Investigations on the beam quality correction factor for ionization chambers in high-energy brachytherapy dosimetry.

. To enhance the investigations on MC calculated beam quality correction factors of thimble ionization chambers from high-energy brachytherapy sources and to develop reliable reference conditions in source and detector setups in water..

Determination of the dose rate around a HDR Ir brachytherapy source with the microDiamond and the microSilicon detector.

Purpose: To employ the microDiamond and the microSilicon detector (mDD and mSD, both PTW-Freiburg, Germany) to determine the dose rate around a HDR Ir brachytherapy source (model mHDR-v2r, Elekta AB, Sweden).

Methods: The detectors were calibrated with a Co beam at the PTW Calibration Laboratory. Measurements around the Ir source were performed inside a PTW MP3 water phantom.

Enhancement of the EGSnrc code egs_chamber for fast fluence calculations of charged particles.

Purpose: Simulation of absorbed dose deposition in a detector is one of the key tasks of Monte Carlo (MC) dosimetry methodology. Recent publications (Hartmann and Zink, 2018; Hartmann and Zink, 2019; Hartmann et al., 2021) have shown that knowledge of the charged particle fluence differential in energy contributing to absorbed dose is useful to provide enhanced insight on how response depends on detector properties.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in borderline-resected pancreatic cancer.

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise RT modality to intensify the irradiation effect for cancer involving upper abdominal structures and organs, generally delivered with electrons (IOERT). Unresectable, borderline and resectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery.

ESTRO IORT Task Force/ACROP recommendations for intraoperative radiation therapy in unresected pancreatic cancer.

Radiation therapy (RT) is a valuable component of multimodal treatment for localized pancreatic cancer. Intraoperative radiation therapy (IORT) is a very precise sub-component of RT that can intensify the irradiation effect for cancer involving an anatomically well-defined volume, generally delivered with electrons (IOERT). Unresectable disease categories benefit from dose-escalated chemoradiation strategies in the context of active systemic therapy and potential radical surgery.

[Detector Based Determination of Water Absorbed Dose According to DIN 6800 Teil 1: Suggestion for an Extension of the Fundamental Formalism].

For any detector to be used for the determination of absorbed dose at the point of measurement in water a basic equation is required to convert the reading of the detector into absorbed dose in water. The German DIN 6800 part 1 provides a general formalism for that. A further differentiated formalism applicable to photon dosimetry is suggested in this work.

Present state and issues in IORT Physics.

Literature was reviewed to assess the physical aspects governing the present and emerging technologies used in intraoperative radiation therapy (IORT). Three major technologies were identified: treatment with electrons, treatment with external generators of kV X-rays and electronic brachytherapy. Although also used in IORT, literature on brachytherapy with radioactive sources is not systematically reviewed since an extensive own body of specialized literature and reviews exists in this field.

Intraoperative electron radiation therapy combined with external beam radiation therapy and limb sparing surgery in extremity soft tissue sarcoma: a retrospective single center analysis of 183 cases.

Background And Purpose: To report our experience with limb-sparing surgery, IOERT and EBRT in extremity STS.

Materials And Methods: 183 patients were retrospectively analyzed. 78% presented in primary situation, with 80% located in the lower limb.

Clinical phase I/II trial to investigate preoperative dose-escalated intensity-modulated radiation therapy (IMRT) and intraoperative radiation therapy (IORT) in patients with retroperitoneal soft tissue sarcoma: interim analysis.

Background: To report an unplanned interim analysis of a prospective, one-armed, single center phase I/II trial (NCT01566123).

Methods: Between 2007 and 2013, 27 patients (pts) with primary/recurrent retroperitoneal sarcomas (size > 5 cm, M0, at least marginally resectable) were enrolled. The protocol attempted neoadjuvant IMRT using an integrated boost with doses of 45-50 Gy to PTV and 50-56 Gy to GTV in 25 fractions, followed by surgery and IOERT (10-12 Gy).

Technical and dosimetric aspects of the total skin electron beam technique implemented at Heidelberg University Hospital.

Aim: To give a technical description and present the dosimetric proporties of the total skin electron beam technique implemented at Heidelberg University Hospital.

Background: Techniques used for total skin electron beam irradiation were developed as early as in the 1960s to 1980s and have, since then, hardly changed. However, new measurements of the established methods allow deeper insight into the dose distributions and reasons for possible deviations from uniform dose.

