title: Radiotherapy and "new" drugs-new side effects?
abstract: OBJECTIVE
  Targeted drugs have augmented the cancer treatment armamentarium. Based on the molecular specificity, it was initially believed that these drugs had significantly less side effects. However, currently it is accepted that all of these agents have their specific side effects. Based on the given multimodal approach, special emphasis has to be placed on putative interactions of conventional cytostatic drugs, targeted agents and other modalities. The interaction of targeted drugs with radiation harbours special risks, since the awareness for interactions and even synergistic toxicities is lacking. At present, only limited is data available regarding combinations of targeted drugs and radiotherapy. This review gives an overview on the current knowledge on such combined treatments.
  
  
  METHODS
  Using the following MESH headings and combinations of these terms pubmed database was searched: Radiotherapy AND cetuximab/trastuzumab/panitumumab/nimotuzumab, bevacizumab, sunitinib/sorafenib/lapatinib/gefitinib/erlotinib/sirolimus, thalidomide/lenalidomide as well as erythropoietin. For citation crosscheck the ISI web of science database was used employing the same search terms.
  
  
  RESULTS
  Several classes of targeted substances may be distinguished: Small molecules including kinase inhibitors and specific inhibitors, antibodies, and anti-angiogenic agents. Combination of these agents with radiotherapy may lead to specific toxicities or negatively influence the efficacy of RT. Though there is only little information on the interaction of molecular targeted radiation and radiotherapy in clinical settings, several critical incidents are reported.
  
  
  CONCLUSIONS
  The addition of molecular targeted drugs to conventional radiotherapy outside of approved regimens or clinical trials warrants a careful consideration especially when used in conjunction in hypo-fractionated regimens. Clinical trials are urgently needed in order to address the open question in regard to efficacy, early and late toxicity.
authors.affiliation: Department of Radiation Oncology, Ludwig-Maximilians-University Munich, Marchioninistr, 15, 81377 München, Germany.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Niyazi
authors.forename: Cornelius
authors.initials: C
authors.lastname: Maihoefer
authors.forename: Mechthild
authors.initials: M
authors.lastname: Krause
authors.forename: Claus
authors.initials: C
authors.lastname: Rödel
authors.forename: Wilfried
authors.initials: W
authors.lastname: Budach
authors.forename: Claus
authors.initials: C
authors.lastname: Belka
mesh_terms: D000970:Antineoplastic Agents / Q000009:adverse effects*; D059248:Chemoradiotherapy / Q000009:adverse effects*; D006801:Humans; D058990:Molecular Targeted Therapy / Q000009:adverse effects*; D009369:Neoplasms / Q000628:therapy*
chemical_list: D000970:Antineoplastic Agents