Patterns of regional recurrence after definitive radiotherapy for cervical cancer

Assessing the Adequacy of Traditional Vertebral Landmarks as Upper Border of Whole Pelvic Radiotherapy Field for Stage IB2-IIB Cervical Cancer

This study investigates the impact of insufficient common iliac lymph node (CIN) irradiation on treatment outcomes in patients with stage IB2-IIB cervical cancer receiving concurrent chemoradiotherapy (CCRT). We retrospectively analyzed 68 patients with Federation of Gynecology and Obstetrics stage IB2-IIB, treated with weekly cisplatin-based CCRT from 2008 to 2018. Patients received external-beam whole pelvic radiotherapy (WPRT) and concurrent cisplatin chemotherapy, followed by high-dose-rate brachytherapy. The WPRT upper border was at L4-5 in 61 patients and L3-4 in 7 patients. Thirty-seven patients had the CIN area fully included (full-CIN group), while 31 had partial inclusion (partial-CIN group). Recurrence rates and survival outcomes were analyzed over a median follow-up of 111 months. Patient characteristics and the irradiated dose were comparable. Treatment failure occurred in three patients (8.1%) in the full-CIN group and in six patients (19.4%) in the partial-CIN group, with CIN and para-aortic lymph node recurrence in two and one patients, respectively. The 5-year cumulative recurrence rate was 0% for the full-CIN group and 11.4% for the partial-CIN group (p = 0.04). Cause-specific survival was 100% vs. 87.1% (p = 0.025), and the overall survival was 94.3% vs. 87.1% (p = 0.44). Fully including the CIN area in WPRT is crucial for stage IB2-IIB cervical cancer. Vascular anatomical margins should be considered over vertebral landmarks.

Efficacy and safety of EGFR inhibitor gefitinib in recurrent or metastatic cervical cancer: a preliminary report

There has been growing interest in the use of epidermal growth factor receptor inhibitors in various cancers. The study was conducted to evaluate the efficacy and safety of gefitinib as a monotherapy in patients with recurrent or metastatic cervical cancer. Patients with cervical carcinoma who experienced locoregional recurrence or distant metastases either at presentation or after definitive combined chemoradiotherapy or postoperative radiotherapy were enrolled. Gefitinib was administered orally at a dose of 250 mg/d to eligible patients. Treatment with Gefitinib was continued until disease progression, intolerable adverse effects were developed, or consent was withdrawn. Clinical and radiological investigations were used to verify the disease response. Toxicity was graded according to the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. The study enrolled 32 patients who met the eligibility criteria. Thirty patients were available for the analysis. The majority of the patients included in the analysis had FIGO stage IIIB disease at their initial presentation. The median follow-up time was 6 months (3-15 months). Two patients (7%) had a complete clinical response, 7 patients (23%) had a partial response, 5 patients (17%) showed a stable disease and 16 patients had progressive disease (53%). The disease control rate was 47%. The median PFS was noted to be 4.5 months and the 1-year PFS was 20%. None of the individuals experienced toxicity of grade 3 or higher. All toxicities were managed conservatively. The study suggests that gefitinib may be a promising therapeutic option for patients with advanced cervical cancer who have limited treatment alternatives.

Insights into the characteristics of primary radioresistant cervical cancer using single-cell transcriptomics

Radioresistance is a major cause of radiotherapy failure among patients with cervical cancer (CC), the fourth most common cause of cancer mortality in women worldwide. Traditional CC cell lines lose intra-tumoral heterogeneity, posing a challenge for radioresistance research. Meanwhile, conditional reprogramming (CR) maintains intra-tumoral heterogeneity and complexity, as well as the genomic and clinical characteristics of original cells and tissues. Three radioresistant and two radiosensitive primary CC cell lines were developed under CR conditions from patient specimens, and their characteristics were verified via immunofluorescence, growth kinetics, clone forming assay, xenografting, and immunohistochemistry. The CR cell lines had homogenous characteristics with original tumor tissues and maintained radiosensitivity in vitro and in vivo, while also maintaining intra-tumoral heterogeneity according to single-cell RNA sequencing analysis. Upon further investigation, 20.83% of cells in radioresistant CR cell lines aggregated in the G2/M cell cycle phase, which is sensitive to radiation, compared to 38.1% of cells in radiosensitive CR cell lines. This study established three radioresistant and two radiosensitive CC cell lines through CR, which will benefit further research investigating radiosensitivity in CC. Our present study may provide an ideal model for research on development of radioresistance and potential therapeutic targets in CC.

Neoadjuvant Chemoradiotherapy With Simultaneous Integrated Boost in Locally Advanced Cervical Cancer: Long Term Results of a Single-Center Experience

Aim of this study was to analyze the efficacy and tolerability of simultaneous integrated boost volumetric modulated arc therapy (SIB-VMAT) associated with cisplatin-based chemotherapy in preoperative setting of patients with locally advanced cervical cancer (LACC). From June 2013 to September 2019, we analyzed patients with LACC who had undergone neoadjuvant chemoradiation (CRT). A radiation dose of 39.6 Gy, 1.8 Gy/fraction was delivered to the pelvis plus a radiation dose to the primary tumor delivered with SIB-VMAT strategy for a total of 50.6Gy, 2.3Gy/fraction in 25 fractions. Cisplatin-based chemotherapy was delivered combined with radiotherapy. Radical hysterectomy plus pelvic with or without aortic lymphadenectomy was performed within 7 to 8 weeks from CRT. One hundred forty-eight patients (median age: 49.5 years; FIGO stage IB2: 7, IIA: 8, IIB: 106, IIIA: 5; IIIB: 16; IVA: 5, IVB: 1; N0: 56, N1: 92) were analyzed. The treatment was well tolerated with good compliance: no grade 3/4 gastrointestinal or genitourinary toxicity was reported; grade 3 neutropenia was described in five cases. Pathological complete response (pCR) was documented in 68 cases (46%) and 32 patients (21.6%) had microscopic residual disease. Pathological nodal involvement was observed in 23 patients (15.5%). At median follow-up of 59 months (range: 27-100), the 3-year local control was 78.5%, whereas the 3-year metastasis-free survival was 70.5%. The 3-year overall survival rate was 89.0%. Neoadjuvant CRT with SIB-VMAT followed by radical surgery results in a high rate of pathologically assessed complete response and a very encouraging local control rate, with acceptable toxicity.

First experiences with PET-MRI/CT in radiotherapy planning for cervical cancer

Purpose

PET-CT has recently been included in the NCCN staging recommendations for cervical cancer stages II–IV and is already routinely applied to radiotherapy planning for other malignancies, as it is expected to provide higher accuracy for the detection of areas with tumor cell spread. In this study, we report on our first experiences of PET-based radiotherapy planning for cervical cancer.

Methods

19 patients with cervical cancer that underwent pre-therapeutic PET imaging treated at our institution between January 2016 and April 2019 were included in the study. Information on the primary tumor, lymph node involvement, metastatic spread and changes in the radiotherapy procedure based on the PET findings are described.

Results

A previously unknown primary tumor extension that was detected by PET imaging in one patient. In patients who underwent a PET before the systematic pelvic and paraaortic lymphonodectomy (n = 2), PET was false negative for pelvic lymph node metastases in 50%. In patients who underwent a PET after the systematic LNE (n = 13), additional lymph node metastases were detected in seven patients (53.80%). Distant metastases were suspected in three patients (15.7%) based on PET imaging. The suspicion was confirmed in one patient (peritoneal spread) and excluded in two patients (supra-diaphragmatic lymph nodes). In 13 patients (68.4%), RT procedures were altered due to findings in PET imaging.

