Citations

AbstractAnti‐CD19 chimeric antigen receptor T‐cell therapy (CART) has revolutionized the outcomes of relapsed and/or refractory B‐cell non‐Hodgkin lymphoma. However, CART is still limited by its availability, toxicity, and response durability. Not all patients make it to the CART infusion phase due to disease progression. Among those who receive CART, a significant number of patients experience life‐threatening cytokine release syndrome toxicity, and less than half maintain a durable response with the majority relapsing in pre‐existing sites of disease present pre‐CART. Radiation therapy stands as a promising peri‐CART and salvage treatment that can improve the outcomes of these patients. Evidence suggests that bridging radiotherapy prior to CART controls the disease during the manufacturing period, augments response rates and local control, cytoreduces/debulks the disease and decreases the severity of cytokine release syndrome, and may prolong disease‐free intervals and survival especially in patients with bulky disease. Consolidative radiotherapy for residual post‐CART disease alters the pattern of relapse and improves local recurrence‐free and progression‐free survivals. Salvage radiotherapy for relapsed post‐CART disease has favorable survival outcomes when delivered comprehensively for patients with limited relapsed disease and palliates symptoms for patients with diffuse relapsed disease. The biology of the disease during the peri‐CART period is poorly understood, and further studies investigating the optimal timing and dosing of radiation therapy (RT) are needed. In this review, we tackle the most significant challenges of CART, review and propose how RT can help mitigate these challenges, and provide The Mayo Clinic experts' approach on incorporating RT with CART.

AbstractBackgroundPrimary cutaneous B‐cell lymphoma (PCBCL) is a group of B‐cell lymphomas of the skin containing primary cutaneous follicle centre lymphoma (PCFCL) and marginal zone B‐cell lymphoma/lymphoproliferative disorder (PCMZL), which are indolent, and diffuse large B‐cell lymphoma, leg type (PCDLBCL‐LT), which is aggressive.ObjectivesTo evaluate treatment outcomes between PCBCL subtypes after treatment with rituximab and to compare the efficacy of intralesional against systemic rituximab in indolent subtypes.MethodsA search for patients diagnosed with PCBCL and treated with rituximab (systemic or intralesional) across all Mayo Clinic sites was performed, yielding 39 patients.ResultsEight patients had PCFCL (six treated intralesionally and two systemically), 11 had PCMZL (four intralesional, eight systemic with one dual‐treated) and 20 had PCDLBCL‐LT (all systemic). The average age at diagnosis was 62.1 years (SD = 15.1), with average follow‐up of 1852.6 days (SD = 1473.2). 69.2% of all patients treated with any form of rituximab experienced a complete response (100% PCFCL, 81.8% PCMZL and 50% PCDLBCL‐LT). When comparing all three subtypes, a significant difference was seen in overall treatment response (p = 0.022), and progressive disease rates (p = 0.015), but not in retreatment with rituximab (p = 0.440), time to retreatment (p = 0.757), recurrence (p = 0.907) or survival (p = 0.093). In the indolent subtypes, no difference in overall treatment response (p = 1.000), progressive disease rates (p = 1.000), recurrence (p = 0.650), rituximab retreatment (p = 0.650) or time to retreatment (p = 0.724) was observed.ConclusionsThis study suggests that rituximab, as systemic therapy and intralesional therapy, is effective in the management of PCBCL, and that intralesional therapy should be considered before more aggressive therapy in indolent disease.

