Post-treatment neutrophil-to-lymphocyte ratio predicts for overall survival in brain metastases treated with stereotactic radiosurgery.

INTRODUCTION: Neutrophil-to-lymphocyte ratio (NLR) is a surrogate for systemic inflammatory response and its elevation has been shown to be a poor prognostic factor in various malignancies. Stereotactic radiosurgery (SRS) can induce a leukocyte-predominant inflammatory response. This study investigates the prognostic impact of post-SRS NLR in patients with brain metastases (BM). METHODS: BM patients treated with SRS from 2003 to 2015 were retrospectively identified. NLR was calculated from the most recent full blood counts post-SRS. Overall survival (OS) and intracranial outcomes were calculated using the Kaplan-Meier method and cumulative incidence with competing risk for death, respectively. RESULTS: 188 patients with 328 BM treated with SRS had calculable post-treatment NLR values. Of these, 51 (27.1%) had a NLR > 6. The overall median imaging follow-up was 13.2 (14.0 vs. 8.7 for NLR ≤ 6.0 vs. > 6.0) months. Baseline patient and treatment characteristics were well balanced, except for lower rate of ECOG performance status 0 in the NLR > 6 cohort (33.3 vs. 44.2%, p = 0.026). NLR > 6 was associated with worse 1- and 2-year OS: 59.9 vs. 72.9% and 24.6 vs. 43.8%, (p = 0.028). On multivariable analysis, NLR > 6 (HR: 1.53; 95% CI 1.03-2.26, p = 0.036) and presence of extracranial metastases (HR: 1.90; 95% CI 1.30-2.78; p < 0.001) were significant predictors for worse OS. No association was seen with NLR and intracranial outcomes. CONCLUSION: Post-treatment NLR, a potential marker for post-SRS inflammatory response, is inversely associated with OS in patients with BM. If prospectively validated, NLR is a simple, systemic marker that can be easily used to guide subsequent management.

Advances in Radiation Therapy for Primary and Metastatic Adult Soft Tissue Sarcomas.

Soft tissue sarcomas (STS) consist of a heterogeneous group of rare malignancies arising from mesenchymal origin. While surgical resection is the primary treatment for STS, the use of radiotherapy (RT) as an adjunctive modality has been shown to improve oncologic outcomes. Technologic improvements, such as image guidance and intensity-modulated radiotherapy that significantly improve both the precision and delivery of RT, have led to the reduction of long-term RT toxicities without compromising outcomes. This review addresses these technologic advancements as well as discussing the most current updates regarding the use of brachytherapy, charged particles, and novel agents with RT.

Pelvic lymph node mapping in prostate cancer: examining the impact of PSMA PET/CT on radiotherapy decision-making in patients with node-positive disease.

INTRODUCTION: Prostate Specific Membrane Antigen (PSMA) imaging with Positron Emission Tomography (PET) plays a crucial role in prostate cancer management. However, there is a lack of comprehensive data on how PSMA PET/CT (Computed Tomography) influences radiotherapeutic decisions, particularly in node-positive prostate cancer cases. This study aims to address this gap by evaluating two primary objectives: (1) Mapping the regional and non-regional lymph nodes (LNs) up to the aortic bifurcation and their distribution using conventional methods with CT compared to PSMA PET/CT, and (2) assessing the impact of PSMA PET/CT findings on radiotherapeutic decisions. METHODS: A retrospective analysis of 95 node-positive prostate cancer patients who underwent both CT and PSMA PET/CT imaging prior to primary radiotherapy and androgen deprivation therapy (ADT) was conducted. The analysis focused on identifying LNs in various regions including the common iliac, external iliac, internal iliac, obturator, presacral, mesorectal, inguinal, and other stations. Treatment plans were reviewed for modifications based on PSMA PET/CT findings, and statistical analysis was performed to identify predictors for exclusive nodal positivity on PSMA PET/CT scans. RESULTS: PSMA PET/CT identified additional positive nodes in 48% of cases, resulting in a staging shift from N0 to N1 in 29% of patients. The most frequent metastatic LNs were located in the external iliac (76 LNs; 34%), internal iliac (43 LNs; 19%), and common iliac (35 LNs; 15%) stations. In patients with nodes only detected on PSMA PET the most common nodes were in the external iliac (27, 40%), internal iliac (13, 19%), obturator (11, 15%) stations. Within the subgroup of 28 patients exclusively demonstrating PSMA PET-detected nodes, changes in radiotherapy treatment fields were implemented in 5 cases (18%), and a dose boost was applied for 23 patients (83%). However, no discernible predictors for exclusive nodal positivity on PSMA PET/CT scans emerged from the analysis. DISCUSSION: The study underscores the pivotal role of PSMA PET/CT compared to CT alone in accurately staging node-positive prostate cancer and guiding personalized radiotherapy strategies. The routine integration of PSMA PET/CT into diagnostic protocols is advocated to optimize treatment precision and improve patient outcomes.

