Oral Exam - Oncology

Question 1

Poorly FDG-avid breast cancers

Answer 1

Lobular or tubular carcinoma
○ Typically low FDG uptake 2° to low-grade tumor
○ With aggressive behavior, mays how ↑ FDG uptake

DCIS
○ Variable linear/branching areas of FDGuptake

Question 2

Primary malignant breast cancer

Answer 2

PET/CT
○ Sensitivities reported inrange of 79-90% ;specificity74- 80%
○ 5-7mm lesions routinely detected, especially if prone PET/CT used

PEM
○ Breast-specific imaging device
○ Optimized for small body parts,with higher sensitivity
than PET (1-2 mm for PEM; 4-6 mm for PET)
○ SensitivitycomparabletoMRandhigherthanPET(93%
vs. 68%)

MBI/BSGI
○ Emerging technology
○ Breast-specificimagingdevice
○ Achievegreaterresolutionbydecreasingdeadspace
between breast and imaging surface

Tc-99m MIBI
○ No longer used due to inferior results compared to PET/CT
Sensitivityof 76-90%; poor sensitivity(<50%) for smallor low-grade malignancies
– Lesion uptake dependent on increased blood flow,
mitochondrial activity and concentration in tumor

Thallium(Tl)-201
○ No longer used due to higher sensitivity with modalities
listed above
○ Poor sensitivity for lesions < 1.5 cm (40-60%)
○ Poor sensitivity for low-grade malignancy

Question 3

Ddx breast abnormality

Answer 3

Benign breast lesion
Infection/inflammation
Trauma/surgery
Lactation

Question 4

Brain mets - hypermetabolic on PET

Answer 4

Lung, breast, colorectal, head and neck, melanoma, thyroid

Question 5

Brain mets - hypometabolic on PET

Answer 5

Mucinous, adenocarcinoma, renal cell carcinoma

Question 6

Brain met ddx on PET

Answer 6

Abscess
INfarct
Primary brain tumour - benign or malignant
Epilepsy

Question 7

Radiation necrosis vs tumour progression on Brain

Answer 7

Low uptake favors radiation necrosis or low-grade tumor

Thallium-201 or Tc-99m sestamibi SPECT
○ Radiation necrosis typically shows decreased uptake
○ Recurrent glioma typically shows increased uptake

Question 8

Melanoma - most common mets

Answer 8

○ Skin, subcutaneous tissue, and lymph nodes: 50-75% 
○ Lungs: 70-87%
○ Liver: 54-77%
○ Brain: 36-54%
○ Bone: 23-49%
○ GI tract: 26-58%

Question 9

Timing of esophageal PET

Answer 9

Indicated to evaluate response to therapy
○ After neoadjuvant therapy, prior to surgery
○ Should be done 5-6 weeks after completion of therapy
• Indicated to detect recurrence
○ High sensitivity for detection of localre current tumoror
regional nodal disease

Question 10

Ddx esophageal malignancy on PET

Answer 10

Esophagitis - infectious or inflammatory
Intramural primary esophageal tumour
Metastatic or adjacent tumour

Question 11

Esophageal primaries that are FDG avid

Answer 11

Adenocarcinoma (Barret, reflux, motility disorders) and squamous cell carcinoma (smoking, alcohol) are F- 18FDG avid

□ F-18 FDG uptake in squamous cell carcinoma >
adenocarcinoma

Question 12

Esophageal node evaluation

Answer 12

– Does not allow reliable differentiation between N0 and N1 disease, due to intense uptake by primary lesion masking adjacent metastatic nodes
– Regional nodes are considered to be cervical to celiac stations
– T1-T3±N+ are resectable

Question 13

Ddx abnormal gastric FDG activity

Answer 13

Gastric Carcinoma

Gastric GIST

Physiologic - low level activity, non-focal

Gastritis/gastric ulcer - mild to moderate uptake

Gastric lymphoma - usually diffuse invovlement with adenopathy

Crohn’s - rarely affects stomach

Question 14

Metastatic spread of CRC

Answer 14

Lymphatic (mostcommon) spread follows major venous outflow from involved segment
□ Colon - pericolic nodes, then superior and inferior mesenteric nodes
□ Upper rectum drains to superior rectal nodes, then
inferior mesenteric nodes
□ Lower rectum followssamedrainagepatternas
upper rectum and also middle rectal nodes, then
internal iliac nodes