Conclusion

PET-based radiochemotherapy planning may improve control rates by identifying areas of tumor cell spread eligible for dose escalation. False positivity, however, should be excluded in patients with findings that lead to major modifications of the therapeutic strategy.

Treatment Strategies and Prognostic Factors of 2018 FIGO Stage IIIC Cervical Cancer: A Review

Cervical cancer is the fourth most common malignant tumor globally in terms of morbidity and mortality. The presence of lymph node metastasis (LNM) is an independent prognostic factor for progression-free survival (PFS) and overall survival (OS) in cervical cancer patients. The International Federation of Gynecology and Obstetrics (FIGO) staging system was revised in 2018. An important revision designates patients with regional LNM as stage IIIC, pelvic LNM only as stage IIIC1, and para-aortic LNM as stage IIIC2. However, the current staging system is only based on the anatomical location of metastatic lymph nodes (LNs). It does not consider other LN status parameters, which may limit its prognostic significance to a certain extent and needs further exploration and confirmation in the future. The purpose of this review is to summarize the choice of treatment for stage IIIC cervical cancer and the effect of different LN status parameters on prognosis.

Risk factors for nodal failure after radiochemotherapy and image guided brachytherapy in locally advanced cervical cancer: An EMBRACE analysis

OBJECTIVE

To assess risk factors for nodal failure (NF) after definitive (chemo)radiotherapy and image-guided brachytherapy for locally advanced cervical cancer (LACC) for patients treated in the EMBRACE I study.

MATERIALS AND METHODS

Data for pelvic NF and para-aortic (PAO) NF (NF_PAO) were analysed. After multiple imputation, univariable and multivariable Cox-regression was performed for clinical and treatment-related variables. For patients with affected pelvic nodes but no PAO nodes at diagnosis, additional analyses were performed for two subgroups: 1. 'small pelvis' nodes in internal and external iliac, obturator, parametrial, presacral and/or common iliac (CI) region and 2. any CI nodes (subgroup of 1).

RESULTS

1338 patients with 152 NF and 104 NF_PAO events were analysed with a median follow-up of 34.2 months (IQR 16.4-52.7). For the entire group, larger tumour width, nodal risk groups (in particular any CI nodes without PAO nodes), local failure, and lower Hb-nadir increased the risk of NF. Elective PAO-irradiation was independently associated with a decreased risk of NF_PAO (HR 0.53, 95%-CI 0.28-1.00, p = 0.05). For subgroup 1, having 'any CI nodes without PAO nodes' and local failure significantly increased NF risk. Additionally, elective PAO-irradiation was associated with less risk of NF_PAO (HR 0.38, 95%-CI 0.17-0.86, p = 0.02). For subgroup 2 only local failure was associated with higher risk of NF.

CONCLUSION

In this patient cohort, nodal disease and tumour width at diagnosis, as well as local failure, are risk factors for NF after definitive treatment. Having either 'any PAO nodes' (with or without pelvic nodes) or 'any CI nodes' (without PAO nodes) are stronger risk factors than involvement of nodes in the small pelvis alone. Elective PAO-irradiation was associated with significantly less NF_PAO, particularly in patients with nodal disease in the 'small pelvis' and/or CI region at time of diagnosis.

Prospective observational study evaluating acute and delayed treatment related toxicities of prophylactic extended field volumetric modulated arc therapy with concurrent cisplatin in cervical cancer patients with pelvic lymph node metastasis

PURPOSE

To evaluate the treatment related acute and delayed toxicities of extended field Volumetric modulated arc therapy (VMAT) with concurrent chemotherapy in patients of locally advanced cervical cancer with pelvic lymph nodes.

MATERIAL AND METHODS

From 2014 to 2016, 15 patients of locally advanced cervical cancer with Fluoro-deoxyglucose positron emission tomography (FDG-PET) positive pelvic lymph nodes were treated with extended field Simultaneous integrated boost (SIB)-VMAT 45 Gy/55 Gy/25#/5weeks and concurrent cisplatin. Acute toxicities were documented according to common terminology criteria for adverse events version 4 (CTCAE v.4). Dose volume parameters and patient characteristics were analyzed for association with toxicities.

RESULTS

Median age of patients at diagnosis was 48 years. 40% (6 patients) were stage IIB & 60% (9 patients) were stage IIIB. Median number of involved pelvic lymph nodes was 2 (range, 1-4), commonest location was external iliac lymph node region (86%). Median number of concurrent chemotherapy cycles received was five. Treatment was well tolerated and there were no grade ≥ 3 acute toxicities. Commonest acute toxicities observed were vomiting (≥grade2 -13.3%) followed by & nausea (grade ≥ 2 in 6%) and were associated with volume of bowel bag receiving 45 Gy. Constitutional symptoms (≥grade 2) were observed in 6% patients and had no dosimetric associations. At a median follow up of 43 months, delayed ≥ grade1, 2, 3 toxicity were observed in 80%, 0%, and 0% respectively with diarrhea being the commonest.

CONCLUSION

Prophylactic para aortic extended field VMAT with concurrent chemotherapy for locally advanced cervical cancer is well tolerated with acceptable acute toxicity profile. Significant grade 3 acute/delayed toxicities were not observed in this cohort of patients.

Molecular landscape of recurrent cervical cancer

Cervical cancer (CC) is a major gynecological problem in developing and underdeveloped countries. Despite the significant advancement in early detection and treatment modalities, several patients recur. Moreover, the molecular mechanisms responsible for CC recurrence remains obscure. The patients with CC recurrence often show poor prognosis and significantly high mortality rates. The clinical management of recurrent CC depends on treatment history, site, and extent of the recurrence. Owing to poor prognosis and limited treatment options, recurrent CC often presents a challenge to the clinicians. Several in vitro, in vivo, and patient studies have led to the identification of the critical molecular changes responsible for CC recurrence. Both aberrant genetic and epigenetic modifications leading to altered cell signaling pathways have been reported to impact CC recurrence. Researchers are currently trying to dissect the molecular pathways in CC and translate these findings for better management of disease. This article attempts to review the existing knowledge of disease relapse, accompanying challenges, and associated molecular players in CC.

Who can benefit from a lymph node boost in definitive chemoradiotherapy for node-positive cervical cancer: an evaluation of nodal failure in patients without nodal boost

This study was performed to identify risk factors for pelvic nodal failure (PNF) after definitive concurrent chemo-radiotherapy (CCRT) in patients with metastatic pelvic lymph nodes (mPLNs) from squamous cell carcinoma (SCC) of the cervix. We retrospectively reviewed data on 80 patients who received definitive CCRT between 2005 and 2014 at our hospital. All patients underwent brachytherapy and whole-pelvic radiotherapy (WPRT) without nodal boost. mPLNs was diagnosed by magnetic resonance imaging and positron emission tomography. The rate of PNF and factors affecting PNF were analysed. A total of 156 mPLNs were found. The median number of mPLNs was 2 per patient (range 1-6); the median short diameter was 1.7 cm (range 1.0-4.2 cm). After a median follow-up of 64 months, 10 (6.4%) mPLNs failed in 13 (16.3%) patients. The 5-year PNF-free survival (PNFFS), disease-free survival and overall survival rates were 83.4, 62.7 and 74.7%, respectively. The mPLN size was not associated with the risk of PNF. However, pre-radiotherapy SCC antigen (SCC-Ag) >6.8 ng/mL and number of mPLNs >2 were significant risk factors for PNF. Using the two risk factors, we categorized the patients into three risk groups. The 5-year PNFFS rates in patients with 0, 1 and 2 risk factors were 100.0, 78.3 and 44.4%, respectively (P < 0.01). SCC-Ag level and number of mPLNs were significant factors for PNF. Patients with both risk factors developed frequent PNF after WPRT without nodal boost. The two risk factors can be a guide in deciding whether to administer nodal boost radiotherapy.

