3D conformal HDR-brachy- and external beam therapy plus simultaneous cisplatin for high-risk cervical cancer: clinical experience with 3 year follow-up

Haemostatic gene variations in cervical cancer-associated venous thrombosis: considerations for clinical strategies

Venous thromboembolism (VTE) is a life-threatening haemostatic disease frequently diagnosed among the cancer population. The Khorana Score is currently the primal risk assessment model to stratify oncological patients according to their susceptibility to VTE, however, it displays a limited performance. Meanwhile, intensive research on VTE pathophysiology in the general population has uncovered a range of single-nucleotide polymorphisms (SNPs) associated with the condition. Nonetheless, their predictive ability concerning cancer-associated thrombosis (CAT) is controversial. Cervical cancer (CC) patients undergoing chemoradiotherapy often experience VTE, which negatively affects their survival. Thus, aiming for an improvement in thromboprophylaxis, new thrombotic biomarkers, including SNPs, are currently under investigation. In this study, the predictive capability of haemostatic gene SNPs on CC-related VTE and their prognostic value regardless of VTE were explored. Six SNPs in haemostatic genes were evaluated. A total of 401 CC patients undergoing chemoradiotherapy were enrolled in a retrospective cohort study. The implications for the time to VTE occurrence and overall survival (OS) were assessed. CAT considerably impacted the CC patients' OS (log-rank test, P < 0.001). SERPINE1 rs2070682 (T > C) showed a significant association with the risk of CC-related VTE (CC/CT vs. TT, log-rank test, P = 0.002; C allele, Cox model, hazard ratio (HR) = 6.99 and P = 0.009), while F2 rs1799963 (G > A) demonstrated an important prognostic value regardless of VTE (AA/AG vs. GG, log-rank test, P = 0.020; A allele, Cox model, HR = 2.76 and P = 0.026). For the remaining SNPs, no significant associations were detected. The polymorphisms SERPINE1 rs2070682 and F2 rs1799963 could be valuable tools in clinical decision-making, aiding in thromboprophylaxis and CC management, respectively.

Thrombogenesis-associated genetic determinants as predictors of thromboembolism and prognosis in cervical cancer

Venous thromboembolism (VTE) is a leading cause of death among cancer patients. Khorana score (KS) is the most studied tool to predict cancer-related VTE, however, it exerts poor sensitivity. Several single-nucleotide polymorphisms (SNPs) have been associated with VTE risk in the general population, but whether they are predictors of cancer-related VTE is a matter of discussion. Compared to other solid tumours, little is known about VTE in the setting of cervical cancer (CC) and whether thrombogenesis-related polymorphisms could be valuable biomarkers in patients with this neoplasia. This study aims to analyse the effect of VTE occurrence on the prognosis of CC patients, explore the predictive capability of KS and the impact of thrombogenesis-related polymorphisms on CC-related VTE incidence and patients' prognosis regardless of VTE. A profile of eight SNPs was evaluated. A retrospective hospital-based cohort study was conducted with 400 CC patients under chemoradiotherapy. SNP genotyping was carried on by using TaqMan® Allelic Discrimination methodology. Time to VTE occurrence and overall survival were the two measures of clinical outcome evaluated. The results indicated that VTE occurrence (8.5%) had a significant impact on the patient's survival (log-rank test, P < 0.001). KS showed poor performance (KS ≥ 3, χ², P = 0.191). PROCR rs10747514 and RGS7 rs2502448 were significantly associated with the risk of CC-related VTE development (P = 0.021 and P = 0.006, respectively) and represented valuable prognostic biomarkers regardless of VTE (P = 0.004 and P = 0.010, respectively). Thus, thrombogenesis-related genetic polymorphisms may constitute valuable biomarkers among CC patients allowing a more personalized clinical intervention.

Dose-volume parameters and local tumor control in cervical cancer treated with central-shielding external-beam radiotherapy and CT-based image-guided brachytherapy

Definitive radiotherapy for cervical cancer consists of external-beam radiotherapy (EBRT) and brachytherapy. In EBRT, a central shield (CS) reduces the dose to the rectum and bladder. The combination of whole-pelvic (WP)- and CS-EBRT and brachytherapy is the standard radiotherapy protocol in Japan. Despite clinical studies, including multi-institutional clinical trials, showing that the Japanese treatment protocol yields favorable treatment outcomes with low rates of late radiation toxicities, dose-volume parameters for the Japanese treatment protocol remain to be established. We conducted a retrospective dose-volume analysis of 103 patients with uterine cervical cancer treated with the Japanese protocol using computed tomography-based adaptive brachytherapy. The 2-year overall survival and 2-year local control rates according to FIGO stage were 100% and 100% for Stage I, 92% and 94% for Stage II, and 85% and 87% for Stage III-IV, respectively. Late adverse effects in the rectum and bladder were acceptable. Receiver operating characteristic analysis discriminated recurrence within the high-risk clinical target volume (HR-CTV) (n = 5) from no local recurrence (n = 96), with the optimal response obtained at a dose of 36.0 GyEQD2 for HR-CTV D90 and 28.0 GyEQD2 for HR-CTV D98. These values were used as cut-offs in Fisher exact tests to show that high HR-CTV D90 and HR-CTV D98 doses for brachytherapy sessions were significantly associated with tumor control within the HR-CTV. These data suggest a contribution of brachytherapy to local tumor control in WP- and CS-EBRT and brachytherapy combination treatment, warranting validation in multi-institutional prospective studies.

Experience with concurrent chemoradiotherapy treatment in advanced cervical cancer: results from a hospital in Argentina

Objective

To describe our experience with concurrent chemoradiotherapy using three-dimensional conformal radiotherapy (3D-CRT) and high-dose-rate intracavitary brachytherapy with weekly cisplatin in the treatment of patients with locally advanced cervical cancer.

Methods

Forty-three patients were identified between January 2009 and December 2015. Their medical records were retrospectively reviewed, and data on patient characteristics, tumour, treatment and toxicities were collected and analysed.

Results

The median age was 45 years (interquartile range (IQR): 26) The median tumour size was 45 mm (IQR: 20). Thirty-eight patients (88%) had a cervical tumour with a size of ≥ 40 mm. The median cervical tumour size evaluated by magnetic resonance imaging (MRI) was 52 mm (IQR: 17). Twenty-two patients (51%) had enlarged lymph nodes on MRI (≥ 10 mm). MRI demonstrated the involvement of the parametrium in 29 patients (67%). Fifteen patients had positive para-aortic nodes (36%). The median total treatment time was 58 days (IQR: 20). Sixteen patients (39%) received extended-field radiotherapy. Cisplatin was administered simultaneously for a median of five courses. The median follow-up period was 32 months (IQR: 28 months). Grade 3 acute toxicity was observed at the gastrointestinal level in seven patients (16%). Late grade 3/4 toxicity was observed in 14 patients (33%). Seven patients (16%) persisted with the disease and five died. The local relapse rate was 9%. Eleven patients underwent a hysterectomy after treatment. The disease-free interval was 24.2 months. The 2-year global survival rate was 82.9%.

Conclusion

Concurrent chemo-radiotherapy appears to be an effective regimen, with acceptable toxicity, for patients with locally advanced cervical cancer.

