Background Stereotactic body radiotherapy (SBRT) in pediatric malignancies offers precise, high-dose radiation delivery to tumors while minimizing exposure to surrounding healthy tissues—an important consideration in preventing adverse effects on growth and development. The use of SBRT in pediatric oncology has been increasing; however, clinical data and outcome reports remain limited. This study aimed to evaluate local control (LC), progression-free survival (PFS), overall survival (OS), and toxicity rates following SBRT in pediatric patients with extracranial metastases. Materials/Methods Between 2012 and 2024, 21 pediatric patients treated in our department for extracranial lesions of malignant tumors using linear accelerator–based, CT-guided SBRT were retrospectively analyzed. LC and OS were assessed using the Kaplan–Meier method. Results All patients received definitive SBRT for oligometastatic disease. At diagnosis, 13 patients (61.9%) presented with metastatic disease. The median follow-up time was 10 months (range, 4–157), and the median age was 13 years (range, 4–17). Ewing sarcoma was the most common histologic subtype (52.4%). A total of 37 extracranial lesions were irradiated; 21 (56.7%) were bone metastases. SBRT was delivered to four sites in one patient and to three simultaneous sites in five patients.The median number of fractions was 5 (range, 3–5), with a median dose per fraction of 5 Gy (range, 5–9 Gy). Median BED₁₀and EQD₂were 37.5 Gy (31.25–72) and 31.2 Gy (31.2–60), respectively. The median PTV volume was 68 cm³ (range, 2.1–541 cm³). Median PFS was 8 ± 1.29 months (95% CI: 5.4–10.5), and median OS was 12 ± 3.07 months (95% CI: 5.98–18).Local recurrence occurred in 10 patients (47.6%), of whom 6 (60%) had in-field recurrences. Among these, 3 of 6 patients had osteosarcoma histology. One- and two-year LC rates were 25% and 18%, respectively, while OS rates were 49% and 30%. There was a statistically significant difference in both PFS and OS among histologic subtypes (p = 0.03 and p = 0.004, respectively). No ≥Grade 3 acute or late toxicity was observed. Conclusion SBRT was well tolerated in pediatric patients, with minimal toxicity. However, longer follow-up is required to assess late effects. The preference for more moderate fractionation schemes due to large tumor volumes and younger age groups may also be related to higher rates of in-field recurrence in histologies that are more resistant to radiotherapy. Further studies are warranted to establish the optimal SBRT dose and fractionation parameters for pediatric malignancies.

Purpose: Whole-brain irradiation is commonly used for patients with multiple brain metastases and poor performance status, often requiring rapid treatment planning. This study compares cone-beam computed tomography (CBCT)-based planning to conventional CT simulation for whole-brain radiotherapy (RT) to evaluate dosimetric differences and cost-effectiveness. Materials and Methods: Ten patients receiving palliative whole-brain RT at Acıbadem Atakent Hospital were included. Both CT simulation and CBCT images were used to create 3D conformal RT (3DCRT) plans. Brain and lens contours were marked, and dose calculations were performed with 6MV photon energy. Plans were normalized to ensure 95% of the target volume received 99,5% of the prescribed dose. Key metrics, including conformity index (CI), lens doses, maximum brain dose, brain volume, Hounsfield Units (HU), and monitor units (MU), were compared using the Wilcoxon test. Findings: Results showed no significant differences in lens contouring or CI between CBCT- and CT-based plans. Brain volume was significantly larger in CBCT images, and CBCT-based plans had higher maximum doses and MU values due to HU adjustments. However, HU values themselves did not differ significantly. Conclusion: CBCT-based planning demonstrated shorter processing times and reduced workload, making it more efficient economically. With proper calibration, CBCT planning offers a viable alternative for urgent whole-brain RT planning, providing comparable dose and plan quality to CT-based methods.