Stereotactic radiosurgery for brain metastases arising from gynecological malignancies: A retrospective treatment outcome analysis.

BACKGROUND: This retrospective study aims to assess the efficacy of stereotactic radiosurgery (SRS) in the treatment of brain metastases (BM) originating from gynecological cancers. It focuses on local control (LC), distant tumor control (DTC), and overall survival (OS). METHODS: The analysis comprised 18 individuals with gynecological-origin BM treated with SRS at the Hadassah Medical Center from 2004 to 2021. Statistical analyses evaluate factors impacting LC, DTC, and OS. RESULTS: A total of 36 BM of gynecological origin underwent SRS. The median age at the first SRS treatment was 60 years, with a median time of 24.5 months from the primary malignancy diagnosis to BM detection. The 12-month LC rate per patient was 84.6 %, and 5.6 % per BM. Only two instances of local recurrence were observed. The DTC at 12 months was 75 %, with a 29 % overall. Non-significant trends indicating a correlation with distant brain failure with increased cumulative volume and the occurrence of craniotomy before SRS. The median OS of the cohort was 16.5 months from SRS treatment. The 6, 12, 18, and 24-month survival rates were 77.8 %, 66.7 %, 50 %, and 22.2 % respectively. Higher number of BM was associated with lower OS (p = 0.046). On multivariate analysis, age was a significant factor for OS (p = 0.03), demonstrating that older age was associated with a more favorable prognosis. CONCLUSION: This study supports SRS effectiveness for treating BM from gynecological cancers and suggests similar outcomes to more common malignancies.

Multiparametric Magnetic Resonance Imaging- Guided Dose-Escalated Radiation Therapy for Localized Prostate Cancer: A Prospective Phase 2 Trial.

PURPOSE: This trial's purpose was to determine the late toxicity associated with dose escalation to Prostate Imaging Reporting and Data System (PI-RADS) III-V lesions on multiparametric magnetic resonance imaging (MRI) with an image guided combined IMRT-stereotactic body radiation therapy (SBRT) approach in men with localized prostate cancer. METHODS AND MATERIALS: In this phase 2 trial patients with localized prostate cancer with clinical tumor stage T1-T3bN0 and at least one PIRADS III-V lesion were recruited to receive 45 Gy in 25 fractions to the prostate and seminal vesicles followed by a boost of 18 Gy in 3 fractions to the prostate with a simultaneous integrated boost 21 Gy in 3 fractions to the PI-RADS lesion(s). The primary endpoint was the cumulative incidence of late grade ≥3 genitourinary and gastrointestinal toxicity by 18 months (National Cancer Institute Common Terminology Criteria for Adverse Events, version 4.0). RESULTS: Overall, 50 patients were enrolled in this study, and 43 patients completed at least 18 months of follow-up. The cumulative incidence of grade 1, 2, and 3 late genitourinary toxicity at 18 months was 18%, 53%, and 2%. One patient was noted to have grade 3 hematuria and needed cystoscopy-guided cauterization. No acute grade 3 gastrointestinal or genitourinary toxicities were observed. The cumulative incidence of grade 1, 2, and 3 late gastrointestinal toxicity at 18 months was 31%, 4%, and 0%, respectively. At a median follow-up of 43.5 months, 3 patients developed biochemical recurrence, each with distant bone metastases without local or nodal recurrence. At 3 years, freedom from biochemical failure rate was 95.3% (95% CI, 89.2%-100%). CONCLUSIONS: Multiparametric MRI-guided dose escalation to PI-RADS III-V lesions using a combined image guided IMRT-SBRT approach is associated with an acceptable risk of late gastrointestinal and genitourinary toxicity. The results should be interpreted with caution considering their single institutional nature, small sample size, and short follow-up and should be validated in a larger study.

