Efficacy of induction chemotherapy in retinoblastoma, alone or combined with other adjuvant modalities.
BACKGROUND
There are not much data available on the use of newer antimetabolites as an initial treatment modality in retinoblastoma, or their effect on vitreous seedings and de novo foci, especially in the Indian subcontinent.


METHODS
To evaluate the efficacy of newer agents as induction chemotherapy, 34 tumors in 22 eyes of 19 children with bilateral retinoblastoma were treated with 2 cycles of carboplatin, etoposide, vincristine, and cyclophosphamide; each cycle was of 1 month duration. The tumor response was evaluated at 2 months and adjuvant salvage modalities (ie, cryotherapy, laser, and/or external beam radiotherapy) were added as needed. The cycles were continued and ophthalmoscopic and ultrasonographic monitorings were performed to determine further tumor response, tumor height regression, effect on vitreous seeds, and other ocular changes.


RESULTS
Mean tumor height at presentation was 4.2 mm, which regressed to 2.61 mm at 6 months (P=0.000). The biggest tumor to respond was 12.5 mm, although smaller multiple tumors regressed better. Adjuvant modalities were used in 28 tumor foci in 16 eyes. A follow up of 6 to 24 months (mean, 12.8+/-6.21 months), showed complete regression in 12/34 tumors, partial regression in 15/34, stable disease in 6/34, and 1 tumor progressed despite all therapy. Results in all 6 eyes with vitreous seeds were most gratifying; at 1 year vitreous seeds disappeared in 4 eyes and showed complete calcification in 2. Fresh new lesions were not seen in any eye with complete response after the first 2 cycles of chemotherapy. Recurrences were nil and complications minor.


CONCLUSIONS
The overall tumor response (complete and partial) of more than 80% indicates that chemoreduction is an effective modality alone and combined with adjuvant salvage modalities. The results with our treatment regime, even in cases with advanced intraocular retinoblastoma, are encouraging.
Ghose
S
S
Dr. Rajendra Prasad Center for Ophthalmic Sciences, Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, Ansari Nagar, New Delhi.
Nizamuddin
S H M
SH
Sethi
A
A
Mohanti
B K
BK
Kumar
H
H
Arya
L S
LS
Thavaraj
V
V
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D016190:Carboplatin / Q000008:administration & dosage; D002675:Child, Preschool; D003131:Combined Modality Therapy; D017679:Cryotherapy / Q000379:methods; D003520:Cyclophosphamide / Q000008:administration & dosage; D005047:Etoposide / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009366:Neoplasm Seeding; D011446:Prospective Studies; D018714:Radiotherapy, Adjuvant / Q000379:methods; D012074:Remission Induction; D019572:Retinal Neoplasms / Q000628:therapy*; D012175:Retinoblastoma / Q000628:therapy*; D016896:Treatment Outcome; D014750:Vincristine / Q000008:administration & dosage
D014750:Vincristine; D005047:Etoposide; D003520:Cyclophosphamide; D016190:Carboplatin