Comprehensive analysis of patient outcome after local recurrence of locally advanced cervical cancer treated with concomitant chemoradiation and image-guided adaptive brachytherapy

INTRODUCTION

Since dose escalation allowed by image-guided adaptive brachytherapy (IGABT) in locally advanced cervical cancer (LACC), local relapses have become a rare event. Only scarce data are available on the outcome of patients experiencing a local relapse after IGABT.

METHODS

Between 2004 and 2016, all consecutive patients treated at Gustave Roussy Institute for LACC and receiving concomitant chemoradiation and IGABT were analysed. Clinical and treatment-related prognostic factors for survival after local relapse were searched, in order to potentially identify patients requiring salvage treatment.

RESULTS

Two hundred and fifty-nine patients were treated during this period. With a median follow-up of 4.1 years, 10.8% (n = 28) had a local relapse. Among these patients, 53.6% had synchronous lymph nodes or distant metastatic relapse and only 13 patients (5% of all patients) had isolated local relapse. After local relapse, median survival was 47 months and three patients were alive at last follow-up. Only three patients with local relapse could receive salvage surgery (10.7%). Metastases occurrence and pelvic wall involvement were the main contraindications (67.9%) for salvage surgery. Among the three patients treated with surgery, two are still alive at last follow-up without significant complication. Improved survival was observed among the two patients who could have surgery (p = .02). Local progression led to serious symptoms in 75% of patients. Only the time interval between brachytherapy and relapse (<1 year) was prognostic for 2-year overall survival (p = .005).

CONCLUSION

Salvage surgery is feasible in a very low number of highly selected patients with local relapse following IGABT. Local failure is a major cause of severe local symptoms, confirming that every effort should be done to achieve long-term local control through dose escalation.

Primary radical hysterectomy vs chemoradiation for IB2-IIA cervical cancer: A systematic review and meta-analysis

BACKGROUND

To compare the clinical outcomes of radical hysterectomy (RH) with chemoradiotherapy (CRT) in women with stage IB2-IIA cervical cancer.

METHODS

Based on articles published up to December 2017, a literature search of PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and Chinese National Knowledge Infrastructure (CNKI) databases was conducted to identify eligible studies. Overall survival (OS), progression-free survival (PFS) with hazard ratios (HRs), and toxicities with odds ratios (ORs) were analyzed.

RESULTS

In total, 7 studies comprising 687 patients were identified for this meta-analysis. RH showed a significant trend toward improved survival outcomes compared with those of CRT, regardless of OS (HR = 0.49, 95% confidence interval [CI] 0.36-0.67, P < .001); or PFS (1.61, 95% CI 1.15-2.26, P = .005) for IB2-IIA cervical cancer. Subgroup analysis revealed that stage IB2 cervical cancer patients obtained better OS (HR = 0.36, 95% CI 0.23-0.56, P < .001; heterogeneity: P = .32, I = 13%). However, a higher incidence of grade 3/4 genitourinary abnormalities was evident with RH (OR = 2.3, 95% CI 1.42-3.87, P = .021).

CONCLUSION

Our study suggested that RH had distinct advantages over CRT for carcinoma of the uterine cervix with FIGO stage IB2-IIA, especially for IB2 cervical cancer.

Importance of Technique, Target Selection, Contouring, Dose Prescription, and Dose-Planning in External Beam Radiation Therapy for Cervical Cancer: Evolution of Practice From EMBRACE-I to II

PURPOSE

To describe the evolution of external beam radiation therapy (EBRT) from EMBRACE-I (general guidelines for EBRT) to the initial phase of the EMBRACE-II study (detailed protocol for EBRT).

METHODS AND MATERIALS

EMBRACE-I enrolled 1416 locally advanced cervical cancer patients treated with chemoradiation including image-guided adaptive brachytherapy during 2008 to 2015. From March 2016 until March 2018, 153 patients were enrolled in the ongoing EMBRACE-II study, which involves a comprehensive detailed strategy and accreditation procedure for EBRT target contouring, treatment planning, and image guidance. EBRT planning target volumes (PTVs), treated volumes (V43 Gy), and conformity index (CI; V43 Gy/PTV) were evaluated in both studies and compared.

RESULTS

For EMBRACE-I, conformal radiation therapy (60% of patients) or intensity-modulated radiation therapy (IMRT) and volumetric arc therapy (VMAT; 40%) was applied with 45 to 50 Gy over 25 to 30 fractions to the elective clinical target volume (CTV). For pelvic CTVs (82%), median PTV and V43 Gy volumes were 1549 and 2390 mL, respectively, and CI was 1.54. For pelvic plus paraortic nodal (PAN) CTVs (15%), median PTV and V43 Gy volumes were 1921 and 2895 mL, and CI was 1.51. For pelvic CTVs treated with 45 to 46 Gy, the use of conformal radiation therapy was associated with a median V43 Gy volume that was 546 mL larger than with IMRT/VMAT. For pelvic CTVs treated with IMRT, the use of a dose prescription ≥48 Gy was associated with a median V43 Gy volumes that was 428 mL larger than with a dose prescription of 45 to 46 Gy. For EMBRACE-II, all patients were treated with: IMRT/VMAT, daily IGRT, 45 Gy over 25 fractions for the elective CTV, and simultaneously integrated boost for pathologic lymph nodes. For pelvic CTVs (61%), median PTV and V43 Gy volumes were 1388 and 1418 mL, and CI was 1.02. For pelvic plus PAN CTVs (32%), median PTV and V43 Gy volumes were 1720 and 1765 mL, and CI was 1.03. From EMBRACE-I to initial II, median V43 Gy was decreased by 972 mL (41%) and 1130 mL (39%), and median CI decreased from 1.54 to 1.02 and 1.51 to 1.03 for pelvic and pelvic plus PAN irradiation, respectively.

CONCLUSIONS

Application of IMRT/VMAT, IGRT, and a 45-Gy dose provides the potential of higher conformality inducing significant reduction of treated volume. Adherence to a detailed protocol including comprehensive accreditation, as in EMBRACE-II, reduces considerably V43 Gy and V50 Gy and improves conformality and interinstitutional consistency.

Robustness of elective lymph node target coverage with shrinking Planning Target Volume margins in external beam radiotherapy of locally advanced cervical cancer

BACKGROUND AND PURPOSE

Image-Guidance decreases set-up uncertainties, which may allow for Planning Target Volume (PTV) margins reduction. This study evaluates the robustness of the elective lymph node target coverage to translational and rotational set-up errors in combination with shrinking PTV margins and determines the gain for the Organs At Risk (OARs).

MATERIAL AND METHODS

Ten cervix cancer patients who underwent external beam radiotherapy with 45 Gy/25Fx were analysed. Daily Image-Guidance was based on bony registration of Cone Beam CT (CBCT) to planning CT (pCT) and daily couch correction (translation and yaw). On each pCT, four Volumetric Modulated Arc Therapy dose-plans were generated with PTV margins of 0, 3, 5 and 8 mm. The elective clinical target volume (CTV-E) was propagated from daily CBCTs to the pCT to evaluate daily CTV-E dose. Additional systematic translational isocenter shifts of 2 mm were simulated. D98% (dose received by 98% of the volume of interest) and D99.9% were extracted from each CTV-E for all dose-plans and scenarios. Total dose was accumulated by Dose-Volume Histogram addition. The dosimetric impact of PTV margin reduction on the OARs was evaluated through V30Gy (volume included within the 30 Gy isodose), V40Gy and body V43Gy.

