In the sentence extracted from biomedical literature, identify all the chemical entities. The required answer format is the same sentence with HTML <span> tags to mark up specific entities. 
### Entity Markup Guides:
Use <span class="chemical"> to denote a chemical.

### Input Text: Our findings suggest that the changes leading to an alteration of myocardial dynamic imaging with I - 131 HA are not the initiating factor in doxorubicin cardiotoxicity .
### Output Text:
Our findings suggest that the changes leading to an alteration of myocardial dynamic imaging with <span class="chemical">I - 131 HA</span> are not the initiating factor in <span class="chemical">doxorubicin</span> cardiotoxicity . 