Biologic target volume delineation and the application of three-dimensional ultrasound image system in hypofractional radiotherapy for prostate cancer.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e16585-e16585
Author(s):  
Jie Wang ◽  
Jiabao Ma ◽  
Jin Yi Lang
Keyword(s):  
Prostate Cancer ◽  
Specific Antigen ◽  
Target Volume ◽  
Emission Computed Tomography ◽  
Resonance Spectroscopy ◽  
Radiation Oncologists ◽  
Biological Target Volume ◽  
Pet Ct ◽  
Significant Difference ◽  
Prescription Dose

e16585 Background: To investigate the value of magnetic resonance spectroscopy (MRS) and positron emission computed tomography (PET-CT) in biological target volume(BTV) delineation of prostate cancer using hypofractional intensity modulated radiotherapy (HF-IMRT) with simultaneously integrated boost(SIB), and the preliminary efficacy and adverse effects of 3D ultrasound (3DUS) guided imaging in the treatment of prostate cancer using HF-IMRT and SIB. Methods: Between August 2015 and May 2016, 13 patients diagnosed with mid-high risk prostate cancer were retrospectively enrolled. All the eligible patients had underwent MRI MRS and PET-CT(18F-FDG or 11C-CHO) examination before radiotherapy. 5 patients had explicit BTV by examinations mentioned above. Radiation oncologists fused 3DUS and CT images and delineated tumor target volume referring to MRS and PET-CT. The target volumes were named as GTVMRI BTVMRS BTVPET-CT respectively and the volume were recorded. 3DUS guided HF-IMRT were applied during the radiotherapy. Results: The volumes of GTVMRI BTVMRS BTVPET-CT among the 5 patients were different. The mean volume of GTVMRI BTVMRS and BTVPET-CT were 3.52±1.69cm3, 6.64±2.27cm3 and 5.47±2.60cm3,respectively. Significant difference was only observed between GTVMRI and BTVMRS( P = 0.046). Compared to GTVMRI, the average increasing volumes of BTVMRS and BTVPET-CT were 89.07% and 55.52%. The prescription dose and biological effective dose(BED) of BTVMRS were 70.09-73.45Gy and 129.06-135.54Gy. The prescription dose and BED of the whole prostate were 66.02-69.40Gy and 113.32-124.82Gy. The dose of bladder and rectum were within safe control. The prostate specific antigen (PSA) were significantly decreased after radiotherapy. No local recurrence or distant metastasis was observed. Conclusions: MRS and PET-CT can be applied to delineation of the BTV of prostate cancer. With the help of multi-modal image guidance, dose painting for prostate cancer is feasible. 3DUS guided HF-IMRT with SIB is an alternative for radiation oncologists based on BTVMRS. With shortened time and less cost, this technique is safe and non-radioactive compared to CBCT guidance.

scholarly journals Detection Rate and Clinical Impact of PET/CT with 18F-FACBC in Patients with Biochemical Recurrence of Prostate Cancer: A Retrospective Bicentric Study

Biomedicines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 177
Author(s):  
Luca Filippi ◽  
Oreste Bagni ◽  
Carmelo Crisafulli ◽  
Ivan Cerio ◽  
Gabriele Brunotti ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Clinical Management ◽  
Biochemical Recurrence ◽  
Detection Rate ◽  
Major Change ◽  
Emission Computed Tomography ◽  
Prostate Bed ◽  
Pet Ct ◽  
Significant Difference ◽  
Clinical Records

Our aim was to assess the detection rate (DR) of positron emission computed tomography (PET/CT) with anti-1-amino-3-[18F]-flurocyclobutane-1-carboxylic acid (18F-FACBC) in patients with biochemical recurrence (BCR) from prostate cancer (PC). As a secondary endpoint, we evaluated 18F-FACBC PET/CT’s impact on patients management. Clinical records of 81 patients submitted to 18F-FACBC PET/CT due to PC BCR in two Italian Nuclear Medicine Units were retrospectively assessed. DR was gauged in the whole cohort and stratifying patients by discrete intervals of PSA levels. PET/CT’s impact on clinical management was scored as (1) major if it entailed an intermodality change (e.g., from systemic to loco-regional therapy); (2) minor if it led to an intramodality change (e.g., modified radiotherapy field). PET/CT’s DR resulted in 76.9% in the whole cohort, with a positive predictive value of 96.7%. Stratified by PSA quartile intervals, PET/CT’s DR was 66.7%, 71.4%, 78.9% and 90% for PSA 0.2–0.57 ng/mL, 0.58–0.99 ng/mL, 1–1.5 ng/mL and >1.5 ng/mL without significant difference among groups (p = 0.81). The most common sites of relapse were prostate bed and pelvic lymph nodes (59.3%). PET/CT impacted on clinical management in 33/81 cases (40.7%), leading to a major change in 30 subjects (90.9%). 18F-FACBC PET/CT localized recurrence in patients with BCR, with meaningful DR also at low PSA levels and significantly impacted on clinical management.

