Effects of proton and combined proton/photon beam radiation on pulmonary function in patients with resectable but medically inoperable non-small cell lung cancer.

STUDY OBJECTIVES: We evaluated the effects on pulmonary function of irradiating lung cancer with protons alone or protons combined with photons. DESIGN: Prospective phase I/II study. SETTING: University medical center. PATIENTS AND INTERVENTIONS: Ten patients with stage I-II non-small cell lung cancer (NSCLC) and FEV(1) < or = 1.0 L were irradiated with protons to areas of gross disease only, using 51 cobalt gray equivalents (CGE) in 10 fractions (protocol 1). Fifteen patients with stage I-IIIA NSCLC and FEV(1) > 1.0 L received 45-Gy photon irradiation to the primary lung tumor and the mediastinum, plus a 28.8-CGE proton boost to the gross tumor volume (protocol 2). MEASUREMENTS: Pulmonary function was evaluated prior to treatment and 1 month, 3 months, and 6 to 12 months following irradiation. RESULTS: In patients receiving protocol 1, no significant changes in pulmonary function occurred. In patients receiving protocol 2, at 6 to 12 months, the diffusion capacity of the lung for carbon monoxide had declined from 61% of predicted to 45% of predicted (p < 0.05), total lung capacity had declined from 114% of predicted to 95% of predicted (p < 0.05), and residual volume had declined from 160% of predicted to 132% of predicted (p < 0.05). Airway resistance increased from 3.8 to 5.2 cm H(2)O/L/s (p < 0.05). No statistically significant changes occurred in vital capacity, FEV(1), or PaO(2). CONCLUSIONS: Our observations indicate that it is feasible to apply higher-than-conventional doses of radiation at a higher-than-conventional dose per fraction without excess pulmonary toxicity when conformal radiation techniques with protons are used.

Proton-beam radiotherapy for early-stage lung cancer.

STUDY OBJECTIVE: A prospective study was undertaken to assess the efficacy and toxicity of conformal proton-beam radiotherapy for early-stage, medically inoperable non-small cell lung cancer. DESIGN: Eligible patients had clinical stage I to IIIa non-small cell lung cancer and were not candidates for surgical resection for medical reasons or because of patient refusal. Patients with adequate cardiopulmonary function received 45 Gy to the mediastinum and gross tumor volume with photons with a concurrent proton boost to the gross tumor volume of an additional 28.8 cobalt gray equivalents (CGE). Total tumor dose was 73.8 CGE given over 5 weeks. Patients with poor cardiopulmonary function received proton-beam radiotherapy to the gross tumor volume only, with 51 CGE given in 10 fractions over a 2-week period. RESULTS: Thirty-seven patients were treated in the study from July 1994 to March 1998. Clinical staging of patients was as follows: stage I, 27 patients; stage II, 2 patients; and stage IIIa, 8 patients. Eighteen patients received a combination of protons and x rays, while 19 patients received proton-beam radiation only. Follow-up of evaluable patients ranged from 3 to 45 months, with a median of 14 months. Two patients in the proton and photon arm developed pneumonitis that resolved with oral steroids; otherwise, no significant toxicities were encountered. The actuarial disease-free survival at 2 years for the entire group was 63%; for stage I patients, disease-free survival at 2 years was 86%. Local disease control was 87%. CONCLUSION: Preliminary results from this study indicate that proton-beam radiotherapy can be used safely in this group of patients. Disease-free survival and local control appear to be good and compare favorably with published reports utilizing conventional photon irradiation.

Pulmonary injury from proton and conventional radiotherapy as revealed by CT.

OBJECTIVE: Although radiation therapy is used in early-stage inoperable lung cancer, it often results in injury to functional lung tissue. A study was undertaken to determine the frequency and severity of pulmonary injury revealed by CT in patients who had undergone conformal proton (to a limited volume) radiation therapy. We compared these findings with those from a group of patients who had undergone a combination of photon and conformal proton (to a larger volume) radiation therapy. CONCLUSION: Proton radiation therapy was associated with a lower frequency of pulmonary injury than the combined regimen. Injury correlated well with the volume of normal lung that was irradiated. Conformal proton radiation therapy appears to be able to reduce the incidence and severity of pulmonary injury revealed by CT.

Exercise-induced complete heart block in a patient with chronic bifascicular block.

Heart block induced by exercise or associated with symptomatic, chronic bifascicular block can progress to high-grade atrioventricular (AV) block and sudden death. The authors describe a case of exercise-induced AV block in a patient with chronic bifascicular block. Thirty seconds of ventricular asystole were observed during exercise treadmill testing. Myocardial ischemia was ruled out, and the cause was determined to be distal AV nodal block. The pathophysiology, diagnosis, and treatment of distal AV nodal block are reviewed. The role of exercise treadmill testing and electrophysiologic studies in distal AV block are outlined in a diagnostic and therapeutic strategy.

Embryonal carcinoma of the testis presenting as a left heart mass.

A 31-year-old man with a history of intravenous drug abuse and tooth abscess was admitted for evaluation of possible infective endocarditis. Echocardiography showed that he had a left atrial mass. The mass removed from the left atrium had the same histology as the primary embryonal carcinoma discovered in the right testicle during hospitalization. The patient made a smooth recovery after surgical intervention and chemotherapy. This is believed to be the first reported case of metastasis from embryonal carcinoma of the testis to the left side of the heart that was successfully removed at surgery.