Online MRI guidance for healthy tissue sparing in patients with cervical cancer: An IMRT planning study

BACKGROUND AND PURPOSE: During cervical cancer treatment, target volumes change position and shape due to organ motion and tumour regression. An MRI-accelerator will provide information on these changes by online magnetic resonance imaging (MRI) guidance throughout each treatment fraction. The purpose of this intensity-modulated radiation therapy (IMRT) planning study is to assess the benefit of online MRI guidance in healthy tissue sparing. MATERIALS AND METHODS: Weekly MRI scans of 11 cervical cancer patients were used. We created four IMRT plans per patient, based on these weekly MRI scans, to simulate an online-IMRT approach. We applied a primary and nodal planning target volume (PTV) margin of 4mm. As reference, we created an IMRT plan based on the pre-treatment MRI scan (pre-IMRT) using a primary and nodal PTV margin of 15 and 10mm. The weekly defined bladder, rectum, bowel, and sigmoid contours were evaluated on the online-IMRT and pre-IMRT dose distributions at six dose levels (V10(Gy), V20(Gy), V30(Gy), V40(Gy), V42.8(Gy), and V45(Gy)). RESULTS: Online-IMRT compared to pre-IMRT significantly reduced the volume of healthy tissue irradiated to all dose levels, except V10(Gy). CONCLUSIONS: Online MRI guidance reduces healthy tissue involvement in patients with cervical cancer.     

基于KVCBCT形变配准的肺癌自适应计划与静态3DCRT计划的比较研究

目的 对肺肿瘤利用千伏级锥形束CT (KVCBCT)图像形变配准的自适应放疗和静态三维适形放疗计划进行比较并评估差异.方法 选5例肺肿瘤患者每3d行1次肺部CBCT扫描,每次扫描两组.把两组图像进行拼接获得10次CBCT拼接图像,将拼接图像和计划CT图像进行形变配准并获得10个新器官轮廓( CBCTf1～CBCTf10).将CBCTf1～CBCTf10移植至计划CT图像上得到CBCTp1～CBCTp10累积剂量计划,并与CT计划的左右及双肺、脊髓、计划靶体积(PTV)的分次剂量、累积剂量和剂量体积直方图进行比较,差异行Wilcoxson符号秩检验.结果 累积剂量计划的FTV最大、最小值,左右及双肺平均剂量,脊髓最大剂量,以及左右及双肺V5 、V10、V20V30、V50均＜CT计划(z=-2.02～-2.03,P均＜0.05);但PTV平均剂量、95％ PTV接受剂最相似(z=-1.48、-1.21,P=0.138、0.225).结论 利用形变配准实施自适应放疗可降低肺组织和脊髓受量,提高PTV剂量,为进一步探索自适应放疗提供了一种方法.     

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.     

Influence of C-choline PET/CT on the treatment planning for salvage radiation therapy in patients with biochemical recurrence of prostate cancer

Background and purpose

The present study evaluates the incidence of ¹¹C-choline PET/CT positive findings in patients with recurrent prostate cancer referred for salvage radiotherapy (SRT) and the influence on the definition of the planning target volume (PTV).

Material and methods

Thirty-seven patients treated with radical prostatectomy and referred to SRT to the prostatic fossa because of biochemical relapse, were analysed retrospectively. All patients underwent ¹¹C-choline PET/CT before radiotherapy. The influence of PET/CT on the extent of the PTV was analysed. The median total follow up after SRT was 51.2 months.

Results

11/37 (30%) patients had a positive finding in the ¹¹C-choline PET/CT, 5 (13%) outside of the prostatic fossa (iliac lymph nodes), implicating an extension of the PTV. Patients with positive ¹¹C-choline PET/CT had a significant higher PSA value than patients with no pathologic uptake (p = 0.03). Overall, at the end of follow up 56% of the patients had a PSA ? 0.2 ng/ml and 44% had a biochemical relapse of prostate cancer.

