Plan robustness and RBE influence for proton dose painting by numbers for head and neck cancers.

Purpose: To investigate the feasibility of dose painting by numbers (DPBN) with respect to robustness for proton therapy for head and neck cancers (HNC), and to study the influence of variable RBE on the TCP and OAR dose burden.

Methods And Materials: Data for 19 patients who have been scanned pretreatment with PET-FDG and subsequently treated with photon therapy were used in the study. A dose response model developed for photon therapy was implemented in a TPS, allowing DPBN plans to be created.

Comparison of Ga-PSMA PET/CT with fluoride PET/CT for detection of bone metastatic disease in prostate cancer.

Background: F-NaF positron emission tomography/computed tomography (fluoride PET/CT) is considered the most sensitive technique to detect bone metastasis in prostate cancer (PCa). Ga-PSMA-11 (PSMA) PET/CT is increasingly used for staging of PCa. This study primarily aimed to compare the diagnostic performance of fluoride PET/CT and gallium-based PSMA PET/CT in identifying bone metastasis followed by a comparison of PSMA PET/CT with contrast-enhanced CT (CE-CT) in identifying soft tissue lesions as a secondary objective.

Does exercise intensity matter for fatigue during (neo-)adjuvant cancer treatment? The Phys-Can randomized clinical trial.

Exercise during cancer treatment improves cancer-related fatigue (CRF), but the importance of exercise intensity for CRF is unclear. We compared the effects of high- vs low-to-moderate-intensity exercise with or without additional behavior change support (BCS) on CRF in patients undergoing (neo-)adjuvant cancer treatment. This was a multicenter, 2x2 factorial design randomized controlled trial (Clinical Trials NCT02473003) in Sweden.

Robust treatment planning of dose painting for prostate cancer based on ADC-to-Gleason score mappings - what is the potential to increase the tumor control probability?

Background And Purpose: The aim of this study was to evaluate the potential to increase the tumor control probability (TCP) with 'dose painting by numbers' (DPBN) plans optimized in a treatment planning system (TPS) compared to uniform dose plans. The DPBN optimization was based on our earlier published formalism for prostate cancer that is driven by dose-responses of Gleason scores mapped from apparent diffusion coefficients (ADC).

Material And Methods: For 17 included patients, a set of DPBN plans were optimized in a TPS by maximizing the TCP for an equal average dose to the prostate volume (CTVT) as for a conventional uniform dose treatment.

Comparison of Ga-PSMA-11 PET/CT with C-acetate PET/CT in re-staging of prostate cancer relapse.

Positron emission tomography (PET) imaging is used to localize recurrent disease in prostate cancer (PCa). The tracer Ga-PSMA-11 visualizes lesions overexpressing prostate-specific membrane antigen (PSMA), while C-acetate visualizes lesions with increased anabolic metabolism. The aim of this study was to compare the performance of PSMA-PET and acetate-PET in re-staging patients with biochemical relapse.

Robust maximization of tumor control probability for radicality constrained radiotherapy dose painting by numbers of head and neck cancer.

Background And Purpose: Radiotherapy with dose painting by numbers (DPBN) needs another approach than conventional margins to ensure a geometrically robust dose coverage for the tumor. This study presents a method to optimize DPBN plans that as opposed to achieve a robust dose distribution instead robustly maximize the tumor control probability (TCP) for patients diagnosed with head and neck cancer.

Material And Methods: Volumetric-modulated arc therapy (VMAT) plans were optimized with a robust TCP maximizing objective for different dose constraints to the primary clinical target volume (CTVT) for a set of 20 patients.

Effects of a nutrition intervention on acute and late bowel symptoms and health-related quality of life up to 24 months post radiotherapy in patients with prostate cancer: a multicentre randomised controlled trial.

Purpose: Radiotherapy to the prostate gland and pelvic lymph nodes may cause acute and late bowel symptoms and diminish quality of life. The aim was to study the effects of a nutrition intervention on bowel symptoms and health-related quality of life, compared with standard care.

Methods: Patients were randomised to a nutrition intervention (n = 92) aiming to replace insoluble fibres with soluble and reduce intake of lactose, or a standard care group (n = 88) who were recommended to maintain their habitual diet.

High efficacy of hypofractionated proton therapy with 4 fractions of 5 Gy as a boost to 50 Gy photon therapy for localized prostate cancer.

Purpose: We report the outcome of hypofractionated proton boost as an alternative to high dose-rate brachytherapy boost, aimed at an equivalent dose exceeding 86 Gy in 2 Gy fractions, for patients with localized prostate cancer and all risk groups.