Efficacy and safety of nedaplatin-based concurrent chemoradiotherapy for FIGO Stage IB2-IVA cervical cancer and its clinical prognostic factors

Cisplatin-based concurrent chemoradiotherapy (CCRT) is a standard treatment for cervical cancer, but nedaplatin-based CCRT is not routinely administered. We evaluated the efficacy and safety of nedaplatin-based CCRT (35 mg/m(2) weekly) and analyzed prognostic factors for survival among 52 patients with International Federation of Gynecology and Obstetrics (FIGO) Stage IB2-IVA cervical cancer treated from 1999 to 2009. Patients were treated with a combination of external beam radiotherapy of 40-56 Gy (in 20-28 fractions) and 13.6-28.8 Gy (in 2-4 fractions) of high-dose-rate (HDR) intracavitary brachytherapy or 18 Gy (in 3 fractions) of HDR interstitial brachytherapy. Overall survival (OS), progression-free survival (PFS), and local control (LC) were estimated using the Kaplan-Meier method. The Cox proportional hazard model was used for multivariate analysis. Acute and late toxicities were evaluated using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period was 52 months. The median patient age was 63 years. The 5-year OS, PFS and LC rates were 78%, 57% and 73%, respectively. Multivariate analysis showed that histologic type, maximum tumor diameter, and pretreatment hemoglobin level were independent risk factors for PFS. Regarding adverse effects, 24 patients (46%) had acute Grade 3-4 leukopenia and 5 (10%) had late Grade 3 gastrointestinal toxicities. No patient experienced renal toxicity. Nedaplatin-based CCRT for FIGO Stage IB2-IVA cervical cancer was efficacious and safe, with no renal toxicity. Histologic type, maximum tumor diameter, and pretreatment hemoglobin level were statistically significant prognostic factors for PFS.

Concomitant cisplatin plus radiotherapy and high-dose-rate brachytherapy versus radiotherapy alone for stage IIIB epidermoid cervical cancer: a randomized controlled trial

PURPOSE

The benefits of chemoradiotherapy (CRT) for cervical cancer compared with radiation (RT) alone seem to diminish in later-stage disease. However, these modalities have not been directly compared for disease-free interval (DFI) and overall survival (OS) of women with stage IIIB cervical cancer.

PATIENTS AND METHODS

We conducted a randomized controlled clinical trial comparing DFI and OS of 147 women with stage IIIB squamous cervical cancer who received either cisplatin plus RT (CRT) or RT alone (72 patients in the CRT group and 75 patients in the RT-only group).

RESULTS

The CRT group had significantly better DFI (hazard ratio [HR], 0.52; 95% CI, 0.29 to 0.93; P = .02). However, patients in the CRT group did not have significantly better OS than those in the RT-only group (HR, 0.67; 95% CI, 0.38 to 1.17; P = .16). Toxicity was graded according to criteria of the Radiation Therapy Oncology Group. The organs affected (excluding hematologic effects) did not differ significantly between groups. Also, late toxicity events and organs affected were not significantly disproportionate between the study groups.

CONCLUSION

For stage IIIB cervical cancer, the addition of cisplatin offers a small but significant benefit in DFI, with acceptable toxicity.

Dosimetric and clinical outcome in image-based high-dose-rate interstitial brachytherapy for anal cancer

PURPOSE

To evaluate dosimetric and clinical outcome in patients of anal cancer treated with image-based interstitial high-dose-rate brachytherapy following chemoradiation.

METHODS AND MATERIALS

Sixteen patients with anal cancer were treated with chemoradiation followed by brachytherapy boost with image-based high-dose-rate interstitial brachytherapy from January 2007 to June 2011. Two brachytherapy dose schedules were used: 21 Gy in seven fractions and 18 Gy in six fractions depending on response to chemoradiation. CT scan was done after placement of needles for confirmation of placement and treatment planning. Target volume was contoured on CT scans. Volumetric quality indices and dose parameters were calculated.

RESULTS

The mean clinical target volume was 17.7 ± 4.98 cm(3), and the median overall tumor size was 4.2cm (3.4-5cm). The mean values of coverage index, dose homogeneity index, overdose volume index, dose non-uniformity ratio, and conformal index were 0.94, 0.83, 0.21, 0.37, and 0.88, respectively. With a median followup of 41 months (range, 20-67.2 months), preservation of the anal sphincter was achieved in 14 patients. The 1- and 2-year local control rates were 93.8% and 87.5%, respectively. Treatment was well tolerated and none of the patients developed Grade 3 or higher late toxicity.

CONCLUSIONS

The combination of external beam radiotherapy with interstitial brachytherapy increases the dose to the tumor volume and limits the volume of irradiated normal tissue, thereby decreasing late toxicity. The use of image-based treatment planning provides better dose conformality with reduced toxicity and helps to prevent a geographic miss.

Evaluation of microscopic tumor extension in early-stage cervical cancer: quantifying subclinical uncertainties by pathological and magnetic resonance imaging findings

We performed a detailed analysis of hysterectomy specimens of uterine cervical cancer to determine the appropriate length of uterine body to include within the clinical target volume. Between 2008 and 2011, 54 patients with uterine cervical carcinoma underwent hysterectomy. Those with quality pre-operative magnetic resonance imaging (MRI) data were included for analysis. Tumor sizes measured by MRI and microscopy were compared with regard to brachytherapy-oriented parameters. Detailed descriptive analysis focusing on the extent of tumor involvement was also performed. A total of 31 specimens were analyzed. The median maximal tumor length measured by MRI was slightly shorter than microscopic length (19 vs. 24 mm, respectively), while the maximal radius was almost identical. No tumors with a maximal size <2 cm by MRI (n = 6) extended to the uterine body ≥ 1/3. The majority of maximal tumor length underestimation on MRI was within 1 cm. Precise tumor delineation can be made by MRI. For patients with tumors <2 cm on MRI, treating the entire uterine body length may not be necessary. A 1-cm margin around an MRI-based gross tumor seems to be adequate to cover the actual tumor involvement.

[Current methods of chemoradiotherapy for locally advanced cervical cancer. Options for reduction of side-effects]

The advantages of cisplatin based radiochemotherapy have been proven for over one and a half decades, particularly in the treatment of advanced solid tumours. In head and neck, and cervical tumours results of prospective studies are available. Those showed that both in the early and advanced stages, local control and overall survival rates are better than radiotherapy alone. The effect of cisplatin can be probably intensified with novel, more effective molecules, such as m-TOR inhibitors and tirapazamine. The authors review cisplatin and non-cisplatin based radiochemotherapy protocols, which improve previous treatment results. It should be considered, however, radiotherapy for cervical cancer can cause hematological, urogenital and intestinal toxicity, similarly to other combined treatments. The authors briefly outline international recommendations and their own experience for the prevention of these side-effects.

Reporting and validation of gynaecological Groupe Euopeen de Curietherapie European Society for Therapeutic Radiology and Oncology (ESTRO) brachytherapy recommendations for MR image-based dose volume parameters and clinical outcome with high dose-rate brachytherapy in cervical cancers: a single-institution initial experience

OBJECTIVE

The objectives are to report the dosimetric analysis, preliminary clinical outcome, and comparison with published data of 3-dimensional magnetic resonance-based high dose rate brachytherapy (BT) in cervical cancer.

MATERIALS AND METHODS

The data set of 24 patients with cervical cancer treated with high dose-rate brachytherapy applications was analyzed. All patients received radiation with or without chemotherapy (10 patients received concomitant chemoradiation). Point A, International Commission on Radiation Units and Measurement (ICRU) point doses, and Groupe Europeen de Curietherapie-European Society for Therapeutic Radiology and Oncology dose volume parameters, namely, high-risk clinical target volume (HR-CTV), D90 and D100 doses, and dose to D0.1cc and D2cc, for rectum, bladder, and sigmoid, were calculated and correlated.

