Triggered Imaging With Auto Beam Hold and Pre-/Posttreatment CBCT During Prostate SABR: Analysis of Time Efficiency, Target Coverage, and Normal Volume Changes.

PURPOSE: Our purpose was to investigate time efficiency and target coverage for prostate stereotactic ablative radiation therapy (SABR) using triggered imaging (TI) and auto beam hold. METHODS AND MATERIALS: A total of 20 patients were treated with volumetric modulated arc-based SABR. Treatment verification consisted of pre- and post-radiation therapy cone beam computed tomography (CBCT) with gold marker-based TI every 3 seconds. In case of ≥3 mm (deviation limit) displacement, the treatment was interrupted and imaging-based correction was performed. Beam interruptions, intrafractional shifts, and treatment times were recorded. Prostate, rectum, and bladder were delineated on each CBCT. Target coverage was evaluated by comparing the individual prostate delineations with 98% isodose contour volumes (% of the evaluated volumes exceeding the reference). Both inter- and intrafractional changes of bladder and rectal volumes were assessed. RESULTS: The average overall treatment time (±standard deviation) was 18 ± 11 min, with a radiation delivery time of 6 ± 3 min if no intrafractional CBCT acquisitions were necessary (91% of fractions). On average, 1.2 beam interruptions per fraction were required with 0/1 correction in 71% of the fractions. The mean residual 3-dimensional shift was 1.6 mm, exceeding the deviation limit in 8%. In the case of intrafractional CBCT and/or ≥2 corrections the treatment time dramatically increased. The 98% isodose lines did not encompass the prostate in only 8/180 (4%) evaluations in 6 different patients, leading to a loss of D98 between 0.1%-6% as a worst case scenario. The bladder volumes showed significant increases during treatment (P < .01) while rectal volumes were stable. CONCLUSIONS: Time efficiency of TI + auto beam hold with 3 mm/3 sec threshold during prostate SABR is comparable with competitive techniques, resulting in minimal 3-dimensional residual errors with maintained target coverage. Technical developments are necessary to further reduce radiation delivery time. Use of CBCT allowed full control of rectal volumes, while bladder volumes showed significant increases over time.

[Preoperative systemic treatment of locally and locoregionally advanced high-risk endometrial cancer]. / Lokálisan és lokoregionálisan elorehaladott, magas kockázatú endometriumtumorok mutét elotti szisztémás elokezelése.

Introduction: Endometrial cancer is the most common invasive gynecologic malignancy in developed countries. The best survival rates are expected after surgical removal, thus the aim of a complex treatment is to achieve resecability in locally and locoregionally advanced disease. Aim: The primary purpose of this study was to evaluate if the neoadjuvant systemic treatment leads to better overall survival compared to irradiation solely. Method: From January 2015 to December 2018, we enrolled 28 patients diagnosed with irresecable, locally and locoregionally advanced high-risk endometrial carcinoma. Patients were treated by neoadjuvant paclitaxel-carboplatin, then radical hysterectomy, bilateral oophorectomy and lymphadenectomy were performed. Results: After administration of 6 cycles of carboplatin-paclitaxel, the control MR test showed tumor shrinkage in all patients. Complete resection was achieved in the case of every patient. Tumor residuum in lymph nodes was verified in 4 cases by pathological evaluation. The 2-year survival and the 2-year progression-free survival rates were 65,1% and 66,1%, respectively. The median overall survival was 16,5 months. Conclusion: Neoadjuvant treatment can be an effective approach in providing the conditions for complete tumor resection, which may result in survival advantage. Despite multimodal treatment, prognosis is poor. Orv Hetil. 2020; 161(11): 425-433.

[Setup margin for head-and-neck cancer patients receiving 2D-2D and 3D image-guided intensity-modulated radiation therapy]. / A beállítási biztonsági margó nagyságának meghatározása fej-nyak daganatok 2D-2D és 3D képvezérelt intenzitásmodulált sugárkezelése esetén.