7556 Background: The majority of R/R NHL progressions after CART involve pre-existing sites, suggesting a promising role for bridging radiotherapy (bRT). We assessed the local control rate of disease sites bridged with radiotherapy prior to CART and identified predictors of in-field recurrence. Methods: We retrospectively reviewed 35 patients with aggressive B-cell NHL who received bRT between leukapheresis and CART infusion between 2018 and 2021 at a multi-site single institution. bRT local control rate (LC), calculated based on the total number of irradiated sites, was defined from bRT end date. Progression-free survival (PFS) and overall-survival (OS) were defined from the date of CART infusion. In-field recurrence was defined as disease relapse occurring within the radiation planning target volume. Kaplan-Meier plots and cox regression modeling were used to estimate the desired output. Results: Median age of the cohort at time of CART infusion was 59 (range 19-73). The median equivalent 2 Gy dose (EQD2) administered was 23.3 Gy (range 4-41 Gy). The median time from end of bRT to CART infusion was 14 days (range 6-42). Five (14%) patients also received bridging chemotherapy with bRT. Among the 34 evaluable patients, 30 (88%) achieved an objective response (59% complete response and 29% partial response). At a median follow-up of 12 months, 1-year PFS was 48% and 1-year OS was 72%. No progression occurred beyond 240 days. On review of treatment plans and pre-treatment PET/CT scans, 59 sites were identified that received bRT prior to CART infusion. The median size and SUVmax of the irradiated sites were 8.7cm (range 1.5-22) and 13 (range 4-46), respectively. Of the 59 irradiated sites, 8 sites (13.6%) in 7 patients had in-field local recurrence, translating to 1-year LC of 84%. No in-field recurrence occurred beyond 180 days. Moreover, no local recurrence occurred in patients who received radiation to all known sites of active disease to EQD2> 30 Gy (n = 4 patients); these patients remained in remission except for 1 who experienced progression outside the bRT field. On univariate analysis, triple hit lymphoma (THL) (OR 22.8, 95% CI: 3.8-138.3; p < 0.001), tumor size (OR 1.25, 95% CI: 1.1-1.4; p < 0.001), specifically ≥ 9cm (OR 9.4, CI: 1.2-77.3; p = 0.036) and SUVmax (OR 1.1, CI: 1.02-1.15; p = 0.008), specifically ≥ 20 (OR 5.6, CI: 1.3-23.7; p = 0.018), were significantly associated with increased risk of in-field recurrence. On multivariate analysis, THL (OR 32.9, CI: 3.2-336.0; p = 0.03) and tumor size (OR 1.3, CI: 1.1-1.6; p = 0.01) retained significant association with in-field recurrence. Conclusions: Bridging radiotherapy prior to CART provides excellent and durable in-field local control for R/R B-cell NHL. Patients with triple hit histology and bulky disease are likely at higher risk of in-field recurrence and may benefit from higher doses of bRT.

Objectives: This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. Methods: The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. Results: The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. Conclusions: Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

Objectives This practice parameter (PP) for Lutetium-177 (Lu-177) DOTATATE peptide receptor radionuclide therapy (PRRT) aims to guide authorized users in selection of appropriate adult candidates with gastroeneropancreatic neuroendocrine tumors (GEP-NETs) from foregut, midgut, and hindgut. The essential selection criteria include somatostatin receptor-positive GEP-NETs, which are usually inoperable and progressed despite standard therapy. Lu-177 DOTATATE is a radiopharmaceutical with high avidity for somatostatin receptors that are overexpressed by these tumors. This document ensures safe handling of Lu-177 DOTATATE by the authorized users and safe management of affected patients. Methods The document was developed according to the systematic process developed by the American College of Radiology (ACR) and described on the ACR Web site (https://www.acr.org/Clinical-Resources/Practice-Parameters-and-Technical-Standards). The PP development was led by 2 ACR Committees on Practice Parameters (Nuclear Medicine and Molecular Imaging and Radiation Oncology) collaboratively with the American College of Nuclear Medicine, American Society of Radiation Oncology, and Society of Nuclear Medicine and Molecular Imaging. Results The Lu-177 DOTATATE PP reviewed pharmacology, indications, adverse effects, personnel qualifications, and required clinical evaluation before starting the treatment, as well as the recommended posttherapy monitoring, quality assurance, documentation, and appropriate radiation safety instructions provided in written form and explained to the patients. Conclusions Lu-177 DOTATATE is available for therapy of inoperable and/or advanced GEP-NETs when conventional therapy had failed. It can reduce tumor size, improve symptoms, and increase the progression free survival. The PP document provides clinical guidance for authorized users to assure an appropriate, consistent, and safe practice of Lu-177 DOTATATE.