scholarly journals Impact of FAPI-PET/CT on Target Volume Definition in Radiation Therapy of Locally Recurrent Pancreatic Cancer

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 796
Author(s):  
Jakob Liermann ◽  
Mustafa Syed ◽  
Edgar Ben-Josef ◽  
Kai Schubert ◽  
Ingmar Schlampp ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Radiation Therapy ◽  
Cancer Patients ◽  
Target Volume ◽  
Radiation Oncologists ◽  
Pet Ct ◽  
Significant Difference ◽  
Target Definition ◽  
Recurrent Pancreatic Cancer ◽  
Locally Recurrent

(1) Background: A new radioactive positron emission tomography (PET) tracer uses inhibitors of fibroblast activation protein (FAPI) to visualize FAP-expressing cancer associated fibroblasts. Significant FAPI-uptake has recently been demonstrated in pancreatic cancer patients. Target volume delineation for radiation therapy still relies on often less precise conventional computed tomography (CT) imaging, especially in locally recurrent pancreatic cancer patients. The need for improvement in precise tumor detection and delineation led us to innovatively use the novel FAPI-PET/CT for radiation treatment planning. (2) Methods: Gross tumor volumes (GTVs) of seven locally recurrent pancreatic cancer cases were contoured by six radiation oncologists. In addition, FAPI-PET/CT was used to automatically delineate tumors. The interobserver variability in target definition was analyzed and FAPI-based automatic GTVs were compared to the manually defined GTVs. (3) Results: Target definition differed significantly between different radiation oncologists with mean dice similarity coefficients (DSCs) between 0.55 and 0.65. There was no significant difference between the volumes of automatic FAPI-GTVs based on the threshold of 2.0 and most of the manually contoured GTVs by radiation oncologists. (4) Conclusion: Due to its high tumor to background contrast, FAPI-PET/CT seems to be a superior imaging modality compared to the current gold standard contrast-enhanced CT in pancreatic cancer. For the first time, we demonstrate how FAPI-PET/CT could facilitate target definition and increases consistency in radiation oncology in pancreatic cancer.

scholarly journals A Conjugation Strategy to Modulate Antigen Binding and FcRn Interaction Leads to Improved Tumor Targeting and Radioimmunotherapy Efficacy with an Antibody Targeting Prostate-Specific Antigen

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3469
Author(s):  
Oskar Vilhelmsson Timmermand ◽  
Anders Örbom ◽  
Mohamed Altai ◽  
Wahed Zedan ◽  
Bo Holmqvist ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Fc Receptor ◽  
Receptor Interaction ◽  
Emission Computed Tomography ◽  
Neonatal Fc Receptor ◽  
Radionuclide Distribution ◽  
Significant Difference ◽  
The Impact

Background: The humanized monoclonal antibody (mAb) hu5A10 specifically targets and internalizes prostate cancer cells by binding to prostate specific antigen (PSA). Preclinical evaluations have shown that hu5A10 is an excellent vehicle for prostate cancer (PCa) radiotheranostics. We studied the impact of different chelates and conjugation ratios on hu5A10′s target affinity, neonatal fc-receptor interaction on in vivo targeting efficacy, and possible enhanced therapeutic efficacy. Methods: In our experiment, humanized 5A10 (hu5A10) was conjugated with DOTA or DTPA at a molar ratio of 3:1, 6:1, and 12:1. Surface plasmon resonance (SPR) was used to study antigen and FcRn binding to the antibody conjugates. [111In]hu5A10 radio-immunoconjugates were administered intravenously into BALB/c mice carrying subcutaneous LNCaP xenografts. Serial Single-photon emission computed tomography (SPECT) images were obtained during the first week. Tumors were harvested and radionuclide distribution was analyzed by autoradiography along with microanatomy and immunohistochemistry. Results: As seen by SPR, the binding to PSA was clearly affected by the chelate-to-antibody ratio. Similarly, FcRn (neonatal fc-receptor) interacted less with antibodies conjugated at high ratios of chelator, which was more pronounced for DOTA conjugates. The autoradiography data indicated a higher distribution of radioactivity to the rim of the tumor for lower ratios and a more homogenous distribution at higher ratios. Mice injected with ratio 3:1 111In-DOTA-hu5A10 showed no significant difference in tumor volume when compared to mice given vehicle over a time period of 3 weeks. Mice given a similar injection of ratio 6:1 111In-DOTA-hu5A10 or 6:1 111In-DTPA-hu5A10 or 12:1 111In-DTPA-hu5A10 showed significant tumor growth retardation. Conclusions: The present study demonstrated that the radiolabeling strategy could positively modify the hu5A10′s capacity to bind PSA and complex with the FcRn-receptor, which resulted in more homogenous activity distribution in tumors and enhanced therapy efficacy.

