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Ann Thorac Surg 2010;89:360-367. doi:10.1016/j.athoracsur.2009.09.052
© 2010 The Society of Thoracic Surgeons
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Right arrow Lung - cancer

Original Articles: General Thoracic

Robotic Brachytherapy and Sublobar Resection for T1 Non-Small Cell Lung Cancer in High-Risk Patients

Justin D. Blasberg, MDa,*, Scott J. Belsley, MDa, Gary S. Schwartz, MDa, Andrew Evans, MDb, Iddo Wernick, PhDb, Robert C. Ashton, Jr, MDc, Faiz Y. Bhora, MDa, Cliff P. Connery, MDa

a Department of Surgery, St. Luke's–Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York
b Department of Radiation Oncology, St. Luke's–Roosevelt Hospital Center, Columbia University College of Physicians and Surgeons, New York
c Division of Cardiothoracic Surgery, Montefiore–Einstein Medical Center, Bronx, New York

Accepted for publication September 16, 2009.

* Address correspondence to Dr Blasberg, Department of Surgery, 1000 Tenth Ave, Suite 2B, New York, NY 10023 (Email: jblasberg{at}chpnet.org).


   Abstract
Top
 Abstract
Introduction
 Material and Methods
 Results
 Comment
 Acknowledgments
 References
 
Background: Sublobar lung resection and brachytherapy seed placement is gaining acceptance for T1 non-small cell lung cancer (NSCLC) in select patients with comorbidities precluding lobectomy. Our institution first reported utilization of the da Vinci system for robotic brachytherapy developed experimentally in swine and applied to high-risk patients 5 years ago. We now report seed dosimetrics and midterm follow-up.

Methods: Eleven high-risk patients with stage IA NSCLC who were not candidates for conventional lobectomy underwent limited resection of 12 primary tumors. To reduce locoregional recurrence, 125I brachytherapy seeds were robotically sutured intracorporeally over resection margins to deliver 14,400 cGy 1 cm from the implant plane. Patients were followed with dosimetric computed tomography scans at 30 ± 16 days. Survival and sites of recurrence were documented.

Results: Resected tumor size averaged 1.48 ± 0.38 cm (range, 1.1 to 2.1 cm). Perioperative mortality was 0% and recurrence was 9% (1 of 11 [margin recurrence at 6 months with resultant mortality at 1 year]). Follow-up duration was 31.82 ± 17.35 months. Dosimetrics confirmed 14,400 cGy delivery using 24.21 ± 4.6 125I seeds (range, 17 to 30 seeds) over a planning target volume of 10.29 ± 2.39 cc3. Overall, 84.1% of the planning target volume was covered by 100% of the prescription dose (V100), and 88.2% was covered by 87% of the prescription dose (V87), comparable to open dosimetric data at our institution. Follow-up imaging confirmed seed stability in all patients.

Conclusions: Robotic 125I brachytherapy seed placement is a feasible adjuvant procedure to reduce the incidence of recurrence after sublobar resection in medically compromised patients. Tailored robotic seed placement delivers an exact dosing regimen in a minimally invasive fashion with equivalent precision to open surgery.


   Introduction
Top
 Abstract
 Introduction
Material and Methods
 Results
 Comment
 Acknowledgments
 References
 
The current standard of care for early stage non-small cell lung cancer (NSCLC) continues to be anatomic surgical resection. Results from the 1995 publication of the Lung Cancer Study Group prospective randomized trial of lobectomy versus limited resection for NSCLC reinforced the survival benefit of conventional lobectomy in stage IA disease [1, 2]. Since that time, the utility of spiral computer tomography (CT) imaging has refined the presentation and diagnosis of early stage NSCLC, facilitating discovery of smaller tumors and identification of ground glass opacities associated with favorable histology. New data has demonstrated that sublobar resection for early stage disease provides a reasonable alternative for patients with limited cardiopulmonary reserve who cannot tolerate anatomic resection [3–8].

The role of adjuvant therapy has also been refined to compensate for deficiencies associated with sublobar resection, namely, an increased risk of locoregional recurrence and reduced 5-year survival [2]. External beam radiation has been used with moderate success as an adjuvant modality [9]; however, damage to surrounding normal lung parenchyma and mediastinal structures creates unacceptable morbidity and reduced pulmonary function after treatment. 125I brachytherapy seeds placed at the time of sublobar resection delivers a concentrated dose of radiation to the operative margin in an efficient and precise manner, with minimal exposure to normal lung tissue [10, 11]. In this setting, localized brachytherapy significantly decreases recurrence rates and associated morbidity compared with external beam radiation, enhancing its utility in patients with limited cardiopulmonary reserve [3, 12].

