The Clinical Significance of Bone Mineral Density Changes Following Long-Term Androgen Deprivation Therapy in Localized Prostate Cancer Patients.

PURPOSE: Long-term androgen deprivation therapy has been associated with decreased bone mineral density in men with prostate cancer. Some evidence suggests that there is no impact on fracture risk despite this bone mineral density loss. Our study aimed to quantify changes in bone mineral density in men with high risk prostate cancer on long-term androgen deprivation therapy and calcium and vitamin D supplementation. MATERIALS AND METHODS: Bone mineral density analysis was conducted for localized high risk prostate cancer patients enrolled in the phase III randomized trial PCS-V (Prostate Cancer Study 5), comparing conventional and hypofractionated radiation therapy. Patients received 28 months of luteinizing hormone-releasing hormone agonist and calcium and vitamin D supplementation (500 mg calcium BID+400 IU vitamin D3 BID). The areal density and T-scores (spine, femoral neck and total femur) at baseline and 30 months of followup were extracted, and the absolute change was calculated. Clinical bone density status (normal, osteopenia, osteoporosis) was monitored. RESULTS: The lumbar spine, femoral neck and total femoral bone mineral density were measured for 226, 231, and 173 patients, respectively. The mean percent change in bone mineral density was -2.65%, -2.76% and -4.27% for these respective sites (p <0.001 for all). The average decrease in bone mineral density across all sites was -3.2%, with no decline in bone mineral density category in most patients (83%). Eight patients (4%) became osteoporotic. CONCLUSIONS: Despite a mild decline in bone mineral density, the change in clinical bone mineral density category remained low with long-term androgen deprivation therapy. Consequently, calcium and vitamin D supplementation alone may suffice for most localized prostate cancer patients on long-term androgen deprivation therapy.

Attitudes and beliefs toward the use of stereotactic body radiotherapy in oligometastatic breast cancer: A commentary on a survey of Canadian Medical Oncologists.

Stereotactic body radiotherapy (SBRT) is a highly ablative local therapy which has emerged as part of the treatment paradigm for patients with oligometastatic (OM) breast cancer (defined by 5 or fewer sites). This patient group has demonstrated improved prognosis in some cases and may therefore, benefit from aggressive local treatment. The role of upfront SBRT in newly diagnosed OM breast cancer in addition to systemic therapy is not clear, yet it is being increasingly utilized within the oncology community. The Canadian medical system is an ideal platform in which to investigate SBRT into the OM breast cancer setting, as it is not routinely implemented across centers at this time, as there is potential for robust collaboration between oncologists in the small community to investigate SBRT, and there is limited financial or industry motivation for early SBRT uptake compared with other countries. It is critical therefore to define the optimal patient population and scenarios for which SBRT should be investigated, as well as offered in the interim to Canadian patients. We therefore conducted a survey of Canadian Medical Oncologists, the primary physicians and gatekeepers of patients with OM breast cancer, to characterize their beliefs, opinions, and areas of controversy in the use of SBRT for OM breast cancer.

Ablative Therapies in Metastatic Breast Cancer: A Systematic Review.

PURPOSE: Patients with oligometastatic breast cancer are being increasingly offered ablative therapies, yet it is unclear which subpopulations may derive long-term benefit. This study sought to explore factors that could define a clinically relevant oligometastatic breast cancer population that benefits from ablative therapies. METHODS: A systematic review using MEDLINE for English language articles published between 1985 and April 2014 was undertaken. Criteria for review included studies that reported overall survival (OS) or progression-free survival (PFS) in breast cancer patients with distant metastases which also: quantified the extent of disease, had metachronous presentation of metastases, and reported on at least 5 patients. RESULTS: Of 59 674 screened studies, 41 studies of 1813 individual patients were identified. All studies were observational cohort studies (level 2B or 4 evidence) and underwent critical review. All outcomes pertaining to OS and PFS were extracted. Extracted data were too heterogeneous to facilitate a meta-analysis. The only factor that suggested worse outcomes was positive margins post-metastasectomy. There was no clear signal for improved outcomes in regards to age, disease extent, disease-free interval, or receptor status. CONCLUSION: Existing evidence does not provide meaningful direction on which metastatic breast cancer patients should have ablation of their residual disease due to heterogeneous reporting of disease factors, patient factors, and outcomes. Thorough demonstration of the absence of high- or moderate-level evidence and the absence of clinical data to guide patient selection suggests that metastatic breast cancer patients being treated with ablative modalities should be placed on clinical trial.