Radiotherapy (RT) in lung cancer emphasizes the use of modern techniques due to the size of the treatment area and doses to critical organs. This study aimed to evaluate dosimetric differences between Helical Tomotherapy (HT) and Volumetric Arc Radiotherapy (VMAT) plans and which technique is more appropriate in patients with stage IIIB inoperable non-small cell lung cancer (NSCLC). Fifteen patients with stage IIIB inoperable NSCLC and a planning target volume (PTV) >200 cc or length >10 cm, treated between January 2024 and December 2024, were included. A prescription of 60 Gy in 30 fractions was applied. Plans were evaluated using conformity index (CI), homogeneity index (HI), and doses to critical organs. The median PTV volume was 385 cc (range: 213–615 cc). Both planning techniques covered 98% of the prescribed dose (p = 0.887), but HT demonstrated significantly better HI (p = 0.011). HT also yielded significantly lower doses in total lung V5, contralateral lung V5, heart mean dose, heart V50, and spinal cord max dose. Esophageal doses showed no significant differences. Although dose constraints for the esophagus were met in both planning systems, a lower dose was achieved with HT." Modern planning systems can achieve desired doses in large volume targets while remaining within dose limits for organs at risk. HT provided significant advantages in critical organ sparing and better homogeneity in dose distribution. The selection of the appropriate technique should be determined based on the characteristics of the tumor and the specific needs of the patient.

ABSTRACT:The adenoid cystic carcinoma (ACC) of Bartholin's gland is a very rare tumor that usually grows aggressively due to perineural invasion. Although there is no guideline for the treatment due to the small number of patients, the primary treatment is considered as surgery. Adjuvant radiotherapy has also been shown to be beneficial. Three cases, which were histopathologically confirmed as ACC of Bartholin's gland and received adjuvant radiotherapy treatment, were presented in this study.

Abstract Objective Preoperative radiotherapy has been used with high-grade bulky tumors or tumors close to neurovascular structures in patients with osteosarcoma. Hypofractionated radiotherapy protocols have been recently preferred upon understanding its similar efficacy and non-increased adverse effects. We aimed to evaluate the impact of preoperative hypofractionated radiotherapy in patients with primary or recurrent osteogenic osteosarcoma. Methods A single-center, retrospective study was performed on patients with primary or recurrent osteogenic osteosarcoma who underwent preoperative hypofractionated radiotherapy between 2014 and 2020. The patients preoperatively received a total dose of 30 to 35 Gy with ten fractions. The demographic and clinical characteristics of the patients were recorded. The patients were grouped as good (necrosis rate of ≥ 90%) and poor responders (necrosis rate of < 90%). Survival rates, including recurrence-free, metastasis-free, and overall, were calculated. Results There were 20 patients with a median age of 17 years. Negative surgical borders were obtained in 88.9% of 18 patients amenable to limb-sparing surgery after preoperative radiotherapy. The median percentage of necrosis was 88.5%, ranging from 30–100%. Half of the patients (50.0%) were good responders. There were two local recurrences (10.0%) and nine metastasis (45.0%). The lungs were the most common for metastasis (40%). The overall mortality and five-year survival rates were 40.0% and 45.0%. The median recurrence-free, metastasis-free, and overall survival were 49.4, 34.4, and 56.1, respectively. Conclusion Preoperative hypofractionated radiotherapy with or without chemotherapy might be a treatment modality in osteosarcoma patients for limb-conserving or that are resectable but hard to achieve clean margins due to local involvement.

OBJECTIVE Adjuvant radiotherapy (RT) has been used often at breast cancer treatment. RT techniques differ from each other in terms of accessibility and applicability. We aimed to compare the dosimetric evaluations of four modern RT techniques through ten breast cancer patients that had been treated previously with intensity-modulated RT (IMRT) technique.METHODS A single-center dosimetric study was performed based on treatment plannings of left-sided breast cancer patients. The patient's images, simulated at computed tomography with deep inspiration breath hold technique between March and June 2023, were used. Four different techniques, field-in-field (FinF), dynamic IMRT (dIMRT), volumetric modulated arc treatment (VMAT), and helical therapy (HT) were created on each patient image. Conformal index (CI) and homogeneity index (HI) were calculated. Mean doses of heart, contralateral breast, volume of doses 5 Grey (Gy) (V5) and 10 Gy (V10) of left lung and to -tal lungs were also calculated for each plan and the descripted and comparisons analysis was performed. RESULTS The better results of CI and HI were reported with dIMRT, VMAT, and HT techniques. However, these approaches were expected with increased percentage of lower doses at organs at risk (OAR). The lowest of V5 of left and total lungs, mean heart, and contralateral breast doses were achieved with FinF tech-niques, HT values were observed similar to FinF by these factors at OAR. Particularly, the lowest V20 value was demonstrated at HT techniques.CONCLUSION Adjuvant RT techniques at breast cancer still carry controversial subtitles. New technologic improve-ments might be indispensable and treatment plannings should be based on the individual properties of patients.

