A Systematic Review of Clinical Applications of Anti-CD20 Radioimmunotherapy for Lymphoma.

PURPOSE: The clinical efficacy of anti-CD20 radioimmunotherapy (RIT) is due to a combination of extracellular mechanisms involving immune-mediated cytotoxicity, and intracellular mechanisms related to inhibition of CD20 signaling and DNA damage from ionizing radiation. In 2002, the first RIT was approved by the U.S. Food and Drug Administration for the treatment of patients with indolent B-cell follicular non-Hodgkin lymphoma (NHL). The 2 approved agents, 90 Y-ibritumomab tiuxetan (90Y-IT, Zevalin, Acrotech Biopharma) and 131 I-tositumomab (131-IT, Bexxar, GlaxoSmithKline) both target CD20. The aim of this study was to review the clinical applications and supporting clinical trial data of anti-CD20 RIT for lymphoma. METHODS: A review of published articles and abstracts on the clinical efficacy and safety of 90Y-IT and iodine I 131 tositumomab was performed. RESULTS: The clinical efficacy and safety of anti-CD20 RIT have been demonstrated in numerous clinical trials and case series. Agents have produced significant responses in patients with follicular NHLs and in off-label applications. Importantly, RIT has demonstrated promising findings in high-risk lymphomas and heavily pretreated and refractory patient populations. Associated toxicity profiles are noted as tolerable, acceptable, and most often reversible. CONCLUSIONS: In the 2 decades since its approval, anti-CD20 RIT continues to demonstrate efficacy, particularly with a proportion of patients maintaining long-term remissions. The combination of prolonged efficacy, tolerability, and treatment convenience makes RIT a reasonable alternative to other systemic therapies. It is recommended that further research on RIT should focus on biomarkers of long-term response, pretargeting, and sequencing of RIT in the treatment course.

Incorporating radiation with anti-CD19 chimeric antigen receptor T-cell therapy for relapsed/refractory non-Hodgkin lymphoma: A multicenter consensus approach.

Anti-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.

Selective salvage radiotherapy could provide favorable outcomes in patients with refractory or relapsed primary central nervous system lymphoma.

INTRODUCTION: To date, there is no relevant data supporting the role of salvage radiotherapy (sRT) in patients with refractory or relapsed primary central nervous system lymphoma (PCNSL). Herein, we aimed to investigate the impact of sRT in patients with refractory or relapsed PCNSL following upfront HD-MTX. METHODS: We retrospectively reviewed 89 patients who had refractory (n = 16) or recurrent disease after an initial favorable response (n = 73); among them, 41 were treated with sRT and 48 were treated without sRT (nRT). Event-free survival (rEFS) and overall survival (rOS) after first recurrence were considered from the date of recurrence to date of each event. RESULTS: Overall, the first failure was diagnosed at a median of 11.0 months [interquartile range (IQR), 5.6-26.4] after first treatment. More than half of the patients had recurrent disease involving initial tumor bed (n = 47), deep structure (n = 67), and multiple lesions (n = 58). Among 19 patients who were initially treated with 23.4 Gy of whole brain RT, 10 patients received sRT as a re-irradiation; other 31 patients in sRT group were RT naïve patients. There was no significant difference in tumor characteristics between sRT and nRT group. Overall and complete response after salvage treatment were 80% and 48%, respectively; sRT provided higher overall response rate than nRT (93% vs. 69%, p = 0.011). With a median follow-up of 14.3 months (IQR, 7.9-31.4), 2-year rEFS and rOS rates were 27% and 57%, respectively. There were no differences in rEFS and rOS according to sRT (sRT vs. nRT, 26% vs. 28%, p = 0.730; 63% vs. 50%, p = 0.690). Poor performance, recurrence interval < 8 months, and unfavorable response following salvage treatment were associated with inferior rEFS and rOS. Additionally, sRT and stem cell transplantation improved response rate independently after multivariate analysis for complete/partial response. CONCLUSIONS: We found favorable response rate and comparable survival outcomes following sRT compared with non-local treatments for patients with refractory/relapsed PCNSL. Further studies of patient selection could stratify patients who can benefit from sRT.

