Dysphagia Knowledge Hub — 吞嚥困難知識庫

Head and Neck Cancer Dysphagia in Hong Kong: From Treatment to Recovery

Head and neck cancer — a category that includes cancers of the nasopharynx, oropharynx, hypopharynx, larynx, oral cavity, and salivary glands — is among the most common cancer groups in Hong Kong. Nasopharyngeal carcinoma (NPC) in particular has one of the highest incidence rates globally in the Cantonese-speaking population, with approximately 20–30 per 100,000 Hong Kong males affected per year. Treatment — whether surgery, radiotherapy, chemotherapy, or a combination — frequently causes or worsens dysphagia, which can persist for months or years after cancer treatment is complete.

Understanding how treatment causes swallowing difficulties, what rehabilitation is available, and how to monitor recovery is essential for patients, families, and the extended care network.

How Head and Neck Cancer Treatment Causes Dysphagia

Dysphagia in this population does not arise from the tumour alone — often the treatment itself is the primary cause.

Surgery

Surgical resection of head and neck tumours may involve the tongue, soft palate, pharynx, larynx, or surrounding structures. Depending on what is removed and whether reconstruction is performed (using flaps from the forearm, thigh, or chest wall), the functional anatomy of swallowing may be permanently altered.

Even when reconstruction is technically successful, reconstructed tissue lacks the sensory feedback and precise coordination of native tissue, and swallowing function in reconstructed areas is typically inferior to the pre-surgical baseline.

Radiotherapy

Radiotherapy to the head and neck causes a cascade of tissue changes that affect swallowing both acutely and in the long term.

Acute toxicity (during and immediately after radiotherapy):

Late radiation toxicity (months to years post-treatment):

Late dysphagia can develop or worsen years after radiotherapy completion — a phenomenon sometimes called “late-onset dysphagia” or “radiation fibrosis syndrome.” Patients who report worsening swallowing long after treatment should be reassessed, not reassured that the treatment is over.

Nasopharyngeal Carcinoma: Hong Kong-Specific Considerations

NPC is biologically and clinically distinct from other head and neck cancers. It originates in the nasopharynx — the upper throat behind the nose — and has a strong association with Epstein-Barr virus (EBV) exposure in the Cantonese population. Because of its location, NPC is not typically resected surgically; primary treatment is radical radiotherapy, frequently combined with chemotherapy.

Radiation fields in NPC treatment encompass the nasopharynx, cervical lymph nodes, and often the base of skull. This means structures critical for swallowing — the soft palate, pharyngeal constrictors, parapharyngeal muscles, and cranial nerve IX/X/XII exit points — are within or near the radiation field.

NPC-specific dysphagia complications:

The NPC clinic at Queen Elizabeth Hospital is one of Hong Kong’s principal centres for NPC follow-up, and the SLT department provides swallowing assessment and rehabilitation as part of the multidisciplinary team. Long-term NPC survivors — who may be decades post-treatment — sometimes present with progressive dysphagia due to late fibrosis and should not be dismissed as having no treatable cause.

Swallowing Rehabilitation Exercises

Swallowing exercises in head and neck cancer have good evidence for improving functional outcomes, particularly when begun prophylactically — before or during radiotherapy — rather than only after dysphagia is established.

Mendelsohn Manoeuvre: The patient consciously prolongs the laryngeal elevation at the peak of the swallow, increasing the duration and extent of upper oesophageal sphincter (UOS) opening. This is particularly useful in patients with reduced hyolaryngeal movement from fibrosis or neuropathy.

Technique: Swallow saliva and focus on the moment when the larynx is at its highest point. Hold it there for a count of 3 before allowing it to drop. Practise 5–10 repetitions, twice daily.

Shaker Exercise (Head Lift Exercise): Designed to strengthen the suprahyoid muscles that pull the hyoid bone and larynx upwards and forward during swallowing, and to improve UOS opening.

Technique: Lying flat on the back without a pillow, lift only the head — not the shoulders — far enough to see the toes. Hold for one minute, rest for one minute. Repeat three times. Then perform 30 rapid repetitions of the same head lift. Perform once daily. Note: patients with neck fibrosis or osteoradionecrosis should not commence this exercise without SLT clearance, as it places traction on compromised cervical structures.