RESULTS

When decreasing the PTV margin from 5 to 0 mm, bowel V30Gy was decreased by 13% (from 247 cm3 to 214 cm3), body V43Gy by 19% (from 1462 cm3 to 1188 cm3) and PTV by 39% (from 1416 to 870 cm3). The dosimetric impact of combined systematic shifts and residual rotations on the elective target with a 0 mm PTV margin was a decrease of D98% (mean ± SD) from 44.1 Gy ± 0.4 Gy to 43.7 Gy ± 0.8 Gy and a minimum of 42.4 Gy.

CONCLUSION

PTV margin reduction from 5 to 0 mm induced significant OARs dosimetric gains while elective target coverage remained robust to positioning uncertainties.

Does external beam radiation boost to pelvic lymph nodes improve outcomes in patients with locally advanced cervical cancer?

Background

Current recommendation for locally advanced cervical cancer includes pelvic external beam radiation therapy (EBRT) with concurrent chemotherapy followed by brachytherapy. Involvement of pelvic lymph nodes is an important prognostic factor in locally advanced cervical cancer and recurrence commonly occurs despite definitive treatment. To date, there is no standard guideline on whether an EBRT boost should be applied to involved pelvic lymph nodes. Our study aims to assess if pelvic EBRT boost would reduce recurrence, benefit survival, and affect associated toxicities.

Methods

We conducted a retrospective review of locally advanced cervical cancer cases treated with definitive treatment at our institution. Involvement of pelvic lymph nodes were assessed on CT, MRI (> 10 mm or suspicious features) or PET scan (SUVmax > 2.5). EBRT dose ranged from 45 to 50.4 Gy with nodal boost ranging from 3.6–19.8 Gy.

Results

Between 2008 to 2015, 139 patients with locally advanced cervical cancer underwent treatment. Sixty-seven patients had positive pelvic lymph nodes, of which 53.7% received a nodal boost. Five-year recurrence free survival was 48.6% with vs. 64.5% without nodal boost (P = 0.169) and 5-year overall survival in those with positive pelvic lymph nodes was 74.3% with vs. 80.6% without nodal boost (P = 0.143). There was no significant difference in toxicity with nodal boost.

Conclusions

EBRT boost to pelvic lymph nodes does not reduce recurrence or improve survival in locally advanced cervical cancer with lymph node involvement at diagnosis.

Efficacy and Toxicity of IMRT-Based Simultaneous Integrated Boost for the Definitive Management of Positive Lymph Nodes in Patients with Cervical Cancer

Background: The optimal radiotherapy regimen for treating metastatic lymphadenopathy in patients with locally advanced cervical cancer remains controversial. This study aimed to investigate the clinical outcomes, as well as associated toxicities, of intensity-modulated radiotherapy (IMRT) with a simultaneous integrated boost (SIB) for pelvic and para-aortic lymph nodes (LNs).

Methods: Between 2011 and 2015, 74 patients with 2014 International Federation of Gynecology and Obstetrics stage IIB-IVB cervical cancer exhibiting pelvic or para-aortic LN involvement were examined. The pelvic field planning dose was 45-50 Gy in 25 fractions, and an SIB of 62.5 Gy in 25 fractions was delivered to positive LNs. Next, CT-guided brachytherapy was performed 24 Gy in 3 fractions to 42 Gy in 6 fractions once or twice weekly.

Results: The median follow-up duration was 36 (range: 3-62) months. The 3-year local control, distant metastasis-free survival, and overall survival rates were 91.7%, 75.7%, and 71.4%, respectively. No residual or recurrent LNs were detected. Six patients developed grade 3 acute gastrointestinal (GI) toxicity. Twenty-nine (39.2%) and 3 (4.1%) patients developed grade 3 and 4 hematological toxicities, respectively. Twenty patients (28.5%) developed grade ≥2 chronic GI toxicity. Only 1 patient (1.4%) experienced a grade 4 rectovaginal fistula, and 3 patients (4.2%) developed grade 2 genitourinary toxicities. SIB to the LNs did not influence acute or chronic toxicity rates.

Conclusions: Our findings demonstrate that a dose of 62.5 Gy to positive LNs using the IMRT with SIB method can achieve excellent clinical outcomes with acceptable toxicity.

18F-FDG PET/CT in locally advanced cervical cancer: A review

Cervical cancer is the second most common gynecological cancer worldwide. In locally advanced cervical cancer, ¹⁸F-FDG PET/CT has become important in the initial staging, particularly in the detection of nodal and distant metastasis, aspects with treatment implications and prognostic value. The aims of this study were to review the role of ¹⁸F-FDG PET/CT in uterine cervical cancer, according to the guidelines of the main scientific institutions (FIGO, NCCN, SEGO, SEOM, ESGO, and ESMO) and its diagnostic accuracy compared to conventional radiological techniques, as well as to review the acquisition protocol and its utility in radiotherapy planning, response assessment and detection of recurrence.

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.

The EMBRACE II study: The outcome and prospect of two decades of evolution within the GEC-ESTRO GYN working group and the EMBRACE studies

The publication of the GEC-ESTRO recommendations one decade ago was a significant step forward for reaching international consensus on adaptive target definition and dose reporting in image guided adaptive brachytherapy (IGABT) in locally advanced cervical cancer. Since then, IGABT has been spreading, particularly in Europe, North America and Asia, and the guidelines have proved their broad acceptance and applicability in clinical practice. However, a unified approach to volume contouring and reporting does not imply a unified administration of treatment, and currently both external beam radiotherapy (EBRT) and IGABT are delivered using a large variety of techniques and prescription/fractionation schedules. With IGABT, local control is excellent in limited and well-responding tumours. The major challenges are currently loco-regional control in advanced tumours, treatment-related morbidity, and distant metastatic disease. Emerging evidence from the RetroEMBRACE and EMBRACE I studies has demonstrated that clinical outcome is related to dose prescription and technique. The next logical step is to demonstrate excellent clinical outcome with the most advanced EBRT and brachytherapy techniques based on an evidence-based prospective dose and volume prescription protocol. The EMBRACE II study is an interventional and observational multicentre study which aims to benchmark a high level of local, nodal and systemic control while limiting morbidity, using state of the art treatment including an advanced target volume selection and contouring protocol for EBRT and brachytherapy, a multi-parametric brachytherapy dose prescription protocol (clinical validation of dose constraints), and use of advanced EBRT (IMRT and IGRT) and brachytherapy (IC/IS) techniques (clinical validation). The study also incorporates translational research including imaging and tissue biomarkers.

Highly conformal combined radiotherapy with cisplatin and gemcitabine for treatment of loco-regionally advanced cervical cancer - a retrospective study

BACKGROUND

Cisplatin and gemcitabine combined with conventional radiation therapy in the treatment of cervical cancer patients results in a favorable outcome but with excess toxicity. The purpose of this study was to evaluate the toxicity profile of dual chemotherapy and highly conformal external beam radiotherapy with image guided adaptive brachytherapy.

METHODS

Seventeen patients with cervical carcinoma FIGO stage IB2-IIIB were treated with curative intent between 2011 and 2015. A total dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Patients with ¹⁸FDG-PET/CT positive lymph nodes (n = 15; 83.3%) received an additional boost to a total dose of 62 Gy. Chemotherapy prescription goals were: concomitant during 5 weeks of external beam radiotherapy (EBRT) 40 mg/m2 cisplatin and 125 mg/m² gemcitabine, followed by adjuvant chemotherapy from week 10 (2 cycles 50 mg/m² cisplatin and 1000 mg/m² gemcitabine). EBRT was followed by 3-4 fractions (6 Gy per fraction) of intrauterine image guided adaptive brachytherapy. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0).

