Retrospective on the Last Quarter-Century in Radiation Oncology

The practice of radiation oncology has been transformed over the past quarter-century in three significant aspects. First was the expanded use of radiation therapy in conjunction with more conservative surgical approaches with the goal of organ preservation. Treatment that accomplished organ preservation represented a seismic paradigm shift in oncology, away from radical surgical and radiotherapeutic approaches that were intended to achieve the cure of localized cancer at any personal cost. Successfully achieving organ preservation without risk to survival outcomes opened the field of research among cancer survivors. This research has examined functional and quality of life outcomes that are now important parameters in today’s comparative effectiveness research. Importantly, patient-centered outcomes are now considered along with survival outcomes, allowing many cancer survivors to return to normal, productive, and even exceptional lives. This message, that we may not only survive cancer, but even “get beyond” the cancer experience provides encouragement to many newly diagnosed cancer patients, and reduces much of the anxiety of cancer screening.

Second was the expansion of multi-disciplinary care to include multi-modality cancer therapy. Previously, each cancer therapy was administered solely, based on fears of additive or supra-additive toxicities. Once it was established that chemotherapeutic agents could be administered during a course of radiation therapy without significant toxicities, the biologics of each therapy could be exploited to improve curative outcomes. This advancement then furthered the opportunity for organ preservation as well as the treatment of more advanced cancers.

Technology is the third, and perhaps most important, advancement in radiotherapy practice. The development of more sophisticated linear accelerators, radiation treatment planning, and the verification of delivered radiation dose ushered in intensity modulated radiation therapy [IMRT]. IMRT proved to be a significant therapeutic advancement that resulted in more precise targeting of radiation dose to the tumor volume and reduced toxicities to uninvolved adjacent tissues. The improvement in the therapeutic ratio from IMRT allowed for the safe administration of higher doses of radiation, and this in turn resulted in improved local control and disease-free survival, particularly in prostate cancer. Recently, proton radiation has continued to build on the IMRT model and its use is currently expanding. Advantageous in pediatric and neuroaxis tumors, the Bragg-Peak effect in proton radiation significantly reduces the entrance and exit dose of radiation, and confines the majority of the radiation to a limited tissue volume. The use of protons for other tumor types is currently under investigation.

Perhaps the most pressing question that is now to be addressed is cost, including both the cost of research and the cost of developing new radiotherapeutic technologies. These costs are passed down to radiation oncology practices, and ultimately to patients and their insurers. Since Medicare and other federal health care programs insure the majority of cancer patients, the American taxpayer also absorbs these costs. Today, healthcare consumes 18% of the gross domestic product and it contributes to burgeoning federal deficits. The Institute of Clinical and Economic Review within the National Institutes of Health has recently performed two comparative effectiveness analyses on the treatment of localized prostate cancer, and this issue has also been addressed by the Medicare Coverage Advisory Committee. We now return to the issue that was addressed first in this quarter century, namely what benefits the patient most with the least personal, and now societal, cost.