Implications for the Head and neck cancer services
The impact of CVAL on clinical services and patients should not be underestimated. In the 12-weeks period of our study, cCVAL cases accounted for around 15% of all fast-tracked lymphadenopathy referrals. With the ongoing expansion of the vaccination programme in the UK to cover younger individuals and more second dose vaccinations, as well as the upcoming rollout the Moderna mRNA vaccine, we predict that the number of referrals will increase exponentially.14,21
Moreover, awareness of clinical features and course of CVAL is also crucial for the radiologists involved in cancer diagnosis and follow-up, and it should nowadays be recognised in the differential diagnosis of cervical or axillary lymphadenopathy.9,10Lymphadenopathy detected clinically or in routine surveillance scans might create a diagnostic and management dilemma for oncology patients.10,21 Not only that CVALs could exhibit abnormal features on ultrasound scans, but they are also shown to be metabolically active on positron emission tomographic (PET) images, with intensities similar to malignant lymphadenopathy.8-10,21 A recent study by Cohen et al. on PET-positive supraclavicular and axillary lymphadenopathy in 728 oncology patients, following the Pfizer/BioNTech vaccine, the incidence of overall and supraclavicular CVAL was 36.5% and 8% respectively, with supraclavicular CVAL being more commonly encountered after the second dose (9.1%) compared to the first dose (5.5%).21
Recommendations for appropriate management of CVAL should aim to strike a balance between avoiding delayed cancer diagnoses, and minimizing patient harm by invasive biopsies, unnecessary scans, and heightened anxiety.8,10,22,24 All requests for imaging in the H&N and breast regions, and referrals to the fast-track cancer services, should include full information about COVID-19 vaccine status, especially the dates, the site, the side, and the type of the vaccine. For patients with pre-existing history of H&N malignancy, administration of the vaccine on the contra-lateral side is recommended. Recently published recommendations from institutions in north America have advised timing H&N and breast imaging for before, or 4-6 weeks after COVID-19 vaccination, and recommended considering a follow-up scan 4-12 weeks after the second dose of the vaccine.7,10,11,24 Moreover, evidence from our current study and previously published data demonstrated that a good proportion of cervical CVAL usually fully resolve within 3-6 weeks.12,13,21 Therefore, it is not unreasonable for primary care physicians to rationalise referrals to specialist cancer clinics, and to prioritise cases with persistent lymphadenopathy beyond 3-6 weeks, or patients with other concerning features of malignancy.10 Until more data becomes available, H&N cancer MDTs should carefully advise against delaying vaccine administration, and should weigh the risks and the benefits of timing any H&N imaging to before or 4-6 weeks after the COVID-19 vaccination.