Prostatic Lesions Research Articles

Cancer Detection Rate of MRI Ultrasound Fusion Prostate Biopsy in 1,039 Patients and Number Needed to Biopsy in Targeted Lesion

Objective: To determine the cancer detection rate (CDR) of magnetic resonance imaging ultrasound fusion prostate biopsy (MRI/US fusion prostate biopsy) in Thailand. The secondary aim was to estimate the number needed to biopsy (NNB) for each prostate lesion in a targeted biopsy, classified by Prostate Imaging-Reporting and Data System (PI-RADS). Materials and Methods: The data of 1,039 consecutive patients who underwent a MRI/US fusion prostate biopsy at Siriraj Hospital between September 2017 and February 2021 was included and retrospectively reviewed. Those included had previous negative biopsies and were biopsy naïve. The data was analyzed to find the detection rate and NNB. Results: The overall detection rate of MRI/US fusion prostate biopsy was 58.71%, whereas that of systematic biopsy was 45.72%. Clinically significant prostate cancer (csPCa) (Gleason score ≥ 3+4) detection rate of MRI/US fusion prostate biopsy was 51.01%. When categorized by PI-RADS category 3, 4, and 5 were 12.16%, 44.98%, 85.71% respectively. NNB in targeted biopsy of PI-RADS 3, 4, and 5 were 8, 7, and 3 times sequentially. Positive predictive factors for prostate cancer (PCa) detection were age, prostate-specific antigen density (PSAD) and PI-RADS, whereas prostate volume was a negative predictive factor. Conclusion: This study supports the role of MRI/US fusion prostate biopsy in PCa detection and should not avoid systematic biopsies. The higher the PI-RADS was, the greater the csPCa detection rate. NNB is helpful in guiding the least amount of biopsied cores for each lesion.

Relative fat fraction of malignant bone lesions from breast cancer, prostate cancer and myeloma are significantly lower than normal bone marrow and shows excellent interobserver agreement.

To compare relative fat fraction (rFF) of active bone lesions from breast, prostate and myeloma malignancies and normal bone marrow; to assess its inter-reader agreement. Patients with breast (n = 26), myeloma (n = 32) and prostate cancer (n = 52) were retrospectively evaluated. 110 baseline rFF maps from whole-body MRI were reviewed by two radiologists. Regions of interest for up to four focal active lesions in each patient were drawn on rFF maps, one each at the cervicothoracic spine, lumbosacral spine, pelvis and extremity. The mean and standard deviation of rFF were recorded. The rFF of normal marrow was measured in the pelvis for patients without diffuse bone disease (n = 88). We compared the rFF of malignant bone lesions and normal marrow using Mann-Whitney test. Interobserver agreement was assessed by interclass correlation coefficient. Malignant bone lesions showed significantly lower median rFF (13.87%) compared with normal marrow (89.76%) with little overlap (p < 0.0001). There was no significant difference in the median rFF of malignant lesions from breast (14.46%), myeloma (13.12%) and prostate cancer (13.67%) (p > 0.017, Bonferroni correction) and in the median rFF of bone disease according to their anatomical locations (p > 0.008, Bonferroni correction). There was excellent interobserver agreement (0.95). The low rFF of active bone lesions in breast, prostate and myeloma malignancies provides high image contrast relative to normal marrow that may be used to detect bone metastases. This study shows the importance of rFF towards detecting bone metastases.

Comparison in Detection Rate of Clinically Significant Prostate Cancer Between Microultrasound-guided Prostate Biopsy (ExactVu) and Multiparametric Resonance Imaging-guided Prostate Biopsy (Koelis System)

ObjectivesTo compare the detection rate of clinically significant prostate cancer (csPC) and prostate cancer and to find out the diagnostic concordance between microultrasound (mUS), a high-resolution imaging system that can identify suspicious prostate lesions and biopsy them in real time, and multiparametric magnetic resonance imaging (mpMRI)-guided prostate fusion biopsies. MethodsA prospective, multicentre, single-blind, single cohort study was conducted involving 80 patients with clinically suspected prostate cancer who underwent concomitant mpMRI-guided fusion prostate biopsy (KoelisTM System) and microultrasound-guided biopsy (ExactVuTM System) Results:The detection rate of csPC was slightly higher for image-guided fusion biopsy (21.25% vs. 18.75%), but this difference was not statistically significant (p=0.453). There was also no significant difference in overall PC diagnosis (50% vs. 51.25%, p = 0.897). The degree of agreement between the two diagnostic techniques for the detection of csPC as assessed by Cohen's Kappa concordance index was satisfactory κ ̂ = 0.676. The degree of ISUP of targeted biopsies obtained from concordant lesions was also represented by satisfactory concordance with a Kappa index of κ ̂ = 0. 696. ConclusionsMicroultrasound-guided biopsy is presented as an effective diagnostic method for the diagnosis of csPC compared to image-guided fusion biopsy. No differences are found in the detection rates of csPC and PC between the two strategies and satisfactory concordance is found in terms of histopathological findings.