Six-Month Prostate Cancer Empowerment Program (PC-PEP) Improves Urinary Function: A Randomized Trial.

Purpose: This is a secondary analysis examining a six-month home-based Prostate Cancer-Patient Empowerment Program (PC-PEP) on patient-reported urinary, bowel, sexual, and hormonal function in men with curative prostate cancer (PC) against standard of care. Methods: In a crossover clinical trial, 128 men scheduled for PC surgery (n = 62) or radiotherapy with/without hormones (n = 66) were randomized to PC-PEP (n = 66) or waitlist-control and received the standard of care for 6 months, and then PC-PEP to the end of the year. PC-PEP included daily emails with video instructions, aerobic and strength training, dietary guidance, stress management, and social support, with an initial PFMT nurse consultation. Over 6 months, participants in the PC-PEP received optional text alerts (up to three times daily) reminding them to follow the PFMT video program, encompassing relaxation, quick-twitch, and endurance exercises; compliance was assessed weekly. Participants completed baseline, 6, and 12-month International Prostate Symptom Score (IPSS) and Expanded Prostate Cancer Index Composite (EPIC) questionnaires. Results: At 6 months, men in the PC-PEP reported improved urinary bother (IPSS, p = 0.004), continence (EPIC, p < 0.001), and irritation/obstruction function (p = 0.008) compared to controls, with sustained urinary continence benefits at 12 months (p = 0.002). Surgery patients in the waitlist-control group had 3.5 (95% CI: 1.2, 10, p = 0.024) times and 2.3 (95% CI: 0.82, 6.7, p = 0.11) times higher odds of moderate to severe urinary problems compared to PC-PEP at 6 and 12 months, respectively. Conclusions: PC-PEP significantly improves lower urinary tract symptoms, affirming its suitability for clinical integration alongside established mental health benefits in men with curative prostate cancer.

A Comprehensive 6-mo Prostate Cancer Patient Empowerment Program Decreases Psychological Distress Among Men Undergoing Curative Prostate Cancer Treatment: A Randomized Clinical Trial.

BACKGROUND: Although survival rates for newly diagnosed prostate cancer patients are very high, most of them will likely suffer significant treatment-related side effects, depression, or anxiety, affecting their quality of life. OBJECTIVE: The aim of this study was to examine the effects of a 6-mo online home-based physical, mental, and social support intervention, the Prostate Cancer Patient Empowerment Program (PC-PEP), on preventing psychological distress among men undergoing curative prostate cancer treatment. DESIGN, SETTING, AND PARTICIPANTS: In a crossover randomized clinical trial of 128 men aged 50-82 yr scheduled for curative prostate cancer surgery or radiotherapy (± hormone treatment), 66 received the 6-mo PC-PEP intervention and 62 were randomized to a waitlist-control arm and received the standard of care for 6 mo, and then PC-PEP to the end of the year. The PC-PEP intervention consisted of daily e-mails with video instructions providing education, patient activation, and empowerment on healthy living including physical and mental health, dietary recommendations, social support, physical and pelvic floor fitness, stress reduction using a biofeedback device, social connection and intimacy, and social support. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was nonspecific psychological distress (clinical cutoff ≥20) measured at baseline, and at 6 and 12 mo using the Kessler Psychological Distress Scale (K10). RESULTS AND LIMITATIONS: At 6 mo, patients in the waitlist-control group had 3.59 (95% confidence interval: 1.12-11.51) times higher odds for nonspecific psychological distress and need for psychological treatment than men who received the PC-PEP intervention. At 12 mo, the wait-list control group that received the intervention at 6 mo had higher psychological distress than the early group. CONCLUSIONS: PC-PEP delivered early following diagnosis significantly prevented the burden of psychological distress in men undergoing curative prostate cancer treatment compared with standard of care, or late (6 mo later) intervention. PATIENT SUMMARY: In this report, we looked at the effectiveness of a program (Prostate Cancer Patient Empowerment Program: PC-PEP) developed with patients' engagement on the mental distress of patients awaiting curative treatment for their prostate cancer. The PC-PEP program lasted for 6 mo, and it prescribed, described, and demonstrated daily aerobic and strength training, kegels (pelvic floor training to help with urinary and sexual function), dietary changes that have been shown to be helpful in the prevention of prostate cancer and prostate cancer progression, stress reduction using a biofeedback device, as well as social and emotional support. All patients in the PC-PEP program were invited to a monthly video conference with the leads of the program who appeared in the 6 mo of daily videos prescribing the activities the patients were asked to watch and follow. The leads were a prostate cancer oncologist and a scientist in prostate cancer quality of life research. Half of the patients in this study received PC-PEP daily for the first 6 mo and were re-assessed at the end of the year. The other half received standard of care for 6 month and then received the intervention to the end of the year. The results of the study show that, at 6 mo, this intervention was effective at reducing the mental distress that accompanies a prostate cancer diagnosis and treatment compared with the standard of care. Mental distress was significantly reduced when the intervention was received early, compared with that received late (6 mo after scheduled curative treatment). We conclude that multi-faceted patient education and empowerment programming of this kind that is developed with patient engagement from the start is crucial to the care of patients diagnosed with prostate cancer and should be implemented in the standard of care. While treatment for prostate cancer is highly successful, side effects that accompany most treatments significantly affect the quality of life of patients. Here, we describe PC-PEP, a patient education and activation program that is cost effective, highly enforced by patients, and successful at reducing the impact of prostate cancer active treatment-related side effects on their psychological state. To learn more about this project, please visit www.pcpep.org. The program is now being tested in a phase 4 implementation trial throughout Canada and internationally (New Zealand), and is being expanded and tested for other types of cancer.

