21 Gy single fraction prostate HDR brachytherapy: 5-year results of a single institution prospective pilot study

PURPOSE

To present the outcome and toxicity results of a prospective trial of 21 Gy single fraction high-dose-rate (HDR) brachytherapy for men with low- or intermediate-risk prostate cancer.

METHODS AND MATERIALS

Patients were treated according to an IRB-approved prospective study of single fraction HDR brachytherapy. Eligible patients had low- or intermediate-risk prostate cancer with tumor stage ≤ T2b, PSA ≤ 15, and Gleason score ≤ 7. Patients underwent trans-rectal ultrasound-guided trans-perineal implant of the prostate followed by single fraction HDR brachytherapy to a dose of 21 Gy. The primary endpoint was grade ≥ 2 urinary/GI toxicity rates.

RESULTS

Twenty-six patients were enrolled with a median follow up of 5.1 years and median age of 64 years. 88.5% of patients had T1 disease, 15.4% had Gleason score 6 (84.6% Gleason 7), and median pre-treatment PSA was 5.0 ng/mL. Acute and chronic grade ≥ 2 urinary toxicity rates were 38.5% and 38.5%, respectively. There were no grade ≥ 2 acute or chronic GI toxicities. Six (23.1%) patients experienced biochemical failure, six (23.1%) patients experienced radiographic local failure, and five (19.2%) patients had biopsy-proven local failure. No patients developed regional lymph node recurrence or distant metastasis. 5-year overall survival and cause-specific survival were 96.2% and 100%, respectively.

CONCLUSIONS

21 Gy single fraction HDR brachytherapy was associated with modestly higher-than-anticipated chronic urinary toxicity, as well as high biochemical and local failure rates. The results from this prospective pilot study do not support the use of this regimen in standard clinical practice.

Comparison of Two Different Adjuvant High Dose Rate Vaginal Brachytherapy Fractionation Regimens in Early-Stage Endometrial Cancer

PURPOSE/OBJECTIVE(S)

Adjuvant vaginal brachytherapy (VBT) as monotherapy is commonly used as treatment for early-stage uterine cancer following hysterectomy. No ABS guidelines existed at the onset of our institution's high dose rate (HDR) brachytherapy program, so a regimen of 30 Gy in six fractions was adopted in this setting. Due to the COVID pandemic in 2020, we implemented the use of 22 Gy in four fractions as our primary regimen to reduce overall treatment duration and healthcare exposure risks. In this analysis, we seek to compare outcomes and toxicities between the two treatment regimens.

MATERIALS/METHODS

This is a single institution retrospective review of patients with Stage I-II endometrial cancer who received adjuvant VBT as monotherapy between 1998 and 2022. HDR VBT was delivered via a vaginal cylinder prescribed to a depth of 5 mm, to a dose of 22 or 30 Gy in four or six fractions, respectively. We evaluated maximum acute and chronic toxicities, defined as ≤6 months and ≥ 6 months following treatment completion, respectively. Toxicities were assessed using the Common Terminology Criteria for Adverse Events (CTCAE) criteria. We evaluated clinical outcomes including local recurrence (LR), distant metastasis (DM), cause-specific survival (CSS) and overall survival (OS). P-values <0.05 were considered significant.

RESULTS

A total of 270 patients were included in our analysis, with a median follow up of 4.98 years (7.7 and 1.3 years for six-fraction and 4-fraction regimen, respectively, p<0.001). The median age at the time of treatment was 66 (range 31-89). 195 patients (72.2%) were treated with six fractions and 75 (27.8%) were treated with four fractions. There was significantly less chronic vaginal dryness (p = 0.017) and vaginal stenosis (p<0.001) with the four-fraction compared to the 6-fraction regimen. There was no difference in acute toxicity (p = 0.468). There were no grade ≥3 toxicities in either group. The 2-year LR, DM, CSS, and OS rates for four/six fractions were 2.4%/3.7%, 6.8%/3.7%, 95.8%/97.9%, and 95.8%/95.8%, respectively. There were no significant differences in outcomes between the two groups.

CONCLUSION

Our experience supports that VBT in four fractions is well tolerated with minimal acute and chronic toxicities. When comparing to our institution's historical data for a six-fraction regimen, the use of a four-fraction regimen resulted in less chronic vaginal dryness and stenosis, supporting its continued use. The clinical outcomes have been similar thus far. Further analysis with a longer follow-up duration and a match-pair analysis is warranted.

High-dose-rate brachytherapy as monotherapy versus as boost in unfavorable intermediate-risk localized prostate cancer: A matched-pair analysis

PURPOSE

High-dose-rate brachytherapy as monotherapy (HDR-M), or as a boost combined with external beam radiotherapy (HDR-B), are both suitable treatments for intermediate-risk prostate cancer. However, data directly comparing these two approaches for men with unfavorable intermediate-risk (UIR) patients are lacking.