Cardiovascular risk factors, radiation therapy, and myocardial infarction among lymphoma survivors.

BACKGROUND: Mediastinal radiation is associated with increased risk of myocardial infarction (MI) among non-Hodgkin lymphoma (NHL) survivors. OBJECTIVE: To evaluate how preexisting cardiovascular risk factors (CVRFs) modify the association of mediastinal radiation and MI among a national population of NHL survivors with a range of CVRFs. MATERIAL AND METHODS: Using Danish registries, we identified adults diagnosed with lymphoma 2000-2010. We assessed MI from one year after diagnosis through 2016. We ascertained CVRFs (hypertension, dyslipidemia, and diabetes), vascular disease, and intrinsic heart disease prevalent at lymphoma diagnosis. We used multivariable Cox regression to test the interaction between preexisting CVRFs and receipt of mediastinal radiation on subsequent MI. RESULTS: Among 3151 NHL survivors (median age 63, median follow-up 6.5 years), 96 were diagnosed with MI. Before lymphoma, 32% of survivors had ≥1 CVRF. 8.5% of survivors received mediastinal radiation. In multivariable analysis, we found that mediastinal radiation (HR = 1.96; 95% CI = 1.09-3.52), and presence of ≥1 CVRF (HR = 2.71; 95% CI = 1.77-4.15) were associated with an increased risk of MI. Although there was no interaction on the relative scale (p = 0.14), we saw a clinically relevant absolute increase in risk for patients with CVRF from 10-year of MI of 10.5% without radiation to 29.5% for those undergoing radiation. CONCLUSION: Patients with CVRFs have an importantly higher risk of subsequent MI if they have mediastinal radiation. Routine evaluation of CVRFs and optimal treatment of preexisting cardiovascular disease should continue after receiving cancer therapy. In patients with CVRFs, mediastinal radiation should only be given if oncologic benefit clearly outweighs cardiovascular harm.

Preclinical study of 212Pb alpha-radioimmunotherapy targeting CD20 in non-Hodgkin lymphoma.

BACKGROUND: Despite therapeutic advances, Non-Hodgkin lymphoma (NHL) relapses can occur. The development of radioimmunotherapy (RIT) with α-emitters is an attractive alternative. In this study, we investigated the potential of α-RIT in conjunction with 212Pb-rituximab for the treatment of NHL. METHODS: EL4-hCD20-Luc cells (mouse lymphoma cell line) were used for in vitro and in vivo studies. Biodistribution and efficacy studies were performed on C57BL/6 mice injected intravenously with 25 × 103 cells. RESULTS: 212Pb-rituximab (0.925-7.4 kBq/mL) inhibit proliferation of EL4-hCD20-Luc cells in vitro. Biodistribution of 203/212Pb-rituximab in mice showed a significant tumour uptake and suggested that the liver, spleen, and kidneys were the organs at risk. For efficacy studies, mice were treated at either 11 days (early stage) or 20-30 days after injection of tumour cells (late stage). Treatment with 277.5 kBq 212Pb-rituximab significantly prolonged survival. Even at an advanced tumour stage, significant tumour regression occurred, with an increase in the median survival time to 28 days, compared with 9 days in the controls. CONCLUSIONS: These results show the efficacy of 212Pb-rituximab in a murine syngeneic lymphoma model, in terms of significant tumour regression and increased survival, thereby highlighting the potency of α-RIT for the treatment of NHL.

FDG PET/CT parameters and correlations with tumor-absorbed doses in a phase 1 trial of 177Lu-lilotomab satetraxetan for treatment of relapsed non-Hodgkin lymphoma.