Effectiveness of radiotherapy for local control in T3N0 rectal cancer managed with total mesorectal excision: a meta-analysis.

INTRODUCTION: The total mesorectal excision (TME) significantly improved rectal cancer outcomes. Radiotherapy's benefit in T3N0 rectal cancer patients managed with TME has not been clearly demonstrated. A systematic review and meta-analysis were undertaken to determine whether radiotherapy altered the risk of locoregional recurrence (LR) in T3N0 rectal cancer patients managed with a TME. MATERIALS AND METHODS: Studies indexed on PubMed or Embase were systematically searched from inception to October 18, 2020. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were observed for the literature search, study screening, and data extraction; the Newcastle Ottawa Scale evaluated bias; Grades of Recommendation, Assessment, Development, and Evaluation Working Group system evaluated certainty; and all were performed independently by at least two investigators. Studies that reported LR data specific to T3N0 rectal cancer patients managed with TME, treated with and without radiotherapy, were included. Data was pooled using a random-effects model. Meta-analyses of the relative risk of local recurrence were conducted. RESULTS: Five retrospective cohort studies involving 932 unique patients reported LR outcomes; no prospective studies met eligibility criteria. Median follow-up ranged from 38.4-78 months. Adjuvant radiotherapy was provided in 3 studies. Chemotherapy was delivered and reported in 4 studies, providing both concurrent and adjuvant chemotherapy. A non-significant LR reduction with radiotherapy alongside TME was estimated, mean relative risk (RR) 0.63 (95% Confidence Interval 0.31-1.29; I2 = 41.8%). CONCLUSIONS: A non-significant LR benefit with radiotherapy's addition was estimated. Meta-analysis of exclusively retrospective cohort studies was concerning for biased results. Adequately powered randomized trials are warranted.

Quality and Quantity: Evaluating Tumor Biology Alongside Novel Imaging on Diagnosis of Metastatic Hormone-sensitive Prostate Cancer.

Tumor biology may play an important role as an effective predictive biomarker that is complementary to functional imaging for metastatic hormone-sensitive prostate cancer.

Magnetic Resonance Imaging Based Radiomic Models of Prostate Cancer: A Narrative Review.

The management of prostate cancer (PCa) is dependent on biomarkers of biological aggression. This includes an invasive biopsy to facilitate a histopathological assessment of the tumor's grade. This review explores the technical processes of applying magnetic resonance imaging based radiomic models to the evaluation of PCa. By exploring how a deep radiomics approach further optimizes the prediction of a PCa's grade group, it will be clear how this integration of artificial intelligence mitigates existing major technological challenges faced by a traditional radiomic model: image acquisition, small data sets, image processing, labeling/segmentation, informative features, predicting molecular features and incorporating predictive models. Other potential impacts of artificial intelligence on the personalized treatment of PCa will also be discussed. The role of deep radiomics analysis-a deep texture analysis, which extracts features from convolutional neural networks layers, will be highlighted. Existing clinical work and upcoming clinical trials will be reviewed, directing investigators to pertinent future directions in the field. For future progress to result in clinical translation, the field will likely require multi-institutional collaboration in producing prospectively populated and expertly labeled imaging libraries.

The p14 FAST protein of reptilian reovirus increases vesicular stomatitis virus neuropathogenesis.

