====== Intravitreal Injection of Chemotherapy for Retinoblastoma ======
===== Indications =====
  * Vitreous Seeding
  * Recalcitrant subretinal and retinal tumors

===== Drugs =====
  * Melphalan hydrochloride
    * use 50 mg lypohilized powder for IV injection
    * 0.25-0.3 mg per 0.5 ml 
    * Deliver 25-30 ug in 0.05 ml 
    * Reconstitue in 0.9% normal saline
    * Must be injected into the eye < 1 hour after being constituted 
  * Topotecan hydrochloride 
    * 20 μg in 0.04 ml (0.2 mg per 0.4 ml)
    * Reconstitue in 0.9% normal saline

===== Tools =====
  * 1 ml syringe or smaller for drug delivery{{:1ml_syringe.png?200|}}
  * 30-33 gauge needle for drug delivery
  * EUA set up (lid speculum, indenter, indirect, condensing lenses, etc.) 
  * Tonopen
  * Cryo machine 
  * Sterile Water
  * 60 ml syringe
  * kidney basin

===== Steps =====
  - Call Pharmacy (x64300) 20 minutes before desired drug delivery time. 
  - Choose an injection site distant from any vitreous or retinal tumors
  - Lower intraocular pressure to <10mmHg with digital massage
  - Prep the eye with a drop of Betadine 5%
  - [[pars_plana_sclerotomy|Inject 2.5-3 mm from limbus]] directing the needle towards the center of the vitreous but avoid known vitreous seeds
  - Before retracting the needle tip from the vitreous apply cryo to the injection site and the needle. 
  - [[https://openophthalmologyjournal.com/VOLUME/8/PAGE/7/|Retract the needle and bathe the fornix with sterile water for 3 minutes]] 
  - Apply a drop of betadine
  - Inspect vitreous and retina if desired  

{{:measuring_limbus.png?400|}}
{{:cryo_the_needle.png?400|}}\\
Source: The role of intravitreal chemotherapy for retinoblastoma. Manjandavida FP, Shields CL. Indian J Ophthalmology 2014;63(2):143



===== Follow-up =====
  * Repeat EUA with plan to inject again for non-response in about 2 weeks
  * If tumors appear to be dead, do one final injection (n+1 rule) 

===== References =====
  * {{ :intravitreal_chemotherapy_for_vitreous_disease_in_retinoblastoma_revisited-_from_prohibition_to_conditional_indications.pdf |Intravitreal chemotherapy for vitreous disease in retinoblastoma revisited: from prohibition to conditional indications. Munier et al. Br J Ophthalmology 2012;96:1078-1083}}
  * {{ :rb_intravitreal_treatment_efficacy_and_toxicity_2017.pdf |Efficacy and Toxicity of Intravitreous Chemotherapy for Retinoblastoma: Four-Year Experience. Francis et.al. Ophthalmology 2017;124:488-495}}
  * {{ :intravitreal_chemotherapy_in_retinoblastoma-_expanded_use_beyond_intravitreal_seeds.pdf |Intravitreal chemotherapy in retinoblastoma: expanded use beyond intravitreal seeds. Abramson et. al. Br J. Ophthalmol 2019;103:488-493}}
  * {{ :the_role_of_intravitreal_chemotherapy_for_retinoblastoma.pdf |The role of intravitreal chemotherapy for retinoblastoma. Manjandavida FP, Shields CL. Indian J Ophthalmology 2014;63(2):141-145}}
  * {{ :water_submersion_for_rb_injections.pdf |Death by Water: Precautionary Water Submersion for Intravitreal Injection of Retinoblastoma Eyes. Francis et. al. Open Ophthalmology Journal 2014;8:7-11}}


{{tag>procedure, drugs, retinoblastoma}}