Question: My brother has had a preliminary diagnosis of lung cancer based on his medical history (smoker) and initial x-rays. He has seen a cardio thoracic surgeon who has ordered further tests. Would you be kind enough to explain the following results of yesterday's PET scan?
PET/CT SKULL BASE TO THIGHS:

IMPRESSION:

1. Large lobulated mass projecting at the superior segment of the right lower lobe with increased metabolic activity compatible with neoplastic process. This confirms the CT chest finding.
2. A 1.5 x 2 x 1.5 cm lymph node at the subcarinal space. There is no increased metabolic activity to indicate active disease. Scattered prevascular lymph nodes as well as anterior superior mediastinum without significant increased metabolic activity.
3. Soft tissue mass with heterogeneous attenuation as well as calcification projecting inferior to the left lobe of thyroid gland with mild increased metabolic activity. Substernal goiter is the first consideration. A lymph node is a possibility.
3. Small right renal cyst.
4. Thickening of the urinary bladder wall without focal mass likely associated with previous inflammatory or infectious process.

END OF IMPRESSION:

INDICATION: A 62-year-old male patient with history of pulmonary mass as well as mediastinal mass for diagnosis.

TECHNIQUE: Following intravenous administration of 15.86 mCi of F-18 FDG, PET scan was obtained from skull base to mid thigh after a 55 minute waiting period. Low dose CT scan was also obtained for soft tissue attention and anatomic localization.

Blood glucose prior to injection was 96 MG/dL before examination.

INJECTION SITE: Right antecubital fossa.

DELAY: Yes.

COMPARISON: Correlation is made with a CT of the chest dated 8/7/2015.

FINDINGS:

REFERENCE SUVS:

Mediastinal Blood pool: 2.37 SUV.
Normal Lung parenchyma: 1.31 SUV.
Normal Hepatic parenchyma: 3.08 SUV.

SKULL BASE AND NECK:
There is normal oral, pharyngeal and laryngeal uptake. No metabolically active masses or adenopathy are identified.

CHEST:
There is a large lobulated mass projecting at the superior segment of right lower lobe, measuring approximately 6.2 x 4.5 x 5.5 cm. There is increased metabolic activity with a maximum SUV of 12.6 on the early and 16.1 on the delayed images. This confirms the previous CT chest finding. Respiratory motion artifact with diffuse ground-glass opacity of the lung parenchyma. Bibasilar dependent atelectasis. Scattered blebs and bulla.
There is a 1.5 x 2 x 1.5 cm lymph node at the subcarinal space. No increased metabolic activity is identified. There are other scattered lymph nodes at the prevascular space and anterior mediastinum, largest of which measures approximately 1.2 cm. No increased metabolic activity is identified to indicate active disease. There is a soft tissue mass with heterogeneous attenuation and calcification measuring approximately 5 x 3.8 x 4.7 cm projecting inferior to the left lobe of the thyroid gland likely associated with substernal goiter. There is mild increased metabolic activity with a maximum SUV of 2.5 seen only on the delayed images.

ABDOMEN AND PELVIS:
There is normal mild heterogenous distribution in the liver and spleen. The gallbladder is normally visualized on CT. The pancreas and adrenal glands are unremarkable both on PET and CT. There is a small right renal cyst. The left kidney is normal. No significant adenopathy is evident on PET or CT. There is thickening of the urinary bladder wall without focal mass. There is normal GI and GU tract uptake.

MUSCULOSKELETAL: Scattered tiny osteophytes. Bilateral lower facet joint arthritis. No blastic or lytic lesion is identified. There is no increased metabolic activity to indicate skeletal metastasis.

The following criteria are included to assist the referring physician with evaluation of PET CT Response to Solid Organ Tumors if needed.

EORTC Response Criteria.
European Organization for Research and Treatment of Cancer.
CMR (Complete Metabolic Response) : Complete resolution of FDG uptake within the tumor volume.
PR (Partial Metabolic Response): A reduction of a minimum of 15-25% in tumor FDG SUV after one cycle of chemotherapy, and greater than 25% after more than one treatment cycle.
PMD (Progressive Metabolic Disease): Increase FDG tumor SUV of greater than 25% within the tumor region, or increase of extend of FDG uptake (20% in longest dimension) or appearance of new lesions.
SMD (Stable Metabolic Disease): Increase of less than 25% or a decrease of less than 15% in tumor FDG SUV and no visible increase in extent (20% in longest dimension)

RECIST
Response Evaluation Criteria in Solid Tumors
CR (complete response) = disappearance of all target lesions
PR (partial response) = 30% decrease in the sum of the longest diameter of target lesions
PD (progressive disease) = 20% increase in the sum of the longest diameter of target lesions
SD (stable disease) = small changes that do not meet above criteria

The following Deauville criteria will applied to ALL Hodgkin's Lymphoma or Aggressive non-Hodgkin's Lymphoma patients who are within the interim following a few cycles of chemotherapy (who possess a baseline PET- CT prior to therapy) ONLY:
Scoring:
1 = No Uptake
2 = Uptake is < Mediastinum
3 = Uptake is > Mediastinum but 4 = Uptake is > than Liver at any site
5 = Uptake is > Liver and new sites of disease
A score of 1-3 are considered NEGATIVE (indicating appropriate response to chemotherapy)
A score of 4 or 5 is considered POSITIVE (indicating lack of response to chemotherapy)