Evolving indications for the application of brachytherapy in early stage NSCLC patients with cardiopulmonary impairment require improved methods of localized resection and tailored delivery of implantable radiation therapy. Surgical robotics offers enhanced visualization and facilitates intracorporeal dexterity compared with video-assisted thoracoscopic surgery (VATS) [10]. The da Vinci platform simulates an open surgical environment without the limitations of traditional minimal access surgery, which is often restricted by the rigid nature of the chest wall, constrained 90-degree motion of laparoscopic-type instruments, and difficulty maneuvering in confined spaces [10]. In addition, the application of three-dimensional imaging and utilization of instruments with numerous degrees of freedom enhances needle placement and seed precision [10, 13]. These attributes may theoretically limit normal tissue damage while providing the potential for radiation dose escalation. We hypothesize that minimally invasive resection in conjunction with the precision of robotic seed placement can provide highly accurate localized treatment for patients unable to tolerate lobectomy.

We initially evaluated brachytherapy seed application in swine using the da Vinci surgical system to demonstrate the technical feasibility and accuracy of robotically assisted radiation delivery. Theoretical dosimetric calculations confirmed localized radiation delivery comparable to open and VATS placement in the swine model [10]. This study describes our early clinical experience with peripheral stage IA NSCLC in 11 patients with extensive medical comorbidities precluding lobectomy who underwent VATS wedge resection and robotic brachytherapy seed placement.


   Material and Methods
Top
 Abstract
 Introduction
 Material and Methods
Results
 Comment
 Acknowledgments
 References
 
Patient Selection
The study protocol was approved and followed the policies of our Institutional Review Board (IRB 08-060x). Between March 2004 and October 2007, 11 patients with stage IA NSCLC were selected for sublobar resection and adjuvant interstitial brachytherapy owing to the presence of medical comorbidities or pulmonary function tests precluding tolerance and safety of anatomic resection.

The primary indication for sublobar resection included a forced expiratory volume in 1 second (FEV1) of 1 L or less, a predicted diffusion capacity for carbon monoxide of 50% or less, or an exercise tolerance of less than one flight of stairs. These limitations were categorized as a pulmonary indication precluding lobectomy. Secondary indications included patients limited by medical or surgically uncorrectable heart disease who were considered to have cardiac limitations to anatomic resection. These limitations included the presence of pulmonary hypertension (pulmonary artery systolic pressure greater than 40 mm Hg) or poor left ventricular function (ejection fraction of 40% or less). Additional secondary indications included patient age greater than 75 years, refusal of lobectomy due to quality of life or risk issues, an FEV1 of 51% to 60% predicted, or a lung carbon monoxide diffusion capacity of 51% to 60% of predicted. Either the primary indication or two secondary indications were necessary for categorization as a limited resection candidate. These inclusion criteria were adopted from the ongoing randomized phase III investigation of high-risk stage IA NSCLC patients (ACOSG Z4032), comparing outcome data after sublobar resection with and without adjuvant brachytherapy.

Preoperative planning included standard laboratory analysis and metastatic workup (CT of chest, abdomen, and pelvis; magnetic resonance imaging, brain; and positron emission tomography [PET] scan). Tissue diagnosis was established by fine-needle aspiration biopsy. Mediastinoscopy was utilized in select patients based on suspicious PET/CT findings, and was negative in all cases included in the study; patients with pathologic evidence of mediastinal lymphadenopathy or distant disease were excluded. Those who met the outlined inclusion criteria were offered robotic brachytherapy after VATS wedge resection, and patients who could not tolerate single-lung ventilation or refused inclusion were treated by open wedge resection and seed placement.

Operative Technique
After double-lumen endotracheal tube placement and verification of position, patients were turned in the lateral decubitus position with the appropriate side up. A thoracostomy was made in the mid axillary line inferiorly in the seventh intercostal space, and a 12-mm camera port was placed. Initial exploration was performed using the robotic camera held manually. Under direct visualization, two additional working ports were placed cephalad in the fourth intercostal space, one in the subpectoral region just medial to the anterior axillary line and the second anterior to the posterior axillary line; however, this placement varied depending on preoperative imaging and the location of the lesion to be resected.

