Treatment modalities and survival outcomes in prostate cancer parenchymal brain metastasis.

BACKGROUND: Prostate cancer (PCa) parenchymal brain metastases are uncommon and troubling observations in the course of the disease. Our study aims to evaluate the prevalence of brain metastases among PCa patients while reporting various therapeutic modalities, clinical features, and oncological outcomes. METHODS: We retrospectively identified 34 patients with parenchymal brain metastasis out of 4575 patients using a prospectively maintained database that contains clinicopathologic characteristics of PCa patients between January 2012 and December 2021. Based on the three treatment modalities used, the patients were divided into three groups: stereotactic radiosurgery (SRS), whole brain radiotherapy (WBRT), and systemic therapy alone. The Kaplan-Meier curve was used to calculate overall survival [OS] probability and the Cox proportional hazards regression model was used to compare between groups. RESULTS: At the time of brain metastasis diagnosis, the median age was 66 years, the median (interquartile range [IQR]) prostate-specific antigen (PSA) was 2.2 (0.1-26.6) ng/ml and the median (IQR) months from initial PCa diagnosis to brain metastasis development was 70.8 (27.6-100.9). The median (IQR) primary Gleason score was 8 (7-9) and over a median (IQR) follow-up time of 2.2 (1.2-16.5) months, 76.5% (n = 26) of the patients died. Thirteen (38.2%) patients had solitary lesion, whereas 21 (61.8%) had ≥2 lesions. The lesions were supratentorial in 19 (55.9%) patients, infratentorial in six (17.6%), and both sides in nine (26.5%). Among all 34 patients, 10 (29.4%) were treated with SRS, seven (20.6%) with WBRT, and 17 (50%) with systemic therapy alone. OS varied greatly between the three treatment modalities (log-rank test, p = 0.049). Those who were treated with SRS and WBRT had better OS compared with patients who were treated with systemic therapy alone (hazard ratio: 0.37, 95% confidence interval: 0.16-0.86, p = 0.022). CONCLUSIONS: In our single-institutional study, we confirmed that PCa brain metastasis is associated with poor survival outcomes and more advanced metastatic disease. Furthermore, we found that SRS and WBRT for brain metastasis in patients with recurrent PCa appear to be associated with improved OS as compared with systemic therapy alone and are likely secondary to selection bias.

A pooled patient-reported outcomes analysis of moderately hypofractionated proton beam therapy and photon-based intensity modulated radiation therapy for low- or intermediate-risk prostate cancer.

BACKGROUND: We sought to characterize and compare late patient-reported outcomes (PROs) after moderately hypofractionated intensity modulated radiation therapy (IMRT) and proton beam therapy (PBT) for localized prostate cancer (PC). METHODS: This multi-institutional analysis included low- or intermediate-risk group PC patients treated with moderately hypofractionated radiation to an intact prostate stratified by treatment modality: IMRT or PBT. The primary outcomes were prospectively collected patient-reported late gastrointestinal (GI) and genitourinary (GU) toxicity assessed by International Prostate Symptom Score (IPSS) and Expanded PC Index Composite (EPIC). Multivariable regression analysis (MVA) controlling for age, race, and risk group tested the effect of time, treatment, and their interaction. RESULTS: 287 IMRT and 485 PBT patients were included. Intermediate risk group (81.2 vs. 68.2%; p < 0.001) and median age at diagnosis (70 vs. 67 years; p < 0.001) were higher in the IMRT group. On MVA, there was no significant difference between modalities. PBT IPSS did not differ from IMRT IPSS at 12 months (odds ratio [OR], 1.19; p = 0.08) or 24 months (OR, 0.99; p = 0.94). PBT EPIC overall GI function at 12 months (OR, 3.68; p = 0.085) and 24 months (OR 2.78; p = 0.26) did not differ from IMRT EPIC overall GI function. At 24 months, urinary frequency was no different between PBT and IMRT groups (OR 0.35; p = 0.096). CONCLUSIONS: This multi-institutional analysis of low- or intermediate-risk PC treated with moderately hypofractionated PBT and IMRT demonstrated low rates of late patient-reported GI and GU toxicities. After covariate adjustment, late GI and GU PROs were not significantly different between PBT or IMRT cohorts.

Conventional versus hypofractionated postmastectomy proton radiotherapy in the USA (MC1631): a randomised phase 2 trial.