Conclusions

¹¹C-choline PET/CT detects abnormalities outside of the prostatic fossa in 13% of patients referred for SRT because of biochemical relapse after radical prostatectomy, affecting the extent of the PTV. Prospective studies need to be implemented to evaluate the benefit of SRT with a PTV based on ¹¹C-choline PET/CT.     

术前术后宫颈癌膀胱充盈度一致性在调强放疗中对靶区及危及器官重要性研究

目的 在宫颈癌调强放疗中使用膀胱容积测量仪(BVI 9400)控制术前及术后宫颈癌患者的膀胱充盈度,比较靶区位移误差及其引起的照射剂量变化、膀胱充盈形态变化,研究膀胱充盈度的一致性在宫颈癌调强放疗中的重要性。方法 选取本院2018年内放疗的45例宫颈癌患者,分成A、B、C组,每组15 例。A组为未手术患者,B组为根治术后患者(两组疗前均使用BVI 9400监测膀胱尿量),C组随机选取患者采取自主憋尿未监测治疗前膀胱尿量。3个组患者疗前均行KV-CBCT扫描进行在线配准分析,计算在左右、头脚,腹背方向的靶区位移误差、处方剂量PTV覆盖体积百分比(V100)及百分比差值(ΔV100)。结果 左右、头脚,腹背方向平均位移误差A组分别为1.67、1.55、1.67 mm,B组分别为1.43、1.58、1.84 mm,C组分别为2.27、2.30、2.08 mm。V100、ΔV100 A组分别为96.96%、1.17%,B组分别为95.9%、1.29%,C组分别为94.02%、2.17%。结论 控制膀胱充盈度的一致性均能在一定程度上减小膀胱充盈程度不一致对误差产生的影响,保证了靶区位置的精度和靶区的照射剂量,对膀胱、小肠、直肠起到一定的保护作用,减轻宫颈癌患者放疗反应。     

Indications for neoadjuvant treatment based on risk factors for poor prognosis before and after neoadjuvant chemotherapy alone in patients with locally advanced rectal cancer

IntroductionThe oncological benefit of neoadjuvant chemotherapy (NAC) alone for locally advanced rectal cancer (LARC) remains controversial. The aim of this study was to clarify the clinical risk factors for poor prognosis before and after NAC for decision making regarding additional treatment in patients with LARC.Materials and methodsWe examined a total of 96 patients with MRI-defined poor-risk locally advanced mid-low rectal cancer treated by NAC alone between 2006 and 2018. Survival outcomes and clinical risk factors for poor prognosis before and after NAC were analyzed.ResultsIn the median follow-up duration after surgery of 60 months (3–120), the rates of 5-year overall survival (OS), relapse-free survival (RFS), and local recurrence (LR) were 83.6%, 78.4%, and 8.2%, respectively. In the multivariate analyses, patients with cT4 disease had a significantly higher risk of poor OS (HR; 6.10, 95% CI; 1.32–28.15, P = 0.021) than those with cT3 disease. After NAC, ycN+ was significantly associated with a higher risk of poor OS (HR; 5.92, 95% CI; 1.27–27.62, P = 0.024) and RFS (HR; 2.55, 95% CI; 1.01–6.48, P = 0.048) than ycN-. In addition, patients with CEA after NAC (post-CEA) ≥ 5 ng/ml had a significantly higher risk LR (HR; 5.63, 95% CI; 1.06–29.93, P = 0.043).ConclusionNAC alone had an insufficient survival effect on patients with cT4 disease, ycN+, or an elevated post-CEA level. In contrast, NAC alone is a potential treatment for other patients with LARC.     

Minimal impact of postmastectomy radiation therapy on locoregional recurrence for breast cancer patients with 1 to 3 positive lymph nodes in the modern treatment era

Introduction

Given modern treatment strategies, controversy remains regarding whether postmastectomy radiation therapy (PMRT) is necessary for breast cancer patients with 1–3 positive axillary lymph nodes (ALN). Our aim was to assess the significance of PMRT in the modern treatment era for these patients.