RESULTS

Mean ± SD HR-CTV was 45.2 ± 15.8 cc. The mean ± SD point A dose was 73.4 ± 4.5 Gy (median, 74.3 Gy) total biologically equivalent dose in 2 Gy per fraction (EQD2), whereas mean ± SD D90 doses were 70.9 ± 10.6 GyEQD2 (median, 68). The mean ± SD ICRU rectal and bladder points were 63.5 ± 8.1 and 80.4 ± 34.4 GyEQD2, respectively. The D0.1cc and D2cc for rectum were 66.0 ± 9.9 GyEQD2 (median, 64.5) and 57.8 ± 7.7 GyEQD2 (median, 58.8), for bladder 139.1 ± 54.7 GyEQD2 (median, 131.9) and 93.4 ± 24.6 GyEQD2 (median, 91), and sigmoid were 109.4 ± 45.2 GyEQD2 (median, 91) and 74.6 ± 19.6 GyEQD2 (median, 69.6). With a median follow-up of 24 months, 3 patients had local nodal failure, 1 had right external iliac nodal failure, and 1 had left supraclavicular nodal failure.

CONCLUSIONS

The 3-D magnetic resonance image-based high dose-rate brachytherapy approach in cervical cancers is feasible. In our experience, the HR-CTV volumes are large, and D0.1cc and D2cc doses to bladder and sigmoid are higher than published literature so far.

MRI-based preplanning using CT and MRI data fusion in patients with cervical cancer treated with 3D-based brachytherapy: feasibility and accuracy study

PURPOSE

Magnetic resonance imaging (MRI)-assisted radiation treatment planning enables enhanced target contouring. The purpose of this study is to analyze the feasibility and accuracy of computed tomography (CT) and MRI data fusion for MRI-based treatment planning in an institution where an MRI scanner is not available in the radiotherapy department.

METHODS AND MATERIALS

The registration inaccuracy of applicators and soft tissue was assessed in 42 applications with CT/MRI data fusion. The absolute positional difference of the center of the applicators was measured in four different planes from the top of the tandem to the cervix. Any inaccuracy of registration of soft tissue in relation to the position of applicators was determined and dose-volume parameters for MRI preplans and for CT/MRI fusion plans with or without target and organs at risk (OAR) adaptation were evaluated.

RESULTS

We performed 6,132 measurements in 42 CT/MRI image fusions. Median absolute difference of the center of tandem on CT and MRI was 1.1 mm. Median distance between the center of the right ovoid on CT and MRI was 1.7 and 1.9 mm in the laterolateral and anteroposterior direction, respectively. Corresponding values for the left ovoid were 1.6 and 1.8 mm. Rotation of applicators was 3.1°. Median absolute difference in position of applicators in relation to soft tissue was 1.93, 1.50, 1.05, and 0.84 mm in the respective transverse planes, and 1.17, 1.28, 1.27, and 1.17 mm in selected angular directions. The dosimetric parameters for organs at risk on CT/MRI fusion plans without OAR adaptation were significantly impaired whereas the target coverage was not influenced. Planning without target adaptation led to overdosing of the target volume, especially high-risk clinical target volume--D₉₀ 88.2 vs. 83.1 (p < 0.05).

CONCLUSIONS

MRI-based preplanning with consecutive CT/MRI data fusion can be safe and feasible, with an acceptable inaccuracy of soft tissue registration.

MRI-based pre-planning in patients with cervical cancer treated with three-dimensional brachytherapy

OBJECTIVE

The aim of this study was to analyse the feasibility and determine the benefits of MRI-based pre-planning with CT/MRI data fusion in patients with cervical cancer treated with radical radiotherapy.

METHODS

Patients underwent MRI examination prior to external beam radiotherapy and prior to the first and fourth fraction of brachytherapy with applicators in place. Insertion of applicators at the radiology department was performed under paracervical anaesthesia. The benefit of MRI pre-planning was determined by comparing conventional treatment planning with dose specification to "point A" and dose specification to 90% of the high-risk clinical target volume (HR-CTV D90). Tolerance of MRI evaluation with applicators, coverage of HR-CTV and dose-volume parameters for organs at risk (OAR) has been assessed in 42 brachytherapy procedures.

RESULTS

Insertion of applicators at the radiology department was successful in all patients and there were no complications. The target dose was higher for MRI planning than for conventional planning (5.3 Gy vs 4.5 Gy). Maximum doses in the bladder and rectum were significantly lower (p<0.05) for MRI planning than for the conventional approach (6.49 Gy vs 7.45 Gy for bladder; 4.57 Gy vs 5.06 Gy for rectum). We found no correlation between the International Commission on Radiation Units (ICRU) point dose for OAR and the maximum dose in OAR. Nevertheless, a strong correlation between the maximum dose in OAR and the minimal dose in a volume of 2 cm(3) has been observed.

CONCLUSION

MRI-based pre-planning with consecutive CT/MRI data fusion is feasible and safe, with the advantage of increasing the dose to the tumour and decreasing the dose to the organs at risk.

Trans-abdominal ultrasound (US) and magnetic resonance imaging (MRI) correlation for conformal intracavitary brachytherapy in carcinoma of the uterine cervix

PURPOSE

Trans-abdominal ultrasonography (US) is capable of determining size, shape, thickness, and diameter of uterus, cervix and disease at cervix or parametria. To assess the potential value of US for image-guided cervical cancer brachytherapy, we compared US-findings relevant for brachytherapy to the corresponding findings obtained from MR imaging.

MATERIALS AND METHODS

Twenty patients with biopsy proven cervical cancer undergoing definitive radiotherapy with/without concomitant Cisplatin chemotherapy and suitable for brachytherapy were invited to participate in this study. US and MR were performed in a similar reproducible patient positioning after intracavitary application. US mid-sagittal and axial image at the level of external cervical os was acquired. Reference points D1 to D9 and distances were identified with respect to central tandem and flange, to delineate cervix, central disease, and external surface of the uterus.

RESULTS

Thirty-two applications using CT/MR compatible applicators were evaluable. The D1 and D3 reference distances which represent anterior surface had a strong correlation with R=0.92 and 0.94 (p<0.01). The D2 and D4 reference distances in contrast, which represent the posterior surface had a moderate (D2) and a strong (D4) correlation with R=0.63 and 0.82 (p<0.01). Of all, D2 reference distance showed the least correlation of MR and US. The D5 reference distance representing the fundal thickness from tandem tip had a correlation of 0.98. The reference distances for D6, D7, D8, and D9 had a correlation of 0.94, 0.82, 0.96, and 0.93, respectively.

CONCLUSIONS

Our study evaluating the use of US, suggests a reasonably strong correlation with MR in delineating uterus, cervix, and central disease for 3D conformal intracavitary brachytherapy planning.

