Author: Rodrigo Arrangoiz MS, MD, FACS, FSSO

• Mechanism of Action:
  • Target:
    • Cetuximab is a chimeric monoclonal IgG1 antibody directed against the epidermal growth factor receptor (EGFR / ErbB1)
  • Binding: 
    • It binds with higher affinity than natural ligands (EGF, TGF-α):
      • Blocking ligand-induced EGFR activation
  • Downstream effects:
    • Inhibition of EGFR autophosphorylation → suppression of downstream pathways (RAS / RAF / MEK / ERK and PI3K / AKT) → reduced proliferation and survival
    • Induces cell cycle arrest and apoptosis.
    • Inhibits angiogenesis:
      • Via VEGF downregulation
    • Enhances radiosensitivity and chemosensitivity
    • Triggers antibody-dependent cellular cytotoxicity (ADCC):
      • Due to IgG1 Fc interaction with NK cells
• Indications in Head & Neck Oncology:
  • Locally Advanced Head & Neck Squamous Cell Carcinoma (HNSCC):
    • In combination with definitive radiotherapy in patients not suitable for high-dose cisplatin
    • Based on the Bonner trial (NEJM 2006):
      • Cetuximab + RT improved locoregional control and OS compared with RT alone
  • Recurrent or Metastatic HNSCC:
    • First-line (EXTREME regimen): 
      • Cetuximab + platinum (cisplatin / carboplatin) + 5-FU:
        • Demonstrated OS benefit (Vermorken et al., NEJM 2008)
    • As monotherapy or maintenance:
      • In platinum-refractory or palliative setting
  • Special Situations:
    • Considered for cisplatin-ineligible patients
    • Investigated in combination with immunotherapy (e.g., PD-1 inhibitors), though data are evolving
• Adverse Effects:
  • Dermatologic (most common):
    • Acneiform rash (papulopustular eruption) in ~ 80%:
      • Correlates with better response
    • Xerosis, pruritus, paronychia
  • Infusion-related reactions:
    • Fever, chills, bronchospasm, hypotension
    • Severe (anaphylaxis-like) reactions more common in the Southeastern US:
      • Linked to preexisting IgE antibodies against galactose-α-1,3-galactose from tick bites
  • Electrolyte disturbances:
    • Hypomagnesemia:
      • Due to renal Mg wasting
    • Hypokalemia
    • Hypocalcemia
  • Other:
    • Diarrhea, mucositis, fatigue
  • Rare:
    • Interstitial lung disease, cardiotoxicity
• Management of Adverse Effects:
  • Skin toxicities:
    • Prophylaxis:
      • Sunscreen, moisturizers, topical steroids, oral tetracyclines (doxycycline / minocycline)
    • Management:
      • Topical antibiotics (clindamycin), systemic tetracyclines; dose modification for grade ≥ 3 rash
  • Infusion reactions:
    • Premedication:
      • H1 antihistamines ± corticosteroids
    • Severe reactions:
      • Immediate discontinuation, epinephrine, airway support
  • Electrolyte disturbances:
    • Routine monitoring of Mg, K, Ca during therapy and up to 8 weeks post-treatment
    • Oral / IV replacement as needed
• References:
  • Bonner JA et al. Radiotherapy plus cetuximab for squamous-cell carcinoma of the head and neck. NEJM. 2006;354:567–78.
  • Vermorken JB et al. Platinum-based chemotherapy plus cetuximab in head and neck cancer. NEJM. 2008;359:1116–27.
  • NCCN Guidelines: Head and Neck Cancers. Version 2025.
    Cohen EEW et al. Cetuximab in HNSCC: updated evidence. JCO.