RESULTS

One (6%) patient developed acute grade 3 diarrhea. We did not record any other acute or late gastrointestinal or urogenital toxicity higher that grade 3. Most common acute hematological toxicity was anemia grade 2 recorded in 10 (59%) patients. There was only one case of grade 3 neutropenia (6%). The number of patients that received the complete chemotherapy regimen was gradually declining during the course of therapy. From week 2 to 5, gemcitabine was omitted in 4 (24%),7 (41%), 8 (47%), and 12 (71%) patients respectively, similarly, cisplatin was omitted in 2 (12%),3 (18%),1 (6%) and 7 (41%) patients respectively. Adjuvant chemotherapy was omitted in 8 patients (47%). During a median follow-up time of 20 months (5 to 63 months) 6 (35%) patients developed disease relapse with 5 (29%) of them in the form of systemic disease.

CONCLUSIONS

In contrast to previous findings cisplatin and gemcitabine in combination with highly conformal radiation therapy seems to have an acceptable toxicity profile. Further studies are needed to determine the optimal dosage of the proposed therapy concept.

Early clinical outcome of coverage probability based treatment planning for simultaneous integrated boost of nodes in locally advanced cervical cancer

INTRODUCTION

More than 50% of patients with locally advanced cervical cancer (LACC) have pathological nodes. Coverage probability (CovP) is a new planning technique allowing for relaxed dose at the boost periphery minimising collateral irradiation. The aim was to report the first early clinical outcome data for CovP based simultaneous integrated boost (SIB) in LACC.

MATERIAL AND METHODS

Twenty-three consecutive node positive patients were analysed. FIGO stage IB2/IIB/IIIB/IVA/IVB was 1/14/3/1/4. Treatment was radio(chemo)therapy (RT) delivering 45 Gy/25 fx whole pelvis ± para-aortic region (PAN) using volumetric arc therapy (VMAT) followed by magnetic resonance imaging (MRI) guided brachytherapy. PAN RT (13 pts) was given if >2 nodes or if node(s) were present at the common iliac vessels or PAN. Nodal gross tumour volumes (GTV-N) were contoured on both PET-CT and MRI. Clinical target volume (CTV-N) was formed by fusion of GTV-N_CT and GTV-N_MRI. A 5-mm isotropic margin was used for planning target volume (PTV-N). Nodes in the small pelvis were boosted to 55.0 Gy/25 fx. Common iliac and para-aortic nodes received 57.5 Gy/25 fx. Planning aims for CovP were PTV-N D₉₈ ≥ 90%, CTV-N D₉₈ ≥ 100% and CTV-N D₅₀ ≥ 101.5%.

RESULTS

Seventy-four nodes were boosted. A consistent 5.0 ± 0.7 Gy dose reduction from CTV-N D₉₈ to PTV-N D₉₈ was obtained. In total, 73/74 nodes were in complete remission at 3 months PET-CT and MRI. Pelvic control was obtained in 21/23 patients. One patient (IB2, clear cell) had salvageable local disease, while another (IIB) failed in a boosted node. Two patients failed in un-irradiated PAN. One patient age 88 (IIIB) did not receive PAN RT, despite a common iliac node. The other (IIB) recurred above L1. Two further patients (IVB) failed systemically.

CONCLUSION

Since complete remission at 3 months is predictive for favourable long-term nodal control, our study indicates that CovP for SIB is promising.

Prophylactic lower para-aortic irradiation using intensity-modulated radiotherapy mitigates the risk of para-aortic recurrence in locally advanced cervical cancer: A 10-year institutional experience

OBJECTIVE

To evaluate the effects of prophylactic sub-renal vein radiotherapy (SRVRT) using intensity-modulated radiotherapy (IMRT) for cervical cancer.

METHODS

A total of 206 patients with FIGO stage IB2-IVA cervical cancer and negative para-aortic lymph nodes (PALNs) who underwent pelvic IMRT (PRT) or SRVRT between 2004 and 2013 at our institution were reviewed. SRVRT cranially extended the PRT field for PALNs up to the left renal vein level. The prescribed dose was consistent 50.4Gy in 28 fractions.

RESULTS

Overall, 110 and 96 patients underwent PRT and SRVRT, respectively. The SRVRT group had more advanced disease based on FIGO stage and positive pelvic lymph nodes (PLNs). The median follow-up time was 60months (range, 7-143). For the total study population, the 5-year PALN recurrence-free survival (PARFS) and overall survival (OS) for PRT vs. SRVRT were 87.6% vs. 97.9% (p=0.03) and 74.5% vs. 87.8% (p=0.04), respectively. In patients with FIGO III-IVA or positive PLNs, the 5-year PARFS and OS for PRT vs. SRVRT were 80.1% vs. 96.4% (p=0.02) and 58.1% vs. 83.5% (p=0.012), respectively. However, there were no significant differences in these outcomes for patients with FIGO IB-IIB and negative PLNs. In a multivariate analysis, only SRVRT was associated with better PARFS (HR, 0.21; 95% CI, 0.06-0.78; p=0.02). The SRVRT did not significantly increase severe late toxicities.

CONCLUSION

Prophylactic SRVRT using IMRT reduced PALN recurrence with tolerable toxicities, supporting the application of risk-based radiation fields for cervical cancer.

Safety and efficacy of semiextended field intensity-modulated radiation therapy and concurrent cisplatin in locally advanced cervical cancer patients: An observational study of 10-year experience

Patients with locally advanced cervical cancer (LACC) are at risk of para-aortic lymph node (PALN) metastasis. Pelvic concurrent chemoradiotherapy, the current standard treatment for LACC, has a PALN failure rate of 9% according to the Radiation Therapy Oncology Group Trial 90-01, suggesting that it may not completely eliminate all microscopic tumors in the PALNs. To minimize the toxicities associated with conventional prophylactic extended-field radiotherapy, our institute use prophylactic semiextended field radiotherapy that includes only the PALNs below the level of the renal vessels. Use of intensity-modulated radiotherapy (IMRT) is another means of reducing the incidence of toxicity. This study evaluated the safety and efficacy of prophylactic semiextended field IMRT (SEF-IMRT) and concurrent cisplatin chemotherapy in patients with LACC.We retrospectively assessed survival and toxicity in 76 patients with stage IB2-IVA cervical cancer and negative PALNs who received prophylactic SEF-IMRT and concurrent weekly cisplatin (40 mg/m) between 2004 and 2013. The region targeted by SEF-IMRT included the PALNs below the level of the renal vessels, and the prescribed dose was 50.4 Gy in 28 fractions. Brachytherapy was administered at a dose of 30 Gy in 6 fractions. Survival outcomes were calculated by using the Kaplan-Meier method, and acute and late toxicities were scored according to the Common Terminology Criteria for Adverse Events, version 3.0.All patients completed the planned SEF-IMRT, as well as brachytherapy. Acute grade ≥3 gastrointestinal, genitourinary, and hematologic toxicities were observed in 2, 0, and 41 patients, respectively. The median follow-up time after SEF-IMRT was 55 (range, 11-124) months. Eight patients developed out-field distant recurrences without PALN failure, and 1 patient experienced out-field PALN failure with simultaneous distant metastasis. No patients had late genitourinary toxicities, and 3 patients had late grade 3 gastrointestinal toxicities. The 5-year overall survival, disease-free survival, local failure-free survival, regional failure-free survival, PALN failure-free survival, and distant metastasis-free survival rates were 85.0%, 84.4%, 96.0%, 97.3%, 98.6%, and 88.4%, respectively.For patients with LACC, prophylactic PALN irradiation up to the level of the renal vessels reduced PALN recurrence and resulted in favorable outcomes with few severe toxicities.