Outcomes of extracranial stereotactic body radiation therapy for induced oligometastatic non-small cell lung cancer on novel systemic therapy.

Background: Stereotactic body radiation therapy (SBRT) is often delivered in patients with oligometastatic disease (OMD). However, the specific subset of patients with polymetastatic non-small cell lung cancer (NSCLC) on novel systemic therapies who develop induced oligopersistant disease (OpersisD) or oligoprogressive disease (OprogD), as defined by the European Organisation for Research and Treatment of Cancer (EORTC) OMD classification, has not been well described. This study explores the outcomes of patients treated with this strategy. Methods: Patients with stage IV NSCLC being treated with osimertinib or immune checkpoint inhibitors (ICIs) who received extracranial SBRT for OpersisD or OprogD were identified in our retrospective analysis. Outcomes reported include progression-free survival (PFS), time to change of systemic treatment (TTCST), overall survival (OS), local control (LC) and treatment-related toxicity. Results: Forty-nine patients received SBRT for OpersisD (34.7%) or OprogD (65.3%) at a median of 5.8 and 15.3 months after start of systemic therapy, respectively. 55.1% received concurrent osimertinib and 44.9% received ICI. Seventy-seven extracranial lesions were treated with various fractionation schemas. At a median of 18.8 months follow-up from first SBRT, LC was achieved in 92.2% of total lesions treated (71). The 1-year OS was 91.7% for OpersisD and 83.3% for OprogD. OpersisD compared to OprogD had a longer median PFS (18.3 vs. 6.1 months) and longer median TTCST (23.6 vs. 13.5 months), median OS was not reached for either cohort. On multivariate analysis, patients treated with osimertinib had shorter PFS (HR: 2.20; 95% CI: 1.01-4.82; P=0.048) and shorter TTCST (HR: 2.83; 95% CI: 1.09-7.33; P=0.032). One patient (2%) experienced grade 3 pneumonitis after SBRT, and no grade 4-5 toxicities were reported with SBRT treatment. Conclusions: This study indicates that SBRT for OpersisD or OprogD in Stage IV NSCLC patients on osimertinib or ICIs is safe, very well tolerated, and may prolong the time before needing a shift in systemic therapy. Further prospective research is needed to validate and expand upon these findings.

Rapid Classification of Sarcomas Using Methylation Fingerprint: A Pilot Study.

Sarcoma classification is challenging and can lead to treatment delays. Previous studies used DNA aberrations and machine-learning classifiers based on methylation profiles for diagnosis. We aimed to classify sarcomas by analyzing methylation signatures obtained from low-coverage whole-genome sequencing, which also identifies copy-number alterations. DNA was extracted from 23 suspected sarcoma samples and sequenced on an Oxford Nanopore sequencer. The methylation-based classifier, applied in the nanoDx pipeline, was customized using a reference set based on processed Illumina-based methylation data. Classification analysis utilized the Random Forest algorithm and t-distributed stochastic neighbor embedding, while copy-number alterations were detected using a designated R package. Out of the 23 samples encompassing a restricted range of sarcoma types, 20 were successfully sequenced, but two did not contain tumor tissue, according to the pathologist. Among the 18 tumor samples, 14 were classified as reported in the pathology results. Four classifications were discordant with the pathological report, with one compatible and three showing discrepancies. Improving tissue handling, DNA extraction methods, and detecting point mutations and translocations could enhance accuracy. We envision that rapid, accurate, point-of-care sarcoma classification using nanopore sequencing could be achieved through additional validation in a diverse tumor cohort and the integration of methylation-based classification and other DNA aberrations.

