A phase Ⅱ trial of comprehensive treatment based on radiotherapy in leptomeningeal metastasis

Objective To evaluate the efficacy and safety of comprehensive treatment based on radiotherapy for patients with leptomeningeal metastases (LM) in this prospective study. Methods A total of 93 patients diagnosed with LM admitted to our hospital undergoing whole brain radiotherapy (WBRT) or craniospinal irradiation (CSI) with or without simultaneous boost from 2014 to 2017 were enrolled. The dynamic changes of clinical signs and symptoms, enhanced magnetic resonance imaging (MRI), cerebrospinal fluid cytology and liquid biopsy detection were recorded. The primary endpoint was overall survival (OS),the secondary endpoints were local control (LC), intracranial progress-free survival (IPFS), brain metastasis specific survival (BMSS) and toxicity. Results The major primary disease was non-small cell lung cancer. The whole cohort received WBRT with boost (40 Gy in 20 fractions (f) for WBRT and 60Gy in 20 f for boost), focal radiation to LM, WBRT and CSI (40 Gy in 20 f or 50Gy in 25 f for WBRT and 36 Gy in 20 f for CSI). For 20 patients, tumor cells were identified and intrathecal chemotherapy was performed. Sixty-three patients received target therapy. The median follow-up time was 33.8 months. The 1-year OS, LC and IPFS was 62.4%, 77.2% and 52.6%, respectively. The median survival time was 15.9 months, and the median BMSS was 42.2 months.Treatment-related grade 3–4 adverse events were rare and only 8 cases was observed to have grade 3 hematological toxicity. Conclusion Reasonable comprehensive treatment including precise radiotherapy, intrathecal chemotherapy and targeted therapy can be well tolerated and prolong the survival time of LM patients.     

Helical tomotherapy and intensity modulated proton therapy in the treatment of early stage prostate cancer: A treatment planning comparison

Purpose

To compare helical tomotherapy (HT) and intensity modulated proton therapy (IMPT) on early stage prostate cancer treatments delivered with simultaneous integrated boost (SIB) in moderate hypofractionation.

Material/methods

Eight patients treated with HT were replanned with two-field IMPT (2fIMPT) and five-field IMPT (5fIMPT), using a small pencil beam size (3 mm sigma). The prescribed dose was 74.3 Gy in 28 fractions on PTV1 (prostate) and PTV2 (proximal seminal vesicles), 65.5 Gy on PTV3 (distal seminal vesicles) and on the overlap between rectum and PTVs.

Results

IMPT and HT achieved similar target coverage and dose homogeneity, with 5fIMPT providing the best results. The conformity indexes of IMPT were significantly lower for PTV1+2 and PTV3. Above 65 Gy, HT and IMPT were equivalent in the rectum, while IMPT spared the bladder and the penile bulb from 0 to 70 Gy. From 0 up to 60 Gy, IMPT dosimetric values were (much) lower for all OARs except the femur heads, where HT was better than 2fIMPT in the 25-35 Gy dose range. OARs mean doses were typically reduced by 30-50% by IMPT. NTCPs for the rectum were within 1% between the two techniques, except when the endpoint was stool frequency, where IMPT showed a small (though statistically significant) benefit.

Conclusions

HT and IMPT produce similar dose distributions in the target volume. The current knowledge on dose-effect relations does not allow to quantify the clinical impact of the large sparing of IMPT at medium-to-low doses.     

Dose specification and quality assurance of radiation therapy oncology group protocol 95-17; a cooperative group study of iridium-192 breast implants as sole therapy

PURPOSE: To introduce a four-dimensional (4D) tomotherapy treatment technique with improved motion control and patient tolerance. METHODS AND MATERIALS: Computed tomographic images at 10 breathing phases were acquired for treatment planning. The full exhalation phase was chosen as the planning phase, and the CT images at this phase were used as treatment-planning images. Region of interest delineation was the same as in traditional treatment planning, except that no breathing motion margin was used in clinical target volume-planning target volume expansion. The correlation between delivery and breathing phases was set assuming a constant gantry speed and a fixed breathing period. Deformable image registration yielded the deformation fields at each phase relative to the planning phase. With the delivery/breathing phase correlation and voxel displacements at each breathing phase, a 4D tomotherapy plan was obtained by incorporating the motion into inverse treatment plan optimization. A combined laser/spirometer breathing tracking system has been developed to monitor patient breathing. This system is able to produce stable and reproducible breathing signals representing tidal volume. RESULTS: We compared the 4D tomotherapy treatment planning method with conventional tomotherapy on a static target. The results showed that 4D tomotherapy can achieve dose distributions on a moving target similar to those obtained with conventional delivery on a stationary target. Regular breathing motion is fully compensated by motion-incorporated breathing-synchronized delivery planning. Four-dimensional tomotherapy also has close to 100% duty cycle and does not prolong treatment time. CONCLUSION: Breathing-synchronized delivery is a feasible 4D tomotherapy treatment technique with improved motion control and patient tolerance.     