Hematogenous spread
□ Via portal system to liver (most common site for distant metastases)
□ Lung

Peritoneal spread
□ Direct peritoneal seeding→peritoneal carcinomatosis

Question 15

Salivary gland tumours and PET

Answer 15

F-18FDG PET/CT
○ Cannot reliably differentiate benign vs. malignant
salivary gland neoplasia
○ Hypermetabolic lesions on F-18FDGPET/CT have~30%
false-positive rate for malignancy (mostly due to high
uptake in Warthin tumor)

Any incidentally detected salivary gland neoplasm should
be evaluated by otolaryngology, whether cold, warm, or hot

Question 16

Ddx salivary gland lesion

Answer 16

○ Parotid carcinoma (most common site of salivary gland
cancer) - different cell types, almost always FDG avid

○ Benign mixed tumors/pleomorphicadenoma - less FDG avid than malignancy or Warthin

○ Warthin tumor - positive on FDG and Tc99 pertechnetate SG studies; smoking history; often multiple

○ Primary lymphoma

Question 17

SCC of head and neck locations

Answer 17

Nasopharynx, larynx, hypopharynx, oralcavity,

oropharynx, nasal cavity, paranasal sinuses, salivary glands, thyroid gland, and unknown primary

Question 18

SCC of head and neck - PET findings

Answer 18

○ Best diagnostic clue
– Intensely FDG-avid, enlarged or necrotic lymphnodes (LNs) in neck on F-18 FDG PET/CT

Location
– Look for primary lesion along mucosal surfaces and
evidence for nodal or distant spread
– LN metastases in expected drainage pattern based on
primary tumor location
– Commonly involves base of tongue, tonsils, or
adenoids

Question 19

SCC head and neck protocol advice

Answer 19

○ Scan with arms down on F-18FDG PET/CT to avoid beam
hardening artifact; use neck immobilization device

○ F-18 FDG PET/CT is superior to conventional imaging
modalities for radiation treatment planning, allowing for improved tumor coverage and sparing of normal tissues

Question 20

SCC lymph nodes ddx

Answer 20

Inflammatory - dual time imaging at 3-6 hours helpful. CA retains more FDG for longer than inflammatory tissues.

Thyroid or Melanoma metastases

Abscess

Lymphoma - associated mucosal lesion or necrotic nodes favours SCC met

Brown fat - Measure HU usingCT; diagnostic if HU measure -50 to -150

Question 21

Head and Neck lymph nodes

Answer 21

Level 1A = submental
Level 1B = submandibular
Level 1 drains anterior oral cavity, lip, sinonasal

Level 2A/2B
Inferior margin of hyoid, posterior margin submandib, SCM muslcles
Level 2 drains Oropharynx, posterior oral cavity, supraglottic larynx, and parotid gland

Level 3
Inferior margin of hyoid, inferior margin of cricoid

Level 4
Inferior margin of cricoid, clavicle
Drains subglottic, thyroid, and cervical esophagus

Level 5
Posterior border of SCM,clavicle; VA/VB inferior margin of cricoid
Drains nasopharynx, skin (neckor occipital scalp)

Level 6
Medial margins of carotid arteries, inferior margin of hyoid, superior aspect of manubrium
Drains subglottic, thyroid, and cervical esophagus

Level 7/superior mediastinal
Superior aspect of manubrium, innominate vein

Supraclavicular nodes
At or caudal to level of clavicle and lateral to medial edge of carotid arteries

Retropharyngeal nodes
Within 2cm of skullbase medial to carotid arteries

Parotid nodes
Primary drainage site: Skin of scalp, orbit, and
nasopharynx

Question 22

HCC PET performance

Answer 22

□ Uptake in small tumors difficult to visualize on F-18
FDG PET/CT because of physiological F-18 FDG
uptake

□ Well-differentiated HCC isointense to liver on F-18
FDG PET/CT (low GLUT1 and high G6Pase
expression); higher SUV if poorly differentiated

□ Variable uptake with intrahepatic CCA

Question 23

DDx liver lesion on PET

Answer 23

Met
Abscess
HCC
Cholangiocarcinoma
GB CA

Question 24

Hodgkin’s lymphoma - time to wait before PET

Answer 24

○ 6-8 weeks after chemotherapy or surgery
○ 8-12 weeks after radiation therapy
○ 2-4 weeks after (G-CSF)

