Serdar Surenkok

Linear accelerator-based stereotactic radiosurgery in recurrent glioblastoma: a single center experience.

BACKGROUND/AIM Management of patients with recurrent glioblastoma (GB) comprises a therapeutic challenge in neurooncology owing to the aggressive nature of the disease with poor local control despite a combined modality treatment. The majority of cases recur within the high-dose radiotherapy field limiting the use of conventional techniques for re-irradiation due to potential toxicity. Stereotactic radiosurgery (SRS) offers a viable noninvasive therapeutic option in palliative treatment of recurrent GB as a sophisticated modality with improved setup accuracy allowing the administration of high-dose, precise radiotherapy. The aim of the study was to, we report our experience with single-dose linear accelerator (LINAC) based SRS in the management of patients with recurrent GB. METHODS Between 1998 and 2010 a total of 19 patients with recurrent GB were treated using single-dose LINAC-based SRS. The median age was 47 (23-65) years at primary diagnosis. Karnofsky Performance Score was > or = 70 for all the patients. The median planning target volume (PTV) was 13 (7-19) cc. The median marginal dose was 16 (10-19) Gy prescribed to the 80%-95% isodose line encompassing the planning target volume. The median follow-up time was 13 (2-59) months. RESULTS The median survival was 21 months and 9.3 months from the initial GB diagnosis and from SRS, respectively. The median progression-free survival from SRS was 5.7 months. All the patients tolerated radiosurgical treatment well without any Common Toxicity Criteria (CTC) grade > 2 acute side effects. CONCLUSION Single-dose LINAC-based SRS is a safe and well- tolerated palliative therapeutic option in the management of patients with recurrent GB.

Evaluation of active breathing control-moderate deep inspiration breath-hold in definitive non-small cell lung cancer radiotherapy.

The purpose of this study is to evaluate the effect of Active Breathing Control-moderate deep inspiration breath-hold (ABC-mDIBH) on tumor motion and critical organ doses in non-small cell lung cancer (NSCLC) radiotherapy. 23 patients with locally advanced NSCLC were included in the study. All patients were scanned at free breathing and ABC-mDIBH for radiation treatment planning. 3 separate treatment plans were generated for each patient including one plan with ABC-mDIBH and uniform margins, one plan with free breathing and uniform margins, and one plan with free breathing and 3-dimensional non-uniform margins determined by Cone Beam Computed Tomography (CBCT) and XVI Motion View (X-ray Volume Imaging, Elekta, UK). Critical organ dose-volumes and physical lung parameters were comparatively evaluated on 3 separate dose-volume histograms of each patient acquired from planning software. Individual tumor motion of each patient with and without ABC-mDIBH was documented and compared. Use of ABC-mDIBH resulted in statistically significant improvement in physical lung parameters of V20 (lung volume receiving ≥ 20 Gy) and mean lung dose (MLD) which are predictors of radiation pneumonitis (p<0.001). Reduction in spinal cord dose and tumor motion with ABC-mDIBH was also statistically significant (p<0.001). ABC-mDIBH increases normal lung tissue sparing in definitive NSCLC radiotherapy by improving physical lung parameters along with spinal cord dose reduction through exact tumor immobilization. The incorporation of ABC-mDIBH into NSCLC radiotherapy may have implications for potential margin reduction and dose escalation to improve treatment outcomes.

Heel spur radiotherapy and radiation carcinogenesis risk estimation

PurposeRadiotherapy is a nonsurgical alternative therapy of painful heel spur patients. Nonetheless, cancer induction is the most important somatic effect of ionizing radiation. This study was designed to evaluate the carcinogenesis risk factor in benign painful heel spur patients treated by radiotherapy.Materials and methodsBetween 1974 and 1999, a total of 20 patients received mean 8.16 Gy total irradiation dose in two fractions. Thermoluminescent dosimeters (TLD100) were placed on multiple phantom sites in vivo within the irradiated volume to verify irradiation accuracy and carcinogenesis risk factor calculation. The 20 still-alive patients, who had a minimum 5-year and maximum 29-year follow-up (mean 11.9 years), have been evaluated by carcinogenic radiation risk factor on the basis of tissue weighting factors as defined by the International Commission on Radiological Protection Publication 60.ResultsReasonable pain relief has been obtained in all 20 patients. The calculated mean carcinogenesis risk factor is 1.3% for radiation portals in the whole group, and no secondary cancer has been clinically observed.ConclusionRadiotherapy is an effective treatment modality for relieving pain in calcaneal spur patients. The estimated secondary cancer risk factor for irradiation of this benign lesion is not as high as was feared.

