Adaptive 3D image-guided brachytherapy: a strong argument in the debate on systematic radical hysterectomy for locally advanced cervical cancer

Clinical significance of intensity-modulated radiotherapy (IMRT) to the distant metastatic lymph nodes for metastatic cervical cancer

OBJECTIVE

To retrospectively explore the clinical significance of radiotherapy to the distant metastatic lymph nodes (cervical/ clavicular/ mediastinal et al.) in metastatic cervical cancer. Hereinto, these cervicothoracic lymph nodes were metastasized from IB1-IVA (initial stage at first treatment), and IVB initially had metastatic disease in these areas at diagnosis.

METHODS

Metastatic cervical cancer only with the distant cervicothoracic metastatic lymph nodes (cervical/ clavicular/ mediastinal et al.), without distant parenchymal organs metastasis such as lung, liver, bone, and peritoneum, were enrolled in the analysis. These patients were classified into IB1-IVA and IVB based on their initial stage of first treatment. All patients received IMRT for the distant metastatic lymph nodes. The progression-free survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method.

RESULTS

Overall, the median PFS was 9 months, and the median OS was 27 months. The subgroup analysis showed that for IB1-IVA, the median PFS was 11 months, and the median OS was 30.5 months. For IVB, the median PFS was 8 months, and the median OS was 16 months.

CONCLUSION

Radiotherapy is beneficial to the distant metastatic lymph nodes (cervical/ clavicular/ mediastinal et al.), and could effectively bring the longer PFS and OS for metastatic cervical cancer.

The safety and efficacy of volumetric modulated Arc therapy combined with computer tomography-guided adaptive brachytherapy for locally advanced cervical cancer: a single institution experience

BACKGROUND

Volumetric modulated arc therapy (VMAT) is a novel form of IMRT, which can deliver more accurate dose distribution and shorten treatment time. Compared to MRI-guided adaptive brachytherapy, which is recommended as gold standard imaging for cervical cancer contours, CT-guided adaptive brachytherapy (CTGAB) is more available, more widespread, and more affordable in many centers. This study aims to retrospectively analyze the efficacy and the safety of VMAT combined with CTGAB for patients with locally advanced cervical cancer.

METHODS AND MATERIALS

This study retrospectively analyzed 102 patients with locally advanced cervical cancer who underwent VMAT and CTGAB. Clinical outcomes including local control (LC), overall survival (OS) and progression-free survival (PFS), tumor response to treatment evaluated by the Response Evaluation Criteria in Solid Tumors (RECIST) (version 1.1), and toxicities including gastrointestinal toxicity, urinary toxicity and hematologic toxicity evaluated by the Common Terminology Criteria for Adverse Events (CTCAE) (version 5.0) were analyzed. The Kaplan-Meier method was used to calculate LC, OS, and PFS.

RESULTS

Median follow-up time was 19 months. Complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD) occurred in 68 (66.7%), 24 (23.5%), 4 (3.92%), and 6 (5.88%), respectively. The 2-year and 3-year OS were 89.6% and 83%, respectively. The 2-year and 3-year PFS were 84.2% and 74.3%, respectively. The 2-year and 3-year LC were 90.1% and 79.3%, respectively. The average cumulative D2cm3 in the rectum, the bladder, the colon, and the small intestine were 78.07 (SD: 0.46) Gy, 93.20 (SD: 0.63) Gy, 63.55 (SD: 1.03) Gy and 61.07 (SD: 0.75) Gy, respectively. The average cumulative D90% of the high-risk clinical target volume (HR-CTV) was 92.26 (SD: 0.35) Gy. Grade ≥ 3 gastrointestinal and urinary toxicities occurred in 4.9% and 0.98%, respectively. 1.96% of patients were observed grade ≥ 4 gastrointestinal toxicities and none of the patients observed grade ≥ 4 urinary toxicities.

CONCLUSION

VMAT combined with CTGAB for locally advanced cervical cancer was an effective and safe treatment method, which showed satisfactory LC, OS, PFS, and acceptable toxicities.

The current state and future perspectives of radiotherapy for cervical cancer

Radiotherapy is an effective treatment method for cervical cancer and is typically administered as external beam radiotherapy followed by intracavitary brachytherapy. In Japan, center shielding is used in external beam radiotherapy to shorten treatment time and reduce the doses delivered to the rectum or bladder. However, it has several challenges, such as uncertainties in calculating the cumulative dose. Recently, external beam radiotherapy has been increasingly performed with intensity-modulated radiotherapy, which reduces doses to the rectum or bladder without center shielding. In highly conformal radiotherapy, uncertainties in treatment delivery, such as inter-fractional anatomical structure movements, affect treatment outcomes; therefore, image-guided radiotherapy is essential for appropriate and safe performance. Regarding intracavitary brachytherapy, the use of magnetic resonance imaging-based image-guided adaptive brachytherapy is becoming increasingly widespread because it allows dose escalation to the tumor and accurately evaluates the dose delivered to the surrounding normal organs. According to current evidence, a minimal dose of D90% of the high-risk clinical target volume is significantly relevant to local control. Further improvements in target coverage have been achieved with combined interstitial and intracavity brachytherapy for massive tumors with extensive parametrical involvement. Introducing artificial intelligence will enable faster and more accurate generation of brachytherapy plans. Charged-particle therapies have biological and dosimetric advantages, and current evidence has proven their effectiveness and safety in cervical cancer treatment. Recently, radiotherapy-related technologies have advanced dramatically. This review provides an overview of technological innovations and future perspectives in radiotherapy for cervical cancer.

Discussion on the Treatment Strategy for Stage ⅡA1 Cervical Cancer (FIGO 2018)

Objective

This study aimed to explore the best treatment strategy for International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IIA1 cervical cancer patients by comparing the survival outcomes of two treatment methods: abdominal radical hysterectomy (ARH) with standard postoperative therapy and radio-chemotherapy (R-CT).

Methods

Patients with FIGO2018 stage IIA1 cervical cancer who underwent ARH or received R-CT were screened from the clinical diagnosis and treatment for cervical cancer in China (Four C) database. The recurrence cases between the two groups were analyzed. The 5-year overall survival (OS) and disease-free survival (DFS) of patients diagnosed with stage IIA1 cervical cancer in 47 hospitals in mainland China between 2004 and 2018 were compared by using propensity score matching (PSM).

Results

A total of 724 patients met the inclusion criteria. In the total study population, The R-CT group had higher recurrence (22.8% for the R-CT group and 11.2% for the ARH group, P<0.001) rates compared to the ARH group.The 5-year OS and DFS of the ARH group (n=658) were significantly higher than those of the R-CT group (n=66) (OS: 85.9% vs. 71.2%, P=0.009; DFS: 79.2%vs. 70.5%, P=0.027). R-CT was associated with worse 5-year OS (HR=3.19, 95% CI: 1.592-6.956, P=0.001) and DFS (HR=2.089, 95% CI: 1.194-3.656, P=0.01). After 1:2 PSM, the 5-year OS and DFS of the ARH group (n=126) were significantly higher than those of the R-CT group (n=64) (OS:88.9% vs. 70.1%, P=0.04; DFS:82.8% vs. 69.8%, P=0.019). R-CT was still associated with worse 5-year OS (HR=2.391, 95% CI: 1.051-5.633, P=0.046) and DFS (HR=2.6, 95% CI: 1.25-5.409, P=0.011).