PURPOSE: 177Lu-lilotomab satetraxetan targets the CD37 antigen and has been investigated in a first-in-human phase 1/2a study for relapsed non-Hodgkin lymphoma (NHL). Tumor dosimetry and response evaluation can be challenging after radioimmunotherapy (RIT). Changes in FDG PET/CT parameters after RIT and correlations with tumor-absorbed doses has not been examined previously in patients with lymphoma. Treatment-induced changes were measured at FDG PET/CT and ceCT to evaluate response at the lesion level after treatment, and correlations with tumor-absorbed doses were investigated. METHODS: Forty-five tumors in 16 patients, with different pre-treatment and pre-dosing regimens, were included. Dosimetry was performed based on multiple SPECT/CT images. FDG PET/CT was performed at baseline and at 3 and 6 months. SUVmax, MTV, TLG, and changes in these parameters were calculated for each tumor. Lesion response was evaluated at 3 and 6 months (PET3months and PET6months) based on Deauville criteria. Anatomical changes based on ceCT at baseline and at 6 and 12 months were investigated by the sum of perpendiculars (SPD). RESULTS: Tumor-absorbed doses ranged from 35 to 859 cGy. Intra- and interpatient variations were observed. Mean decreases in PET parameters from baseline to 3 months were ΔSUVmax-3months 61%, ΔMTV3months 80%, and ΔTLG3months 77%. There was no overall correlation between tumor-absorbed dose and change in FDG PET or ceCT parameters at the lesion level or significant difference in tumor-absorbed doses between metabolic responders and non-responders after treatment. CONCLUSION: Our analysis does not show any correlation between tumor-absorbed doses and changes in FDG PET or ceCT parameters for the included lesions. The combination regimen, including cold antibodies, may be one of the factors precluding such a correlation. Increased intra-patient response with increased tumor-absorbed doses was observed for most patients, implying individual variations in radiation sensitivity or biology. TRIAL REGISTRATION: ClinicalTrials.gov Identifier (NCT01796171). Registered December 2012.

Low grade, indolent lymphomas of the head and neck: Comparative toxicity of standard versus very low dose radiation therapy.

National Comprehensive Cancer Network guidelines recommend radiation therapy (RT) for localized indolent non-Hodgkin lymphomas (iNHL). Many referring physicians avoid RT to the head and neck (HN) due to fears of toxicity. Very low-dose radiation (4 Gy) for select patients produces sustained local control and recently gained popularity. We compared early and late toxicities of standard 24-30 Gy to 4 Gy in patients with HN iNHL. We retrospectively analyzed 266 consecutive patients with HN iNHL receiving RT from 1994 to 2017. Patient characteristics, outcomes, and toxicities were collected from medical records. Early (≤2 months post-RT) and late (>2 months post-RT) toxicities were graded per Common Terminology Criteria for Adverse Events version 4. Grades 1-2 were defined as "low-grade" and 3-4 "high-grade." Toxicity incidence was compared between 4 and >4 Gy, grouped by treated site (orbit, nonorbital head, neck, skin) and early versus late. Median follow-up was 23 months (2-145) and 68 months (2-256) for 4Gy and >4 Gy cohorts, respectively. Median dose for the >4 Gy cohort was 30 Gy (10.5-54 Gy). Early and late toxicity incidences were lower in the 4 Gy cohort compared to >4 Gy across all RT-sites: early toxicity, orbit, 42% versus 96%; nonorbital head, 24% versus 96%; neck, 22% versus 94%; skin, 31% versus 87%; late toxicity, orbit, 20% versus 71%; nonorbital head, 6% versus 66%; neck, 6% versus 57%; skin, 0% versus 46% (4 Gy vs. >4 Gy, respectively). Toxicities among both cohorts were largely low-grade. High-grade early and late toxicities did not occur in the 4 Gy cohort. There was 1 high-grade early toxicity (Grade 3 dry mouth) and 17 high-grade late toxicities (Grade 3 cataracts) in the >4 Gy cohort. RT to HN for iNHL is associated with minimal short- and long-term toxicity and excellent local control among 4 Gy and >4 Gy treatments. In this setting, "toxicity" concerns should not deter oncologists from potentially curative RT. In select patients where toxicity remains a concern, very low dose 4 Gy could be considered.

