Parotid-sparing irradiation for cancer of the oral cavity: maintenance of oral nutrition and body weight by preserving parotid function.

The purpose of this study was to assess the nutritional benefit of parotid-sparing irradiation, comparing the body weights of patients irradiated with parotid-sparing technique versus those irradiated with bilateral opposed photon beams, including both parotid glands in the radiation fields. One hundred fourteen patients with cancer of the oral cavity were irradiated with curative intent. Two-dimensional radiotherapy techniques sparing at least one parotid gland from the radiation beams were used to treat 31 patients (parotid-sparing techniques). Eighty-three patients were irradiated using bilateral opposed photon beams, which included both parotid glands (bilateral technique). Body weight during and after irradiation, treatment outcome, and survival were compared. Patients treated with parotid-sparing techniques maintained their nutritional intake and baseline body weight during and after irradiation. Patients treated with the bilateral technique that included both parotid glands had poor nutritional intake, leading to a more than 10% decline in their initial body weight; these patients did not regain their body weight during the 2-year follow-up period. Primary tumor control rate was higher for patients treated with parotid-sparing techniques than for patients who had both parotid glands irradiated (70% versus 48%; p = 0.05). This difference is because a higher percentage of patients treated with parotid-sparing techniques had early-stage tumors (54%) compared with patients treated with the bilateral technique (24%). When analyzed according to the tumor stage, the primary tumor control rates for patients treated with parotid-sparing techniques and for patients treated with the bilateral technique showed no difference; control rates were 93% and 87% (p = 1.00) for early-stage tumors and 42% and 36% (p = 0.75) for advanced-stage tumors, respectively. Nodal control rates in the ipsilateral side of the neck and in the contralateral side of the neck for patients treated with parotid-sparing techniques and with the bilateral technique were not significantly different-74% versus 76% (p = 0.86) and 70% versus 82% (p = 0.21), respectively. Sparing at least one parotid gland during irradiation of patients with head and neck cancer will preserve parotid function and prevent xerostomia. Patients treated with parotid-sparing techniques were able to maintain their oral nutrition and body weight, compared with patients who had both parotid glands irradiated. A higher percentage of patients treated with parotid-sparing techniques had early-stage tumors, resulting in higher rates of primary tumor control and survival in this group of patients.

The extent of biopsy involvement as an independent predictor of extraprostatic extension and surgical margin status in low risk prostate cancer: implications for treatment selection.

PURPOSE: We identify predictors of extraprostatic extension and positive surgical margins in patients with low risk prostate cancer (prostate specific antigen [PSA] 10 ng./ml. or less, biopsy Gleason score 7 or less and clinical stage T1c-2b). MATERIALS AND METHODS: From August 1997 to January 1999, 143 previously untreated patients underwent radical retropubic prostatectomy for clinically localized prostate cancer. A total of 62 patients were low risk, with PSA 10 ng./ml. or less, biopsy Gleason score 7 or less and clinical stage T1c-2b, and had sextant biopsy with separate pathological evaluation of each sextant cores. PSA, clinical stage, biopsy Gleason score, average percentage of cancer in the entire biopsy specimen, maximum percentage of cancer on the most involved core, number of cores involved and bilaterality were evaluated for association with extraprostatic extension, seminal vesicle involvement and positive surgical margins. RESULTS: Of the 62 patients 13 (21%) had extraprostatic extension, 6 (10%) seminal vesicle involvement and 20 (32%) positive surgical margins. Average percentage greater than 10% and maximum percentage greater than 25% were associated with extraprostatic extension (p = 0.01 and 0.004, respectively). Average percentage greater than 10%, maximum percentage greater than 25%, more than 2 cores involved and bilaterality were associated with positive surgical margins (p = 0.007, 0.01, 0.002 and 0.03, respectively). On multivariate analysis maximum percentage remained the only independent predictor of extraprostatic extension (p = 0.03), and the number of cores involved remained an independent predictor of positive surgical margins (p = 0.01). Biopsy Gleason score, PSA and clinical stage did not correlate with extraprostatic extension or positive surgical margins in this patient population. CONCLUSIONS: In low risk prostate cancer the extent of biopsy involvement significantly correlates with the risk of extraprostatic extension and positive surgical margins. Biopsy information should be considered when selecting and modifying treatment modalities.