Malignant tumors were resected thoracoscopically with serial applications of a thick tissue stapler (Endopath ETS45; Ethicon, Somerville, NJ) buttressed with pericardial strips. Resections were performed estimating a gross margin of approximately 2 cm from the tumor edge. Specimens were reviewed intraoperatively by pathological analysis with touch preparation and frozen section to confirm negative circumferential margins before seed application.

The robotic cart was subsequently aligned so that the camera and two robotic arms corresponded to the three ports previously arranged in a triangular fashion. Two Black-Diamond Micro-Forceps (Intuitive Surgical, Sunnyvale, CA) were used for intracorporeal suturing. Radioactive strands consisted of 10 125I brachytherapy seeds embedded in polyglactin 910 suture (Amersham Health, Princeton, NJ). Seeds were implanted along the suture line and placed parallel in a longitudinal fashion run back and forth on each side of the resection margin forming a planar implant with 0.5 cm between each strand. Implants were designed to encompass a plane consisting of the staple line and a 2-cm margin of surrounding visceral pleura. A radiation oncologist and pathologist were present during the case to assist the operating surgeon in refining seed placement. This refinement was accomplished after review of preoperative imaging, assessment of the wedge resection specimen and its associated margins in the x, y, and z axis, and collaboration during needle placement of each respective seed in relation to the resection margin. Source strength averaged 0.7 mCi per seed and was designed to deliver a dose of 14,400 cGy at 1 cm from the plane of the implant delivered over 10 months (5 half-lives). For a given implant, all seeds delivered identical source strength. Operator exposure to radiation during the procedure was measured at 1 m from the implants using a survey meter measured in millirem per hour (mrem/h [Ludlum Model 3, Sweetwater, TX]). At the conclusion of the procedure, 32F chest tubes were placed through the inferior thoracostomy incision under direct vision.

Dosimetrics
Dosimetric calculations were performed in all patients assessed postoperatively with CT imaging. The planning target volume was contoured by a radiation oncologist on the dosimetric CT scan taken 30 ± 16 days (range, 27 to 41) postoperatively. Variseed 7.1 software (Varian Medical Systems, Palo Alto, CA) was used for three-dimensional calculations and postimplant dosimetry, respectively. Dosimetric imaging is shown (Fig 1).


Figure 1
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  		Fig 1. Dosimetric distribution of 125I seeds sewn intracorporeally over the margins of thoracoscopically resected lung cancer in close proximity to vertebrae. Note the limited radiation field surrounding the resection bed. The thick red line shows the contoured planning target volume (PTV); the green dots in the images connote seeds identified on the dosimetric computed tomography scan; the remaining colored lines (isodose lines) surround regions containing minimum doses as a percent of the prescription dose: yellow = 80%; blue = 87%, aqua = 100%; red = 150%; and white = 175%.

 
Follow-Up
Patients were evaluated 2 weeks postoperatively and every 3 months thereafter. Routine follow-up chest radiography was performed at 3-month intervals, and repeat CT scans were performed at 1-month (dosimetric CT) and 6-month intervals to evaluate seed stability and evidence of locoregional recurrence (staple line recurrence versus hilar or mediastinal disease progression). Recurrence by CT scan was defined by the presence of a new parenchymal lesion within the lobe of resection, or the growth of a parenchymal opacification of 25% or greater at the staple line compared with prior imaging. Suspicion of recurrence was confirmed by PET/CT scan or CT-guided biopsy if accessible.


   Results
Top
 Abstract
 Introduction
 Material and Methods
 Results
Comment
 Acknowledgments
 References
 
Eight women and 3 men with a median age of 73 years (range, 62 to 82) comprised the study population. Patient demographics are shown in Table 1. Four patients had an FEV1 less than 1 L, with a median value of 1.50 ± 0.4 L (range, 0.89 L to 2.15 L), and 7 patients had a carbon monoxide diffusion capacity of less 50% predicted, with a median value of 52.5% ± 12.9% (range, 42% to 75%). Four patients had evidence of significant coronary artery disease with associated congestive heart failure (EF < 40%), all with limited exercise tolerance. One patient presented with bilateral primary lung lesions and pulmonary function tests precluding conventional resection. Six patients underwent limited resection owing to advanced age (median 79 years; range, 76 to 82).


