SUPERFICIAL HYPERTHERMIA
TREATING TUMOURS CLOSE TO THE SKIN SURFACE
Microwave applicators placed directly on the skin heat tumours within 3โ4 cm of the surface โ making radiation dramatically more effective for chest wall recurrence, melanoma, and lymph node metastases.
analyticsAt a Glance
- check_circleHeats tumours within 3โ4 cm of the skin surface to 40โ43ยฐC
- check_circleStandard of care for recurrent breast chest wall disease
- check_circlePhase III evidence in chest wall recurrence, melanoma, and H&N nodes
- check_circleNon-invasive, outpatient โ no anaesthesia required
What Is Superficial Hyperthermia?
Superficial hyperthermia is a non-invasive cancer treatment that heats tumours located within 3โ4 cm of the skin surface to 40โ43ยฐC. Applicators are placed directly against the skin, and heat is delivered via microwave or radiofrequency energy โ primarily as a radiosensitiser to boost the effectiveness of radiation therapy.
โFor tumours just beneath the skin, surface applicators deliver therapeutic heat with millimetre precision โ and decades of phase III evidence prove the radiation-boosting benefit.โ
How It Differs from Deep Regional Hyperthermia
Deep regional systems use a ring of antennae to penetrate 15โ20 cm and treat pelvic or abdominal tumours. Superficial systems use a single applicator placed flat against the skin and reach only 3โ4 cm โ ideal for chest wall lesions or lymph node metastases that deep systems would overshoot.
How It Differs from HIFU
HIFU (high-intensity focused ultrasound) is an ablation technology โ it heats tissue above 60ยฐC to physically destroy the tumour. Superficial hyperthermia stays at 40โ43ยฐC and works as a sensitiser, not an ablator. The two are distinct treatments with different intents and patient indications.
How Surface Applicators Heat Tumours Near the Skin
Superficial hyperthermia uses dedicated applicators designed for limited depth penetration. The engineering challenge is the opposite of deep regional systems โ keep energy concentrated in the first 3โ4 cm without it spreading deeper or causing surface burns.
Microwave or Radiofrequency Energy at 433โ915 MHz
Higher frequencies (915 MHz, used in the US) deposit energy in a shallower layer, ideal for thin tumours. Lower frequencies (433 MHz, common in Europe) penetrate slightly deeper for thicker chest wall recurrences. Frequency selection is matched to tumour thickness on imaging.
Applicator Designs Match Tumour Shape
Single waveguide applicators are used for small, focal lesions. Spiral microstrip antennas and current sheet applicators cover larger areas like the full chest wall. Multi-element microstrip arrays (e.g., the BSD-500 system) allow segmented heating across irregular surfaces.
Water Bolus Cools the Skin and Ensures Coupling
A circulating-water cushion sits between the applicator and the skin. The water cools the surface to prevent burns and acts as an impedance match โ allowing microwave energy to enter the tissue efficiently rather than reflecting off the skin.
Temperature Probes Monitor Tissue Heat in Real Time
Thin probes are placed in the tumour (via small catheters) and on the skin surface to monitor temperatures every few seconds. The operator adjusts power output to maintain 40โ43ยฐC in the target while keeping skin temperature within safe limits.
Leading Clinical Systems
The BSD-500 (Pyrexar) is the most widely used superficial system globally. The ALBA 4D (Med-Logix) is common in European cancer centres. The HY-DEEP series (Andromedic) and Oncotherm EHY-1000+ offer additional approaches for surface tumours. All operate within the 40โ43ยฐC therapeutic range.
Tumours Treated with Superficial Hyperthermia
Superficial hyperthermia is used for tumours within 3โ4 cm of the skin surface, almost always combined with radiation therapy.
| Tumour Type | Clinical Setting | Combined With | Evidence Strength |
|---|---|---|---|
| Recurrent Breast Cancer (Chest Wall) | Local recurrence in previously irradiated chest wall | Re-irradiation (30โ40 Gy) | Strong โ phase III RCT (Vernon et al, 1996) |
| Malignant Melanoma | Recurrent or metastatic cutaneous lesions | Radiation therapy | Strong โ phase III RCT (Overgaard, ESHO 1995) |
| Head & Neck Lymph Node Metastases | Fixed cervical nodes; recurrent disease | Definitive or salvage radiation | Strong โ phase III (Valdagni trial) |
| Cutaneous Metastases | Skin and subcutaneous metastases from breast, lung, sarcoma | Radiation or chemoradiation | Moderate โ multiple phase II series |
| Cutaneous T-Cell Lymphoma (CTCL) | Mycosis fungoides plaques and tumour stage | Local radiation therapy | Moderate โ institutional experience |
| Recurrent Vulvar / Vaginal Cancer | Superficial recurrence accessible to surface applicators | Re-irradiation; concurrent chemotherapy | Moderate โ small phase II series |
| Superficial Sarcomas | Skin and subcutaneous sarcomas | Radiation ยฑ chemotherapy | Moderate โ case series |
| Kaposi Sarcoma | Cutaneous lesions in HIV-positive and elderly patients | Local radiation therapy | Limited โ historical experience |
What Happens During a Superficial Hyperthermia Session
Sessions are outpatient and typically last 75โ90 minutes from arrival to discharge. The procedure is straightforward and well tolerated.