Question 25

Interim or post-therapy PET/CT: Deauville criteria

Answer 25

– Grades the most intense uptake (SUV) in initial site of disease on interim or end-of-treatment PET/CT – 1: No uptake – 2: Uptake ≤ mediastinal bloodpool – 3: Uptake > mediastinal blood pool but ≤ liver – 4: Uptake moderately higher thanliver – 5:Uptakemarkedlyhigherthanliver&/ornewlesions – X: New areas of uptake unlikely to be related to lymphoma ○ Score of 1 and 2: Complete metabolic response (CMR) ○ Score of 3: Likely a CMR Score 4 and 5: Residual hypermetabolic disease

Question 26

Ann Arbour staging with Lugano modifiers

Answer 26

Modifiers ○ A or B: Absence ("A") or presence ("B") of B symptoms ○ E: Relevant only for limited extranodal disease in absence of nodal involvement (IE) or in patients with stage II disease and direct extension to a non-nodal site (IIE) StageI – 1nodeorgroupofadjacentnodes(1lymphnode region) (I) StageII – 2ormorenodalregionsonthesamesideofthe diaphragm (II) Stage IV – Nodal disease + noncontiguous extranodal involvement

Question 27

NHL

Answer 27

Hematogenous spread of NHL is unpredictable in comparison to contiguous spread of HL Report findings according to Deauville criteria (5-point scale) – Score 1 and 2: Complete metabolic response (CMR) – Score 3: Likely CMR – Score 4 and 5: Residual disease – Score 5 with no decrease in uptake or new FDG-avid disease: Treatment failure

Question 28

FDG avid NHL

Answer 28

Diffuse large B-cell DLBCL, Burkitt lymphoma, anaplastic large cell, natural killer/T-cell, high-grade follicular, adult T cell, peripheral T cell

Question 29

Low grade minimally FDG avid lymphoma

Answer 29

– Chronic lymphocytic leukemia/small lymphocytic (CLL), Waldenström macroglobulinemia, cutaneous T cell (mycosis fungoides), marginal zone (MZL), mantle cell, low-grade follicular

Question 30

Carcinoid syndrome

Answer 30

Flushing, diarrhea, telangiectasia, and asthma ``` Secretes serotonin, which is metabolized to 5- hydroxyindoleacetic acid (5-HIAA) ```

Question 31

Lab values to check in NET

Answer 31

Elevated serum chromogranin A (sensitivity80%) Elevated 24-hour urinary 5-HIAA High Ki-67 implies worse survival Number of mitoses/HPF

Question 32

NET imaging

Answer 32

Somatostatin receptor imaging (SRI) – Indium-111 octreoscan – High percentage of lesions > 1.5cm positive □ 4hr: Whole body anterior/posterior planar optional; consider targeted SPECT based on history and planar imaging (low bowel excretion then) □ 24hr: Whole body anterior/posterior planar; targeted SPECT, SPECT usually best at 24 hours □ 48hr:Whole body anterior/posterior planar optional; consider targeted SPECT □ Image with large FOV at symmetric 20% energy windows over 173 keV and 247 keV photopeaks of In-111

Question 33

NET other imaging options

Answer 33

FDG PET or I131 MIBG

Question 34

Treatment options for NET

Answer 34

• Surgery ○ Curative resection of smaller masses ○ Debulk tumor to ↓symptoms and improve survival * Systemic chemotherapy with alpha interferon and cytotoxic agents * Livermetastases ○ Resection,radiofrequencyablation,cryotherapy,and chemoembolization • Somatostatinanalogs ○ Symptomaticblockade,butsubjecttotachyphylaxis ○ Radiolabelled analogs to target metastases

Question 35

Pancreatic neuroendocrine tumours - octrepotide sensitivity

Answer 35

Wide variability in sensitivity by cell type: Gastrinomas typically high, insulinomas often low (50-60%)

Question 36

Pancreatic NET findings

Answer 36

○ In-111DTPA-D-Pheoctreotide(Octreoscan): Radiolabeled derivative of octreotide, binds to somatostatin receptor (subtypes 2, 5, rarely 3) ○ Determination of somatostatin-receptor status to guide octreotide therapy ○ Selection of patients with metastatic tumors for peptide receptor radionuclide therapy (PRRT)

Question 37

Other somatostatin receptor avid tumours

Answer 37

Pituitary adenoma; adrenal medullary tumors; paraganglioma; benign and malignant thyroid tissue; Merkel cell; melanoma; carcinoid; small cell lung cancer; non-pancreatic neuroendocrine carcinoma; meningioma; well-differentiated glial-derived tumor; breast, prostate, renal carcinomas; lymphoma, granuloma, infection, and inflammation

