Radiomics is an evolving field in which the extraction of large amounts of features from diagnostic medical images may be used to predict underlying molecular and genetic characteristics, thereby improving treatment response prediction and prognostication and potentially allowing personalisation of cancer treatment. There is increasing interest in extracting additional data from PET images, particularly novel features that describe the heterogeneity of voxel intensities, but a number of potential limitations need to be recognised and overcome. Nevertheless, some early data suggest that extraction of additional quantitative data may offer further predictive and prognostic information in individual patients.

PurposeTo assess the day-to-day repeatability of global and local-regional magnetic resonance (MR) imaging texture features derived from primary rectal cancer.Materials and MethodsAfter ethical approval and patient informed consent were obtained, two pretreatment T2-weighted axial MR imaging studies performed prospectively with the same imaging unit on 2 consecutive days in 14 patients with rectal cancer (11 men [mean age, 61.7 years], three women [mean age, 70.0 years]) were analyzed to extract (a) global first-order statistical histogram and model-based fractal features reflecting the whole-tumor voxel intensity histogram distribution and repeating patterns, respectively, without spatial information and (b) local-regional second-order and high-order statistical texture features reflecting the intensity and spatial interrelationships between adjacent in-plane or multiplanar voxels or regions, respectively. Repeatability was assessed for 46 texture features, and mean difference, 95% limits of agreement, within-subject coefficient of variation (wCV), and repeatability coefficient (r) were recorded.ResultsRepeatability was better for global parameters than for most local-regional parameters. In particular, histogram mean, median, and entropy, fractal dimension mean and standard deviation, and second-order entropy, homogeneity, difference entropy, and inverse difference moment demonstrated good repeatability, with narrow limits of agreement and wCVs of 10% or lower. Repeatability was poorest for the following high-order gray-level run-length (GLRL) gray-level zone size matrix (GLZSM) and neighborhood gray-tone difference matrix (NGTDM) parameters: GLRL intensity variability, GLZSM short-zone emphasis, GLZSM intensity nonuniformity, GLZSM intensity variability, GLZSM size zone variability, and NGTDM complexity, demonstrating wider agreement limits and wCVs of 50% or greater.ConclusionMR imaging repeatability is better for global texture parameters than for local-regional texture parameters, indicating that global texture parameters should be sufficiently robust for clinical practice.Online supplemental material is available for this article.

BackgroundPatients who have undergone treatment for head and neck cancer are at risk for neck lymphedema, which can severely affect quality of life. Liposuction has been used successfully in cancer patients who suffer from post-treatment limb lymphedema. The purpose of our study was to review the outcomes of head and neck cancer patients at our center who have undergone submental liposuction for post-treatment lymphedema and compare their subsequent results with a control group.MethodsAll head and neck cancer patients at an oncology center in tertiary hospital setting who complained to their attending surgeon or radiation oncologist regarding cervical lymphedema secondary to head and neck cancer treatment, and had been disease-free for a minimum of one year, with no previous facial plastic surgical procedures were eligible for inclusion into the study. Study design was a non-blinded randomized controlled trial. Twenty patients were randomized into a treatment arm (underwent submental liposuction n = 10) and control arm (n = 10). Both groups of patients completed two surveys (Modified Blepharoplasty Outcome Evaluation and the validated Derriford Appearance Scale) on initial office visit after consenting for the trial. The treatment group then completed the surveys 6 months post-operatively while the control group filled the surveys 6 months after the initial assessment but had no intervention. Mann-Whitney U tests were performed to compare the responses of those that did and did not receive liposuction.ResultsOur study demonstrated a statistically significant improvement in patients’ self-perception of appearance and statistically significant subjective scoring of appearance following submental liposuction.ConclusionsSubmental liposuction is an effective and safe procedure to improves the quality of life for head and neck cancer patients suffering from post-treatment lymphedema.

Purpose To compare [ 18 F]-fluorodeoxyglucose (FDG) and [ 18 F]-sodium fluoride (NaF) positron emission tomography/computed tomography (PET/CT) with whole-body magnetic resonance with diffusion-weighted imaging (WB-MRI), for endocrine therapy response prediction at 8 weeks in bone-predominant metastatic breast cancer. Patients and methods Thirty-one patients scheduled for endocrine therapy had up to five bone metastases measured [FDG, NaF PET/CT: maximum standardized uptake value (SUV max ); WB-MRI: median apparent diffusion coefficient (ADC med )] at baseline and 8 weeks. To detect the flare phenomenon, a 12-week NaF PET/CT was also performed if 8-week SUV max increased. A 25% parameter change differentiated imaging progressive disease (PD) from non-PD and was compared to a 24-week clinical reference standard and progression-free survival (PFS). Results Twenty-two patients (median age, 58.6 years, range, 40–79 years) completing baseline and 8-week imaging were included in the final analysis. Per-patient % change in NaF SUV max predicted 24-week clinical PD with sensitivity, specificity and accuracy of 60, 73.3, and 70%, respectively. For FDG SUV max the results were 0, 100, and 76.2% and for ADC med , 0, 100 and 72.2%, respectively. PFS < 24 weeks was associated with % change in SUV max (NaF: 41.7 vs. 0.7%, p = 0.039; FDG: − 4.8 vs. − 28.6%, p = 0.005) but not ADC med (− 0.5 vs. 10.1%, p = 0.098). Interlesional response heterogeneity occurred in all modalities and NaF flare occurred in seven patients. Conclusions FDG PET/CT and WB-MRI best predicted clinical non-PD and both FDG and NaF PET/CT predicted PFS < 24 weeks. Lesional response heterogeneity occurs with all modalities and flare is common with NaF PET/CT.