Clinical Characteristics, Response to Platinum-Based Chemotherapy and Poly (Adenosine Phosphate-Ribose) Polymerase Inhibitors in Advanced Lung Cancer Patients Harboring BRCA Mutations.

The oncogenic role and clinical relevance of BRCA mutations in NSCLC remain unclear. We aim to evaluate the characteristics and clinical outcomes of patients with NSCLC harboring BRCA mutations treated at Hadassah Medical Center (HMC). We retrospectively assessed all patients with advanced NSCLC who underwent next-generation sequencing (NGS) and were found to have pathogenic somatic BRCA mutations (p-BRCA). We compared clinical outcomes in NSCLC patients with wild-type BRCA (wt-BRCA) matched by age, stage, gender, smoking, PDL-1 and driver mutations. Between 2015 and 2022, we evaluated 598 patients with advanced NSCLC using NGS and found 26 patients with p-BRCA, of whom 17 (65.4%) were carriers of germline BRCA variants and represented 1% of all BRCA carriers HMC. The median age of diagnosis was 67 years old (40-78), 13 patients (50%) had a history of smoking and 9 patients (34.6%) had additional driver mutations (EGFR, ALK, BRAF, MET or ERBB2). Objective response rate and median progression-free survival (PFS) for first-line platinum-based chemotherapy in the p-BRCA group compared to wt-BRCA controls were 72.2% and 16 months (CI 95%, 5-22), compared to 47.4% and 7 months (CI 95%, 5-9), respectively, and HR for PFS was 0.41 (CI 95%, 0.17-0.97). Six patients in the p-BRCA group were treated with advanced-line poly (adenosine-phosphate-ribose) polymerase inhibitors (PARPi), with a durable response observed in four patients (66%). In this cohort, patients with NSCLC harboring p-BRCA exhibit high-sensitivity PARPi and a prolonged response to platinum, suggesting some oncogenic role for BRCA mutations in NSCLC. The results support further prospective trials of the treatment of NSCLC harboring p-BRCA with PARPi.

Neoadjuvant Osimertinib Followed by Sequential Definitive Radiation Therapy and/or Surgery in Stage III Epidermal Growth Factor Receptor-Mutant Non-Small Cell Lung Cancer: An Open-Label, Single-Arm, Phase 2 Study.