METHODS AND MATERIALS

Patients with NCCN-defined UIR prostate cancer treated from 1997 to 2020 were identified in a prospectively maintained, single institution database. HDR-M and HDR-B patients were matched using three factors: age ±3 years; Gleason score (major and minor); and clinical T stage. Biochemical failure was defined as PSA nadir (nPSA) + 2. Available acute and chronic toxicities are additionally reported.

RESULTS

A total of 247 patients were identified (170 receiving HDR-B, 77 receiving HDR-M), ultimately yielding 70 matched pairs (140 patients) for inclusion. The median followup time was 5.2 years for HDR-M compared with 9.3 years for HDR-B (p < 0.001). The two cohorts had similar calculated prostate EQD2 (HDR-B 118 Gy vs. HDR-M 115 Gy, p = 0.977). No significant differences in OS, CSS, DM, LRR, or FFBF were identified. HDR-B had an increased rate of any acute grade 2+ gastrointestinal toxicity and worse acute dysuria and diarrhea. Chronic gastrointestinal and genitourinary toxicity was similar.

CONCLUSIONS

These data suggest that HDR brachytherapy as monotherapy is an effective treatment option for selected patients with unfavorable intermediate-risk prostate cancer and provides a more favorable gastrointestinal toxicity profile than HDR-B. Prospective trials should be conducted to refine the selection process for this heterogeneous cohort of patients.

Toxicity and Efficacy After Adjuvant Vaginal Brachytherapy Using 30 Gy in 6 Fractions for Stages I and II Endometrial Cancer

Purpose

This study aimed to evaluate outcomes and toxicity in patients with endometrial cancer per our institutional adjuvant vaginal cuff brachytherapy (VBT) fractionation scheme.

Methods and Materials

We identified women with International Federation of Gynecology and Oncology stages I and II endometrial cancer who underwent surgical staging and adjuvant high-dose-rate VBT without external beam radiation. All patients received 30 Gy in 6 fractions to the upper one-third of the vagina, prescribed to a depth of 5 mm and delivered twice weekly. Toxicities were prospectively elicited at each follow up, and rates of recurrence and survival were retrospectively assessed.

Results

We identified 247 eligible patients treated between 1992 and 2018 with a median follow up of 5.8 years (range, 0.1-24.7 years). Most patients had stage I disease (52% stage IA; 37% stage IB), and 11% of patients were stage II. Deep myometrial invasion was predictive of local recurrence (P = .002). The 5-year rates of local recurrence, regional recurrence, and distant metastases were 5%, 5%, and 7%, respectively. Five-year overall and disease-free survival were 91% and 83%, respectively. The most common grade 1 toxicities were acute fatigue (11% crude rate), urinary frequency (11%), chronic (>6 months) urinary frequency (13%), urinary incontinence (13%), and vaginal stenosis (21%). There were few grade 2 toxicities (all <5%) and no grade 3 to 5 toxicities.

Conclusions

The adjuvant VBT fractionation scheme of 30 Gy in 6 fractions results in low rates of toxicity, with no grade ≥3 adverse events, and local control rates comparable with those from other published series using different fractionation schemes.

Benign prostate hyperplasia as a potential protective factor against prostate cancer: Insights from a magnetic resonance imaging study of compositional characteristics

PURPOSE

The structural relationship between benign prostate hyperplasia (BPH) and prostate cancer (Pca) is controversial. The purpose of our study was to examine the association between quantitative prostate compositional metrics by magnetic resonance imaging (MRI) and Pca.

METHODS

We identified 405 patients who underwent prostate MRI and biopsy and/or prostatectomy from January 2019 to January 2021 at our institution. Segmentation volumetric methods were used to assess central gland (CG) and peripheral zone (PZ) volume. PZ mean thickness and mean apparent diffusion coefficient (ADC), marker of underlying histologic components, were measured. Multivariable logistic regression was performed with outcomes of ≥Grade Group (GG) 2 Pca and for multifocal disease.

RESULTS

On multivariable analysis, higher CG volumes were at lower odds of ≥GG2 disease (n = 227) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001), taking into account PZ volume (p = 0.18) and thickness (p = 0.70). For every one cc increase in CG volume, there was an approximately 3% decrease in odds of ≥GG2 disease. Similar findings were noted for multifocal disease (n = 180) (OR: 0.97, 95% CI 0.96-0.98, p < 0.0001). Notably, ADC of the normal PZ was not significantly associated with CG volume (p = 0.21) nor a predictor of disease (p = 0.49).

