title: Analyzing adjuvant radiotherapy suggests a non monotonic radio-sensitivity over tumor volumes.
abstract: BACKGROUND
  Adjuvant Radiotherapy (RT) after surgical removal of tumors proved beneficial in long-term tumor control and treatment planning. For many years, it has been well concluded that radio-sensitivities of tumors upon radiotherapy decrease according to the sizes of tumors and RT models based on Poisson statistics have been used extensively to validate clinical data.
  
  
  RESULTS
  We found that Poisson statistics on RT is actually derived from bacterial cells despite of many validations from clinical data. However cancerous cells do have abnormal cellular communications and use chemical messengers to signal both surrounding normal and cancerous cells to develop new blood vessels and to invade, to metastasis and to overcome intercellular spatial confinements in general. We therefore investigated the cell killing effects on adjuvant RT and found that radio-sensitivity is actually not a monotonic function of volume as it was believed before. We present detailed analysis and explanation to justify above statement. Based on EUD, we present an equivalent radio-sensitivity model.
  
  
  CONCLUSIONS
  We conclude that radio sensitivity is a sophisticated function over tumor volumes, since tumor responses upon radio therapy also depend on cellular communications.
authors.affiliation: Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA. jyang@bwh.harvard.edu
authors.forename: Jack Y
authors.initials: JY
authors.lastname: Yang
authors.forename: Andrzej
authors.initials: A
authors.lastname: Niemierko
authors.forename: Mary Qu
authors.initials: MQ
authors.lastname: Yang
authors.forename: Youping
authors.initials: Y
authors.lastname: Deng
mesh_terms: D001419:Bacteria / Q000528:radiation effects; D006801:Humans; D008954:Models, Biological; D009369:Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D016012:Poisson Distribution; D011836:Radiation Tolerance; D018714:Radiotherapy, Adjuvant / Q000379:methods*; D015398:Signal Transduction / Q000528:radiation effects; D047368:Tumor Burden