Meningeal carcinomatosis: an extremely rare involvement of urinary bladder carcinoma

Meningeal carcinomatosis (MC) is a rare presentation of solid tumors, particularly breast cancer, lung cancer, and malignant melanoma. Recently, the incidence of MC has been reported to be increasing. It has a bad prognosis despite aggressive therapy. The usual clinical presentation is multifocal involvement of the neuraxis, with headache and radicular pain being the most common initial symptoms. The most frequent signs are motor deficits, altered mental status, and cranial nerve involvement. The treatment of MC remains controversial and no straightforward guidelines exist in the literature. MC from urinary bladder tumors is rare. In this case report, we present a 52-year-old male patient with meningeal metastasis from a primary urinary bladder carcinoma along with a review of the related literature.

Dosimetric evaluation of critical organs at risk in mastectomized left-sided breast cancer radiotherapy using breath-hold technique

AIMS AND BACKGROUND The aim of the study was to evaluate the dosimetric impact of the active breathing control-moderate deep inspiration breath-hold (ABC-mDIBH) technique on normal tissue sparing in locally advanced left-sided breast cancer radiotherapy. METHODS AND STUDY DESIGN Twenty-seven consecutive patients with left-sided locally advanced breast cancer referred to our department for adjuvant radiotherapy were enrolled in the study. Each patient was scanned at free breathing and ABC-mDIBH for radiation treatment planning. Two separate radiotherapy treatment plans were generated with and without ABC-mDIBH to investigate the dosimetric impact of ABC-mDIBH in breast cancer radiotherapy. RESULTS Between June 2011 and February 2012, 27 consecutive patients with left-sided locally advanced breast cancer referred to our department for adjuvant radiotherapy were enrolled in the study. Dose-volume parameters of left anterior descending coronary artery, lungs, heart, contralateral breast, esophagus and spinal cord were significantly reduced with the use of ABC-mDIBH (P <0.001). CONCLUSIONS Our study revealed that the use of ABC-mDIBH in the practice of locally advanced mastectomized left-sided breast cancer radiotherapy improves normal tissue sparing with the expected potential of decreasing treatment-related morbidity and mortality. Moreover, the resultant reduction achieved with ABC in doses to the left anterior descending coronary artery, which plays a central role in cardiac perfusion, may have implications for decreasing the potential of radiation-induced cardiac morbidity and mortality.

The management of gastric adenocarcinoma with postoperative chemoirradiation. A non-randomized comparison of oral UFT and 5-FU.

Aims and background We assessed the therapeutic results and tolerability of postoperative chemoradiotherapy with either oral UFT or 5-fluorouracil for carcinoma of the stomach. Methods and study design Forty-six patients treated with chemoradiotherapy following total or subtotal gastrectomy for gastric carcinoma formed the cohort evaluated. The group included 39 males and 7 females whose ages ranged from 21 to 74 years (median, 53 years). In all patients, surgical therapy was the initial approach with a curative intent. The types of operations performed were total gastrectomy in 11 or subtotal gastrectomy in 35 patients. Radiotherapy began from 14 to 161 days after surgery (median, 55 days). Twenty patients received concomitant oral UFT (200 mg/m2), and 26 patients were given 5-fluorouracil (425 mg/m2, iv bolus) concurrently with irradiation consisting of one or two cycles, usually as a 3-day bolus at the start and last 3 days of irradiation therapy for radiosensitizing purposes. The patients were treated using either cobalt-60 or 6 MV photons, and irradiation doses delivered to the tumor bed and regional lymphatics ranged from 40 to 50 Gy (median, 46 Gy). Results Median follow-up for the entire group was 24 months (range, 2–67). The 2-year overall survival of the entire group of patients was 64%. The 2-year overall survival rates for 5-fluorouracil and oral UFT groups were 72% and 66%, respectively (P = 0.3). Treatment-related factors were reviewed to identify any impact on survival. Analyses included type of surgery and dissection, fraction size, the total dose of irradiation and the type of chemotherapy. A significant detrimental effect in survival in the patients treated with D2 dissection compared to the patients treated with D1 dissection was noted (P = 0.01). Overall grade II-III toxicity of oral UFT was significantly lower than 5-FU (4 patients vs 14 patients, P = 0.03). Conclusions Concomitant use of oral UFT with radiation seems to be more tolerable and an equally effective regimen in the treatment of locally advanced gastric cancer compared with 5-fluorouracil. D2 dissection was found to have detrimental effects on survival in this cohort.

