Multiparametric MRI and [18F]fluorodeoxyglucose positron emission tomography imaging is a potential prognostic imaging biomarker in recurrent glioblastoma

Purpose/objectivesMultiparametric advanced MR and [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging may be important biomarkers for prognosis as well for distinguishing recurrent glioblastoma multiforme (GBM) from treatment-related changes.Methods/materialsWe retrospectively evaluated 30 patients treated with chemoradiation for GBM and underwent advanced MR and FDG-PET for confirmation of tumor progression. Multiparametric MRI and FDG-PET imaging metrics were evaluated for their association with 6-month overall (OS) and progression-free survival (PFS) based on pathological, radiographic, and clinical criteria.Results17 males and 13 females were treated between 2001 and 2014, and later underwent FDG-PET at suspected recurrence. Baseline FDG-PET and MRI imaging was obtained at a median of 7.5 months [interquartile range (IQR) 3.7–12.4] following completion of chemoradiation. Median follow-up after FDG-PET imaging was 10 months (IQR 7.2–13.0). Receiver-operator characteristic curve analysis identified that lesions characterized by a ratio of the SUVmax to the normal contralateral brain (SUVmax/NB index) >1.5 and mean apparent diffusion coefficient (ADC) value of ≤1,400 × 10−6 mm2/s correlated with worse 6-month OS and PFS. We defined three patient groups that predicted the probability of tumor progression: SUVmax/NB index >1.5 and ADC ≤1,400 × 10−6 mm2/s defined high-risk patients (n = 7), SUVmax/NB index ≤1.5 and ADC >1,400 × 10−6 mm2/s defined low-risk patients (n = 11), and intermediate-risk (n = 12) defined the remainder of the patients. Median OS following the time of the FDG-PET scan for the low, intermediate, and high-risk groups were 23.5, 10.5, and 3.8 months (p < 0.01). Median PFS were 10.0, 4.4, and 1.9 months (p = 0.03). Rates of progression at 6-months in the low, intermediate, and high-risk groups were 36, 67, and 86% (p = 0.04).ConclusionRecurrent GBM in the molecular era is associated with highly variable outcomes. Multiparametric MR and FDG-PET biomarkers may provide a clinically relevant, non-invasive and cost-effective method of predicting prognosis and improving clinical decision making in the treatment of patients with suspected tumor recurrence

Ablative five-fraction stereotactic body radiation therapy for inoperable pancreatic cancer using online MR-guided adaptation

Purpose: Patients with inoperable pancreatic adenocarcinoma have limited options, with traditional chemoradiation providing modest clinical benefit and an otherwise poor prognosis. Stereotactic body radiation therapy for pancreatic cancer is limited by proximity to organs-at-risk (OAR). However, stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) has shown promise in delivering ablative doses safely. We sought to demonstrate the benefits of SMART using a 5-fraction approach with daily on-table adaptation. Methods and Materials: Patients with locally advanced, nonmetastatic pancreatic adenocarcinoma were treated with 50 Gy in 5 fractions (biologically effective dose Results: Forty-four patients were treated with SMART at our institution from 2014 to 2019. Median follow-up from date of diagnosis was 16 months (range, 6.7-51.6). Late toxicity was limited to 2 (4.6%) grade 3 (gastrointestinal ulcers) and 3 (6.8%) grade 2 toxicities (duodenal perforation, antral ulcer, and gastric bleed). Tumor abutted OARs in 35 patients (79.5%) and tumor invaded OARs in 5 patients (11.1%). Reoptimization was performed for 93% of all fractions. Median overall survival was 15.7 months (95% confidence interval, 10.2-21.2), while 1-year and 2-year overall survival rates were 68.2% and 37.9%, respectively. One-year local control was 84.3%. Conclusions: This is the first reported experience using 50 Gy in 5 fractions for inoperable pancreatic cancer. SMART allows this ablative dose with promising outcomes while minimizing toxicity. Additional prospective trials evaluating efficacy and safety are warranted

