Ayse Hicsonmez

Melatonin prevents inflammation and oxidative stress caused by abdominopelvic and total body irradiation of rat small intestine

We investigated the day-night differences in intestinal oxidative-injury and the inflammatory response following total body (TB) or abdominopelvic (AP) irradiation, and the influence of melatonin administration on tissue injury induced by radiation. Rats (male Wistar, weighing 220-280 g) in the irradiated groups were exposed to a dose of 8 Gy to the TB or AP region in the morning (resting period - 1 h after light onset) or evening (activity span - 13 h after light onset). Vehicle or melatonin was administered immediately before, immediately after and 24 h after irradiation (10, 2.0 and 10 mg/kg, ip, respectively) to the irradiated rats. AP (P < 0.05) and TB (P < 0.05) irradiation applied in the morning caused a significant increase in thiobarbituric acid reactive substance (TBARS) levels. Melatonin treatment in the morning (P < 0.05) or evening (P < 0.05) decreased TBARS levels after TB irradiation. After AP irradiation, melatonin treatment only in the morning caused a significant decrease in TBARS levels (P < 0.05). Although we have confirmed the development of inflammation after radiotherapy by histological findings, neither AP nor TB irradiation caused any marked changes in myeloperoxidase activity in the morning or evening. Our results indicate that oxidative damage is more prominent in rats receiving TB and AP irradiation in the morning and melatonin appears to have beneficial effects on oxidative damage irrespective of the time of administration. Increased neutrophil accumulation indicates that melatonin administration exerts a protective effect on AP irradiation-induced tissue oxidative injury, especially in the morning.

Effect of melatonin and time of administration on irradiation-induced damage to rat testes

The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol) or melatonin administered 24 h before (10 mg/kg), immediately before (20 mg/kg) and 24 h after irradiation (10 mg/kg), all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05). Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05). Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonin-treated group.

Cases of glioblastoma multiforme metastasizing to spinal cord

Cases of glioblastoma multiforme (GBM) metastasizing to the leptomeninx or the intramedullary spine are quite rare and prognoses are relatively poor. We present three cases of GBM with spinal metastasis, one of which also had leptomeningeal dissemination. Three patients with GBM were admitted to our clinic for postoperative radiotherapy after surgery. Leptomeningeal metastasis and dissemination were diagnosed with magnetic resonance imaging. Radiotherapy provided only temporary relief from pain with small improvement in neurological deficit but no survival advantage.

Three-dimensional conformal breast irradiation in the prone position

The prone position can be used for the planning of adjuvant radiotherapy after conservative breast surgery in order to deliver less irradiation to lung and cardiac tissue. In the present study, we compared the results of three-dimensional conformal radiotherapy planning for five patients irradiated in the supine and prone position. Tumor stage was T1N0M0 in four patients and T1N1M0 in one. All patients had been previously submitted to conservative breast surgery. Breast size was large in three patients and moderate in the other two. Irradiation in the prone position was performed using an immobilization foam pad with a hole cut into it to accommodate the breast so that it would hang down away from the chest wall. Dose-volume histograms showed that mean irradiation doses reaching the ipsilateral lung were 8.3+/-3.6 Gy with the patient in the supine position and 1.4+/-1.0 Gy with the patient in the prone position (P = 0.043). The values for the contralateral lung were 1.3+/-0.7 and 0.3+/-0.1 Gy (P = 0.043) and the values for cardiac tissue were 4.6+/-1.6 and 3.0+/-1.7 Gy (P = 0.079), respectively. Thus, the dose-volume histograms demonstrated that lung tissue irradiation was significantly lower with the patient in the prone position than in the supine position. Large-breasted women appeared to benefit most from irradiation in the prone position. Prone position breast irradiation appears to be a simple and effective alternative to the conventional supine position for patients with large breasts, since they are subjected to lower pulmonary doses which may cause less pulmonary side effects in the future.

Treatment outcome of nasal and paranasal sinus carcinoma.

PURPOSEnMost authors recommend aggressive management for sinonasal carcinoma treatment. In an attempt to determine the optimal treatment, we assessed the treatment results of our patients with nasal cavity and paranasal sinus carcinoma.nnnMATERIALS AND METHODSnFrom January 1980 to December 2001, 40 patients with malignant tumours of the nasal cavity and the paranasal sinuses were treated. The median follow-up was 6 years. Thirty-two patients had tumours originating from the maxillary sinus. Thirteen patients had T1-T2 (32.5%) tumours and 27 patients had T3-T4 (67.5%) tumours. The treatment method was surgery plus radiotherapy in 24 patients (60%) and radiotherapy alone in 16 patients (40%).nnnRESULTSnThe 5-year overall survival rate was 61%, whereas it was 65% for T1-T2 disease and 56% for T3-T4 disease. The 5-year local control rate was 58%, whereas it was 75% and 50% (p = .219) for T1-T2 and T3-T4 disease, respectively. In multivariate analysis; localization (p = .016), adjuvant radiotherapy (p = .040), local control (p = .05), and gender (p = .013 for female) were statistically significant factors.nnnCONCLUSIONnThe prognosis for patients with tumours of the sinonasal area is dependent on localization, tumour stage, and treatment modality. Because the most common site of treatment failure is the primary site, efforts to maximize local control should be undertaken.