Dose volume analysis of radiotherapy for inoperable patients with stage I-II endometrial carcinoma

This study aims to assess the efficacy and toxicity of definitive radiotherapy for early-stage endometrial carcinoma. The correlation between CT-based dosimetric parameters and clinical outcomes is also evaluated. Between 2002 and 2006, 10 medically inoperable patients with T1-2 endometrial carcinoma were treated with radiotherapy alone. A combination of external beam radiotherapy (EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT) was used for 9 patients, and one was treated with HDR-ICBT alone. Dose prescription of HDR-ICBT was determined in reference to CT images at brachytherapy, and a total dose of 22-24 Gy in 4 fractions was delivered to the outer perimeter of the uterine corpus. Dose-volume parameters of the gross tumor volume (GTV), clinical target volume (CTV), and organs at risk were assessed retrospectively using the dose-volume histograms derived from the CT image-based treatment planning system. After a median follow-up of 55 months, 9 patients were alive without evidence of recurrence. One patient died from liver cirrhosis 17 months after radiotherapy. Severe acute and late toxicities were not observed in any of the patients. Average minimum dose to 90% of GTV and CTV (D90) was 88.0 and 45.9 Gy(EQD2), respectively. The minimum dose delivered to 2 cc of the most irradiated volumes of the rectum and sigmoid colon (D(2cc)) was 78.9 and 65.9 Gy(EQD2), respectively. These patients developed Grade 1 late complications. In this study, stage I-II endometrial carcinoma was well-controlled locally with minimum late toxicity by radiotherapy alone with HDR-ICBT. 3D image-based brachytherapy may potentially deliver a sufficiently high dose to the whole tumor without significant increase in dose to surrounding normal tissues.

Clinical outcome of protocol based image (MRI) guided adaptive brachytherapy combined with 3D conformal radiotherapy with or without chemotherapy in patients with locally advanced cervical cancer

Background

To analyse the overall clinical outcome and benefits by applying protocol based image guided adaptive brachytherapy combined with 3D conformal external beam radiotherapy (EBRT) ± chemotherapy (ChT).

Methods

Treatment schedule was EBRT with 45–50.4 Gy ± concomitant cisplatin chemotherapy plus 4 × 7 Gy High Dose Rate (HDR) brachytherapy. Patients were treated in the “protocol period” (2001–2008) with the prospective application of the High Risk CTV concept (D90) and dose volume constraints for organs at risk including biological modelling. Dose volume adaptation was performed with the aim of dose escalation in large tumours (prescribed D90 > 85 Gy), often with inserting additional interstitial needles. Dose volume constraints (D_2cc) were 70–75 Gy for rectum and sigmoid and 90 Gy for bladder.

Late morbidity was prospectively scored, using LENT/SOMA Score. Disease outcome and treatment related late morbidity were evaluated and compared using actuarial analysis.

Findings

One hundred and fifty-six consecutive patients (median age 58 years) with cervix cancer FIGO stages IB–IVA were treated with definitive radiotherapy in curative intent. Histology was squamous cell cancer in 134 patients (86%), tumour size was >5 cm in 103 patients (66%), lymph node involvement in 75 patients (48%). Median follow-up was 42 months for all patients.

Interstitial techniques were used in addition to intracavitary brachytherapy in 69/156 (44%) patients. Total prescribed mean dose (D90) was 93 ± 13 Gy, D_2cc 86 ± 17 Gy for bladder, 65 ± 9 Gy for rectum and 64 ± 9 Gy for sigmoid.

Complete remission was achieved in 151/156 patients (97%). Overall local control at 3 years was 95%; 98% for tumours 2–5 cm, and 92% for tumours >5 cm (p = 0.04), 100% for IB, 96% for IIB, 86% for IIIB. Cancer specific survival at 3 years was overall 74%, 83% for tumours 2–5 cm, 70% for tumours >5 cm, 83% for IB, 84% for IIB, 52% for IIIB. Overall survival at 3 years was in total 68%, 72% for tumours 2–5 cm, 65% for tumours >5 cm, 74% for IB, 78% for IIB, 45% for IIIB.

In regard to late morbidity in total 188 grade 1 + 2 and 11 grade 3 + 4 late events were observed in 143 patients. G1 + 2/G3 + 4 events for bladder were n = 32/3, for rectum n = 14/5, for bowel (including sigmoid) n = 3/0, for vagina n = 128/2, respectively.

Interpretation

3D conformal radiotherapy ± chemotherapy plus image (MRI) guided adaptive intracavitary brachytherapy including needle insertion in advanced disease results in local control rates of 95–100% at 3 years in limited/favourable (IB/IIB) and 85–90% in large/poor response (IIB/III/IV) cervix cancer patients associated with a moderate rate of treatment related morbidity. Compared to the historical Vienna series there is relative reduction in pelvic recurrence by 65–70% and reduction in major morbidity. The local control improvement seems to have impact on CSS and OS. Prospective clinical multi-centre studies are mandatory to evaluate these challenging mono-institutional findings.

Dose effect relationship for late side effects of the rectum and urinary bladder in magnetic resonance image-guided adaptive cervix cancer brachytherapy

PURPOSE

To establish dose-response relationships for late side effects of the rectum and bladder in cervix cancer patients after magnetic resonance image-guided adaptive brachytherapy (IGABT).

METHODS AND MATERIALS

A cohort of 141 patients was treated with 45 to 50.4 Gy with or without cisplatin plus 4 fractions of 7 Gy IGABT. Doses for the most exposed 2, 1, and 0.1-cm(3) (D(2 cc), D(1 cc), D(0.1 cc)) volumes of the rectum and bladder were converted into the equivalent dose in 2 Gy fractions (EQD2), using a linear quadratic model (α/β = 3 Gy). Late side effects were prospectively assessed (using late effects in normal tissues subjective, objective, management and analytic [LENT SOMA]) scales. Dose-response relationships were determined by logit analyses.

RESULTS

Eleven patients developed rectal side effects, and 23 patients had urinary side effects. A significant dose effect was found for all rectal dose-volume histogram (DVH) parameters for patients with side effect grades of 1 to 4 but was only significant for D(2 cc) and D(1 cc) for grades ≥ 2. The ED10 values for D(2 cc) were 73 Gy for grades 1 to 4 and 78 Gy for grades 2 to 4 rectal morbidity. For bladder side effects, a significant dose effect was shown for all DVH parameters for complication grades ≥ 2; the respective ED10 was 101 Gy.

CONCLUSIONS

Well-defined dose-response curves could be established for D(2 cc) in the rectum and the urinary bladder.

Nedaplatin: a radiosensitizing agent for patients with cervical cancer

Despite the recent advances in the management of cervical cancer using cisplatin-based concurrent chemoradiotherapy, substantial treatment failure still occurs, especially in advanced-stage patients and early-stage cervical cancer patients with high-risk prognostic factors. Therefore, efforts to further improve the survival and quality of life of these patients are necessary. Nedaplatin (cis-diammine-glycoplatinum), a derivative of cisplatin, was developed with the aim of producing a treatment with a similar effectiveness to cisplatin but decreased renal and gastrointestinal toxicities. Based on the promising results of preclinical studies, the clinical efficacy of nedaplatin as a radiosensitizing agent was evaluated in patients with cervical cancer. Retrospective analysis of nedaplatin-based concurrent chemoradiotherapy (CCRT) against cervical cancer suggested that nedaplatin-based CCRT can be considered as an alternative to cisplatin-based CCRT in both early-stage and advanced-stage cervical cancer patients. However, due to the lack of a randomized controlled study, nedaplatin-based CCRT has not been convincingly proven to be clinically effective in patients with cervical cancer. Further investigations in randomized controlled trials are therefore needed.

A phase II trial of less than 7 weeks of concomitant cisplatin-paclitaxel chemoradiation in locally advanced cervical cancer

OBJECTIVES

This study was undertaken to determine the tolerability of a 7-week schedule of external beam radiation therapy, high-dose-rate brachytherapy, and weekly cisplatin and paclitaxel in patients with locally advanced carcinoma of the cervix.

METHODS

Twenty-nine patients with International Federation of Gynecology and Obstetrics stages IB2 to IVa cervical cancer were treated with 40 mg/m per week of intravenous (i.v.) cisplatin and 50 mg/m per week of i.v. paclitaxel combined with 45 Gy of pelvic external beam radiation therapy and 30 Gy of high-dose-rate brachytherapy.