• Ductal carcinoma in situ (DCIS):
  • Is a noninvasive carcinoma of the breast
  • It is defined as the proliferation of malignant epithelial cells:
    • Confined to the mammary ducts and without evidence of invasion through the basement membrane
  • Because it is noninvasive:
    • DCIS does not pose a risk of metastasis
• Lobular carcinoma in situ (LCIS):
  • Was previously considered a form of noninvasive carcinoma:
    • But is now understood to be a benign entity that is a pathologic marker of increased breast cancer risk:
      • In either breast
  • Atypical lobular hyperplasia (ALH) and LCIS:
    • Are both forms of lobular neoplasia and, together with atypical ductal hyperplasia (ADH):
      • Represent proliferative nonmalignant breast lesions

• Mechanisms of Action:
  • 5-Fluorouracil (5-FU):
    • Converted intracellularly to:
      • Fluorodeoxyuridine monophosphate (FdUMP), which forms a ternary complex with thymidylate synthase (TS) and reduced folate:
        • Blocks deoxythymidine monophosphate (dTMP) synthesis, leading to “thymineless death”
    • Other metabolites (fluorouridine triphosphate, FUTP; fluorodeoxyuridine triphosphate, FdUTP):
      • Misincorporate into RNA and DNA, contributing to cytotoxicity
    • Leucovorin:
      • Enhances TS inhibition
  • Methotrexate (MTX):
    • Antifolate:
      • That inhibits dihydrofolate reductase (DHFR)
    • Intracellular polyglutamation increases potency and extends inhibition to other folate-dependent enzymes:
      • Impairing purine and pyrimidine synthesis:
        • Leading to cell death
• Indications in Head and Neck Squamous Cell Carcinoma (HNSCC):
  • 5-Fluorouracil (5-FU):
    • Induction therapy:
      • Used in docetaxel + cisplatin + 5-FU (TPF) regimen:
        • Which improved progression-free survival (PFS) and overall survival (OS) vs. cisplatin + 5-FU (PF) in TAX 323 / 324
    • Concurrent chemoradiation (CRT):
      • Carboplatin + 5-FU with radiation therapy (RT):
        • Is an option for cisplatin-ineligible patients
    • Recurrent / Metastatic (R/M):
      • Backbone of the EXTREME regimen (platinum + 5-FU + cetuximab):
      • Which improved OS compared to platinum + 5-FU alone
  • Methotrexate (MTX):
    • Single-agent palliative therapy:
      • Historically a standard for recurrent / metastatic HNSCC:
      • Often given weekly intravenous (IV) 40 mg/m², with activity and tolerability in frail or heavily pretreated patients
    • Combination therapy:
      • Sometimes paired with cetuximab in cisplatin-unfit patients
• Adverse Effects and Management:
  • 5-Fluorouracil (5-FU):
    • Mucositis, diarrhea, myelosuppression, hand-foot syndrome (HFS):
      • Supportive care; oral cryotherapy may reduce mucositis (bolus 5-FU)
    • Cardiotoxicity (vasospasm, ischemia):
      • Discontinue 5-FU
      • Treat as vasospastic angina with nitrates and / or calcium channel blockers
    • Neurotoxicity (cerebellar syndrome, hyperammonemic encephalopathy):
      • Stop 5-FU
      • Hydrate, correct metabolic derangements
    • Dihydropyrimidine dehydrogenase (DPD) deficiency:
      • Screen with DPYD testing where available:
        • Poor metabolizers should avoid fluoropyrimidines
      • Antidote:
        • Uridine triacetate (Vistogard) within 96 hours of overdose or early severe toxicity
  • Methotrexate (MTX):
    • Mucositis, myelosuppression, hepatotoxicity:
      • Monitor complete blood count (CBC) and liver function tests (LFTs); hold dose for grade ≥3 toxicity.
      • Folinic acid (leucovorin) rescue may be used for high-dose or severe toxicity
    • Renal elimination:
      • Requires dose adjustment in renal impairment
      • Avoid interactions with trimethoprim-sulfamethoxazole (TMP-SMX), nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), and some penicillins, which increase MTX toxicity
• Key References:
  • Vermorken JB et al., NEJM 2007; Posner MR et al., NEJM 2007; Lorch JH et al., Lancet Oncol 2011 – TPF vs PF in induction therapy.
  • Vermorken JB et al., NEJM 2008 – EXTREME regimen in R/M HNSCC.
  • NCCN Guidelines: Head and Neck Cancers, 2025 Insights.
  • Amstutz U, Froehlich TK, Largiadèr CR. Clin Pharmacol Ther 2011 – DPD deficiency and 5-FU toxicity.
  • US FDA Label: Uridine triacetate (Vistogard).
    Specenier P, Vermorken JB. Oral Oncol 2009 – Methotrexate in head and neck cancer.

