HI-CHART: a phase I/II study on the feasibility of high-dose continuous hyperfractionated accelerated radiotherapy in patients with inoperable non-small-cell lung cancer.

PURPOSE: To determine the feasibility of high-dose continuous hyperfractionated accelerated radiotherapy in patients with inoperable non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: In a prospective, Phase I/II study, according to the risk for radiation pneumonitis, three risk groups were defined: V(20) <25%, V(20) 25-37%, and V(20) >37%. The dose was administered in three steps from 61.2 Gy/34 fractions/23 days to 64.8 Gy/36 fractions/24 days to 68.40 Gy/38 fractions/25 days (1.8 Gy b.i.d. with 8-h interval), using a three-dimensional conformal technique. Only the mediastinal lymph node areas that were positive on the pretreatment (18)F-deoxy-D-glucose positron emission tomography scan were included in the target volume. The primary endpoint was toxicity. RESULTS: A total of 48 Stage I-IIIB patients were included. In all risk groups, 68.40 Gy/38 fractions/25 days could be administered. Maximal toxicity according to the risk groups was as follows: V(20) <25% (n = 35): 1 Grade 4 (G4) lung and 1 G3 reversible esophageal toxicity; V(20) 35-37% (n = 12): 1 G5 lung and 1 G3 reversible esophageal toxicity. For the whole group, local tumor recurrence occurred in 25% (95% confidence interval 14%-40%) of the patients, with 1 of 48 (2.1%; upper one-sided 95% confidence limit 9.5%) having an isolated nodal recurrence. The median actuarial overall survival was 20 months, with a 2-year survival rate of 36%. CONCLUSIONS: High-dose continuous hyperfractionated accelerated radiotherapy up to a dose of 68.40 Gy/38 fractions/25 days (a biologic equivalent of approximately 80 Gy when delivered in conventional fractionation) in patients with inoperable NSCLC and a V(20) up to 37% is feasible.

Tumor volume combined with number of positive lymph node stations is a more important prognostic factor than TNM stage for survival of non-small-cell lung cancer patients treated with (chemo)radiotherapy.

PURPOSE: The current tumor, node, metastasis system needs refinement to improve its ability to predict survival of patients with non-small-cell lung cancer (NSCLC) treated with (chemo)radiation. In this study, we investigated the prognostic value of tumor volume and N status, assessed by using fluorodeoxyglucose-positron emission tomography (PET). PATIENTS AND METHODS: Clinical data from 270 consecutive patients with inoperable NSCLC Stages I-IIIB treated radically with (chemo)radiation were collected retrospectively. Diagnostic imaging was performed using either integrated PET-computed tomography or computed tomography and PET separately. The Kaplan-Meier method, as well as Cox regression, was used to analyze data. RESULTS: Univariate survival analysis showed that number of positive lymph node stations (PLNSs), as well as N stage on PET, was associated significantly with survival. The final multivariate Cox model consisted of number of PLNSs, gross tumor volume (i.e., volume of the primary tumor plus lymph nodes), sex, World Health Organization performance status, and equivalent radiation dose corrected for time; N stage was no longer significant. CONCLUSIONS: Number of PLNSs, assessed by means of fluorodeoxyglucose-PET, was a significant factor for survival of patients with inoperable NSCLC treated with (chemo)radiation. Risk stratification for this group of patients should be based on gross tumor volume, number of PLNSs, sex, World Health Organization performance status, and equivalent radiation dose corrected for time.

Individualized radical radiotherapy of non-small-cell lung cancer based on normal tissue dose constraints: a feasibility study.