Methods: Proton boost of 20 Gy given in 4 daily fractions to the prostate was followed after a one-week rest by photon therapy to 50 Gy in 2 Gy fractions. Outcomes are presented per risk group according to both NCCN and ISUP classifications.

Prospective observational study of Lu-DOTA-octreotate therapy in 200 patients with advanced metastasized neuroendocrine tumours (NETs): feasibility and impact of a dosimetry-guided study protocol on outcome and toxicity.

Purpose: Peptide receptor radionuclide therapy in patients with neuroendocrine tumours has yielded promising results. This prospective study investigated the feasibility of dosimetry of the kidneys and bone marrow during therapy and its impact on efficacy and outcome.

Methods: The study group comprised 200 consecutive patients with metastasized somatostatin receptor-positive neuroendocrine tumours progressing on standard therapy or not suitable for other therapeutic options.

Dose painting of prostate cancer based on Gleason score correlations with apparent diffusion coefficients.

Background: Gleason scores for prostate cancer correlates with an increased recurrence risk after radiotherapy (RT). Furthermore, higher Gleason scores correlates with decreasing apparent diffusion coefficient (ADC) data from diffusion weighted MRI (DWI-MRI). Based on these observations, we present a formalism for dose painting prescriptions of prostate volumes based on ADC images mapped to Gleason score driven dose-responses.

Kidney dosimetry during Lu-DOTATATE therapy in patients with neuroendocrine tumors: aspects on calculation and tolerance.

Background: Fractionated therapy with Lu-DOTATATE has been reported to be an effective treatment for patients with metastasized neuroendocrine tumors. To optimize the treatment, absorbed doses to risk organs are calculated for the individual patient. For each organ, absorbed dose due to activity in the organ itself (self-dose) and that originating from other organs (cross-dose) are calculated from serial measurements to obtain the activity distribution following treatment.

Repeatability of quantitative parameters of 18F-fluoride PET/CT and biochemical tumour and specific bone remodelling markers in prostate cancer bone metastases.

Purpose: 18F-fluoride PET/CT exhibits high sensitivity to delineate and measure the extent of bone metastatic disease in patients with prostate cancer. 18F-fluoride PET/CT could potentially replace traditional bone scintigraphy in clinical routine and trials. However, more studies are needed to assess repeatability and biological uptake variation.

Dose painting by numbers based on retrospectively determined recurrence probabilities.

Background And Purpose: The aim of this study is to derive "dose painting by numbers" prescriptions from retrospectively observed recurrence volumes in a patient group treated with conventional radiotherapy for head and neck squamous cell carcinoma.

Materials And Methods: The spatial relation between retrospectively observed recurrence volumes and pre-treatment standardized uptake values (SUV) from fluorodeoxyglucose positron emission tomography (FDG-PET) imaging was determined. Based on this information we derived SUV driven dose-response functions and used these to optimize ideal dose redistributions under the constraint of equal average dose to the tumor volumes as for a conventional treatment.

Malignant lipogenesis defined by C-acetate PET/CT predicts prostate cancer-specific survival in patients with biochemical relapse after prostatectomy.

Purpose: Malignant de novo lipogenesis is strongly linked to the aggressiveness of prostate cancer (PCa) under experimental conditions. C-Acetate PET/CT is a potential noninvasive biomarker of malignant lipogenesis in PCa, but its prognostic value is not known. The objective of this study was to analyse C-acetate PET/CT image metrics in relation to survival.

Assessment of Whether Patients' Knowledge, Satisfaction, and Experience Regarding Their 18F-Fluoride PET/CT Examination Affects Image Quality.

Unlabelled: The aim of this study was to investigate patients' previous knowledge, satisfaction, and experience regarding an (18)F-fluoride PET/CT examination and to explore whether any discomfort or pain during the examination was associated with reduced image quality. A further aim was to explore whether patients' health-related quality of life (HRQoL) was associated with their satisfaction and experience regarding the examination.

Methods: Between November 2011 and April 2013, 50 consecutive patients with a histopathologic diagnosis of prostate cancer who were scheduled for (18)F-fluoride PET/CT were asked to participate in the study.

Method dependence, observer variability and kidney volumes in radiation dosimetry of (177)Lu-DOTATATE therapy in patients with neuroendocrine tumours.

Background: Radionuclide therapy can be individualized by performing dosimetry. To determine absorbed organ doses in (177)Lu-DOTATATE therapy, three methods based on activity concentrations are currently in use: the small volume of interest (sVOI) method, and two methods based on large VOIs either on anatomical CT (aVOI) or on thresholds on functional images (tVOI). The main aim of the present work was to validate the sVOI in comparison to the other two methods regarding agreement and time efficiency.

