Adjunctive therapy with interstitial irradiation for prostate cancer

Thirty patients with clinically localized adenocarcinoma of the prostate underwent simultaneous staging pelvic lymphadenectomy and interstitial irradiation. Patients were followed for eighteen to forty-five months with regard to progression of disease and development of long-term complications. Upstaging to Stage D₁ by virtue of discovering pelvic node involvement was noted in 16 patients (53.3 per cent). Subsequent disease progression (defined as development of bone or soft tissue metastasis) was seen in 9 of 16 upstaged patients with an average time to progression of 12.2 months. Three Stage D₁ patients have died with an average time to death of 19.6 months. Only 1 patient whose lymphadenectomy was negative has experienced disease progression, and none has died. Adjuvant chemotherapy (cyclophosphamide and doxorubicin hydrochloride) was given to 9 upstaged patients, in only 3 did disease progress. In contrast, in 6 of 7 upstaged patients not receiving chemotherapy metastatic disease developed, with an average time to progression of 10.3 months. In an attempt to improve local tumor control achieved by interstitial irradiation alone, 18 patients received additional external beam radiation therapy to the prostate, in doses ranging from 2,000 to 40,000 rad. There were sixteen long-term complications in the 30 patients, 75 per cent of which were seen in patients receiving added external beam irradiation.