Time-dose factors in positive neck nodes treated with irradiation only.

This article describes an analysis of time-dose and clinical factors which affect the 2 year rate of control of cervical node metastases from squamous cell carcinoma of the head and neck following external beam radiotherapy in a series of 140 patients. We find that node diameter and normalized total dose are the most important factors, and that overall treatment time is not statistically significant.     

SV40 and human cancer: a review of recent data

An unknown proportion of formalin-inactivated poliovirus vaccine lots administered to millions of US residents between 1955 and 1963 was contaminated with small amounts of infectious simian virus 40 (SV40), a polyomavirus of the rhesus macaque. It has been reported that mesothelioma, brain tumors, osteosarcoma and non-Hodgkin lymphoma (NHL) contain SV40 DNA sequences and that SV40 infection introduced into humans by the vaccine probably contributed to the development of these cancers. The Immunization Safety Review Committee of the Institute of Medicine (IOM) reviewed this topic in 2002. The present review of recent studies showed that the earlier results describing the recovery of SV40 DNA sequences from a large proportion of the above tumors were not reproducible and that most studies were negative. Contamination with laboratory plasmids was identified as a possible source of false positive results in some previous studies. The low-level immunoreactivity of human sera to SV40 was very likely the result of cross-reactivity with antibodies to the SV40-related human polyomaviruses BKV and JCV, rather than of authentic SV40 infection. SV40 sero-reactivity in patients with the suspect tumors was no greater than that in controls. In epidemiologic studies, the increased incidence of some of the suspect tumors in the 1970s to 1980s was not related to the risk of exposure to SV40-contaminated vaccines. In summary, the most recent evidence does not support the notion that SV40 contributed to the development of human cancers.     

Carbon ion radiotherapy in the treatment of gliomas: a review

Journal of Neuro-Oncology - Gliomas are among the most common primary brain malignancies, with a poor prognosis for high grade gliomas despite aggressive therapy. Carbon ions, which exhibit...     

Fractionated stereotactic radiotherapy: a short review

Currently, optimally precise delivery of intracranial radiotherapy is possible with stereotactic radiosurgery and fractionated stereotactic radiotherapy. We present in this article a review of the underlying basic physical and radiobiological principles of fractionated stereotactic radiotherapy and review the clinical experience for ateriovenus malformations, pituitary adenomas, mengiomas, vestibular schwanomas, low grade astrocytomas, malignant gliomas, and brain metastases.     

Intraoperative radiotherapy in pancreatic cancer: a systematic review.

BACKGROUND AND PURPOSE: Intraoperative radiotherapy (IORT) has been considered for treatment of pancreas cancer since local recurrence rates are very high. This study assesses the efficacy and safety of IORT in pancreatic cancer. MATERIALS AND METHODS: We conducted a systematic review of scientific literature from January 1995 to February 2007, including Medline, Embase, ISI Web of Science and HTA (Health Technology Assessment). By applying a series of inclusion criteria, two independent reviewers selected those studies in which a minimum of 30 patients received IORT and which furnished survival results based on a minimum 3-month follow-up. RESULTS: Fourteen papers were included, one was an IORT assessment report, 5 were cohort studies, and the remaining 8 were case series studies, 2 of which belonged to the same series. In general, these studies showed that IORT could slightly increase survival among patients with pancreatic cancer in localized stages. However, the results were not conclusively in favor of IORT in the case of pancreatic cancer in locally advanced and metastatic stages. There were no published studies that assessed quality of life. CONCLUSIONS: There is no clear evidence to indicate that IORT is more effective than other therapies in treating pancreatic cancer in locally advanced and metastatic stages.     

Concomitant hydroxyurea plus radiotherapy versus radiotherapy for carcinoma of the uterine cervix: a systematic review

We identified eight randomised control trials of hydroxyurea and radiation versus radiotherapy alone (six published in full and two abstracts). Most concluded that outcomes were improved by use of hydroxyurea. However, methodological problems associated with these trials included small sample size, a large number of patient exclusions post randomisation, differing outcome definitions, subgroup analyses of already small numbers of patients and questionable rules for censoring, particularly a failure to include treatment related deaths in the survival analysis. All but two studies were of less than 50 patients. Patients were excluded from some analyses for treatment related reasons. The exclusion of such patients undoubtedly altered the conclusions of the studies. Even if there was a survival advantage attributed to hydroxyurea, overall survival was somewhat poor. We found the evidence regarding the use of hydroxyurea and radiotherapy to be inadequate for assessing its role in the treatment of cervical cancer.     