The fusogenic orthoreoviruses express nonstructural fusion-associated small transmembrane (FAST) proteins that induce cell-cell fusion and syncytium formation. It has been speculated that the FAST proteins may serve as virulence factors by promoting virus dissemination and increased or altered cytopathology. To directly test this hypothesis, the gene encoding the p14 FAST protein of reptilian reovirus was inserted into the genome of a heterologous virus that does not naturally form syncytia, vesicular stomatitis virus (VSV). Expression of the p14 FAST protein by the VSV/FAST recombinant gave the virus a highly fusogenic phenotype in cell culture. The growth of this recombinant fusogenic VSV strain was unaltered in vitro but was significantly enhanced in vivo. The VSV/FAST recombinant consistently generated higher titers of virus in the brains of BALB/c mice after intranasal or intravenous infection compared to the parental VSV/green fluorescent protein (GFP) strain that expresses GFP in place of p14. The VSV/FAST recombinant also resulted in an increased incidence of hind-limb paralysis, it infected a larger volume of brain tissue, and it induced more extensive neuropathology, thus leading to a lower maximum tolerable dose than that for the VSV/GFP parental virus. In contrast, an interferon-inducing mutant of VSV expressing p14 was still attenuated, indicating that this interferon-inducing phenotype is dominant to the fusogenic properties conveyed by the FAST protein. Based on this evidence, we conclude that the reovirus p14 FAST protein can function as a bona fide virulence factor.

A combined biological and clinical rationale for evaluating metastasis directed therapy in the management of oligometastatic prostate cancer.

The initial management of potentially oligometastatic hormone sensitive prostate cancer has been complicated by rapid advances in the field. Clinically, subgroup analyses of two randomized control trials have suggested that a specific synchronous oligometastatic prostate cancer state may be predictive for benefit from radiation to the primary. Further exploration of metastasis-directed therapy has been supported for various prostate cancer populations among three phase II clinical trials. There are numerous caveats in applying this evidence, a dilemma being addressed by present and upcoming clinical trials. Despite existing clinical equipoise and an avenue to address this uncertainty, the temptation to combine this evidence off-trial exists. Matters have become more complex as our ability to evaluate metastatic disease and tumour biology have also matured. This paper synthesizes our understanding of prostate cancer's natural history into a model which rationalizes both the theoretical benefits and limitations of metastasis directed therapy. We postulate that a metastatic prostate cancer's total disease activity is primarily driven by the combination of its burden of disease and underlying biology, namely genomic instability, then highlight the numerous remaining questions that challenge this hypothesis. This review focuses on harmonizing the language used to describe the disease, the current efforts exploring this hypothesis, and the need for clinical trial participation to appropriately advance patient care.

Combined Long-Term Androgen Deprivation and Pelvic Radiotherapy in the Post-operative Management of Pathologically Defined High-Risk Prostate Cancer Patients: Results of the Prospective Phase II McGill 0913 Study.

Purpose: Following radical prostatectomy, prostate bed radiotherapy (PBRT) has been combined with either long-term androgen deprivation therapy (LT-ADT) or short-term ADT with pelvic lymph node radiotherapy (PLNRT) to provide an oncological benefit in randomized trials. McGill 0913 was designed to characterize the efficacy of combining PBRT, PLNRT, and LT-ADT. It is the first study to do so prospectively. Methods: In a single arm phase II trial conduced from 2010 to 2016, 46 post-prostatectomy prostate cancer patients at a high-risk for relapse (pathological Gleason 8+ or T3) were assessed for treatment with combined LT-ADT (24 months), PBRT, and PLNRT. Patients received PLNRT and PBRT (44 Gy in 22 fractions) followed by a PBRT boost (22 Gy in 11 fractions). The primary endpoint was progression-free survival (PFS). Toxicity and quality of life (QoL) were evaluated using CTCAE V3.0 and EQ-5D-3L questionnaires, respectively. Results: Among the 43 patients were treated as per protocol, median PSA was 0.30 µg/L. On surgical pathology, 51% had positive margins, 40% had Gleason 8+ disease, 42% had seminal vesicle involvement, and 19% had lymph node involvement. At a median follow-up of 5.2 years, there were no deaths or clinical progression. At 5 years, PFS was 78.0% (95% Confidence Interval 63.7-95.5%). Not including erectile dysfunction, patients experienced: 14% grade 2 endocrine toxicity while on ADT, one incident of long-term gynecomastia, 5% grade 2 acute urinary toxicity, 5% grade 2 late Urinary toxicity, and 24% long-term hypogonadism. No comparison between the average or minimum self-reported QoL at baseline, during ADT, nor after ADT demonstrated a statistically significant difference. Conclusions: Combining PBRT, PLNRT, and LT-ADT had an acceptable PFS in patients with significant post-operative risk factors for recurrence. While therapy was well-tolerated, long-term hypogonadism was a substantial risk. Further investigations are needed to determine if this combination is beneficial. Trial registration: NCT01255891.