Computerized Tomography (CT) Updates and Challenges in Diagnosis of Bone Metastases During Prostate Cancer

2020 ◽  
Vol 16 (5) ◽  
pp. 565-571
Author(s):  
Jinguo Zhang ◽  
Guanzhong Zhai ◽  
Bin Yang ◽  
Zhenhe Liu
Keyword(s):  
Prostate Cancer ◽  
Computed Tomography ◽  
Bone Metastases ◽  
Computerized Tomography ◽  
Single Photon ◽  
Photon Emission ◽  
Major Complication ◽  
Tracer Uptake ◽  
Emission Computed Tomography ◽  
Pet Ct

Prostate cancer is one of the most common cancers in men. This cancer is often associated with indolent tumors with little or no lethal potential. Some of the patients with aggressive prostate cancer have increased morbidity and early deaths. A major complication in advanced prostate cancer is bone metastasis that mainly results in pain, pathological fractures, and compression of spinal nerves. These complications in turn cause severe pain radiating to the extremities and possibly sensory as well as motor disturbances. Further, in patients with a high risk of metastases, treatment is limited to palliative therapies. Therefore, accurate methods for the detection of bone metastases are essential. Technical advances such as single-photon emission computed tomography/ computed tomography (SPECT/CT) have emerged after the introduction of bone scans. These advanced methods allow tomographic image acquisition and help in attenuation correction with anatomical co-localization. The use of positron emission tomography/CT (PET/CT) scanners is also on the rise. These PET scanners are mainly utilized with 18F-sodium-fluoride (NaF), in order to visualize the skeleton and possible changes. Moreover, NaF PET/CT is associated with higher tracer uptake, increased target-to-background ratio and has a higher spatial resolution. However, these newer technologies have not been adopted in clinical guidelines due to lack of definite evidence in support of their use in bone metastases cases. The present review article is focused on current perspectives and challenges of computerized tomography (CT) applications in cases of bone metastases during prostate cancer.

scholarly journals Differential expression of steroid 5α-reductase isozymes and association with disease severity and angiogenic genes predict their biological role in prostate cancer

2010 ◽  
Vol 17 (3) ◽  
pp. 757-770 ◽  
Author(s):  
Kakoli Das ◽  
Pia D N Lorena ◽  
Lai Kuan Ng ◽  
Diana Lim ◽  
Liang Shen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Growth Factor ◽  
Transforming Growth Factor ◽  
Specific Antigen ◽  
Biological Role ◽  
Prostate Cell ◽  
Cellular Expression ◽  
Significant Difference ◽  
Angiogenic Genes ◽  
Angiogenesis Pathway