PURPOSE: Local recurrence is a major problem after (chemo-)radiation for non-small-cell lung cancer. We hypothesized that for each individual patient, the highest therapeutic ratio could be achieved by increasing total tumor dose (TTD) to the limits of normal tissues, delivered within 5 weeks. We report first results of a prospective feasibility trial. METHODS AND MATERIALS: Twenty-eight patients with medically inoperable or locally advanced non-small-cell lung cancer, World Health Organization performance score of 0-1, and reasonable lung function (forced expiratory volume in 1 second > 50%) were analyzed. All patients underwent irradiation using an individualized prescribed TTD based on normal tissue dose constraints (mean lung dose, 19 Gy; maximal spinal cord dose, 54 Gy) up to a maximal TTD of 79.2 Gy in 1.8-Gy fractions twice daily. No concurrent chemoradiation was administered. Toxicity was scored using the Common Terminology Criteria for Adverse Events criteria. An (18)F-fluoro-2-deoxy-glucose-positron emission tomography-computed tomography scan was performed to evaluate (metabolic) response 3 months after treatment. RESULTS: Mean delivered dose was 63.0 +/- 9.8 Gy. The TTD was most often limited by the mean lung dose (32.1%) or spinal cord (28.6%). Acute toxicity generally was mild; only 1 patient experienced Grade 3 cough and 1 patient experienced Grade 3 dysphagia. One patient (3.6%) died of pneumonitis. For late toxicity, 2 patients (7.7%) had Grade 3 cough or dyspnea; none had severe dysphagia. Complete metabolic response was obtained in 44% (11 of 26 patients). With a median follow-up of 13 months, median overall survival was 19.6 months, with a 1-year survival rate of 57.1%. CONCLUSIONS: Individualized maximal tolerable dose irradiation based on normal tissue dose constraints is feasible, and initial results are promising.

Long-term survival of stage T4N0-1 and single station IIIA-N2 NSCLC patients treated with definitive chemo-radiotherapy using individualised isotoxic accelerated radiotherapy (INDAR).

BACKGROUND: Non-small cell lung cancer (NSCLC) stage T4N0-1 or single nodal station IIIA-N2 are two stage III sub-groups for which the outcome of non-surgical therapy is not well known. We investigated the results of individualised isotoxic accelerated radiotherapy (INDAR) and chemotherapy in this setting. METHODS: Analysis of NSCLC patients included in 2 prospective trials (NCT00573040 and NCT00572325) stage T4N0-1 or IIIA-N2 with 1 pathologic nodal station, treated with chemo-radiotherapy (CRT) using INDAR with concurrent or sequential platinum-based chemotherapy. Overall survival (OS) was updated and calculated from date of diagnosis (Kaplan-Meier). Toxicity was scored following CTCAEv3.0. To allow comparison with other articles the subgroups were also analysed separately for toxicity, progression free and overall survival. RESULTS: 83 patients (42 T4N0-1 and 41 IIIA-N2) were identified: the median radiotherapy dose was 65Gy. Thirty-seven percent of patients received sequential CRT and 63% received concurrent CRT. At a median follow-up of 48 months the median OS for T4N0-1 patients was 34 months with 55% 2-year survival and 25% 5-year survival. For stage IIIA-N2 at a median follow-up of 50 months the median OS was 26 months with 2- and 5-year survival rates of 53% and 24%, respectively. CONCLUSION: Chemo-radiation using INDAR yields promising survival results in patients with single-station stage IIIA-N2 or T4N0-1 NSCLC.

Early body weight loss during concurrent chemo-radiotherapy for non-small cell lung cancer.

BACKGROUND AND PURPOSE: Radiation-esophagitis and weight loss are frequently observed toxicities in patients treated with concurrent chemo-radiotherapy (CT-RT) for non-small cell lung cancer (NSCLC) and might be related. The purpose was to investigate whether weight loss already starts early after initiation of CT-RT and precedes radiation-esophagitis. MATERIALS AND METHODS: In a retrospective cohort, weight and esophagitis grade ≥2 were assessed during the first weeks of (CT-)RT in patients treated with concurrent (n = 102) or sequential (n = 92) therapy. In a prospective validation study, data on body weight, esophagitis grade ≥2, nutritional intake and muscle strength were obtained before, during and following CT-RT. RESULTS: In the retrospective cohort, early weight loss was observed in concurrently treated patients (p = 0.002), independent of esophagitis ≥ grade 2. Early weight loss was also observed in the prospective cohort (p = 0.003) and was not accompanied by decreases in nutritional intake. In addition lower limb muscle strength rapidly declined (p = 0.042). In the later weeks of treatment, further body weight loss occurred (p < 0.001) despite increased nutritional supplementation and body weight was only partly recovered after 4 weeks post CT-RT (p = 0.003). CONCLUSIONS: Weight loss during concurrent CT-RT for NSCLC starts early and prior to onset of esophagitis, requiring timely and intense nutritional rehabilitation.

