Objectives: We aimed to evaluate the age-related changes of oxidative injury in the brain tissues of rats produced by radiotherapy that is widely used on cancer treatment. Study Design: Fifty-five male Wistar albino rats [ages of rats were 1, 4, 12 weeks (n=10) and 1 year (n=5)] were divided into four groups. Irradiation were performed on a Cobalt-60 unit using a single fraction of 8 Gy. The brain tissues were homogenized and divided into two portions. One portion was used for the measurement of the malondialdehyde (MDA). The other portion was used for the measurement of the protein concentration, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx) enzyme activities. Results: The SOD activity decreased significantly in 1-week-old rats (pl0.05). The decreases in GSHPx and CAT activities were more obvious in 1-week and 1-year-old rats than that in others. No significant changes were observed in adolescent and adult rats. The MDA levels of all groups increased. The highest MDA levels were seen in 1-year-old rats (pl0.05). Conclusion: Ionizing radiation used in radiotherapy affected antioxidant systems and increased MDA levels. These changes were more in the 1-week and 1-year-old rats than in others. This can be due to incomplete development of many systems in newborn rats and the loss of physiological capacities associated with aging in 1-year-old rats. Turkish Baslik: Farkli Yaslardaki Ratlarin Beyin Dokularinda Radyasyonla Induklenen Oksidatif Hasarin Degerlendirilmesi Anahtar Kelimeler: Radyoterapi; yaslanma; oksidan hasar; beyin; serbest radikaller Amac: Bu calismada, kanser tedavisinde yaygin olarak kullanilan radyoterapinin farkli yaslardaki ratlarin beyin dokusunda olusturdugu oksidatif hasarin degerlendirilmesi amaclandi. Calisma Plani: Elli bes Wistar albino tipi erkek rat, 1, 4 ve 12 haftalik (n=10) ve 1 yas (n=5) olmak uzere dort gruba ayrildi. Tum gruptaki ratlara Co-60 cihazi ile 8 Gy tek fraksiyon radyasyon uygulandi. Ratlarin beyin dokulari homojenize edilerek ikiye ayrildi. Bir yarisi ile malondialdehid (MDA) olcumu yapildi. Diger yarisindan elde edilen supernatant ile protein miktar tayini yapildi, superoksit dismutaz (SOD), katalaz (CAT), glutatyon peroksidaz (GSHPx) aktiviteleri olculdu. Bulgular: SOD aktivitesinin 1 haftalik ratlarda anlamli derecede azaldigi bulundu (pl0.05). GSHPx ve CAT aktivitesindeki azalma 1 haftalik ve 1 yasindaki ratlarda daha belirgindi. Ergen ve eriskin ratlarda onemli degismeler olmadi (pl0.05). MDA duzeyinde tum yas gruplarinda artma gozlendi. En yuksek MDA duzeyi 1 yasindaki ratlarda gozlendi (pl0.05). Sonuc: Radyoterapide kullanilan iyonize radyasyon antioksidan sistemleri etkilemekte ve doku MDA duzeylerini artirmaktadir. Bu degisiklikler 1 haftalik ve 1 yasindaki ratlarda daha fazladir. Bu durumun yeni dogan ratlarda henuz bircok sistemin tam olarak yerlesmemis olusundan ve 1 yasindaki ratlarda ise yaslanmaya bagli olarak ortaya cikan fizyolojik kapasitedeki kayiplardan kaynaklandigini soyleyebiliriz.
This study evaluates the use of recursive partitioning analysis (RPA) grouping in an attempt to predict the survival probabilities in patients with brain metastases from non-small-cell lung cancer (NSCLC).Seventy-two patients with brain metastases from NSCLC treated with radiation therapy were included in the study. Sixty-three patients were male and nine patients were female. Their median age was 57 years and their median Karnofsky performance status was 70. At the time of brain metastases, there was no evidence of the intrathoracic disease in 27 patients and the extrathoracic disease was limited to the intracranial disease in 42 patients. In accordance with RPA grouping, 12 patients were in Group 1, 24 patients were in Group 2, and 36 patients were in Group 3. Radiation therapy was delivered to the whole brain at a dose of 30 Gy in 10 fractions in most of the patients.The median survival time was 7 months for Group 1, 5 months for Group 2 and 3 months for Group 3. The survival probability at 1 year was 50% for Group 1, 26% for Group 2 and 14% for Group 3.This study presents evidence supporting the use of RPA grouping in an attempt to predict the survival probabilities in patients with brain metastases from NSCLC.