Question 38

Ddx pancreatic NET

Answer 38

Panc ductal adenocarcinoma Mucinous or serous pancreatic tumour Mets

Question 39

Pheo/paraganglioma findings

Answer 39

I-123 MIBG scintigraphy ○ Use for occult, ectopic, recurrent, metastatic tumors ○ Patient should discontinue drugs that interfere with MIBG for 48-72 hrs prior • F-18FDGPET ○ Sensitivity similar to MIBG, best for malignant pheochromocytoma/paragangliomas

Question 40

Pheo 10% rule

Answer 40

``` 10% familial 10% bilateral 10% malignant 10% in children 10% not associated with HTN ``` Malignancy diagnosed by presence of metastatic deposits, not by presence of local invasion

Question 41

Ddx pheo/paraganglioma

Answer 41

Other neuroendocrine tumours (MIBG + in carcinoma, neuroblastoma, ganglioneuroma) Adrenal adenoma/myelolipoma - uptake < liver on MIBG/FDG ACC Adrenal mets

Question 42

Pheo or paraganglioma associations

Answer 42

``` MEN IIA/IIB NF VHL TS SW ```

Question 43

Medullary thyroid CA findings

Answer 43

• Somatostatin receptor scintigraphy ○ Uptake in solid, usually well-circumscribed mass in thyroid gland; ± calcifications; nodal and distant metastases • F-18FDGPET/CT:Sensitivity70-100%,specificity79-90% • Tc-99m sestamibi or tetrofosmin scintigraphy: Sensitivity 25-40%, specificity 100% • Not iodine avid: Scanning and treatment with radioiodine not effective

Question 44

Ddx medullary thyroid CA

Answer 44

Follicular adenoma MNG Parathyroid adenoma Papillary/follicular thyroid CA

Question 45

Ovarian CA findings

Answer 45

○ FDG PET/CT – FDG-avid ovarian mass (SUV>3) – ± hypermetabolic lymphadenopathy, diffuse peritoneal involvement – ± distant metastases (usually liver/lung) or malignant pleural effusion – PET has difficulty with differentiation of benign vs. malignant w/ borderline elevated SUV – Physiologic uptake of ovary is highest in early secretory phase, best to image just after menstruation to

Question 46

Cervical CA findings

Answer 46

○ FDG PET/CT – Intense FDG activity in primary cervical mass – Variable uptake in uterus, vagina, and parametria, depending on spread – Pelvic and paraaortic FDG-avid lymphadenopathy – Distant metastases in lung, liver, bone

Question 47

Prostate mets

Answer 47

Metastases are usually axial, then follow distribution of red bone marrow ○ Vertebra and rib involvement common due to tumor cell dissemination from prostate through Batson venous plexus • Uptake on Tc-99m MDP bone scan has low specificity for metastatic disease when PSA < 10 ng/mL in patient not on antiandrogen therapy □ Recommended for symptomatic patients or asymptomatic patients at risk for occult metastases □ Patients considered at risk for occult metastases include those with PSA > 20 ng/mL or PSA > 10 with T2-T4 primary or Gleason score > 8

Question 48

Malignant pleural mesothelioma

Answer 48

F-18 FDGPET/CT ○ Directs biopsy to hypermetabolic pleuralplaques ○ Most complete staging when compared with CT ○ Hypermetabolic pleural masses &/ or pleural rind with associated pleural effusion ○ Canbeassociatedwithhypermetabolicevidenceof direct invasion or distant metastatic disease

Question 49

Malignant pleural mesothelioma ddx

Answer 49

Inflammatory - absbestos, talc, organized empyema Other neoplasms - mets, fibrous pleural tumour, lymphoma

Question 50

NSCLC ddx

Answer 50

• Granulomatous disease ○ Symmetrical mildly FDG-avid hilar & mediastinal nodes • Pneumonia ○ FDG uptake can be high, but more rapid temporal change • Mediastinal mass ○ Consider small cell lungcancer, lymphoma • Hamartoma ○ Typically low FDG activity, popcorn calcification • Pulmonary infarct ○ FDG uptake as great as with lung cancer • Carcinoid ○ MaynotbehighlyFDGavid • Small cell carcinoma ○ Requires biopsyt odifferentiate

