PET SCANS: THE WHO, WHEN AND WHY & HOW TO GET REIMBURSED

Transcription

1 PET SCANS: THE WHO, WHEN AND WHY & HOW TO GET REIMBURSED Cecelia E. Schmalbach, MD, FACS Associate Professor of Surgery Head & Neck Surgery Otolaryngology Residency Program Director

2 No Financial Disclosures

3 PET SCANS: THE WHO, WHEN AND WHY & HOW TO GET REIMBURSED Background Applications Evaluation of the Unknown Primary Tumor Staging Incidentalomas Thyroid Salivary Gland Reimbursement

4 THEORY OF POSITRON EMISSION TOMOGRAPHY (PET) IMAGING Non-invasive diagnostic imaging introduced to measure metabolic activity within the human body 1977: Sokoloff et al. [ 14 C]deoxyglucose cerebral glucose metabolic rate

5 PET Theory [ 18 fluoro] deoxyglucose ( 18 FDG) Introduced 1979 Warburg Effect (1930s): Cancer cells have aberrantly high rates of glycolysis Tumor hypoxia leads to anaerobic glycolysis

6 PET Theory Tumor cells lose efficient production of ATP by Krebs cycle 19-fold increase in glucose consumption per mole ATP FDG Increased transporter enzyme Glut-1 = rapid uptake Phosphorylated and trapped in tumor cells Fluorine prevents further metabolism 2000: PET received FDA approval for use in H&N cancer

7 FDG-PET Imaging Fast for 4-8 hours prior to scan Whole blood glucose checked Mod. elevated ( mg/dl) -> 2-4 U insulin Marked elevation (> 250mg/dl) -> reschedule mci FDG IV CT obtained prior to PET emission min delay

8 FDG-PET Imaging PET imaging in 4-5 bed positions Axial, coronal, sagittal views 5 min per position Brain through mid-thigh Standardized Uptake Value: SUV = Maximum tissue activity of FDG Injected dose of FDG/ Body Weight

9 Normal FDG Distribution 78 non-h&n cancer patients Multiple factors Age Smoking Location > 4 SUV = concern Nakamoto et al. Radiology. 2005; 234(3):879.

10 PET Limitations PET interpretation requires experience b/c non-malignant tissue can take up FDG Inflammation/Infection Asymmetry from surgery Movement (coughing; talking) H&N regions with variable FDG uptake: Nasal turbinates Pterygoid and extraocular muscles Salivary tissue (Parotid; SMG) Waldeyer ring/lympoid tissue FDG uptake reduced with elevated glucose levels Decreased sensitivity with tumors < 10mm

11 PET IN EVALUATION OF THE UNKNOWN PRIMARY (3 7% of H&N Patients)

12 PET in Evaluation of Unknown Primary 26 pts unknown primary H&N 8 pts (30.8%) detected by PET 3 Palatine tonsils 2 BOT 2 Lung (negative on CXR) 1 Hypopharynx 2/8 also detected by panendo and bx 6/8 only identified following PET Miller et al, Arch OTO/HNS. 2005; 131:626.

13 PET in Evaluation of Unknown Primary 26 pts unknown primary H&N 1 false positive (tonsil) 4 /26 (15.4%) False Negative All 8 mm 2 tonsil; 2 BOT Miller et al, Arch OTO/HNS. 2005; 131:626.

14 PET in Evaluation of Unknown Primary Sensitivity = 66% Specificity = 92.9% PPV = 88.8% NPV = 76.5% CONCLUSION: A positive PET can help guide the surgeon in directed biopsies, but a negative PET does NOT preclude the need for careful examination (panendo, bx, tonsillectomy) Miller et al, Arch OTO/HNS. 2005; 131:626.