Consolidation Treatment for Primary Central Nervous System Lymphoma: Which Modality for Whom?

Primary central nervous system lymphoma is a rare aggressive disease that largely affects elderly patients and is associated with poor prognosis. The optimal treatment approach is not yet defined and it consists of induction and consolidation phases. The combination of high-dose (HD) methotrexate-based chemotherapy followed by whole-brain radiotherapy (WBRT) prolongs the median progression-free survival (PFS) and overall survival 2- to 3-fold as compared to WBRT alone but is associated with significant delayed neurotoxicity. Alternative strategies are being investigated in order to improve disease outcomes and spare patients the neurocognitive side effects. These include reduced-dose WBRT, non-myeloablative HD chemotherapy, or HD chemotherapy with autologous stem cell transplantation (HDC/ASCT). There are no randomized studies that compare all these consolidation regimens head to head but recently HDC/ASCT has been evaluated versus WBRT in prospective randomized studies. These studies proved that WBRT and HDC/ASCT yield similar 2-year PFS with preserved or improved cognitive function after HDC/ASCT. Yet, the proportion of patients treated with such intensive consolidation is low, both in real life and in specialized centers, leaving many unsettled issues. This review is appraising current dilemmas related to the choice of consolidating therapeutic modalities, their associated acute and delayed toxicity, and future prospects for alternative approaches in the elderly.

Primary Paraspinal and Spinal Epidural Non-Hodgkin Lymphoma in Childhood.

Primary paraspinal/spinal epidural lymphoma (PPSEL) is rare in childhood. Here, we retrospectively evaluated patients with PPSEL treated in our department. We also reviewed the cases reported in the literature. Fifteen of 1354 non-Hodgkin lymphoma cases diagnosed over a 38-year period were PPSEPL. There were 11 male individuals and 4 female individuals with a median age of 13 years. Most common symptoms were pain and limb weakness. Physical examination revealed spinal cord compression in 80% of patients. The most common tumor location was the lumbar region. Histopathologic subtypes were lymphoblastic lymphoma in 6 and Burkitt lymphom in 5 patients. Subtotal or near-total excision of the tumor with laminectomy was performed in 6 patients. Thirteen and 9 patients received chemotherapy and radiotherapy, respectively. Neurologic recovery was observed in 70% of patients. Seven patients were alive without disease at a median of 88 months. Overall and event-free survival rates were 61.7% and 50.1%, respectively. We reviewed clinical features, treatment, and outcome of 69 PPSEL cases reported in the literature. Neurologic recovery and long-term survival was achieved in 66.7% of them. Heterogeneity in diagnostic methods and treatment have made it difficult to establish the prognostic indicators for neurologic outcome and survival. Multicenter prospective studies with more cases are necessary to determine the prognostic factors.

Early experience using salvage radiotherapy for relapsed/refractory non-Hodgkin lymphomas after CD19 chimeric antigen receptor (CAR) T cell therapy.

Radiotherapy is potentially an important salvage strategy post-chimeric antigen receptor T cell therapy (CART), but limited data exist. We reviewed 14 patients treated with salvage radiation post-CART progression (SRT). Most received SRT for first post-CART relapse (71%) to sites previously PET-avid pre-CART (79%). Median overall survival (OS) post-SRT was 10 months. Post-SRT, six localized relapses achieved 100% response (3 = complete, 3 = partial), with improved freedom from subsequent relapse (P = 0·001) and OS (P = 0·004) compared to advanced stage relapses. Three were bridged to allogeneic transplantation; at analysis, all were alive/NED. SRT has diverse utility and can integrate with novel agents or transplantation to attempt durable remissions.

