Inclusion Criteria:

- Patient has biopsy proven limited stage SCLC

- receiving radical concurrent chemoradiotherapy

- no prior chest RT

- no prior surgical resection of lung tumor

- no prior chemotherapy

- patients' lung tumors should be centrally-located to minimize the effect of
respiratory motion

- patient has biopsy proven TCC bladder

- receiving radical concurrent chemoradiotherapy or RT alone

- no prior chemotherapy

- patient signs study-specific consent form

Exclusion Criteria:

- mixed small cell and non small cell histology

- patient not being treated with concurrent chemoradiotherapy

- chemoradiotherapy given sequentially

- previous chest RT

- previous chemotherapy

- prior surgical resection of lung mass

- patient ineligible for pelvic RT

- patient does not sign study consent