PURPOSE: The treatment for unresectable, locally advanced stage III non-small cell lung cancer (NSCLC) is concurrent chemoradiation therapy (CRT) followed by consolidation durvalumab. This study aimed to evaluate the benefit of neoadjuvant osimertinib as an alternative therapy to this approach with the aim of reducing the radiation field. METHODS AND MATERIALS: This investigation was a nonrandomized, open-label, single-arm, phase 2, prospective, proof-of-concept study. Eligible patients were classified as having treatment-naïve, nonoperable, stage III epidermal growth factor receptor-mutant NSCLC. Patients received 80 mg of oral osimertinib daily for 12 weeks before definitive radiation therapy (RT) and/or surgery. The response was assessed at weeks 6 and 12. For responders, sequential definitive RT and/or surgery were planned. Nonresponders were started on standard CRT. After RT ± surgery or CRT, patients were followed for 2 years without adjuvant therapy. The primary endpoint was the objective response rate (ORR), with September 20, 2022, set as the cut-off for data collection. Secondary endpoints were safety and the gross tumor volume (GTV), planned tumor volume (PTV), and the percentage of total lung volume minus GTV exceeding 20 Gy (V20%) before versus after osimertinib. Exploratory analyses included assessments of the presence of plasma circulating tumor-free DNA (ctDNA) before osimertinib treatment, at weeks 6 and 12, at the end of RT, and 6 weeks post-RT. RESULTS: Twenty-four patients were included (19 women; median age, 73 years; range, 51-82 years). Nineteen of 24 had never smoked, 20 of 24 had adenocarcinoma, 16 of 24 had exon 19 deletions, and 8 of 24 had exon 21 mutations. Participants had stage IIIA (10), IIIB (9), or IIIC (5) disease. Three patients were excluded from the analysis (1 dropped out and 2 were still undergoing osimertinib treatment at the cut-off date). The ORR to induction osimertinib was 95.2% (17 partial response, 3 complete response, and 1 progressive disease). After induction osimertinib, 13 of 20 patients were definitively radiated, 3 of 20 underwent surgery, and 5 of 20 were excluded. Four patients were restaged as stage IV (contralateral ground-glass opacities responded to osimertinib), and 1 patient withdrew informed consent. Three patients underwent surgery, one of whom was treated with RT. Two patients achieved pT1aN0, and one achieved pathologic complete response. The median GTV, PTV, and V20% before osimertinib treatment were 47.4 ± 76.9 cm3 (13.5-234.9), 227.0 ± 258.8 cm3 (77.8-929.2), and 27.1 ± 16.4% (6.2-60.3), respectively. The values after osimertinib treatment were 27.5 ± 42.3 cm3 (2.99-137.7; -48 ± 20%; P = .02), 181.9 ±198.4 cm3 (54-718.1; -31 ± 20%; P = .01), and 21.8 ± 11.7% (9.1-44.15; -24 ± 40%; P = .04), respectively. PTV/GTV/V20% reduction was associated with tumor size and central location. The median follow-up time was 28.71 months (range, 0.4-45.1 months), and median disease-free survival was not reached (mean, 30.59; standard error, 3.94; 95% confidence interval, 22.86-38.31). ctDNA was detected in 5 patients; 4 of 5 were positive for ctDNA at baseline and became negative during osimertinib induction but were again positive after osimertinib treatment was terminated. Interestingly, 3 patients who were ctDNA negative at baseline became weakly positive after RT and then were negative at follow-up. No significant adverse events were reported during the osimertinib or radiation phases. CONCLUSIONS: Neoadjuvant osimertinib therapy is feasible in patients with stage III lung cancer NSCLC, followed by definitive radiation and/or surgery, with an ORR of 95.2% and an excellent safety profile. Osimertinib induction for 12 weeks before definitive radiation (chemo-free) significantly reduced the radiation field by nearly 50% with a linear association with tumor size. Further studies are needed to test this chemo-free approach for long-term outcomes before practices are changed.

Endovascular management of life threatening bleeding from a radiation induced internal iliac artery branch pseudoaneurysm.

BACKGROUND: Among radiation induced arterial complications, stenoses and occlusions are commonly reported. Radiation induced pseudoaneurysms (PSA) and their management outcomes are rarely reported. CASE PRESENTATION: A 48 year old male underwent low anterior resection surgery for a clinically staged T2N0M0 rectal adenocarcinoma and adjuvant chemoradiation for the findings of lymphovascular invasion and focally positive distal margin 2 years prior to current admission. The patient now presented with syncope and anemia. The patient was hypotensive after an episode of hematochezia during the hospital stay. An urgent sigmoidoscopy revealed bleeding from friable necrotic rectal mucosa with focal pulsations along the left posterolateral aspect of the rectal wall. An emergent pelvic angiogram revealed active extravasation from a 3 mm PSA from the anterior division of left internal iliac artery. After coil embolization of the affected vascular branch on either side of the neck of PSA, there was no opacification of PSA or extravasation. The patient remained asymptomatic for 3 years. CONCLUSIONS: Radiation induced PSA must be considered in the absence of trauma. Endovascular coil-embolization of radiation induced PSAs from small caliber vessels can be an effective treatment.

