PURPOSE: Local tumor control and outcome remain poor in patients with advanced non-small-cell lung cancer (NSCLC) treated by external beam radiotherapy. We investigated the therapeutic gain of individualized dose prescription with dose escalation based on normal tissue dose constraints for various hypofractionation schemes delivered with intensity-modulated radiation therapy. METHODS AND MATERIALS: For 38 Stage III NSCLC patients, the dose level of an existing curative treatment plan with standard fractionation (66 Gy) was rescaled based on dose constraints for the lung, spinal cord, esophagus, brachial plexus, and heart. The effect on tumor total dose (TTD) and biologic tumor effective dose in 2-Gy fractions (TED) corrected for overall treatment time (OTT) was compared for isotoxic and maximally tolerable schemes given in 15, 20, and 33 fractions. Rescaling was accomplished by altering the dose per fraction and/or the number of fractions while keeping the relative dose distribution of the original treatment plan. RESULTS: For 30 of the 38 patients, dose escalation by individualized hypofractionation yielded therapeutic gain. For the maximally tolerable dose scheme in 33 fractions (MTD(33)), individualized dose escalation resulted in a 2.5-21% gain in TTD. In the isotoxic schemes, the number of fractions could be reduced with a marginal increase in TED. For the maximally tolerable dose schemes, the TED could be escalated up to 36.6%, and for all patients beyond the level of the isotoxic and the MTD(33) schemes (range, 3.3-36.6%). Reduction of the OTT contributed to the therapeutic gain of the shortened schemes. For the maximally tolerable schemes, the maximum esophageal dose was the dominant dose-limiting constraint in most patients. CONCLUSIONS: This modeling study showed that individualized dose prescription for hypofractionation in NSCLC radiotherapy, based on scaling of existing treatment plans up to normal tissue dose constraints, enables dose escalation with therapeutic gain in 79% of the cases.
PURPOSE: Local tumor control and outcome remain poor in patients with advanced non-small-cell lung cancer (NSCLC) treated by external beam radiotherapy. We investigated the therapeutic gain of individualized dose prescription with dose escalation based on normal tissue dose constraints for various hypofractionation schemes delivered with intensity-modulated radiation therapy. METHODS AND MATERIALS: For 38 Stage III NSCLCpatients, the dose level of an existing curative treatment plan with standard fractionation (66 Gy) was rescaled based on dose constraints for the lung, spinal cord, esophagus, brachial plexus, and heart. The effect on tumor total dose (TTD) and biologic tumor effective dose in 2-Gy fractions (TED) corrected for overall treatment time (OTT) was compared for isotoxic and maximally tolerable schemes given in 15, 20, and 33 fractions. Rescaling was accomplished by altering the dose per fraction and/or the number of fractions while keeping the relative dose distribution of the original treatment plan. RESULTS: For 30 of the 38 patients, dose escalation by individualized hypofractionation yielded therapeutic gain. For the maximally tolerable dose scheme in 33 fractions (MTD(33)), individualized dose escalation resulted in a 2.5-21% gain in TTD. In the isotoxic schemes, the number of fractions could be reduced with a marginal increase in TED. For the maximally tolerable dose schemes, the TED could be escalated up to 36.6%, and for all patients beyond the level of the isotoxic and the MTD(33) schemes (range, 3.3-36.6%). Reduction of the OTT contributed to the therapeutic gain of the shortened schemes. For the maximally tolerable schemes, the maximum esophageal dose was the dominant dose-limiting constraint in most patients. CONCLUSIONS: This modeling study showed that individualized dose prescription for hypofractionation in NSCLC radiotherapy, based on scaling of existing treatment plans up to normal tissue dose constraints, enables dose escalation with therapeutic gain in 79% of the cases.
Authors: Marie Wanet; Antoine Delor; François-Xavier Hanin; Benoît Ghaye; Aline Van Maanen; Vincent Remouchamps; Christian Clermont; Samuel Goossens; John Aldo Lee; Guillaume Janssens; Anne Bol; Xavier Geets Journal: Strahlenther Onkol Date: 2017-07-21 Impact factor: 3.621
Authors: Yijun Ding; Harrison H Barrett; Matthew A Kupinski; Yevgeniy Vinogradskiy; Moyed Miften; Bernard L Jones Journal: Med Phys Date: 2019-06-07 Impact factor: 4.071
Authors: Krista C J Wink; Erik Roelofs; Timothy Solberg; Liyong Lin; Charles B Simone; Annika Jakobi; Christian Richter; Philippe Lambin; Esther G C Troost Journal: Front Oncol Date: 2014-10-29 Impact factor: 6.244
Authors: Stephanie L A Govaert; Esther G C Troost; Olga C J Schuurbiers; Lioe-Fee de Geus-Oei; Ariën Termeer; Paul N Span; Johan Bussink Journal: Radiat Oncol Date: 2012-09-07 Impact factor: 3.481
Authors: Sana D Karam; Zachary D Horne; Robert L Hong; Don McRae; David Duhamel; Nadim M Nasr Journal: Radiat Oncol Date: 2013-07-10 Impact factor: 3.481