Whole brain radiotherapy improves survival outcomes in primary CNS lymphoma patients ineligible for systemic therapy.

PURPOSE: Primary central nervous system lymphoma (PCNSL) is a very rare type of malignancy with a poor prognosis. The role of whole brain radiotherapy (WBRT) in PCNSL has been questioned due to the significant neurotoxicity and lack of convincing data for survival benefit. Even its role in a palliative setting remains to be clearly elucidated. Our study aims to investigate the benefit of WBRT in patients who are ineligible for systemic therapy. METHODS: A single-institution retrospective study was conducted on patients diagnosed with PCNSL between 2002 and 2017. Patients were excluded if they received systemic therapy or focal radiation only. Data on patient demographics and WBRT were collected and correlated with clinical outcomes. RESULTS: A total of 48 patients were selected for analysis, among which 31 (64.6%) patients received WBRT and 17 (35.4%) patients received supportive care only. Patient baseline characteristics were similar between the two groups. Median overall survival (OS) was 4.3 months among the entire cohort. WBRT was associated with improved median OS (8.0 months, range 1.4-62.3 months) compared with supportive care only (3.3 months, range 0.7-18.3 months) (HR 0.39, 95% CI 0.20-0.75, p = 0.005). Among patients who received WBRT, higher radiation dose to the whole brain was not associated with survival (p = 0.10), but higher radiation dose to the gross tumor was associated with improved survival (p = 0.007). CONCLUSION: Patients with PCNSL who are ineligible for systemic therapy may still benefit from WBRT with improvement in survival, compared with the best supportive care. Dose escalation through the addition of a gross tumor boost in these patients was associated with improved overall survival. Further studies in the prospective setting are necessary to confirm the findings from the study.

Outcomes of cardiac surgery after mediastinal radiation therapy: A single-center experience.

BACKGROUND: Mediastinal radiation therapy (MRT) is a widely used therapy for thoracic malignancies. This therapy has the potential to cause cardiovascular injuries, which may require surgery. The primary aim of this study is to identify the perioperative outcomes of cardiac surgery in patients with a history of MRT. Second, potential predictors of mortality and adverse events were identified. METHODS: A retrospective study was conducted among 59 patients with prior MRT who underwent cardiac surgery between December 2009 and March 2015. Included surgeries consisted of procedures through median- and ministernotomy. Baseline, perioperative, and follow-up data were obtained and analyzed. RESULTS: The majority of patients had a history of breast cancer (n = 43), followed by Hodgkin lymphoma (n = 10) and non-Hodgkin lymphoma (n = 3). Preoperative estimated mortality with the Euroscore II was 3.4%. Overall 30-day mortality was 6.8% (n = 4), with a total in-hospital mortality of 10.2% (n = 6). Postoperatively, nine rethoracotomies (15.3%) had to be performed. During a mean follow-up of 53 months, an additional 10 patients (16.9%) died, of which 60% (n = 6) as a result of cancer-related events. Cox proportional modeling showed no differences in mortality between primary malignancies (P > .05). CONCLUSION: This study shows that cardiac surgery after mediastinal radiotherapy is associated with increased short- and long-term mortality when compared to preoperative mortality risks predicted by the Euroscore II. Surgery-related events caused all short-term mortality cases, while malignancy-related events were the main cause of death during the follow-up. Mortality was higher in patients with a previous stroke and a lower estimated glomerular filtration rate.

Consolidative mediastinal irradiation of malignant lymphoma using active scanning proton beams: clinical outcome and dosimetric comparison.

