Radionecrosis (RN) in patients with brain metastases treated with stereotactic radiosurgery (SRS) and immunotherapy.

OBJECTIVES: Limited data exist regarding radionecrosis (RN) rates when patients receive immunotherapy (IT) and SRS for brain metastases. This study assesses the influence of such treatments on the rate of RN. METHODS: We retrospectively reviewed 352 lesions from 105 patients with metastatic melanoma or NSCLC treated with SRS and IT from 2012 to 2018. Lesions were excluded from analysis if patients had received WBRT or prior GK to the same lesion, if RN occurred before IT, or if IT had been discontinued >6 months pre-SRS or initiated >1 year post-SRS. IT was delivered concurrently (±30 days of SRS) or sequentially. Overall survival and RN rates were assessed with Kaplan-Meier analysis. Univariate analysis and multivariate analysis were performed to identify characteristics predicting RN. RESULTS: Of 195 lesions from 63 patients included in analysis, the median prescription dose, IDL, lesion volume, and maximum tumor dimension (MTD) were 19 Gy, 50%, 0.15 cc and 0.8 cm, respectively. RN rates at 1, 2, and 3 years were 7.3%, 10.4% and 10.4%. On UVA, RN risk increased with, isodose volume (IDV), MTD, and tumor volume (TV) whereas conformity index was associated with a trend toward decreased RN risk. Two-year RN rates increased with TV ≥ 0.3 cc (16% vs 1.1% p = 0.001), MTD ≥ 1.3 cm (19.1% vs 1.8% p < 0.003), and IDV ≥ 1.5 cc (19.6% vs 1.7% p = 0.001). Concurrent vs sequential timing of IT did not predict for RN. CONCLUSIONS: Patients who received IT and SRS had acceptably low rates of RN. Timing of IT did not predict for RN. Further investigation is warranted to define RN risk with combined SRS and IT.

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.

Prostatic Urethral Length on MRI Potentially Predicts Late Genitourinary Toxicity After Prostate Cancer Radiation.

RATIONALE AND OBJECTIVES: The purpose of our study was to evaluate pretreatment prostate quantitative magnetic resonance imaging (MRI) measurements and clinical characteristics in predicting genitourinary (GU) toxicity after radiotherapy (RT) for prostate cancer. MATERIALS AND METHODS: In this single-institution retrospective cohort study, we evaluated patients with prostate adenocarcinoma who underwent MRI within 6 months before completing definitive RT and follow-up information in our GU toxicity database from June 2016 to February 2023. MRI measurements included quantitative urethra, prostate, and bladder measurements. GU toxicity was physician-scored using the Common Terminology Criteria for Adverse Events (CTCAE v4.0) with acute toxicity defined as ≤180 days and late defined as >180 days. Multivariable logistic regression model was constructed for grade ≥2 acute toxicity and Cox proportional hazards regression for late toxicity, adjusted for clinical factors and RT method. RESULTS: A total of 361 men (median age 68 years, interquartile range [IQR] 62-73) were included; 14.4% (50/347) men experienced grade ≥2 acute toxicity. Brachytherapy (odds ratio [OR]: 2.9, 95% confidence interval [CI]: 1.5-5.8), P < 0.01) was associated with increased odds of acute GU toxicity, and longer MUL (OR: 0.41 [95%CI: 0.18-0.92], P = 0.03) with decreased odds. Median follow-up for late toxicity was 15.0 months (IQR: 9.0-28.0) with approximately 88.7% and 72.0% patients free of toxicity at 1 and 3 years, respectively. Only longer prostatic urethral length (hazard ratio [HR]: 1.6, 95%CI: 1.2-2.1, P < 0.01) was associated with increased risk of late GU toxicity, notably urinary frequency/urgency symptoms (HR: 1.7 [95%CI: 1.3-2.3], P < 0.01). CONCLUSION: Longer prostatic urethral length measured on prostate MRI is independently associated with higher risk of developing late grade ≥2 GU toxicity after radiation therapy for prostate cancer. This pretreatment metric may be potentially valuable in risk-stratification models for quality of life following prostate RT.

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.

Combined Adjuvant Chemotherapy and Radiation Therapy Improves Disease-Free Survival for Uterine Serous Cancer.