调强适形放疗治疗鼻咽癌的系统评价

目的 评价调强适形放疗治疗鼻咽癌的有效性和安全性.方法 计算机检索Cochrane Library、PubMed、EMBASE、中国生物医学文献数据库(CBM)、中国期刊全文数据库(CNKI)、维普和万方数据库,检索时间从建库至2012年6月15日,同时辅助其他检索.纳入调强适形放疗与常规放疗对比治疗鼻咽癌的随机对照试验(RCT).两位研究者独立评价纳入研究的质量及提取资料,并用RevMan5.1软件进行统计分析.结果 共纳入15个RCT,结果显示:与常规放疗相比,调强适形放疗可提高放疗后刺激性全唾液流量率、刺激性腮腺唾液流量率;显著减少急性期口干(RR=0.46,P＜0.000 1)、黏膜反应(RR =0.86,P=0.04)、皮肤反应(RR =0.33,P＜0.000 1)以及远期口干(RR =0.28,P=0.01)、张口受限(RR =0.42,P=0.008)等并发症,并有提高近期疗效(RR=1.22,P=0.02)和长期疗效(RR=l.25,P =0.04)的趋势.此外,调强放疗可能缩短治疗时间,但同时增加治疗费用.结论 与常规放疗相比,调强适形放疗治疗鼻咽癌可保护唾液腺功能,减轻口干等并发症,并具有提高疗效的趋势.但纳入研究数及总样本量较小,结论仍有待更多高质量RCT明确.     

调强适形放疗在乳腺癌保乳术后应用的系统评价

Objective

The aim of this study was to assess the long-term effect of breast conservation with breast intensity-modulated radiotherapy (IMRT) for early-stage breast cancers.

Methods

Pub Med, EMBASE, Cochrane Library, Chinese Biomedical Literature Database were searched to identify relevant original published trails, and the references of eligible studies were manually screened. Randomized controlled trails reported in any language, comparing breast IMRT with conventional radiotherapy (RT) in patients with early-stage breast cancer were eligible for inclusion. Two investigators independently assessed the quality of included trials and extracted data. The RevMan 5.0 software was used for statistical analysis.

Results

Four trials involving 1440 patients were included. The results showed that in the IMRT group, the occurrence of acute moist dermatitis, the edema of the mammary gland and the occurrence of hyperpigmentation were lower than those of RT group, the pooled risk ratio value and 95% confidence interval were 0.28 (0.17–0.48), 0.03 (0.00–0.21) and 0.06 (0.02–0.15) respectively. The use of IMRT did not correlate with pain and quality of life, but the presence of moist desquamation did significantly correlate with pain and reduced quality of life.

Conclusion

The currently available evidence showed that IMRT significantly reduces the occurrence of moist acute dermatitis anywhere in the breast and alleviates the suffering of patients and improves the quality of life of patients. Future large-scale, high-quality, double-blind trials are needed.     

Image-guided radiotherapy for rectal cancer: a systematic review

Radiotherapy for rectal cancer is becoming more conformal. Both the rectum and the mesorectum are mobile structures and the use of image-guided radiotherapy techniques may improve treatment delivery. Studies up to 2008 have previously been reviewed; rectal motion was mostly studied in bladder and prostate cancer cases. Large variations were seen in both the rectal volume and rectal wall displacement during the treatment course. We reviewed the literature on primary rectal cancer. A systematic review was conducted using Medline and Embase databases using the keywords 'rectal, radiotherapy, IGRT, image guided, organ motion, internal margin, target shape/volume'. Nine studies looked at both inter- and intrafractional motion of the gross tumour volume, rectum, mesorectum and the clinical target volume using a variety of imaging modalities. There was significant movement in the upper mesorectum. There was a strong relationship between rectal filling and mesorectal motion. Differences according to gender and body mass index have been reported. One study showed adequate dose to the rectum despite rectal motion and deformation. Current margin recipes may not apply to deformable structures. Suggested margins for the clinical target volume to planning target volume expansion are between 1 and 3.5cm. There may be a role for re-imaging and re-planning during a treatment course. From the available data, electronic portal imaging devices should continue to be used to match for bony anatomy. Additional information on internal motion can be obtained by cone beam computer tomography or tomotherapy and if available its use should be considered. Individualised anisotropic margins may be required. Further work is required to assess the optimal imaging modality, whether to match to bone or soft tissue, and to assess if internal motion affects treatment outcome.     

