Active breathing control guided stereotactic body ablative radiotherapy for management of liver metastases from colorectal cancer.

Background: Liver metastases may occur during the course of several cancer types and may be associated with significant morbidity and mortality. There is paucity of data regarding the utility of Active Breathing Control (ABC) guided Stereotactic Ablative Body Radiotherapy (SABR) for management of Liver Metastases from Colorectal Cancer (LMCC). Our aim is to investigate the role of ABC guided SABR for management of liver metastases. Patients and methods: 42 liver metastases of 29 patients treated with ABC guided SABR between February 2015 and October 2018 were retrospectively assessed for local control (LC), overall survival (OS), and toxicity outcomes. Primary endpoint was LC. Secondary endpoints were OS and treatment toxicity. Results: At a median follow up duration of 16 months (range: 9-74 months), median OS was 20 months and 3 patients were still alive at last follow up. 1-year OS was 83% and 2-year OS was 28%. LC rates were 92% and 61% at 1 and 2 years, respectively. Comparative analysis of Biological Effective Dose (BED) values revealed that higher BED10 values were associated with higher LC rates (p=0.007). While LC rates for BED10 ≥ 100 Gray (Gy) were 94% and 86% at 1 and 2 years, corresponding LC rates for BED10 < 100 Gy were 89% and 36%, respectively with statistical significance (p=0.007). Assessment of acute and late toxicity outcomes revealed that most common toxicity was fatigue, however, no patients had ≥ grade 3 toxicity. Conclusion: ABC guided SABR is an effective and safe treatment modality for LMCC management.

The Effect of the iNOS Inhibitor S-Methylisothiourea and Hyperbaric Oxygen Treatment on Radiation Colitis in Rats.

INTRODUCTION: External radiotherapy is one of the main treatment modalities for a variety of malignancies. However, the lower gastrointestinal tract is sensitive to the ionizing radiation. Hyperbaric oxygen treatment (HOT) has been suggested as a viable treatment for refractory radiation colitis, but the effect of S-Methylisothiourea (SMT) in the radiation colitis have not reported. To investigate the effect of SMT, HOT and the combination of both in an acute radiation-induced enterocolitis model. METHODS: Sixty Sprague-Dawley rats were divided randomly into five equal groups. A single dose of gamma irradiation (25 Gy) was administered through the colorectal region to anesthetized rats. In the control group, we applied 2 ml of saline solution intraperitoneally for five days. In the HOT group, 100-per-cent oxygen at 2.5 atm pressure was applied for five days. In the SMT group, 10 mg/kg/day of SMT was applied intraperitoneally for five days. In the HOT+SMT group, HOT and SMT were both applied in the same dosages as in the preceding two groups. At the end of five days, the rats were sacrificed and colon samples were collected for histological grading. Blood samples were collected to test for : tumor necrosis factor-α (TNF-α), interleukin-10 (IL-10), IL-1ß, transforming growth factor-ß (TGF-ß) and intercellular adhesion molecule-1 (ICAM-1) mRNA. RESULTS: The TNF-α, IL-1ß, IL-10 and TGF-ß levels were reduced by SMT, HOT and HOT+SMT applications (p < 0.05). However ICAM-1 mRNA levels were not significantly lower (p:0.19). The microscopic scores differed significantly between the SMT, HOT and HOT+SMT groups and the control group. There was significant improvement histologically, especially in the HOT+SMT group. When we compared the weight of the rats before and after the study, weight loss was significantly lower in the SMT, HOT and HOT+SMT groups compared with the control group (p < 0.05). CONCLUSION: HOT and SMT together were significantly more effective in preventing weight loss and in reducing inflammation and the severity of colitis histology when compared with HOT and SMT separately.

Evaluation of treatment outcomes of early-stage endometrial cancer radiotherapy: a single center experience.