RESULTS

Eleven patients (37.9%) were able to complete the 6 scheduled cycles of chemotherapy. The median number of weekly chemotherapy cycles administered was 5 (range, 2-7). Thirty-five (20.1%) of 174 cycles of chemotherapy were not given because of toxicity. The median dose intensity of cisplatin was 31 mg/m per week (95% confidence interval [CI], 25.2-36.8); that of paclitaxel was 44 mg/m per week (95% CI, 39.9-48.3). Twenty-two patients (78.6%) were able to complete the planned radiation course in less than 7 weeks. Median radiation treatment length was 45 days (95% CI, 43.4-46.6). After a median follow-up of 48 months, 7 patients (24.1%) experienced severe (Radiation Therapy Oncology Group grade 3 or higher) late toxicity. No fatal events were observed. Seven patients have failed, 1 locally and 6 at distant sites. The 8-year local/pelvic control rate was 95.7%, and the 8-year freedom from systemic failure rate was 76.1%. Eight-year actuarial disease-free survival and overall survival were 63.1% and 75.9%, respectively.

CONCLUSIONS

This study demonstrated unacceptable toxicity of combining the stated doses of concurrent cisplatin and paclitaxel chemotherapy with definitive radiotherapy for patients with advanced cervical cancer. Additional phase I/II trials are recommended to clearly establish the recommended phase II dose for these drugs.

Dose-volume histogram parameters and late side effects in magnetic resonance image-guided adaptive cervical cancer brachytherapy

PURPOSE

To evaluate the predictive value of dose-volume histogram (DVH) parameters for late side effects of the rectum, sigmoid colon, and bladder in image-guided brachytherapy for cervix cancer patients.

METHODS AND MATERIALS

A total of 141 patients received external-beam radiotherapy and image-guided brachytherapy with or without chemotherapy. The DVH parameters for the most exposed 2, 1, and 0.1 cm(3) (D(2cc), D(1cc), and D(0.1cc)) of the rectum, sigmoid, and bladder, as well as International Commission on Radiation Units and Measurements point doses (D(ICRU)) were computed. Total doses were converted to equivalent doses in 2 Gy by applying the linear-quadratic model (α/β = 3 Gy). Late side effects were prospectively assessed using the Late Effects in Normal Tissues-Subjective, Objective, Management and Analytic score. The following patient groups were defined: Group 1: no side effects (Grade 0); Group 2: side effects (Grade 1-4); Group 3: minor side effects (Grade 0-1); and Group 4: major side effects (Grade 2-4).

RESULTS

The median follow-up was 51 months. The overall 5-year actuarial side effect rates were 12% for rectum, 3% for sigmoid, and 23% for bladder. The mean total D(2cc) were 65 ± 12 Gy for rectum, 62 ± 12 Gy for sigmoid, and 95 ± 22 Gy for bladder. For rectum, statistically significant differences were observed between Groups 1 and 2 in all DVH parameters and D(ICRU). Between Groups 3 and 4, no difference was observed for D(0.1cc). For sigmoid, significant differences were observed for D(2cc) and D(1cc), but not for D(0.1cc) in all groups. For bladder, significant differences were observed for all DVH parameters only comparing Groups 3 and 4. No differences were observed for D(ICRU).

CONCLUSIONS

The parameters D(2cc) and D(1cc) have a good predictive value for rectal toxicity. For sigmoid, no prediction could be postulated because of limited data. In bladder, DVH parameters were predictive only for major toxicity.

CT-based 3D dose-volume parameter of the rectum and late rectal complication in patients with cervical cancer treated with high-dose-rate intracavitary brachytherapy

This study evaluated the efficacy of computed tomography (CT)-based three-dimensional (3D) dose-volume parameters of the rectum as predictor for late rectal complication (LRC) in cervical cancer patients treated with radiotherapy alone. Eighty-four patients treated with a combination of external radiotherapy and high-dose-rate intracavitary brachytherapy between January 2000 and December 2004 were retrospectively analyzed. Brachytherapy was prescribed with standard 2D planning. Patients underwent pelvic CT at brachytherapy. The external rectal wall was contoured on the CT images, and the minimum doses delivered to 0.1cc, 1cc, and 2cc of the most irradiated rectal volumes were calculated with dose-volume histograms. The International Commission of Radiation Units and Measurements (ICRU) rectal point dose was also calculated by conventional method. Total dose (external radiotherapy plus brachytherapy) to the rectum was transformed to the biologically equivalent dose in 2-Gy fractions with alpha/beta of 3 Gy (D(0.1cc), D(1cc), D(2cc) and D(ICRU)). The relationships between these dosimetric parameters and the incidence of LRC were analyzed. The 5-year overall actuarial rate of LRC was 26.4%. The values of D(0.1cc), D(1cc), and D(2cc) were significantly higher in patients with LRC than in those without (p < 0.001), but the difference in the values of D(ICRU) was not statistically significant (p = 0.10). The rate of LRC increased significantly with increasing D(0.1cc), D(1cc), and D(2cc) (p = 0.001). However, no positive dose-response relationship was observed between D(ICRU) and the rate of LRC (p = 0.42). The present study has suggested that CT-based 3D dose-volume parameters of the rectum may be effective for predicting LRC.

Dose-effect relationship for local control of cervical cancer by magnetic resonance image-guided brachytherapy

BACKGROUND AND PURPOSE

To analyse dose-response relationships for local control of cervical cancer after MR image-guided brachytherapy (IGBT) based on dose-volume histogram parameters.

METHODS AND MATERIALS

The analysis includes 141 patients with cervix cancer (stages IB-IVA) treated with 45-50.4 Gy EBRT+/-cisplatin plus 4 x 7 Gy IGBT. Gross tumour volume (GTV), high risk clinical target volume (HR CTV) and intermediate risk CTV (IR CTV) were delineated and DVH parameters (D90, D100) were assessed. Doses were converted to the equivalent dose in 2 Gy (EQD2) using linear-quadratic model (alpha/beta=10 Gy). Groups of patients were formed according to tumour size at diagnosis (GTV(D)) of 2-5 cm (group 1) or >5 cm (2), with subgroups of the latter for HR CTV size at first IGBT 2-5 cm (2a) or >5 cm (2b). Dose-response dependence for local recurrence was evaluated by logit analysis.

RESULTS

Eighteen local recurrences in the true pelvis were observed. Dose-response analyses revealed a significant effect of HR CTV D100 (p=0.02) and D90 (p=0.005). The ED50-values for tumour control were 33+/-15 Gy (D100) and 45+/-19 Gy (D90). ED90-values were 67 Gy (95% confidence interval [50;104]) and 86 Gy [77;113], respectively.

CONCLUSIONS

A significant dependence of local control on D100 and D90 for HR CTV was found. Tumour control rates of >90% can be expected at doses >67 Gy and 86 Gy, respectively.