Massive pre-prostatic nodal metastasis from localized aggressive prostate cancer removed during robotic-assisted radical prostatectomy with extended pelvic lymph node dissection: a case report with brief literature review

BackgroundDuring robotic-assisted radical prostatectomy (RARP) for prostate cancer (PCa), few attention is given to pre-prostatic fat tissue (PPT) even during pelvic lymph node dissection (PLND). However, the rare potential involvement of PPT lymph nodes (LN) by PCa metastasis has already been reported by several authors and may influence therapeutic strategy in intermediate and high-risk patients. We present the case of a 69-year-old man who underwent RARP with extended PLND (ePLND) for aggressive PCa with massive pre-prostatic nodal metastasis, sampled during prostate biopsies. We sought to report this case for the particular preoperative images and reinforce benefits of resecting PPT during PLND for PCa.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [Moncef] Last name [Al Barajraji].OkCase presentationA 69-year-old man consulted our department for high serum prostate specific antigen level (57 ng/mL). He had familial history of PCa only at first degree. On digital rectal evaluation, induration of left prostatic lobe was felt. Transrectal ultrasonography showed hypoechogenic lesion in left prostatic lobe with supra-centimetric nodule in PPT. Pelvic magnetic resonance revealed two lesions in the peripheral zone with a 19-mm nodule on right paramedian side of PPT (see Fig. 1). Transrectal ultrasound-guided prostate biopsies were performed, including the nodule. On left side, 2 biopsies out 6 showed Gleason 10 prostate cancer. On right side, all biopsies showed Gleason 9 prostate cancer. The PPT nodule showed Gleason 9 prostate cancer. Prostate specific membrane antigen (PSMA) positron emission tomography computed tomography scan showed hypermetabolic expression from left prostate lesions and PPT nodule. Transperitoneal RARP with ePLND was performed including PPT. Histopathological study revealed advanced prostate cancer with lymphovascular invasion and ECE (see Fig. 2). Evaluation of ePLND material showed metastasis in on pelvic LN and 23 mm nodal metastasis in PPT (see Fig. 2). Therefore, adjuvant therapy was initiated.Please check the edit made in the article title.OPkConclusionsPPT resection is not part of routine RARP with ePLND for PCa. However, this tissue might contain LN harbouring metastasis independently from pelvic LN, indicating adjuvant therapy in case of upstaging. Considering the low morbidity of resecting PPT and its facility, it should always been resected and sent for analysis in intermediate and high-risk PCa.

Quantitative Evaluation of Apparent Diffusion Coefficient Values, ISUP Grades and Prostate-Specific Antigen Density Values of Potentially Malignant PI-RADS Lesions

The aim of this study was to demonstrate the correlation between ADC values and the ADC/PSAD ratio for potentially malignant prostate lesions classified into ISUP grades and to determine threshold values to differentiate benign lesions (noPCa), clinically insignificant (nsPCa) and clinically significant prostate cancer (csPCa). We enrolled a total of 403 patients with 468 prostate lesions, of which 46 patients with 50 lesions were excluded for different reasons. Therefore, 357 patients with a total of 418 prostate lesions remained for the final evaluation. For all lesions, ADC values were measured; they demonstrated a negative correlation with ISUP grades (p &lt; 0.001), with a significant difference between csPCa and a combined group of nsPCa and noPCa (ns-noPCa, p &lt; 0.001). The same was true for the ADC/PSAD ratio, but only the ADC/PSAD ratio proved to be a significant discriminator between nsPCa and noPCa (p = 0.0051). Using the calculated threshold values, up to 31.6% of biopsies could have been avoided. Furthermore, the ADC/PSAD ratio, with the ability to distinguish between nsPCa and noPCa, offers possible active surveillance without prior biopsy.

Prostate-specific antigen doubling time predicts the efficacy of site-directed therapy for oligoprogressive castration-resistant prostate cancer

BackgroundIn recent years, site-directed therapies (SDTs) targeting progressive lesions in patients with oligometastatic prostate cancer have attracted attention. However, whether they effectively treat oligoprogressive castration-resistant prostate cancer (CRPC) remains unclear. Here, we investigated the efficacy of SDT in patients with oligoprogressive CRPC and identified prognostic factors. MethodsWe reviewed 59 patients with oligoprogressive CRPC who underwent SDT targeting prostate or metastatic lesions between April 2014 and March 2022. We evaluated the associations between several pretreatment clinical variables and treatment procedures and a >50% prostate-specific antigen (PSA) response, progression-free survival (PFS), and time to next treatment (TTNT). ResultsA PSA response of >50% was observed in 66% of patients. The median PFS and TTNT were 8.3 months and 9.9 months, respectively. Patients with PSA doubling time ≥6 months showed a higher >50% PSA response rate (87% vs. 45%; P < 0.001), longer PFS (median, 15.0 vs. 5.0 months; P < 0.001), and longer TTNT (median, 16.3 vs. 5.9 months; P < 0.001) than patients with PSA doubling time <6 months. In multivariate analyses, a PSA doubling time of ≥6 months independently predicted a >50% PSA response, favorable PFS, and TTNT (P = 0.037, 0.025, and 0.017, respectively). ConclusionPSA doubling time of ≥6 months may be a key indicator of the favorable efficacy of SDT for oligoprogressive CRPC.