• Mechanism of Action:
  • Paclitaxel and docetaxel:
    • Are microtubule-stabilizing agents:
      • They bind to the β-subunit of tubulin:
        • Promoting microtubule assembly while inhibiting depolymerization
      • This leads to stabilization of the mitotic spindle:
        • Blocking cell cycle progression in the G2 /M phase, ultimately triggering apoptosis
    • Additional effects:
      • Anti-angiogenic activity at low doses
      • Modulation of apoptotic pathways:
        • Bcl-2 phosphorylation
      • Potential immune-modulatory effects
• Indications in Head and Neck Squamous Cell Carcinoma (HNSCC):
  • Locally Advanced / Induction Therapy
    TPF regimen (Docetaxel + Cisplatin + 5-FU) has demonstrated improved survival and locoregional control compared with PF (cisplatin + 5-FU)
    • TAX 323 and TAX 324 trials showed significant OS and PFS benefit with TPF in unresectable or locally advanced disease
• Concurrent Chemoradiation:
  • Weekly paclitaxel or docetaxel (often combined with carboplatin) is used as an alternative for patients ineligible for cisplatin
  • Demonstrated radiosensitizing effects.
• Recurrent / Metastatic HNSCC:
  • Single-agent docetaxel or paclitaxel provides palliative benefit with response rates ~ 20% to 30%
  • Often used as part of combination chemotherapy (e.g., taxane + platinum + cetuximab)
• Adverse Effects:
  • Hematologic:
    • Neutropenia (dose-limiting, especially with docetaxel)
    • Febrile neutropenia
  • Neurologic:
    • Peripheral neuropathy (sensory > motor), cumulative and dose-dependent
    • Hypersensitivity Reactions:
      • Due to the lipid solvent:
        • Cremophor EL in paclitaxel
        • Polysorbate 80 in docetaxel
      • Flushing, rash, bronchospasm, anaphylaxis
    • Other:
      • Mucositis
      • Stomatitis
      • Alopecia
      • Fluid retention:
        • More with docetaxel
      • Onycholysis
      • Skin / nail changes
      • Fatigue
      • Myalgia / arthralgia
• Management of Adverse Events:
  • Premedication:
    • Paclitaxel:
      • Corticosteroids + H1/H2 antagonists (e.g., dexamethasone, diphenhydramine, ranitidine)
    • Docetaxel:
      • Dexamethasone to reduce hypersensitivity and fluid retention
  • Neutropenia:
    • Dose reduction, prophylactic G-CSF for high-risk regimens (especially TPF)
  • Neuropathy:
    • Dose modification or discontinuation
    • Supportive care:
      • Duloxetine may help with painful neuropathy
  • Mucositis:
    • Oral hygiene, saline rinses, cryotherapy, topical analgesics
  • Fluid Retention (docetaxel):
    • Steroid premedication, diuretics if symptomatic
• Key References:
  • Vermorken JB, Remenar E, van Herpen C, et al. Cisplatin, fluorouracil, and docetaxel in unresectable head and neck cancer. N Engl J Med. 2007;357(17):1695–704. 【TAX 323】
  • Posner MR, Hershock DM, Blajman CR, et al. Cisplatin and fluorouracil alone or with docetaxel in head and neck cancer. N Engl J Med. 2007;357(17):1705–15. 【TAX 324】
  • NCCN Clinical Practice Guidelines in Oncology: Head and Neck Cancers. Version 2.2025.
  • Hitt R, et al. Phase III study comparing TPF with PF in locally advanced head and neck cancer. J Clin Oncol. 2005;23(34):8636–45.
  • Colevas AD, et al. Chemotherapy options for patients with cisplatin-ineligible head and neck cancer. J Clin Oncol. 2018;36(19):1942–50.