BACKGROUND: Proton therapy is under investigation in breast cancer as a strategy to reduce radiation exposure to the heart and lungs. So far, studies investigating proton postmastectomy radiotherapy (PMRT) have used conventional fractionation over 25-28 days, but whether hypofractionated proton PMRT is feasible is unclear. We aimed to compare conventional fractionation and hypofractionation in patients with indications for PMRT, including those with immediate breast reconstruction. METHODS: We did a randomised phase 2 trial (MC1631) at Mayo Clinic in Rochester (MN, USA) and Mayo Clinic in Arizona (Phoenix, AZ, USA) comparing conventional fractionated (50 Gy in 25 fractions of 2 Gy [relative biological effectiveness of 1·1]) and hypofractionated (40·05 Gy in 15 fractions of 2·67 Gy [relative biological effectiveness of 1·1]) proton PMRT. All patients were treated with pencil-beam scanning. Eligibility criteria included age 18 years or older, an Eastern Cooperative Oncology Group performance status of 0-2, and breast cancer resected by mastectomy with or without immediate reconstruction with indications for PMRT. Patients were randomly assigned (1:1) to either conventional fractionation or hypofractionation, with presence of immediate reconstruction (yes vs no) as a stratification factor, using a biased-coin minimisation algorithm. Any patient who received at least one fraction of protocol treatment was evaluable for the primary endpoint and safety analyses. The primary endpoint was 24-month complication rate from the date of first radiotherapy, defined as grade 3 or worse adverse events occurring from 90 days after last radiotherapy or unplanned surgical interventions in patients with immediate reconstruction. The inferiority of hypofractionation would not be ruled out if the upper bound of the one-sided 95% CI for the difference in 24-month complication rate between the two groups was greater than 10%. This trial is registered with ClinicalTrials.gov, NCT02783690, and is closed to accrual. FINDINGS: Between June 2, 2016, and Aug 23, 2018, 88 patients were randomly assigned (44 to each group), of whom 82 received protocol treatment (41 in the conventional fractionation group and 41 in the hypofractionation group; median age of 52 years [IQR 44-64], 79 [96%] patients were White, two [2%] were Black or African American, one [1%] was Asian, and 79 [96%] were not of Hispanic ethnicity). As of data cutoff (Jan 30, 2023), the median follow-up was 39·3 months (IQR 37·5-61·2). The median mean heart dose was 0·54 Gy (IQR 0·30-0·72) for the conventional fractionation group and 0·49 Gy (0·25-0·64) for the hypofractionation group. Within 24 months of first radiotherapy, 14 protocol-defined complications occurred in six (15%) patients in the conventional fractionation group and in eight (20%) patients in the hypofractionation group (absolute difference 4·9% [one-sided 95% CI 18·5], p=0·27). The complications in the conventionally fractionated group were contracture (five [12%] of 41 patients]) and fat necrosis (one [2%] patient) requiring surgical intervention. All eight protocol-defined complications in the hypofractionation group were due to infections, three of which were acute infections that required surgical intervention, and five were late infections, four of which required surgical intervention. All 14 complications were in patients with immediate expander or implant-based reconstruction. INTERPRETATION: After a median follow-up of 39·3 months, non-inferiority of the hypofractionation group could not be established. However, given similar tolerability, hypofractionated proton PMRT appears to be worthy of further study in patients with and without immediate reconstruction. FUNDING: The Department of Radiation Oncology, Mayo Clinic, Rochester, MN, the Department of Radiation Oncology, Mayo Clinic, Phoenix, AZ, USA, and the US National Cancer Institute.

Development and validation of a recursive partitioning analysis-based pretreatment decision-making tool identifying ideal candidates for spine stereotactic body radiation therapy.

BACKGROUND: This study was aimed at developing and validating a decision-making tool predictive of overall survival (OS) for patients receiving stereotactic body radiation therapy (SBRT) for spinal metastases. METHODS: Three hundred sixty-one patients at one institution were used for the training set, and 182 at a second institution were used for external validation. Treatments most commonly involved one or three fractions of spine SBRT. Exclusion criteria included proton therapy and benign histologies. RESULTS: The final model consisted of the following variables and scores: Spinal Instability Neoplastic Score (SINS) ≥ 6 (1), time from primary diagnosis < 21 months (1), Eastern Cooperative Oncology Group (ECOG) performance status = 1 (1) or ECOG performance status > 1 (2), and >1 organ system involved (1). Each variable was an independent predictor of OS (p < .001), and each 1-point increase in the score was associated with a hazard ratio of 2.01 (95% confidence interval [CI], 1.79-2.25; p < .0001). The concordance value was 0.75 (95% CI, 0.71-0.78). The scores were discretized into three groups-favorable (score = 0-1), intermediate (score = 2), and poor survival (score = 3-5)-with 2-year OS rates of 84% (95% CI, 79%-90%), 46% (95% CI, 36%-59%), and 21% (95% CI, 14%-32%), respectively (p < .0001 for each). In the external validation set (182 patients), the score was also predictive of OS (p < .0001). Increasing SINS was predictive of decreased OS as a continuous variable (p < .0001). CONCLUSIONS: This novel score is proposed as a decision-making tool to help to optimize patient selection for spine SBRT. SINS may be an independent predictor of OS.