Conclusion

Our study demonstrated that for stage FIGO2018 stage IIA1 cervical cancer patients, ARH offers better oncological outcomes than R-CT.

Clinical Outcomes of MRI-Guided Adaptive Brachytherapy for Each Fraction in Locally Advanced Cervical Cancer: A Single Institution Experience

Purpose

This study aims to evaluate clinical outcomes of MRI-guided adaptive brachytherapy (MR-IGABT) for each brachytherapy fraction in patients with locally advanced cervical cancer (LACC).

Methods and Materials

A retrospective analysis was performed on 97 consecutive patients with LACC treated with 44.0–50.4 Gy external beam radiotherapy (EBRT) ± concurrent platinum-containing chemotherapy followed by 4 × 7 Gy MR-IGABT between September 2014 and April 2019. Intracavitary (IC)/interstitial (IS)/hybrid intracavitary and interstitial (IC/IS) brachytherapy was used in MR-IGABT. Brachytherapy planning and dose reporting followed the GEC-ESTRO recommendations. Clinical outcomes including overall survival (OS), cancer-specific survival (CSS), progression-free survival (PFS), local control (LC), and treatment-related toxicity evaluated by the RTOG criteria were analyzed. Kaplan–Meier and univariable and multivariable Cox regression analyses were used to analyze the prognostic factor.

Results

Median follow-up was 21.1 months. Median dose to 90% (D₉₀) of the high-risk clinical target volume (HR-CTV) was 91.7 Gy (range 76.7~107.2 Gy). Two-year OS, CSS, PFS, and LC were 83.5%, 84.1%, 71.1%, and 94.8%, respectively. Four patients (4.1%) suffered from grade 3 late gastrointestinal radiation toxicity, and no other grade 3 or greater radiation toxicity occurred. Initial HR-CTV was an independent factor of OS (p = 0.001, HR = 1.018/cm³), PFS (p = 0.012, HR = 1.012/cm³), and LC (p = 0.011, HR = 1.028/cm³). The HR-CTV D₉₀ (p = 0.044, HR = 0.923/Gy) was an independent factor of PFS. Age was an independent factor of LC (p = 0.010, HR = 1.111/year).

Conclusion

For patients with LACC, MR-IGABT was effective and safe. It showed favorable LC, OS, and minimal toxicity. Moreover, initial HR-CTV, HR-CTV D₉₀, and age were significant prognostic factors.

Role of adjuvant chemotherapy after concurrent chemoradiotherapy in patients with locally advanced cervical cancer

Objectives: With the use of concurrent chemoradiotherapy (CCRT) for locally advanced cervical cancer (LACC), survival outcomes are still not optimal. This study was designed to evaluate the efficacy and safety of adjuvant chemotherapy (ACT) for patients with LACC after treatment with CCRT. Methods: Patients diagnosed with stage IIA-IIIB LACC, were retrospectively analyzed. All patients received cisplatin-based CCRT and were divided into two groups: ACT after CCRT (CCRT + ACT group) and observation after CCRT (CCRT group). Overall survival (OS), progression-free survival (PFS) and adverse effects were recorded and analyzed. Results: In total, 375 patients were included; 262 patients accepted ACT after CCRT while the remaining 113 patients chose observation. With a median follow-up of 40 months, no significant differences were found in the OS rates for patients in the CCRT + ACT and CCRT groups at 1 year, 3 years and the end of follow-up. There was also no significant discrepancy in PFS between groups. Subgroup analysis showed the International Federation of Gynecology and Obstetrics (FIGO) stage and age had negligible influence on both OS and PFS. Acute adverse events (grades 3-4) happened more frequently in CCRT + ACT group than in the CCRT group, with significant differences in neutropenia, anemia and creatinine. Conclusion: ACT after CCRT did not show benefit in survival but did induce some adverse effects. Therefore, this regimen is not recommended unless further large-scale randomized controlled trials are executed.

Modelling a new approach for radio-ablation after resection of breast ductal carcinoma in-situ based on the BAT-90 medical device

The majority of local recurrences, after conservative surgery of breast cancer, occurs in the same anatomical area where the tumour was originally located. For the treatment of ductal carcinoma in situ (DCIS), a new medical device, named BAT-90, (BetaGlue Technologies SpA) has been proposed. BAT-90 is based on the administration of ⁹⁰Y β-emitting microspheres, embedded in a bio-compatible matrix. In this work, the Geant4 simulation toolkit is used to simulate BAT-90 as a homogenous cylindrical ⁹⁰Y layer placed in the middle of a bulk material. The activity needed to deliver a 20 Gy isodose at a given distance z from the BAT-90 layer is calculated for different device thicknesses, tumour bed sizes and for water and adipose bulk materials. A radiobiological analysis has been performed using both the Poisson and logistic Tumour Control Probability (TCP) models. A range of radiobiological parameters (α and β), target sizes, and densities of tumour cells were considered. Increasing α values, TCP increases too, while, for a fixed α value, TCP decreases as a function of clonogenic cell density. The models predict very solid results in case of limited tumour burden while the activity/dose ratio could be further optimized in case of larger tumour beds.

Can we reduce dose to ureters as avoidance organs for MRI based brachytherapy for cervical cancer? A dosimetric feasibility study

BACKGROUND AND PURPOSE

Ureteral stenosis (US) is an underreported complication of brachytherapy (BT) for cervical cancer (CC), with limited data on toxicity risk reduction. A previous study demonstrated ureter EQD2 D0.1cc > 77 Gy correlated with US development. We sought to assess feasibility of this constraint while maintaining similar HR-CTV coverage.

MATERIALS AND METHODS

Patients with locally advanced CC treated with EBRT plus HDR MRI-based brachytherapy boost without hydronephrosis at diagnosis and with ureter dose EQD2 D0.1cc > 77 Gy were included. Replan was attempted to achieve HR-CTV D90 ≥ 80-85 Gy and ureter dose reduction. Ureter distance from lateral margin of HR-CTV and tandem was recorded. t-test was performed to compare ureteral dose and HR-CTV D90.

RESULTS

Of 25 patients were identified. Hundred percent received 45 Gy in 25 fractions to the pelvis ± paraaortic lymph nodes and 80% receiving median additional parametrial dose of 5.4 Gy. Replan meeting ureteral dose of ≤77 Gy was feasible in 18 of 25 patients, with a reduction in median ureter D0.1cc from 82.3 to 76.8 Gy (p < 0.001). Median HR-CTV D90 was similar (84.7 vs. 85.0 Gy). Replan achieved D0.1cc ≤77 Gy in 56% of patients who experienced US. All unilateral US cases occurred in the ureter closest to HR-CTV.

CONCLUSIONS

Optimization to reduce ureter dose to ≤77 Gy is feasible when ureters are visible and contoured. Ureters may be considered as potential OAR during MRI-based brachytherapy treatment. Reduced ring to tandem total reference air kerma (TRAK) ratio may provide an additional metric by which to lower US risk.

Patterns of Treatment Failure after Concurrent Chemoradiotherapy or Adjuvant Radiotherapy in Patients with Locally Advanced Cervical Cancer

OBJECTIVE

To identify patterns of therapy failure after radiotherapy in Chinese patients with locally advanced cervical cancer (LACC).

METHODS

A retrospective study was conducted at a Chinese hospital from June 2012 to July 2018. All analyses were done using SPSS 26.