Total gross tumor volume is an independent prognostic factor in patients treated with selective nodal irradiation for stage I to III small cell lung cancer.

PURPOSE: In non-small cell lung cancer, gross tumor volume (GTV) influences survival more than other risk factors. This could also apply to small cell lung cancer. METHODS AND MATERIALS: Analysis of our prospective database with stage I to III SCLC patients referred for concurrent chemo radiation therapy. Standard treatment was 45 Gy in 1.5-Gy fractions twice daily concurrently with carboplatin-etoposide, followed by prophylactic cranial irradiation (PCI) in case of non-progression. Only fluorodeoxyglucose (FDG)-positron emission tomography (PET)-positive or pathologically proven nodal sites were included in the target volume. Total GTV consisted of post chemotherapy tumor volume and pre chemotherapy nodal volume. Survival was calculated from diagnosis (Kaplan-Meier ). RESULTS: A total of 119 patients were included between May 2004 and June 2009. Median total GTV was 93 ± 152 cc (7.5-895 cc). Isolated elective nodal failure occurred in 2 patients (1.7%). Median follow-up was 38 months, median overall survival 20 months (95% confidence interval = 17.8-22.1 months), and 2-year survival 38.4%. In multivariate analysis, only total GTV (P=.026) and performance status (P=.016) significantly influenced survival. CONCLUSIONS: In this series of stage I to III small cell lung cancer patients treated with FDG-PET-based selective nodal irradiation total GTV is an independent risk factor for survival.

Radical treatment of non-small-cell lung cancer patients with synchronous oligometastases: long-term results of a prospective phase II trial (Nct01282450).

BACKGROUND: Stage IV non-small-cell lung cancer (NSCLC) patients with oligometastases (< 5 metastatic lesions) may experience long-term survival when all macroscopic tumor sites are treated radically, but no prospective data on NSCLCs with synchronous oligometastases are available. METHODS: A prospective single-arm phase II trial was conducted. The main inclusion criteria were pathologically proven NSCLC stage IV with less than five metastases at primary diagnosis, amendable for radical local treatment (surgery or radiotherapy). The study is listed in clinicaltrials.gov, number NCT01282450. RESULTS: Forty patients were enrolled, 39 of whom were evaluable (18 men, 21 women); mean age was 62.1 ± 9.2 years (range, 44-81). Twenty-nine (74%) had local stage III; 17 (44%) brain, seven (18%) bone, and four (10%) adrenal gland metastases. Thirty-five (87%) had a single metastatic lesion. Thirty-seven (95%) of the patients received chemotherapy as part of their primary treatment. Median overall survival (OS) was 13.5 months (95% confidence interval 7.6-19.4); 1-, 2-, and 3-year OS was 56.4%, 23.3%, and 17.5%, respectively. Median progression-free survival (PFS) was 12.1 months (95% confidence interval 9.6-14.3); 1-year PFS was 51.3%, and both 2- and 3-year PFS was 13.6%. Only two patients (5%) had a local recurrence. No patient or tumor parameter, including volume and F-deoxyglucose uptake was significantly correlated with OS or PFS. The treatment was well tolerated. CONCLUSION: In this phase II study, long-term PFS was found in a subgroup of NSCLC patients with synchronous oligometastases when treated radically. Identification of this favorable subgroup before therapy is needed.