Consolidative radiotherapy for residual fluorodeoxyglucose activity on day +30 post CAR T-cell therapy in non-Hodgkin lymphoma.

Majority of non-Hodgkin lymphoma (NHL) patients who achieve partial response (PR) or stable disease (SD) to CAR T-cell therapy (CAR T) on day +30 progress and only 30% achieve spontaneous complete response (CR). This study is the first to evaluate the role of consolidative radiotherapy (cRT) for residual fluorodeoxyglucose (FDG) activity on day +30 post- CAR T in NHL. We retrospectively reviewed 61 patients with NHL who received CAR T and achieved PR or SD on day +30. Progression-free survival (PFS), overall survival (OS), and local relapse-free survival (LRFS) were assessed from CAR T infusion. cRT was defined as comprehensive - treated all FDG-avid sites - or focal. Following day +30 positron emission tomography scan, 45 patients were observed and 16 received cRT. Fifteen (33%) observed patients achieved spontaneous CR, and 27 (60%) progressed with all relapses involving initial sites of residual FDG activity. Ten (63%) cRT patients achieved CR, and four (25%) progressed with no relapses in the irradiated sites. The 2-year LRFS was 100% in the cRT sites and 31% in the observed sites (P<0.001). The 2-year PFS was 73% and 37% (P=0.025) and the 2-year OS was 78% and 43% (P=0.12) in the cRT and observation groups, respectively. Patients receiving comprehensive cRT (n=13) had superior 2- year PFS (83% vs. 37%; P=0.008) and 2-year OS (86% vs. 43%; P=0.047) compared to observed or focal cRT patients (n=48). NHL patients with residual FDG activity following CAR T are at high risk of local progression. cRT for residual FDG activity on day +30 post-CAR T appears to alter the pattern of relapse and improve LRFS and PFS.

Safety and Efficacy of CT-Guided Percutaneous Biopsy of Suspicious Subcentimeter Pelvic and Retroperitoneal Lymph Nodes Detected by 11C-Choline PET in Patients With Prostate Cancer.

BACKGROUND. In patients with prostate cancer, PET using targeted radiotracers can identify increased activity in small morphologically normal lymph nodes, facilitating earlier detection of metastatic disease. OBJECTIVE. The purpose of this article was to assess the efficacy and safety of CT-guided biopsy of suspicious pelvic and retroperitoneal lymph nodes measuring smaller than 1 cm detected by 11C-choline PET in patients with prostate cancer, with comparison with nodes measuring 1 cm or larger. METHODS. This retrospective study included patients with prostate cancer who underwent CT-guided percutaneous biopsy of suspicious pelvic or retroperitoneal lymph nodes detected by 11C-choline PET/CT or PET/MRI (performed because of a rising or elevated PSA level or known recurrent or metastatic disease) between June 1, 2012, and March 20, 2020. Patient, lymph node, and procedural characteristics, as well as biopsy outcomes and complications, were recorded. Biopsies of lymph nodes measuring smaller than 1 cm and of lymph nodes measuring 1 cm and larger were compared. RESULTS. A total of 269 patients (mean age, 68.7 ± 6.8 [SD] years) were included. A total of 156 patients underwent biopsy of lymph nodes measuring smaller than 1 cm (range, 3-9 mm); 113 patients underwent biopsy of lymph nodes measuring 1 cm or larger (range, 10-35 mm). Lymph nodes smaller than 1 cm and lymph nodes 1 cm and larger showed no significant difference in diagnostic yield (89.7% vs 92.9%; p = .40). Diagnostic yield was not significantly different between nodes smaller than 1 cm and nodes 1 cm and larger for any individual anatomic location within the pelvis or retroperitoneum (all p > .05). Malignant yield was lower for nodes smaller than 1 cm than for nodes 1 cm and larger (44.9% vs 63.7%; p = .003). The single biopsied 3-mm node had a nondiagnostic specimen. Diagnostic yield and malignant yield were 100.0% and 40.0%, respectively, for 4-mm nodes, and 95.5% and 45.5%, respectively, for 5-mm nodes. Patients with nodes smaller than 1 cm and nodes 1 cm and larger showed no significant difference in minor (12.8% vs 7.1%; p = .16) or major (0.6% vs 2.7%; p = .31) complication rate. CONCLUSION. The findings support the safety and efficacy of CT-guided biopsy of suspicious subcentimeter pelvic and retroperitoneal lymph nodes detected on 11C-choline PET in patients with prostate cancer. CLINICAL IMPACT. Earlier diagnosis of metastatic lymphadenopathy will impact prognostic assessment and management decisions in patients with recurrent prostate cancer.