PURPOSE: Uterine serous carcinoma (USC) is a rare but aggressive endometrial cancer histology. We reviewed outcomes for patients with USC to identify the best adjuvant treatment strategy. METHODS AND MATERIALS: We retrospectively identified 162 patients with The International Federation of Gynecology and Obstetrics (FIGO) stage I-IVA USC treated at our institution. Baseline characteristics, treatment details, clinical outcomes, and toxicity data were recorded. RESULTS: Median follow-up was 3.4 years (0.3-26 years). A variety of adjuvant therapy strategies were employed: 14% no adjuvant therapy, 28% radiation alone, 15% chemotherapy alone, and 43% combined chemotherapy and radiation. Distant metastasis was the most common type of recurrence (37% at 5 years). For patients with stage I-IVA disease, there were no significant differences in outcomes by treatment type. For patients with stage I-II disease (70% of the cohort), disease-free survival was significantly higher after chemotherapy (alone or with radiation therapy, P = .005) and after combined chemotherapy and radiation compared with all other treatments (P = .025). Toxicity outcomes were favorable, with minimal grade 3 and no grade 4 or 5 events. CONCLUSIONS: Patients with USC experience high rates of recurrence and mortality. Distant metastasis is the most common pattern of failure for all stages. For patients with early-stage disease, combined chemotherapy and radiation improves 5-year disease-free survival compared with either single adjuvant treatment alone or no adjuvant treatment. The relatively large group of patients with USC included in this study may account for our ability to detect this improvement whereas clinical trials have failed to do so, possibly owing to the relatively small percentages of patients with USC enrolled.

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.

Sequencing of Adjuvant Chemoradiation for Advanced Stage Endometrial Cancer: Outcomes and Toxicity Profiles.

OBJECTIVES: Radiation is frequently added to chemotherapy for adjuvant treatment of advanced stage endometrial cancer. Multiple adjuvant therapy sequencing options exist, and little data is available to compare these. We compared outcomes and toxicities after "sandwich" chemoradiation (chemotherapy, then radiation, then chemotherapy) and nonsandwich sequences (chemotherapy then radiation, radiation then chemotherapy, or concurrent chemoradiation). MATERIALS AND METHODS: We recorded baseline characteristics, adjuvant treatment details, clinical outcomes, and toxicities for stage III to IVA patients who underwent surgical staging followed by both adjuvant chemotherapy and radiation therapy at our institution. Effects of adjuvant treatment order (sandwich or nonsandwich) on these outcomes were analyzed. Toxicities were graded according to CTCAE v4.0. RESULTS: We identified 107 patients with a median follow-up of 3.2 years. Five-year local, regional, and distant recurrence were 7%, 15%, and 33%; disease-free and overall survival were 61% and 68%, respectively. Outcomes did not differ by sequence group. The overall rate of acute toxicity did not differ by sequence group. The overall rate of chronic toxicity was significantly lower for sandwich patients (P<0.001), as were overall rates of chronic genitourinary (P=0.048) and gynecologic (P<0.001) toxicities. There were no grade 4 or 5 acute or chronic toxicities. CONCLUSIONS: Advanced stage endometrial cancer is an aggressive disease and adjuvant chemotherapy and radiation therapy are indicated. Clinical outcomes were similar amongst the different sequences; however, sandwich therapy led to less chronic toxicity, offering an opportunity for improved quality of life in survivorship.

Utility of graded prognostic assessment in evaluation of patients with brainstem metastases treated with radiosurgery.

OBJECTIVES: Prospective data regarding the safety and efficacy of stereotactic radiosurgery (SRS) for patients with metastatic disease involving the brainstem are lacking. The aim of this study was to assess the efficacy and toxicity of SRS for patients with brainstem metastases treated at our institution. PATIENTS AND METHODS: From September 2007 to October 2015, patients treated with SRS for brain metastases were prospectively entered into an institutional database. Forty eight patients with 51 lesions involving the brainstem with clinical follow-up were identified. Local control (LC), elsewhere brain failure (EBF) and overall survival (OS) were assessed from the date of radiosurgery using the Kaplan-Meier method. Univariate and multivariate analyses of factors related to OS were performed using a Cox proportional hazards model. RESULTS: Median clinical follow-up was 4.8 months. Median patient age was 62 (range: 28-87); non-small cell lung and breast cancer were the most common primaries at 54% and 21% respectively. Median brainstem lesion volume was 0.12cm(3) (range: 0.01-3.67cm(3)). Whole brain radiotherapy was previously utilized in 19 patients (40%). The median OS was 7.6 months and the 12 month LC rate was 89%. Only 2 patients (4%) experienced grade 3 motor toxicity secondary to SRS. 11 of the 16 patients (69%) initially presenting with symptoms related to brainstem metastases had symptom improvement or resolution following SRS. On multivariate analysis, graded prognostic assessment (GPA) score>2 was predictive of improved survival (p<0.01) while prior chemotherapy use predicted decreased survival (p=0.049). CONCLUSIONS: SRS is associated with high LC rates and low toxicity for brainstem metastases. Improved OS was seen for patients with GPA score>2. GPA appears to be a useful tool for assessing prognosis in patients with brainstem metastases. Small volume lesions were safely treated with or without prior whole brain radiotherapy.

Brachytherapy provides comparable outcomes and improved cost-effectiveness in the treatment of low/intermediate prostate cancer.