Head-to-Head Comparison of 68Ga-PSMA-11 with 68Ga-P137 in Patients with Suspected Prostate Cancer.

P137 is a novel oxalyldiaminopropionic acid-urea-based prostate-specific membrane antigen (PSMA) targeting agent. This study compared the uptake patterns of 68Ga-P137 and the FDA-approved PET tracer 68Ga-PSMA-11 for diagnosing prostate cancer (PCa). Sixteen patients suspected of PCa were scanned by 68Ga-PSMA-11 and 68Ga-P137 PET/CT, respectively, followed by prospective analysis. The tumor-to-background ratio was calculated using normal prostate tissue, blood pool, muscle, and urine as backgrounds. Pathology or follow-up results were used to analyze uptake patterns of benign/malignant lesions and various organs. Thirteen patients were diagnosed with PCa and three with benign prostate diseases (BPD). The number and location of primary lesions, lymph node metastasis (LNM) (n = 25), bone metastasis (n = 30), and liver metastasis (n = 3) detected by the two tracers were identical. Maximum standardized uptake value (SUVmax), tumor/normal prostate ratio, as well as semiquantitative miPSMA-ES and PRIMARY diagnostic scores (P all >0.05) showed similar uptake levels of primary lesions between 68Ga-P137 and 68Ga-PSMA-11. Compared to 68Ga-P137, the SUVmax of 68Ga-PSMA-11 was significantly higher for bone metastasis, LNM, and liver metastasis (14.9 ± 7.2 vs 9.1 ± 4.4, 14.4 ± 5.0 vs 7.5 ± 2.4, 13.9 ± 2.0 vs 8.8 ± 2.4, P all <0.05). One-hour postinjection, SUVmax of the duodenum (9.4 ± 2.1 vs 16.2 ± 6.1), kidney (19.4 ± 4.3 vs 45.6 ± 20.9), and urine (14.1 ± 7.1 vs 42.1 ± 25.9) were significantly lower for 68Ga-P137 than for 68Ga-PSMA-11 (P all <0.05), whereas the radioactivity accumulation of blood pool and muscle (3.9 ± 0.5 vs 1.6 ± 0.4, 1.0 ± 0.1 vs 0.6 ± 0.1, P all <0.05) of 68Ga-P137 was significantly higher than 68Ga-PSMA-11. The uptake level of 68Ga-P137 has no significant difference from that of 68Ga-PSMA-11 in prostate primary lesions, and their imaging performances are visually equivalent for both primary and metastatic lesions, despite a higher blood pool and muscle background and a lower uptake in metastatic lesions. Due to the lower urine excretion of 68Ga-P137, primary prostate lesions near the urine can potentially be displayed clearer than 68Ga-PSMA-11.

Lutétium-177 en Médecine Nucléaire

The most developed clinical fields using lutetium 177 initially concerned neuroendocrine tumors overexpressing somatostatin receptors. Secondary prostate lesions expressing prostate-specific membrane antigen (PSMA) represent a potentially significant new field of application. This article proposes a synthesis concerning this radionuclide, both γ and β- emitter, which is of medical interest for theranostic applications.

SAT521 Predictive Value of Tumor Volumetrics in Patients with Medullary Thyroid Cancer

Abstract Disclosure: N. Behairy: None. S. Gubbi: None. M.G. Pascoal: None. A. Bharadwaj: None. E.C. Wright: None. T. Abijo: None. N. Uttarkar Vikram: None. P. Veeraraghavan: None. C. Cochran: None. J. Glod: None. J. Klubo-Gwiezdzinska: None. Predictive Value of Tumor Volumetrics in Patients with Medullary Thyroid Cancer Background Medullary thyroid cancer (MTC) is a rare endocrine malignancy that can present either as a sporadic disease or as a part of inherited autosomal dominant multiple endocrine neoplasia type 2A (MEN2A) and 2B (MEN2B) syndromes. There is limited data on the prognostic value of the tumor volume (TV) doubling time (TVDT) in patients with sporadic and familial MTC. Therefore, the goal of this study was to examine the association between TVDT and disease-specific survival (DSS) in patients with metastatic MTC. Material and Methods This cohort study included patients with metastatic MTC for whom at least 3 follow-up CT/MRI scans revealed ≥2 measurable lesions and up to the 5 largest lesions in each affected organ were analyzed. The tumor volumes were measured in 2 dimensions (2D) per standard practice reporting and 3 dimensions (3D) using an ellipsoid formula. The average TVDT of all measured lesions in each organ with metastatic deposits was calculated using a previously reported formula. Calcitonin (Ct-DT) and CEA doubling times (CEA-DT) were assessed using the American Thyroid Association Guidelines calculator. The association between DSS and TVDT, Ct-DT, and CEA-DT was tested using Cox regression. Correlations were assessed using a Spearman correlation coefficient. The study was approved by the Institution Review Board. Results The study cohort consisted of 51 patients (27 women, 53%) with age at the initial scan 24 ± 17 years and an average primary tumor size of 3.3±2.0 cm. Seven patients presented with sporadic MTC, 12 with MEN2A and 32 with MEN2B. During a follow-up of 8.0±4.3 years, 28/51 (55%) patients had disease progression and required systemic or local therapies and 9/51 (18%) patients died. A total of 456 scans were analyzed documenting that the organs with the most rapid TVDT were neck masses in 25/51 (49%), liver metastases in 16/51 (31%), lung nodules in 7/51 (14%) and prostate lesions in 3/51 (6%) patients. There was a strong correlation between 2D and 3D TVDT (r = 0.96) as well as between Ct-DT and CEA-DT (r = 0.82). However, the correlation between 2D TVDT and Ct-DT and CEA-DT were low (r = 0.45 for both). The DSS hazard ratios (HR) for DT &amp;lt;1 year compared to ≥3 years were 8.2 (1.5-45.4) for 2D TVDT, 8.7 (1.6-48.2) for 3D TVDT, 15.9 (1.72-146.7) for Ct-DT, and 11.72 (2.0-68.7) for CEA-DT. DSS was not associated with either familial or sporadic etiology of MTC (p = 0.38), gender (p = 0.12), or age at initial scan (p = 0.85). Conclusions Apart from Ct-DT and CEA-DT, TVDT is a valuable prognostic factor in metastatic MTC. Given a strong correlation between 2D and 3D TVDT, standard 2D-based TVDT measurements might be used as an easily obtained and clinically feasible prognostic marker of DSS in MTC patients. Presentation Date: Saturday, June 17, 2023