Chemical radioprotection: a critical review of amifostine as a cytoprotector in radiotherapy

The use of chemical radioprotectors represents an obvious strategy to improve the therapeutic index in radiotherapy. Amofostine (WR-2721) has recently been approved for use in head and neck cancer to protect against radiation-induced xerostomia. Currently, the question has arisen whether amifostine could be used for radioprotection in broader terms. Amifostine may have the potential to enable intensified treatment by ameliorating mucosal reactions that are often a limiting factor in accelerated fractionation or concomitant chemoradiation. However, it has as yet not been clarified whether sufficient amifostine to reduce mucositis can be administered before each radiation fraction without causing unacceptable toxicity. Also, the optimal dosage and schedule of amifostine in chemoradiation combinations have not yet been established. The major concern related to radioprotectiors is the potential hazard of collateral tumor protection. A number of clinical studies have concluded that amifostine does not reduce antitumor efficacy. However, not even the largest study conducted, with over 300 patients, has sufficient statistical power to detect a clinically significant reduction in tumor control rate. To put this issue ultimately to a rest, a clinical trial with a sufficient accrual to definitely rule out a tumor protective effect of amifostine needs to be conducted. Substances reducing radiation-induced toxicity by modulating the biological response to radiation injury may represent an alternative concept in radioprotection. However, such agents are still at a developmental stage.     

Charged particles in radiotherapy: a 5-year update of a systematic review

Although proton therapy has been used for many decades because of their superior dose distribution over photons and reduced integral dose, their clinical implementation is still controversial. We updated a systematic review of charged particle therapy. Although still no randomised trials were identified, the field is moving quickly and we therefore also formulated ways to move forward. In our view, the aim should be to build enough proton therapy facilities with interest in research to further improve the treatment and to run the needed clinical trials.     

Conformal radiotherapy of prostatic cancer: a general review]

Recent progress in radiotherapeutic management of localized prostate cancer is reviewed. Clinical aspects--including dose-effect beyond 70 Gy, relative role of conformal radiation therapy techniques and of early hormonal treatment--are discussed as well as technical components--including patient immobilization, organ motion, prostate contouring, beam arrangement, 3-D treatment planning and portal imaging. The local control and biological relapse-free survival rates appear to be improved by high dose conformal radiotherapy from 20 to 30% for patients with intermediate and high risk of relapse. A benefit of overall survival is expected but not yet demonstrated. Late reactions, especially the rectal toxicity, remain moderate despite the dose escalation. However, conformal radiotherapy demands a high precision at all steps of the procedure.     

Hemopoietic growth factors: a review

Several hemopoietic growth factors have now been purified, cloned, and produced in bacteria. Granulocyte colony stimulating factor and granulocyte-macrophage colony stimulating factor are already being used in clinical trials. Within 12 months two more hemopoietic growth factors, macrophage colony stimulating factor (also called colony stimulating factor 1) and interleukin 3 (also called multi-colony stimulating factor) will be used for patient treatment. This review discusses the recent advances in our knowledge of the molecular properties and biological specificities of these factors. It is now clear that these molecules are able to modulate selectively the activity of mature blood cells as well as stimulating the production of specific lineages of blood cells. The availability of recombinant hemopoietic growth factors purified from animal or yeast cell conditioned medium or bacteria has facilitated in vivo experiments, as well as the clinical trials. Each of the growth factors has a unique spectrum of biological activities and it appears that the growth factors will enhance the recovery and function of circulating white blood cells after cancer therapy or bone marrow transplantation.