Adjuvant radiotherapy for completely resected stage 2 thymoma

Abstract

BACKGROUND: The clinical benefit of postoperative mediastinal radiation for completely resected Masaoka stage 2 thymoma remains controversial. Due to its indolent nature and infrequent recurrences, no study has definitively determined the optimal approach. METHODS: We retrospectively reviewed 175 consecutive patients who underwent thymic resection from January 1990 to July 2008 at the University of Pennsylvania. The primary endpoint was local recurrence, defined as recurrence within the surgical bed, treated by resection alone versus resection plus radiation. Patients with high recurrence risk were referred for adjuvant radiotherapy. RESULTS: Seventy‐four Masaoka stage 2 patients were resected; 62 underwent complete resections with adequate postsurgical follow‐up. Thirty‐seven patients received adjuvant radiotherapy and 25 patients were observed. The median radiation dose was 5040 cGy. The median follow‐up for all patients was 52 months. The local recurrence rate was 3.2%. The proportion of recurrences in patients observed after surgery was 8% versus 0% in those who received adjuvant radiotherapy (P = .15). Size was not an independent predictor of recurrence (P = .81). The tumor‐related death rate was 0%, and overall death rate was 3.2%. One death occurred in each group, observation, and radiation. There were no grade 3 or 4 complications with radiation. CONCLUSIONS: Recurrence rates were low following resection of stage 2 thymoma either with or without adjuvant radiotherapy. Adjuvant radiotherapy, although well‐tolerated, did not significantly decrease the local relapse rate. Differences may be observed in future studies of patients who are at higher risk for local recurrence, based on completeness of resection, World Health Organization histology, and tumor size. Cancer 2011. © 2011 American Cancer Society.

A Review of the Place and Role of Radiotherapy in Thymoma

“…7 To obtain clear resection margins that can be deemed monotherapy-adequate, 1 one might require resection of adjacent critical structures. However, some investigators recommend that postoperative RT (PORT) can be considered for various indications [8][9][10][11][12] and others do not find the use of PORT beneficial. [13][14][15][16][17][18] Where there is R1 or R2 resection PORT is sometimes recommended and with the latter, chemotherapy administration might even be considered.…”

Thymic tumors and outcomes after radiotherapy

“…[3,7] EIII-IV olgularda TE sonrası adjuvan RT önerilirken, EII olup TE timomalı olgularda adjuvan tedavi kararı-nın kötü risk faktörleri varlığında verilmesi gerektiği vurgulanmaktadır. [13][14][15][16] Sağkalım açısından invazivlik, rezeksiyon tipi, MG varlığı, ileri yaş, tümör çapı, hücre siklus protein ekspresyonu gibi birçok PF ortaya konmasına rağmen genel olarak Masaoka ve DSÖ sınıflaması en iyi ve geçerli prediktörler olarak kabul edilmekte ve adjuvan tedavi kararının PF'ye göre verilmesi gerektiği bildirilmektedir. [1,3,[17][18][19][20] Masaoka evresine göre beş yıllık GSK EI-III timoma için %85, EIV için %65 bildirilmektedir.…”

Radiation Therapy for Patients with Thymoma: When, Where and How?

“…There was no difference in OS with a 5 year-OS of 91%. An updated subset analysis in high-risk stage II patients after complete resection was done by Berman et al in 175 patients treated between years 1990-2008 from University of Pennsylvania [4]. Complete resection was done in 62 patients and 37 had high-risk features treated to a dose of 50.4 Gy.…”

“…A dose of 45-50. 4 Gy given in 180-200 cGy per fraction over 5-6 weeks duration in a postoperative situation with clear/negative margins, 54 Gy for positive margins, 60-70 Gy for gross residual disease.…”