In vivo Study to Evaluate the Protective Effects of Amifostine on Radiation-Induced Damage of Testis Tissue

Objective: To investigate the early protective effects of amifostine against radiation-induced damage on rat testis tissue. Methods: Eighty adult male Wistar rats were randomized to 4 groups: Saline solution was given to group A for control, 200 mg/kg amifostine (WR-2721) to group B, a single fraction of 6 Gy local irradiation to testes in group C and 200 mg/kg amifostine 15–30 min before 6 Gy testicular irradiation to group D. Animals were sacrificed 3 weeks after treatment and their testes were removed for macroscopic, microscopic and ultrastructural histopathological examination. Results: The weights, widths and lengths of testes in the last 3 groups had decreased significantly when compared with the control group, but the decrease in widths after irradiation was found to be significantly less only in the amifostine plus radiation group. There was a significant reduction of testis weights in relation to the individual body weights in the irradiated testes compared with the other groups (p < 0.005), while there was no significant change of testis weight/total body weight ratio in amifostine plus irradiation group. Spermatogonium A and primary spermatocyte counts were also less in the treatment groups, and primary spermatocyte numbers were significantly higher in amifostine plus radiation group when compared with radiation alone group (p < 0.005). Pretreatment with amifostine reduced the decrease of primary spermatocyte counts by a factor of 1.28. Electron microscopic analysis did not show any cytotoxic effect of amifostine alone, and furthermore, ultrastructural findings were normal with the addition of amifostine prior to irradiation, though there was damage in the radiation exposure group. Conclusion: Amifostine when given alone by itself appears to cause adverse alterations in testis tissue; however, it has a radioprotective effect on spermiogenetic cells when used prior to radiation.

Lack of a time-dependent effect of melatonin on radiation-induced apoptosis in cultured rat lymphocytes

Ionizing radiation is widely used for the treatment of solid tumors and it is thought to act by directly targeting tumor clonogens, also known as stem cells. Apoptosis is a genetically programmed mechanism of cell death often characterized by internucleosomal DNA cleavage. Although it has been previously shown that lymphocytes readily undergo apoptosis in patients receiving anticancer drugs or treatment with ionizing radiation, this is the first study to investigate the influence of radiotherapy and melatonin on apoptosis in rat lymphocytes at two different times of the day. Melatonin, a free radical scavenger, is an endogenous neurohormone predominantly synthesized in and secreted by the pineal gland. It has been shown that melatonin inhibits apoptosis in normal cells but it increases the rate of apoptosis in various cancer cells. Therefore, in the present study, the effect of melatonin on apoptosis in cultured lymphocytes was studied after total body irradiation (TBI) was given to rats in the morning (1 HALO) or evening (13 HALO) with morphological and DNA fragmentation analysis. Two‐way analysis of variance (ANOVA) revealed that radiation increased the rate of apoptosis in rat lymphocytes after TBI, and melatonin treatment did not reduce the rate of apoptosis after TBI at either time point. We conclude that the lack of an effect of melatonin on the apoptosis rate in rat lymphocytes might be due to the dose‐dependent effect of melatonin, the time course of apoptosis investigated, or the cell type in which apoptosis was examined.

Evaluation of the Radiation Pneumonia Development Risk in Lung Cancer Cases

BACKGROUNDnConcurrent chemo-radiotherapy is the recommended standard treatment modality for patients with locally advanced lung cancer. The purpose of three-dimensional conformal radiotherapy (3DCRT) is to minimize normal tissue damage while a high dose can be delivered to the tumor. The most common dose limiting side effect of thoracic RT is radiation pneumonia (RP). In this study we evaluated the relationship between dose-volume histogram parameters and radiation pneumonitis. This study targeted prediction of the possible development of RP and evaluation of the relationship between dose-volume histogram (DVH) parameters and RP in patients undergoing 3DCRT.nnnMATERIALS AND METHODSnDVHs of 41 lung cancer patients treated with 3DCRT were evaluated with respect to the development of grade ≥ 2 RP by excluding gross tumor volume (GTV) and planned target volume (PTV) from total (TL) and ipsilateral (IPSI) lung volume.nnnRESULTSnWere admitted statistically significant for p<0.05.nnnCONCLUSIONSnThe cut-off values for V5, V13, V20, V30, V45 and the mean dose of TL-GTV; and V13, V20,V30 and the mean dose of TL-PTV were statistically significant for the development of Grade ≥ 2 RP. No statistically significant results related to the development of Grade ≥ 2 RP were observed for the ipsilateral lung and the evaluation of PTV volume. A controlled and careful evaluation of the dose-volume histograms is important to assess Grade ≥ 2 RP development of the lung cancer patients treated with concurrent chemo-radiotherapy. In the light of the obtained data it can be said that RP development may be avoided by the proper analysis of the dose volume histograms and the application of optimal treatment plans.

Gliosarcoma: a study of four cases

Gliosarcomas (GS) are highly malignant and rare tumors of the central nervous system with a poor prognosis. We report here on four patients with GS, the median survival for whom was 9.25 months. Prognosis of GS remains poor, and a multidisciplinary approach (surgery, radiation therapy, and chemotherapy) seems to be associated with slightly more prolonged survival times.

Outcome of Aggressive Fibromatosis Treated with Radiation Therapy

Introduction The purpose of this study is to report the clinical course and outcome in 7 patients with aggressive fibromatosis. Material and Methods Between the years 2000 and 2003, 7 patients who were treated with combined modalities were evaluated retrospectively. Patients demographic information, including age and gender, tumour characteristics, surgical resection, and the use of radiotherapy were recorded and evaluated. Results The mean patient age was 34 years. The median time to follow-up was 15.5 months. Resection was performed with positive surgical margins in three cases. Three patients were evaluated as inoperable and one patient was treated with debulking surgery. All patients received radiation therapy with a median dose of 51 Gy. At followup, three patients had no evidence of disease, three patients were alive with disease, and one patient died 15 days after radiotherapy. Conclusion Local control is the primary problem in aggressive fibromatosis. There is no appropriate treatment for aggressive fibromatosis and the type of treatment depends on tumour characteristics and location as well as patient characteristics.