• What each test is built to do:
  • Afirma GSC (± Xpression Atlas): 
    • RNA whole-transcriptome classifier optimized as a rule-out test:
      • XA adds variants / fusions if GSC is Suspicious PMCVeracyte
  • ThyroSeq v3 GC: 
    • DNA / RNA next-gen panel across many genes (mutations, fusions, copy-number alterations, helpful in oncocytic cell lesions / Hürthle cell lesions) designed for rule-out + rule-in and therapy-relevant profiling JAMA NetworkThyroSeq
  • ThyGeNEXT + ThyraMIR v2 (Interpace): 
    • Two-step oncogene panel → reflex miRNA classifier; aims for balanced rule-out with stronger rule-in when driver / miRNA high-risk pattern is present PMCThygenext Thyramir
• Performance (typical ranges in Bethesda III–IV):
  • Afirma GSC: 
    • High sensitivity / NPV in VS and real-world cohorts:
      • PPV modest to moderate
    • Many studies report:
      • NPV ~ 94% to 97%
      • PPV ~ 45% to 65%
    • Real-world series show improved yield vs validation PMCScienceDirect
  • ThyroSeq v3: 
    • Validation and multi-center series show high sensitivity / NPV with higher PPV than Afirma in several cohorts:
      • PPV ~ 60% to 65%
    • Institutional data show sensitivity ~ 92% to 95% (Bethesda III to IV) JAMA NetworkACS Publications
  • ThyGeNEXT/ThyraMIR v2: 
    • Reported NPV ~ 93% to 96%
    • Useful PPV when drivers / miRNA risk present
    • 2025 systematic review suggests high surgical avoidance rates among platforms PMCResearchGate
• Prognostic/management information (actionability):
  • Afirma GSC + XA: 
    • If Suspicious, XA reports fusions / variants (e.g., RET, NTRK, ALK):
      • Which can guide targeted therapy decisions down the line
    • GSC itself primarily aids avoiding surgery Veracyte
  • ThyroSeq v3: 
    • Reports BRAF, RAS, TERT-p, RET / NTRK/ ALK, gene expression and copy-number profiles:
      • Useful for risk stratification (e.g., TERT / BRAF V600E for aggressiveness) and for operative planning (extent, LN assessment) and potential targeted options
      • Particularly helpful in Hürthle-predominant nodules JAMA NetworkThyroSeq
  • ThyGeNEXT/ThyraMIR v2: 
    • Calls out high-risk drivers (BRAF V600E, TERT, ALK, etc.) and refines intermediate results with miRNA pairs:
      • Useful for deciding between surveillance vs diagnostic lobectomy when imaging / clinical risk is equivocal PMCInterpace Biosciences®, Inc.
• Independent comparisons and guidelines:
  • Contemporary reviews / meta-analyses: 
    • Afirma GSC and ThyroSeq v3 both excel as rule-out tests (high sensitivity / NPV), with ThyroSeq often showing higher PPV (rule-in)
    • Interpace’s combined platform performs comparably on NPV with strong rule-in behavior in some studies ScienceDirect+1PMC
• Societal guidance (ETA 2023):
  • Molecular tests can reduce diagnostic surgery and should be selected to match pretest risk and clinical goals rather than “one best test for all.” PMC
• Bottom line (how to choose today):
  • If your primary goal is to avoid surgery (rule-out) in Bethesda III to IV with low–intermediate pretest risk:
    • Afirma GSC or ThyroSeq v3 are both appropriate:
      • Real-world data support high NPV for both PMCJAMA Network
  • If you want both strong rule-out and richer “what kind of cancer is this if positive?” detail to guide extent of surgery and future therapy:
    • ThyroSeq v3 generally provides more granular prognostic / actionable data (TERT/driver profile, CNA burden, Hürthle copy-number signature) and often a higher PPV than Afirma
    • This makes it my usual pick when operative planning may hinge on genotype JAMA NetworkThyroSeq
  • If you favor a stepwise, cost-conscious approach with meaningful rule-in capability when drivers /miRNA are high-risk:
    • ThyGeNEXT + ThyraMIR v2 is reasonable:
      • Pooled data show competitive NPV and good surgical-avoidance rates PMCResearchGate
• Practical take for your clinic:
  • For Bethesda III to IV nodules with indeterminate US where you want to minimize unnecessary operations and inform extent if positive: 
    • ThyroSeq v3 is the most versatile single test today
  • For surgeon’s “rule-out first” workflows with straightforward nodules and low pretest risk: 
    • Afirma GSC is perfectly acceptable:
      • Add XA if suspicious and you want therapy targets.
  • For equivocal cases where a rule-in signal would materially change from surveillance to surgery, or when prior testing is ambiguous: 
    • ThyGeNEXT + ThyraMIR v2 is a solid option

Interpretation & Take-Home

• Best Rule-Out (Highest NPV and Sensitivity):
  • Afirma GSC (real-world meta-analysis: SN ~97%, NPV ~99%) and ThyroSeq v3 (UCLA trial: SN 97%, NPV 99%) are essentially neck-and-neck in ruling out malignancy. Both demonstrate excellent reliability in avoiding unnecessary surgeries.
• Better Rule-In (Higher PPV):
  • ThyroSeq v3 edges ahead slightly with PPV ~64% versus Afirma’s ~57% in comparable settings, meaning a positive result is more likely to indicate true malignancy.