Individualised isotoxic accelerated radiotherapy and chemotherapy are associated with improved long-term survival of patients with stage III NSCLC: a prospective population-based study.

BACKGROUND: Individualised, isotoxic, accelerated radiotherapy (INDAR) allows the delivery of high biological radiation doses, but the long-term survival associated with this approach is unknown. METHODS: Patients with stage III NSCLC in the Netherlands Cancer Registry/Limburg from January 1, 2002 to December 31, 2008 were included. RESULTS: Patients (1002) with stage III NSCLC were diagnosed, of which 938 had T4 and/or N2-N3 disease. Patients treated with curative intent were staged with FDG-PET scans and a contrast-enhanced CT or an MRI of the brain. There were no shifts over time in the patient or tumour characteristics at diagnosis. The number of stage III NSCLC patients remained stable over time, but the proportion treated with palliative intent decreased from 47% in 2002 to 37% in 2008, and the percentage treated with chemo-radiation (RT) increased from 24.6% in 2002 to 47.8% in 2008 (p<0.001). The proportion of surgical patients remained below 5%. Sequential chemotherapy and conventional RT resulted in a median and a 5-year survival of 17.5 months and 8.4%, respectively, whereas with sequential chemotherapy and INDAR this was 23.6 months and 31%, respectively (p<0.001). Concurrent chemotherapy and INDAR was associated with a median and 2-year survival that was not reached and 66.7%, respectively (p=0.004). CONCLUSIONS: The proportion of patients treated with a curative intention with chemo-RT has increased markedly over time of observation. INDAR is associated with longer survival when compared to standard dose RT alone given with or without chemotherapy.

Mature results of a phase II trial on individualised accelerated radiotherapy based on normal tissue constraints in concurrent chemo-radiation for stage III non-small cell lung cancer.

BACKGROUND: Sequential chemotherapy and individualised accelerated radiotherapy (INDAR) has been shown to be effective in non-small cell lung cancer (NSCLC), allowing delivering of high biological doses. We therefore performed a phase II trial (clinicaltrials.gov; NCT00572325) investigating the same strategy in concurrent chemo-radiation in stage III NSCLC. METHODS: 137 stage III patients fit for concurrent chemo-radiation (PS 0-2; FEV(1) and DLCO ≥ 30%) were included from April 2006 till December 2009. An individualised prescribed dose based on normal tissue dose constraints was applied: mean lung dose (MLD) 19 Gy, spinal cord 54 Gy, brachial plexus 66 Gy, central structures 74 Gy. A total dose between 51 and 69 Gy was delivered in 1.5 Gy BID up to 45 Gy, followed by 2 Gy QD. Radiotherapy was started at the 2nd or 3rd course of chemotherapy. Primary end-point was overall survival (OS) and secondary end-point toxicity common terminology criteria for adverse events v3.0 (CTCAEv3.0). FINDINGS: The median tumour volume was 76.4 ± 94.1 cc; 49.6% of patients had N2 and 32.1% N3 disease. The median dose was 65.0 ± 6.0 Gy delivered in 35 ± 5.7 days. Six patients (4.4%) did not complete radiotherapy. With a median follow-up of 30.9 months, the median OS was 25.0 months (2-year OS 52.4%). Severe acute toxicity (≥ G3, 35.8%) consisted mainly of G3 dysphagia during radiotherapy (25.5%). Severe late toxicity (≥ G3) was observed in 10 patients (7.3%). INTERPRETATION: INDAR in concurrent chemo-radiation based on normal tissue constraints is feasible, even in patients with large tumour volumes and multi-level N2-3 disease, with acceptable severe late toxicity and promising 2-year survival.

Treatment with curative intent of stage III non-small cell lung cancer patients of 75 years: a prospective population-based study.

