Pancreatic cancer outcome-local treatment with radiation using MRI-LINAC.

Introduction: Stereotactic MR-guided on-table adaptive radiotherapy (SMART) allows the precise delivery of high-dose radiation to tumors in great proximity to radiation-sensitive organs. The aim of this study is to evaluate the toxicity and clinical outcome in locally advanced or recurrent pancreatic tumors, with or without prior irradiation, treated with SMART. Methods: Patients were treated for pancreatic cancer (PC) using SMART technology to a prescribed dose of 50 Gy (BED10, 100 Gy) in five fractions, with daily on-table adaptation of treatment plan. Endpoints were acute and late toxicities, local control, local disease-free period, and overall survival. Results: A total of 54 PC patients were treated between August 2019 and September 2022, with a median follow-up of 8.9 months from SMART. The median age was 70.4 (45.2-86.9) years. A total of 40 patients had upfront inoperable PC (55% were locally advanced and 45% metastatic), and 14 had local recurrence following prior pancreatectomy (six patients also had prior adjuvant RT). Of the patients, 87% received at least one chemotherapy regimen (Oxaliplatin based, 72.2%), and 25.9% received ≥2 regimens. Except from lower CA 19-9 serum level at the time of diagnosis and 6 weeks prior to SMART in previously operated patients, there were no significant differences in baseline parameters between prior pancreatectomy and the inoperable group. On-table adaptive replanning was performed for 100% of the fractions. No patient reported grade ≥2 acute GI toxicity. All previously irradiated patients reported only low-grade toxicities during RT. A total of 48 patients (88.9%) were available for evaluation. Complete local control was achieved in 21.7% (10 patients) for a median of 9 months (2.8-28.8); three had later local progression. Eight patients had regional or marginal recurrence. Six- and 12-month OS were 75.0% and 52.1%, respectively. Apart from mild diarrhea 1-3 months after SMART and general fatigue, there were no significant differences in toxicity and outcomes between post-pancreatectomy and inoperable groups. Conclusion: SMART allows safe delivery of an ablative dose of radiotherapy, with minimal treatment-related toxicity, even in previously resected or irradiated patients. In this real-world cohort, local control with complete response was achieved by 20% of the patients. Further studies are needed to evaluate long-term outcome and late toxicity.

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.

Prophylactic Breast Irradiation for Prevention of Bicalutamide-induced Painful Gynecomastia in Patients with Low- and Intermediate-risk Prostate Cancer.

BACKGROUND: Bicalutamide monotherapy (BMT) is an option for androgen deprivation therapy (ADT) in patients with low- and intermediate-risk prostate cancer (LIR-PC). Painful gynecomastia (PG) is a common side effect of BMT. Few therapeutic options are available for preventing BMT-induced PG. OBJECTIVES: To assess the efficacy and side effects of single fraction (SF) prophylactic breast irradiation (PBI) to prevent painful gynecomastia (PG) in patients LIR-PC treated with BMT. METHODS: We reviewed the results of bilateral PBI in a prospective cohort of LIR-PC patients who received 150 mg bicalutamide daily as a first-line treatment for at least 12 months. A single fraction of 8 Gy was administered to both breasts by a stationary field of 10 × 10 cm, using 10-15 MeV electron beam. PBI was commenced on the same day as BMT, but prior to the first dose of bicalutamide. A radiotherapy treatment plan was designed to cover breast tissue by the 90% isodose line. Subsequent monthly physical examinations were scheduled for all patients during the first year of BMT to evaluate any PG symptoms. RESULTS: Seventy-six patients received BMT and PBI, 80% (61/76) showed no signs of PG; 20% (15/76) experienced mild gynecomastia. The main adverse effect of PBI was grade 1 radiation dermatitis. CONCLUSIONS: PBI using a SF of 8 Gy is an effective, safe, and low-cost strategy for the prevention of BMT-induced PG in LIR-PC patients.

Safety of the BNT162b2 mRNA COVID-19 vaccine in oncologic patients undergoing numerous cancer treatment options: A retrospective single-center study.

ABSTRACT: The COVID-19 pandemic, caused by the SARS-CoV2 virus, has infected millions worldwide with cancer patients demonstrating a higher prevalence for severe disease and poorer outcomes. Recently, the BNT162b2 mRNA COVID-19 vaccine was released as the primary means to combat COVID-19. The currently reported incidence of local and systemic side effects was 27% in the general public. The safety of the BNT162b2 mRNA COVID-19 vaccine has not been studied in patients with an active cancer diagnosis who are either ongoing or plan to undergo oncologic therapy.This single center study reviewed the charts of 210 patients with active cancer diagnoses that received both doses of the BNT162b2 mRNA COVID-19 vaccine. The development of side effects from the vaccine, hospitalizations or exacerbations from various oncologic treatment were documented. Type of oncologic treatment (immunotherapy, chemotherapy, hormonal, biologic, radiation or mixed) was documented to identify if side effects were related to treatment type. The time at which the vaccine was administered in relation to treatment onset (on long term therapy, within 1 month of therapy or prior to therapy) was also documented to identify any relationships.Sixty five (31%) participants experienced side effects from the BNT162b2 mRNA COVID-19 vaccine, however most were mild to moderate. Treatment protocol was not linked to the development of vaccine related side effects (P = .202), nor was immunotherapy (P = .942). The timing of vaccine administered in relation to treatment onset was also not related to vaccine related side effects (P = .653). Six (2.9%) participants were hospitalized and 4 (2%) died.The incidence of side effects in cancer patients is similar to what has been reported for the general public (31% vs 27%). Therefore, we believe that the BNT162b2 mRNA COVID-19 vaccine is safe in oncologic patients undergoing numerous cancer treatments.