Impact of forced diuresis at two different time points on pelvic imaging in prostatic carcinoma with 68Ga-PSMA PET/CT.

We compared diagnostic quality of 68Ga-PSMA PET/CT imaging focused on the pelvic structures using two furosemide protocols in two different groups of patients. A total of 55 patients with prostate cancer were retrospectively enrolled in the study. Out of 55, 31 patients were in group 1 (median age: 66 years, Range 44-78 years) in which furosemide injection was given after completion of whole-body 68Ga-PSMA PET/CT scan and 24 patients were in group 2 (median age: 63.5 years, range: 50-82 years) in which it was given along with the 68Ga-PSMA injection. In both groups, an initial time point scan (T0 scan) and a delayed time point scan (T1scan) were done. The images were analyzed qualitatively as well as quantitatively. Quantitatively there was no statistically significant difference between the SUVmax and T:B of prostatic lesion and seminal vesicle invasion (SVI) in both the groups at two time points (P > 0.05). Early furosemide injection caused a washout of the urinary bladder radiotracer concentration in significantly higher number of patients in group 2 (62.5% vs. 6.45% patients, P < 0.001). There was significant clearance of radiotracer activity from the ureters in group 2 (SUVmax: 9.28 vs. 3.09, P = 0.002). The simultaneous furosemide and 68Ga-PSMA injection can reduce the urinary excretion of the tracer and improve the diagnostic confidence of prostatic lesion, SVI and lymph nodal metastasis, along with reducing the scanning time and radiation burden, making this protocol an effective alternative to the present protocol of delayed furosemide injection.

Radiation-Associated Lymphopenia in Advanced Prostate Cancer Treated with Contemporary Radiation Techniques.

Lymphocytes play a critical role in the immune system as primary effector cells for cancer control, often depleted by external beam radiation therapy (EBRT). Radiation-associated lymphopenia (RAL) has been shown to be a poor prognostic factor in the management of multiple solid tumors. We hypothesize RAL is similarly observed in advanced prostate cancer (PC) RT with contemporary techniques. We identified patients with advanced PC (high-risk or clinical/pathologic node-positive) receiving EBRT including lymph node/prostatic lesion boost on a prospective collection protocol for whom 1 baseline and ≥2 subsequent complete blood count (CBC) with differential samples were available, collected at RT end, 3-, 6-, and 12-months post-RT. Clinicopathological characteristics were retrieved from chart review. Common Terminology Criteria for Adverse Events (CTCAE)v5 was used to grade absolute lymphocyte count (ALC); RAL was defined as CTCAEv5 grade ≥2. As these patients received pelvic nodal irradiation, they were pooled with low/intermediate-risk PC cohort treated with high dose-rate (HDR) brachytherapy or prostate alone EBRT with similar CBC timepoints for univariable analysis to understand RT field size effect on RAL. Between 2019 and 2022, among 17 patients in the low/intermediate-risk PC cohort, 6 patients had grade ≥2 lymphopenia. Among 25 patients in the advanced PC cohort, all received androgen deprivation therapy (ADT), 6 received lymph node boost, and 5 received prostatic lesion boost. At RT end, leukopenia was prominently observed (median nadir count 75.1% of baseline), with ALC as major driver (median nadir count 27.3% of baseline). Grade ≥2 lymphopenia was observed in 76% of patients (n = 19) Of 19 advanced PC patients who reached 6 months post-RT follow-up, median ALC was 53.0% of baseline, and Grade ≥2 lymphopenia remained in 37% (n = 7) of patients. Of 8 advanced PC patients who reached 12 months post-RT follow-up, median ALC was 55.6% of baseline. When evaluating whether RT dose or field size contributed to lower nadir ALC counts, combining the low/intermediate-risk and advanced PC cohorts (n = 42), univariable analysis demonstrated Gleason grade group (p = 0.009), RT field size (p = 0.020), ADT use (p = 0.020), baseline ALC (p = 0.037), and baseline hemoglobin (p = 0.009) were independent predictors of Grade ≥2 lymphopenia. Age, prostatic lesion/lymph node boost, and equivalent dose in 2 Gy/fraction (EQD2) were nonsignificant. Grade ≥2 RAL was observed in patients with advanced PC at end of RT, irrespective of age, RT boost, or EQD2. Lymphocyte recovery from baseline can be prolonged even at 12 months post-RT. Ongoing analyses include expanding data with additional serial CBC, increasing cohort size, and integrating effect of additional systemic therapies. RAL has downstream implications for future chemotherapy/radiopharmaceuticals.