The orbit is an uncommon primary site for non-Hodgkin's lymphomas (NHL), and it accounts for less than 1% of all sites of primary presentations. We report the experience of the Department of Radiation Oncology at Ankara University Faculty of Medicine with radiation therapy in treatment of patients with stage I primary orbital NHL.From February 1978 through August 1993, 14 patients with stage I primary orbital NHL were treated with radiation therapy. According to the Working Formulation classification, 8 patients had low-grade and 6 had intermediate-grade lymphomas. The most commonly used radiation therapy technique was a single anterior field with a Cobalt-60 unit, delivering 40 Gy in 2 Gy daily fractions. Two patients with intermediate-grade lymphomas received the CHOP regimen following radiation therapy.Follow-up ranged from 0.8 to 18.3 years (median, 10.3 years). Local control was achieved in all patients. Two patients with low-grade lymphomas relapsed locally and were successfully salvaged with radiation therapy. Three patients with intermediate-grade lymphomas failed systemically. Salvage therapy consisted of combination chemotherapy for 2 of them but was unsuccessful. Overall survival probabilities at 2, 5 and 10 years were 78.6%, 61.1% and 52.4%, respectively, for the entire group of 14 patients. Overall, cause-specific and disease-free survival probabilities were higher for patients with low-grade lymphomas than for those with intermediate-grade lymphomas (P = 0.03, P = 0.03 and P = 0.06, respectively). Cataracts were observed in 9 and lacrimal disorders in 4 patients.The study suggests that among stage I primary orbital NHL, low-grade lymphomas could be treated with radiation therapy alone, whereas combination chemotherapy could accompany radiation therapy for intermediate-grade lymphomas.
Background. A conceptual study was undertaken to correlate the clinical target volume and the margins to define the planning target volume with the beam arrangements for a three-dimensional conformal radiation therapy delivery on two patients with prostate cancer having considerably different prostate shapes and volumes. Material and methods. The clinical target volume was defined as prostate and seminal vesicles. Uniform margins of 0.4, 0.8 and 1.2 cm were added around the clinical target volume to define three planning target volumes. Three well-established coplanar beam arrangements were simulated for all planning target volumes. Dose-volume histograms were calculated and quantitatively compared. Results. The mean dose (Dm) for PTVs ranged from 98.7 to 99.9%, with standard deviations ranging from 1.5 to 1.7%. Plan I appeared to be the best considering the Dm for the rectum, whereas Plan II appeared to be the best considering V95 (fraction of volume receiving a dose higher than 95% of the isocenter dose for the rectum). Plan III appeared to be the best considering the Dm and V95 for the bladder and also considering the Dm and V50 for the femur. Conclusions. This conceptual study suggested that the differences in shapes and volumes of planning target volume might be taken into consideration in an attempt to individually establish the optimum beam arrangements for three-dimensional conformal radiation therapy delivery in prostate cancer.
Abstract Introduction The purpose of this study was to assess the incidence, distribution and MRI characteristics of pelvic bone complications after radiation therapy. Methods The medical charts of 345 patients who received pelvic radiation therapy were retrospectively reviewed. A total of 122 patients, 99 women and 23 men, with a mean age of 57 (range 32–87 years) were included in this study. The MR images were retrospectively reviewed by two radiologists. Results Fatty replacement of bone marrow was seen in all patients. Pelvic bone complications and focal red marrow changes were identified in a total of 38 patients (31.1%). Pelvic insufficiency fracture was diagnosed in 17 patients (13.9%, with a total of 64 lesions) and radiation osteitis was diagnosed in 5 patients (4.1%, with a total of 13 lesions). Avascular necrosis of the femoral head was detected in one patient (0.8%). Focal red bone marrow changes were seen in 15 patients (12.3%). The median time from the end of radiotherapy to the diagnosis of pelvic bone complications or changes was 25 months (range 2–45 months). The 1‐, 2‐, and 3‐year cumulative incidences were 22%, 41% and 49%, respectively. The distribution of insufficiency fractures was as follows: sacral ala, sacral body, ilium, acetabulum, pubis and lumbar spinal vertebra. The distribution of radiation osteitis was as follows: sacral ala, ilium and pubis. Conclusion Radiation‐induced pelvic bone complications are not uncommon, and knowledge of characteristic imaging patterns is essential in order to rule out bone metastases and to avoid inaccurate or excessive treatment.