BACKGROUND: There is little data on the survival of elderly patients with stage III non-small cell lung cancer (NSCLC). METHODS: Patients with stage III NSCLC in the Netherlands Cancer Registry/Limburg from January 1, 2002 to December 31, 2008 were included. FINDINGS: One thousand and two patients with stage III were diagnosed, of which 237 were 75 years or older. From 228 patients, co-morbidity scores were available. Only 33/237 patients (14.5%) had no co-morbidities, 195 (85.5%) had one or more important co-morbidities, 60 (26.3%) two or more co-morbidities, 18 (7.9%) three or more co-morbidities and 2 patients (0.9%) suffered from four co-morbidities. Forty-eight percent were treated with curative intent. No significant difference in Charlson co-morbidity, age or gender was found between patients receiving curative or palliative intent treatment. Treatment with curative intent was associated with increased overall survival (OS) compared to palliative treatment: median OS 14.2 months (9.6-18.7) versus 5.2 months (4.3-6.0), 2-year OS 35.5% versus 12.1%, for curative versus palliative treatment. FINDINGS: Patients who received only radiotherapy with curative intent had a median OS of 11.1 months (95% confidence interval [95% CI] 6.4-15.8) and a 5-year OS of 20.3%; for sequential chemotherapy and radiotherapy, the median OS was 18.0 months (95% CI 12.2-23.7), with a 5-year OS of 14.9%. Only four patients received concurrent chemo-radiation. INTERPRETATION: In this prospective series treating elderly patients with stage III NSCLC with curative intent was associated with significant 5-year survival rates.

Mature results of an individualized radiation dose prescription study based on normal tissue constraints in stages I to III non-small-cell lung cancer.

PURPOSE: We previously showed that individualized radiation dose escalation based on normal tissue constraints would allow safe administration of high radiation doses with low complication rate. Here, we report the mature results of a prospective, single-arm study that used this individualized tolerable dose approach. PATIENTS AND METHODS: In total, 166 patients with stage III or medically inoperable stage I to II non-small-cell lung cancer, WHO performance status 0 to 2, a forced expiratory volume at 1 second and diffusing capacity of lungs for carbon monoxide >or= 30% were included. Patients were irradiated using an individualized prescribed total tumor dose (TTD) based on normal tissue dose constraints (mean lung dose, 19 Gy; maximal spinal cord dose, 54 Gy) up to a maximal TTD of 79.2 Gy in 1.8 Gy fractions twice daily. Only sequential chemoradiation was administered. The primary end point was overall survival (OS), and the secondary end point was toxicity according to Common Terminology Criteria of Adverse Events (CTCAE) v3.0. RESULTS: The median prescribed TTD was 64.8 Gy (standard deviation, +/- 11.4 Gy) delivered in 25 +/- 5.8 days. With a median follow-up of 31.6 months, the median OS was 21.0 months with a 1-year OS of 68.7% and a 2-year OS of 45.0%. Multivariable analysis showed that only a large gross tumor volume significantly decreased OS (P < .001). Both acute (grade 3, 21.1%; grade 4, 2.4%) and late toxicity (grade 3, 4.2%; grade 4, 1.8%) were acceptable. CONCLUSION: Individualized prescribed radical radiotherapy based on normal tissue constraints with sequential chemoradiation shows survival rates that come close to results of concurrent chemoradiation schedules, with acceptable acute and late toxicity. A prospective randomized study is warranted to further investigate its efficacy.

18FDG-PET-CT in the follow-up of non-small cell lung cancer patients after radical radiotherapy with or without chemotherapy: an economic evaluation.