• Manufacturer-Reported MPTX (ThyGeNEXT + ThyraMIR):
  • Claims very strong performance (SN ~ 95%, SP ~ 90%, NPV ~ 97%, PPV ~ 75%):
    • But these results may reflect idealized cohorts with prevalence adjustments
    • Real-world studies show more conservative metrics:
      • SN ~ 76%, SP ~ 75%, NPV ~ 83%, PPV ~ 67%).
• In Summary:
  • For maximum confidence in rule-out:
    • Afirma GSC and ThyroSeq v3 are clearly superior
  • If positive actionable findings (e.g., higher PPV, molecular prognostic detail) are crucial:
    • ThyroSeq v3 offers an advantage
  • MPTX is promising, especially if you value a modular approach, but real-world validation remains less robust than for the other two

• ThyroSeq® test results refine cancer probability in thyroid nodules with indeterminate cytology, informing the most appropriate management of these patients

• Negative Results:
  • According to NCCN guidelines, if molecular testing, in conjunction with clinical and ultrasound features, predicts a risk of cancer comparable to the risk of malignancy seen in a benign FNA cytology (roughly 5% or less):
    • Active surveillance can be considered
  • Therefore, in those clinical situations where the pretest probability of cancer in nodules with Bethesda III and IV cytology is less than 44%:
    • A negative ThyroSeq test results would confer the cancer probability of 5% or less:
      • Justifying observation in lieu of surgical management in appropriately selected cases
    • Because the probability of cancer in such nodules is comparable to benign FNA cytology, the management of patients may follow the recommendations for nodules with benign cytology:
      • Which, based on the 2015 ATA guidelines, should be determined based on ultrasound (US) pattern (Recommendation #23)
  • In nodules with Bethesda V cytology and negative ThyroSeq result:
    • The residual cancer risk of ~20% does not allow to avoid surgical management:
      • Thyroid lobectomy may be sufficient initial treatment for many of these patients
• Currently Negative Results:
  • Test results are reported as currently negative:
    • When the sample is found positive for a low risk and / or low-level gene mutation, DNA copy number alterations (CNA) or gene expression alterations (GEA) that alone is not sufficient for full cancer development
  • Although at the time of sampling most of these nodules are benign:
    • Some of them may undergo clonal expansion and acquire additional mutations
  • In the absence of suspicious US features or other clinical risk factors:
    • Many of these patients are likely to benefit from active surveillance with repeat of clinical exam and potentially FNA and molecular testing in 1 year
• Positive RAS-Like or GEA Results:
  • ThyroSeq test positive for an isolated RAS mutation or RAS-like alteration (e.g. BRAF K601E mutation, THADA fusion, RAS-like GEA):
    • Indicates that the nodule is a tumor (not hyperplasia) and predicts, depending on the specific alteration:
      • A 30% to 80% probability of either a low-risk cancer or a pre-cancerous tumor, NIFTP
  • Many of these nodules may be managed by therapeutic lobectomy:
    • Which is currently recommended by the ATA guidelines for low-risk papillary and follicular carcinomas (Recommendation #35) and NIFTP
• Positive BRAF-Like of GEA Results:
  • ThyroSeq test positive for an isolated BRAF V600E or BRAF V600E-like alteration (e.g. RET / PTC, BRAF fusions, BRAF V600E-like GEA):
    • Confers a very high (greater than 95%) probability of cancer
  • According to the ATA guidelines:
    • BRAF-mutated unifocal intrathyroidal carcinoma less than 1 cm in size has low risk for recurrence:
      • Therefore may be treated with thyroid lobectomy alone
    • Whereas 1 cm to 4 cm BRAF-positive PTC is an intermediate-risk tumor:
      • Where total thyroidectomy or lobectomy should be considered based on clinical and US findings
• Postive Oncocytic Cell Type (formely Hurthle Cell Type) CNA Results:
  • ThyroSeq test positive for isolated oncocytic cell type / Hürthle cell-type copy number alterations (CNA) confers, in different nodule size groups:
    • A 40% to 80% probability of Hürthle Cell carcinoma:
      • Whereas the rest of these nodules are benign Hurthle Cell adenomas
• Positive High Risk Mutations Results:
  • ThyroSeq test positive for multiple high-risk mutations (e.g. BRAF V600E and TERT) confers a very high probability of cancer and predicts an increased risk of disease recurrence by the ATA guidelines and of tumor-related mortality
  • Most of these patients would likely benefit from total thyroidectomy, with possible consideration for regional lymph node dissection if one of the mutations is BRAFV600E

• A unique feature of ThyroSeq as compared to other molecular tests for thyroid FNA samples is that, in addition to the diagnostic utility:
  • It provides information that helps to prognosticate cancer pre-operatively
• Based on the current thyroid cancer management guidelines from the ATA, cancer risk stratification is important in:
  • Determining the appropriate extent of surgery (lobectomy vs total thyroidectomy ), radioactive iodine (RAI) administration, and intensity of follow-up
• Most thyroid cancers are indolent and these patients are at low risk for disease recurrence after cancer removal:
  • These patients can be treated by lobectomy and are unlikely to benefit from RAI ablation and TSH suppression