- 1
Tumour Mapping and Applicator Selection
The treatment area is marked using imaging (ultrasound or recent MRI). An applicator is selected based on lesion size, shape, and depth. For thicker chest wall lesions, a lower frequency is chosen to penetrate adequately.
- 2
Temperature Probe Placement
A thin temperature catheter is inserted under local anaesthesia into the tumour (or alongside it) to monitor real-time temperature. Surface probes are placed on the skin under the bolus. For very superficial lesions, only surface probes may be needed.
- 3
Applicator Placement and Heating to 40โ43ยฐC
The applicator is positioned over the treatment area with the water bolus against the skin. Microwave power is gradually increased over 5โ10 minutes until target temperature is reached, then maintained for 45โ60 minutes of plateau time.
- 4
Radiation Therapy Coordination
A radiation fraction is delivered within 30โ60 minutes of the hyperthermia session โ either immediately before or after, depending on logistics. This timing window is when tumours are most sensitised.
- 5
Post-Session Skin Check and Discharge
The skin is inspected for any redness, blistering, or hotspot reaction. Most patients have mild warmth and faint redness that resolves within hours. The temperature probe is removed and the patient discharged the same day.
Clinical Outcomes by Cancer Type
Phase III randomised trials demonstrating the impact of adding superficial hyperthermia to radiation therapy across the main indications.
Recurrent Breast Cancer (Chest Wall) โ International Collaborative Hyperthermia Group
Re-irradiation alone vs re-irradiation + superficial hyperthermia in 306 patients with chest wall recurrence in a previously irradiated field.
- Complete Response โ RT Alone41%
- Complete Response โ RT + Superficial HT59%
- 2-Year Local Control โ RT Alone30%
- 2-Year Local Control โ RT + Superficial HT50%
Malignant Melanoma โ ESHO 3-85 Trial
Radiation alone vs radiation + superficial hyperthermia in 134 patients with recurrent or metastatic cutaneous melanoma lesions.
- Complete Response โ RT Alone35%
- Complete Response โ RT + Superficial HT62%
- 2-Year Local Control โ RT Alone28%
- 2-Year Local Control โ RT + Superficial HT46%
Head & Neck Lymph Node Metastases โ Valdagni Trial
Radiation alone vs radiation + local hyperthermia for fixed cervical lymph node metastases in head and neck cancer.
- Complete Response โ RT Alone37%
- Complete Response โ RT + Superficial HT83%
- 5-Year Overall Survival โ RT Alone0%
- 5-Year Overall Survival โ RT + Superficial HT53%
Benefits and Limitations of Superficial Hyperthermia
Superficial hyperthermia is one of the most thoroughly validated thermal therapies in oncology โ but its anatomical scope is naturally limited to tumours close to the skin.
Benefits
- Strongest Evidence in HyperthermiaThree phase III RCTs (chest wall, melanoma, H&N nodes) with consistent radiation-boosting effects.
- Non-Invasive and OutpatientNo incisions, no general anaesthesia, no inpatient stay required for routine sessions.
- Enables Re-Irradiation in Recurrent DiseaseCritical for patients with chest wall recurrence after prior breast cancer radiation โ often their only meaningful local option.
- Well-Tolerated Across Age GroupsSuitable for elderly and frail patients who cannot tolerate chemotherapy or extensive surgery.
- Widely Available EquipmentSurface applicators are less expensive and more broadly deployed than deep regional systems.
Limitations
- Limited Penetration DepthOnly treats tumours within 3โ4 cm of the skin โ useless for deep pelvic, abdominal, or visceral disease.
- Risk of Skin Burns at HotspotsPower deposition non-uniformities can cause localised burns or blistering if monitoring lapses.
- Tumour Shape and Position ConstraintsIrregular surfaces (axilla, joint creases) and curved anatomy may produce uneven heating.