RESULTS

105 patients with treatment failure were included. After a median follow-up of 27 months (range 10-82), the 3-year survival rate after therapy failure was 19.4%. In multivariate analysis, squamous cell carcinoma antigen (SCC-Ag) <4 ng/mL (p < 0.001) and disease-free interval >12 months (p = 0.013) showed significant survival benefits. We identified 3 types of failure: distant lymph node metastasis (n = 50), hematogenous metastasis (n = 53) and pelvic failure (n = 48). Most metastatic para-aortic lymph nodes (PALN) were inferior to the level of left renal hilum (84.8%, n = 28). A total of 80% of patients with supraclavicular lymph nodes (SCLN) metastasis ignored imaging on supraclavicular region. For solitary SCLN or lung metastasis, the prognosis was better than that combined with other sites failure, respectively (p = 0.005; p = 0.001). Many patients with central sites recurrence received insufficient doses of intracavitary brachytherapy (IBT) for low tolerance to pain.

CONCLUSION

The distribution of metastatic PALN is asymmetrical and optimizing clinical target volume to minimize toxicity of para-aortic radiation is necessary. The effect of ultrasonography as preliminary screening and follow-up means on SCLN metastasis can be expected. Pain management and psychological interventions are essential for patients receiving IBT.

Working title: high dose rate intra-cavitary brachytherapy with cobalt 60 source for locally advanced cervical cancer: the Zimbabwean experience

BACKGROUND AND PURPOSE

Cervical cancer is the fourth commonest cancer in women in the world with the highest regional incidence and mortality seen in Southern, Eastern and Western Africa. It is the commonest cause of cancer morbidity and mortality among Zimbabwean women. Most patients present with locally advanced disease that is no longer amenable to surgery. Definitive concurrent chemoradiation (CCRT), which is the use of external beam radiotherapy (EBRT) and weekly cisplatin, includes use of intracavitary brachytherapy, as the standard treatment. In the setting of this study, cobalt-60 (Co⁶⁰)-based high dose rate brachytherapy (HDR-BT) has been in use since 2013. This study sought to review practices pertaining to use of brachytherapy in Zimbabwe, including timing with external beam radiotherapy, adverse effects and patient outcomes.

METHODS

A retrospective analysis of data from records of patients with histologically confirmed cervical cancer treated with HDR-BT at the main radiotherapy centre in Zimbabwe from January 2013 to December 2014 was done. Outcome measures were local control, overall survival as well as gastro-intestinal and genito-urinary toxicity.

RESULTS

A total of 226 patients were treated with HDR-BT during the study period, with a 97% treatment completion rate. All patients received between 45-50Gy of pelvic EBRT. Seventy-four percent received concurrent platinum-based chemotherapy. In 52% of the patients, HDR-BT was started when they were still receiving EBRT. The commonest fractionation schedule used was the 7Gy × 3 fractions, once a week (87%). Clinical complete tumour response was achieved in 75% at 6 weeks post treatment, 23% had partial response. Follow-up rates at 1 year and 2 years were 40 and 19% respectively. Disease free survival at 1 year and 2 years was 94 and 95% respectively. Vaginal stenosis was the commonest toxicity recorded, high incidence noted with increasing age. Four patients developed vesico-vaginal fistulae and two patients had rectovaginal fistulae.

CONCLUSION

One hundred and seventeen patients patients started HDR-BT during EBRT course, with a treatment completion rate of 97%. The overall treatment duration was within 56 days in the majority of patients. Early local tumour control was similar for all the HDR-BT fractionation regimes used in the study, with a high rate (75%) of complete clinical response at 6 weeks post-treatment. Prospective studies to evaluate early and long-term outcomes of HDR-BT in our setting are recommended.

Glassy cell carcinoma of the uterine cervix: 20-year experience from a comprehensive cancer center

PURPOSE

Glassy cell carcinoma (GCC) of the uterine cervix is a rare entity. This study aims at describing the clinical characteristics and outcomes of cervical GCC patients treated in a comprehensive cancer center.

MATERIAL AND METHODS

We retrospectively reported patients and tumors characteristics, therapeutic management, overall survival (OS), progression-free progression (PFS), relapse rates, and toxicities.

RESULTS

Between 1994 and 2014, 55 patients were treated with curative intent. The median age at diagnosis was 41 years (range, 20-68). Among 22 patients with early stage tumors (IA2-IB1-IIA1), 17 had preoperative brachytherapy, followed by radical hysterectomy. Among 33 patients with locally advanced disease (≥IB2), 32 underwent chemoradiation±brachytherapy boost. After a median follow-up of 5.4 years (range, 0.15-21.7 years), 18/55 (33%) patients experienced tumor relapse. Local recurrence occurred in 2/22 (9%) patients with early disease (treated with upfront surgery) and in 3/32 (9%) patients with locally advanced disease. Most frequent relapses were distant, occurring in a total of 11/55 patients (20%). PFS rates at 5-year were 86.4% (95% CI: 63.4-95.4) for early stage versus 75.9% (95% CI: 55.2-89.2) for locally advanced stages, respectively (P=0.18).

CONCLUSION

Large cohort data are warranted to guide the optimal management of GCC. From this retrospective analysis, a multimodal approach yielded to good disease control in early stages tumors. Given the high-risk of distant failure, consideration should be given to adjuvant chemotherapy in locally advanced disease.

Skin dose measurement and estimating the dosimetric effect of applicator misplacement in gynecological brachytherapy: A patient and phantom study

OBJECTIVES

To evaluate skin dose differences between TPS (treatment planning system) calculations and TLD (thermo-luminescent dosimeters) measurements along with the dosimetric effect of applicator misplacement for patients diagnosed with gynecological (GYN) cancers undergoing brachytherapy.

METHODS

The skin doses were measured using TLDs attached in different locations on patients' skin in pelvic regions (anterior, left, and right) for 20 patients, as well as on a phantom. In addition, the applicator surface dose was calculated with TLDs attached to the applicator. The measured doses were compared with TPS calculations to find TPS accuracy. For the phantom, different applicator shifts were applied to find the effect of applicator misplacement on the surface dose.

RESULTS

The mean absolute dose differences between the TPS and TLDs results for anterior, left, and right points were 3.14±1.03, 6.25±1.88, and 6.20±1.97 %, respectively. The mean difference on the applicator surface was obtained 1.92±0.46 %. Applicator misplacements of 0.5, 2, and 4 cm (average of three locations) resulted in 9, 36, and 61%, dose errors respectively.

CONCLUSIONS

The surface/skin differences between the calculations and measurements are higher in the left and right regions, which relate to the higher uncertainty of TPS dose calculation in these regions. Furthermore, applicator misplacements can result in high skin dose variations, therefore it can be an appropriate quality assurance method for future research.

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.

Brachytherapy: An overview for clinicians

Brachytherapy is a specific form of radiotherapy consisting of the precise placement of radioactive sources directly into or next to the tumor. This technique is indicated for patients affected by various types of cancers. It is an optimal tool for delivering very high doses to the tumor focally while minimizing the probability of normal tissue complications. Physicians from a wide range of specialties may be involved in either the referral to or the placement of brachytherapy. Many patients require brachytherapy as either primary treatment or as part of their oncologic care. On the basis of high-level evidence from randomized controlled trials, brachytherapy is mainly indicated: 1) as standard in combination with chemoradiation in patients with locally advanced cervical cancer; 2) in surgically treated patients with uterine endometrial cancer for decreasing the risk of vaginal vault recurrence; 3) in patients with high-risk prostate cancer to perform dose escalation and improve progression-free survival; and 4) in patients with breast cancer as adjuvant, accelerated partial breast irradiation or to boost the tumor bed. In this review, the authors discuss the clinical relevance of brachytherapy with a focus on indications, levels of evidence, and results in the overall context of radiation use for patients with cancer.

