Defining and sparing sexual function-related organs at risk for rectal cancer radiotherapy.

Background And Purpose: Sexual dysfunction is a common consequence of pelvic radiotherapy, influenced by psychological, physical, social, and relational factors. Research has focused on vaginal dose and stenosis in females and penile bulb dose and erectile dysfunction in males, with limited attention to domains, such as arousal, desire, and satisfaction. In the Danish Colorectal Cancer Radiotherapy Group, we aimed to: (1) Develop an atlas of sexual function-related organs at risk and (2) Evaluate if these organs at risk could be spared without compromising target coverage in rectal cancer radiotherapy planning.

Evaluating primary tumor position variation for rectal cancer patients treated with long course radiotherapy.

To quantify interfraction shape and positional variations of primary tumor volumes for rectal cancer patients receiving long course radiotherapy by comparing two quantification strategies: a center-of-mass (COM) method and a surface-based metric that captures local deformations.This study utilized repeat MRI scans before and during radiotherapy (RT) for rectal cancer to investigate the positional variation of the primary gross tumor volume (GTVp). Sixteen patients underwent six MRI exams, with the initial three before the RT course and the subsequent three at one, two, and four weeks into the RT course.

Individual lymph node position variation for rectal cancer patients treated with long course chemoradiotherapy.

Background And Purpose: Delivery of high precision radiotherapy lymph node boosts requires detailed information on the interfraction positional variation of individual lymph nodes. In this study we characterized interfraction positional shifts of suspected malignant lymph nodes for rectal cancer patients receiving long course radiotherapy. Furthermore, we investigated parameters which could affect the magnitude of the position variation.

Treatment planning for patients with low rectal cancer in a multicenter prospective organ preservation study.

Background: Non-surgical management of rectal cancer relies on (chemo)radiotherapy as the definitive treatment modality. This study reports and evaluates the clinical high dose radiotherapy treatment plans delivered to patients with low resectable rectal cancer in a Danish multicenter trial.

Methods: The Danish prospective multicenter phase II Watchful Waiting 2 trial (NCT02438839) investigated definitive chemoradiation for non-surgical management of low rectal cancer.

Geometric distortions in clinical MRI sequences for radiotherapy: insights gained from a multicenter investigation.

Background: As magnetic resonance imaging (MRI) becomes increasingly integrated into radiotherapy (RT) for enhanced treatment planning and adaptation, the inherent geometric distortion in acquired MR images pose a potential challenge to treatment accuracy. This study aimed to evaluate the geometric distortion levels in the clinical MRI protocols used across Danish RT centers and discuss influence of specific sequence parameters. Based on the variety in geometric performance across centers, we assess if harmonization of MRI sequences is a relevant measure.

Ga-PSMA PET/CT compared with MRI/CT and diffusion-weighted MRI for primary lymph node staging prior to definitive radiotherapy in prostate cancer: a prospective diagnostic test accuracy study.

Background: The aim was to compare the diagnostic accuracy of Ga-PSMA PET/CT with conventional cross-sectional imaging and diffusion-weighted MRI (DW-MRI) for detecting lymph node metastasis (LNM) to stage prostate cancer patients. Twenty consecutive, newly- diagnosed prostate cancer patients were prospectively enrolled and underwent Ga-PSMA-11 PET/CT, anatomical MRI or contrast-enhanced CT, and DW-MRI prior to laparoscopic, template-based, extended lymph node dissection. Histopathological findings served as the reference test.

Prospective comparison of Ga-PSMA PET/CT, F-sodium fluoride PET/CT and diffusion weighted-MRI at for the detection of bone metastases in biochemically recurrent prostate cancer.

Purpose: To prospectively compare diagnostic accuracies for detection of bone metastases by Ga-PSMA PET/CT, F-NaF PET/CT and diffusion-weighted MRI (DW-MRI) in prostate cancer (PCa) patients with biochemical recurrence (BCR).

Methods: Sixty-eight PCa patients with BCR participated in this prospective study. The patients underwent Ga-PSMA PET/CT, a F-NaF PET/CT and a DW-MRI (performed in accordance with European Society of Urogenital Radiology guidelines, with b values of 0 and 600 s/mm).

Urethra sparing - potential of combined Nickel-Titanium stent and intensity modulated radiation therapy in prostate cancer.

Background And Purpose: To investigate a novel method for sparing urethra in external beam radiotherapy of prostate cancer and to evaluate the efficacy of such a treatment in terms of tumour control using a mathematical model.

Materials And Methods: This theoretical study includes 20 patients previously treated for prostate cancer using external beam radiotherapy. All patients had a Nickel-Titanium (Ni-Ti) stent inserted into the prostate part of urethra.