2 Gy Total Body Irradiation As Part Of Conditioning Treatment For Patients With Acute Lymphoblastic Leukemia Undergoing CAR T Cell Therapy

Inclusion Criteria: * Patients must have a confirmed diagnosis of Acute Lymphoblastic Lymphoma and are planned to undergo CAT T cell therapy. The patient should not be planned to receive craniospinal irradiation prior to CAR T therapy; the latter group will be excluded from this study. Prior Radiation would not exclude patients from getting 2 Gy TBI, including prior TBI, in the event of a prior stem cell transplant. * Age ≥18 years. * ECOG performance status ≤2 (Karnofsky ≥60%,). * Patients must have adequate organ and marrow function as defined below: absolute neutrophil count ≥1,000/mcL Platelets ≥100,000/mcL total bilirubin ≤ institutional upper limit of normal (ULN) AST(SGOT)/ALT(SGPT) ≤3 × institutional ULN creatinine ≤ institutional ULN The above are guidelines that align with recommendations for any patient who is undergoing CAR T cell therapy. * For patients with evidence of chronic hepatitis B virus (HBV) infection, the HBV viral load must be undetectable on suppressive therapy, if indicated. * Patients with a history of hepatitis C virus (HCV) infection must have been treated and cured. Patients with HCV infection who are currently on treatment are eligible if they have an undetectable HCV viral load. * Patients with a prior or concurrent malignancy whose natural history or treatment does not interfere with the safety or efficacy assessment of the investigational regimen are eligible for this trial. * Approved methods of birth control are as follows: Hormonal contraception (i.e. birth control pills, injection, implant, transdermal patch, vaginal ring), Intrauterine device (IUD), Tubal Ligation or hysterectomy, Subject/Partner post vasectomy, Implantable or injectable contraceptives, and condoms plus spermicide. Not engaging in sexual activity for the total duration of the trial and the drug washout the rhythm method, and the withdrawal method are not acceptable methods of birth control. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. * Men treated or enrolled in this protocol must also agree to use adequate contraception before the study, for the duration of study participation, and 6- 12 months after completion of CAR T cell therapy administration. * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: * Patients who are receiving any other investigational agents. * Patients who need craniospinal irradiation for CNS leukemia prior to CAR T cell therapy. * Patients with uncontrolled intercurrent illness (Indicate clearly what type or extent) * Patients with psychiatric illness/social situations that would limit compliance with study requirements. * Pregnant women are excluded from this study because the conditioning regimen before CAR T, as well as radiation, will have both teratogenic and abortifacient effects. Because there is an unknown but potential risk for adverse events in nursing infants secondary to the treatment of the mother, breastfeeding should be discontinued. These potential risks may also apply to other agents used in this study.