To establish whether non-invasive measurement of changes in F-fluoride metabolic flux to bone mineral (Ki) by positron emission tomography/ computed tomography (PET/CT) can provide incremental value in response assessment of bone metastases in breast cancer compared to maximum and mean standardized uptake values (SUV, SUVmean). Twelve breast cancer patients starting endocrine treatment for de-novo or progressive bone metastases were included. StaticF-fluoride PET/CT scans were acquired 60 minutes post-injection, before and 8 weeks after commencing treatment. Venous blood samples were taken at 55 and 85 minutes post-injection to measure plasma F-fluoride activity concentrations. This allowed calculation of Ki in individual bone metastases using a previously validated method. Percentage changes in Ki, SUV and SUVmean were calculated from the same ≤ 5 index lesions from each patient. Clinical response up to 24 weeks, assessed in consensus by two experienced oncologists blinded to PET imaging findings, was used as a reference standard. In the 4 patients with clinical progressive disease (PD), mean Ki significantly increased (>25%) in all, SUV in 3 and SUVmean in 2. In the 8 non-PD patients, Ki decreased or remained stable in 7, SUV in 5 and SUVmean in 6. A significant mean percentage increase in Ki from baseline occurred in the 4 patients with PD compared with SUV and SUVmean (89.7% vs 41.9% and 43.8%, respectively; p<0.001). After 8 weeks of endocrine treatment for bone-predominant metastatic breast cancer, Ki more reliably differentiated PD from non-PD than SUV and SUVmean, probably because measurement of SUVs underestimates fluoride clearance as changes in input function are not accounted for.

Our ability to accurately assess the skeleton for metastases in breast and prostate cancers has improved significantly in recent years with hybrid imaging methods. Nevertheless, no consensus has been reached on the best imaging modality for diagnosis and treatment response assessment of skeletal disease. Hybrid SPECT/CT has low false-positive and false-negative rates compared with planar bone scintigraphy (BS) or BS augmented with SPECT in breast and prostate cancers. In breast cancer, 18F-FDG PET is more sensitive and accurate at detecting bone metastases than BS. Currently, little evidence has accrued to support the superiority of 18F-fluoride (18F-NaF) PET in diagnosing osseous metastases or monitoring treatment response in breast cancer when compared with conventional imaging. In prostate cancer, the sensitivities of 18F-NaF PET/CT, 18F-fluorocholine (18F-choline), or 11C-choline PET/CT are equivalent, although 11C-/18F-choline PET/CT scans are more specific. Whole-body MRI, using anatomical sequences complemented by diffusion-weighted MRI, shows early evidence of utility for diagnosis and monitoring therapy response. We review the literature for staging and response assessment in metastatic breast and prostate cancer. While staging accuracy has significantly improved with hybrid imaging, optimal methods for assessing early treatment response have not been determined, and this is an area of active research.

If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections. General rightsCopyright and moral rights for the publications made accessible in the Research Portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognize and abide by the legal requirements associated with these rights. •Users may download and print one copy of any publication from the Research Portal for the purpose of private study or research. •You may not further distribute the material or use it for any profit-making activity or commercial gain •You may freely distribute the URL identifying the publication in the Research Portal Download date: 11. Jul. 2022 • [ 18 F]FDG PET/CT may help detect and facilitate monitoring of immunotherapy toxicity and help distinguish toxicity from disease progression or alternative inflammatory or infective pathology. (page 12) • Novel radiopharmaceuticals provide an opportunity to better characterize individual tumors and help define the immune tumor microenvironment. In vivo whole-body and longitudinal molecular imaging may allow dynamic real-time assessment and direct therapeutic approaches. (page 15

PurposeOsteoclast activity is an important factor in the pathogenesis of skeletal metastases and is a potential therapeutic target. This study aimed to determine if selective uptake of 99mTc-maraciclatide, a radiopharmaceutical targeting αvβ3 integrin, occurs in prostate cancer (PCa) bone metastases and to observe the changes following systemic therapy.MethodsThe study group comprised 17 men with bone-predominant metastatic PCa who underwent whole-body planar and single-photon emission computed tomography/computed tomography (SPECT/CT) imaging with 99mTc-maraciclatide before (n = 17) and 12 weeks after (n = 11) starting treatment with abiraterone. Tumour to normal bone (T:N) ratios, tumour to muscle (T:M) ratios and CT Hounsfield units (HU) were measured in up to five target metastases in each subject. An oncologist blinded to study scans assessed clinical responses up to 24 weeks using conventional criteria.ResultsBefore treatment, metastases showed specific 99mTc-maraciclatide accumulation (mean planar T:N and T:M ratios 1.43 and 3.06; SPECT T:N and T:M ratios 3.1 and 5.19, respectively). Baseline sclerotic lesions (389–740 HU) showed lower T:M ratios (4.22 vs. 7.04, p = 0.02) than less sclerotic/lytic lesions (46–381 HU). Patients with progressive disease (PD; n = 5) showed increased planar T:N and T:M ratios (0.29 and 12.1%, respectively) and SPECT T:N and T:M ratios (11.9 and 20.2%, respectively). Patients without progression showed decreased planar T:N and T:M ratios (0.27 and −8.0%, p = 1.0 and 0.044, respectively) and SPECT T:N and T:M ratios (−21.9, and −27.2%, p = 0.3 and 0.036, respectively). The percentage change in CT HU was inversely correlated with the percentage change in SPECT T:M ratios (r = −0.59, p = 0.006).Conclusions99mTc-maraciclatide accumulates in PCa bone metastases in keeping with increased αvβ3 integrin expression. Greater activity in metastases with lower CT density suggests that uptake is related to osteoclast activity. Changes in planar and SPECT T:M ratios after 12 weeks of treatment differed between patients with and without PD and 99mTc-maraciclatide imaging may be a potential method for assessing early response.