The Biology of Oligometastatic Prostate Cancer: A Different Beast than Polymetastatic Prostate Cancer.

The natural history and molecular biology of oligometastatic prostate cancer differentiate it from polymetastatic disease. Clinically, oligometastatic disease is also predictive and prognostic for different outcomes. Studies specific to this population are required to establish the benefits of intervention.

Radiomics in Glioblastoma: Current Status and Challenges Facing Clinical Implementation.

Radiomics analysis has had remarkable progress along with advances in medical imaging, most notability in central nervous system malignancies. Radiomics refers to the extraction of a large number of quantitative features that describe the intensity, texture and geometrical characteristics attributed to the tumor radiographic data. These features have been used to build predictive models for diagnosis, prognosis, and therapeutic response. Such models are being combined with clinical, biological, genetics and proteomic features to enhance reproducibility. Broadly, the four steps necessary for radiomic analysis are: (1) image acquisition, (2) segmentation or labeling, (3) feature extraction, and (4) statistical analysis. Major methodological challenges remain prior to clinical implementation. Essential steps include: adoption of an optimized standard imaging process, establishing a common criterion for performing segmentation, fully automated extraction of radiomic features without redundancy, and robust statistical modeling validated in the prospective setting. This review walks through these steps in detail, as it pertains to high grade gliomas. The impact on precision medicine will be discussed, as well as the challenges facing clinical implementation of radiomic in the current management of glioblastoma.

Does Interfraction Cone Beam Computed Tomography Improve Target Localization in Prostate Bed Radiotherapy?

PURPOSE: In this prospective phase II study, we investigated whether cone beam computed tomography scan was a superior method of image-guided radiotherapy relative to 2D orthogonal kilovoltage images in the post-radical prostatectomy setting. METHODS: A total of 419 treatment fractions were included in this analysis. The shifts required to align the patient for each treatment were performed using 3D matching between cone beam computed tomography scans and the corresponding computed tomography images used for planning. This was compared with the shifts obtained from 2D orthogonal kilovoltage images, matching with the corresponding digitally reconstructed radiographs. Patients did not have fiducials inserted to assist with localization. Interfractional changes in the bladder and rectal volumes were subsequently measured on the cone beam computed tomography images for each fraction and compared to the shift differences between orthogonal kilovoltage and cone beam computed tomography scans. The proportion of treatment fractions with a shift difference exceeding the planning target volume of 7 mm, between orthogonal kilovoltage and cone beam computed tomography scans, was calculated. RESULTS: The mean vertical, lateral, and longitudinal shifts resulted from 2D match between orthogonal kilovoltage images and corresponding digitally reconstructed radiographs were 0.353 cm (interquartile range: 0.1-0.5), 0.346 cm (interquartile range: 0.1-0.5), and 0.289 cm (interquartile range: 0.1-0.4), compared to 0.388 cm (interquartile range: 0.1-0.5), 0.342 cm (interquartile range: 0.1-0.5), and 0.291 cm (interquartile range: 0.1-0.4) obtained from 3D match between cone beam computed tomography and planning computed tomography scan, respectively. Our results show a significant difference between the kilovoltage and cone beam computed tomography shifts in the anterior-posterior direction ( P = .01). The proportion of treatment fractions in which the differences in kilovoltage and cone beam computed tomography shifts between exceeded the 7 mm planning target volume margin was 6%, 2%, and 3% in the anterior-posterior, lateral, and superior-inferior directions, respectively. CONCLUSION: We prospectively demonstrated that the daily use of volumetric cone beam computed tomography for treatment localization in post-radical prostatectomy patients demonstrated an increased need for a shift in patient position. This suggests that in post-radical prostatectomy patients the daily cone beam computed tomography imaging improved localization of the prostate bed and may have prevented a limited number of geographic misses, compared to daily kilovoltage imaging that was not assisted with fiducials.

Multimodal Radiomic Features for the Predicting Gleason Score of Prostate Cancer.