Added Value of Prostate-specific Antigen Density in Selecting Prostate Biopsy Candidates Among Men with Elevated Prostate-specific Antigen and PI-RADS ≥3 Lesions on Multiparametric Magnetic Resonance Imaging of the Prostate: A Systematic Assessment by PI-RADS Score

BackgroundA significant proportion of patients with positive multiparametric magnetic resonance imaging (mpMRI; Prostate Imaging-Reporting and Data System [PI-RADS] scores of 3–5) have negative biopsy results. ObjectiveTo systematically assess all prostate-specific antigen density (PSAD) values and identify an appropriate cutoff for identification of patients with positive mpMRI who could potentially avoid biopsy on the basis of their PI-RADS score. Design, setting, and participantsThe study included a cohort of 1341 patients with positive mpMRI who underwent combined targeted and systematic biopsies. Outcome measurements and statistical analysisMultivariable logistic regression analysis (MVA) was used to assess the association between PSAD and the risk of clinically significant prostate cancer (csPCa, grade group ≥2) after adjusting for confounders. We used locally weighted scatterplot smoothing to explore csPCa risk according to PSAD and PI-RADS scores. PSAD utility was observed only for patients with PI-RADS 3 lesions, so we plotted the effect of each PSAD value as a cutoff for this subgroup in terms of biopsies saved, csPCa cases missed, and clinically insignificant PCa (ciPCa, grade group 1) cases not detected. Results and limitationsOverall, 667 (50%) csPCa cases were identified. On MVA, PSAD independently predicted csPCa (odds ratio 1.57; p < 0.001). For PI-RADS ≥4 lesions, the csPCa risk was ≥40% regardless of PSAD. Conversely, among patients with PI-RADS 3 lesions, csPCa risk ranged from 0% to 60% according to PSAD values, and a PSAD cutoff of 0.10 ng/ml/cm3 corresponded to a threshold probability of 10% for csPCa. Using this PSAD cutoff for patients with PI-RADS 3 lesions would have saved 32% of biopsies, missed 7% of csPCa cases, and avoided detection of 34% of ciPCa cases. Limitations include selection bias and the high experience of the radiologists and urologists involved. ConclusionsPatients with PI-RADS ≥4 lesions should undergo prostate biopsy regardless of their PSAD, while PSAD should be used to stratify patients with PI-RADS 3 lesions. Using a threshold probability of 10% for csPCa, our data suggest that the appropriate strategy is to avoid biopsy in patients with PI-RADS 3 lesions and PSAD <0.10 ng/ml/cm3. Our results also provide information to help in tailoring an appropriate strategy for every patient with positive mpMRI findings. Patient summaryWe investigated whether a cutoff value for PSAD (prostate-specific antigen density) could identify patients with suspicious prostate lesions on MRI (magnetic resonance imaging) who could avoid biopsy according to the PI-RADS score for their scan. We found that patients with PI-RADS ≥4 should undergo prostate biopsy regardless of their PSAD. A PSAD cutoff of 0.10 should be used to stratify patients with PI-RADS 3.

Use of Focal Radiotherapy Boost for Prostate Cancer and Perceived Barriers toward its Implementation: A Survey.

In a recent phase III randomized control trial (FLAME), delivering a focal radiotherapy (RT) boost to tumors visible on MRI was shown to improve outcomes for prostate cancer patients without increasing toxicity. The aim of this study was to assess how widely this technique is being applied in current practices worldwide as well as physicians' perceived barriers toward its implementation. An online survey assessing the use of intraprostatic focal boost was conducted in December 2022 and February 2023. The survey link was distributed to radiation oncologists worldwide via email list, group text platform, and social media. Survey questions included how many prostate cancer cases participants treat in a typical month; how often they use focal boost, if at all; the degree to which their practice is genitourinary (GU)-subspecialized; main barriers to implementing focal boost more often in their practice; and demographic information. Subgroup analyses were also conducted for participants from high-income or low-to-middle-income countries, as defined by the World Bank. The survey initially collected 205 responses from various countries over a two-week period in December 2022. The survey was then reopened for one week in February 2023 to allow for more participation, leading to a total of 263 responses. The highest-represented countries were the United States (42%), Mexico (13%), and the United Kingdom (8%). The majority of respondents worked at an academic medical center (52%) and considered their practice to be at least partially GU-subspecialized (74%). 57% of participants overall reported not routinely using intraprostatic focal boost. Even among complete subspecialists, a substantial proportion (39%) do not routinely use focal boost. Less than half of participants in both high-income and low-to-middle-income countries were shown to routinely use focal boost. Perceived barriers to implementation are shown in Table 1. Despite the promising level 1 results of the FLAME trial, many radiation oncologists worldwide are not routinely offering focal RT boost. Adoption of this technique might be accelerated by increased access to high-quality MRI, better registration algorithms of MRI to CT simulation images, physician education on benefit-to-harm ratio, automated planning algorithms, and physician training on contouring prostate lesions on MRI.

