National Cancer Institute Workshop on Advanced Technologies in Radiation Oncology December 1, 2006. Edward C. Halperin, M.D., M.A. Dean of the School of Medicine Ford Foundation Professor of Medical Education Professor of Radiation Oncology, Pediatrics, and History University of Louisville.
Edward C. Halperin, M.D., M.A.Dean of the School of MedicineFord Foundation Professor of Medical EducationProfessor of Radiation Oncology, Pediatrics, and HistoryUniversity of Louisville
I have therefore concurred with myself and can assure you that the following views represent the unanimous opinion of the active membership.
Compare, in reference to toxicity and survival, for childhood cancer, radiotherapy with conformal v. stereotactic v. IM/IGRT v. proton, neutron, carbon ions, pions et al. techniques
Outline childhood cancer, radiotherapy with conformal v. stereotactic v. IM/IGRT v. proton, neutron, carbon ions, pions et al. techniques Is the question(s) moot? Is the answer(s) self-evident? What questions didn’t Dr. Vikram ask that he should have? What do the data show in reference to the charge I have been given? What shall we do?
ACGME Requirements in Radiation Oncology for Residency Training “The clinical core curriculum shall include experience in . . . pediatric [tumors]. . . . Residents must treat no fewer than 12 pediatric patients [in 4 years of residency] of whom a minimum of 9 have solid tumors.”
An estimate of the number of pediatric radiation oncology patients per year in the U.S. available for residency training and, potentially, for investigation of radiation treatment modality
124 cases/year ÷ 569 trainees = 0.2 cases/year/trainee
So, in a 4-year residency, casting aside the problem of the “big assumptions,” our trainee will see 0.8 cases of the most common malignancy of childhood.
“… if you want to lead, you have to adjust to the environment in which you find yourself. You cannot wait for it to adjust to you.”J.L. Gaddis, describing Dean Acheson. New Republic, 10/16/06, p.28
Many people assert that the Watergate scandal demonstrates that a free press is essential to democracy. All forms of print and electronic press are pleased to take credit for this achievement.
It can be argued, however, that it wasn’t the press at large who broke the Watergate story, it was two Washington Post reporters: Woodward and Bernstein.
Similarly, we have all seen dramatic images used to promote IMRT/IGRT and proton therapy in childhood tumors. It would be wrong to promote this technology on the basis of, from a public health standpoint, a tiny number of cases.
It is disingenuous to show your hospital administrator proton dosimetry for treating childhood craniopharyngioma as a technique for getting him/her to buy protons for treating bone metastases.
“There is never any reason to give any dose to uninvolved normal tissue. An increase in dose to the tumor will, to a point, improve local control. Achieving these objectives is self-evidently true and does not require randomized prospective trials.”
Perhaps we should worry more about the provision of services to more of the world’s population, and less about inordinately expensive machines of unproven benefit for the wealthy?
“… in a world where more of the 100 largest economic entities are companies (52) than countries (48), a new set of rules will inevitably apply.”Penn. Gaz., 11/12/2006, p. 54
These are some sites/situations in which the target is such that it is nearly impossible to envision an improvement by new technology over standard techniques.
The target is the entire structure and, while IMRT/IGRT could be used to deal with tissue heterogeneity, that is likely to be “a long run for a short slide.” Also, with current technology IMRT may increase second malignant neoplasms.
For some diseases the local control rate is dismal, few children live to suffer late effects, dose escalation has generally been fruitless, and high LET therapy has either been without benefit or made a bad situation worse.
For some diseases, the radiation dose is so low that it is hard to imagine a discernable benefitto technological innovation. (A better dose distribution does not equal a discernable benefit.)
Langerhans cell histiocytosis (4-6 Gy) hard to imagine a discernable benefitPost-transplant lymphoproliferative disorder (4-8 Gy)Transplantation Aplastic anemia Fanconi’s anemia Sickle cell anemia Intentional induction of chimerism
In childhood cancer the push to use IMRT, IGRT, protons, etc. (all external beam techniques) inhibits the prudent use of superior alternatives.
Hearing loss for cisDDP treated patients receiving posterior fossa irradiation (at the price of endocrinopathy?)Neuroendocrine, salivary gland, and TMJ injury in juvenile nasopharngeal angiofibroma and of nasopharngeal carcinoma and rhabdomyosarcoma
“[The] clinical benefits of technological advances [in radiotherapy] including image-guided radiotherapy, are challenging to describe. Randomised data for patients treated with and without image guidance is unlikely to ever exist.”Dawson and Sharpe (PMH)Lancet Oncol 2006;7:848
What shall we do? pediatric 1. Re-engineering Linacs 2. Forensic pathology 3. Investing in late effects clinical research 4. Dose escalation in ependymoma 5. Invest in reasonably-priced radiotherapy solutions in low-income countries 6. Delete pediatrics from most radiotherapy residency programs 7. Establish late effects of childhood cancer fellowship trainingThank you.