Implications of pneumonitis after chemoradiation and durvalumab for locally advanced non-small cell lung cancer

Background: Consolidation durvalumab improved overall survival (OS) in locally advanced non-small cell lung cancer (LA-NSCLC) treated with chemoradiotherapy (CRT) in the PACIFIC trial; however, pneumonitis was increased with durvalumab. We sought to examine real-world outcomes with the PACIFIC paradigm, especially factors associated with pneumonitis, using a multi-institutional review. Methods: Patients with LA-NSCLC treated with CRT followed by durvalumab from January 2017-February 2019 were identified at 2 institutions. We characterized demographics, tumor factors, radiotherapy, and duration of durvalumab. We examined pneumonitis outcomes including re-challenge success, with secondary endpoints of progression-free survival (PFS) and OS. Results: Thirty-four patients were included with median follow-up of 12 months (range, 3 to 20 months); 94% had stage III disease. The cumulative grade \u3e2 pneumonitis rate was 26.5% with 2 patients developing grade 3 pneumonitis and no grade 4/5 events. Median time to pneumonitis after RT was 2.4 months (range, 0 to 4.9 months). Pneumonitis management included median prednisone dose of 60 mg for median taper of 6 weeks with durvalumab held for median of 4.5 weeks (range, 2 to 8 weeks); 70% of pneumonitis patients received durvalumab re-challenge, with pneumonitis recurring in 14% of patients. 3-month and 6-month pneumonitis-free-survival were 76.9% and 73.6%, respectively; 9- and 12-month OS were 96% (75.1-99.8%), 86.6% (63.5-95.5%), respectively; 9- and 12-month PFS were 68% (47.5-82.5%), 48.7% (25.3-68.3%). Pneumonitis development did not significantly impact PFS or OS (P\u3e0.05). Conclusions: Among LA-NSCLC patients treated with CRT followed by consolidation durvalumab, more than 25% developed symptomatic pneumonitis. In this small case series, pneumonitis did not appear to negatively impact survival, and durvalumab re-challenge appeared feasible after pneumonitis treatment with steroids

A competing risk nomogram to predict severe late toxicity after modern re-irradiation for squamous carcinoma of the head and neck

PURPOSE: Severe late toxicity is common after re-irradiation for recurrent or second primary (RSP) squamous carcinoma of the head and neck. However, many patients experience complications from tumor progression before manifesting late effects. We constructed a nomogram to examine this relationship between late toxicity and competing risks. METHODS AND MATERIALS: Patients with RSP squamous carcinoma originating in a field previously irradiated to ≥40 Gy and treated with IMRT-based re-irradiation to ≥40 Gy were collected. Grade ≥3 late toxicity developing ≥90 days after re-irradiation was collected. A multivariable competing-risk model was fit to the actuarial risk of late toxicity with progression or death as the competing risk. The final bootstrap optimized model was converted into a nomogram. RESULTS: From 9 institutions, 505 patients were included. The 2-year incidence of grade ≥3 late toxicity was 16.7% (95% CI 13.2-20.2%) whereas progression or death was 64.2% (95% CI 59.7-68.8%). The median freedom from late toxicity, progression or death was 10.7, 5.5 and 3.2 months for RPA class I-III patients respectively, whereas the median OS was 44.9, 15.9 and 7.9 months, respectively. The final model included six clinical factors. Notably, dose, volume and fractionation did not significantly impact toxicity. CONCLUSIONS: After re-irradiation, the risk of progression or death is approximately four times the risk of radiation-related severe late toxicity. The risk of late toxicity may be more dependent on patient and disease factors than modifiable treatment factors. This model is useful for patient selection, pre-treatment consent and post-treatment survivorship following re-irradiation

Refining Patient Selection for Reirradiation of Head and Neck Squamous Carcinoma in the IMRT Era: A Multi-institution Cohort Study by the MIRI Collaborative