PURPOSE: To evaluate the cost-effectiveness and outcomes of low-dose-rate (LDR) and high-dose-rate (HDR) brachytherapy compared with intensity-modulated radiation therapy (IMRT) in patients with low/intermediate risk of prostate cancer. METHODS AND MATERIALS: One thousand three hundred twenty-eight patients with low or intermediate risk of prostate cancer were treated with LDR (n=207), HDR with four fractions (n=252), or IMRT (n=869) between January 1992 and December 2008. LDR patients were treated with palladium seeds to a median dose of 120 Gy, whereas HDR patients were treated to a median dose 38.0 Gy (four fractions). IMRT patients received 42-44 fractions with a median dose of 75.6 Gy. Clinical outcomes were compared, including biochemical failure, cause-specific survival, and overall survival. RESULTS: Overall, no differences in 5-year biochemical control (BC) or cause-specific survival were noted among treatment modalities. The calculated reimbursement for LDR brachytherapy, HDR brachytherapy with four fractions, and IMRT was $9,938; $17,514; and $29,356, respectively. HDR and LDR brachytherapy were statistically less costly to Medicare and the institution than IMRT (p<0.001), and LDR brachytherapy was less costly than HDR brachytherapy (p=0.01 and p<0.001). Incremental cost-effectiveness ratios for cost to Medicare for BC with IMRT were $4045 and $2754 per percent of BC for LDR and HDR brachytherapy, respectively. Incremental cost-effectiveness ratio using institutional cost comparing IMRT with LDR and HDR brachytherapy was $4962 and $4824 per 1% improvement in BC. CONCLUSIONS: In this study of patients with low and intermediate risk of prostate cancer, comparable outcomes at 5 years were noted between modalities with increased costs associated with IMRT.

Phase I study of conformal radiotherapy and concurrent full-dose gemcitabine with erlotinib for unresected pancreatic cancer.

PURPOSE: To determine the recommended dose of radiotherapy when combined with full-dose gemcitabine and erlotinib for unresected pancreas cancer. METHODS AND MATERIALS: Patients with unresected pancreatic cancer (Zubrod performance status 0-2) were eligible for the present study. Gemcitabine was given weekly for 7 weeks (1,000 mg/m(2)) with erlotinib daily for 8 weeks (100 mg). A final toxicity assessment was performed in Week 9. Radiotherapy (starting at 30 Gy in 2-Gy fractions, 5 d/wk) was given to the gross tumor plus a 1-cm margin starting with the first dose of gemcitabine. A standard 3 plus 3 dose escalation (an additional 4 Gy within 2 days for each dose level) was used, except for the starting dose level, which was scheduled to contain 6 patients. In general, Grade 3 or greater gastrointestinal toxicity was considered a dose-limiting toxicity, except for Grade 3 anorexia or Grade 3 fatigue alone. RESULTS: A total of 20 patients were treated (10 men and 10 women). Nausea, vomiting, and infection were significantly associated with the radiation dose (p = .01, p = .03, and p = .03, respectively). Of the 20 patients, 5 did not complete treatment and were not evaluable for dose-escalation purposes (3 who developed progressive disease during treatment and 2 who electively discontinued it). Dose-limiting toxicity occurred in none of 6 patients at 30 Gy, 2 of 6 at 34 Gy, and 1 of 3 patients at 38 Gy. CONCLUSION: The results of the present study have indicated that the recommended Phase II dose is 30 Gy in 15 fractions.

Outcomes of breast cancer patients with triple negative receptor status treated with accelerated partial breast irradiation.

PURPOSE: Triple negative receptor status (TNRS) of patients undergoing breast-conserving therapy treated with whole-breast irradiation has been associated with increased distant metastasis and decreased disease-free and overall survival. This paper reports the outcomes of TNRS patients treated with accelerated partial breast irradiation (APBI). METHODS AND MATERIALS: We studied 455 patients who received APBI at our institution, using interstitial, intracavitary, and three-dimensional conformal radiation therapy. TNRS was assigned if a patient tested negative for all three (ER [estrogen receptor], PR [progesterone receptor], and HER2/neu) receptors. Of 202 patients with all receptor results available, 20 patients were designated TNRS, and 182 patients had at least one receptor positive (RP). We analyzed ipsilateral breast tumor recurrence (IBTR), regional nodal failure (RNF), distant metastasis (DM), and overall survival (OS). RESULTS: Mean follow-up was 4.1 years for the TNRS group and 5.1 years for the RP cohort (p = 0.11). TNRS patients had a higher histologic grade (59% TNRS vs. 13% RP; p < 0.001). Mean tumor size, stage N1 disease, and margin status were similar. Based on a 5-year actuarial analysis, the TNRS cohort experienced no IBTR, RNF, or DM, with an OS of 100% versus rates of 1.4% IBTR, 1.5% RNF, and 2.8% DM in the RP cohort (p > 0.52). OS for the RP cohort was 93% at 5 years (p > 0.28). CONCLUSIONS: In our patient population, TNRS conferred a clinical outcome similar to that of patients with RP disease treated with APBI. Further investigation with larger patient populations and longer follow-up periods is warranted to confirm that APBI is a safe and effective treatment for patients with localized TNRS breast cancer.