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St. Joe’s Multidisciplinary Head & Neck Cancer Program Multidisciplinary Approach to Oral Cancer Symposium Dr. Ashok Balasundaram, BDS,DDS,MDS,MS Diplomate, ABOMR Consultant Oral & Maxillofacial Radiologist Associate Professor, Radiology Department of Biomedical & Diagnostic Sciences School of Dentistry University of Detroit Mercy, Detroit, MI 48208 Email: [email protected] Ph:313-494-6677 Objectives Head, Neck & Oral Cancer Epidemiology Indications for Imaging in Oral Cancer Current best practices in Imaging Pre-treatment Post-treatment Challenges in Imaging Future Directions Head, Neck & Oral Cancer Definition: Head and neck cancer refers to a group of biologically similar cancers that arise in the oral cavity, nasal cavity, paranasal sinuses, pharynx and larynx, parotid glands Oral cancer sites – lip, buccal mucosa, gingiva, floor of mouth, tongue, alveolus, retromolar trigone Etiology of oral cancer – Smoking, alcohol, UV light (lip), Immune suppression, oncogenic viruses, oncogenes & tumor suppressor genes HNSCC - Spectrum Laryngeal & Hypopharyngeal Nasal cavity & Paranasal sinus Nasopharyngeal Oral & Oropharyngeal Salivary Gland Oral cancer statistics 3% of all cancers 6th most common cancer 45000 new cases annually 8650 mortalities (2015) 94% squamous cell carcinoma Annual incidence rate : 7.7 per 1,00,000 Increased incidence in white males - HPV Indications for Pre-treament imaging Identify disease (i) Pretreatment assessment of size, extent & pattern of spread a. Direct extension over mucosal surface, muscle & bone i.e. depth of invasion* b. Lymphatic drainage pathways c. Extension along neurovascular bundles d. Metastasis in head & neck from other sites Identify unknown primary Disease staging e.g. TNM staging Determine surgical & therapeutic options * Brian Trotta, Clinton Pease, John Rasamny, Prashant Raghavan, Sugoto Mukherjee. Oral cavity and Oropharyngeal Squamous Cell Cancer: Key Imaging Findings for Staging and Treatment Planning. Radiographics 2011; 31(2):339-354. Current best practices CT (Computed Tomography) a. Ionizing radiation b. Deep spaces & submucosal spaces c. Fast, well-tolerated & readily available d. Contrast-enhanced CT e. Less affected by swallowing & breathing artifacts MRI (Magnetic Resonance Imaging) a. Non-ionizing radiation b. T1, T2 & fat-saturation protocols used in cancer imaging c. Unenhanced/Contrast-enhanced d. Superior in detection of tumor spread into bone & marrow e. No clear advantage of CT for evaluation of nodal disease, esp. extracapsular spread Current best practices (contd.,) PET/CT (Positron Emission Tomography/Computed Tomography) a. Metabolic activity of tumor, i. SUV – Standard Uptake volume Higher sensitivity than MRI/CT c. Combined modality of choice d. Eliminates false-positive & false-negative findings e. Agent used: 18-F Fluoro – deoxyglucose f. FDG dose, timing of scan & injection, imaging time, surrounding muscular activity and technical factors associated with image acquisition g. Characterization of primary tumors, nodal disease & distant metastasis b. FDG PET/CT – Cancer Diagnosis & Management Sensitivity in the detection of recurrent/residual disease – 84 to 100% Specificity – 61 to 93% (site of occurrence) Specificity – 95% (regional/distant recurrence) Specificity – 79% (local recurrence) False negatives & False positives too soon after chemo and radiotherapy Decrease/absent radiotracer uptake on follow-up images after treatment interval in comparison with uptake on pretreatment images, is indicative of favorable response to treatment High negative predictive value of FDG-PET/CT questions necessity of neck dissection in patients with negative findings after initial chemo- and radio-therapy Cone Beam Computed Tomography (CBCT) Routinely used in clinical practice ENT Dental implantology Lower radiation dose High spatial resolution Fewer metal-induced artifacts Not suitable for soft tissue assessment Potential use in detecting bone invasion in oral cancer* * C.Linz, U.D.A.Muller-Richter, A.K.Buck et.al. Performance of cone beam computed tomography in comparison to conventional imaging techniques for the detection of bone invasion in oral cancer. Int.J.Oral Maxillofac.Surg.2015;44:815. 