A Phase II prospective study of hypofractionated proton therapy of prostate and pelvic lymph nodes: Acute effects on patient-reported quality of life.

BACKGROUND: The objective of this study was to report acute changes in patient-reported quality of life (PRQOL) using the 26-item Expanded Prostate Index Composite (EPIC-26) questionnaire in a prospective study using hypofractionated intensity-modulated proton beam therapy (H-IMPT) targeting the prostate and the pelvic lymph nodes for high-risk or unfavorable intermediate-risk prostate cancer. METHODS: Fifty-five patients were enrolled. H-IMPT consisted of 45 GyE to the pelvic lymph nodes and 67.5 GyE to the prostate and seminal vesicles in 25 fractions. PRQOL was assessed with the urinary incontinence (UI), urinary irritative/obstructive symptoms (UO), and bowel function (BF) domains of EPIC-26 questionnaire. Mean changes in domain scores were analyzed from pretreatment to the end of treatment and 3 months posttreatment. A clinically meaningful change (or minimum important change) was defined as a score change > 50% of the baseline standard deviation. RESULTS: The mean scores of UO, UI, and BF at baseline were 84.6, 91.1, and 95.3, respectively. At the end of treatment, there were statistically significant and clinically meaningful declines in UO and BF scores (-13.5 and -2.3, respectively), while the decline in UI score was statistically significant but not clinically meaningful (-13.7). A clinically meaningful decline in UO, UI, and BF scores occurred in 53.5%, 22.7%, and 73.2% of the patients, respectively. At 3 months posttreatment, all three mean scores showed an improvement, with fewer patients having a clinically meaningful decline in UO, UI, and BF scores (18.4%, 20.5%, and 45.0%, respectively). There was no significant reduction in the mean UO and UI scores compared to baseline, although the mean BF score remained lower than baseline and the difference was clinically meaningful. CONCLUSIONS: UO, UI, and BF scores of PRQOL declined at the end of H-IMPT. UO and UI scores showed improvement at 3 months posttreatment and were similar to the baseline scores. However, BF score remained lower at 3 months posttreatment with a clinically meaningful decline.

Cost effectiveness of treatment strategies for high risk prostate cancer.

BACKGROUND: Patients with high-risk prostate cancer (HRPC) have multiple accepted treatment options. Because there is no overall survival benefit of one option over another, appropriate treatment must consider patient life expectancy, quality of life, and cost. METHODS: The authors compared quality-adjusted life years (QALYs) and cost effectiveness among treatment options for HRPC using a Markov model with three treatment arms: (1) external-beam radiotherapy (EBRT) delivered with 20 fractions, (2) EBRT with 23 fractions followed by low-dose-rate (LDR) brachytherapy boost, or (3) radical prostatectomy alone. An exploratory analysis considered a simultaneous integrated boost according to the FLAME trial (ClinicalTrials.gov identifier NCT01168479). RESULTS: Treatment strategies were compared using the incremental cost-effectiveness ratio (ICER). EBRT with LDR brachytherapy boost was a cost-effective strategy (ICER, $20,929 per QALY gained). These results were most sensitive to variations in the biochemical failure rate. However, the results still demonstrated cost effectiveness for the brachytherapy boost paradigm, regardless of any tested parameter ranges. Probabilistic sensitivity analysis demonstrated that EBRT with LDR brachytherapy was favored in 52% of 100,000 Monte Carlo iterations. In an exploratory analysis, EBRT with a simultaneous integrated boost was also a cost-effective strategy, resulting in an ICER of $62,607 per QALY gained; however, it was not cost effective compared with EBRT plus LDR brachytherapy boost. CONCLUSIONS: EBRT with LDR brachytherapy boost may be a cost-effective treatment strategy compared with EBRT alone and radical prostatectomy for HRPC, demonstrating high-value care. The current analysis suggests that a reduction in biochemical failure alone can result in cost-effective care, despite no change in overall survival.

Androgen Deprivation Therapy Use and Risk of Mild Cognitive Impairment in Prostate Cancer Patients.

