ABSTRACT
Many pediatric and adolescent cancer patients are treated with carcinogenic chemotherapeutic agents and radiation therapy to achieve permanent control of their malignancy. These modalities may induce a new cancer in the successfully treated patient. To identify disease and treatment factors which increased the risk of occurrence of a second malignant tumor following modern treatment for cancer during childhood or adolescence, we reviewed the courses of 1,406 previously untreated patients who were less than 20 years of age at diagnosis and were treated at Roswell Park Cancer Institute between January 1, 1960 and December 31, 1989. Eighteen patients developed a second malignant tumor, including two meningiomas, 2.65-25.65 years after diagnosis of the first cancer. The actuarial risk of a second malignant tumor was 5.6% at 25 years after diagnosis. Using Cox proportional hazards modelling, we identified prior therapy with BCNU (P = 0.0055) and doxorubicin (P = 0.0254) as the only factors that were significantly associated with the risk of a second malignant tumor. Three second malignant tumors of the central nervous system occurred following treatment with a nitrosourea. Successfully treated patients must be carefully followed to identify treatment related malignant tumors at an early stage.
Subject(s)
Neoplasms, Second Primary/etiology , Neoplasms/therapy , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Child , Child, Preschool , Combined Modality Therapy/adverse effects , Female , Humans , Incidence , Infant , Male , Neoplasms/drug therapy , Neoplasms/radiotherapy , Neoplasms, Second Primary/chemically induced , Proportional Hazards Models , Radiotherapy/adverse effects , Risk FactorsABSTRACT
The radiation dose in the vicinity of metal mandibular implants was measured using lithium fluoride (TLD-100) thermoluminescent dosimeters. Dosimeters were positioned in contact with Vitallium and stainless steel (AO) reconstruction plates. Simple transmission was measured with a solid state detector removed from the implant at a depth of 2.5 cm in a polystyrene phantom. The measurements were made for a 6 mV photon beam from a linear accelerator. At points in front of, but in contact with the metal implants, the dose was greater by 23 percent for Vitallium and 17 percent for stainless steel than that with no implant. At contact behind the implant, the dose was reduced considerably: 14 percent for Vitallium and 13 percent for stainless steel. At remote points behind the implant, the dose was reduced due to attenuation.
