Locally dose-escalated radiotherapy may improve intracranial local control and overall survival among patients with glioblastoma.

Background: The dismal overall survival (OS) prognosis of glioblastoma, even after trimodal therapy, can be attributed mainly to the frequent incidence of intracranial relapse (ICR), which tends to present as an in-field recurrence after a radiation dose of 60 Gray (Gy). In this study, molecular marker-based prognostic indices were used to compare the outcomes of radiation with a standard dose versus a moderate dose escalation.

Methods: This retrospective analysis included 156 patients treated between 2009 and 2016.

Dosimetric implications of inter- and intrafractional prostate positioning errors during tomotherapy : Comparison of gold marker-based registrations with native MVCT.

Introduction: For high-dose radiation therapy (RT) of prostate cancer, image-guided (IGRT) and intensity-modulated RT (IMRT) approaches are standard. Less is known regarding comparisons of different IGRT techniques and the resulting residual errors, as well as regarding their influences on dose distributions.

Patients And Methods: A total of 58 patients who received tomotherapy-based RT up to 84 Gy for high-risk prostate cancer underwent IGRT based either on daily megavoltage CT (MVCT) alone (n = 43) or the additional use of gold markers (n = 15) under routine conditions.

Spinal cord constraints in the era of high-precision radiotherapy : Retrospective analysis of 62 spinal/paraspinal lesions with possible infringements of spinal cord constraints within a minimal volume.

Objective: Current constraints aim to minimize the risk of radiation myelitis by the use of restrictive maximal spinal cord doses, commonly 50 Gy. However, several studies suggested that a dose-volume effect could exist. Based on these observations, we evaluated patients receiving potentially excessive doses to the spinal cord within minimal volumes.

The impact of 18 F-FET PET-CT on target definition in image-guided stereotactic radiotherapy in patients with skull base lesions.

Background: 18 F-fluoro-ethyl-tyrosine PET is gaining more indications in the field of oncology. We investigated the potentials of usage of FET-PET/CT in addition to MRI for definition of gross tumor volume (GTV) in stereotactic radiotherapy of lesions of skull base.

Methods: We included in a prospective setting 21 cases.

Permanent interstitial low-dose-rate brachytherapy for patients with low risk prostate cancer: An interim analysis of 312 cases.

Purpose: The biochemical relapse-free survival (bRFS) rate after treatment with permanent iodine-125 seed implantation (PSI) or combined seeds and external beam radiotherapy (COMB) for clinical stage T1-T2 localized prostate cancer is a clinically relevant endpoint. The goal of this work was to evaluate the influence of relevant patient- and treatment-related factors.

Materials And Methods: The study population comprised 312 consecutive patients treated with permanent seed implantation.

Image-guided stereotactic radiosurgery for cranial lesions: large margins compensate for reduced image guidance frequency.

Background: We investigated patient positioning during radiosurgery of cranial lesions, and calculated clinical target volume (CTV) to planning target volume (PTV) margins using a modified common margin recipe. We simulated CTV-to-PTV margins for reduced image guidance, and repositioning for the first table angle only.

Patients And Methods: Patients were immobilized with a thermoplastic mask.

Image-guided intensity-modulated radiotherapy for patients with locally advanced gastric cancer: a clinical feasibility study.

Background: The aim of this study was to determine the medical and technical feasibility of intensity-modulated radiotherapy (IMRT) in high-risk nonmetastatic gastric cancer stage II and III after primary gastrectomy and D2 lymphadenectomy.

Methods And Materials: A prospective nonrandomized phase II trial was performed on 25 consecutive patients with gastric cancer with high risk (T3-4, N1-3, G2-3, R0-1). The dose delivered was 45 Gy (1.

Image-guided radiotherapy with implanted markers and kilovoltage imaging and 6-dimensional position corrections for intrafractional motion of the prostate.