PURPOSE: Current research approaches in lymphoma focus on reduction of therapy-associated long-term side effects. Especially in mediastinal lymphoma, proton beam radiotherapy (PT) may be a promising approach for reducing the dose to organs at risk (OAR). PATIENTS: In total, 20 patients were irradiated with active scanning PT at Heidelberg Ion Beam Therapy Center (HIT) between September 2014 and February 2017. For comparative analysis, additional photon irradiation plans with helical intensity-modulated radiotherapy (IMRT) were calculated and quantitative and qualitative dose evaluations were made for both treatment modalities. Toxicity and survival outcomes were evaluated. RESULTS: Clinical target volume coverage was comparable in both treatment modalities and did not significantly differ between IMRT and PT. Nevertheless, PT showed superiority regarding the homogeneity index (HIPT = 1.041 vs. HIIMRT = 1.075, p < 0.001). For all OAR, PT showed significantly higher dose reductions compared with IMRT. In particular, the dose to the heart was reduced in PT (absolute dose reduction of Dmean of 3.3 Gy [all patients] and 4.2 Gy [patients with pericardial involvement]). Likewise, the subgroup analysis of female patients, who were expected to receive higher doses to the breast, showed a higher dose reduction in Dmean of 1.2 Gy (right side) and 2.2 Gy (left side). After a median follow-up of 32 months (range 21-48 months), local and distant progression free survival (LPFS and DPFS) were 95.5% and 95.0%, respectively. Radiotherapy was tolerated well with only mild (grade 1-2) radiation-induced acute and chronic side effects. CONCLUSION: A significant reduction in the dose to the surrounding OAR was achieved with PT compared with photon irradiation, without compromising target volume coverage. Dosimetric advantages may have the potential to translate into a reduction of long-term radiation-induced toxicity in young patients with malignant lymphoma of the mediastinum.

Non-Small-Cell Lung Cancer After Mantle Radiation: A Case Report and Brief Review.

Survivors of childhood and young adult cancer are at risk for developing subsequent malignant neoplasms, including lung cancer. As survival rates in this group continue to improve and patients enter later decades in life, determining the optimal surveillance and counseling strategies with regards to subsequent cancers remains a challenge. In this case report, we present a non-Hodgkin lymphoma survivor who was incidentally found to have non-small-cell lung cancer 30 years after undergoing treatment that included mantle radiation. We discuss the treatment-related risk factors for lung cancer in this population and potential implications for long-term follow-up.

Gonadal Function Recovery and Fertility in Women Treated with Chemo- and/or Radiotherapy for Hodgkin's and Non-Hodgkin Lymphoma.

BACKGROUND: Fertility and gonadal function represent one of the most important aspects for long-term lymphoma survivors. AIMS: The aim of our study was to determine possible risk factors, such as age at treatment, chemotherapeutic regimen, protection with oral contraceptives (OCs), and gonadotropin-releasing hormone (GnRH) analogues in female patients treated for Hodgkin's lymphoma (HL) or non-Hodgkin lymphoma (NHL) at a reproductive age. METHODS: Patients between the age of 16 and 50 years at the time of HL or NHL diagnosis were selected. Eligible patients were requested to respond to a questionnaire by phone interview about fertility, menstrual status, sexual aspects, and treatment with OCs or GnRH analogues during chemotherapy. RESULTS: The resumption of menstrual activity was associated with the use of the OCs and GnRH analogues during chemotherapy (p = 0.008 and 0.034, respectively). At univariate analysis, the use of OCs during chemotherapy was associated with a lower risk of amenorrhea (prevalence ratio [PR] = 0.37; 95% CI 0.17-0.82). A higher age at the time of treatment correlated positively with therapy-induced amenorrhea, with a difference of 12.8 years between the mean age at diagnosis of the women with therapy-induced amenorrhea and those who resumed their menses. Amenorrhea was significantly higher in women receiving R-CHOP than in women treated with ABVD (PR = 6.00; 95% CI 2.32-15.54). Moreover, NHL had an infertility PR of 1.51 (95% CI 0.86-2.45) at multivariate analysis compared to HL. CONCLUSIONS: This study suggests a possible role of pharmacological prophylaxis with OCs and GnRH analogues.