[Place of radiotherapy and surgery in the treatment of cervical cancer patients]

The treatment of cervical cancer patients relies on surgery and radiotherapy (according to the stage) and requires a multimodal discussion before any treatment to avoid adding the morbidities of each individual intervention and to optimize functional and oncological outcomes. The places of surgery and radiotherapy have been highlighted in recent international guidelines. For early stage tumors, an exclusive surgery with or without fertility sparing (according to well defined criteria) is the therapeutic standard. For tumors with risk factors (measuring more than 2cm in size and/or presence of lymphovascular invasion) a preoperative brachytherapy can be proposed to minimize the need for postoperative external beam radiotherapy and optimize local control. For locally advanced disease, the standard treatment relies on chemoradiation followed by a brachytherapy boost. A primary paraaortic lymph node dissection may guide radiotherapy volumes and is useful to identify patients requiring a para-aortic radiotherapy. The technical evolutions of surgical approaches and technological improvement of radiotherapy and brachytherapy should be analyzed in the context of prospective studies. We review the literature on the respective places of radiotherapy and surgery for the treatment of cervical cancer.

Comparative analysis of image-guided adaptive interstitial brachytherapy and intensity-modulated arc therapy versus conventional treatment techniques in cervical cancer using biological dose summation

Purpose

To compare image-guided adaptive interstitial brachytherapy (BT) and intensity-modulated arc therapy (IMAT) with conventional treatment techniques in cervical cancer using an alternative biological dose summation method.

Material and methods

Initially, 21 interstitial BT and IMAT plans of patients with cervical cancer were included and additional plans were created (inverse optimized interstitial, optimized intracavitary, non-optimized intracavitary BT plans, and conformal external beam radiotherapy [EBRT]). The most exposed volume of critical organs in BT were identified manually on EBRT CT images. Biological total doses (EQD2) were calculated and compared between each combination of BT and EBRT plans. This method was compared with uniform dose conception (UDC) in IMAT and conformal EBRT plans.

Results

The D₉₀ of high-risk CTV and D₂ of bladder and sigmoid were different in BT techniques only: p = 0.0149, < 0.001, < 0.001, respectively. The most advantageous values were obtained in the interstitial treatment plans and inverse optimized interstitial plans did not differ dosimetrically from these, while optimized intracavitary plans resulted in worse dose-volume parameters, and the worst of all were intracavitary plans without optimization. The D₂ of rectum was significantly lower with IMAT than with conformal EBRT plans (p = 0.037) and showed the same trend in BT plans as the other parameters (p < 0.001). The UDC dose summation method overestimated D₂ of bladder, rectum, and sigmoid (p < 0.001 for all).

Conclusions

Although optimization improves the quality of conventional BT plans, interstitial plans produce significantly higher dose coverage of high-risk clinical target volume (HR-CTV) and lower doses to organs at risk (OARs). IMAT plans decrease the dose to the rectum. UDC overestimates OARs doses.

Image-guided brachytherapy in cervical cancer: Experience in the Complejo Hospitalario de Navarra

Purpose

To evaluate dosimetric and clinical findings of MRI-guided HDR brachytherapy (HDR-B) for cervical carcinoma.

Material and methods

All patients had a CT, MRI and pelvic-paraaortic lymphadenectomy. Treatment: pelvic (+/-)para-aortic3D/IMRT radiotherapy (45 Gy), weekly cisplatin and HDR-B and pelvic node/parametrial boost 60 Gy until interstitial brachytherapy was done. Two implants: 2008-2011: 5 fractions of 6 Gy, 2011: 2016, 4 fractions of 7 Gy. MRI/TAC were done in each implant. The following were defined: GTV, CTH-HR, CTV-IR; OAR: rectum, bladder and sigmoid.

Results

From 2007 to 2016: 57 patients. Patients: T1b2-T2a: 4p, T2b 41p, T3a: 2p; T3B 8p T4a: 2p; N0: 32p, N1 21p, no lymphadenectomy: 4p. Median follow up: 74.6 m (16-122 m), recurrence: 5p local, 6p node, 9p metastasis and 37p without recurrence.Local control 5 years: 90.1%; Ib2-IIB: 94.8%, III-IVa: 72.2%. (p:0.01). RDFS 5y was 92.5%; IB2-IIB: 93%, III: 85% (p:0.024); for pN0: 100%; pN+ iliac-paraaortic: 71.4% (p: 0.007). MFS 5y was 84.1%. Overall survival (OS) at 5y: 66.6% and the cancer specific survival (CEOS) was 74%. Univariate analysis survival: stage Ib2-II 83% vs. III-IVa 41% (p = 0.001); histology: squamous 78%, adenocarcinoma 59.7% (p: ns); lymph node: N0 85% vs. PA+P- 72%, and PA+P+ 35% (p = 0.010). In relation with: HR-CTV dose > 85 Gy, CEOS: 82.5% vs. 77%, and volume CTV-HR < 30 cc: 81.8% and >30 cc: 67%; p: ns. Acute grade 2-3 toxicity: rectal 15.7%, intestinal 15.7% and vesical 15.5%.

Conclusion

Use of interstitial HDR-BQ guided by RM increased CTV-HR dose and local control, like EMBRACE results. Nodal boost improves RDFS and perhaps OS.

Physician assessed and patient reported urinary morbidity after radio-chemotherapy and image guided adaptive brachytherapy for locally advanced cervical cancer

BACKGROUND AND PURPOSE

The EMBRACE study is a prospective multi-institutional study on MRI guided adaptive brachytherapy (IGABT) in locally advanced cervix cancer (LACC). This analysis describes early to late urinary morbidity assessed by physicians and patients (PRO).

MATERIAL AND METHODS

A total of 1176 patients were analysed. Median follow up (FU) was 27 (1-83) months. Morbidity (CTCAE v.3) and PRO (EORTC QLQ-C30&CX24) was prospectively assessed at baseline (BL), and during FU.

RESULTS

The most frequent symptoms were frequency/urgency, incontinence, and cystitis with grade 2-4 prevalence rates of 4.3%, 5.0% and 1.7% and grade 1-4 prevalence rates of 24.5%, 16.1% and 5.8% at 3-years. The most frequent PRO endpoints were "urinary frequency" and "leaking of urine". Prevalence of "Quite a bit" or "very much" bother fluctuated from 14.0% to 21.5% for "frequency", while "leaking of urine" increased from 4.6% at BL to 9.3% at 3-years. Actuarial 3-year incidence of grade 3-4 urinary morbidity was 5.3% with most events being urinary frequency, incontinence and ureteral strictures. Grade 3-4 fistula, bleeding, spasm and cystitis were all <1.0% at 3/5-years. No grade 5 toxicity occurred.

CONCLUSION

Urinary grade 3-4 morbidity with IGABT was limited. Urinary morbidity grade 2-4 comprises mainly frequency/urgency, incontinence and cystitis and has considerable prevalence in PRO. Various urinary morbidity endpoints have different patterns of manifestation and time course.

