Medical Policy:
06.01.061-001
Topic:
Oncologic Applications of Positron Emission Tomography Scanning (Gastrointestinal and Pancreatic)
Section:
Radiology
Effective Date:
September 22, 2024
Issued Date:
September 22, 2024
Last Revision Date:
July 2024
Annual Review:
July 2025
 
 

Description

Positron emission tomography (PET) scans are based on the use of positron-emitting radionuclide tracers coupled to organic molecules, such as glucose, ammonia, or water. The radionuclide tracers simultaneously emit 2 high-energy photons in opposite directions that can be simultaneously detected (referred to as coincidence detection) by a PET scanner, comprising multiple stationary detectors that encircle the area of interest.

The utility of PET scanning for the diagnosis, staging and restaging, and surveillance of malignancies varies by type of cancer. In general, PET scanning can distinguish benign from malignant masses in certain circumstances and improve the accuracy of staging by detecting additional disease not detected by other imaging modalities. Therefore, PET scanning for diagnosis and staging of malignancies can be considered medically necessary when specific criteria are met for specific cancers, as outlined in the policy statements. For follow-up, after initial diagnosis and staging have been performed, there are a few situations in which PET can improve detection of recurrence, and lead to changes in management that improve the net health outcome. The use of PET for interim scanning to assess early response is addressed in policy 6.01.51.

Summary of Evidence

Colorectal Cancer

For individuals who have diagnosed colorectal cancer (CRC) and in need of staging or restaging information who receive FDG-PET or FDG-PET/CT, the evidence includes several meta-analyses. Relevant outcome is test validity. A meta-analysis evaluating the diagnostic accuracy of PET or PET/CT found a high sensitivity but low specificity. Several pooled analyses evaluating staging or restaging using PET or PET/CT resulted in wide ranges of sensitivities and specificities, from 16% to 99%. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have suspected CRC or who are asymptomatic after completing CRC treatment who receive FDG-PET or FDG-PET/CT, the evidence includes a randomized controlled trial (RCT). Relevant outcome is test validity. The RCT found no differences in outcomes when FDG-PET/CT was added to usual surveillance compared to usual surveillance only. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Esophageal Cancer

For individuals who have diagnosed esophageal cancer and in need of staging or restaging information who receive FDG-PET or FDG-PET/CT, the evidence includes several meta-analyses. Relevant outcome is test validity. Pooled estimates have shown high sensitivities and specificities compared to other diagnostic imaging techniques. Clinical guidelines include PET and CT to inform management decisions that may offer clinical benefit. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have suspected esophageal cancer or who are asymptomatic after completing esophageal cancer treatment who receive FDG-PET or FDG-PET/CT, the evidence includes meta-analyses. Relevant outcome is test validity. Pooled analyses have shown adequate sensitivities but low specificities. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Gastric Cancer

For individuals who have suspected or diagnosed gastric cancer and in need of staging or restaging information who receive FDG-PET or FDG-PET/CT, the evidence includes several meta-analyses. Relevant outcome is test validity. Pooled analyses, with sensitivities and specificities ranging from 78% to 88%, have shown that PET or PET/CT can inform staging or restaging of individuals with gastric cancer. Clinical guidelines include PET/CT to inform management decisions that may offer clinical benefit. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are asymptomatic after completing gastric cancer treatment who receive FDG-PET or FDG-PET/CT, the evidence includes meta-analyses. Relevant outcome is test validity. Pooled analyses have shown low sensitivities and specificities. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

Pancreatic Cancer

For individuals who have suspected or diagnosed pancreatic cancer and with inconclusive results from other imaging techniques who receive adjunctive FDG-PET or FDG-PET/CT for staging or restaging, the evidence includes a TEC Assessment, systematic reviews, and a large observational study. Relevant outcome is test validity. The evidence has shown that PET and PET/CT do not have a high enough negative predictive value to surpass current standard decision thresholds. The large observational study, which assessed the incremental diagnostic value of PET/CT when added to standard workup with CT, showed significant improvements in sensitivity and specificity compared with CT alone. Clinical guidelines state that PET or PET/CT should only be considered if the results from standard staging methods are inconclusive. The evidence is sufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who have suspected or diagnosed pancreatic cancer and in need of staging or restaging information who receive FDG-PET or FDG-PET/CT, the evidence includes an AHRQ systematic review, a TEC Assessment, and a meta-analysis published after the review and assessment. Relevant outcome is test validity. The evidence has shown that PET and PET/CT do not have a high enough negative predictive value to surpass current standard decision thresholds. Therefore, PET or PET/CT should only be considered if the results from standard staging methods are inconclusive. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

For individuals who are asymptomatic after completing pancreatic cancer treatment who receive FDG-PET or FDG-PET/CT, there is no evidence. Relevant outcome is test validity. The evidence is insufficient to determine that the technology results in an improvement in the net health outcome.

This policy is designed to address medical guidelines that are appropriate for the majority of individuals with a particular disease, illness, or condition. Each person's unique clinical circumstances may warrant individual consideration, based on review of applicable medical records.

Policy Position Coverage is subject to the specific terms of the member's benefit plan.

All policy statements apply to both positron emission tomography (PET) scans and PET plus computed tomography (CT) scans (ie, PET scans with or without PET/CT fusion).

For the clinical situations indicated that may be considered medically necessary, this assumes that the results of the PET scan will influence treatment decisions. If the results will not influence treatment decisions, these situations would be considered not medically necessary.