Yttrium-90-Ibritumomab Tiuxetan (Zevalin®) Radioimmunotherapy after Cytoreduction with ESHAP Chemotherapy in Patients with Relapsed Follicular Non-Hodgkin Lymphoma: Final Results of a Phase II Study.

BACKGROUND: Radioimmunotherapy (RIT) is effective in treating relapsed/refractory follicular lymphoma (FL), with durable remissions in first-line consolidation. We hypothesized that RIT with ibritumomab tiuxetan (Zevalin®) would result in durable remissions by eliminating minimal residual disease after cytoreduction. METHODS: Patients with FL received 2 cycles of ESHAP (etoposide, methylprednisolone, cytarabine, cisplatin) every 28 days, followed by Zevalin 4-6 weeks later if there was no disease progression and bone marrow biopsy showed < 25% involvement. RESULTS: Twenty-eight patients were treated, with a median age of 61 years, median of 3 prior therapies, 49% high-risk disease (Follicular Lymphoma International Prognostic Index, FLIPI), and 39% progressive disease. Three patients did not receive Zevalin due to residual bone marrow involvement. The main toxicities were cytopenias, with 11% febrile neutropenia. The overall response rate (ORR) was 72%, with 45% achieving complete response. With a median follow-up of 73 months, 1-year progression-free survival (PFS) was 38%, and median PFS was 10 months, but median overall survival (OS) was not reached. CONCLUSION: The study did not reach its primary endpoint of a 1-year PFS of 67.3%. Reasons for this could include low accrual, high-risk disease, and inadequate debulking provided by 2 cycles of ESHAP. However, this protocol was associated with tolerable toxicity, high ORR, and high OS. Further studies would optimize debulking and focus on high-risk FL patients.

Pre-dosing with lilotomab prior to therapy with 177Lu-lilotomab satetraxetan significantly increases the ratio of tumor to red marrow absorbed dose in non-Hodgkin lymphoma patients.

PURPOSE: 177Lu-lilotomab satetraxetan is a novel anti-CD37 antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma (NHL). Four arms with different combinations of pre-dosing and pre-treatment have been investigated in a first-in-human phase 1/2a study for relapsed CD37+ indolent NHL. The aim of this work was to determine the tumor and normal tissue absorbed doses for all four arms, and investigate possible variations in the ratios of tumor to organs-at-risk absorbed doses. METHODS: Two of the phase 1 arms included cold lilotomab pre-dosing (arm 1 and 4; 40 mg fixed and 100 mg/m2 BSA dosage, respectively) and two did not (arms 2 and 3). All patients were pre-treated with different regimens of rituximab. The patients received either 10, 15, or 20 MBq 177Lu-lilotomab satetraxetan per kg body weight. Nineteen patients were included for dosimetry, and a total of 47 lesions were included. The absorbed doses were calculated from multiple SPECT/CT-images and normalized by administered activity for each patient. Two-sided Student's t tests were used for all statistical analyses. RESULTS: Organs with distinct uptake of 177Lu-lilotomab satetraxetan, in addition to tumors, were red marrow (RM), liver, spleen, and kidneys. The mean RM absorbed doses were 0.94, 1.55, 1.44, and 0.89 mGy/MBq for arms 1-4, respectively. For the patients not pre-dosed with lilotomab (arms 2 and 3 combined) the mean RM absorbed dose was 1.48 mGy/MBq, which was significantly higher than for both arm 1 (p = 0.04) and arm 4 (p = 0.02). Of the other organs, the highest uptake was found in the spleen, and there was a significantly lower spleen absorbed dose for arm-4 patients than for the patient group without lilotomab pre-dosing (1.13 vs. 3.20 mGy/MBq; p < 0.01). Mean tumor absorbed doses were 2.15, 2.31, 1.33, and 2.67 mGy/MBq for arms 1-4, respectively. After averaging the tumor absorbed dose for each patient, the patient mean tumor absorbed dose to RM absorbed dose ratios were obtained, given mean values of 1.07 for the patient group not pre-dosed with lilotomab, of 2.16 for arm 1, and of 4.62 for arm 4. The ratios were significantly higher in both arms 1 and 4 compared to the group without pre-dosing (p = 0.05 and p = 0.02). No statistically significant difference between arms 1 and 4 was found. CONCLUSIONS: RM is the primary dose-limiting organ for 177Lu-lilotomab satetraxetan treatment, and pre-dosing with lilotomab has a mitigating effect on RM absorbed dose. Increasing the amount of lilotomab from 40 mg to 100 mg/m2 was found to slightly decrease the RM absorbed dose and increase the ratio of tumor to RM absorbed dose. Still, both pre-dosing amounts resulted in significantly higher tumor to RM absorbed dose ratios. The findings encourage continued use of pre-dosing with lilotomab.