Results of concomitant chemoradiation for cervical cancer using high dose rate intracavitary brachytherapy: study of JROSG (Japan Radiation Oncology Study Group)

The purpose of this study was to clarify outcome for concurrent chemoradiation (CT-RT) in locally advanced cervix cancer in Japan. This is a non-randomized retrospective analysis of 226 patients treated with definitive CT-RT or radiotherapy alone (RT alone) in nine institutions between 2001 and 2003. External irradiation consisted of whole pelvic irradiation and pelvic side wall boost irradiation, using a central shield during the latter half of the treatment with the anteroposterior parallel opposing technique. The external beam irradiation was performed with 1.8 or 2 Gy per fraction. High-dose-rate intracavitary brachytherapy (HDR) was performed in all cases. In chemotherapy, platinum based drugs were used alone or in combination with other drugs such as 5FU. Grade of late complications was scaled retrospectively with CTCv2.0. Overall survival rate at 50 months of stage Ib, II and III, IV was 82% and 66% in CR-RT and 81% and 43% in R alone, respectively. Disease-free survival rate at 50 months of stage Ib, II and III, IV was 74% and 59% in CR-RT and 76% and 52% in R alone, respectively. There was no significant difference between CT-RT and RT for overall survival and disease free survival. Univariate analysis suggested that loco-regional control was better with CT-RT, but multivariate analysis could not confirm this finding. Compared to RT alone, CT-RT caused significantly more acute and late complications. Thus, late complication (grade 3-4) free survival rate at 50 month was 69% for CT-RT and 86% for RT alone (p<0.01). The therapeutic window with concomitant radiochemotherapy and HDR brachytherapy may be narrow, necessitating a close control of dose volume parameters and adherence to systems for dose prescription.

Does the entire uterus need to be treated in cancer of the cervix? Role of adaptive brachytherapy

PURPOSE

To evaluate local control and toxicity by use of a method of adaptive cervical brachytherapy (ACB).

METHODS AND MATERIALS

From 1998 to 2008, we identified 65 cervical cancer patients with FIGO (International Federation of Gynecology and Obstetrics) Stage IB1-IVA disease who received definitive external beam radiation therapy and high-dose rate brachytherapy with tandem and ovoid applicators. As tumors regressed, 45 of 65 patients had the tandem source retracted from the uterine fundus at successive brachytherapy insertions, thus decreasing the number of (192)Ir dwell positions. Tests of trend and Fisher's exact test were used to identify the effect of ACB on disease control and toxicity. Kaplan-Meier analyses were performed to evaluate disease control and late complications.

RESULTS

The median follow-up was 24.5 months. Of the patients, 92% received chemotherapy. The 3-year overall survival, 3-year disease-free survival, 3-year distant metastasis-free survival, and local control rates were 67%, 76%, 79%, and 97%, respectively. There was only 1 isolated local failure, and there were no local failures beyond 1 year. Distant failure was involved in 93% of recurrences. No significant trend was identified regarding the extent of retraction of the tandem source start position with either failure or toxicity. Acute and actuarial 3-year late Grade 3 toxicity or greater occurred in 24.6% and 17% of patients, respectively.

CONCLUSIONS

ACB determined by clinical response yielded excellent local control rates. These data indicate that ACB may be useful in decreasing late toxicities from high-dose rate brachytherapy. With the advent of three-dimensional image-guided brachytherapy, additional methods to adapt treatment technique to changes in tumor volume warrant investigation.

MRI assessment of cervical cancer for adaptive radiotherapy

PURPOSE

To assess the importance of the information obtained from MRI for adaptive cervix cancer radiotherapy.

PATIENTS AND METHODS

49 patients with cervix cancer, treated by external-beam radiotherapy (EBRT) and MRI-assisted high-dose-rate brachytherapy +/- concomitant cisplatin, underwent MRI at diagnosis and at the time of brachytherapy fractions. 190 MRI examinations were performed. Pretreatment scans were correlated with clinical examination (CE) findings. Measurements in 3-D of the tumor extension and also of the distance from the tumor to the pelvic side wall were performed using both MRI and CE. The tumor volume regression induced initially by EBRT and the subsequent regression after each brachytherapy fraction were assessed.

RESULTS

MRI and CE showed 92% agreement in overall parametrial staging and 73% agreement in terms of vaginal involvement. There was, however, disagreement in parametrial side (right/left) classification in 25% of the parametria examined. These were patients with unilateral displacement of the cervix and contralateral invasion of the parametrium. The mean tumor volume on the pretreatment MRI scan (GTVD) was 61 cm(3). At the time of the four brachytherapy fractions the mean was 16 cm(3), 10 cm(3), 9 cm(3), and 8 cm(3), defined as the GTVBT plus the gray zones in the parametria.

CONCLUSION

CE and MRI findings agree well in terms of overall staging. The clinical assessment of side-specific parametrial invasion improved when having access to the additional knowledge obtained from MRI. The greatest decrease in tumor volume occurs during EBRT, whereas tumor regression between the first and subsequent brachytherapy fractions is minor.

High-dose rate brachytherapy using inverse planning simulated annealing for locoregionally advanced cervical cancer: a clinical report with 2-year follow-up

PURPOSE

We present clinical outcomes of image-guided brachytherapy using inverse planning simulated annealing (IPSA) planned high-dose rate (HDR) brachytherapy boost for locoregionally advanced cervical cancer.

METHODS AND MATERIALS

From February 2004 through December 2006, 51 patients were treated at the University of California, San Francisco with HDR brachytherapy boost as part of definitive radiation for International Federation of Gynecology and Obstetrics Stage IB1 to Stage IVA cervical cancer. Of the patients, 46 received concurrent chemotherapy, 43 with cisplatin alone and 3 with cisplatin/5-fluorouracil. All patients had IPSA-planned HDR brachytherapy boost after whole-pelvis external radiation to a total tumor dose of 85 Gy or greater (for alpha/beta = 10). Toxicities are reported according to National Cancer Institute CTCAE v3.0 (Common Terminology Criteria for Adverse Events version 3.0) guidelines.

RESULTS

At a median follow-up of 24.3 months, there were no toxicities of Grade 4 or greater and the frequencies of Grade 3 acute and late toxicities were 4% and 2%, respectively. The proportion of patients having Grade 1 or 2 gastrointestinal and genitourinary acute toxicities was 48% and 52%, respectively. Low-grade late toxicities included Grade 1 or 2 vaginal, gastrointestinal, and hormonal toxicities in 31%, 18%, and 4% of patients, respectively. During the follow-up period, local recurrence developed in 2 patients, regional recurrence developed in 2, and new distant metastases developed in 15. The rates of locoregional control of disease and overall survival at 24 months were 91% and 86%, respectively.

CONCLUSIONS

Definitive radiation by use of inverse planned HDR brachytherapy boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease.

Dose-volume histogram parameters and local tumor control in magnetic resonance image-guided cervical cancer brachytherapy

PURPOSE

To investigate the value of dose-volume histogram (DVH) parameters for predicting local control in magnetic resonance (MR) image-guided brachytherapy (IGBT) for patients with cervical cancer.

METHODS AND MATERIALS

Our study population consists of 141 patients with cervical cancer (Stages IB-IVA) treated with 45-50 Gy external beam radiotherapy plus four times 7 Gy IGBT with or without cisplatin. Gross tumor volume (GTV), high-risk clinical target volume (HRCTV), and intermediate-risk clinical target volume (IRCTV) were contoured, and DVH parameters (minimum dose delivered to 90% of the volume of interest [D90] and D100) were assessed. Doses were converted to the equivalent dose in 2 Gy (EQD2) by applying the linear quadratic model (alpha/beta = 10 Gy). Groups were defined for patients with or without local recurrence (LR) in the true pelvis for tumor size at diagnosis (GTV at diagnosis [GTVD] of 2-5 cm (Group 1) or greater than 5 cm (Group 2) and for tumor size response at IGBT (HRCTV) of 2-5 cm (Group 2a) or greater than 5 cm (Group 2b).