The Changing Paradigm of Radiotherapy in the Elderly Population.

There is increasing awareness of the special needs for care of the elderly cancer patient. Newer precise conformal radiotherapy techniques allow the safe delivery of higher doses of radiotherapy to the target tumor while reducing the dose to surrounding critical organs. This has led to a shortening of radiotherapy protocols for both curative and palliative indications. We review these novel techniques and protocols and the published clinical studies that include elderly patients treated with these techniques. Despite the fact that the elderly are a growing significant proportion of cancer patients, and the need for radiotherapy in the elderly is expected to rise with increasing life expectancy, they are underrepresented in most clinical studies of radiotherapy, and there are few studies specifically investigating radiotherapy in the elderly. The treatment of early-stage primary lung cancer with stereotactic body radiotherapy is a prime example how new highly conformal techniques and shortened treatment protocols are changing the approach to radiotherapy in the elderly. With improved imaging and radiotherapy treatment precision, it is expected that such techniques will become increasingly used in other cancer sites. It is important for radiation oncologists to be aware of the special needs of the elderly cancer patient and in particular to assess these patients based on functional status and not only chronological age. In addition, geriatric oncologists should be aware of modern radiotherapy techniques that can be particularly appropriate for the elderly patient.

Lung stereotactic body radiation therapy (SBRT) for early-stage non-small cell lung cancer in the very elderly (≥80years old): Extremely safe and effective.

OBJECTIVE: Stereotactic body radiotherapy (SBRT) for early-stage non-small-cell lung cancer (NSCLC) is the standard of care in medically inoperable patients. In very elderly patients, previous studies have shown SBRT to offer excellent local control, though with higher toxicities than in younger populations. We report our institutional experience using SBRT in the definitive management of NSCLC in patients ≥80years old. MATERIALS AND METHODS: Using an IRB-approved registry of 158 patients treated with definitive-intent lung SBRT for early-stage NSCLC at our institution between 2010 and 2016, 31 consecutively treated patients ≥80years of age were identified. CTCAEv4 scales were prospectively recorded during follow-ups and utilized for toxicity assessments. Kaplan-Meier estimates were utilized for survival analyses. RESULTS: For the 31 patients (with 34 lesions) included, median age was 83 (R: 80-93), median ECOG performance status was 2 (R: 0-3), and median follow-up was 15.8months (R: 3.1-48.3). Median PTV size was 24.0cm3 (R: 5.83-62.1cm3). Median prescription dose was 54Gy in 3 fractions (R: 50-60Gy in 3-8 fractions). Local control was 100% at 1year and 92.3% at 2years. Median survival was 29.1months. There were no grade 2-5 toxicities. Grade 1 toxicities included: fatigue in 5 patients (16.1%), asymptomatic (radiographic) pneumonitis in 12 (38.7%), and dyspnea in 2 (6.5%). CONCLUSIONS: Lung SBRT with a BED of ≥100Gy10 for very elderly patients with NSCLC is extremely safe and effective, with inordinately low toxicity rates (zero grade 2-5 toxicities). With stringent dosimetric parameters and planning guidelines, patients ≥80years remain excellent candidates for full-dose SBRT. SUMMARY: SBRT for early-stage NSCLC is the accepted standard of care in medically inoperable patients, though in many very elderly patients, dose is either de-intensified or withheld for concern of toxicity in the setting of advanced age and competing risks. In this study of our very elderly (≥80years old) early-stage NSCLC patients, we highlight both the extremely high efficacy and tolerability (zero grade 2 or above toxicities) associated with definitive intent SBRT.