Prediction of cervical cancer recurrence using textural features extracted from 18F-FDG PET images acquired with different scanners

Objectives

To identify an imaging signature predicting local recurrence for locally advanced cervical cancer (LACC) treated by chemoradiation and brachytherapy from baseline ¹⁸F-FDG PET images, and to evaluate the possibility of gathering images from two different PET scanners in a radiomic study.

Methods

118 patients were included retrospectively. Two groups (G1, G2) were defined according to the PET scanner used for image acquisition. Eleven radiomic features were extracted from delineated cervical tumors to evaluate: (i) the predictive value of features for local recurrence of LACC, (ii) their reproducibility as a function of the scanner within a hepatic reference volume, (iii) the impact of voxel size on feature values.

Results

Eight features were statistically significant predictors of local recurrence in G1 (p < 0.05). The multivariate signature trained in G2 was validated in G1 (AUC=0.76, p<0.001) and identified local recurrence more accurately than SUV_max (p=0.022). Four features were significantly different between G1 and G2 in the liver. Spatial resampling was not sufficient to explain the stratification effect.

Conclusion

This study showed that radiomic features could predict local recurrence of LACC better than SUV_max. Further investigation is needed before applying a model designed using data from one PET scanner to another.

Neutrophilia in locally advanced cervical cancer: A novel biomarker for image-guided adaptive brachytherapy?

Objective

To study the prognostic value of leucocyte disorders in a prospective cohort of cervical cancer patients receiving definitive chemoradiation plus image—guided adaptive brachytherapy (IGABT).

Results

113 patients were identified. All patients received a pelvic irradiation concomitant with chemotherapy, extended to the para-aortic area in 13 patients with IVB disease. Neutrophilia and leukocytosis were significant univariate prognostic factors for poorer local failure-free survival (p = 0.000 and p = 0.002, respectively), associated with tumor size, high-risk clinical target volume (HR-CTV) and anemia. No effect was shown for distant metastases but leukocytosis and neutrophila were both poor prognostic factors for in-field relapses (p = 0.003 and p < 0.001). In multivariate analysis, HR-CTV volume (p = 0.026) and neutrophils count > 7,500/μl (p = 0.018) were independent factors for poorer survival without local failure, with hazard ratio (HR) of 3.1.

Materials and methods

We examined patients treated in our Institution between April 2009 and July 2015 by concurrent chemoradiation (45 Gy in 25 fractions +/− lymph node boosts) followed by a magnetic resonance imaging (MRI)-guided adaptive pulse-dose rate brachytherapy (15 Gy to the intermediate-risk clinical target volume). The prognostic value of pretreatment leucocyte disorders was examined. Leukocytosis and neutrophilia were defined as a leukocyte count or a neutrophils count exceeding 10,000 and 7,500/μl, respectively.

Conclusions

Neutrophilia is a significant prognostic factor for local relapse in locally advanced cervical cancer treated with MRI-based IGABT. This biomarker could help identifying patients with higher risk of local relapse and requiring dose escalation.

Locally advanced cervical cancer with bladder invasion: clinical outcomes and predictive factors for vesicovaginal fistulae

Objective

We report outcomes of cervical cancer patients with bladder invasion (CCBI) at diagnosis, with focus on the incidence and predictive factors of vesicovaginal fistula (VVF).

Results

Seventy-one patients were identified. Twenty-one (30%) had para-aortic nodal involvement. Eight had VVF at diagnosis. With a mean follow-up time of 34.2 months (range: 1.9 months–14.8 years), among 63 patients without VVF at diagnosis, 15 (24%) developed VVF. A VVF occurred in 19% of patients without local relapses (9/48) and 40% of patients with local relapse (6/15). Two-year overall survival (OS), disease-free survival (DFS) and local control rates were 56.4% (95% CI: 44.1–67.9%), 39.1% (95% CI: 28.1–51.4%) and 63.8% (95% CI: 50.4–75.4%), respectively. Para-aortic nodes were associated with poorer OS (adjusted HR = 3.78, P-value = 0.001). In multivariate analysis, anterior tumor necrosis on baseline MRI was associated with VVF formation (63% vs 0% at 1 year, adjusted-HR = 34.13, 95% CI: 4.07–286, P-value = 0.001), as well as the height of the bladder wall involvement of >26 mm (adjusted-HR = 5.08, 95% CI: 1.38–18.64, P-value = 0.014).

Conclusions

A curative intent strategy including brachytherapy is feasible in patients with CCBI, with VVF occurrence in 24% of the patients. MRI patterns help predicting VVF occurrence.

Methods

Patients with locally advanced CCBI treated with (chemo)radiation ± brachytherapy in our institute from 1989 to 2015 were analyzed. Reviews of baseline magnetic resonance imaging (MRI) scans were carried out blind to clinical data, retrieving potential parameters correlated to VVF formation (including necrosis and tumor volume).

Chemoradiotherapy in combination with radical surgery is associated with better outcome in cervical cancer patients

Objectives

To retrospectively assess the influence of radical surgery following concurrent chemoradiotherapy (CCRT) on outcomes in cervical cancer (CC) patients.

Methods

Patients diagnosed with cervical squamous cell carcinoma or adenocarcinoma (FIGO stages IB2 to IIB) at the Yinbin Second People's Hospital between September 2008 and September 2013, were included in this study. Patients were classified into 2 groups based on the treatment received: surgery group (CCRT plus radical surgery) and non-surgery groups (CCRT only). In addition to clinical information, inter-group differences with respect to local control rate (LCR), local recurrence rate (LRR), metastasis rate, overall survival (OS), progress free survival(PFS) and complications were assessed.

Results

A total of 314 patients were included in the analysis. Parametrial invasion, pelvic lymph node metastasis, tumor diameter > 4 cm and presence of residual disease were risk factors for recurrence in the non-surgery group. In patients with risk factors, radical surgery significantly improved their clinical outcome. The 3-year/5-year LCR in the surgery and non-surgery groups was 88.3%/87.4% and 82.3%/77.5%, respectively (P = 0.04). The 3-year/5-year OS rate in the two groups was 87.1%/81.7% and 72.8%/67.3%, respectively (P = 0.001). The 3-year/5-year LRR in the two groups were 11.7%/12.6% and 17.7%/22.5%, respectively (P = 0.04). The metastasis rates in the two groups were 19.9% and 24.8%, respectively (P = 0.09).

Conclusions

Surgery following CCRT could improve overall survival and progressfree survival. Radical surgery following CCRT appears to confer significant benefits including an increase in LCRs and decrease in LRR in CC patients with risk factors.

A score combining baseline neutrophilia and primary tumor SUVpeak measured from FDG PET is associated with outcome in locally advanced cervical cancer

PURPOSE

We investigated whether a score combining baseline neutrophilia and a PET biomarker could predict outcome in patients with locally advanced cervical cancer (LACC).

METHODS

Patients homogeneously treated with definitive chemoradiation plus image-guided adaptive brachytherapy (IGABT) between 2006 and 2013 were analyzed retrospectively. We divided patients into two groups depending on the PET device used: a training set (TS) and a validation set (VS). Primary tumors were semi-automatically delineated on PET images, and 11 radiomics features were calculated (LIFEx software). A PET radiomic index was selected using the time-dependent area under the curve (td-AUC) for 3-year local control (LC). We defined the neutrophil SUV grade (NSG = 0, 1 or 2) score as the number of risk factors among (i) neutrophilia (neutrophil count >7 G/L) and (ii) high risk defined from the PET radiomic index. The NSG prognostic value was evaluated for LC and overall survival (OS).