BACKGROUND: The optimal follow-up strategy of non-small cell lung cancer (NSCLC) patients after curative intent therapy is still not established. In a recent prospective study with 100 patients, we showed that a FDG-PET-CT 3 months after radiotherapy (RT) could identify progression amenable for curative treatment in 2% (95% confidence interval (CI): 1-7%) of patients, who were all asymptomatic. Here, we report on the economic evaluation of this study. PATIENTS AND METHODS: A decision-analytic Markov model was developed in which the long-term cost-effectiveness of 3 follow-up strategies was modelled with different imaging methods 3 months after therapy: a PET-CT scan; a chest CT scan; and conventional follow-up with a chest X-ray. A probabilistic sensitivity analysis was performed to account for uncertainty. Because the results of the prospective study indicated that the advantage seems to be confined to asymptomatic patients, we additionally examined a strategy where a PET-CT was applied only in the subgroup of asymptomatic patients. Cost-effectiveness of the different follow-up strategies was expressed in incremental cost-effectiveness ratios (ICERs), calculating the incremental costs per quality adjusted life year (QALY) gained. RESULTS: Both PET-CT- and CT-based follow-up were more costly but also more effective than conventional follow-up. CT-based follow-up was only slightly more effective than conventional follow-up, resulting in an incremental cost-effectiveness ratio (ICER) of euro 264.033 per QALY gained. For PET-CT-based follow-up, the ICER was euro 69.086 per QALY gained compared to conventional follow-up. The strategy in which a PET-CT was only performed in the asymptomatic subgroup resulted in an ICER of euro 42.265 per QALY gained as opposed to conventional follow-up. With this strategy, given a ceiling ratio of euro 80.000, PET-CT-based follow-up had the highest probability of being cost-effective (73%). CONCLUSIONS: This economic evaluation shows that a PET-CT scan 3 months after (chemo)radiotherapy with curative intent is a potentially cost-effective follow-up method, and is more cost-effective than CT alone. Applying a PET-CT scan only in asymptomatic patients is probably as effective and more cost-effective. It is worthwhile to perform additional research to reduce uncertainty regarding the decision concerning imaging in the follow-up of NSCLC.

Selective nodal irradiation on basis of (18)FDG-PET scans in limited-disease small-cell lung cancer: a prospective study.

PURPOSE: To evaluate the results of selective nodal irradiation on basis of (18)F-deoxyglucose positron emission tomography (PET) scans in patients with limited-disease small-cell lung cancer (LD-SCLC) on isolated nodal failure. METHODS AND MATERIALS: A prospective study was performed of 60 patients with LD-SCLC. Radiotherapy was given to a dose of 45 Gy in twice-daily fractions of 1.5 Gy, concurrent with carboplatin and etoposide chemotherapy. Only the primary tumor and the mediastinal lymph nodes involved on the pretreatment PET scan were irradiated. A chest computed tomography (CT) scan was performed 3 months after radiotherapy completion and every 6 months thereafter. RESULTS: A difference was seen in the involved nodal stations between the pretreatment (18)F-deoxyglucose PET scans and computed tomography scans in 30% of patients (95% confidence interval, 20-43%). Of the 60 patients, 39 (65%; 95% confidence interval [CI], 52-76%) developed a recurrence; 2 patients (3%, 95% CI, 1-11%) experienced isolated regional failure. The median actuarial overall survival was 19 months (95% CI, 17-21). The median actuarial progression-free survival was 14 months (95% CI, 12-16). 12% (95% CI, 6-22%) of patients experienced acute Grade 3 (Common Terminology Criteria for Adverse Events, version 3.0) esophagitis. CONCLUSION: PET-based selective nodal irradiation for LD-SCLC resulted in a low rate of isolated nodal failures (3%), with a low percentage of acute esophagitis. These findings are in contrast to those from our prospective study of CT-based selective nodal irradiation, which resulted in an unexpectedly high percentage of isolated nodal failures (11%). Because of the low rate of isolated nodal failures and toxicity, we believe that our data support the use of PET-based SNI for LD-SCLC.

Dyspnea evolution after high-dose radiotherapy in patients with non-small cell lung cancer.

