Lung Cancer.pdf

Surgical Treatment of Locally Advanced Non–Small Cell Lung Cancer 135
diation therapy because it is associated with an increased risk of wound
healing problems (especially at bronchial margins) after surgery and because
the dose that can be delivered before surgery is lower than the dose
that can be delivered after (45 Gy vs 66 Gy). If the final pathologic margins
after surgery are involved, postoperative radiation therapy is delivered to
reduce the risk of local-regional recurrence.
Patients with T4N0–1 Pancoast tumors are treated in a phase II study
evaluating surgical resection followed by postoperative chemoradiation.
After surgery, radiation therapy is delivered over 5 to 6 weeks. Patients
receive 2 fractions per day, to a total dose of 60 Gy in patients with negative
margins or 64.8 Gy in patients with positive margins, plus concurrent
chemotherapy (cisplatin 50 mg/m 2 on days 1 and 8 and etoposide
given by mouth 30 to 60 minutes prior to each administration of radiation
therapy on days 1 through 5 and 8 through 12, with this chemotherapy
cycle repeated starting on day 29). Prophylactic cranial irradiation
(25 Gy in 10 fractions of 2.5 Gy) is given on completion of chest irradiation
because of the high risk of brain recurrences. Three additional cycles
of chemotherapy are delivered after prophylactic cranial irradiation.
This aggressive approach has resulted in long-term survival in a fraction
of patients in whom negative pathologic margins can be obtained
(Gandhi et al, 1999). Because of the complexity of this operation, careful
coordination between the medical oncologists, surgical oncologists, and
radiation oncologists is required. These rare tumors should be treated at
an experienced referral center to ensure the maximum chance for overall
success.
Operative Strategy
Surgery for T4N0–1 non-Pancoast tumors is usually performed after induction
chemotherapy. In some cases, the preoperative chemotherapy has
significantly downstaged the tumor (Figure 7–2). Nevertheless, the original
extent of the tumor must be kept in mind to avoid leaving behind tissue
that may still contain microscopic deposits of viable tumor. To help ensure
complete resection, scans showing the original extent of the tumor
are displayed in the operating room during surgery. The main T4 tumors
approached surgically are tumors that invade the carina, vertebral body,
or atrium. Resection of the vertebral body will be discussed in the discussion
of Pancoast tumors.
Invasion of the carina is rare and should be approached surgically only
if all the mediastinal nodes are negative on cervical mediastinoscopy. All
carinal resections should focus on minimizing the tension on airway anastomoses
by developing a pretracheal plane without interrupting the lateral
blood supply of the trachea. The hilum can also be mobilized with an
inferior hilar release of the pericardium on either side, and a suprahyoid
laryngeal release can be performed if necessary. After surgery, all patients
are put in cervical flexion, with a stitch secured from the chin to the ante-