INTRODUCTION: We examined the association between androgen deprivation therapy (ADT) use and the risk of mild cognitive impairment (MCI) among prostate cancer patients. METHODS: We included 241 cognitively unimpaired men, aged 70 to 90, with a history of prostate cancer before enrollment in the population-based Mayo Clinic Study of Aging. Using the Rochester Epidemiology Project medical records-linkage system, ADT use and length of exposure were abstracted. Follow-up visits occurred every 15 months and MCI diagnoses were made based on clinical consensus. Cox proportional hazards models, with age as the timescale, were used to examine the association between ADT use (yes/no) and length of exposure with the risk of MCI adjusting for education, apolipoprotein E, depression, and the Charlson Index score. RESULTS: There was no association between any ADT use (27.8% of participants) and the risk of MCI in the multivariable model [hazard ratio (HR), 1.25; 95% confidence interval (CI), 0.75-2.10]. Although not significant, there was an ADT dose-response relationship for risk of MCI: <5 years versus no use (HR, 1.08; 95% CI, 0.60-1.96) and ≥5 years versus not use (HR, 1.89; 95% CI, 0.83-4.27). CONCLUSION: ADT use among prostate cancer patients was not associated with an increased risk of developing MCI.

Prostate Cancer, Use of Androgen Deprivation Therapy, and Cognitive Impairment: A Population-based Study.

INTRODUCTION: The association of prostate cancer and androgen deprivation therapy (ADT) use with the odds of developing mild cognitive impairment (MCI) was determined in men from the population-based Mayo Clinic Study of Aging (MCSA). METHODS: The study included 2513 men (mean age of 73.1 y) enrolled in the MCSA. A history of prostate cancer, ADT use, and length of ADT exposure before their first MCSA visit was abstracted using the Rochester Epidemiology Project medical records-linkage system. MCI was diagnosed at the baseline visit. Logistic regression was used to determine whether prostate cancer and ADT use was associated with odds of MCI. RESULTS: Of the 2513 participants, 349 (13.9%) had a history of prostate cancer; among whom 99 (28.3%) were treated with ADT before MCSA enrollment. There were 382 (15.2%) with a diagnosis of MCI. In the univariate logistic regression models, prostate cancer (odds ratio, 1.50; 95% confidence interval, 1.12-2.00), and ADT exposure (odds ratio, 1.57; 95% confidence interval, 0.96-2.58) were associated with higher odds of MCI. These associations were greatly attenuated and not significant in multivariable models. CONCLUSIONS: Neither a diagnosis of prostate cancer nor ADT use was associated with odds of MCI in this cross-sectional population-based study.

Patient-Reported Functional and Quality of Life Outcomes in a Large Cohort of Long-Term Survivors of Ewing Sarcoma.

BACKGROUND: Little data exist regarding long-term functional and quality of life (QOL) outcomes for survivors of Ewing sarcoma (ES). Specifically, there are few reports assessing the impact of patient characteristics and local therapy modalities on patient-reported outcomes (PRO). PROCEDURE: Long-term survivors of ES treated between 1977 and 2009 completed self-assessed functional and QOL surveys, using the Toronto Extremity Salvage Score (TESS) and PEDSQL 4.0 generic core instruments, respectively. Statistical analyses were performed to correlate these outcomes to clinical presentations and treatment regimens. RESULTS: Subjects (n = 74) with a mean duration from diagnosis of 17.8 years completed the survey. Mean TESS and PEDSQL total scores for the entire cohort were 93.0 ± 10.3 and 81.6 ± 18.0, respectively. No significant differences were appreciated between adult and pediatric patients, although increasing age was associated with lower functional scores (P = 0.04). Mean PEDSQL total scores were significantly lower for female patients (74.6 ± 19.7) compared to males (85.7 ± 15.7) (P = 0.01). Mild to moderate disability was reported by 32% of respondents and was associated with lower TESS and PEDSQL scores. Local control modality did not significantly affect functional and QOL scores. Patients with pelvic tumors had significantly lower TESS scores compared to those with nonpelvic tumors (P = 0.04), especially amongst patients treated with both surgery and radiation. CONCLUSIONS: Although many survivors of ES report excellent functional and QOL outcomes, a significant number report long-term disability and impairments. Older patients, females, and those with pelvic primary tumors appear at the greatest risk for long-term decrements and may benefit from early therapeutic interventions.

Color VISION for improved ultrasound visualization of brachytherapy needles.