Clinical implementation of coverage probability planning for nodal boosting in locally advanced cervical cancer

PURPOSE

To implement coverage probability (CovP) for dose planning of simultaneous integrated boost (SIB) of pathologic lymph nodes in locally advanced cervical cancer (LACC).

MATERIAL AND METHODS

CovP constraints for SIB of the pathological nodal target (PTV-N) with a central dose peak and a relaxed coverage at the perimeter were generated for use with the treatment planning system Eclipse: PTV-N D98 >90%, CTV-N D98 >100% and CTV-N D50 >101.5% of prescribed dose. Dose of EBRT was 45Gy/25 fx with a SIB of 55-57.5Gy depending on expected dose from brachytherapy (BT). Twenty-five previously treated patients with 47 boosted nodes were analysed. Nodes were contoured on cone beam CT (CBCT) and the accumulated dose in GTV-N_CBCT and volume of body, pelvic bones and bowel receiving >50Gy (V50) were determined.

RESULTS

Nearly all nodes (89%) were visible on CBCT and showed considerable concentric regression during EBRT. Total EBRT and BT D98 was >57 Gy_EQD2 in 98% of the visible nodes. Compared to treatment plans aiming for full PTV-N coverage, CovP significantly reduced V50 of body, bones and bowel (p<0.001) CONCLUSION: CovP is clinically feasible for SIB of pathological nodes and significantly decreases collateral SIB dose to nearby OAR.

The dosimetric impact of target volume delineation variation for cervical cancer radiotherapy

BACKGROUND

Cervical cancer inter-observer delineation variation has been demonstrated. This article addresses its dosimetric impact.

METHODS

21 centres outlined two INTERLACE trial quality assurance test cases. A gold standard clinical target volume (GSCTV) was created from a consensus and STAPLE outline. RapidArc plans were created for all centres' planning target volumes (PTVs; PTV1+2). Gold standard PTVs (GSPTVs) were created for each plan by applying each centre's CTV-PTV margins to GSCTV. DVH parameters including D95% and Dmean for each PTV1+2 and GSPTV were compared, representing planned versus GSPTV delivered dose. PTV1+2 and GSPTV V95% was also calculated.

RESULTS

Reviewing all parameters, no plans achieved acceptable GSPTV coverage. GSPTV V95%⩾95% was not achieved for any plan. GSPTV V95%<90% in 15/21 (case 1) and 14/22 (case 2) and <80% in 2 plans from both cases. GSPTV V95% is on average 10-15% lower than planned and GSPTV D95% is 10-20% lower than planned. Most common GSCTV anatomical areas not receiving 95% dose were vagina, obturator and external iliac nodes and, in case 1, the superior nodal aspect.

CONCLUSION

Cervical cancer CTV delineation variation leads to significant reductions in dose delivered to GSPTV. This highlights the ongoing importance of standardising delineation in the IMRT era.

Implication of Bifurcation of Abdominal Aorta for Radiotherapy Planning for Cervical Cancers

INTRODUCTION

External Beam Radiotherapy plays a major role in the management of Carcinoma Cervix. The Radiotherapy treatment portals are designed to adequately cover the gross disease and areas of microscopic spread. The upper border of Radiotherapy field is traditionally placed at the level of L4-L5 intervertebral space to cover the common iliac nodal area. It is determined based on anatomical and surgical series which have shown that division of Abdominal aorta occurs at that level.

AIM

To study the level of the division of abdominal aorta in relation to the lumbar vertebral levels. To propose the change in the upper border of Radiotherapy portals used in the treatment of Cervical Cancers.

MATERIALS AND METHODS

Patients who underwent Radiotherapy for Cervical Cancer from December 2010 to January 2012 formed the subjects of this prospective study. All the patients underwent aquaplast immobilization in supine position and contrast enhanced Computed Tomography (CT) simulation for Radiotherapy planning following bladder protocol. The Radiotherapy planning was done on commercial treatment planning system, Prowess version 4.71. The level of division of Abdominal Aorta into right and left Common Iliac arteries with respect to vertebral level was determined and studied.

RESULTS

The division of abdominal aorta into common iliac arteries occurred at the level of L3-L4 intervertebral space, in front of body of L4 vertebra and L4-L5 intervertebral space in 53.84%, 30.76% and 15.40% of the patients respectively.

CONCLUSION

The division of abdominal aorta occurs at a higher level than L4-L5 intervertebral space in majority of patients. It is highly recommended to use CT scan based planning. However, in institutes where there are no facilities for CT based planning, it is advisable to shift the upper border of Radiotherapy treatment portal above the L3-L4 intervertebral space for delivering adequate doses to the common iliac lymphnodes.

Optimal Extent of Prophylactic Irradiation of Paraaortic Lymph Nodes in Patients with Uterine Cervical Cancer

Purpose

The purpose of this study was to determine optimal extent of prophylactic irradiation of paraaortic lymph nodes (PALN) in patients with uterine cervical cancer who had metastatic pelvic LNs.

Methods and Materials

We retrospectively evaluated 103 patients with cervical cancer and pelvic lymph node metastasis who were treated with prophylactic semi-extended field radiotherapy (SEFRT) between 1990 and 2012. The semi-extended field included PALN below the second lumbar spine with prescribed doses of 45 to 50 Gy. Survival outcomes were calculated using the Kaplan-Meier method, and acute and late toxicities were scored using the Radiation Therapy Oncology Group and European Organisation for Research and Treatment of Cancer toxicity criteria.

Results

The median follow-up after SEFRT was 61 (range 5–296) months. Overall, 28 patients (27.2%) experienced treatment failures, which were classified as local in 8 patients (7.8%), regional in 8 patients (7.8%), and distant in 13 patients (12.6%). Of the regional failures, only two involved PALN failure around the renal artery or the renal hilum area at the upper margin of the semi-extended field. At 5 years, the overall survival was 82%. Grade 3 or higher acute gastrointestinal and genitourinary toxicities occurred in one and two patients, respectively. As a late toxicity, one patient developed grade 3 small bowel obstruction.

Conclusion

Prophylactic SEFRT provided favorable outcomes with little acute or late gastrointestinal toxicity. For prophylaxis of PALN recurrences, upper part of PALN might not need to be included in patients with uterine cervical cancer and metastatic pelvic LNs.

Durable Control and Overall Survival Benefit with Focal Reirradiation in Cervical Cancer

Local recurrence following definitive chemoradiation in cervical cancer ranges from 5-18%. Currently, there are limited options available for patients recurring in para-aortic or iliac lymph nodes. We present two cases of reirradiation for non-central recurrences with intensity-modulated radiotherapy (IMRT). Both patients achieved a complete response with manageable short-term toxicities and no late adverse effects with a follow-up of over one year and three years after reirradiation. While further follow-up is needed, IMRT is a feasible and safe option in cervical cancer patients with recurrent in-field failures involving the lymph nodes.

Dose escalated intensity modulated radiotherapy in the treatment of cervical cancer

PURPOSE

Standard dose of external beam radiotherapy seems to be insufficient for satisfactory control of loco-regionally advanced cervical cancer. Aim of our study is to evaluate the outcome as well as early and chronic toxicities in patients with loco-regionally advanced cervical cancer, treated with dose escalated intensity modulated radiotherapy (IMRT) combined with cisplatin chemotherapy.

