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Background and purpose Second malignancies (SM) after external beam radiotherapy (EBRT) or brachytherapy (BT) for prostate cancer (PCa) are rare but serious sequelae. Materials and methods The Surveillance, Epidemiology, and End Results (SEER) database was used to identify men diagnosed with cT1-2N0M0 PCa between 1999 and 2005, who underwent EBRT, BT or radical prostatectomy (RP). Patients with time interval to second malignancy or follow-up shorter than five and two years were excluded for solid and hematopoietic SM analyses respectively. Risks for solid and hematopoietic SM were evaluated via the multivariate Fine and Gray proportional hazards model. Results EBRT and BT resulted in similar increases in solid and hematopoietic SM compared to RP. In subgroup analysis stratified by treatment modality, only the EBRT cohort demonstrated significantly decreased solid and hematopoietic SM in years 2002–2005 compared to years 1999–2001, with adjusted-hazard ratios of 0.752 ( p =0.001) and 0.815 ( p =0.018) respectively. Conclusions EBRT and BT resulted in statistically equivalent increase in both solid and hematopoietic SM compared to RP. EBRT in more recent years resulted in significantly decreased solid and hematopoietic SM, coinciding with increased utilization of IMRT.

Spontaneous brain tumors in 25 pet dogs were diagnosed and treated with a modified Cr scanner. Five or more weekly 9-Gy fractions resulted in marked clinical improvement in most dogs and a significant decrease in tumor size in many dogs without adverse effects from the radiotherapy.

The age dependence of poor cosmesis from breast irradiation and the frequency of micronuclei (MN) in buccal cells provide indirect evidence for the presence of a relatively radiosensitive subpopulation of ataxia telangiectasia (AT) heterozygotes in breast cancer patients

Summary Loading tissue with iodine enhances the radiation dose absorbed from low energy X-rays. In order to test whether this is a useful procedure for treating brain tumors, we infused radiographic contrast media into rabbits carrying VX-2 brain tumors and delivered 15 Gy of 120 kVp X-rays in 3 fractions to the tumor. From CT scans we estimated that the dose enhancement was approximately 30%. The median survival times, after tumor detection on CT, of untreated rabbits, treated with radiation alone, and treated with radiation plus contrast media were 3, 25.5, 38.5 days, respectively. The repeated infusion of contrast media, 3.5 g of iodine per kg of body weight, did not affect kidney function as measured by serum creatinine levels. This method of enhancing radiation dose in brain tumors therefore appears promising.