Background/Aim: Significantly lower heart doses can be achieved by breath-hold technique at left-sided breast cancer radiotherapy (RT). We see high doses at organs at risk such as lung, heart, and contralateral breast during right-sided breast cancer RT planning especially in the presence of RT indication for mammaria interna (MI) lymph nodes. This study compared RT-planning methods that are conformal with intensity-modulated RT (IMRT) with breath holding and free breathing for right-sided breast cancer RT including full axillary and MI lymph node fields. Methods: Computed tomography (CT) simulations were performed using free-breath (FB) and breath-hold (BH) methods in 10 patients with right-sided breast cancer. A total of 40 RT treatment plans were calculated. Right-sided breast, level 1-2-3 axillary regions, and MI regions served for the target-planning volume. Left-sided breast, heart, as well as right-sided and left lungs were contoured as critical organs according to the atlas of the "Radiation Therapy Oncology Group." We used a Varian Eclipse v.13 for treatment planning. Conformal “FieldinField” RT (FinFRT) and dynamic IMRT (dIMRT) planning were performed separately for each patient over breath-hold and free-breath images. For PTV, 50 Gy was prescribed in 25 fractions and optimized such that the planned target volume (PTV) remained between 95% and 110% of the dose. The mean and maximum doses of the heart, V5 and V20 of the lungs, as well as V95 doses for MI were recorded. Statistical analyses were performed with SPSS version 22, and a paired t-test was used for comparison. Results: Four treatment plans (FB FinFRT, BH FinFRT, FB dIMRT, BH dIMRT) were made separately for 10 patients. For comparison, common FB FinFRT plans were accepted as the baseline plan. As expected, there were no significant differences in PTV coverage. The mean dose received by 95% of the MI volume was between 42.27 Gy and 42.4 Gy. For the maximum heart dose, the breath hold technique had no significant effect on plans. The lowest average maximum heart dose was seen in the BH FinFRT group. Mean heart doses are between 1.28 Gy – 4.85 Gy. There was no significance between BH FinFRT and FB FinFRT plan (P=0.504), and there was a significant difference for heart mean dose versus dIMRT plans (P=0.001). The mean V20 of the lungs ranged from 11.9 to 17.8. There was a significant decrease in V20 with BH or FB dIMRT plans (P=0.001). There was no difference between BH FinFRT (P=0.138). On the contrary, lung V5 values were significantly higher in dIMRT plans, and the lowest mean V5 value was seen in BH FinFRT plan. Conclusion: With the BH method, lower doses (but not significantly lower doses) were obtained in critical organ doses. There was a significant decrease with FinFRT plans in terms of heart mean and maximum dose and lung V5 percentages. The dIMRT plans were significant only in lung V20 percentages. When planning RT, we recommend evaluating all treatment techniques individually for right-sided breast cancer patients to obtain lower doses in critical organs.

Radiation oncology is a field of medicine that has been rapidly growing with advances in technology, radiobiology, treatment algorithms and quality of life of modern radiotherapy over the last century. In the context of these advances, it is critical to be aware of the role of the young radiation oncologists and enable them to discover new perspectives. For this purpose, "The Young Radiation Oncologists Group" (GROG) has been established by the Turkish Society for Radiation Oncology (TROD), a subgroup which has focused on the professional developments, early career and integrating into the TROD family while supporting education and innovative research of young radiation oncologists. The purpose of this paper was to outline the structure and responsibilities of GROG and its scientific and social activities within TROD and in its own right.

The urachus is a canal between the allantois and the early fetal bladder. Urachal carcinoma is a rare and aggressive type of bladder cancer. This cancer usually presents at an advanced stage. We report a 70-year-old patient with malignant transformation of urachal cyst several years later. The patient was treated with partial cystectomy and adjuvant radiotherapy. A review of the published literature is also presented.