MATERIAL AND METHODS

Thirty-nine patients with cervical carcinoma FIGO stage IB2 - IVA were treated with curative intent between 2006 and 2010. The dose of 50.4 Gy was prescribed to the elective pelvic nodal volume. Primary tumors < 4 cm in diameter (n = 6; 15.4 %) received an external beam radiotherapy (EBRT) boost of 5.4 Gy, primary tumors > 4 cm in diameter (n = 33; 84.6 %) received an EBRT boost of 9 Gy. Patients with positive lymph nodes detected with (18)FDG-PET/CT (n = 22; 56.4 %) received a boost to a total dose of 59.4 - 64.8 Gy. The para-aortic region was included in the radiation volume in 8 (20.5 %) patients and in 5 (12.8 %) patients the para-aortic macroscopic lymph nodes received an EBRT boost. IMRT was followed with a 3D planned high dose rate intrauterine brachytherapy given to 36 (92.3 %) patients with a total dose ranging between 15-18 Gy in three fractions (single fraction: 4-6.5 Gy). Patients without contraindications (n = 31/79.5 %) received concomitantly a cisplatin-based chemotherapy (40 mg/kg) weekly. Toxicities were graded according to the common terminology criteria for adverse events (CTCAE v 4.0).

RESULTS

Mean overall survival for the entire cohort was 61.1 months (±3.5 months). Mean disease free survival was 47.2 months (±4.9 months) and loco-regional disease free survival was 55.2 months (±4.4 months). 65 % of patients developed radiotherapy associated acute toxicities grade 1, ca. 30 % developed toxicities grade 2 and just two (5.2 %) patients developed grade 3 toxicities, one acute diarrhea and one acute cystitis. 16 % of patients had chronic toxicities grade 1, 9 % grade 2 and one patient (2.6 %) toxicities grade 3 in the form of vaginal dryness.

CONCLUSION

Dose escalated IMRT appears to have a satisfactory outcome with regards to mean overall survival, disease free and loco-regional disease free survival, whereas the treatment-related toxicities remain reasonably low.

Intensity-modulated extended-field chemoradiation plus simultaneous integrated boost in the pre-operative treatment of locally advanced cervical cancer: a dose-escalation study

OBJECTIVE

To investigate the feasibility and determine the recommended pre-operative intensity-modulated radiotherapy (IMRT) dose of extended-field chemoradiation along with simultaneous integrated boost (SIB) dose escalation.

METHODS

A radiation dose of 40 Gy over 4 weeks, 2 Gy/fraction, was delivered to the tumour and the lymphatic drainage (planning target volume, PTV3), which encompassed a volume larger than standard (common iliac lymphatic area up to its apex, in front of the L3 vertebra), concurrently with chemotherapy (cisplatin and 5-fluorouracil). Radiation dose was escalated to the pelvis (PTV2) and to the macroscopic disease (PTV1) with the SIB-IMRT strategy. Three dose levels were planned: Level 1 (PTV3: 40/2 Gy; PTV2: 40/2 Gy; PTV1: 45/2.25 Gy), Level 2 (PTV3: 40/2 Gy; PTV2: 45/2.25 Gy; PTV1: 45/2.25 Gy) and Level 3 (PTV3: 40/2 Gy; PTV2: 45/2.25 Gy; PTV1: 50/2.5 Gy). All treatments were delivered in 20 fractions. Patients were treated in cohorts of between three and six per group using a Phase I study design. The recommended dose was exceeded if two of the six patients in a cohort experienced dose-limiting toxicity within 3 months from treatment.

RESULTS

19 patients [median age: 46 years; The International Federation of Gynecology and Obstetrics (FIGO) stage IB2: 3, IIB: 10, IIIA-IIIB: 6] were enrolled. Median follow-up was 24 months (9-60 months). The most common grade 3/4 toxicity was gastrointestinal (GI) (diarrhoea, mucous discharge, rectal/abdominal pain). At Levels 1 and 2, only one grade 3 GI toxicity per level was recorded, whereas at Level 3, two grade 3 GI toxicities (diarrhoea, emesis and nausea) were recorded.

CONCLUSION

The SIB-IMRT technique was found to be feasible and safe at the recommended doses of 45 Gy to PTV1 and PTV2 and 40 Gy to PTV3 in the pre-operative treatment of patients with locally advanced cervical cancer. Unfortunately, this complex technique was unable to safely escalate dose beyond levels already achieved with three-dimensional conformal radiotherapy technique given acute GI toxicity.

ADVANCES IN KNOWLEDGE

A Phase I radiotherapy dose-escalation trial with SIB-IMRT technique is proposed in cervical cancer. This complex technique is feasible and safe at the recommended doses.

Impact of radiation dose and standardized uptake value of (18)FDG PET on nodal control in locally advanced cervical cancer

BACKGROUND

Despite local control now exceeding 90% with image-guided adaptive brachytherapy (IGABT), regional and distant metastases continue to curb survival in locally advanced cervical cancer. As regional lymph nodes often represent first site of metastatic spread, improved nodal control could improve survival. The aim of this study was to examine optimal volume and dose of external beam radiotherapy (EBRT) to maximize regional control including dose contribution from IGABT.

MATERIAL AND METHODS

In total 139 patients from the EMBRACE study were analyzed. Individual nodal dose was determined by dose-maps from EBRT and IGABT. All PET/CT scans were re-evaluated and nodal maximal standard uptake value (SUVmax) was determined. Nodal failures were registered to planning scans and related to boosted nodes and treated volume. Relation between SUVmax and nodal control as well as the pattern of regional nodal failure were analyzed.

RESULTS

Eighty-four patients were node positive. Nine patients had all metastatic nodes surgically removed. Seventy-five patients had 209 nodes boosted with EBRT. Median nodal boost dose was 62 Gy EQD2 (53-69 Gy EQD2). Median SUVmax was 6 (2-22). No patients had persistent nodal disease, but six patients recurred in a boosted node. SUVmax was significantly higher in nodes that recurred (p = 0.02). However, there was no correlation to nodal dose or volume. Twenty-one patients had a nodal failure including para-aortic nodal (PAN) metastases above the irradiated volume. Nine patients had a PAN-only failure. Patients receiving ≤ 4 cycles of weekly cisplatin had higher risk of nodal failure (p < 0.01).

CONCLUSION

Current RT practice provides a high level of control in both boosted nodes and the elective irradiated regional target. However, a high nodal SUVmax is a negative prognostic predictor for nodal control. Attention should be raised to administration of a complete schedule of concurrent chemotherapy as well as treatment of para-aortic nodes.

Variability in clinical target volume delineation for intensity modulated radiation therapy in 3 challenging cervix cancer scenarios

PURPOSE

The purpose of this study was to assess variability in contouring the gross tumor volume (GTV) and clinical target volume (CTV) of 3 clinical cervix cancer cases by a cohort of international experts in the field in preparation for the development of an online teaching atlas.

METHODS AND MATERIALS

Twelve international experts participated. Three clinical scenarios: node positivity (PLN), retroverted uterus (RV), and parametrial invasion (PI) were used. Sagittal and axial magnetic resonance images of the clinical cases were downloaded to participants' treatment planning systems for contouring. The GTV/cervix/uterus/parametria/vagina and nodal CTV were contoured. Contour consensus was assessed for sensitivity/specificity using an expectation maximization algorithm called Simultaneous Truth and Performance Level Estimation and experts' overall agreement was summarized by kappa statistics.