RESULTS

Data from 108 patients were analyzed. Estimated 3-year LC was 72% in the TS (n = 69) and 65% in the VS (n = 39). In the TS, SUV_peak was selected as the most LC-predictive biomarker (td-AUC = 0.75), and was independent from neutrophilia (p = 0.119). Neutrophilia (HR = 2.6), high-risk SUV_peak (SUV_peak > 10, HR = 4.4) and NSG = 2 (HR = 9.2) were associated with low probability of LC in TS. In multivariate analysis, NSG = 2 was independently associated with low probability of LC (HR = 7.5, p < 0.001) and OS (HR = 5.8, p = 0.001) in the TS. Results obtained in the VS (HR = 5.2 for OS and 3.5 for LC, p < 0.02) were promising.

CONCLUSION

This innovative scoring approach combining baseline neutrophilia and a PET biomarker provides an independent prognostic factor to consider for further clinical investigations.

Outcomes with volume-based dose specification in CT-planned high-dose-rate brachytherapy for stage I-II cervical carcinoma: A 10-year institutional experience

OBJECTIVE

To determine prognostic factors for progression-free survival (PFS) and overall survival (OS) for stage I-II cervical-cancer patients treated using computed-tomography (CT)-planned high-dose-rate (HDR) intracavitary brachytherapy (BT).

METHODS

A total of 150 patients were treated for Stage I-II cervical cancer using CT-planned BT between 4/2004 and 10/2014. Of these, 128 were eligible for inclusion. Kaplan-Meier local control (LC), pelvic control (PC), overall survival (OS), and PFS estimates were calculated.

RESULTS

After a median follow-up of 30months, the 2-year LC rate was 96%, PFS was 88%, and OS was 88%. Overall, 18 patients (14%) experienced any recurrence (AR), 8 had distant recurrence only and 10 had a combination of local, pelvic, regional, and distant recurrence. No patients had LR only. A prognostic factor for AR was tumor size >4cm (p=0.01). Patients with tumors >4cm were 3.3 times more likely to have AR than those with tumors ≤4cm (hazard ratio [HR]=3.3; 95% confidence interval [CI] 1.28-9.47). Point A was 85% of prescription for tumors < 4 cm and decreased approximately 3% over 5 fractions compared to 90% of prescription for tumors > 4 cm that decreased approximately 4% over 5 fractions. Two patients (2%) experienced grade≥2 late toxicity. There were no acute or late grade≥3 toxicities.

CONCLUSION

CT-planned BT resulted in excellent local control and survival. Large tumor size was associated with an increased risk of recurrence outside the radiation field and worse PFS and OS. A volume-optimized plan treated a smaller area than a point A standard plan for patients with Stage I-II cervical cancer that have received chemoradiation. Given the outstanding LC achieved with modern therapy including chemoradiation, HDR, and image-based BT, further efforts to combat spread outside the radiation field with novel therapies are warranted.

Adaptive radiotherapy strategies for pelvic tumors - a systematic review of clinical implementations

Introdution: Variation in shape, position and treatment response of both tumor and organs at risk are major challenges for accurate dose delivery in radiotherapy. Adaptive radiotherapy (ART) has been proposed to customize the treatment to these motion/response patterns of the individual patients, but increases workload and thereby challenges clinical implementation. This paper reviews strategies and workflows for clinical and in silico implemented ART for prostate, bladder, gynecological (gyne) and ano-rectal cancers.

MATERIAL AND METHODS

Initial identification of papers was based on searches in PubMed. For each tumor site, the identified papers were screened independently by two researches for selection of studies describing all processes of an ART workflow: treatment monitoring and evaluation, decision and execution of adaptations. Both brachytherapy and external beam studies were eligible for review.

RESULTS

The review consisted of 43 clinical studies and 51 in silico studies. For prostate, 1219 patients were treated with offline re-planning, mainly to adapt prostate motion relative to bony anatomy. For gyne 1155 patients were treated with online brachytherapy re-planning while 25 ano-rectal cancer patients were treated with offline re-planning, all to account for tumor regression detected by magnetic resonance imaging (MRI)/computed tomography (CT). For bladder and gyne, 161 and 64 patients, respectively, were treated with library-based online plan selection to account for target volume and shape variations. The studies reported sparing of rectum (prostate and bladder cancer), bladder (ano-rectal cancer) and bowel cavity (gyne and bladder cancer) as compared to non-ART.

CONCLUSION

Implementations of ART were dominated by offline re-planning and online brachytherapy re-planning strategies, although recently online plan selection workflows have increased with the availability of cone-beam CT. Advantageous dosimetric and outcome patterns using ART was documented by the studies of this review. Despite this, clinical implementations were scarce due to challenges in target/organ re-contouring and suboptimal patient selection in the ART workflows.

Tumor dose-volume response in image-guided adaptive brachytherapy for cervical cancer: A meta-regression analysis

PURPOSE

Image-guided adaptive brachytherapy is a high precision technique that allows dose escalation and adaptation to tumor response. Two monocentric studies reported continuous dose-volume response relationships, however, burdened by large confidence intervals. The aim was to refine these estimations by performing a meta-regression analysis based on published series.

METHODS AND MATERIALS

Eligibility was limited to series reporting dosimetric parameters according to the Groupe Européen de Curiethérapie-European SocieTy for Radiation Oncology recommendations. The local control rates reported at 2-3 years were confronted to the mean D90 clinical target volume (CTV) in 2-Gy equivalent using the probit model. The impact of each series on the relationships was pondered according to the number of patients reported.

RESULTS

An exhaustive literature search retrieved 13 series reporting on 1299 patients. D90 high-risk CTV ranged from 70.9 to 93.1 Gy. The probit model showed a significant correlation between the D90 and the probability of achieving local control (p < 0.0001). The D90 associated to a 90% probability of achieving local control was 81.4 Gy (78.3-83.8 Gy). The planning aim of 90 Gy corresponded to a 95.0% probability (92.8-96.3%). For the intermediate-risk CTV, less data were available, with 873 patients from eight institutions. Reported mean D90 intermediate-risk CTV ranged from 61.7 to 69.1 Gy. A significant dose-volume effect was observed (p = 0.009). The D90 of 60 Gy was associated to a 79.4% (60.2-86.0%) local control probability.

CONCLUSION

Based on published data from a high number of patients, significant dose-volume effect relationships were confirmed and refined between the D90 of both CTV and the probability of achieving local control. Further studies based on individual data are required to develop nomograms including nondosimetric prognostic criteria.

Dosimetric study for cervix carcinoma treatment using intensity modulated radiation therapy (IMRT) compensation based on 3D intracavitary brachytherapy technique

Purpose

Intensity modulated radiation therapy (IMRT) compensation based on 3D high-dose-rate (HDR) intracavitary brachytherapy (ICBT) boost technique (ICBT + IMRT) has been used in our hospital for advanced cervix carcinoma patients. The purpose of this study was to compare the dosimetric results of the four different boost techniques (the conventional 2D HDR intracavitary brachytherapy [CICBT], 3D optimized HDR intracavitary brachytherapy [OICBT], and IMRT-alone with the applicator in situ).