RESULTS

Eighteen LRs were observed. The most important DVH parameters correlated with LR were the D90 and D100 for HRCTV. Mean D90 and D100 values for HRCTV were 86 +/- 16 and 65 +/- 10 Gy, respectively. The D90 for HRCTV greater than 87 Gy resulted in an LR incidence of 4% (3 of 68) compared with 20% (15 of 73) for D90 less than 87 Gy. The effect was most pronounced in the tumor group (Group 2b).

CONCLUSIONS

We showed an increase in local control in IGBT in patients with cervical cancer with the dose delivered, which can be expressed by the D90 and D100 for HRCTV. Local control rates greater than 95% can be achieved if the D90 (EQD2) for HRCTV is 87 Gy or greater.

Correlation of dose-volume parameters, endoscopic and clinical rectal side effects in cervix cancer patients treated with definitive radiotherapy including MRI-based brachytherapy

PURPOSE

Correlation of dosimetric parameters for MRI-based 3D treatment planning with rectoscopic findings and clinical rectal side effects.

METHODS AND MATERIALS

Rectosigmoidoscopy and rectal morbidity assessment were performed on 35 cervical cancer patients treated with external beam radiotherapy (EBRT) and HDR-intracavitary brachytherapy (ICB). The total doses, normalised to 2 Gy fractions (EQD2, alpha/beta=3 Gy), in 0.1, 1.0 and 2.0 cm(3) (D(0.1 cc), D(1 cc), D(2 cc)) of rectum were determined by summation of EBRT and ICB plans. Correlation analysis between clinical symptoms (LENT/SOMA) and rectoscopic changes (Vienna Rectoscopy Score, VRS) was performed. For dose-response analyses, the logit model was applied.

RESULTS

Mean follow-up was 18 months. LENT/SOMA score was 1 in 4 patients, 2 in 8 patients, 4 in 1 patient. Telangiectasia was found in 26 patients (74%), five of them had ulceration corresponding to the 0.1 cm(3) volume (anterior wall). Mean values D(0.1 cc), D(1 cc), and D(2 cc) were 81+/-13, 70+/-9 and 66+/-8 Gy, respectively. The ED50 values for VRS > or = 3 and for LENT/SOMA > or = 2 significantly increased with decreasing volumes. D(2 cc) was higher in patients with VRS > or = 3 compared to VRS<3 (72+/-6 vs 62+/-7 Gy; p<0.001) and in symptomatic vs asymptomatic patients (72+/-6 vs 63+/-8 Gy; p<0.001). VRS correlated with the LENT/SOMA score.

CONCLUSIONS

Rectosigmoidoscopy is sensitive in detecting mucosal changes, independent of clinical symptoms. The localization of these changes corresponds to the high dose volumes as defined by imaging. The development of mucosal and clinical changes in the rectum follows a clear dose-effect and volume-effect. DVH parameters could be established.

Current status and perspectives of brachytherapy for cervical cancer

Standard definitive radiotherapy for cervical cancer consists of whole pelvic external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT). In Japan, high-dose-rate ICBT (HDR-ICBT) has been utilized in clinical practice for more than 40 years. Several randomized clinical trials demonstrated that HDR-ICBT achieved comparative outcomes, both for pelvic control and incidences of late complications, to low-dose-rate (LDR) ICBT. In addition, HDR-ICBT has some potential advantages over LDR-ICBT, leading to further improvement in treatment results. Prior to the current computer planning systems, some excellent treatment planning concepts were established. At present, systems modified from these concepts, or novel approaches, such as image-guided brachytherapy (IGBT) are under investigation. One serious problem to be solved in HDR-ICBT for cervical cancer is that of the discrepancy in standard treatment schedules for combination HDR-ICBT and EBRT between the United States and Japan. Prospective studies are ongoing to assess the efficacy and toxicity of the Japanese schedule.

Inter-observer comparison of target delineation for MRI-assisted cervical cancer brachytherapy: application of the GYN GEC-ESTRO recommendations

BACKGROUND AND PURPOSE

To investigate the inter-observer variation of target contouring when using the GYN GEC-ESTRO recommendations for MR image-guided brachytherapy (IGBT) for cervical cancer.

MATERIALS AND METHODS

Nineteen cervical cancer patients, treated by radiotherapy at the Institut Gustave Roussy (IGR) in France (n=9) or at the Medical University of Vienna (AKH) in Austria (n=10) were included in this study. IGBT was used for all patients. Two radiation oncologists, one from IGR and the other from AKH, outlined the target volumes on MRI at the time of brachytherapy according to the GYN GEC-ESTRO recommendations. The absolute, common and encompassing volumes and their conformity indices (CIs) were assessed for the GTV, HR CTV and IR CTV. D90 and D100 for each volume were assessed. Visual evaluation was made to assess the reasons for the most frequent inter-observer differences.

RESULTS

The mean volumes of GTV and HR CTV did not differ significantly between the observers, p>0.05. Significant differences were observed only for the mean volumes of the IR CTV of both centres, p<0.05. CIs ranged from 0.5 to 0.7. DVH-parameter analyses did not reveal any statistical differences, except for the D100 for the GTV at AKH, and the D90 for the IR CTV at IGR, p<0.05. Underlying reasons for inter-observer differences included image contrast adjustment and neglecting to consider anatomical borders.

CONCLUSIONS

The results of this inter-observer study show that the application of the GYN GEC-ESTRO recommendations for IGBT contouring at two different institutions with two different traditions for applicators, CTV assessment, MR image acquisition and dose prescription is feasible, and it produces acceptable inter-observer variability.

Inter- and intraobserver variation in HR-CTV contouring: intercomparison of transverse and paratransverse image orientation in 3D-MRI assisted cervix cancer brachytherapy

AIM

To analyze agreement between target volumes, delineated by two observers on transverse (T) and paratransverse (perpendicular to the long cervical axis - PT) MR images for cervix cancer brachytherapy.

MATERIALS AND METHODS

In 13 patients, High Risk-CTV (HR-CTV) was outlined by two observers in T and PT MR image plane, respecting the GYN GEC-ESTRO recommendations for 3D-image based cervix cancer brachytherapy [1]. Contouring time was measured. HR-CTV sizes were compared, and conformity index (CI) was assessed. Interobserver variations in contour-extent along eight radial directions were compared between delineation planes. After applying a standard treatment plan, an intercomparison of DVH-parameters V100, D90, and D100 for the HR-CTV was carried out.

RESULTS

Contouring time was slightly longer in T than PT orientation. Interplane CI did not differ significantly between observers (0.72 vs. 0.71), nor did the interobserver CI between planes (0.79 vs. 0.78). Variations in contour-extent between different radial directions and interplane deviations in DVH parameters were non-significant.

CONCLUSION

Contouring in PT, as compared to T plane, allows for a "circumferential view of the cervix" and facilitates comprehensive understanding of spatial relations between the applicator and patho-anatomical structures. It is marked by a lower contouring difficulty and leads to a comparable outcome in terms of DVH parameters. Interobserver inconsistencies can be minimized by systematic training and following the published recommendations.

Image-guided adaptive brachytherapy for cervix carcinoma

Sectional imaging has played an important role in the management of cervical cancer, in particular for staging, and is now considered for image-guided treatment planning, in particular for brachytherapy. Image-based three-dimensional brachytherapy is a relatively new approach that is increasingly replacing the traditional two-dimensional X-ray-based method. This overview focuses on the potential and some practicalities of this approach. The pros and cons of computed tomography- and magnetic resonance imaging-based brachytherapy are considered and an overview of the current state of research is given. The first encouraging clinical results are presented and future perspectives are discussed.