Excellent local control with IOERT and postoperative EBRT in high grade extremity sarcoma: results from a subgroup analysis of a prospective trial.

Background: To report the results of a subgroup analysis of a prospective phase II trial focussing on radiation therapy and outcome in patients with extremity soft tissue sarcomas (STS).

Methods: Between 2005 and 2010, 50 patients (pts) with high risk STS (size ≥ 5 cm, deep/extracompartimental location, grade II-III (FNCLCC)) were enrolled. The protocol comprised 4 cycles of neoadjuvant chemotherapy with EIA (etoposide, ifosfamide and doxorubicin), definitive surgery with IOERT, postoperative EBRT and 4 adjuvant cycles of EIA.

Intraoperative electron radiation therapy (IOERT) in patients with locally recurrent renal cell carcinoma.

Background: To analyze our experience with intraoperative electron radiation therapy (IOERT) followed by moderate doses of external beam radiation therapy (EBRT) in patients with locally recurrent renal cell carcinoma.

Methods: From 1992 to 2010, 17 patients with histologically proven, locally recurrent renal cell carcinoma (median tumor size 7 cm) were treated by surgery and IOERT with a median dose of 15 Gy. All patients met the premise of curative intent including 7 patients with oligometastases at the time of recurrent surgery, which were resected and/or irradiated.

Primary radiotherapy with endobronchial high-dose-rate brachytherapy boost for inoperable lung cancer: long-term results.

Background: To retrospectively evaluate the outcome of patients with inoperable non-small-cell lung cancer treated with primary external beam radiotherapy combined with high-dose-rate endobronchial brachytherapy boost.

Patients And Methods: Between 1988 and 2005, 35 patients with non-small-cell lung cancer (stage I-III) ineligible for surgical resection and/or chemotherapy, were primarily treated with external beam radiotherapy with a median total dose of 50 Gy (range, 46-60). A median of 3 fractions high-dose-rate endobronchial brachytherapy was applied as a boost after external beam radiotherapy, the median total dose was 15 Gy (range, 8-20).

Dosimetric verification of source strength for HDR afterloading units with Ir-192 and Co-60 photon sources: Comparison of three different international protocols.

Before clinical use of a brachytherapy source, regulations or recommendations by medical physics societies require an independent measurement of its air kerma strength by a qualified medical physicist. Currently, in addition to Ir-192, also HDR-Co-60 sources are increasingly coming into operation. However, the existing dosimetry protocols do not provide any guidelines for Co-60 sources.

Intraoperative Electron Radiation Therapy (IOERT) in the management of locally recurrent rectal cancer.

Background: To evaluate disease control, overall survival and prognostic factors in patients with locally recurrent rectal cancer after IOERT-containing multimodal therapy.

Methods: Between 1991 and 2006, 97 patients with locally recurrent rectal cancer have been treated with surgery and IOERT. IOERT was preceded or followed by external beam radiation therapy (EBRT) in 54 previously untreated patients (median dose 41.

Total skin electron beam therapy as palliative treatment for cutaneous manifestations of advanced, therapy-refractory cutaneous lymphoma and leukemia.

Background: To retrospectively access the outcome and toxicity of a total skin electron beam therapy (TSEBT) in patients with cutaneous lymphoma (CL) or leukemia.

Patients And Methods: Treatment results of 25 patients (median age 63 years; 5 female, 20 male) with cutaneous manifestations of advanced and therapy-refractory CL (n = 21; T-cell lymphomas n = 18, B-cell lymphomas n = 3) stage IIB-IV or leukemia (n = 4; AML n = 2, CLL n = 1, PDC n = 1) treated between 1993 and 2010 were reviewed. All patients were symptomatic.

Aggressive local treatment containing intraoperative radiation therapy (IORT) for patients with isolated local recurrences of pancreatic cancer: a retrospective analysis.

Background: To evaluate the use of intraoperative radiation therapy (IORT) in the multimodality treatment of patients with isolated local recurrences of pancreatic cancer.

Methods: We retrospectively analyzed 36 patients with isolated local recurrences of pancreatic cancer who have been treated with a combination of surgery, IORT and EBRT. Median time from initial treatment to recurrence was 20 months.

