Inclusion Criteria:

- Patient is >18 years and male or female of any race / ethnicity

- Patient or patient's legally acceptable representative provides written informed
consent and is willing to comply with protocol procedures

- Patient must have histopathologically confirmed head/neck, lung, liver, rectal or
cervical cancer with tumor size ≥ 3cm

- Patient has tumor tissue samples available before treatment for future
immunohistochemistry biomarker tests (HIF1alpha and CA-IX)

- Patient is scheduled to have or already had a clinical [F 18]FDG PET/CT scan
recommended to be within 14 days of the first pre-treatment [F 18]HX4 PET/CT scan and
have no treatment intervention in between these two scans

- Patient is scheduled or is intended to be scheduled to receive chemotherapy,
radiation or chemoradiotherapy treatment(s) after the pre-treatment [F 18]HX4 PET/CT
and [F 18]FDG PET/CT scans for his/her cancer care

- Patient must have hepatic and renal functions as defined by laboratory results within
the following ranges:

- Total bilirubin within 2 times institutional upper limit of normal

- AST (SGOT) and ALT (SGPT) ≤ 2.5 times institutional upper limits of normal

- Serum creatinine ≤ 2.5 times institutional limit of normal

- BUN within 2 times institutional upper limit of normal

Exclusion Criteria:

- Patient is not capable of complying with study procedures

- Female patient is pregnant or nursing

o Exclude the possibility of pregnancy by one of the following:

- Confirming in medical history that the patient is post-menopausal for a minimum
of one year, or surgically sterile

- Confirming the patient is using one of the following methods of birth control
for a minimum of one month prior to entry into this study: IUD, oral
contraceptives, Depo-Provera, or Norplant

- Confirming a negative urine dipstick test taken the morning of but before
receiving [F 18]HX4

- Patient has been involved in an investigative, radioactive research procedure within
7 days and during the study participation period

- Patient has any other condition or personal circumstance that, in the judgment of the
investigator, might interfere with the collection of complete data