Inclusion Criteria:

          -  Newly diagnosed and a histopathologically potentially resectable soft tissue sarcoma
             of the extremity or trunk of the following subtypes:

               -  Cohort 1: liposarcoma (excluding myxoid liposarcoma)

               -  Cohort 2: leiomyosarcoma

               -  Cohort 3: undifferentiated pleomorphic sarcoma (UPS)/ malignant fibrous
                  histiosarcoma (MFH)

          -  Sites permissible for biopsy include

               -  Extremities: upper (including shoulder) and lower (including hip)

               -  Trunk: Body wall

          -  Patients must have a histologically determined grade 2 or 3 tumor by the French
             Federation of Cancer Centers Sarcoma Group (FNCLCC) sarcoma grading system

          -  Patients must have localized disease with a primary tumor > 5 cm by magnetic resonance
             imaging (MRI) or computed tomography (CT) scan.

          -  Patients must have a primary tumor that are determined by multidisciplinary team
             (medical oncology, orthopedic/surgical oncology, and radiation oncology) to require
             radiation therapy for optimal management prior to surgical resection

          -  Patients must have a sarcoma in the extremity or trunk in location, which is
             accessible to direct or ultrasound guided injections

          -  Karnofsky performance score >= 70

          -  Absolute neutrophil count (ANC) >= 1500/uL

          -  Absolute lymphocyte count (ALC) >= 800/uL

          -  Platelets >= 100,000/uL

          -  Hemoglobin >= 9 g/dL

          -  Total bilirubin =< 1.5 x institutional upper limit of normal (ULN)

          -  Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =< 2.5 x
             institutional ULN

          -  Calculated creatinine clearance > 70 mL/min/1.73 m^2

          -  Patient must have a life expectancy of at least 3 months with appropriate therapy

          -  Patients must agree to use contraception during study treatment and for 4 months after
             the end of treatment

               -  NOTE: Talimogene laherparepvec (T-VEC), as well as other therapeutic agents used
                  in this trial, may cause fetal harm when administered to a pregnant woman; women
                  of child-bearing potential and men must agree to use adequate contraception
                  (hormonal or barrier method of birth control; abstinence) prior to study entry,
                  during the study participation, and for four months after the last dose of the
                  drug; women of child-bearing potential must have a negative serum pregnancy test
                  within 7 days prior to registration and agree to use effective contraception
                  throughout the treatment period and for 4 months after the last dose of study
                  treatment; 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

          -  Ability to understand and the willingness to sign a written informed consent document

          -  Willingness to provide mandatory blood and tissue samples for correlative studies and
             central pathology confirmation of surgical specimens collected during study
             participation

          -  Willingness to provide a tissue sample that is mandatory at the time of surgery (if
             applicable) and the determination of the primary objective of the study

        Exclusion Criteria:

          -  Patients with localized sarcomas that are not of the extremity or trunk wall
             (including head/neck, retroperitoneum, visceral organs, peritoneum, pelvis within the
             confines of the bony pelvis, and tumors arising in bone)

          -  Patients who have had prior treatment with anti-PD1 or anti-CTLA4 therapy

          -  Patients with grade 1 non-rhabdomyosarcoma soft tissue sarcomas (NRSTS) tumors of any
             size are not eligible

          -  Patients with evidence of active bleeding or bleeding diathesis will be excluded
             (patients with excess of 2.5 mL of hemoptysis are not eligible)

          -  Patients requiring any therapeutic anticoagulation

          -  Patients must have had no prior radiotherapy to tumor-involved sites

          -  Patients with gross total resection of the primary tumor or who have developed tumor
             recurrence after gross total tumor resection prior to enrollment are not eligible

          -  History of serious or non-healing wound, ulcer, or bone fracture

          -  Patients who have not recovered from adverse events due to prior anti-cancer therapy
             (i.e., have residual toxicities > grade 1)

          -  Use of other investigational drugs within 28 days (or five half-lives, whichever is
             shorter; with a minimum of 14 days from the last dose) preceding the first dose of
             talimogene laherparepvec (T-VEC) and during the study

          -  Previous treatment with talimogene laherparepvec (T-VEC) or any other oncolytic virus

          -  Patients with metastatic disease

          -  Have a known immediate or delayed hypersensitivity reaction or idiosyncrasy to
             talimogene laherparepvec (T-VEC) or any of its components

          -  History or evidence of active autoimmune disease (e.g., pneumonitis,
             glomerulonephritis, vasculitis, or other); or history of active autoimmune disease
             that has required systemic treatment (i.e., use of corticosteroids, immunosuppressive
             drugs or biological agents used for treatment of autoimmune diseases) within 2 months
             of enrollment; (replacement therapy [e.g., thyroxine for hypothyroidism, insulin for
             diabetes or physiologic corticosteroid replacement therapy for adrenal or pituitary
             insufficiency] is not considered a form of systemic treatment for autoimmune disease)

               -  Evidence of clinically significant immunosuppression such as

                    -  Primary immunodeficiency state such as severe combined immunodeficiency
                       disease

                    -  Concurrent opportunistic infection

                    -  Receiving systemic immunosuppressive therapy (> 2 weeks) including oral
                       steroid doses > 10 mg/day of prednisone or equivalent within 2 months prior
                       to enrollment

          -  Active herpetic skin lesions or prior complications of herpetic infection (e.g.,
             herpetic keratitis or encephalitis)

          -  Viral infections requiring intermittent or chronic systemic (intravenous or oral)
             treatment with an anti-herpetic drug, other than intermittent topical use (e.g.,
             acyclovir)

          -  Other viral infections

               -  Known to have acute or chronic active hepatitis B or hepatitis C infection

               -  Known to have human immunodeficiency virus (HIV) infection

               -  Prior therapy with viral-based tumor vaccine

               -  Received live vaccine within 28 days prior to enrollment

          -  Patients who are unwilling to minimize exposure with his/her blood or other body
             fluids to individuals who are at higher risks for herpes simplex virus (HSV)-1 induced
             complications such as immunosuppressed individuals, individuals known to have HIV
             infection, pregnant women, or children under the age of 1 year, during talimogene
             laherparepvec (T-VEC) treatment and through 30 days after the last dose of talimogene
             laherparepvec (T-VEC)

          -  Uncontrolled intercurrent illness including, but not limited to, ongoing or active
             infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
             arrhythmia, or psychiatric illness/social situations that would limit compliance with
             study requirements

          -  Patients who are pregnant, breastfeeding or plan to become pregnant

               -  NOTE: Although no effects on embryo-fetal development have been observed in
                  animal studies, adequate and well-controlled studies with talimogene
                  laherparepvec (T-VEC) have not been conducted in pregnant women.; therefore,
                  sexually active patients and their partners must be willing to use adequate
                  contraception (hormonal or barrier method of birth control; abstinence) prior to
                  study entry, during the study participation, and for four months after the last
                  dose of T-VEC