PURPOSE: To determine what the influence is of dyspnea (CTCAE3.0) before high-dose radiotherapy (RT) on the incidence and severity of subsequent lung toxicity in patients with non-small cell lung cancer (NSCLC). METHODS: In 197 patients with stage I-III NSCLC maximal dyspnea scores (CTCAE3.0) were obtained prospectively at three time periods: before RT, the first 6 months post-RT and 6-9 months post-RT. Only patients who were clinically progression-free 12 months or more after RT were included, thus minimizing dyspnea due to tumor progression. Time-trends of dyspnea as a function of baseline dyspnea were investigated and correlated with gender, age, chemotherapy, mean lung dose (MLD), lung function parameters (FeV1 and DLCO), stage, PTV dose, overall treatment time and smoking habits. RESULTS: The proportion developing less, the same or more dyspnea 6-9 months post-treatment according to their baseline dyspnea scores was: Grade 0: none, 82.9%, 17.1%; Grade 1: 21.2%, 51.9%, 26.9%; Grade 2: 27.3%, 54.5%, 18.2%, respectively. Only age was associated with increased dyspnea after RT. CONCLUSIONS: Patients with dyspnea before therapy have a realistic chance to improve after high-dose radiotherapy. Reporting only dyspnea at one time-point post-RT is insufficient to determine radiation-induced dyspnea.

Follow-up with 18FDG-PET-CT after radical radiotherapy with or without chemotherapy allows the detection of potentially curable progressive disease in non-small cell lung cancer patients: a prospective study.

BACKGROUND: Follow-up of patients treated with curative intent for non-small cell lung cancer (NSCLC) with X-ray or CT-scans is of unproven value. Furthermore, most patients with progressive disease present with symptoms outside of follow-up visits. Because the accuracy of (18)FDG-PET-CT is superior to CT, we hypothesised that FDG-PET-CT scans 3 months post-treatment could lead to early detection of progressive disease (PD) amenable for radical treatment. PATIENTS AND METHODS: Hundred patients with NSCLC, treated with curative intent with (chemo) radiation, were prospectively evaluated. All patients underwent a planned FDG-PET-CT scan 3 months after the start of radiotherapy. RESULTS: Twenty four patients had PD 3 months post-treatment. 16/24 patients were symptomatic. No curative treatment could be offered to any of these patients. In 3/8 asymptomatic patients progression, potentially amenable for radical therapy was found, which were all detected with PET, not with CT only. CONCLUSIONS: PET-scanning after curative treatment for NSCLC led to the detection of progression potentially amenable for radical treatment in a small proportion (3%) of patients. Selectively offering a PET-CT scan to the patient group without symptoms could possibly lead to an effective follow-up method.

Identification of residual metabolic-active areas within individual NSCLC tumours using a pre-radiotherapy (18)Fluorodeoxyglucose-PET-CT scan.

BACKGROUND AND PURPOSE: Non-small cell lung cancer (NSCLC) tumours are mostly heterogeneous. We hypothesized that areas within the tumour with a high pre-radiation (18)F-deoxyglucose (FDG) uptake, could identify residual metabolic-active areas, ultimately enabling selective-boosting of tumour sub-volumes. MATERIAL AND METHODS: Fifty-five patients with inoperable stage I-III NSCLC treated with chemo-radiation or with radiotherapy alone were included. For each patient one pre-radiotherapy and one post-radiotherapy FDG-PET-CT scans were available. Twenty-two patients showing persistent FDG uptake in the primary tumour after radiotherapy were analyzed. Overlap fractions (OFs) were calculated between standardized uptake value (SUV) threshold-based auto-delineations on the pre- and post-radiotherapy scan. RESULTS: Patients with residual metabolic-active areas within the tumour had a significantly worse survival compared to individuals with a complete metabolic response (p=0.002). The residual metabolic-active areas within the tumour largely corresponded (OF>70%) with the 50%SUV high FDG uptake area of the pre-radiotherapy scan. The hotspot within the residual area (90%SUV) was completely within the GTV (OF=100%), and had a high overlap with the pre-radiotherapy 50%SUV threshold (OF>84%). CONCLUSIONS: The location of residual metabolic-active areas within the primary tumour after therapy corresponded with the original high FDG uptake areas pre-radiotherapy. Therefore, a single pre-treatment FDG-PET-CT scan allows for the identification of residual metabolic-active areas.