BACKGROUND: Postoperative adjuvant radiotherapy (RT) in the management of early stage endometrial cancer (EC) is still controversial. Here we report our institutional experience with patients who received postoperative RT for stage I-II EC over a period of 35 years and assess potential predictors of local recurrence (LR), distant metastasis (DM), and overall survival (OS). MATERIALS AND METHODS: A total of 188 patients undergoing postoperative RT for stage IA-II EC between 1977 and 2012 were evaluated. Some 96 received median 46 Gy whole pelvic radiotherapy (WPRT) (range: 40-60 Gy), 37 were given WPRT with vaginal cuff therapy (VCT), and 55 received only VCT either with brachytherapy (BT) or stereotactic body radiotherapy (SBRT). Chemotherapy was given to 5 patients with uterine papillary serous carcinoma (UPSC). Logistic regression analysis was used to assess the effect of clinicopathological factors on LR, DM, and OS. RESULTS: Median follow-up time was 11 years (range: 1-35 years). At the time of analysis, 34 patients were not alive. Of the 15 patients with LR, 7 (46.7%) recurred in the vaginal stump, 5 (33.3%) in the pelvic region, and 3 (20%) in the paraaortic nodal region, while 12 had distant metastasis. UPSC histology (p=0.027), sole VCT (p=0.041), high histologic grade (p=0.034), and age≥71 (p=0.04) were poor prognostic factors on univariate analysis. CONCLUSIONS: In our patients receiving radiotherapy for early-stage EC, grade III disease and age≥71 were associated with shorter OS whereas UPSC histology was an independent predictor for both LR and DM.

Evaluation of linear accelerator-based stereotactic radiosurgery in the management of meningiomas: a single center experience.

PURPOSE: Stereotactic radiosurgery (SRS) has emerged as a viable alternative to surgery in the management of meningioma through exploiting the advantage of being minimally invasive with few complications and acceptable local control rates. The aim of this study was to evaluate the efficiency of linear accelerator (LINAC)-based SRS in the management of meningiomas and to report our experience using this sophisticated technique. METHODS: Between July 1998 and March 2012, 79 patients (42 female, 37 male) were treated using LINAC-based SRS in the Department of Radiation Oncology, Gulhane Military Medical Academy. Median dose was 13 Gy (range 10- 16) prescribed to the 80-95% isodose line encompassing the target. RESULTS: Median follow-up time was 53 months (range 9-112). Median tumor volume was 3.43 cc (range 0.3-14.1). Local tumor control was 89.7% in the 68 patients with adequate follow-up. CONCLUSION: LINAC-based SRS offers a safe and effective treatment alternative to surgery in intracranial meningiomas with high local control rates and low morbidity.

Evaluation of the role of radiotherapy in the management of dermatofibrosarcoma protuberans.

PURPOSE: The aim of this study was to evaluate the role of radiotherapy (RT) in the management of dermatofibrosarcoma protuberans (DFSP). METHODS: Twenty-eight patients treated with RT for DFSP between 1974 and 2012 at Gulhane Military Medical Academy (GMMA) Radiation Oncology Department were retrospectively evaluated. Twenty-five out of 28 patients (89%) received postoperative RT and 3 received definitive RT alone. In the 25 patients receiving postoperative RT, the type of surgical excision was limited excision in 5 patients and wide excision in the remaining 20. Median RT dose was 63.21±3.7 Gy (range 50-70). RESULTS: At a median follow-up of 5 years, 5-year overall survival (OS) for the whole patient group was 93%. No relationship was determined between the total delivered RT dose and OS. The 5-year OS of the 10 female patients was 90% whereas it was 94% for the 18 male patients (p>0.05). Five-year disease-free survival (DFS) for the patients undergoing wide excision with RT vs. those undergoing limited excision with RT was significantly superior (p <0.05) in patients treated with wide excision and RT. CONCLUSION: RT is an effective treatment option for DFSP patients with positive postoperative margins, recurrent disease and selected inoperable cases.

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.

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.