Paul Chomiak, MD, Director, Thoracic Surgical Oncology, Sarasota Memorial Health Care System
Lung cancer is an epidemic in our country. Historically, most patients do not think of seeking care for lung conditions until they experience symptoms. Lung cancer patients are customarily diagnosed in an advanced stage that requires multidisciplinary chemotherapy, radiation therapy, and possibly immunotherapy. The success of cancer treatment relies on having an opportunity to screen and identify asymptomatic patients with an early stage of cancer that has a higher chance for cure. Other cancer screening programs that screen patients for breast cancer, colon cancer, and prostate cancer have been successfully implemented for decades. Today, according to the American Cancer Society, more people die from lung cancer than from those cancers combined.
The National Lung Cancer Trial demonstrated convincing evidence that validated the use of low dose non-contrast screening in high risk individuals. Most accredited multidisciplinary cancer centers now offer robust lung cancer screening programs. Recent trials have demonstrated a reduction in lung cancer associated mortality through lung cancer screening.
The growing use of lung cancer screening also has identified an increasing incidence of ground glass opacification (GGO) reported in up to 63% of all screening studies. Though historically a GGO was considered to represent an inflammatory lung disease, GGO may also represent a lung cancer. Hence the increased incidence of GGO identified on lung cancer screening studies is resulting in a clinical concern.
"GGO is an increasingly frequent finding observed in lung cancer screening studies and, though it may represent a pulmonary inflammatory condition, a change in GGO size or development of a solid component could indicate malignancy"
Often incidentally identified lung nodules may be further risk stratified with the use of a PET/CT. Routine use of a PET/CT to evaluate GGO’s is considered by some authors as inappropriate due to unacceptable reported false negative rates. Accurate histologic biopsy of a GGO is difficult secondary to its architecture. CT guided biopsies of GGO dominant lesions demonstrate a diagnostic yield between 35% - 80% depending on the lesion size. However, GGO biopsy diagnostic accuracy was enhanced utilizing a combined technique of endobronchial ultrasound with a virtual navigation bronchoscopy.
For patients identified with pure GGO, an interval course of observation with a repeat CT scan may be appropriate. However, intervention should be offered if the pure GGO increases in size or there is identification of a solid component in the GGO. Patients who have previously undergone a lung resection for lung cancer and develop a new pure GGO should be offered intervention versus observation due to an increased risk of tumor recurrence.
Due to the documented range of false negative biopsy results for GGO lesions, many physicians are recommending to proceed with upfront surgical resection that can offer both diagnosis and therapeutics in one single setting. Various thoracic surgical approaches can be offered depending on the location and size of the GGO. Historically, a traditional thoracotomy was utilized to offer the opportunity for manual palpation of the lung to identify small nodules. However, pure GGO lesions are difficult to localize with manual palpation. Minimal invasive approaches such as da Vinci robotic surgery or video assisted thoracoscopic surgery (VATS) currently lack normal haptic feedback for the surgeon. If minimal invasive thoracic surgical techniques are utilized alone, more than half of the time the surgeon failed to palpate or visualize an indeterminate nodule such as a GGO.
Minimally invasive thoracic surgery (da Vincirobotic or VATS) has demonstrated notable benefits in allowing a patient to recover and return to their preoperative quality of life at a faster rate. Various techniques have evolved to aid in localizing indeterminate nodules, facilitating a successful limited lung resection using minimally invasive surgery. Early experience required introduction of a wire hook, injectable dyes, coils, markers or radiotracers via a separate CT guided percutaneous process performed in radiology. With the advent of electromagnetic navigational bronchoscopy (ENB), indeterminate nodule dye marking could be offered in the operating room followeddirectly by minimallyinvasive surgical resection. The use of Indocyanine green (ICG) with intraoperative near-infrared imaging (Firefly) offers patients with a GGO the opportunity to benefit from a da Vincirobotic thoracic surgical intervention.
An elderly male with a former history of tobacco abuse and two prior malignancies was incidentally identified with a pure GGO in the right middle lobe. Over a course of surveillance, the GGO had doubled in size to 16 mm and demonstrated an 8 mm central solid component. The location of this GGO was not ideal for either a transthoracic needle biopsy or bronchoscopic approach. Considering the change in size and architecture, a concern was raised over malignancy. I recommended a single visit Monarch robotic bronchoscopy ICG dye marking followed by a da Vinci robotic exploration and resection of the GGO.
Unlike current ENB bronchoscopy, the Monarch robotic bronchoscope provided an accurate platform that utilizes both optical recognition and navigational guidance. Once the ICG dye was delivered to the region of the GGO, the da Vinci robot utilizing Firefly near-infrared imaging was able to easily identify the right middle lobe GGO that was not visualized by the naked eye. A limited lung resection was performed and immediately interpreted by pathology as an adenocarcinoma lung cancer. The patient underwent a da Vinci robotic completion lobectomy and lymph node dissection.
The patient’s recovery was uneventful and only required a 2 day length of stay in a general ward bed. The final pathology demonstrated a pT1bN0 stage IA2 adenocarcinoma lung cancer. One week following surgery, the patient no longer was utilizing any narcotic pain medication. The patient was resuming an active lifestyle and was eager to return to playing golf.
I am hopeful that lung cancer screening will follow the footsteps of other screening modalities. Being able to identify cancer at an earlier stage would be more amenable to curative resection. GGO is an increasingly frequent finding observed in lung cancer screening studies and, though it may represent a pulmonary inflammatory condition, a change in GGO size or development of a solid component could indicate malignancy.
Conventional lung nodule diagnostic methods of needle biopsy or PET/CT may result in unacceptable false negative rates for a GGO. The combination of a Monarch robotic bronchoscopy ICG marking followed by immediate da Vinci® robotic lung exploration with Firefly can provide a “one-stop shop” to diagnose and treat a suspicious GGO. This combination of robotic technologies provides a highly accurate and efficient method of managing a GGO with minimal impact to patient quality of life.
I believe that every multidisciplinary cancer program involved in lung cancer screening must be able to offer robotic minimal invasive options for GGO diagnosis and therapy.