• Similarly, surgical excision of a pre-cancer tumor:
  • NIFTP, by lobectomy is likely to be curative since the risk of tumor recurrence is less than 1%
• On the other hand, patients with high-risk cancers would benefit from up-front total thyroidectomy:
  • Which facilitates post-operative RAI administration and disease monitoring 
• ThyroSeq is the only molecular test that provides cancer risk assessment pre-operatively based on the analysis of multiple mutational markers associated with cancer prognosis

• Specifically, finding of single RAS mutations or RAS-like mutations without other higher-risk mutations tested by ThyroSeq is associated with:
  • A low risk for recurrence
• Whereas identification of isolated BRAF V600E and other BRAF V600E-like mutations is associated with:
  • An intermediate risk for disease recurrence (Yip et al. Ann Surg, 2015)
• Identification of TERT promoter mutations, and specifically the co-occurrence of TERT with other, early driver mutations or finding of multiple cancer driver mutations is associated with:
  • A high risk for cancer recurrence (Nikiforov YE. Endocrine Practice, 2017)
• Importantly, cancer prognostication requires the analysis of all genes associated with thyroid cancer behavior which are included in the ThyroSeq panel
  • For example, the finding of RAS mutation by a small panel of genes carries no prognostic information, because while an isolated RAS mutation confers a low risk of disease reoccurence:
    • The coexistence of RAS with TERT or TP53 gene mutations is a molecular signature of a high-risk cancer (Nikiforova et al. 2016)
• In addition, the ThyroSeq test is able to diagnose a high-risk cancer in nodules which may be very small and have no particularly worrisome ultrasonographic features:
  • As an illustration, a tumor as small as 0.6 cm may already have a molecular signature of aggressive thyroid cancer developed (Shrestha RT et al. Thyroid. 2015)

• Background:
  • Parathyroid gland identification during thyroidectomy or parathyroidectomy is critical to avoid inadvertent removal or devascularization:
    • Which may lead to hypocalcemia
• In 2011, Paras et al:
  • First described the use of near-infrared (NIR) autofluorescence for parathyroid detection
  • Parathyroid glands naturally emit autofluorescence:
    • When excited by NIR light (785 to 820 nm):
      • Which distinguishes them from surrounding tissues
• Mechanism:
  • Parathyroid tissue emits intrinsic autofluorescence in the NIR spectrum:
    • Peaking at around 820 to 830 nm
  • The specific fluorophore responsible is still under investigation:
    • But mitochondrial content and calcium-sensing receptors have been implicated
• Key Milestones in the Literature:
  • 2011:
    • First Description:
      • Paras et al., J Biomed Optics: Described intrinsic autofluorescence of parathyroid glands using NIR light in animal models and humans
      • Sensitivity and specificity for parathyroid detection were promising:
        • Initially ~ 80% to 90%
  • 2015 to 2018:
    • Early Clinical Studies:
      • McWade et al., Surgery (2016):
        • Showed high sensitivity (97%) and specificity (95%) in parathyroid identification using NIR autofluorescence
        • Autofluorescence was effective without contrast agents
        • Faster identification of parathyroids during thyroidectomy
  • 2018 to 2021:
    • Commercial Devices & Validation
      Fluobeam®, PTeye®, and EleVision IR became available
    • Systematic reviews and meta-analyses (e.g., Demarchi et al., 2019, Ann Surg Oncol) confirmed:
      • Higher parathyroid identification rates
      • Reduced inadvertent parathyroidectomy
      • Improved preservation of gland vascularity
  • 2021 to 2024:
    • Comparative & Outcome Studies:
      • Meta-analyses (e.g., Wang et al., Langenbecks Arch Surg, 2022):
        • NIR autofluorescence vs. white light: reduced transient hypocalcemia (RR ~ 0.42)
        • Time to identify parathyroid was significantly shorter (mean ~ 4 min faster)
      • Zhao et al., JAMA Otolaryngol Head Neck Surg (2023):
        • Showed that NIR imaging decreased inadvertent excision and increased confidence in preserving parathyroids
        • Combination with Indocyanine Green (ICG) angiography has been studied to assess gland viability after identification
• Clinical Applications:
  • Parathyroid preservation in thyroidectomy
  • Localization in reoperative neck surgery
  • Autotransplantation planning
  • Training tool for junior surgeons
• Limitations:
  • Autofluorescence intensity can vary between patients and may be affected by lighting, fat tissue, or gland pathology
  • Does not assess vascularization; ICG angiography is needed for viability
  • Cost and device availability may be limiting factors in community hospitals
• Conclusion:
  • Autofluorescence has emerged as a reliable, non-invasive, and real-time tool for parathyroid gland identification
  • The technique has consistently shown benefits in reducing complications such as hypocalcemia, minimizing gland devascularization, and enhancing surgical efficiency
  • Combining NIR autofluorescence with ICG fluorescence may offer a comprehensive approach to both identifying and preserving functional parathyroid glands
• Key References:
  • Paras C et al. J Biomed Opt. 2011;16(6):067004.