Material and methods

For 30 patients with locally advanced cervical carcinoma, after the completion of external beam radiotherapy (EBRT) for whole pelvic irradiation 45 Gy/25 fractions, five fractions of ICBT + IMRT boost with 6 Gy/fractions for high risk clinical target volume (HRCTV), and 5 Gy/fractions for intermediate risk clinical target volume (IRCTV) were applied. Computed tomography (CT) and magnetic resonance imaging (MRI) scans were acquired using an in situ CT/MRI-compatible applicator. The gross tumor volume (GTV), the high/intermediate-risk clinical target volume (HRCTV/IRCTV), bladder, rectum, and sigmoid were contoured by CT scans.

Results

For ICBT + IMRT plan, values of D₉₀, D₁₀₀ of HRCTV, D₉₀, D₁₀₀, and V₁₀₀ of IRCTV significantly increased (p < 0.05) in comparison to OICBT and CICBT. The D_2cc values for bladder, rectum, and sigmoid were significantly lower than that of CICBT and IMRT alone. In all patients, the mean rectum V₆₀ Gy values generated from ICBT + IMRT and OICBT techniques were very similar but for bladder and sigmoid, the V₆₀ Gy values generated from ICBT + IMRT were higher than that of OICBT. For the ICBT + IMRT plan, the standard deviations (SD) of D₉₀ and D_2cc were found to be lower than other three treatment plans.

Conclusions

The ICBT + IMRT technique not only provides good target coverage but also maintains low doses (D_2cc) to the OAR. ICBT + IMRT is an optional technique to boost parametrial region or tumor of large size and irregular shape when intracavitary/interstitial brachytherapy cannot be used.

Image-guided adaptive brachytherapy in cervical cancer: Patterns of relapse by brachytherapy planning parameters

PURPOSE

Cervical cancer patients with a bulky high-risk clinical target volume (HR-CTV) get the largest benefit of dose escalation in terms of local control. However, the expected survival benefit could be lessened by a higher metastatic risk. We examined the patterns of relapse according to major prognostic factors: the HR-CTV volume and to the D90 HR-CTV.

METHODS AND MATERIALS

The clinical records of patients treated with pulsed-dose-rate image-guided adaptive brachytherapy after concurrent pelvic chemoradiation were reviewed. All patients had an optimal workup before treatment comprising a 18-fluorodeoxyglucose positron emission tomography/computed tomography and a para-aortic lymph node dissection. Patients with initial extrapelvic disease were excluded.

RESULTS

A total of 109 patients fulfilled inclusion criteria. Median followup was 39 months. An HR-CTV volume ≥40 cm(3) was associated with a poorer local failure-free survival. There was a strong inverse correlation between the HR-CTV volume and the D90 of the HR-CTV (correlation coefficient r = -0.696; p < 0.001) with increasing HR-CTV volume being associated with a decreasing D90 HR-CTV. A D90 HR-CTV <85 Gy and an HR-CTV volume ≥40 cm(3) were significant univariate factors for experiencing nonlocal failure (p = 0.002 and 0.035, respectively), even after exclusion of local relapses.

CONCLUSION

A lower ability to reach the target D90 HR-CTV planning and an HR-CTV volume ≥ 40 cm(3) correlated with a high propensity of relapsing at distance, these factors being interrelated. Next step of treatment personalization should design strategies integrating this risk, which is now the main cause of failure.

Long term experience with 3D image guided brachytherapy and clinical outcome in cervical cancer patients

BACKGROUND AND PURPOSE

To report our 10years' experience and learning curve of the treatment of cervical cancer patients with chemo radiotherapy and MRI (or CT in 9 selected patients) guided brachytherapy using pulsed dose rate (PDR) brachytherapy (BT).

METHODS AND MATERIALS

Hundred and seventy consecutive patients with cervical cancer FIGO stage IB-IVB (without metastases beyond the para-aortic nodal region) were treated in our institute between 2002 and 2012. Patients received external beam radiotherapy (nodal boost to the lymph nodes positive at diagnosis)±chemotherapy followed by a pulsed or low dose rate brachytherapy boost. MRI (or CT) images were taken with the applicator in situ. The first 16 patients were treated according to X-ray-based plans, optimized on MRI. High-risk CTV, intermediate-risk CTV, bladder, rectum and sigmoid were retrospectively contoured according to the GEC-ESTRO recommendations. In all other patients, treatment plans were optimized after delineation of the target volumes and organs at risk at MRI (or CT). Doses were converted to the equivalent dose in 2Gy (EQD2) by applying the linear quadratic model. The median age of the patients was 55years (range 16-88). 41% had stage III or IV disease. Of the 170 patients, 91 patients had on imaging metastatic lymph nodes at diagnosis (62 patients pelvic lymph node involvement and 29 para-aortic). In 27 (16%) patients the intracavitary technique was combined with interstitial brachytherapy.

RESULTS

The mean D90 and D100 for the high-risk CTV were 84.8±8.36Gy and 67.5±6.29Gy for the entire patient group. Mean D90 and D100 values for the IR CTV were 68.7±5.5Gy and 56.5±6.25Gy. There was an important learning curve between both patient groups, with an increase in mean D90 of 75.8Gy for the first 16 patients compared to 85.8Gy for the second group. At the same time, the mean dose to 2cm³ of bladder and sigmoid decreased from 86.1Gy to 82.7Gy and from 70Gy to 61.7Gy, respectively. At a median follow-up of 37months (range 2-136months), local control rate for all patients was 96%, the regional control (pelvic and para-aortic) rate 81% and crude disease free survival rate 55%. The overall survival at 5years is 65%. The higher dose to the target volume resulted in an increase in local control from 88% in the first 16 patients compared to 97% in the second patient group. Regarding late toxicity, 21 patients (12%) presented grade 3-4 late morbidity. Rectal, urinary, sigmoid and vaginal morbidity was 5%, 6%, 2% and 5%, respectively. A correlation between rectal D2cm³ >65Gy and grade >3 late morbidity was found (p=0.006).

CONCLUSION

Although the majority of the patients presented with locally advanced carcinoma, excellent local and regional control rates were achieved. Rectal, urinary, sigmoid and vaginal grade 3-4 morbidity was 5%, 6%, 2% and 5%, respectively. A correlation between rectal D2cm³ >65Gy and grade >3 late morbidity was found (p=0.006).

Simulation analysis of optimized brachytherapy for uterine cervical cancer: Can we select the best brachytherapy modality depending on tumor size?

PURPOSE

To choose the optimal brachytherapeutic modality for uterine cervical cancer, we performed simulation analysis.

METHODS AND MATERIALS

For each high-risk clinical target volume (HR CTV), we compared four modalities [classical conventional intracavitary brachytherapy (ConvICBT), Image-guided ICBT (IGICBT), intracavitary/interstitial brachytherapy (ICISBT), and interstitial brachytherapy (ISBT) with perineal approach] using dose-volume histograms using eight sizes of HR CTV (2 × 2 × 2 cm to 7 × 4 × 4 cm) and organs at risk model.