OBJECTIVE We developed “sandglass” technique using volumetric arc therapy (VMAT) with two avoidance sectors and make comparison between two intensity-modulated radiotherapy (IMRT) techniques, “butterfly” with three anterior and two posterior beams, and “rainbow” with five anterior beams. Conformity index (CI), homogeneity index (HI), organ of risk doses, and monitor unit (MU) values are used as evaluation tools.

AIMS:To evaluate the results of chemoradiation with intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT) for the treatment of anal canal cancer patients at three institutions that had advanced devices. MATERIALS AND METHODS:A retrospective analysis was performed for patients treated with 5-fluorouracil and mitomycin-based chemotherapy and IMRT or VMAT for anal cancer from 2011 to 2013. Complete response (CR) rates, colostomy-free survival (CFS), disease-free survival (DFS), overall survival (OS), and toxicities were investigated. Toxicities were evaluated with the Common Terminology Criteria for Adverse Events, Version 3.0. RESULTS:Fifteen patients were included in the analysis. The majority of patients had T2 (53.3%) and N0 (40%) disease according to the staging system that was developed by the American Joint Committee on Cancer. CR was observed in 14 patients (93%), and the median follow-up was 26 months (13-42 months). The 3-year CFS, DFS, and OS were 86%, 86%, and 88%, respectively. Acute Grade 3 toxicities were observed as 6% of hematological, 26% of gastrointestinal, and 26% of dermatological. CONCLUSION:Early results confirm that IMRT or VMAT for anal cancer treatment reduces acute toxicities while maintaining high control rates.

Purpose:The aim of this study was to evaluate the nutritional status of patients receiving definitive or adjuvant radiotherapy with head and neck, pelvic, thorax and intraabdominal tumors and to determine their weight loss. Patients and Methods:40 patients admitted to the radiation oncology outpatient clinic since 01.11.2015 and planned head, thoracic, abdominal and pelvic radiotherapy were included in the study. The patients were evaluated before the treatment and in addition to the daily nutrition of the patients, special nutritional support was provided as 35 kcal/kg energy, 2gr/kg protein and 15 mg glutamine daily. The weight loss of the patients evaluated by radiation oncologist and nurse was recorded. Results:The mean age was 61 years (range, 39-86 years). 9 patients with lung cancer were over 70 years old and had definitive radiotherapy. All patients underwent radiotherapy treatment without interrupting treatment, except for a 86-year-old patient scheduled for adjuvant therapy with gastric cancer and two patients with lung cancer receiving chemoradiotherapy. 72% of the patients continued their nutritional support during the entire treatment. When weight loss was evaluated, only 8% of patients had more than 10% weight loss. According to the nutritional support, weight loss rates were found to be significantly lower in patients who fully applied nutritional support (p: 0.003). Conclusion:Early and intense nutritional support of cancer patients with risk of malnutrition may lead to less weight loss during radiotherapy.

OBJECTIVE:We identified factors influencing outcomes in patients with medically inoperable early stage lung cancer (MIESLC) treated with stereotactic ablative radiation therapy (SABR) at 14 centers in Turkey. MATERIALS AND METHODS:We retrospectively analyzed 431 patients with stage I-II MIESLC treated with SABR from 2009 through 2017. Age; sex; performance score; imaging technique; tumor histology and size; disease stage radiation dose, fraction and biologically effective dose with an α/β ratio of 10 (BED10 ); tumor location and treatment center were evaluated for associations with overall survival (OS), local control (LC) and toxicity. RESULTS:Median follow-up time was 27 months (range 1-115); median SABR dose was 54 Gy (range 30-70) given in a median three fractions (range 1-10); median BED10 was 151 Gy (range 48-180). Tumors were peripheral in 285 patients (66.1%), central in 69 (16%) and <1 cm from mediastinal structures in 77 (17.9%). Response was evaluated with PET/CT in most cases at a median 3 months after SABR. Response rates were: 48% complete, 36.7% partial, 7.9% stable and 7.4% progression. LC rates were 97.1% at 1 year, 92.6% at 2 years and 91.2% at 3 years; corresponding OS rates were 92.6%, 80.6% and 72.7%. On multivariate analysis, BED10 > 100 Gy (P = .011), adenocarcinoma (P = .025) and complete response on first evaluation (P = .007) predicted favorable LC. BED10 > 120 Gy (hazard ratio [HR] 1.9, 95% confidence interval [CI] 1.1-3.2, P = .019) and tumor size (<2 cm HR 1.9, 95% CI 1.3-3, P = .003) predicted favorable OS. No grade 4-5 acute side effects were observed; late effects were grade ≤3 pneumonitis (18 [4.2%]), chest wall pain (11 [2.5%]) and rib fracture (1 [0.2%]). CONCLUSION:SABR produced encouraging results, with satisfactory LC and OS and minimal toxicity. BED10 > 120 Gy was needed for better LC and OS for large, non-adenocarcinoma tumors.