15 1. Neck Mass SCC; adenoca; anaplastic FNA 2. Chest imaging 3. Contrast CT or MRI (skull base to thoracic inlet) 4. PET/CT *** BEFORE BIOPSY 5. HPV/EBV testing of neck mass Positive status suggests occult primary in BOT or tonsil May help customize radiation to these mucosal targets

16 Case #1: Unknown Primary 63 y.o. male Right neck mass x 2 mon. Tobacco use 20 pack/yr history Quit 3 years prior PMH: Prostate cancer s/p TURP and XRT 6 cm matted level II LN

17 Case #1 Unknown Primary PET: 2 enlarged Rt IIA LNs; Max SUV 16.6 Symmetric activity B BOT at 3.9 No abnormal mucosal uptake

18 Case #1: TxN3M0 SCC R Neck Surgical Management Panendoscopy Directed biopsies Negative B tonsillectomy Right MRND (6cm mass) Chemo/XRT Waldyer s Ring Right neck Currently NED

19 Case #2: Unknown Primary 43 y.o. male Right neck swelling x 2 mon. Non-smoker; social etoh FNA: atypical cells concerning for SCC 2.4x2.7x3.4 cm Heterogeneous Mass Right II

20 Case #2: Unknown Primary PET: no primary identified Surgical Management Panendoscopy Directed biopsies (Right BOT) B tonsillectomy Right ND Final Pathology: 0.5 cm non-keratinizing SCC Rt Tonsil P-16+

21 Case #2: T1N2aM0 SCC Rt Tonsil Adjuvant chemo/xrt Currently NED

22 PET in Evaluation of Unknown Primary PET does not replace careful PE & CT/MRI Consider PET prior to panendoscopy/bx Positive PET more meaningful than Negative PET!

23 STAGING WITH PET

24 PET in Initial Staging: N-0 NECK Brouwer et al, Eur Arch Otorhinolaryngol, 2004 Sensitivity 2/3 (67%) Civantos et al, Head and Neck, 2003 Sensitivity 3/11 (27%) Hyde et al, Oral Oncol, 2003 Sensitivity 0/4 Stoeckli et al, Head Neck, 2002 Sensitivity 2/5 (40%)

25 PET in Initial Staging: N-0 NECK KEY POINT: PET/CT does not replace standard evaluation for and treatment of regional disease Decision is based on risk of occult nodal metastasis T-stage Site PNI Depth of invasion

26 PET in Evaluating: Meta-analysis of PET/CT to detect recurrent locoregional disease Seven studies, patients Inclusion PET/CT Raw data Recurrent/Residual Disease Adequate follow-up or confirmatory pathology

27 PET in Evaluating: Recurrent/Residual Disease Sensitivity was 73% (95% CI: 56% - 85%) Specificity was 92% (95% CI: 87% - 95%)

28 PET in Evaluating: Recurrent/Residual Disease NO disease in the neck following curative nonoperative treatment Negative PET/CT fairly accurate Close observation Persistent disease in the neck disease Variable PET/CT results Less accuracy **PET-CT should not be used as the sole determinant of the need for salvage neck dissection

29 PET in In Evaluating: Recurrent/Residual Disease Key Points: 1. Sensitivity appears to be good, but not great PET/CT will not always be positive when there is recurrent/residual LR disease 2. Use PET/CT along with other measures (symptoms, PE, endoscopy, dedicated CT/MRI) to evaluate for recurrent/residual disease 3. Do NOT get PET less than 3 months after completion of treatment

30 PET in Evaluating: Distant Disease

31 PET in Evaluating: Distant Disease Gourin et al, Laryngoscope, 2009 N=64, previously treated Sensitivity 7/10 (70%); NPV 47/50 (94%) Gourin et al, Laryngoscope, 2008 N= 27, untreated Sensitivity 3/3 (100%); NPV 23/23 (100%) Teknos et al, Head & Neck, 2001 N=12, untreated Sensitivity 3/3 (100%); NPV 9/9 (100%) Many other studies, difficult to interpret don t know total number of patients with met dz

32 PET in Evaluating: Distant Disease Key Points: 1. PET-CT may improve detection of distant metastatic disease in the high risk untreated patient 2. PET-CT may be considered as part of the evaluation of patients with recurrence prior to salvage, particularly if salvage surgery carries high morbidity

33 PET-CT Accuracy by Indication 100 Accuracy (%) unknown primary distant recurrence Zanation AM et al, Laryngoscope, 2005

34 PET FOR NON-HNSCC INDICATIONS & WHAT TO DO WITH INCIDENTALOMAS

35 PET for THYROID Blodgett et al, Radiographics 2005 Diffuse, asymmetric, focal or no FDG uptake Reasons for uptake Physiologic Toxic adenoma Goiters Thyroiditis Malignancies