Masako Manoeuvre (Tongue-Hold Exercise): The patient holds the tongue gently between the teeth while swallowing, forcing increased pharyngeal wall contraction to compensate. This exercises the posterior pharyngeal wall muscles and increases tongue base-pharyngeal wall contact.

Technique: Hold the tongue between the front teeth (gently, not biting). Swallow in this position. Practise dry (saliva) swallows, 5–10 repetitions per session, twice daily. Not appropriate as a compensatory strategy for mealtime use — this is an exercise only.

Trismus exercises: Mouth-opening exercises — using stacked wooden tongue depressors between the teeth, or a commercial device such as the Therabite — are essential for patients with radiation-induced trismus. Passive stretching must be sustained; brief opening and closing exercises are less effective than sustained stretching for fibrotic tissue.

Prophylactic exercise during radiotherapy: Multiple trials (including the DIGEST study and SWALLOW trial) support the concept of prophylactic swallowing exercise during radiotherapy to reduce long-term dysphagia rates. Some HA oncology centres in Hong Kong have implemented this; ask your SLT whether a prophylactic exercise programme is available.

VFSS in Post-Treatment Monitoring

Instrumental swallowing assessment — most commonly VFSS or FEES — plays a central role in monitoring swallowing function after head and neck cancer treatment.

VFSS is particularly useful for identifying the anatomical basis of post-treatment dysphagia (reduced tongue base retraction, restricted UOS opening, pharyngeal residue patterns) and for safe diet advancement. A patient who has been on enteral tube feeding during radiotherapy will typically require VFSS before oral diet is reintroduced. Repeat studies at 3, 6, and 12 months post-treatment are common in centres with established protocols.

FEES is useful where radiation changes make the anatomy difficult to interpret fluoroscopically, or for bedside assessment of patients who cannot travel to radiology.

HA Oncology SLT Services in Hong Kong

The Hospital Authority’s oncology centres coordinate SLT services as part of the multidisciplinary cancer team. Head and neck cancer patients at the following hospitals have access to SLT assessment and swallowing rehabilitation:

For patients who complete radiotherapy or surgery and are discharged to the community, outpatient SLT follow-up should be arranged before discharge. Gaps in community SLT access remain a challenge; private SLT practitioners with oncology experience are available in major districts.

Dietary Progression Timeline

Recovery of swallowing after head and neck cancer treatment is highly individual and depends on tumour site, treatment modality, and rehabilitation engagement. A generalised timeline:

Timepoint Typical Dietary Status
During radiotherapy IDDSI Level 4–5 (puréed/minced) or enteral tube feeding; xerostomia severe
4–6 weeks post-radiotherapy Mucositis resolving; cautious oral diet trial if tube-fed; Level 4–5 for oral patients
3 months post-radiotherapy Gradual progression if exercises maintained; Level 5–6 possible for many
6 months Most patients who will recover substantially have done so; Level 6–7 achievable for some
1–2 years Late fibrosis may cause plateau or regression; surveillance VFSS recommended
>2 years Progressive late toxicity possible; any new dysphagia warrants reassessment

Patients should not be told that swallowing “will return to normal” without qualification. For many, particularly those with bulky tumours requiring wide radiation fields, permanent modification of diet and swallowing technique is the realistic outcome.

Support Organisations in Hong Kong

Hong Kong Cancer Fund (HKCF): Offers practical and emotional support to cancer patients and families, including caregiver training, nutrition counselling, and access to support groups. The HKCF CancerLink centres in multiple districts provide in-person support in Cantonese.

Hong Kong Anti-Cancer Society: Provides education, rehabilitation support, and patient services across cancer types.

The Hong Kong Society of Head and Neck Oncology: Professional society; useful for clinician referrals and specialist information.

Patients and caregivers navigating dysphagia after head and neck cancer should seek SLT follow-up as a standard part of their post-treatment care — not as an optional add-on. Swallowing difficulties that are left unmanaged lead to malnutrition, aspiration pneumonia, social isolation, and significantly reduced quality of life. Early engagement with rehabilitation offers the best chance of recovery and adaptation.