AIM To evaluate the efficacy and tolerability of neoadjuvant hyperfractionated accelerated radiotherapy (HART) and concurrent chemotherapy in patients with locally advanced infraperitoneal rectal cancer. METHODS A total of 30 patients with histopathologically confirmed T2-3/N0+ infraperitoneal adenocarcinoma of rectum cancer patients received preoperative 42 Gy/1.5 Gy/18 days/bid radiotherapy and continuous infusion of 5-fluorouracil (325 mg/m2). All patients were operated 4-8 wk after neoadjuvant concomitant therapy. RESULTS In the early phase of treatment, 6 patients had grade III-IV gastrointestinal toxicity, 2 patients had grade III-IV hematologic toxicity, and 1 patient had grade V toxicity due to postoperative sepsis during chemotherapy. Only 1 patient had radiotherapy-related late side effects, i.e., grade IV tenesmus. Complete pathological response was achieved in 6 patients (21%), while near-complete pathological response was obtained in 9 (31%). After a median follow-up period of 60 mo, the local tumor control rate was 96.6%. In 13 patients, distant metastasis occurred. Disease-free survival rates at 2 and 5 years were 63.3% and 53%, and corresponding overall survival rates were 70% and 53.1%, respectively. CONCLUSION Although it has excellent local control and complete pathological response rates, neoadjuvant HART concurrent chemotherapy appears to not be a feasible treatment regimen in locally advanced rectal cancer, having high perioperative complication and intolerable side effects. Effects of reduced 5-fluorouracil dose or omission of chemotherapy with the aim of reducing toxicity may be examined in further studies.

Objective To investigate the role of positron emission tomography (PET) and magnetic resonance imaging (MRI) in evaluating the feasibility of skin-sparing mastectomy in patients with locally-advanced breast cancer (LABC) who will undergo neoadjuvant chemotherapy (NAC) by evaluating the sensitivity and specificity of PET and MRI compared with skin biopsy results before and after NAC treatment. Methods Patients with LABC who were treated with NAC between November 2013 and November 2015 were included in this study. Demographic, clinical, radiological and histopathological features of the patients were recorded. Results A total of 30 patients were included in the study with a mean age of 52.6 years (range, 35-70 years). Sensitivity and specificity for detecting skin involvement in LABC was 100%/10% (62%/85%) with MRI and 60%/80% (12%/92%) with PET before (after) NAC, respectively. When radiological skin involvement was assessed in relation to the final histopathological results, the preNAC PET results and histopathological skin involvement were not significantly different; and there was no difference between postNAC MRI and histopathological skin involvement. Conclusions As preNAC PET and postNAC MRI more accurately determined skin involvement, it might be possible to use these two radiological evaluation methods together to assess patient suitability for skin-sparing mastectomy in selected patients.