PURPOSE: The therapeutic ratio of reirradiation for recurrent or second primary (RSP) squamous carcinoma of the head and neck may be improved in the intensity modulated radiation therapy (IMRT) era. However, patient selection for reirradiation remains challenging. We performed a multi-institution cohort study to investigate modern outcomes after IMRT-based reirradiation and to identify prognostic subgroups. PATIENTS AND METHODS: Patients with RSP squamous carcinoma originating in a previously irradiated field (≥40 Gy) who underwent reirradiation with IMRT (≥40 Gy re-IMRT) were included. Locoregional failure and late toxicity were calculated using the Gray competing risk method. Cox proportional hazards regression was used to identify factors associated with overall survival (OS). Factors associated with OS were entered into a recursive partitioning analysis (RPA) for OS. RESULTS: From 7 institutions, 412 patients were included. The median dose of re-IMRT was 60 Gy, and the median time between RT courses was 2.4 years. Chemotherapy was used in 76% of patients. The rates of grade ≥3, grade ≥4, and grade 5 acute toxicities were 19%, 4.4%, and 1.2%, respectively. The 2-year cumulative incidence of grade ≥3 late toxicity adjusted for the competing risks of recurrence or death was 14.2%. RPA identified 3 prognostic subgroups with distinct and homogenous OS (P2 years from their initial course of RT with resected tumors (2-year OS, 61.9%); class II included patients \u3e2 years with unresected tumors or those ≤2 years and without feeding tube or tracheostomy dependence (2-year OS, 40.0%), and the remaining patients formed class III (2-year OS, 16.8%). Fifty-nine percent of class III patients underwent postoperative re-irradiation. CONCLUSIONS: This study informs outcomes and expectations with IMRT-based reirradiation. The RPA classification identifies 3 distinct subgroups, which can guide patient selection for therapy and clinical trial design. RPA class III patients are not ideal candidates for protracted chemoradiation regardless of resection status

Volume, Dose, and Fractionation Considerations for IMRT-based Reirradiation in Head and Neck Cancer: A Multi-institution Analysis

PURPOSE: Limited data exist to guide the treatment technique for reirradiation of recurrent or second primary squamous carcinoma of the head and neck. We performed a multi-institution retrospective cohort study to investigate the effect of the elective treatment volume, dose, and fractionation on outcomes and toxicity. METHODS AND MATERIALS: Patients with recurrent or second primary squamous carcinoma originating in a previously irradiated field (≥40 Gy) who had undergone reirradiation with intensity modulated radiation therapy (IMRT); (≥40 Gy re-IMRT) were included. The effect of elective nodal treatment, dose, and fractionation on overall survival (OS), locoregional control, and acute and late toxicity were assessed. The Kaplan-Meier and Gray\u27s competing risks methods were used for actuarial endpoints. RESULTS: From 8 institutions, 505 patients were included in the present updated analysis. The elective neck was not treated in 56.4% of patients. The median dose of re-IMRT was 60 Gy (range 39.6-79.2). Hyperfractionation was used in 20.2%. Systemic therapy was integrated for 77.4% of patients. Elective nodal radiation therapy did not appear to decrease the risk of locoregional failure (LRF) or improve the OS rate. Doses of ≥66 Gy were associated with improvements in both LRF and OS in the definitive re-IMRT setting. However, dose did not obviously affect LRF or OS in the postoperative re-IMRT setting. Hyperfractionation was not associated with improved LRF or OS. The rate of acute grade ≥3 toxicity was 22.1% overall. On multivariable logistic regression, elective neck irradiation was associated with increased acute toxicity in the postoperative setting. The rate of overall late grade ≥3 toxicity was 16.7%, with patients treated postoperatively with hyperfractionation experiencing the highest rates. CONCLUSIONS: Doses of ≥66 Gy might be associated with improved outcomes in high-performance patients undergoing definitive re-IMRT. Postoperatively, doses of 50 to 66 Gy appear adequate after removal of gross disease. Hyperfractionation and elective neck irradiation were not associated with an obvious benefit and might increase toxicity