The deep inspiration breath-hold technique in the treatment of inoperable non-small-cell lung cancer

Purpose: Conventional radiotherapeutic techniques are associated,vith lung toxicity that limits the treatment dose. Motion of the tumor during treatme nt requires the use of large safety margins that affect the feasibility of treatment. To address the control of tumor motion and decrease the volume o f normal lung irradiated, we investigated the use of three-dimensional conf ormal radiation therapy (3D-CRT) in conjunction with the deep inspiration b reath-hold (DIBH) technique. Methods and Materials: In the DIBH technique, the patient is initially main tained at quiet tidal breathing, followed by a deep inspiration, a deep exp iration, a second deep inspiration, and breath-hold. At this point the pati ent is at approximately 100% vital capacity, and simulation, verification, and treatment take place during this phase of breath-holding. Results: Seven patients have received a total of 164 treatment sessions and have tolerated the technique well. The estimated normal tissue complicatio n probabilities decreased in all patients at their prescribed dose when com pared to free breathing. The dose to which patients could be treated with D IBH increased on average from 69.4 Gy to 87.9 Gy, without increasing the ri sk of toxicity. Conclusions: The DIBH technique provides an advantage to conventional free- breathing treatment by decreasing lung density, reducing normal safety marg ins, and enabling more accurate treatment. These improvements contribute to the effective exclusion of normal lung tissue from the high-dose region an d permit the use of higher treatment doses without increased risks of toxic ity. (C) 2000 Elsevier Science Inc.