To review treatment outcomes for SABR in medically inoperable early stage lung cancer (NSCLC) patients treated by Turkish Radiation Oncology Group (TROG) member centers. Between 2009 and 2017, a total of 386 patients with NSCLC treated with SABR in 12 TROG centers. Patient, disease, and treatment related prognostic factors were analyzed. Primary endpoints were, overall survival (OS), progression free survival (PFS), local control (LC) and regional control (RC) and radiation-related toxicities. Median follow-up was 15 months. The median age at diagnosis was 72 years (43-93) and 79% were men. Median tumor size was 30 mm (5 - 78 mm). Seventy-two percent of the patients have histologically confirmed diagnosis whereas 28% of patients were treated with clinical and radiological findings only without pathological diagnosis. Staging was as follows; T1N0 in 215, T2N0 in 166, T3N0 in 2 and T4N0 in 3 patients because of bilaterally tumors. Median SABR dose was 54Gy (30-70Gy), corresponding to a biological equivalent dose (BED) of 112Gy (48 - 180Gy) administered in median 5 (1-10) fractions. Response evaluation was made either with PET/CT or CT in median 3 months after SABR and complete response, partial response, stable disease and progression rates were 48%, 36%, 5.7% and 0.5%, respectively. The cumulative locoregional failure rate was 15%. Among these, 23 were local (6%) and 35 regional (9%) failures. Distant failure was reported in 67 (17%) patients. One to 3 years LC and RC rates were 97%, 91% and 93%, 86%, respectively. One and 3 years PFS and OS were 88%, 72% and 90%, 65%, respectively. At their last follow up 271 patients (71%) were alive. Prognostic factors associated with LC, RC and OS were summarized in table 1. No severe acute side effects were observed. Overall 18 patients experienced ≥ grade 3 pneumonitis, 11 patients had chest wall pain and 1 patient had rib fracture. The results of this retrospective study have shown that SABR is a promising technique with satisfactory LC and OS rates and minimal toxicity in patients with medically inoperabl NSCLC.Abstract TU_25_3568; Table 1Prognostic factors affecting overall survival and recurrenceUnivariateMultivariateLocal Control @ 3 yearsBED10 ≥90GyBED10 ≥90, 92% BED10 <90, %71 p=0.003HR:3.6, 95% CI (1.3-9.9) p=0.011Tumor Size (17mm)≤17mm, 100% >17mm, 89% p=0.035p=0.98Histology (Squamous/Adeno)Adeno, 96% Squamous, 88% p=0.006HR:2.2, 95% CI (1.2-4.0) p=0.008PET/CT Response (Complete/Partial)CR, 96% PR, 74% p<0.0001HR:3.5, 95% CI (1.6-7.5) p=0.002Regional Control @ 3 yearsTumor Size (30mm)≤30mm, 95.5% >30mm, 77.5% p=0.025HR:2.1, 95% CI (1.1-4.2) p=0.028PET/CT Response (Complete/Partial)CR, 87% PR, 62% p<0.033p=0.06Overall Survival @ 3 yearsTumor Size (28mm)≤28mm, 69,6% >28mm, 59,8% p=0.009HR:1.6;95% CI (1-2.5) p=0.03Abbreviations: BED = Biological Effective Dose; HR = Hazard Ratio; CR = Complete Response; PR = Partial response. Open table in a new tab

AIM:Radiation-induced fibrosis (RIF) has since long been considered as irreversible. Further understanding of its mechanisms has led to trials investigating RIF treatment and prevention. The effect of superoxide dismutase (SOD)-gliadin, an oral form of SOD that resists gastrointestinal inactivation, on RIF treatment was evaluated in this experimental study.MATERIALS AND METHODS:A total of 36 Wistar albino mice were randomly distributed into four groups. According to group, 25 Gy radiation or sham-radiation were performed on day 0. Acute and late reactions were recorded. After 6 months, mice were treated with SOD-gliadin, 10,000 units per kg per day, or placebo. SOD-gliadin and placebo treatments were administered daily for 8 days by oral gavage. Later the mice were sacrificed, dissected and histopathologically analyzed. Accumulated hyaline and collagen at the dermis is an indicator of fibrosis. Therefore measurements of the dermal thickness were used to quantify the degree of RIF. Additionally, the morphological changes were analyzed, and the differences reported.RESULTS:The mean and standard deviation for dermal thickness were 0.45±0.09 mm in the sham-irradiated placebo-treated group, 0.51 mm±0.16 mm in the sham-irradiated SOD-gliadin-treated group, 0.92 mm±0.23 mm in the irradiated placebo-treated group and 0.71 mm±0.17 mm in the irradiated SOD-gliadin-treated group. The difference in mean dermal thickness between irradiated placebo-treated and irradiated SOD-gliadin-treated mice was statistically significant (p=0.002).CONCLUSION:Quality of life while prolonging survival has an increasing importance in patients with cancer. RIF can be a crucial problem after all radiotherapy modalities. SOD-gliadin has advantageous effects on conditions that call for an increased expression of antioxidant enzymes. The results of our study suggest that oral SOD-gliadin may prevent or ameliorate RIF and patients can benefit from the positive effects of SOD.