CONCLUSIONS

Increasing central gland volume, driven by BPH, is associated with lower odds of significant Pca, including multifocal disease, while PZ anatomic and histologic surrogate changes were noncontributory. Findings support BPH impediment of global tumor growth predicted by theoretical mechanobiological model. This potential stabilizing factor should be further studied for risk stratification and in consideration for BPH therapy.

Adjuvant radiotherapy improves overall survival when added to surgery and chemotherapy for uterine carcinosarcoma: a surveillance, epidemiology, and end results analysis

BACKGROUND

Uterine carcinosarcoma (UCS) confers a high recurrence risk following surgery, and adjuvant chemotherapy (CHT) is typically administered in all stages. The benefit of radiation therapy (RT) in UCS, when added to adjuvant CHT, is unknown. We sought to analyze the Surveillance, Epidemiology, and End Results (SEER) database to ascertain whether RT improves overall survival (OS) when added to surgery and CHT for UCS.

METHODS

SEER 18 Custom Data registries (Nov 2018 submission) were queried for uterine (ICD10 C54.1-9, C55.9) carcinosarcoma (ICD-0-3 8980-3). Patients with stage I-III UCS who underwent surgery and CHT ± RT were analyzed with univariate analysis (UVA) and multivariable analysis (MVA) using Kaplan-Meier and Cox proportional hazards regression modeling. Propensity-score matched analysis with inverse probability of treatment weighting (IPTW) was performed to account for indication bias. Furthermore, conditional landmark analysis (minimum three-month follow-up) was performed to minimize immortal time bias.

RESULTS

All 1541 patients (1988-2016) underwent surgery and CHT and 54% received RT. On UVA, RT improved median and 5-year OS from 41 to 87 months and 43-55%, respectively (HR 0.65, 95% CI 0.56-0.77) (p < 0.001). After IPTW adjustment, RT improved median and 5-year OS from 46 to 65 months and 46-53%, respectively (HR 0.74, 95% CI 0.63-0.87) (p < 0.001). The benefit of RT remained on unadjusted and adjusted MVA and conditional landmark analysis.

CONCLUSION

In stage I-III UCS treated with surgery and CHT, receipt of RT is associated with OS benefit. Further prospective data are needed to investigate the RT's benefit in UCS.

Outcomes After Salvage Radiation Therapy for Recurrent Endometrial Cancer in Patients With No Prior Adjuvant Therapy: An Institutional Review

Purpose

After definitive surgery, women with early-stage, low-risk endometrial cancer are observed. However, some will require salvage radiation therapy for recurrence. The purpose of this study was to evaluate our experience using salvage radiation for recurrent endometrial cancer in patients who did not receive upfront adjuvant therapy.

Methods and Materials

Twenty-eight women with endometrial cancer who had undergone initial definitive hysterectomy without adjuvant therapy developed isolated local or regional recurrence and were treated with salvage radiation in our department from 2004 to 2018. Salvage radiation included whole pelvic radiation, vaginal brachytherapy, or both. Patient and tumor characteristics, treatment details, and toxicities were recorded and analyzed.

Results

The median time to first recurrence was 1.7 years. First recurrences consisted of local recurrence in 23 patients, regional recurrence in 4, and both in 1. The median times from hysterectomy to first recurrence, local and regional, were 1.2 and 4.0 years, respectively. All patients underwent salvage radiation for management of their first recurrence. The median total equivalent dose in 2 Gy fractions for this treatment was 67.6 Gy (37.5–81.8 Gy). Two second recurrences occurred following salvage treatment, both local recurrence, at 6.5 and 13.5 months after radiation. The 2-year rates of local control, disease-free survival, and overall survival were 93%, 80%, and 88%, respectively. Treatment was well-tolerated, with low rates of gastrointestinal and genitourinary toxicity.

Conclusions

In this group of patients, salvage radiation therapy for local or regional recurrence of endometrial cancer resulted in excellent control with low rates of acute and chronic toxicities.

Trends in Medicare Reimbursement and Work Relative Value Unit Production in Radiation Oncology

PURPOSE

Medicare payments to individual physicians are released annually by the CMS. The purpose of this study is to analyze trends in Medicare reimbursement and work relative value unit (wRVU) production to radiation oncologists.

MATERIALS AND METHODS

The Medicare Physician Supplier and Other Provider Public Use File and the CMS Physician Fee Schedule Relative Value Files (to calculate wRVUs) for the calendar years 2012 to 2015 were used in this analysis. Medicare reimbursement was aggregated for each calendar year. Using the CMS Physician Fee Schedule Relative Value Files, the number of Medicare wRVUs was calculated for each radiation oncologist.