Dosimetric Plan Evaluation of Biology Guided Radiotherapy Using [18F]-DCFPyL PSMA Radiotracer in Patients with Prostate Cancer

The X1 system represents a cutting-edge solution in radiotherapy delivery, with its capability to perform Biology Guided Radiotherapy (BgRT). The system utilizes real-time positron emission tomography (PET) signal as biological fiducials to provide tracked dose delivery and is initially available for use with [18F]-Fluorodeoxyglucose (FDG). The aim of this research study is to assess the quality of BgRT treatment plans for prostate cancer using patients' PSMA PET images obtained on the X1 system. Sixteen patients with at least one PET-avid tumor identified on their whole-body diagnostic PSMA PET scan were selected. These patients were scanned on X1 following their diagnostic scan without additional radiotracer administration. Based on the X1 PET images, a BgRT plan was created for each patient, with the prescription dose determined by the location of treatment sites. The planning objectives of organs-at-risk (OARs) were established in accordance with the 2018 Timmerman guidelines. Target coverage objective was the dose covering 95% (D95%) of the planning target volume (PTV) to be higher than 100%. The following parameters were analyzed: PTV D95%, the minimal dose (Dmin) of gross tumor volume (GTV), plan maximum dose (Dmax), conformity index (CI), gradient index (GI), and maximum point dose (D0.03cc) to the nearest OARs. The X1 BgRT planning system also generated dose volume histogram (DVH) bounds, which model variations in BgRT delivery. The low boundary of GTV Dmin, representing the minimum GTV dose in the worst-case scenario, was recorded. BgRT plans were created for all patients, except for one where the target signal was indistinguishable from the bladder. The prescription dose was 2700 cGy or 3000 cGy in 3 fractions for lymph node lesions, 2400 cGy to 3000 cGy in 3 fractions for bone metastasis, and 4500 cGy in 5 fractions for lesions in prostate. All plans met the dose constraints for OARs as per the Timmerman guidelines. The Dmax of all plans was 129.9% ± 6.9% (mean ± standard deviation). The PTV D95% and GTV Dmin were 101.7% ± 1.0% and 111.0% ± 7.6%, respectively. The low boundary of GTV Dmin was 95.9% ± 5.8%. The CI and GI were 1.22 ± 0.11 and 9.40 ± 2.12, respectively. The D0.03cc to nearest OARs was 84.6% ± 25.4%. The estimated treatment time was 699 ± 228 seconds. This study is a pioneering effort to evaluate the quality of BgRT plans for prostate cancer patients using the [18F]-DCFPyL PSMA radiotracer. Our results showed that all BgRT plans met the planning objectives defined in the Timmerman protocol. BgRT with [18F]-DCFPyL represents a promising treatment modality for patients with prostate cancer. Further research is needed to validate this approach, including a comprehensive assessment of the dosimetric and tracking accuracy through physical measurements.

Validation of Hypoxia Detection Sequences on the MR Linac

Magnetic resonance linear accelerator (MRL) systems permit acquisition of novel imaging at the time of radiotherapy. A validated MR hypoxia imaging biomarker could select patients for adaptive radiotherapy with hypoxia modification or dose escalation. The aims of this study were (1) to develop a protocol for quantitative hypoxia sensitive MRI (2) to validate these in prostate cancer (PCa) against pimonidazole-stained prostatectomy sections. Blood oxygen level dependent (BOLD), intravoxel incoherent motion (IVIM), oxygen-enhanced (OE) and dynamic contrast enhanced (DCE) MRI were used. Sequences were developed on a diagnostic 1.5 T MR (MRD) and MRL with healthy volunteers and PCa patients. The Hyprogen trial includes men with localized PCa scheduled for prostatectomy. Imaging is acquired twice prior to surgery and oral pimonidazole is taken 8-16 hours before surgery. Whole prostate (WP) and dominant prostatic lesion (DIL) were outlined on T2-weighted (T2W) images and a 'normal prostate' (NP) volume created by subtracting DIL from WP. Contours were applied to parametric maps from the quantitative MRI, with median and IQR extracted. Patient-specific 3D-printed prostate molds were created from WP volumes and used to guide prostate whole organ dissection. Three of 20 patients recruited to date. MRI data were acquired successfully. A personalized prostate mold was produced for each patient and facilitated dissection of the prostatectomy specimen in a matching plane to MRI to validate hypoxia detection of the MR protocol. Correlation with pimonidazole staining is underway. Imaging parameter median values for NP and DIL acquired on MRD and MRL for the first patient are shown (Table 1). The expected differences between NP and DIL for T1 and D are seen and median values for T2* are consistent with reported values in the literature. The MR hypoxia protocol can be acquired safely and is well-tolerated on the MRL. Once validated against pimonidazole staining adaptive radiotherapy protocols will be developed to use this information.