Helical tomotherapy in oncodermatology: Case report of circumferential cutaneous lymphoma treated by this optimized radiotherapy

Helical tomotherapy is a recent modality of intensity-modulated, rotational irradiation being developed for treatment of an increasing number of malignancies. It allows delivering an accurate treatment while sparing critical organs thus optimizing the therapeutic ratio. In particular, it allows treating some tumour locations that could not be efficiently irradiated through more conventional irradiation devices. We report the usefulness of this approach for the treatment of complex lesions such as circumferential cutaneous lymphoma of the trunk.     

Study on dosimetric and radiation safety performance parameters of helical tomotherapy unit

Objective To understand the functional status and radiation protection requirements of helical tomotherapy (TOMO) unit when it is applied in clinic treatment so as to promote the construction of TOMO q...     

Left-sided breast cancer irradiation using rotational and fixed-field radiotherapy

The 3-dimensional conformal radiotherapy (3DCRT) technique is the standard for breast cancer radiotherapy. During treatment planning, not only the coverage of the planning target volume (PTV) but also the minimization of the dose to critical structures, such as the lung, heart, and contralateral breast tissue, need to be considered. Because of the complexity and variations of patient anatomy, more advanced radiotherapy techniques are sometimes desired to better meet the planning goals. In this study, we evaluated external-beam radiation treatment techniques for left breast cancer using various delivery platforms: fixed-field including TomoDirect (TD), static intensity-modulated radiotherapy (sIMRT), and rotational radiotherapy including Elekta volumetric-modulated arc therapy (VMAT) and tomotherapy helical (TH). A total of 10 patients with left-sided breast cancer who did or did not have positive lymph nodes and were previously treated with 3DCRT/sIMRT to the entire breast were selected, their treatment was planned with Monaco VMAT, TD, and TH. Dosimetric parameters including PTV coverage, organ-at-risk (OAR) sparing, dose-volume histograms, and target minimum/maximum/mean doses were evaluated. It is found that for plans providing comparable PTV coverage, the Elekta VMAT plans were generally more inhomogeneous than the TH and TD plans. For the cases with regional node involvement, the average mean doses administered to the heart were 9.2 (± 5.2) and 8.8 (± 3.0) Gy in the VMAT and TH plans compared with 11.9 (± 6.4) and 11.8 (± 9.2) Gy for the 3DCRT and TD plans, respectively, with slightly higher doses given to the contralateral lung or breast or both. On average, the total monitor units for VMAT plans are 11.6% of those TH plans. Our studies have shown that VMAT and TH plans offer certain dosimetric advantages over fixed-field IMRT plans for advanced breast cancer requiring regional nodal treatment. However, for early-stage breast cancer fixed-field radiotherapy is potentially more beneficial in terms of OAR sparing.     

放疗为主的综合方案治疗脑膜转移瘤Ⅱ期临床研究

目的 前瞻性分析脑膜转移瘤以放疗为主的综合治疗方案的有效性及安全性。方法 纳入2014-2017年中国医学科学院肿瘤医院收治的93例脑膜转移瘤患者,接受螺旋断层放疗技术实施的全脑放疗、局部推量和/或全脊髓照射为基础的综合治疗,记录临床症状、磁共振检查、脑脊液细胞学、液体活检变化情况及不良反应。主要研究终点为总生存(OS),次要研究终点为局部控制(LC)、颅内无进展生存(IPFS)及脑转移专项生存(BMSS)及不良反应。结果 主要原发病为非小细胞肺癌。全组接受全脑放疗±局部推量(中位剂量分别为40Gy分20次、60Gy分20次)或全脑、全脊髓照射(中位剂量分别为40Gy分20次或50Gy分25次、36Gy分20次)。20例找到肿瘤细胞并行鞘注化疗;63例接受靶向治疗。中位随访时间33.8个月,1年OS、LC及IPFS分别为62%、77%及53%。中位生存时间15.9个月,中位BMSS时间42.2个月。3-4级不良反应少见,仅观察到8例3级血液学不良反应。结论 精准放疗结合鞘注化疗或靶向治疗的综合治疗方法,可有效延长脑膜转移瘤患者的生存时间,且不良反应可耐受。