INTRODUCTION: Image-guided intensity-modulated radiation therapy is essential for oncology treatment of head-and-neck cancer patients. AIM: MV-kV and CBCT modalities were compared in case of IGRT treatment for head-and-neck cancer patients. Setup error, setup margin (SM), imaging and evaluation times and imaging doses were analyzed. METHOD: Eight patients' elective treatment was evaluated, 66 orthogonal MV-kV images and 66 CBCT series were acquired. Setup error measurement was based on bony manual image registration in three translational directions. Normality test and F-test were performed followed by the comparison with independent-samples T-test (p<0,05). The necessary target volume setup margin was calculated based on Van Herk's equation. Imaging time and setup error determination time were measured. Imaging doses were estimated based on the literature. RESULTS: No statistically significant difference was found between setup errors determined by MV-kV and CBCT (VRT: 0.5 mm, SD = 1.9 vs. 0.4 mm, SD = 2.1, p = 0.371; LNG: 0.2 mm, SD = 2.2 vs. -0.1 mm, SD = 2.2, p = 0.188; LAT: 0.2 mm, SD = 2.2 vs. 0.3 mm, SD = 2.1, p = 0.41). SM values were: VRT: 2.7 mm vs. 2.5 mm; LNG: 2.1 mm vs. 1.3 mm; LAT: 2.2 mm vs. 2.3 mm. Mean imaging time was 0.65 min (MV-kV) vs. 2.29 min (CBCT). Mean setup error determination time was 2.41 min for both modalities. Estimated imaging doses were 6.88 mGy (MV-kV) vs. 17.2 mGy (CBCT) per fraction. CONCLUSION: The bony anatomy derived image registration based translational setup error determination results in similar values either by MV-kV or by CBCT. Using 3 mm setup margin in all the directions might be adequate. Imaging time is less by MV-kV, significant difference in imaging doses did not appear. Using CBCT is generally suggested. MV-kV might be an alternative in case of need for shortened imaging time. Orv Hetil. 2018; 159(29): 1193-1200.

[Multimodal treatment of malignant mixed Müllerian tumor]. / Malignus kevert Müller-cso-eredetu tumor komplex kezelése.

INTRODUCTION AND AIM: The aim of our study was to evaluate the prognostic factors and treatment options of a very rare and highly aggressive type of uterine neoplasms, the malignant mixed Müllerian tumor, known as carcinosarcoma. METHOD: Between 2009 and 2017, 29 patients were treated with malignant mixed Müllerian tumor. At stage I, surgery and postoperative radiotherapy were performed. At stages II-IV, trimodal treatment (surgery, chemotherapy and radiotherapy) was administered. RESULTS: The average age of patients was 68.51 (49-90) years, mean body mass index was 30.22 (20.90-37.22). We have experienced recurrence of disease after complete resection in 6 cases (4 of 6 patients did not accept radiation therapy). Local recurrence has occurred after an average 15.52 (6-36) months, distant metastasis with an average 19.2 (8-32) months. Overall survival was 11.92 (1-75) months. Six patients are free of tumours at the moment. CONCLUSIONS: As overall survival has not increased in recent decades by using combined chemotherapy, there is no congruent consensus associated with the optimal treatment. The standard surgical treatment is total abdominal hysterectomy with bilateral oophorectomy, although due to high rates of recurrence and metastases, the necessity of lymphadenectomy and postoperative treatment is in the focus of recent studies. Though postoperative irradiation improves local control, the beneficial effect on overall survival is still not proven. Adjuvant chemotherapy decreases the rate of both pelvic and extrapelvic recurrence at the same time, although there is no recommendation for the optimal chemoterapeutic agent. Multimodal therapy should lead to better outcomes. Recently there are many ongoing studies with biologic and target therapies to improve efficiency, however, the relevant results will be disclosed in many years only, due to the small number of patients. Orv Hetil. 2018; 159(19): 741-7747.

[Clinical experience in image-guided ultra-conformal hypofractionated radiotherapy in case of metastatic diseases at the University of Pécs]. / Áttétes betegségek képvezérelt, ultrakonformális, hipofrakcionált sugárkezelésével szerzett klinikai tapasztalatok ismertetése a Pécsi Tudományegyetem Onkoterápiás Intézetében.

With the development of radiation therapy technology, the utilization of more accurate patient fixation, inclusion of PET/CT image fusion into treatment planning, 3D image-guided radiotherapy, and intensity-modulated dynamic arc irradiation, the application of hypofractionated stereotactic radiotherapy can be extended to specified extracranial target volumes, and so even to the treatment of various metastases. Between October 2012 and August 2014 in our institute we performed extracranial, hypofractionated, image-többguided radiotherapy with RapidArc system for six cases, and 3D conformal multifield technique for one patient with Novalis TX system in case of different few-numbered and slow-growing metastases. For the precise definition of the target volumes we employed PET/CT during the treatment planning procedure. Octreotid scan was applied in one carcinoid tumour patient. Considering the localisation of the metastases and the predictable motion of the organs, we applied 5 to 20 mm safety margin during the contouring procedure. The average treatment volume was 312 cm3. With 2.5-3 Gy fraction doses we delivered 39-45 Gy total dose, and the treatment duration was 2.5 to 3 weeks. The image guidance was carried out via ExacTrac, and kV-Cone Beam CT equipment based on an online protocol, therefore localisation differences were corrected before every single treatment. The patients tolerated the treatments well without major (Gr>2) side effects. Total or near total regression of the metastases was observed at subsequent control examinations in all cases (the median follow-up time was 5 months). According to our first experience, extracranial, imageguided hypofractionated radiotherapy is well-tolerated by patients and can be effectively applied in the treatment of slow-growing and few-numbered metastases.