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  		Table 1 Patient Demographics, Robotic Cohort
 
The 11 patient cases proceeded without an intraoperative event. Anesthesia time averaged 3.1 ± 0.16 hours (range, 2.5 to 3.4). Total surgery time averaged 2.3 ± 0.26 hours (range, 1.6 to 2.9). Patients were monitored overnight in the intensive care unit and transferred to the floor. All chest tubes were removed on the second postoperative day, and patients were discharged a short time thereafter in excellent functional status. Mean hospital stay was 4.6 ± 1.3 days (range, 3 to 8). Mean tumor size was 1.48 ± 0.38 cm (range, 1.1 cm to 2.1 cm); 2-cm margins or greater were achieved in all specimens, and histologic margins were negative for carcinoma as per pathology assessment. Two patients had postoperative complications, including an episode of bradycardia in patient 3 and superventricular tachycardia in patient 7. Both patients were managed pharmacologically without event. Pathology and follow-up CT imaging results are shown in Table 2.


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  		Table 2 Pathology and Follow-Up Computed Tomography (CT) Results
 
Patient 3 demonstrated CT evidence of disease recurrence at the resection margin 6 months postoperatively. One year prior, the patient underwent open lobectomy for a T1N1 (2.5 cm) right upper lobe invasive adenocarcinoma with marked atypia, and adjuvant chemotherapy was initiated. Routine screening at 1 year follow-up defined a contralateral 1.3-cm tumor with radiographic features highly suspicious for malignancy. Owing to poor pulmonary function and advanced age, VATS wedge resection and robotic brachytherapy seed placement were performed; pathology was also consistent with invasive adenocarcinoma with marked atypia. Follow-up CT scan 6 months postoperatively defined both suture line and regional evidence of recurrence, and diffuse metastatic disease was confirmed by PET/CT. Chemotherapy was initiated; however, the patient died 12 months postoperatively. For the remainder of the patients assessed, follow-up chest radiographs and CT scans at 6-month intervals demonstrated stability of seed placement and lack of tumor recurrence, with 2-year follow-up imaging available for 6 patients (Figs 2 and 3). Go Median follow-up was 31.81 ± 17.35 months (range, 12 to 61).


Figure 2
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  		Fig 2. Chest radiography performed (A) in the immediate postoperative period and (B) at follow-up evaluation 2 years postoperatively for patient 6. Radioactive seeds maintained a fixed position without migration (arrows).

 

Figure 3
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  		Fig 3. (A) Dosimetric computed tomography scan and (B) 2-year follow-up imaging of patient 6, demonstrating residual scar and stability of seed placement (arrows) with no evidence of disease recurrence.

 
Dosimetric calculations confirmed that the prescription dose of 14,400 Gy was achieved using an average number of 24.44 ± 4.8 I125 seeds (range, 17 to 30). This was accomplished over an average PTV volume of 10.26 ± 2.38 cc3. Dosimetric analysis also confirmed a PTV V100 of 83.79% ± 15.10% and V87 of 87.85% ± 12.91%. The V100 metric is a standard measure for evaluation of postimplant analysis for other brachytherapy implant procedures. The latter dosimetric measure (V87) is relevant because dose calculations for lung implants require adjustment due to the lower density of lung tissue [14]. Radiation exposure to the operating surgeon measured during robotic seed placement averaged 0.5 mrem/h (range, 0.4 to 0.8 mrem/h) at 1 m from the implants.

Dosmetrics were concurrently assessed in a cohort of 8 patients with stage IA NSCLC treated by open wedge resection and brachytherapy seed placement, with similar comorbidities and inclusion criteria as previously defined (Table 3). Anesthesia time averaged 2.7 ± 0.55 hours (range, 2.2 to 2.9). Total surgery time averaged 1.95 ± 0.22 hours (range, 1.2 to 2.2). Mean hospital stay was 6.8 ± 1.8 days (range, 4 to 11). Mean tumor size was 1.69 ± 0.42 cm (range, 1.2 cm to 2.2 cm). Perioperative mortality and recurrence was 0% over a mean follow-up of 32.5 ± 11.84 months. In the open resection group, a prescription dose of 14,400 Gy was achieved using an average of 24.79 ± 3.3 I125 seeds (range, 17 to 35). This was accomplished over an average PTV volume of 11.18 ± 2.25 cc3. Dosimetric analysis also confirmed a PTV V100 of 77.41% ± 9.91% and V87 of 81.48% ± 13.21%. Radiation exposure to the operating surgeon measured during open seed placement averaged 1.9 mrem/h (range, 1.5 to 2.2 mrem/h) at 1 m from the implants.