Management of pulmonary oligometastases by stereotactic body radiotherapy.

AIMS AND BACKGROUND The aim of the study was to evaluate the feasibility, toxicity and effectiveness of active breathing control-guided stereotactic body radiotherapy in the management of pulmonary oligometastases. METHODS AND STUDY DESIGN Between June 2010 and June 2012, 20 patients (13 males, 7 females) with 31 pulmonary metastases referred to the Department of Radiation Oncology, Gulhane Military Medical Academy were treated using active breathing control-guided stereotactic body radiotherapy. Response Evaluation Criteria in Solid Tumors and Common Terminology Criteria for Adverse Events were used in the assessment of treatment response and toxicity, respectively. RESULTS Assessment of treatment response revealed complete response, partial response, stable disease, and progressive disease in 30%, 25%, 30%, and 15% of the patients, respectively. At a median follow-up of 14 months, local control was 85% and overall survival was 70%, with negligible treatment-related toxicity. CONCLUSIONS Stereotactic body radiotherapy is safe and effective in the management of pulmonary oligometastases. It offers favorable treatment outcomes as a viable non-invasive therapeutic modality.

Evaluation of stereotactic body radiotherapy (SBRT) boost in the management of endometrial cancer.

The purpose of this study is to evaluate the use of linear accelerator (LINAC)-based stereotactic body radiotherapy (SBRT) boost with multileaf collimator technique after pelvic radiotherapy (RT) in patients with endometrial cancer. Consecutive patients with endometrial cancer treated using LINAC-based SBRT boost after pelvic RT were enrolled in the study. All patients had undergone surgery including total abdominal hysterectomy and bilateral salpingo-oophorectomy ± pelvic/paraortic lymphadenectomy before RT. Prescribed external pelvic RT dose was 45 Gray (Gy) in 1.8 Gy daily fractions. All patients were treated with SBRT boost after pelvic RT. The prescribed SBRT boost dose to the upper two thirds of the vagina including the vaginal vault was 18 Gy delivered in 3 fractions with 1-week intervals. Gastrointestinal and genitourinary toxicity was assessed using the Common Terminology Criteria for Adverse Events version 3 (CTCAE v3).Between April 2010 and May 2011, 18 patients with stage I-III endometrial cancer were treated with LINAC-based SBRT boost after pelvic RT. At a median follow-up of 24 (8-26) months with magnetic resonance imaging (MRI) and gynecological examination, local control rate of the study group was 100 % with negligible acute and late toxicity.LINAC-based SBRT boost to the vaginal cuff is a feasible gynecological cancer treatment modality with excellent local control and minimal toxicity that may replace traditional brachytherapy boost in the management of endometrial cancer.

Dosimetric Evaluation of Intensity Modulated Radiotherapy and 4-Field 3-D Conformal Radiotherapy in Prostate Cancer Treatment

OBJECTIVE The purpose of this dosimetric study is the targeted dose homogeneity and critical organ dose comparison of 7-field Intensity Modulated Radiotherapy (IMRT) and 3-D 4-field conformal radiotherapy. STUDY DESIGN Cross sectional study. MATERIAL AND METHODS Twenty patients with low and moderate risk prostate cancer treated at Gülhane Military Medical School Radiation Oncology Department between January 2009 and December 2009 are included in this study. Two seperate dosimetric plans both for 7-field IMRT and 3D-CRT have been generated for each patient to comparatively evaluate the dosimetric status of both techniques and all the patients received 7-field IMRT. RESULTS Dose-comparative evaluation of two techniques revealed the superiority of IMRT technique with statistically significantly lower femoral head doses along with reduced critical organ dose-volume parameters of bladder V60 (the volume receiving 60 Gy) and rectal V40 (the volume receiving 40 Gy) and V60. CONCLUSION It can be concluded that IMRT is an effective definitive management tool for prostate cancer with improved critical organ sparing and excellent dose homogenization in target organs of prostate and seminal vesicles.