[NOVEL STRATEGY IN THE RADIOTHERAPY OF METASTATIC BRAIN TUMORS: SIMULTANEOUS WHOLE BRAIN RADIOTHERAPY AND INTEGRATED STEREOTACTIC RADIOSURGERY]. / ÚJ LEHETOSÉG AZ AGYI ÁTTÉTEK SUGÁRKEZELÉSÉBEN: EGYÜTTESEN ALKALMAZOTT TELJESKOPONYA-BESUGÁRZÁS ÉS INTEGRÁLT SZTEREOTAXIÁS SUGÁRSEBÉSZETI ELLÁTÁS.

BACKGROUND AND PURPOSE: Treatment of central nervous system (CNS) tumors has always played an important role in development of radiotherapy techniques. Precise patient immobilisation, non-coplanar field arrangement, conformal treatment, arc therapy, radiosurgery, application of image fusion to radiation planning or re-irradiation were first introduced into clinical routine in the treatment of brain tumors. METHODS: A modern multifunctional radiation instrument, Novalis TX has been installed at the University of Pécs two years ago. New methods, such as real time 3D image guided therapy, dynamic arc therapy and ultra-conformity offer further progress in treatment of CNS tumors. Whole brain irradiation and simultaneous fractionated stereotactic radiosurgery or integrated boost seem to be an optimal method in the treatment of not only soliter or oligo, but even a higher number (4-9) and not typically radiosensitive brain metastases. The new treatment strategy is illustrated by presentation of four case histories. RESULTS: Treatment protocol was completed in all cases. Treatment period of 1.5 to 3 weeks, and treatment time of only a few minutes were not stressful for the patients. A quite remarkable clinical improvement as to general condition of the patients was experienced in three cases. Follow-up images confirmed either remission or a stable disease. CONCLUSIONS: Simultaneous whole brain radiotherapy and integrated stereotactic radiosurgery is a reproducible, safe method that offers an effective irradiation with delivery of definitive dosage even in cases with radio-insensitive brain metastasis.

Single dose irradiation of defined region of rat brain with stereotactic brainlab system.

UNLABELLED: Background and purpose of our study was to develop a precise dose delivery technique for partial brain irradiation of two rats simultaneously. METHODS: Using a self-developed frame stereotactic radiotherapy with single doses of 30-90 Gy was delivered to the frontal lobe of 22 animals. Tolerability and reproducibility of the method were evaluated and dosimetric measurements were conducted to verify the treatment plans. 2, 4 and 6 months after the irradiation magnetic resonance imaging (MRI) scans and histopathological examinations were performed to detect late radiation induced biological changes. RESULTS: Immobilization device provided excellent reproducibility and tolerability. Dosimetry revealed good correspondence with planned dose distribution, but the measured absorbed dose was 30% lower than the planned dose. During the 6 months follow-up period the procedure related death of subject animals after 30 Gy, 70 Gy and 90 Gy were 0%, 20% and 100% respectively. T2 signal and structural changes on MRI scans found to be dose and time dependent. While 30 Gy caused no detectable structural changes, 70 Gy lead to cystic necrosis in 2 cases after 4 month. Histopathology revealed signs of necrosis on macroscopic examination after 70 Gy in the high dose region involving both frontal lobes, and no obvious microscopic changes in the surrounding area were detectable. CONCLUSION: Our technique of rat cranial irradiation using human stereotactic system provided high accuracy of single dose delivery for a pair of small animals, resulting in brain injury in the defined area. This method proved to be a reproducible model for preclinical studies on radiation effects.

[New methods in the treatment of localized prostate cancer: use of dynamic arc therapy and kV cone-beam CT positioning]. / Új módszerek a prosztatadaganatok sugárkezelésében: dinamikus ívbesugárzás és kilovoltos "cone-beam" komputertomográfiás ellenorzés.

INTRODUCTION: Prostate cancer is a common disease among elderly male patients in developed countries. In addition to prostatectomy, definitive irradiation plays an increasing role in the treatment of localized disease. AIM: The authors wanted to share their experience obtained with the use of the Novalis TX linear accelerator for the application of dose-escalation, dynamic, intensity modulated arc therapy with the routine usage of cone-beam computer tomography based or image guided radiotherapy in patients with prostate cancer. METHOD: Between 2011, December and 2013, February the authors performed 102 treatments. In 10 low risk and 10 high risk prostate cancer patients (median age: 72.5 years) three-dimensional conformal plans with the same target volume coverage were created and tolerance doses of organs at risk (OAR) were compared. RESULTS: Compared to three-dimensional conformal techniques, intensity modulated arc therapy treatments produced a significantly lower dose at organ at risk that led to a more favorable early toxicity rate. CONCLUSIONS: The intensity modulated arc therapy with image guided radiotherapy proved to be a safe standard treatment mode in the daily routine in the institute of the authors. Late toxicity and local control rates need to be further examined.