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  		Table 3 Patient Demographics, Open Seed Cohort
 

   Comment
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
Acknowledgments
 References
 
Surgical management of peripheral stage IA NSCLC was standardized after publication of the Lung Cancer Study Group results in 1995. This study suggested that limited resection was associated with a threefold increase in locoregional recurrence (17.2% versus 6.4%) and no preservation of pulmonary function when compared with conventional lobectomy, regardless of tumor size [2]. Since that time, compelling literature comparing anatomic versus sublobar resection for early stage NSCLC has evaluated the equivalency of disease-free survival [4, 15, 16]. The advent of enhanced CT technology and screening protocols for high-risk patients has established a cohort of patients presenting with smaller tumors and increased resectability. Specifically, much research has focused on the role of sublobar resection in high-risk patients with small peripheral tumors and physiology precluding lobectomy [1, 17–20].

Although limited resection increases the rate of locoregional recurrence, in a subset of patients with stage IA NSCLC and limited cardiopulmonary reserve, the risk of recurrence after 5-year follow-up is outweighed by the patients' medical comorbidities precluding the more definitive operation. Landreneau and the Pittsburgh group [15] attributed decreased 5-year survival in compromised patients undergoing limited resection to noncancer-related deaths, and suggested the adequacy of wedge resection for early stage disease in this setting. Theoretical advantages of sublobar resection, including preservation of pulmonary function, improvements in perioperative morbidity and mortality, and increased potential for a second resection due to a subsequent primary tumor, are important considerations for patients with compromised cardiopulmonary function [2]. More recent analysis has demonstrated that sublobar resection can afford equivalent recurrence risk and survival to conventional lobectomy for early stage disease, correlating tumor size (less than 2 cm) with improved outcome [16, 21–23]. These studies have demonstrated the feasibility of sublobar resection in patients with limited cardiopulmonary reserve.

To address the concern of increased locoregional recurrence associated with nonanatomic resection, interstitial implantable radioactive sources have been developed to provide targeted radiation delivery while sparing exposure to surrounding normal lung [4]. Localized tissue radiation was initially performed percutaneously [24]; however, the need for more precise application combined with fears of seed mobility lead to intracorporeal applications, including iodine seeds sandwiched between gel foam and secured with Vicryl (Ethicon) mesh [24–26]. More recently, seeds have been utilized as strands placed longitudinally to a resection margin, a technique associated with lower rates of recurrence [7]. These advancements have spawned outcome data from large sublobar resection groups that employ brachytherapy, demonstrating rates of disease-free survival comparable to those for lobectomy [12] and significant improvement in locoregional control compared with sublobar resection alone [3, 27, 28].

The application of minimal access surgery to limited resection and adjuvant therapy is associated with theoretical advantages of increased magnification and improved seed accuracy, reduced postoperative pain, and shorter hospital length of stay [11]. Minimally invasive lung resection and brachytherapy placement by VATS is associated with long-term stability of radioactive seeds and rates of survival comparable to historical data from open surgery [11, 29]. However, VATS seed placement is severely restricted by limitations associated with the mechanics of thoracoscopic instruments. This platform constrains the operator to 90-degree instrument manipulation, similar to the limited movements associated with laparoscopy. Restricted rotational freedom due to the rigidity of the chest wall and stiffness of VATS instruments theoretically limit precise radioactive seed implantation compared with open surgery. Intracorporeal suturing with traditional thoracoscopic instrumentation is also restricted because the rib cage limits the full motion of operating ports and acts as a fulcrum. This makes suture placement prone to torquing forces on friable lung tissue and increases the risk of seed displacement from a planned position alerting dose distribution. As of yet, the dosimetric equivalency of VATS brachytherapy placement with open surgery has not been validated in the literature.

To date, little research has focused on the utilization of a robotics platform for contoured implantation of brachytherapy seeds after sublobar resection. The need for tailored application of seed placement as well as the relevance of specific geometric patterns for brachytherapy in multiple organ systems has remained largely theoretical because of the inherent difficulty of orienting numerous seeds in complex three-dimensional space. Theoretical advantages of a robotics platform include precision of seed placement, enhanced dexterity especially in narrow regions with reduced visibility, and limited radiation exposure of the operator in comparison with open surgery. Robotic instruments articulate with 360-degree rotation in all directions utilizing three-dimensional visualization, which ensures accurate manipulation of a brachytherapy suture needle and placement in a manner that is technically equivalent to open surgery [30]. Also, seed misplacement resulting in deviation of radiation delivery is reduced by robotic seed implantation, providing an optimal platform for accurately locating and orientating the suture needle before penetration, as well as achieving proper penetration depth into lung tissue [30]. The use of robotic instruments in the chest, which simulates hand movements associated with open surgery in a minimally invasive format, is thus well suited for precise brachytherapy seed placement in patients with limited cardiopulmonary reserve.

