The goal of this study is to learn if the intervention using a fluorescent agent 5-Aminolevulinic acid (5-ALA) to aid in the surgical approach to visualize the soft-tissue sarcoma (STS) during surgical resection. 5-ALA goes through the blood stream and into the tumor tissue allowing it to light up when the surgeon uses a special light in the operating room. The technique is called 5-ALA fluorescence-guided surgery (FGS). The main question aims to answer if 5-ALA provide intraoperative fluorescent visualization of soft-tissue sarcoma versus surrounding tissue and demonstrate the efficacy of tumor and surgical margin resections by a gross and histological analysis of fluorescing and non-fluorescing samples immediately after removal. Participants will be asked to orally administer 5-ALA three to four hours prior to surgery in preoperative area.

Inclusion Criteria:

1. Histological confirmation of any subtype of primary Grades 2 or 3 soft tissue sarcomas (STS), per biopsy evaluation by a pathologist, according to Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC).

2. Treatment decision includes planned surgical resection of STS.

3. Age ≥18 years at time of consent.

4. ECOG Performance Status 0 - 1.

5. Hematology and blood chemistry parameters defined by:

   1. Leukocytes ≥ 3 × 10(9)/L
   2. Absolute neutrophil count ≥ 1.5 × 10(9)/L
   3. Platelets ≥ 100 × 109/L, transfusions may be used to raise platelets to ≥ 100 × 10(9)/L (no washout required)
   4. Hemoglobin ≥ 9 g/dL, transfusions may be used to raise Hgb to ≥ 9 g/dL (no washout required)
   5. Total bilirubin ≤ 1.5 × institutional upper limit of normal (ULN)
   6. Aspartate transaminase (AST) / alanine transaminase (ALT) ≤ 2.5 × institutional ULN
   7. Creatinine within normal institutional limits OR creatinine clearance ≥ 30 mL/min/1.73 m2 for patients with creatinine above institutional ULN

6. Participants of reproductive potential must agree to using adequate contraception (e.g., hormonal or barrier method of birth control; abstinence, an intrauterine device) for the duration of study participation (including dosing interruptions) and up to 42 days after end of study intervention; or be surgically sterilized (e.g., hysterectomy, tubal ligation, or vasectomy).

7. Ability to swallow study agent.

8. Ability to understand and willingness to sign an informed consent form.

9. Ability and stated willingness to adhere to the study visit schedule and other protocol procedures/requirements for the duration of the study.

Inclusion of Minorities and Other Underrepresented Populations Recruitment is open and encouraged to all genders, all minorities, and underrepresented populations. Although distributions may vary by disease type, our recruitment procedures have been developed to enroll participants who are representative of the respective target population.

Exclusion Criteria:

1. Acute/chronic forms of porphyria.
2. Uncontrolled, known concurrent illness, including but not limited to ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness.
3. Patient has had chemotherapy, tumor resection, or radiation treatment ≤ 21 days prior to surgery.
4. Simultaneous participation in another clinical trial ≤ 21 days of enrollment or during the duration of the study period.
5. Planned use of other potentially phototoxic substances (e.g., St. John's wort, griseofulvin, thiazide diuretics, sulfonylureas, phenothiazines, sulfonamides, quinolones and tetracyclines), and topical preparations containing aminolevulinic acid (5-ALA) for 24 hours during the perioperative period (defined as 24 hours prior to surgery to up to 24 hours post-surgery).
6. Pregnant or planning to become pregnant during study participation or breastfeeding.
7. Any condition that is in the opinion of the investigator would prohibit the understanding or rendering of informed consent or interfere with the participant's safety or compliance while on trial.