RESULTS

Agreement for GTV in the 3 clinical cases was high (Simultaneous Truth and Performance Level Estimation sensitivity, 0.54-0.92; specificity, 0.97-0.98; and kappa measure for PLN, RV, and PI was 0.86, 0.76, and 0.42; P < .0001). Moderate to substantial agreement was seen for nodal CTV (kappa statistics for PLN, RV, and PI was 0.65, 0.58, and 0.62; P < .0001), uterus (kappa for PLN, RV, and PI was 0.45, 0.74, and 0.77; P < .0001), and parametria (kappa for PLN, RV, and PI was 0.49, 0.62, and 0.50; P < .0001). Contouring heterogeneity was greatest for the cervix (kappa measure for PLN, RV, and PI was 0.15, 0.4, and 0.24; P < .0001) and vagina (kappa for PLN, RV, and PI was 0.47, 0.36 and 0.46; P < .0001), reflecting difficulties in determining the interface between GTV and these tissues.

CONCLUSION

Kappa statistics of the different CTV components generally demonstrated moderate to substantial agreement among international experts in the field of gynecological radiation therapy. Further planning target volume margins accounting for organ motion and setup errors are a necessary addition to the CTV.

Clinical impact of FDG PET-CT on the management of patients with locally advanced cervical carcinoma

AIM

To evaluate the impact of staging FDG PET-CT on the initial management of patients with locally advanced cervical carcinoma (LACC) and any prognostic variables predicting survival.

MATERIALS AND METHODS

Retrospective analysis of consecutive patients undergoing FDG PET-CT for staging of LACC in a single tertiary referral centre, between April 2008 and August 2011. Comparison was made between MRI and PET-CT findings and any subsequent impact on treatment intent or radiotherapy planning was evaluated.

RESULTS

Sixty-three patients underwent FDG PET-CT for initial staging of LACC. Major impact on management was found in 20 patients (32%), a minor impact in five (8%), and no impact in 38 (60%). In those patients where PET-CT had a major impact, 12 had more extensive local nodal involvement, five had occult metastatic disease, two had synchronous tumours, and one patient had equivocal lymph nodes on MRI characterized as negative. PET-positive nodal status at diagnosis was found to be a statistically significant predictor of relapse-free survival (p < 0.05).

CONCLUSION

Staging FDG PET-CT has a major impact on the initial management of approximately one-third of patients with LACC by altering treatment intent and/or radiotherapy planning. PET-defined nodal status is a poor prognostic indicator.

Pelvic nodal CTV from L4-L5 or aortic bifurcation? An audit of the patterns of regional failures in cervical cancer patients treated with pelvic radiotherapy

OBJECTIVE

To assess the patterns of recurrence in cervical cancer patients treated with pelvic nodal clinical target volume at L4-L5 junction instead of aortic bifurcation.

METHODS

Records of patients with locally advanced cervical cancer treated with chemo-radiation were reviewed. Patients treated with standard pelvic fields (superior border of the field at L4/L5 junction), without any radiological evidence of regional lymphadenopathy (<10 mm) were included in the study. The level of aortic bifurcation was retrospectively documented on computed tomography. Patterns of recurrences were correlated to the aortic bifurcation and the superior border of the radiation fields (L4/L5).

RESULTS

Aortic bifurcation was above the radiation fields (above L4/5) in 82 of 116 (70.7%) patients. Of the nine patients that recurred above the radiation field, 5 (55%) were above L4/5 failures, i.e. between aortic bifurcation and L4/5, and 4 (45%) had para-aortic failures. On retrospective analysis, 16 patients were found to have subcentimeter lymph nodes and higher nodal failures (7/16) were observed in patients with subcentimeter regional lymph nodes at diagnosis.

CONCLUSIONS

Superior border of nodal clinical target volume should ideally include the aortic bifurcation instead of L4-L5 inter space in patients with locally advanced cervical cancer. Radiotherapy fields need to be defined cautiously in patients with subcentimeter pelvic lymph nodes.

Image guided adaptive brachytherapy for cervical cancer: dose contribution to involved pelvic nodes in two cancer centers

PURPOSE

The goal of this study was to determine the dose contributions from image guided adaptive brachytherapy (IGABT) to individual suspicious pelvic lymph nodes (pLNN) in cervical cancer patients. Data were collected in two cancer centers, University of Pittsburgh Cancer Institute (UPCI) and University Medical Center Utrecht (UMCU).

MATERIAL AND METHODS

27 and 15 patients with node positive cervical cancer treated with HDR (high dose rate) or PDR (pulsed dose rate)-IGABT were analyzed. HDR-IGABT (UPCI) was delivered with CT/MRI compatible tandem-ring applicators with 5.0-6.0 Gy × five fractions. PDR-IGABT (UMCU) dose was delivered with Utrecht tandem-ovoid applicators with 32 × 0.6 Gy × two fractions. Pelvic lymph nodes with short axis diameter of ≥ 5 mm on pre-treatment MRI or PET-CT were contoured for all BT-plans. Dose contributions to individual pLNN expressed as D90 (dose to 90% of the volume) were calculated from dose-volume histograms as absolute and relative physical dose (% of the reference dose) for each fraction. For each node, the total dose from all fractions was calculated, expressed in EQD2 (equivalent total dose in 2 Gy fractions).

RESULTS

Fifty-seven (UPCI) and 40 (UMCU) individual pLNN were contoured. The mean D90 pLNN was 10.8% (range 5.7-25.1%) and 20.5% (range 6.8-93.3%), respectively, and therefore different in the two centers. These values translate into 2.7 Gy (1.3-6.6 Gy) EQD2 and 7.1 Gy (2.2-36.7 Gy) EQD2, respectively. Differences are caused by the location of the individual nodes in relation to the spatial dose distribution of IGABT, differences in total dose administered and radiobiology (HDR versus PDR).

CONCLUSIONS

The IGABT dose contribution to individual pelvic nodes depends on patient and treatment related factors, and varies considerably.

IMRT with ¹⁸FDG-PET\CT based simultaneous integrated boost for treatment of nodal positive cervical cancer

Background

To evaluate toxicity and outcome of intensity modulated radiotherapy (IMRT) with simultaneous integrated boost (SIB) to the positive lymph nodes in patients with loco-regional advanced cervical cancer (LRACC).

Methods

The study population comprised ten patients with ¹⁸FDG-PET\CT positive lymph nodes (LNs), who underwent chemoradiation with IMRT and SIB. A dose of 50.4 Gy, in daily fractions of 1.8 Gy, was delivered to primary tumor and draining LNs. Primary tumor received an additional external beam boost to a total dose of 55.8 Gy. A SIB of 62 Gy, in daily fractions of 2 Gy, was delivered to the ¹⁸FDG-PET\CT positive LNs. Finally, a high dose rate brachytherapy (HDRB) boost (15 – 18 Gy) was administered to the primary tumor. The primary goal of this study was to evaluate acute and early late toxicity and loco-regional control.

Results

The median number of irradiated LNs per patient was 3 (range: 1–6) with a median middle nodal SIB-volume of 26.10 cm³ (range, 11.9-82.50 cm³). Median follow-up was 20 months (range, 12 to 30 months). Acute and late grade 3 toxicity was observed in 1 patient. Three of the patients developed a recurrence, one in the form of a local tumor relapse, one had a paraaortic LN metastasis outside the treated volume and the last one developed a distant metastasis.

Conclusion

IMRT with SIB in the region of 18FDG-PET positive lymph nodes appears to be an effective therapy with acceptable toxicity and might be useful in the treatment of patients with locally advanced cervical cancer.