Temporal Lung Tumor Volume Changes in Small-Cell Lung Cancer Patients Undergoing Chemoradiotherapy

• Published in: International journal of radiation oncology, biology, physics Vol. 80; no. 1; pp. 142 - 147
• Main Authors: Yee, Don, M.D., F.R.C.P.C, Rathee, Satyapal, Ph.D, Robinson, Don, Ph.D, Murray, Brad, M.Sc
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.2011; Elsevier
• Subjects: Adaptive radiotherapy; Aged; Aged, 80 and over; Antineoplastic agents; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Biological and medical sciences; BODY; CAT SCANNING; CHEST; Combined Modality Therapy - methods; COMBINED THERAPY; Combined treatments (chemotherapy of immunotherapy associated with an other treatment); COMPUTERIZED TOMOGRAPHY; DIAGNOSTIC TECHNIQUES; DISEASES; Female; Hematology, Oncology and Palliative Medicine; Humans; Image-guided radiotherapy; Investigative techniques of respiratory function; Investigative techniques, diagnostic techniques (general aspects); Lung Neoplasms - diagnostic imaging; Lung Neoplasms - drug therapy; Lung Neoplasms - pathology; Lung Neoplasms - radiotherapy; LUNGS; Male; Medical sciences; MEDICINE; Middle Aged; Neoplasm Staging; NEOPLASMS; ORGANS; Pharmacology. Drug treatments; Pneumology; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; Radiotherapy Dosage; Respiration; RESPIRATORY SYSTEM; SHRINKAGE; Small cell lung cancer; Small Cell Lung Carcinoma - diagnostic imaging; Small Cell Lung Carcinoma - drug therapy; Small Cell Lung Carcinoma - pathology; Small Cell Lung Carcinoma - radiotherapy; THERAPY; TOMOGRAPHY; Tomography, X-Ray Computed; Tumor Burden - drug effects; Tumor Burden - radiation effects; Tumors of the respiratory system and mediastinum; VARIATIONS; VOLUME; Image-guided radiotherapy; Small cell lung cancer; Adaptive radiotherapy; Human; Lung disease; Respiratory disease; Lung cancer; Malignant tumor; Radiotherapy; Chemoradiotherapy; Guidance; Lung volume; Chemotherapy; Treatment; Bronchus disease; Cancer
• ISSN: 0360-3016; 1879-355X
• DOI: 10.1016/j.ijrobp.2010.01.056

Purpose Small-cell lung cancer is considered to be relatively chemosensitive and radiosensitive. Small-cell tumor volume changes during concurrent chemoradiotherapy have not been quantified. The purpose of this work is to quantify small-cell lung tumor volume variations in limited-stage patients undergoing chemoradiotherapy. Methods and Materials Eligible patients had pathologically confirmed limited-stage small-cell lung cancer, underwent concurrent chemoradiotherapy, and signed study-specific consent forms. Patients underwent serial chest computed tomography (CT) scans on a CT simulator with images acquired at the same phase of patients' respiratory cycle. Computed tomography scans were obtained at the time of planning CT scan and 3 times a week during radiotherapy (RT). Gross tumor volumes (GTVs) were contoured on each CT scan. Gross tumor volumes defined on each CT scan were analyzed for volume changes relative to pre-RT scans. Results We obtained 104 CT scans (median, 11.5 scans per patient). The median tumor dose was 50 Gy. The median pre-RT GTV was 98.9 cm3 (range, 57.8–412.4 cm3 ). The median GTV at the final serial CT scan was 10.0 cm3 (range, 4.2–81.6 cm3 ). The mean GTV relative to pre-RT volume at the end of each RT week was 53.0% for Week 1, 29.8% for Week 2, 22.9% for Week 3, 19.5% for Week 4, and 12.4% for Week 5. Conclusions Dramatic shrinkage of small-cell lung tumors occurred in patients undergoing chemoradiotherapy in this trial. Most of the observed GTV shrinkage occurred during the first week of RT.