Improved Value of Multiplexed Sensitivity Encoding DWI with Reversed Polarity Gradients in Diagnosing Prostate Cancer: A Comparison Study with Single-Shot DWI and MUSE DWI

This study aimed to investigate the value of multiplexed sensitivity encoding with reversed polarity gradients in improving the quality of diffusion-weighted imaging (DWI) images of the prostate and the diagnostic efficacy of prostate cancer. Seventy-three patients with prostate disease underwent multiplexed sensitivity encoding with reversed polarity gradients (RPG-MUSE), multiplexed sensitivity encoding (MUSE), and single-shot echo-planar imaging (ssEPI) DWI. Three radiologists performed a qualitative image analysis of the three DWI sequences. Qualitative image analysis included artifact minimization, anatomical detail, and sharpness of prostate edges. Two radiologists measured the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), geometric distortion rate, and the apparent diffusion coefficient (ADC) values of the prostate disease tissue. Two radiologists jointly performed Prostate Imaging Reporting and Data System scoring of prostate lesions and compared the diagnostic efficacy of the three DWI sequences for prostate cancer. There was good agreement among radiologists in the evaluation and measurement of the three DWI sequence images (intraclass correlation coefficient >0.75, P<0.05). The RPG-MUSE DWI images were rated higher than those of MUSE and ssEPI in terms of artifact minimization, anatomical details, and sharpness of prostate edges (P<0.05). The SNR and CNR of the RPG-MUSE DWI images were higher than those of MUSE and ssEPI (P<0.05), and the geometric distortion rate was lower than that of the other two sequences (P<0.05). There were no statistical differences in ADC values between the three DWI sequences (P>0.05). The diagnostic efficacy of RPG-MUSE and MUSE DWI was higher than that of ssEPI (P<0.017). RPG-MUSE can reduce the artifacts and geometric distortion in DWI images of the prostate, improve the SNR and CNR of the images, improve the clarity of anatomical details and boundaries without affecting the measurement of ADC values, has the potential to improve the diagnostic efficacy of prostate lesions, and facilitates the clear display and accurate assessment of prostate lesions.

Histopathological Spectrum of Prostatic Lesions in a Tertiary Care Hospital

Background: Prostatic lesions like nodular hyperplasia, inflammation and carcinoma are common causes of morbidity and mortality in males. The incidence of these lesions increases with advancing age. Prostatic diseases show varying incidence in different geographical locations worldwide.&#x0D; Objectives: To evaluate the histopathological spectrum of various prostatic lesions in biopsy specimen.&#x0D; Methods: This was a retrospective study comprising 220 cases, carried out at the Department of Pathology, Enam Medical College and Hospital from January 2014 to December 2020. The histopathological slides were analyzed according to type of specimen, age of the patient, and histopathological pattern. Adenocarcinomas were graded according to Gleason score.&#x0D; Results: Of the total 220 specimens, 202 (91.8%) were of nodular hyperplasia, 14 (6.4%) were carcinoma and 4 (1.8%) cases were high grade prostatic intraepithelial neoplasia (HGPIN). All the cases of prostatic malignancies were adenocarcinoma and majority were belonged to Gleason’s score 7. Maximum numbers of cases of nodular hyperplasia were seen in the 61-70 years age group and carcinomas were peak in the 71-80 years age group.&#x0D; Conclusion: Non-neoplastic lesions of the prostate are more common than neoplastic ones. Histopathological diagnosis and grading plays a definitive role in the management of prostatic carcinoma.&#x0D; Mugda Med Coll J. 2023; 6(1): 5-10

Improving diagnostic efficacy of primary prostate cancer with combined 99mTc-PSMA SPECT/CT and multiparametric-MRI and quantitative parameters.