- Multiple Sessions RequiredA full treatment course typically requires 4โ10 sessions over several weeks alongside radiation.
- Variable Insurance CoverageReimbursement is inconsistent outside of Europe; self-pay arrangements are common for international patients.
Related Treatments & Resources
Explore the full hyperthermia knowledge base and related cancer treatment pages.
- Hyperthermia Therapy โ Full Treatment Page
- What Is Hyperthermia Therapy and How Does It Help Cancer Treatment?
- Deep Regional Hyperthermia: Heating Tumours Inside the Pelvis and Abdomen
- How Heat Makes Radiation Work Better: Radiosensitisation Explained
- How Heat Makes Chemotherapy Work Better: Drug-Heat Interactions
- Hyperthermia Therapy in China
Frequently Asked Questions
Common questions from patients and caregivers about superficial hyperthermia for surface tumours.
The Procedure
How does superficial hyperthermia feel?
Most patients describe a sensation of warmth and gentle pressure under the applicator. The skin contact through the water bolus feels like a warm compress. Mild discomfort can occur at hotspots and is the signal to adjust power. Sharp pain is uncommon and prompts immediate operator review rather than dose escalation.
How many sessions will I need?
Most protocols deliver 4โ10 superficial hyperthermia sessions, usually twice per week. Each session is paired with a radiation fraction. The exact number depends on tumour size, total radiation dose, and how well the tumour is responding during the course.
Is general anaesthesia required?
No. Superficial hyperthermia is non-invasive and does not require general anaesthesia. If a temperature probe needs to be placed via a small catheter, that brief procedure uses local anaesthesia at the entry point. Most patients tolerate the full session comfortably without sedation.
What are the side effects?
The most common side effects are local: mild skin redness, transient warmth, and occasional small blisters or fat necrosis at hotspots. These are minimised by experienced operators using real-time temperature monitoring and proper bolus cooling. Serious skin injury is uncommon and typically heals with standard wound care.
Eligibility & Access
Am I a candidate for superficial hyperthermia?
The best candidates have tumours within 3โ4 cm of the skin surface โ chest wall recurrence after breast cancer, cutaneous melanoma, head and neck lymph nodes, or skin metastases โ and are receiving (or eligible for) radiation therapy. CancerFax can review your imaging and treatment history to determine suitability.
Can superficial hyperthermia be used if I have already had radiation in this area?
Yes โ this is one of its most valuable roles. For patients with recurrent disease in a previously irradiated chest wall or pelvis, where re-irradiation dose is limited by cumulative toxicity, adding superficial hyperthermia allows a lower repeat radiation dose to be effective. The Vernon trial established this benefit specifically in pre-irradiated chest wall recurrence.
Where can I access superficial hyperthermia internationally?
Germany, the Netherlands, and Italy have the longest-established programmes. The Netherlands Cancer Institute, Erasmus MC Rotterdam, and University Hospitals in Germany all run active superficial hyperthermia clinics. China offers the treatment at major cancer centres in Beijing, Shanghai, and Guangzhou at significantly lower cost. Selected centres in India also provide the modality.
How does CancerFax help patients access this treatment?
CancerFax reviews your medical records, identifies whether superficial hyperthermia is technically appropriate for your tumour, and shortlists centres with the right equipment and expertise. Our team coordinates appointment scheduling, interpreter support, visa assistance, and end-to-end logistics so the focus stays on treatment rather than coordination.
How CancerFax Helps
CancerFax is a specialist cancer access and patient-navigation platform. We help patients and families understand their options, organise medical records, coordinate hospital communication, and support cross-border treatment planning where appropriate.
We help collect and organise reports, scans, pathology, biomarker results, and treatment history for structured case review.
We communicate with hospitals or trial teams to assess whether a case may be suitable for further screening.
We support appointment coordination, document submission, translation, and direct communication with international departments.
For international patients, we help with practical coordination โ travel planning, hospital admission guidance, and local support.
If this option is not suitable, we help explore other relevant treatments, clinical trials, or advanced care pathways.
From inquiry through to follow-up, our coordinators provide a single point of contact for the family.
CancerFax does not guarantee treatment access, eligibility, or clinical outcome. Our role is to help patients access accurate information, structured review, and appropriate specialist pathways.
Could Superficial Hyperthermia Improve Your Radiation Outcome?
Upload your medical reports and our oncology team will review your case to determine whether superficial hyperthermia โ combined with radiation therapy โ is suitable for your tumour, and identify the right specialist centre.
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.