BACKGROUND: High dose rate brachytherapy is commonly used in the treatment of prostate cancer. Treatment planning is often performed under transrectal ultrasound (US) guidance, but brachytherapy needles can be challenging to digitize due to the presence of poor US conspicuity and imaging artifacts. The plan accuracy and quality, however, are dependent on the proper visualization of the needles with millimeter accuracy. PURPOSE: This work describes a technique for generating a color overlay of needle locations atop the grayscale US image. Prototype devices were developed to produce vibrations in the brachytherapy needles that generate a high contrast color Doppler (CD) signal that highlights the needle locations with superior contrast and reduced artifacts. Denoted by the acronym color VISION (Vibrationally Induced Shimmering for Identifying an Object's Nature), the technology has the potential to improve applicator conspicuity and facilitate automated applicator digitization. METHODS: Three prototype vibrational devices with frequencies between 200-450 Hz were designed in-house and evaluated with needle implants in a phantom and cadaveric male pelvis using: (1) an actuator attached to the front of a prostate needle template; (2) an actuator attached to the top of the needle template; and (3) a hand-held actuator with a stylet, inserted directly into a needle's inner lumen. Acquired images were postprocessed in MATLAB to evaluate the potential for automated digitization. RESULTS: All prototype devices produced localized shimmering in implanted brachytherapy needles in both the axial and sagittal planes. The template mounted actuators provided better vibrational coupling and ease of operation than the stylet prototype. The Michelson contrast, or visibility, of the shimmering CD signal was 100% compared with ≤40% for B-mode imaging of a single needle. Proof-of-principle for automated applicator digitization using only the CD signal was demonstrated. CONCLUSIONS: The color VISION prototype devices successfully coupled mechanical vibrations into brachytherapy needles to generate US CD shimmering and accurately highlight brachytherapy needle locations. The high contrast and natively registered signal are promising for future work to automate the needle digitization and provide a real-time visual overlay of the applicator on the B-mode US image.

Dosimetric Features of Ultra-Hypofractionated Intensity Modulated Proton Therapy for Prostate Cancer.

Purpose: To report clinical and dosimetric characteristics of 5-fraction stereotactic ablative radiotherapy (SABR) using intensity modulated proton therapy (IMPT) for localized prostate cancer. Materials and Methods: All patients receiving IMPT SABR from 2017 to 2021 for localized prostate cancer at our institution were included. Five fractions were delivered every other day to the prostate +/- seminal vesicles [clinical target volume (CTV)] with 3 mm/3% robustness. A 4-field arrangement with 2 anterior oblique and 2 opposed lateral beams was used in most patients (97%), and most (99%) had a retroprostatic hydrogel spacer. Results: A total of 534 patients with low (14%), favorable intermediate (45%), unfavorable intermediate (36%), high (4.0%), or very high-risk (0.6%) disease are evaluated. Prescription dose was 36.25 Gy (31%), 38 Gy (38%), or 40 Gy (31%) was prescribed. Median volume percentage of CTV receiving at least 100% of prescription dose [V100% (%)] was 100% [interquartile range: 99.99-100]. Rectum V50% (%), V80% (%), and V90% (%) were significantly lower in patients who had spacer, with a mean difference of -9.70%, -6.59%, and -4.42%, respectively, compared to those who did not have spacer. Femoral head dose was lower with a 4-field arrangement. Mean differences in left and right femoral head V40% (%) were -6.99% and -10.74%, respectively. Conclusion: We provide a large, novel report of patients treated with IMPT SABR for localized prostate cancer. Four-field IMPT with hydrogel spacer provides significant sparing of rectum and femoral heads without compromising target coverage.

Prostate Cancer Lung Metastasis: Clinical Insights and Therapeutic Strategies.

Prostate cancer lung metastasis represents a clinical conundrum due to its implications for advanced disease progression and the complexities it introduces in treatment planning. As the disease progresses to distant sites such as the lung, the clinical management becomes increasingly intricate, requiring tailored therapeutic strategies to address the unique characteristics of metastatic lesions. This review seeks to synthesize the current state of knowledge surrounding prostate cancer metastasis to the lung, shedding light on the diverse array of clinical presentations encountered, ranging from subtle radiological findings to overt symptomatic manifestations. By examining the diagnostic modalities utilized in identifying this metastasis, including advanced imaging techniques and histopathological analyses, this review aims to provide insights into the diagnostic landscape and the challenges associated with accurately characterizing lung metastatic lesions in prostate cancer patients. Moreover, this review delves into the nuances of therapeutic interventions employed in managing prostate cancer lung metastasis, encompassing systemic treatments such as hormonal therapies and chemotherapy, as well as metastasis-directed therapies including surgery and radiotherapy.

Assessment of minimum target dose as a predictor of local failure after spine SBRT.