36 THYROID PETomas Nishimori H, et al. Can J Surg. 2011;54(2): PET Scans Focal thyroid uptake n=103 (2.2%) Cytology/histology evaluation n=30 9 (30%) malignant

37 PET for THYROID Blodgett et al, Radiographics 2005 Useful in thyroid ca f/u with increasing thyroglobulin but negative 131 I scan Pts with intense, asymmetric, focal uptake in lesion 10mm warrant evaluation and FNA

38 PET for Salivary Glands Unilateral & bilateral uptake can be caused by benign or malignant disease FDG-avid lesions: Warthin s tumor Pleomorphic adenoma Lymphoma Infections/granulomatous processes (sarcoid) Parotid malignancies may have little FDG avidity

39 PET-CT in Salivary Malignancy (N=55) Sensitivity = 74.4% Specificity = 100% PPV = 100%; NPV = 61.5% No difference in sensitivity by grade Useful if positive but not if negative High accuracy in detecting recurrence and distant disease Razfar A et al, Laryngoscope, 2010; 120(4):734.

40 PET for non-hnscc Indications

41 PET for Salivary Glands KEY POINTS: 1. Benign and malignant parotid tumors cannot be distinguished by PET alone 2. Lack of FDG uptake does NOT preclude salivary malignancy 3. Correlate with history (oncologic and surgical), clinical presentation, and examination

42 What to Do With Incidentalomas Lymphoid Tissue Uptake due to infection, inflammation, or malignancy Generally symmetric in Waldeyer s ring Malignancy can hide in symmetric uptake When searching for an unknown primary with no focal uptake on PET, perform usual directed biopsies, including bilateral tonsillectomy

43 What to Do With Incidentalomas 68 yo male with PET/CT for f/u after lymphoma treatment, referred for uptake in NP.

44 What to Do With Incidentalomas Muscle & Brown Fat uptake Easier to identify on PET-CT Can be due to talking, swallowing, coughing during uptake phase Take Home Points: 1. Communicate with radiologist/nuclear medicine physician 2. Know surgical history, anatomy. Review your scans!

45 PET for Non-HNSCC Indications

46 PET REIMBURSEMENT

47 PET Reimbursement CMS reimbursement is determined by: National Coverage Determination(NCD) Local Coverage Determination criteria (LCD) - TX FDG PET for Head and Neck Cancers ( )

48 National Coverage Determination Medicare coverage is limited to items and services that are reasonable and necessary for the diagnosis or treatment of an illness or injury (and within the scope of a Medicare benefit category). National coverage determinations (NCDs) are made through an evidence-based process, with opportunities for public participation.

49 CMS changes ~ June 11, Ending the requirement for coverage with evidence development (CED) under 1862(a)(1)(E) of the Social Security Act. B. 2. CMS has determined that three FDG PET scans are covered under 1862(a)(1)(A) when used to guide subsequent management of anti-tumor treatment strategy after completion of initial anticancer therapy. Coverage of any additional FDG PET scans (> 3) used to guide subsequent management after completion of initial anti-tumor therapy will be determined by local Medicare Administrative Contractors.

50 PET reimbursement (Nov10, 2009)

51 PET reimbursement Timing of scans--initial Only one initial scan with PI modifier per cancer indication

52 PET reimbursement Timing of scans FOLLOW-UP F/U scans for approved cancer types covered for up to 3 studies

53 PET Reimbursement: FDG PET coverage as of November 10, 2009 Melanoma: Non-covered for initial staging of regional lymph nodes All other indications for initial treatment strategy are covered. Thyroid: Covered for subsequent treatment strategy of recurrent or residual thyroid cancer (follicular cell origin) previously treated by thyroidectomy and radioiodine ablation and have a serum thyroglobulin >10ng/ml and have a negative I-131 whole body scan. All other indications for subsequent treatment strategy are CED.

54 Use of PET Scans: Are we being smart? Post Coverage Analysis: Use of PET Scans; Virnig and Durham, Research Data Assistance Center; 9/20/04;

55 Use of PET Scans: Are we being smart? Post Coverage Analysis: Use of PET Scans; Virnig and Durham, Research Data Assistance Center; 9/20/04;

56 Use of PET Scans: Are we being smart? Post Coverage Analysis: Use of PET Scans; Virnig and Durham, Research Data Assistance Center; 9/20/04;

57 Questions?