BACKGROUND: Novel radiomic features are enabling the extraction of biological data from routine sequences of MRI images. This study's purpose was to establish a new model, based on the joint intensity matrix (JIM), to predict the Gleason score (GS) of prostate cancer (PCa) patients. METHODS: A retrospective dataset comprised of the diagnostic imaging data of 99 PCa patients was used, extracted from The Cancer Imaging Archive's (TCIA) T2-Weighted (T2-WI) and apparent diffusion coefficient (ADC) images. Radiomic features derived from JIM and the grey level co-occurrence matrix (GLCM) were extracted from the reported tumor locations. The Kruskal-Wallis test and Spearman's rank correlation identified features related to the GS. The Random Forest classifier model was implemented to identify the best performing signature of JIM and GLCM radiomic features to predict for GS. RESULTS: Five JIM-derived features: contrast, homogeneity, difference variance, dissimilarity, and inverse difference were independent predictors of GS (p < 0.05). Combined JIM and GLCM analysis provided the best performing area-under-the-curve, with values of 78.40% for GS ≤ 6, 82.35% for GS = 3 + 4, and 64.76% for GS ≥ 4 + 3. CONCLUSION: This retrospective study produced a novel predictive model for GS by the incorporation of JIM data from standard diagnostic MRI images.

Evaluation of pseudoprogression in patients with glioblastoma.

BACKGROUND: Management of glioblastoma is complicated by pseudoprogression, a radiological phenomenon mimicking progression. This retrospective cohort study investigated the incidence, prognostic implications, and most clinically appropriate definition of pseudoprogression. METHODS: Consecutive glioblastoma patients treated at the Juravinski Hospital and Cancer Centre, Hamilton, Ontario between 2004 and 2012 with temozolomide chemoradiotherapy and with contrast-enhanced MRI at standard imaging intervals were included. At each imaging interval, patient responses as per the RECIST (Response Evaluation Criteria in Solid Tumors), MacDonald, and RANO (Response Assessment in Neuro-Oncology) criteria were reported. Based on each set of criteria, subjects were classified as having disease response, stable disease, pseudoprogression, or true progression. The primary outcome was overall survival. RESULTS: The incidence of pseudoprogression among 130 glioblastoma patients treated with chemoradiotherapy was 15%, 19%, and 23% as defined by RANO, MacDonald, and RECIST criteria, respectively. Using the RANO definition, median survival for patients with pseudoprogression was 13.0 months compared with 12.5 months for patients with stable disease (hazard ratio [HR]=0.70; 95% confidence interval [CI], 0.35-1.42). Similarly, using the MacDonald definition, median survival for the pseudoprogression group was 11.8 months compared with 12.0 months for the stable disease group (HR=0.86; 95% CI, 0.47-1.58). Furthermore, disease response compared with stable disease was also similar using the RANO (HR=0.52; 95% CI, 0.20-1.35) and MacDonald (HR=0.51: 95% CI, 0.20-1.31) definitions. CONCLUSIONS: Of all conventional glioblastoma response criteria, the RANO criteria gave the lowest incidence of pseudoprogression. Regardless of criteria, patients with pseudoprogression did not have statistically significant difference in survival compared with patients with stable disease.

Assessing the impact of incidental findings in a lung cancer screening study by using low-dose computed tomography.

PURPOSE: To assess the prevalence and nature of incidental findings (IF) seen in low-dose computed tomographies (LDCT) from a lung cancer screening study for at-risk individuals. MATERIALS AND METHODS: Radiology reports from LDCTs of 4073 participants of a lung cancer screening study were retrospectively reviewed for findings other than lung nodules, that is, IFs, which were regarded as actionable. The frequency, nature, and expected cost of these IFs, and their anticipated follow-up were estimated. RESULTS: There were 880 IFs described in 782 study participants (19%); the median age of the participants was 62 years (range, 46-80 years). More IFs were found in men (55%) than in women. The majority of these findings were noncardiovascular (76%), for which imaging was suggested for 74%. There were 7 severe IFs (0.8%) that merited immediate attention. Seven known cancers were diagnosed from follow-ups of the IFs. The majority of IFs (n = 486 [55%]) would require imaging follow-up if clinically indicated, with an estimated total a cost of CAN$45,500 to CAN$51,000 to provide initial diagnostic workup. CONCLUSION: IFs on lung cancer screening studies are not uncommon and frequently require imaging or other follow-up for definitive diagnoses and to assess their clinical relevance. The implication of IFs has to be considered when determining a cost-effective and ethical protocol for the utilisation of LDCT in a high-risk population.