TREATMENT PROCESS FOR
ONCOLYTIC VIRUS THERAPY
What actually happens before, during, and after each T-VEC injection โ including the enlargement-before-regression pattern nobody warns patients about until they are already alarmed.
Three Phases of T-VEC Treatment
T-VEC treatment follows a structured three-phase process. Understanding each phase before it happens prevents the most common management errors.
- 1
Pre-Treatment Evaluation
Immune status checked, injectable lesions identified, baseline imaging obtained. Household contact precautions reviewed โ specific instructions given if immunocompromised, pregnant, or neonatal contacts are present.
- 2
Treatment โ Injection Schedule
Day 1: lower dose (10^6 PFU/mL) across up to four lesions. Day 15: full therapeutic dose (10^8 PFU/mL). From Day 15 forward: every two weeks. No preset cycle limit โ response guides duration.
- 3
Response Assessment
Formal response assessment at six months. Periodic imaging of treated and untreated distant lesions throughout. Complete responses can continue deepening beyond the six-month assessment point.
The Enlargement-Before-Regression Pattern
Injected lesions get bigger before they get smaller. This is the most important thing to know before Day 1 โ and the most common cause of premature treatment discontinuation when it is not explained in advance.
โStopping T-VEC because the injected lesion looks worse is one of the most common T-VEC management errors. Enlargement is the immune response the treatment is designed to produce.โ
Expected Response Pattern
Enlargement, increased redness, induration, occasionally ulceration at injection sites in the first weeks. Lesions may look worse than before treatment started. This is local viral replication and immune cell recruitment โ exactly what is supposed to happen.
When to Call Same Day
Vesicular rash spreading beyond the injection site boundary. Fever above 38ยฐC. Anything suggesting viral spread past the treated area. These differ from expected local injection site reactions and require same-day clinical contact.
Dose Volume by Lesion Size
Injection volume is calibrated by lesion size to deliver adequate viral dose without pushing virus into surrounding tissue.
| Lesion Size | Injection Volume |
|---|---|
| Above 5 cm | 4 mL |
| 2.5โ5 cm | 2 mL |
| 1.5โ2.5 cm | 1 mL |
| Below 1.5 cm | 0.5 mL or less |
Injection Site Care: Do and Don't
Do
- Cover treated sites with occlusive bandage immediately after injection
- Wash hands after any contact with injection sites
- Report vesicular rash spreading beyond the site boundary
- Continue regular medications unless told otherwise
Don't
- Allow immunocompromised, pregnant, or neonatal contacts to touch treated sites
- Stop treatment because the injected lesion looks worseEnlargement is the expected response pattern, not failure.
- Fast before injections โ no dietary restriction required
Frequently Asked Questions
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.
Questions About the T-VEC Treatment Process?
CancerFax connects patients with specialist centres experienced in T-VEC administration and supports the full treatment journey from eligibility assessment through post-injection monitoring.
This content is for informational purposes only and does not constitute medical advice. Always consult a qualified oncologist before making treatment decisions.