Background/aim: To assess intrafractional prostate and patient movement using intra-prostatic fiducials and stereoscopic kilovoltage (kV) X-ray imaging in a 6-dimensional (6D) position correction protocol. To evaluate potential gains of intra-treatment repositioning with respect to treatment margins.

Patients And Methods: In intensity-modulated radiotherapy of prostate cancer patients were positioned according to internal fiducials in six dimensions by the use of ExacTrac/Novalis Body™ (ET/NB) System and a robotic couch.

Anal carcinoma: surgery does not influence prognosis when performed prior to concurrent radiochemotherapy.

Background: Concurrent radiochemotherapy (cRCT) is the standard-of-care for patients with locally advanced anal cancer. There is a subgroup of patients however, vastly with small tumors, which undergo local excision before combined modality treatment. It was suggested that local excision prior to cRCT might improve the local control in comparison with cRCT.

Results for local control and functional outcome after linac-based image-guided stereotactic radiosurgery in 190 patients with vestibular schwannoma.

Background: We assessed local control (LC) and functional outcome after linac-based stereotactic radiosurgery (SRS) for vestibular schwannoma (VS).

Methods: Between 1998 and 2008, 190 patients with VS were treated with SRS. All patients had tumors <2 cm diameter.

Contribution of (18)F-Fluoro-ethyl-tyrosine Positron Emission Tomography to Target Volume Delineation in Stereotactic Radiotherapy of Malignant Cranial Base Tumours: First Clinical Experience.

Increased amino acid uptake has been demonstrated in intracerebral tumours and head and neck carcinomas of squamous cell origin. We investigated the potential impact of using (18)F-fluoro-ethyl-tyrosine ((18)F-FET)-PET/CT in addition to conventional imaging for gross tumour volume (GTV) delineation in stereotactic radiotherapy of skull base tumours. The study population consisted of 14 consecutive patients with cranial base tumours (10 with squamous cell histology, 4 others).

Appropriate patient instructions can reduce prostate motion.

Background: Interfraction prostate motion must be compensated by increased safety margins. If filling status of rectum and bladder is constant, motion should be reduced. We attempted to reduce interfraction motion errors by proper patient instruction.

Contribution of 68Ga-DOTATOC PET/CT to target volume delineation of skull base meningiomas treated with stereotactic radiation therapy.

Purpose: To investigate the potential impact of 68Ga-DOTATOC positron emission tomography (68Ga-DOTATOC-PET) in addition to magnetic resonance imaging (MRI) and computed tomography (CT) for retrospectively assessing the gross tumor volume (GTV) delineation of meningiomas of the skull base in patients treated with fractionated stereotactic radiation therapy (FSRT).

Methods And Materials: The study population consisted of 48 patients with 54 skull base meningiomas, previously treated with FSRT. After scans were coregistered, the GTVs were first delineated with MRI and CT data (GTVMRI/CT) and then by PET (GTVPET) data.

Interfraction rotation of the prostate as evaluated by kilovoltage X-ray fiducial marker imaging in intensity-modulated radiotherapy of localized prostate cancer.

To quantify the daily rotation of the prostate during a radiotherapy course using stereoscopic kilovoltage (kV) x-ray imaging and intraprostatic fiducials for localization and positioning correction. From 2005 to 2009, radio-opaque fiducial markers were inserted into 38 patients via perineum into the prostate. The ExacTrac/Novalis Body X-ray 6-day image acquisition system (ET/NB; BrainLab AG, Feldkirchen, Germany) was used to determine and correct the target position.

Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy--a case series.

Introduction: Magnetic resonance imaging (MRI) and computed tomography (CT) with (68)Ga-DOTATOC positron emission tomography ((68)Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy.

Methods: Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and (68)Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) or PET, and were evaluated further.

Residual translational and rotational errors after kV X-ray image-guided correction of prostate location using implanted fiducials.