RESULTS

In ConvICBT, the doses covered 90% of the HR CTV [D90(HR CTV)] decreased from 197% prescribed dose (PD) for the HR CTV size (2 × 2 × 2 cm) to 73% PD for 5 × 4 × 4 cm, whereas the other three modalities could achieve 100% PD for all HR CTV sizes. The minimum doses received by the maximally irradiated 2-cm(3) volumes for organs at risks of IGICBT demonstrated lower values than those of ConvICBT for the HR CTV size of 4 × 3 × 3 cm or smaller. ICISBT demonstrated lower values than those of IGICBT for 4 × 3 × 3 cm or larger. ISBT demonstrated lowest values for 5 × 4 × 4 cm or larger.

CONCLUSIONS

HR CTV size of 4 × 3 × 3 cm seems to be a threshold volume in this simulation analysis, and IGICBT is a better choice for smaller HR CTV than the threshold volume. On larger HR CTV, ICISBT or ISBT is the better choice.

45 or 50 Gy, Which is the Optimal Radiotherapy Pelvic Dose in Locally Advanced Cervical Cancer in the Perspective of Reaching Magnetic Resonance Image-guided Adaptive Brachytherapy Planning Aims?

AIMS

In locally advanced cervical cancer, the dose delivered results from the sum of external beam radiotherapy and brachytherapy, and is limited by the surrounding organs at risk. The balance between both techniques influences the total dose delivered to the high-risk clinical target volume (HR-CTV). The aim of the present study was to compare the ability of reaching different planning aims after external beam radiotherapy pelvic doses of 45 Gy in 25 fractions or 50.4 Gy in 28 fractions, both considered as standard prescriptions.

MATERIALS AND METHODS

The optimised plans of 120 patients treated with pelvic chemoradiation followed by magnetic resonance image-guided intracavitary brachytherapy were reviewed. The doses per pulse were calculated, and the number of pulses required to reach the planning aims, or a limiting dose constraint to organs at risk, was calculated. All doses were converted to 2-Gy equivalents. Three scenarios were applied consisting of different sets of planning aims: 85 and 60 Gy for the HR-CTV and the intermediate-risk CTV (IR-CTV) D90 (minimal dose received by 90% of the volume) in scenario 1, 90 and 60 Gy, respectively, for scenarios 2 and 3. For organs at risk, dose constraints were 90, 75 and 75 Gy to the bladder, rectum and sigmoid D2cm(3), respectively, in scenarios 1 and 2, and 80, 65 and 70 Gy in scenario 3.

RESULTS

A similar HR-CTV D90 could have been reached in scenarios 1 and 2 according to both pelvic doses. In scenario 3, a higher mean HR-CTV could have been reached in the 45 Gy arm (83.5 ± 8.0 versus 82.4 ± 8.0, P < 0.0001). The mean D2cm(3) of organs at risk was systematically and significantly increased after a delivery of 50.4 Gy to the pelvis, from 0.9 to 2.89 Gy. The proportions of plans reaching planning aims were 85.8, 72.5 and 42.5% after 45 Gy and 85.5, 67.5 and 33.3% after 50.4 Gy according to scenarios 1, 2 and 3, respectively. According to scenario 3, 50.4 Gy, the reachable HR-CTV D90 was higher in 30% of the cases, by 2 Gy in two cases. Those cases were unpredictable and due to unfavourable organs at risk topography and poor response to external beam radiotherapy.

CONCLUSION

The delivery of 45 Gy in 25 fractions to the pelvis before brachytherapy warrants a higher probability to reach brachytherapy planning aims, in comparison with 50.4 Gy in 28 fractions.

Details of recurrence sites after definitive radiation therapy for cervical cancer

Objective

This is a retrospective study aimed at clarifying the details of recurrence patterns and sites in patients with cervical cancer treated with definitive radiation therapy (RT).

Methods

Data were analyzed from consecutive patients, admitted to the University of Tokyo Hospital (Tokyo, Japan) between 2001 and 2013, who had received definitive RT, with or without chemotherapy, for International Federation of Gynecology and Obstetrics stages IB–IVA cervical cancer.

Results

One hundred and thirty-seven patients formed the patient cohort. The median follow-up period for surviving patients was 57.0 months. A complete response was achieved in 121 patients (88%). Of these, 36 (30%) developed a cancer recurrence during follow-up. The first sites of recurrence were located in intra-RT fields in nine, outside RT fields in 20, and both in seven patients. In the intra-RT field group, all patients showed a local recurrence, while no one experienced an isolated pelvic lymph node (PLN) recurrence. In the outside RT field group, the most frequent site of recurrence was lung (60%), and three-quarters of patients were free from intra-RT field recurrence until the last follow-up. Of the entire cohort, including 48 PLN-positive patients, only seven patients (5.1%) developed PLN persistence or recurrence, all in the common iliac, internal iliac, and/or obturator nodes, and all with another synchronous relapse.

Conclusion

Local disease was a major type of intra-RT field recurrence, while PLN control was favorable even in initially PLN-positive patients. The predominance of outside RT field recurrence alone highlights issues concerning distant control, including the intensity enhancement of systematic therapy.

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.

Clinical outcomes of definitive chemoradiation followed by intracavitary pulsed-dose rate image-guided adaptive brachytherapy in locally advanced cervical cancer

OBJECTIVE

To report the outcomes and late toxicities of patients with locally advanced cervical cancer treated with concomitant chemoradiation (CRT) followed by intracavitary image-guided adaptive brachytherapy (IGABT).

METHODS

Data from consecutive patients with histologically proven stage IB-IVA cervical cancer treated with curative intent in a single institution were analyzed. After pelvic +/- para-aortic external-beam radiation therapy, they received pulsed-dose rate IGABT following GEC-ESTRO recommendations.

RESULTS

Two hundred and twenty-five patients were enrolled. Sixty-five percent were stage≥IIB according to FIGO classification. Ninety-five percent received CRT. Mean D90 to HR and IR-CTV were 80.4+/-10.3Gy and 67.7+/-6.1Gy. After a median follow-up of 38.8months, 3-year local control and overall survival rates were 86.4% and 76.1%, respectively. A trend for a detrimental effect of tumor stage on local control rates was observed with 3-year local control rates of 100% for stages IB1 and IIA, 90.5 for IB2, 85.8% for IIB, 50% for IIIA, 77.1 for IIIB, and 66.7% for IVA tumors (p=0.06). Local control rates at 3years were 95.6% in the group of patients with D90 of HR-CTV≥85Gy, 88.8% in those with D90 between 80 and 85Gy, and 80% when D90<80Gy (p=0.018). Eighteen severe late gastrointestinal and urinary effects affecting 14 patients were reported corresponding with a crude incidence of 6.6%.

CONCLUSIONS

CRT followed by IGABT provides high local control rates with limited toxicity. Reaching high doses is mandatory to achieve local control and interstitial brachytherapy is necessary in advanced diseases.

Image-Based Brachytherapy for the Treatment of Cervical Cancer

Cervical cancer is a disease that requires considerable multidisciplinary coordination of care and labor in order to maximize tumor control and survival while minimizing treatment-related toxicity. As with external beam radiation therapy, the use of advanced imaging and 3-dimensional treatment planning has generated a paradigm shift in the delivery of brachytherapy for the treatment of cervical cancer. The use of image-based brachytherapy, most commonly with magnetic resonance imaging (MRI), requires additional attention and effort by the treating physician to prescribe dose to the proper volume and account for adjacent organs at risk. This represents a dramatic change from the classic Manchester approach of orthogonal radiographic images and prescribing dose to point A. We reviewed the history and currently evolving data and recommendations for the clinical use of image-based brachytherapy with an emphasis on MRI-based brachytherapy.