59 year old male / Gingival growth – left mandible Indications for Post-treatment Imaging Response to therapy Tumor control Detect tumor recurrence Deferring Planned neck dissection Differentiate tumor recurrence from radiation/chemotherapy changes * Naoko Saito, Rohini N.Nadgir, Mitsushiko Nakahira et.al. Post-treatment CT and MR Imaging in Head and Neck Cancer. What the Radiologist should know. Radiographics 2012;32:12611282. Early radiation changes Thickening of skin and muscle Reticulation of subcutaneous fat Edema and fluid in retropharyngeal space Mucosal necrosis Increased enhancement of major salivary glands Thickening, increased enhancement of pharyngeal walls * Naoko Saito, Rohini N.Nadgir, Mitsushiko Nakahira et.al. Post-treatment CT and MR Imaging in Head and Neck Cancer. What the Radiologist should know. Radiographics 2012;32:12611282 Late radiation changes Accelerated dental caries Soft tissue necrosis Osteoradionecrosis Radiation-induced vascular complications Radiation-induced lung disease Radiation-induced Brain necrosis Radiation-induced neoplasms * Naoko Saito, Rohini N.Nadgir, Mitsushiko Nakahira et.al. Post-treatment CT and MR Imaging in Head and Neck Cancer. What the Radiologist should know. Radiographics 2012;32:12611282 70-year-old male treated for oropharyngeal squamous cell carcinoma 58 y.o male post chemo / RT for recurrent laryngeal cancer. Developed radioosteochondronecrosis. Post-total laryngectomy. Myocutaneous free flap reconstruction from thigh. Contributing factors for Osteoradionecrosis • • • • • • • • • • • • • • Irradiation technique Total radiation dose Photon energy Brachytherapy Field size Fractionation Xerostomia Periodontitis Pre-radiation bone surgery Poor oral hygiene Alcohol and tobacco use Dental extractions Tumor location Proximity of primary tumor to bone Devitalized bone: hypoxic, hypovascular and hypocellular, inability to meet demand for repair. Surgical complications Fistulas, flap necrosis Tumor recurrence Identified as a slightly expansile lesion in operative bed Progressive thickening of soft tissues deep to flap CT – infiltrating slightly hyperattenuating mass with enhancement, attenuation=muscle MR – Infiltrative mass with intermediate T1weighted signal intensity, intermediate to high T2weighted signal intensity, and enhancement High signal on diffusion weighted MR – Recurrence Low ADC (Apparent Diffusion Coefficient) – recurrence? D/D : Vascularized scar, retraction Perineural spread – risk of local recurrence Post treatment surveillance Imaging US,CT,MR and FDG PET/CT Early detection Early Intervention of recurrence Early intervention of salvage treatment Differentiate altered anatomy due to surgery from tumor recurrence Timing – 4 to 6 weeks after treatment, 3-4 months – first year, 4-6 months in 2-5 years & annual afterwards CT – rapid, identify cervical lymph nodes MR – sinonasal, salivary gland, nasopharyngeal and skull base tumors with risk of perineural spread Post-treatment findings Summary Challenges in imaging Selection of imaging modality Diagnosis Evaluate prognosis & treatment Tumor recurrence Timing of post-treatment imaging Combination of modalities to increase diagnostic yield False +ve findings False –ve findings Summary Diagnostic value of Pre-treatment and Post treatment Imaging Selection of most appropriate imaging modality US,CT,MRI, FDG-PET, FDG-PET/CT CT – Identify lesion, staging, mode of therapy MRI – Identify spread into tissue planes, marrow, recurrence/treatment-related changes FDG PET/ PET-CT – Lesion progression, response to therapy Future: CBCT for bone invasion – metal artifacts (scatter)