In this study, 11 patients with stage IA NSCLC were treated by VATS wedge resection and robotic brachytherapy seed placement. Comparison of the dosimetric data suggests the equivalency of the open and robotically placed I125 brachytherapy seeds by the technique described. Within a similar PTV, both modalities demonstrated equivalent V87 and V100 treatment dosing. This result is not surprising, as our previous robotic investigations have demonstrated the technical similarity of robotic and open surgery [10]. Open resection and seed placement was associated with shorter operative duration (1.95 ± 0.22 versus 2.3 ± 0.26 hours), but longer hospital length of stay (6.8 ± 1.8 versus 4.6 ± 1.3 days) compared with robotic placement. This result is also consistent with many of the VATS procedures performed at our institution and highlights a significant advantage of minimal access surgery, namely, shorter hospital length of stay. Extended operative times for robotic brachytherapy seed implantation was likely due to the learning curve associated with robotic integration both for the operator and ancillary staff. However, this difference was on average less than 21 minutes per procedure and will likely improve with increased experience and a larger sample cohort. Intraoperative radiation monitoring demonstrated a fourfold increase in operator exposure for open seed placement compared with robotics (1.9 mrem/h [range, 1.5 to 2.2 mrem/h] versus 0.5 mrem/h [range, 0.4 to 0.8 mrem/h]). Although both procedures are associated with significantly less radiation exposure than the limits suggested by the American Academy of Physicists in Medicine Task Force, protection from exposure by a closed chest cavity is an important consideration and a technical advantage of minimally invasive brachytherapy seed placement. These radiation exposure results are comparable to those from previously reported VATS brachytherapy investigations [31].

Mean follow-up for all patients was more than 31 months, and only 1 patient had evidence of disease recurrence at 6 months, resulting in mortality at 1 year (highly aggressive pathology), also comparable to follow-up data from our institution regardless of comorbidity or stage. Mean tumor size was 1.48 ± 0.38 cm, a pathologic feature associated with improved survival and reduced recurrence in sublobar resection literature [3, 4]. Follow-up imaging demonstrated seed stability and lack of migration in all patients. These results suggest that limited resection with robotic brachytherapy seed placement is a reasonable treatment protocol for the management stage IA NSCLC in compromised patients.

Robotic 125I seed placement will become more important if the trend of radiation dose escalation appearing in treatment for NSCLC is proven to be applicable to brachytherapy [32]. Permanent implant seed placement and dose distribution optimization models have been proposed for other organ systems [33, 34]. While the efficacies of brachytherapy for stage I NSCLC and more advanced margin positive NSCLC are still relatively controversial, the robotic placement of 125I seeds provides an opportunity for a more interactive treatment strategy between the radiation oncologist and the thoracic surgeon. This technique combines the advantages of a minimally invasive resection with the same precision and control of open brachytherapy placement.

Appreciable weaknesses of this study include a small sample size and a lack of VATS brachytherapy data for dosimetric comparison. Continued enrollment of patients with limited cardiopulmonary reserve who qualify for sublobar resection and brachytherapy seed placement, as well as accrual of long-term outcome data, will likely strengthen the conclusions reached by this study. Despite developments in three-dimensional imaging and articulating instruments for VATS application, the investigators believe that the innate advantages of robotic technology, which has been further strengthened by concurrent integration of magnetic resonance imaging, CT, and ultrasonography to improve three-dimensional seed precision [35], will likely have a place in the armamentarium of future surgeons.

In conclusion, the use of robotics as a minimally invasive tool in limited lung resection is associated with precise and reproducible placement of radioactive brachytherapy seeds. Multiple degrees of freedom associated with robotic instruments allow accurate placement of brachytherapy seeds in a restricted operative field such as the thoracic cavity, with dosimetric data that are comparable to open surgery. The magnitude of this new procedure's benefit will depend on a concurrent evolving need for more specific and accurate intraoperative brachytherapy. Further studies will employ dosimetric analysis and attempts to further improve precision with brachytherapy delivery using the da Vinci system. Our midterm follow-up will be compared with studies such as ACOSG Z4032 to provide further information regarding 5-year survival.


