title: Changes in global function and regional ventilation and perfusion on SPECT during the course of radiotherapy in patients with non-small-cell lung cancer.
abstract: OBJECTIVE
  This study aimed to (1) examine changes in dyspnea, global pulmonary function test (PFT) results, and functional activity on ventilation (V)/perfusion (Q) single-photon emission computerized tomography (SPECT) scans during the course of radiation (RT), and (2) factors associated with the changes in patients with non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  Fifty-six stage I to III NSCLC patients treated with definitive RT with or without chemotherapy were enrolled prospectively. Dyspnea was graded according to Common Terminology Criteria for Adverse Events version 3.0 prior to and weekly during RT. V/Q SPECT-computed tomography (CT) and PFTs were performed prior to and during RT at approximately 45 Gy. Functions of V and Q activities were assessed using a semiquantitative scoring of SPECT images.
  
  
  RESULTS
  Breathing improved significantly at the third week (mean dyspnea grade, 0.8 vs. 0.6; paired t-test p = 0.011) and worsened during the later course of RT (p > 0.05). Global PFT results did not change significantly, while regional lung function on V/Q SPECT improved significantly after ∼45 Gy. The V defect score (DS) was 4.9 pre-RT versus 4.3 during RT (p = 0.01); Q DS was 4.3 pre-RT versus 4.0 during RT (p < 0.01). Improvements in V and Q functions were seen primarily in the ipsilateral lung (V DS, 1.9 pre-RT versus 1.4 during RT, p < 0.01; Q DS, 1.7 pre-RT versus 1.5 during RT, p < 0.01). Baseline primary tumor volume was significantly correlated with pre-RT V/Q DS (p < 0.01). Patients with central lung tumors had greater interval changes in V and Q than those with more peripheral tumors (p <0.05 for both V and Q DS).
  
  
  CONCLUSIONS
  Regional ventilation and perfusion improved during RT at 45 Gy. This suggests that adaptive planning based on V/Q SPECT during RT may allow sparing of functionally recoverable lung tissue.
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Shuanghu Tiger
authors.initials: ST
authors.lastname: Yuan
authors.forename: Kirk A
authors.initials: KA
authors.lastname: Frey
authors.forename: Milton D
authors.initials: MD
authors.lastname: Gross
authors.forename: James A
authors.initials: JA
authors.lastname: Hayman
authors.forename: Doug
authors.initials: D
authors.lastname: Arenberg
authors.forename: Xu-Wei
authors.initials: XW
authors.lastname: Cai
authors.forename: Nithya
authors.initials: N
authors.lastname: Ramnath
authors.forename: Khaled
authors.initials: K
authors.lastname: Hassan
authors.forename: Jean
authors.initials: J
authors.lastname: Moran
authors.forename: Avraham
authors.initials: A
authors.lastname: Eisbruch
authors.forename: Randall K
authors.initials: RK
authors.lastname: Ten Haken
authors.forename: Feng-Ming Spring
authors.initials: FM
authors.lastname: Kong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D004417:Dyspnea / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging / Q000528:radiation effects; D008175:Lung Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000503:physiopathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D059351:Organ Sparing Treatments / Q000379:methods; D011446:Prospective Studies; D011653:Pulmonary Diffusing Capacity / Q000502:physiology / Q000528:radiation effects; D011879:Radiotherapy Dosage; D012119:Respiration / Q000528:radiation effects; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014797:Vital Capacity / Q000502:physiology / Q000528:radiation effects