Colorectal Cancer

PET scanning may be considered medically necessary as a technique for

  • Staging or restaging to detect and assess resectability of hepatic or extrahepatic metastases of colorectal cancer, and

  • To evaluate a rising and persistently elevated carcinoembryonic antigen levels when standard imaging, including CT scan, is negative.

PET scanning is considered investigational as:

  • A technique to assess the presence of scarring versus local bowel recurrence in individuals with previously resected colorectal cancer.

  • A technique contributing to radiotherapy treatment planning.

Esophageal Cancer

PET scanning may be considered medically necessary in the

  • Staging of esophageal cancer, and

  • Determining response to preoperative induction therapy.

PET scanning is considered investigational in other aspects of the evaluation of esophageal cancer, including but not limited to the following applications:

  • Detection of primary esophageal cancer.

Gastric Cancer

PET scanning may be considered medically necessary in the:

  • Initial diagnosis and staging of gastric cancer, and

  • Evaluation for recurrent gastric cancer after surgical resection, when other imaging modalities are inconclusive.

Pancreatic Cancer

PET scanning may be considered medically necessary in the initial diagnosis and staging of pancreatic cancer when other imaging and biopsy are inconclusive.

PET scanning is considered investigational as a technique to evaluate other aspects of pancreatic cancer.

A PET scan involves 3 separate activities: (1) manufacture of the radiopharmaceutical, which may be on site or at a regional center with delivery to the institution performing PET; (2) actual performance of the PET scanner; and (3) interpretation of the results. There are Current Procedural Terminology (CPT) and Healthcare Common Procedure Coding System (HCPCS) codes available to code for PET scans.

When the radiopharmaceutical is provided by an outside distribution center, there may be an additional separate charge, or this charge may be passed through and included in the hospital bill. In addition, an extra transportation charge will be likely for radiopharmaceuticals that are not manufactured on site.

The Centers for Medicare & Medicaid Services added 2 new modifiers in 2009 to facilitate the changes in the Medicare national coverage policy for PET. The modifiers are:

PI - Positron emission tomography (PET) or PET/computed tomography (CT) to inform the initial treatment strategy of tumors that are biopsy proven or strongly suspected of being cancerous based on other diagnostic testing, 1 per cancer diagnosis.

PS - Positron emission tomography (PET) or PET/computed tomography (CT) to inform the subsequent treatment strategy of cancerous tumors when the beneficiary's treating physician determines that the PET study is needed to inform subsequent anti-tumor strategy.

 

CPT

78811-78816

Positron emission tomography (PET) imaging; with/without CT; specific to body area

 

78608-78609

Brain imaging, positron emission tomography (PET); by evaluation method

ICD-10-PCS

 

ICD-10-PCS is for use only on inpatient services. There are a few specific PET ICD-10-PCS codes such as the following:

 

CB32KZZ, CB32YZZ

Nuclear medicine, respiratory system, positron emission tomographic (PET) imaging, lungs and bronchi, code by radionuclide

 

CB3YYZZ

Nuclear medicine, respiratory system, positron emission tomographic (PET) imaging, respiratory system



HCPCS G0235 PET imaging, any site not otherwise specified
  A9552 Fluorodeoxyglucose F-18 FDG, diagnostic, per study dose, up to 45 millicuries
  A9597 Positron emission tomography radiopharmaceutical, diagnostic, for tumor identification, not otherwise classified
  A9598 Positron emission tomography radiopharmaceutical, diagnostic, for non-tumor identification, not otherwise classified



ICD-10-CM C15.3-C15.9 Malignant neoplasm of esophagus code range
  C16.0-C16.9 Malignant neoplasm of stomach code range
  C18.0-C18.9 Malignant neoplasm of colon code range
  C19 Malignant neoplasm of rectosigmoid junction (includes colon with rectum)
  C25.0-C25.9 Malignant neoplasm of pancreas code range
  C49.A0-C49.A9 GI Stromal tumor code range


Reference to Our Policy Information Guidelines

Patient Selection

As with any imaging technique, the medical necessity of positron emission tomography (PET) scanning depends in part on what imaging techniques are used before or after the PET scanning. Due to its expense, PET scanning is typically considered after other techniques, such as computed tomography (CT), magnetic resonance imaging (MRI), or ultrasonography, provide inconclusive or discordant results. If so, the medical necessity of subsequent imaging during the same diagnostic evaluation is unclear. Thus, PET should be considered for the medically necessary indications above only when standard imaging (eg, CT, MRI) is inconclusive or not indicated.

Patient selection criteria for PET scanning may also be complex. For example, it may be difficult to determine whether a PET scan in a patient with colorectal cancer is being performed to detect hepatic disease or evaluate local recurrence. Due to the complicated hierarchy of imaging options in individuals with malignancy and complex patient selection criteria, a possible implementation strategy for this policy is its use for retrospective review, possibly focusing on cases with multiple imaging tests, including PET scans.

Use of PET scanning for surveillance as described in the policy statement and policy rationale refers to the use of PET to detect disease in asymptomatic individuals at various intervals. This is not the same as the use of PET for detecting recurrent disease in symptomatic individuals; these applications of PET are considered within tumor-specific categories in the policy statements.


Place of Service: Inpatient/Outpatient


The policy position applies to all commercial lines of business




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