How much will linked deformable registrations decrease the quality of multi-atlas segmentation fusions?

Background And Purpose: Multi-atlas segmentation can yield better results than single atlas segmentation, but practical applications are limited by long calculation times for deformable registration. To shorten the calculation time pre-calculated registrations of atlases could be linked via a single atlas registered in runtime to the current patient. The primary purpose of this work is to investigate and quantify segmentation quality changes introduced by such linked registrations.

Clinical evaluation of multi-atlas based segmentation of lymph node regions in head and neck and prostate cancer patients.

Background: Semi-automated segmentation using deformable registration of selected atlas cases consisting of expert segmented patient images has been proposed to facilitate the delineation of lymph node regions for three-dimensional conformal and intensity-modulated radiotherapy planning of head and neck and prostate tumours. Our aim is to investigate if fusion of multiple atlases will lead to clinical workload reductions and more accurate segmentation proposals compared to the use of a single atlas segmentation, due to a more complete representation of the anatomical variations.

Methods: Atlases for lymph node regions were constructed using 11 head and neck patients and 15 prostate patients based on published recommendations for segmentations.

The clinical safety, biodistribution and internal radiation dosimetry of [¹⁸F]fluciclovine in healthy adult volunteers.

Purpose: We report on the biodistribution and internal radiation dosimetry in humans of [(18)F]fluciclovine, a synthetic L-leucine analogue being investigated as a potential diagnostic biomarker for neoplasia.

Methods: Whole-body positron emission tomography (PET) scans of 6 healthy volunteers were acquired at up to 16 time points up to about 5 h after a bolus administration of [(18)F]fluciclovine (153.8 ± 2.

Individualized dosimetry of kidney and bone marrow in patients undergoing 177Lu-DOTA-octreotate treatment.

Unlabelled: The organs at risk in radionuclide therapy with (177)Lu-octreotate are the bone marrow and the kidneys. The primary aim of this study was to develop an individualized dosimetry protocol for the bone marrow. The secondary aim was to identify those patients, undergoing fractionated therapy with 7.

Regional distribution and kinetics of [18F]fluciclovine (anti-[18F]FACBC), a tracer of amino acid transport, in subjects with primary prostate cancer.

Purpose: [(18)F]Fluciclovine (anti-[(18)F]FACBC) is a synthetic amino acid developed for PET assessment of the anabolic component of tumour metabolism in clinical routine. This phase 1 trial evaluated the safety, tracer stability and uptake kinetics of [(18)F]fluciclovine in patients.

Methods: Six patients with biopsy-proven prostate cancer were investigated with 3-T MRI and PET/CT.

Whole-body diffusion-weighted MRI compared with (18)F-NaF PET/CT for detection of bone metastases in patients with high-risk prostate carcinoma.

Objective: The purpose of this study was to evaluate the accuracy of whole-body diffusion-weighted MRI (DWI) and (18)F-NaF PET/CT for detection of bone metastases in patients with high-risk prostate cancer.

Subjects And Methods: Both patient- and lesion-based analyses were performed on 49 consecutive patients (median age, 67 years; age range, 57-80 years) with recently diagnosed high-risk prostate cancer. All patients underwent bone scintigraphy, whole-body MRI including DWI and (18)F-NaF PET/CT before treatment.

Hypofractionated proton boost combined with external beam radiotherapy for treatment of localized prostate cancer.

Proton boost of 20 Gy in daily 5 Gy fractions followed by external beam radiotherapy (EBRT) of 50 Gy in daily 2 Gy fractions were given to 278 patients with prostate cancer with T1b to T4N0M0 disease. Fifty-three percent of the patients received neoadjuvant androgen deprivation therapy (N-ADT). The medium followup was 57 months.

Lessons on Tumour Response: Imaging during Therapy with (177)Lu-DOTA-octreotate. A Case Report on a Patient with a Large Volume of Poorly Differentiated Neuroendocrine Carcinoma.

Favourable outcomes of peptide receptor radiotherapy (PRRT) of neuroendocrine tumours have been reported during the last years. Still, there are uncertainties on the radionuclides to be used, the treatment planning, and the indication in patients with a high proliferation rate.This case report describes a patient with a high tumour burden of poorly differentiated neuroendocrine carcinoma of unknown primary with a proliferation rate in liver metastases up to 50%, undergoing fractionated treatment with 7 cycles of (177)Lu-DOTA-octreotate (7.