OBJECTIVES: Metastasis-directed stereotactic body radiation therapy (SBRT) has demonstrated robust clinical benefits in carefully selected patients, improving local control and even overall survival (OS). We assess a large database to determine clinical and dosimetric predictors of local failure after spine SBRT. METHODS: Spine SBRT treatments with imaging follow-up were identified. Patients were treated with a simultaneous integrated boost technique using 1 or 3 fractions, delivering 20-24 Gy in 1 fraction to the gross tumor volume (GTV) and 16 Gy to the low dose volume (or 27-36 Gy and 21-24 Gy for 3 fraction treatments). Exclusions included: lack of imaging follow-up, proton therapy, and benign primary histologies. RESULTS: 522 eligible spine SBRT treatments (68 % single fraction) were identified in 377 unique patients. Patients had a median OS of 43.7 months (95 % confidence interval: 34.3-54.4). The cumulative incidence of local failure was 10.5 % (7.4-13.4) at 1 year and 16.3 % (12.6-19.9) at 2 years. Local control was maximized at 15.3 Gy minimum dose for single-fraction treatment (HR = 0.31, 95 % CI: 0.17 - 0.56, p < 0.0001) and confirmed via multivariable analyses. Cumulative incidence of local failure was 6.1 % (2.6-9.4) vs. 14.2 % (8.3-19.8) at 1 year using this cut-off, with comparable findings for minimum 14 Gy. Additionally, epidural and soft tissue involvement were predictive of local failure (HR = 1.77 and 2.30). CONCLUSIONS: Spine SBRT offers favorable local control; however, minimum dose to the GTV has a strong association with local control. Achieving GTV minimum dose of 14-15.3 Gy with single fraction SBRT is recommended whenever possible.

Patterns of progression after immune checkpoint inhibitors for Hodgkin lymphoma: implications for radiation therapy.

ABSTRACT: Immune checkpoint inhibitors (ICIs) have demonstrated remarkable response rates in relapsed or refractory Hodgkin lymphoma (HL). Still, most patients eventually progress. Patterns of progression after ICIs are not well described and are essential to defining the role of local therapies in combination with ICIs. We identified patients who received ICIs for HL between 2013 and 2022. Fludeoxyglucose-18 positron emission tomography (FDG-PET) before initiating ICI and at progression on/after ICI were reviewed, and areas of active HL were recorded. An exploratory analysis of treatable progression included patients with ≤5 sites of disease on pre-ICI FDG-PET and progression only at pre-ICI sites. Ninety patients were identified; 69 had complete records, and of these, 32 (52%) had relapsed at ICI initiation, 17 (25%) were refractory, and 16 (23%) received ICI as first-line therapy. Forty-five of 69 patients had ≤5 sites of disease (limited) on pre-ICI FDG-PET. Patients with >5 sites of disease had a higher risk of progression, and every site of disease >5 sites conferred an additional 1.2x higher chance of progression. At a median follow-up of 4.0 years, 41 of 69 patients had progressed on/after ICIs (cumulative incidence 66.4%), and of these, 22 of 41 patients progressed only at pre-ICI sites (cumulative incidence 39.4%). In an exploratory analysis, the cumulative incidence of a treatable progression among 45 patients with limited disease was 34%. The cumulative incidence of any progression among this cohort was 58.9%. More than one-third of patients with limited disease before ICIs experienced progression only at pre-ICI sites of disease. These patients could be candidates for radiation during or after ICIs.

Improving ultrasound-based brachytherapy needle conspicuity by applying an echogenic coating.

BACKGROUND: Applicator conspicuity in ultrasound-guided brachytherapy procedures is commonly impaired by imaging artifacts or non-ideal imaging geometry, which can slow down applicator position digitization and increase the geometric uncertainty of the delivered dose distribution. PURPOSE: The purpose of this study was to improve the conspicuity of high-dose rate (HDR) brachytherapy needles under B-mode ultrasound imaging by applying an echogenic surface coating. Our hypothesis was that an echogenic coating would reduce artifacts and improve needle visualization within regions of signal degradation. METHODS: In this study, 17-gauge, 25-cm long titanium HDR brachytherapy needles were coated with acoustically reflective microspheres over a 2.5 cm region starting from the needle tip. Three coating thicknesses (27 µm, 40 µm, 64 µm) were compared against an uncoated control needle. The coated and uncoated needles were imaged using B-mode ultrasound in a tissue-equivalent prostate phantom and in a cadaverous male pelvis using a transrectal probe. Needle conspicuity was assessed under multiple conditions: a single needle implant, an implant with multiple needles between the probe and the needle of interest, and an angled needle implant. All images were assessed qualitatively for needle conspicuity and the presence of artifacts and quantitatively using grey-scale image intensity values. RESULTS: The 64 µm echogenic coating reduced the magnitude of reverberation artifacts by 31 ± 14% and comet tail artifacts by 40%-70%. The echogenic coating also improved needle contrast, measured by the relative differences in signal intensity compared with the adjacent environment, when needles were angled up to 30° with respect to the transducer probe in the cadaver. The improvements in conspicuity and artifact reduction increased with increasing coating thickness. The performance of the needles coated with the 64 µm thickness was qualitatively superior and yielded high-contrast, well-circumscribed signals in the cadaverous male pelvis, even under situations where a needle was acoustically shadowed by multiple other needles. CONCLUSIONS: An echogenic surface coating reduced imaging artifacts and improved needle conspicuity under realistic clinical conditions for ultrasound-based prostate or gynecological brachytherapy. The improved conspicuity has the potential to improve the efficiency of needle placement and the accuracy of needle position digitization during brachytherapy procedures.