The biological role of steroid 5α-reductase isozymes (encoded by the SRD5A1 and SRD5A2 genes) and angiogenic factors that play important roles in the pathogenesis and vascularization of prostate cancer (PC) is poorly understood. The sub-cellular expression of these isozymes and vascular endothelial growth factor (VEGF) in PC tissue microarrays (n=62) was examined using immunohistochemistry. The effect of SRD5A inhibition on the angiogenesis pathway genes in PC was also examined in prostate cell lines, LNCaP, PC3, and RWPE-1, by treating them with the SRD5A inhibitors finasteride and dutasteride, followed by western blot, quantitative PCR, and ELISA chip array techniques. In PC tissues, nuclear SRD5A1 expression was strongly associated with higher cancer Gleason scores (P=0.02), higher cancer stage (P=0.01), and higher serum prostate specific antigen (PSA) levels (P=0.01), whereas nuclear SRD5A2 expression was correlated with VEGF expression (P=0.01). Prostate tumor cell viability was significantly reduced in dutasteride-treated PC3 and RWPE-1 cells compared with finasteride-treated groups. Expression of the angiogenesis pathway genes transforming growth factor β 1 (TGFB1), endothelin (EDN1), TGFα (TGFA), and VEGFR1 was upregulated in LNCaP cells, and at least 7 out of 21 genes were upregulated in PC3 cells treated with finasteride (25 μM). Our findings suggest that SRD5A1 expression predominates in advanced PC, and that inhibition of SRD5A1 and SRD5A2 together was more effective in reducing cell numbers than inhibition of SRD5A2 alone. However, these inhibitors did not show any significant difference in prostate cell angiogenic response. Interestingly, some angiogenic genes remained activated after treatment, possibly due to the duration of treatment and tumor resistance to inhibitors.

The Current Role of Immunotherapy in mCRPC: A Systematic Review

2021 ◽  
Vol 8 (7) ◽  
Author(s):  
Dalibey H ◽  
◽  
Hansen TF ◽  
Zedan AH ◽  
◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Systematic Review ◽  
Overall Survival ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Response Rate ◽  
Checkpoint Inhibitors ◽  
Specific Antigen ◽  
Treatment Modalities ◽  
Significant Difference

Background: The development of immunotherapy has shown promising results in several malignant diseases, including prostate cancer, calling for a systematic review of the current literature. This review aims to evaluate the present data and prospects of immune checkpoint inhibitors in metastatic Castration Resistant Prostate Cancer (mCRPC). Methods: Articles were identified via a systematic search of the electronic database Pubmed, in accordance with the PICO process and following the PRISMA guidelines. Articles in English studying immune checkpoint inhibitors in patients with mCRPC published between March 2010 and March 2020 were eligible for inclusion. Endpoints of interest were Overall Survival (OS), Progression-Free Survival (PFS), clinical Overall Response Rate (ORR), and Prostate-Specific Antigen (PSA) response rate. Results: Ten articles were identified as eligible for inclusion. The studies primarily explored the use of Ipilimumab, a CTLA-4 inhibitor, and Pembrolizumab, a PD-1 inhibitor. These drugs were both used either as monotherapy or in combination with other treatment modalities. The largest trial included in the review demonstrated no significant difference in overall survival between the intervention and placebo. However, two studies presented promising data combing immunotherapy and immune vaccines. Grade 3 and 4 adverse events ranging from 10.1% to 82.3%, whit diarrhea, rash, and fatigue were the most frequently reported. Forty relevant ongoing trials were identified exploring immunotherapy with or without a parallel treatment modality. Conclusion: Overall, the current data shows that the effect of immune checkpoint inhibitors as monotherapy may have limited impact on mCRPC, and the results from ongoing combinational trials are eagerly awaited.

Bony-based and prostate-based image guidance for lo-calized prostate cancer radiotherapy

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Saulo Santos Fortes ◽  
Luiz Antonio Ribeiro Da Rosa
Keyword(s):  
Prostate Cancer ◽  
Normal Tissue ◽  
Bone Structure ◽  
Absorbed Dose ◽  
Target Volume ◽  
Image Guided Radiotherapy ◽  
Beam Modulation ◽  
Significant Difference ◽  
Treatment Volume ◽  
Treatment Plans

An important modality for the treatment of prostate cancer is teletherapy. The use of image-guided radiotherapy (IGRT) is a valuable tool in this treatment. This study retrospectively compared how repositioning the patient based on bone structure (B-ISO) and the prostate itself (P-ISO) affected the volumetric dose in the rectum, bladder, and clinical treatment volume (CTV). Additionally, the probability of normal tissue complication (NTCP) for the rectum was computed. We evaluated 155 cone-beam computed tomography (CBCT) from 8 patients. The treatment plans used beam modulation techniques. The planning target volume (PTV) margin adopted in both scenarios was 1 cm. The organs of interest were outlined over each CBCT and then treatment plans were applied so that the absorbed dose could be computed. NTCP values were calculated for the rectum. Analyzing dose-volume metrics published by the Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC), there was no significant difference between the two repositioning strategies for the rectum and bladder. There was a slight degradation in CTV coverage for the B-ISO strategy, but still with adequate coverage. Analysis of the uniform equivalent dose (EUD) and NTCP for the rectum showed little sensitivity to the strategy used. The present study showed that the use of CBCT in radiotherapy for prostate cancer treatment did not significantly improve volumetric doses for the rectum, bladder, and CTV, as well as NTCP for the rectum.

