Radiation pneumonitis following combined modality therapy for lung cancer: analysis of prognostic factors.

PURPOSE: To identify factors associated with radiation pneumonitis (RP) resulting from combined modality therapy (CMT) for lung cancer. MATERIALS AND METHODS: Series published before 1994 that used CMT for the treatment of lung cancer and explicitly reported the incidence of RP are the basis for this analysis. Factors evaluated included the radiation dose per fraction (Fx), total radiation dose, fractionation scheme (split v continuous), type of chemotherapy and intended dose-intensity, overall treatment time, histology (small-cell lung cancer [SCLC] v non-small-cell lung cancer [NSCLC]), and treatment schedule (concurrent v induction, sequential, or alternating CMT). RESULTS: Twenty-four series, including 27 treatment groups and 1,911 assessable patients, met our criteria for inclusion in this analysis. The median total dose of radiation used in the trials analyzed was 50 Gy (range, 25 to 63 Gy). The median daily Fx used was 2.0 Gy (range, 1.5 to 4.0 Gy). Nineteen series included 22 treatment groups and 1,745 patients treated with single daily fractions. Among these patients, 136 received a daily Fx greater than 2.67 Gy. Five series used twice-daily radiotherapy and included 166 patients (Fx, 1.5 to 1.7 Gy). The incidence of RP was 7.8%. In a multivariate analysis, only daily Fx, number of daily fractions, and total dose were associated with the risk of RP (P < .0001, P < .018, and P < .003, respectively). CONCLUSION: In this analysis, the use of Fx greater than 2.67 Gy was the most significant factor associated with an increased risk of RP. High total dose also appears to be associated with an increased risk, but twice-daily irradiation seems to reduce the risk expected if the same total daily dose is given as a single fraction. High-Fx radiotherapy should be avoided in patients who receive CMT with curative intent.

Radiotherapy for nasolacrimal tract epithelial cancer.

PURPOSE: Tumors of the lacrimal sac are rare and have traditionally been treated surgically. We investigated the use of irradiation for treatment. METHODS AND MATERIALS: Three consecutive patients with primary epithelial cancer of the nasolacrimal apparatus were treated with irradiation. A tumor dose of 52-66 Gy was delivered with conventional fractionation to fields limited to the primary site and immediately surrounding tissues. RESULTS: Local tumor control was achieved in all three patients. Two patients subsequently developed metastatic cervical adenopathy; both were controlled with irradiation to the neck. One of these two died of distant metastases. Two patients are alive and well at 13 years and at 26 months. CONCLUSION: We conclude that epithelial lacrimal sac tumors are controllable by radiation therapy and with a good cosmetic result. Poorly differentiated lesions require elective cervical nodal irradiation.

Predicting the risk of lymph node involvement using the pre-treatment prostate specific antigen and Gleason score in men with clinically localized prostate cancer.

PURPOSE: To evaluate the predictive value of an empirically derived equation for identifying patients with clinically localized prostate cancer at low and high risk for harboring occult lymph node metastasis. METHODS AND MATERIALS: A simple equation for estimating the risk of positive lymph nodes was empirically derived from a nomogram published by Partin et al. demonstrating the value of combining the pre-treatment prostate specific antigen and Gleason Score in predicting the risk of lymph node metastasis for patients with clinically localized prostate cancer. The risk of positive nodes (N+) was calculated using the equation; N+ = 2/3(PSA) + (GS-6) x 10, where PSA and GS are the pre-treatment prostate specific antigen and Gleason Score respectively, and the calculated risk is constrained between 0-65% for a PSA < or = 40 ng/ml (as in the nomogram). To test the general applicability of this equation, we reviewed the pathologic features of 282 of our patients who had undergone a radical prostatectomy. RESULTS: Based on 212 patients for whom the pre-operative prostate specific antigen's and Gleason Scores were available, we identified 145 patients with a calculated risk of positive nodes of < 15%, (low risk group) and 67 patients with a calculated risk as > or = 15% (high risk group). The observed incidence of positive nodes was 6% and 40% among the low and high risk groups respectively (p < 0.001). When used alone neither clinical stage, pre-treatment prostate specific antigen nor the pre-treatment Gleason Score was as useful in identifying the largest low and high risk groups. CONCLUSION: Using the equation described we confirmed the general applicability of the nomogram reported by Partin et al. and identified patients at low and high risk for lymph node involvement. Based on these data we have adopted a policy of omitting whole pelvic irradiation in patients identified as low risk.

Immobilization improves the reproducibility of patient positioning during six-field conformal radiation therapy for prostate carcinoma.

PURPOSE: To determine the magnitude of patient positioning errors associated with six field conformal therapy for carcinoma of the prostate, and to assess the impact of alpha-cradle immobilization on these errors. METHODS AND MATERIALS: The records of 22 patients, treated at two of the treatment facilities within our department, using computed tomography-planned conformal six field therapy for carcinoma of the prostate, were reviewed. At one facility (UCD), patients were routinely treated with immobilization, while at the other (UCSF) no rigid immobilization was used. Portal films of patients treated at both facilities were subsequently reviewed, and the deviation of each portal from the simulation film was determined (simulation-to-treatment variability). In addition, for each patient, the average deviation of each portal film from the average portal film (treatment-to-treatment variability) was determined. RESULTS: The mean and median simulation-to-treatment variability was 0.4 cm for those patients treated with immobilization, versus 0.6 cm for those treated without immobilization. The 90th percentile of simulation-to-treatment variability was 0.7 cm for those patients treated with immobilization, versus 1.1 cm for those not immobilized. There was a significant reduction in the number of portals observed with errors of > or = 0.50 cm (132/201 vs. 37/87, 66% vs. 43%; p < 0.001), 0.75 cm (184/201 vs. 59/87, 92% vs. 68%; p < 0.001), and 1.0 cm (196/201 vs. 74/87, 98% vs. 85%; p < 0.001) for patients treated with immobilization. There was also a significant reduction in the number of patients with treatment-to-treatment variability > or = 0.5 cm (1/10 vs. 8/12; p = 0.01) for patients treated with immobilization. CONCLUSION: The use of immobilization devices significantly reduces errors in patient positioning, potentially permitting the use of smaller treatment volumes. Immobilization should be a component of conformal radiation therapy programs for prostate carcinoma.

Chondrosarcoma of the larynx after radiation treatment for vocal cord cancer.

The case of a 57-year-old man with chondrosarcoma of the laryngeal cartilage is presented, occurring 16 years after radiation treatment for squamous cell carcinoma of the right true vocal cord. Chondrosarcoma of the larynx is an uncommon tumor. The location, grade, and time elapsed from initial treatment make it probably that this patient's chondrosarcoma is associated with his prior radiation treatment. However, it is a rare occurrence, this being the second case reported in the literature.