Purpose: To evaluate the residual errors and required safety margins after stereoscopic kilovoltage (kV) X-ray target localization of the prostate in image-guided radiotherapy (IGRT) using internal fiducials.

Patients And Methods: Radiopaque fiducial markers (FMs) have been inserted into the prostate in a cohort of 33 patients. The ExacTrac/Novalis Body™ X-ray 6d image acquisition system (BrainLAB AG, Feldkirchen, Germany) was used.

Potential impact of (68)Ga-DOTATOC PET/CT on stereotactic radiotherapy planning of meningiomas.

Purpose: Since meningiomas show a high expression of somatostatin receptor subtype 2, PET with (68)Ga-DOTATOC was proposed as an additional imaging modality beside CT and MRI for planning radiotherapy. We investigated the input of (68)Ga-DOTATOC-PET/CT on the definition of the "gross tumour volume" (GTV) in meningiomas, in order to assess the potential value of this method.

Methods: Prior to radiotherapy, 42 patients with meningiomas (26 f, 16 m, mean age 55) underwent MRI and (68)Ga-DOTATOC-PET/CT examinations.

Potentials of on-line repositioning based on implanted fiducial markers and electronic portal imaging in prostate cancer radiotherapy.

Background: To evaluate the benefit of an on-line correction protocol based on implanted markers and weekly portal imaging in external beam radiotherapy of prostate cancer. To compare the use of bony anatomy versus implanted markers for calculation of setup-error plus/minus prostate movement. To estimate the error reduction (and the corresponding margin reduction) by reducing the total error to 3 mm once a week, three times per week or every treatment day.

Postimplantation analysis enables improvement of dose-volume histograms and reduction of toxicity for permanent seed implantation.

Purpose: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity.

Patients And Methods: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis.

A non-randomised, single-centre comparison of induction chemotherapy followed by radiochemotherapy versus concomitant chemotherapy with hyperfractionated radiotherapy in inoperable head and neck carcinomas.

Background: The application of induction chemotherapy failed to provide a consistent benefit for local control in primary treatment of advanced head and neck (H&N) cancers. The aim of this study was to compare the results of concomitant application of radiochemotherapy for treating locally advanced head-and-neck carcinoma in comparison with the former standard of sequential radiochemotherapy.

Methods: Between 1987 and 1995 we treated 122 patients with unresectable (stage IV head and neck) cancer by two different protocols.

Dose-escalated conformal radiotherapy of glioblastomas -- results of a retrospective comparison applying radiation doses of 60 and 70 Gy.

Background: Dose escalated three-dimensional conformal radiotherapy with 70 Gy against glioblastomas was compared retrospectively with the standard scheme of 60 Gy using 2-D-planning.

Patients And Methods: In the period from 1994 to 1998, a series of 135 patients with glioblastomas was treated by surgery and postoperative radiotherapy. A conversion from 2-D into 3-D-planning was carried out in 4/1996.

Regional hyperthermia in conjunction with definitive radiotherapy against recurrent or locally advanced prostate cancer T3 pN0 M0.

Background And Purpose: Since long-term results of the standard treatment of locally advanced or recurrent prostatic carcinoma are unsatisfactory, the role for additional regional hyperthermia was evaluated in a phase I/II study.

Patients And Methods: From 08/1996 to 03/2000, 22 patients were treated by a standard irradiation regimen (68.4 Gy) in combination with regional hyperthermia (weekly, five to six times), and five of 22 patients received short-term (neoadjuvant) hormonal treatment.

Clinical and physical determinants for toxicity of 125-I seed prostate brachytherapy.

Background And Purpose: To assess acute as well as long-term toxicity after permanent prostate seed implantation. To find predictive clinical or dosimetric factors for side effects in order to work out strategies for improvement.

Patients And Methods: A group of 174 patients with localised prostate cancer was treated with permanent seed implantation between 1999 and 2001, either alone (140 patients) or in combination with external radiotherapy (34 patients).