  • McWade MA et al. Surgery. 2016;159(3):865-871.
  • Demarchi MS et al. Ann Surg Oncol. 2019;26(1):165-172.
  • Wang X et al. Langenbecks Arch Surg. 2022;407(2):655–664.
  • Zhao H et al. JAMA Otolaryngol Head Neck Surg. 2023;149(4):359–367.

• Concurrent chemoradiotherapy with cisplatin:
  • Is the standard of care for patients with locally advanced head and neck squamous cell carcinoma (HNSCC):
    • With the most widely accepted regimen being cisplatin 100 mg/m² administered intravenously every 3 weeks for up to three cycles during radiotherapy
  • This approach is supported by multiple large randomized trials demonstrating survival benefit in patients with good performance status and is endorsed by major guidelines, including those from the American Society of Clinical Oncology and NCCN.
• The rationale for exploring low-dose weekly cisplatin (20 to 50 mg/m²):
  • Stems from the significant acute and chronic toxicities associated with the high-dose regimen, including:
    • Nephrotoxicity, ototoxicity, and myelosuppression:
      • Which can limit compliance and preclude delivery of the intended cumulative dose
  • Weekly regimens are hypothesized to:
  • Improve tolerability and allow more patients to achieve a cumulative cisplatin dose of at least 200 mg/m²:
    • Which is considered important for optimal tumor control
• Efficacy: Survival and Disease Control:
  • Meta-analyses and large retrospective studies indicate that overall survival and response rates are similar between high-dose and low-dose cisplatin regimens in the definitive chemoradiation setting:
    • For example, a large population-based study in US veterans found no significant difference in overall survival between high-dose (100 mg/m² every 3 weeks) and low-dose (40 mg/m² weekly) cisplatin:
      • Though high-dose was associated with greater toxicity
    • Similarly, systematic reviews and meta-analyses have not demonstrated a meaningful survival difference between the two dosing strategies in either definitive or postoperative settings
    • However, some studies and clinical guidelines suggest that high-dose cisplatin may offer superior locoregional control and overall survival:
      • Particularly in altered fractionation or postoperative settings
    • For instance, randomized trials and meta-analyses have reported improved locoregional control and, in some analyses, overall survival with high-dose regimens, especially when combined with altered fractionation radiotherapy
• The American Society of Clinical Oncology recommends the every-3-week high-dose regimen as the standard:
  • Noting that weekly regimens lack level I evidence and may be associated with inferior outcomes in some studies
• Achieving a cumulative cisplatin dose of ≥ 200 mg/m² is consistently associated with better survival and locoregional control:
  • Regardless of the dosing schedule
• Toxicity and Compliance:
  • High-dose cisplatin regimens are associated with increased rates of severe hematologic, renal, and ototoxic toxicities compared to weekly low-dose regimens
  • In contrast, weekly low-dose cisplatin is generally better tolerated and associated with improved compliance, with more patients able to complete the planned cumulative dose
  • Notably, patients with low skeletal muscle mass are at higher risk for dose-limiting toxicity with high-dose cisplatin and may particularly benefit from weekly regimens to improve compliance and reduce toxicity
  • However, some studies have reported increased rates of grade 3 to 4 dysphagia and weight loss with weekly regimens in the postoperative setting
• Guideline Recommendations and Ongoing Controversies:
  • Current US and international guidelines, including those from the American Society of Clinical Oncology:
    • Continue to endorse high-dose cisplatin (100 mg/m² every 3 weeks) as the standard regimen for concurrent chemoradiation in eligible patients
  • Weekly low-dose cisplatin is widely used in clinical practice, particularly for patients with comorbidities or poor performance status, but is considered investigational pending results from ongoing prospective trials
  • The optimal dosing schedule remains an area of active research, and further adequately powered randomized trials are needed to clarify the relative efficacy and toxicity of these regimens, especially in specific subgroups such as HPV-positive, elderly, or comorbid patients
• In summary, high-dose cisplatin every 3 weeks remains the standard of care for concurrent chemoradiation in locally advanced HNSCC, with weekly low-dose regimens offering a reasonable alternative for selected patients, particularly those at higher risk for toxicity or with difficulty tolerating high-dose therapy
• References:
  • Head and Neck Cancer. Chow LQM. The New England Journal of Medicine. 2020;382(1):60-72. doi:10.1056/NEJMra1715715.
