The Impact of Dose Escalation Using Gold Markers in Image Guided Volumetric Modulated Arc Radiotherapy to the Focal Lesion Micro Boost of Localized Prostate Cancer
试验速览
- 阶段
- 2 期
- 状态
- 已完成
- 发起方
- 入组人数
- 30
- 试验地点
- 2
- 主要终点
- Measurement of systemic error in mm and random error in cm in the different three direction X-Y-Z
研究概览
简要总结
Gold markers implanted in the prostate are used frequently for position verification of the prostate during external-beam radiotherapy. By using the markers as a surrogate for the prostate itself, not only set-up errors, but also the internal motion of the prostate relative to the bony anatomy can be identified.
It is thus believed that escalated dose marker guided radiotherapy should result in better biochemical control compared to conventional external beam radiotherapy, with a similar or lower incidence of toxicity. However, clinical data to support this is still limited. The purpose of this study is to directly compare late toxicity as well as biochemical control between patients treated with dose escalated marker guided radiotherapy versus conventional dose non-marker guided radiotherapy who has otherwise been treated with similar radiotherapy planning techniques and equipment.
Prostate magnetic resonance imaging has undergone several technical improvements and shows promises for prostate tumor detection and localization. In addition to morphological information, magnetic resonance imaging allows an estimation of physiological properties of tissues. Diffusion-weighted magnetic resonance imaging is sensitive to restriction of diffusion of water molecules, and dynamic contrast enhanced magnetic resonance imaging can analyze tissue micro vascular properties. Multi para metric magnetic resonance imaging combining Diffusion-weighted and Dynamic contrast enhanced has demonstrated its value in distinguishing malignant from benign prostate tissue.
Higher radiation dose levels were consistently associated with improved biochemical control outcomes and reduction in distant metastases. Radiation dose was one of the important predictors of long-term biochemical tumor control. Dose levels < 70.2 Grey and 70.2-79.2 Grey were associated with 2.3 and 1.3-fold increased risks of pro static specific antigen relapse compared with higher doses. However, further dose escalation to the whole gland is limited due to an unacceptable high risk of acute and late toxicity. Moreover, local recurrences often originate at the location of the macroscopic tumor, so boosting the radiation dose at the macroscopic tumor within the prostate might increase local control. A reduction of distant metastases and improved survival can be expected by reducing local failure. Treating the dominant focus or boosting the dose to this area while reducing the dose to as much healthy tissue as possible has significant potential for improving treatment.
详细描述
Thirty consecuative loclized prostate cancer patients will be recruited according to inclusion & exclusion criteria. Once the patient meets the selection criteria stratification will be done according to the following risk group classification:
Stage Gleason score PSA Low risk T1-T2a 2-6 < 10 ng/mL Intermediate risk T2b-T2c 7 10-20 ng/mL High risk T3a 8-10 > 20 ng/mL
The patient will receive 2-6 months of neo adjuvant hormonal treatment, followed with concomitant hormonal treatment during the radiation course for intermediate and high risk groups then adjuvant hormonal for 2-3 years in the high risk group.
For each patient the radio-opaque marker (used for treatment verification) will be inserted by ultrasound guidance & local anesthetic with an 17 GA x 30 cm brachy therapy needle that has 1.2 mm x 3 mm one gold marker. The ultrasound probe (as used for trans rectal biopsy) will be introduced rectally with the patient in the left lateral position. After measuring the volume of the prostate and determining the desired position (preferably in the corpus of prostate), three gold markers will be inserted as follows: one into right side, one into left side of the base and the third in the apex of the prostate. All patients will receive a course of preventive antibiotic treatment that consists of ciprofloxacine 500 mg BID, 1 day before implantation and 4 consecutive days. Patients under anti-platelet therapy will be told to stop the medication 5 days before implantation.
CT images will be done within 5 days of markers insertion in the same treatment supine position with Knee & ankle support. CT images will be taken in 1.25 mm slice thickness from the top of the 4th lumbar vertebrae to ischial tuberosities. Patients will be asked to evacuate bowels prior to scanning, and bladder will be kept comfortably full by drinking two glasses of water (250-500 ml) 30 min prior to the scan.
研究设计
- 研究类型
- Interventional
- 分配方式
- Na
- 干预模型
- Single Group
- 主要目的
- Health Services Research
- 盲法
- None
入排标准
- 年龄范围
- 40 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Performance status ECOG: 0-2
- •Pathologically proven prostatic adenocarcinoma.
- •Localized prostate cancer (Gleason's score: 2-10, Baseline serum prostatic antigen: >4 ng/dl, T1a-T3b).
- •No extra prostatic invading adjacent structures.
- •Adequate hematological, renal & hepatic profile.
- •Insertion of more than one fiducial marker in the prostate.
- •Patient did verbal & written consent and adherence to treatment.
排除标准
- •Patient weight >130 kg.
- •Performance status EGOG: 3-
- •Distant metastasis.
- •Previous pelvic radiotherapy.
- •Previous prostatectomy.
- •Urinary bladder stones.
- •General contraindications for MRI (i.e. cardiac pacemaker, metal implants or history of severe allergic reaction after administration of contrast agent).
- •Concomitant neoplastic disease or previous anti neoplastic therapy.
研究组 & 干预措施
Dose escaltion
insertion of 3 fiducial markers, prostate will receive 78 Gy with dose escalation to prostate focal lesion up to 87 Gy
干预措施: Dose escalation to prostate focal lesion (Radiation)
结局指标
主要结局
Measurement of systemic error in mm and random error in cm in the different three direction X-Y-Z
时间窗: 12 months
Position verification will be done guided with implanted gold markers with daily portal imaging (AP \& lateral) correction protocol in mediolateral, superior-inferior \& inward-outward directions by mm for 35 fraction. The off-line portal pre-correction images will be verified daily to detect average shifts in the three diresctions. Random or inter-fraction errors which are deviations between different fractions will be taken weekly during a treatment series. Systematic errors Which are deviations between the planned patient position and the average patient position of a course of fractioned therapy will be taken in the first three settings. The mean and standard deviation (SD) of the systematic error and SD of random errors will be analyzed.
次要结局
- subjective toxicity assessment(12 months)
- Objective toxicity assessment(12 months)
- Biochemical relapse of PSA above normal level 4 ng/dl(12 months)
研究者
Radwa Fawzy
assistant Lecturer of Clinical Oncology
Kasr El Aini Hospital