Page 392 - 2014 Printable Abstract Book
P. 392
(SNC01) Pediatric Normal Tissue Effects in the Clinic when, why, and how compared with adults. Louis
S. Constine, MD, FASTRO, University of Rochester, Rochester, NY
With advances in multimodality therapy, childhood cancer cure rates approach 80%. However,
both radiotherapy and chemotherapy may cause debilitating or even fatal “late effects” that are critical
to understand, mitigate, or prevent. QUANTEC (Quantitative Analysis of Normal Tissue Effects in the Clinic)
pointed out the uncertainties relating to chronic adverse effects of adult treatments, but the situation is
more complicated for children in whom a mosaic of tissues develops at different rates and temporal
sequences. Childhood cancer survivors have long life expectancy and may develop treatment-induced
secondary cancers and severe organ/tissue injury long after treatment. Collaborative long-term
observational studies and clinical research programs for survivors of pediatric and adolescent cancer
provide some dose response data for follow-up periods exceeding 40 years. Data analysis is challenging
due the influence of both therapeutic and developmental variables. PENTEC (Pediatric Normal Tissue
Effects in the Clinic) is a group of physicians, physicists and epidemiologists conducting a critical synthesis
of existing literature aiming to (1) develop quantitative evidence based dose/volume guidelines to inform
treatment planning and improve outcomes for survivors of radiation therapy for childhood cancers, (2)
describe relevant physics issues specific to pediatric radiotherapy, and (3) propose dose-volume-outcome
reporting standards to systematically inform future treatment guidelines. This presentation will address
(1) Special considerations for normal tissue radiation response of children/adolescents, e.g. the interplay
between development and RT effects; (2) Epidemiology of organ/tissue injuries and secondary cancers;
(3) Important differences between normal tissue effects in pediatric and adult radiation therapy patients;
(4) Exploration of dose- response differences between children and adults; (5) Identification of situations
where there is ‘interplay’ between organ development and radiation-induced complications.
(SNC02) Challenges and Opportunities in Conducting Proton Therapy Comparative Effectiveness
Research. Justin E. Bekelman, Department of Radiation Oncology, Abramson Cancer Center, Univ. of
Pennsylvania, Philadelphia, PA
Proton therapy comparative effectiveness research is a particular priority. Compared with photon
therapies such as intensity-modulated radiotherapy (IMRT), proton therapy reduces low and intermediate
radiation dose to nearby normal tissue, holding promise as more effective or better tolerated radiation
treatment. However, proton therapy has greater physical and biologic uncertainties. For example,
because we cannot determine where proton therapy terminates in tissue with enough precision, we
routinely overshoot tumor targets to ensure adequate radiation coverage. Proton therapy uncertainties
could affect clinical outcomes; thus, we must establish whether its novel advantages actually translate
into clinical benefits. Randomized trials are essential when existing evidence suggests modest or uncertain
treatment effects, although there is general consensus that observational cohort studies are suitable for
discerning effects when existing evidence suggests larger treatment benefits. This presentation will
discuss the challenges and opportunities in conducting studies to evaluate the potential benefits of proton
therapy.
S. Constine, MD, FASTRO, University of Rochester, Rochester, NY
With advances in multimodality therapy, childhood cancer cure rates approach 80%. However,
both radiotherapy and chemotherapy may cause debilitating or even fatal “late effects” that are critical
to understand, mitigate, or prevent. QUANTEC (Quantitative Analysis of Normal Tissue Effects in the Clinic)
pointed out the uncertainties relating to chronic adverse effects of adult treatments, but the situation is
more complicated for children in whom a mosaic of tissues develops at different rates and temporal
sequences. Childhood cancer survivors have long life expectancy and may develop treatment-induced
secondary cancers and severe organ/tissue injury long after treatment. Collaborative long-term
observational studies and clinical research programs for survivors of pediatric and adolescent cancer
provide some dose response data for follow-up periods exceeding 40 years. Data analysis is challenging
due the influence of both therapeutic and developmental variables. PENTEC (Pediatric Normal Tissue
Effects in the Clinic) is a group of physicians, physicists and epidemiologists conducting a critical synthesis
of existing literature aiming to (1) develop quantitative evidence based dose/volume guidelines to inform
treatment planning and improve outcomes for survivors of radiation therapy for childhood cancers, (2)
describe relevant physics issues specific to pediatric radiotherapy, and (3) propose dose-volume-outcome
reporting standards to systematically inform future treatment guidelines. This presentation will address
(1) Special considerations for normal tissue radiation response of children/adolescents, e.g. the interplay
between development and RT effects; (2) Epidemiology of organ/tissue injuries and secondary cancers;
(3) Important differences between normal tissue effects in pediatric and adult radiation therapy patients;
(4) Exploration of dose- response differences between children and adults; (5) Identification of situations
where there is ‘interplay’ between organ development and radiation-induced complications.
(SNC02) Challenges and Opportunities in Conducting Proton Therapy Comparative Effectiveness
Research. Justin E. Bekelman, Department of Radiation Oncology, Abramson Cancer Center, Univ. of
Pennsylvania, Philadelphia, PA
Proton therapy comparative effectiveness research is a particular priority. Compared with photon
therapies such as intensity-modulated radiotherapy (IMRT), proton therapy reduces low and intermediate
radiation dose to nearby normal tissue, holding promise as more effective or better tolerated radiation
treatment. However, proton therapy has greater physical and biologic uncertainties. For example,
because we cannot determine where proton therapy terminates in tissue with enough precision, we
routinely overshoot tumor targets to ensure adequate radiation coverage. Proton therapy uncertainties
could affect clinical outcomes; thus, we must establish whether its novel advantages actually translate
into clinical benefits. Randomized trials are essential when existing evidence suggests modest or uncertain
treatment effects, although there is general consensus that observational cohort studies are suitable for
discerning effects when existing evidence suggests larger treatment benefits. This presentation will
discuss the challenges and opportunities in conducting studies to evaluate the potential benefits of proton
therapy.