Question 51

NSCLC cell types

Answer 51

○ Squamous cell carcinoma, large cell carcinoma, adenocarcinoma, and adenocarcinoma in situ • Best diagnostic clue ○ Irregular mass in bronchus or lung parenchyma – Squamous cell carcinomas tend to be more central in location – Adenocarcinomas tend to occur more peripherally – Large cell carcinomas tend to be peripheral

Question 52

False - PET for NSCLC

Answer 52

Tumor with low metabolic rate (low-grade adenoCA, adenocarcinoma in situ, carcinoid), tumor < 10 mm, "stunned" tumor post therapy, high serum glucose (competition)

Question 53

Associated findings NSCLC

Answer 53

Recurrent laryngeal nerve: Hoarseness Superior vena cave syndrome

Question 54

Small cell lung CA findings

Answer 54

○ Hilar mass with bulky mediastinal adenopathy ○ Often infiltrates submucosa, obstructs bronchus ○ May have small primary tumor

Question 55

Thymoma/thymic carcinoma findings

Answer 55

○ Thymoma – Low-risk thymoma: TypesA, AB, and B1 – High-risk thymomas: Types B2 and B3 ○ Thymic carcinoma * Higheruptake of F-18 FDG with thymic carcinomas in comparison to thymomas * Thymic carcinoma has more heterogeneous uptake * Thymic rebound may have increased F-18 FDGuptake

Question 56

SPN ddx

Answer 56

``` FDG positive: Malignant - Primary lung - Metastases - Lymphoma ``` Benign Infection Inflammation (sarcoid, RA, granulomatosis with polyangitis) Round atelectasis Variable to low FDG uptake Malignant - Primary lung (adencarcinoma spectrum, carcinoid) - Mets (mucinous adenocarcinoma, RCC, prostate, hepatocellular) FDG negative Inactive granulomatous disease Hamartoma AVM

Question 57

Papillary and follicular thyroid Ca findings

Answer 57

I-123 whole-body scan ○ I-123 localizes to thyroid tissue that transports and organifies iodine ○ Detects thyroid remnant, lymphadenopathy, and distant metastatic or recurrent disease ○ 159 keV gamma rays more optimal for LEAP collimators ○ Physiologic uptake in salivary glands, stomach, lactating breasts ○ Renal excretion I-131 whole-body scan ○ I-131 is gamma (364 keV) and beta (0.606 MeV) emitter ○ Higher radiation burden as compared to I-123 ○ Possible risk of thyroid stunning prior to I-131ablation due to high-energy beta ○ Imaging characteristics not as good as I-123 F-18 FDG PET/CT ○ Uptake of radioactive glucose analogue into thyroid tissuethrough GLUT1 transporter ○ Can be used to evaluate patients with tumors that are not iodine avid and have elevated thyroglobulin levels (> 10 ng/mL) Tc-99m MDP bone scan ○ For skeletal survey if bone metastases suspected

Question 58

Thyroid procotol

Answer 58

TSH stimulation □ Thyroid hormone withdrawal for 3weeks (goal TSH > 30 mU/L) □ Thyrogen stimulation: Thyrogen (human recombinant TSH) stimulation with 0.9 mg IM on 2 consecutive days – Low-iodine diet: Usually followed for 7-14 days to increase uptake of radioactive iodine by thyroid tissue

Question 59

RCC findings

Answer 59

Iso or hypermetabolic mass on FDG PET

Question 60

Transitional cell carcinoma

Answer 60

F-18 FDG PET/CT – Focal increased FDG activity in primary tumor, regional nodes, and distant metastases – Best for staging and monitoring for recurrenceq

Question 61

Ewing Sarcoma findings

Answer 61

• Destructive osseous lesion with associated soft tissue mass • Femur is single most common site (~ 20%) • > 85% in pelvis, extremities and ribs – Long bones □ Metadiaphyseal > diaphyseal □ Proximal > distal – Originate in medullary canal, spread outward ○ Extraosseous ES – Paravertebral and lower extremity most common MDP • Tc-99m MDP bone scan shows increased uptake in tumor in all phases, but is not adequate for local staging (poor sensitivity for "skip lesions") • FDG PET/CT ○ Defines primary tumor better than MDP bones can

Question 62

Ewing ddx

Answer 62

Other malignant bone primary (osteosarcoma, primary lymphoma) Osteomyelitis Benign bone tumours Fracture Bone mets (neuroblastoma, rhabdomyosarcoma)

Question 63

PRRT - things to consider

Answer 63

Treat with Lu-177 dotatate if Krenning 3-4 Kidneys are dose limiting organs - need to protect with amino acids (inhibits proximal tubular resportion) Marrow suppression Liver failure

Question 64

MIBG therapy - considerations

Answer 64

Thyroid blockade - SSKI day before, day of, and continue 10-15 days after Discontinue interfering meds Slow administration - anaphlyaxis

Question 65

Liver - intra-arterial therapy

Answer 65

Yttrium 90 microspheres (non-resectable primary and secondary lesions) Must assess lung shunt ratio with MAA - if < 10%, no reduction - if 10-15%, 20% reduction - if 15-20%, 40% reduction

Question 66

Neuroendocrine tumour types

Answer 66

Adrenal/sympathetic chain: 1. Neuroblastoma 2. Pheochromoctytoma 3. Paraganglioma Gastropancreatic neuroendocine tumours: - Carcinoid, neuroendocrine carcinoma - Pancreatic endocrine Medullary thyroid cancer Syndromes MEN I, II, VHL, NF

Question 67

Pheochromocytoma biochemical testing

Answer 67

Plasma/urine metanephrines | Plasma/urine catecholamines

Question 68

Paraganglioma types

Answer 68

Carotid body Glomus tympanicum - middle ear mass; pulsatile tinnitis Glomus jugulare - Glomus vagale Octreotide or MIBG avid Ddx always includes meningioma or neuroendocrine tumour met (as both octreotide avid) +/- pituitary adenoma

Question 69

MEN 2

Answer 69

2A: MTC, pheo, hyperparathyroidism 2B: MTC, pheo, multiple neuromas

Question 70

Gastropancreatic NETs classification

Answer 70

Grade 1 NET: < 2 mitoses/HPF, <3% ki-index Grade 2 NET: 2-20 mitosees/HPF, 3-20% Ki-index Grade 3 NET: >20, >20

Question 71

Scintimammography false postive

Answer 71

Fibroadenoma | Malignant tumours other than breast CA

Question 72

Blood work carcinoid

Answer 72

Chromogranin A levels elevated | 5-HIAA levels elevated

Question 73

Other octreotide avid tumours

Answer 73