Purpose To compare the dosimetric performances of small‐spot three‐dimensional (3D) and four‐dimensional (4D) robustly optimized intensity‐modulated proton (IMPT) plans in the presence of uncertainties and interplay effect simultaneously for distal esophageal carcinoma. Method and Materials Thirteen (13) patients were selected and re‐planned with small‐spot ( ~ 2–6 mm) 3D and 4D robust optimization in IMPT, respectively. The internal clinical target volumes (CTV high3d , CTV low3d ) were used in 3D robust optimization. Different CTVs (CTV high4d , CTV low4d ) were generated by subtracting an inner margin of the motion amplitudes in three cardinal directions from the internal CTVs and used in 4D robust optimization. All patients were prescribed the same dose to CTVs (50 Gy[RBE] for CTV high3d /CTV high4d and 45 Gy[RBE] for CTV low3d /CTV low4d ). Dose–volume histogram (DVH) indices were calculated to assess plan quality. Comprehensive plan robustness evaluations that consisted of 300 perturbed scenarios (10 different motion patterns to consider irregular motion (sampled from a Gaussian distribution) and 30 different uncertainties scenarios (sampled from a 4D uniform distribution) combined), were performed to quantify robustness to uncertainties and interplay effect simultaneously. Wilcoxon signed‐rank test was used for statistical analysis. Results Compared to 3D robustly optimized plans, 4D robustly optimized plans had statistically improved target coverage and better sparing of lungs and heart (heart D mean , P = 0.001; heart V 30Gy[RBE] , P = 0.001) in the nominal scenario. 4D robustly optimized plans had better robustness in target dose coverage (CTV high4d V 100% , P = 0.002) and the protection of lungs and heart (heart D mean , P = 0.001; heart V 30Gy[RBE] , P = 0.001) when uncertainties and interplay effect were considered simultaneously. Conclusions Even with small spots in IMPT, 4D robust optimization outperformed 3D robust optimization in terms of normal tissue protection and robustness to uncertainties and interplay effect simultaneously. Our findings support the use of 4D robust optimization to treat distal esophageal carcinoma with small spots in IMPT.

Background:Case reports suggest photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) is an effective treatment for refractory mycosis fungoides (MF). No prospective trials have examined the use of ALA-PDT in MF. Objective:We aimed to assess the efficacy of ALA-PDT in refractory MF. Methods:This was a prospective study at Mayo Clinic in Scottsdale, Arizona in patients ≥ 18 years with plaque-stage treatment-refractory MF. Monthly sessions of ALA with blue light PDT were administered for up to six months. Responses were measured by Composite Assessment of Index Lesion Severity (CAILS) and Physician Global Assessment (PGA). Ad hoc analysis with modified CAILS (mCAILS) was performed, eliminating hyperpigmentation from scoring. Results:Eleven patients (30 total lesions) were treated. Six patients completed the trial per protocol. Objective response rates were 36.4% by PGA (10.9-69.2%), 18.2% by CAILS (2.3-51.8%), and 36.4% by mCAILS (10.9-69.2%). Limitations:Five patients did not complete all six PDT cycles per protocol, possibly accounting for reduced efficacy. Conclusion:ALA-PDT with blue light irradiation was moderately effective and well tolerated in refractory plaque stage MF. Lower response rates compared to similar trials may be partially explained by utilization of strict lesional assessment criteria and other variations in methodology. Disclosures Mangold: MiRagen:Research Funding;Sun Pharma:Research Funding;Elorac:Research Funding;Kirin:Membership on an entity's Board of Directors or advisory committees;Solagenix:Research Funding. OffLabel Disclosure: Photodynamic therapy is a two-step therapy in which a drug that acts as a photosensitizer is administered to target a diseased tissue, followed by illumination with visible light to activate the drug and destroy the target tissue. PDT has been used to treat internal cancers as well as treatment of cancer and precancer of the skin.