   Acknowledgments
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 Acknowledgments
References
 
This study was supported by funding from the Continuum Cancer Centers of New York, the Eliana Center for the Care and Treatment of Thoracic Malignancies, and the St. Luke's–Roosevelt Department of Surgery.


   References
Top
 Abstract
 Introduction
 Material and Methods
 Results
 Comment
 Acknowledgments
 References
 

  1. Warren WH, Faber LP. Segmentectomy versus lobectomy in patients with stage I pulmonary carcinoma. Five-year survival and patterns of intrathoracic recurrence. J Thorac Cardiovasc Surg 1994;107:1087-1094.[Abstract/Free Full Text]
  2. Ginsberg RJ, Rubinstein LV. Randomized trial of lobectomy versus limited resection for T1 N0 non-small cell lung cancer. Lung Cancer Study Group. Ann Thorac Surg 1995;60:615-623.[Abstract/Free Full Text]
  3. Fernando HC, Santos RS, Benfield JR, et al. Lobar and sublobar resection with and without brachytherapy for small stage IA non-small cell lung cancer J Thorac Cardiovasc Surg 2005;129:261-267.[Abstract/Free Full Text]
  4. El-Sherif A, Gooding WE, Santos R, et al. Outcomes of sublobar resection versus lobectomy for stage I non-small cell lung cancer: a 13-year analysis Ann Thorac Surg 2006;82:408-416.[Abstract/Free Full Text]
  5. Henschke CI, Yankelevitz DF, Altorki NK. The role of CT screening for lung cancer Thorac Surg Clin 2007;17:137-142.[Medline]
  6. Miller DL, Rowland CM, Deschamps C, Allen MS, Trastek VF, Pairolero PC. Surgical treatment of non-small cell lung cancer 1 cm or less in diameter Ann Thorac Surg 2002;73:1545-1551.[Abstract/Free Full Text]
  7. Lee W, Daly BD, DiPetrillo TA, et al. Limited resection for nonsmall-cell lung cancer: observed local control with implantation of I-125 brachytherapy seeds Ann Thorac Surg 2003;75:237-243.[Abstract/Free Full Text]
  8. Lewis JW, Ajlouni M, Kvale PA, et al. Role of brachytherapy in the management of pulmonary and mediastinal malignancies Ann Thorac Surg 1990;49:728-733.[Abstract/Free Full Text]
  9. Miller JI, Hatcher CR. Limited resection of bronchogenic carcinoma in the patient with marked impairment of pulmonary function Ann Thorac Surg 1987;44:340-343.[Abstract/Free Full Text]
  10. Pisch J, Belsley SJ, Ashton R, Wang L, Woode R, Connery C. Placement of (125)I implants with the da Vinci robotic system after video-assisted thoracoscopic wedge resection: a feasibility study Int J Radiat Oncol Biol Phys 2004;60:928-932.[Medline]
  11. d'Amato TA, Galloway M, Szydlowski G, Chen A, Landreneau RJ. Intraoperative brachytherapy following thoracoscopic wedge resection of stage I lung cancer Chest 1998;114:1112-1115.[Abstract/Free Full Text]
  12. Birdas TJ, Koehler RP, Colonias A, et al. Sublobar resection with brachytherapy versus lobectomy for stage Ib nonsmall-cell lung cancer Ann Thorac Surg 2006;81:434-439.[Abstract/Free Full Text]
  13. Ma GW, Pytel M, Trejos AL, et al. Robot-assisted thoracoscopic brachytherapy for lung cancer: comparison of the ZEUS robot, VATS, and manual seed implantation Comput Aided Surg 2007;12:270-277.[Medline]
  14. Prasad SC, Bassano DA, Perg JG. Lung density effect on 125I dose distribution Med Phys 1985;12:99-100.[Medline]
  15. Landreneau RJ, Sugarbaker DJ, Mack MJ, et al. Wedge resection versus lobectomy for stage I (T1 N0 M0) non-small-cell lung cancer J Thorac Cardiovasc Surg 1997;113:691-700.[Abstract/Free Full Text]
  16. Campione A, Ligabue T, Luzzi L, et al. Comparison between segmentectomy and larger resection of stage IA non-small cell lung carcinoma J Cardiovasc Surg (Torino) 2004;45:67-70.[Medline]
  17. Okada M, Nishio W, Sakamoto T, et al. Effect of tumor size on prognosis in patients with non-small cell lung cancer: the role of segmentectomy as a type of lesser resection J Thorac Cardiovasc Surg 2005;129:87-93.[Abstract/Free Full Text]