  • Management of the Neck in Squamous Cell Carcinoma of the Oral Cavity and Oropharynx: ASCO Clinical Practice Guideline. Koyfman SA, Ismaila N, Crook D, et al. Journal of Clinical Oncology : Official Journal of the American Society of Clinical Oncology. 2019;37(20):1753-1774. doi:10.1200/JCO.18.01921.
  • Low-Dose vs. High-Dose Cisplatin: Lessons Learned From 59 Chemoradiotherapy Trials in Head and Neck Cancer. Szturz P, Wouters K, Kiyota N, et al. Frontiers in Oncology. 2019;9:86. doi:10.3389/fonc.2019.00086.
  • Concurrent Chemoradiotherapy With Cisplatin Given Once-a-Week Versus Every-Three Weekly in Head and Neck Squamous Cell Carcinoma: Non-Inferior, Equivalent, or Superior?. Gupta T, Kannan S, Ghosh-Laskar S, Agarwal JP. Oral Oncology. 2022;134:106130. doi:10.1016/j.oraloncology.2022.106130.
  • Cisplatin Every 3 Weeks Versus Weekly With Definitive Concurrent Radiotherapy for Squamous Cell Carcinoma of the Head and Neck. Bauml JM, Vinnakota R, Anna Park YH, et al. Journal of the National Cancer Institute. 2019;111(5):490-497. doi:10.1093/jnci/djy133.
  • Weekly Low-Dose Versus Three-Weekly High-Dose Cisplatin for Concurrent Chemoradiation in Locoregionally Advanced Non-Nasopharyngeal Head and Neck Cancer: A Systematic Review and Meta-Analysis of Aggregate Data. Szturz P, Wouters K, Kiyota N, et al. The Oncologist. 2017;22(9):1056-1066. doi:10.1634/theoncologist.2017-0015.
  • Low Dose Cisplatin Weekly Versus High Dose Cisplatin Every Three Weeks in Primary Chemoradiotherapy in Head and Neck Cancer Patients With Low Skeletal Muscle Mass: The CISLOW-study Protocol. Schaeffers AWMA, Devriese LA, van Gils CH, et al. PloS One. 2023;18(11):e0294147. doi:10.1371/journal.pone.0294147.
  • Comparison of Standard-Dose 3-Weekly Cisplatin and Low-Dose Weekly Cisplatin for Concurrent Chemoradiation of Patients With Locally Advanced Head and Neck Squamous Cell Cancer: A Multicenter Retrospective Analysis. Lee SY, Choi YS, Song IC, et al. Medicine. 2018;97(21):e10778. doi:10.1097/MD.0000000000010778.
  • Altered Fractionation Radiotherapy Combined With Concurrent Low-Dose or High-Dose Cisplatin in Head and Neck Cancer: A Systematic Review of Literature and Meta-Analysis. Szturz P, Wouters K, Kiyota N, et al. Oral Oncology. 2018;76:52-60. doi:10.1016/j.oraloncology.2017.11.025.
  • Comparison of Weekly Administration of Cisplatin Versus Three Courses of Cisplatin 100 mg/M(2) for Definitive Radiochemotherapy of Locally Advanced Head-and-Neck Cancers. Rades D, Seidl D, Janssen S, et al. BMC Cancer. 2016;16:437. doi:10.1186/s12885-016-2478-8.