Understanding Active Surveillance for Prostate Cancer

2021 ◽  
pp. OP.20.00929
Author(s):  
Lillian Y. Lai ◽  
Vahakn B. Shahinian ◽  
Mary K. Oerline ◽  
Samuel R. Kaufman ◽  
Ted A. Skolarus ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Active Surveillance ◽  
Guideline Development ◽  
Multinomial Logistic Regression ◽  
Specific Antigen ◽  
National Sample ◽  
Logistic Regression Models ◽  
Radiation Oncologists ◽  
Medical Oncologists ◽  
Testing Patterns

PURPOSE: To assess how active surveillance for prostate cancer is apportioned across specialties and how testing patterns and transition to treatment vary by specialty. METHODS: We used a 20% national sample of Medicare claims to identify men diagnosed with prostate cancer from 2010 through 2016 initiating surveillance (N = 13,048). Patients were assigned to the physician responsible for the bulk of surveillance care based on billing patterns. Freedom from treatment was assessed by specialty of the responsible physician (urology, radiation oncology, medical oncology, and primary care). Multinomial logistic regression models were used to examine associations between specialty and treatment patterns. RESULTS: Urologists were responsible for surveillance in 93.7% of patients in 2010 and 96.2% of patients in 2016 ( P for trend = .01). Testing patterns varied by specialty. For example, patients of medical oncologists had more frequent prostate-specific antigen testing compared with patients of urologists (1.85 v 2.39 tests per year, respectively; P < .01). Three years after diagnosis, a significantly smaller proportion of patients managed by radiation oncologists (64.3%) remained on surveillance compared with patients managed by other physicians (75.8%-79.5%; P < .01). Although radiation was the most common treatment among all men who transitioned to treatment, a disproportionate percentage of patients followed by radiation oncologists (28.9%) ultimately underwent radiation compared with patients followed by other physicians (15.1%-15.4%; P < .01). CONCLUSION: Nontrivial percentages of patients on active surveillance are managed by physicians outside of urology. Given the interspecialty variations observed, efforts to strengthen the evidence underlying surveillance pathways and to engage other specialties in guideline development are needed.

scholarly journals PSA and PSA Kinetics Thresholds for the Presence of 68Ga-PSMA-11 PET/CT-Detectable Lesions in Patients with Biochemical Recurrent Prostate Cancer

Cancers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 398 ◽  
Author(s):  
Manuela Andrea Hoffmann ◽  
Hans-Georg Buchholz ◽  
Helmut J. Wieler ◽  
Matthias Miederer ◽  
Florian Rosar ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Characteristic Curve ◽  
Specific Antigen ◽  
Recurrent Prostate Cancer ◽  
Psa Kinetics ◽  
Scan Time ◽  
Positron Emission ◽  
Pet Ct ◽  
Positive Scan ◽  
Previously Treated

68Ga-PSMA-11 positron-emission tomography/computed tomography (PET/CT) is commonly used for restaging recurrent prostate cancer (PC) in European clinical practice. The goal of this study is to determine the optimum time for performing these PET/CT scans in a large cohort of patients by identifying the prostate-specific-antigen (PSA) and PSA kinetics thresholds for detecting and localizing recurrent PC. This retrospective analysis includes 581 patients with biochemical recurrence (BC) by definition. The performance of 68Ga-PSMA-11 PET/CT in relation to the PSA value at the scan time as well as PSA kinetics was assessed by the receiver-operating-characteristic-curve (ROC) generated by plotting sensitivity versus 1-specificity. Malignant prostatic lesions were identified in 77%. For patients that were treated with radical prostatectomy (RP) a PSA value of 1.24 ng/mL was found to be the optimal cutoff level for predicting positive and negative scans, while for patients previously treated with radiotherapy (RT) it was 5.75 ng/mL. In RP-patients with PSA value <1.24 ng/mL, 52% scans were positive, whereas patients with PSA ≥1.24 ng/mL had positive scan results in 87%. RT-patients with PSA <5.75 ng/mL had positive scans in 86% and for those with PSA ≥5.75 ng/mL 94% had positive scans. This study identifies the PSA and PSA kinetics threshold levels for the presence of 68Ga-PSMA-11 PET/CT-detectable PC-lesions in BC patients.

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