Unilateral localized conjunctival amyloidosis in a patient with a history of contralateral orbit/eyelid lymphoma.

Amyloidosis is a disorder characterized by the deposition of insoluble abnormal proteins in the extracellular space. It may occur as a localized lesion or as a systemic disease involving multiple organs and systems. Localized conjunctival amyloidosis is rare and is less frequently associated with systemic involvement. Although amyloidosis itself is a benign lesion involvement of multiple organs and systems is associated with poor prognosis. Diagnosis of amyloidosis is made on biopsy specimens with Congo red staining for the appearance of apple-green birefringence under polarized light microscopy. Liquid chromatography tandem-mass spectrometry (LC-MS/MS) is much more sensitive in diagnosing amyloidosis and can determine the type of amyloid deposit. Here we reported a case of conjunctival amyloidosis in a 52 year-old male patient who was presented with left lower eyelid swelling to our medical center. He has a complicated past medical history of anti-phospholipid antibody syndrome, Buerger's disease (thromboangitis obliterans), and small cell lymphoma (SLL) of the right orbit/eyelid. The patient received radiation to the right orbit to treat SLL with therapy completed one and a half years prior to presentation. Physical examination revealed a firm, raised yellowish colored lesion in the left lower conjunctiva. The conjunctival lesion was biopsied, and tissue sections were examined with Congo red stains and LC-MS/MS analysis. The biopsy showed amyloid deposits without evidence of malignancy, and the type of proteins in the deposit was immunoglobulin light chain (AL) of kappa type. A complete work up was taken for possible systemic involvement of amyloidosis and results were all negative. To our knowledge, this is the first case of localized conjunctival amyloidosis with a history of contralateral orbit/eyelid SLL.

INFRADIAPHRAGMAL RADIOTHERAPY IN PATIENTS WITH LYMPHOMA: VOLUME DEFINITION AND SIDE EFFECTS.

- Lymphomas are very radiosensitive and radiotherapy (RT) was the first treatment modality that enabled cure. It is the most effective single modality for local control of lymphomas. However, as a local form of treatment, curative intention is only possible if all lymphoma tissue can be incorporated in the volume to be irradiated with the prescribed total irradiation dose. That is why RT is a single modality only in early stage of nodular lymphocyte predominance Hodgkin's lymphoma and low grade non-Hodgkin's lymphoma. In most patients, RT can be used as consolidation therapy after chemotherapy or as salvage after failure of chemotherapy. In the past two decades, irradiation techniques have been improved in order to spare critical tissues and reduce toxicity. Although effective, RT is a neglected modality of treatment because of the appearance of new drugs and fear of side effects after irradiation. Radiation has been shown to be effective in the treatment of all stages and forms of lymphoma. Study data are still mostly derived from patients that received supradiaphragmal RT; therefore, there is no agreement about the best management approach in patients with infradiaphragmal lymphoma.