Abstract Purpose To compare the dosimetric performances of intensity‐modulated proton therapy (IMPT) plans generated with two different beam angle configurations (the Right–Left oblique posterior beams and the Superior–Inferior oblique posterior beams) for the treatment of distal esophageal carcinoma in the presence of uncertainties and interplay effect. Methods and Materials Twenty patients’ IMPT plans were retrospectively selected, with 10 patients treated with the R‐L oblique posterior beams (Group R‐L) and the other 10 patients treated with the S‐I oblique posterior beams (Group S‐I). Patients in both groups were matched by their clinical target volumes (CTVs—high and low dose levels) and respiratory motion amplitudes. Dose‐volume‐histogram (DVH) indices were used to assess plan quality. DVH bandwidth was calculated to evaluate plan robustness. Interplay effect was quantified using four‐dimensional (4D) dynamic dose calculation with random respiratory starting phase of each fraction. Normal tissue complication probability (NTCP) for heart, liver, and lung was calculated, respectively, to estimate the clinical outcomes. Wilcoxon signed‐rank test was used for statistical comparison between the two groups. Results Compared with plans in Group R‐L, plans in Group S‐I resulted in significantly lower liver D mean and lung V 30Gy[RBE] with slightly higher but clinically acceptable spinal cord D max . Similar plan robustness was observed between the two groups. When interplay effect was considered, plans in Group S‐I performed statistically better for heart D mean and V 30Gy[RBE] , lung Dmean and V 5Gy[RBE] , and liver D mean , with slightly increased but clinically acceptable spinal cord D max . NTCP for liver was significantly better in Group S‐I. Conclusions IMPT plans in Group S‐I have better sparing of liver, heart, and lungs at the slight cost of spinal cord maximum dose protection, and are more interplay‐effect resilient compared to IMPT plans in Group R‐L. Our study supports the routine use of the S‐I oblique posterior beams for the treatments of distal esophageal carcinoma.

494 Background: Our aim was to compare survival between patients receiving neoadjuvant chemoradiation and orthotopic liver transplantation (OLT group) versus definitive chemoradiation (CRT group) for extrahepatic or hilar cholangiocarcinoma. Methods: 49 patients (20 in OLT group vs. 29 in CRT group) with unresectable hilar/extrahepatic cholangiocarcinoma were treated at Mayo Clinic Arizona between Feb. 1998–Sep. 2019. Treatment included external beam radiation therapy (median 4500cGy) and boost (median 900cGy) with either continuous 5-flurouracil (dose range 180–225 mg/m2) or capecitabine (dose range 825–1000 mg/m2 BID) prior to or without OLT. Radiation boosts were delivered with EBRT or bile duct brachytherapy. Patients were between 27.9–84.3 years (median 64.3) at diagnosis. 18 patients had previous diagnosis of PSC. Results: Between Feb. 1998–Sep. 2019, 31(63%) of 49 patients died by the end of follow-up. Of patients treated with neoadjuvant therapy and OLT, 7(35%) of 20 patients died. 24(86%) of 28 patients treated with definitive therapy died. The OLT cohort were younger (mean age 56.5 vs. 69.0 years), more likely to have PSC and UC (65% vs. 17%), and had a lower CA 19-9 (median 43 vs. 535)(P < 0.003). From the end date of radiation, median overall survival was 76.8 months vs. 15.6 months for the OLT and CRT groups, respectively. Survival rates at 3 and 5 years were 78% and 69% in the OLT group compared to 19% and 6% in the CRT group (HR 7.73; 3.04-19.65:(P < 0.0001)). Progression-free survival (89% vs. 30% at 3 years), and distant metastasis-free survival (88% vs. 66% at 3 years) favored OLT versus CRT alone (HR 5.74;1.12-29.34:(P < 0.02)). Univariate analysis demonstrated that the method of treatment (OLT vs. CRT) was the only variable associated with better clinical outcomes. Conclusions: In patients with unresectable extrahepatic/hilar cholangiocarcinoma, survival was higher in those who underwent chemoradiation and OLT. Patients who received definitive chemoradiation in the absence of OLT were expected to have worse overall, progression-free, and metastasis-free survival.