RESULTS

In 2015, 4,323 radiation oncologists produced 12,895,298 wRVUs compared with 11,352,286 wRVUs produced in 2012. These datasets include only Medicare reimbursements and do not include wRVUs from private insurance or other payers. In 2015, radiation oncologists produced a median of 2,486 wRVUs from Medicare (range 3 to 24,349). Billing to Healthcare Common Procedure Coding System Code 77427 (radiation treatment management, five treatments), a proxy for total radiation treatments, fell from 1,111,670 in 2012 to 1,039,403 in 2015, a decline of 7%.

CONCLUSION

The total number of wRVUs produced by radiation oncologists has risen by 14% from 2012 to 2015. However, the number of external beam radiation fractions has declined by approximately 7% over this same period, likely due to a trend toward hypofractionated courses of treatment and use of special treatment modalities such as proton beam therapy or stereotactic body radiation therapy.

Possible biliary disease: diagnostic performance of high-spatial-resolution isotropic 3D T2-weighted MRCP

PURPOSE

To retrospectively assess the diagnostic performance of magnetic resonance cholangiopancreatography (MRCP) performed by using a high-spatial-resolution isotropic three-dimensional (3D) fast-recovery fast spin-echo (FSE) sequence with parallel imaging for the evaluation of possible biliary disease.

MATERIALS AND METHODS

This HIPAA-compliant study was approved by the institutional review board; informed consent was waived. Ninety-five patients (58 female, 37 male; mean age, 51 years; range, 15-91 years) underwent MRCP by using the respiratory-triggered isotropic 3D fast-recovery FSE sequence and endoscopic or percutaneous direct visualization between March 2003 and June 2007. Two independent readers evaluated the MRCP images for strictures, dilatation, and intraductal filling defects. Sensitivity, specificity, and interobserver agreement (kappa statistics) were determined.

RESULTS

The respective sensitivity and specificity for strictures, dilatation, and intraductal filling defects (all choledocholithiasis) were 86% (40 of 47) and 94% (45 of 48), 98% (57 of 58) and 100% (37 of 37), and 68% (19 of 28) and 97% (65 of 67) for reader 1 and 88% (41 of 47) and 94% (45 of 48), 96% (56 of 58) and 100% (37 of 37), and 75% (21 of 28) and 99% (66 of 67) for reader 2. The sensitivity for stones larger than 3 mm was 94% (15 of 16) for reader 1 and 100% (16 of 16) for reader 2, whereas the sensitivity for stones 3 mm or smaller was 33% (four of 12) for reader 1 and 42% (five of 12) for reader 2. Agreement between readers was good to excellent, with kappa values of 0.76, 0.85, and 0.98 for strictures, dilatation, and choledocholithiasis, respectively.

CONCLUSION

MRCP by using the respiratory-triggered isotropic 3D fast-recovery FSE sequence with parallel imaging demonstrates excellent diagnostic capabilities for possible biliary disease, although it is limited for stones 3 mm or smaller in size.

Diagnostic performance of positron emission tomography in the detection of coronary artery disease: a meta-analysis

RATIONALE AND OBJECTIVES

Although myocardial perfusion positron emission tomography (PET), using either cyclotron-produced ammonia or generator-produced rubidium 82, has reported excellent diagnostic capabilities in the detection of coronary artery disease (CAD) in individual studies, the technique is not widely used in practice. This may be driven by cost and availability or by unawareness of performance. The purpose of our study was to conduct an evidence-based evaluation of PET in the diagnosis of CAD.

MATERIALS AND METHODS

We examined studies from January 1977 to July 2007 using MEDLINE and EMBASE. A study was included if it (1) used PET as a diagnostic test for CAD and (2) used catheter x-ray angiography as the reference standard (> or =50% diameter stenosis). Analysis was performed on a subject and coronary territory level.

RESULTS

Nineteen studies (1442 patients) met the inclusion criteria. On a patient level, PET demonstrated a sensitivity of 0.92 (95% confidence interval [CI]: 0.90-0.94) and specificity of 0.85 (CI: 0.79-0.90), with a positive likelihood ratio (LR+) of 6.2 (CI: 3.3-11.8) and negative likelihood ratio (LR-) of 0.11 (CI: 0.08-0.14). On a coronary territory level (n = 1130), PET showed a sensitivity of 0.81 (CI: 0.77-0.84) and specificity of 0.87 (CI: 0.84-0.90), with an LR+ of 5.9 (CI: 4.5-7.9) and an LR- of 0.19 (CI: 0.09-0.38).

CONCLUSION

PET demonstrates excellent diagnostic properties in the diagnosis of CAD, especially at the patient level. The capabilities appear superior to those reported in meta-analyses for perfusion imaging with Tl-201 and sestamibi, or anatomical imaging with coronary MDCT angiography or MRA. Given that previous studies have found PET to be cost-effective and the current findings of excellent sensitivity and specificity, the modality should be more widely considered as an initial test in the diagnosis of CAD.