This prospective study aimed to evaluate the difference between 99mTc-PSMA single-photon emission computed tomography (SPECT)/CT and multiparametric magnetic resonance imaging (mpMRI) in the detection of primary prostate cancer (PCa). Fifty-six men with suspected PCa between October 2019 and November 2022 were prospectively enrolled in this study. The median age of the patients was 70 years (range, 29-87 years). Patients were divided into high-(Gleason score>7, n=31), medium- (Gleason score=7, n=6) and low-risk groups (Gleason score < 7, n=6). All patients underwent 99mTc-PSMA SPECT/CT and mpMRI at an average interval of 3 days (range, 1-7 days). The maximum standardized uptake value (SUVmax), the minimum apparent diffusion coefficient (ADCmin), and their ratio (SUVmax/ADCmin) were used as imaging parameters to distinguish benign from malignant prostatic lesions. Of the 56 patients, 12 were pathologically diagnosed with a benign disease, and 44 were diagnosed with PCa. 99mTc-PSMA SPECT/CT and mpMRI showed no significant difference in the detection of primary PCa (kappa =0.401, P=0.002), with sensitivities of 97.7% (43/44) and 90.9% (40/44), specificities of 75.0% (9/12) and 75.0% (9/12), and AUC of 97.4% and 95.1%, respectively. The AUC of SUVmax/ADCmin was better than those of SUVmax or ADCmin alone. When SUVmax/ADCmin in the prostatic lesion was >7.0×103, the lesion was more likely to be malignant. When SUVmax/ADCmin in the prostatic lesion is >27.0×103, the PCa patient may have lymph node and bone metastases. SUVmax was positively correlated with the Gleason score (r=0.61, P=0.008), whereas ADCmin was negatively correlated with the Gleason score (r=-0.35, P=0.023). SUVmax/ADCmin was positively correlated with the Gleason score (r=0.59, P=0.023). SUVmax/ADCmin was the main predictor of the high-risk group, with an optimal cut-off value of 15.0×103. The combination of 99mTc-PSMA SPECT/CT and mpMRI can improve the diagnostic efficacy for PCa compared with either modality alone; SUVmax/ADCmin is a valuable differential diagnostic imaging parameter.

T2-Weighted MRI Radiomic Features Predict Prostate Cancer Presence and Eventual Biochemical Recurrence.

Prostate cancer (PCa) is the most diagnosed non-cutaneous cancer in men. Despite therapies such as radical prostatectomy, which is considered curative, distant metastases may form, resulting in biochemical recurrence (BCR). This study used radiomic features calculated from multi-parametric magnetic resonance imaging (MP-MRI) to evaluate their ability to predict BCR and PCa presence. Data from a total of 279 patients, of which 46 experienced BCR, undergoing MP-MRI prior to surgery were assessed for this study. After surgery, the prostate was sectioned using patient-specific 3D-printed slicing jigs modeled using the T2-weighted imaging (T2WI). Sectioned tissue was stained, digitized, and annotated by a GU-fellowship trained pathologist for cancer presence. Digitized slides and annotations were co-registered to the T2WI and radiomic features were calculated across the whole prostate and cancerous lesions. A tree regression model was fitted to assess the ability of radiomic features to predict BCR, and a tree classification model was fitted with the same radiomic features to classify regions of cancer. We found that 10 radiomic features predicted eventual BCR with an AUC of 0.97 and classified cancer at an accuracy of 89.9%. This study showcases the application of a radiomic feature-based tool to screen for the presence of prostate cancer and assess patient prognosis, as determined by biochemical recurrence.

Direct Patlak Reconstruction of [68Ga]Ga-PSMA PET for the Evaluation of Primary Prostate Cancer Prior Total Prostatectomy: Results of a Pilot Study.

To investigate the use of kinetic parameters derived from direct Patlak reconstructions of [68Ga]Ga-PSMA-11 positron emission tomography/computed tomography (PET/CT) to predict the histological grade of malignancy of the primary tumor of patients with prostate cancer (PCa). Thirteen patients (mean age 66 ± 10 years) with a primary, therapy-naïve PCa (median PSA 9.3 [range: 6.3-130 µg/L]) prior radical prostatectomy, were recruited in this exploratory prospective study. A dynamic whole-body [68Ga]Ga-PSMA-11 PET/CT scan was performed for all patients. Measured quantification parameters included Patlak slope (Ki: absolute rate of tracer consumption) and Patlak intercept (Vb: degree of tracer perfusion in the tumor). Additionally, the mean and maximum standardized uptake values (SUVmean and SUVmax) of the tumor were determined from a static PET 60 min post tracer injection. In every patient, initial PSA (iPSA) values that were also the PSA level at the time of the examination and final histology results with Gleason score (GS) grading were correlated with the quantitative readouts. Collectively, 20 individual malignant prostate lesions were ascertained and histologically graded for GS with ISUP classification. Six lesions were classified as ISUP 5, two as ISUP 4, eight as ISUP 3, and four as ISUP 2. In both static and dynamic PET/CT imaging, the prostate lesions could be visually distinguished from the background. The average values of the SUVmean, slope, and intercept of the background were 2.4 (±0.4), 0.015 1/min (±0.006), and 52% (±12), respectively. These were significantly lower than the corresponding parameters extracted from the prostate lesions (all p < 0.01). No significant differences were found between these values and the various GS and ISUP (all p > 0.05). Spearman correlation coefficient analysis demonstrated a strong correlation between static and dynamic PET/CT parameters (all r ≥ 0.70, p < 0.01). Both GS and ISUP grading revealed only weak correlations with the mean and maximum SUV and tumor-to-background ratio derived from static images and dynamic Patlak slope. The iPSA demonstrated no significant correlation with GS and ISUP grading or with dynamic and static PET parameter values. In this cohort of mainly high-risk PCa, no significant correlation between [68Ga]Ga-PSMA-11 perfusion and consumption and the aggressiveness of the primary tumor was observed. This suggests that the association between SUV values and GS may be more distinctive when distinguishing clinically relevant from clinically non-relevant PCa.