer death among women. Radiotherapy has been used successfully to treat cervical cancer for nearly a century. The combination of external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT) has become a standard treatment modality for cervical cancer. Depending on the difference in dose rate on 'Point A' (located 2 cm above the cervical os and 2 cm lateral to the central axis of the uterus), the ICBT is divided into three modalities: low dose rate (LDR), high dose rate (HDR) and medium dose rate (MDR). Despite the practical advantages of HDR, it is necessary to investigate further the efficacy and safety of HDR brachytherapy compared to LDR brachytherapy. Questions arise as to whether HDR or LDR brachytherapy improves results for patients with cervical cancer in terms of local control rates, survival and complications related to treatment.

OBJECTIVES

To assess the efficacy and safety of HDR- versus LDR-ICBT for patients with uterine cervical cancer.

SEARCH STRATEGY

We searched the Cochrane Gynaecological Cancer Group Specialised Register and the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 4), MEDLINE (1966 to November 2009), EMBASE (1974 to November 2009), Chinese Biomedical Literature Database (CBM) (1978 to November 2009) for relevant original, published trials.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs that compared HDR- with LDR-ICBT, combined with EBRT, for patients with locally advanced uterine cervical cancer.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data using standardised forms. Primary outcome measures included overall survival (OS), relapse-free survival (RFS) and pelvic control rate, while secondary outcomes included rates of recurrence and complications.

MAIN RESULTS

Four studies involving 1265 patients met the inclusion criteria. In our meta-analysis to compare HDR and LDR, the pooled RRs were 0.95 (95% CI 0.79 to 1.15), 0.93 (95% CI 0.84 to 1.04) and 0.79 (95% CI 0.52 to 1.20) for 3-, 5- and 10-year overall survival rates; and 0.95 (95% CI 0.84 to 1.07) and 1.02 (0.88 to 1.19) for 5- and 10-year disease-specific survival (DSS) rates. The RR for RFS was 1.04 (95% CI 0.71 to 1.52) and 0.96 (95% CI 0.81 to 1.14) at three and five years. For local control rates the RR was 0.95 (95% CI 0.86 to 1.05) and 0.95 (95% CI 0.87 to 1.05) at three and five years; with a RR of 1.09 (95% CI 0.83 to 1.43) for locoregional recurrence, 0.79 (95% CI 0.40 to 1.53) for local and distance recurrence, 2.23 (95% CI 0.78 to 6.34) for para-aortic lymph node metastasis and 0.99 (95% CI 0.72 to 1.35) for distance metastasis. For bladder, rectosigmoid and small bowel complications, the RR was 1.33 (95% CI 0.53 to 3.34), 1.00 (95% CI 0.52 to 1.91) and 3.37 (95% CI 1.06 to 10.72), respectively. These results indicate that there were no significant differences except for increased small bowel complications with HDR (P = 0.04).

AUTHORS' CONCLUSIONS

This review showed no significant differences between HDR- and LDR-ICBT when considering OS, DSS, RFS, local control rate, recurrence, metastasis and treatment related complications for women with cervical carcinoma. Due to some potential advantages of HDR-ICBT (rigid immobilization, outpatient treatment, patient convenience, accuracy of source and applicator positioning, individualized treatment) we recommend the use of HDR-ICBT for all clinical stages of cervix cancer.

MR imaging-guided interventions in the genitourinary tract: an evolving concept

MR imaging-guided interventions are well established in routine patient care in many parts of the world. There are many approaches, depending on magnet design and clinical need, based on MR imaging providing excellent inherent tissue contrast without ionizing radiation risk for patients. MR imaging-guided minimally invasive therapeutic procedures have advantages over conventional surgical procedures. In the genitourinary tract, MR imaging guidance has a role in tumor detection, localization, and staging and can provide accurate image guidance for minimally invasive procedures. The advent of molecular and metabolic imaging and use of higher strength magnets likely will improve diagnostic accuracy and allow targeted therapy to maximize disease control and minimize side effects.

Management of early and locally advanced cervical cancer

Cervical cancer is the second most common malignancy in women and the third most common cause of cancer mortality worldwide. While primary and secondary preventions exist, the lack of widespread adoption leaves the treatment of cervical cancer an important oncologic problem. In this article, the management of early and locally advanced cervical carcinoma is reviewed, including staging, imaging, prognostic factors, and primary and adjuvant therapy and their outcomes.

Brachytherapy for cervix cancer: low-dose rate or high-dose rate brachytherapy - a meta-analysis of clinical trials

Background

The literature supporting high-dose rate brachytherapy (HDR) in the treatment of cervical carcinoma derives primarily from retrospective series. However, controversy still persists regarding the efficacy and safety of HDR brachytherapy compared to low-dose rate (LDR) brachytherapy, in particular, due to inadequate tumor coverage for stage III patients. Whether LDR or HDR brachytherapy produces better results for these patients in terms of survival rate, local control rate and the treatment complications remain controversial.