A clinical phase I/II trial to investigate preoperative dose-escalated intensity-modulated radiation therapy (IMRT) and intraoperative radiation therapy (IORT) in patients with retroperitoneal soft tissue sarcoma.

Background: Local control rates in patients with retroperitoneal soft tissue sarcoma (RSTS) remain disappointing even after gross total resection, mainly because wide margins are not achievable in the majority of patients. In contrast to extremity sarcoma, postoperative radiation therapy (RT) has shown limited efficacy due to its limitations in achievable dose and coverage. Although Intraoperative Radiation Therapy (IORT) has been introduced in some centers to overcome the dose limitations and resulted in increased outcome, local failure rates are still high even if considerable treatment related toxicity is accepted.

Safety and efficacy of thoracic external beam radiotherapy after airway stenting in malignant airway obstruction.

Purpose: We retrospectively evaluated the outcome and toxicity of external beam radiotherapy (EBRT) after airway stents were placed in patients treated for malignant airway obstruction.

Methods And Materials: Between 2004 and 2009, we performed airway stenting followed by EBRT in 43 patients for symptomatic primary lung cancer (n = 31) or other thoracic malignancies (n = 12). The median time interval between stent placement and first irradiation was 14 days.

Clinical phase I/II trial to investigate neoadjuvant intensity-modulated short term radiation therapy (5 × 5 Gy) and intraoperative radiation therapy (15 Gy) in patients with primarily resectable pancreatic cancer - NEOPANC.

Background: The current standard treatment, at least in Europe, for patients with primarily resectable tumors, consists of surgery followed by adjuvant chemotherapy. But even in this prognostic favourable group, long term survival is disappointing because of high local and distant failure rates. Postoperative chemoradiation has shown improved local control and overalls survival compared to surgery alone but the value of additional radiation has been questioned in case of adjuvant chemotherapy.

Deletion of running-induced hippocampal neurogenesis by irradiation prevents development of an anxious phenotype in mice.

Recent evidence postulates a role of hippocampal neurogenesis in anxiety behavior. Here we report that elevated levels of neurogenesis elicit increased anxiety in rodents. Mice performing voluntary wheel running displayed both highly elevated levels of neurogenesis and increased anxiety in three different anxiety-like paradigms: the open field, elevated O-maze, and dark-light box.

Dose consumption for quality assurance and maintenance at a dedicated IORT accelerator.

Dedicated accelerators for intra-operative radiation therapy (IORT) are operated at high dose rates in order to achieve short treatment times within which the anaesthetisized patient must be remotely monitored (e.g. via video cameras and telemetric anesthesia instruments).

Intraoperative electron radiotherapy for the management of aggressive fibromatosis.

Purpose: We analyzed our experience with intraoperative electron radiotherapy (IOERT) followed by moderate doses of external beam radiotherapy (EBRT) after organ-sparing surgery in patients with primary or recurrent aggressive fibromatosis.

Methods And Materials: Indication for IOERT and postoperative EBRT as an individual treatment approach to avoid mutilating surgical procedures was seen when complete surgical removal seemed to be unlikely or impossible. A total of 31 lesions in 30 patients were treated by surgery and IOERT with a median dose of 12 Gy.

Palliative total skin electron beam therapy (TSEBT) for advanced cutaneous T-cell lymphoma.

Our aim was to analyze the effectiveness of palliative total skin electron beam therapy (TSEBT) in the management of advanced cutaneous T-cell non-Hodgkin's lymphoma (CTCL). Eighteen patients (median age 59 years) with advanced and therapy-refractory CTCL in stages IIB-IV were treated with TSEBT for the first time. The most common histological subtype was Mycosis fungoides (72%).

Patterns of failure and local control after intraoperative electron boost radiotherapy to the presacral space in combination with total mesorectal excision in patients with locally advanced rectal cancer.

Purpose: To evaluate local control and patterns of failure in patients treated with intraoperative electron beam radiotherapy (IOERT) after total mesorectal excision (TME), to appraise the effectiveness of intraoperative target definition.

Methods And Materials: We analyzed the outcome of 243 patients with rectal cancer treated with IOERT (median dose, 10 Gy) after TME. Eighty-eight patients received neoadjuvant and 122 patients adjuvant external beam radiotherapy (EBRT) (median dose, 41.