Association of Insurance and Community-Level Socioeconomic Status With Treatment and Outcome of Squamous Cell Carcinoma of the Pharynx.

Importance: Community-level socioeconomic status, particularly insurance status, is increasingly becoming important as a possible determinant in patient outcomes. Objective: To determine the association of insurance and community-level socioeconomic status with outcome for patients with pharyngeal squamous cell carcinoma (SCC). Design, Setting, and Participants: This study extracted data from more than 1500 Commission on Cancer-accredited facilities collected in the National Cancer Database. A total of 35 559 patients diagnosed with SCC of the pharynx from 2004 through 2013 were identified. The χ2 test, Kaplan-Meier method, and Cox regression models were used to analyze data from April 1, 2016, through April 16, 2017. Main Outcomes and Measures: Overall survival was defined as time to death from the date of diagnosis. Results: Among the 35 559 patients identified (75.6% men and 24.4% women; median age, 61 years [range, 18-90 years]), 15 146 (42.6%) had Medicare coverage; 13 061 (36.7%), private insurance; 4881 (13.7%), Medicaid coverage; and 2471 (6.9%), no insurance. Uninsured patients and Medicaid recipients were more likely to be younger, black, or Hispanic; to have lower median household income and lower educational attainment; to present with higher TNM stages of disease; and to start primary treatment at a later time from diagnosis. Those with private insurance (reference group) had significantly better overall survival than uninsured patients (hazard ratio [HR], 1.72; 95% CI, 1.59-1.87), Medicaid recipients (HR, 1.99; 95% CI, 1.88-2.12), or Medicare recipients (HR, 2.07; 95% CI, 1.99-2.16), as did those with median household income of at least $63 000 (reference) vs $48 000 to $62 999 (HR, 1.19; 95% CI, 1.13-1.26), $38 000 to $47 999 (HR, 1.31; 95% CI, 1.24-1.38), and less than $38 000 (HR, 1.51; 95% CI, 1.43-1.59). On multivariable analysis, insurance status and median household income remained independent prognostic factors for overall survival even after accounting for educational attainment, race, Charlson/Deyo comorbidity score, disease site, and TNM stage of disease. Conclusions and Relevance: Insurance status and household income level are associated with outcome in patients with SCC of the pharynx. Those without insurance and with lower household income may significantly benefit from improving access to adequate, timely medical care. Additional investigations are necessary to develop targeted interventions to optimize access to standard medical treatments, adherence to physician management recommendations, and subsequently, prognosis in these patients at risk.

Transperineal prostate biopsy under magnetic resonance image guidance: a needle placement accuracy study.

PURPOSE: To quantify needle placement accuracy of magnetic resonance image (MRI)-guided core needle biopsy of the prostate. MATERIALS AND METHODS: A total of 10 biopsies were performed with 18-gauge (G) core biopsy needle via a percutaneous transperineal approach. Needle placement error was assessed by comparing the coordinates of preplanned targets with the needle tip measured from the intraprocedural coherent gradient echo images. The source of these errors was subsequently investigated by measuring displacement caused by needle deflection and needle susceptibility artifact shift in controlled phantom studies. Needle placement error due to misalignment of the needle template guide was also evaluated. RESULTS: The mean and standard deviation (SD) of errors in targeted biopsies was 6.5 +/- 3.5 mm. Phantom experiments showed significant placement error due to needle deflection with a needle with an asymmetrically beveled tip (3.2-8.7 mm depending on tissue type) but significantly smaller error with a symmetrical bevel (0.6-1.1 mm). Needle susceptibility artifacts observed a shift of 1.6 +/- 0.4 mm from the true needle axis. Misalignment of the needle template guide contributed an error of 1.5 +/- 0.3 mm. CONCLUSION: Needle placement error was clinically significant in MRI-guided biopsy for diagnosis of prostate cancer. Needle placement error due to needle deflection was the most significant cause of error, especially for needles with an asymmetrical bevel.