Thesis in Radiotherapy by Dr. Kundan
M.D. (Radiotherapy)Department of Radiotherapy K.G.M.C. Lucknow.
October, 2001 – November 2002
Topic: To study the role of radiation with concurrent late chemotherapy intensification (Chemoboost) for locally advanced head and neck cancer
The concurrent late chemotherapy intensification (chemoboost) regimen was devised by extrapolating the findings from fractionation studies using radiation alone to combined modality treatment. The rationale was that with radiation therapy alone the most effective time for a concomitant boost has been shown to be the last 2 weeks of radiation therapy. It is recognized that chemotherapy given concurrently with radiation therapy is more effective than when given sequentially hence, the extrapolation of giving chemotherapy as the boost in the last 2 weeks of radiation therapy.Smaller radiation fields are in use with smaller mucosal volumes receiving combined therapy, thus increasing patient tolerance; and It increases treatment intensity to the tumor dense volumes in a time period where accelerated repopulation of surviving clonogens is known to occur during treatmentIt is unnecessary to give chemotherapy concurrently with initial (large) radiation volumes, where radiation therapy alone is capable of sterilizing sub-clinical disease. By delivering the systemic therapies at the end of the radiation, we believed patients would be able to tolerate the therapy best because the toxic effect will not occur until the later portion of the therapy.