Article

Systematic review and meta-analysis of radiotherapy in various head and neck cancers: Comparing photons, carbon-ions and protons

Department of Radiation Oncology (MAASTRO), GROW, School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
Cancer Treatment Reviews (Impact Factor: 6.47). 05/2011; 37(3):185-201. DOI: 10.1016/j.ctrv.2010.08.004
Source: PubMed

ABSTRACT To synthesize and compare available evidence considering the effectiveness of carbon-ion, proton and photon radiotherapy for head and neck cancer.
A systematic review and meta-analyses were performed to retrieve evidence on tumor control, survival and late treatment toxicity for carbon-ion, proton and the best available photon radiotherapy.
In total 86 observational studies (74 photon, 5 carbon-ion and 7 proton) and eight comparative in-silico studies were included. For mucosal malignant melanomas, 5-year survival was significantly higher after carbon-ion therapy compared to conventional photon therapy (44% versus 25%; P-value 0.007). Also, 5-year local control after proton therapy was significantly higher for paranasal and sinonasal cancer compared to intensity modulated photon therapy (88% versus 66%; P-value 0.035). No other statistically significant differences were observed. Although poorly reported, toxicity tended to be less frequent in carbon-ion and proton studies compared to photons. In-silico studies showed a lower dose to the organs at risk, independently of the tumor site.
For carbon-ion therapy, the increased survival in mucosal malignant melanomas might suggest an advantage in treating relatively radio-resistant tumors. Except for paranasal and sinonasal cancer, survival and tumor control for proton therapy were generally similar to the best available photon radiotherapy. In agreement with included in-silico studies, limited available clinical data indicates that toxicity tends to be lower for proton compared to photon radiotherapy. Since the overall quantity and quality of data regarding carbon-ion and proton therapy is poor, we recommend the construction of an international particle therapy register to facilitate definitive comparisons.

3 Followers
 · 
111 Views
  • Source
    • "Combining several clinical characteristics has led to the development of publicly available predictive models for several cancer types (www.predictcancer.org) [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19]. However, variation in response between patients with identical clinical characteristics indicates that these models can be improved, for example by adding blood-based (e.g. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiotherapy is an important component of anti-cancer treatment. However, not all cancer patients respond to radiotherapy, and with current knowledge clinicians are unable to predict which patients are at high risk of recurrence after radiotherapy. There is therefore an urgent need for biomarkers to guide clinical decision-making. Although the importance of epigenetic alterations is widely accepted, their application as biomarkers in radiotherapy has not been studied extensively. In addition, it has been suggested that radiotherapy itself introduces epigenetic alterations. As epigenetic alterations can potentially be reversed by drug treatment, they are interesting candidate targets for anticancer therapy or radiotherapy sensitizers. The application of demethylating drugs or histone deacetylase inhibitors to sensitize patients for radiotherapy has been studied in vitro, in vivo as well as in clinical trials with promising results. This review describes the current knowledge on epigenetics in radiotherapy.
    Radiotherapy and Oncology 05/2014; 111(2). DOI:10.1016/j.radonc.2014.05.001 · 4.86 Impact Factor
  • Source
    • "Combining several clinical characteristics has led to the development of publicly available predictive models for several cancer types (www.predictcancer.org) [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19]. However, variation in response between patients with identical clinical characteristics indicates that these models can be improved, for example by adding blood-based (e.g. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Radiotherapy is an important component of anti-cancer treatment. However, not all cancer patients respond to radiotherapy, and with current knowledge clinicians are unable to predict which patients are at high risk of recurrence after radiotherapy. There is therefore an urgent need for biomarkers to guide clinical decision-making. Although the importance of epigenetic alterations is widely accepted, their application as biomarkers in radiotherapy has not been studied extensively. In addition, it has been suggested that radiotherapy itself introduces epigenetic alterations. As epigenetic alterations can potentially be reversed by drug treatment, they are interesting candidate targets for anticancer therapy or radiotherapy sensitizers. The application of demethylating drugs or histone deacetylase inhibitors to sensitize patients for radiotherapy has been studied in vitro, in vivo as well as in clinical trials with promising results. This review describes the current knowledge on epigenetics in radiotherapy.
  • Source
    • "Due to their higher RBE, the treatment with carbon ions might be more effective for the cure of radioresistant tumors. A recent meta-analysis performed in different head and neck cancers compared the efficacies of photons, protons, and carbon ions (Ramaekers et al. 2011) but, so far, only revealed a survival benefit for mucosal malignant melanomas after a carbon-ion-based therapy, which might reflect a high grade of resistance of this particular tumor entity toward irradiation in general. Other work suggests that due to the reduced volume of normal tissue that is exposed to modest doses, particle therapy may confer advantages in treatments using concurrent drug administration (Nystrom 2010). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Based on its potent capacity to induce tumor cell death and to abrogate clonogenic survival, radiotherapy is a key part of multimodal cancer treatment approaches. Numerous clinical trials have documented the clear correlation between improved local control and increased overall survival. However, despite all progress, the efficacy of radiation-based treatment approaches is still limited by different technological, biological, and clinical constraints. In principle, the following major issues can be distinguished: (1) The intrinsic radiation resistance of several tumors is higher than that of the surrounding normal tissue, (2) the true patho-anatomical borders of tumors or areas at risk are not perfectly identifiable, (3) the treatment volume cannot be adjusted properly during a given treatment series, and (4) the individual heterogeneity in terms of tumor and normal tissue responses toward irradiation is immense. At present, research efforts in radiation oncology follow three major tracks, in order to address these limitations: (1) implementation of molecularly targeted agents and 'omics'-based screening and stratification procedures, (2) improvement of treatment planning, imaging, and accuracy of dose application, and (3) clinical implementation of other types of radiation, including protons and heavy ions. Several of these strategies have already revealed promising improvements with regard to clinical outcome. Nevertheless, many open questions remain with individualization of treatment approaches being a key problem. In the present review, the current status of radiation-based cancer treatment with particular focus on novel aspects and developments that will influence the field of radiation oncology in the near future is summarized and discussed.
    Biophysik 10/2013; 53(1). DOI:10.1007/s00411-013-0497-2 · 1.58 Impact Factor
Show more