MRI-guided 3D optimization significantly improves DVH parameters of pulsed-dose-rate brachytherapy in locally advanced cervical cancer

PURPOSE

To compare dose-volume histogram parameters of standard Point A and magnetic resonance imaging-based three-dimensional optimized dose plans in 21 consecutive patients who underwent pulsed-dose-rate brachytherapy (PDR-BT) for locally advanced cervical cancer.

METHODS AND MATERIALS

All patients received external beam radiotherapy (elective target dose, 45 Gy in 25-30 fractions; tumor target dose, 50-60 Gy in 25-30 fractions). PDR-BT was applied with a tandem-ring applicator. Additional ring-guided titanium needles were used in 4 patients and a multichannel vaginal cylinder in 2 patients. Dose planning was done using 1.5 Tesla T(1)-weighted and T(2)-weighted paratransversal magnetic resonance imaging scans. T(1)-weighted visible oil-containing tubes were used for applicator reconstruction. The prescribed standard dose for PDR-BT was 10 Gy (1 Gy/pulse, 1 pulse/h) for two to three fractions to reach a physical dose of 80 Gy to Point A. The total dose (external beam radiotherapy plus brachytherapy) was normalized to an equivalent dose in 2-Gy fractions using alpha/beta = 10 Gy for tumor, alpha/beta = 3 Gy for normal tissue, and a repair half-time of 1.5 h. The goal of optimization was dose received by 90% of the target volume (D(90)) of > or =85 Gy(alpha/beta10) in the high-risk clinical target volume (cervix and remaining tumor at brachytherapy), but keeping the minimal dose to 2 cm(3) of the bladder and rectum/sigmoid at <90 and <75 Gy(alpha/beta3), respectively.

RESULTS

Using three-dimensional optimization, all dose-volume histogram constraints were met in 16 of 21 patients compared with 3 of 21 patients with two-dimensional library plans (p < 0.001). Optimization increased the minimal target dose (D(100)) of the high-risk clinical target volume (p < 0.007) and decreased the minimal dose to 2 cm(3) for the sigmoid significantly (p = 0.03). For the high-risk clinical target volume, D(90) was 91 +/- 8 Gy(alpha/beta10) and D(100) was 76 +/- 5 Gy(alpha/beta10). The minimal dose to 2 cm(3) for the bladder, rectum, and sigmoid was 73 +/- 6, 67 +/- 6, and 69 +/- 6 Gy(alpha/beta3), respectively.

CONCLUSION

The results of our study have shown that magnetic resonance imaging-guided optimization of PDR-BT for locally advanced cervical cancer significantly improved the dose-volume histogram parameters.

Clinical impact of MRI assisted dose volume adaptation and dose escalation in brachytherapy of locally advanced cervix cancer

BACKGROUND

To investigate the clinical impact of MRI based cervix cancer brachytherapy combined with external beam radiochemotherapy applying dose volume adaptation and dose escalation in a consecutive group of patients with locally advanced cervix cancer.

METHODS

In the period 1998-2003, 145 patients with cervix cancer stages IB-IVA were treated with definitive radiotherapy +/- cisplatin chemotherapy. Median age was 60 years. In 67 patients, the tumour size was 2-5 cm, in 78 patients it was >5 cm. In 29 cases the standard intracavitary technique was combined with interstitial brachytherapy. Total prescribed dose was 80-85 Gy (total biologically equivalent dose in 2 Gy fractions). Since 2001, MRI based treatment planning integrated systematic concepts for High Risk Clinical Target Volume (HR CTV) and organs at risk (OAR), biological modelling, Dose-Volume-Histogram analysis, dose-volume-adaptation (D90, D 2 cm(3)), and dose escalation, if appropriate and feasible.

FINDINGS

Dose volume adaptation was performed in 130/145 patients. The mean D90 during the whole period was 86 Gy, with a mean D90 of 81 Gy and 90 Gy during the first and second period, respectively (p<<0.01). Median follow-up was 51 months. Complete remission at 3 months was achieved in 138/145 patients (95%). Actuarial continuous complete remission for true pelvis (CCRtp) was 88% at 3 years. For tumours 2-5 cm, CCRtp was 96% both in 1998-2000 and 2001-2003. For tumours >5 cm it was 71% in 1998-2000 and 90% in 2001-2003 (p=0.05). Progression free survival (PFS) for true pelvis (local control) was 85%, PFS for distant metastases was 80%, both at 3 years. Local control for tumours >5 cm was 64% in 1998-2000 and 82% in 2001-2003 (p=0.09) and 100% and 96%, respectively, for tumours 2-5 cm. PFS for distant metastases remained the same during the two treatment periods with 79% and 80%. Overall survival (OS) was 58%, and cancer-specific survival (CSS) was 68% at 3 years. In the two different periods improvement in OS was from 53% to 64% (p=0.03) and in CSS from 62% to 74% (p=0.13). Improvement occurred only in tumours >5 cm: OS 28% versus 58% (p=0.003); CSS 40% versus 62% (p=0.07). Actuarial late morbidity rate (LENT SOMA, grades 3 and 4) at 3 years was gastrointestinal 4%, urinary 4% and vaginal 5% (stage IIA/IIIA). Gastrointestinal and urinary late morbidity (G3,G4) was 10% in 1998-2000 and 2% in 2001-2003.

INTERPRETATION

In locally advanced extensive cervix cancer, local control of > or = 85% can be achieved with low treatment related morbidity (G3/G4), when exploiting the potential of MRI based 3D treatment planning including dose volume adaptation and dose escalation and a combined intracavitary/interstitial brachytherapy, if appropriate. A significant impact of this improvement of local control on survival is to be expected. For locally advanced limited disease the MRI based approach will likely result in assuring excellent local control (> or = 95%) and in minimizing treatment related morbidity.

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.

Image-based three-dimensional treatment planning of intracavitary brachytherapy for cancer of the cervix: Dose-volume histograms of the bladder, rectum, sigmoid colon, and small bowel

PURPOSE

The purpose of this study was to evaluate dose-volume histograms (DVHs) of bladder, rectum, sigmoid colon, and small bowel using image-based three-dimensional treatment planning for intracavitary brachytherapy.

METHODS AND MATERIALS

Between 2001 and 2003, 22 patients with cancer of the cervix (1 IB1, 5 IB2, 11 IIB, 5 IIIB) were treated with computerized tomography (CT)-compatible high-dose-rate intracavitary applicators and underwent postimplant pelvic CT scans with the applicator in place. The volumes of organs at risk were digitized. For radiography-based planning, International Commission on Radiation Units and Measurements (ICRU) bladder and rectum point doses were calculated. For the CT-based planning, the DVHs were computed for the bladder, rectum, sigmoid colon, and small bowel. To compare doses to organs at risk, the minimum dose in 2.0cm(3) volume receiving the highest dose (D(2)) was determined from DVHs. These D(2) doses were compared with radiography-based ICRU point doses.

RESULTS

The mean ICRU bladder point dose (401cGy) was markedly underestimated compared to the mean bladder D(2) dose (484cGy). However, the mean ICRU rectal point dose (412cGy) did not differ significantly from the mean rectal D(2) dose (373cGy). The most frequent organ receiving the highest D(2) dose was the sigmoid colon in 9 of 22 patients (41%) followed by the rectum in 7 of 22 patients (32%) and small bowel in 6 of 22 patients (27%).

CONCLUSIONS

From CT-based three-dimensional (3-D) evaluation, the ICRU bladder point dose was substantially lower than bladder D(2) dose. Special attention should also be given to the areas of proximal rectum and sigmoid colon due to more frequent high D(2) dose in these areas.