Methods

A meta-analysis of RCT was performed comparing LDR to HDR brachytherapy for cervix cancer treated for radiotherapy alone. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, as well as abstracts published in the annual proceedings were systematically searched. We assessed methodological quality for each outcome by grading the quality of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. We used "recommend" for strong recommendations, and "suggest" for weak recommendations.

Results

Pooled results from five randomized trials (2,065 patients) of HDR brachytherapy in cervix cancer showed no significant increase of mortality (p = 0.52), local recurrence (p = 0.68), or late complications (rectal; p = 0.7, bladder; p = 0.95 or small intestine; p = 0.06) rates as compared to LDR brachytherapy. In the subgroup analysis no difference was observed for overall mortality and local recurrence in patients with clinical stages I, II and III. The quality of evidence was low for mortality and local recurrence in patients with clinical stage I, and moderate for other clinical stages.

Conclusion

Our meta-analysis shows that there are no differences between HDR and LDR for overall survival, local recurrence and late complications for clinical stages I, II and III. By means of the GRADE system, we recommend the use of HDR for all clinical stages of cervix cancer.

A cost comparison of two strategies for treating stage IB2 cervical cancer

Patients with stage IB2 cervical cancer at our institution are treated primarily with definitive chemoradiation, or chemoradiation followed by adjuvant hysterectomy. We sought to compare the cost differences associated with these two strategies. We identified all patients with stage IB2 cervical cancer who received their entire treatment regimen at our institution between 1995 and 2004. All patients received a combination of chemotherapy, external beam radiation, and one brachytherapy procedure, followed by either a second brachytherapy procedure or a simple hysterectomy. We retrieved cost data associated with hospitalization for the completion of respective treatment, including pharmacy, laboratory and pathology, radiation, and operating room services, as well as the costs of supplies and room and board. We identified 46 patients with stage IB2 cervical cancer, 23 who received a second brachytherapy procedure and 23 who underwent simple hysterectomy. Patients displayed similar demographics and similar disease characteristics including initial tumor diameter and histology. The cost of care for adjuvant hysterectomy group was greater ($8,316.70 vs 5,508.70, P < 0.0001). Specific differences included higher operating room costs ($1520 vs 414, P < 0.0001), pharmacy costs ($675 vs 342, P < 0.0001), and laboratory/pathology costs ($597 vs 89, P < 0.0001). We conclude that definitive chemoradiation appears to be associated with lower costs for management of stage IB2 cervical cancer when compared to simple adjuvant hysterectomy.

MR imaging-guided interventions in the genitourinary tract: an evolving concept

MR imaging-guided interventions are well established in routine patient care in many parts of the world. There are many approaches, depending on magnet design and clinical need, based on MR imaging providing excellent inherent tissue contrast without ionizing radiation risk for patients. MR imaging-guided minimally invasive therapeutic procedures have advantages over conventional surgical procedures. In the genitourinary tract, MR imaging guidance has a role in tumor detection, localization, and staging and can provide accurate image guidance for minimally invasive procedures. The advent of molecular and metabolic imaging and use of higher strength magnets likely will improve diagnostic accuracy and allow targeted therapy to maximize disease control and minimize side effects.

Multimodality therapy for locally advanced cervical carcinoma: state of the art and future directions

Globally, cervical cancer is the second most common cause of cancer-related mortality among women causing approximately 234,000 deaths annually among developing countries and killing 40,000 in developed nations. Most of these deaths occur in women with bulky or locally advanced cervical cancer, International Federation of Gynecology and Obstetrics (FIGO) stages IIB through IVA, when lesions are not amenable to high cure rates with surgery or radiation (RT). The standard prescription for RT used to treat locally advanced cervical cancer has been dictated by common practice and patterns of care studies. In contrast, the addition of concomitant chemotherapy to RT has been studied in a number of randomized prospective trials, which are discussed in detail. When added to RT, cisplatin reduces the relative risk of death from cervical carcinoma by approximately 50% by decreasing local/pelvic failure and distant metastases. In 1999, weekly intravenous cisplatin at 40 mg/m2 for 6 weeks in combination with RT was established as a new standard for the treatment of locally advanced cervical carcinoma. More recently, this recommendation has been expanded to include women with FIGO stage IB2 lesions as well as those with bulky stage IIA cancers. This monograph reviews the state of the art in treating locally advanced cervical cancer with combined chemotherapy and RT and discusses clinical and pathologic prognostic factors that impact cure. Quality of life during and after multimodality therapy is considered as well as ongoing clinical trials and future directions.