  18. Okada M, Koike T, Higashiyama M, Yamato Y, Kodama K, Tsubota N. Radical sublobar resection for small-sized non-small cell lung cancer: a multicenter study J Thorac Cardiovasc Surg 2006;132:769-775.[Abstract/Free Full Text]
  19. Mery CM, Pappas AN, Bueno R, et al. Similar long-term survival of elderly patients with non-small cell lung cancer treated with lobectomy or wedge resection within the surveillance, epidemiology, and end results database Chest 2005;128:237-245.[Abstract/Free Full Text]
  20. Chang MY, Mentzer SJ, Colson YL, et al. Factors predicting poor survival after resection of stage IA non-small cell lung cancer J Thorac Cardiovasc Surg 2007;134:850-856.[Abstract/Free Full Text]
  21. El-Sherif A, Luketich JD, Landreneau RJ, Fernando HC. New therapeutic approaches for early stage non-small cell lung cancer Surg Oncol 2005;14:27-32.[Medline]
  22. Martin-Ucar AE, Nakas A, Pilling JE, West KJ, Waller DA. A case-matched study of anatomical segmentectomy versus lobectomy for stage I lung cancer in high-risk patients Eur J Cardiothorac Surg 2005;27:675-679.[Abstract/Free Full Text]
  23. Griffin JP, Eastridge CE, Tolley EA, Pate JW. Wedge resection for non-small cell lung cancer in patients with pulmonary insufficiency: prospective ten-year survival J Thorac Oncol 2006;1:960-964.[Medline]
  24. Heelan RT, Hilaris BS, Anderson LL, et al. Lung tumors: percutaneous implantation of I-125 sources with CT treatment planning Radiology 1987;164:735-740.[Abstract/Free Full Text]
  25. Voynov G, Heron DE, Lin CJ, et al. Intraoperative (125)I Vicryl mesh brachytherapy after sublobar resection for high-risk stage I non-small cell lung cancer Brachytherapy 2005;4:278-285.[Medline]
  26. Coloni GF, Loasses A, Di Egidio M, et al. Preliminary observations on lung cancer therapy by interstitial irradiation with iodine 125 Ital J Surg Sci 1983;13:49-53.[Medline]
  27. Santos R, Colonias A, Parda D, et al. Comparison between sublobar resection and 125Iodine brachytherapy after sublobar resection in high-risk patients with stage I non-small-cell lung cancer Surgery 2003;134:691-697.[Medline]
  28. McKenna RJ, Mahtabifard A, Yap J, et al. Wedge resection and brachytherapy for lung cancer in patients with poor pulmonary function Ann Thorac Surg 2008;85(Suppl):733-736.
  29. Chen A, Galloway M, Landreneau R, et al. Intraoperative 125I brachytherapy for high-risk stage I non-small cell lung carcinoma Int J Radiat Oncol Biol Phys 1999;44:1057-1063.[Medline]
  30. Nag S, Ciezki JP, Cormack R, et al. Intraoperative planning and evaluation of permanent prostate brachytherapy: report of the American Brachytherapy Society Int J Radiat Oncol Biol Phys 2001;51:1422-1430.[Medline]
  31. National Council on Radiation Protection and Measurements Limitation of exposure to ionizing radiationNCRP Report, 116http://www.ncrponline.org/Publications/Statements/Statement_10.pdf 2001.
  32. Rosenzweig KE, Amols H, Ling CC. New radiotherapy technologies Semin Surg Oncol 2003;21:190-195.[Medline]
  33. Lee EK, Gallagher RJ, Silvern D, Wuu CS, Zaider M. Treatment planning for brachytherapy: an integer programming model, two computational approaches and experiments with permanent prostate implant planning Physics Med Biol 1999;44:145-165.[Medline]
  34. Leclerc G, Lavallee MC, Tubic D, Metivier J, Vigneault E, Beaulieu L. Idealized line source configuration for permanent 125I prostate implants Radiother Oncol 2004;72:213-220.[Medline]
  35. Macura KJ, Stoianovici D. Advancements in magnetic resonance-guided robotic interventions in the prostate Top Magn Reson Imaging 2008;19:297-304.[Medline]




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