``` Carcinoid Gastrinoma Glucagonoma Pheochromocytoma Neuroblastoma ``` MTC ``` Small cell lung cancer Lymphoma Breast cancer Astrocytoma Meningioma Pituitary adenoma Thymoma ```

Question 74

FDG prep

Answer 74

NPO 4 hrs; ideally 8-12 | Blood sugar < 10

Question 75

Laryngeal nerve injury

Answer 75

Paralysis/Decreased FDG on that side Compensatory hypermetabolism on other side Ddx: malignancy/infection/inflammation on the hypermetabolic side

Question 76

Thallium for brain spect

Answer 76

Distinguish radiation necrosis from recurrent disease Distinguish lymphoma/other malignancy from toxoplasmosis

Question 77

MIBG uptake

Answer 77

NB Pheochromoctyoma Carcinoid MTC

Question 78

Pheochromocytoma markers

Answer 78

MIBG is not screening test | Need elevated serum or urinary catecholamine levels

Question 79

Benign pelvic uptake FDG in females

Answer 79

``` CLC Dermoid cyst Diverticulitis Leoiomyoma Fibroma/thecoma Ureteric Endometriosis ```

Question 80

Gallium avid tumours

Answer 80

``` HL NHL Melanoma Sarcoma Hepatoma Lung CA ``` + sarcoid, infection

Question 81

Diffuse marrow uptake FDG

Answer 81

Benign marrow stimulatiomn Widespread marrow-based tumour Altered biodistribution

Question 82

Ddx hypermetabolic solitary nodule

Answer 82

Primary lung CA Pulmonary metastases Inflammation/Infection (TB, histo, sarcoid)

Question 83

Hypermetabolic focus pancreas

Answer 83

Panc adenocarcinoma Focal pancreatitis Metastasis

Question 84

FDG avid focus parotid gland

Answer 84

Primary salivary gland tumour | Focal parotatitis

Question 85

Ddx increased abdominal uptake on octreotide study

Answer 85

Neuroendocrine tumour Other malignancy expressing somatostatin receptors (melanoma, breast) Inflammatory conditions expressing somatostatin receptors (granulomatous disease)