A new way to visualize prostate brachytherapy needles using ultrasound color Doppler and needle surface modifications.

PURPOSE: Suboptimal ultrasound conspicuity of the brachytherapy applicator can lead to inaccurate image reconstructions of the applicator resulting in decreased tumor control or increased normal tissue dose. This feasibility study aims to improve ultrasound conspicuity of high-dose rate (HDR) brachytherapy needles by modifying the surface of the needles to produce a color Doppler twinkling signature. MATERIALS AND METHODS: Surface modifications of standard 17-gauge titanium HDR brachytherapy needles included laser-scribing, application of polymethyl methacrylate (PMMA), and coating with a commercially available echogenic coating. Laser-scribing was performed with variable widths (0.1-1 mm) and depths (10-100 µm). The echogenic coating was applied with 3 different thicknesses (27, 40, and 64 µm). Unmodified and modified needles were imaged under B-mode and color Doppler ultrasound in phantom and cadaver, and the signal strength was recorded. RESULTS: Laser-scribed, PMMA-coated, and echogenic-coated brachytherapy needles produced a twinkling signature along the needle shaft on color Doppler ultrasound. Twinkling was observed with laser-scribe depths >20 µm and widths >0.1 mm and from echogenic coatings 40 µm and 64 µm thick. Twinkling was not observed with unmodified needles. The twinkling signature had a spectral composition with a uniform magnitude between the velocities of 2 to 16 cm/s. CONCLUSIONS: Color Doppler ultrasound of surface-modified brachytherapy applicators may improve applicator conspicuity aiding applicator placement and digitization. HDR brachytherapy needles may be modified to produce the twinkling signature via laser-scribing, PMMA rings, or applying an echogenic coating.

Use of focal radiotherapy boost for prostate cancer and perceived barriers toward its implementation: a survey.

Background: 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 practice as well as physicians' perceived barriers toward its implementation. Methods: 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. Results: 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 participants worked at an academic medical center (52%) and considered their practice to be at least partially genitourinary (GU)-subspecialized (74%). 57% of participants 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. The most commonly cited barriers were concerns about registration accuracy between MRI and CT (37%), concerns about risk of additional toxicity (35%), and challenges to accessing high-quality MRI (29%). Conclusion: Despite level 1 evidence from the FLAME trial, most radiation oncologists surveyed 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, and training on contouring prostate lesions on MRI.

Use of focal radiotherapy boost for prostate cancer: radiation oncologists' perspectives and perceived barriers to implementation.

BACKGROUND: In a recent phase III randomized control trial, delivering a focal radiotherapy (RT) boost to tumors visible on MRI was shown to improve disease-free survival and regional/distant metastasis-free survival for patients with prostate cancer-without increasing toxicity. The aim of this study was to assess how widely this technique is being applied in current practice, as well as physicians' perceived barriers toward its implementation. METHODS: We invited radiation oncologists to complete an online questionnaire assessing their use of intraprostatic focal boost in December 2022 and February 2023. To include perspectives from a broad range of practice settings, the invitation was distributed to radiation oncologists worldwide via email list, group text platform, and social media. RESULTS: 263 radiation oncologist participants responded. The highest-represented countries were the United States (42%), Mexico (13%), and the United Kingdom (8%). The majority of participants worked at an academic medical center (52%) and considered their practice to be at least partially genitourinary (GU)-subspecialized (74%). Overall, 43% of participants reported routinely using intraprostatic focal boost. Complete GU-subspecialists were more likely to implement focal boost, with 61% reporting routine use. In both high-income and low-to-middle-income countries, less than half of participants routinely use focal boost. The most cited barriers were concerns about registration accuracy between MRI and CT (37%), concerns about risk of additional toxicity (35%), and challenges to accessing high-quality MRI (29%). CONCLUSIONS: Two years following publication of a randomized trial of patient benefit without increased toxicity, almost half of the radiation oncologists surveyed are now routinely offering focal RT boost. Further adoption of this technique might be aided by increased access to high-quality MRI, better registration algorithms of MRI to CT simulation images, physician education on benefit-to-harm ratio, and training on contouring prostate lesions on MRI.